Abdollahi, A, Liu, Y, Pradhan, B, Huete, A, Dikshit, A & Nguyen Tran, N 2022, 'Short-time-series grassland mapping using Sentinel-2 imagery and deep learning-based architecture', The Egyptian Journal of Remote Sensing and Space Science, vol. 25, no. 3, pp. 673-685.
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In the present work, a deep learning-based network called LeNet is applied for accurate grassland map production from Sentinel-2 data for the Greater Sydney region, Australia. First, we apply the technique to the base date Sentinel-2 data (non-seasonal) to make the vegetation maps. Then, we combine short time-series (seasonal) data and enhanced vegetation index (EVI) information to the base date imagery to improve the classification results and generate high-resolution grassland maps. The proposed model obtained an overall accuracy (OA) of 88.36% for the mono-temporal data, and 92.74% for the multi-temporal data. The experimental products proved that, by combining the short time-series images and EVI information to the base date, the classification maps' accuracy is increased by 4.38%. Moreover, the Sentinel-2 produced grassland maps are compared with the pre-existing maps such as Australian Land Use and Management (ALUM) 50 m resolution and Dynamic Land Cover Dataset (DLCD) with 250 m resolution as well as some traditional machine learning methods such as Support Vector Machine (SVM) and Random Forest (RF). The results show the effect of the LeNet network's performance and efficiency for grassland map production from short time-series data. As a result, decision-makers and urban planners can benefit from this work in terms of grassland change identification, monitoring, and planning assessment.
Abdollahi, A, Pradhan, B & Alamri, A 2022, 'SC-RoadDeepNet: A New Shape and Connectivity-Preserving Road Extraction Deep Learning-Based Network From Remote Sensing Data', IEEE Transactions on Geoscience and Remote Sensing, vol. 60, no. 99, pp. 1-15.
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Existing automated road extraction approaches concentrate on regional accuracy rather than road shape and connectivity quality. Most of these techniques produce discontinuous outputs caused by obstacles, such as shadows, buildings, and vehicles. This study proposes a shape and connectivity-preserving road identification deep learning-based architecture called SC-RoadDeepNet to overcome the discontinuous results and the quality of road shape and connectivity. The proposed model comprises a state-of-the-art deep learning-based network, namely, the recurrent residual convolutional neural network, boundary learning (BL), and a new measure based on the intersection of segmentation masks and their (morphological) skeleton called connectivity-preserving centerline Dice (CPclDice). The recurrent residual convolutional layers accumulate low-level features for segmentation tasks, thus allowing for better feature representation. Such representation enables us to construct a UNet network with the same number of network parameters but improved segmentation effectiveness. BL also aids the model in improving the road’s boundaries by penalizing boundary misclassification and fine-tuning the road form. Furthermore, the CPclDice method aids the model in maintaining road connectivity and obtaining accurate segmentations. We demonstrate that CPclDice ensures connection preservation for binary segmentation, thereby allowing for efficient road network extraction at the end. The proposed model improves F1 score accuracy to 5.49%, 4.03%, 3.42%, and 2.27% compared with other comparative models, such as LinkNet, ResUNet, UNet, and VNet, respectively. Furthermore, qualitative and quantitative assessments demonstrate that the proposed SC-RoadDeepNet can improve road extraction by tackling shadow and occlusion-related interruptions. These assessments can also produce high-resolution results, particularly in the area of road network completeness.
Abdollahi, A, Pradhan, B & Alamri, AM 2022, 'An ensemble architecture of deep convolutional Segnet and Unet networks for building semantic segmentation from high-resolution aerial images', Geocarto International, vol. 37, no. 12, pp. 3355-3370.
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Building objects is one of the principal features that are essential for updating the geospatial database. Extracting building features from high-resolution imagery automatically and accurately is challenging because of the existence of some obstacles in these images, such as shadows, trees, and cars. Although deep learning approaches have shown significant improvements in the results of image segmentation in recent years, most deep neural networks still cannot achieve highly accurate results with correct segmentation map when processing high-resolution remote sensing images. Therefore, we implemented a new deep neural network named Seg–Unet method, which is a composition of Segnet and Unet techniques, to exploit building objects from high-resolution aerial imagery. Results obtained 92.73% accuracy carried on the Massachusetts building dataset. The proposed technique improved the performance to 0.44%, 1.17%, and 0.14% compared with fully convolutional neural network (FCN), Segnet, and Unet methods, respectively. Results also confirmed the superiority of the proposed method in building extraction.
Abdullah, NHB, Mijan, NA, Taufiq-Yap, YH, Ong, HC & Lee, HV 2022, 'Environment-friendly deoxygenation of non-edible Ceiba oil to liquid hydrocarbon biofuel: process parameters and optimization study', Environmental Science and Pollution Research, vol. 29, no. 34, pp. 51143-51152.
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Abharian, S, Sarfarazi, V, Marji, MF & Rasekh, H 2022, 'Experimental and numerical evaluation of the effects of interaction between multiple small holes and a single notch on the mechanical behavior of artificial gypsum specimens', Theoretical and Applied Fracture Mechanics, vol. 121, pp. 103462-103462.
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The mechanical behavior of cubic gypsum specimens containing five small circular holes in a linear configuration and a single notch under uniaxial compression test were studied to evaluate interactions between these flaws during crack development under loading. Multiple angles between the line of holes and the horizontal axis were evaluated (15°, 45°, and 75°), as were different notch apertures (2, 4, 6 and 8 mm). Acoustic emission (AE) data were used to evaluate the fracture development process in each case. Following the experiments, numerical simulations of the tests were conducted using the particle flow code (PFC2D). The compressive strengths of the specimens were found to be associated with the failure mechanism and fracturing geometry, which were in turn controlled by the geometric attributes of the flaws considered. The compressive strength of specimens were affected by the number of tensile cracks. The induced tensile cracked number were increased by decreasing the joint length. Only few AE events were detected in the initial phase of loading, but then AE hits grew rapidly prior to reaching the peak stress. The AE hits increased by increasing the filling thickness. Failure pattern and compressive strength of specimens were nearly similar in both numerical and experimental approaches.
Abharian, S, Sarfarazi, V, Rasekh, H & Behzadinasab, M 2022, 'Effects of concrete/gypsum bedding layers and their inclination angles on the tensile failure mechanism: Experimental and numerical studies', Case Studies in Construction Materials, vol. 17, pp. e01272-e01272.
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This paper investigates the influence of concrete/gypsum bedding layers and their orientation angles on the tensile failure mechanism in the three-point bending test based on experiments and numerical simulations. Rectangular samples containing different combinations of concrete and gypsum layers were prepared, i.e. one layer of gypsum and one layer of concrete, one layer of gypsum and two layers of concrete, and two layers of gypsum and two layers of concrete. In each configuration, bedding layer angles varied between 0° and 90° with increment of 30°. A total of 36 specimens including 12 configurations were prepared and tested. In addition, numerical simulations were conducted on the concrete/gypsum bedding layers at different angles of 0°, 15°, 30°, 45°, 60°, 75°, and 90°. Results show that the bedding layer orientation and bedding layer thickness affect the observed tensile failure process including the failure pattern and tensile strength. A pure tensile failure occurred when the bedding layer angle was 0°, while a sliding failure evolved by increasing the joint angle. When the bedding layer angle was 90°, the failure in boundary of layer was observed. Specimens with one layer of concrete and one layer of gypsum at 0° inclination angle had the highest tensile strength. However, increasing the number of layers and inclination angles decreased the tensile strength of specimens as the number of weak layers in the direction of loading increased.
Abraham, MT, Satyam, N & Pradhan, B 2022, 'Effect of data splitting and selection of machine learning algorithms for landslide susceptibility mapping'.
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<p>Landslide susceptibility maps (LSMs) are inevitable parts of regional scale landslide forecasting models. The susceptibility maps can provide the spatial probability of occurrence of landslides and have crucial role in the development and planning activities of any region. With the wide availability of satellite-based data and advanced computational facilities, data driven LSMs are being developed for different regions across the world. Since a decade, machine learning (ML) algorithms have gained wide acceptance for developing LSMs and the performance of such maps depends highly on the quality of input data and the choice of ML algorithm. This study employs a k fold cross validation technique for evaluating the performance of five different ML models, viz., Na&#239;ve Bayes (NB), Logistic Regression (LR), Random Forest (RF), K Nearest Neighbors (KNN) and Support Vector Machines (SVM), to develop LSMs, by varying the train to test ratio. The ratio is varied by changing the number folds used for k fold cross validation from 2 to 10, and its effect on each algorithm is assessed using Receiver Operating Characteristic (ROC) curves and accuracy values. The method is tested for Wayanad district, Kerala, India, which is highly affected by landslides during monsoon. The results show that RF algorithm performs better among all the five algorithms considered, and the maximum accuracy values were obtained with the value of k as 8, for all cases. The variation between the minimum and maximum accuracy values were found to be 0.6 %, 0.74 %, 1.71 %, 1.92 % and 1.83 % for NB, LR, KNN, RF and SVM respectively.</p>
Abraham, MT, Satyam, N, Pradhan, B & Segoni, S 2022, 'Proposing an easy-to-use tool for estimating landslide dimensions using a data-driven approach', All Earth, vol. 34, no. 1, pp. 243-258.
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Abraham, MT, Satyam, N, Pradhan, B & Tian, H 2022, 'Debris flow simulation 2D (DFS 2D): Numerical modelling of debris flows and calibration of friction parameters', Journal of Rock Mechanics and Geotechnical Engineering, vol. 14, no. 6, pp. 1747-1760.
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Abraham, MT, Satyam, N, Pradhan, B, Segoni, S & Alamri, A 2022, 'Developing a prototype landslide early warning system for Darjeeling Himalayas using SIGMA model and real-time field monitoring', Geosciences Journal, vol. 26, no. 2, pp. 289-301.
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Rainfall thresholds are commonly utilized to forecast landslides using the historical relationship between occurrence of slope failures and rainfall in an area. SIGMA (Sistema Integrato Gestione Monitoraggion Allerta) is a rainfall threshold model, which uses the statistical distribution of rainfall for forecasting the occurrence of landslides. The threshold curves are functions of standard deviation of the cumulated rainfall data, taking into account both long-term and short term-rainfall. To overcome the limitations of statistical rainfall threshold, the real-time monitoring data from MicroElectroMechanical Systems (MEMS) tilt sensors have been integrated with SIGMA model using a decisional algorithm for a test site (Kalimpong) in Darjeeling Himalayas, in the northeastern part of India. Three different models, the SIGMA model, tilt meter readings and the combination of both are compared quantitatively using the precipitation and landslide data of Kalimpong town between July 2017 and September 2020. The results indicate that the integration of tilt meter readings has lowered the number of false alarms issued by SIGMA model from 70 to 38 in the studied period, with an increase in the likelihood ratio from 18.10 to 20.23. The Receiver Operating Characteristic (ROC) curves indicate that the combined approach has the best performance among the models considered in this study, with an area under the curve 0.976. The proposed method was found to have better performance than the other rainfall thresholds derived for Kalimpong region so far, and the prototypal model can be further fine-tuned to develop an operational Landslide Early Warning System (LEWS) for the region.
Adak, A, Pradhan, B & Shukla, N 2022, 'Sentiment Analysis of Customer Reviews of Food Delivery Services Using Deep Learning and Explainable Artificial Intelligence: Systematic Review', Foods, vol. 11, no. 10, pp. 1500-1500.
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During the COVID-19 crisis, customers’ preference in having food delivered to their doorstep instead of waiting in a restaurant has propelled the growth of food delivery services (FDSs). With all restaurants going online and bringing FDSs onboard, such as UberEATS, Menulog or Deliveroo, customer reviews on online platforms have become an important source of information about the company’s performance. FDS organisations aim to gather complaints from customer feedback and effectively use the data to determine the areas for improvement to enhance customer satisfaction. This work aimed to review machine learning (ML) and deep learning (DL) models and explainable artificial intelligence (XAI) methods to predict customer sentiments in the FDS domain. A literature review revealed the wide usage of lexicon-based and ML techniques for predicting sentiments through customer reviews in FDS. However, limited studies applying DL techniques were found due to the lack of the model interpretability and explainability of the decisions made. The key findings of this systematic review are as follows: 77% of the models are non-interpretable in nature, and organisations can argue for the explainability and trust in the system. DL models in other domains perform well in terms of accuracy but lack explainability, which can be achieved with XAI implementation. Future research should focus on implementing DL models for sentiment analysis in the FDS domain and incorporating XAI techniques to bring out the explainability of the models.
Adak, A, Pradhan, B, Shukla, N & Alamri, A 2022, 'Unboxing Deep Learning Model of Food Delivery Service Reviews Using Explainable Artificial Intelligence (XAI) Technique', Foods, vol. 11, no. 14, pp. 2019-2019.
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The demand for food delivery services (FDSs) during the COVID-19 crisis has been fuelled by consumers who prefer to order meals online and have it delivered to their door than to wait at a restaurant. Since many restaurants moved online and joined FDSs such as Uber Eats, Menulog, and Deliveroo, customer reviews on internet platforms have become a valuable source of information about a company’s performance. FDS organisations strive to collect customer complaints and effectively utilise the information to identify improvements needed to enhance customer satisfaction. However, only a few customer opinions are addressed because of the large amount of customer feedback data and lack of customer service consultants. Organisations can use artificial intelligence (AI) instead of relying on customer service experts and find solutions on their own to save money as opposed to reading each review. Based on the literature, deep learning (DL) methods have shown remarkable results in obtaining better accuracy when working with large datasets in other domains, but lack explainability in their model. Rapid research on explainable AI (XAI) to explain predictions made by opaque models looks promising but remains to be explored in the FDS domain. This study conducted a sentiment analysis by comparing simple and hybrid DL techniques (LSTM, Bi-LSTM, Bi-GRU-LSTM-CNN) in the FDS domain and explained the predictions using SHapley Additive exPlanations (SHAP) and Local Interpretable Model-Agnostic Explanations (LIME). The DL models were trained and tested on the customer review dataset extracted from the ProductReview website. Results showed that the LSTM, Bi-LSTM and Bi-GRU-LSTM-CNN models achieved an accuracy of 96.07%, 95.85% and 96.33%, respectively. The model should exhibit fewer false negatives because FDS organisations aim to identify and address each and every customer complaint. The LSTM model was chosen over the other two DL models, Bi-LSTM and Bi-GRU-LSTM-CNN...
Aditya, L, Mahlia, TMI, Nguyen, LN, Vu, HP & Nghiem, LD 2022, 'Microalgae-bacteria consortium for wastewater treatment and biomass production', Science of The Total Environment, vol. 838, no. Pt 1, pp. 155871-155871.
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The diversity of microalgae and bacteria allows them to form a complementary consortium for efficient wastewater treatment and nutrient recovery. This review highlights the potential of wastewater-derived microalgal biomass as a renewable feedstock for producing animal feed, biofertilisers, biofuel, and many valuable biochemicals. Data corroborated from this review shows that microalgae and bacteria can thrive in many environments. Microalgae are especially effective at utilising nutrients from the water as they grow. This review also consolidates the current understanding of microalgae characteristics and their interactions with bacteria in a consortium system. Recent studies on the performance of only microalgae and microalgae-bacteria wastewater treatment are compared and discussed to establish a research roadmap for practical implementation of the consortium systems for various wastewaters (domestic, industrial, agro-industrial, and landfill leachate wastewater). In comparison to the pure microalgae system, the consortium system has a higher removal efficiency of up to 15% and shorter treatment time. Additionally, this review addresses a variety of possibilities for biomass application after wastewater treatment.
Afrane, S, Ampah, JD, Agyekum, EB, Amoh, PO, Yusuf, AA, Fattah, IMR, Agbozo, E, Elgamli, E, Shouran, M, Mao, G & Kamel, S 2022, 'Integrated AHP-TOPSIS under a Fuzzy Environment for the Selection of Waste-To-Energy Technologies in Ghana: A Performance Analysis and Socio-Enviro-Economic Feasibility Study', International Journal of Environmental Research and Public Health, vol. 19, no. 14, pp. 8428-8428.
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Energy recovery from waste presents a promising alternative for several countries, including Ghana, which has struggled with unsustainable waste treatment methods and an inadequate power supply for several decades. The current study adopts a comprehensive multi-criteria decision-making approach for the selection of an optimal waste-to-energy (WtE) technology for implementation in Ghana. Four WtE technologies are evaluated against twelve selection criteria. An integrated AHP-fuzzy TOPSIS method is applied to estimate the criteria’s weights and rank the WtE alternatives. From the AHP results, technical criteria obtained the highest priority weight, while social criteria emerged as the least important in the selection process. The overall ranking order of WtE technologies obtained by fuzzy TOPSIS is as follows: anaerobic digestion > gasification > pyrolysis > plasma gasification. The sensitivity analysis indicates highly consistent and sturdy results regarding the optimal selection. This study recommends adopting a hybrid system of anaerobic digestion and gasification technologies, as this offers a well-balanced system under all of the evaluation criteria compared to the standalone systems. The results of the current study may help the government of Ghana and other prospective investors select a suitable WtE technology, and could serve as an index system for future WtE research in Ghana.
Afroz, S, Nguyen, QD, Zhang, Y, Kim, T & Castel, A 2022, 'Evaluation of cracking potential parameters for low to high grade concrete with fly ash or slag', Construction and Building Materials, vol. 350, pp. 128891-128891.
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Cracking induced by early age restrained shrinkage can lead to durability issues in concrete structures and premature deterioration that reduce service life of reinforced concrete members. Despite the increasing demand for using Supplementary Cementitious Materials (SCMs) in concrete, the effect of binders and strength grades on early-age restrained concrete cracking has not been fully understood. This study investigated 21 concrete mixes with 30 % fly ash, 40 % and 60 % slag having compressive strengths ranging between 25 MPa and 100 MPa using a restrained ring test. Their cracking potential was evaluated by considering three different methods. The results showed that the time to cracking was short for high grade concretes and concretes with slag. Fly ash delayed the cracking for all strength grades. Though all cracking estimators used in this study did not outstandingly predict the potential of early-age cracking in concrete, the stress rate method performed the best. The cracking strain method and the R ratio method were significantly influenced by the supplementary cementitious materials. The most dominant factor governing the cracking potential of concrete was the rate of stress or strain development for all strength grade and binder types.
Afroz, S, Zhang, Y, Nguyen, QD, Kim, T & Castel, A 2022, 'Effect of limestone in General Purpose cement on autogenous shrinkage of high strength GGBFS concrete and pastes', Construction and Building Materials, vol. 327, pp. 126949-126949.
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This work investigates the autogenous shrinkage of pastes and concretes prepared using General Purpose cement and GGBFS (40% and 60%) up to 100 days. To determine the underlying factors influencing autogenous shrinkage, hydration progression and evolution of microstructure were investigated. Results showed that autogenous shrinkage of GGBFS blends continuously increased after 28 days (until 100 days) whereas the control samples reached a plateau after about 28 days. Late reaction between limestone from the General Purpose cement and alumina from GGBFS progressed untill 90 days forming a high amount of monocarboaluminates. General Purpose cement blends with high GGBFS content can behave as ternary blends and not as binary blends due to the small amount of limestone usually added to General Purpose cements. These long term reactions lead to a significant refinement of the pore structure which is responsible of the late autogenous shrinkage in GGBFS blends.
Afsari, M, Ghorbani, AH, Asghari, M, Shon, HK & Tijing, LD 2022, 'Computational fluid dynamics simulation study of hypersaline water desalination via membrane distillation: Effect of membrane characteristics and operational parameters', Chemosphere, vol. 305, pp. 135294-135294.
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Ahmad, FB, Kalam, MA, Zhang, Z & Masjuki, HH 2022, 'Sustainable production of furan-based oxygenated fuel additives from pentose-rich biomass residues', Energy Conversion and Management: X, vol. 14, pp. 100222-100222.
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Ahmadi, H, Zakertabrizi, M, Hosseini, E, Cha-Umpong, W, Abdollahzadeh, M, Korayem, AH, Chen, V, Shon, HK, Asadnia, M & Razmjou, A 2022, 'Heterogeneous asymmetric passable cavities within graphene oxide nanochannels for highly efficient lithium sieving', Desalination, vol. 538, pp. 115888-115888.
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Lithium is a critical energy element that plays a pivotal role in transitions to sustainable energy. Numerous two-dimensional (2D) membranes have been developed to extract Li+ from different resources. However, their Li+ extraction efficacy is not high enough to meet industrial requirements. Here, we introduce an approach that boosts Li+ selectivity of 2D membranes by inducing asymmetricity in the morphology and chemistry of their nanochannels. Our approach provides an opportunity to manipulate cation hydration shells via a sudden change in the nanochannel size. Then, the addition of nucleophilic traps in the nanochannel intersections results in high Li+ selectivity. Our design leads to a new ion transport mechanism named “Energy Surge Baffle” (ESB) that substantially enriches Li+ in the feed by increasing the monovalent/lithium-ion selectivity up to six times that of other graphene oxide-based membranes. Our approach can be extended to other 2D materials, creating a platform for designing advanced membranes.
Ahmed, N, Hoque, MA-A, Arabameri, A, Pal, SC, Chakrabortty, R & Jui, J 2022, 'Flood susceptibility mapping in Brahmaputra floodplain of Bangladesh using deep boost, deep learning neural network, and artificial neural network', Geocarto International, vol. 37, no. 25, pp. 8770-8791.
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Ahmed, N, Hoque, MA-A, Howlader, N & Pradhan, B 2022, 'Flood risk assessment: role of mitigation capacity in spatial flood risk mapping', Geocarto International, vol. 37, no. 25, pp. 8394-8416.
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Ahmed, SF, Kumar, PS, Kabir, M, Zuhara, FT, Mehjabin, A, Tasannum, N, Hoang, AT, Kabir, Z & Mofijur, M 2022, 'Threats, challenges and sustainable conservation strategies for freshwater biodiversity', Environmental Research, vol. 214, no. Pt 1, pp. 113808-113808.
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Increasing human population, deforestation and man-made climate change are likely to exacerbate the negative effects on freshwater ecosystems and species endangerment. Consequently, the biodiversity of freshwater continues to dwindle at an alarming rate. However, this particular topic lacks sufficient attention from conservation ecologists and policymakers, resulting in a dearth of data and comprehensive reviews on freshwater biodiversity, specifically. Despite the widespread awareness of risks to freshwater biodiversity, organized action to reverse this decline has been lacking. This study reviews prospective conservation and management strategies for freshwater biodiversity and their associated challenges, identifying current key threats to freshwater biodiversity. Engineered nanomaterials pose a significant threat to aquatic species, and will make controlling health risks to freshwater biodiversity increasingly challenging in the future. When fish are exposed to nanoparticles, the surface area of their respiratory and ion transport systems can decline to 60% of their total surface area, posing serious health risks. Also, about 50% of freshwater fish species are threatened by climate change, globally. Freshwater biodiversity that is heavily reliant on calcium perishes when the calcium content of their environments degrades, posing another severe threat to world biodiversity. To improve biodiversity, variables such as species diversity, population and water quality, and habitat are essential components that must be monitored continuously. Existing research on freshwater biota and ecosystems is still lacking. Therefore, data collection and the establishment of specialized policies for the conservation of freshwater biodiversity should be prioritized.
Ahmed, SF, Kumar, PS, Rozbu, MR, Chowdhury, AT, Nuzhat, S, Rafa, N, Mahlia, TMI, Ong, HC & Mofijur, M 2022, 'Heavy metal toxicity, sources, and remediation techniques for contaminated water and soil', Environmental Technology & Innovation, vol. 25, pp. 102114-102114.
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Ahmed, SF, Mehejabin, F, Momtahin, A, Tasannum, N, Faria, NT, Mofijur, M, Hoang, AT, Vo, D-VN & Mahlia, TMI 2022, 'Strategies to improve membrane performance in wastewater treatment', Chemosphere, vol. 306, pp. 135527-135527.
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Membrane technology has rapidly gained popularity in wastewater treatment due to its cost-effectiveness, environmentally friendly tools, and elevated productivity. Although membrane performance in wastewater treatment has been reviewed in several past studies, the key techniques for improving membrane performance, as well as their challenges, and solutions associated with the membrane process, were not sufficiently highlighted in those studies. Also, very few studies have addressed hybrid techniques to improve membrane performance. The present review aims to fill those gaps and achieve public health benefits through safe water processing. Despite its higher cost, membrane performance can result in a 36% reduction in flux degradation. The issue with fouling has been identified as one of the key challenges of membrane technology. Chemical cleaning is quite effective in removing accumulated foulant. Fouling mitigation techniques have also been shown to have a positive effect on membrane photobioreactors that handle wastewater effluent, resulting in a 50% and 60% reduction in fouling rates for backwash and nitrogen bubble scouring techniques. Membrane hybrid approaches such as hybrid forward-reverse osmosis show promise in removing high concentrations of phosphorus, ammonium, and salt from wastewater. The incorporation of the forward osmosis process can reject 99% of phosphorus and 97% of ammonium, and the reverse osmosis approach can achieve a 99% salt rejection rate. The control strategies for membrane fouling have not been successfully optimized yet and more research is needed to achieve a realistic, long-term direct membrane filtering operation.
Ahmed, SF, Mofijur, M, Ahmed, B, Mehnaz, T, Mehejabin, F, Maliat, D, Hoang, AT & Shafiullah, GM 2022, 'Nanomaterials as a sustainable choice for treating wastewater', Environmental Research, vol. 214, no. Pt 1, pp. 113807-113807.
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Wastewater containing toxic substances is a major threat to the health of both aquatic and terrestrial ecosystems. In order to treat wastewater, nanomaterials are currently being studied intensively due to their unprecedented properties. The unique features of nanoparticles are prompting an increasing number of studies into their use in wastewater treatment. Although several studies have been undertaken in recent years, most of them did not focus on some of the nanomaterials that are now often utilized for wastewater treatment. It is essential to investigate the most recent advances in all the types of nanomaterials that are now frequently employed for wastewater treatment. The recent advancements in common nanomaterials used for sustainable wastewater treatment is comprehensively reviewed in this paper. This paper also thoroughly assesses unique features, proper utilization, future prospects, and current limitations of green nanotechnology in wastewater treatment. Zero-valent metal and metal oxide nanoparticles, especially iron oxides were shown to be more effective than traditional carbon nanotubes (CNTs) for recovering heavy metals in wastewater. Iron oxide achieved 75.9% COD (chemical oxygen demand) removal efficiency while titanium oxide (TiO2) achieved 75.5% COD. Iron nanoparticles attained 72.1% methyl blue removal efficiency. However, since only a few types of nanomaterials have been commercialized, it is important to also focus on the economic feasibility of each nanomaterial. This study found that the large surface area, high reactivity, and strong mechanical properties of nanoparticles means they can be considered as a promising option for successful wastewater treatment.
Ahmed, SF, Mofijur, M, Chowdhury, SN, Nahrin, M, Rafa, N, Chowdhury, AT, Nuzhat, S & Ong, HC 2022, 'Pathways of lignocellulosic biomass deconstruction for biofuel and value-added products production', Fuel, vol. 318, pp. 123618-123618.
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As the world attempts to transition from fossil fuels, lignocellulosic biomass (LCB) serves as a promising alternative due to its high abundance. Hydrolysing LCB can generate various bioproducts, such as biofuels and value-added chemicals. However, the presence of lignin inhibits the solubilization of LCBs, presenting a major techno-economic challenge in the biorefinery concept. Therefore, this paper addresses the gaps left by most of the recent review works that fail to comprehensively review different pretreatment methods and the full scope of applications of LCBs, and do not incorporate techno-economic considerations of the technologies, the latter being the greatest bottleneck in the commercialization of the processes. The literature review revealed that while many of the physical and chemical pretreatment methods exhibit great effectiveness, they have a huge dependence on energy, chemicals, water, and/or specialized equipment, and produce harmful waste and inhibitory compounds. The pretreatment of lignocellulosic biomass can account for 40% of total production costs. Biological pretreatment can address these challenges but is limited by long incubation times. For instance, the bacterial pretreatment can noticeably reduce sawdust cellulose, hemicelluloses, and lignin contents by 35.8%, 37.1%, and 46.2%, respectively. Recently, integrated/coupling (hybrid) methods, such as chemical-assisted liquid hot water/steam and microwave or ultrasound-assisted alkaline pretreatment, have been gaining popularity due to their potential to improve chemical yield, but at the expense of the high cost of operation. To make pretreatment processes more techno-economically feasible, there is a need for process integration and the standardization and optimization of process parameters.
Ahmed, SF, Mofijur, M, Islam, N, Parisa, TA, Rafa, N, Bokhari, A, Klemeš, JJ & Indra Mahlia, TM 2022, 'Insights into the development of microbial fuel cells for generating biohydrogen, bioelectricity, and treating wastewater', Energy, vol. 254, pp. 124163-124163.
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Bio-electrochemical systems, such as microbial fuel cells (MFCs), serve as greener alternatives to conventional fuel energy. Despite the burgeoning review works on MFCs, comprehensive discussions are lacking on MFC designs and applications. This review paper provides insights into MFC applications, substrates used in MFC and the various design, technological, and chemical factors affecting MFC performance. MFCs have demonstrated efficacy in wastewater treatment of at least 50% and up to 98%. MFCs have been reported to produce ∼30 W/m2 electricity and ∼1 m3/d of biohydrogen, depending on the design and feedstock. Electricity generation rates of up to 5.04 mW/m−2–3.6 mW/m−2, 75–513 mW/m−2, and 135.4 mW/m−2 have been found for SCMFCs, double chamber MFCs, and stacked MFCs with the highest being produced by the single/hybrid single-chamber type using microalgae. Hybrid MFCs may emerge as financially promising technologies worth investigating due to their low operational costs, integrating low-cost proton exchange membranes such as PVA-Nafion-borosilicate, and electrodes made of natural materials, carbon, metal, and ceramic. MFCs are mostly used in laboratories due to their low power output and the difficulties in assessing the economic feasibility of the technology. The MFCs can generate incomes of as much as $2,498.77 × 10−2/(W/m2) annually through wastewater treatment and energy generation alone. The field application of MFC technology is also narrow due to its microbiological, electrochemical, and technological limitations, exacerbated by the gap in knowledge between laboratory and commercial-scale applications. Further research into novel and economically feasible electrode and membrane materials, the improvement of electrogenicity of the microbes used, and the potential of hybrid MFCs will provide opportunities to launch MFCs from the laboratory to the commercial-scale as a bid to improve the global energy security in an eco-friendly way.
Ahmed, SF, Mofijur, M, Nahrin, M, Chowdhury, SN, Nuzhat, S, Alherek, M, Rafa, N, Ong, HC, Nghiem, LD & Mahlia, TMI 2022, 'Biohydrogen production from wastewater-based microalgae: Progresses and challenges', International Journal of Hydrogen Energy, vol. 47, no. 88, pp. 37321-37342.
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Microalgae originating from wastewater has been exhibiting particularly promising results in terms of biohydrogen production and wastewater treatment. This paper aims to review the factors affecting production, pretreatment techniques to improve synthesis, advanced technologies utilized for enhancing biohydrogen production, and techno-economic feasibility evaluation of the processes at a commercial scale. Microalgae possess metabolic components to synthesize biohydrogen using photobiological and fermentative processes but must undergo pretreatment for efficient biohydrogen production. The efficiency of these processes is influenced by factors such as the microalgae species, light intensity, cell density, pH, temperature, substrates, and the type of bioreactors. Moreover, many limitations, such as oxygen sensitivity, altered thylakoid constitution, low photon conversion efficiency, light capture disruption, and the evolution of harmful by-products hinder the sustainability of biohydrogen production processes. High operational and maintenance costs serve as the major bottleneck in the scaling up of the process as an industrial technology. Therefore, future research needs to be directed towards increasing optimization of the processes by reducing energy and resource demand, recycling metabolic wastes and process components, genetically engineered microalgae to adopt more efficient routes, and conducting pilot studies for commercialization.
Ahmed, SF, Mofijur, M, Nuzhat, S, Rafa, N, Musharrat, A, Lam, SS & Boretti, A 2022, 'Sustainable hydrogen production: Technological advancements and economic analysis', International Journal of Hydrogen Energy, vol. 47, no. 88, pp. 37227-37255.
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Hydrogen (H2) is pivotal to phasing out fossil fuel-based energy systems. It can be produced from different sources and using different technologies. Very few studies comprehensively discuss all available state-of-the-art technologies for H2 production, the challenges facing each process, and their economic feasibility and sustainability. The current study thus addresses these gaps to effectively direct future research towards improving H2 production techniques. Many conventional methods contribute to large greenhouse gas footprints, with high production costs and low efficiency. Steam methane reforming and coal gasification dominate the supply side of H2, due to their low production costs (<$3.50/kg). Water-splitting offers one of the most environmentally benign production methods when integrated with renewable energy sources. However, it is considerably expensive and ridden with the flaw of production of harmful by-products that affect efficiency. Fossil fuel processing technologies remain one of the most efficient forms of H2 production sources, with yields exceeding 80% and reaching up to 100%, with the lowest cost despite their high reliance on expensive catalysts. Whereas solar-driven power systems cost slightly less than $10 kg−1, coal gasification and steam reforming cost below $3.05 kg−1. Future research thus needs to be directed towards cost reduction of renewable energy-based H2 production systems, as well as in their decarbonization and designing more robust H2 storage systems that are compatible with long-distance distribution networks with adequate fuelling stations.
Ahmed, SF, Mofijur, M, Parisa, TA, Islam, N, Kusumo, F, Inayat, A, Le, VG, Badruddin, IA, Khan, TMY & Ong, HC 2022, 'Progress and challenges of contaminate removal from wastewater using microalgae biomass', Chemosphere, vol. 286, no. Pt 1, pp. 131656-131656.
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The utilization of microalgae in treating wastewater has been an emerging topic focussed on finding an economically sustainable and environmentally friendly approach to treating wastewater. Over the last several years, different types of con microalgae and bacteria consortia have been experimented with to explore their potential in effectively treating wastewater from different sources. The basic features considered while determining efficiency is their capacity to remove nutrients including nitrogen (N) and phosphorus (P) and heavy metals like arsenic (As), lead (Pb), and copper (Cu). This paper reviews the efficiency of microalgae as an approach to treating wastewater from different sources and compares conventional and microalgae-based treatment systems. The paper also discusses the characteristics of wastewater, conventional methods of wastewater treatment that have been used so far, and the technological mechanisms for removing nutrients and heavy metals from contaminated water. Microalgae can successfully eliminate the suspended nutrients and have been reported to successfully remove N, P, and heavy metals by up to 99.6 %, 100 %, and 13%-100 % from different types of wastewater. However, although a microalgae-based wastewater treatment system offers some benefits, it also presents some challenges as outlined in the last section of this paper. Performance in eliminating nutrients from wastewater is affected by different parameters such as temperature, biomass productivity, osmotic ability, pH, O2 concentration. Therefore, the conducting of pilot-scale studies and exploration of the complexities of contaminants under complex environmental conditions is recommended.
Ahmed, SF, Mofijur, M, Rafa, N, Chowdhury, AT, Chowdhury, S, Nahrin, M, Islam, ABMS & Ong, HC 2022, 'Green approaches in synthesising nanomaterials for environmental nanobioremediation: Technological advancements, applications, benefits and challenges', Environmental Research, vol. 204, no. Pt A, pp. 111967-111967.
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Green synthesis approaches of nanomaterials (NMs) have received considerable attention in recent years as it addresses the sustainability issues posed by conventional synthesis methods. However, recent works of literature do not present the complete picture of biogenic NMs. This paper addresses the previous gaps by providing insights into the stability and toxicity of NMs, critically reviewing the various biological agents and solvents required for synthesis, sheds light on the factors that affect biosynthesis, and outlines the applications of NMs across various sectors. Despite the advantages of green synthesis, current methods face challenges with safe and appropriate solvent selection, process parameters that affect the synthesis process, nanomaterial cytotoxicity, bulk production and NM morphology control, tedious maintenance, and knowledge deficiencies. Consequently, the green synthesis of NMs is largely trapped in the laboratory phase. Nevertheless, the environmental friendliness, biocompatibility, and sensitivities of the resulting NMs have wider applications in biomedical science, environmental remediation, and consumer industries. To the scale-up application of biogenic NMs, future research should be focused on understanding the mechanisms of the synthesis processes, identifying more biological and chemical agents that can be used in synthesis, and developing the practicality of green synthesis at the industrial scale, and optimizing the factors affecting the synthesis process.
Ahmed, SF, Rafa, N, Mehnaz, T, Ahmed, B, Islam, N, Mofijur, M, Hoang, AT & Shafiullah, GM 2022, 'Integration of phase change materials in improving the performance of heating, cooling, and clean energy storage systems: An overview', Journal of Cleaner Production, vol. 364, pp. 132639-132639.
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Phase change materials (PCMs) have garnered significant attention as low-cost thermal energy storage systems that efficiently capture and store solar energy. Recent review works have largely focused only on thermal conductivity enhancement techniques, and/or applications of PCMs, while others have mainly discussed the performance enhancement of either heating, cooling, or clean energy storage systems integrating with PCMs. However, not enough studies recently reviewed all of these techniques/systems comprehensively to provide insights into them. This paper thus comprehensively reviews the integration of PCMs as an enhancement to most types of heating, cooling, and clean energy storage system performance, and the techniques to enhance thermal conductivity. The integration of PCMs with these systems has shown promising performance. For instance, an improvement of 13.5% is found in the efficiency of photovoltaic (PV) system when it is integrated with PCM/Al2O3 nanoparticles. In addition, the solar air heater's daily energy efficiency reaches 17% on its own, but when combined with PCM, it reaches 33%. However, the major drawback of using PCM–TES (thermal energy storage) for cooling is that PCM does not entirely solidify at night. The literature also shows that the issues related to PCMs' low thermal conductivity, phase separation, and subcooling/supercooling, their poor compatibility with other materials, and the environmental hazards they pose hinder their application on a large scale. It is necessary to implement international standards for assessing the thermophysical properties of PCMs and compile data to better facilitate the utilization of PCMs by end-users.
Akbal, E, Barua, PD, Dogan, S, Tuncer, T & Acharya, UR 2022, 'DesPatNet25: Data encryption standard cipher model for accurate automated construction site monitoring with sound signals', Expert Systems with Applications, vol. 193, pp. 116447-116447.
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Akbal, E, Barua, PD, Tuncer, T, Dogan, S & Acharya, UR 2022, 'Development of novel automated language classification model using pyramid pattern technique with speech signals', Neural Computing and Applications, vol. 34, no. 23, pp. 21319-21333.
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Akter, S, Zakia, MA, Mofijur, M, Ahmed, SF, Vo, D-VN, Khandaker, G & Mahlia, TMI 2022, 'SARS-CoV-2 variants and environmental effects of lockdowns, masks and vaccination: a review', Environmental Chemistry Letters, vol. 20, no. 1, pp. 141-152.
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The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is continuously evolving and four variants of concern have been identified so far, including Alpha, Beta, Gamma and Delta variants. Here we review the indirect effect of preventive measures such as the implementation of lockdowns, mandatory face masks, and vaccination programs, to control the spread of the different variants of this infectious virus on the environment. We found that all these measures have a considerable environmental impact, notably on waste generation and air pollution. Waste generation is increased due to the implementation of all these preventive measures. While lockdowns decrease air pollution, unsustainable management of face mask waste and temperature-controlled supply chains of vaccination potentially increases air pollution.
AL Hunaity, SA, Far, H & Saleh, A 2022, 'Vibration behaviour of cold-formed steel and particleboard composite flooring systems', Steel and Composite Structures, vol. 43, no. 3, pp. 403-417.
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Recently, there has been an increasing demand for buildings that allow rapid assembly of construction elements, have ample open space areas and are flexible in their final intended use. Accordingly, researchers have developed new competitive structures in terms of cost and efficiency, such as cold-formed steel and timber composite floors, to satisfy these requirements. Cold-formed steel and timber composite floors are light floors with relatively high stiffness, which allow for longer spans. As a result, they inherently have lower fundamental natural frequency and lower damping. Therefore, they are likely to undergo unwanted vibrations under the action of human activities such as walking. It is also quite expensive and complex to implement vibration control measures on problematic floors. In this study, a finite element model of a composite floor reported in the literature was developed and validated against four-point bending test results. The validated FE model was then utilised to examine the vibration behaviour of the investigated composite floor. Predictions obtained from the numerical model were compared against predictions from analytical formulas reported in the literature. Finally, the influence of various parameters on the vibration behaviour of the composite floor was studied and discussed.
Algayyim, S, Yusaf, T, Hamza, N, Wandel, A, Fattah, I, Laimon, M & Rahman, S 2022, 'Sugarcane Biomass as a Source of Biofuel for Internal Combustion Engines (Ethanol and Acetone-Butanol-Ethanol): A Review of Economic Challenges', Energies, vol. 15, no. 22, pp. 8644-8644.
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The objective of this review is to provide a deep overview of liquid biofuels produced from sugarcane bagasse and to address the economic challenges of an ethanol and acetone-butanol-ethanol blend in commercial processes. The chemistry of sugarcane bagasse is presented. Pretreatment technologies such as physical, chemical pretreatment, biological, and combination pretreatments used in the fermentation process are also provided and summarised. Different types of anaerobic bacteria Clostridia (yeast) are discussed to identify the ingredient best suited for sugarcane bagasse, which can assist the industry in commercializing ethanol and acetone-butanol-ethanol biofuel from biomass sugarcane. The use of an acetone-butanol-ethanol mixture and ethanol blend in internal combustion engines is also discussed. The literature then supports the proposal of the best operating conditions for fermentation to enhance ethanol and acetone-butanol-ethanol plant efficiency in the sugar waste industry and its application in internal combustion engines.
Alharbi, SK, Ansari, AJ, Nghiem, LD & Price, WE 2022, 'New transformation products from ozonation and photolysis of diclofenac in the aqueous phase', Process Safety and Environmental Protection, vol. 157, pp. 106-114.
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Alibeikloo, M, Khabbaz, H & Fatahi, B 2022, 'Random Field Reliability Analysis for Time-Dependent Behaviour of Soft Soils Considering Spatial Variability of Elastic Visco-Plastic Parameters', Reliability Engineering & System Safety, vol. 219, pp. 108254-108254.
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Low embankment strategy is one of the effective methods to control time-dependent settlement of soft soils in infrastructure construction projects. Spatial variability of soil characteristics is a crucial factor, affecting the reliability of predictions of the long-term settlement in soft soils. In this paper, the time-dependent behaviour of soft soils is analysed incorporating spatial variability of elastic visco-plastic model parameters. Standard Gaussian random fields for correlated elastic-plastic model parameter (λ/V) and the initial creep coefficient (ψ0/V) are generated adopting Karhunen-Loeve expansion method based on the spectral decomposition of correlation function into eigenvalues and eigenfunctions. Then the generated random fields are incorporated in the proposed non-linear elastic visco-plastic (EVP) creep model. The impacts of spatially variable elastic visco-plastic model parameters (i.e. ψ0/V and λ/V) on long-term settlement predictions are evaluated through random field analysis (RF) with different spatial correlation lengths, and results are then compared to a single random variable (SRV) analysis. The probability of failure (PF) is calculated adopting RF and SRV analysis to determine the critical spatial correlation length, resulted in a maximum probability of failure. This study can be employed by design engineers to determine the critical spatial correlation length for safe design in the absence of adequate data to determine the exact spatial correlation length. The results also confirm that SRV analysis is not always the most conservative analysis in predicting time-dependent settlement of soft soils; and it is essential to perform RF analysis considering the spatial correlation length to reduce the risk and increase the reliability of the design to be applied in construction.
Aljaafari, A, Fattah, IMR, Jahirul, MI, Gu, Y, Mahlia, TMI, Islam, MA & Islam, MS 2022, 'Biodiesel Emissions: A State-of-the-Art Review on Health and Environmental Impacts', Energies, vol. 15, no. 18, pp. 6854-6854.
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Biodiesel is an alternative source of fuel for various automotive applications. Because of the increasing demand for energy and the scarcity of fossil fuels, researchers have turned their attention to biodiesel production from various sources in recent years. The production of biofuels from organic materials and waste components allows for the use of these waste resources in transporting resources and people over long distances. As a result, developing sustainable measures for this aspect of life is critical, as knowledge of appropriate fuel sources, corresponding emissions, and health impacts will benefit the environment and public health assessment, which is currently lacking in the literature. This study investigates biodiesel’s composition and production process, in addition to biodiesel emissions and their associated health effects. Based on the existing literature, a detailed analysis of biodiesel production from vegetable oil crops and emissions was undertaken. This study also considered vegetable oil sources, such as food crops, which can have a substantial impact on the environment if suitable growing procedures are not followed. Incorporating biodegradable fuels as renewable and sustainable solutions decreases pollution to the environment. The effects of biodiesel exhaust gas and particulates on human health were also examined. According to epidemiologic studies, those who have been exposed to diesel exhaust have a 1.2–1.5 times higher risk of developing lung cancer than those who have not. In addition, for every 24 parts per billion increase in NO2 concentration, symptom prevalence increases 2.7-fold. Research also suggests that plain biodiesel combustion emissions are more damaging than petroleum diesel fuel combustion emissions. A comprehensive analysis of biodiesel production, emissions, and health implications would advance this field’s understanding.
Al-Juboori, RA, Bakly, S, Bowtell, L, Alkurdi, SSA & Altaee, A 2022, 'Innovative capacitive deionization-degaussing approach for improving adsorption/desorption for macadamia nutshell biochar', Journal of Water Process Engineering, vol. 47, pp. 102786-102786.
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Allahabadi, H, Amann, J, Balot, I, Beretta, A, Binkley, C, Bozenhard, J, Bruneault, F, Brusseau, J, Candemir, S, Cappellini, LA, Chakraborty, S, Cherciu, N, Cociancig, C, Coffee, M, Ek, I, Espinosa-Leal, L, Farina, D, Fieux-Castagnet, G, Frauenfelder, T, Gallucci, A, Giuliani, G, Golda, A, van Halem, I, Hildt, E, Holm, S, Kararigas, G, Krier, SA, Kuhne, U, Lizzi, F, Madai, VI, Markus, AF, Masis, S, Mathez, EW, Mureddu, F, Neri, E, Osika, W, Ozols, M, Panigutti, C, Parent, B, Pratesi, F, Moreno-Sanchez, PA, Sartor, G, Savardi, M, Signoroni, A, Sormunen, H-M, Spezzatti, A, Srivastava, A, Stephansen, AF, Theng, LB, Tithi, JJ, Tuominen, J, Umbrello, S, Vaccher, F, Vetter, D, Westerlund, M, Wurth, R & Zicari, RV 2022, 'Assessing Trustworthy AI in Times of COVID-19: Deep Learning for Predicting a Multiregional Score Conveying the Degree of Lung Compromise in COVID-19 Patients', IEEE Transactions on Technology and Society, vol. 3, no. 4, pp. 272-289.
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Almuntashiri, A, Hosseinzadeh, A, Badeti, U, Shon, H, Freguia, S, Dorji, U & Phuntsho, S 2022, 'Removal of pharmaceutical compounds from synthetic hydrolysed urine using granular activated carbon: Column study and predictive modelling', Journal of Water Process Engineering, vol. 45, pp. 102480-102480.
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Human urine contains high concentration of pharmaceuticals, a concern that must be addressed if used as a fertiliser. This study systematically evaluated granular activated carbon (GAC) adsorption in removing five most commonly found pharmaceuticals in the environment – naproxen (NAP), carbamazepine (CBZ), ibuprofen (IBP), acetaminophen (APAP) and metronidazole (MTZ) from hydrolysed urine. Fixed-bed column experiments were conducted to obtain breakthrough curves and assess GAC (1000 m2g−1) performance in the adsorption of pharmaceuticals at different adsorbent mass (4–12 g·L−1), flow rate (1.15–4.32 L·d−1) and adsorption/contact time at ambient room temperature and pH 9. The highest adsorption capacity was observed at a lower adsorbent mass (4 g·L−1) and lower flow rate (1.15 L·d−1) for all micropollutants. The breakthrough curves showed the highest GAC adsorption capacity for CBZ (56.1 mg·g−1) while MTZ (32.2 mg·g−1) with the lowest adsorption will be the design limiting for column adsorption application. Thomas and Yoon-Nelson models fitted well for predicting empirical breakthrough curves for fixed-bed GAC column adsorption. The artificial neural network (ANN) modelling was able to predict the removal effectiveness of over 99% except for APAP at 84.5%. The study showed that the potential application of GAC column adsorption for micropollutant removal is significant although this study was limited in the range of parameters studied.
Alotaibi, AA, Maerz, NH, Boyko, KJ, Youssef, AM & Pradhan, B 2022, 'Temporal LiDAR scanning in quantifying cumulative rockfall volume and hazard assessment: A case study at southwestern Saudi Arabia', The Egyptian Journal of Remote Sensing and Space Science, vol. 25, no. 2, pp. 435-443.
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Rockfalls and unstable slopes pose a serious threat to people and property along roads/highways in the southwestern mountainous regions of Saudi Arabia. In this study, the application of terrestrial light detection and ranging (LiDAR) technology was applied aiming to propose a strategy to analyze and accurately depict the detection of rockfall changes, calculation of rockfall volume, and evaluate rockfall hazards along the Habs Road, Jazan Region, Saudi Arabia. A series of temporal LiDAR scans were acquired at three selected sites. Our results show that these three sites have different degrees of hazard due to their geological differences. The mean volume loss of sites A1, A2, and A3 is 327.1, 424.4, and 3.7 L, respectively. Statistical analysis confirms the significance of the influence of site type on rockfall volume, with a probability value of < 0.0105. The rockfall volume and change detection values are then correlated with precipitation, which is a triggering factor. The study also reveals that the use of terrestrial LiDAR could reduce time and effort, increase accessibility, and produce effective solutions. LiDAR could be an indispensable tool for disaster risk assessment, response and recovery process.
Alshahrani, AA, Al-Zoubi, H, Alotaibi, SE, Hassan, HMA, Alsohaimi, IH, Alotaibi, KM, Alshammari, MS, Nghiem, L & Panhuis, MIH 2022, 'Assessment of commercialized nylon membranes integrated with thin layer of MWCNTs for potential use in desalination process', Journal of Materials Research and Technology, vol. 21, pp. 872-883.
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Al-Zainati, N, Subbiah, S, Yadav, S, Altaee, A, Bartocci, P, Ibrar, I, Zhou, J, Samal, AK & Fantozzi, F 2022, 'Experimental and theoretical work on reverse osmosis - Dual stage pressure retarded osmosis hybrid system', Desalination, vol. 543, pp. 116099-116099.
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Two-pass reverse osmosis desalination is a common process to treat high-salinity feed solution and provides a low-salinity permeate solution. This study investigated the significance of the energy generated by the dual-stage pressure retarded osmosis (DSPRO) from the reverse osmosis (RO) brine stream. The main components of the DSPRO-RO hybrid system are RO, pressure retarded osmosis (PRO), and energy recovery device, and their models are determined. Dymola software, using Modelica modelling language, was utilized for solving the hybrid system models. Two different flowsheets were built; the first included a two-pass RO, while the second is a hybrid of a two-pass RO (2RO)-DSPRO system. Seawater salinities of 40 and 45 g/L were the RO feed solution, and 1 g/L tertiary treated wastewater was the feed solution of the DSPRO process. The net specific energy consumption was calculated for the 2RO and 2RO-DSPRO systems for 40 and 45 g/L salinities. At a 47% recovery rate and 40 g/L seawater salinity, the 2RO-DSPRO system was 14.7% more energy efficient than the 2RO system. The corresponding energy saving at a 47% recovery rate and 45 g/L seawater salinity was 17.5%. The desalination energy for the 2RO system was between 3.25 and 3.49 kWh/m3, and for the 2RO-DSPRO system was between 2.91 and 2.97 kWh/m3. The results demonstrate the great potential of integrating the 2RO with the DSPRO to reduce desalination's energy consumption and environmental impacts.
AlZainati, N, Yadav, S, Altaee, A, Subbiah, S, Zaidi, SJ, Zhou, J, Al-Juboori, RA, Chen, Y & Shaheed, MH 2022, 'Impact of hydrodynamic conditions on optimum power generation in dual stage pressure retarded osmosis using spiral-wound membrane', Energy Nexus, vol. 5, pp. 100030-100030.
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Ampah, JD, Yusuf, AA, Agyekum, EB, Afrane, S, Jin, C, Liu, H, Fattah, IMR, Show, PL, Shouran, M, Habil, M & Kamel, S 2022, 'Progress and Recent Trends in the Application of Nanoparticles as Low Carbon Fuel Additives—A State of the Art Review', Nanomaterials, vol. 12, no. 9, pp. 1515-1515.
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The first part of the current review highlights the evolutionary nuances and research hotspots in the field of nanoparticles in low carbon fuels. Our findings reveal that contribution to the field is largely driven by researchers from Asia, mainly India. Of the three biofuels under review, biodiesel seems to be well studied and developed, whereas studies regarding vegetable oils and alcohols remain relatively scarce. The second part also reviews the application of nanoparticles in biodiesel/vegetable oil/alcohol-based fuels holistically, emphasizing fuel properties and engine characteristics. The current review reveals that the overall characteristics of the low carbon fuel–diesel blends improve under the influence of nanoparticles during combustion in diesel engines. The most important aspect of nanoparticles is that they act as an oxygen buffer that provides additional oxygen molecules in the combustion chamber, promoting complete combustion and lowering unburnt emissions. Moreover, the nanoparticles used for these purposes exhibit excellent catalytic behaviour as a result of their high surface area-to-volume ratio—this leads to a reduction in exhaust pollutants and ensures an efficient and complete combustion. Beyond energy-based indicators, the exergy, economic, environmental, and sustainability aspects of the blends in diesel engines are discussed. It is observed that the performance of the diesel engine fuelled with low carbon fuels according to the second law of efficiency improves under the influence of the nano-additives. Our final part shows that despite the benefits of nanoparticles, humans and animals are under serious threats from the highly toxic nature of nanoparticles.
Anand, U, Li, X, Sunita, K, Lokhandwala, S, Gautam, P, Suresh, S, Sarma, H, Vellingiri, B, Dey, A, Bontempi, E & Jiang, G 2022, 'SARS-CoV-2 and other pathogens in municipal wastewater, landfill leachate, and solid waste: A review about virus surveillance, infectivity, and inactivation', Environmental Research, vol. 203, pp. 111839-111839.
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This review discusses the techniques available for detecting and inactivating of pathogens in municipal wastewater, landfill leachate, and solid waste. In view of the current COVID-19 pandemic, SARS-CoV-2 is being given special attention, with a thorough examination of all possible transmission pathways linked to the selected waste matrices. Despite the lack of works focused on landfill leachate, a systematic review method, based on cluster analysis, allows to analyze the available papers devoted to sewage sludge and wastewater, allowing to focalize the work on technologies able to detect and treat pathogens. In this work, great attention is also devoted to infectivity and transmission mechanisms of SARS-CoV-2. Moreover, the literature analysis shows that sewage sludge and landfill leachate seem to have a remote chance to act as a virus transmission route (pollution-to-human transmission) due to improper collection and treatment of municipal wastewater and solid waste. However due to the incertitude about virus infectivity, these possibilities cannot be excluded and need further investigation. As a conclusion, this paper shows that additional research is required not only on the coronavirus-specific disinfection, but also the regular surveillance or monitoring of viral loads in sewage sludge, wastewater, and landfill leachate. The disinfection strategies need to be optimized in terms of dosage and potential adverse impacts like antimicrobial resistance, among many other factors. Finally, the presence of SARS-CoV-2 and other pathogenic microorganisms in sewage sludge, wastewater, and landfill leachate can hamper the possibility to ensure safe water and public health in economically marginalized countries and hinder the realization of the United Nations' sustainable development goals (SDGs).
Andaryani, S, Nourani, V, Pradhan, B, Jalali Ansarudi, T, Ershadfath, F & Torabi Haghighi, A 2022, 'Spatiotemporal evaluation of future groundwater recharge in arid and semi-arid regions under climate change scenarios', Hydrological Sciences Journal, vol. 67, no. 6, pp. 979-995.
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Angeloski, A, Price, JR, Ennis, C, Smith, K, McDonagh, AM, Dowd, A, Thomas, P, Cortie, M, Appadoo, D & Bhadbhade, M 2022, 'Thermosalience Revealed on the Atomic Scale: Rapid Synchrotron Techniques Uncover Molecular Motion Preceding Crystal Jumping', Crystal Growth & Design, vol. 22, no. 3, pp. 1951-1959.
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The solid-state phase transformation in nickel(II) bis(diisopropyldithiocarbonate) is analyzed using a combination of high-speed in situ single-crystal diffraction, terahertz spectroscopy, optical microscopy, thermal analysis, and density functional theory. We show that the monoclinic P21/c structure of this compound undergoes a displacive phase change at about 3 °C. The monoclinic angles and unit cell volumes change reversibly between 110.3°/2265 Å3 and 103.8°/2168 Å3. An analysis of atomic positions using high-resolution in situ synchrotron X-ray diffraction data revealed details of the atomic displacements that show a change in order that precedes and accompanies the change in structure. The structural changes are rapid and are manifested as reversible macroscale crystal movement and jumping (thermosalience) and represent the first case of thermosalience in dithiocarbamate complexes.
Arabameri, A, Santosh, M, Moayedi, H, Tiefenbacher, JP, Pal, SC, Nalivan, OA, Costache, R, Ahmed, N, Hoque, MA-A, Chakrabortty, R & Cerda, A 2022, 'Application of the novel state-of-the-art soft computing techniques for groundwater potential assessment', Arabian Journal of Geosciences, vol. 15, no. 10.
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Arachchige, CMK, Indraratna, B, Qi, Y, Vinod, JS & Rujikiatkamjorn, C 2022, 'Deformation and degradation behaviour of Rubber Intermixed Ballast System under cyclic loading', Engineering Geology, vol. 307, pp. 106786-106786.
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Arachchige, CMK, Indraratna, B, Qi, Y, Vinod, JS & Rujikiatkamjorn, C 2022, 'Geotechnical characteristics of a Rubber Intermixed Ballast System', Acta Geotechnica, vol. 17, no. 5, pp. 1847-1858.
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This study aims to promote the concept of using rubber granules from waste tyres as elastic aggregates blended with traditional ballast particles for better performance of rail tracks, i.e. a Rubber Intermixed Ballast System (RIBS). This paper describes the mechanical and compressibility characteristics of RIBS under monotonic loads and a criterion designed to determine the optimum rubber content in the proposed RIBS. The most interesting findings of this study embrace how the rubber granules in the blended rockfill assembly significantly reduce the dilation and modulus degradation, and the breakage of ballast aggregates. RIBS with more than 10% of rubber demonstrates a seemingly consistent reduction in dilation under changing confining pressures. Increased deviator stress and larger effective confining pressure compress the rubber particles within the RIBS which may cause relatively large initial settlements in the ballast layer, if the rubber content becomes excessive. It is also evident from the results that rubber particles ranging from 9.5 to 19 mm with similar angularity to ballast aggregates is advantageous, because, they reduce the breakage of load-bearing larger aggregates, thus effectively controlling ballast fouling within the granular matrix.
Areerachakul, N, Prongnuch, S, Longsomboon, P & Kandasamy, J 2022, 'Quantitative Precipitation Estimation (QPE) Rainfall from Meteorology Radar over Chi Basin', Hydrology, vol. 9, no. 10, pp. 178-178.
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This study of the Quantitative Estimation Precipitation (QEP) of rainfall, detected by two Meteorology Radars over Chi Basin, North-east Thailand, used data from the Thai Meteorological Department (TMD). The rainfall data from 129 rain gauge stations in the Chi Basin area, covering a period of two years, was also used. The study methodology consists of: firstly, deriving the QPE between radar and rainfall based on meteorological observations using the Marshall Palmer Stratiform, the Summer Deep Convection, and Regression Model and calibrating with rain gauge station data; secondly, Bias Correction using statistical method; thirdly, determining spatial variation using three methods, namely Kriging, Inverse Distance Weight (IDW), and the Minimum Curvature Method. The results of the study demonstrated the accuracy of estimating precipitation using meteorological radar. Estimated precipitation compared against an equivalent of 2 years of rain station measurement had a probability of detection (POD) of 0.927, where a value of 1 indicated perfect agreement, demonstrating the effectiveness of the method used to calibrate the radar data. The bias correction method gave high accuracy compared with measured rainfall. Furthermore, of the spatial estimation of rainfall methods, the Kriging methodology showed the best fit between estimation of rainfall distribution and measured rainfall distribution. Therefore, the results of this study showed that the rainfall estimation, using data from a meteorology radar, has good accuracy and can be useful, especially in areas where it is not possible to install and operate rainfall measurement stations, such as in heavily forested areas and/or in steep terrain. Additionally, good accuracy rainfall data derived from radar data can be integrated with other data used for water management and natural disasters for applications to reduce economic losses, as well as losses of life and property.
Arivalagan, J, Indraratna, B, Rujikiatkamjorn, C & Warwick, A 2022, 'Effectiveness of a Geocomposite-PVD system in preventing subgrade instability and fluidisation under cyclic loading', Geotextiles and Geomembranes, vol. 50, no. 4, pp. 607-617.
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Arjmandi, A, Peyravi, M, Arjmandi, M & Altaee, A 2022, 'Taking advantage of large water-unstable Zn4O(BDC)3 nanoparticles for fabricating the PMM-based TFC FO membrane with improved water flux in desalination process', Chemical Engineering Research and Design, vol. 186, pp. 112-124.
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Arora, S, Nag, A, Kalra, A, Sinha, V, Meena, E, Saxena, S, Sutaria, D, Kaur, M, Pamnani, T, Sharma, K, Saxena, S, Shrivastava, SK, Gupta, AB, Li, X & Jiang, G 2022, 'Successful application of wastewater-based epidemiology in prediction and monitoring of the second wave of COVID-19 with fragmented sewerage systems–a case study of Jaipur (India)', Environmental Monitoring and Assessment, vol. 194, no. 5, p. 342.
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The present study tracked the city-wide dynamics of severe acute respiratory syndrome-corona virus 2 ribonucleic acids (SARS-CoV-2 RNA) in the wastewater from nine different wastewater treatment plants (WWTPs) in Jaipur during the second wave of COVID-19 out-break in India. A total of 164 samples were collected weekly between February 19th and June 8th, 2021. SARS-CoV-2 was detected in 47.2% (52/110) influent samples and 37% (20/54) effluent samples. The increasing percentage of positive influent samples correlated with the city's increasing active clinical cases during the second wave of COVID-19 in Jaipur. Furthermore, wastewater-based epidemiology (WBE) evidence clearly showed early detection of about 20 days (9/9 samples reported positive on April 20th, 2021) before the maximum cases and maximum deaths reported in the city on May 8th, 2021. The present study further observed the presence of SARS-CoV-2 RNA in treated effluents at the time window of maximum active cases in the city even after tertiary disinfection treatments of ultraviolet (UV) and chlorine (Cl2) disinfection. The average genome concentration in the effluents and removal efficacy of six commonly used treatments, activated sludge process + chlorine disinfection (ASP + Cl2), moving bed biofilm reactor (MBBR) with ultraviolet radiations disinfection (MBBR + UV), MBBR + chlorine (Cl2), sequencing batch reactor (SBR), and SBR + Cl2, were compared with removal efficacy of SBR + Cl2 (81.2%) > MBBR + UV (68.8%) > SBR (57.1%) > ASP (50%) > MBBR + Cl2 (36.4%). The study observed the trends and prevalence of four genes (E, RdRp, N, and ORF1ab gene) based on two different kits and found that prevalence of N > ORF1ab > RdRp > E gene suggested that the effective genome concentration should be calculated based on the presence/absence of multiple genes. Hence, it is imperative to say that using a combination of different detection genes (E, N, RdRp, & ORF1ab genes) increases the sensitivity in WBE.
Aryal, B, Gurung, R, Camargo, AF, Fongaro, G, Treichel, H, Mainali, B, Angove, MJ, Ngo, HH, Guo, W & Puadel, SR 2022, 'Nitrous oxide emission in altered nitrogen cycle and implications for climate change', Environmental Pollution, vol. 314, pp. 120272-120272.
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Natural processes and human activities play a crucial role in changing the nitrogen cycle and increasing nitrous oxide (N2O) emissions, which are accelerating at an unprecedented rate. N2O has serious global warming potential (GWP), about 310 times higher than that of carbon dioxide. The food production, transportation, and energy required to sustain a world population of seven billion have required dramatic increases in the consumption of synthetic nitrogen (N) fertilizers and fossil fuels, leading to increased N2O in air and water. These changes have radically disturbed the nitrogen cycle and reactive nitrogen species, such as nitrous oxide (N2O), and have impacted the climatic system. Yet, systematic and comprehensive studies on various underlying processes and parameters in the altered nitrogen cycle, and their implications for the climatic system are still lacking. This paper reviews how the nitrogen cycle has been disturbed and altered by anthropogenic activities, with a central focus on potential pathways of N2O generation. The authors also estimate the N2O-N emission mainly due to anthropogenic activities will be around 8.316 Tg N2O-N yr-1 in 2050. In order to minimize and tackle the N2O emissions and its consequences on the global ecosystem and climate change, holistic mitigation strategies and diverse adaptations, policy reforms, and public awareness are suggested as vital considerations. This study concludes that rapidly increasing anthropogenic perturbations, the identification of new microbial communities, and their role in mediating biogeochemical processes now shape the modern nitrogen cycle.
Atgur, V, Manavendra, G, Desai, GP, Rao, BN, Fattah, IMR, Mohamed, BA, Sinaga, N & Masjuki, HH 2022, 'Thermogravimetric and combustion efficiency analysis of Jatropha curcas biodiesel and its derivatives', Biofuels, vol. 13, no. 9, pp. 1069-1079.
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Thermal behavior of diesel, Jatropha curcas methyl ester (JOME), and its B20 blend (20% biodiesel and 80% diesel) are examined from the profiles of thermogravimetry–differential scanning calorimetry (TG-DSC) under air. TG profiles of samples indicate the mass loss steps to volatilization and combustion of methyl esters. Due to the higher temperature combustion of the intermediate stable compounds that are formed, the peak temperature of combustion is high for JOME compared to diesel and B20 blend. DSC profiles of diesel and B20 JOME indicate an endothermic peak associated with the vaporization of methyl esters for B20 JOME and the volatilization of a small fraction of the diesel. The ignition temperature for diesel and B20 blend is 128 °C, whereas JOME has an ignition temperature of 220 °C. The burnout temperatures for the diesel, JOME, and B20 blend are 283.24, 470.02, and 376.92 °C, respectively. The ignition index for the B20 blend was found to be 73.73% more compared to diesel. The combustion index for the B20 blend was found to be 37.81% higher compared to diesel. The B20 blend exhibits high enthalpy, better thermal stability, and a reduced peak temperature of combustion, with an improved combustion index and an intensity of combustion making it nearly comparable with diesel.
Atif, Y, Soulaimani, A, Ait lamqadem, A, Pour, AB, Pradhan, B, Nouamane, EA, Abdelali, K, Muslim, AM & Hossain, MS 2022, 'Identifying hydrothermally altered rocks using ASTER satellite imageries in Eastern Anti-Atlas of Morocco: a case study from Imiter silver mine', International Journal of Image and Data Fusion, vol. 13, no. 4, pp. 337-361.
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Atique, MN, Imran, S, Razzaq, L, Mujtaba, MA, Nawaz, S, Kalam, MA, Soudagar, MEM, Hussain, A, Veza, I & Arshad, A 2022, 'Hydraulic characterization of Diesel, B50 and B100 using momentum flux', Alexandria Engineering Journal, vol. 61, no. 6, pp. 4371-4388.
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Awang, MSN, Mohd Zulkifli, NW, Abbas, MM, Zulkifli, MSA, Kalam, MA, Mohd Yusoff, MNA, Ahmad, MH & Wan Daud, WMA 2022, 'Effect of plastic pyrolytic oil and waste cooking biodiesel on tribological properties of palm biodiesel–diesel fuel blends', Industrial Lubrication and Tribology, vol. 74, no. 8, pp. 932-942.
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PurposeThe purpose of this paper was to investigate the lubricity of palm biodiesel (PB)–diesel fuel with plastic pyrolysis oil (PPO) and waste cooking biodiesel (WCB).Design/methodology/approachThree quaternary fuels were prepared by mechanical stirring. B10 (10% PB in diesel) fuel was blended with 5%, 10% and 15% of both PPO and WCB. The results were compared to B30 (30% PB in diesel) and B10. The lubricity of fuel samples was determined using high-frequency reciprocating rig in accordance with ASTM D6079. The tribological behavior of all fuels was assessed by using scanning electron microscopy on worn steel plates to determine wear scar diameter (WSD) and surface morphology. The reported WSD is the average of the major and minor axis of the wear scar.FindingsThe addition of PPO and WCB to B10 had improved its lubricity while lowering wear and friction coefficients. Among the quaternary fuels, B40 showed the greatest reduction in coefficient of friction and WSD, with 7.63% and 44.5%, respectively, when compared to B10. When compared to B30a, the quaternary fuel mixes (B40, B30b and B20) exhibited significant reduction in WSD by 49.66%, 42.84% and 40.24%, respectively. Among the quaternary fuels, B40 exhibited the best overall lubricating performance, which was supported by surface morphology analysis. The evaluation of B40 indicated a reduced adhesive wear and tribo-oxidation, as well as a smoother metal surface, as compared to B20 and B30b.Originality/valueIncorporation of PPO and WCB in PB–diesel blend as a quaternary fuel blend in diesel engines has not been reported. O...
Awang, MSN, Zulkifli, NWM, Abbas, MM, Zulkifli, SA, Kalam, MA, Yusoff, MNAM, Daud, WMAW & Ahmad, MH 2022, 'Effect of diesel-palm biodiesel fuel with plastic pyrolysis oil and waste cooking biodiesel on tribological characteristics of lubricating oil', Alexandria Engineering Journal, vol. 61, no. 9, pp. 7221-7231.
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Aydemir, E, Dogan, S, Baygin, M, Ooi, CP, Barua, PD, Tuncer, T & Acharya, UR 2022, 'CGP17Pat: Automated Schizophrenia Detection Based on a Cyclic Group of Prime Order Patterns Using EEG Signals', Healthcare, vol. 10, no. 4, pp. 643-643.
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Background and Purpose: Machine learning models have been used to diagnose schizophrenia. The main purpose of this research is to introduce an effective schizophrenia hand-modeled classification method. Method: A public electroencephalogram (EEG) signal data set was used in this work, and an automated schizophrenia detection model is presented using a cyclic group of prime order with a modulo 17 operator. Therefore, the presented feature extractor was named as the cyclic group of prime order pattern, CGP17Pat. Using the proposed CGP17Pat, a new multilevel feature extraction model is presented. To choose a highly distinctive feature, iterative neighborhood component analysis (INCA) was used, and these features were classified using k-nearest neighbors (kNN) with the 10-fold cross-validation and leave-one-subject-out (LOSO) validation techniques. Finally, iterative hard majority voting was employed in the last phase to obtain channel-wise results, and the general results were calculated. Results: The presented CGP17Pat-based EEG classification model attained 99.91% accuracy employing 10-fold cross-validation and 84.33% accuracy using the LOSO strategy. Conclusions: The findings and results depicted the high classification ability of the presented cryptologic pattern for the data set used.
Bachosz, K, Zdarta, J, Nghiem, LD & Jesionowski, T 2022, 'Multienzymatic conversion of monosaccharides from birch biomass after pretreatment', Environmental Technology & Innovation, vol. 28, pp. 102874-102874.
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Badeti, U, Jiang, J, Almuntashiri, A, Pathak, N, Dorji, U, Volpin, F, Freguia, S, Ang, WL, Chanan, A, Kumarasingham, S, Shon, HK & Phuntsho, S 2022, 'Impact of source-separation of urine on treatment capacity, process design, and capital expenditure of a decentralised wastewater treatment plant', Chemosphere, vol. 300, pp. 134489-134489.
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In this study, the impact of urine diversion on the treatment capacity, treatment process, and capital costs of a decentralised wastewater treatment plant (WWTP) was simulated using BioWin. The data for simulation including for economic analysis were obtained from a real decentralised WWTP at Sydney. Simulation was conducted for two alternative process design scenarios of a WWTP: membrane bioreactor (MBR) without denitrification and anaerobic MBR in place of aerobic MBR and compared to existing process design. The simulation shows that with about 75% urine diversion (through source separation), the treatment capacity of the existing WWTP can be doubled although above 40% urine diversion, the impact appears less rapid. When the urine diversion exceeds 75%, it was found that the anoxic tank for biological denitrification becomes redundant and the current wastewater treatment process could be replaced with a simpler and much less aeration intensive membrane bioreactor (MBR) producing similar effluent quality with a 24% reduction in capital expenditure (footprint) cost. Anaerobic MBR can be a potential alternative to aerobic MBR although pre-treatment becomes essential before reverse osmosis treatment for water reuse applications. Sensitivity analysis has revealed that by operating the bioreactor at higher mixed liquor suspended solids concentrations (9 g/L instead of 5 g/L) could help increase the WWTP treatment capacity by about 3.5 times at 75% urine diversion. Hence, urine diversion (until nitrogen-limiting conditions occur above 75% urine diversion) can increase the treatment capacity of an existing WWTP and reduce the capital expenses due to reduced plant footprint.
Baharvand, S & Pradhan, B 2022, 'Erosion and flood susceptibility evaluation in a catchment of Kopet-Dagh mountains using EPM and RFM in GIS', Environmental Earth Sciences, vol. 81, no. 20, p. 490.
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Erosion and flood events can damage soils, water, quality, and sediment transportation, causing many cumulative hazards. In developing countries, such as Iran, the empirical models, which are low-cost procedures to mitigate environmental hazards, are necessary to plan the watersheds. Hence, the main aim of this study is to evaluate erosion and flood susceptibility using empirical models of erosion potential method (EPM) and rational flood model (RFM) to prioritize the GIS-based prone zones in a catchment of the Kopet-Dagh Mountains. The results revealed that the heavy classes of erosion and flood susceptibility include 40.4–58.2% of the total study area, dominantly in the upstream catchments. The correlation test revealed a strong, significant, and direct association (R equal to 0.705) between W and Qp at the 99% confidence level. Consequently, the results of our research indicated the prioritization of the three sub-catchments based on their slight sensitivity and susceptibility to occurrences of soil erosion and flood events through future spatial developments. Ultimately, the model validity explained the AUC (area under the curve) values averagely equal to 0.898 and 0.917 for erosion and flood susceptibility evaluations (i.e., EPM and RFM), explaining the very good performance of the models and excellent sensitivities.
Ball, JE 2022, 'Modelling accuracy for urban design flood estimation', Urban Water Journal, vol. 19, no. 1, pp. 87-96.
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Management of flood risk remains a major problem in many urban environments. To generate the data needed for estimation of the flood risk, catchment models have been used with the reliability of the predicted catchment response for design flood estimation dependent upon the model calibration. However, the level of calibration required to achieve reliable design flood estimation remains unspecified. The purpose of this paper is to assess the event modelling accuracy needed if data from the calibrated model are to be used for continuous simulation of data for flood frequency analysis. For this purpose, a SWMM-based catchment model was investigated using 25 monitored events, while the assessment of the calibration was based on a normalised peak flow error. Alternative sets of parameter values were used to obtain estimates of the peak flow for each of the selected events. The best performing sets of these sets of parameter values were used with SWMM in a continuous simulation mode to predict flow sequences for extraction of Annual Maxima Series for an At-Site Flood Frequency Analysis. From the analysis of these At-Site Flood Frequency Analyses, it was concluded that the normalised peak flow error needed to be less than 10% if reliable design flood quantile estimates were to be obtained.
Balogun, A-L, Sheng, TY, Sallehuddin, MH, Aina, YA, Dano, UL, Pradhan, B, Yekeen, S & Tella, A 2022, 'Assessment of data mining, multi-criteria decision making and fuzzy-computing techniques for spatial flood susceptibility mapping: a comparative study', Geocarto International, vol. 37, no. 26, pp. 12989-13015.
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This study develops an Adaboost-GIS model for flood susceptibility mapping and evaluates its relative performance by undertaking a comparative assessment of the machine learning model with Multi-Criteria Decision Making (MCDM) and soft computing models integrated with GIS. An Analytic Hierarchy Process (AHP), Analytic Network Process (ANP), Fuzzy-AHP, Fuzzy-ANP and AdaBoost machine learning models were developed and integrated with GIS to classify the susceptibility of the study area. Out of 70 sample validation locations, Adaboost’s performance was the best with a 95.72% similarity match with very high and high susceptibility locations followed by F-ANP, ANP, F-AHP and AHP with 95.65%, 92.75%, 81.42% and 77.14% similarity matches, respectively. It also had the highest AUC (0.864). Thus, the Adaboost machine learning, Fuzzy computing and conventional MCDM models can be adopted by stakeholders for accurately assessing flood susceptibility, thereby fostering safe and resilient cities.
Bardhan, A, GuhaRay, A, Gupta, S, Pradhan, B & Gokceoglu, C 2022, 'A novel integrated approach of ELM and modified equilibrium optimizer for predicting soil compression index of subgrade layer of Dedicated Freight Corridor', Transportation Geotechnics, vol. 32, pp. 100678-100678.
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This study proposes a high-performance machine learning model to sidestep the time of conducting actual laboratory tests of soil compression index (Cc), one of the important criteria for determining the settlement of subgrade layers of roadways, railways, and airport runways. The suggested method combines the modified equilibrium optimizer (MEO) and the extreme learning machine (ELM) in a novel way. In this study, Gaussian mutation with an exploratory search mechanism was incorporated to construct the MEO and used to enhance the performance of conventional ELM by optimizing its learning parameters. PCA (Principal component analysis)-based results exhibit that the developed ELM-MEO attained the most precise prediction with R2 = 0.9746, MAE = 0.0184, and RMSE = 0.0284 in training, and R2 = 0.9599, MAE = 0.0232, and RMSE = 0.0357 in the testing phase. The results showed that the proposed ELM-MEO model outperformed the other developed models, confirming the ELM-MEO model's superiority over the other models, such as random forest, gradient boosting machine, genetic programming, including the ELM and artificial neural network (ANN)-based models optimized with equilibrium optimizer, particle swarm optimization, Harris hawks optimization, slime mould algorithm, and marine predators algorithm. Based on the experimental results, the proposed ELM-MEO can be used as a promising alternative to predict soil Cc in civil engineering projects, including rail and road projects.
Bardhan, A, Subbiah, S, Mohanty, K, Ibrar, I & Altaee, A 2022, 'Feasibility of Poly (Vinyl Alcohol)/Poly (Diallyldimethylammonium Chloride) Polymeric Network Hydrogel as Draw Solute for Forward Osmosis Process', Membranes, vol. 12, no. 11, pp. 1097-1097.
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Forward osmosis (FO) has been identified as an emerging technology for the concentration and crystallization of aqueous solutions at low temperatures. However, the application of the FO process has been limited due to the unavailability of a suitable draw solute. An ideal draw solute should be able to generate high osmotic pressure and must be easily regenerated with less reverse solute flux (RSF). Recently, hydrogels have attracted attention as a draw solution due to their high capacity to absorb water and low RSF. This study explores a poly (vinyl alcohol)/poly (diallyldimethylammonium chloride) (PVA-polyDADMAC) polymeric network hydrogel as a draw solute in forward osmosis. A low-pressure reverse osmosis (RO) membrane was used in the FO process to study the performance of the hydrogel prepared in this study as a draw solution. The robust and straightforward gel synthesis method provides an extensive-scale application. The results indicate that incorporating cationic polyelectrolyte poly (diallyldimethylammonium chloride) into the polymeric network increases swelling capacity and osmotic pressure, thereby resulting in an average water flux of the PVA-polyDADMAC hydrogel (0.97 L m−2 h−1) that was 7.47 times higher than the PVA hydrogel during a 6 h FO process against a 5000 mg L−1 NaCl solution (as a feed solution). The effect of polymer and cross-linker composition on swelling capacity was studied to optimize the synthesized hydrogel composition. At 50 °C, the hydrogel releases nearly >70% of the water absorbed during the FO process at room temperatures, and water flux can be recovered by up to 86.6% of the initial flux after 12 hydrogel (draw solute) regenerations. Furthermore, this study suggests that incorporating cationic polyelectrolytes into the polymeric network enhances FO performances and lowers the actual energy requirements for (draw solute) regeneration. This study represents a significant step toward the commercial implementati...
Bargshady, G, Zhou, X, Barua, PD, Gururajan, R, Li, Y & Acharya, UR 2022, 'Application of CycleGAN and transfer learning techniques for automated detection of COVID-19 using X-ray images', Pattern Recognition Letters, vol. 153, pp. 67-74.
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Barua, PD, Baygin, N, Dogan, S, Baygin, M, Arunkumar, N, Fujita, H, Tuncer, T, Tan, R-S, Palmer, E, Azizan, MMB, Kadri, NA & Acharya, UR 2022, 'Automated detection of pain levels using deep feature extraction from shutter blinds-based dynamic-sized horizontal patches with facial images', Scientific Reports, vol. 12, no. 1, p. 17297.
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AbstractPain intensity classification using facial images is a challenging problem in computer vision research. This work proposed a patch and transfer learning-based model to classify various pain intensities using facial images. The input facial images were segmented into dynamic-sized horizontal patches or “shutter blinds”. A lightweight deep network DarkNet19 pre-trained on ImageNet1K was used to generate deep features from the shutter blinds and the undivided resized segmented input facial image. The most discriminative features were selected from these deep features using iterative neighborhood component analysis, which were then fed to a standard shallow fine k-nearest neighbor classifier for classification using tenfold cross-validation. The proposed shutter blinds-based model was trained and tested on datasets derived from two public databases—University of Northern British Columbia-McMaster Shoulder Pain Expression Archive Database and Denver Intensity of Spontaneous Facial Action Database—which both comprised four pain intensity classes that had been labeled by human experts using validated facial action coding system methodology. Our shutter blinds-based classification model attained more than 95% overall accuracy rates on both datasets. The excellent performance suggests that the automated pain intensity classification model can be deployed to assist doctors in the non-verbal detection of pain using facial images in various situations (e.g., non-communicative patients or during surgery). This system can facilitate timely detection and management of pain.
Barua, PD, Karasu, M, Kobat, MA, Balık, Y, Kivrak, T, Baygin, M, Dogan, S, Demir, FB, Tuncer, T, Tan, R-S & Acharya, UR 2022, 'An accurate valvular heart disorders detection model based on a new dual symmetric tree pattern using stethoscope sounds', Computers in Biology and Medicine, vol. 146, pp. 105599-105599.
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Barua, PD, Tuncer, I, Aydemir, E, Faust, O, Chakraborty, S, Subbhuraam, V, Tuncer, T, Dogan, S & Acharya, UR 2022, 'L-Tetrolet Pattern-Based Sleep Stage Classification Model Using Balanced EEG Datasets', Diagnostics, vol. 12, no. 10, pp. 2510-2510.
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Background: Sleep stage classification is a crucial process for the diagnosis of sleep or sleep-related diseases. Currently, this process is based on manual electroencephalogram (EEG) analysis, which is resource-intensive and error-prone. Various machine learning models have been recommended to standardize and automate the analysis process to address these problems. Materials and methods: The well-known cyclic alternating pattern (CAP) sleep dataset is used to train and test an L-tetrolet pattern-based sleep stage classification model in this research. By using this dataset, the following three cases are created, and they are: Insomnia, Normal, and Fused cases. For each of these cases, the machine learning model is tasked with identifying six sleep stages. The model is structured in terms of feature generation, feature selection, and classification. Feature generation is established with a new L-tetrolet (Tetris letter) function and multiple pooling decomposition for level creation. We fuse ReliefF and iterative neighborhood component analysis (INCA) feature selection using a threshold value. The hybrid and iterative feature selectors are named threshold selection-based ReliefF and INCA (TSRFINCA). The selected features are classified using a cubic support vector machine. Results: The presented L-tetrolet pattern and TSRFINCA-based sleep stage classification model yield 95.43%, 91.05%, and 92.31% accuracies for Insomnia, Normal dataset, and Fused cases, respectively. Conclusion: The recommended L-tetrolet pattern and TSRFINCA-based model push the envelope of current knowledge engineering by accurately classifying sleep stages even in the presence of sleep disorders.
Barua, PD, Vicnesh, J, Gururajan, R, Oh, SL, Palmer, E, Azizan, MM, Kadri, NA & Acharya, UR 2022, 'Artificial Intelligence Enabled Personalised Assistive Tools to Enhance Education of Children with Neurodevelopmental Disorders—A Review', International Journal of Environmental Research and Public Health, vol. 19, no. 3, pp. 1192-1192.
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Mental disorders (MDs) with onset in childhood or adolescence include neurodevelopmental disorders (NDDs) (intellectual disability and specific learning disabilities, such as dyslexia, attention deficit disorder (ADHD), and autism spectrum disorders (ASD)), as well as a broad range of mental health disorders (MHDs), including anxiety, depressive, stress-related and psychotic disorders. There is a high co-morbidity of NDDs and MHDs. Globally, there have been dramatic increases in the diagnosis of childhood-onset mental disorders, with a 2- to 3-fold rise in prevalence for several MHDs in the US over the past 20 years. Depending on the type of MD, children often grapple with social and communication deficits and difficulties adapting to changes in their environment, which can impact their ability to learn effectively. To improve outcomes for children, it is important to provide timely and effective interventions. This review summarises the range and effectiveness of AI-assisted tools, developed using machine learning models, which have been applied to address learning challenges in students with a range of NDDs. Our review summarises the evidence that AI tools can be successfully used to improve social interaction and supportive education. Based on the limitations of existing AI tools, we provide recommendations for the development of future AI tools with a focus on providing personalised learning for individuals with NDDs.
Basack, S, Nimbalkar, S, Karakouzian, M, Bharadwaj, S, Xie, Z & Krause, N 2022, 'Field Installation Effects of Stone Columns on Load Settlement Characteristics of Reinforced Soft Ground', International Journal of Geomechanics, vol. 22, no. 4.
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Baygin, M, Barua, PD, Dogan, S, Tuncer, T, Key, S, Acharya, UR & Cheong, KH 2022, 'A Hand-Modeled Feature Extraction-Based Learning Network to Detect Grasps Using sEMG Signal', Sensors, vol. 22, no. 5, pp. 2007-2007.
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Recently, deep models have been very popular because they achieve excellent performance with many classification problems. Deep networks have high computational complexities and require specific hardware. To overcome this problem (without decreasing classification ability), a hand-modeled feature selection method is proposed in this paper. A new shape-based local feature extractor is presented which uses the geometric shape of the frustum. By using a frustum pattern, textural features are generated. Moreover, statistical features have been extracted in this model. Textures and statistics features are fused, and a hybrid feature extraction phase is obtained; these features are low-level. To generate high level features, tunable Q factor wavelet transform (TQWT) is used. The presented hybrid feature generator creates 154 feature vectors; hence, it is named Frustum154. In the multilevel feature creation phase, this model can select the appropriate feature vectors automatically and create the final feature vector by merging the appropriate feature vectors. Iterative neighborhood component analysis (INCA) chooses the best feature vector, and shallow classifiers are then used. Frustum154 has been tested on three basic hand-movement sEMG datasets. Hand-movement sEMG datasets are commonly used in biomedical engineering, but there are some problems in this area. The presented models generally required one dataset to achieve high classification ability. In this work, three sEMG datasets have been used to test the performance of Frustum154. The presented model is self-organized and selects the most informative subbands and features automatically. It achieved 98.89%, 94.94%, and 95.30% classification accuracies using shallow classifiers, indicating that Frustum154 can improve classification accuracy.
Baygin, M, Yaman, O, Barua, PD, Dogan, S, Tuncer, T & Acharya, UR 2022, 'Exemplar Darknet19 feature generation technique for automated kidney stone detection with coronal CT images', Artificial Intelligence in Medicine, vol. 127, pp. 102274-102274.
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Kidney stone is a commonly seen ailment and is usually detected by urologists using computed tomography (CT) images. It is difficult and time-consuming to detect small stones in CT images. Hence, an automated system can help clinicians to detect kidney stones accurately. In this work, a novel transfer learning-based image classification method (ExDark19) has been proposed to detect kidney stones using CT images. The iterative neighborhood component analysis (INCA) is employed to select the most informative feature vectors and these selected features vectors are fed to the k nearest neighbor (kNN) classifier to detect kidney stones with a ten-fold cross-validation (CV) strategy. The proposed ExDark19 model yielded an accuracy of 99.22% with 10-fold CV and 99.71% using the hold-out validation method. Our results demonstrate that the proposed ExDark19 detect kidney stones over 99% accuracies for two validation techniques. This developed automated system can assist the urologists to validate their manual screening of kidney stones and hence reduce the possible human error.
Bendoy, AP, Zeweldi, HG, Park, MJ, Shon, HK, Kim, H, Chung, W-J & Nisola, GM 2022, 'Silicene nanosheets as support fillers for thin film composite forward osmosis membranes', Desalination, vol. 536, pp. 115817-115817.
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Development of membranes with enhanced separation and transport properties remains crucial for the advancement of forward osmosis (FO). Herein, a novel thin film composite (TFC) FO membrane with silicene-loaded polysulfone support (SN) is reported. Silicene loading was varied to obtain different SNs grown with polyamide (PA) layers to afford TFC-SN FO membranes. Characterization results reveal that optimal silicene loading (0.25 wt%) produced the most porous and most hydrophilic SN0.25 with finger-like pore structures. Low silicene loading showed minimal impact, whereas, excessive addition resulted in aggregation which diminished its effect in SN. Meanwhile, silicene had no influence on PA layer formation as all TFC-SNs registered similar solute permeability coefficient B = 0.14–0.16 LMH. On the other hand, TFC-SN0.25 achieved the highest water permeability coefficient A = 1.56 LMH bar−1 attributable to the favorable properties of SN0.25. TFC-SN0.25 also exhibited the lowest structural parameter S = 334 μm, which explains its superior FO performance relative to other TFC-SNs. Results from FO runs indicate that internal concentration polarization was reduced by 27.5–33% in TFC-SN0.25 compared with the control (TFC-SN0). FO runs in simulated low salinity water and seawater feed highlight the potential of TFC-SN0.25 for desalination. The developed TFC-SN0.25 can be repeatedly used and deliver consistent Jv values. Overall findings demonstrate the benefits of silicene for improved performance of TFC FO membranes.
Bendoy, AP, Zeweldi, HG, Park, MJ, Shon, HK, Kim, H, Chung, W-J & Nisola, GM 2022, 'Thermo-responsive hydrogel with deep eutectic mixture co-monomer as drawing agent for forward osmosis', Desalination, vol. 542, pp. 116067-116067.
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Deep eutectic mixture (DEM) and N-isopropylacrylamide (NIPAM) were co-polymerized as thermo-responsive P(NIPAM-co-DEM) hydrogel drawing agents for forward osmosis (FO). N-hexyl-N,N-dihydroxyethyl-N-methylammonium chloride–acrylic acid ([DHEA]Cl-AA) DEM is non-toxic and highly conductive due to its ionic (R4N+, Cl−) and hydrophilic (-OH, -C=O) groups. Addition of DEM at different contents (0–7.5 wt%) afforded P(NIPAM-co-DEM) with wide open pores as excellent water channels during water absorption. Their critical temperatures ranged Tc = 34.7–51.4 °C. At T < Tc, P(NIPAM-co-DEM) attained equilibrium swelling ratios = 32–43 (vs. 19 for PNIPAM), highlighting the advantage of DEM for enhanced water absorption. Heating the hydrogels at T > Tc resulted in 87.6–96 % dewatering efficiencies. Among the fabricated hydrogels, P(NIPAM-co-DEM) with 5 wt% DEM exhibited the highest water uptake and dewatering efficiency at moderate Tc. It achieved the highest FO water flux (initial Jv = 2.38 LMH in DI water feed). P(NIPAM-co-DEM) with 5 wt% DEM effectively and consistently desalinated low salinity water (2000 mg L−1 NaCl, Jv = 1.81 LMH) and treated domestic wastewater (Jv = 1.90 LMH) at T = 25 °C in cycled operations via efficient water recovery T = 45 °C and hydrogel drying via solar irradiation (1 kW m−2 for 1.5 h). Overall results demonstrate the potential of deep eutectic mixtures for the development of hydrogels as effective FO drawing agents.
Bhol, P, Swain, S, Altaee, A, Saxena, M & Samal, AK 2022, 'Cobalt–iron decorated tellurium nanotubes for high energy density supercapacitor', Materials Today Chemistry, vol. 24, pp. 100871-100871.
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We report the synthesis of cobalt-iron (Co-Fe) decorated tellurium nanotubes (Te NTs) using semiconductive Te NTs as a sacrificial template using the wet chemical method. The Co and Fe precursor concentration incorporated into Te NT plays a significant role in obtaining various bimetallic telluride structures. The one-dimensional (1-D) structure of Co-Fe decorated Te NTs with Te NTs in the backbone provides superior conductivity and exhibits high electrochemical performance with battery type electrode behaviour. The Co-Fe decorated Te NTs electrode is combined with the electric double-layer capacitors (EDLC) type electrode activated carbon (AC) to tune the energy density performance. The asymmetric assembly shows an excellent specific capacitance of 179.2 F g-1 (48.7 mAh g-1) at a current density of 0.9 A g-1 in 4 M KOH electrolyte. More importantly, it exhibits a maximum energy density of 62.1 Wh Kg-1 at a power density of 1138.2 W Kg-1 under a potential window of 1.58 V. This potential finding shows the significant applicability of Te NTs as a template for the synthesis of bimetallic tellurides with unique morphologies. The synergistic effect from multimetals and anisotropic morphology is beneficial for energy storage applications.
Bo, L, Li, Q, Tian, Y, Wu, D, Yu, Y, Chen, X & Gao, W 2022, 'Nonlinear dynamic investigation of the perovskite solar cell with GPLR-FGP stiffeners under blast impact', International Journal of Mechanical Sciences, vol. 213, pp. 106866-106866.
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The perovskite solar cell (PSC), as a potential disruptive space market entrant, has fascinated both the scientific community and aerospace industry due to the high specific power, flexibility, and low fabrication cost. With the aim of reducing structure weight while strengthening the blast-carrying capacity of the PSC, the novel graphene platelets (GPL) reinforced functionally graded porous (GPLR-FGP) stiffeners have been incorporated as enhancements against impact. This research explores the nonlinear dynamic characteristics of the PSC with GPLR-FGP stiffeners under blast load. Integrating the von-Kármán geometric nonlinearity and the first-order shear deformation theory, the governing motion equations are derived by utilizing Airy's stress function and the Galerkin method. The fourth-order Runge-Kutta approach is employed to capture the solutions of dynamic equations effectively. Diverse influences of the stiffener material, boundary condition, plate theory, porosity distribution, GPL dispersion, porosity coefficient, GPL weight fraction, GPL geometry, damping, nonlinear elastic foundation, and initial imperfection are investigated in the numerical study. Besides, the optimal parameters of the PSC with GPLR-FGP stiffeners are discovered, facilitating the following paces of space design and practical implementation in extraterrestrial circumstances.
Bordbar, M, Neshat, A, Javadi, S, Pradhan, B, Dixon, B & Paryani, S 2022, 'Improving the coastal aquifers’ vulnerability assessment using SCMAI ensemble of three machine learning approaches', Natural Hazards, vol. 110, no. 3, pp. 1799-1820.
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The main objective of this study is to integrate adaptive neuro-fuzzy inference system (ANFIS), support vector machine (SVM) and artificial neural network (ANN) to design an integrated supervised committee machine artificial intelligence (SCMAI) model to spatially predict the groundwater vulnerability to seawater intrusion in Gharesoo-Gorgan Rood coastal aquifer placed in the northern part of Iran. Six hydrological GALDIT parameters (i.e., G groundwater occurrence, A aquifer hydraulic conductivity, L level of groundwater above sea level, D distance from the shore, I impact of the existing status of seawater intrusion in the region, and T thickness of the aquifer) were considered as inputs for each model. In the training step, the values of GALDIT’s vulnerability index were conditioned by using the values of TDS concentration in order to obtain the conditioned vulnerability index (CVI). The CVI was considered as the target for each model. After training the models, each model was tested using a separate TDS dataset. The results indicated that the ANN and ANFIS algorithms performed better than the SVM algorithm. The values of correlation were obtained as 88, 87, and 80% for ANN, ANFIS, and SVM models, respectively. In the testing step of the SCMAI model, the values of RMSE, R2, and r were obtained as 6.4, 0.95, and 97%, respectively. Overall, SCMAI model outperformed other models to spatially predicting vulnerable zones. The result of the SCMAI model confirmed that the western zones along the shoreline had the highest vulnerability to seawater intrusion; therefore, it seems critical to consider emergency protection plans for study area. Graphic abstract: [Figure not available: see fulltext.]
Breda, A, Saco, PM, Rodríguez, JF, Sandi, SG & Riccardi, G 2022, 'Assessing the effects of sediment and tidal level variability on coastal wetland evolution', Journal of Hydrology, vol. 613, pp. 128387-128387.
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Bui, P, Ngo, T & Huynh, T 2022, 'Effect of ground rice husk ash on engineering properties and hydration products of SRC eco‐cement', Environmental Progress & Sustainable Energy, vol. 41, no. 2.
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AbstractThe effect of ground rice husk ash (GRHA) (R) on engineering properties and hydration products of eco‐cements containing ground granulated blast furnace slag (GGBFS) (S) and circulating fluidized bed combustion ash (CFA) (C) was studied. Four mixture proportions of SRC eco‐cements with GRHA replacement at levels of 0%, 15%, 30%, and 45% by mass of binder were investigated. A reference mixture proportion of paste with 100% ordinary Portland cement (OPC) was prepared for comparison purposes. A series of laboratory tests including setting time, compressive strength, water absorption, porosity, thermal conductivity, scanning electron microscope coupled with energy dispersive spectroscopy, X‐ray diffraction, and Fourier‐transform infrared spectroscopy analysis was carried out. Measured results showed that the GRHA increased setting time and porosity in the SRC eco‐cements having a water‐to‐powder (w/p) of 0.4, leading to the decrease in compressive strength and thermal conductivity while the increase in water absorption. The GRHA increased the cristobalite amount and decreased the portlandite amount in the SRC eco‐cements at the age of 28 days, resulting in the more significant long‐term compressive strength development when compared with the reference paste with 100% OPC. Consequently, the GRHA could be used at a level of 15% by mass of binder to produce the SRC eco‐cement with the compressive strength at 28 days of higher than 30 MPa and the thermal conductivity of 0.713 W/mK, resulting from the formations of AFt, C–S–H, and C–A–S–H gels.
Bui, VG, Tu Bui, TM, Ong, HC, Nižetić, S, Bui, VH, Xuan Nguyen, TT, Atabani, AE, Štěpanec, L, Phu Pham, LH & Hoang, AT 2022, 'Optimizing operation parameters of a spark-ignition engine fueled with biogas-hydrogen blend integrated into biomass-solar hybrid renewable energy system', Energy, vol. 252, pp. 124052-124052.
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The smart control of the biogas-hydrogen engine is needed to improve the overall energy efficiency of the hybrid renewable energy system. The paper presents some simulation results of the optimal control parameters of the engine aiming to achieve the compromise between performance and pollutant emissions of the biogas-hydrogen engine. In neat biogas fueling mode, the optimal equivalence ratio changes from 1.05 to 1.01 as the CH4 composition in biogas increases from 60% to 80%. By adding 20% hydrogen into biogas, the optimal equivalence ratio practically reaches the stoichiometric value, despite the variation of CH4 concentration. At the same operating condition and hydrogen content, an increase of 10% CH4 in biogas leads to a decrease of 2°CA in the optimal advanced ignition angle. However, at a given engine speed and biogas composition, the optimal advanced ignition angle decreased by 3°CA when adding 10% hydrogen into biogas. The optimal ignition angle is independent of the load regime. Under optimal operating conditions, the addition of 20% hydrogen content into biogas is found to improve the indicated engine cycle work by 6%, to reduce CO and HC emissions by 5–10 times; however, it increases NOx emission by 10–15% compared to neat biogas fueling mode.
Cai, G, Wang, C, Li, J, Xu, Z, He, X & Zhao, C 2022, 'Study on Tensile Properties of Unsaturated Soil Based on Three Dimensional Discrete Element Method', Yingyong Jichu yu Gongcheng Kexue Xuebao/Journal of Basic Science and Engineering, vol. 30, no. 5, pp. 1228-1244.
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Based on the discrete element method for unsaturated materials proposed by the author, the PFC3D (Particle Flow Code in Three Dimensions) particle flow discrete element analysis program is improved, and a discrete element model suitable for both clay and sand under uniaxial tension is established. The relationship between uniaxial tensile stress and displacement and uniaxial tensile strength are studied. The influence of different microstructure parameters on the tensile failure of soil is explored, and the relationship between saturation and cohesive strength between particles is established by taking uniaxial tensile strength as a bridge. The uniaxial tensile test of clay and sand with different initial void ratio and saturation is studied, and the tensile properties of unsaturated soil and the applicability of discrete element model and program to simulate unsaturated soil are deeply studied. The results show that:among the five microstructure parameters of normal bond strength, shear bond strength, Young's modulus, stiffness ratio and friction coefficient, the influence of normal bond strength on uniaxial tensile simulation is the largest, followed by shear bond strength, Young's modulus and stiffness ratio, and the friction coefficient has the least influence; the uniaxial tensile strength of clay increases at first and then decreases with the increase of saturation. The results show that the increase rate of uniaxial tensile strength on the left side (dry side) is greater than that on the right side (wet side); the uniaxial tensile strength of sand shows a 'increase-decrease-increase' rule with the increase of saturation; the simulation results are in good agreement with the experimental results, which verifies the applicability of the discrete element model and the numerical analysis program in the simulation of uniaxial tensile properties of unsaturated materials.
Cai, Y, Zhu, M, Meng, X, Zhou, JL, Zhang, H & Shen, X 2022, 'The role of biochar on alleviating ammonia toxicity in anaerobic digestion of nitrogen-rich wastes: A review', Bioresource Technology, vol. 351, pp. 126924-126924.
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This paper reviewed the mechanisms of biochar in relieving ammonia inhibition. Biochar affects nitrogen-rich waste's anaerobic digestion (AD) performance through four ways: promotion of direct interspecies electron transfer (DIET) and microbial growth, adsorption, pH buffering, and provision of nutrients. Biochar enhances the DIET pathway by acting as an electron carrier. The role of DIET in relieving ammonia nitrogen may be exaggerated because many related studies don't provide definite evidence. Therefore, some bioinformatics technology should be used to assist in investigating DIET. Biochar absorbs ammonia nitrogen by chemical adsorption (electrostatic attraction, ion exchange, and complexation) and physical adsorption. The absorption efficiency, mainly affected by the properties of biochar, pH and temperature of AD, can reach 50 mg g-1 on average. The biochar addition can buffer pH by reducing the concentrations of VFAs, alleviating ammonia inhibition. In addition, biochar can release trace elements and increase the bioavailability of trace elements.
Cao, TN-D, Bui, X-T, Le, L-T, Dang, B-T, Tran, DP-H, Vo, T-K-Q, Tran, H-T, Nguyen, T-B, Mukhtar, H, Pan, S-Y, Varjani, S, Ngo, HH & Vo, T-D-H 2022, 'An overview of deploying membrane bioreactors in saline wastewater treatment from perspectives of microbial and treatment performance', Bioresource Technology, vol. 363, pp. 127831-127831.
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Chakraborty, S 2022, 'TOPSIS and Modified TOPSIS: A comparative analysis', Decision Analytics Journal, vol. 2, pp. 100021-100021.
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Chakraborty, SC, Qamruzzaman, M, Zaman, MWU, Alam, MM, Hossain, MD, Pramanik, BK, Nguyen, LN, Nghiem, LD, Ahmed, MF, Zhou, JL, Mondal, MIH, Hossain, MA, Johir, MAH, Ahmed, MB, Sithi, JA, Zargar, M & Moni, MA 2022, 'Metals in e-waste: Occurrence, fate, impacts and remediation technologies', Process Safety and Environmental Protection, vol. 162, pp. 230-252.
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Electronic waste (e-waste) is generated from the discarded electronic products. The generation of e-waste has increased significantly in the recent decades. Globally, the increased rate of e-waste generation is almost 2 metric tonnes (Mt) per year. It is estimated that about 74 Mt of e-waste will be produced in 2030. Therefore, e-waste can be a significant threat to the environment. Toxic metals (e.g., lead, mercury, nickel, and cadmium) are released to the environment from the e-waste and eventually enter into soil, sediment, groundwater, and surface water. The release of toxic metals in the environment causes adverse effects on human health, aquatic animals, and plants. Therefore, the proper management of e-waste is essential and becomes a major concern in the world. In this regard, this review provides a comprehensive summary of the occurrence, fate, and remediation of metals generated from e-waste. The literature survey revealed that household electrical appliances are the primary source of e-waste, comprising approximately 50% of the overall production of e-waste. Among different remediation technologies, the combination of biological, physical, and chemical processes shows relatively high removal efficiency; and they possess multiple advantages over other remediation technologies. Finally, this review also includes future outlook on e-waste management and remediation technologies.
Chakraborty, SC, Zaman, MWU, Hoque, M, Qamruzzaman, M, Zaman, JU, Hossain, D, Pramanik, BK, Nguyen, LN, Nghiem, LD, Mofijur, M, Mondal, MIH, Sithi, JA, Shahriar, SMS, Johir, MAH & Ahmed, MB 2022, 'Metals extraction processes from electronic waste: constraints and opportunities', Environmental Science and Pollution Research, vol. 29, no. 22, pp. 32651-32669.
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The skyrocketing demand and progressive technology have increased our dependency on electrical and electronic devices. However, the life span of these devices has been shortened because of rapid scientific expansions. Hence, massive volumes of electronic waste (e-waste) is generating day by day. Nevertheless, the ongoing management of e-waste has emerged as a major threat to sustainable economic development worldwide. In general, e-waste contains several toxic substances such as metals, plastics, and refractory oxides. Metals, particularly lead, mercury, nickel, cadmium, and copper along with some valuable metals such as rare earth metals, platinum group elements, alkaline and radioactive metal are very common; which can be extracted before disposing of the e-waste for reuse. In addition, many of these metals are hazardous. Therefore, e-waste management is an essential issue. In this study, we critically have reviewed the existing extraction processes and compared among different processes such as physical, biological, supercritical fluid technologies, pyro and hydrometallurgical, and hybrid methods used for metals extraction from e-waste. The review indicates that although each method has particular merits but hybrid methods are eco-friendlier with extraction efficiency > 90%. This study also provides insight into the technical challenges to the practical realization of metals extraction from e-waste sources.
Chandra Shit, R, Sharma, S, Watters, P, Yelamarthi, K, Pradhan, B, Davison, R, Morgan, G & Puthal, D 2022, 'Privacy‐preserving cooperative localization in vehicular edge computing infrastructure', Concurrency and Computation: Practice and Experience, vol. 34, no. 14.
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SummaryAdvancement of computing and communication techniques transforms the traditional transport system into the intelligent transportation system (ITS). The development of distributed computing in a vehicular network platform also called Vehicular Edge Computing (VEC) promise to address most of the challenges faced by the ITS. Localization is important in these vehicular networks because of its key contribution in autonomous driving, smart traffic monitoring, and collision avoidance services. For localization, current GPS and hybrid methods are in‐efficient because of GPS outage in urban infrastructure and dynamic nature of the vehicular networks. The cooperative localization approaches, on the other hand, use dedicated short range communication to broadcast messages and estimate location. However, these messages are un‐encrypted and periodic which gives a privacy risk for vehicles. This article presents a privacy‐preserving cooperative localization in vehicular network based upon dynamic pseudonym changing strategy. First, the localization delay is addressed with the implementation of dynamic vehicular edge assignment for computational task management. In the next step, the localization is estimated from the neighbor and road side unit ranging measurement followed by a real‐time prediction of the vehicle. The performance of the proposed algorithms is analyzed in terms of localization accuracy and privacy preservation strength. Furthermore, the proposed method is simulated in a real city scenario followed by localization accuracy and privacy analysis. Finally, the localization accuracy and privacy strength of the proposed approach are compared with the state‐of‐the‐art methods.
Chang, Z, Long, G, Xie, Y & Zhou, JL 2022, 'Chemical effect of sewage sludge ash on early-age hydration of cement used as supplementary cementitious material', Construction and Building Materials, vol. 322, pp. 126116-126116.
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Sewage sludge ash has potential to be used as supplementary cementitious material in the production of building materials. The chemical effect of sewage sludge ash on early-age hydration of cement was investigated in this study. Two types of sludge ash calcined at 600 °C (S600) and 800 °C (S800) were blended with cement for analysis of hydration heat evolution, solid phase assemblage and aqueous composition. The aluminate dissolution of S600 ash promoted the formation of ettringite and consumption of gypsum, resulting in a high initial hydration heat. However, high concentrations of Al and Si caused by continuous dissolution of aluminate and silicate in S600 ash inhibited significantly the C3S dissolution. Interestingly, S800 ash had slight effect on early cement hydration since higher calcination temperature decreased the activity of aluminate. As compared with the reference, cumulative hydration heat of blended paste with 30% S800 ash at 7 days was increased by 18.72% indicating the occurrence of reaction between sludge ash and cement. Further study is recommended to focus on the long-term performance of cement-based materials blended with sludge ash.
Chang, Z, Long, G, Xie, Y & Zhou, JL 2022, 'Pozzolanic reactivity of aluminum-rich sewage sludge ash: Influence of calcination process and effect of calcination products on cement hydration', Construction and Building Materials, vol. 318, pp. 126096-126096.
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The application of aluminum-based flocculant in wastewater treatment results in a large amount of aluminum-rich sewage sludge. This work investigated the influence of calcination process on physicochemical characteristics and pozzolanic activity of aluminum (Al)-rich sludge ash and studied the effect of sludge ash on cement hydration. The results showed that higher calcination temperature from 600 ℃ to 900 ℃ increased the amorphous content in sludge ash. The pozzolanic activity of sludge ash calcined at 800 ℃ and 900 ℃ was confirmed by Frattini test. In view of strength activity index of blended mortar and energy conservation, the optimal calcination condition of sewage sludge ash was calcined at 800 ℃ with air-cooling. The addition of sludge ash promoted the transformation of ettringite to monosulfate phase in cement paste. However, the high Al concentration dissolved from S6 and S7 ash inhibited significantly the cement hydration and resulted in low compressive strength values of the blended mortars. The pozzolanic reaction of S8 and S9 ash produced more hydration heat and additional Al-bearing products such as katoite and monosulfate which contributed to the strength development of mortars. Furthermore, the heavy metals in sewage sludge can be immobilized in ash structure during calcination process and the structure of hydration products, which ensures the environmental security of sludge ash utilization in construction materials.
Chang, Z, Long, G, Xie, Y & Zhou, JL 2022, 'Recycling sewage sludge ash and limestone for sustainable cementitious material production', Journal of Building Engineering, vol. 49, pp. 104035-104035.
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Supplementary cementitious materials have significant potential to reduce greenhouse gas emissions in the production of construction materials. This work investigated the synergistic effect of partially replacing cement by sewage sludge ash and limestone for sustainable cementitious material production. The hydration phases and pore structure characteristics were determined by X-ray diffraction and the BET nitrogen sorption method, respectively. A central composite rotational design (CCRD) was used to study the effect of the water binder ratio (w/b), sludge ash and limestone content on the compressive strength. The results of microstructure tests showed that the addition of limestone enhanced the formation of carboaluminate hydrates. The additional hydration products filled in large pores of paste, resulting in a well-refined microstructure of the ternary mixture. Thus, the 90-day strength activity index (SAI) of mortar with 15% sludge ash and 7.5% limestone was 100.6% compared to the reference. Despite the adverse effect of limestone on the compressive strength, the synergistic effect of sludge ash and limestone contributed to the reduction of economic cost and greenhouse gas emission in the production of sustainable cementitious materials. For the same compressive strength level, the ternary mixture composed of 15% sludge ash and 7.5% ground limestone reduced Portland cement consumption by 23.13% and CO2-eq emission intensity by 13.52%.
Chen, D, Wu, C, Li, J & Liao, K 2022, 'A numerical study of gas explosion with progressive venting in a utility tunnel', Process Safety and Environmental Protection, vol. 162, pp. 1124-1138.
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A numerical model of a progressive vented gas explosion is presented. A CFD tool in combination with correlation analysis and an artificial neural network (ANN) were utilized to establish and refine the numerical model. The experimental results of 44 fixed vented gas explosions and one progressive vented gas explosion with moving obstacles were used to validate the numerical accuracy. The results indicated that the method to estimate the activation pressure of the pressure relief panels for a fixed vented gas explosion achieved a lower overpressure prediction compared to that for a progressive vented gas explosion. The progressive venting procedure was modelled by two-layer pressure relief panels with the upper layer having activation pressures with a linear ascent trend. The vents on the tunnel had an insignificant impact on the explosion load after being lifted over the tunnel top, and their falling process was unnecessary to be modelled. A non-negligible impact of the obstacles inside the tunnel on the flow field upon being pushed away from their initial positions was demonstrated. By employing an ANN, the critical parameters in the numerical model were determined, which were used to accurately replicate the experimental results. The findings clarified a revenue for the modeling of a progressive vented gas explosion as well as some shortcomings of the CFD tool.
Chen, J, Vinod, JS, Indraratna, B, Ngo, NT, Gao, R & Liu, Y 2022, 'A discrete element study on the deformation and degradation of coal-fouled ballast', Acta Geotechnica, vol. 17, no. 9, pp. 3977-3993.
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AbstractThis paper presents the results of Discrete Element Modelling (DEM) which quantitively examine the effect of coal fouling on the deformation and degradation of ballast upon cyclic loading. The degradation model described herein considers the Weibull distribution effects in tandem with a granular medium hardening law that incorporates the maximum contact criterion to capture surface abrasion and corner breakage of angular ballast. The DEM model had been calibrated initially with laboratory data obtained from large-scale direct shear testing. Subsequently, a series of cubical shear test simulations have been carried out using DEM to understand the behaviour of fouled ballast whereby the numerical particle degradation modelling could simulate the experimental response of the ballast assembly at various fouling levels. The results show that the increased level of fouling exacerbates the sleeper settlement, while decreasing the resilient modulus and the particle breakage. Ballast beneath the sleeper experiences significant breakage compared to the crib ballast, and not surprisingly, the extent of damage decreases with depth. Rigorous microscopic analysis is also presented in relation to inter-particle contacts, particle velocity and anisotropy of the ballast assembly. This micromechanical examination highlights that the decrease in ballast breakage for fouled assemblies is predominantly attributed to the inevitable decrease in inter-particle contact pressures as effected by the coating of ballast aggregates by the coal fines.
Chen, Q, Guo, D, Ke, W, Xu, C & Nimbalkar, S 2022, 'Novel Open Trench Techniques in Mitigating Ground-Borne Vibrations due to Traffic under a Wide Range of Ground Conditions', International Journal of Geomechanics, vol. 22, no. 6.
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Chen, W, Wang, Y, Wang, L, Ji, Y, Wang, Q, Li, M & Gao, L 2022, 'Emerging investigator series: effects of sediment particle size on the spatial distributions of contaminants and bacterial communities in the reservoir sediments', Environmental Science: Water Research & Technology, vol. 8, no. 5, pp. 957-967.
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This study investigates the effects of sediment particle size on the spatial distributions of contaminants and bacterial communities in the reservoir sediments, which can guide the implementation of partial desilting in the reservoirs.
Chen, W-H, Chen, K-H, Chein, R-Y, Ong, HC & Arunachalam, KD 2022, 'Optimization of hydrogen enrichment via palladium membrane in vacuum environments using Taguchi method and normalized regression analysis', International Journal of Hydrogen Energy, vol. 47, no. 100, pp. 42280-42292.
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Chen, X, Huo, P, Yang, L, Wei, W & Ni, B-J 2022, 'A Comprehensive Analysis of Evolution and Underlying Connections of Water Research Themes in the 21st Century', Sci Total Environ, vol. 835, pp. 155411-155411.
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This work aimed to reflect the advancements in water-related science, technology, and policy and shed light on future research opportunities related to water through a systematic overview of Water Research articles published in the first 21.5 years of the 21st century. Specific bibliometric analyses were performed to i) reveal the temporal and spatial trends of water-related research themes and ii) identify the underlying connections between research topics. The results showed that while top topics including wastewater (treatment), drinking water, adsorption, model, biofilm, and bioremediation remained constantly researched, there were clear shifts in topics over the years, leading to the identification of trending-up and emerging research topics. Compared to the first decade of the 21st century, the second decade not only experienced significant uptrends of disinfection by-products, anaerobic digestion, membrane bioreactor, advanced oxidation processes, and pharmaceuticals but also witnessed the emerging popularity of PFAS, anammox, micropollutants, emerging contaminants, desalination, waste activated sludge, microbial community, forward osmosis, antibiotic resistance genes, resource recovery, and transformation products. On top of the temporal evolution, distinct spatial evolution existed in water-related research topics. Microplastics and Covid-19 causing global concerns were hot topics detected, while metagenomics and machine learning were two technical approaches emerging in recent years. These consistently popular, trending-up and emerging research topics would most likely attract continuous/increasing research input and therefore constitute a major part of the prospective water-related research publications.
Chen, X, Huo, P, Yang, L, Wei, W, Yang, L, Wei, W & Ni, B-J 2022, 'Influences of Granule Properties on the Performance of Autotrophic Nitrogen Removal Granular Reactor: A Model-Based Evaluation', Bioresour Technol, vol. 356, pp. 127307-127307.
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This work studied the impacts of key granule properties on the granular reactor performing partial nitritation/anammox from the modeling perspective. The results could guide not only future reliable modeling but also practical startup/operation of the reactor. To achieve high total nitrogen (TN) removal whilst avoiding significant N2O production, inoculated granules should be big and anammox-enriched. The optimum boundary layer thickness for maximum TN removal increased with the decreasing diffusivity of soluble components in the granule structure. Even though a thick boundary layer could protect anammox bacteria from elevated dissolved oxygen (DO) (e.g., 0.5 g-O2/m3) and obtain high TN removal (>90.0%) and low N2O production (<1.8%), even complete removal of the boundary layer would fail to provide sufficient substrate for anammox and therefore couldn't increase TN removal to 90.0% and decrease N2O production to <2.4% at insufficient DO (e.g., 0.3 g-O2/m3 in the presence of lifted influent NH4+ concentration).
Chen, X, Li, F, Huo, P, Liu, J, Yang, L, Li, X, Wei, W & Ni, B-J 2022, 'Influences of longitudinal gradients on methane-driven membrane biofilm reactor for complete nitrogen removal: A model-based investigation', Water Research, vol. 220, pp. 118665-118665.
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Integrating anammox with denitrifying anaerobic methane oxidation (DAMO) in the membrane biofilm reactor (MBfR) is a promising technology capable of achieving complete nitrogen removal from wastewater. However, it remains unknown whether reactor configurations featuring longitudinal gradients parallel to the membrane surface would affect the performance of the CH4-driven MBfR. To this end, this work aims to study the impacts of longitudinal heterogeneity potentially present in the gas and liquid phases on a representative CH4-driven MBfR performing anammox/DAMO by applying the reported modified compartmental modeling approach. Through comparing the modeling results of different reactor configurations, this work not only offered important guidance for better design, operation and monitoring of the CH4-driven MBfR, but also revealed important implications for prospective related modeling research. The total nitrogen removal efficiency of the MBfR at non-excessive CH4 supply (e.g., surface loading of ≤0.064 g-COD m-2 d-1 in this work) was found to be insensitive to both longitudinal gradients in the liquid and gas phases. Comparatively, the longitudinal gradient in the liquid phase led to distinct longitudinal biomass stratification and therefore played an influential role in the effective CH4 utilization efficiency, which was also related to the extent of reactor compartmentation considered in modeling. When supplied with non-excessive CH4, the MBfR is recommended to be designed/operated with both the biofilm reactor and the membrane lumen as plug flow reactors (PFRs) with co-current flow of wastewater and CH4, which could mitigate dissolved CH4 discharge in the effluent. For the reactor configurations with the biofilm reactor designed/operated as a PFR, multi-spot sampling in the longitudinal direction is needed to obtain a correct representation of the microbial composition of the MBfR.
Chen, Y, Lin, S, Liang, Z, Surawski, NC & Huang, X 2022, 'Smouldering organic waste removal technology with smoke emissions cleaned by self-sustained flame', Journal of Cleaner Production, vol. 362, pp. 132363-132363.
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Smouldering is slow, low-temperature and flameless, and has been potentially regarded as an alternative for organic waste removal technology. However, as an incomplete combustion process, toxic smoke and pollution from the smouldering are significant concerns that limit its popularization. This work applies a newly developed smouldering-based waste removal technology to investigate the removal of coffee waste, wood waste, and organic soil (simulated sludge) via using a flame to clean smouldering emissions at different airflow velocities (3–24 mm/s). Once ignited from the top, the smouldering front first propagates downwards where a stable flame situated above could be piloted and sustained to purify the smouldering emissions until the smouldering front reached the bottom of the fuel bed. The efficiency of pollution mitigation was demonstrated by significantly lower CO and VOCs emission after purification by self-sustained flame. The equivalent critical mass flux of flammable gases required for igniting the smouldering emissions is 0.5 g/m2∙s, regardless of the fuel type. The smouldering temperature, propagation rate and burning flux all increase with the airflow velocity but are also slightly sensitive to the type of waste. This work enriches strategies for the clean treatment of smouldering emissions and promotes an energy efficient and environmentally friendly method for organic waste removal.
Chen, Y, Wu, D, Dai, K & Gao, W 2022, 'A numerically efficient framework in failure mode evaluation of a wind turbine tower under cyclones', Marine Structures, vol. 86, pp. 103303-103303.
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With more wind turbines being constructed in cyclone-prone regions, tower failure cases are increasingly reported in recent years. To simulate the genuine tower performance under extreme events, nonlinear dynamic analyses on a highly refined finite element model were adopted in recent research. However, existing research based on such practice has certain deficiencies in terms of computational cost reduction, aero-structure interaction characterization and failure mode classification. This article proposed a numerically efficient framework in the failure mode identification and evaluation of a wind turbine tower under cyclones (hurricanes/typhoons) to cope with the forenamed deficiencies. The aero-structure interaction, geometric and material nonlinearity of a turbine structure are realized and validated before involved into that framework, in which three different failure modes can be classified and analyzed with high numerical efficiency. At last, the effects of external environmental and internal structural parameters, e.g., wind velocity, turbine scale, parking status, section slenderness and material model are considered for both onshore and offshore wind turbines (OWTs), so as to reflect the wide applicability of this proposed framework and provide instructive reference for wind turbine design under extreme conditions like cyclones.
Chen, Y, Wu, D, Li, H & Gao, W 2022, 'Quantifying the fatigue life of wind turbines in cyclone-prone regions', Applied Mathematical Modelling, vol. 110, pp. 455-474.
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Wind turbines are designed to harvest kinetic energy of the wind, which are more susceptible to the impact of tropical cyclones compared with other high-rise structures. Most of the existing research of cyclone (hurricane/typhoon) impacts on wind turbine merely concentrated on its short-term failure (strength or stability failure). However in this paper, it is evidently demonstrated that cyclones can also have a significant impact on the long-term failure (fatigue failure) of a wind turbine. In this study, a novel framework is developed in the fatigue life evaluation of a wind turbine, in which two external factors, i.e., the progressive change of cyclone direction and intensity observed at a specific site, combined with one internal factor, i.e., a parked wind turbine with feathered or unfeathered blades are considered. Subsequently, the effect of cyclone-normal-wind direction misalignment and cyclone average recurrence intervals are included to have a synthetic assessment on the damage potential of cyclones. The proposed fatigue analysis framework can be also extended to other structures, e.g., the hybrid wind-tidal energy conversion system in cyclone-prone regions.
Chen, Z, Fang, J, Wei, W, Ngo, HH, Guo, W & Ni, B-J 2022, 'Emerging adsorbents for micro/nanoplastics removal from contaminated water: Advances and perspectives', Journal of Cleaner Production, vol. 371, pp. 133676-133676.
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Micro/nanoplastics (MPs/NPs) are emerging pollutants in the water environment. MPs/NPs' high buoyant and persistent properties and potential toxic effects on living organisms make them priority pollutants in water. To overcome plastic pollution, great efforts have been made to remove MPs/NPs from contaminated water. Recently, adsorption has been proved as an efficient strategy, and emerging adsorbents have shown promising removal performance. In this review, we provide a comprehensive review of recent advancements in adsorbents for the eradication of MPs/NPs from water. Engineered adsorbents (e.g., carbon materials, sponge/aerogel/fiber materials, metal (hydr)oxides, and metal-organic frameworks (MOFs)) are first summarized, and the adsorbents' structure-performance correlation is emphasized. Afterward, critical experimental factors (e.g., pH value, metal ions, anions, dissolved organic matters (DOM)) are analyzed. At last, challenges and prospects in this field are highlighted to guide the development of novel high-performance adsorbents for MPs/NPs pollution control.
Chen, Z, Liu, X, Wei, W, Chen, H & Ni, B-J 2022, 'Removal of microplastics and nanoplastics from urban waters: Separation and degradation', Water Research, vol. 221, pp. 118820-118820.
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The omnipresent micro/nanoplastics (MPs/NPs) in urban waters arouse great public concern. To build a MP/NP-free urban water system, enormous efforts have been made to meet this goal via separating and degrading MPs/NPs in urban waters. Herein, we comprehensively review the recent developments in the separation and degradation of MPs/NPs in urban waters. Efficient MP/NP separation techniques, such as adsorption, coagulation/flocculation, flotation, filtration, and magnetic separation are first summarized. The influence of functional materials/reagents, properties of MPs/NPs, and aquatic chemistry on the separation efficiency is analyzed. Then, MP/NP degradation methods, including electrochemical degradation, advanced oxidation processes (AOPs), photodegradation, photocatalytic degradation, and biological degradation are detailed. Also, the effects of critical functional materials/organisms and operational parameters on degradation performance are discussed. At last, the current challenges and prospects in the separation, degradation, and further upcycling of MPs/NPs in urban waters are outlined. This review will potentially guide the development of next-generation technologies for MP/NP pollution control in urban waters.
Chen, Z, Ren, Z, Zheng, R, Gao, H & Ni, B-J 2022, 'Migration behavior of impurities during the purification of waste graphite powders', Journal of Environmental Management, vol. 315, pp. 115150-115150.
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Metal-laden solid wastes (e.g., waste graphite powders) have attracted great attention owing to their hazardous effects on the surrounding soil and water. Additionally, the metal-bearing impurities also hinder the reutilization of waste graphite powders. Thus, it is necessary to remove these inorganic impurities and figure out the removal mechanism of impurities in the purification process. In this study, an alkaline roasting-water washing-acid leaching (AWA) method was used to upgrade the waste graphite powders, and the migration behavior of diverse impurities has been qualitatively and quantitatively investigated. A graphite product with high impurity removal efficiencies is attained under optimal conditions. The removal of impurities mainly follows three routes: (1) V-, P-, and S-bearing impurities were complete removed (some formed soluble salts during alkaline roasting, and the remainder was dissolved in acid); (2) most Al-, K-, and Si-bearing impurities were removed by alkaline roasting, with the remainder was dissolved in the acid-leaching process; and (3) Fe-, Mg-, Ti-, Ca-, and Zn-bearing impurities were decomposed at high temperature and reacted with alkali to form hydroxides or oxides, which was subsequently dissolved in acid. In addition, the treatment of the generated wastewater is also discussed. The uncovered migration mechanisms of diverse impurities would guide the purification and reutilization process of other metal-bearing solid wastes efficiently.
Chen, Z, Wei, W & Ni, B-J 2022, 'Transition metal chalcogenides as emerging electrocatalysts for urea electrolysis', Current Opinion in Electrochemistry, vol. 31, pp. 100888-100888.
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Urea electrolysis is an up-and-coming approach to realize sustainable energy-saving hydrogen fuel production and purification of urea-bearing wastes (e.g. urine, industrial wastewater). To attain a high urea electrolysis efficiency, high-performance electrocatalysts are highly required. Of late, transition metal (TM) chalcogenides-based materials are emerging as promising candidates for urea electrolysis. The catalytic performance of TM chalcogenides-based catalysts is optimized by tuning the internal/external characteristics, including nanostructure control, composition optimization, and heterostructuring. In this review, recent achievements in high-efficiency electrocatalysts based on TM chalcogenides for urea electrolysis are critically discussed. First, the electrochemistry of urea electrolysis is analyzed. Next, recent progress in TM chalcogenides-based electrocatalysts for urea electrolysis is detailed. The electrocatalyst design strategies are particularly elucidated, as well as the catalyst structure–performance correlation. Ultimately, perspectives on crucial scientific issues in this booming field are highlighted.
Chen, Z, Wei, W, Chen, H & Ni, B-J 2022, 'Recent advances in waste-derived functional materials for wastewater remediation', Eco-Environment & Health, vol. 1, no. 2, pp. 86-104.
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Chen, Z, Wei, W, Liu, X & Ni, B-J 2022, 'Emerging electrochemical techniques for identifying and removing micro/nanoplastics in urban waters', Water Research, vol. 221, pp. 118846-118846.
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The ubiquitous micro/nanoplastics (MPs/NPs) in urban waters are priority pollutants due to their toxic effects on living organisms. Currently, great efforts have been made to realize a plastic-free urban water system, and the identification and removal of MPs/NPs are two primary issues. Among diverse methods, emerging electrochemical techniques have gained growing interests owing to their facile implementation, high efficiency, eco-compatibility, onsite operation, etc. Herein, recent progress in the electrochemical identification and removal of MPs/NPs in urban waters are comprehensively reviewed. The electrochemical sensing of MPs/NPs and their released pollutants (e.g., bisphenol A (BPA)) has been analyzed, and the sensing principles and the featured electrochemical devices/electrodes are examined. Afterwards, recent applications of electrochemical methods (i.e., electrocoagulation, electroadsorption, electrokinetic separation and electrochemical degradation) in MPs/NPs removal are discussed in detail. The influences of critical parameters (e.g., plastics' property, current density and electrolyte) in the electrochemical identification and removal of MPs/NPs are also analyzed. Finally, the current challenges and prospects in electrochemical sensing and removal of MPs/NPs in urban waters are elaborated. This review would advance efficient electrochemical technologies for future MPs/NPs pollutions management in urban waters.
Chen, Z, Wei, W, Ni, B-J & Chen, H 2022, 'Plastic wastes derived carbon materials for green energy and sustainable environmental applications', Environmental Functional Materials, vol. 1, no. 1, pp. 34-48.
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Chen, Z, Wei, W, Song, L & Ni, B-J 2022, 'Hybrid Water Electrolysis: A New Sustainable Avenue for Energy-Saving Hydrogen Production', Sustainable Horizons, vol. 1, pp. 100002-100002.
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Chen, Z, Wei, W, Zou, W, Li, J, Zheng, R, Wei, W, Ni, B-J & Chen, H 2022, 'Integrating electrodeposition with electrolysis for closed-loop resource utilization of battery industrial wastewater', Green Chemistry, vol. 24, no. 8, pp. 3208-3217.
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Closed-loop reutilization of battery industrial wastewater by converting wastewater pollutants into highly efficient electrocatalysts for wastewater electrolysis.
Chen, Z, Zheng, R, Li, S, Wang, R, Wei, W, Wei, W, Ni, B-J & Chen, H 2022, 'Dual-anion etching induced in situ interfacial engineering for high-efficiency oxygen evolution', Chemical Engineering Journal, vol. 431, pp. 134304-134304.
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Designing novel catalysts for oxygen evolution reaction (OER) with high cost-effectiveness plays a central role in sustainably driving renewable energy conversion and storage. Here we demonstrate the in situ interfacial engineering for constructing efficient OER catalysts based on the electrochemical dual-anion etching of natural arsenopyrite. The OER catalyst (FeAsS) prepared from natural arsenopyrite via an environment-friendly ball milling approach achieves a current density of 10 mA cm−2 at an overpotential of 200 mV, outperforming many state-of-the-art catalysts. The in-depth study indicates that the co-etching of lattice As and S under the OER conditions triggers the in situ surface self-reconstruction, and a self-optimized catalytic active and stable FeAsS/α-FeOOH interface has been developed. Computational studies further confirm that the strong electronic coupling effect between α-FeOOH and FeAsS significantly tunes the binding energy between reaction intermediates and active sites, finally leading to an enhanced OER activity. The dual-anion etching of precatalysts induced in situ interfacial engineering demonstrated here expands the way of exploring other multiple nonmetallic elements involved nanomaterials as efficient OER precatalysts. This study also stimulates further study on the eco-design of electroactive materials for advanced energy conversion/storage applications from earth-abundance natural resources.
Chen, Z, Zheng, R, Wei, W, Wei, W, Zou, W, Li, J, Ni, B-J & Chen, H 2022, 'Recycling spent water treatment adsorbents for efficient electrocatalytic water oxidation reaction', Resources, Conservation and Recycling, vol. 178, pp. 106037-106037.
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Heavy metal contaminated spent adsorbents are of great environmental concern due to their hazardous effects and large-scale accumulation in the natural environment. Converting massive spent adsorbents into efficient electrocatalysts with a facile strategy can address the challenge of growing energy demand and achieving carbon neutral goal. Herein, we demonstrated a 'spent adsorbents to heterostructured electrocatalysts' conversion strategy based on the 'waste-to-wealth' principle. Via a facile boriding process, the metal ions laden biochar-based spent adsorbents (SA) have been totally transformed into magnetic metal borides/biochar heterostructures, which exhibit excellent activities towards oxygen evolution reaction. The optimized NiCuFeB/SA catalyst takes a low overpotential of 251 mV to drive a current density of 10 mA cm−2, outperforming many Ni/Fe-based catalysts synthesized from commercial material resources. Comprehensive analyses suggest the high catalytic efficiency mainly attributes to the porous biochar confined well-dispersed nano-sized metallic borides, the in-situ evolved active metal (oxy)hydroxides, favourable charge-transfer kinetics, as well as the heterostructure and amorphous feature. This work offers a general strategy to efficiently reutilize the spent metal-bearing biochar-based adsorbents, which can be extended to advanced energy applications-oriented reutilization of other metal-contaminated solid wastes in an economically and environmental-benign manner.
Cheng, D, Ngo, HH, Guo, W, Chang, SW, Nguyen, DD, Bui, XT, Wei, W, Ni, B, Varjani, S & Hoang, NB 2022, 'Enhanced photo-fermentative biohydrogen production from biowastes: An overview', Bioresource Technology, vol. 357, pp. 127341-127341.
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Clean energy like hydrogen can be a promising strategy to solve problems of global warming. Photo-fermentation (PF) is an attractive technology for producing biohydrogen from various biowastes cost-effectively and environmentally friendly. However, challenges of low light conversion efficiency and small yields of biohydrogen production still limit its application. Thus, advanced strategies have been investigated to enhance photo-fermentative biohydrogen production. This review discusses advanced technologies that show positive outcomes in improving biohydrogen production by PF, including the following. Firstly, genetic engineering enhances light transfer efficiency, change the activity of enzymes, and improves the content of ATP, ammonium and antibiotic tolerance of photosynthetic bacteria. Secondly, immobilization technology is refined. Thirdly, nanotechnology makes great strides as a scientific technique and fourthly, integration of dark and photo-fermentation technology is possible. Some suggestions for further studies to achieve high levels of efficiency of photo-fermentative biohydrogen production are mentioned in this paper.
Cheng, D, Ngo, HH, Guo, W, Chang, SW, Nguyen, DD, Deng, L, Chen, Z, Ye, Y, Bui, XT & Hoang, NB 2022, 'Advanced strategies for enhancing dark fermentative biohydrogen production from biowaste towards sustainable environment', Bioresource Technology, vol. 351, pp. 127045-127045.
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Cheng, D, Ngo, HH, Guo, W, Chang, SW, Nguyen, DD, Zhang, S, Deng, S, An, D & Hoang, NB 2022, 'Impact factors and novel strategies for improving biohydrogen production in microbial electrolysis cells', Bioresource Technology, vol. 346, pp. 126588-126588.
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Cheng, J, You, H, Tian, M, Kuang, S, Liu, S, Chen, H, Li, X, Liu, H & Liu, T 2022, 'Occurrence of nitrite-dependent anaerobic methane oxidation bacteria in the continental shelf sediments', Process Safety and Environmental Protection, vol. 168, pp. 626-632.
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Nitrite-dependent anaerobic methane oxidation (N-damo) is a key bioprocess coupling global carbon and nitrogen cycles and is mediated by NC10 bacteria. So far, the distribution of N-damo bacteria in marine sediments has rarely been reported. In this study, the sediments from the Bohai Sea, Yellow Sea and East China Sea were taken as the research objects, and the ecological distribution of N-damo bacteria was investigated by quantitative PCR and amplicon sequencing. Quantitative PCR results demonstrated that the highest average copy number of N-damo bacterial 16S rRNA gene was in the Bohai Sea, followed by the East China Sea, while the lowest was observed in the Yellow Sea. Based on the OTU numbers, the N-damo bacterial diversity was highest in East China Sea, followed by the Bohai Sea, while lowest in the Yellow Sea. The N-damo bacterial community structure exhibited an obvious spatial distribution among the three seas. Sediment nitrite nitrogen content is the key environmental factor affecting the abundance and diversity of N-damo bacteria, and sediment ammonia nitrogen content is the key environmental factor affecting the community structure of N-damo bacteria.
Chi, K, Li, J & Wu, C 2022, 'Behavior of Reinforced Ultra-High Performance Concrete Slabs Under Impact Loading After Exposure to Elevated Temperatures', International Journal of Computational Methods.
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Steel fiber-reinforced ultra-high performance concrete (UHPC) material is prone to explosive spalling under elevated temperatures. With the addition of polypropylene (PP) fiber, thermal spalling of UHPC can be mitigated and its fire resistance can be improved. This research investigates the impact resistance of steel and PP fiber-reinforced UHPC slabs after exposure to elevated temperatures, and the structural behavior and damage were compared against normal strength concrete (NSC) slabs. Karagozian & Case concrete (KCC) model was adopted to simulate both NSC and UHPC materials. With consideration of thermal hazards, the material damage, equation of state and strain rate sensitivity were adapted. The validity of this numerical model was evaluated against available experimental results. The numerical model was used to investigate the impact resistance of the reinforced UHPC slabs after exposure to fire hazards. The effect of fire exposure time, impact velocity and impact mass on the resistance of the reinforced NSC and UHPC slabs were analyzed. The simulation results revealed that punching shear failure areas in the NSC slabs were 2.5 times, 3.4 times, 3.0 times and 1.2 times larger than the UHPC slabs after exposure to international standardization ISO-834 standard fire for 1[Formula: see text]h, 2[Formula: see text]h, 3[Formula: see text]h and 4[Formula: see text]h, respectively. After exposure to the standard fire ISO-834 for 2 h, the punching shear failure on the bottom side of NSC increased 90.9% with the increase in falling height from 1[Formula: see text]m to 7[Formula: see text]m, while for the UHPC slabs, the increment was around 67.9%. After exposure to the standard fire ISO-834 for 2[Formula: see text]h, the punching shear damage of the NSC slabs increased by 72.9% with the punch weight increased from 100[Formula: see text]kg to 700[Formula: see text]kg, whereas the damage in the UHPC slabs increased by 53.8%.
Chiniforush, AA, Gharehchaei, M, Akbar Nezhad, A, Castel, A, Moghaddam, F, Keyte, L, Hocking, D & Foster, S 2022, 'Numerical simulation of risk mitigation strategies for early-age thermal cracking and DEF in concrete', Construction and Building Materials, vol. 322, pp. 126478-126478.
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Choi, PJ, Lim, S, Shon, H & An, AK 2022, 'Incorporation of negatively charged silver nanoparticles in outer-selective hollow fiber forward osmosis (OSHF-FO) membrane for wastewater dewatering', Desalination, vol. 522, pp. 115402-115402.
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Thin film nanocomposite (TFN) outer selective hollow fiber forward osmosis (OSHF FO) membranes incorporated with negatively charged silver nanoparticles (NPs) were fabricated for wastewater dewatering. The performances of five silver loading concentrations, namely 0% (pristine), 0.0002%, 0.0005%, 0.0010%, and 0.0015%, were compared. Among the four non-zero loading concentrations, 0.0010% showed the best performance. The pristine membrane had a better flux performance than the silver-loaded membranes; however, the silver-loaded membranes lasted longer (over 30 days) and had a higher flux recovery after salt cleaning. The pristine membrane also concentrated the feed solution 4 h faster than the silver-loaded membranes (68 h); however, the performance was not stable, and the water flux continuously decreased. In contrast, the performance of the silver-load membranes was more stable and plateaued between 2 LMH and 3 LMH. Due to the negatively charged silver NPs, the TFN OSHF FO membranes showed a stronger fouling resistance and stable performance, and thus a longer life expectancy. Therefore, the use of TFN OSHF FO membranes with embedded silver NPs can be an alternative strategy for wastewater treatment and dewatering.
Choo, Y, Hwa, Y & Cairns, EJ 2022, 'A review of the rational interfacial designs and characterizations for solid‐state lithium/sulfur cells', Electrochemical Science Advances, vol. 2, no. 6.
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AbstractThe high theoretical specific energy of lithium/sulfur (Li/S) cells (2600 Wh/kg) has positioned the Li/S cell as one of the most promising candidates for the beyond lithium‐ion cell. Despite the evident advantages, there are remaining problems mainly associated with the unique solution‐based reaction chemistry involving lithium polysulfide (Li‐PS) that hinder the commercialization of the Li/S cells. Incorporating solid‐state electrolytes (SSEs) can avoid the Li‐PS shuttle problem while preserving the benefits of Li/S cells, but it introduces other challenges related to the electrode/electrolyte solid interfaces. This topical review summarizes the current status of solid‐state Li/S cells and their major challenges and discusses the recent efforts to improve cell performance and durability. Various solid‐state electrolytes, including oxides, sulfides, and solid polymer electrolytes, are briefly reviewed. In particular, we focus on the recent progress to improve the interfacial properties by two major approaches, morphological and chemical modifications of the electrode/electrolyte interfaces. The design strategy and implementation to overcome the prominent issues associated with sulfur electrodes are critically discussed. Also, several electrochemical and physicochemical characterization methods to examine the electron/ion transport at the interface are outlined. Given the superior theoretical physicochemical properties of the Li/S cells, we emphasize that the inappropriate interfacial design of the solid‐state Li/S cells is the major challenge to bring solid‐state Li/S cells to a commercially attractive level.
Choo, Y, Snyder, RL, Shah, NJ, Abel, BA, Coates, GW & Balsara, NP 2022, 'Complete Electrochemical Characterization and Limiting Current of Polyacetal Electrolytes', Journal of The Electrochemical Society, vol. 169, no. 2, pp. 020538-020538.
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We investigate a polyacetal-based electrolyte, poly(1,3,6-trioxocane) (P(2EO-MO)) mixed with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt, and report full electrochemical characterization of the transport parameters and a thermodynamic property in comparison to the previously reported poly(ethylene oxide) (PEO) electrolyte data [D. Gribble et al., J. Electrochem. Soc., 166, A3228 (2019)]. While the steady-state current fraction (ρ +) of P(2EO-MO) electrolyte is greater than that of PEO electrolyte in the entire salt concentration window we explored, the rigorously defined transference number using Newman’s concentrated solution theory ( t + 0 ) appears to be similar to that of PEO electrolyte. On the basis of full electrochemical characterization, we calculate the salt concentration profile as a function of position in the cell and predict limiting current density (i L ...
Choukimath, MC, Banapurmath, NR, Riaz, F, Patil, AY, Jalawadi, AR, Mujtaba, MA, Shahapurkar, K, Khan, TMY, Alsehli, M, Soudagar, MEM & Fattah, IMR 2022, 'Experimental and Computational Study of Mechanical and Thermal Characteristics of h-BN and GNP Infused Polymer Composites for Elevated Temperature Applications', Materials, vol. 15, no. 15, pp. 5397-5397.
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Polymer-based nanocomposites are being considered as replacements for conventional materials in medium to high-temperature applications. This article aims to discover the synergistic effects of reinforcements on the developed polymer-based nanocomposite. An epoxy-based polymer composite was manufactured by reinforcing graphene nanoplatelets (GNP) and h-boron nitride (h-BN) nanofillers. The composites were prepared by varying the reinforcements with the step of 0.1 from 0.1 to 0.6%. Ultrasonication was carried out to ensure the homogenous dispersion of reinforcements. Mechanical, thermal, functional, and scanning electron microscopy (SEM) analysis was carried out on the novel manufactured composites. The evaluation revealed that the polymer composite with GNP 0.2 by wt % has shown an increase in load-bearing capacity by 265% and flexural strength by 165% compared with the pristine form, and the polymer composite with GNP and h-BN 0.6 by wt % showed an increase in load-bearing capacity by 219% and flexural strength by 114% when compared with the pristine form. Furthermore, the evaluation showed that the novel prepared nanocomposite reinforced with GNP and h-BN withstands a higher temperature, around 340 °C, which is validated by thermogravimetric analysis (TGA) trials. The numerical simulation model is implemented to gather the synthesised nanocomposite’s best composition and mechanical properties. The minor error between the simulation and experimental data endorses the model’s validity. To demonstrate the industrial applicability of the presented material, a case study is proposed to predict the temperature range for compressor blades of gas turbine engines containing nanocomposite material as the substrate and graphene/h-BN as reinforcement particles.
Cu Thi, P, Ball, JE & Dao, NH 2022, 'Early stopping technique using a genetic algorithm for calibration of an urban runoff model', International Journal of River Basin Management, vol. 20, no. 4, pp. 545-554.
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Identifying suitable parameter sets for use in catchment modelling remains a critical issue in hydrology. This paper describes an early stopping technique (EST) for use during calibration of a multi-parameter urban catchment modelling system. The proposed method takes advantage of MODE and lower confidence limit (LCL) functions in statistical analysis of spanning set of objective function values. The paper also introduces a monitoring process and regularization techniques to avoid under/overfitting during the calibration and to enhance generalisation performance. The methodology is assessed using SWMM and linked with a Genetic Algorithm for calibration of a Powells Creek catchment model in Sydney, Australia. Results demonstrate that the statistical spanning set analysis approach overcomes issues of poor interpretation and deterioration in the model’s generalisation properties. By stopping early, the calibration process avoided overfitting; this was indicated by too closely fitting to the calibration dataset and a failure to fit to the monitoring dataset.
Cui, Z, Wang, X, Ngo, H & Zhu, G 2022, 'In-situ monitoring of membrane fouling migration and compression mechanism with improved ultraviolet technique in membrane bioreactors', Bioresource Technology, vol. 347, pp. 126684-126684.
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da Rocha, CG, Saldanha, RB, Tonini de Araújo, M & Consoli, NC 2022, 'Social and environmental assessments of Eco-friendly Pavement alternatives', Construction and Building Materials, vol. 325, pp. 126736-126736.
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Dai, W, Mu, J, Chen, Z, Zhang, J, Pei, X, Luo, W & Ni, B-J 2022, 'Design of Few-Layer Carbon Nitride/Bifeo3 Composites for Efficient Organic Pollutant Photodegradation', Environ Res, vol. 215, no. Pt 1, pp. 114190-114190.
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Heterojunction-driven photocatalysis can degrade various organic pollutants, and developing carbon nitride-based composite photocatalysts is of great significance and gains growing interest. In this study, a two-dimensional graphitic carbon nitride nanosheets/BiFeO3 (GCNNs/BiFeO3) Z-scheme heterojunction has been synthesized through the electrostatic spinning and post-calcination The obtained GCNNs/BiFeO3 nanofibers show large surface contact between GCNNs the and BiFeO3 nanostructures. The Z-scheme heterojunction shows a remarkably enhanced photocatalytic performance, which could degrade 94% of tetracycline (TC) and 88% of Rhodamine B (RhB) under LED visible light irradiation in 150 min. Radical trapping experiments demonstrate the effective construction of Z-scheme heterojunctions, and •O2- and h+ are the main active species in the photocatalytic degradation process. This study realizes a novel nanostructured GCNNs/BiFeO3 heterojunction for photodegradation applications, which would guide the design of next-generation efficient photocatalysts.
Dai, Y, Zhang, X, Liu, Y, Yu, H, Su, W, Zhou, J, Ye, Q & Huang, Z 2022, '1,6;2,3-Bis-BN Cyclohexane: Synthesis, Structure, and Hydrogen Release', Journal of the American Chemical Society, vol. 144, no. 19, pp. 8434-8438.
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BN/CC isosterism has been widely investigated as a strategy to expand carbon-based compounds. The introduction of BN units in organic molecules always results in novel properties. In this work, we reported the first synthesis and characterization of 1,6;2,3-bis-BN cyclohexane, an isostere of cyclohexane with two adjacent BN pairs. Its ring flipping barrier is similar to that of cyclohexane. Protic hydrogens on N in 1,6;2,3-bis-BN cyclohexane show higher reactivity than its isomeric bis-BN cyclohexane. This compound exhibits an appealing hydrogen storage capability of >9.0 wt %, nearly twice as much as the 1,2;4,5-bis-BN cyclohexane.
Dang, B-T, Bui, X-T, Tran, DPH, Hao Ngo, H, Nghiem, LD, Hoang, T-K-D, Nguyen, P-T, Nguyen, HH, Vo, T-K-Q, Lin, C, Yi Andrew Lin, K & Varjani, S 2022, 'Current application of algae derivatives for bioplastic production: A review', Bioresource Technology, vol. 347, pp. 126698-126698.
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Improper use of conventional plastics poses challenges for sustainable energy and environmental protection. Algal derivatives have been considered as a potential renewable biomass source for bioplastic production. Algae derivatives include a multitude of valuable substances, especially starch from microalgae, short-chain length polyhydroxyalkanoates (PHAs) from cyanobacteria, polysaccharides from marine and freshwater macroalgae. The algae derivatives have the potential to be used as key ingredients for bioplastic production, such as starch and PHAs or only as an additive such as sulfated polysaccharides. The presence of distinctive functional groups in algae, such as carboxyl, hydroxyl, and sulfate, can be manipulated or tailored to provide desirable bioplastic quality, especially for food, pharmaceutical, and medical packaging. Standardizing strains, growing conditions, harvesting and extracting algae in an environmentally friendly manner would be a promising strategy for pollution control and bioplastic production.
Dang, B-T, Nguyen, T-T, Bui, X-T, Hao Ngo, H, Andrew Lin, K-Y, Tomoaki, I, Saunders, T, Huynh, T-N, Ngoc-Dan Cao, T, Visvanathan, C, Varjani, S & Rene, ER 2022, 'Non-submerged attached growth process for domestic wastewater treatment: Influence of media types and internal recirculation ratios', Bioresource Technology, vol. 343, pp. 126125-126125.
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Dang, B-T, Nguyen, T-T, Ngo, HH, Pham, M-D-T, Le, LT, Nguyen, N-K-Q, Vo, T-D-H, Varjani, S, You, S-J, Lin, KA, Huynh, K-P-H & Bui, X-T 2022, 'Influence of C/N ratios on treatment performance and biomass production during co-culture of microalgae and activated sludge', Science of The Total Environment, vol. 837, pp. 155832-155832.
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Dang, B-T, Tran, DPH, Nguyen, N-K-Q, Cao, HTN, Tomoaki, I, Huynh, K-P-H, Pham, T-T, Varjani, S, Hao Ngo, H, Wang, Y-F, You, S-J & Bui, X-T 2022, 'Comparison of degradation kinetics of tannery wastewater treatment using a nonlinear model by salt-tolerant Nitrosomonas sp. and Nitrobacter sp.', Bioresource Technology, vol. 351, pp. 127000-127000.
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Dayarathne, HNP, Angove, MJ, Paudel, SR, Ngo, HH, Guo, W & Mainali, B 2022, 'Optimisation of dual coagulation process for the removal of turbidity in source water using streaming potential', Groundwater for Sustainable Development, vol. 16, pp. 100714-100714.
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De Carvalho Gomes, S, Zhou, JL, Zeng, X & Long, G 2022, 'Water treatment sludge conversion to biochar as cementitious material in cement composite', Journal of Environmental Management, vol. 306, pp. 114463-114463.
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Water treatment sludge was successfully thermally converted to obtain biochar as a stable material with resource potential. This research explored the application of sludge biochar as a supplementary cementitious material. The cement paste samples incorporating different amounts of sludge biochar were prepared, hardened, and analyzed for performance. The results show an improvement in hydration kinetics and mechanical properties of cement paste incorporating biochar, compared to raw sewage sludge. The mineralogical, thermal and microscopic analyses show evidence of pozzolanic activity of the biochar. The samples with 2% and 5% biochar showed higher heat release than the reference material. Specimens with 1%, 2% and 5% biochar showed a slightly higher compressive strength at 28 days compared to the reference material. Sludge conversion to biochar will incur an estimated cost of US$398.23/ton, which is likely to be offset by the substantial benefits from avoiding landfill and saving valuable cementitious materials. Therefore, this research has demonstrated that through conversion to biochar, water treatment sludge can be promoted as a sustainable and alternative cementitious material for cement with minimum environmental impacts, hence contributing to circular economy.
Deng, L, Guo, W, Ngo, HH, Zhang, X, Chen, C, Chen, Z, Cheng, D, Ni, S-Q & Wang, Q 2022, 'Recent advances in attached growth membrane bioreactor systems for wastewater treatment', Science of The Total Environment, vol. 808, pp. 152123-152123.
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Deng, L, Ngo, HH, Guo, W, Chang, SW, Nguyen, DD, Pandey, A, Varjani, S & Hoang, NB 2022, 'Recent advances in circular bioeconomy based clean technologies for sustainable environment', Journal of Water Process Engineering, vol. 46, pp. 102534-102534.
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Deng, S, Peng, S, Ngo, HH, Oh, SJ-A, Hu, Z, Yao, H & Li, D 2022, 'Characterization of nitrous oxide and nitrite accumulation during iron (Fe(0))- and ferrous iron (Fe(II))-driven autotrophic denitrification: mechanisms, environmental impact factors and molecular microbial characterization', Chemical Engineering Journal, vol. 438, pp. 135627-135627.
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The iron (Fe(0))-/ferrous iron (Fe(II))-driven autotrophic denitrification processes have been alternative methods for nitrogen removal from low organic carbon (OC) wastewater, but the accumulation of nitrous oxide (N2O) and nitrite (NO2−) along with these processes remains unclear. This research aimed to systematically characterize the N2O/NO2− accumulation in Fe(0)-/Fe(II)-ADN processes through investigating the mechanisms, impact factors, and molecular biological characteristics. Results showed that Fe(II)-ADN was effective in NO3− reduction but was less efficient in N2O reduction (k = 0.50 h−1) than Fe(0)-ADN (k = 1.82 h−1). NO2−/N2O accumulation in Fe(II)-ADN (28.6%/30.7%) was much higher than that in Fe(0)-ADN (12.6%/1.5%). Introducing hydrogenotrophic denitrification (H-ADN) into Fe(II)-ADN system significantly (p < 0.05) reduced NO2−/N2O accumulation. Fe(0)-ADN was proved a coupled process of Fe(II)- and H-ADN by in-situ generating Fe(II)/H2, and Fe(II)-ADN and H-ADN mainly contributed to NO3− and NO2−/N2O reduction, respectively. Optimum pH (7.5) and temperature (30–35 °C) were confirmed with controlled NO2–/N2O accumulation and effective denitrification. Dosing inorganic carbon (IC) and OC enhanced denitrification and reduced NO2–/N2O accumulation, where OC was more efficient with an optimum dosage of 0.25 mmol C/mmol N. 16S rRNA high-throughput sequencing and Pearson Correlation Coefficients verified that Thiobacillus was the main contributor to NO3− reduction, whereas Thauera and Acidovorax possessed high NO2−/N2O reduction capability. Real-time quantitative polymerase chain reaction and enzyme activity assay demonstrated that the nitrite reductase encoded by gene nirK and the nitrous oxide reductase encoded by gene nosZ were efficient in catalyzing the further reduction of NO2− and N2O, respectively. This study could provide an in-depth understanding of NO2−/N2O accumulation in Fe(II)-/Fe(0)-ADN processes and contribute to their application, optimiza...
des Ligneris, E, Merenda, A, Chen, X, Wang, J, Johannessen, B, Bedford, NM, Callahan, DL, Dumée, LF & Kong, L 2022, 'In Situ Growth of Cu/CuO/Cu2O Nanocrystals within Hybrid Nanofibers for Adsorptive Arsenic Removal', ACS Applied Nano Materials, vol. 5, no. 10, pp. 14437-14446.
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Dhana Raju, V, Nair, JN, Venu, H, Subramani, L, M. Soudagar, ME, Mujtaba, MA, Khan, TMY, Ismail, KA, Elfasakhany, A, Yusuf, AA, Mohamed, BA & Fattah, IMR 2022, 'Combined assessment of injection timing and exhaust gas recirculation strategy on the performance, emission and combustion characteristics of algae biodiesel powered diesel engine', Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, vol. 44, no. 4, pp. 8554-8571.
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Currently, the vehicle industry is confronted with issues such as the depletion of fossil resources, an increase in crude oil costs, and stricter emission regulatory standards. In this scenario, the use of viable alternatives to diesel as a fuel is necessary. This study discusses the combined effects of injection time and exhaust gas recirculation (EGR) on neat algal biodiesel-powered diesel engines. The transesterification technique was used to extract algal oil methyl ester (AOME), and the majority of the fuel qualities of AOME were quite comparable to diesel. The practicality of neat AOME for diesel engines operating at varied injection timings such as 19º BTDC, 23º BTDC, and 27º BTDC was investigated. The results of the tests revealed that advanced injection timing has a 3.02% higher BTE than standard fuel injection timing at maximum load for the AOME. Compared to other injection timings at full load, the neat AOME at 27º BTDC has better combustion characteristics and lower exhaust emissions. At full load, however, NOx emissions were higher. NOx emission was reduced by 35.24% when AOME was burned at 27º BTDC combined with 10% exhaust gas recirculation (EGR) compared to 27º BTDC without EGR.
Dhandapani, Y, Joseph, S, Bishnoi, S, Kunther, W, Kanavaris, F, Kim, T, Irassar, E, Castel, A, Zunino, F, Machner, A, Talakokula, V, Thienel, K-C, Wilson, W, Elsen, J, Martirena, F & Santhanam, M 2022, 'Durability performance of binary and ternary blended cementitious systems with calcined clay: a RILEM TC 282-CCL, review', Materials and Structures, vol. 55, no. 5.
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Dhandapani, Y, Joseph, S, Geddes, DA, Zhao, Z, Boustingorry, P, Bishnoi, S, Vieira, M, Martirena, F, Castel, A, Kanavaris, F & Riding, KA 2022, 'Fresh properties of concrete containing calcined clays: a review by RILEM TC-282 CCL', Materials and Structures, vol. 55, no. 6, p. 151.
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This state of the art presents an overview on the effects of calcined clay inclusion on the fresh properties of concrete under the framework of RILEM TC-282 CCL. Progress in recent literature was reviewed to determine the effects of calcined clay, particularly metakaolin and lower grade kaolinite clays, on fresh concrete properties and how to control them using admixtures, particle packing, and mixture proportioning. A summary of recent studies on the use of superplasticizers in modified (or combined form) to improve compatibility have shown promising outcomes to control the rheological properties of calcined clay binders. Superplasticizer demand required to achieve workable concrete increases with increasing dosage of calcined clay and increases substantially for concrete produced with calcined clay at water-to-cementitious material ratios below 0.40. A comparative analysis of data from several literature shows that the addition of calcined clay could reduce setting time when used without superplasticizers. Addition of superplasticizers could help to control and increase the setting time significantly. Calcined clay can be used to make concrete with similar workability and setting times as concrete containing Portland cement through the use of polycarboxylate-based superplasticizers. However, more studies in future should focus on retention of workability by suitable methodologies for various construction activities. Care should be exercised to avoid long setting times with high dosages of superplasticizers.
Dikshit, A, Pradhan, B & Santosh, M 2022, 'Artificial neural networks in drought prediction in the 21st century–A scientometric analysis', Applied Soft Computing, vol. 114, pp. 108080-108080.
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Droughts are the most spatially complex geohazard, which often lasts for years, thereby severely impacting socio-economic sectors. One of the critical aspects of drought studies is developing a reliable and robust forecasting model, which could immensely help drought management planners in adopting adequate measures. Further, the prediction of drought events are extremely challenging due to the involvement of several hydro-meteorological factors, which are further aggravated by the effect of climate change. Among the several techniques such as statistical, physical and data-driven that are used to forecast droughts, artificial neural networks provide one of the most robust approach. As droughts are inherently non-linear and multivariate in nature, the capability of neural networks to capture the dynamic relationship easily and efficiently has seen a rise in its use. Here we evaluate the most used architectures in the last two decades, using scientometric analysis. A general framework used in drought prediction studies is explained and examples from various continents are provided, thus exploring the topic in a global context. The findings show that using sophisticated input representation, the artificial intelligence-based solutions applied to drought prediction of hydro-meteorological variables have promising success, particularly in complex geographical scenarios. The future works need to focus on interpretable models, use of deep learning architectures for long lead time forecasting and use of neural networks to predict different drought characteristics like drought propagation and flash droughts. We also summarize the most widely used neural network approaches in spatial drought prediction, which would serve as a foundation for future research in drought prediction studies.
Dikshit, A, Pradhan, B, Assiri, ME, Almazroui, M & Park, H-J 2022, 'Solving transparency in drought forecasting using attention models', Science of The Total Environment, vol. 837, pp. 155856-155856.
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Droughts are one of the most devastating and recurring natural disaster due to a multitude of reasons. Among the different drought studies, drought forecasting is one of the key aspects of effective drought management. The occurrence of droughts is related to a multitude of factors which is a combination of hydro-meteorological and climatic factors. These variables are non-linear in nature, and neural networks have been found to effectively forecast drought. However, classical neural nets often succumb to over-fitting due to various lag components among the variables and therefore, the emergence of new deep learning and explainable models can effectively solve this problem. The present study uses an Attention-based model to forecast meteorological droughts (Standard Precipitation Index) at short-term forecast range (1-3 months) for five sites situated in Eastern Australia. The main aim of the work is to interpret the model outcomes and examine how a deep neural network achieves the forecasting results. The plots show the importance of the variables along with its short-term and long-term dependencies at different lead times. The results indicate the importance of large-scale climatic indices at different sequence dependencies specific to the study site, thus providing an example of the necessity to build a spatio-temporal explainable AI model for drought forecasting. The use of such interpretable models would help the decision-makers and planners to use data-driven models as an effective measure to forecast droughts as they provide transparency and trust while using these models.
Dikshit, A, Pradhan, B, Huete, A & Park, H-J 2022, 'Spatial based drought assessment: Where are we heading? A review on the current status and future', Science of The Total Environment, vol. 844, pp. 157239-157239.
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Droughts are the most spatially complex natural hazards that exert global impacts and are further aggravated by climate change. The investigation of drought events is challenging as it involves numerous factors ranging from detection and assessment to modelling, management and mitigation. The analysis of these factors and their quantitative assessments have significantly evolved in recent times. In this paper, we review recent methods used to examine and model droughts from a spatial viewpoint. Our analysis was conducted at three spatial scales (point-wise, regional and global) and we evaluated how recent spatial methods have advanced our understanding of drought through case study examples. Further, we also examine and provide a broad overview of relevant case studies related to future drought occurrences under climate change. This study is a comprehensive synthesis of the various quantitative techniques used to assess the spatial characteristics of droughts at different spatial scales, and not an exhaustive review of all drought aspects. However, this serves as a basis for understanding the key milestones and advances accomplished through new spatial concepts relative to the traditional approaches to study drought. This work also aims to address the gaps in knowledge that are in need of further attention and provides recommendations to improve our understanding of droughts.
Ding, A, Lin, W, Chen, R, Ngo, HH, Zhang, R, He, X, Nan, J, Li, G & Ma, J 2022, 'Improvement of sludge dewaterability by energy uncoupling combined with chemical re-flocculation: Reconstruction of floc, distribution of extracellular polymeric substances, and structure change of proteins', Science of The Total Environment, vol. 816, pp. 151646-151646.
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Ding, A, Ren, Z, Hu, L, Zhang, R, Ngo, HH, Lv, D, Nan, J, Li, G & Ma, J 2022, 'Oxidation and coagulation/adsorption dual effects of ferrate (VI) pretreatment on organics removal and membrane fouling alleviation in UF process during secondary effluent treatment', Science of The Total Environment, vol. 850, pp. 157986-157986.
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Ding, W, Zhou, X, Jin, W, Zhao, Z, Gao, S, Chen, Y, Han, W, Liu, H & Wang, Q 2022, 'A novel aquatic worm (Limnodrilus hoffmeisteri) conditioning method for enhancing sludge dewaterability by decreasing filamentous bacteria', Science of The Total Environment, vol. 849, pp. 157949-157949.
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In this study, a novel aquatic worm conditioning method was proposed to enhance sludge dewaterability by reducing filamentous bacteria. The optimal treatment time was 4 days and the optimal sludge concentration was 5000 mg/L. Under these conditions, the sludge dewaterability was improved with CST of 16.69 s, reduction in sludge SRF of 48.95 %, and reduction in LfA of 58.23 %. After bio-conditioning, sludge flocs broke up by the aquatic worm predation. The absolute zeta potential decreased to -8.27 mV, and the particle size increased from 36.64 μm to 48.05 μm. Proteins, polysaccharides and other organic substances in sludge EPS and microbial cells were released, with the viscosity reduced to 1.16 mPa·s and the bound water converted into free water. Besides, the number and abundance of representative filamentous Chloroflexi decreased, resulting in the enhancement of sludge dewatering performance. Overall, the aquatic worm conditioning process can be divided into two steps: Sludge destruction by the aquatic worm predation and sludge re-coagulation by filamentous bacteria as a skeleton.
Ditta, A, Tabish, AN, Mujtaba, MA, Amjad, M, Yusuf, AA, Chaudhary, GQ, Razzaq, L, Abdelrahman, A & Kalam, MA 2022, 'Experimental investigation of a hybrid configuration of solar thermal collectors and desiccant indirect evaporative cooling system', Frontiers in Energy Research, vol. 10.
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This paper presents the integrated performance of a solar-assisted desiccant dehumidifier along with Maisotsenko cycle (M-cycle) counter flow heat and mass exchanger. This system handles latent load and sensible load separately. The hybrid configuration of solar thermal collectors was analyzed for efficiency of solar collectors and solar fraction. High consumption of fossil fuels, which are already present in a limited amount, is also associated with environmental problems and climate change issues, as these increase the chances of global warming. These issues demand of us to shift towards renewable energy resources. Increase in world energy use results in a number of environmental problems, such as climate change, in addition to global warming and ozone depletion. In building services, HVAC systems are major concerns. To overcome the requirement, conventional air conditioning and vapor compression systems are mainly used for air conditioning, although these also have some environmental problems. Solar thermal applications in combination with other renewable-energy-dependent cooling practices have generated a huge interest towards sustainable solutions, keeping in view several techno-economical, environmental, and climatic advantages. The experimental investigation reveals that the maximum outlet temperature and efficiency of solar thermal collectors was 87°C and 56% respectively. The maximum cooling capacity of the system is evaluated at 4.6 kW.
Do, MH, Ngo, HH, Guo, W, Chang, SW, Nguyen, DD, Liu, Q, Nghiem, DL, Thanh, BX, Zhang, X & Hoang, NB 2022, 'Performance of a dual-chamber microbial fuel cell as a biosensor for in situ monitoring Bisphenol A in wastewater', Science of The Total Environment, vol. 845, pp. 157125-157125.
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This research explores the possibilities of a dual-chamber microbial fuel cell as a biosensor to measure Bisphenol A (BPA) in wastewater. BPA is an organic compound and is considered to be an endocrine disruptor, affecting exposed organisms, the environment, and human health. The performance of the microbial fuel cells (MFCs) was first controlled with specific operational conditions (pH, temperature, fuel feeding rate, and organic loading rate) to obtain the best accuracy of the sensor signal. After that, BPA concentrations varying from 50 to 1000 μg L-1 were examined under the biosensor's cell voltage generation. The outcome illustrates that MFC generates the most power under the best possible conditions of neutral pH, 300 mg L-1 of COD, R 1000 Ω, and ambient temperature. In general, adding BPA improved the biosensor's cell voltage generation. A slight linear trend between voltage output generation and BPA concentration was observed with R2 0.96, which indicated that BPA in this particular concentration range did not real harm to the MFC's electrogenic bacteria. Scanning electron microscope (SEM) images revealed a better cover biofilm after BPA injection on the surface electrode compared to it without BPA. These results confirmed that electroactive biofilm-based MFCs can serve to detect BPA found in wastewaters.
Do, MH, Ngo, HH, Guo, W, Chang, SW, Nguyen, DD, Pandey, A, Sharma, P, Varjani, S, Nguyen, TAH & Hoang, NB 2022, 'A dual chamber microbial fuel cell based biosensor for monitoring copper and arsenic in municipal wastewater', Science of The Total Environment, vol. 811, pp. 152261-152261.
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Dogan, S, Barua, PD, Baygin, M, Chakraborty, S, Ciaccio, EJ, Tuncer, T, Abd Kadir, KA, Md Shah, MN, Azman, RR, Lee, CC, Ng, KH & Acharya, UR 2022, 'Novel multiple pooling and local phase quantization stable feature extraction techniques for automated classification of brain infarcts', Biocybernetics and Biomedical Engineering, vol. 42, no. 3, pp. 815-828.
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Dogan, S, Datta Barua, P, Kutlu, H, Baygin, M, Fujita, H, Tuncer, T & Acharya, UR 2022, 'Automated accurate fire detection system using ensemble pretrained residual network', Expert Systems with Applications, vol. 203, pp. 117407-117407.
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Nowadays, fires have been commonly seen worldwide and especially forest fires are big disasters for humanity. The prime objective of this work is to develop an accurate fire warning model by using images. In this work, two new deep feature engineering models are proposed to detect the fire accurately using images. To create deep features, residual networks (ResNet) are chosen since these networks are one of the highly accurate convolutional neural networks. In this work, four pretrained ResNets: ResNet18, ResNet50, ResNet101, and InceptionResNetV2 are used. These networks were trained using a cluster of ImageNet dataset and features were extracted using the last pooling and fully connected layers of these networks. Hence, eight feature vectors are chosen using these networks and the top 256 features of these networks are chosen using neighborhood component analysis (NCA). Support vector machine (SVM) classifier has been used for classification. Moreover, by using the eight feature vectors generated, two ensemble models have been presented. In the first ensemble model, generated all features are concatenated and the top 1000 features are chosen using a feature selector used (NCA), and these features are classified using SVM. In the second ensemble model, iterative hard majority voting (IHMV) has been applied to the generated results. The developed ensemble ResNet models attained 98.91% and 99.15% classification accuracies using an SVM classifier with a 10-fold cross-validation strategy. Our results obtained demonstrate the high classification accuracy of our presented ensemble pretrained ResNet-based deep feature extraction models. These developed models are ready to be tested with higher databases before actual real-world application.
Dong, L, Yang, Y, Liu, Z, Ren, Q, Li, J, Zhang, Y & Wu, C 2022, 'Microstructure and mechanical behaviour of 3D printed ultra-high performance concrete after elevated temperatures', Additive Manufacturing, vol. 58, pp. 103032-103032.
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This study investigated the characteristics of 3D printed ultra-high performance concrete (3DP-UHPC) after elevated temperatures. The effects of the bonding strip, steel fibre, specimen preparation method, loading direction and temperature on the fire resistance of 3DP-UHPC were analysed. The variations in microstructure and mineral composition of 3DP-UHPC after different temperatures were examined using scanning electron microscopy (SEM) and energy spectrum analyser (EDS). The strength degradation mechanism of 3DP-UHPC after the elevated temperatures was revealed in terms of the macro and micro levels. Meanwhile, the compressive strength of 3DP-UHPC after the elevated temperatures was measured, and its corresponding compressive constitutive model was proposed. The experimental results indicated that 3DP-UHPC had certain fire resistance, and the addition of steel fibre and the preparation method improved its fire resistance. The expansion of the crack at the junction of the steel fibre and matrix, as well as the oxidation and decarburization of steel fibre, affected the compressive strength of 3DP-UHPC after 400 ℃. During heating, water vapour escaped from the weak interface of the bonding strip endowed 3DP-UHPC with slightly better elevated-temperature burst resistance as compared to mould-casting ultra-high performance concrete (MC-UHPC). The compressive strength of 3DP-UHPC was the highest after 300 ℃ for the target temperatures set in this study, but the temperature had little effect on the strength difference between each direction of 3DP-UHPC. The compressive constitutive model of 3DP-UHPC after the elevated temperatures was developed, facilitating its engineering application in the field of fire safety.
Dong, W, Li, W, Guo, Y, Qu, F, Wang, K & Sheng, D 2022, 'Piezoresistive performance of hydrophobic cement-based sensors under moisture and chloride-rich environments', Cement and Concrete Composites, vol. 126, pp. 104379-104379.
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Silicone hydrophobic powder (SHP) and crystalline waterproofing admixture (CWA) were used to improve the impermeability of carbon black (CB)/cement-based sensors. The mechanical, electrical and piezoresistive properties, waterproofing and chloride resistance of CB/cementitious composites were investigated in this study. The piezoresistivity before or after different durations of immersion in freshwater and 3% sodium chloride solution and the stability in freshwater and marine environment were studied and compared. The results show that compressive strength increased with the additions of CWA and SHP, while the tensile strength slightly decreased with CWA, due to the formation of crystalline. Moreover, cementitious composites with SHP exhibited the best water impermeability, while the counterpart containing CWA presented the optimal chloride resistance. Although cementitious composites with SHP exhibited the highest electrical resistivity, the most stable piezoresistivity occurred after 90 days of immersion in freshwater. On the other hand, cementitious composites incorporating CWA presented the lowest electrical resistivity, but the piezoresistivity continually decreased with the immersion duration. Because of the free ions, piezoresistivity increased as a result of the immersion in sodium chloride solution. The related results will provide an insight into the piezoresistivity of hydrophobic cement-based sensors under moisture and chloride environments for future structural health monitoring.
Dong, W, Li, W, Guo, Y, Wang, K & Sheng, D 2022, 'Mechanical properties and piezoresistive performances of intrinsic graphene nanoplate/cement-based sensors subjected to impact load', Construction and Building Materials, vol. 327, pp. 126978-126978.
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The electrical, mechanical properties, and piezoresistive performances of intrinsic graphene nanoplate (GNP)/cementitious composites were investigated after subjected to impact load in this paper. The stabilized electrical resistivity before/after exposure to impact load and real-time electrical response under dynamic load were simultaneously studied. The cement hydration and microstructures of (GNP)/cementitious composites were characterized by thermal gravity analysis (TGA) and scanning electron microscope. The nearly identical hydration degree of 1.0% GNP filled cement mortar (1GNPCM) and mortar with 2% GNP (2GNPCM) indicates the physical interactions between the GNP and cement matrix. The excellent intrinsic physical properties of GNP played an important role in the enhancements of GNP/cementitious composites. After exposed to impact, the stabilized electrical resistivity, mechanical performance, and piezoresistivity of 1GNPCM were greatly changed, whereas the counterpart of 2GNPCM was well-maintained and nearly unaffected. Therefore, the severe microstructural deteriorations in 1GNPCM could be responsible for the variations, which damaged the conductive passages. The almost unchanged mechanical, electrical and piezoresistive properties enable 2GNPCM as a promising cement-based senor to provide stable piezoresistivity even after exposure to impact load. The related outcomes provide an insight into the development of impact-resistant cement-based sensors and promote the applications of cement-based sensors under extreme loading conditions.
Dong, W, Li, W, Sun, Z, Ibrahim, I & Sheng, D 2022, 'Intrinsic graphene/cement-based sensors with piezoresistivity and superhydrophobicity capacities for smart concrete infrastructure', Automation in Construction, vol. 133, pp. 103983-103983.
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Dong, W, Li, W, Wang, K, Shah, SP & Sheng, D 2022, 'Multifunctional cementitious composites with integrated self-sensing and self-healing capacities using carbon black and slaked lime', Ceramics International, vol. 48, no. 14, pp. 19851-19863.
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This study aims to develop multifunctionality of cementitious composites with the integrated self-sensing and self-healing capacities by incorporating conductive carbon black (CB) with CB-encapsulated slaked lime (SL). The microsized SL particles were premixed with a half of designed content of nanosized CB particles. When CB agglomerations coat around the SL surfaces, SL does not hydrate until the CB coating is removed. Another half of designed weight of CB is uniformly dispersed using ultrasonication with superplasticizer and added to obtain piezoresistivity. The results show that the stress sensing capacity of CB-SL-cementitious composite performs well with the compressive stress. Autogenous healing performances presented significantly can improve the self-healing capacity with the increase of SL. Furthermore, the healing efficiency is affected by the crack width and dispersion of SL, and the smaller cracks with SL are more easily healed. The size of CB agglomerations decreases with the added SL, and the main product of self-healing is calcium carbonate.
Dorji, P, Phuntsho, S, Kim, DI, Lim, S, Park, MJ, Hong, S & Shon, HK 2022, 'Electrode for selective bromide removal in membrane capacitive deionisation', Chemosphere, vol. 287, no. Pt 2, pp. 132169-132169.
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Due to the shortage of freshwater around the world, seawater is becoming an important water source. However, seawater contains a high concentration of bromide that can form harmful disinfection by-products during water disinfection. Therefore, the current seawater reverse osmosis (SWRO) has to adopt two-pass reverse osmosis (RO) configuration for effective bromide removal, increasing the overall desalination cost. In this study, a bromide selective composite electrode was developed for membrane capacitive deionisation (MCDI). The composite electrode was developed by coating a mixture of bromide selective resin and anion exchange polymer on the surface of the commercial activated carbon electrode, and its performance was compared to that of conventional carbon electrode. The results demonstrated that the composite electrode has ten times better bromide selectivity than the conventional carbon electrode. The study shows the potential application of MCDI for the selective removal of target ions from water sources and the potential for resource recovery through basic modification of commercial electrode.
Dorji, U, Dorji, P, Shon, H, Badeti, U, Dorji, C, Wangmo, C, Tijing, L, Kandasamy, J, Vigneswaran, S, Chanan, A & Phuntsho, S 2022, 'On-site domestic wastewater treatment system using shredded waste plastic bottles as biofilter media: Pilot-scale study on effluent standards in Bhutan', Chemosphere, vol. 286, no. Pt 2, pp. 131729-131729.
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In this study, a 1000 L/d capacity one-off on-site wastewater treatment system was operated for over a year as a pilot alternative to the conventional on-site treatment as currently used in urban Bhutan. An up-flow anaerobic sludge blanket (UASB) was used for blackwater treatment (to replace 'septic tank followed by an anaerobic biofilter (ABF) (to replace soak pits) for the treatment of a mixture of greywater and UASB effluent. Shredded waste plastic bottles were used as the novel biofilter media in the ABF. During a yearlong operation, the pilot system produced a final treated effluent from ABF with average BOD5 28 mg/L, COD 38 mg/L, TSS 85 mg/L and 5 log units of Escherichia coli. These effluents met three out of four of the national effluent discharge limits of Bhutan, but unsuccessful to meet the Escherichia coli standard over a yearlong operation. Further, process optimisation may enable more significant Escherichia coli removal. An economic analysis indicates that the total unit cost (capital and operating expenditures) of this alternative wastewater treatment system for more than 50 users range between USD 0.27-0.37/person/month comparable to USD 0.29-0.42/person/month for the current predominant on-site system, i.e., 'septic tanks'. This pilot study, therefore, indicates that this wastewater treatment system using shredded waste plastic biofilter media has high potential to replace the current conventional treatment, i.e., 'septic tanks', which are often overloaded with greywater and discharging effluents which does not meet the national standards.
Dou, Y, Cheng, X, Miao, M, Wang, T, Hao, T, Zhang, Y, Li, Y, Ning, X & Wang, Q 2022, 'The impact of chlorination on the tetracycline sorption behavior of microplastics in aqueous solution', Science of The Total Environment, vol. 849, pp. 157800-157800.
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Considering the large volumes of treated water and incomplete elimination of pollutants, wastewater treatment plants (WWTPs) remain a considerable source of microplastics (MPs). Chlorine, the most frequently used disinfectant in WWTPs, has a strong oxidizing impact on MPs. However, little is documented, to date, about the impact of chlorination on the transformation of MPs and the subsequent environmental behaviors of the chlorinated MPs when released into the aquatic environment. This study explored the response of the physicochemical properties of specific thermoplastics, namely polyurethane (TPU) MPs and polystyrene (PS) MPs, to chlorination and their emerging pollutant [tetracycline (TC)] adsorption behavior in aqueous solution. The results indicated that the O/C ratio of the MP surface did not significantly change, and that there were increases in the O-containing functional groups of the TPU and PS MPs, after chlorination. The surface area of the chlorinated TPU MPs increased by 45 %, and that of the chlorinated PS increased by 21 %, compared with the pristine ones, which contributed to the TC adsorption. The adsorption isotherm fitting parameters suggested that the chlorinated TPU fitted the multilayer adsorption, and the chlorinated PS was inclined to the monolayer adsorption. The relative abundance of the O-containing functional groups, on the TPU surface, led to the release of CHCl3 molecules, and the clear surface irregularities and fissures occurred after chlorine treatment. No fissures were found on the surface of the chlorinated PS MPs. The hydrophobicity and electrostatic adsorption were proved to be the major impacts on the TC adsorption of the chlorinated MPs, and the subsequently formed hydrogen bonds led to the stronger adsorption capacity of the chlorinated TPU than the chlorinated PS MPs.
Du, T, Li, C, Wang, X, Ma, L, Qu, F, Wang, B, Peng, J & Li, W 2022, 'Effects of pipe diameter, curing age and exposure temperature on chloride diffusion of concrete with embedded PVC pipe', Journal of Building Engineering, vol. 57, pp. 104957-104957.
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Concrete structures are often embedded with pipe opening for the installation of pipelines which tends to weaken the integrity and durability. The effects of pipe diameter, curing age, and exposure temperature, on the chloride ion resistance of concrete with embedded PVC pipe (CEPP) were investigated in this paper. The testing parameters include compressive strength, electric flux density, chloride ion diffusion coefficient, chloride ion penetration depth, and chloride ion content. The results showed that electric flux density and chloride ion diffusion coefficient of CEPP increased with the diameter of PVC pipes following a second-degree parabola and a linear relation respectively, while the chloride ion diffusion coefficient decreased with the prolonging curing age. The chloride ion resistance and compressive strength of CEPP were decreased with the increase of pipe diameters, because the weak areas formed in the transition interfaces between the PVC pipes and concrete matrices and expanded with increased diameter. The chloride ion penetration depth and chloride ion content were relatively higher in the testing points near the PVC pipes than the ones far away from the PVC pipes. In addition, the rate of chloride ion penetration of CEPP could be accelerated by the higher exposure temperatures, leading to severer chloride ion penetration of CEPP. Finally, a novel modified Fick's second law diffusion model considering the effects of pipe diameters and curing age was proposed to predict the chloride ion resistance of CEPP.
Du, Y, Ma, R, Wang, L, Qian, J & Wang, Q 2022, '2D/1D BiOI/g-C3N4 nanotubes heterostructure for photoelectrochemical overall water splitting', Science of The Total Environment, vol. 838, no. Pt 2, pp. 156166-156166.
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To boost the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performances, the BiOI/graphitic carbon nitride nanotubes (g-C3N4 nanotubes) heterojunction was synthesized herein through the hydrothermal method. BiOI in-situ grew on the surface of g-C3N4 nanotubes derived from melamine. The rapid recombination between photoexcited electrons and holes of pristine semiconductors was prevented via building the stable heterojunction. The SEM results indicated that the BiOI was wrapped around the surface of g-C3N4 nanotubes, resulting in an optimized electronic transmission pathway. Much lower charge transfer resistance at the p-n heterojunction was demonstrated compared with pristine BiOI according to the EIS results, thus leading to the faster surface reaction rates. Moreover, the composite exhibited both outstanding OER and HER activities under illuminated conditions. This study may shed light upon establishing a bifunctional photoelectrocatalysis for photoelectrochemical water splitting based on stable 2D metal and 1D metal-free nanocomposite.
Duong, HC, Nghiem, LD, Ansari, AJ, Vu, TD & Nguyen, KM 2022, 'Assessment of pilot direct contact membrane distillation regeneration of lithium chloride solution in liquid desiccant air-conditioning systems using computer simulation', Environmental Science and Pollution Research, vol. 29, no. 28, pp. 41941-41952.
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Membrane distillation (MD) has been increasingly explored for treatment of various hyper saline waters, including lithium chloride (LiCl) solutions used in liquid desiccant air-conditioning (LDAC) systems. In this study, the regeneration of liquid desiccant LiCl solution by a pilot direct contact membrane distillation (DCMD) process is assessed using computer simulation. Unlike previous experimental investigations, the simulation allows to incorporate both temperature and concentration polarisation effects in the analysis of heat and mass transfer through the membrane, thus enabling the systematic assessment of the pilot DCMD regeneration of the LiCl solution. The simulation results demonstrate distinctive profiles of water flux, thermal efficiency, and LiCl concentration along the membrane under cocurrent and counter-current flow modes, and the pilot DCMD process under counter-current flow is superior to that under cocurrent flow regarding the process thermal efficiency and LiCl concentration enrichment. Moreover, for the pilot DCMD regeneration of LiCl solution under the counter-current flow, the feed inlet temperature, LiCl concentration, and especially the membrane leaf length exert profound impacts on the process performance: the process water flux halves from 12 to 6 L/(m2·h) whilst thermal efficiency decreases by 20% from 0.46 to 0.37 when the membrane leaf length increases from 0.5 to 1.5 m.
Dwivedi, KA, Kumar, V, Wang, C-T, Chong, WT & Ong, HC 2022, 'Design and feasibility study of novel swirler incorporated microbial fuel cell for enhancing power generation and domestic wastewater treatment', Journal of Cleaner Production, vol. 337, pp. 130382-130382.
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El Hassan, M, Assoum, H, Bukharin, N, Al Otaibi, H, Mofijur, M & Sakout, A 2022, 'A review on the transmission of COVID-19 based on cough/sneeze/breath flows', The European Physical Journal Plus, vol. 137, no. 1, p. 1.
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COVID-19 pandemic has recently had a dramatic impact on society. The understanding of the disease transmission is of high importance to limit its spread between humans. The spread of the virus in air strongly depends on the flow dynamics of the human airflows. It is, however, known that predicting the flow dynamics of the human airflows can be challenging due to different particles sizes and the turbulent aspect of the flow regime. It is thus recommended to present a deep analysis of different human airflows based on the existing experimental investigations. A validation of the existing numerical predictions of such flows would be of high interest to further develop the existing numerical model for different flow configurations. This paper presents a literature review of the experimental and numerical studies on human airflows, including sneezing, coughing and breathing. The dynamics of these airflows for different droplet sizes is discussed. The influence of other parameters, such as the viscosity and relative humidity, on the germs transmission is also presented. Finally, the efficacy of using a facemask in limiting the transmission of COVID-19 is investigated.
El‐Hawat, O, Fatahi, B & Taciroglu, E 2022, 'Novel post‐tensioned rocking piles for enhancing the seismic resilience of bridges', Earthquake Engineering & Structural Dynamics, vol. 51, no. 2, pp. 393-417.
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AbstractThe rocking pile foundation system is a relatively new design concept that can be implemented in bridges to improve their seismic performance. This type of foundation prevents plastic damage at the bridge piers and the foundation system, which are difficult to repair and can lead to collapse. However, lack of adequate energy dissipation in this type of foundation can result in large deck displacements and subsequent catastrophic failures of the bridge. The present study proposes a novel foundation system that integrates post‐tensioned piles with the rocking foundation to simultaneously prevent plastic hinging at the piers and reduce the deck displacements during severe earthquakes. The effectiveness of the proposed foundation system is investigated and compared against the rocking pile and conventional fixed‐base foundation systems using identical bridge configurations. Three‐dimensional finite element models of these bridges were developed to capture possible nonlinear behavior of the bridge as well as soil‐structure interaction effects. Six strong earthquakes with both horizontal components were selected and scaled to the appropriate seismic hazard level with a return period of 2475 years. Static pushover and nonlinear time‐history analyses were then performed to compare the dynamic response of the bridges, including deck displacements, pier and pile inertial forces, and other nonlinear behavior experienced by the structure. The results reveal that by integrating the post‐tensioned piles with the rocking foundation, the deck displacements were reduced to an acceptable limit without subjecting the bridge to any damage. In contrast, the bridge with the fixed base foundation experienced extensive damage at the piers, and the bridge with the rocking foundation experienced substantial deck displacements that ultimately led to unseating, resulting in the collapse of both bridges. It was therefore concluded that the p...
Fallahpoor, M, Chakraborty, S, Heshejin, MT, Chegeni, H, Horry, MJ & Pradhan, B 2022, 'Generalizability assessment of COVID-19 3D CT data for deep learning-based disease detection', Computers in Biology and Medicine, vol. 145, pp. 105464-105464.
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Fang, J, Ge, Y, Chen, Z, Xing, B, Bao, S, Yong, Q, Chi, R, Yang, S & Ni, B-J 2022, 'Flotation purification of waste high-silica phosphogypsum', Journal of Environmental Management, vol. 320, pp. 115824-115824.
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High-silica phosphogypsum (PG) is a kind of industrial by-product with great utilization potential. However, it is difficult to reuse PG directly due to the related gangue minerals (e.g., SiO2), and thus efficient purification is required to allow its further applications. Herein, a typical high-silica phosphogypsum waste was purified by a new 'reverse-direct flotation' method. The organic matters and fine slimes were removed by reverse flotation, and then, the silica impurity was removed by direct flotation. Via the closed-circuit flotation process, the whiteness of the PG concentrate is improved from 33.23 to 63.42, and the purity of gypsum in the PG concentrate increases from 83.90% to 96.70%, with a gypsum recovery of 85%. Additionally, the content of SiO2 is significantly reduced from 11.11% to 0.07%. In-depth investigations suggest that the difference in the floatability of gypsum and quartz is prominently intensified by flotation reagents at pH = 2-2.5, and thus leads to good desilication performance. Further characteristics of the PG concentrate prove that impurities have been well removed, and the PG concentrate meets the requirement of related standards for gypsum building materials. The flotation method reported here paves the way for the purification of high-silica phosphogypsum, which can be extended to the purification and value-added reutilization of other industrial solid wastes.
Farooq, MA & Nimbalkar, S 2022, 'Novel sustainable base material for concrete slab track', Construction and Building Materials, vol. 366.
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Fathipour, H, Payan, M, Jamshidi Chenari, R & Fatahi, B 2022, 'General failure envelope of eccentrically and obliquely loaded strip footings resting on an inherently anisotropic granular medium', Computers and Geotechnics, vol. 146, pp. 104734-104734.
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Faust, O, Hong, W, Loh, HW, Xu, S, Tan, R-S, Chakraborty, S, Barua, PD, Molinari, F & Acharya, UR 2022, 'Heart rate variability for medical decision support systems: A review', Computers in Biology and Medicine, vol. 145, pp. 105407-105407.
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Heart Rate Variability (HRV) is a good predictor of human health because the heart rhythm is modulated by a wide range of physiological processes. This statement embodies both challenges to and opportunities for HRV analysis. Opportunities arise from the wide-ranging applicability of HRV analysis for disease detection. The availability of modern high-quality sensors and the low data rate of heart rate signals make HRV easy to measure, communicate, store, and process. However, there are also significant obstacles that prevent a wider use of this technology. HRV signals are both nonstationary and nonlinear and, to the human eye, they appear noise-like. This makes them difficult to analyze and indeed the analysis findings are difficult to explain. Moreover, it is difficult to discriminate between the influences of different complex physiological processes on the HRV. These difficulties are compounded by the effects of aging and the presence of comorbidities. In this review, we have looked at scientific studies that have addressed these challenges with advanced signal processing and Artificial Intelligence (AI) methods.
Fayaz, H, Khan, SA, Saleel, CA, Shaik, S, Yusuf, AA, Veza, I, Fattah, IMR, Rawi, NFM, Asyraf, MRM & Alarifi, IM 2022, 'Developments in Nanoparticles Enhanced Biofuels and Solar Energy in Malaysian Perspective: A Review of State of the Art', Journal of Nanomaterials, vol. 2022, pp. 1-22.
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The rapid rise in global oil prices, the scarcity of petroleum sources, and environmental concerns have all created severe issues. As a result of the country’s rapid expansion and financial affluence, Malaysia’s energy consumption has skyrocketed. Biodiesel and solar power are currently two of the most popular alternatives to fossil fuels in Malaysia. These two types of renewable energy sources appear to be viable options because of their abundant availability together with environmental and performance competence to highly polluting and fast depleting fossil fuels. The purpose of adopting renewable technology is to expand the nation’s accessibility to a reliable and secure power supply. The current review article investigates nonconventional energy sources added with nanosized metal particles called as nanomaterials including biodiesel and solar, as well as readily available renewable energy options. Concerning the nation’s energy policy agenda, the sources of energy demand are also investigated. The article evaluates Malaysia’s existing position in renewable energy industries, such as biodiesel and solar, as well as the impact of nanomaterials. This review article discusses biodiesel production, applications, and government policies in Malaysia, as well as biodiesel consumption and recent developments in the bioenergy sector, such as biodiesel property modifications utilizing nanoparticle additions. In addition, the current review study examines the scope of solar energy, different photovoltaic concentrators, types of solar energy harvesting systems, photovoltaic electricity potential in Malaysia, and the experimental setup of solar flat plate collectors (FPC) with nanotechnology.
Feng, A, Akther, N, Duan, X, Peng, S, Onggowarsito, C, Mao, S, Fu, Q & Kolev, SD 2022, 'Recent Development of Atmospheric Water Harvesting Materials: A Review', ACS Materials Au, vol. 2, no. 5, pp. 576-595.
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Feng, S, Ngo, HH, Guo, W, Chang, SW, Nguyen, DD, Liu, Y, Zhang, S, Phong Vo, HN, Bui, XT & Ngoc Hoang, B 2022, 'Volatile fatty acids production from waste streams by anaerobic digestion: A critical review of the roles and application of enzymes', Bioresource Technology, vol. 359, pp. 127420-127420.
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Volatile fatty acids (VFAs) produced from organic-rich wastewater by anaerobic digestion attract attention due to the increasing volatile fatty acids market, sustainability and environmentally friendly characteristics. This review aims to give an overview of the roles and applications of enzymes, a biocatalyst which plays a significant role in anaerobic digestion, to enhance volatile fatty acids production. This paper systematically overviewed: (i) the enzymatic pathways of VFAs formation, competition, and consumption; (ii) the applications of enzymes in VFAs production; and (iii) feasible measures to boost the enzymatic processes. Furthermore, this review presents a critical evaluation on the major obstacles and feasible future research directions for the better applications of enzymatic processes to promote VFAs production from wastewater.
Feng, S, Ngo, HH, Guo, W, Chang, SW, Nguyen, DD, Liu, Y, Zhang, X, Bui, XT, Varjani, S & Hoang, BN 2022, 'Wastewater-derived biohydrogen: Critical analysis of related enzymatic processes at the research and large scales', Science of The Total Environment, vol. 851, no. Pt 2, pp. 158112-158112.
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Organic-rich wastewater is a feasible feedstock for biohydrogen production. Numerous review on the performance of microorganisms and the diversity of their communities during a biohydrogen process were published. However, there is still no in-depth overview of enzymes for biohydrogen production from wastewater and their scale-up applications. This review aims at providing an insightful exploration of critical discussion in terms of: (i) the roles and applications of enzymes in wastewater-based biohydrogen fermentation; (ii) systematical introduction to the enzymatic processes of photo fermentation and dark fermentation; (iii) parameters that affect enzymatic performances and measures for enzyme activity/ability enhancement; (iv) biohydrogen production bioreactors; as well as (v) enzymatic biohydrogen production systems and their larger scales application. Furthermore, to assess the best applications of enzymes in biohydrogen production from wastewater, existing problems and feasible future studies on the development of low-cost enzyme production methods and immobilized enzymes, the construction of multiple enzyme cooperation systems, the study of biohydrogen production mechanisms, more effective bioreactor exploration, larger scales enzymatic biohydrogen production, and the enhancement of enzyme activity or ability are also addressed.
Figiela, M, Wysokowski, M, Stanisz, E, Hao, D & Ni, B 2022, 'Highly Sensitive, Fast Response and Selective Glucose Detection Based on CuO/Nitrogen‐doped Carbon Non‐enzymatic Sensor', Electroanalysis, vol. 34, no. 11, pp. 1725-1734.
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AbstractThis work presents development of an innovative CuO/nitrogen‐doped carbon composite (CuO−C) that may be effectively applied for the modification of a glassy carbon electrode (GCE) and creation of a non‐enzymatic sensor for glucose detection. The structure of the CuO−C nanostructured material was analyzed by scanning electron microscopy, Fourier transform infrared spectroscopy, X‐ray diffraction, and atomic absorption spectroscopy. The prepared electroactive material, based on CuO including carbon structures derived from chitosan, showed excellent performance in terms of electrocatalytic oxidation of glucose. Under optimal conditions, the modified electrode displays high sensitivity (1546 μA mM−1 cm−2), a low detection limit (1.95 μM) and short response time (4 s).
Fleck, R, Westerhausen, MT, Killingsworth, N, Ball, J, Torpy, FR & Irga, PJ 2022, 'The hydrological performance of a green roof in Sydney, Australia: A tale of two towers', Building and Environment, vol. 221, pp. 109274-109274.
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This study describes the sister buildings Daramu house and International house in Barangaroo, Sydney (Australia's largest metropolitan city), with and without a green roof, respectively. Trace metal samples were collected from both roofs and analysed using ICP-MS to determine the bioretention potential of the green roof to remediate soluble and particulate stormwater trace metal contamination. Retention of ambient trace metal contamination by the green roof substrate was deemed significant for soluble copper and particulate zinc, chromium and copper. In addition, hydrological models (DRAINS and SWMM) were applied to predict the performance of the green roof to identify its ability to manage stormwater runoff and frequency, as well as to analyse the green roof's performance in complex surface flooding situations where storage or backwater effects occur in overflow routes and surface flows. Our results demonstrate a reduction in peak stormwater flow by 18.29 L/s (∼50%) for storms as infrequent as 1 in 5 years, and peak flow reductions up to 90% storms of lower intensities. These results are significant as it demonstrates that a green roof could remediating trace metals contamination, thus reducing the impact on aquatic environments through stormwater runoff. It also highlights their potential to reduce stormwater flow, and utilise this additional water for evapotranspiration, leading to cooler ambient temperatures. Future works should aim to quantify the remediation effect of various planted species on in-situ green roofs, as well as determine the specific retention capabilities of various substrate compositions.
Fonseka, C, Ryu, S, Naidu, G, Kandasamy, J & Vigneswaran, S 2022, 'Recovery of water and valuable metals using low pressure nanofiltration and sequential adsorption from acid mine drainage', Environmental Technology & Innovation, vol. 28, pp. 102753-102753.
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Acid mine drainage (AMD) contains an array of valuable resources such as Rare Earth Elements (REE) and Copper (Cu) which can be recovered along with fresh water. Low pressure nanofiltration with NF90 membrane was first studied to recover fresh water from synthetic AMD and concentration of dissolved metals for subsequent efficient selective recovery. Organic matter (OM) present in AMD was found to cause membrane fouling which resulted in significant flux decline. Powdered eggshell was investigated as a low-cost adsorbent for OM removal. The study showed that a 0.2 mg/l dose of powdered eggshell adsorbed 100% of OM and Fe with no significant loss of other dissolved metals. A steady permeate flux of 15.5 ± 0.2 L/m2h (LMH) was achieved for pre-treated AMD with a solute rejection rate of more than 98%. A chromium-based metal organic framework (MOF) modified with N- (phosphonomethyl) iminodiacetic acid (PMIDA) and an amine-grafted mesoporous silica (SBA15) material was synthesized for selective recovery of REE and Cu, respectively. The two adsorbents were used sequentially to selectively adsorb REE (91%) and Cu (90%) from pH adjusted concentrated feed. The formation of coordinating complexes with carboxylate and phosphonic groups on MOF was found to be the primary driving force for selective REE adsorption. Selective uptake of Cu onto amine-grafted SBA15 was due to the formation of strong chelating bonds between Cu and amine ligands. Both adsorbents remained structurally stable over 5 regeneration cycles. The findings here highlight the practical potential of membrane/adsorption hybrid systems for water and valuable metal (REE) recovery from AMD.
Fowler, K, Peel, M, Saft, M, Peterson, TJ, Western, A, Band, L, Petheram, C, Dharmadi, S, Tan, KS, Zhang, L, Lane, P, Kiem, A, Marshall, L, Griebel, A, Medlyn, BE, Ryu, D, Bonotto, G, Wasko, C, Ukkola, A, Stephens, C, Frost, A, Gardiya Weligamage, H, Saco, P, Zheng, H, Chiew, F, Daly, E, Walker, G, Vervoort, RW, Hughes, J, Trotter, L, Neal, B, Cartwright, I & Nathan, R 2022, 'Explaining changes in rainfall–runoff relationships during and after Australia's Millennium Drought: a community perspective', Hydrology and Earth System Sciences, vol. 26, no. 23, pp. 6073-6120.
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Abstract. The Millennium Drought lasted more than a decade and is notable for causing persistent shifts in the relationship between rainfall and runoff in many southeastern Australian catchments. Research to date has successfully characterised where and when shifts occurred and explored relationships with potential drivers, but a convincing physical explanation for observed changes in catchment behaviour is still lacking. Originating from a large multi-disciplinary workshop, this paper presents and evaluates a range of hypothesised process explanations of flow response to the Millennium Drought. The hypotheses consider climatic forcing, vegetation, soil moisture dynamics, groundwater, and anthropogenic influence. The hypotheses are assessed against evidence both temporally (e.g. why was the Millennium Drought different to previous droughts?) and spatially (e.g. why did rainfall–runoff relationships shift in some catchments but not in others?). Thus, the strength of this work is a large-scale assessment of hydrologic changes and potential drivers. Of 24 hypotheses, 3 are considered plausible, 10 are considered inconsistent with evidence, and 11 are in a category in between, whereby they are plausible yet with reservations (e.g. applicable in some catchments but not others). The results point to the unprecedented length of the drought as the primary climatic driver, paired with interrelated groundwater processes, including declines in groundwater storage, altered recharge associated with vadose zone expansion, and reduced connection between subsurface and surface waterprocesses. Other causes include increased evaporative demand and harvestingof runoff by small private dams. Finally, we discuss the need for long-termfield monitoring, particularly targeting internal catchment processes andsubsurface dynamics. We recommend continued investment in the understanding of hydrological shifts, particularly given their relevance to water planning under ...
Fu, J, Huang, C-H, Dang, C & Wang, Q 2022, 'A review on treatment of disinfection byproduct precursors by biological activated carbon process', Chinese Chemical Letters, vol. 33, no. 10, pp. 4495-4504.
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Disinfection by-products (DBPs) in water systems have attracted increasing attention due to their toxic effects. Removal of precursors (mainly natural organic matter (NOM)) prior to the disinfection process has been recognized as the ideal strategy to control the DBP levels. Currently, biological activated carbon (BAC) process is a highly recommended and prevalent process for treatment of DBP precursors in advanced water treatment. This paper first introduces the fundamental knowledge of BAC process, including the history, basic principles, typical process flow, and basic operational parameters. Then, the selection of BAC process for treatment of DBP precursors is explained in detail based on the comparative analysis of dominant water treatment technologies from the aspects of mechanisms for NOM removal as well as the treatability of different groups of DBP precursors. Next, a thorough overview is presented to summarize the recent developments and breakthroughs in the removal of DBP precursors using BAC process, and the contents involved include effect of pre-BAC ozonation, removal performance of various DBP precursors, toxicity risk reduction, fractional analysis of NOM, effect of empty bed contact time (EBCT) and engineered biofiltration. Finally, some recommendations are made to strengthen current research and address the knowledge gaps, including the issues of microbial mechanisms, toxicity evaluation, degradation kinetics and microbial products.
Galvão, N, Matos, JC, Hajdin, R, Ferreira, L & Stewart, MG 2022, 'Impact of construction errors on the structural safety of a post-tensioned reinforced concrete bridge', Engineering Structures, vol. 267, pp. 114650-114650.
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The ageing of bridge stock in developed countries worldwide and the increasing number of recorded bridge collapses have underlined the need for more sophisticated and comprehensive assessment procedures concerning the safety and serviceability of structures. In many recent failures, construction errors or deficiencies have contributed to the unfortunate outcome either by depleting the safety margin or speeding up the deterioration rate of structures. This research aims to quantify the impact of construction errors on the structural safety of a bridge considering corresponding models available in the literature that probabilistically characterise the occurrence rate and severity of some of these errors. The nominal probability of failure of structures, neglecting construction errors, is typically computed in numerous works in the literature. Therefore, the novelty of this paper lies in the consideration of an additional source of uncertainty (i.e., construction errors) combined with sophisticated numerical methods leading to a more refined estimation of the probability of failure of structures. Accordingly, some benchmark results focussing on error-free and error-included scenarios are established, providing useful information to close the gap between the nominal and the actual probability of failure of a railway bridge.
Ganbat, N, Altaee, A, Zhou, JL, Lockwood, T, Al-Juboori, RA, Hamdi, FM, Karbassiyazdi, E, Samal, AK, Hawari, A & Khabbaz, H 2022, 'Investigation of the effect of surfactant on the electrokinetic treatment of PFOA contaminated soil', Environmental Technology & Innovation, vol. 28, pp. 102938-102938.
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Gao, F, Zhang, S, He, X & Sheng, D 2022, 'Experimental Study on Migration Behavior of Sandy Silt under Cyclic Load', Journal of Geotechnical and Geoenvironmental Engineering, vol. 148, no. 5.
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This paper presents experimental investigation into the effects of particle size distribution of subgrade soil on mud pumping. The results show that subgrade soils with higher fine contents do not necessarily lead to more serious mud pumping. A soil with a higher silt content tends to cause the formation of a less permeable interlayer at the bottom of the ballast, which effectively reduces the particle migration magnitude. Increasing the median particle size (d50) or reducing the coefficient of uniformity (d60/d10) of the studied sandy silt promotes the migration distance of particles. While mud pumping is essentially an internal erosion problem caused by cyclic loads, existing filter theories do not directly apply to mud pumping. The findings from this study can help selecting proper rail embankment fills to reduce mud pumping.
Gao, X, Yang, F, Yan, Z, Zhao, J, Li, S, Nghiem, L, Li, G & Luo, W 2022, 'Humification and maturation of kitchen waste during indoor composting by individual households', Science of The Total Environment, vol. 814, pp. 152509-152509.
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This study evaluated the humification and maturation of kitchen waste during indoor composting by individual households. In total, 50 households were randomly selected to participate in this study using kitchen waste of their own for indoor composting using a standard 20 L sealed composter. Garden waste was also collected from their local communities and used as the bulking agent. Both effective microorganisms and lime were inoculated at 1% (wet weight) of raw composting materials to facilitate the composting initiation. Results from this study demonstrate for the first time that ordinary residents could correctly follow the instruction to operate indoor composting at household level to manage urban kitchen waste at source. Overall, 30 households provided valid and complete data to show an increase (to ~50 °C) and then decrease in temperature in response to the decline of biodegradable organic substances during indoor composting. The compost physiochemical characteristics varied significantly toward maturation with an increase in seed germination index to above 50% for most households. Furthermore, organic humification occurred continuously during indoor composting as indicated by the enhanced content of humic substances, degree of polymerization, and spectroscopic characteristics.
Gaur, VK, Gautam, K, Sharma, P, Gupta, P, Dwivedi, S, Srivastava, JK, Varjani, S, Ngo, HH, Kim, S-H, Chang, J-S, Bui, X-T, Taherzadeh, MJ & Parra-Saldívar, R 2022, 'Sustainable strategies for combating hydrocarbon pollution: Special emphasis on mobil oil bioremediation', Science of The Total Environment, vol. 832, pp. 155083-155083.
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The global rise in industrialization and vehicularization has led to the increasing trend in the use of different crude oil types. Among these mobil oil has major application in automobiles and different machines. The combustion of mobil oil renders a non-usable form that ultimately enters the environment thereby causing problems to environmental health. The aliphatic and aromatic hydrocarbon fraction of mobil oil has serious human and environmental health hazards. These components upon interaction with soil affect its fertility and microbial diversity. The recent advancement in the omics approach viz. metagenomics, metatranscriptomics and metaproteomics has led to increased efficiency for the use of microbial based remediation strategy. Additionally, the use of biosurfactants further aids in increasing the bioavailability and thus biodegradation of crude oil constituents. The combination of more than one approach could serve as an effective tool for efficient reduction of oil contamination from diverse ecosystems. To the best of our knowledge only a few publications on mobil oil have been published in the last decade. This systematic review could be extremely useful in designing a micro-bioremediation strategy for aquatic and terrestrial ecosystems contaminated with mobil oil or petroleum hydrocarbons that is both efficient and feasible. The state-of-art information and future research directions have been discussed to address the issue efficiently.
Gaur, VK, Sharma, P, Gupta, S, Varjani, S, Srivastava, JK, Wong, JWC & Ngo, HH 2022, 'Opportunities and challenges in omics approaches for biosurfactant production and feasibility of site remediation: Strategies and advancements', Environmental Technology & Innovation, vol. 25, pp. 102132-102132.
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Biosurfactants are molecules of 21st century. Their application(s) intercedes in daily life of living beings. Major limitation in the wide applicability of biosurfactant(s) is the economicity of production. To overcome this several strategies can be employed. This review is centered on the recent technological advancements in biosurfactant research. The advancement(s) include the use of metabolomic and sequence based omics approaches that has become a high-throughput indispensable tool for the identification of biosurfactant producers. A plethora of microorganisms synthesize biosurfactants, along with other value-added products namely ethanol, microbial lipids, and polyhydroxyalkanoates has been reported. This can significantly improve the economics of the overall process and limitations can further be dealt by employing metabolic engineering approaches. Tailoring strategy enables modification in the composition of congeners produced and improves the yield of biosurfactant. Bio-based surfactants have shown promising results against combating the pollution in terrestrial and aquatic ecosystems either by increasing their bioavailability or aqueous solubility. Owing to the ever-increasing market of biosurfactant(s), this review summarized technologically feasible advancement(s) in biosurfactant research that may enable the researchers to develop more safer and reliable technologies.
Ghasemi, M, Khedri, M, Didandeh, M, Taheri, M, Ghasemy, E, Maleki, R, Shon, HK & Razmjou, A 2022, 'Removal of Pharmaceutical Pollutants from Wastewater Using 2D Covalent Organic Frameworks (COFs): An In Silico Engineering Study', Industrial & Engineering Chemistry Research, vol. 61, no. 25, pp. 8809-8820.
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Goh, BHH, Chong, CT, Ong, HC, Milano, J, Shamsuddin, AH, Lee, XJ & Ng, J-H 2022, 'Strategies for fuel property enhancement for second-generation multi-feedstock biodiesel', Fuel, vol. 315, pp. 123178-123178.
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Fatty acids from non-edible bioresources are highly sought after as biofuel feedstock and the use of multi-stream feedstock for biodiesel production is of interest. This study explores the potential of using blended feedstock consisting of inedible jatropha oil (JO) and waste cooking oil (WO) for biodiesel production. Prior to blending, the unfavourable high acid value of jatropha oil was esterified under the most optimal conditions of 60 °C, 1% H2SO4 catalyst and alcohol to oil molar ratio of 11:1 to maximise the esterified yield (81.1 %). Based on the acid value measurement, the optimum volumetric blend of WO/EJO was determined to be 90/10 with the lowest acid value of 1.9 mg KOH g−1, which was then utilised as feedstock for base-catalysed transesterification. The KOH catalysed transesterification was optimised at 60 °C, 1 wt% KOH catalyst and alcohol to oil molar ratio of 6:1 to produce biodiesel with low acid value (0.2 mg KOH g−1), high calorific value (38.4 MJ kg−1), high oxidation stability (∼11 h) and favourable viscosity (4.7 mm2 s−1). The results show that the produced biodiesel has acceptable physicochemical properties but its properties can further be improved by blending with petroleum diesel and antioxidant. Among those produced blend derivatives, petroleum diesel and biodiesel blend (80:20) or B20 showed the best improvement with high calorific value (46.6 MJ/kg), high oxidation stability (∼37 h) and low acid value (0.3 mg KOH g−1). Based on the study, in situ feedstock blending of WO/EJO can improve the physicochemical properties of the produced biodiesel and reduce the dependency on single feedstock. Biodiesel blending with commercial diesel can enhance the biodiesel fuel properties and such derivatives can be directly applied in an existing engine.
Goh, BHH, Chong, CT, Ong, HC, Seljak, T, Katrašnik, T, Józsa, V, Ng, J-H, Tian, B, Karmarkar, S & Ashokkumar, V 2022, 'Recent advancements in catalytic conversion pathways for synthetic jet fuel produced from bioresources', Energy Conversion and Management, vol. 251, pp. 114974-114974.
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Sustainable Aviation Fuel (SAF) has become an important measure in the aviation industry's efforts to mitigate carbon emissions and reduce their overall environmental impacts. However, commercial usage is relatively stunted due to a plethora of drawbacks in the production process and economic feasibility of the fuel. In this study, the currently accepted technologies for producing synthetic jet fuels under the American Society for Testing Material (ASTM D7566) standard specification for aviation turbine fuel are reviewed. The emphasis is placed in terms of their reactions, type of catalysts used for the conversion pathways of Fisher-Tropsch (FT), Hydroprocessed Esters and Fatty Acids (HEFA) and Alcohol-to-Jet (ATJ), and the use of biomass resources as feedstock. The advancement in the production process and physicochemical properties of the uncertified biojet fuels are reviewed and discussed. Generally, Co- and Fe-based catalysts are commonly used for the FT process, while bimetallic catalysts consisting of Pt, Pd, Ni and Mo have shown excellent activities and selectivities for the HEFA process. For the ATJ process, zeolites such as HZSM-5, beta and SAPO have shown remarkable ethanol dehydration efficiency, while TiO2 and ferrierite have been studied for the combined iso-butanol dehydration and oligomerisation processes. Fundamental factors influencing the reaction efficiency including the feedstock properties, reaction conditions, catalytic reusability and catalyst supports are discussed. Finally, the key challenges and prospects for biojet fuel commercialisation are addressed.
Gong, S, Ball, J & Surawski, N 2022, 'Urban land-use land-cover extraction for catchment modelling using deep learning techniques', Journal of Hydroinformatics, vol. 24, no. 2, pp. 388-405.
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AbstractThroughout the world, the likelihood of floods and managing the associated risk are a concern to many catchment managers and the population residing in those catchments. Catchment modelling is a popular approach to predicting the design flood quantiles of a catchment with complex spatial characteristics and limited monitoring data to obtain the necessary information for preparing the flood risk management plan. As an important indicator of urbanisation, land use land cover (LULC) plays a critical role in catchment parameterisation and modelling the rainfall–runoff process. Digitising LULC from remote sensing imagery of urban catchment is becoming increasingly difficult and time-consuming as the variability and diversity of land uses occur during urban development. In recent years, deep learning neural networks (DNNs) have achieved remarkable image classification and segmentation outcomes with the powerful capacity to process complex workflow and features, learn sophisticated relationships and produce superior results. This paper describes end-to-end data assimilation and processing path using U-net and DeepLabV3+, also proposes a novel approach integrated with the clustering algorithm MeanShift. These methods were developed to generate pixel-based LULC semantic segmentation from high-resolution satellite imagery of the Alexandria Canal catchment, Sydney, Australia, and assess the applicability of their outputs as inputs to different catchment modelling systems. A significant innovation is using the MeanShift clustering algorithm to reduce the spatial noise in the raw image and propagate it to the deep learning network to improve prediction. All three methods achieved excellent classification performance, where the MeanShift+U-net has the highest accuracy and consistency on the test imagery. The final suitability assessment illustrates that all three methods are more suitable for the parameterisation of semi-distr...
Gong, Y, Bai, Y, Zhao, D & Wang, Q 2022, 'Aggregation of carboxyl-modified polystyrene nanoplastics in water with aluminum chloride: Structural characterization and theoretical calculation', Water Research, vol. 208, pp. 117884-117884.
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Nanoplastics (NPs) pollution of aquatic systems is becoming an emerging environmental issue due to their stable structure, high mobility, and easy interactions with ambient contaminants. Effective removal technologies are urgently needed to mitigate their toxic effects. In this study, we systematically investigated the removal effectiveness and mechanisms of a commonly detected nanoplastics, carboxyl-modified polystyrene (PS-COOH) via coagulation and sedimentation processes using aluminum chloride (AlCl3) as a coagulant. PS-COOH appeared as clearly defined and discrete spherical nanoparticles in water with a hydrodynamic diameter of 50 nm. The addition of 10 mg/L AlCl3 compressed and even destroyed the negatively charged PS-COOH surface layer, decreased the energy barrier, and efficiently removed 96.6% of 50 mg/L PS-COOH. The dominant removal mechanisms included electrostatic adsorption and intermolecular interactions. Increasing the pH from 3.5 to 8.5 sharply enhanced the PS-COOH removal, whereas significant loss was observed at pH 10.0. High temperature (23 °C) favored the removal of PS-COOH compared to lower temperature (4 °C). High PS-COOH removal efficiency was observed over the salinity range of 0 - 35‰. The presence of positively charged Al2O3 did not affect the PS-COOH removal, while negatively charged SiO2 reduced the PS-COOH removal from 96.6% to 93.2%. Moreover, the coagulation and sedimentation process efficiently removed 90.2% of 50 mg/L PS-COOH in real surface water even though it was rich in inorganic ions and total organic carbon. The fast and efficient capture of PS-COOH by AlCl3 via a simple coagulation and sedimentation process provides a new insight for the treatment of NPs from aqueous environment.
Gravina da Rocha, C, Korb, S & Sacks, R 2022, 'Work structuring and product design for customized repetitive projects', Construction Management and Economics, vol. 40, no. 7-8, pp. 526-547.
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Grzybowska, H, Wijayaratna, K, Shafiei, S, Amini, N & Travis Waller, S 2022, 'Ramp Metering Strategy Implementation: A Case Study Review', Journal of Transportation Engineering, Part A: Systems, vol. 148, no. 5.
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Guan, R, Zheng, H, Liu, Q, Ou, K, Li, D-S, Fan, J, Fu, Q & Sun, Y 2022, 'DIW 3D printing of hybrid magnetorheological materials for application in soft robotic grippers', Composites Science and Technology, vol. 223, pp. 109409-109409.
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A new hybrid magnetorheological material is prepared by DIW 3D printing technology, which is composed of magnetorheological fluid and magnetorheological elastomer. It does not only exhibit high magnetorheological effect of magnetorheological fluid, but also shows high mechanical stability of magnetorheological elastomer. The maxima absolute and relative magnetorheological effect of hybrid magnetorheological material are about 11.1 MPa and 7474%, which are simultaneously improved to be 2.9 times and 7.8 times comparing to single magnetorheological elastomer. Furthermore, the hybrid magnetorheological material is evaluated for application in soft robotic grippers. It shows larger clamping force (7.0 × 10−3 N) and faster response rate (ca.2.0s) comparing to other actuators. The work provides a new method to prepare hybrid magnetorheological material with high performance for various applications.
Gudigar, A, U., R, Samanth, J, Vasudeva, A, A. J., AA, Nayak, K, Tan, R-S, Ciaccio, EJ, Ooi, CP, Barua, PD, Molinari, F & Acharya, UR 2022, 'Role of Four-Chamber Heart Ultrasound Images in Automatic Assessment of Fetal Heart: A Systematic Understanding', Informatics, vol. 9, no. 2, pp. 34-34.
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The fetal echocardiogram is useful for monitoring and diagnosing cardiovascular diseases in the fetus in utero. Importantly, it can be used for assessing prenatal congenital heart disease, for which timely intervention can improve the unborn child’s outcomes. In this regard, artificial intelligence (AI) can be used for the automatic analysis of fetal heart ultrasound images. This study reviews nondeep and deep learning approaches for assessing the fetal heart using standard four-chamber ultrasound images. The state-of-the-art techniques in the field are described and discussed. The compendium demonstrates the capability of automatic assessment of the fetal heart using AI technology. This work can serve as a resource for research in the field.
Gul, M, Kalam, MA, Mohd Zulkifli, NW, Hj. Hassan, M, Abbas, MM, Yousuf, S, Al-Dahiree, OS, Gaffar Abbas, MK, Ahmed, W & Imran, S 2022, 'Enhancing AW/EP tribological characteristics of biolubricant synthesized from chemically modified cotton methyl-esters by using nanoparticle as additives', Industrial Lubrication and Tribology, vol. 74, no. 4, pp. 411-420.
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PurposeThe purpose of this study is to improve the tribological characteristics of cotton-biolubricant by adding nanoparticles at extreme pressure (EP) conditions in comparison with commercial lubricant SAE-40.Design/methodology/approachThis research involved the synthesis of cotton-biolubricant by transesterification process and then the addition of nanoparticles in it to improve anti wear (AW)/EP tribological behavior. SAE-40 was studied as a reference commercial lubricant. AW/EP characteristics of all samples were estimated by the four-ball tribo-tester according to the American Society for Testing and Materials D2783 standard.FindingsThe addition of 1-Wt.% TiO2 and Al2O3 with oleic acid surfactant in cotton-biolubricant decreased wear scar diameter effectively and enhanced the lubricity, load-wear-index, weld-load and flash-temperature-parameters. This investigation revealed that cotton-biolubricant with TiO2 nano-particle additive is more effective and will help in developing new efficient biolubricant to replace petroleum-based lubricants.Research limitations/implicationsCotton biolubricant with TiO2 nano-particles appeared as an optimistic solution for the global bio-lubricant market.Originality/valueNo one has not studied the cotton biolubricant with nanoparticles for internal combustion engine applications at high temperature and EP conditions.
Gullino, ML, Albajes, R, Al-Jboory, I, Angelotti, F, Chakraborty, S, Garrett, KA, Hurley, BP, Juroszek, P, Lopian, R, Makkouk, K, Pan, X, Pugliese, M & Stephenson, T 2022, 'Climate Change and Pathways Used by Pests as Challenges to Plant Health in Agriculture and Forestry', Sustainability, vol. 14, no. 19, pp. 12421-12421.
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Climate change already challenges people’s livelihood globally and it also affects plant health. Rising temperatures facilitate the introduction and establishment of unwanted organisms, including arthropods, pathogens, and weeds (hereafter collectively called pests). For example, a single, unusually warm winter under temperate climatic conditions may be sufficient to assist the establishment of invasive plant pests, which otherwise would not be able to establish. In addition, the increased market globalization and related transport of recent years, coupled with increased temperatures, has led to favorable conditions for pest movement, invasion, and establishment worldwide. Most published studies indicate that, in general, pest risk will increase in agricultural ecosystems under climate-change scenarios, especially in today’s cooler arctic, boreal, temperate, and subtropical regions. This is also mostly true for forestry. Some pests have already expanded their host range or distribution, at least in part due to changes in climate. Examples of these pests, selected according to their relevance in different geographical areas, are summarized here. The main pathways used by them, directly and/or indirectly, are also discussed. Understanding these pathways can support decisions about mitigation and adaptation measures. The review concludes that preventive mitigation and adaptation measures, including biosecurity, are key to reducing the projected increases in pest risk in agriculture, horticulture, and forestry. Therefore, the sustainable management of pests is urgently needed. It requires holistic solutions, including effective phytosanitary regulations, globally coordinated diagnostic and surveillance systems, pest risk modeling and analysis, and preparedness for pro-active management.
Guo, H, Dai, R, Xie, M, Peng, LE, Yao, Z, Yang, Z, Nghiem, LD, Snyder, SA, Wang, Z & Tang, CY 2022, 'Tweak in Puzzle: Tailoring Membrane Chemistry and Structure toward Targeted Removal of Organic Micropollutants for Water Reuse', Environmental Science & Technology Letters, vol. 9, no. 4, pp. 247-257.
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Membrane-based water reuse through reverse osmosis (RO) and nanofiltration (NF) faces a critical challenge from organic micropollutants (OMPs). Conventional polyamide RO and NF membranes often lack adequate selectivity to achieve sufficient removal of toxic and harmful OMPs in water. Tailoring membrane chemistry and structure to allow highly selective removal of OMPs has risen as an important topic in membrane-based water reuse. However, a critical literature gap remains to be addressed: how to design membranes for more selective removal of OMPs. In this review, we critically analyzed the roles of membrane chemistry and structure on the removal of OMPs and highlighted opportunities and strategies toward more selective removal of OMPs in the context of water reuse. Specifically, we statistically analyzed rejection of OMPs by conventional polyamide membranes to illustrate their drawbacks on OMPs removal, followed by a discussion on the underlying fundamental mechanisms. Corresponding strategies to tailor membrane properties for improving membrane selectivity against OMPs, including surface modification, nanoarchitecture construction, and deployment of alternative membrane materials, were systematically assessed in terms of water permeance, OMPs rejection, and water-OMPs selectivity. In the end, we discussed the potential and challenges of various strategies for scale-up in real applications.
Guo, Y, Li, W, Dong, W, Luo, Z, Qu, F, Yang, F & Wang, K 2022, 'Self-sensing performance of cement-based sensor with carbon black and polypropylene fibre subjected to different loading conditions', Journal of Building Engineering, vol. 59, pp. 105003-105003.
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Different dosages of carbon black (CB) were used to manufacture the cost-effective and highly sensitive polypropylene (PP) fibre cement-based sensors in this paper. The distribution of conductive phases and static electrical resistivity were firstly investigated through microscopic characterization and static resistivity, respectively. Then the self-sensing performance of the CB/PP fibre cementitious composites in response to different loading conditions was comprehensively assessed by cyclic compression, notched bending, and splitting tensile conditions. The results indicate that the improvement of PP fibres on conductivity and self-sensing performance is heavily dependent on the coating efficiency of CB nanoparticles on the surfaces of PP fibres. In particular, the cement-based sensors with excellent CB coating efficiency demonstrate the most promising pre-crack flexural sensing capacity. Additionally, the strain hardening characteristics and damage sensing ability for the intrinsic cement-based sensors were explored by splitting tension together with digital image correlation tracking. Apart from a strong linear correlation between fractional change of resistivity and tensile strain during the strain hardening stage, the distinct sensing characteristics between the strain hardening stage and softening stage can give the diagnosis of damage stage (strain hardening stage or softening stage) and crack width (microcracking or macrocracking). Therefore, the intrinsic CB/PP fibre cementitious composites as robust cement-based sensors can provide a great potential to sense strain and deformation as well as detect crack and damage for concrete infrastructure subjected to various loading conditions.
Guo, Y, Li, W, Dong, W, Wang, K, He, X, Vessalas, K & Sheng, D 2022, 'Self-sensing cement-based sensors with superhydrophobic and self-cleaning capacities after silane-based surficial treatments', Case Studies in Construction Materials, vol. 17, pp. e01311-e01311.
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A novel cement-based sensors was developed with integrated self-sensing superhydrophobicity, and self-cleaning functions in this paper. The synthesis was carried out by penetrating precast graphene nanoplate/cement-based sensors with silane/isopropanol solutions. The silane-treated cement-based sensors showed satisfactory stress/strain sensing performance with an average gauge factor of 141.8, and exhibited excellent hydrophobic behaviour with the highest water contact angle of 163° on the intact surface. The contact angle decreased to 148° and 142°, for the surface with scratches and for the inner part of sensors, respectively. The reduction was due to the spalling and less amount of silane particles within the scratches and the harder entry of silane to the inner part of sensor. The self-cleaning properties of silane-treated cement-based sensor were evaluated by the visual observation of removing efficiency of hydrophilic carbon black dust and lipophilic sauces after water rinsing. It was found that the silane-treated cement-based sensor showed excellent self-cleaning performance using hydrophilic carbon dust. Despite the removing efficiency decreased for the lipophilic sauces, the silane-treated cement-based sensors maintained much less stain than that of untreated ones on the surface. The related results will promote the synthesis and practical applications of multifunctional cement-based sensors for the application of intrisic structural health monitoring.
Guo, Y, Xian, H, Shereen, T, Qiang, F, Jin, X, Daniel, M, Qiao, GG & Zhang, H 2022, 'Feasibility of corneal epithelial transplantation with polyethylene glycol hydrogel membrane as a carrier for limbal stem cell deficiency', Chinese Journal of Experimental Ophthalmology, vol. 40, no. 12, pp. 1125-1133.
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Objective To investigate whether polyethylene glycol hydrogel films (PHFs) can be used as a carrier for the expansion of corneal epithelial cells (CECs) in vitro and whether PHFs can be used in the treatment of limbal stem cell deficiency (LSCD). Methods Sebacoyl chloride, dihydroxyl PCL and glycerol ethoxylate were used to synthesize PHFs. The thickness, transmittance and mechanical tensile properties of PHFs were measured. Four clean-grade New Zealand white rabbits were selected to culture primary limbal epithelial cells. The expression of keratin marker AE1/AE3 and stem cell marker p63 in the cultured cells were observed under a fluorescence microscope. The cells were divided into negative control group cultured with common cell culture solution, positive control group cultured with cell culture solution containing 100 μmol/L H2O2, and PHFs + CECs group lined with PHFs cultured with common cell culture solution for 24 hours. The proliferation and apoptosis of cells in the three groups were observed by MTT and TUNEL staining, respectively. Fifteen clean-grade New Zealand white rabbits were divided into control group, PHFs group and PHFs+CECs group by random number table method, with 5 rabbits in each group. LSCD model was constructed in the three groups. The control group was not given any treatment after modeling. In PHFs group, empty PHFs were placed on the corneal surface of rabbits. In PHFs + CECs group, tissue-engineered grafts constructed with CECs after passage implanted on PHFs were placed on the corneal surface of rabbits. The corneal defect area of rabbits was detected and scored by fluorescein sodium staining. The histological characteristics of rabbits corneal epithelium was observed by hematoxylin-eosin staining. The use and care of animals complied with Guide for the Care and Use of Laboratory Animals by the U. S. National Research Council. The experimental protocol was approved by the Research and Clinical Trial Ethics Committee of The ...
Haider, JB, Haque, MI, Hoque, M, Hossen, MM, Mottakin, M, Khaleque, MA, Johir, MAH, Zhou, JL, Ahmed, MB & Zargar, M 2022, 'Efficient extraction of silica from openly burned rice husk ash as adsorbent for dye removal', Journal of Cleaner Production, vol. 380, pp. 135121-135121.
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Rice is the staple food in many countries including Bangladesh. In Bangladesh, >80% of the total irrigated area is planted with rice, which generates a huge amount of rice husk (RH) as a solid waste which requires proper management. This study, therefore, aimed to extract amorphous silica from openly burned rice husk ash (RHA) using a simple method by avoiding calcination or combustion processes. The extracted silica was then applied for the removal of environmental contaminants i.e., methylene blue dye from an aqueous solution. It was found that the yield of silica produced from sulfuric acid-pretreated RHA was 72.4%. The FTIR absorption peaks at 1057 and 783 cm−1 indicate the presence of a highly condensed silica-containing asymmetric and symmetric siloxane (Si–O–Si) network mixture. The broad maximum bond peak intensity at 2θ = 22° by x-ray diffraction analysis also indicates that the produced silica was amorphous with a mesoporous structure. The surface area of sulfuric acid treated RHA-based silica was 183 m2/g. This silica resulted in a maximum adsorption capacity of 107 mg/g of methylene blue at pH 8 with a faster equilibrium reached at 60 min. The mechanistic study indicated that both Langmuir and Freundlich adsorption isotherms were both fitted well which suggested homogeneous adsorbent surfaces involving monolayer and multilayer adsorption processes.
Hallad, SA, Ganachari, SV, Soudagar, MEM, Banapurmath, NR, Hunashyal, AM, Fattah, IMR, Hussain, F, Mujtaba, MA, Afzal, A, Kabir, MS & Elfasakhany, A 2022, 'Investigation of flexural properties of epoxy composite by utilizing graphene nanofillers and natural hemp fibre reinforcement', Polymers and Polymer Composites, vol. 30, pp. 096739112210936-096739112210936.
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This study aims to determine the optimum reinforcement required to attain the best combination of flexural strength of modified green composites (graphene oxide + hemp fibre reinforced epoxy composites) for potential use in structural applications. An attempt was also made for the combination of graphene and hemp fibres to enhance load-bearing ability. The infusion of hemp and graphene was made by the weight of the base matrix (epoxy composite). Results showed that graphene reinforcement at 0.4 wt.% of matrix showed load-sustaining capacity of 0.76 kN or 760 MPa. In the case of hemp fibre reinforcement at 0.2 wt.% of the matrix, infusion showed enhanced load-bearing ability (0.79 kN or 790 MPa). However, the combination of graphene (0.1 wt.% graphene nanofillers) and hemp (5 wt.% hemp fibre) indicated a load-sustaining ability of 0.425 kN or 425 MPa, whereas maximum deflection was observed for specimen with hemp 7.5 % + graphene 0.2 % with 1.9 mm. Graphene addition to the modified composites in combination with natural fibres showed promising results in enhancing the mechanical properties under study. Moreover, graphene-modified composites exhibited higher thermal resistance compared to natural fibre reinforced composites. However, when nanofiller reinforcement exceeded a threshold value, the composites exhibited reduced flexural strength as a result of nanofiller agglomeration.
Hamdani, H, Sabri, FS, Harapan, H, Syukri, M, Razali, R, Kurniawan, R, Irwansyah, I, Sofyan, SE, Mahlia, TMI & Rizal, S 2022, 'HVAC Control Systems for a Negative Air Pressure Isolation Room and Its Performance', Sustainability, vol. 14, no. 18, pp. 11537-11537.
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The controlled environment room, called an isolation room, has become a must have for medical facilities, due to the spreading of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), to isolate the high risk infected patients. To avoid the transmission of the virus through airborne routes, guidelines were published by the government and the association. A medical facility must comply with this document for high-risk patient treatment. A full-scale N class isolation room was built at Syiah Kuala University to investigate the performance in terms of the controller, temperature, pressure, humidity, and energy consumption. The isolation room was equipped with a proper capacity heating, ventilating, and air conditioning (HVAC) system, which consisted of an air conditioning compressor and a negative pressure generator (NPG), and its installation was ensured to fulfil the guidelines. Since the current NPG was controlled manually, a computer-based control system was designed, implemented, and compared with the manual control. The results showed that the computer-based control outputs better stability of pressure and electric power. For that reason, a computer-based control was chosen in the real case. To investigate the performance of the isolation room, a 24 h experiment was carried out under different parameter setups. The results showed that improvement of the control strategy for temperature and humidity is still necessary. The energy consumption during the activation of the NPG for the recommended negative pressure was slightly different. An additional piece of equipment to absorb the heat from the exhaust air would be promising to improve the energy efficiency.
Hamidi, BA, Hosseini, SA & Hayati, H 2022, 'Forced torsional vibration of nanobeam via nonlocal strain gradient theory and surface energy effects under moving harmonic torque', Waves in Random and Complex Media, vol. 32, no. 1, pp. 318-333.
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Han, C, Han, R, Zhang, X, Xu, Z, Li, W, Yamauchi, Y & Huang, Z 2022, '2D boron nanosheet architectonics: opening new territories by smart functionalization', Journal of Materials Chemistry A, vol. 10, no. 6, pp. 2736-2750.
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The lack of stability hinders the applications of pristine borophene. Functionalization imparts both stability and tunable properties allowing for wide application. This review focuses on the applications of functionalized 2D boron nanosheets.
Han, C, Li, W, Wang, J & Huang, Z 2022, 'Boron leaching: Creating vacancy-rich Ni for enhanced hydrogen evolution', Nano Research, vol. 15, no. 3, pp. 1868-1873.
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Creating vacancy is often highly effective in enhancing the hydrogen evolution performance of transition metal-based catalysts. Vacancy-rich Ni nanosheets have been fabricated via topochemical formation of two-dimentional (2D) Ni2B on graphene precursor followed by boron leaching. Anchored on graphene, a few atomic layered Ni2B nanosheets are first obtained by reduction and annealing. Large number of atomic vacancies are then generated in the Ni2B layer via leaching boron atoms. When used for hydrogen evolution reaction (HER), the vacancy-rich Ni/Ni(OH)2 heterostructure nanosheets demonstrate remarkable performance with a low overpotential of 159 mV at a current density of 10 mA·cm−2 in alkaline solution, a dramatic improvement over 262 mV of its precursor. This enhancement is associated with the formation of vacancies which introduce more active sites for HER along Ni/Ni(OH)2 heterointerfaces. This work offers a facile and universal route to introduce vacancies and improve catalytic activity. [Figure not available: see fulltext.]
Han, Z, Huo, J, Zhang, X, Ngo, HH, Guo, W, Du, Q, Zhang, Y, Li, C & Zhang, D 2022, 'Characterization and flocculation performance of a newly green flocculant derived from natural bagasse cellulose', Chemosphere, vol. 301, pp. 134615-134615.
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A newly green natural polymer bagasse cellulose based flocculant (PBCF) was synthesized utilizing a grafting copolymerization method for effectively enhancing humic acid (HA) removal from natural water. This work aims to investigate flocculation behavior of PBCF in synthetic water containing HA, and the effects of flocculant dose and initial solution pH on flocculation performance. Results showed that PBCF functioned well at a flocculant dose of 60 mg/L and pH ranging from 6.0 to 9.0. The organic removal efficiency in synthetic water in terms of HA (UV254) and chemical oxygen demand (COD Mn) were up to 90.6% and 91.3%, respectively. Furthermore, the charge neutralization and adsorption bridging played important roles in HA removal. When applied for lake water, PBCF removed 91.6% turbidity and 50.0% dissolved organic matter, respectively. In short, PBCF demonstrates great potential in water treatment in a safe and environmentally friendly or 'green' way.
Hannan, MA, Abd Rahman, MS, Al-Shetwi, AQ, Begum, RA, Ker, PJ, Mansor, M, Mia, MS, Hossain, MJ, Dong, ZY & Mahlia, TMI 2022, 'Impact Assessment of COVID-19 Severity on Environment, Economy and Society towards Affecting Sustainable Development Goals', Sustainability, vol. 14, no. 23, pp. 15576-15576.
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The COVID-19 pandemic has affected every sector in the world, ranging from the education sector to the health sector, administration sector, economic sector and others in different ways. Multiple kinds of research have been performed by research centres, education institutions and research groups to determine the extent of how huge of a threat the COVID-19 pandemic poses to each sector. However, detailed analysis and assessment of its impact on every single target within the 17 Sustainable Development Goals (SDGs) have not been discussed so far. We report an assessment of the impact of COVID-19 effect towards achieving the United Nations SDGs. In assessing the pandemic effects, an expert elicitation model is used to show how the COVID-19 severity affects the positive and negative impact on the 169 targets of 17 SDGs under environment, society and economy groups. We found that the COVID-19 pandemic has a low positive impact in achieving only 34 (20.12%) targets across the available SDGs and a high negative impact of 54 targets (31.95%) in which the most affected group is the economy and society. The environmental group is affected less; rather it helps to achieve a few targets within this group. Our elicitation model indicates that the assessment process effectively measures the mapping of the COVID-19 pandemic impact on achieving the SDGs. This assessment identifies that the COVID-19 pandemic acts mostly as a threat in enabling the targets of the SDGs.
Hao, D, Ma, T, Jia, B, Wei, Y, Bai, X, Wei, W & Ni, B-J 2022, 'Small molecule π-conjugated electron acceptor for highly enhanced photocatalytic nitrogen reduction of BiOBr', Journal of Materials Science & Technology, vol. 109, pp. 276-281.
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Artificial ammonia synthesis using solar energy is of great significance as it can help narrow the gap to the zero-net emission target. However, the current photocatalytic activity is generally too low for mass production. Herein, we report a novel bismuth bromide oxide (BiOBr)-Tetracyanoquinodimethane (TCNQ) photocatalyst prepared via a facile self-assembly method. Due to the well-match band structure of TCNQ and BiOBr, the separation and transfer of photogenerated electron-hole pairs were significantly boosted. More importantly, the abundant delocalized π electrons of TCNQ, and the electron-withdrawing property of TNCQ made electrons efficiently accumulated on the catalysts, which can strengthen the adsorption and cleavage of nitrogen molecules. As a result, the photocatalytic activity increased significantly. The highest ammonia yield of the optimized sample reached 2.617 mg/(h gcat), which was 5.6-fold as that of pristine BiOBr and higher than the reported BiOBr-based photocatalysts. The isotope labeled 15N2 was used to confirm that the ammonia is formed form the fixation of N2. Meanwhile, the sample also had good stability. After 4-time usage, the photocatalysts still had about 81.8% as the fresh sample. The results of this work provide a new way for optimizing the electronic structure of photocatalysts to achieve highly efficient photochemical N2 reduction.
Hao, D, Wei, Y, Mao, L, Bai, X, Liu, Y, Xu, B, Wei, W & Ni, B-J 2022, 'Boosted selective catalytic nitrate reduction to ammonia on carbon/bismuth/bismuth oxide photocatalysts', Journal of Cleaner Production, vol. 331, pp. 129975-129975.
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Using solar energy to catalytically convert nitrate into ammonia is attractive for waste recycling and sustainable development. However, the rapid recombination of electron-hole pairs and the poor selectivity are obstructing photocatalytic nitrate reduction to ammonia to be mass applied currently. In this work, we reported a facile synthesis of carbon/bismuth/bismuth oxide photocatalyst via a one-pot hydrothermal reaction without using reducing reagent. Compared with α-bismuth oxide (α-Bi2O3), the photocatalytic ammonia yield of the optimum sample increased 3.65 times. In addition, the ammonia selectivity increased from 65.21% to 95.00%. The highly enhanced photocatalytic performance was attributed to the surface plasmon resonance of metallic bismuth. Meanwhile, the formation of carbon enables to boost the transfer of electrons significantly. Under light irradiation, electrons can be accumulated on metallic bismuth, effectively boosting the reduction of nitrate. The findings of this work will contribute to the recycling of nitrate for ammonia synthesis and sustainable environmental development.
Hao, J, Zhu, X, Yu, Y, Zhang, C & Li, J 2022, 'Damage localization and quantification of a truss bridge using PCA and convolutional neural network', Smart Structures and Systems, vol. 30, no. 6, pp. 673-686.
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Deep learning algorithms for Structural Health Monitoring (SHM) have been extracting the interest of researchers and engineers. These algorithms commonly used loss functions and evaluation indices like the mean square error (MSE) which were not originally designed for SHM problems. An updated loss function which was specifically constructed for deep-learning-based structural damage detection problems has been proposed in this study. By tuning the coefficients of the loss function, the weights for damage localization and quantification can be adapted to the real situation and the deep learning network can avoid unnecessary iterations on damage localization and focus on the damage severity identification. To prove efficiency of the proposed method, structural damage detection using convolutional neural networks (CNNs) was conducted on a truss bridge model. Results showed that the validation curve with the updated loss function converged faster than the traditional MSE. Data augmentation was conducted to improve the anti-noise ability of the proposed method. For reducing the training time, the normalized modal strain energy change (NMSEC) was extracted, and the principal component analysis (PCA) was adopted for dimension reduction. The results showed that the training time was reduced by 90% and the damage identification accuracy could also have a slight increase. Furthermore, the effect of different modes and elements on the training dataset was also analyzed. The proposed method could greatly improve the performance for structural damage detection on both the training time and detection accuracy.
Hao, Y, Xiao, D, Hao, H, Li, J & Li, J 2022, 'Experimental study of reinforced concrete beams reinforced with hybrid spiral-hooked end steel fibres under static and impact loads', Advances in Structural Engineering, vol. 25, no. 15, pp. 3019-3030.
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Discrete short steel fibres were proposed to be mixed with concrete for arresting cracks and enhancing the post-cracking resistance. It has been proven in previous tests that spiral steel fibres possessed markedly higher bonding to concrete matrix, leading to significantly improved performance of steel fibre reinforced concrete (SFRC) in terms of crack controllability, impact resistance, deformability and energy absorption capability. However, at the initial stage of cracking, SFRC reinforced with spiral fibres has relatively lower resistance to crack opening as compared to that reinforced with other types of steel fibres because of spiral shape stretching. To overcome this shortcoming, in the present study, short hooked-end steel fibres that exhibit high pull-out resistance at the crack initiation stage were mixed with spiral steel fibres in the normal-strength concrete matrix. A total volume fraction of 1% of hybrid steel fibres was mixed to cast SFRC specimens. With various mix ratios between spiral and hooked-end fibres considered, five batches of SFRC specimens were tested. Uniaxial compressive tests and four-point bending tests were carried out to compare the mechanical properties of SFRC materials with hybrid fibres while three-point bending tests on SFRC structural beams under static, drop-weight impact and post-impact static loading tests were conducted to investigate the structural performances. An equal dosage of hooked-end and spiral fibres was found to outperform other blend proportions to provide synergetic reinforcement to concrete matrix in terms of post-cracking resistance, energy absorption capacity and post-impact performance.
Hao, Y, Zhang, X, Du, Q, Wang, H, Ngo, HH, Guo, W, Zhang, Y, Long, T & Qi, L 2022, 'A new integrated single-chamber air-cathode microbial fuel cell - Anaerobic membrane bioreactor system for improving methane production and membrane fouling mitigation', Journal of Membrane Science, vol. 655, pp. 120591-120591.
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Haribabu, K, Sivasubramanian, V, Deepanraj, B & Ong, HC 2022, 'Thematic issue: Bioenergy and biorefinery approaches for environmental sustainability', Biomass Conversion and Biorefinery, vol. 12, no. 5, pp. 1433-1433.
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Hasan, H 2022, 'NUMERICAL SIMULATION OF PERVIOUS CONCRETE PILE IN LOOSE AND SILTY SAND AFTER TREATING WITH MICROBIALLY INDUCED CALCITE PRECIPITATION', International Journal of GEOMATE, vol. 22, no. 90, pp. 32-39.
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It is essential to provide a stable foundation system for construction projects to reduce the geotechnical risk of failure due to static or dynamic loads. Pile foundations are recommended to increase bearing capacity and decrease the dynamic oscillations of soils. Recently, soil stabilization using microbially induced calcite precipitation (MICP) was widely used to increase shear strength parameters and reduce the hydraulic conductivity of sand. In this study, the technique of using MICP was reviewed based on previous studies and analyzed using Plaxis 3D to evaluate the enhancement of a single pervious concrete pile under static, free vibration and earthquake stages of loose and silty sand. In the static stage, under the applying load to reach prescribed displacement of 76 mm, the results of loose sand demonstrate that the static load capacity was increased from 470 kN of untreated loose sand to 582, 598 and 612 kN after treating by MICP along the shaft and tip of a concrete pile with 0.5,0.75 and 1 m, respectively. In the earthquake stage, the result of treated loose sand such as vertical and lateral displacement was insignificant compared with untreated loose sand. The Plaxis 3D models have clarified the benefit of using MICP with the pile foundation model.
Hassanpour, M, Cai, G, Cooper, T, Wang, Q, O'Hara, IM & Zhang, Z 2022, 'Triple action of FeCl3-assisted hydrothermal treatment of digested sludge for deep dewatering', Science of The Total Environment, vol. 848, pp. 157727-157727.
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In this study, a FeCl3-assisted hydrothermal treatment (HTT) process under mild conditions (90 °C-130 °C) was developed for deep dewatering of anaerobically digested sludge. HTT of sludge at 90 °C-130 °C with 4%-6% Fe3+ ions loading based on total sludge solids followed by mechanical dewatering reduced sludge water content from 82% to 38%-53% and sludge weight by 62%-72%. The treatment increased the flowability of sludge through reduction of apparent viscosity and disintegration of colloidal forces between sludge particles. This study unveiled that FeCl3-assisted HTT process had three mechanisms for improving sludge dewaterability and flowability. The treatment hydrolysed sludge flocs in the presence of Lewis acid FeCl3 and high temperature (90-130 °C). Fe3+ ions also improved dewaterability through the formation of double electric layers and neutralisation of surface negative charges, leading to flocculation of sludge flocs. More importantly, the hydrolysed sludge components produced during HTT process acted as reducing agents and led to in-situ generation of iron oxyhydroxide nanoparticles through reduction-oxidation reactions, further enhancing flocculation/co-precipitation of sludge flocs. The treatment reduced EPS content and changed conformational structures of EPS proteins by breaking down hydrogen bond-maintaining α-helix which led to a loose EPS protein structure and enhanced hydrophobicity and flocculability. Furthermore, the FeCl3-assisted treatment promoted immobilisation of the majority of heavy metals in the sludge matrix through co-precipitation/complexation reactions with iron species and organic/inorganic matters. This indicates that the FeCl3-assisted treatment reduced direct toxicity/bioavailability of the majority of heavy metals and the treated sludge may be suitable for land application. Overall, this study provides new insights into mechanism of FeCl3-assisted HTT process for dewaterability of anaerobically digested sludge and imm...
Hazrat, MA, Rasul, MG, Khan, MMK, Ashwath, N, Fattah, IMR, Ong, HC & Mahlia, TMI 2022, 'Correction: Biodiesel production from transesterification of Australian Brassica napus L. oil: optimisation and reaction kinetic model development', Environment, Development and Sustainability, vol. 26, no. 1, pp. 2739-2741.
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Unfortunately, the original article contains error in Sect. 3.3. Fuel Composition. The correct data have been provided below in this correction article. 3.3. Fuel composition The fatty acid composition of the produced biodiesel through the optimisation process is shown in Table 8. From the table, it can be seen that Australian canola oil is mostly composed of methyl oleate, with 42.47 wt% included in the composition. This is followed by 27.85 wt% and 16.65 wt% methyl linoleate and methyl linoleate, respectively. A similar FAC was observed by Issariyakul and Dalai (2010) with slight difference in methyl oleate and methyl linolenate percentages. The main component of their canola oil biodiesel is methyl oleate which contains 60.92 wt% of this component. Based on the composition, canola biodiesel contains a total of 12.89 wt% saturated FAME component, 42.61 wt% monounsaturated FAME and 44.5 wt% polyunsaturated FAME. Table 9 compares the properties of produced canola biodiesel and diesel. According to the table, canola oil biodiesel has a 21.5% higher cetane number but a 6% lower LHV than diesel fuel.
Hazrat, MA, Rasul, MG, Khan, MMK, Ashwath, N, Silitonga, AS, Fattah, IMR & Mahlia, TMI 2022, 'Kinetic Modelling of Esterification and Transesterification Processes for Biodiesel Production Utilising Waste-Based Resource', Catalysts, vol. 12, no. 11, pp. 1472-1472.
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Process optimisation and reaction kinetic model development were carried out for two-stage esterification-transesterification reactions of waste cooking oil (WCO) biodiesel. This study focused on these traditional processes due to their techno-economic feasibility, which is an important factor before deciding on a type of feedstock for industrialisation. Four-factor and two-level face-centred central composite design (CCD) models were used to optimise the process. The kinetic parameters for the esterification and transesterification processes were determined by considering both pseudo-homogeneous irreversible and pseudo-homogeneous first-order irreversible processes. For the esterification process, the optimal conditions were found to be an 8.12:1 methanol to oil molar ratio, 1.9 wt.% of WCO for H2SO4, and 60 °C reaction temperature for a period of 90 min. The optimal process conditions for the transesterification process were a 6.1:1 methanol to esterified oil molar ratio, 1.2 wt.% of esterified oil of KOH, reaction temperature of 60 °C, and a reaction time of 110 min in a batch reactor system; the optimal yield was 99.77%. The overall process conversion efficiency was found to be 97.44%. Further research into reaction kinetics will aid in determining the precise reaction process kinetic analysis in future.
He, HS, Teng, JD, Zhang, S & Sheng, DC 2022, 'Rationality of frost susceptibility of soils', Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering, vol. 44, no. 2, pp. 224-234.
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The frost heave and thaw weakening are the critical issues for the infrastructures in cold regions. How to reasonably assess the frost susceptibility of soils has been a hotspot in cold-region geotechnics. The frost susceptibility has been studied for about one hundred years since Casagrande (1931) proposed fine content as a main index to evaluate the frost susceptibility of soils. In most cases, the frost characteristics defined by fines content are clear and very simple, and work well in guiding the engineering construction in cold regions. However, the recent studies show that: (1) The frost heave occurs frequently in the subgrade which is designed and constructed absolutely according to the existing frost susceptibility criteria. (2) The current frost susceptibility criteria vary greatly in different countries and regions with different accuracies. (3) The vapour flow can lead to considerable frost heave in coarse-grained soils, which is not considered in the existing frost susceptibility. The above issues challenge the existing frost susceptibility. It is worth to analyze whether the concept of frost susceptibility is reasonable or not as well as its evaluation system. This study tries to analyze the advantages and disadvantages of the existing frost susceptibility criteria. The main findings are: (1) The reliability of the existing frost susceptibility is generally low, within the range of 50% to 80%. (2) The existing frost susceptibility criteria are not suitable to the case that the frost heave in coarse-grained soils is caused by vapour transfer. The freezing environmental factors should be considered in defining the frost susceptibility. (3) The existing frost susceptibility may be suitable to indicate the thaw weakening property of soils. The outcome of this study is helpful to replenishing the classification of frost susceptibility criteria. It would be of great significance to frost disaster prevention in cold regions.
He, X, Wang, F, Li, W & Sheng, D 2022, 'Deep learning for efficient stochastic analysis with spatial variability', Acta Geotechnica, vol. 17, no. 4, pp. 1031-1051.
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Using machine-learning models as surrogate models is a popular technique to increase the computational efficiency of stochastic analysis. In this technique, a smaller number of numerical simulations are conducted for a case, and obtained results are used to train machine-learning surrogate models specific for this case. This study presents a new framework using deep learning, where models are trained with a big dataset covering any soil properties, spatial variabilities, or load conditions encountered in practice. These models are very accurate for new data without re-training. So, the small number of numerical simulations and training process are not needed anymore, which further increases efficiency. The prediction of bearing capacity of shallow strip footings is taken as an example. We start with a simple scenario, and progressively consider more complex scenarios until the full problem is considered. More than 12,000 data are used in training. It is shown that one-hidden-layer fully connected networks can give reasonable results for simple problems, but they are ineffective for complex problems, where deep neural networks show a competitive edge, and a deep-learning model achieves a very high accuracy (the root-mean-square relative error is 3.1% for unseen data). In testing examples, this model is proven very accurate if the parameters of specific cases are well in the defined limits. Otherwise, the capability of deep-learning models can be extended by simply generating more data outside the current limits and re-training the models.
He, Y, Liu, Y, Yan, M, Zhao, T, Liu, Y, Zhu, T & Ni, B-J 2022, 'Insights into N2O turnovers under polyethylene terephthalate microplastics stress in mainstream biological nitrogen removal process', Water Research, vol. 224, pp. 119037-119037.
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The ubiquitous microplastics in wastewater have raised growing concerns due to their unintended effects on microbial activities. However, whether and how microplastics affect nitrous oxide (N2O) (a potent greenhouse gas) turnovers in mainstream biological nitrogen removal (BNR) process remain unclear. This work therefore aimed to fill such knowledge gap by conducting both long-term and batch tests. After over 100 days of feeding with wastewater containing polyethylene terephthalate (PET) microplastics (0-500 μg/L), the long-term results showed that both production and reduction of N2O during denitrification were reduced, as well as the N2O production during nitrification. Accordingly, 60% reduction in N2O accumulation and 70% reduction in N2O production were observed in the denitrification and nitrification batch tests, respectively. Nevertheless, the long-term N2O emission factors under PET microplastics stress were comparable to that in the control reactor, mainly because PET microplastics led to more nitrite accumulation in anoxic period. With the aid of online N2O sensors and site-preference analysis, it was demonstrated that the heterotrophic bacteria pathway and ammonia oxidizing bacteria denitrification pathway for N2O production were negatively affected by PET microplastics, whereas a clear increase in the contribution of hydroxylamine pathway (+ 22.9%) was observed. Further investigation revealed that PET microplastics even at environmental level (i.e. 10 μg/L) significantly reshaped the BNR sludge characteristics (e.g. much larger particle size) and microbial communities (e.g. Thauera, Rhodobacte and Nitrospira) as well as the nitrogen metabolism pathways, which were chiefly responsible for the changes of N2O turnovers and N2O production pathways under the PET microplastics stress.
Hoang, AT, Foley, AM, Nižetić, S, Huang, Z, Ong, HC, Ölçer, AI, Pham, VV & Nguyen, XP 2022, 'Energy-related approach for reduction of CO2 emissions: A critical strategy on the port-to-ship pathway', Journal of Cleaner Production, vol. 355, pp. 131772-131772.
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The maritime sector has been searching for efficient solutions to change energy consumptions patterns of ports and ships to ensure sustainable operation and to reduce CO2 emissions to support sustainable transport in line with International Maritime Organization (IMO) policy guidelines. Therefore, pursuing smart strategies by utilizing renewable energy sources, clean fuels, smart grid, as well as measures of efficient-energy use are beneficial towards attaining the core goals of the IMO, specifically CO2 emission reduction in the future. In this review work, the main methods and criteria for monitoring CO2 emission from ports and ships are meticulously presented. Advanced renewable energy technologies connected with sources such as solar, wind, tidal, wave, and alternative fuels and their application in ports to reduce CO2 are thoroughly examined. In addition, energy-saving techniques and strategies for alternative power and fuels in ships are comprehensively evaluated. The key finding is that port-to-ship interactions such as using zero-emission energy sources or nearly zero-emission approaches could offer significant benefits for CO2 emission reduction. Finally, it is recommended that smart approaches associated with efficient and clean energy use for the port-to-ship pathways to generate net zero-CO2 emissions for the maritime shipping sector need further urgent investigation.
Hoang, AT, Huang, Z, Nižetić, S, Pandey, A, Nguyen, XP, Luque, R, Ong, HC, Said, Z, Le, TH & Pham, VV 2022, 'Characteristics of hydrogen production from steam gasification of plant-originated lignocellulosic biomass and its prospects in Vietnam', International Journal of Hydrogen Energy, vol. 47, no. 7, pp. 4394-4425.
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Hossain, SM, Ibrahim, I, Choo, Y, Razmjou, A, Naidu, G, Tijing, L, Kim, J-H & Shon, HK 2022, 'Preparation of effective lithium-ion sieve from sludge-generated TiO2', Desalination, vol. 525, pp. 115491-115491.
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Hossain, SM, Tijing, L, Suzuki, N, Fujishima, A, Kim, J-H & Shon, HK 2022, 'Visible light activation of photocatalysts formed from the heterojunction of sludge-generated TiO2 and g-CN towards NO removal', Journal of Hazardous Materials, vol. 422, pp. 126919-126919.
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The feasibility of preparing TiO2/g-CN heterojunction from Ti-incorporated dried dye wastewater sludge is explored in this study. Two reaction routes of composite formation were evaluated. In the initial approach, one-step calcination of dried sludge and melamine mixture @600 °C was carried out. Detailed morphological and chemical characterizations showed that the one-step calcination route did not create TiO2/g-CN composites; instead, only N-doped anatase TiO2 composites were formed. Moreover, due to the non-uniform composition of organic content in the dried sludge, it was not easy to control the N doping level by varying melamine content (0-100%) in the precursor mix. However, successful formation of anatase TiO2 and g-CN was observed when a two-step calcination route was followed, i.e., via synthesis of anatase TiO2 from dried sludge, and later development of heterojunction by calcining (@550 °C) the TiO2 and melamine mixture. X-ray diffraction along with infrared and X-ray photoelectron spectroscopy verified the effective heterojunction. In addition, maximum atmospheric NO removal under UV and visible light were observed for the prepared composite when the melamine content in the precursor mixture was 70%. After 1 h of UV and visible light irradiation, the best TiO2/g-CN composite removed 25.71% and 13.50% of NO, respectively. Optical characterization suggested that the enhanced NO oxidation under UV/visible light was due to the bandgap narrowing and diminished photogenerated electron-hole recombination.
Hosseinzadeh, A, Zhou, JL, Altaee, A & Li, D 2022, 'Machine learning modeling and analysis of biohydrogen production from wastewater by dark fermentation process', Bioresource Technology, vol. 343, pp. 126111-126111.
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Dark fermentation process for simultaneous wastewater treatment and H2 production is gaining attention. This study aimed to use machine learning (ML) procedures to model and analyze H2 production from wastewater during dark fermentation. Different ML procedures were assessed based on the mean squared error (MSE) and determination coefficient (R2) to select the most robust models for modeling the process. The research showed that gradient boosting machine (GBM), support vector machine (SVM), random forest (RF) and AdaBoost were the most appropriate models, which were optimized by grid search and deeply analyzed by permutation variable importance (PVI) to identify the relative importance of process variables. All four models demonstrated promising performances in predicting H2 production with high R2 values (0.893, 0.885, 0.902 and 0.889) and small MSE values (0.015, 0.015, 0.016 and 0.015). Moreover, RF-PVI demonstrated that acetate, butyrate, acetate/butyrate, ethanol, Fe and Ni were of high importance in decreasing order.
Hosseinzadeh, A, Zhou, JL, Li, X, Afsari, M & Altaee, A 2022, 'Techno-economic and environmental impact assessment of hydrogen production processes using bio-waste as renewable energy resource', Renewable and Sustainable Energy Reviews, vol. 156, pp. 111991-111991.
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Hosseinzadeh, A, Zhou, JL, Zyaie, J, AlZainati, N, Ibrar, I & Altaee, A 2022, 'Machine learning-based modeling and analysis of PFOS removal from contaminated water by nanofiltration process', Separation and Purification Technology, vol. 289, pp. 120775-120775.
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Hu, JY, Zhang, SS, Chen, E & Li, WG 2022, 'A review on corrosion detection and protection of existing reinforced concrete (RC) structures', Construction and Building Materials, vol. 325, pp. 126718-126718.
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Performance deterioration of existing reinforced concrete (RC) structures due to corrosion of inside steel reinforcement has been a worldwide issue for long, in particular for RC structures in aggressive environments. Although extensive research on steel corrosion has been carried out over past decades, it is still a challenging problem in civil engineering. Starting from a brief introduction on corrosion mechanism of steel in concrete, this paper presents a comprehensive review on corrosion detection techniques and protection methods for existing RC structures where corrosion has already occurred. Direct detection methods based on electrochemical and physical principles related to the steel corrosion process, and indirect methods based on measurement of corrosion-induced damages in reinforced concrete are critically reviewed, with the basic working mechanism and state of the art of each method given. According to protecting mechanism, corrosion protection methods are categorized into “prevention solutions” and “therapy solutions”, with the former including high-performance fiber-reinforced cementitious composite (HPFRCC) overlay, anti-corrosion coating and corrosion inhibitor while the latter including cathodic protection (CP) and electrochemical chloride extraction (ECE). Among them, HPFRCC overlay is regarded as effective in corrosion prevention due to its high durability although it is mainly used for strengthening because of its excellent mechanical properties, while carbon fiber reinforced polymer (CFRP) can be acted as both strengthening material and anode in CP and ECE. The dual functions of these materials make them very promising in protecting corrosion-damaged RC structures. The paper aims to not only provide useful information to researchers working on detection and protection of steel corrosion, but also shed lights on the advanced strengthening strategies for corrosion-damaged structures.
Huang, L, Liu, Z, Wu, C, Liang, J & Pei, Q 2022, 'A three-dimensional indirect boundary integral equation method for the scattering of seismic waves in a poroelastic layered half-space', Engineering Analysis with Boundary Elements, vol. 135, pp. 167-181.
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Huang, Y, Lee, CKC, Yam, Y-S, Mok, W-C, Zhou, JL, Zhuang, Y, Surawski, NC, Organ, B & Chan, EFC 2022, 'Rapid detection of high-emitting vehicles by on-road remote sensing technology improves urban air quality', Science Advances, vol. 8, no. 5, p. eabl7575.
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Vehicle emissions are the most important source of air pollution in the urban environment worldwide, and their detection and control are critical for protecting public health. Here, we report the use of on-road remote sensing (RS) technology for fast, accurate, and cost-effective identification of high-emitting vehicles as an enforcement program for improving urban air quality. Using large emission datasets from chassis dynamometer testing, RS, and air quality monitoring, we found that significant percentages of in-use petrol and LPG vehicles failed the emission standards, particularly the high-mileage fleets. The RS enforcement program greatly cleaned these fleets, in terms of high-emitter percentages, fleet average emissions, roadside and ambient pollutant concentrations, and emission inventory. The challenges of the current enforcement program are conservative setting of cut points, single-lane measurement sites, and lack of application experience in diesel vehicles. Developing more accurate and vertical RS systems will improve and extend their applications.
Huang, Y, Lee, CKC, Yam, Y-S, Zhou, JL, Surawski, NC, Organ, B, Lei, C & Shon, HK 2022, 'Effective emissions reduction of high-mileage fleets through a catalytic converter and oxygen sensor replacement program', Science of The Total Environment, vol. 850, pp. 158004-158004.
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High-mileage vehicles such as taxis make disproportionately large contributions to urban air pollution due to their accelerated engine deterioration rates and high operation intensities despite their small proportions of the total fleet. Controlling emissions from these high-mileage fleets is thus important for improving urban air quality. This study evaluates the effectiveness of a pilot repair program in reducing emissions from taxis in Hong Kong which account for about 2 % of the total licensed vehicles. The emission factors of a large sample of 684 in-service taxis (including 121 for an emission survey program and 563 for a pilot repair program) were measured on transient chassis dynamometers. The results showed that 63 % of the sampled taxis failed the driving cycle test before the pilot repair program. Most of failed taxis were NO related and 91 % of failed taxis exceeded the emission limits of at least two regulated pollutants simultaneously. After the pilot repair program by replacing catalytic converters and oxygen sensors, the failure rate was significantly reduced to only 7 %. In addition, the fleet average NO, HC and CO emission factors were reduced by 85 %, 82 % and 56 %, respectively. In addition, on-road remote sensing measurements confirmed the real-world emission reductions from the taxis that participated in the pilot repair program. These findings led to the implementation of a large-scale replacement program for all taxis in Hong Kong during 2013-2014, which was estimated to have reduced the total HC, CO and NO emissions by about 420, 2570 and 1000 t per year, respectively (equivalent to 5-8 % emission reductions from the whole road transport sector). Therefore, reducing emissions from the small high-mileage fleets is a highly cost-effective measure to improve urban air quality.
Huang, Y, Ng, ECY, Surawski, NC, Zhou, JL, Wang, X, Gao, J, Lin, W & Brown, RJ 2022, 'Effect of diesel particulate filter regeneration on fuel consumption and emissions performance under real-driving conditions', Fuel, vol. 320, pp. 123937-123937.
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Diesel particulate filters (DPF) are widely adopted in diesel vehicles to meet the increasingly stringent emission regulations, which require continuous passive regenerations or/and periodic active regenerations to burn off the accumulated particulate matter (PM). In spite of many laboratory studies using DPF benches and engine/chassis dynamometers, there is currently a lack of investigation on DPF regeneration under real-world conditions. Therefore, this study was conducted to investigate the impact of active DPF regenerations on the fuel consumption and gaseous and particulate emissions performance of a diesel light goods vehicle under real-driving conditions by using the state-of-the-art portable emission measurement system. In total, 60 real-driving emission (RDE) tests (∼1200 km in total) were performed on the same route during the same periods of a day, to minimise the effect of uncontrollable real-world factors on the performance evaluation. The results showed that real-world active DPF regenerations occurred every 130 km for the studied vehicle. Although they did not occur frequently, DPF regenerations increased the trip-averaged fuel consumption rate by 13% on average. CO and THC emission factors tended to increase with DPF regenerations because the post combustion used to achieve the high exhaust temperature for regeneration of the filter occurred under oxygen-lean conditions. Total NOx emissions were not affected but NO2/NOx ratio was greatly reduced by DPF regeneration due to lower NO oxidation by the diesel oxidation catalyst and higher NO2 reduction by the DPF. Finally, DPF regenerations sharply increased PM emission factors by 27 times compared with a trip without DPF regeneration, resulting in significant exceedance of the emission limit.
Huo, P, Chen, X, Yang, L, Wei, W & Ni, B-J 2022, 'Modeling of Sulfur-Driven Autotrophic Denitrification Coupled with Anammox Process', Bioresour Technol, vol. 349, pp. 126887-126887.
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While sulfur-driven autotrophic denitrification (SDAD) occurring in the anoxic reactor of the sulfate reduction, autotrophic denitrification and nitrification integrated (SANI) system has been regarded as the main nitrogen removal bioprocess, little is known about the accompanying Anammox bacteria whose presence is made possible by the co-existence of NH4+ and NO2-. Therefore, this work firstly developed an integrated SDAD-Anammox model to describe the interactions between sulfur-oxidizing bacteria and Anammox bacteria. The model was subsequently used to explore the impacts of influent conditions on the reactor performance and microbial community structure of the anoxic reactor. The results revealed that at a relatively low ratio of <1.5 mg S/mg N, Anammox bacteria could survive and even take a dominant position (up to 58.9%). Finally, a modified SANI system configuration based on the effective collaboration between SDAD and Anammox processes was proposed to improve the efficiency of the treatment of sulfate-rich saline sewage.
Huq, T, Ong, HC, Chew, BT, Leong, KY & Kazi, SN 2022, 'Review on aqueous graphene nanoplatelet Nanofluids: Preparation, Stability, thermophysical Properties, and applications in heat exchangers and solar thermal collectors', Applied Thermal Engineering, vol. 210, pp. 118342-118342.
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Ibrahim, I, Hossain, SM, Seo, DH, McDonagh, A, Foster, T, Shon, HK & Tijing, L 2022, 'Insight into the role of polydopamine nanostructures on nickel foam-based photothermal materials for solar water evaporation', Separation and Purification Technology, vol. 293, pp. 121054-121054.
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Ibrahim, I, Seo, DH, Park, MJ, Angeloski, A, McDonagh, A, Bendavid, A, Shon, HK & Tijing, L 2022, 'Highly stable gold nanolayer membrane for efficient solar water evaporation under a harsh environment', Chemosphere, vol. 299, pp. 134394-134394.
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Ibrar, I, Yadav, S, Altaee, A, Safaei, J, Samal, AK, Subbiah, S, Millar, G, Deka, P & Zhou, J 2022, 'Sodium docusate as a cleaning agent for forward osmosis membranes fouled by landfill leachate wastewater', Chemosphere, vol. 308, no. Pt 2, pp. 136237-136237.
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Membrane cleaning is critical for economic and scientific reasons in wastewater treatment systems. Sodium docusate is a laxative agent and removes cerumen (ear wax). Docusate penetrates the hard ear wax, making it softer and easier to remove. The same concept could be applied to soften and remove fouling layers on the membrane surface. Once softened, the foulants can be easily flushed with water. This innovative approach can address the challenge of developing superior methods to mitigate membrane fouling and material degradation. In this study, we evaluated the efficiency of sodium docusate for cleaning fouled forward osmosis membranes with real landfill leachate wastewater. Experiments were conducted to examine the impact of dose rate, contact time, flow or static conditions, and process configuration (forward osmosis (FO) or pressure retarded osmosis (PRO) upon fouling created by landfill leachate dewatering. A remarkable (99%) flux recovery was achieved using docusate at a small concentration of only 0.1% for 30 min. Furthermore, docusate can also effectively restore flux with static cleaning without using pumps to circulate the cleaning solution. Furthermore, cleaning efficiency can be achieved at neutral pH compatible with most membrane materials. From an economic and energy-saving perspective, static cleaning can almost achieve the same cleaning efficiency as kinetic cleaning for fouled forward osmosis membranes without the expense of additional pumping energy compared to kinetic cleaning. Since pumping energy is a major contributor to the overall energy of the forward osmosis system, it can be minimized to a certain degree by using a static cleaning approach and can bring good energy savings when using larger membrane areas. Studies of the contact angle on the membrane surface indicated that the contact angle was decreased compared to the fouled membrane after cleaning (e.g. 70.3° to 63.2° or FO mode and static cleaning). Scanning Electron Micro...
Ibrar, I, Yadav, S, Braytee, A, Altaee, A, HosseinZadeh, A, Samal, AK, Zhou, JL, Khan, JA, Bartocci, P & Fantozzi, F 2022, 'Evaluation of machine learning algorithms to predict internal concentration polarization in forward osmosis', Journal of Membrane Science, vol. 646, pp. 120257-120257.
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Internal concentration polarization (ICP) is currently a major bottleneck in the forward osmosis process. Proper modelling of the internal concentration polarization is therefore vital for improving the process performance and efficiency. This study assessed the feasibility of several machine learning methods for internal concentration polarization prediction, including artificial neural networks, extreme gradient boosting (XGBoost), Categorical boosting (CatBoost), Random forest, and linear regression. Among the many algorithms evaluated, the CatBoost regression outperformed other methods in terms of coefficient of determination (R2) and the mean square error. The CatBoost algorithm's prediction power was then evaluated using non-training (user-provided) data and compared to solution diffusion models. The results indicated that the machine learning algorithms could predict ICP in the process with high accuracy for the provided dataset and excellent generalizability for future testing data. Furthermore, machine learning algorithms may offer insights into the input features that majorly affect ICP modelling in the forward osmosis process.
Ibrar, I, Yadav, S, Naji, O, Alanezi, AA, Ghaffour, N, Déon, S, Subbiah, S & Altaee, A 2022, 'Development in forward Osmosis-Membrane distillation hybrid system for wastewater treatment', Separation and Purification Technology, vol. 286, pp. 120498-120498.
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Ideris, F, Zamri, MFMA, Shamsuddin, AH, Nomanbhay, S, Kusumo, F, Fattah, IMR & Mahlia, TMI 2022, 'Progress on Conventional and Advanced Techniques of In Situ Transesterification of Microalgae Lipids for Biodiesel Production', Energies, vol. 15, no. 19, pp. 7190-7190.
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Global warming and the depletion of fossil fuels have spurred many efforts in the quest for finding renewable, alternative sources of fuels, such as biodiesel. Due to its auxiliary functions in areas such as carbon dioxide sequestration and wastewater treatment, the potential of microalgae as a feedstock for biodiesel production has attracted a lot of attention from researchers all over the world. Major improvements have been made from the upstream to the downstream aspects related to microalgae processing. One of the main concerns is the high cost associated with the production of biodiesel from microalgae, which includes drying of the biomass and the subsequent lipid extraction. These two processes can be circumvented by applying direct or in situ transesterification of the wet microalgae biomass, hence substantially reducing the cost. In situ transesterification is considered as a significant improvement to commercially produce biodiesel from microalgae. This review covers the methods used to extract lipids from microalgae and various in situ transesterification methods, focusing on recent developments related to the process. Nevertheless, more studies need to be conducted to further enhance the discussed in situ transesterification methods before implementing them on a commercial scale.
Inan, DI, Beydoun, G & Pradhan, B 2022, 'Disaster Management Knowledge Analysis Framework Validated.', Inf. Syst. Frontiers, vol. 24, no. 6, pp. 2077-2097.
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In Disaster Management (DM), reusing knowledge of best practices from past experiences is envisaged as the best approach for dealing with future disasters. But analysing and modelling processes involved in those experiences is a well-known challenge. But the efficient storage of those processes to allow reuse by others in future DM endeavours is even more challenging and less discussed. Without an efficient process in place, DM knowledge reuse becomes even more remote as the effort incurred gets construed as a hindrance to more pressing activities during the execution of disaster activities. Efficiency has to also be pursued without compromising the effectiveness of the knowledge analysis and reuse. It is important to ensure that knowledge remains meaningful and relevant after it is transformed. This paper presents and validates a DM knowledge analysis framework (DMKAF 2.0) that caters for efficient transformation of DM knowledge intended for reuse. The paper demonstrates that undertaking knowledge transformation and storage in the context of its use is crucial in DM for both, effectiveness and efficiency of the transformation process. Design Science Research methodology guides the research undertaken, by informing enhancements and how the framework is evaluated. A real case study of flood DM from the State Emergency Service of Victoria State Australia is successfully used to validate these enhancements.
Indraratna, B, Haq, S, Rujikiatkamjorn, C & Israr, J 2022, 'Microscale boundaries of internally stable and unstable soils', Acta Geotechnica, vol. 17, no. 5, pp. 2037-2046.
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This study presents a microscale approach for evaluating the internal instability of natural granular soils using the discrete element method. The coordination number and the stress reduction factor are combined to assess the internal instability of soil. Distinct boundaries are identified between various soils that are internally stable and unstable. The microscale investigations are then compared with constriction and particle size-based criteria. The findings reveal that the constriction-based criterion predicts internal instability with significantly better accuracy. The relationship between microscale parameters and the constriction-based retention ratio is also examined for practical purposes.
Indraratna, B, Medawela, SK, Athuraliya, S, Heitor, A & Baral, P 2022, 'Chemical clogging of granular media under acidic groundwater conditions', Environmental Geotechnics, vol. 9, no. 7, pp. 450-462.
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Generation of acidic groundwater attributed to pyrite oxidation in low-lying acid sulfate soil has caused substantial damage to the soil-water environment and civil infrastructure in coastal Australia. The installation of permeable reactive barriers (PRBs) is a frontier technology in the field of acid neutralisation and removal of toxic heavy metal cations – for example, soluble iron (Fe) and aluminium (Al). This study aims to assess the potential of limestone (calcite) aggregates as the PRB’s main reactive material in low-lying pyritic land. During long-term laboratory column experiments, a significant capacity of limestone for removing contaminant chemical species was observed. Nevertheless, the formation of secondary mineral precipitates upon geochemical reactivity within the granular media in the PRB caused armouring and chemical clogging, which diminished the rate of reactivity – that is, the treatment capacity of calcite aggregates – mainly at the entrance zone of the porous media. Flow properties were altered due to blockage of pores; for instance, hydraulic conductivity was reduced by 25% at the inlet zone. Non-homogeneous clogging towards the outlet was analysed, and the time-dependent effect on the longevity of a limestone column was studied and quantified.
Indraratna, B, Mehmood, F, Mishra, S, Ngo, T & Rujikiatkamjorn, C 2022, 'The role of recycled rubber inclusions on increased confinement in track substructure', Transportation Geotechnics, vol. 36, pp. 100829-100829.
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Large cyclic and impact loads exerted by heavy haul trains can cause significant deformation and degradation of ballast, leading to poor track geometry and track instability. The application of recycled rubber elements in track substructure to increase confinement of both sub-ballast and shoulder ballast is an innovative solution. In Australia, there is a lack of adequate recycling that leads to large stockpiles of waste tyres. In addition, the reusability of giant off-the-road tyres discarded from mining industry is seriously limited due to their size and weight (over 3.0 m in diameter weighing about 3 tonnes). This study presents a real-size prototype test using the Australia's first and only National Facility for Cyclic Testing of High-speed Rail to investigate the performance of a hybrid track where tyre-infilled granular waste materials were placed below the ballast layer to replace the traditional capping layer, and arc segments cut from the giant off-the-road tyres were used to confine shoulder ballast. The performance of this hybrid track is compared with an unreinforced track conducted earlier at the same loading conditions. Test results demonstrate that the use of this hybrid system with recycled rubber elements significantly decreases vertical and lateral displacements of ballast and effectively controls the distribution of vertical stress with depth, while reducing vibration and ballast breakage. The outcomes of this study provide a unique solution in a circular economy perspective to strengthen railways to cater for heavier and faster freight trains.
Indraratna, B, Qi, Y, Malisetty, RS, Navaratnarajah, SK, Mehmood, F & Tawk, M 2022, 'Recycled materials in railroad substructure: an energy perspective', Railway Engineering Science, vol. 30, no. 3, pp. 304-322.
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AbstractGiven that the current ballasted tracks in Australia may not be able to support faster and significantly heavier freight trains as planned for the future, the imminent need for innovative and sustainable ballasted tracks for transport infrastructure is crucial. Over the past two decades, a number of studies have been conducted by the researchers of Transport Research Centre (TRC) at the University of Technology Sydney (UTS) to investigate the ability of recycled rubber mats, as well as waste tyre cells and granulated rubber to improve the stability of track substructure including ballast and subballast layers. This paper reviews four applications of these novel methods, including using recycled rubber products such as CWRC mixtures (i.e., mixtures of coal wash (CW) and rubber crumbs (RC)) and SEAL mixtures (i.e., mixtures of steel furnace slag, CW and RC) to replace subballast/capping materials, tyre cells reinforcements for subballast/capping layer and under ballast mats; and investigates the energy dissipation capacity for each application based on small-scale cyclic triaxial tests and large-scale track model tests. It has been found that the inclusion of these rubber products increases the energy dissipation effect of the track, hence reducing the ballast degradation efficiently and increasing the track stability. Moreover, a rheological model is also proposed to investigate the effect of different rubber inclusions on their efficiency to reduce the transient motion of rail track under dynamic loading. The outcomes elucidated in this paper will lead to a better understanding of the performance of ballast tracks upgraded with resilient rubber products, while promoting environmentally sustainable and more affordable ballasted tracks for greater passenger comfort and increased safety.
Indraratna, B, Qi, Y, Tawk, M, Heitor, A, Rujikiatkamjorn, C & Navaratnarajah, SK 2022, 'Advances in ground improvement using waste materials for transportation infrastructure', Proceedings of the Institution of Civil Engineers - Ground Improvement, vol. 175, no. 1, pp. 3-22.
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Recycling waste materials for transport infrastructure such as coal wash (CW), steel furnace slag (SFS), fly ash (FA) and recycled tyre products is an efficient way of minimising the stockpiles of waste materials while offering significant economic and environmental benefits, as well as improving the stability and longevity of infrastructure foundations. This paper presents some of the most recent state-of-the-art studies undertaken at the University of Wollongong, Australia on the use of waste materials such as (a) CW-based granular mixtures (i.e. SFS + CW, CW + FA) for port reclamation and road base/subbase and (b) using recycled tyre products (i.e. rubber crumbs, tyre cell, under-sleeper pads and under-ballast mats) to increase track stability and reduce ballast degradation. Typical methods of applying these waste materials for different infrastructure conditions are described and the results of comprehensive laboratory and field tests are presented and discussed.
Indraratna, B, Singh, M, Nguyen, TT, Rujikiatkamjorn, C, Malisetty, RS, Arivalagan, J & Nair, L 2022, 'Internal Instability and Fluidisation of Subgrade Soil under Cyclic Loading', Indian Geotechnical Journal, vol. 52, no. 5, pp. 1226-1243.
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AbstractRapid globalisation and the rise in population have substantially increased the demand for rail infrastructure which have been critical in transporting passengers and freight across landmasses for over a century. The surge in demand often leads to the construction of railway lines along with unfavourable soil conditions which result in different forms of substructure challenges such as uneven track deformations, ballast degradation, and subgrade mud pumping. A widespread site investigation along the eastern coast of New South Wales, Australia, indicated the prevalence of mud holes or bog holes along the tracks. The field studies suggest that low-to-medium plasticity soils are highly susceptible to mud pump when subjected to heavy axle loads under impeding drainage conditions. Subsequent laboratory investigations conducted on the remoulded soil samples collected from the sites indicated the sharp rise in cyclic axial strains and excess pore pressures along with the internal redistribution of moisture content as the governing mechanism for mud pumping. Numerical simulations performed using discrete element method coupled with computational fluid dynamics show that at a high hydraulic gradient, there is a substantial loss of soil contact network which leads to the upward migration of soil particles. The role of plastic fines and the inclusion of geosynthetic layer between the ballast and subgrade are also discussed in this paper. It was observed that the addition of 10% of cohesive fines increased the resistance of subgrade soils to mud pumping. On the other hand, geosynthetic inclusions not only assist in dissipating high cyclic excess pore pressures but also inhibit the upward migration of fine particles.
Irfan, S, Khan, SB, Lam, SS, Ong, HC, Aizaz Ud Din, M, Dong, F & Chen, D 2022, 'Removal of persistent acetophenone from industrial waste-water via bismuth ferrite nanostructures', Chemosphere, vol. 302, pp. 134750-134750.
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Jaafari, A, Panahi, M, Mafi-Gholami, D, Rahmati, O, Shahabi, H, Shirzadi, A, Lee, S, Bui, DT & Pradhan, B 2022, 'Swarm intelligence optimization of the group method of data handling using the cuckoo search and whale optimization algorithms to model and predict landslides', Applied Soft Computing, vol. 116, pp. 108254-108254.
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The robustness of landslide prediction models has become a major focus of researchers worldwide. We developed two novel hybrid predictive models that combine the self-organizing, deep-learning group method of data handling (GMDH) with two swarm intelligence optimization algorithms, i.e., cuckoo search algorithm (CSA) and whale optimization algorithm (WOA) for spatially explicit prediction of landslide susceptibility. Eleven landslide-causing factors and 334 historic landslides in a 31,340 km2 landslide-prone area in Iran were used to produce geospatial training and validation datasets. The GMDH model was employed to develop a basic predictive model that was then restructured and its parameters were optimized using the CSA and WOA algorithms, yielding the novel hybrid GMDH-CSA and GMDH-WOA models. The hybrid models were validated and compared to the standalone GMDH model by calculating the area under the receiver operating characteristic (AUC) curve and root mean square error (RMSE). The results demonstrated that the hybrid models overcame the computational shortcomings of the basic GMDH model and significantly improved landslide susceptibility prediction (GMDH-CSA, AUC = 0.909 and RMSE = 0.089; GMDH-WOA, AUC = 0.902 and RMSE = 0.129; standalone GMDH, AUC = 0.791 and RMSE = 0.226). Further, the hybrid models were more robust than the standalone GMDH model, showing consistently excellent performance when the training and validation datasets were changed. Overall, the swarm intelligence-optimized models, but not the standalone model, identified the best trade-offs among objectives, accuracy, and robustness.
Jain, K, Pradhan, B & Mishra, V 2022, 'Preface', Springer Proceedings in Mathematics and Statistics, vol. 404, pp. v-vi.
Jamshaid, M, Masjuki, HH, Kalam, MA, Zulkifli, NWM, Arslan, A & Qureshi, AA 2022, 'Experimental investigation of performance, emissions and tribological characteristics of B20 blend from cottonseed and palm oil biodiesels', Energy, vol. 239, pp. 121894-121894.
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Japelaghi, M, Hajian, F, Gholamalifard, M, Pradhan, B, Maulud, KNA & Park, H-J 2022, 'Modelling the Impact of Land Cover Changes on Carbon Storage and Sequestration in the Central Zagros Region, Iran Using Ecosystem Services Approach', Land, vol. 11, no. 3, pp. 423-423.
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Central Zagros region in Iran is a major hotspot of carbon storage and sequestration which has experienced severe land cover change in recent decades that has led to carbon emission. In this research, using temporal Landsat images, land cover maps were produced and used in Land Change Modeler to predict land cover changes in 2020, 2030, 2040 and 2050 using Multilayer Perceptron Neural Network and Markov Chain techniques. Next, resultant maps were used as inputs to Ecosystem Services Modeler. The Intergovernmental Panel on Climate Change (IPCC) report data was used to extract carbon data. Results show that between 1989–2013 about half of forests have been destroyed. Prediction results show that by 2050 about 75% of existing forests will be lost and between 2013–2020 about 157,000 Mg carbon and by 2050 about 565,000 Mg carbon will be lost with more than US$1.9 million to 2020 and AU$3.2 million by 2050 economic compensation.
Jena, R, Pradhan, B, Beydoun, G, Alamri, A & Shanableh, A 2022, 'Spatial earthquake vulnerability assessment by using multi-criteria decision making and probabilistic neural network techniques in Odisha, India', Geocarto International, vol. 37, no. 25, pp. 8080-8099.
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Jennifer, JJ, Saravanan, S & Pradhan, B 2022, 'Persistent Scatterer Interferometry in the post-event monitoring of the Idukki Landslides', Geocarto International, vol. 37, no. 5, pp. 1514-1528.
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Ji, J, Sun, X, He, W, Liu, Y, Duan, J, Liu, W, Nghiem, LD, Wang, Q & Cai, Z 2022, 'Built-in electric field enabled in carbon-doped Bi3O4Br nanocrystals for excellent photodegradation of PAHs', Separation and Purification Technology, vol. 302, pp. 122066-122066.
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A new type of solar active carbon-doped Bi3O4Br catalyst was synthesized by combining hydrothermal and post-thermal treatment. The activity of the material under sunlight and visible light was 3.3 times and 2.7 times that of Bi3O4Br, respectively. The C-doping on Bi3O4Br nanosheets increased the built-in electric field strength, thus significantly promoted the migration of charge carriers and enhanced the photocatalytic activity. In addition, replacing Br with C with a smaller atomic radius can shorten the interlayer spacing, which is beneficial to carrier separation. Experiments showed that the doping of C shortened the semiconductor band gap by 9.8% and expanded the absorption range of visible light. Among the photogenerated reactive species, h+ played a major role in the degradation of 1-methylpyrene (a typical polycyclic aromatic hydrocarbons), followed by O2∙- and •OH. Based on intermediate analysis and DFT calculation, we proposed the degradation mechanism and pathways. Quantitative structure–activity relationship (QSAR) analysis showed that some toxic intermediates were produced during the photocatalysis process, but the overall environmental risk was greatly reduced. This work provides new perspective for understanding non-metallic doping in semiconductor photocatalysts to enhance the built-in electric field, and this technology can be extended to other semiconductor materials.
Jiang, C, Ni, B-J, Zheng, X, Lu, B, Chen, Z, Gao, Y, Zhang, Y, Zhang, S & Luo, G 2022, 'The changes of microplastics’ behavior in adsorption and anaerobic digestion of waste activated sludge induced by hydrothermal pretreatment', Water Research, vol. 221, pp. 118744-118744.
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Waste activated sludge (WAS) contains high concentrations of microplastics (MPs), which could serve as vectors of various organic pollutants and heavy metals, causing synergistic transportation and pollution. The application of combined hydrothermal pretreatment (HTP) and anaerobic digestion (AD) has raised growing concerns since the low-temperature hydrothermal treatment could enhance the biogas production of WAS. However, the changes in physicochemical properties, adsorption performances, and effects on AD of MPs by HTP have not been studied. The study used three typical MPs in WAS, and it was found that the HTP (170°C & 30min) increased MPs' specific surface area and carbonyl index (CI) while decreasing the relative crystallinity. The adsorption capacity to Cd increased through the carbonylation for polyethylene microplastic (PE-MP) and polystyrene microplastic (PS-MP) while decreasing by the dechlorination for polyvinyl chloride microplastic (PVC-MP). Meanwhile, increased hydrophilicity reduced the adsorption capacities of all three typical MPs for ofloxacin. The above results indicated that the HTP could be worth blocking the adsorption of polar MPs for polar pollutants. For the pristine MPs, only PVC-MP at the highest concentration (0.5 g kg-1 VS) significantly (p < 0.05) reduced methane production by 16.2 ± 3.3% of WAS without the HTP. However, the HTP resulted in significant (p < 0.05) inhibition of methane production of WAS at high concentrations of PE-MP and PVC-MP (e.g., 0.1 and 0.5 g kg-1 VS), which was due to the acceleration of the released toxic plastic additives (dibutyl phthalate, dimethyl phthalate, and bisphenol-A). Microbial analysis showed the abundances of vital anaerobes, such as acid-producing bacteria (Acetoanerrobium and Mesotoga), proteolytic bacteria (Proteiniborus), and methanogens (Methanosaeta) clearly decreased with the PE-MP and PVC-MP after the HTP, which might result in the decreased methane production. The study provi...
Jiang, G, Wu, J, Weidhaas, J, Li, X, Chen, Y, Mueller, J, Li, J, Kumar, M, Zhou, X, Arora, S, Haramoto, E, Sherchan, S, Orive, G, Lertxundi, U, Honda, R, Kitajima, M & Jackson, G 2022, 'Artificial neural network-based estimation of COVID-19 case numbers and effective reproduction rate using wastewater-based epidemiology', Water Research, vol. 218, pp. 118451-118451.
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As a cost-effective and objective population-wide surveillance tool, wastewater-based epidemiology (WBE) has been widely implemented worldwide to monitor the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA concentration in wastewater. However, viral concentrations or loads in wastewater often correlate poorly with clinical case numbers. To date, there is no reliable method to back-estimate the coronavirus disease 2019 (COVID-19) case numbers from SARS-CoV-2 concentrations in wastewater. This greatly limits WBE in achieving its full potential in monitoring the unfolding pandemic. The exponentially growing SARS-CoV-2 WBE dataset, on the other hand, offers an opportunity to develop data-driven models for the estimation of COVID-19 case numbers (both incidence and prevalence) and transmission dynamics (effective reproduction rate). This study developed artificial neural network (ANN) models by innovatively expanding a conventional WBE dataset to include catchment, weather, clinical testing coverage and vaccination rate. The ANN models were trained and evaluated with a comprehensive state-wide wastewater monitoring dataset from Utah, USA during May 2020 to December 2021. In diverse sewer catchments, ANN models were found to accurately estimate the COVID-19 prevalence and incidence rates, with excellent precision for prevalence rates. Also, an ANN model was developed to estimate the effective reproduction number from both wastewater data and other pertinent factors affecting viral transmission and pandemic dynamics. The established ANN model was successfully validated for its transferability to other states or countries using the WBE dataset from Wisconsin, USA.
Jifroudi, HM, Mansor, SB, Pradhan, B, Halin, AA, Ahmad, N & Abdullah, AFB 2022, 'A new approach to derive buildings footprint from light detection and ranging data using rule-based learning techniques and decision tree', Measurement, vol. 192, pp. 110781-110781.
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Jin, X, Kaw, HY, Liu, Y, Zhao, J, Piao, X, Jin, D, He, M, Yan, X-P, Zhou, JL & Li, D 2022, 'One-step integrated sample pretreatment technique by gas-liquid microextraction (GLME) to determine multi-class pesticide residues in plant-derived foods', Food Chemistry, vol. 367, pp. 130774-130774.
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Gas-liquid microextraction technique (GLME) has been integrated with dispersive solid phase extraction to establish a one-step sample pretreatment approach for rapid analysis of multi-class pesticides in different plant-derived foods. A 50 μL of organic solvent plus 40 mg of PSA were required throughout the 5-minute pretreatment procedure. Good trueness (recoveries of 67.2 - 105.4%) and precision (RSD ≤ 18.9%) were demonstrated by the one-step GLME method, with MLOQs ranged from 0.001 to 0.011 mg kg-1. As high as 93.6% pesticides experienced low matrix effect through this method, and the overall matrix effects (ME%) were generally better or comparable to QuEChERS. This method successfully quantified 2-phenylphenol, quintozene, bifenthrin and permethrin in the range of 0.001 - 0.008 mg kg-1 in real food samples. The multiresidue analysis feature of GLME has been validated, which displays further potential for on-site determination of organic pollutants in order to safeguard food safety and human health.
John, CB, Raja, SA, Deepanraj, B & Ong, HC 2022, 'Palm stearin biodiesel: preparation, characterization using spectrometric techniques and the assessment of fuel properties', Biomass Conversion and Biorefinery, vol. 12, no. 5, pp. 1679-1693.
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In the contemporary era, our planet has been experiencing an unprecedented energy shortage and degradation of the environment. The exhaustion of crude oil reserves, fluctuation in fuel prices, and the escalating environmental pollution problems are driving the researchers worldwide to search for sustainable alternative fuels. This study discusses an enhanced protocol for the production of biodiesel using crude palm stearin (CPS), the nonedible solid portion of palm oil, through alkali-catalyzed transesterification. The significant physicochemical properties of CPS and palm stearin biodiesel (PSB) were analyzed by adopting American Society for Testing and Materials (ASTM) test procedures and contrasted with the commonly used biodiesels, petro-diesel, and ASTM biodiesel standards. The kinematic viscosity, density, gross calorific value, and cetane number of PSB were noticed to be 0.566 cSt, 0.882 kg/m3, 38,676.90 kJ/kg, and 47.5, respectively. The fatty acid composition and the functional groups present in CPS and PSB were determined by gas chromatography mass spectrometry (GCMS) and Fourier transform infrared spectrometry (FTIR) techniques. GCMS spectra for PSB demonstrated a composition consisting of myristic acid, palmitoleic acid, palmitic acid, elaidic acid, oleic acid, stearic acid, linoleic acid, and eicosapentaenoic acid in varying percentages. The conversion of triglycerides in the CPS into methyl esters in PSB was confirmed by the FTIR analysis. The results of thermogravimetric analyses were also in good agreement with GCMS and FTIR. The closeness of the estimated properties of PSB with petro-diesel and the conformance with ASTM standards indicate the prospective of PSB as an alternative fuel for compressed ignition engines.
Joshua Tapas, M, Thomas, P, Vessalas, K & Sirivivatnanon, V 2022, 'Mechanisms of Alkali-Silica Reaction Mitigation in AMBT Conditions: Comparative Study of Traditional Supplementary Cementitious Materials', Journal of Materials in Civil Engineering, vol. 34, no. 3.
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This study investigates the mechanisms of alkali-silica reaction (ASR) mitigation by supplementary cementitious materials (SCMs) under accelerated mortar bar test (AMBT) conditions. The study compares the effect of traditional SCMs (fly ash, slag, metakaolin, and silica fume) on ASR expansion, calcium silicate hydrate (C-S-H) composition, and portlandite consumption as well as on the availability of silicon and aluminum in solution. Results show that at typical SCM replacement levels for effective ASR mitigation (15% metakaolin, 25% fly ash, and 65% slag), the Si/Ca and Al/Si ratios of C-S-H are increased to comparable values, suggesting that at these dosages the SCMs contribute almost equivalent amounts of silicon and aluminum in solution. Studies of blended cement + SCM pastes show that the order of pozzolanicity is as follows: silica fume > metakaolin > fly ash > slag, which is consistent with the order of efficacy of SCMs in mitigating ASR expansion and the measured concentrations of silicon in solution. Solubility studies of the SCMs showed formation of sodium aluminum silicate hydrate (N-A-S-H) in fly ash and metakaolin and formation of calcium aluminum silicate hydrate (C-A-S-H) in slag after 28 days of exposure to AMBT conditions. This highlights the role of alkali activation of SCMs in ASR mitigation under AMBT conditions.
Kabir, MM, Alam, F, Akter, MM, Gilroyed, BH, Didar-ul-Alam, M, Tijing, L & Shon, HK 2022, 'Highly effective water hyacinth (Eichhornia crassipes) waste-based functionalized sustainable green adsorbents for antibiotic remediation from wastewater', Chemosphere, vol. 304, pp. 135293-135293.
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Kacprzak, S & Tijing, LD 2022, 'Microplastics in indoor environment: Sources, mitigation and fate', Journal of Environmental Chemical Engineering, vol. 10, no. 2, pp. 107359-107359.
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Kaplan, E, Altunisik, E, Ekmekyapar Firat, Y, Datta Barua, P, Dogan, S, Baygin, M, Burak Demir, F, Tuncer, T, Palmer, E, Tan, R-S, Yu, P, Soar, J, Fujita, H & Rajendra Acharya, U 2022, 'Novel nested patch-based feature extraction model for automated Parkinson's Disease symptom classification using MRI images', Computer Methods and Programs in Biomedicine, vol. 224, pp. 107030-107030.
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Kaplan, E, Chan, WY, Dogan, S, Barua, PD, Bulut, HT, Tuncer, T, Cizik, M, Tan, R-S & Acharya, UR 2022, 'Automated BI-RADS classification of lesions using pyramid triple deep feature generator technique on breast ultrasound images', Medical Engineering & Physics, vol. 108, pp. 103895-103895.
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Ultrasound (US) is an important imaging modality used to assess breast lesions for malignant features. In the past decade, many machine learning models have been developed for automated discrimination of breast cancer versus normal on US images, but few have classified the images based on the Breast Imaging Reporting and Data System (BI-RADS) classes. This work aimed to develop a model for classifying US breast lesions using a BI-RADS classification framework with a new multi-class US image dataset. We proposed a deep model that combined a novel pyramid triple deep feature generator (PTDFG) with transfer learning based on three pre-trained networks for creating deep features. Bilinear interpolation was applied to decompose the input image into four images of successively smaller dimensions, constituting a four-level pyramid for downstream feature generation with the pre-trained networks. Neighborhood component analysis was applied to the generated features to select each network's 1,000 most informative features, which were fed to support vector machine classifier for automated classification using a ten-fold cross-validation strategy. Our proposed model was validated using a new US image dataset containing 1,038 images divided into eight BI-RADS classes and histopathological results. We defined three classification schemes: Case 1 involved the classification of all images into eight categories; Case 2, classification of breast US images into five BI-RADS classes; and Case 3, classification of BI-RADS 4 lesions into benign versus malignant classes. Our PTDFG-based transfer learning model attained accuracy rates of 79.29%, 80.42%, and 88.67% for Case 1, Case 2, and Case 3, respectively.
Kaplan, E, Ekinci, T, Kaplan, S, Barua, PD, Dogan, S, Tuncer, T, Tan, R-S, Arunkumar, N & Acharya, UR 2022, 'PFP-LHCINCA: Pyramidal Fixed-Size Patch-Based Feature Extraction and Chi-Square Iterative Neighborhood Component Analysis for Automated Fetal Sex Classification on Ultrasound Images', Contrast Media & Molecular Imaging, vol. 2022, pp. 1-10.
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Objectives. Fetal sex determination with ultrasound (US) examination is indicated in pregnancies at risk of X-linked genetic disorders or ambiguous genitalia. However, misdiagnoses often arise due to operator inexperience and technical difficulties while acquiring diagnostic images. We aimed to develop an efficient automated US-based fetal sex classification model that can facilitate efficient screening and reduce misclassification. Methods. We have developed a novel feature engineering model termed PFP-LHCINCA that employs pyramidal fixed-size patch generation with average pooling-based image decomposition, handcrafted feature extraction based on local phase quantization (LPQ), and histogram of oriented gradients (HOG) to extract directional and textural features and used Chi-square iterative neighborhood component analysis feature selection (CINCA), which iteratively selects the most informative feature vector for each image that minimizes calculated feature parameter-derived k-nearest neighbor-based misclassification rates. The model was trained and tested on a sizeable expert-labeled dataset comprising 339 males’ and 332 females’ fetal US images. One transverse fetal US image per subject zoomed to the genital area and standardized to 256 × 256 size was used for analysis. Fetal sex was annotated by experts on US images and confirmed postnatally. Results. Standard model performance metrics were compared using five shallow classifiers—k-nearest neighbor (kNN), decision tree, naïve Bayes, linear discriminant, and support vector machine (SVM)—with the hyperparameters tuned using a Bayesian optimizer. The PFP-LHCINCA model achieved a sex classification accuracy of ≥88% with all five classifiers and the best accuracy rates (>98%) with kNN and SVM classifiers. Conclusions. US-based fetal sex classification is feasible and accurate using the presented PFP-LHCINCA model. The salutary results support its clinical use for fetal US image screening for...
Karbassiyazdi, E, Fattahi, F, Yousefi, N, Tahmassebi, A, Taromi, AA, Manzari, JZ, Gandomi, AH, Altaee, A & Razmjou, A 2022, 'XGBoost model as an efficient machine learning approach for PFAS removal: Effects of material characteristics and operation conditions', Environmental Research, vol. 215, no. Pt 1, pp. 114286-114286.
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Due to the implications of poly- and perfluoroalkyl substances (PFAS) on the environment and public health, great attention has been recently made to finding innovative materials and methods for PFAS removal. In this work, PFAS is considered universal contamination which can be found in many wastewater streams. Conventional materials and processes used to remove and degrade PFAS do not have enough competence to address the issue particularly when it comes to eliminating short-chain PFAS. This is mainly due to the large number of complex parameters that are involved in both material and process designs. Here, we took the advantage of artificial intelligence to introduce a model (XGBoost) in which material and process factors are considered simultaneously. This research applies a machine learning approach using data collected from reported articles to predict the PFAS removal factors. The XGBoost modeling provided accurate adsorption capacity, equilibrium, and removal estimates with the ability to predict the adsorption mechanisms. The performance comparison of adsorbents and the role of AI in one dominant are studied and reviewed for the first time, even though many studies have been carried out to develop PFAS removal through various adsorption methods such as ion exchange, nanofiltration, and activated carbon (AC). The model showed that pH is the most effective parameter to predict PFAS removal. The proposed model in this work can be extended for other micropollutants and can be used as a basic framework for future adsorbent design and process optimization.
KC, S, Shrestha, S, Nguyen, TPL, Das Gupta, A & Mohanasundaram, S 2022, 'Groundwater governance: a review of the assessment methodologies', Environmental Reviews, vol. 30, no. 2, pp. 202-216.
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Groundwater, the world’s largest and most exploited freshwater resource is a crucial ingredient for global socio-economic development. However, the domination of human-induced drivers such as climate change, rapid demographic escalation, alteration in land use, industrialisation, and an increase in water demand has further stressed the unfrozen freshwater resources. This review provides a comprehensive literature-based analysis on different assessment methodologies for groundwater governance, and critically analysed the applicability and knowledge gaps in the assessment methodologies for evaluating groundwater governance under climatic and nonclimatic stresses. Furthermore, in the absence of a designated groundwater governance framework under stress, the study emphasized the need for developing a ready-to-use groundwater governance framework to assess the existing state of governance, tackling the prevailing knowledge gaps. A multidimensional framework consisting of key groundwater governance elements, the inclusion of the vulnerable and marginalised groups, current and future stressors, and an approach for aggregating multiple elements would overcome the limitations in previous assessment methodologies. Additionally, this framework would contribute to understanding current governance provisions and the capacity to manage those provisions, realise the strengths, gaps, and areas for improvement, and quantitatively visualise the prevailing state of groundwater governance for planning multiple strategies to possible threats and conflicts from the stresses.
Key, S, Demir, S, Gurger, M, Yilmaz, E, Barua, PD, Dogan, S, Tuncer, T, Arunkumar, N, Tan, R-S & Acharya, UR 2022, 'ViVGG19: Novel exemplar deep feature extraction-based shoulder rotator cuff tear and biceps tendinosis detection using magnetic resonance images', Medical Engineering & Physics, vol. 110, pp. 103864-103864.
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BACKGROUND AND PURPOSE: Rotator cuff tear (RCT) and biceps tendinosis (BT) are the two most common shoulder disorders worldwide. These disorders can be diagnosed using magnetic resonance imaging (MRI), but the expert interpretation is manual, time-consuming, and subjected to human errors. Therefore, a fixed-size feature extraction model was created to objectively and accurately perform automated binary classification of RCT vs. normal and BT vs. normal on MRI images. MATERIALS AND METHODS: We have developed an exemplar deep feature extraction model to diagnose RCT and BT disorders. The model was tested on a new MR image dataset comprising transverse, sagittal, and coronal MRI images of the shoulder that had been organized into three cases. BT was studied on transverse MRI images (Case 1), while RCT was studied on sagittal (Case 2) and coronal MRI images (Case 3). Our model comprised deep feature generation using a pre-trained VGG19, feature selection using iterative neighborhood component analysis (INCA), and classification using shallow standard classifiers k-nearest neighbors (KNN), support vector machine (SVM), and artificial neural network (ANN). In the feature extraction phase, two fully connected layers were used to extract deep features from the original image, and sixteen fixed-size patches obtained by the division of the original image. This model was named Vision VGG19 (ViVGG), analogous to vision transformers (ViT). The feature vector is extracted from the raw image dataset, and 16 feature vectors are extracted from each fixed-size patch. Seventeen feature vectors obtained from each image are obtained from fc6 and fc7 layers of the pre-trained VGG19, are merged to obtain final feature vector. INCA was used to choose the top features from the created features, and the chosen features were classified using shallow classifiers. RESULTS: We defined three cases to evaluate the proposed ViVGG19 to diagnose RT and BCT disorders. Our proposed ViVGG19...
Khalid, Z, Alnuwaiser, MA, Ahmad, HA, Shafqat, SS, Munawar, MA, Kamran, K, Abbas, MM, Kalam, MA & Ewida, MA 2022, 'Experimental and Computational Analysis of Newly Synthesized Benzotriazinone Sulfonamides as Alpha-Glucosidase Inhibitors', Molecules, vol. 27, no. 20, pp. 6783-6783.
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Diabetes mellitus is a chronic metabolic disorder in which the pancreas secretes insulin but the body cells do not recognize it. As a result, carbohydrate metabolism causes hyperglycemia, which may be fatal for various organs. This disease is increasing day by day and it is prevalent among people of all ages, including young adults and children. Acarbose and miglitol are famous alpha-glucosidase inhibitors but they complicate patients with the problems of flatulence, pain, bloating, diarrhea, and loss of appetite. To overcome these challenges, it is crucial to discover new anti-diabetic drugs with minimal side effects. For this purpose, benzotriazinone sulfonamides were synthesized and their structures were characterized by FT-IR, 1H-NMR and 13C-NMR spectroscopy. In vitro alpha-glucosidase inhibition studies of all synthesized hybrids were conducted using the spectrophotometric method. The synthesized compounds revealed moderate-to-good inhibition activity; in particular, nitro derivatives 12e and 12f were found to be the most effective inhibitors against this enzyme, with IC50 values of 32.37 ± 0.15 µM and 37.75 ± 0.11 µM. In silico studies, including molecular docking as well as DFT analysis, also strengthened the experimental findings. Both leading compounds 12e and 12f showed strong hydrogen bonding interactions within the enzyme cavity. DFT studies also reinforced the strong binding interactions of these derivatives with biological molecules due to their lowest chemical hardness values and lowest orbital energy gap values.
Khan, A, Yadav, S, Ibrar, I, Al Juboori, RA, Razzak, SA, Deka, P, Subbiah, S & Shah, S 2022, 'Fouling and Performance Investigation of Membrane Distillation at Elevated Recoveries for Seawater Desalination and Wastewater Reclamation', Membranes, vol. 12, no. 10, pp. 951-951.
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This study reports on the impact of elevated recovery (i.e., 80%, 85%, and 90%) on the fouling and performance of air gap membrane distillation (AGMD) with real seawater and landfill leachate wastewater samples using polytetrafluoroethylene (PTFE) polymer membranes. Increasing the feed temperature from 55 °C to 65 °C improved the water flux of seawater and wastewater and shortened the operating time by 42.8% for all recoveries. The average water flux in the 80%, 85%, and 90% recovery experiments at the 65 °C feed temperature was 32%, 37.32%, and 36.7% higher than the case of 55 °C for the same recoveries. The water flux decline was more severe at a higher temperature and recovery. The highest flux decline was observed with a 90% recovery at 65 °C feed temperature, followed by an 85% recovery at 65 °C. Close examination of the foulants layer revealed that seawater formed a cake fouling layer made predominantly of metal oxides. In contrast, the landfill leachate fouling was a combination of pore blocking and cake formation, consisting mainly of carbonous and nitrogenous compounds. Physical cleaning with deionized (DI) water at 55 °C and 65 °C and chemical cleaning with hydrogen peroxide (H2O2) were investigated for their efficiency in removing membrane foulants. Analytical results revealed that seawater fouling caused membrane pore blockage while wastewater fouling formed a porous layer on the membrane surface. The results showed that membrane cleaning with hydrogen peroxide restored >97% of the water flux. Interestingly, the fouling factor in seawater tests was 10%, while it was 16% for the wastewater tests.
Khan, HA, Yasir, M & Castel, A 2022, 'Performance of cementitious and alkali-activated mortars exposed to laboratory simulated microbially induced corrosion test', Cement and Concrete Composites, vol. 128, pp. 104445-104445.
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This research presents a laboratory simulated microbially induced corrosion (MIC) test method allowing to assess the performance of low calcium fly ash based geopolymer mortar (FA-GPm), alkali-activated slag-based mortar (AASm), sulphate resistant Portland cement mortar (SRPCm) and calcium aluminate cement mortar (CACm). This experiment runs for a period of six months in which sulphur oxidizing microbes (SOMs) (A. thiooxidans and T. intermedius) were grown in liquid media containing the thiosulphate ion. This test methodology aims to investigate the bacterial attachment phase (stage 2) followed by the initiation of acid attack (stage 3) of MIC. Lowering of the pH of liquid medium and the growth of microorganism was measured to evaluate the aggressiveness of this microbial environment. Visual, physical, chemical and microstructural investigations of mortars were performed over time to estimate the deteriorations. Ions leaching from the matrix and formation of sulphate (SO42−) was monitored using inductively coupled plasma mass spectroscopy (ICP-MS) and ion chromatography (IC), respectively. The results showed that the neutralization of CACm after exposure to biotic reactor was lesser compared to the other mortars, indicating its resistance towards biocorrosion. Moreover, formation of sulphuric acid (H2SO4) and the growth of SOMs showed its dependence on the type of mortar. Scanning electron microscopy (SEM) with energy-dispersive X-ray (EDX) spectroscopy was used to predict the depth of degradation and morphological variations at microstructural level. Patterns of deterioration and nucleation of minerals identified were similar to infield exposure, indicating the suitability of this testing method to simulate sewer biocorrosion.
Kim, J, Kim, H-W, Tijing, LD, Shon, HK & Hong, S 2022, 'Elucidation of physicochemical scaling mechanisms in membrane distillation (MD): Implication to the control of inorganic fouling', Desalination, vol. 527, pp. 115573-115573.
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Kim, J, Yun, E-T, Tijing, L, Shon, HK & Hong, S 2022, 'Mitigation of fouling and wetting in membrane distillation by electrical repulsion using a multi-layered single-wall carbon nanotube/polyvinylidene fluoride membrane', Journal of Membrane Science, vol. 653, pp. 120519-120519.
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Kobat, SG, Baygin, N, Yusufoglu, E, Baygin, M, Barua, PD, Dogan, S, Yaman, O, Celiker, U, Yildirim, H, Tan, R-S, Tuncer, T, Islam, N & Acharya, UR 2022, 'Automated Diabetic Retinopathy Detection Using Horizontal and Vertical Patch Division-Based Pre-Trained DenseNET with Digital Fundus Images', Diagnostics, vol. 12, no. 8, pp. 1975-1975.
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Diabetic retinopathy (DR) is a common complication of diabetes that can lead to progressive vision loss. Regular surveillance with fundal photography, early diagnosis, and prompt intervention are paramount to reducing the incidence of DR-induced vision loss. However, manual interpretation of fundal photographs is subject to human error. In this study, a new method based on horizontal and vertical patch division was proposed for the automated classification of DR images on fundal photographs. The novel sides of this study are given as follows. We proposed a new non-fixed-size patch division model to obtain high classification results and collected a new fundus image dataset. Moreover, two datasets are used to test the model: a newly collected three-class (normal, non-proliferative DR, and proliferative DR) dataset comprising 2355 DR images and the established open-access five-class Asia Pacific Tele-Ophthalmology Society (APTOS) 2019 dataset comprising 3662 images. Two analysis scenarios, Case 1 and Case 2, with three (normal, non-proliferative DR, and proliferative DR) and five classes (normal, mild DR, moderate DR, severe DR, and proliferative DR), respectively, were derived from the APTOS 2019 dataset. These datasets and these cases have been used to demonstrate the general classification performance of our proposal. By applying transfer learning, the last fully connected and global average pooling layers of the DenseNet201 architecture were used to extract deep features from input DR images and each of the eight subdivided horizontal and vertical patches. The most discriminative features are then selected using neighborhood component analysis. These were fed as input to a standard shallow cubic support vector machine for classification. Our new DR dataset obtained 94.06% and 91.55% accuracy values for three-class classification with 80:20 hold-out validation and 10-fold cross-validation, respectively. As can be seen from steps of the proposed...
Kohn, C, Duong, HC, Hoang, NB & Nghiem, LD 2022, 'Digital Transformation of Packaged Reverse Osmosis Plants for Industrial and Sewer Mining Applications', Current Pollution Reports, vol. 8, no. 4, pp. 360-368.
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Kolli, MK, Opp, C, Karthe, D & Pradhan, B 2022, 'Automatic extraction of large-scale aquaculture encroachment areas using Canny Edge Otsu algorithm in Google earth engine – the case study of Kolleru Lake, South India', Geocarto International, vol. 37, no. 26, pp. 11173-11189.
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Kotobuki, M, Zhou, C, Su, Z, Yang, L, Wang, Y, Jason, CJJ, Liu, Z & Lu, L 2022, 'Importance of substrate materials for sintering Li1.5Al0.5Ge1.5(PO4)3 solid electrolyte', Journal of Solid State Chemistry, vol. 310, pp. 123043-123043.
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Li1.5Al0.5Ge1.5(PO4)3 (LAGP) solid electrolyte with a NASICON (Na super ionic conductor) structure is a promising electrolyte for all-solid-state Li batteries. It is well-known that Al contamination occurs in garnet-type solid electrolytes when Al2O3 substrate is used for sintering. In this paper, the influence of substrate materials for sintering on properties of LAGP solid electrolyte is studied. The LAGP samples are sintered on Al2O3 or Pt substrate at 950 °C. TEM-EDS results show that oxides of Ge and Al are observed when sintering is performed on Pt substrate while phosphates of Li and Al are detected in the sample sintered on Al2O3 substrate. Also, the sample sintered on Al2O3 contains more Al due to Al contamination from the substrate. The Li ion conductivity is also affected by the substrate, and higher conductivity is observed in the sample sintered on the Al2O3 substrate. It is concluded that the Al contamination occurs in the LAGP solid electrolyte sintered on Al2O3 substrate. The selection of substrate is a key factor for development of LAGP solid electrolyte.
Koul, Y, Devda, V, Varjani, S, Guo, W, Ngo, HH, Taherzadeh, MJ, Chang, J-S, Wong, JWC, Bilal, M, Kim, S-H, Bui, X-T & Parra-Saldívar, R 2022, 'Microbial electrolysis: a promising approach for treatment and resource recovery from industrial wastewater', Bioengineered, vol. 13, no. 4, pp. 8115-8134.
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Wastewater is one of the most common by-products of almost every industrial process. Treatment of wastewater alone, before disposal, necessitates an excess of energy. Environmental concerns over the use of fossil fuels as a source of energy have prompted a surge in demand for alternative energy sources and the development of sophisticated procedures to extract energy from unconventional sources. Treatment of municipal and industrial wastewater alone accounts for about 3% of global electricity use while the amount of energy embedded in the waste is at least 2-4 times greater than the energy required to treat the same effluent. The microbial electrolysis cell (MEC) is one of the most efficient technologies for waste-to-product conversion that uses electrochemically active bacteria to convert organic matter into hydrogen or a variety of by-products without polluting the environment. This paper highlights existing obstacles and future potential in the integration of Microbial Electrolysis Cell with other processes like anaerobic digestion coupled system, anaerobic membrane bioreactor and thermoelectric micro converter.
Kouretzis, G, Sheng, D & Thomas, HR 2022, 'In memory of Scott William Sloan (1954–2019)', Computers and Geotechnics, vol. 143, pp. 104593-104593.
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Kuluozturk, M, Kobat, MA, Barua, PD, Dogan, S, Tuncer, T, Tan, R-S, Ciaccio, EJ & Acharya, UR 2022, 'DKPNet41: Directed knight pattern network-based cough sound classification model for automatic disease diagnosis', Medical Engineering & Physics, vol. 110, pp. 103870-103870.
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Kumar, S, Lyalin, A, Huang, Z & Taketsugu, T 2022, 'Catalytic Oxidative Dehydrogenation of Light Alkanes over Oxygen Functionalized Hexagonal Boron Nitride', ChemistrySelect, vol. 7, no. 1.
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AbstractThe catalytic activity of oxygen functionalized hexagonal boron nitride (h‐BN) with >B−O−O−B< and >B−O−B< active sites at the zigzag edges for oxidative dehydrogenation (ODH) of light alkanes, specifically ethane (C2H6), propane (C3H8), butane (C4H10), and isobutane (HC(CH3)3) is explored. It has been found that the reaction pathway involves two H atom transfer steps with small activation energies. We demonstrate that the synergy of two active sites, >B−O−O−B< and >B−O−B<, is crucial for the first and second H‐transfer, respectively. With the increase in molecular mass of the considered light alkanes, the ODH reaction temperature decreases. In the case of butane and isobutane, the ODH reaction occurs almost at the same temperature indicating that the reaction is independent of the shape of the isomer. The rate‐limiting nature of the first H‐transfer step is predicted. The charge redistribution during H‐transfers and localized oxygen atomic states in the conduction band are explored to suggest possible descriptors for the rational design of new catalysts. The universal action of the >B−O−O−B< and >B−O−B< active sites for ODH of the light alkanes paves the way for metal‐free BN‐based materials for future catalytic applications.
Kumari, P, Bahadur, N, Conlan, XA, Laleh, M, Kong, L, O'Dell, LA, Dumée, LF & Merenda, A 2022, 'Atomically-thin Schottky-like photo-electrocatalytic cross-flow membrane reactors for ultrafast remediation of persistent organic pollutants', Water Research, vol. 218, pp. 118519-118519.
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The remediation of persistent organic pollutants in surface and ground water represents a major environmental challenge worldwide. Conventional physico-chemical techniques do not efficiently remove such persistent organic pollutants and new remediation techniques are therefore required. Photo-electro catalytic membranes represent an emerging solution that can combine photocatalytic and electrocatalytic degradation of contaminants along with molecular sieving. Herein, macro-porous photo-electro catalytic membranes were prepared using conductive and porous stainless steel metal membranes decorated with nano coatings of semiconductor photocatalytic metal oxides (TiO2 and ZnO) via atomic layer deposition, producing highly conformal and stable coatings. The metal - semiconductor junction between the stainless steel membranes and photocatalysts provides Schottky - like characteristics to the coated membranes. The PEC membranes showed induced hydrophilicity from the nano-coatings and enhanced electro-chemical properties due to the Schottky junction. A high electron transfer rate was also induced in the coated membranes as the photocurrent efficiency increased by 4 times. The photo-electrocatalytic efficiency of the TiO2 and ZnO coated membranes were demonstrated in batch and cross flow filtration reactors for the degradation of persistent organic pollutant solution, offering increased degradation kinetic factors by 2.9 and 2.3 compared to photocatalysis and electrocatalysis, respectively. The recombination of photo-induced electron and hole pairs is mitigated during the photo-electrocatalytic process, resulting in an enhanced catalytic performance. The strategy offers outstanding perspectives to design stimuli-responsive membrane materials able to sieve and degrade simultaneously toxic contaminants towards greater process integration and self-cleaning operations.
Kumari, P, Bahadur, N, Kong, L, O’Dell, LA, Merenda, A & Dumée, LF 2022, 'Engineering Schottky-like and heterojunction materials for enhanced photocatalysis performance – a review', Materials Advances, vol. 3, no. 5, pp. 2309-2323.
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Photocatalysis with nanostructured semiconductors is emerging for environmental remediation.
Kurniawan, T, Nuryoto, N, Milenia, ND, Lestari, KD, Nandiyanto, ABD, Bilad, MR, Abdullah, H & Mahlia, TMI 2022, 'Improved Natural Mordenite as Low-Cost Catalyst for Glycerol Acetalization into Solketal – An Effective Fuel Additive', Materials Science Forum, vol. 1057, pp. 71-87.
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The increase in biodiesel production results in an excessive amount of crude glycerol by-product. Therefore, production of solketal –an effective additive of gasoline fuel-from glycerol and acetone via catalytic acetalization could improve the added value of glycerol. This study investigates enhancement of natural mordenite catalytic properties through the hydrothermal recrystallization method for glycerol acetalization. The hydrothermal temperature was varied at 150, 170 and 190 oC to form ZT 150, ZT 170 and ZT 190, respectively. The samples were characterized using the x-ray diffraction and the scanning electron microscope-Energy dispersive X-Ray. They were later used as catalysts for glycerol acetalization with acetone. The best obtained catalyst was further studied to explore the effect of acetone on glycerol ration. The glycerol conversion was deter-mined using the ASTM D7637-10 titration method. Solketal product was identified by using the Fourier transform infrared spectroscopy. The results show that the recrystallization temperature affects the intensity of the mordenite phase and quartz impurity phase in the modified zeolites. A high recrystallization temperature led to a higher phase of mordenite, peaking at 170oC, beyond which the quartz impurity phase increased. Glycerol acetalization conversions over zeolite parent, ZT 150, ZT 170 and ZT190 with acetone to glycerol ratio of 3 were 16.1%, 30.4%, 33.9% and 32.5%, respectively. When the ratio of acetone to glycerol was increased to 12, the glycerol conversion over ZT 170 catalyst reached 59%, a good starting point for further modifications. Overall finding demonstrated a straight-forward fabrication of catalyst from natural resource to enhance glycerol as the biodiesel production by-product into a higher value end-product of solketal.
Kusumo, F, Mahlia, TMI, Pradhan, S, Ong, HC, Silitonga, AS, Fattah, IMR, Nghiem, LD & Mofijur, M 2022, 'A framework to assess indicators of the circular economy in biological systems', Environmental Technology & Innovation, vol. 28, pp. 102945-102945.
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In regional and global contexts, the circular economy (CE) has gained significant traction to sustain the economy while maintaining environmental and social justice. However, the literature on CE lacks substantial information regarding the theory and methodology of putting CE into practice. The goal of this work is to create a framework for evaluating CE indicators and CE implementation in biological systems. The findings of this study suggest that CE may be more complicated than previously thought, involving a wide variety of interconnected mechanisms. The CE's guiding principles differentiate between biological and man-made (artificial) material and resource cycles. Biological cycles concern the safe and efficient movement of renewable biotic resources into and out of the biosphere. This study looks at the 13 different indicators of a circular economy, with a particular emphasis on the biological approaches that make up the biological cycle. The 13 papers were broken down as follows: four at the macro level, three at the meso level, and seven at the micro level. Furthermore, through the analysis of various literary sources, this paper proposed a framework for calculating and quantifying the CE. The framework's first steps are measurement criteria, the second are level monitoring procedures, and the third is the impact of CE. The proposed framework will aid in disseminating knowledge across regions, industries, and stakeholders, as well as accelerating CE implementation.
Kusumo, F, Mahlia, TMI, Shamsuddin, AH, Ahmad, AR, Silitonga, AS, Dharma, S, Mofijur, M, Ideris, F, Ong, HC, Sebayang, R, Milano, J, Hassan, MH & Varman, M 2022, 'Optimisation of biodiesel production from mixed Sterculia foetida and rice bran oil', International Journal of Ambient Energy, vol. 43, no. 1, pp. 4380-4390.
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The present study is to investigate the feasibility of mixed non-edible oils, Sterculia foetida (SFO), and rice bran oil (RBO) for biodiesel production. The transesterification process variables of SFO50RBO50 as the suitable blend were optimised using response surface methodology. The optimum conditions of the transesterification process are as follow; KOH catalyst concentration of 0.7% wt, the ratio of methanol to oil of 42%, the reaction time of 50.64 min, resulted in the methyl ester yield of 98.93%. The result shows that the SF50RB50 methyl ester properties satisfy the biodiesel requirements laid in ASTM D6751 and EN 14214 standards.
Kuzhiumparambil, U, Labeeuw, L, Commault, A, Vu, HP, Nguyen, LN, Ralph, PJ & Nghiem, LD 2022, 'Effects of harvesting on morphological and biochemical characteristics of microalgal biomass harvested by polyacrylamide addition, pH-induced flocculation, and centrifugation', Bioresource Technology, vol. 359, pp. 127433-127433.
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The effects of microalgae harvesting methods on microalgal biomass quality were evaluated using three species namely the freshwater green alga Chlorella vulgaris, marine red alga Porphyridium purpureum and marine diatom Phaeodactylum tricornutum. Harvesting efficiencies of polyacrylamide addition, alkaline addition, and centrifugation ranged from 85 to 95, 59-92 and 100%, respectively, across these species. Morphology of the harvested cells (i.e. compromised cell walls) was significantly impacted by alkaline pH-induced flocculation for all three species. Over 50% of C. vulgaris cells were compromised with alkaline pH compared to < 10% with polyacrylamide and centrifugation. The metabolic profiles varied depending on harvesting methods. Species-specific decrease of certain metabolites was observed. These results suggest that the method of harvest can alter the metabolic profile of the biomass amongst the three harvesting methods, polyacrylamide addition showed higher harvesting efficiency with less compromised cells and higher retention of industry important biochemicals.
La, DD, Ngo, HH, Nguyen, DD, Tran, NT, Vo, HT, Nguyen, XH, Chang, SW, Chung, WJ & Nguyen, MD-B 2022, 'Advances and prospects of porphyrin-based nanomaterials via self-assembly for photocatalytic applications in environmental treatment', Coordination Chemistry Reviews, vol. 463, pp. 214543-214543.
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A class of compounds called porphyrins are involved in the gas transport, catalysis, and light absorption processes of many animals and plants throughout the world. This natural mechanism can be obtained via supramolecular self-assembly of porphyrin derivatives. Porphyrin-based nanomaterials obtained via self-assembly can be utilized in many promising applications, such as optical energy or information storage devices, solar energy conversion, sensors, nanocatalysts, photoelectronics, and photodynamic therapy. This paper critically reviews recent advances in porphyrin nanostructures fabricated via self-assembly for visible-light photocatalytic reactions, and discusses their properties and applications, especially for environmental treatment. Firstly, it introduced porphyrin and a self-assembly method for fabricating porphyrin nanomaterials. Methods for fabricating porphyrin nanostructures via self-assembly were then presented, such as re-precipitation, coordination polymerization, and ionic self-assembly. Finally, the applications of porphyrin-based nanomaterials with a focus on photovoltaic applications were overviewed with highlights from recent works in this field.
Larpruenrudee, P, Surawski, NC & Islam, MS 2022, 'The Effect of Metro Construction on the Air Quality in the Railway Transport System of Sydney, Australia', Atmosphere, vol. 13, no. 5, pp. 759-759.
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Sydney Metro is the biggest project of Australia’s public transport, which was designed to provide passengers with more trains and faster services. This project was first implemented in 2017 and is planned to be completed in 2024. As presented, the project is currently in the construction stage located on the ground stations of the Sydney Trains Bankstown line (T3). Based on this stage, several construction activities will generate air pollutants, which will affect the air quality around construction areas. Moreover, it might cause health problems to people around there and also the passengers who usually take the train on the T3 line. However, there is no specific data for air quality inside the train that may be affected by the construction from each area. Therefore, the aim of this study is to investigate the air quality inside the train carriage of all related stations from the T3 line. A sampling campaign was conducted over 3 months to analyze particulate matter (PM) concentration, the main indoor pollutants including formaldehyde (HCHO) and total volatile organic compounds (TVOC). The results of the T3 line were analyzed and compared to Airport & South line (T8) that were not affected by the project’s construction. The results of this study indicate that Sydney Metro construction activities insignificantly affected the air quality inside the train. Average PM2.5 and PM10 inside the train of T3 line in the daytime were slightly higher than in the nighttime. The differences in PM2.5 and PM10 concentrations from these periods were around 6.8 μg/m3 and 12.1 μg/m3, respectively. The PM concentrations inside the train from the T3 line were slightly higher than the T8 line. However, these concentrations were still lower than those recommended by the national air quality standards. For HCHO and TVOC, the average HCHO and TVOC concentrations were less than the recommendation criteria.
Le, A, Nimbalkar, S, Zobeiry, N & Malek, S 2022, 'An efficient multi-scale approach for viscoelastic analysis of woven composites under bending', Composite Structures, vol. 292, pp. 115698-115698.
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Le, L-T, Nguyen, K-QN, Nguyen, P-T, Duong, HC, Bui, X-T, Hoang, NB & Nghiem, LD 2022, 'Microfibers in laundry wastewater: Problem and solution', Science of The Total Environment, vol. 852, pp. 158412-158412.
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Data corroborated in this study highlights laundry wastewater as a primary source of microfibers (MFs) in the aquatic environment. MFs can negatively impact the aquatic ecosystem via five possible pathways, namely, acting as carriers of other contaminats, physical damage to digestive systems of aquatic organisms, blocking the digestive tract, releasing toxic chemicals, and harbouring invasive and noxious plankton and bacteria. This review shows that small devices to capture MFs during household laundry activities are simple to use and affordable at household level in developed countries. However, these low cost and small devices are unrealiable and can only achieve up to 40 % MF removal efficiency. In line filtration devices can achieve higher removal efficiency under well maintained condition but their performance is still limited compared to over 98 % MF removal by large scale centralized wastewater treatment. These results infer that effort to increase sanitation coverage to ensure adequate wastewater treatment prior to environmental discharge is likely to be more cost effective than those small devices for capturing MFs. This review also shows that natural fabrics would entail significantly less environmental consequences than synthetic materials. Contribution from the fashion industry to increase the share of natural frabics in the current textile market can also reduce the loading of plastic MFs in the environment.
Le, T-S, Nguyen, P-D, Ngo, HH, Bui, X-T, Dang, B-T, Diels, L, Bui, H-H, Nguyen, M-T & Le Quang, D-T 2022, 'Two-stage anaerobic membrane bioreactor for co-treatment of food waste and kitchen wastewater for biogas production and nutrients recovery', Chemosphere, vol. 309, no. Pt 1, pp. 136537-136537.
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Co-digestion of organic waste and wastewater is receiving increased attention as a plausible waste management approach toward energy recovery. However, traditional anaerobic processes for co-digestion are particularly susceptible to severe organic loading rates (OLRs) under long-term treatment. To enhance technological feasibility, this work presented a two-stage Anaerobic Membrane Bioreactor (2 S-AnMBR) composed of a hydrolysis reactor (HR) followed by an anaerobic membrane bioreactor (AnMBR) for long-term co-digestion of food waste and kitchen wastewater. The OLRs were expanded from 4.5, 5.6, and 6.9 kg COD m-3 d-1 to optimize biogas yield, nitrogen recovery, and membrane fouling at ambient temperatures of 25-32 °C. Results showed that specific methane production of UASB was 249 ± 7 L CH4 kg-1 CODremoved at the OLR of 6.9 kg TCOD m-3 d-1. Total Chemical Oxygen Demand (TCOD) loss by hydrolysis was 21.6% of the input TCOD load at the hydraulic retention time (HRT) of 2 days. However, low total volatile fatty acid concentrations were found in the AnMBR, indicating that a sufficiently high hydrolysis efficiency could be accomplished with a short HRT. Furthermore, using AnMBR structure consisting of an Upflow Anaerobic Sludge Blanket Reactor (UASB) followed by a side-stream ultrafiltration membrane alleviated cake membrane fouling. The wasted digestate from the AnMBR comprised 42-47% Total Kjeldahl Nitrogen (TKN) and 57-68% total phosphorous loading, making it suitable for use in soil amendments or fertilizers. Finally, the predominance of fine particles (D10 = 0.8 μm) in the ultrafiltration membrane housing (UFMH) could lead to a faster increase in trans-membrane pressure during the filtration process.
Le, VG, Vo, DVN, Tran, HT, Duy Dat, N, Luu, SDN, Rahman, MM, Huang, YH & Vu, CT 2022, 'Response to Comment on “Recovery of Magnesium from Industrial Effluent and Its Implication on Carbon Capture and Storage”', ACS Sustainable Chemistry & Engineering, vol. 10, no. 48, pp. 15619-15621.
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Lee, T, Min, C, Naidu, G, Huang, Y, Shon, HK & Kim, S-H 2022, 'Optimizing the performance of sweeping gas membrane distillation for treating naturally heated saline groundwater', Desalination, vol. 532, pp. 115736-115736.
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Lee, XJ, Ong, HC, Ooi, J, Yu, KL, Tham, TC, Chen, W-H & Ok, YS 2022, 'Engineered macroalgal and microalgal adsorbents: Synthesis routes and adsorptive performance on hazardous water contaminants', Journal of Hazardous Materials, vol. 423, pp. 126921-126921.
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Leng, D, Zhu, Z, Liu, G & Li, Y 2022, 'Neuro fuzzy logic control of magnetorheological elastomer isolation system for vibration mitigation of offshore jacket platforms', Ocean Engineering, vol. 253, pp. 111293-111293.
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Leong, KY, Hasbi, S, Ku Ahmad, KZ, Mat Jali, N, Ong, HC & Md Din, MF 2022, 'Thermal properties evaluation of paraffin wax enhanced with carbon nanotubes as latent heat thermal energy storage', Journal of Energy Storage, vol. 52, pp. 105027-105027.
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An efficient phase change material (PCM) should not only exhibit high latent heat, but also high thermal conductivity. Combination of these favourable properties leads to an efficient latent heat thermal energy storage. Paraffin wax is one of the popular options for organic PCMs. However, paraffin wax has a low thermal conductivity, hindering its heat charging and discharging process. This study explores the effect of multi-walled carbon nanotube (MWCNT) weight percentage (0–0.08 wt%) and various surfactants (gum arabic (GA), polyvinylpyrrolidone (PVP), sodium docecylbenzene sulfonate (SDBS), and sodium dodecyl sulfate (SDS)) on the thermal conductivity, melting temperature, melting latent heat and thermal stability of paraffin wax. It is found that the maximum thermal conductivity enhancement (48%) is exhibited by paraffin wax/0.06 wt% MWCNT without surfactant compared to paraffin wax. The thermal conductivity of paraffin wax/0.08 wt% MWCNT added with PVP, SDBS and SDS are higher than samples added with GA. Overall, all samples exhibit single-step decomposition characteristics, as shown in thermogravimetric analysis (TGA).
Li, C, Fang, J, Wu, C, Sun, G, Steven, G & Li, Q 2022, 'Phase field fracture in elasto-plastic solids: Incorporating phenomenological failure criteria for ductile materials', Computer Methods in Applied Mechanics and Engineering, vol. 391, pp. 114580-114580.
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Phase field approaches have been developed to analyze the failure behavior of ductile materials. In the previous phase field models, a constant critical energy or strain threshold is commonly introduced to the formulation of the driving force, aiming to avoid damage initiation at a low level of elastic and plastic deformations. However, it may not suffice to describe complex ductile fracture behavior of materials subject to various stress states. In this study, a new phase field approach is proposed to consider the effects of stress triaxiality and Lode angle, by incorporating phenomenological ductile fracture criteria. The proposed models are formulated using variational principles and implemented numerically in the finite element framework. Analytical homogeneous solutions for uniaxial tension, simple shear, and equibiaxial tension loads are derived to demonstrate the effectiveness of the proposed models. Three groups of numerical examples, covering a wide range of stress states, are utilized to further examine the proposed models. The results show that the models can reproduce the experimental response of the specimen in terms of force versus displacement curve, crack initiation, and crack propagation under various loading conditions. The proposed models are able to capture the stress-state dependence of fracture behavior of ductile materials.
Li, D, Qing, L, Li, M, Cheng, H, Yang, G, Fu, Q & Sun, Y 2022, 'Ultra-fast self-repairing of anti-corrosive coating based on synergistic effect between cobalt octoate and linseed oil', Progress in Organic Coatings, vol. 166, pp. 106776-106776.
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A new microcapsule was prepared by a facile emulsions process for improving the self-repairing speed of anti-corrosive polymer coating. The microcapsule is based on the cobalt octoate/linseed oil and GO nanosheets, which acts as core and shell. The new microcapsule in polyurethane coating provided the ultra-fast self-repairing speed (ca.5.0 min). The result was attributed to synergistic catalytic curing reaction of linseed oil in presence of cobalt octoate and O2. Furthermore, it also improved their anti-corrosion properties due to the good barrier of the GO nanosheets. The work confirms the formation of anti-corrosive polymer coating with ultra-fast self-repairing performance for various applications.
Li, H, Li, J & Bi, K 2022, 'A quasi-active negative stiffness damper for structural vibration control under earthquakes', Mechanical Systems and Signal Processing, vol. 173, pp. 109071-109071.
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This paper proposes a novel quasi-active negative stiffness damper (QANSD) for effective and robust seismic protection. By integrating the negative stiffness element and controllable damping element together, the proposed device enables to closely achieve active control performance with much less energy to operate compared to an active control system. Such a control system has been named as “Quasi-Active” control (QAC) in this study. To introduce the concept of QAC, this paper reiterates the fundamentals of active and semi-active vibration control systems from the perspective of control force, and numerically examines a few examples via comprehensive evaluation indices. The inherent shortfall of semi-active methods on control effectiveness is illustrated by an example of semi-active dampers. It is clearly revealed that the incapacity of semi-active control to capture the entire required active control force (RACF) is due to the fact that the amount of control force that can be generated by a semi-active control system is based on the responses of the structure, which prevents the semi-active control to achieve equivalent active control performance. To address this issue, this paper introduces the QAC concept and a specific realization, i.e. QANSD, including its principles, control strategy and realization. Furthermore, a generalized design approach and related formulae for designing the QANSD are developed with a special interest in obtaining its negative stiffness thresholds. Moreover, to demonstrate its control effectiveness and superiorities, comparative numerical studies are conducted based on a three-storey frame model. The comparisons are made among the same structure without control, with active control, semi-active control, passive control, as well as QAC. In the study, four scaled earthquakes are used as ground motion excitations and five evaluation criteria are adopted to assess the control performances. The results show that, with much less r...
Li, J, Guo, J, Zhu, X & Yu, Y 2022, 'Nonlinear characteristics of damaged bridges under moving loads using parameter optimization variational mode decomposition', Journal of Civil Structural Health Monitoring, vol. 12, no. 5, pp. 1009-1026.
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Investigation on the dynamic characteristics of bridges for structural condition assessment is challenging when nonlinear breathing cracks in the bridge and nonstationary vehicle-bridge interaction are considered. Variational mode decomposition (VMD) method has been widely used to analyze the nonlinear time-series, but its performance is highly dependent on the parameter setting, i.e., the number of modes and the penalty factor. A new method based on the parameter optimization VMD is proposed to extract the nonlinear dynamic characteristics from responses of bridge under moving vehicle loads in this paper. The Chicken Swarm Optimization algorithm is used to optimize the VMD parameters to improve the decomposition and characterization. A general breathing crack model is introduced to simulate the bridge damage. The acceleration response of bridge considering the cracks is decomposed by the proposed method. The instantaneous frequency (IF) is then obtained from the time–frequency representation of the bridge-related response component using the ridge detection. Numerical simulations are performed to investigate the effect of the crack location and extent on the IFs for structural damage detection. The effect of the vehicle–bridge interaction is also discussed. The method is further verified using the laboratory experimental results of a concrete bridge model under the vehicle load. The nonstationary and nonlinear dynamic properties of the bridge model with different damage scenarios are successfully identified. The results show that the extracted IF clearly reveals the behaviour of breathing crack that can be a potential indicator of the damage in the bridge.
Li, J, Ou, R, Liao, H, Ma, J, Sun, L, Jin, Q, He, D & Wang, Q 2022, 'Natural lighting enhancing the algae proliferation and nitrogen removal in membrane-aerated bacterial-algal biofilm reactor', Science of The Total Environment, vol. 851, no. Pt 1, pp. 158063-158063.
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Membrane-aerated bacterial-algal biofilm reactor (MABAR) is an emerging and novel technology in recent years, which has been attracting increasing attention due to its cost-effectiveness and superior removal performance of pollutants by versatile removal pathways in symbiotic bacterial-algal biofilm. However, the wider application of MABAR is hindered by the dilemma of insufficient algae biomass. In this study, an MABAR under natural sunlight was developed and operated for 160 d to access the feasibility of enhancing algae proliferation by natural lighting. Results showed that the MABAR with natural sunlight (nMABAR) demonstrated better performance of pollutants removal. High removal efficiencies of organic matter and NH4-N in nMABAR were 90 % and 92 %, respectively. In particular, the removal efficiency of TN in nMABAR, under less aeration, was up to 80 %, which was 15 % higher than the control reactor. The Chlorophyll-a content indicated that natural sunlight facilitated to algae growth in MABAR, and algae assimilation might be the dominant contributor to NH4-N removal. Moreover, there were microbial shifts in bacterial-algal biofilm in a response to the natural lighting, the nMABAR uniquely possessed a bacterial phylotype termed Thiocapsa, which could play an important role in bacterial nitrification. Algal phylotype Chlorophyceae significantly contributed to pollutants removal and synergistic relationship with bacteria. In addition, the superb performance of nMABAR under less aeration condition suggested that abundant algae were capable of supplying enough O2 for the system. These results provided insight into the natural lighting on algae-bacteria synergistic growth and cost-effective operation strategy for MABAR.
Li, J, Wang, W, Wu, C, Liu, Z & Wu, P 2022, 'Impact response of ultra-high performance fiber-reinforced concrete filled square double-skin steel tubular columns', Steel and Composite Structures, vol. 42, no. 3, pp. 325-351.
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This paper studies the lateral impact behavior of ultra-high performance fiber-reinforced concrete (UHPFRC) filled double-skin steel tubular (UHPFRCFDST) columns. The impact force, midspan deflection, and strain histories were recorded. Based on the test results, the influences of drop height, axial load, concrete type, and steel tube wall thickness on the impact resistance of UHPFRCFDST members were analyzed. LS-DYNA software was used to establish a finite element (FE) model of UHPFRC filled steel tubular members. The failure modes and histories of impact force and midspan deflection of specimens were obtained. The simulation results were compared to the test results, which demonstrated the accuracy of the finite element analysis (FEA) model. Finally, the effects of the steel tube thickness, impact energy, type of concrete and impact indenter shape, and void ratio on the lateral impact performances of the UHPFRCFDST columns were analyzed.
Li, J, Zhu, X & Guo, J 2022, 'Bridge modal identification based on successive variational mode decomposition using a moving test vehicle', Advances in Structural Engineering, vol. 25, no. 11, pp. 2284-2300.
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Bridge modal identification using an instrumented test vehicle as a moving sensor is promising but challenging. A key factor is to extract bridge dynamic components from vehicle responses measured when the bridge is operating. A new method based on an advanced adaptive signal decomposition technique, the successive variational mode decomposition (SVMD), has been developed to estimate the bridge modal parameters from the dynamic responses of a passing test vehicle. When bridge-related dynamic components are extracted from the decomposition, the natural excitation technique and/or random-decrement technique based fitting methods are used to estimate the modal frequencies and damping ratios of the bridge. Effects of measurement noise, moving speed and vehicle properties on the decomposition are investigated numerically. The superiority of SVMD in the decomposition is verified by comparing to another adaptive decomposition technique, the singular spectrum decomposition. The results of the proposed method confirm that the bridge modal frequencies can be identified from bridge related components with high accuracy, while damping ratio is more sensitive to the random operational load. Finally, the feasibility of the proposed method for bridge monitoring using a moving test vehicle is further verified by an in-situ experimental test on a cable-stayed bridge. The components related to the bridge dynamic responses are successfully extracted from vehicle responses.
Li, J, Zhu, X & Guo, J 2022, 'Enhanced drive‐by bridge modal identification via dual Kalman filter and singular spectrum analysis', Structural Control and Health Monitoring, vol. 29, no. 5.
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The drive-by bridge health monitoring is to assess the bridge condition using the acceleration responses measured on the body or axle of instrumented vehicles. The vehicle responses are greatly affected by the road surface roughness that makes the bridge dynamic information blurred. Instead of direct using vehicle responses for the bridge monitoring, the dynamic response of contact point (CP) between the vehicle and bridge is further explored to enhance the drive-by bridge modal identification. A novel three-step framework is proposed to extract the components related to the bridge vibration from vehicle responses. The first step is to identify the input forces of two successive vehicles by solving the combined state-input estimation problem using dual Kalman filter. The CP responses of two contact points are calculated using the input forces and vehicle parameters. In the second step, the subtraction technique is applied to the identified CP responses of the two instrumented vehicles and the effect of the road surface roughness can be significantly reduced. Finally, an automatic singular spectrum analysis technique (auto SSA) is incorporated to decompose the response residual. Then the mono-component modes related to the bridge response are extracted from the response residual for drive-by bridge modal identification and/or the nonstationary characteristic identification of vehicle–bridge interaction (VBI) system. Results of numerical and experimental study demonstrate that the method can significantly suppress the vehicle response component and reduce the effect of road surface roughness to enhance the bridge modal identification.
Li, K, Duan, H, Liu, L, Qiu, R, van den Akker, B, Ni, B-J, Chen, T, Yin, H, Yuan, Z & Ye, L 2022, 'An Integrated First Principal and Deep Learning Approach for Modeling Nitrous Oxide Emissions from Wastewater Treatment Plants', Environmental Science & Technology, vol. 56, no. 4, pp. 2816-2826.
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Mathematical modeling plays a critical role toward the mitigation of nitrous oxide (N2O) emissions from wastewater treatment plants (WWTPs). In this work, we proposed a novel hybrid modeling approach by integrating the first principal model with deep learning techniques to predict N2O emissions. The hybrid model was successfully implemented and validated with the N2O emission data from a full-scale WWTP. This hybrid model is demonstrated to have higher accuracy for N2O emission modeling in the WWTP than the mechanistic model or pure deep learning model. Equally important, the hybrid model is more applicable than the pure deep learning model due to the lower requirement of data and the pure mechanistic model due to the less calibration requirement. This superior performance was due to the hybrid nature of the proposed model. It integrated the essential wastewater treatment knowledge as the first principal component and the less understood N2O production processes by the data-driven deep learning approach. The developed hybrid model was also successfully implemented under different circumstances for the prediction of N2O flux, which showed the generalizability of the model. The hybrid model also showed great potential to be applied for the N2O mitigation work. Nevertheless, the capability of the hybrid model in evaluating N2O mitigation strategies still requires validation with experiments. Going beyond N2O modeling in WWTP, the novel hybridization modeling concept can potentially be applied to other environmental systems.
Li, K, Zhang, Y, Zhang, X, Ni, B-J, Wei, Y, Xu, B & Hao, D 2022, 'A readily synthesized bismuth oxyiodide/attapulgite for the photodegradation of tetracycline under visible light irradiation', CrystEngComm, vol. 24, no. 16, pp. 3064-3073.
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Bismuth oxyiodide and attapulgite have proven to be potential materials for the removal of emerging contaminants in wastewater.
Li, N, Asteris, PG, Tran, TT, Pradhan, B & Nguyen, H 2022, 'Modelling the deflection of reinforced concrete beams using the improved artificial neural network by imperialist competitive optimization', Steel and Composite Structures, vol. 42, no. 6, pp. 733-745.
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This study proposed a robust artificial intelligence (AI) model based on the social behaviour of the imperialist competitive algorithm (ICA) and artificial neural network (ANN) for modelling the deflection of reinforced concrete beams, abbreviated as ICA-ANN model. Accordingly, the ICA was used to adjust and optimize the parameters of an ANN model (i.e., weights and biases) aiming to improve the accuracy of the ANN model in modelling the deflection reinforced concrete beams. A total of 120 experimental datasets of reinforced concrete beams were employed for this aim. Therein, applied load, tensile reinforcement strength and the reinforcement percentage were used to simulate the deflection of reinforced concrete beams. Besides, five other AI models, such as ANN, SVM (support vector machine), GLMNET (lasso and elastic-net regularized generalized linear models), CART (classification and regression tree) and KNN (k-nearest neighbours), were also used for the comprehensive assessment of the proposed model (i.e., ICA-ANN). The comparison of the derived results with the experimental findings demonstrates that among the developed models the ICA-ANN model is that can approximate the reinforced concrete beams deflection in a more reliable and robust manner.
Li, N, Nguyen, H, Rostami, J, Zhang, W, Bui, X-N & Pradhan, B 2022, 'Predicting rock displacement in underground mines using improved machine learning-based models', Measurement, vol. 188, pp. 110552-110552.
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Displacement of rock mass in tunnels and underground mines is considered one of the most hazardous phenomena that can cause the collapse of the structures. In this study, the rock properties, such as the depth of the tunnels (H), the angle of rock layers (α), anti-bending moment (Wc), the width of the tunnels (b), the tensile strength of rock layers (Rn), and monitoring distance (Lb), and observation time (t), were investigated to predict rock displacement in tunnels and underground mines. Two novel soft computing models, namely Harris Hawks optimization algorithm (HHOA)-based support vector machine (SVM) model (i.e., HHOA-SVM) and Grasshopper optimization algorithm (GOA)-based SVM model (i.e., GOA-SVM), were developed for this aim based on the field measurements. A total of 12 measurement stations and 63 observations of vertical rock mass displacement, rock properties, and observation time in some underground coal mines in the Donbas region (Ukraine) were compiled as the dataset for developing soft computing models. In addition, a constraint was also added to the proposed HHOA-SVM and GOA-SVM models to prevent the model from offering negative results in predicting rock displacement. The conventional models, such as SVM (without optimization) and artificial neural network (ANN), were also investigated to compare favorably with the two proposed HHOA-SVM and GOA-SVM models. Furthermore, linear and nonlinear equations were also established to predict rock displacement and compared to the soft computing models. The results showed that the novel HHOA-SVM and GOA-SVM models provided better performances than conventional SVM and ANN models. Besides, the sensitivity of the input variables was also analyzed to discover the certain characteristics of the rock displacement phenomenon through the properties of rock and observation time. The findings show that H, Lb, t, and α are the most influential parameters for predicting rock displacement in tunnels and undergr...
Li, Q, Yuan, X, Hu, X, Meers, E, Ong, HC, Chen, W-H, Duan, P, Zhang, S, Lee, KB & Ok, YS 2022, 'Co-liquefaction of mixed biomass feedstocks for bio-oil production: A critical review', Renewable and Sustainable Energy Reviews, vol. 154, pp. 111814-111814.
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Li, S, Show, PL, Ngo, HH & Ho, S-H 2022, 'Algae-mediated antibiotic wastewater treatment: A critical review', Environmental Science and Ecotechnology, vol. 9, pp. 100145-100145.
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Li, W, Dong, W, Guo, Y, Wang, K & Shah, SP 2022, 'Advances in multifunctional cementitious composites with conductive carbon nanomaterials for smart infrastructure', Cement and Concrete Composites, vol. 128, pp. 104454-104454.
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Conductive carbon nanomaterials have been extensively developed for smart cementitious composites to gain multifunctionalities (e.g. self-sensing, self-healing, self-heating, and electromagnetic interference shielding). This paper critically reviewed dispersion and percolation of 0 dimension (0D), 1 dimension (1D) and 2 dimensions (2D) carbon materials used in cementitious composites and their effects on the electrical and piezoresistive performances. The different dispersion methods summarized are from mechanical dispersion, ultrasonic and high shearing, chemical modification, mineral additives, to carbon materials at multiple dimensions and hybrid dispersion methods. The electrical resistivity and piezoresistivity of cementitious composites with single carbon material or hybrid carbon materials are comprehensively analysed and compared in terms of efficiency and self-sensing mechanism. Furthermore, the existing theoretical modelling studies have been reviewed, indicating that many factors related to the electrical and piezoresistive behaviours, such as water content and nanocomposite agglomeration, have not been considered yet. Although some previous studies demonstrated the potential of applying conductive cementitious composites for self-sensing or heating pavements, further explorations still should be conducted on sustainable and economical manufacturing. Subsequently, the challenges and perspectives of the self-sensing stability, data acquisition system and sensor configuration are proposed with potential solutions for future smart infrastructure.
Li, W, Konsta-Gdoutos, M, Shi, X, Sobolev, K & Shah, SP 2022, 'Editorial: Intelligent Concrete, New Functionalities and Nanotechnology', Frontiers in Materials, vol. 9.
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Li, W, Qu, F, Dong, W, Mishra, G & Shah, SP 2022, 'A comprehensive review on self-sensing graphene/cementitious composites: A pathway toward next-generation smart concrete', Construction and Building Materials, vol. 331, pp. 127284-127284.
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Two-dimension graphene-based nanomaterials (GBNs), such as multi-layers graphene (GNPs) and graphene oxide (GOs) have been extensively applied to enhance the mechanical properties, durability, and self-sensing performance of construction materials. Although there are some reviews on the mechanical properties and durability of graphene-based cementitious composites (GBCCs), very few papers have comprehensively covered the nano-, micro- and meso-scale properties, components, structures, and self-sensing properties, and the applications of the GBCCs. In this review, the characteristics of various GBNs with different dimensions were firstly illustrated and compared, and the enhancement methods for dispersion of 2D GBNs before mixed with cementitious materials were also comprehensively compared and discussed. When GBNs were mixed with cement, the nano- and micro-scale characteristics of GBCCs with respect to the hydration, phase transformations, microstructures, and pore characteristics were also systematically discussed. Macroscale performances of GBCCs, such as rheology, flowability, mechanical strength were analyzed, and the durability performances (e.g. chemical and fire attack, shrinkage and transport properties) of GBCCs were evaluated correspondingly. On the other hand, the self-sensing properties (e.g. electrical resistivity, piezoresistivity, and electromagnetic properties) of GBCCs were assessed for potential practical applications for structural health monitoring (SHM). Furthermore, some case studies and applications of GBCCs as advanced cement-based sensors for SHM were also evaluated. Finally, the application challenges and perspectives of adopting 2D GBNs for smart and sustainable concrete structures were proposed and discussed correspondingly. The conclusions of this review will promote future researchers and civil engineers in the concrete-related industry with the aim to developing sustainable and functional graphene-based concrete for the n...
Li, X, Johnson, I, Mueller, K, Wilkie, S, Hanzic, L, Bond, PL, O'Moore, L, Yuan, Z & Jiang, G 2022, 'Corrosion mitigation by nitrite spray on corroded concrete in a real sewer system', Science of The Total Environment, vol. 806, no. Pt 3, pp. 151328-151328.
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Microbially influenced concrete corrosion (MICC) in sewers is caused by the activity of sulfide-oxidizing microorganisms (SOMs) on concrete surfaces, which greatly deteriorates the integrity of sewers. Surface treatment of corroded concrete by spraying chemicals is a low-cost and non-intrusive strategy. This study systematically evaluated the spray of nitrite solution in corrosion mitigation and re-establishment in a real sewer manhole. Two types of concrete were exposed at three heights within the sewer manhole for 21 months. Nitrite spray was applied at the 6th month for half of the coupons which had developed active corrosion. The corrosion development was monitored by measuring the surface pH, corrosion product composition, sulfide uptake rate, concrete corrosion loss, and the microbial community on the corrosion layer. Free nitrous acid (FNA, i.e. HNO2), formed by spraying a nitrite solution on acidic corrosion surfaces, was shown to inhibit the activity of SOMs. The nitrite spray reduced the corrosion loss of concrete at all heights by 40-90% for six months. The sulfide uptake rate of sprayed coupons was also reduced by about 35%, leading to 1-2 units higher surface pH, comparing to the control coupons. The microbial community analysis revealed a reduced abundance of SOMs on nitrite sprayed coupons. The long-term monitoring also showed that the corrosion mitigation effect became negligible in 15 months after the spray. The results consistently demonstrated the effectiveness of nitrite spray on the MICC mitigation and identified the re-application frequencies for full scale applications.
Li, X, Kulandaivelu, J, Guo, Y, Zhang, S, Shi, J, O’Brien, J, Arora, S, Kumar, M, Sherchan, SP, Honda, R, Jackson, G, Luby, SP & Jiang, G 2022, 'SARS-CoV-2 shedding sources in wastewater and implications for wastewater-based epidemiology', Journal of Hazardous Materials, vol. 432, pp. 128667-128667.
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Wastewater-based epidemiology (WBE) approach for COVID-19 surveillance is largely based on the assumption of SARS-CoV-2 RNA shedding into sewers by infected individuals. Recent studies found that SARS-CoV-2 RNA concentration in wastewater (CRNA) could not be accounted by the fecal shedding alone. This study aimed to determine potential major shedding sources based on literature data of CRNA, along with the COVID-19 prevalence in the catchment area through a systematic literature review. Theoretical CRNA under a certain prevalence was estimated using Monte Carlo simulations, with eight scenarios accommodating feces alone, and both feces and sputum as shedding sources. With feces alone, none of the WBE data was in the confidence interval of theoretical CRNA estimated with the mean feces shedding magnitude and probability, and 63% of CRNA in WBE reports were higher than the maximum theoretical concentration. With both sputum and feces, 91% of the WBE data were below the simulated maximum CRNA in wastewater. The inclusion of sputum as a major shedding source led to more comparable theoretical CRNA to the literature WBE data. Sputum discharging behavior of patients also resulted in great fluctuations of CRNA under a certain prevalence. Thus, sputum is a potential critical shedding source for COVID-19 WBE surveillance.
Li, X, Wang, X, Pan, X, Zhu, P, Zhang, Q, Huang, X, Deng, X, Wang, Z, Ding, Y, Liu, X & Zhou, JL 2022, 'Potential Hormetic Effects of Cimetidine on Aerobic Composting of Human Feces from Rural China', Sustainability, vol. 14, no. 21, pp. 14454-14454.
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Aerobic composting is widely used worldwide as a natural process for handling human waste. Such waste often contains pharmaceutical residues from human consumption, yet their impact on composting has not been studied. The aim of this study is to investigate the impact of the antihistamine cimetidine (10 mg/kg, 100 mg/kg) on the aerobic composting of human feces. The key results show that 10 mg/kg of cimetidine accelerates temperature increase and moisture removal of the composting substrate. The organic matter in all the groups gradually decreased, and the pH values increased first and then declined with the composting time, with no significant differences between the groups. The NH4+-N concentrations and NH3 emission reached the maximum at 1.5 days and then declined rapidly, while the NO2−-N concentrations increased and then decreased, and the NO3−-N contents tended to increase all the time during the composting. The 100 mg/kg cimetidine caused a higher maximal NH4+-N concentration of compost, and a lower maximal NH3 emission at 1.5 days, while 10 mg/kg cimetidine led to more NO2−-N and NO3−-N contents. In addition, 10 mg/kg cimetidine enhanced the aromatization and humification of dissolved organic matter and promoted the degradation of aliphatic substances. Furthermore, 100 mg/kg cimetidine generated a larger influence on the microorganisms than 10 mg/kg cimetidine, especially for the microorganisms related to nitrogen transformation. The findings imply that cimetidine has a dose-dependent impact on the decomposition of organic matter and the conversion of nitrogen in human feces during composting. It deserves further investigation of the possible hormesis effect.
Li, Y & Whitacre, BE 2022, 'Economic Growth and Adult Obesity Rates in Rural America', REVIEW OF REGIONAL STUDIES, vol. 52, no. 3, pp. 387-410.
Li, Y, Zeng, X, Shi, Y, Yang, K, Zhou, J, Umar, HA, Long, G & Xie, Y 2022, 'A comparative study on mechanical properties and environmental impact of UHPC with belite cement and portland cement', Journal of Cleaner Production, vol. 380, pp. 135003-135003.
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Developing an eco-friendly UHPC with Belite cement (BC) is a great challenge because the mechanical strength of concrete with BC develops much more slowly than Ordinary Portland cement (alite-rich cement, OPC). However, BC has a lower CO2 footprint than OPC due to a lower calcined temperature and less limestone demand, making it green cement. Besides, concrete with BC has better long-age performance. In this study, the utilization of BC in UHPC was compared to that of OPC. Three curing regimes were used for the designed UHPC. The compressive and flexural strengths of UHPC-BC are lower than of UHPC-OPC at one day but higher after 28 and 90 days of standard curing. After heat curing, the mechanical strength development of UHPC-BC improves noticeably and exceeds UHPC-OPC. UHPC-BC has a higher flexural strength to compressive strength ratio (ff/fcu), and there are more C–S–H, less CH and lower pore coarsening of UHPC-BC paste than UHPC-OPC, especially after heat curing. UHPC-BC has lower environmental impact indices at long age than UHPC-OPC. At 90 days of autoclaved curing, the compressive of UHPC-BC reaches up to 197.5 MPa with the embodied carbon content of 934.37 kg/m3, which is much lower than most UHPCs.
Li, Y, Zhang, X, Ngo, HH, Guo, W, Zhang, D, Wang, H & Long, T 2022, 'Magnetic spent coffee biochar (Fe-BC) activated peroxymonosulfate system for humic acid removal from water and membrane fouling mitigation', Journal of Water Process Engineering, vol. 49, pp. 103185-103185.
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Liang, Y, Liu, Y, Zhou, Y, Shi, Q, Zhang, M, Li, Y, Wen, W, Feng, L & Wu, J 2022, 'Efficient and stable electrorheological fluids based on chestnut-like cobalt hydroxide coupled with surface-functionalized carbon dots', Soft Matter, vol. 18, no. 20, pp. 3845-3855.
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The synergistic effect of the lipophilic groups on the surface of CDs and the biomimetic chestnut-like structure give Co(OH)2@CDs good wettability with silicone oil, great electrorheological efficiency and dynamic shear stress stability.
Lim, AC, Tang, SGH, Zin, NM, Maisarah, AM, Ariffin, IA, Ker, PJ & Mahlia, TMI 2022, 'Chemical Composition, Antioxidant, Antibacterial, and Antibiofilm Activities of Backhousia citriodora Essential Oil', Molecules, vol. 27, no. 15, pp. 4895-4895.
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The essential oil of Backhousia citriodora, commonly known as lemon myrtle oil, possesses various beneficial properties due to its richness in bioactive compounds. This study aimed to characterize the chemical profile of the essential oil isolated from leaves of Backhousia citriodora (BCEO) and its biological properties, including antioxidant, antibacterial, and antibiofilm activities. Using gas chromatography–mass spectrometry, 21 compounds were identified in BCEO, representing 98.50% of the total oil content. The isomers of citral, geranial (52.13%), and neral (37.65%) were detected as the main constituents. The evaluation of DPPH radical scavenging activity and ferric reducing antioxidant power showed that BCEO exhibited strong antioxidant activity at IC50 of 42.57 μg/mL and EC50 of 20.03 μg/mL, respectively. The antibacterial activity results showed that BCEO exhibited stronger antibacterial activity against Gram-positive bacteria (Staphylococcus aureus and Staphylococcus epidermidis) than against Gram-negative bacteria (Escherichia coli and Klebsiella pneumoniae). For the agar disk diffusion method, S. epidermidis was the most sensitive to BCEO with an inhibition zone diameter of 50.17 mm, followed by S. aureus (31.13 mm), E. coli (20.33 mm), and K. pneumoniae (12.67 mm). The results from the microdilution method showed that BCEO exhibited the highest activity against S. epidermidis and S. aureus, with the minimal inhibitory concentration (MIC) value of 6.25 μL/mL. BCEO acts as a potent antibiofilm agent with dual actions, inhibiting (85.10% to 96.44%) and eradicating (70.92% to 90.73%) of the biofilms formed by the four tested bacteria strains, compared with streptomycin (biofilm inhibition, 67.65% to 94.29% and biofilm eradication, 49.97% to 89.73%). This study highlights that BCEO can potentially be a natural antioxidant agent, antibacterial agent, and antibiofilm agent that could be applied in the pharmaceutical and food industries. To ...
Lim, S-M, Indraratna, B, Heitor, A, Yao, K, Jin, D, Albadri, WM & Liu, X 2022, 'Influence of matric suction on resilient modulus and CBR of compacted Ballina clay', Construction and Building Materials, vol. 359, pp. 129482-129482.
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Lin, C, Cheruiyot, NK, Bui, X-T & Ngo, HH 2022, 'Composting and its application in bioremediation of organic contaminants', Bioengineered, vol. 13, no. 1, pp. 1073-1089.
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This review investigates the findings of the most up-to-date literature on bioremediation via composting technology. Studies on bioremediation via composting began during the 1990s and have exponentially increased over the years. A total of 655 articles have been published since then, with 40% published in the last six years. The robustness, low cost, and easy operation of composting technology make it an attractive bioremediation strategy for organic contaminants prevalent in soils and sediment. Successful pilot-and large-scale bioremediation of organic contaminants, e.g., total petroleum hydrocarbons, plasticizers, and persistent organic pollutants (POPs) by composting, has been documented in the literature. For example, composting could remediate >90% diesel with concentrations as high as 26,315 mg kg-a of initial composting material after 24 days. Composting has unique advantages over traditional single- and multi-strain bioaugmentation approaches, including a diverse microbial community, ease of operation, and the ability to handle higher concentrations. Bioremediation via composting depends on the diverse microbial community; thus, key parameters, including nutrients (C/N ratio = 25-30), moisture (55-65%), and oxygen content (O2 > 10%) should be optimized for successful bioremediation. This review will provide bioremediation and composting researchers with the most recent finding in the field and stimulate new research ideas.
Lin, W, Chen, R, Liu, X, Hao Ngo, H, Nan, J, Li, G, Ma, J, He, X & Ding, A 2022, 'Deep mechanism of enhanced dewaterability of residual sludge by Na+: Comprehensive analyses of intermolecular forces, hydrophilicity and water-holding capacity of EPS', Chemical Engineering Journal, vol. 450, pp. 138505-138505.
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Extracellular polymeric substance (EPS) is generally considered as the limiting factor affecting sludge dewatering due to its complex components and water-holding capacity. Conventional flocculation conditioning could improve the dewaterability by generating a certain number of channels for water discharge. However, the hydrophilicity and water-holding capacity of EPS still cannot change, resulting in the inability to further consolidate sludge dewaterability. To overcome this challenge, the study explores the application ability of sodium chloride via Na+ conditioning for sludge dewatering and compared with calcium chloride (CaCl2) and ferric chloride (FeCl3) conditioning effects. Results confirmed that the specific resistance to filtration (SRF) and water content (WC) fell dramatically from 14.3 × 1012 m/kg to 8.1 × 1012 m/kg and 80.8 % to 75.4 %, respectively, at the Na+ concentration of 80 mmol/L. The mechanism investigations indicated that addition of Na+ clearly destroyed the structure of EPS and promoted the declines in hydrophilicity and water-holding capability of EPS, resulting in much less bound water, changes in secondary structure and functional groups (e.g. N[sbnd]H, and C[dbnd]O) of EPS proteins. Furthermore, analyses of surface thermodynamic illustrated that the aggregation ability of sludge enhanced after the conditioning of Na+ combined with re-flocculation. Additionally, compared with Ca2+ and Fe3+, applying the combined conditioning method led to stronger hydrophobicity of EPS through the analysis of two-dimension correlation spectroscopy (2D-COS). This work can drive innovation in applying salty water containing sodium for effectively sludge dewatering.
Lin, W, Ding, A, Ngo, HH, Ren, Z, Nan, J, Li, G & Ma, J 2022, 'Effects of the metabolic uncoupler TCS on residual sludge treatment: Analyses of the microbial community and sludge dewaterability potential', Chemosphere, vol. 288, pp. 132473-132473.
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Lin, W, Liu, X, Ding, A, Ngo, HH, Zhang, R, Nan, J, Ma, J & Li, G 2022, 'Advanced oxidation processes (AOPs)-based sludge conditioning for enhanced sludge dewatering and micropollutants removal: A critical review', Journal of Water Process Engineering, vol. 45, pp. 102468-102468.
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Applying advanced oxidation processes (AOPs) in sludge dewatering to improve sludge treatment, disposal and environmental protection has attracted much interest due to the difficulties arising in extracellular polymeric substances (EPS) degradation during the sludge dewatering process. Oxidants can produce different types of free radicals and exert specific oxidation effects through different action mechanisms on water saturated sludge. This plays an important role in sludge dewatering, sludge minimization and removal of different types of micropollutants and/or their transformation. The current review critically evaluates the role of AOP in improving the efficiency of sludge dewatering. Characteristics of advanced oxidation methods applied to sludge dewatering are systematically illustrated through different mechanisms using free radical reactions and various sludge dewatering conditions. Factors which impact on influencing the minimization of sludge and removals of typical micropollutants during the sludge conditioning process are also analyzed. Finally, applications of advanced oxidation methods in the future are proposed based on a technoeconomic analyses of dewatering efficiency and operation cost. This review provides theoretical support regarding the application of advanced oxidation processes in sludge dewatering and avenues for practical engineering. In the current review, it is determined that the efficiency of AOP for the improvement of sludge dewatering, micropollutants removal and sludge minimization in the treatment and disposal of sludge have been fully investigated. Unfortunately, there is still lack of comparing the ability of different free radicals on published review.
Lin, W, Zeng, J, Zhang, R, He, X, Nan, J, Li, G, Ma, J, Ngo, HH & Ding, A 2022, 'Selection of metal ions in different valence states on sludge conditioning: Analysis of hydrophobicity and evaluation of resource recovery capacity', Journal of Water Process Engineering, vol. 50, pp. 103297-103297.
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Lin, W-T, Chen, G & Huang, Y 2022, 'Incentive edge-based federated learning for false data injection attack detection on power grid state estimation: A novel mechanism design approach', Applied Energy, vol. 314, pp. 118828-118828.
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With the growing concern in security and privacy of smart grid, false data injection attack detection on power grid state estimation now faces new challenges including unknown system parameters and small decentralized data sets with strategic data owners. To deal with these technical bottlenecks, this paper proposes a novel edge-based federated learning framework for false data injection attack detection on power grid state estimation, which has great potential in real-world applications with unknown system parameters. Furthermore, to seek a high detection accuracy with small decentralized data set and strategic data owners, an incentive mechanism is designed to encourage the desired data owners contributing to false data injection attack detection. To explore the impact of the incentive mechanism on the detection accuracy, a bi-level model depicting the data owners’ participation in false data injection attack detection is formulated, based on which the impact is quantified. Moreover, a novel preference criterion is proposed for optimal mechanism design. It can achieve the optimal detection accuracy under a certain incentive budget. The incentive mechanism is designed and tested for 100 Monte Carlo scenarios. Simulations of false data injection attack detection on power grid state estimation show that the proposed framework outperforms the existing works without mechanism design.
Lin, Y, Huo, P, Li, F, Chen, X, Yang, L, Jiang, Y, Zhang, Y, Ni, B-J & Zhou, M 2022, 'A critical review on cathode modification methods for efficient Electro-Fenton degradation of persistent organic pollutants', Chemical Engineering Journal, vol. 450, pp. 137948-137948.
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The Electro-Fenton (EF) technology has received significant research attention because of its efficacy in the degradation of persistent organic pollutants (POPs), which mainly relies on the in-situ generation of H2O2 via the 2-electron oxygen reduction reaction and the subsequent formation of •OH. However, the practical application of the EF technology still needs to deal with shortcomings such as the limited performance of the traditional heterogeneous catalyst and the restricted generation of •OH that could be overcome by performing modification on the cathode. This work reviewed the reported cathode modification methods including thermal and (electro)chemical treatment and modification based on materials such as metals, graphene, carbon nanotubes, and polymers. Furthermore, the documented performances of the EF systems with differently modified cathodes in degrading specific POPs were presented. Finally, the advantages and limitations of these cathode modification methods were discussed, and some research perspectives were proposed to improve the practicability and feasibility of the EF technology.
Liu, A, Lin, S, Wang, J & Kong, X 2022, 'A Succinct Method for Non-Line-of-Sight Mitigation for Ultra-Wideband Indoor Positioning System', Sensors, vol. 22, no. 21, pp. 8247-8247.
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Ultra-wideband (UWB) is a promising indoor position technology with centimetre-level positioning accuracy in line-of-sight (LOS) situations. However, walls and other obstacles are common in an indoor environment, which can introduce non-line-of-sight (NLOS) and deteriorate UWB positioning accuracy to the meter level. This paper proposed a succinct method to identify NLOS induced by walls and mitigate the error for improved UWB positioning with NLOS. First, NLOS is detected by a sliding window method, which can identify approximately 90% of NLOS cases in a harsh indoor environment. Then, a delay model is designed to mitigate the error of the UWB signal propagating through a wall. Finally, all the distance measurements, including LOS and NLOS, are used to calculate the mobile UWB tag position with ordinary least squares (OLS) or weighted least squares (WLS). Experiment results show that with correct NLOS indentation and delay model, the proposed method can achieve positioning accuracy in NLOS environments close to the level of LOS. Compared with OLS, WLS can further optimise the positioning results. Correct NLOS indentation, accurate delay model and proper weights in the WLS are the keys to accurate UWB positioning in NLOS environments.
Liu, G, Liu, L, Huo, Y, Dai, Z, Zhang, L & Wang, Q 2022, 'Enhanced two-phase anaerobic digestion of waste activated sludge by combined free nitrous acid and manganese dioxide', Journal of Cleaner Production, vol. 379, pp. 134777-134777.
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Anaerobic digestion (AD) is a mature and reliable technology for sludge treatment, but it still faces many technical problems including slow hydrolysis rate and low methane yield. Free nitrous acid (FNA) pretreatment was previously confirmed in enhancing sludge hydrolysis and extracellular polymeric substances (EPS) disruption in anaerobic digestion. It was hypothesized that, due to the manganese dioxide (MnO2) addition during methanogenic stage, direct interspecies electron transfer (DIET) facilitated the biological activities, thus boosting the methane production in FNA-pretreated two-phase AD model. The results showed that the methane production of the combination of FNA pretreatment and MnO2 addition was improved by 18.64% and 22.23%, compared with reactors that solely treated by either MnO2 addition or FNA pretreatment. The changes of microbial metabolism activity were evaluated by measuring the coenzyme F420 and electron transfer system (ETS). The activities of coenzyme F420 and ETS were increased to 156.26% and 134.71% in two-phase AD model, respectively. Meanwhile, the obvious microbial community succession was found with the enrichment of methanogens such as Methanosarcina and Methanobacterium. Overall, the combination of FNA pretreatment and MnO2 addition avoided the inhibition of FNA pretreatment on methanogenesis in the early stage, and showed positively synergistic effect on methane production. The enhancement of microbial metabolism was responsible for, promoting methane production in the two-stage AD model. This research provides an alternative strategy for efficiency improvement of anaerobic sludge digestion as well as methane production.
Liu, H, Li, X, Zhang, Z, Nghiem, LD & Wang, Q 2022, 'Urine pretreatment significantly promotes methane production in anaerobic waste activated sludge digestion', Science of The Total Environment, vol. 853, pp. 158684-158684.
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Methane production of waste activated sludge (WAS) in anaerobic digestion is hindered due to the rate-limited hydrolysis process and the low methane potential of WAS. Pretreatment of WAS is a common and appealing strategy to improve methane production in anaerobic digestion. In this study, we proposed to use urine, an easily obtained human waste with high ammonium concentration and pH, as a novel pretreatment strategy for anaerobic WAS digestion. Urine pretreatment at levels of 5-30 % (Vurine/Vurine+WAS) could substantially enhance methane production by 5-35 % in biochemical methane potential (BMP) tests, with the highest methane production of 179.6 ± 3.3 mL/g volatile solids (VS) achieved under the highest level of urine (i.e. 30 % urine addition). Based on the model analysis, the biochemical methane potential (B0) and hydrolysis rate of WAS (k) rose from 131.9 mL/g VS and 0.19 d-1 in the control without pretreatment to 136.3-178.2 mL/g VS and 0.22-0.30 d-1, respectively, after the urine pretreatment (5-30 % addition). Urine pretreatment with 5-30 % addition also improved the degradation extent (Y) of WAS by 3-35 %. The promising results indicate that urine pretreatment in anaerobic digestion is a promising technology to improve the efficiency of anaerobic digestion with environmental and economic benefits.
Liu, J, Li, J, Fang, J, Liu, K, Su, Y & Wu, C 2022, 'Investigation of ultra-high performance concrete slabs under contact explosions with a calibrated K&C model', Engineering Structures, vol. 255, pp. 113958-113958.
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Karagozian and Case (K&C) concrete model is extensively adopted in the numerical simulations of ultra-high performance concrete (UHPC) structural members subjected to impulsive loads such as impact and blast. In this study, a calibration of the K&C concrete model was conducted for UHPC in terms of three strength surfaces, equation of state, shear dilatancy, damage evolution and strain rate effect to offer simple and general guidelines on the determination of key model parameters for this new class of concrete. With the calibrated concrete model, a single element method was adopted to verify its accuracy through a comparison to the results from the static tests of the uniaxial compression, direct tension and triaxial compression. Furthermore, the numerical simulations of contact explosion tests on the UHPC slabs with the incorporation of the strain rate effect were performed and the numerical results exhibited good predictions regarding the failure mode, crater and scabbing damage as compared to the test results. More importantly, this proposed numerical model and simulation methodology are reasonable to be generally used for structural members constructed of UHPC materials under contact explosions when lacking sufficient static and dynamic test data. Using the calibrated and validated K&C concrete model, parametric studies were conducted to derive a new empirical equation for predicting the local damage mode of UHPC slabs under contact explosions.
Liu, J, Li, J, Fang, J, Su, Y & Wu, C 2022, 'Ultra-high performance concrete targets against high velocity projectile impact – a-state-of-the-art review', International Journal of Impact Engineering, vol. 160, pp. 104080-104080.
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Known for its high mechanical strength and ductility, ultra-high performance concrete (UHPC) emerges as a promising material in civil and military constructions to resist hazardous loads such as high velocity projectile impact (HVPI). Due to its unique material properties, structures built with UHPC perform differently to its counterparts made of conventional concrete under HVPI, and thus the empirical and semi-empirical resistant functions for conventional concrete against HVPI require careful evaluation before application to UHPC structures. This study presents a comprehensive review of the research advances in thick UHPC targets to resist HVPI for projectiles at normal incidence. First, the static and dynamic material properties of UHPC are briefly introduced in comparison to conventional concrete. Second, based on physical tests, key aspects in UHPC design to resist HVPI are reviewed, which include fibre reinforcement, high strength coarse aggregate, alternative binder system as well as structural reinforcement and designs. Third, in a view of the development in material constitutive models under complex dynamic loads and computational techniques, numerical simulations of UHPC under HVPI are reviewed and discussed. Further, empirical and semi-empirical formulae to predict the depth of penetration (DOP) on conventional concrete are collected and evaluated on their suitability for UHPC.
Liu, J, Liu, C, Qu, K, Li, J & Wu, C 2022, 'Calibration of Holmquist Johnson Cook (HJC) model for projectile penetration of geopolymer-based ultra-high performance concrete (G-UHPC)', Structures, vol. 43, pp. 149-163.
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Holmquist Johnson Cook (HJC) model has been extensively adopted to simulate the projectile penetration of concrete targets. In this study, based on the available experimental data of uniaxial compression, triaxial compression, split Hopkinson pressure bar (SHPB) and Hugoniot tests, HJC model parameters in terms of the strength surface, strain rate effect, damage evolution and equation of state (EOS) were systematically calibrated for a newly fabricated ultra-high performance concrete termed as geopolymer-based ultra-high performance concrete (G-UHPC). Using the HJC model with calibrated model parameters, numerical simulations of projectile penetration into plain and fibre reinforced G-UHPC targets were performed in a commercial finite element program LS-DYNA. The numerical results for the depth of penetration (DOP) exhibited fair agreement with the test data. The numerical projectile velocity and displacement evolutions were also validated through comparing to the semi-analytical model. These observations demonstrated the applicability and validity of the calibrated HJC model to estimate DOP of G-UHPC targets subjected to projectile impact. With the calibrated and validated HJC model, parametric studies were further conducted to explore the effect of uniaxial compressive strength of G-UHPC, projectile impact velocity, mass, diameter and nose shape on the final DOP values. Based on the numerical results from the parametric studies, an empirical equation concerning the aforementioned variables was proposed, which could help design G-UHPC protective barriers against projectile penetration.
Liu, J, Liu, C, Xu, S, Li, J, Fang, J, Su, Y & Wu, C 2022, 'G-UHPC slabs strengthened with high toughness and lightweight energy absorption materials under contact explosions', Journal of Building Engineering, vol. 50, pp. 104138-104138.
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This study investigates the dynamic characteristics of geopolymer-based ultra-high performance concrete (G-UHPC) slabs strengthened with high toughness and lightweight energy absorption materials under the 1 kg TNT contact explosions. A total of four slabs were tested, including plain G-UHPC slab (G-UHPC-P), 20-layer basalt textile reinforced G-UHPC slab (G-UHPC-BFM), 20-layer steel wire mesh reinforced G-UHPC slab (G-UHPC-SWM) and 1.5 vol-% steel fibre reinforced G-UHPC slab with polyurethane coating (G-UHPC–SF–PU). The test results revealed that the steel wire mesh reinforcement was more effective in resisting contact explosions than the basalt textile reinforcement for G-UHPC. The polyurethane coating on the rear face of the slab exhibited its high tensile strength and deformability to absorb the blast-induced energy so as to enhance the anti-explosion performance of the slab, and additionally prevented the splash of slab fragments upon contact explosions to minimise secondary hazards. Based on the multi-material arbitrary Lagrangian-Eulerian (ALE) algorithm, local damage of G-UHPC-SWM and G-UHPC–SF–PU induced by contact explosions was reproduced using the explicit finite element software LS-DYNA. Fair agreement between the numerical and test results demonstrated that the numerical model could simulate the response of G-UHPC-SWM and G-UHPC–SF–PU with reasonable accuracy. Extensive numerical studies by varying polyurethane strain rate, coating thickness and the bonding between the polyurethane coating and the slab were further performed to analyse their effect on the maximum bulge depth of the polyurethane coating subjected to contact explosions.
Liu, K, Song, R, Li, J, Guo, T, Li, X, Yang, J & Yan, Z 2022, 'Effect of steel fiber type and content on the dynamic tensile properties of ultra-high performance cementitious composites (UHPCC)', Construction and Building Materials, vol. 342, pp. 127908-127908.
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As one of the most promising construction and building materials in the past 30 years, ultra-high performance concrete (UHPC) has attracted a great deal of attention and the studies on its improvement and dynamic tensile behaviors become more important for its wider use in the related fields. In this contribution, a novel ultra-high performance cementitious composites (UHPCC) was developed with lower cement content, 20% of cement is replaced with fly ash and blast furnace slag, to reduce the raw material cost and carbon emission in production. Uniaxial compression, quasi-static and dynamic splitting tests were carried out to investigate the influences of steel fiber type (straight fiber and waved fiber) and content (volume fraction (0%, 1%, 2%)) on the uniaxial compressive strength, static tensile strength and dynamic tensile behaviors for current UHPCC material. The dynamic splitting tests were conducted on 100 disc specimens (75 mm in diameter and 37.5 mm in thickness) under five different impact pressure at a strain-rate range of 20–110 s−1 to study the strain rate effect by using a Split Hopkinson pressure bar (SHPB) system and the samples’ failure processes were captured by a high-speed camera. Based on the test results, the variations of energy absorption with the fiber type and content under static and dynamic tensile conditions are also analyzed, and combined with the experimental data from previous studies, an improved empirical tensile strength rate sensitivity (DIFft) model is proposed, which agrees well with the experiment results and can be used in the numerical simulation. At last, the failure process and pattern of different types of UHPCCs in the dynamic splitting test are also studied.
Liu, K, Wu, C, Li, X, Tao, M, Li, J, Liu, J & Xu, S 2022, 'Fire damaged ultra-high performance concrete (UHPC) under coupled axial static and impact loading', Cement and Concrete Composites, vol. 126, pp. 104340-104340.
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The load bearing structural components such as columns could experience axial static loads during the service life. High temperature induced by fire would have a significant detrimental impact on the mechanical properties of concrete materials. The structure could be severely damaged as the column was simultaneously loaded by other impact loads. In this study, the behavior of fire damaged ultra-high performance concrete (UHPC) with a compressive strength of 128.3 MPa under coupled axial static and impact loading was studied. UHPC specimens were heated to the target temperatures (250, 500 and 750 °C) in an electric furnace and then naturally cooled down to room temperature. The results demonstrated that the P-wave velocity and compressive strength of the heated-cooled treatment UHPC degraded significantly as the target temperature exceeded 250 °C. The impact tests were then conducted on the heated-cooled treatment UHPC specimens with axial static compression. The experimental results indicated that the axial static compression could enhance the dynamic mechanical properties such as compressive strength and elastic modulus in the elastic phase and weaken the dynamic mechanical properties in the plastic phase. In addition, the dynamic increase factor (DIF) of UHPC exhibited an increase with the temperature. The UHPC specimen could withstand a temperature of 250 °C, but lost most of its strength at temperatures of 500 and 750 °C. Thus, the axially loaded static force accelerated the failure of the specimen after being heated to above 250 °C.
Liu, L, Yang, R, Cui, J, Chen, P, Ri, HC, Sun, H, Piao, X, Li, M, Pu, Q, Quinto, M, Zhou, JL, Shang, H-B & Li, D 2022, 'Circular Nonuniform Electric Field Gel Electrophoresis for the Separation and Concentration of Nanoparticles', Analytical Chemistry, vol. 94, no. 23, pp. 8474-8482.
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A circular nonuniform electric field strategy coupled with gel electrophoresis was proposed to control the precise separation and efficient concentration of nano- and microparticles. The circular nonuniform electric field has the feature of exponential increase in the electric field intensity along the radius, working with three functional zones of migration, acceleration, and concentration. The distribution form of electric field lines is regulated in functional zones to control the migration behaviors of particles for separation and concentration by altering the relative position of the ring electrode (outside) and rodlike electrode (inner). The circular nonuniform electric field promotes the target-type and high-precision separation of nanoparticles based on the difference in charge-to-size ratio. The concentration multiple of nanoparticles is also controlled randomly with the alternation of radius, taking advantage of vertical extrusion and concentric converging of the migration path. This work provides a brand new insight into the simultaneous separation and concentration of particles and is promising for developing a versatile tool for the separation and preparation of various samples instead of conventional methods.
Liu, L-Y, Xie, G-J, Ding, J, Liu, B-F, Xing, D-F, Ren, N-Q & Wang, Q 2022, 'Microbial methane emissions from the non-methanogenesis processes: A critical review', Science of The Total Environment, vol. 806, no. Pt 4, pp. 151362-151362.
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Methane, a potent greenhouse gas of global importance, has traditionally been considered as an end product of microbial methanogenesis of organic matter. Paradoxically, growing evidence has shown that some microbes, such as cyanobacteria, algae, fungi, purple non-sulfur bacteria, and cryptogamic covers, produce methane in oxygen-saturated aquatic and terrestrial ecosystems. The non-methanogenesis process could be an important potential contributor to methane emissions. This systematic review summarizes the knowledge of microorganisms involved in the non-methanogenesis process and the possible mechanisms of methane formation. Cyanobacteria-derived methane production may be attributed to either demethylation of methyl phosphonates or linked to light-driven primary productivity, while algae produce methane by utilizing methylated sulfur compounds as possible carbon precursors. In addition, fungi produce methane by utilizing methionine as a possible carbon precursor, and purple non-sulfur bacteria reduce carbon dioxide to methane by nitrogenase. The microbial methane distribution from the non-methanogenesis processes in aquatic and terrestrial environments and its environmental significance to global methane emissions, possible mechanisms of methane production in each open water, water-to-air methane fluxes, and the impact of climate change on microorganisms are also discussed. Finally, future perspectives are highlighted, such as establishing more in-situ experiments, quantifying methane flux through optimizing empirical models, distinguishing individual methane sources, and investigating nitrogenase-like enzyme systems to improve our understanding of microbial methane emission from the non-methanogenesis process.
Liu, M, Blankenship, JR, Levi, AE, Fu, Q, Hudson, ZM & Bates, CM 2022, 'Miktoarm Star Polymers: Synthesis and Applications', Chemistry of Materials, vol. 34, no. 14, pp. 6188-6209.
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Polymers with precisely controlled structure and function are in high demand across a diverse array of applications spanning the life sciences and nanotechnology. One prototypical example is a class of branched block copolymers known as miktoarm stars (μ-stars), which contain two or more arm compositions connected at a common junction. Miktoarm stars have attracted considerable attention since their physical properties can be different from conventional linear block copolymers. This perspective highlights the latest developments and historical context in the field of miktoarm star polymers, including design strategies, synthetic techniques, and advanced characterization tools used to avoid common preparation pitfalls and tailor properties for emerging applications. Our contemporary perspective on μ-star polymers is a resource for inspiring future research into this exciting class of materials at the intersection of chemistry, physics, and advanced technology.
Liu, M, Nothling, MD, Zhang, S, Fu, Q & Qiao, GG 2022, 'Thin film composite membranes for postcombustion carbon capture: Polymers and beyond', Progress in Polymer Science, vol. 126, pp. 101504-101504.
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Liu, Q, Zhang, Q, Jiang, S, Du, Z, Zhang, X, Chen, H, Cao, W, Nghiem, LD & Ngo, HH 2022, 'Enhancement of lead removal from soil by in-situ release of dissolved organic matters from biochar in electrokinetic remediation', Journal of Cleaner Production, vol. 361, pp. 132294-132294.
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Liu, X, Deng, Q, Zheng, Y, Wang, D & Ni, B-J 2022, 'Microplastics aging in wastewater treatment plants: Focusing on physicochemical characteristics changes and corresponding environmental risks', Water Research, vol. 221, pp. 118780-118780.
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Microplastics (MPs) have been frequently detected in effluent wastewater and sludge in wastewater treatment plants (WWTPs), the discharge and agricultural application of which represent a primary source of environmental MPs contamination. As important as quantitative removal is, changes of physicochemical characteristics of MPs (e.g., shapes, sizes, density, crystallinity) in WWTPs are crucial to their environmental behaviors and risks and have not been put enough attention yet. This review is therefore to provide a current overview on the changes of physicochemical characteristics of MPs in WWTPs and their corresponding environmental risks. The changes of physicochemical characteristics as well as the underlying mechanisms of MPs in different successional wastewater and sludge treatment stages that mainly driven by mechanical (e.g., mixing, pumping, filtering), chemical (e.g., flocculation, advanced oxidation, ultraviolet radiation, thermal hydrolysis, incineration and lime stabilization), biological (e.g., activated sludge process, anaerobic digestion, composition) and their combination effects were first recapitulated. Then, the inevitable correlations between physicochemical characteristics of MPs and their environmental behaviors (e.g., migration, adsorption) and risks (e.g., animals, plants, microbes), are comprehensively discussed with particular emphasis on the leaching of additives and physicochemical characteristics that affect the co-exist pollutants behavior of MPs in WWTPs on environmental risks. Finally, knowing the summarized above, some relating unanswered questions and concerns that need to be unveiled in the future are prospected. The physicochemical properties of MPs change after passing through WWTP, leading to subsequent changes in co-contaminant adsorption, migration, and toxicity. This could threaten our ecosystems and human health and must be worth investigating.
Liu, X, Duan, X, Bao, T, Hao, D, Chen, Z, Wei, W, Wang, D, Wang, S & Ni, B-J 2022, 'High-performance photocatalytic decomposition of PFOA by BiOX/TiO2 heterojunctions: Self-induced inner electric fields and band alignment', Journal of Hazardous Materials, vol. 430, pp. 128195-128195.
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BiOX (X = Cl, Br and I) and BiOX/TiO2 photocatalysts were prepared by a facile hydrothermal approach. The BiOX/TiO2 heterojunctions demonstrated significantly enhanced efficiency for photocatalytic decomposition of perfluorooctanoic acid (PFOA) compared with sole BiOX or TiO2. PFOA (10 mg L1) was completely degraded by BiOCl(Br)/TiO2 in 8 h. Moreover, BiOCl/TiO2 attained deep decomposition of PFOA with a high defluorination ratio of 82%. The p-n heterojunctions between BiOX and TiO2 were confirmed by a series of characterizations. The photo-induced holes would migrate from the valance band (VB) of TiO2 to BiOX, driven by the built-in electric field (BIEF) near the interfaces of p-n heterojunctions, the inner electric fields (IEF) in BiOX and the higher VB position of BiOX. The X-ray diffraction (XRD) and TEM characterizations indicated that TiO2 combined with BiOX along the [110] facet, which facilitated photo-induced electron transfer in the [001] direction, thus benefiting PFOA decomposition.
Liu, X, Wang, D, Chen, Z, Wei, W, Mannina, G & Ni, B-J 2022, 'Advances in pretreatment strategies to enhance the biodegradability of waste activated sludge for the conversion of refractory substances', Bioresource Technology, vol. 362, pp. 127804-127804.
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Anaerobic digestion (AD) is a low-cost technology widely used to divert waste activated sludge (WAS) to renewable energy production, but is generally restricted by its poor biodegradability which mainly caused by the endogenous and exogenous refractory substances present in WAS. Several conventional methods such as thermal-, chemical-, and mechanical-based pretreatment have been demonstrated to be effective on organics release, but their functions on refractory substances conversion are overlooked. This paper firstly reviewed the presence and role of endogenous and exogenous refractory substances in anaerobic biodegradability of WAS, especially on their inhibition mechanisms. Then, the pretreatment strategies developed for enhancing WAS biodegradability by facilitating refractory substances conversion were comprehensively reviewed, with the conversion pathways and underlying mechanisms being emphasized. Finally, the future research needs were directed, which are supposed to improve the circular bioeconomy of WAS management from the point of removing the hindering barrier of refractory substances on WAS biodegradability.
Liu, Y, Liu, Z, Gao, K, Huang, Y & Zhu, C 2022, 'Efficient Graphical Algorithm of Sensor Distribution and Air Volume Reconstruction for a Smart Mine Ventilation Network', Sensors, vol. 22, no. 6, pp. 2096-2096.
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The accurate and reliable monitoring of ventilation parameters is key to intelligent ventilation systems. In order to realize the visualization of airflow, it is essential to solve the airflow reconstruction problem using few sensors. In this study, a new concept called independent cut set that depends on the structure of the underlying graph is presented to determine the minimum number and location of sensors. We evaluated its effectiveness in a coal mine owned by Jinmei Corporation Limited (Jinmei Co., Ltd., Shanghai, China). Our results indicated that fewer than 30% of tunnels needed to have wind speed sensors set up to reconstruct the well-posed airflow of all the tunnels (>200 in some mines). The results showed that the algorithm was feasible. The reconstructed air volume of the ventilation network using this algorithm was the same as the actual air volume. The algorithm provides theoretical support for flow reconstruction.
Liu, Y, Luo, G, Ngo, HH & Zhang, S 2022, 'New approach of bioprocessing towards lignin biodegradation', Bioresource Technology, vol. 361, pp. 127730-127730.
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Liu, Y, Zhang, S, Fang, H, Wang, Q, Jiang, S, Zhang, C & Qiu, P 2022, 'Inactivation of antibiotic resistant bacterium Escherichia coli by electrochemical disinfection on molybdenum carbide electrode', Chemosphere, vol. 287, no. Pt 4, pp. 132398-132398.
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Antibiotic-resistant bacteria (ARB) pose a substantial threat to public health worldwide. Electrochemistry, as a low energy consumption and environmentally friendly technique, is ideal for inactivating ARB. This study explored the utility of electrochemical disinfection (ED) for inactivating ARB (Escherichia coli K-12 LE392 resistant to kanamycin, tetracycline, and ampicillin) and the regrowth potential of the treated ARB. The results revealed that 5.12-log ARB removal was achieved within 30 min of applying molybdenum carbide as the anode and cathode material under a voltage of 2.0 V. No ARB regrowth was observed in the cathode chamber after 60 min of incubation in unselective broth, demonstrating that the process in the cathode chamber was more effective for permanent inactivation of ARB. The mechanisms underlying the ARB inactivation were verified based on intercellular reactive oxygen species (ROS) measurement, membrane integrity detection, and genetic damage assessment. Higher ROS production and membrane permeability were observed in the cathode and anode groups (p < 0.001) compared to the control group (0 V). In addition, the DNA was more likely to be damaged during the ED process. Collectively, our results demonstrate that ED is a promising technology for disinfecting water to prevent the spread of ARB.
Lloret-Cabot, M & Sheng, D 2022, 'Assessing the accuracy and efficiency of different order implicit and explicit integration schemes', Computers and Geotechnics, vol. 141, pp. 104531-104531.
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A first order accurate fully implicit integration scheme and four different order explicit substepping integration schemes with automatic error control are used in this paper to integrate the constitutive relations of a critical state model for saturated soils. Their respective computational performance in terms of accuracy and efficiency is assessed in order to provide practical guidance for deciding which of the five is most suitable for solving numerical problems in geotechnical engineering involving critical state models. Even though existing literature of integration schemes applied to geotechnical problems has traditionally been focussed on the first order accurate implicit backward Euler and on the second order accurate explicit modified Euler with substepping almost exclusively, the findings of this paper suggest that the little extra work required in the implementation of an explicit third order Runge-Kutta substepping scheme is worth the effort, especially in terms of computational cost.
Loganathan, P, Kandasamy, J, Jamil, S, Ratnaweera, H & Vigneswaran, S 2022, 'Ozonation/adsorption hybrid treatment system for improved removal of natural organic matter and organic micropollutants from water – A mini review and future perspectives', Chemosphere, vol. 296, pp. 133961-133961.
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Loh, HW, Ooi, CP, Barua, PD, Palmer, EE, Molinari, F & Acharya, UR 2022, 'Automated detection of ADHD: Current trends and future perspective', Computers in Biology and Medicine, vol. 146, pp. 105525-105525.
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Attention deficit hyperactivity disorder (ADHD) is a heterogenous disorder that has a detrimental impact on the neurodevelopment of the brain. ADHD patients exhibit combinations of inattention, impulsiveness, and hyperactivity. With early treatment and diagnosis, there is potential to modify neuronal connections and improve symptoms. However, the heterogeneous nature of ADHD, combined with its comorbidities and a global shortage of diagnostic clinicians, means diagnosis of ADHD is often delayed. Hence, it is important to consider other pathways to improve the efficiency of early diagnosis, including the role of artificial intelligence. In this study, we reviewed the current literature on machine learning and deep learning studies on ADHD diagnosis and identified the various diagnostic tools used. Subsequently, we categorized these studies according to their diagnostic tool as brain magnetic resonance imaging (MRI), physiological signals, questionnaires, game simulator and performance test, and motion data. We identified research gaps include the paucity of publicly available database for all modalities in ADHD assessment other than MRI, as well as a lack of focus on using data from wearable devices for ADHD diagnosis, such as ECG, PPG, and motion data. We hope that this review will inspire future work to create more publicly available datasets and conduct research for other modes of ADHD diagnosis and monitoring. Ultimately, we hope that artificial intelligence can be extended to multiple ADHD diagnostic tools, allowing for the development of a powerful clinical decision support pathway that can be used both in and out of the hospital.
Loh, HW, Ooi, CP, Seoni, S, Barua, PD, Molinari, F & Acharya, UR 2022, 'Application of explainable artificial intelligence for healthcare: A systematic review of the last decade (2011–2022)', Computer Methods and Programs in Biomedicine, vol. 226, pp. 107161-107161.
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BACKGROUND AND OBJECTIVES: Artificial intelligence (AI) has branched out to various applications in healthcare, such as health services management, predictive medicine, clinical decision-making, and patient data and diagnostics. Although AI models have achieved human-like performance, their use is still limited because they are seen as a black box. This lack of trust remains the main reason for their low use in practice, especially in healthcare. Hence, explainable artificial intelligence (XAI) has been introduced as a technique that can provide confidence in the model's prediction by explaining how the prediction is derived, thereby encouraging the use of AI systems in healthcare. The primary goal of this review is to provide areas of healthcare that require more attention from the XAI research community. METHODS: Multiple journal databases were thoroughly searched using PRISMA guidelines 2020. Studies that do not appear in Q1 journals, which are highly credible, were excluded. RESULTS: In this review, we surveyed 99 Q1 articles covering the following XAI techniques: SHAP, LIME, GradCAM, LRP, Fuzzy classifier, EBM, CBR, rule-based systems, and others. CONCLUSION: We discovered that detecting abnormalities in 1D biosignals and identifying key text in clinical notes are areas that require more attention from the XAI research community. We hope this is review will encourage the development of a holistic cloud system for a smart city.
Loh, HW, Xu, S, Faust, O, Ooi, CP, Barua, PD, Chakraborty, S, Tan, R-S, Molinari, F & Acharya, UR 2022, 'Application of photoplethysmography signals for healthcare systems: An in-depth review', Computer Methods and Programs in Biomedicine, vol. 216, pp. 106677-106677.
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Lou, B, Barbieri, DM, Passavanti, M, Hui, C, Gupta, A, Hoff, I, Lessa, DA, Sikka, G, Chang, K, Fang, K, Lam, L, Maharaj, B, Ghasemi, N, Qiao, Y, Adomako, S, Foroutan Mirhosseini, A, Naik, B, Banerjee, A, Wang, F, Tucker, A, Liu, Z, Wijayaratna, K, Naseri, S, Yu, L, Chen, H, Shu, B, Goswami, S, Peprah, P, Hessami, A, Abbas, M & Agarwal, N 2022, 'Air pollution perception in ten countries during the COVID-19 pandemic', Ambio, vol. 51, no. 3, pp. 531-545.
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AbstractAs largely documented in the literature, the stark restrictions enforced worldwide in 2020 to curb the COVID-19 pandemic also curtailed the production of air pollutants to some extent. This study investigates the perception of the air pollution as assessed by individuals located in ten countries: Australia, Brazil, China, Ghana, India, Iran, Italy, Norway, South Africa and the USA. The perceptions towards air quality were evaluated by employing an online survey administered in May 2020. Participants (N = 9394) in the ten countries expressed their opinions according to a Likert-scale response. A reduction in pollutant concentration was clearly perceived, albeit to a different extent, by all populations. The survey participants located in India and Italy perceived the largest drop in the air pollution concentration; conversely, the smallest variation was perceived among Chinese and Norwegian respondents. Among all the demographic indicators considered, only gender proved to be statistically significant.
Lu, Z, Xu, Y, Peng, L, Liang, C, Liu, Y & Ni, B-J 2022, 'A two-stage degradation coupling photocatalysis to microalgae enhances the mineralization of enrofloxacin', Chemosphere, vol. 293, pp. 133523-133523.
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The coupling of photocatalytic and algal processes has been used for the removal of widespread antibiotics. The removal capacities of the individual and the combined system against enrofloxacin were tested and compared in this work. Due to the low tolerance of the algae to enrofloxacin, the target compound was barely degraded during the individual algal treatment. In the individual photocatalytic process, the mineralization efficiency (defined as the ratio between the produced carbon dioxide and the initial) reached ∼57% with the remaining formed as transformation products. In contrast, a two-stage treatment incorporating photocatalytic and algal processes removed enrofloxacin completely and increased the mineralization efficiency to ∼64% or more. The addition of the citric acid as external co-substrate further elevated the mineralization efficiency with a factor of 1.25 compared to that of the individual photocatalysis. Different degradation products in both individual and integrated processes were identified and compared. The degradation pathways were found to involve the attack of the piperazine moiety and quinolone core. The results indicated the potential application of the combined photocatalytic-algal treatment in removal of veterinary antibiotics and improved our understanding of the underlying mechanisms and pathways.
Lu, Z-H, Wang, J, Tang, Z, Zhao, Y-G & Li, W 2022, 'A novel cohesive zone model for predicting the interface bonding behaviours of the ballastless track of high-speed railway', Structures, vol. 41, pp. 1-14.
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The interface damage is one of the main concerns for high-speed railway ballastless track structures during its whole service life, as it would affect the reliability of track structures or even cause the high-speed train accident. In this paper, various existing cohesive zone models (CZMs) were identified and compared regarding the performance in modeling the interface behaviors of ballastless track structures. The results show that the existing CZMs cannot accurately represent the nonlinear relationship of the ascending and descending sections in the interface traction-separation curve concurrently. Therefore, a new CZM was proposed in this study, and the feasibility of the proposed model was examined by the experimental results. It indicates that the proposed model can reasonably describe the nonlinear behaviors of the ascending and descending sections in the traction-separation curve by introducing exponential coefficients. The proposed CZM also exhibits higher accuracy in predicting the normal and tangential cracking behaviors of the interlayer interface of the ballastless track structures in comparison with the existing models, with the coefficients of determination (R2) in the fitting results all above 0.85. As a result, this model can be used for the analysis of the interface behaviours of ballastless track structures.
Luo, T, Xu, Q, Wei, W, Sun, J, Dai, X & Ni, B-J 2022, 'Performance and Mechanism of Fe3O4 Improving Biotransformation of Waste Activated Sludge into Liquid High-Value Products', Environmental Science & Technology, vol. 56, no. 6, pp. 3658-3668.
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This study demonstrated that Fe3O4 simultaneously improves the total production and formation rate of medium-chain fatty acids (MCFAs) and long-chain alcohols (LCAs) from waste activated sludge (WAS) in anaerobic fermentation. Results revealed that when Fe3O4 increased from 0 to 5 g/L, the maximal MCFA and LCA production increased significantly, and the optimal fermentation time was also remarkably shortened from 24 to 9 days. Moreover, Fe3O4 also enhanced WAS degradation, and the corresponding degradation rate in the fermentation system increased from 43.86 to 72.38% with an increase in Fe3O4 from 0 to 5 g/L. Further analysis showed that Fe3O4 promoted the microbe activities of all the bioprocesses (including hydrolysis, acidogenesis, and chain elongation processes) involved in the MCFA and LCA production from WAS. Microbial community analysis indicated that Fe3O4 increased the abundances of key microbes involved in abovementioned bioprocesses correspondingly. Mechanistic investigations showed that Fe3O4 increased the conductivity of the fermented sludge, providing a better conductive environment for the anaerobic microbes. The redox cycle of Fe(II) and Fe(III) existed in the fermentation system with Fe3O4, which was likely to act as electron shuttles to conduct electron transfer (ET) from the electron donor to the acceptor, thus increasing ET efficiency. This study provides an effective method for enhancing the biotransformation of WAS into high-value products, potentially bringing economic benefits to WAS treatment.
Luo, Z, Li, W, Wang, K, Shah, SP & Sheng, D 2022, 'Nano/micromechanical characterisation and image analysis on the properties and heterogeneity of ITZs in geopolymer concrete', Cement and Concrete Research, vol. 152, pp. 106677-106677.
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Heterogeneity of interfacial transition zones (ITZs) is a key factor for the properties and failure mechanism of geopolymer concrete. The nano/microscale properties and heterogeneity of the ITZs (the top, bottom and lateral interfaces) prepared by encompassing polished aggregates in the modelled fly ash-based geopolymer concrete were statistically investigated in this study. The nanoindentation and nanoscratch results show that the nano/micromechanical properties of the gel-related phases of ITZs at the top and bottom boundaries are higher than the corresponding ones at the lateral boundaries and bulk paste. The mechanism of the better properties of ITZs at the top and bottom boundaries is unveiled based on quantitative image analysis of the amount, diameter and proportion distribution of fly ash particles. A strategy of controlling heterogeneity of ITZs and using polished aggregates, rapid scratch and statistical analysis is proposed to investigate more complicated ITZs within acceptable testing duration.
Ly, QV, Truong, VH, Ji, B, Nguyen, XC, Cho, KH, Ngo, HH & Zhang, Z 2022, 'Exploring potential machine learning application based on big data for prediction of wastewater quality from different full-scale wastewater treatment plants', Science of The Total Environment, vol. 832, pp. 154930-154930.
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Lyu, Z, Yu, Y, Samali, B, Rashidi, M, Mohammadi, M, Nguyen, TN & Nguyen, A 2022, 'Back-Propagation Neural Network Optimized by K-Fold Cross-Validation for Prediction of Torsional Strength of Reinforced Concrete Beam', Materials, vol. 15, no. 4, pp. 1477-1477.
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Due to the limitation of sample size in predicting the torsional strength of Reinforced Concrete (RC) beams, this paper aims to discuss the feasibility of employing a novel machine learning approach with K-fold cross-validation in a small sample range, which combines the advantages of a Genetic Algorithm (GA) and a Neural Network (NN) to predict the torsional strength of RC beams. This research study not only utilizes the application of a Back Propagation (BP) neural network and the Gene Algorithm-Back Propagation (GA-BP) neural network in the prediction of the torsional strength of the RC beam, but it also investigates neural network parameter optimization, including connection weights and thresholds, using K-fold cross-validation. The root mean square error (RMSE), mean absolute error (MAE), mean square error (MSE), mean absolute percentage error (MAPE) and correlation coefficient (R2) are among the evaluation metrics used to assess the performance of the trained model. To elaborate on the superiority of the proposed network models in predicting the torsional strength of RC beams, a parametric study is conducted by comparing the proposed model to three commonly used empirical formulae from existing design codes. The comparative findings of this research study demonstrate that the performance of the BP neural network is highly similar to that of design codes; however, its accuracy is inadequate. After improving the weights and thresholds by k-fold cross-validation and GA, the prediction of the BP neural network shows higher consistency with the actual measured values. The outcome of this study can be used as a theoretical reference for the optimal design of RC beams in practical applications.
M. B., B, B., RP, Tripathi, A, Yadav, S, John, NS, Thapa, R, Altaee, A, Saxena, M & Samal, AK 2022, 'A Unique Bridging Facet Assembly of Gold Nanorods for the Detection of Thiram through Surface-Enhanced Raman Scattering', ACS Sustainable Chemistry & Engineering, vol. 10, no. 22, pp. 7330-7340.
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Concerns have grown in recent years about the widespread use of the pesticide thiram (TRM), which has been linked to negative effects on local ecosystems. This highlights the critical need for quick and accurate point-of-need pesticide analysis tools for real-time applications. The detection of TRM using gold nanorods (Au NRs) with a limit of detection of 10-11M (10 pM) and an enhancement factor of 2.8 × 106along with 6.2% of signal homogeneity (with respect to the peak at 1378 cm-1) is achieved through surface-enhanced Raman scattering (SERS). The formation of an Au-S bond emphasizes the adsorption of TRM on Au NRs. The addition of Au NRs to TRM of higher and lower concentrations yields a side-by-side assembly (SSA) and a bridging facet assembly (BFA), respectively, and exhibited excellent hotspots for the ultralow detection of TRM. Bridging facets of Au NRs, such as (5 12 0) and (5 0 12) planes, are mainly responsible for the BFA. This kind of interaction is observed for the first time and not reported elsewhere. The detailed facets of Au NRs, namely, side facets, bridging facets, and pyramid facets were demonstrated with the 3D model of Au NRs. The computational studies confirming the SSA and BFA for Au NRs with varying concentrations of TRM are in well agreement with the experimental results. The interaction of Au NRs with TRM is highly sensitive, and the ultralow detection of hazardous TRM through SERS is an ideal technique for environmental protection, real-time applications, and analysis of one-of-a-kind materials.
Ma, B, Teng, J, Li, H, Zhang, S, Cai, G & Sheng, D 2022, 'A New Strength Criterion for Frozen Soil Considering Pore Ice Content', International Journal of Geomechanics, vol. 22, no. 7, p. 04022107.
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Pore ice content is crucial in evaluating the mechanical properties of frozen soils. Existing strength criterion models are usually empirical and ignore the influence of pore ice content. By assuming that the critical state shear stress ratio of soil is a function of the stress level, a critical state line of frozen soil is proposed to consider pore ice content. By combining the Mohr-Coulomb (M-C) and Drucker-Prager strength criteria to describe the failure shape characteristics on the deviatoric plane, a new strength criterion is established for complex stress conditions. The proposed model is validated against existing models and measured data in the literature. In addition, the proposed model can uniformly describe the CSL of different types of geotechnical materials and has a clear physical meaning, which may provide a theoretical basis for constitutive models.
Ma, Y, Huang, Y, Wu, J, E, J, Zhang, B, Han, D & Ong, HC 2022, 'A review of atmospheric fine particulate matters: chemical composition, source identification and their variations in Beijing', Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, vol. 44, no. 2, pp. 4783-4807.
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Fine particulate matter (PM2.5) is a major air pollutant worldwide. Characterizing its chemical compositions and source contributions is a critical prerequisite for effective control of PM2.5 pollution. This paper systematically reviews the sampling methods, chemical compositions, and source apportionments of PM2.5. Sampling methods have significant influences on the identification of chemical compositions and source contributions, with Quartz and Teflon filters being the most widely used. Receptor models are commonly adopted for identifying the sources of PM2.5, such as positive matrix factorization, chemical mass balance, principal component analysis, and UNMIX models, which have their respective advantages and limitations that determine their applications. The variations of PM2.5 compositions and sources in the past two decades in Beijing are also reviewed, which is the political, economic, and cultural center of China and is experiencing severe haze pollution events frequently. It was found that organic matters were the largest component (28.2%) in PM2.5, followed by sulfate (15.1%) during 2004–2013, which was overtaken by nitrate (14.9%) after 2013. Each PM2.5 source demonstrated significant seasonal and annual variations due to changes in climatic conditions and anthropogenic activities. Future research on the impacts of these external factors is urgently needed. This review is expected to provide valuable advice and evidence for those fast-growing megacities like Beijing to identify and control their PM2.5-related air pollution problems.
Mahmood, AH, Babaee, M, Foster, SJ & Castel, A 2022, 'Capturing the early-age physicochemical transformations of alkali-activated fly ash and slag using ultrasonic pulse velocity technique', Cement and Concrete Composites, vol. 130, pp. 104529-104529.
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Mahmud, MA, Zheng, J, Tang, S, Wang, G, Bing, J, Bui, AD, Qu, J, Yang, L, Liao, C, Chen, H, Bremner, SP, Nguyen, HT, Cairney, J & Ho‐Baillie, AWY 2022, 'Cation‐Diffusion‐Based Simultaneous Bulk and Surface Passivations for High Bandgap Inverted Perovskite Solar Cell Producing Record Fill Factor and Efficiency', Advanced Energy Materials, vol. 12, no. 36, pp. 2201672-2201672.
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AbstractHigh bandgap perovskite solar cells are integral to perovskite‐based multi‐junction tandem solar cells with efficiency potentials over 40%. However, at present, high bandgap perovskite devices underperform compared to their mid bandgap counterparts in terms of voltage outputs and fill factors resulting in lower than ideal efficiencies. Here, the low fill factor aspect of high bandgap perovskite is addressed by developing a cation‐diffusion‐based double‐sided interface passivation scheme that simultaneously provides bulk passivation for a 1.75 eV perovskite cell that is also compatible with a p‐i‐n cell architecture. The champion cell achieves a record fill factor of 86.5% and a power conversion efficiency of 20.2%. Results of ionic distribution profiling, Fourier transform infrared spectroscopy, and X‐ray diffraction crystallography reveal evidence of cation diffusion from the surface perovskite passivation layer into bulk. The diffused cations reduce Shockley–Read–Hall recombination in the perovskite bulk and at the surfaces with the latter being more dominant as confirmed by light‐intensity dependent and temperature‐dependent open‐circuit voltage measurements as well as thermal admittance spectroscopy. This concurrent bulk and surface passivation scheme renders record fill factor and efficiency in the double‐side passivated cells. This provides new insights for future passivation strategies based on ionic diffusion of functionalized materials.
Mahmudul, HM, Rasul, MG, Akbar, D, Narayanan, R & Mofijur, M 2022, 'Food waste as a source of sustainable energy: Technical, economical, environmental and regulatory feasibility analysis', Renewable and Sustainable Energy Reviews, vol. 166, pp. 112577-112577.
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Anaerobic digestion (AD) is a viable technique to address food waste (FW) problems by converting FW into sustainable energy. Despite the advantages of the AD process, large-scale AD plants like in Germany and the USA have not been developed in Australia. Therefore, this paper aims to study the technological, economic, and environmental feasibility of sustainable energy production from household FW in Australia. In addition, this paper discusses the different waste to energy (WtE) technologies along with the operational parameters as well as the challenges in developing a biogas plant. The energy and economic potential analysis of the AD process indicates that the processing of 10% FW from Australian states and territories can generate 1.22 GWh to 35.4 GWh electricity which can subsequently earn AUD 0.54 million to AUD 15.7 million revenue per year. The greenhouse gas (GHG) emissions analysis indicates that conversion of the 10% of Australian FW has the potential to lower GHG emissions by 639,852 tonnes per annum. Hence, it can be said that FW plays a vital role as a promising source of sustainable energy and is capable of benefiting the country's economy significantly and reducing GHG emissions.
Maidi, AM, Kalam, MA & Begum, F 2022, 'Photonic Crystal Fiber Sensor for Detecting Sulfuric Acid in Different Concentrations', Photonics, vol. 9, no. 12, pp. 958-958.
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A high-performance photonic crystal fiber sensor for sulfuric acid detection is designed and investigated, undertaken through a full vector Finite Element Method on COMSOL Multiphysics software to establish the optical properties of effective refractive index, power fraction, relative sensitivity, confinement loss, chromatic dispersion, and propagation constant. Different aqueous sulfuric acid concentrations of 0%, 10%, 20%, 30%, and 40% were selected as the test analytes. The dimensions of two cladding rings of the hexagon- and circular-shaped air holes and a circular core hole denoted outstanding outcomes of relative sensitivity and confinement loss. At 1.1 µm optimum wavelength, 0%, 10%, 20%, 30%, and 40% sulfuric acid concentrations depict relative sensitivities of 97.08%, 97.67%, 98.06%, 98.39%, and 98.67%, respectively, and confinement losses of 1.32 × 10−12 dB/m, 4.11 × 10−12 dB/m, 1.46 × 10−12 dB/m, 6.34 × 10−12 dB/m, and 2.12 × 10−12 dB/m, respectively.
Maithri, M, Raghavendra, U, Gudigar, A, Samanth, J, Prabal Datta Barua, Murugappan, M, Chakole, Y & Acharya, UR 2022, 'Automated emotion recognition: Current trends and future perspectives', Computer Methods and Programs in Biomedicine, vol. 215, pp. 106646-106646.
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Malik, K, Kumar, D, Perissin, D & Pradhan, B 2022, 'Estimation of ground subsidence of New Delhi, India using PS-InSAR technique and Multi-sensor Radar data', Advances in Space Research, vol. 69, no. 4, pp. 1863-1882.
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Globally the land subsidence is a significant problem of the rapidly growing urban area. The factor responsible for the land subsidence caused by over-exploitation of the underground fluid such as water, petroleum, and gas respectively. In present study we present the result of detail investigation of active ground subsidance in New Delhi, National Capital Region (NCR). This area indicates a high rate of urban growth during the past decades. To analyze the land subsidence, we used multiple SAR sensor data and exploited the PS-InSAR technique. The data used for this study are Cosmo-skymed acquired between 08/06/2011 to 15/11/2017, Sentinel-1A-B (18-12-2014 to 27-11-2018), and ALOS PALSAR acquired between 19/01/2007 and 20/01/2011. These radar sensors operate in X, C, and L-band, which covers over ten years, from 2007 to 2018. The PSI results of Cosmo-skymed reveals that the Delhi NCR region has undergone an average deformation ± 15 mm/y, a maximum surface deformation observed from ALOS-PALSAR is 10 to 18 mm/y and the ground displacement observed from the SENTINAL-1A data is −2 to 16 mm/y. Groundwater level data also collected for the same period and a ground water level depletion compared with the subsidence. Monitoring land subsidence with ground-based conventional technology is time-consuming and can be carried out in a limited area due to the financial implication. PS-InSAR is an established method to detect the surface movement using the SAR sensor's time-series data. The result shows that a twenty centimeter of land subsidence is visible in some areas, validated with the collected ground evidence. The affected area is also showing resemblance to the groundwater depleting condition in those areas. This study also establish that multiple sensor data can be used to monitor the long term land subsidence.
Mannina, G, Gulhan, H & Ni, B-J 2022, 'Water reuse from wastewater treatment: The transition towards circular economy in the water sector', Bioresource Technology, vol. 363, pp. 127951-127951.
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Water is crucial for economic development since it interacts with the agricultural, production, and energy sectors. However, the increasing demand and climate change put pressure on water sources. This paper argued the necessity of using reclaimed water for irrigation within the scope of a circular economy. The barriers (i.e., technological and economic, institutional/regulatory, and social) to water reuse practices were revealed. Lessons on how to overcome the barriers were learned from good practices. The roadmaps adopted in the European Union for the transition towards the circular economy were reviewed. It has been observed that these roadmaps are generally on the circularity of solid wastes. However, water is too important for the economy to be ignored in the transition towards circular economy. Research needs and perspective for a comprehensive roadmap to widen water-smart solutions such as water reuse were drawn.
Mao, S, Onggowarsito, C, Feng, A, Zhang, S, Fu, Q & Nghiem, LD 2022, 'A cryogel solar vapor generator with rapid water replenishment and high intermediate water content for seawater desalination', Journal of Materials Chemistry A, vol. 11, no. 2, pp. 858-867.
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By selecting appropriate polymer precursors, we developed a novel cryogel solar vapor generator for seawater desalination with high intermediate water content for lower evaporation enthalpy and interconnected macropores for rapid water replenishment.
Matin, SS & Pradhan, B 2022, 'Challenges and limitations of earthquake-induced building damage mapping techniques using remote sensing images-A systematic review', Geocarto International, vol. 37, no. 21, pp. 6186-6212.
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Matta, SM, Selam, MA, Manzoor, H, Adham, S, Shon, HK, Castier, M & Abdel-Wahab, A 2022, 'Predicting the performance of spiral-wound membranes in pressure-retarded osmosis processes', Renewable Energy, vol. 189, pp. 66-77.
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A process simulator has been developed to model and predict the performance of spiral-wound membrane modules in pressure retarded osmosis processes. This has involved automation of generalized protocols for the numerical integration of the solvent and solute flux equations (in conjunction with a suitable electrolyte equation of state) along the surface area of a spiral-wound membrane leaf. Performance equations are solved for discrete area elements and the spiral-wound character of the module as a whole is realized through the programmed sequence in which discrete elements are evaluated. This arrangement allows for mirroring the parabolic flow pattern of the feed stream in the spiral-wound membrane leaf. The total permeation (and, by extension, power density) is thus calculated in a manner that accounts for the driving force profile consistent with flow patterns specific to spiral-wound membranes. This effective treatment of each discrete element as a flat-sheet membrane enables the transferability of membrane parameters characterized in standard, coupon-scale experiments to the simulation of spiral-wound modules. This transferability is illustrated through comparisons of model predictions with published pilot-scale PRO data.
Medawela, S, Indraratna, B, Athuraliya, S, Lugg, G & Nghiem, LD 2022, 'Monitoring the performance of permeable reactive barriers constructed in acid sulfate soils', Engineering Geology, vol. 296, pp. 106465-106465.
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Two pilot-scale permeable reactive barriers (PRBs) were installed in an acidic terrain to treat contaminated groundwater with low pH and high concentrations of Al and Fe. The first pilot-scale barrier (PRB-1) was installed in 2006 using recycled concrete aggregates (RCA) as the reactive material, and the second barrier (PRB-2) was installed in late 2019 using limestone aggregates (LA) as the reactive material. Although the initial material cost of the recycled concrete aggregates is low, laboratory trials conducted before the field applications deduced that limestone is capable of more reliable and efficient pH neutralisation in the long term, reducing frequent maintenance or material replacement in the PRB. The performance of PRB-1 has been monitored continuously over the past 14 years. In particular, both internal (within PRB) and external (upgradient and downgradient) variations in acidity (pH), ion concentrations, and the flow conditions, including the piezometric heads, have been analysed. These decade long field observations have resulted in a comprehensive understanding of the temporal variations of treatment by RCA along the groundwater flow path through the alkaline granular mass and its biogeochemical clogging. For instance, acid neutralisation at the entrance of PRB-1 decreased by 31% over 14 years, whereas the corresponding reduction at the outlet is only 6%. The non-homogeneous biogeochemical clogging in different PRB zones was evident by a 48% reduction in hydraulic conductivity at the inlet and a 34% reduction at the outlet.
Mehrabi, N & Khabbaz, H 2022, 'A trustful transition zone for high-speed rail using stone columns', Australian Journal of Civil Engineering, vol. 20, no. 1, pp. 56-66.
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The high-speed railway projects have encountered several geotechnical challenges. One of the most important challenges is the differential settlement control in transition zones. Cement-treated soil is a common method to prevent the differential settlement at transition zones. An alternative method uses stone columns for controlling the differential settlement in approaching embankment of bridges. In this study, numerical modelling using PLAXIS 2D is selected for the assessment of stone columns in the reduction of total and differential settlements. One of the overpass bridges of the track constructed for the Tehran–Isfahan railway, the first high-speed railway in the country, is chosen as the case study. Three models are created based on the properties of the selected case study. The first one is a typical approaching embankment. The second one is the bridge abutment section, and the last one is a typical reinforced approaching embankment with stone columns.
Melhem, MM, Caprani, CC & Stewart, MG 2022, 'Reliability updating of partial factors for empirical codes: Application to Super-T PSC girders designs at the ultimate limit state in bending', Structures, vol. 35, pp. 233-242.
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Reliability design code calibrations typically involve the comparison of calculated levels of safety (β) of designs to a range of prospective partial safety factors with the minimum acceptable level of safety (βT). When updating the calibration and the original βT is unknown or undocumented, design-specific probability models and the code-implied level of safety are necessary. This study presents a methodology for updating capacity reduction factors ϕ for a suite of PSC bridge girder section designs for ultimate strength in bending for a design code for which βT is unknown. In the methodology, the code-implied safety as inferred from the notional traffic design load, and the designed girder safety under actual traffic loading are computed. The method is applied to the suite of prestressed concrete Super-T girders designed to the Australian bridge standards AS 5100, in which the implicit βT is not known. The results find both code-implied safety and designed girder safety far surpasses the usual recommendations for βT for all designs and regardless of ϕ. As such, only through the relative comparison of code-implied safety and designed girder safety can recommendations be made on increasing ϕ in AS 5100 for Super-T girder ultimate strength in bending. Moreover, the comparison with code-implied safety is taken to indicate the desired degree of reserve capacity available for future traffic growth. The results inform on possible improvements for the next version of AS 5100. More significantly, the work illustrates a way to reliability-update partial factors of design codes when βT is not known, and future-proofing structures is seen as necessary.
Meng, X, Li, X, Nghiem, LD, Ruiz, E, Johir, MA, Gao, L & Wang, Q 2022, 'Improved stormwater management through the combination of the conventional water sensitive urban design and stormwater pipeline network', Process Safety and Environmental Protection, vol. 159, pp. 1164-1173.
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With rapid urbanization, flooding events become more frequently in daily life, causing enormous economic damage and loss of life. Water Sensitive Urban Design (WSUD) is a common approach for mitigating stormwater runoff. However, it showed limited performance in big catchment areas (>1000 ha). This study proposed an innovative approach by combining conventional WSUD projects with the stormwater pipeline network through linear connections for better stormwater runoff management for a big catchment. The performance of combined WSUD projects and conventional WSUD was evaluated using the urban water system of a catchment (over 1200 ha) in Sydney, Australia, through the water mass balance modelling approach using annual rainfall data of 70 years (from 1950 to 2020). Combined WSUD reduced the stormwater runoff by over 124 ML/yr compared to that of the conventional WSUD model in accommodating future development. Combined WSUD restored the evapotranspiration and infiltration under high, average and low annual rainfall scenarios with an increasing 20–30% increase of evapotranspiration and infiltration in combined WSUD than the conventional WSUD. The results obtained from the study demonstrated that combining WSUDs with the stormwater pipeline network through linear connections is a promising approach in stormwater management and restoring the natural hydrological cycle.
Milano, J, Shamsuddin, AH, Silitonga, AS, Sebayang, AH, Siregar, MA, Masjuki, HH, Pulungan, MA, Chia, SR & Zamri, MFMA 2022, 'Tribological study on the biodiesel produced from waste cooking oil, waste cooking oil blend with Calophyllum inophyllum and its diesel blends on lubricant oil', Energy Reports, vol. 8, pp. 1578-1590.
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Biodiesel or biodiesel–diesel fuel is the current fuel used to power transportation engines. Contamination on lubricating oil is a common issue due to leakage or extensive use of engines. This study explores the lubricant oil blend's friction and wear with the biodiesel derived from waste cooking oil, waste cooking oil blend withCalophyllum inophyllum oil, and biodiesel–diesel blend. The blending of biodiesels and biodiesel–diesel blend with lubricant oil varies from 5% to 25% of biodiesels and biodiesel–diesel with 95% to 75% of lubricating oil based on volume ratio. The test was conducted using a four-ball tribotester according to the ASTM D 4172. The result showed that blending of BWCIL75 with biodiesel–diesel has the lowest friction coefficient (0.072) among tested oil. The wear scar on the ball bearing lubricated with the blending mixture showed an acceptable diameter value. The wear morphology has shown that a worn surface with black spots provides more protection to the tested ball. The result found that fatty acid contained in the biodiesel and the low viscosity of biodiesel significantly reduced the frictional coefficient of the lubricating oil and worked as wear prevention. Mechanical efficiency of machinery component favour low coefficient of friction. This study indicated that biodiesel produced from waste cooking oil blended with Calophyllum inophyllum oil shows better lubricity and can be used as an additive to petroleum-based lubricant for better automotive engine performance.
Min, C, Kim, JE, Shon, HK & Kim, S-H 2022, 'Low energy resonance vibration submerged membrane system for microalgae harvesting: Performance and feasibility', Desalination, vol. 539, pp. 115895-115895.
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This study investigated an energy-efficient harvesting method to collect microalgae of Chlorella Vulgaris (C. vulgaris). The method proposed in the current study was a combination of a resonance vibration submerged membrane (RVSM) system and centrifugation. The result showed that the RVSM system was able to concentrate the C. vulgaris solution by 17 times (0.61 g·L−1 to 10.4 g·L−1) without chemical cleaning during filtration with intermittent relaxation (i.e., filtration for 9 min and relaxation for 1 min) at a flux of 40 LMH (L·m−2·h−1) until the transmembrane pressure (TMP) reached 70 kPa. In addition, extracellular polymeric substances such as polysaccharides and protein were found mainly responsible for membrane fouling during the operation of concentrating C. vulgaris solution. Integrating the RVSM system with the centrifugation process required the total specific energy consumption of 0.56 kWh·m−3 (0.09 kWh·m−3 for the RVSM and 0.47 kWh·m−3 for the centrifugation). This study demonstrated the combination of the RVSM system and centrifugation to be a feasible C. vulgaris harvesting method by showing lower energy consumption than other conventional processes.
Mofijur, M, Ashrafur Rahman, SM, Nguyen, LN, Mahlia, TMI & Nghiem, LD 2022, 'Selection of microalgae strains for sustainable production of aviation biofuel', Bioresource Technology, vol. 345, pp. 126408-126408.
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This study develops and applies the PROMETHEE-GAIA method as a new tool to select microalgae strains for aviation fuel production. Assessment involves 19 criteria with equal weighting in three aspects, namely biomass production, lipid quality, and fatty acid methylester properties. Here, the method is demonstrated for evaluating 17 candidate microalgae strains. Chlorella sp. NT8a is assessed as the most suitable strain for aviation fuel production. The results also show that unmodified biofuel from the most suitable strain could not meet all jet fuel standards. In particular, microalgae-based fuel could not satisfy the required density, heating value and freezing points of the international jet fuel standards. These results highlight the need for a broad action plan including improvement in the processing or modification of biofuel produced from microalgae and revision of the current jet fuel standards to facilitate the introduction of microalgae-based biofuel for the aviation industry.
Mohamed, BA, Bilal, M, Salama, E-S, Periyasamy, S, Fattah, IMR, Ruan, R, Awasthi, MK & Leng, L 2022, 'Phenolic-rich bio-oil production by microwave catalytic pyrolysis of switchgrass: Experimental study, life cycle assessment, and economic analysis', Journal of Cleaner Production, vol. 366, pp. 132668-132668.
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This study aims to determine the environmental impacts and feasibility of optimizing the production of phenolic-rich bio-oil, via switchgrass microwave catalytic pyrolysis. K3PO4 (Tripotassium phosphate) was used as the catalyst, at different temperatures, throughout this life cycle assessment (LCA) study. Results were compared with non-catalytic microwave pyrolysis (SiC-400) and conventional pyrolysis. K3PO4 (KP) was used as the microwave absorber and catalyst to enhance the low microwave absorption of switchgrass during microwave pyrolysis, and to improve the bio-oil quality and selectivity for phenolics production. Pyrolysis temperatures made a considerable difference to the LCA. There was an 86% reduction in the pyrolysis time when heating the sample to 300 °C (KP-300), as compared to 400 °C (KP-400), resulting in a significant reduction of the amount of energy required, and GHG's emitted. The total global warming potential (GWP) for microwave catalytic pyrolysis is observed within 159–223 kg CO2-eq/1000 kg of dried switchgrass (SG), with the baseline case (SiC-400) being the highest, and KP-300 being the lowest. Using the produced biochar, which is rich in nutrients for soil application, brings the net GWP to negative values through carbon sequestration. KP-300 also showed the highest selectivity for phenol and alkylphenols production, which increased by 252% and 420% respectively, compared to the baseline. The results clearly indicate that introducing K3PO4 showed great potential for accelerating microwave heating, and improving bio-oil selectivity towards alkylphenols, which can be used to replace petroleum-based phenol. This in turn can reduce GHG emissions, due to higher conversion efficiencies and lower energy consumption compared with non-catalytic microwave pyrolysis and conventional pyrolysis.
Mohamed, BA, Fattah, IMR, Yousaf, B & Periyasamy, S 2022, 'Effects of the COVID-19 pandemic on the environment, waste management, and energy sectors: a deeper look into the long-term impacts', Environmental Science and Pollution Research, vol. 29, no. 31, pp. 46438-46457.
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The COVID-19 pandemic not only has caused a global health crisis but also has significant environmental consequences. Although many studies are confirming the short-term improvements in air quality in several countries across the world, the long-term negative consequences outweigh all the claimed positive impacts. As a result, this review highlights the positive and the long-term negative environmental effects of the COVID-19 pandemic by evaluating the scientific literature. Remarkable reduction in the levels of CO (3 - 65%), NO2 (17 - 83%), NOx (24 - 47%), PM2.5 (22 - 78%), PM10 (23 - 80%), and VOCs (25 - 57%) was observed during the lockdown across the world. However, according to this review, the pandemic put enormous strain on the present waste collection and treatment system, resulting in ineffective waste management practices, damaging the environment. The extensive usage of face masks increased the release of microplastics/nanoplastics (183 to 1247 particles piece-1) and organic pollutants in land and water bodies. Furthermore, the significant usages of anti-bacterial hand sanitizers, disinfectants, and pharmaceuticals have increased the accumulation of various toxic emerging contaminants (e.g., triclocarban, triclosan, bisphenol-A, hydroxychloroquine) in the treated sludge/biosolids and discharged wastewater effluent, posing great threats to the ecosystems. This review also suggests strategies to create long-term environmental advantages. Thermochemical conversions of solid wastes including medical wastes and for treated wastewater sludge/biosolids offer several advantages through recovering the resources and energy and stabilizing/destructing the toxins/contaminants and microplastics in the precursors.
Mojiri, A, Ozaki, N, Kazeroon, RA, Rezania, S, Baharlooeian, M, Vakili, M, Farraji, H, Ohashi, A, Kindaichi, T & Zhou, JL 2022, 'Contaminant Removal from Wastewater by Microalgal Photobioreactors and Modeling by Artificial Neural Network', Water, vol. 14, no. 24, pp. 4046-4046.
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The potential of microalgal photobioreactors in removing total ammonia nitrogen (TAN), chemical oxygen demand (COD), caffeine (CAF), and N,N-diethyl-m-toluamide (DEET) from synthetic wastewater was studied. Chlorella vulgaris achieved maximum removal of 62.2% TAN, 52.8% COD, 62.7% CAF, and 51.8% DEET. By mixing C. vulgaris with activated sludge, the photobioreactor showed better performance, removing 82.3% TAN, 67.7% COD, 85.7% CAF, and 73.3% DEET. Proteobacteria, Bacteroidetes, and Chloroflexi were identified as the dominant phyla in the activated sludge. The processes were then optimized by the artificial neural network (ANN). High R2 values (>0.99) and low mean squared errors demonstrated that ANN could optimize the reactors’ performance. The toxicity testing showed that high concentrations of contaminants (>10 mg/L) and long contact time (>48 h) reduced the chlorophyll and protein contents in microalgae. Overall, a green technology for wastewater treatment using microalgae and bacteria consortium has demonstrated its high potentials in sustainable management of water resources.
Mojiri, A, Ozaki, N, Zhou, JL, Kazeroon, RA, Zahed, MA, Rezania, S, Vakili, M, Gavanji, S & Farraji, H 2022, 'Integrated Electro-Ozonation and Fixed-Bed Column for the Simultaneous Removal of Emerging Contaminants and Heavy Metals from Aqueous Solutions', Separations, vol. 9, no. 10, pp. 276-276.
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In the current study, an integrated physiochemical method was utilized to remove tonalide (TND) and dimethyl phthalate (DMP) (as emerging contaminants, ECs), and nickel (Ni) and lead (Pb) (as heavy metals), from synthetic wastewater. In the first step of the study, pH, current (mA/cm2), and voltage (V) were set to 7.0, 30, and 9, respectively; then the removal of TND, DMP, Ni, and Pb with an electro-ozonation reactor was optimized using response surface methodology (RSM). At the optimum reaction time (58.1 min), ozone dosage (9.4 mg L−1), initial concentration of ECs (0.98 mg L−1), and initial concentration of heavy metals (28.9 mg L−1), the percentages of TND, DMP, Ni, and Pb removal were 77.0%, 84.5%, 59.2%, and 58.2%, respectively. For the electro-ozonation reactor, the ozone consumption (OC) ranged from 1.1 kg to 3.9 kg (kg O3/kg Ecs), and the specific energy consumption (SEC) was 6.95 (kWh kg−1). After treatment with the optimum electro-ozonation parameters, the synthetic wastewater was transferred to a fixed-bed column, which was filled with a new composite adsorbent (named BBCEC), as the second step of the study. BBCEC improved the efficacy of the removal of TND, DMP, Ni, and Pb to more than 92%.
Mojiri, A, Zhou, JL, Nazari V, M, Rezania, S, Farraji, H & Vakili, M 2022, 'Biochar enhanced the performance of microalgae/bacteria consortium for insecticides removal from synthetic wastewater', Process Safety and Environmental Protection, vol. 157, pp. 284-296.
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The presence of pesticides in aquatic environments has threatened marine food resources, aquaculture, fisheries and human health; therefore, two most used insecticides were removed during this study. Two photobioreactors, including biochar and Chlorella vulgaris/activated sludge (reactor 1), and Chlorella vulgaris/activated sludge (reactor 2) were run to remove chlorpyrifos (CPF) and cypermethrin (CYP). Proteobacteria, Bacteroidetes and Chloroflexi were the dominant phyla of activated sludge. The optimization performance of both reactors was conducted by response surface methods. The performance of first photobioreactor was better than that in the second reactor, achieving abatement of 88.80% CPF and 93.12% CYP, at 69.7 h contact time and 0.32 mg/L initial concentration. The toxicity of CPF and CYP to Chlorella vulgaris was monitored under 0–4 mg/L of insecticide concentrations and 0–72 h contact time. The minimum chlorophyll content (2 mg/L) and protein (16.7%), and maximum growth inhibition (89.7%) were recorded at 4 mg/L insecticides concentration and 72 h contact time. Moreover, molecular docking simulation for catalytic enzyme degradation of Proteobacteria, Bacteroidetes and microalgae was carried out using individual hydrolase enzymes: carboxypeptidase in microalgae, isochorismatase hydrolase in Proteobacteria and alpha-L-arabinofuranosidase in Bacteroidetes. Ligand-binding energy, affinity and dimensions of ligands-binding sites in the enzyme cavity were calculated in each case. Hydrolase is an enzyme group that offers a promising practical application for the degradation of CYP and CPF due to its cavity features. This analysis demonstrated the mode of interaction of ligands with hydrolase enzymes in different species.
Mojiri, A, Zhou, JL, Ratnaweera, H, Rezania, S & Nazari V, M 2022, 'Pharmaceuticals and personal care products in aquatic environments and their removal by algae-based systems', Chemosphere, vol. 288, no. Pt 2, pp. 132580-132580.
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The consumption of pharmaceuticals and personal care products (PPCPs) has been widely increasing, yet up to 90-95% of PPCPs consumed by human are excreted unmetabolized. Moreover, the most of PPCPs cannot be fully removed by wastewater treatment plants (WWTPs), which release PPCPs to natural water bodies, affecting aquatic ecosystems and potentially humans. This study sought to review the occurrence of PPCPs in natural water bodies globally, and assess the effects of important factors on the fluxes of pollutants into receiving waterways. The highest ibuprofen concentration (3738 ng/L) in tap water was reported in Nigeria, and the highest naproxen concentration (37,700 ng/L) was reported in groundwater wells in Penn State, USA. Moreover, the PPCPs have affected aquatic organisms such as fish. For instance, up to 24.4 × 103 ng/g of atenolol was detected in P. lineatus. Amongst different technologies to eliminate PPCPs, algae-based systems are environmentally friendly and effective because of the photosynthetic ability of algae to absorb CO2 and their flexibility to grow in different wastewater. Up to 99% of triclosan and less than 10% of trimethoprim were removed by Nannochloris sp., green algae. Moreover, variable concentrations of PPCPs might adversely affect the growth and production of algae. The exposure of algae to high concentrations of PPCPs can reduce the content of chlorophyll and protein due to producing reactive oxygen species (ROS), and affecting expression of some genes in chlorophyll (rbcL, psbA, psaB and psbc).
Mong, GR, Chong, CT, Chong, WWF, Ng, J-H, Ong, HC, Ashokkumar, V, Tran, M-V, Karmakar, S, Goh, BHH & Mohd Yasin, MF 2022, 'Progress and challenges in sustainable pyrolysis technology: Reactors, feedstocks and products', Fuel, vol. 324, pp. 124777-124777.
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Pyrolysis is a thermo-chemical decomposition process that converts organic or inorganic materials into solid, liquid and gaseous products. The pyrolysis process involves multiple complex chemical reactions, and the derived products are highly dependent on the pyrolysis operating parameters and type of feedstock. In the present review, progress on the state-of-the-art pyrolysis technology, feedstock and properties of the end products are thoroughly reviewed. The potential application of the pyrolysis products in the industries is discussed: solid leftover can be upgraded and used as a bio-adsorbant, soil amendment, fertilizer or solid fuel; pyrolysis liquid can be used as a bio-chemical source or upgraded into liquid fuel; gaseous products can be used as recirculating gas for the pyrolysis environment or burnt as fuel for heat and power generation. Despite the potential of pyrolysis in processing agricultural or industrial wastes, studies regarding the economic feasibility and environment sustainability of scaled-up pyrolysis plant are scarce. A comprehensive overview on the type of pyrolysis reactor technology, potential feedstock and the properties of the derived products is presented. Further, the sustainability of the technology is assessed from the aspects of energy balance, environment and economics. In spite of the potential benefits to the environment and recovery of valuable products, there are several challenges that need to be addressed to ensure the sustainability and commercialibility of the pyrolysis technologies.
Muhit, IB, Masia, MJ & Stewart, MG 2022, 'Monte-Carlo laboratory testing of unreinforced masonry veneer wall system under out-of-plane loading', Construction and Building Materials, vol. 321, pp. 126334-126334.
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This paper presents the results of a probabilistic experimental study into the behaviour of full-scale unreinforced masonry (URM) veneer walls with flexible backup subjected to out-of-plane loading. The actual safety and reliability of the contemporary Australian URM structures are unknown due to the absence of information regarding the probabilistic behaviour of the whole veneer wall system and material characterisation of the wall constituent materials. The study focused on masonry typologies representative of modern URM buildings in the Australian context. In this study, 18 full-scale URM veneer wall systems with theoretically identical geometries and properties were tested under inward and outward out-of-plane loading. For each loading type, one specimen was tested under semi-cyclic loading to check whether the monotonic loading can capture the overall behaviour of the cyclic response. For each mortar batch mixed, bond wrench testing was conducted at the same age as the test for the associated wall constructed using that mix. Batch to batch variabilities were statistically analysed, and probability distributions for flexural tensile strength were established. Lognormal distributions with aggregated means of 0.40 MPa and 0.42 MPa for inward and outward loading, respectively, were estimated for flexural tensile strengths. After the wall tests, all timber studs used to build the veneer walls were tested to evaluate the probabilistic characterisation of timber stiffness. This probabilistic information is essential for a stochastic finite element analysis (FEA) to conduct the reliability analysis. From the wall tests, veneer wall system behaviour was observed and measured until the collapse or 20% post-peak drop of the peak load. Outward loaded specimens exhibited higher variabilities for masonry cracking and system peak load compared to inward loading due to variabilities from materials, testing arrangements and failure mechanism. The true coefficient o...
Muhit, IB, Stewart, MG & Masia, MJ 2022, 'Probabilistic constitutive law for masonry veneer wall ties', Australian Journal of Structural Engineering, vol. 23, no. 2, pp. 97-118.
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In a masonry veneer wall system, tie strengths and stiffnesses vary randomly and so are not consistent for all ties throughout the wall. To ensure an economical and safe design, this paper uses tie calibration experimental approach in accordance with the standard AS2699.1 to investigate the tie failure load under compression and tension loading. Probabilistic wall tie characterisations are accomplished by estimating the mean, coefficient of variation and characteristic axial compressive and tensile strength from 50 specimens. The displacement across the cavity is recorded, which resulted the complete load versus displacement response. Using the maximum likelihood method, a range of probability distributions are fitted to tie strengths at different displacement histogram data sets, and a best-fitted probability distribution is selected for each case. The inverse cumulative distribution function plots are also used along with the Anderson-Darling test to infer a goodness-of-fit for the probabilistic models. An extensive statistical correlation analysis is also conducted to check the correlation between different tie strengths and associated displacement for both compression and tension loading. Based on the findings, a wall tie constitutive law is proposed to define probabilistic tie behaviour in numerical modelling.
Mukund Deshpande, N, Gite, S, Pradhan, B & Ebraheem Assiri, M 2022, 'Explainable Artificial Intelligence–A New Step towards the Trust in Medical Diagnosis with AI Frameworks: A Review', Computer Modeling in Engineering & Sciences, vol. 133, no. 3, pp. 843-872.
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Machine learning (ML) has emerged as a critical enabling tool in the sciences and industry in recent years. Today’s machine learning algorithms can achieve outstanding performance on an expanding variety of complex tasks–thanks to advancements in technique, the availability of enormous databases, and improved computing power. Deep learning models are at the forefront of this advancement. However, because of their nested nonlinear structure, these strong models are termed as “black boxes,” as they provide no information about how they arrive at their conclusions. Such a lack of transparencies may be unacceptable in many applications, such as the medical domain. A lot of emphasis has recently been paid to the development of methods for visualizing, explaining, and interpreting deep learning models. The situation is substantially different in safety-critical applications. The lack of transparency of machine learning techniques may be limiting or even disqualifying issue in this case. Significantly, when single bad decisions can endanger human life and health (e.g., autonomous driving, medical domain) or result in significant monetary losses (e.g., algorithmic trading), depending on an unintelligible data-driven system may not be an option. This lack of transparency is one reason why machine learning in sectors like health is more cautious than in the consumer, e-commerce, or entertainment industries. Explainability is the term introduced in the preceding years. The AI model’s black box nature will become explainable with these frameworks. Especially in the medical domain, diagnosing a particular disease through AI techniques would be less adapted for commercial use. These models’ explainable natures will help them commercially in diagnosis decisions in the medical field. This paper explores the different frameworks for the explainability of AI models in the medical field. The available frameworks are compared with other parameters, and their suitability fo...
Nagy, E, Ibrar, I, Braytee, A & Iván, B 2022, 'Study of Pressure Retarded Osmosis Process in Hollow Fiber Membrane: Cylindrical Model for Description of Energy Production', Energies, vol. 15, no. 10, pp. 3558-3558.
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A new mathematical model was developed to predict the cylindrical effect of the membrane performance in the pressure retarded osmosis process. The cylindrical membrane transport layers (the draw side boundary and the porous membrane) were divided into very thin sublayers with constant mass transport parameters, among others with a constant radius in every sublayer. The obtained second-order differential mass balance equations were solved analytically, with constant parameters written for every sublayer. The algebraic equation system involving 2N equations was then solved for the determinant solution. It was shown that the membrane properties, water permeability (A), salt permeability (B), structural parameter (S) and the operating conditions (inlet draw side solute concentration and draw side mass transfer coefficient) affect the water flux strongly, and thus the membrane performance, due to the cylindrical effect caused by the variable surface and volume of the sublayers. This effect significantly depends on the lumen radius. The lower radius means a larger change in the internal surface/volume of sublayers with ΔR thickness. The predicted results correspond to that of the flat-sheet membrane layer at ro = 10,000 μm. At the end of this manuscript, the calculated mass transfer rates were compared to those measured. It was stated that the curvature effect in using a capillary membrane must not be left out of consideration when applying hollow fiber membrane modules due to their relatively low lumen radius. The presented model provides more precise prediction of the performance in the case of hollow fiber membranes.
Ng, BYS, Ong, HC, Lau, HLN, Ishak, NS, Elfasakhany, A & Lee, HV 2022, 'Production of sustainable two-stroke engine biolubricant ester base oil from palm fatty acid distillate', Industrial Crops and Products, vol. 175, pp. 114224-114224.
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In this study, palm fatty acid distillate (PFAD) was selected as the feedstock for biolubricant base oil production in two-stroke engine oils’ formulation. PFAD is a low-cost palm refinery by-product with a high free fatty acid (FFA) content (85%). The esterification of PFAD with neopentyl glycol (NPG) was conducted in the presence of a solid acid catalyst (SO42-/Fe2O3/Al2O3) to produce PFAD-NPG ester. Optimization profile indicated that PFAD conversion and PFAD-NPG ester yield were 84% and 82%, respectively, under optimum reaction conditions of 180 °C, 4 h, 2.0 wt% SO42-/Fe2O3/Al2O3 catalyst loading and a 2:1 PFAD to NPG molar ratio. The physicochemical properties of the base oil successfully comply with the Japanese Automotive Standards Organization (JASO) M345:2018 requirements for two-stroke oils in terms of sulfated ash content, kinematic viscosity at 100 °C and flash point. In addition, reusability of solid acid catalyst, SO42-/Fe2O3/Al2O3 was investigated, where PFAD conversion and PFAD-NPG ester yield were found to be excellent at 81% and 80%, respectively, which showed that the catalyst had good consistency after 5 cycles.
Ngo, T, Indraratna, B & Ferreira, F 2022, 'Influence of synthetic inclusions on the degradation and deformation of ballast under heavy-haul cyclic loading', International Journal of Rail Transportation, vol. 10, no. 4, pp. 413-435.
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This study investigates the benefits of artificial inclusions placed underneath the ballast layer. A series of large-scale cyclic triaxial tests were carried out on ballast with and without these inclusions under 25-tonne and 35-tonne axle loads and frequencies of f = 15 Hz and 25 Hz, using a Process Simulation Prismoidal Triaxial Apparatus. The laboratory results show that a geogrid installed between the ballast and capping layer decreases both deformation and degradation of the aggregates, which can be attributed to enhanced internal confinement and restricted particle movement. Laboratory tests also showed that placing a rubber mat underneath the ballast layer significantly reduced ballast breakage. A numerical model using the discrete element method (DEM) was developed and validated against the experimental observations. The DEM model was utilized to explore the contact forces that developed across the granular assemblies, and to study the interaction between aggregates and the synthetic inclusions from a particle-level perspective.
Nguyen, AQ, Nguyen, LN, Johir, MAH, Ngo, HH & Nghiem, LD 2022, 'Linking endogenous decay and sludge bulking in the microbial community to membrane fouling at sub-critical flux', Journal of Membrane Science Letters, vol. 2, no. 1, pp. 100023-100023.
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This study examined membrane fouling and associated microbial taxa in a membrane bioreactor operating at a sub-critical flux condition using next-generation amplicon sequencing. The membrane was operated at a sub-critical flux, thus, fouling was not observed until endogenous decay. The observed fouling could be attributed to endogenous decay which was driven by nutrient deficiency at high sludge age and low food-to-microorganisms ratio (decreasing from 0.15 to 0.09 gBOD/gMLVSS.d). Endogenous decay resulted in a sharp decrease of the number of species and evenness between different species (49.7 and 58.9% compared to the inoculum, respectively). The release of dissolved organic matters and cell debris from endogenous decay as well as the excessive growth of filamentous bacteria, e.g. Thiotrichales were the main contributors to membrane fouling. The relative abundance of Thiotrichales significantly correlated with TMP (Pearson R = 0.996, p-value <0.001), indicating this order's contribution to membrane fouling. Other dominant orders in the mixed liquor after endogenous decay such as Rhizobiales, Burkholderiales, Rhodospirillales and Myxococcales, Flavobacteriales can produce extracellular polymeric substances and aggravating membrane fouling. Fouling layers possess highly similar microbial composition with the mixed liquor, with some filamentous microbial orders, e.g. Corynebacteriales and Oligoflexales showing increased relative abundance by 6.83 and 5.64 folds, respectively.
Nguyen, AQ, Nguyen, LN, McDonald, JA, Nghiem, LD, Leusch, FDL, Neale, PA & Khan, SJ 2022, 'Chiral inversion of 2-arylpropionoic acid (2-APA) enantiomers during simulated biological wastewater treatment', Water Research, vol. 209, pp. 117871-117871.
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Nguyen, AQ, Nguyen, LN, Xu, Z, Luo, W & Nghiem, LD 2022, 'New insights to the difference in microbial composition and interspecies interactions between fouling layer and mixed liquor in a membrane bioreactor', Journal of Membrane Science, vol. 643, pp. 120034-120034.
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This work examined fouling-associated microbial community in a carefully controlled laboratory-scale membrane bioreactor (MBR) at different fouling stages. In agreement with the literature, fouling severity was positively correlated with bound polysaccharide and protein content (indicators) in the mixed liquor. UPGMA clustering analysis with different indices indicated that although the biofouling layer (biofilm) and mixed liquor possessed highly similar microbial identity, important differences between the two communities' structures were also observed. This appears to be the first comprehensive study to apply differential abundance analysis (ANCOM) to identify microbial taxa driven the divergence in microbial structure including Victivallales, Coxiellales, unassigned Microgenomatia and Blastocatellia 11–24 (all presented at <1% abundance). Network analysis also identified Victivallales and Blastocatellia 11–24 among the few key players in the mixed liquor and biofilm community, respectively. Despite their low abundances, key players in both communities positively correlated (Pearson's correlation coefficient >0.6) with fouling indicators, confirming their important contributions to fouling propensity. The biofilm community exhibited a more complex structure with higher level of inter-species interaction and prevalence of positive connections (74.6%) compared to the mixed liquor community (42.2%), reflecting higher stability and synergy between microbial taxa in the biofilm. Results from this comprehensive investigation can support the development of new fouling control strategies.
Nguyen, B-P, Nguyen, TT, Nguyen, THY & Tran, T-D 2022, 'Performance of Composite PVD–SC Column Foundation under Embankment through Plane-Strain Numerical Analysis', International Journal of Geomechanics, vol. 22, no. 9, p. 04022155.
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The combination of soil-cement (SC) columns and prefabricated vertical drains (PVDs) has indicated great success in improving ground stabilization in recent years; however, there is a lack of proper plane-strain numerical modeling to detail the role of PVDs in improving the performance of the SC column method. This study thus presents a numerical analysis of soft soil ground improved by the coupled PVD-SC column method based on a proposed equivalent plane-strain model considering the combined effects of PVDs and SC columns in the ground. The model is verified by applying it to a test embankment where long PVDs were installed in soft soil in combination with floating SC columns. To investigate the role of PVDs in the composite foundation, the numerical analysis is then conducted for two cases, with and without PVDs. The effects of discharge capacity of PVDs on the SC column behavior are also examined. The results show that the PVDs significantly improve performance of the composite foundation as they considerably reduce both postconstruction settlement and lateral displacement, while increasing the efficiency of soil arching and the bending moment capacity in SC columns. The numerical results obtained from the proposed model are in good agreement with the field data. The current study also shows that the discharge capacity of PVDs should be larger than 20 m3/year to enhance the positive influence of PVDs on the entire performance of the composite foundation.
Nguyen, KT, Navidpour, AH, Ahmed, MB, Mojiri, A, Huang, Y & Zhou, JL 2022, 'Adsorption and desorption behavior of arsenite and arsenate at river sediment-water interface', Journal of Environmental Management, vol. 317, pp. 115497-115497.
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The adsorption of inorganic arsenic (As) plays an important role in the mobility and transport of As in the river environment. In this work, the adsorption and desorption of arsenite [As(III)] and arsenate [As(V)] on river sediment were conducted under different pH, initial As concentrations, river water and sediment composition to assess As adsorption behavior and mechanism. Both adsorption kinetics and equilibrium results showed higher adsorption capacity of sediment for As(V) than As(III). Adsorption of As(III) and As(V) on river sediment was favored in acidic to neutral conditions and on finer sediment particles, while sediment organic matter marginally reduced adsorption capacity. In addition, higher adsorption affinity of As(III) and As(V) in river sediment was observed in deionised water than in river water. For the release process, the desorption of both As(III) and As(V) followed nonlinear kinetic models well, showing higher amount of As(III) release from sediment than As(V). Adsorption isotherm was well described by both Langmuir and Freundlich models, demonstrating higher maximum adsorption capacity of As(V) at 298.7 mg/kg than As(III) at 263.3 mg/kg in deionised water, and higher maximum adsorption capacity of As(III) of 234.3 mg/kg than As(V) of 206.2 mg/kg in river water. The XRD showed the changes in the peaks of mineral groups of sediment whilst FTIR results revealed the changes related to surface functional groups before and after adsorption, indicating that Fe-O/Fe-OH, Si(Al)-O, hydroxyl and carboxyl functional groups were predominantly involved in As(III) and As(V) adsorption on sediment surface. XPS analysis evidenced the transformation between these As species in river sediment after adsorption, whilst SEM-EDS revealed higher amount of As(V) in river sediment than As(III) due to the lower signal of Al.
Nguyen, LN, Aditya, L, Vu, HP, Johir, AH, Bennar, L, Ralph, P, Hoang, NB, Zdarta, J & Nghiem, LD 2022, 'Nutrient Removal by Algae-Based Wastewater Treatment', Current Pollution Reports, vol. 8, no. 4, pp. 369-383.
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AbstractAlgae cultivation complements wastewater treatment (WWT) principles as the process uptakes nutrients while assimilates CO2 into biomass. Thus, the application of algae-based WWT is on the upward trajectory as more attention for recovery nutrients and CO2 capture while reducing its economic challenge in the circular economy concept. However, the complexity of wastewater and algal ecological characteristics induces techno-economic challenges for industry implementation. Algae-based WWT relies totally on the ability of algae to uptake and store nutrients in the biomass. Therefore, the removal efficiency is proportional to biomass productivity. This removal mechanism limits algae applications to low nutrient concentration wastewater. The hydraulic retention time (HRT) of algae-based WWT is significantly long (i.e. > 10 days), compared to a few hours in bacteria-based process. Phototrophic algae are the most used process in algae-based WWT studies as well as in pilot-scale trials. Application of phototrophic algae in wastewater faces challenges to supply CO2 and illumination. Collectively, significant landscape is required for illumination. Algae-based WWT has limited organic removals, which require pretreatment of wastewaters before flowing into the algal process. Algae-based WWT can be used in connection with the bacteria-based WWT to remove partial nutrients while capturing CO2. Future research should strive to achieve fast and high growth rate, strong environmental tolerance species, and simple downstream processing and high-value biomass. There is also a clear and urgent need for more systematic analysis of biomass for both carbon credit assessment and economic values to facilitate identification and prioritisation of barriers to lower the cost algae-based WWT. Graphical abstract
Nguyen, LN, Vu, HP, Fu, Q, Abu Hasan Johir, M, Ibrahim, I, Mofijur, M, Labeeuw, L, Pernice, M, Ralph, PJ & Nghiem, LD 2022, 'Synthesis and evaluation of cationic polyacrylamide and polyacrylate flocculants for harvesting freshwater and marine microalgae', Chemical Engineering Journal, vol. 433, pp. 133623-133623.
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This study addresses the challenge of microalgae harvesting through the development of flocculants. Two positively charged cationic polymers including poly[2 (acryloyloxy)ethyl]trimethylammonium chloride (PAETAC) and poly(3 acrylamidopropyl)trimethylammonium chloride (PAmPTAC) were synthesized using the UV-induced radical polymerization, for harvesting both freshwater and marine microalgae. The results show that the synthesized polymers have excellent flocculation performance for both freshwater green microalgae (Chlorella vulgaris) and marine red microalgae (Porphyridium purpureum). PAETAC outperformed PAmPTAC for both Chlorella vulgaris and Porphyridium purpureum microalgae. The optimal PAETAC doses for Chlorella vulgaris and Porphyridium purpureum microalgae were 50 and 4.8 mg/g of dry biomass while the optimal PAmPTAC doses were 252 and 35 mg/g of dry biomass respectively. Additionally, the floc formation with the PAETAC was more stable than PAmPTAC, which supported the dewatering step via sieving. The superior performance can be attributed to the higher molecular weight of the PAETAC polymer when compared to the PAmPTAC polymer. In comparison to commercially available polydiallyldimethylammonium chloride (PolyDADMAC), the newly synthesised PAETAC and PAmPTAC polymers demonstrated superior flocculation efficiency at a lower dose. The findings of this study established a platform technology for designing and synthesising cationic flocculants for use in microalgae harvesting.
Nguyen, NHT, Nguyen, TT & Phan, QT 2022, 'Dynamics and runout distance of saturated particle-fluid mixture flow on a horizontal plane: A coupled VOF-DEM study', Powder Technology, vol. 408, pp. 117759-117759.
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This study investigates the dynamics and runout of particle-water mixture column collapse using a modelling method coupling Discrete Element Method (DEM) and Volume of Fluid (VOF). From the numerical results, we observe similar and distinct responses between the dry and saturated mixture flows. Both exhibit two different flow behaviours for low and high column collapse. However, the presence of water reduces dissipative interactions between particles, hence increasing the mobility of mixture flows compared to their dry counterparts. The reduction of particle interaction forces also weakens the transition from sliding-dominant to inertial-dominant flows with increasing column aspect ratio. Therefore, the runout distance of mixture flows can be described by a single scaling law rather than by two different functions as for the dry flows. Additionally, the impacts of particle density on mixture flows become more significant in which the flows run out less and retain greater height with increasing particle density.
Nguyen, NPT, Sultana, A, Areerachakul, N & Kandasamy, J 2022, 'Evaluating the Field Performance of Permeable Concrete Pavers', Water, vol. 14, no. 14, pp. 2143-2143.
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The benefits of using permeable interlocking concrete pavement systems (PICPs) have not translated into widespread adoption in Australia, where their uptake has been slow. This paper communicates the actual performance of PICPs installed in the field by providing evidence of their long-term efficiency. There are currently no Australian standards for design, specification and installation of PICPs. In this study, field measurements were conducted to determine the infiltration capacity of PICPs in Sydney and Wollongong, New South Wales, applying the single ring infiltrometer test (SRIT) and the stormwater infiltration field test (SWIFT). A strong correlation was found between the results of the two tests in a previous study, which was verified in this study. The long-term performance of PICPs is demonstrated by their high infiltration rates (ranging from 125 mm/h to 25,000 mm/h) measured in this study at field sites under a diverse range of conditions. The influences of conditions such as age of installation, slope and tree cover on infiltration rates were explored.
Nguyen, PM, Do, PT, Pham, YB, Doan, TO, Nguyen, XC, Lee, WK, Nguyen, DD, Vadiveloo, A, Um, M-J & Ngo, HH 2022, 'Roles, mechanism of action, and potential applications of sulfur-oxidizing bacteria for environmental bioremediation', Science of The Total Environment, vol. 852, pp. 158203-158203.
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Sulfur (S) is a crucial component in the environment and living organisms. This work is the first attempt to provide an overview and critical discussion on the roles, mechanisms, and environmental applications of sulfur-oxidizing bacteria (SOB). The findings reveal that key enzymes of SOB embarked on oxidation of sulfide, sulfite, thiosulfate, and elemental S. Conversion of reduced S compounds was oxidatively catalyzed by various enzymes (e.g. sulfide: quinone oxidoreductase, flavocytochrome c-sulfide dehydrogenase, dissimilatory sulfite reductase, heterodisulfide reductase-like proteins). Environmental applications of SOB discussed include detoxifying hydrogen sulfide, soil bioremediation, and wastewater treatment. SOB producing S0 engaged in biological S soil amendments (e.g. saline-alkali soil remediation, the oxidation of sulfide-bearing minerals). Biotreatment of H2S using SOB occurred under both aerobic and anaerobic conditions. Sulfide, nitrate, and sulfamethoxazole were removed through SOB suspension cultures and S0-based carriers. Finally, this work presented future perspectives on SOB development, including S0 recovery, SOB enrichment, field measurement and identification of sulfur compounds, and the development of mathematical simulation.
Nguyen, QD, Afroz, S, Zhang, Y, Kim, T, Li, W & Castel, A 2022, 'Autogenous and total shrinkage of limestone calcined clay cement (LC3) concretes', Construction and Building Materials, vol. 314, pp. 125720-125720.
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In this study, the developments of autogenous and total shrinkage of limestone calcined clay cement (LC3) concretes were investigated. Three concrete grades including 25 MPa, 32 MPa and 45 MPa of both LC3 and general purpose cement (GPC) concretes were considered. Compressive strength and tensile strength were measured until curing of 28 days. In addition, pore size distribution of cementitious pastes was evaluated by using nitrogen adsorption. Several models were used to assess their applicability for LC3 concretes in predicting mechanical properties and shrinkage development. The LC3 concretes showed higher autogenous shrinkage at a later age up to 100 days due to continuous refinement of the pore structure whilst the development of total shrinkage was similar between LC3 and OPC concretes. All models underestimated LC3 concrete autogenous shrinkage and the Bazant B4 model provided the best prediction of total shrinkage development.
Nguyen, TAH, Le, TV, Ngo, HH, Guo, WS, Vu, ND, Tran, TTT, Nguyen, THH, Nguyen, XC, Nguyen, VH & Pham, TT 2022, 'Hybrid use of coal slag and calcined ferralsol as wetland substrate for improving phosphorus removal from wastewater', Chemical Engineering Journal, vol. 428, pp. 132124-132124.
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Nguyen, TH, Loganathan, P, Nguyen, TV, Vigneswaran, S, Ha Nguyen, TH, Tran, HN & Nguyen, QB 2022, 'Arsenic removal by pomelo peel biochar coated with iron', Chemical Engineering Research and Design, vol. 186, pp. 252-265.
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Nguyen, TH, Ryu, S, Loganathan, P, Kandasamy, J, Nguyen, TV & Vigneswaran, S 2022, 'Arsenic adsorption by low-cost laterite column: Long-term experiments and dynamic column modeling', Process Safety and Environmental Protection, vol. 160, pp. 868-875.
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Arsenic (As) contamination of drinking water supplies is a major concern in many countries due to its large concentration in groundwater and high toxicity. In this study, batch adsorption experiments on a natural laterite adsorbent from Vietnam (NLTT) were firstly conducted, followed by four column adsorption experiments using NLTT working with synthetic water under different experimental conditions (initial arsenate As(V) concentration: 0.1 and 0.5 mg/L; bed height: 0.15 and 0.41 m). Results from the batch equilibrium adsorption study show that all three models - Sips, Langmuir, and Freundlich - fitted the experimental data very well. The Sips and Langmuir maximum adsorption capacities were 0.76 mg/g and 0.58 mg/g, respectively. At an As(V) concentration of 0.5 mg/L, adsorption breakthrough occurred at 28 h and 122 h for column heights of 0.15 m and 0.41 m, respectively. When As(V) concentration fell to 0.1 mg/L, the breakthrough times rose to 144 h and 240 h, respectively. A linear driving force approximation (LDFA) model incorporating the Sips equation was calibrated with data from the equilibrium and kinetic adsorption experiments and one column adsorption experiment (initial concentration: 0.1 mg/L; bed height: 0.15 m). The LDFA model with the calibrated model coefficients could predict the breakthrough curves and adsorption time in the three other column experiments and four household column filters used to treat As contaminated groundwater in Vietnam. The study revealed that application potential for NLTT in column adsorption studies and field trials to remove As(V) is significant despite this study having limited data. Subsequently, refining the model based on simulation of results is cost-effective, saves time and effort, and negates the need for multiple experiments to optimize filter conditions.
Nguyen, TH, Tran, HN, Nguyen, TV, Vigneswaran, S, Trinh, VT, Nguyen, TD, Ha Nguyen, TH, Mai, TN & Chao, H-P 2022, 'Single-step removal of arsenite ions from water through oxidation-coupled adsorption using Mn/Mg/Fe layered double hydroxide as catalyst and adsorbent', Chemosphere, vol. 295, pp. 133370-133370.
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This study developed a layered double hydroxides (Mn/Mg/Fe-LDH) material through a simple co-precipitation method. The Mn/Mg/Fe-LDH oxidized arsenite [As(III)] ions into arsenate [As(V)] anions. The As(III) and oxidized As(V) were then adsorbed on Mn/Mg/Fe-LDH. The adsorption process of arseniate [As(V)] oxyanions by Mn/Mg/Fe-LDH was simultaneously conducted for comparison. Characterization results indicated that (i) the best Mg/Mn/Fe molar ratio was 1/1/1, (ii) the Mn/Mg/Fe-LDH structure was similar to that of hydrotalcite, (iii) the Mn/Mg/Fe-LDH possessed a positively charged surface (pHIEP of 10.15) and low Brunauer-Emmett-Teller surface area (SBET = 75.2 m2/g), and (iv) Fe2+/Fe3+ and Mn2+/Mn3+/Mn4+ coexisted in Mn/Mg/Fe-LDH. The As(III) adsorption process by Mn/Mg/Fe-LDH was similar to that of As(V) under different experimental conditions (initial solutions pH, coexisting foreign anions, contact times, initial As concentrations, temperatures, and desorbing agents). The Langmuir maximum adsorption capacity of Mn/Mg/Fe-LDH to As(III) (56.1 mg/g) was higher than that of As(V) (32.2 mg/g) at pH 7.0 and 25 °C. X-ray photoelectron spectroscopy was applied to identify the oxidation states of As in laden Mn/Mg/Fe-LDH. The key removal mechanism of As(III) by Mn/Mg/Fe-LDH was oxidation-coupled adsorption, and that of As(V) was reduction-coupled adsorption. The As(V) mechanism adsorption mainly involved: (1) the inner-sphere and outer-sphere complexation with OH groups of Mn/Mg/Fe-LDH; and (2) anion exchange with host anions (NO3-) in its interlayer. The primary mechanism adsorption of As(III) was the inner-sphere complexation. The redox reactions made Mn/Mg/Fe-LDH loss its original layer structure after adsorbing As(V) or As(III). The adsorption process was highly irreversible. Mn/Mg/Fe-LDH can decontaminate As from real groundwater samples from 45-92 ppb to 0.35-7.9 ppb (using 1.0 g/L). Therefore, Mn/Mg/Fe-LDH has great potential as a material for removing As.
Nguyen, TN, Sanchez, LFM, Li, J, Fournier, B & Sirivivatnanon, V 2022, 'Correlating alkali-silica reaction (ASR) induced expansion from short-term laboratory testings to long-term field performance: A semi-empirical model', Cement and Concrete Composites, vol. 134, pp. 104817-104817.
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Correlating short-term expansion of concrete specimens in the laboratory and long-term expansion of concrete in the field is crucial to evaluate the reliability of laboratory test methods and essential for the prognosis of alkali-silica reaction (ASR) in concrete infrastructures. In this study, a novel semi-empirical approach is proposed for forecasting ASR-induced expansion of unrestrained concrete in the field using laboratory measurements data. In addition to the use of short-term laboratory expansion data, the model accounts for the effects of alkali leaching, alkali contribution from aggregates, and environmental conditions (i.e., temperature and relative humidity). A comprehensive database from the literature was gathered for the development and calibration of the proposed model. Finally, the model was used for various concrete blocks incorporating different reactive aggregates and exposed to three outdoor conditions in Canada and the USA. Model outcomes show that it is highly promising for forecasting the induced expansion of concrete in the field from the accelerated laboratory tests data. Analysing the modelling results also highlights the importance of alkali leaching and environmental conditions on the correlation between laboratory and field performance.
Nguyen, TT & Indraratna, B 2022, 'Fluidization of soil under increasing seepage flow: an energy perspective through CFD-DEM coupling', Granular Matter, vol. 24, no. 3.
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AbstractIncreasing seepage flow causes soil particles to migrate, i.e., from local piping to complete fluidization, resulting in reduced effectives stress and degraded shear stiffness of the soil foundation. This process has received considerable attention in the past years, however, majority of them concentrate on macro-aspects such as the internal erosion and soil deformation, while there is a lack of fundamental studies addressing the energy transport at micro-scale of fluid-soil systems during soil approaching fluidization. In this regard, the current study presents an assessment of the energy evolution in soil fluidization based on the discrete element method (DEM) coupled with computation fluid dynamics (CFD). In this paper, an upward seepage flow of fluid is modelled by CFD based on the modified Navier–Stokes equations, while soil particles are governed by DEM with their mutual interactions being computed through fluid-particle force models. The energy transformation from the potential state to kinetic forms during fluid flowing is discussed with respect to numerical (CFD-DEM) results and the energy conservation concepts. The results show that majority of the potential energy induced by fluid flows has lost due to frictional mechanisms, while only a small amount of energy is needed to cause the soil to fluidize completely. The contribution of rotational and translational components to the total kinetic energy of particles, and their changing roles during soil fluidization is also presented. The effect of boundary condition on the energy transformation and fluidization of soil is also investigated and discussed. Graphical abstract
Nguyen, TT & Indraratna, B 2022, 'Rail track degradation under mud pumping evaluated through site and laboratory investigations', International Journal of Rail Transportation, vol. 10, no. 1, pp. 44-71.
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This paper presents the results of field and laboratory studies of slurry tracks along the South Coast rail line in NSW, Australia. Site investigations on fouled tracks were followed by a series of laboratory tests to determine the properties of mud fines, and how they can reduce track performance. This study reveals two distinctly different ways of forming slurry tracks, i.e., non-subgrade and subgrade mud pumping, resulting in different characteristics of degraded tracks. More cohesive the fouling materials are, the greater the reduction in hydraulic conductivity (kb) and shear strength (Sb) of the contaminated ballast. When the fouling index FI > 30%, kb drops severely, causing insufficient drainage capacity of the track while the loss of Sb can exceed 22%. Different types of fouling index are also discussed with reference to the field and laboratory data, followed by proposed empirical equations to estimate the values of kb and Sb.
Nguyen, TT, Indraratna, B & Leroueil, S 2022, 'Localized behaviour of fluidized subgrade soil subjected to cyclic loading', Canadian Geotechnical Journal, vol. 59, no. 10, pp. 1844-1849.
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Recent investigations have shown that under adverse cyclic triaxial loading, the upper part of soil specimens can turn into a fluid-like state with increased water content (i.e., fluidization), whereas the lower layers can maintain a relatively high stiffness. This paper aims to gain further insight into this behaviour by monitoring the development in excess pore water pressure (EPWP) at the top and bottom of the test specimens, followed by post-analysis of water content distribution along the specimen. The results show that the EPWP at the uppermost part of the specimen develops rapidly and approaches the zero-effective stress level, whereas the EPWP at the bottom part of the specimen tends to stabilize while undergoing densification. Accompanied with this process is a redistribution of the water content along the specimen height where the water content at the upper soil layer increases to approach the liquid limit while increasing the void ratio.
Nguyen, TT, Indraratna, B & Rujikiatkamjorn, C 2022, 'A numerical approach to modelling biodegradable vertical drains', Environmental Geotechnics, vol. 9, no. 8, pp. 515-523.
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Because of their distinct features such as biodegradability and favourable engineering properties, naturally occurring materials including jute and coconut fibres have been used increasingly in numerous geoengineering applications in recent years. However, these materials can sometimes decompose rapidly when subjected to adverse environmental conditions, resulting in severe degradation of their engineering characteristics and consequently causing damage to the design target. This paper presents a numerical approach where the finite-element method (FEM) is used to estimate the influence that the degradation of natural fibre drains can have on soil consolidation. A subroutine which can describe the reduction in drain discharge capacity over time is incorporated into the FEM model. Different cases including those varying the rate and time-dependent form of biodegradation are examined in this paper. The results of this investigation indicate that the dissipation of excess pore pressure can be hampered significantly if drains decay too early and speedily, particularly when the discharge capacity falls below 0·03 m3/d. Different rates of decay can impose different consolidation responses in the surrounding soft soil. Application of the proposed FEM to compare with laboratory data indicates an acceptable agreement between the predictions and the measurements.
Nguyen, TT, Ngo, HH, Guo, W, Chang, SW, Nguyen, DD, Nguyen, CT, Zhang, J, Liang, S, Bui, XT & Hoang, NB 2022, 'A low-cost approach for soil moisture prediction using multi-sensor data and machine learning algorithm', Science of The Total Environment, vol. 833, pp. 155066-155066.
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A high-resolution soil moisture prediction method has recently gained its importance in various fields such as forestry, agricultural and land management. However, accurate, robust and non- cost prohibitive spatially monitoring of soil moisture is challenging. In this research, a new approach involving the use of advance machine learning (ML) models, and multi-sensor data fusion including Sentinel-1(S1) C-band dual polarimetric synthetic aperture radar (SAR), Sentinel-2 (S2) multispectral data, and ALOS Global Digital Surface Model (ALOS DSM) to predict precisely soil moisture at 10 m spatial resolution across research areas in Australia. The total of 52 predictor variables generated from S1, S2 and ALOS DSM data fusion, including vegetation indices, soil indices, water index, SAR transformation indices, ALOS DSM derived indices like digital model elevation (DEM), slope, and topographic wetness index (TWI). The field soil data from Western Australia was employed. The performance capability of extreme gradient boosting regression (XGBR) together with the genetic algorithm (GA) optimizer for features selection and optimization for soil moisture prediction in bare lands was examined and compared with various scenarios and ML models. The proposed model (the XGBR-GA model) with 21 optimal features obtained from GA was yielded the highest performance (R2 = 0. 891; RMSE = 0.875%) compared to random forest regression (RFR), support vector machine (SVM), and CatBoost gradient boosting regression (CBR). Conclusively, the new approach using the XGBR-GA with features from combination of reliable free-of-charge remotely sensed data from Sentinel and ALOS imagery can effectively estimate the spatial variability of soil moisture. The described framework can further support precision agriculture and drought resilience programs via water use efficiency and smart irrigation management for crop production.
Nguyen, TT, Pham, TD, Nguyen, CT, Delfos, J, Archibald, R, Dang, KB, Hoang, NB, Guo, W & Ngo, HH 2022, 'A novel intelligence approach based active and ensemble learning for agricultural soil organic carbon prediction using multispectral and SAR data fusion', Science of The Total Environment, vol. 804, pp. 150187-150187.
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Monitoring agricultural soil organic carbon (SOC) has played an essential role in sustainable agricultural management. Precise and robust prediction of SOC greatly contributes to carbon neutrality in the agricultural industry. To create more knowledge regarding the ability of remote sensing to monitor carbon soil, this research devises a state-of-the-art low cost machine learning model for quantifying agricultural soil carbon using active and ensemble-based decision tree learning combined with multi-sensor data fusion at a national and world scale. This work explores the use of Sentinel-1 (S1) C-band dual polarimetric synthetic aperture radar (SAR), Sentinel-2 (S2) multispectral data, and an innovative machine learning (ML) approach using an integration of active learning for land-use mapping and advanced Extreme Gradient Boosting (XGBoost) for robustness of the SOC estimates. The collected soil samples from a field survey in Western Australia were used for the model validation. The indicators including the coefficient of determination (R2) and root - mean - square - error (RMSE) were applied to evaluate the model's performance. A numerous features computed from optical and SAR data fusion were employed to build and test the proposed model performance. The effectiveness of the proposed machine learning model was assessed by comparing with the two well-known algorithms such as Random Forests (RF) and Support Vector Machine (SVM) to predict agricultural SOC. Results suggest that a combination of S1 and S2 sensors could effectively estimate SOC in farming areas by using ML techniques. Satisfactory accuracy of the proposed XGBoost with optimal features was achieved the highest performance (R2 = 0.870; RMSE = 1.818 tonC/ha) which outperformed RF and SVM. Thus, multi-sensor data fusion combined with the XGBoost lead to the best prediction results for agricultural SOC at 10 m spatial resolution. In short, this new approach could significantly contribute to var...
Nguyen, T-T-D, Bui, X-T, Nguyen, T-T, Hao Ngo, H, Yi Andrew Lin, K, Lin, C, Le, L-T, Dang, B-T, Bui, M-H & Varjani, S 2022, 'Co-culture of microalgae-activated sludge in sequencing batch photobioreactor systems: Effects of natural and artificial lighting on wastewater treatment', Bioresource Technology, vol. 343, pp. 126091-126091.
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Nguyen, XC, Nguyen, TTH, Le, QV, Le, PC, Srivastav, AL, Pham, QB, Nguyen, PM, La, DD, Rene, ER, Ngo, HH, Chang, SW & Nguyen, DD 2022, 'Developing a new approach for design support of subsurface constructed wetland using machine learning algorithms', Journal of Environmental Management, vol. 301, pp. 113868-113868.
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Knowing the effluent quality of treatment systems in advance to enable the design of treatment systems that comply with environmental standards is a realistic strategy. This study aims to develop machine learning - based predictive models for designing the subsurface constructed wetlands (SCW). Data from the SCW literature during the period of 2009-2020 included 618 sets and 10 features. Five algorithms namely, Random forest, Classification and Regression trees, Support vector machines, K-nearest neighbors, and Cubist were compared to determine an optimal algorithm. All nine input features including the influent concentrations, C:N ratio, hydraulic loading rate, height, aeration, flow type, feeding, and filter type were confirmed as relevant features for the predictive algorithms. The comparative result revealed that Cubist is the best algorithm with the lowest RMSE (7.77 and 21.77 mg.L-1 for NH4-N and COD, respectively) corresponding to 84% of the variance in the effluents explained. The coefficient of determination of the Cubist algorithm obtained for NH4-N and COD prediction from the test data were 0.92 and 0.93, respectively. Five case studies of the application of SCW design were also exercised and verified by the prediction model. Finally, a fully developed Cubist algorithm-based design tool for SCW was proposed.
Nuruzzaman, M, Liu, Y, Ren, J, Rahman, MM, Zhang, H, Hasan Johir, MA, Shon, HK & Naidu, R 2022, 'Capability of Organically Modified Montmorillonite Nanoclay as a Carrier for Imidacloprid Delivery', ACS Agricultural Science & Technology, vol. 2, no. 1, pp. 57-68.
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Organically modified clays have attracted increasing research attention for their various commercial and industrial applications, such as being carriers for pesticide delivery. Besides, the suitability and performance of commercially available organoclays could further promote their applicability. Hence, this study investigated the potential application of a commercially available alkylamine-modified montmorillonite (MMT) nanoclay as a carrier for a widely used insecticide, imidacloprid. X-ray diffraction and thermogravimetric analysis were employed to illustrate the arrangement, orientation, and conformation of surface-modifying agents (SMAs) on MMT nanoclay. It was observed that the clay was modified at an ∼1.0 cation exchange capacity, with the SMAs, especially octadecylamine, arranged in the MMT nanoclay as a bilayer to a pseudo-trilayer or a paraffin monolayer with a tilting angle of ∼25°, which indicated the nanoclay’s ability to adsorb a large amount of imidacloprid. The adsorption-desorption of imidacloprid to MMT nanoclay further confirmed this applicability. A high adsorption capacity (∼85 mg g-1) was observed, with a high reversibility in desorption, showing a hysteresis value of 0.75. Further, the adsorption kinetics and response of the nanoclay to imidacloprid revealed that, initially, a rapid sorption occurred due to a hydrophobic interaction. This was followed by a slower diffusion-controlled sorption due to hydrogen bonding to the internal binding sites. The releasing pattern of imidacloprid from the MMT nanoclay indicated its potential for the preparation of a slow-releasing pesticide formulation where the nanoclay will reduce the instantaneous release of the total amount of pesticide.
O’Connor, J, Bolan, NS, Kumar, M, Nitai, AS, Ahmed, MB, Bolan, SS, Vithanage, M, Rinklebe, J, Mukhopadhyay, R, Srivastava, P, Sarkar, B, Bhatnagar, A, Wang, H, Siddique, KHM & Kirkham, MB 2022, 'Distribution, transformation and remediation of poly- and per-fluoroalkyl substances (PFAS) in wastewater sources', Process Safety and Environmental Protection, vol. 164, pp. 91-108.
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Omar, KR, Fatahi, B & Nguyen, LD 2022, 'Impacts of Pre-contamination Moisture Content on Mechanical Properties of High-Plasticity Clay Contaminated with Used Engine Oil', Journal of Testing and Evaluation, vol. 50, no. 6, pp. 3001-3027.
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Abstract The oil contamination of soils and the remediation techniques to enhance the engineering properties of the ground have been an emerging challenge in the geoenvironmental field. While several studies were conducted to examine the behavior of the contaminated granular soils, little is known about the mechanical properties of the oil-contaminated clays. This paper investigates the impacts of the in situ pre-contamination moisture content (PMC) on the behavior of fine-grained soil contaminated with various levels of used engine oil. Extensive laboratory experiments were performed on sandy clay with different initial moisture conditions and various amounts of used engine oil varying from 0 to 16 %. The experimental results, including the Atterberg limits, linear shrinkage (LS), unconfined compressive strength, shear strength, and small-strain shear modulus in conjunction with microstructural image analysis, were reported and discussed. It is observed that when oil content was increased, both LS and plastic limit (PL) increased while the liquid limit decreased in the contaminated soil. Moreover, the inclusion of engine oil contributed to the reduction in the plasticity index, which was also impacted by the PMC of the soil. An increment in the PL was correlated with a significant decrease in shear strength, shear modulus, and other associated parameters such as friction angle and cohesion. In agreement with the results, a broader range of elasticity and improved stability at the microstructure level was associated with a lower pre-contamination water content (PMC). Overall, this paper shows that knowledge of site moisture levels before contamination is essential to evaluate the implications of contamination by used engine oil.
Onggowarsito, C, Feng, A, Mao, S, Nguyen, LN, Xu, J & Fu, Q 2022, 'Water Harvesting Strategies through Solar Steam Generator Systems', ChemSusChem, vol. 15, no. 23, p. e202201543.
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AbstractSolar steam generator (SSG) systems have attracted increasing attention, owing to its simple manufacturing, material abundance, cost‐effectiveness, and environmentally friendly freshwater production. This system relies on photothermic materials and water absorbing substrates for a clean continuous distillation process. To optimize this process, there are factors that are needed to be considered such as selection of solar absorber and water absorbent materials, followed by micro/macro‐structural system design for efficient water evaporation, floating, and filtration capability. In this contribution, we highlight the general interfacial SSG concept, review and compare recent progresses of different SSG systems, as well as discuss important factors on performance optimization. Furthermore, unaddressed challenges such as SSG's cost to performance ratio, filtration of untreatable micropollutants/microorganisms, and the need of standardization testing will be discussed to further advance future SSG studies.
Onggowarsito, C, Feng, A, Mao, S, Zhang, S, Ibrahim, I, Tijing, L, Fu, Q & Ngo, HH 2022, 'Development of an innovative MnO2 nanorod for efficient solar vapor generator', Environmental Functional Materials, vol. 1, no. 2, pp. 196-203.
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Ortega-Delgado, B, Palenzuela, P, Altaee, A, Alarcón-Padilla, D-C, Hawari, AH & Zaragoza, G 2022, 'Thermo-economic assessment of forward osmosis as pretreatment to boost the performance and sustainability of multi-effect distillation for seawater desalination', Desalination, vol. 541, pp. 115989-115989.
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Osatiashtiani, A, Orr, SA, Durndell, LJ, García, IC, Merenda, A, Lee, AF & Wilson, K 2022, 'Liquid phase catalytic transfer hydrogenation of ethyl levulinate to γ-valerolactone over ZrO2/SBA-15', Catalysis Science & Technology, vol. 12, no. 18, pp. 5611-5619.
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γ-Valerolactone (GVL) is an important bio-derived platform molecule whose atom- and energy efficient, and scalable, catalytic synthesis is highly desirable.
Ottenhaus, L-M, Li, Z & Crews, K 2022, 'Half hole and full hole dowel embedment Strength: A review of international developments and recommendations for Australian softwoods', Construction and Building Materials, vol. 344, pp. 128130-128130.
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Ouchchen, M, Boutaleb, S, Abia, EH, El Azzab, D, Miftah, A, Dadi, B, Echogdali, FZ, Mamouch, Y, Pradhan, B, Santosh, M & Abioui, M 2022, 'Exploration targeting of copper deposits using staged factor analysis, geochemical mineralization prospectivity index, and fractal model (Western Anti-Atlas, Morocco)', Ore Geology Reviews, vol. 143, pp. 104762-104762.
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Panahi, M, Khosravi, K, Golkarian, A, Roostaei, M, Barzegar, R, Omidvar, E, Rezaie, F, Saco, PM, Sharifi, A, Jun, C, Bateni, SM, Lee, C-W & Lee, S 2022, 'A country-wide assessment of Iran's land subsidence susceptibility using satellite-based InSAR and machine learning', Geocarto International, vol. 37, no. 26, pp. 14065-14087.
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Park, MJ, Akther, N, Phuntsho, S, Naidu, G, Razmjou, A, An, AK & Shon, HK 2022, 'Development of highly permeable self-standing nanocomposite sulfonated poly ether ketone membrane using covalent organic frameworks', Desalination, vol. 538, pp. 115935-115935.
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This study developed a new symmetric and ultrathin membrane by incorporating Schiff base network-1 (SNW-1), which are covalent organic framework (COF) nanoparticles, as fillers in the sulfonated poly ether ketone (SPEK) matrix to improve forward osmosis (FO) performance. The amine-rich and porous SNW-1 nanoparticles enhanced the surface wettability of the SPEK membranes and offered additional passages for the water molecules' transport, which assisted in the elevation of membrane water flux. The modified membrane loaded with 20 wt% SNW-1 (COF-20) exhibited the best performance with a significantly higher water flux (28.5 L m−2 h−1) and lower specific reverse solute flux (SRSF, 0.05 g L−1) than that of the unmodified SPEK (COF-0) membrane (water flux of 12 L m−2 h−1 and SRSF of 0.16 g L−1) when experimented with deionized water and 1 M Na2SO4 as feed and draw solutions, respectively. The impressive FO performances of nanocomposite SPEK membranes suggest that SNW-1 nanoparticles could be used as fillers for improving the SPEK membrane's performance in the FO application.
Park, MJ, Wang, C, Gonzales, RR, Phuntsho, S, Matsuyama, H, Drioli, E & Shon, HK 2022, 'Fabrication of thin film composite polyamide membrane for water purification via inkjet printing of aqueous and solvent inks', Desalination, vol. 541, pp. 116027-116027.
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Patil, AY, Hegde, C, Savanur, G, Kanakmood, SM, Contractor, AM, Shirashyad, VB, Chivate, RM, Kotturshettar, BB, Mathad, SN, Patil, MB, Soudagar, MEM & Fattah, IMR 2022, 'Biomimicking Nature-Inspired Design Structures—An Experimental and Simulation Approach Using Additive Manufacturing', Biomimetics, vol. 7, no. 4, pp. 186-186.
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Whether it is a plant- or animal-based bio-inspiration design, it has always been able to address one or more product/component optimisation issues. Today’s scientists or engineers look to nature for an optimal, economically viable, long-term solution. Similarly, a proposal is made in this current work to use seven different bio-inspired structures for automotive impact resistance. All seven of these structures are derived from plant and animal species and are intended to be tested for compressive loading to achieve load-bearing capacity. The work may even cater to optimisation techniques to solve the real-time problem using algorithm-based generative shape designs built using CATIA V6 in unit dimension. The samples were optimised with Rhino 7 software and then simulated with ANSYS workbench. To carry out the comparative study, an experimental work of bioprinting in fused deposition modelling (3D printing) was carried out. The goal is to compare the results across all formats and choose the best-performing concept. The results were obtained for compressive load, flexural load, and fatigue load conditions, particularly the number of life cycles, safety factor, damage tolerance, and bi-axiality indicator. When compared to previous research, the results are in good agreement. Because of their multifunctional properties combining soft and high stiffness and lightweight properties of novel materials, novel materials have many potential applications in the medical, aerospace, and automotive sectors.
Peellage, WH, Fatahi, B & Rasekh, H 2022, 'Experimental investigation for vibration characteristics of jointed rocks using cyclic triaxial tests', Soil Dynamics and Earthquake Engineering, vol. 160, pp. 107377-107377.
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Peng, M, Tian, Y, Gaudin, C, Zhang, L & Sheng, D 2022, 'Application of a coupled hydro‐mechanical interface model in simulating uplifting problems', International Journal for Numerical and Analytical Methods in Geomechanics, vol. 46, no. 17, pp. 3256-3280.
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AbstractThis paper presents the detailed formulation of a coupled hydro‐mechanical structure‐soil interface and demonstrates its application in simulating uplifting problems. This interface features real‐time prediction of the pore pressure generation and structure‐soil separation, and thus rate dependency and ‘breakaway’ can be modeled without user intervention. Constitutive relations of this interface were derived by considering the coupling between soil skeleton and fluid along the interface. A complete finite element formulation and numerical implementation of the interface is provided based on an eight‐node element. The performance of this interface is demonstrated by simulating lifting a surface footing at varying rates (spanning across undrained, partially drained and drained conditions), compared with existing theoretical solutions, numerical results and experimental data. The good agreement achieved indicates that this interface is capable of modelling uplift at varying rates, which is an extremely challenging topic in offshore engineering. Sensitivity studies were conducted to investigate the parameters affecting uplifting behaviour. A unified backbone curve was established correspondingly, which is shown to be different from existing studies in compression, due to the difference in the mechanism between the two cases.
Peng, X, Li, Y, Tsang, IW, Zhu, H, Lv, J & Zhou, JT 2022, 'XAI beyond Classification: Interpretable Neural Clustering', Journal of Machine Learning Research, vol. 23, no. -.
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In this paper, we study two challenging problems in explainable AI (XAI) and data clustering. The first is how to directly design a neural network with inherent interpretability, rather than giving post-hoc explanations of a black-box model. The second is implementing discrete k-means with a differentiable neural network that embraces the advantages of parallel computing, online clustering, and clustering-favorable representation learning. To address these two challenges, we design a novel neural network, which is a differentiable reformulation of the vanilla k-means, called inTerpretable nEuraL cLustering (TELL). Our contributions are threefold. First, to the best of our knowledge, most existing XAI works focus on supervised learning paradigms. This work is one of the few XAI studies on unsupervised learning, in particular, data clustering. Second, TELL is an interpretable, or the so-called intrinsically explainable and transparent model. In contrast, most existing XAI studies resort to various means for understanding a black-box model with post-hoc explanations. Third, from the view of data clustering, TELL possesses many properties highly desired by k-means, including but not limited to online clustering, plug-and-play module, parallel computing, and provable convergence. Extensive experiments show that our method achieves superior performance comparing with 14 clustering approaches on three challenging data sets. The source code could be accessed at www.pengxi.me.
Peng, Y, Azeem, M, Li, R, Xing, L, Li, Y, Zhang, Y, Guo, Z, Wang, Q, Ngo, HH, Qu, G & Zhang, Z 2022, 'Zirconium hydroxide nanoparticle encapsulated magnetic biochar composite derived from rice residue: Application for As(III) and As(V) polluted water purification', Journal of Hazardous Materials, vol. 423, pp. 127081-127081.
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Finding a low-cost and suitable adsorbent is still in urgent need for efficient decontamination of As(III) and As(V) elements from the polluted waters. A novel zirconium hydroxide nanoparticle encapsulated magnetic biochar composite (ZBC) derived from rice residue was synthesized for the adsorptive capture of As(III) and As(V) from aqueous solutions. The results revealed that ZBC showed an acceptable magnet separation ability and its surface was encapsulated with lots of hydrous zirconium oxide nanoparticles. Compared to As(III), the adsorption of As(V) onto ZBC was mainly dependent on the pH of the solution. The intraparticle diffusion model described the adsorption process. ZBC showed satisfactory adsorption performances to As(III) and As(V) with the highest adsorption quantity of 107.6 mg/g and 40.8 mg/g at pH 6.5 and 8.5, respectively. The adsorption of As(III) and As(V) on ZBC was almost impervious with the ionic strength while the presence of coexisting ions, especially phosphate, significantly affected the adsorption process. The processes of complexation reaction and electrostatic attraction contributed to the adsorption of As(III) and As(V) onto ZBC. ZBC prepared from kitchen rice residue was found to be a low cost environmentally friendly promising adsorbent with high removal capacity for As(III) and As(V) and could be recycled easily from contaminated waters.
Petrik, LF, Ngo, HH, Varjani, S, Osseweijer, P, Xevgenos, D, van Loosdrecht, M, Smol, M, Yang, X & Mateo-Sagasta, J 2022, 'From wastewater to resource', One Earth, vol. 5, no. 2, pp. 122-125.
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Pham, HN, Dang, KB, Nguyen, TV, Tran, NC, Ngo, XQ, Nguyen, DA, Phan, TTH, Nguyen, TT, Guo, W & Ngo, HH 2022, 'A new deep learning approach based on bilateral semantic segmentation models for sustainable estuarine wetland ecosystem management', Science of The Total Environment, vol. 838, pp. 155826-155826.
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Pham, T, Faust, O, Koh, JEW, Ciaccio, EJ, Barua, PD, Omar, N, Ng, WL, Ab Mumin, N, Rahmat, K & Acharya, UR 2022, 'Fusion of B‐mode and shear wave elastography ultrasound features for automated detection of axillary lymph node metastasis in breast carcinoma', Expert Systems, vol. 39, no. 5.
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AbstractIn this study, we evaluate and compare the diagnostic performance of ultrasound for non‐invasive axillary lymph node (ALN) metastasis detection. The study was based on fusing shear wave elastography (SWE) and B‐mode ultrasonography (USG) images. These images were subjected to pre‐processing and feature extraction, based on bi‐dimensional empirical mode decomposition and higher order spectra methods. The resulting nonlinear features were ranked according to their p‐value, which was established with Student's t‐test. The ranked features were used to train and test six classification algorithms with 10‐fold cross‐validation. Initially, we considered B‐mode USG images in isolation. A probabilistic neural network (PNN) classifier was able to discriminate positive from negative cases with an accuracy of 74.77% using 15 features. Subsequently, only SWE images were used and as before, the PNN classifier delivered the best result with an accuracy of 87.85% based on 47 features. Finally, we combined SWE and B‐mode USG images. Again, the PNN classifier delivered the best result with an accuracy of 89.72% based on 71 features. These three tests indicate that SWE images contain more diagnostically relevant information when compared with B‐mode USG. Furthermore, there is scope in fusing SWE and B‐mode USG to improve non‐invasive ALN metastasis detection.
Pourzeynali, S, Zhu, X, Ghari Zadeh, A, Rashidi, M & Samali, B 2022, 'Simultaneous Identification of Bridge Structural Damage and Moving Loads Using the Explicit Form of Newmark-β Method: Numerical and Experimental Studies', Remote Sensing, vol. 14, no. 1, pp. 119-119.
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Bridge infrastructures are always subjected to degradation because of aging, their environment, and excess loading. Now it has become a worldwide concern that a large proportion of bridge infrastructures require significant maintenance. This compels the engineering community to develop a robust method for condition assessment of the bridge structures. Here, the simultaneous identification of moving loads and structural damage based on the explicit form of the Newmark-β method is proposed. Although there is an extensive attempt to identify moving loads with known structural parameters, or vice versa, their simultaneous identification considering the road roughness has not been studied enough. Furthermore, most of the existing time domain methods are developed for structures under non-moving loads and are commonly formulated by state-space method, thus suffering from the errors of discretization and sampling ratio. This research is believed to be among the few studies on condition assessment of bridge structures under moving vehicles considering factors such as sensor placement, sampling frequency, damage type, measurement noise, vehicle speed, and road surface roughness with numerical and experimental verifications. Results indicate that the method is able to detect damage with at least three sensors, and is not sensitive to sensors location, vehicle speed and road roughness level. Current limitations of the study as well as prospective research developments are discussed in the conclusion.
Pradhan, B, Jena, R, Talukdar, D, Mohanty, M, Sahu, BK, Raul, AK & Abdul Maulud, KN 2022, 'A New Method to Evaluate Gold Mineralisation-Potential Mapping Using Deep Learning and an Explainable Artificial Intelligence (XAI) Model', Remote Sensing, vol. 14, no. 18, pp. 4486-4486.
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Geoscientists have extensively used machine learning for geological mapping and exploring the mineral prospect of a province. However, the interpretation of results becomes challenging due to the complexity of machine learning models. This study uses a convolutional neural network (CNN) and Shapley additive explanation (SHAP) to estimate potential locations for gold mineralisation in Rengali Province, a tectonised mosaic of volcano-sedimentary sequences juxtaposed at the interface of the Archaean cratonic segment in the north and the Proterozoic granulite provinces of the Eastern Ghats Belt in Eastern India. The objective is to integrate multi-thematic data involving geological, geophysical, mineralogical and geochemical surveys on a 1:50 K scale with the aim of prognosticating gold mineralisation. The available data utilised during the integration include aero-geophysical (aeromagnetic and aerospectrometric), geochemical (national geochemical mapping), ground geophysical (gravity), satellite gravity, remote sensing (multispectral) and National Geomorphology and Lineament Project structural lineament maps obtained from the Geological Survey of India Database. The CNN model has an overall accuracy of 90%. The SHAP values demonstrate that the major contributing factors are, in sequential order, antimony, clay, lead, arsenic content and a magnetic anomaly in CNN modelling. Geochemical pathfinders, including geophysical factors, have high importance, followed by the shear zones in mineralisation mapping. According to the results, the central parts of the study area, including the river valley, have higher gold prospects than the surrounding areas. Gold mineralisation is possibly associated with intermediate metavolcanics along the shear zone, which is later intruded by quartz veins in the northern part of the Rengali Province. This work intends to model known occurrences with respect to multiple themes so that the results can be replicated in surrou...
Pu, Y, Tang, J, Zeng, T, Hu, Y, Wang, Q, Huang, J, Pan, S, Wang, XC, Li, Y, Hao Ngo, H & Abomohra, A 2022, 'Enhanced energy production and biological treatment of swine wastewater using anaerobic membrane bioreactor: Fouling mechanism and microbial community', Bioresource Technology, vol. 362, pp. 127850-127850.
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Punetha, P & Nimbalkar, S 2022, 'Geotechnical rheological modeling of ballasted railway tracks considering the effect of principal stress rotation', Canadian Geotechnical Journal, vol. 59, no. 10, pp. 1793-1818.
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The rotation of principal stress direction experienced by the soil elements in a railway track substructure during a train passage influences the magnitude of accumulated settlement. However, the existing methods to evaluate the track response under repeated train loads disregard the influence of principal stress rotation (PSR). This article presents a novel approach for assessing the behavior of ballasted railway tracks incorporating the contribution of PSR on track deformation. The proposed technique employs a geotechnical rheological model to evaluate the track behavior, in which the material plasticity is captured through plastic slider elements. The influence of PSR is accounted for by extending an existing constitutive relationship for the slider elements for the substructure layers, which is successfully validated against experimental data reported in the literature. The results reveal that PSR causes significant cumulative deformation in the substructure layers, and disregarding it in the analysis leads to inaccurate predictions. The proposed approach is then applied to an open track-bridge transition with heterogeneous support conditions, in which the differential settlement is found to be largely influenced by PSR. The findings from this study highlight the importance of including the effect of PSR in predictive models for a reliable evaluation of track performance.
Punetha, P & Nimbalkar, S 2022, 'Performance improvement of ballasted railway tracks using three-dimensional cellular geoinclusions', Geotextiles and Geomembranes, vol. 50, no. 6, pp. 1061-1082.
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Qi, C, Yin, R, Cheng, J, Xu, Z, Chen, J, Gao, X, Li, G, Nghiem, L & Luo, W 2022, 'Bacterial dynamics for gaseous emission and humification during bio-augmented composting of kitchen waste with lime addition for acidity regulation', Science of The Total Environment, vol. 848, pp. 157653-157653.
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This study investigated the impacts of lime addition and further microbial inoculum on gaseous emission and humification during kitchen waste composting. High-throughput sequencing was integrated with Linear Discriminant Analysis Effect Size (LEfSe) and Functional Annotation of Prokaryotic Taxa (FAPROTAX) to decipher bacterial dynamics in response to different additives. Results showed that lime addition enriched bacteria, such as Taibaiella and Sphingobacterium as biomarkers, to strengthen organic biodegradation toward humification. Furthermore, lime addition facilitated the proliferation of thermophilic bacteria (e.g. Bacillus and Symbiobacterium) for aerobic chemoheterotrophy, leading to enhanced organic decomposition to trigger notable gaseous emission. Such emission profile was further exacerbated by microbial inoculum to lime-regulated condition given the rapid enrichment of bacteria (e.g. Caldicoprobacter and Pusillimonas as biomarkers) for fermentation and denitrification. In addition, microbial inoculum slightly hindered humus formation by narrowing the relative abundance of bacteria for humification. Results from this study show that microbial inoculum to feedstock should be carefully regulated to accelerate composting and avoid excessive gaseous emission.
Qian, H, Li, J, Pan, Y, Zong, Z & Wu, C 2022, 'Numerical derivation of P-I diagrams for shallow buried RC box structures', Tunnelling and Underground Space Technology, vol. 124, pp. 104454-104454.
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To perform quick damage assessment and preliminary blast resistant design, the present study develops Pressure-Impulse (P-I) diagrams for the shallow-buried box structures based on high fidelity numerical modelling. Shock wave propagation in the soil and its interaction with the roof slab and vertical wall are considered in the blast load modelling, both flexure and shear damage of the roof slab under surface blast loads are considered in the P-I diagram. Parametric studies are carried out to investigate the effects of roof span, wall thickness, concrete strength, flexure and shear reinforcement ratio on the P-I diagram. Based on the numerical results, analytical formulae to predict the P-I diagrams for buried box structures are derived. The applicability of the improved P-I diagrams approaches in practical evaluation is illustrated through case studies.
Qian, J, Zhang, Y, Bai, L, Yan, X, Du, Y, Ma, R & Ni, B-J 2022, 'Revealing the mechanisms of polypyrrole (Ppy) enhancing methane production from anaerobic digestion of waste activated sludge (WAS)', Water Research, vol. 226, pp. 119291-119291.
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Anaerobic digestion (AD) is a promising method for treating waste activated sludge (WAS), but the low methane yield limits its large-scale application. The addition of conductive nanomaterials has been demonstrated to enhance the activity of AD via promoting the direct interspecies electron transfer (DIET). In this study, novel conductive polypyrrole (Ppy) was prepared to effectively improve the AD performance of WAS. The results showed that the accumulative methane production was enhanced by 27.83% by Ppy, with both acidogenesis and methanogenesis being efficiently accelerated. The microbial community analysis indicated that the abundance of bacteria associated with acidogenesis process was significantly elevated by Ppy. Further investigation by metatranscriptomics revealed that fadE and fadN genes (to express the key enzymes in fatty acid metabolism) were highly expressed in the Ppy-driven AD, suggesting that Ppy promoted electron generation during acid production. For methanogenesis metabolism, genes related to acetate utilization and CO2 utilization methanogenesis were also up-regulated by Ppy, illustrating that Ppy facilitates the utilization of acetate and electrons by methanogenic archaea, thus potentially promoting the methanogenesis through DIET.
Qin, J, Liu, X, Zhong, S, Tian, K & Zhang, J 2022, 'Amorphous CoxOy with nano-flake structure for activated persulfate degradation of p-nitrophenol', Journal of Water Process Engineering, vol. 47, pp. 102776-102776.
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Transition metal oxides can activate peroxymonosulfate (PMS) to produce reactive species to degrade pollutants. In this work, we prepared an amorphous CoxOy with nanosheet structure activator to activate PMS and remove p-nitrophenol (PNP). We discussed the degradation performance of PNP by CoxOy/PMS system under different parameters, under the optimum technological conditions, CoxOy has excellent and rapid catalytic activity. In the presence of different anions (Cl−, HCO3−), humic acids and pH (3–11), CoxOy can still maintain favourable catalytic activity. Active species produced in the CoxOy/PMS system were investigated, Sulfate radical (SO4[rad]–) and singlet oxygen (1O2) dominated the degradation of pollutants. This work demonstrates the favourable activity of amorphous CoxOy for degradation of organic pollutants.
Qin, L, Yang, G, Li, D, Ou, K, Zheng, H, Fu, Q & Sun, Y 2022, 'High area energy density of all-solid-state supercapacitor based on double-network hydrogel with high content of graphene/PANI fiber', Chemical Engineering Journal, vol. 430, pp. 133045-133045.
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In order to improve the energy and power density of all-solid-state supercapacitor, more attention is currently focused on the development of electrodes and electrolyte materials with various chemical structure and compositions. However, current studies rarely report hydrogel electrodes with high content of active materials (i.e. > 20.0 wt%), and study their influence on the performance of supercapacitors. Here, a double-network hydrogel electrode was developed and prepared by blade-coating and 3D printing for application in all-solid-state supercapacitor. Moreover, the hydrogel electrode has an unusually high content (25.0 wt%) of active material, leading to high area specific capacitance (871.4mF/cm2) and area energy density (0.14 mWh/cm2 at 0.27 mW/cm2.). This study opens a new pathway to develop high-performance all-solid-state supercapacitors on large-scale.
Qiu, N, Zhang, J, Yuan, F, Jin, Z, Zhang, Y & Fang, J 2022, 'Mechanical performance of triply periodic minimal surface structures with a novel hybrid gradient fabricated by selective laser melting', Engineering Structures, vol. 263, pp. 114377-114377.
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Triply periodic minimal surface (TPMS) structures have been extensively investigated for their excellent mechanical properties and lightweight potential. In this study, a new hybrid gradient (HG) TPMS structure was proposed by combining geometrically deformed gradient (GDG) and volume fraction gradient (VFG). All designed structures were fabricated by selective laser melting (SLM) using Ti-6Al-4V. They were investigated experimentally in terms of deformation behavior, stress–strain curve and energy absorption. The results demonstrated that the GDG structure can develop a better deformation mode to enhance the energy absorption, while the VFG structure can help to reduce the initial peak force and delay the densification point. Most importantly, the hybridization of these two gradients can both greatly enhance the energy absorption capacity and delay the densification point. Compared with the uniform structures, the hybrid gradient structures can almost double the energy absorption under compression. The results of this research may provide valuable insights for the design of high-performance energy-absorbing structures in the future.
Qu, F, Li, W, Guo, Y, Zhang, S, Zhou, JL & Wang, K 2022, 'Chloride-binding capacity of cement-GGBFS-nanosilica composites under seawater chloride-rich environment', Construction and Building Materials, vol. 342, pp. 127890-127890.
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The effects of granulated blast furnace slag (GGBFS) and nano-silica (NS) on the chloride-binding capacity of cement paste after 6-month exposure to seawater chloride-rich solutions were investigated in this paper. The pH, chloride-binding ratio (CBR), leaching behavior, and phase transformation were investigated by various experimental and analysis methods. Thermodynamic modeling was also used to study the phase assemblages for the Portland cement-GGBFS-NS composites exposed to the NaCl and MgCl2 solutions. It was found that for all cementitious composites, more chlorides were bounded in samples exposed to the salt solutions with sodium ions than that with magnesium ions. Proper additions of GGBFS and NS can enhance the chloride-binding capacity of cementitious composites. The results confirm that the addition of GGBFS can improve the chemical chloride-binding capacity because of the increased amount of chloroaluminate. The increased amount of hydrated gels in the cementitious composites with GGBFS also improved the physical chloride-binding capacity. The addition of NS increased the physical chloride-binding capacity due to the more formation of C-S-H/C-A-S-H gels, while the excessive addition of NS left less aluminum phase available for the formation of chloroaluminate, thus further decreased the chemical chloride-binding capacity. Magnesium ions in solutions increased the amount of chloride in the diffuse layer of C-S-H gels and hydrotalcite. The related results provide novel insight into the influences of GGBFS and NS on the chloride-binding capacity of cementitious composites under chloride-rich environments.
Qu, J, Beznasyuk, DV, Cassidy, M, Tanta, R, Yang, L, Holmes, NP, Griffith, MJ, Krogstrup, P & Cairney, JM 2022, 'Atomic-Scale Characterization of Planar Selective-Area-Grown InAs/InGaAs Nanowires', ACS Applied Materials & Interfaces, vol. 14, no. 42, pp. 47981-47990.
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Atomic-scale information about the structural and compositional properties of novel semiconductor nanowires is essential to tailoring their properties for specific applications, but characterization at this length scale remains a challenging task. Here, quasi-1D InAs/InGaAs semiconductor nanowire arrays were grown by selective area epitaxy (SAE) using molecular beam epitaxy (MBE), and their subsequent properties were analyzed by a combination of atom probe tomography (APT) and aberration-corrected transmission electron microscopy (TEM). Results revealed the chemical composition of the outermost thin InAs layer, a fine variation in the indium content at the InAs/InGaAs interface, and lightly incorporated element tracing. The results highlight the importance of correlative microscopy approaches in revealing complex nanoscale structures, with TEM being uniquely suited to interrogating the crystallography of InGaAs NWs, whereas APT is capable of three-dimensional (3D) elemental mapping, revealing the subtle compositional variation near the boundary region. This work demonstrates a detailed pathway for the nanoscale structural assessment of novel one-dimensional (1D) nanomaterials.
Quevedo, RP, Maciel, DA, Uehara, TDT, Vojtek, M, Rennó, CD, Pradhan, B, Vojteková, J & Pham, QB 2022, 'Consideration of spatial heterogeneity in landslide susceptibility mapping using geographical random forest model', Geocarto International, vol. 37, no. 25, pp. 8190-8213.
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Most previous studies of landslide susceptibility mapping (LSM) have not contemplated spatial heterogeneity and the commonly used models for LSM are aspatial, which could reduce model performance. Therefore, aiming to evaluate the applicability of spatial algorithms to predict landslide susceptibility, the performance of geographical random forest (GRF) was evaluated, in comparison to random forest (RF) and extreme gradient boosting (XGBoost). Based on the results, GRF presented the better performance (AUC = 0.876), followed by RF (AUC = 0.748) and XGBoost (AUC = 0.745). GRF also provided the most suitable susceptibility map. While RF and XGBoost presented almost 50% of the study area as susceptible, the GRF presented more concentrated susceptibility areas spatially, with a reasonable area for moderate (15.55%), high (8.73%) and very-high (2.59%) susceptibility classes. Finally, it can be inferred that spatial assessment may improve model performance, and that spatial models have a great potential for LSM.
Quijano-Baron, J, Carlier, R, Rodriguez, JF, Sandi, SG, Saco, PM, Wen, L & Kuczera, G 2022, 'And we thought the Millennium Drought was bad: Assessing climate variability and change impacts on an Australian dryland wetland using an ecohydrologic emulator', Water Research, vol. 218, pp. 118487-118487.
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Quijano-Baron, J, Saco, PM & Rodriguez, JF 2022, 'Modelling the effects of above and belowground biomass pools on erosion dynamics', CATENA, vol. 213, pp. 106123-106123.
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R., J, Gurunathan, B, K, S, Varjani, S, Ngo, HH & Gnansounou, E 2022, 'Advancements in heavy metals removal from effluents employing nano-adsorbents: Way towards cleaner production', Environmental Research, vol. 203, pp. 111815-111815.
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Due to the development in science field which gives not only benefit but also introducesundesirable pollution to the environment. This pollution is due to poor discharge activities of industrial effluents into the soil and water bodies, surface run off from fields of agricultural lands, dumping of untreated wastes by municipalities, and mining activites, which deteriorates the cardinal virtue of our environment and causes menace to human health and life. Heavy metal(s), a natural constituent on earth's crust and economic important mineral, due to its recalcitrant effects creates heavy metal pollution which affects food chain and also reduces the quality of water. For this, many researchers have performed studies to find efficient methods for wastewater remediation. One of the most promising methods from economic point of view is adsorption, which is simple in design, but leads to use of a wide range of adsorbents and ease of operations. Due to advances in nanotechnology, many nanomaterials were used as adsorbents for wastewater remediation, because of their efficiency. Many researchers have reported that nanoadsorbents are unmitigatedly a fruitful solution to address this world's problem. This review presents a potent view on various classes of nanoadsorbents and their application to wastewater treatment. It provides a bird's eye view of the suitability of different types of nanomaterials for remediation of wastewater and Backspace gives up-to-date information about polymer based and silica-based nanoadsorbents.
Rana, AK, Thakur, MK, Saini, AK, Mokhta, SK, Moradi, O, Rydzkowski, T, Alsanie, WF, Wang, Q, Grammatikos, S & Thakur, VK 2022, 'Recent developments in microbial degradation of polypropylene: Integrated approaches towards a sustainable environment', Science of The Total Environment, vol. 826, pp. 154056-154056.
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Fossil-fuel-based plastics have many enticing properties, but their production has resulted in significant environmental issues that require immediate attention. Despite the fact that these polymers are manmade, some bacteria can degrade and metabolise them, suggesting that biotechnologies based on the principle of plastic biodegradation could be beneficial. Among different types of plastics, polypropylene (PP), either having low or high density, is one of the most consumed plastics (18.85%). Their debasement under natural conditions is somewhat tricky. Still, their debasement under natural conditions is rather difficult slightly. However, different scientists have still made efforts by employing other microbes such as bacteria, fungi, and guts bacteria of larvae of insects to bio-deteriorate the PP plastic. Pre-irradiation techniques (ultraviolet and gamma irradiations), compatibilizers, and bio-additives (natural fibers, starch, and polylactic acid) have been found to impact percent bio-deterioration of different PP derivatives stronglythe various. The fungal and bacterial study showed that PP macro/microplastic might serve as an energy source and sole carbon during bio-degradation. Generally, gravimetric method or physical characterization techniques such as FTIR, XRD, SEM, etc., are utilized to affirm the bio-degradation of PP plastics-based materials. However, these techniques are not enough to warrant the bio-deterioration of PP. In this regard, a new technique approach that measures the amount of carbon dioxide emitted during bacterial or fungus degradation has also been discussed. In addition, further exploration is needed on novel isolates from plastisphere environments, sub-atomic strategies to describe plastic-debasing microorganisms and improve enzymatic action strategies, and omics-based innovations to speed up plastic waste bio-deterioration.
Rao, P, Ouyang, P, Wu, J, Li, P, Nimbalkar, S & Chen, Q 2022, 'Seismic Stability of Heterogeneous Slopes with Tensile Strength Cutoff Using Discrete-Kinematic Mechanism and a Pseudostatic Approach', International Journal of Geomechanics, vol. 22, no. 12.
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Rao, P, Xiang, Y, Ouyang, P, Nimbalkar, S & Chen, Q 2022, 'Finite Element Analysis of Electro-Thermal Coupling of Sandstone Under Lightning Currents', Geotechnical and Geological Engineering, vol. 40, no. 5, pp. 2593-2604.
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Rao, P-P, Ouyang, P-H, Nimbalkar, S, Chen, Q-S, Wu, Z-L & Cui, J-F 2022, 'Analytical modelling of the mechanical damage of soil induced by lightning strikes capturing electro-thermal, thermo-osmotic, and electro-osmotic effects', Journal of Mountain Science, vol. 19, no. 7, pp. 2027-2043.
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Rasal, AS, Yadav, S, Kashale, AA, Altaee, A & Chang, J-Y 2022, 'Stability of quantum dot-sensitized solar cells: A review and prospects', Nano Energy, vol. 94, pp. 106854-106854.
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Rasouli, H & Fatahi, B 2022, 'Liquefaction and post-liquefaction resistance of sand reinforced with recycled geofibre', Geotextiles and Geomembranes, vol. 50, no. 1, pp. 69-81.
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The present study provides an insight into the effect of recycled carpet fibre on the mechanical response of clean sand as backfill material subjected to monotonic loading and cyclic loading as well as post-liquefaction resistance of both unreinforced and carpet fibre reinforced soils. To achieve these goals, a series of multi-stage soil element tests under cyclic loading event resulting in liquefaction followed by undrained monotonic shearing without excess pore water pressure dissipation as well as a series of monotonic undrained shear test is conducted. All the specimens are isotropically consolidated under a constant effective confining stress of 100 kPa by considering the effect of cyclic stress ratio and carpet fibre content ranging from 0.25% to 0.75%. The obtained results revealed the efficiency of carpet fibre inclusion in increasing the secant shear modulus and ductility of clean sand under monotonic shearing without previous loading history. The impact of carpet fibre inclusion on the trend of cyclic excess pore water pressure generation and cyclic stiffness degradation was minimal. However, adding carpet fibre significantly improved both liquefaction and post-liquefaction resistances of clean sand. The liquefaction resistance of clean sand, at a constant 15 loading cycles, improved by 26.3% when the soil was reinforced with 0.75% recycled carpet fibre. In addition, the initial shear modulus of the liquefied specimen significantly increased by adding recycled carpet fibre.
Rasouli, H, Fatahi, B & Nimbalkar, S 2022, 'Re-liquefaction resistance of lightly cemented sands', Canadian Geotechnical Journal, vol. 59, no. 12, pp. 2085-2101.
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The re-liquefaction resistance of cemented sands under multiple liquefaction events such as pre-shock, main-shock, and after-shock earthquakes is a complex phenomenon because the response may alter due to bond breakage. A series of multistage liquefaction–re-consolidation soil element tests under undrained stress-controlled cyclic loading condition using cyclic triaxial were carried out to assess the liquefaction and re-liquefaction resistance of cemented sands with varying degrees of cementation. Lightly cemented specimens were reconstituted using Sydney sand and high early strength Portland cement with cement content ranging from 0.25% to 1% and unconfined compression strength from 15 to 80 kPa. The results showed that the re-liquefaction resistance of cemented sands with different amounts of cement decreased after the first liquefaction event and then increased for succeeding liquefaction events. While the trend of residual excess pore water pressure ratio and cyclic stiffness degradation index of untreated sand under successive liquefaction events remained consistent, the corresponding responses for cemented sands altered for the second to the fifth liquefaction events. In fact, the residual excess pore water pressure ratio and cyclic stiffness of cemented sand increased and degraded faster during the early cycles of loading for the second to fifth liquefaction events.
Ravindran, MXY, Asikin-Mijan, N, Ong, HC, Derawi, D, Yusof, MR, Mastuli, MS, Lee, HV, Wan Mahmood, WNAS, Razali, MS, Abdulkareem Al-Sultan, G & Taufiq-Yap, YH 2022, 'Feasibility of advancing the production of bio-jet fuel via microwave reactor under low reaction temperature', Journal of Analytical and Applied Pyrolysis, vol. 168, pp. 105772-105772.
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Raza, M, Ali, L, Inayat, A, Rocha‐Meneses, L, Ahmed, SF, Mofijur, M, Jamil, F & Azimoh, CL 2022, 'Sustainability of biodiesel production using immobilized enzymes: A strategy to meet future bio‐economy challenges', International Journal of Energy Research, vol. 46, no. 13, pp. 19090-19108.
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Biodiesel is an evolving energy substitute for petroleum-based fuel products. In terms of antropogenic impacts, it is an environmentally friendly and sustainable energy source. Biodiesel is produced from a wide variety of biomass materials and its production costs are mainly related to the feedstock and production process. Transesterification is the most commonly used method for biodiesel production. Enzymatic transesterification using lipase-enzyme has certain advantages over acid-alkaline transesterification. The issues relating to enzyme stability, separation, and recyclability in enzymatic transesterification are further improved using immobilized enzymes. Here, we review the potential of immobilized-enzyme technology in biodiesel production as a safer strategy to meet the needs of a sustainable future economy and will conduct future research studies. We critically analyze the state-of-the-art and latest research on the production of biodiesel using immobilized lipase enzymes. Results indicate that liquid lipase's immobilization increases the stability, reactivity, and reusability and significantly decreases biodiesel production costs.
Razzaq, L, Abbas, MM, Miran, S, Asghar, S, Nawaz, S, Soudagar, MEM, Shaukat, N, Veza, I, Khalil, S, Abdelrahman, A & Kalam, MA 2022, 'Response Surface Methodology and Artificial Neural Networks-Based Yield Optimization of Biodiesel Sourced from Mixture of Palm and Cotton Seed Oil', Sustainability, vol. 14, no. 10, pp. 6130-6130.
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In this present study, cold flow properties of biodiesel produced from palm oil were improved by adding cotton seed oil into palm oil. Three different mixtures of palm and cotton oil were prepared as P50C50, P60C40, and P70C30. Among three oil mixtures, P60C40 was selected for biodiesel production via ultrasound assisted transesterification process. Physiochemical characteristics—including density, viscosity, calorific value, acid value, and oxidation stability—were measured and the free fatty acid composition was determined via GCMS. Response surface methodology (RSM) and artificial neural network (ANN) techniques were utilized for the sake of relation development among operating parameters (reaction time, methanol-to-oil ratio, and catalyst concentration) ultimately optimizing yield of palm–cotton oil sourced biodiesel. Maximum yield of P60C40 biodiesel estimated via RSM and ANN was 96.41% and 96.67% respectively, under operating parameters of reaction time (35 min), M:O molar ratio (47.5 v/v %), and catalyst concentration (1 wt %), but the actual biodiesel yield obtained experimentally was observed 96.32%. The quality of the RSM model was examined by analysis of variance (ANOVA). ANN model statistics exhibit contented values of mean square error (MSE) of 0.0001, mean absolute error (MAE) of 2.1374, and mean absolute deviation (MAD) of 2.5088. RSM and ANN models provided a coefficient of determination (R2) of 0.9560 and a correlation coefficient (R) of 0.9777 respectively.
Ren, J, Zhang, B, Zhu, X & Li, S 2022, 'Damaged cable identification in cable-stayed bridge from bridge deck strain measurements using support vector machine', Advances in Structural Engineering, vol. 25, no. 4, pp. 754-771.
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A new two-step approach is developed for damaged cable identification in a cable-stayed bridge from deck bending strain responses using Support Vector Machine. A Damaged Cable Identification Machine (DCIM) based on support vector classification is constructed to determine the damaged cable and a Damage Severity Identification Machine (DSIM) based on support vector regression is built to estimate the damage severity. A field cable-stayed bridge with a long-term monitoring system is used to verify the proposed method. The three-dimensional Finite Element Model (FEM) of the cable-stayed bridge is established using ANSYS, and the model is validated using the field testing results, such as the mode shape, natural frequencies and its bending strain responses of the bridge under a moving vehicle. Then the validated FEM is used to simulate the bending strain responses of the longitude deck near the cable anchors when the vehicle is passing over the bridge. Different damage scenarios are simulated for each cable with various severities. Based on damage indexes vector, the training datasets and testing datasets are acquired, including single damaged cable scenarios and double damaged cable scenarios. Eventually, DCIM is trained using Support Vector Classification Machine and DSIM is trained using Support Vector Regression Machine. The testing datasets are input in DCIM and DSIM to check their accuracy and generalization capability. Different noise levels including 5%, 10%, and 20% are considered to study their anti-noise capability. The results show that DCIM and DSIM both have good generalization capability and anti-noise capability.
Ren, Z, Zhang, X, Huang, Z, Hu, J, Li, Y, Zheng, S, Gao, M, Pan, H & Liu, Y 2022, 'Controllable synthesis of 2D TiH2 nanoflakes with superior catalytic activity for low-temperature hydrogen cycling of NaAlH4', Chemical Engineering Journal, vol. 427, pp. 131546-131546.
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Nanosized titanium compounds are particularly effective in catalyzing hydrogen cycling by NaAlH4. Titanium hydride (TiH2), as a catalyst, is highly interesting since it contributes hydrogen in addition to active Ti. However, it has been challenging to fabricate nanosized TiH2 due to the strong affinity of Ti with oxygen. Herein, TiH2 nanoflakes with a lateral size of ~10 nm and thickness of ~1 nm are successfully synthesized through a novel facile one-pot solvothermal process. In an anhydrous THF solution, LiH reacts with TiCl4 rapidly at 100 °C forming TiH2 and LiCl. The newly formed TiH2 nucleates and grows epitaxially on the graphene surface due to the well-matched lattice parameters, giving rise to the formation of TiH2 nanoflakes. Both theoretical calculations and experiments reveal the generation of Cl· radicals and unsaturated C[dbnd]C bonds when TiCl4 reacts with THF, which promotes the formation of TiH2. The nanoflake-like TiH2 on graphene enables an outstanding hydrogen storage performance of NaAlH4, i.e., full dehydrogenation at 80 °C and hydrogenation at 30 °C and under 100 bar H2, with a practical hydrogen capacity of 4.9 wt%, which has been never reported before.
Rene, ER, Kennes, C, Nghiem, LD & Varjani, S 2022, 'New insights in biodegradation of organic pollutants', Bioresource Technology, vol. 347, pp. 126737-126737.
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Riayatsyah, TMI, Geumpana, TA, Fattah, IMR & Mahlia, TMI 2022, 'Techno-Economic Analysis of Hybrid Diesel Generators and Renewable Energy for a Remote Island in the Indian Ocean Using HOMER Pro', Sustainability, vol. 14, no. 16, pp. 9846-9846.
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This study is about the electrification of the remote islands in the Indian Ocean that were severely affected by the tsunami in the 2004 earth earthquake. To supply electricity to the islands, two diesel generators with capacities of 110 kW and 60 kW were installed in 2019. The feasibility of using renewable energy to supplement or replace the units in these two generators is investigated in this work. In 2019, two diesel generators with capacities of 110 kW and 60 kW were installed in the islands to supply electricity. This work analyses whether the viability of using renewable energy can be used to supplement or replace these two generators. Among the renewable energy options proposed here are a 100 kW wind turbine, solar PV, a converter, and batteries. As a result, the study’s goal is to perform a techno-economic analysis and optimise the proposed hybrid diesel and renewable energy system for a remote island in the Indian Ocean. The Hybrid Optimisation Model for Electric Renewable (HOMER) Pro software was used for all simulations and optimisation for this analysis. The calculation is based on the current diesel price of USD 0.90 per litre (without subsidy). The study found that renewable alone can contribute to 29.2% of renewable energy fractions based on the most optimised systems. The Net Present Cost (NPC) decreased from USD 1.65 million to USD 1.39 million, and the levelised Cost of Energy (CoE) decreased from 0.292 USD/kWh to 0.246 USD/kWh, respectively. The optimised system’s Internal Rate of Return (IRR) is 14% and Return on Investment (ROI) 10%, with a simple payback period of 6.7 years. This study shows that it would be technically feasible to introduce renewable energy on a remote island in Indonesia, where numerous islands have no access to electricity.
Riayatsyah, TMI, Geumpana, TA, Fattah, IMR, Rizal, S & Mahlia, TMI 2022, 'Techno-Economic Analysis and Optimisation of Campus Grid-Connected Hybrid Renewable Energy System Using HOMER Grid', Sustainability, vol. 14, no. 13, pp. 7735-7735.
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This study aimed to conduct a techno-economic performance and optimisation analysis of grid-connected PV, wind turbines, and battery packs for Syiah Kuala University, situated at the tip of Sumatra island in the tsunami-affected region. The simulation software Hybrid Optimisation Model for Electric Renewables (HOMER) was used to analyse and optimise the renewable energy required by the institution. The methodology began with the location specification, average electric load demand, daily radiation, clearness index, location daily temperature, and system architecture. The results revealed that the energy storage system was initially included in the simulation, but it was later removed in order to save money and optimise the share of renewable energy. Based on the optimisation results, two types of energy sources were chosen for the system, solar PV and wind turbine, which contributed 62% and 20%, respectively. Apart from the renewable energy faction, another reason for the system selection is cost of energy (CoE), which decreased to $0.0446/kWh from $0.060/kWh. In conclusion, the study found that by connecting solar PV and wind turbines to the local grid, this renewable energy system is able to contribute up to 82% of the electricity required. However, the obstacle to implementing renewable energy in Indonesia is the cheap electricity price that is mainly generated using cheap coal, which is abundantly available in the country.
Riayatsyah, TMI, Sebayang, AH, Silitonga, AS, Padli, Y, Fattah, IMR, Kusumo, F, Ong, HC & Mahlia, TMI 2022, 'Current Progress of Jatropha Curcas Commoditisation as Biodiesel Feedstock: A Comprehensive Review', Frontiers in Energy Research, vol. 9, p. 815416.
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This article looks at the national and global actors, social networks, and narratives that have influenced Jatropha’s worldwide acceptability as a biofuel crop. Jatropha Curcas is a genus of around 175 succulent shrubs and trees in the Euphorbiaceae family (some of which are deciduous, such as Jatropha Curcas L.). It’s a drought-tolerant perennial that thrives in poor or marginal soil and produces a large amount of oil per hectare. It is easy to grow, has a fast growth rate, and can generate seeds for up to 50 years. Jatropha Curcas has been developed as a unique and promising tropical plant for augmenting renewable energy sources due to its various benefits. It is deserving of being recognised as the only competitor in terms of concrete and intangible environmental advantages. Jatropha Curcas is a low-cost biodiesel feedstock with good fuel properties and more oil than other species. It is a non-edible oilseed feedstock. Thus it will have no impact on food prices or the food vs fuel debate. Jatropha Curcas emits fewer pollutants than diesel and may be used in diesel engines with equivalent performance. Jatropha Curcas also makes a substantial contribution to the betterment of rural life. The plant may also provide up to 40% oil yield per seed based on weight. This study looks at the features characteristics of Jatropha Curcas as biodiesel feedstock and performance, and emissions of internal combustion engine that operates on this biodiesel fuel.
Rodd, J & Castel, A 2022, 'Structural considerations to minimise the risk of horizontal cracks in the wall of circular concrete tanks', Structures, vol. 40, pp. 1091-1106.
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Rony, ZI, Mofijur, M, Ahmed, SF, Kabir, Z, Chowdhury, AA & Almomani, F 2022, 'Recent advances in the solar thermochemical splitting of carbon dioxide into synthetic fuels', Frontiers in Energy Research, vol. 10, p. 982269.
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Recent years have seen a sharp rise in CO2 emissions into the atmosphere, which has contributed to the issue of global warming. In response to this several technologies have been developed to convert CO2 into fuel. It is discovered that the employment of a solar-driven thermochemical process (S-DTCP) that transforms CO2 into fuels can increase the efficiency of the production of sustainable fuels. The process involves the reduction of metal oxide (MO) and oxidizing it with CO2 in a two-step process using concentrated solar power (CSP) at higher and lower temperatures, respectively. This study summarizes current advancements in CO2 conversion methods based on MO thermochemical cycles (ThCy), including their operating parameters, types of cycles, and working principles. It was revealed that the efficiency of the solar conversion of CO2 to fuel is not only influenced by the composition of the MO, but also by its morphology as well as the available surface area for solid/gas reactions and the diffusion length. The conversion mechanism is governed by surface reaction, which is influenced by these two parameters (diffusion length and specific surface area). Solar energy contributes to the reduction and oxidation steps by promoting reaction kinetics and heat and mass transport in the material. The information on recent advances in metal oxide-based carbon dioxide conversion into fuels will be beneficial to both the industrial and academic sectors of the economy.
Roslan, MF, Hannan, MA, Ker, PJ, Mannan, M, Muttaqi, KM & Mahlia, TMI 2022, 'Microgrid control methods toward achieving sustainable energy management: A bibliometric analysis for future directions', Journal of Cleaner Production, vol. 348, pp. 131340-131340.
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Recently, numerous significant advances in control methods have been made in Microgrid development especially in grid-connected mode to ensure a reliable and sustainable operation. The concept of control strategies for inverter systems to ensure proper microgrid integration has sparked a lot of research towards innovation. This review provides a comprehensive overview and analysis of microgrid integrated control methods and energy management systems for both grid-connected and island-based systems. The Scopus database is used to compile a list of the most cited published papers in the field of microgrid control methods and energy management systems, based on predetermined criteria. In the second week of January 2021, the study was performed using the Scopus database. The papers with the most citations were published in 33 different journals from 30 different countries. An 85% of the published articles are based on the control system development and experimental setup whereas 15% are review-based articles. Thus, it can be deduced that this research topic has always been under constant investigation and development in order to enhance the sustainability of microgrid systems in the electric power sector. The paper aims to identify and analyze the highly cited published articles on the respective field to provide future research direction on the microgrid integrated control method and energy management system. The review also underlines numerous factors, issues, challenges, and difficulties that next-generation microgrids must compete with in regards to grid sustainability. Thus, this review will strengthen the scopes and provide context for the development of microgrid integrated control methods and energy management systems in order to achieve an efficient, reliable, cost-effective, and sustainable power supply.
Rozali, S, Abd Latif, Z, Adnan, NA, Hussin, Y, Blackburn, A & Pradhan, B 2022, 'Estimating feature extraction changes of Berkelah Forest, Malaysia from multisensor remote sensing data using and object-based technique', Geocarto International, vol. 37, no. 11, pp. 3247-3264.
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Sabetamal, H, Sheng, D & Carter, JP 2022, 'Coupled hydro-mechanical modelling of unsaturated soils; numerical implementation and application to large deformation problems', Computers and Geotechnics, vol. 152, pp. 105044-105044.
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This paper presents coupled hydro-mechanical modelling of unsaturated soil problems by incorporating some advanced numerical and constitutive models in a general-purpose commercial software package, Abaqus. Two different strategies for the interpretation of unsaturated soil behaviour with respect to the soil volume change are considered and the relevant constitutive models are implemented through user-defined subroutines. The first approach that is commonly used in geomechanics considers suction as an additional variable and uses a constitutive model in the space of effective stress–suction assuming that soil compressibility is a function of suction. The second approach treats the constitutive model in the space of effective stress and degree of saturation assuming that the soil compressibility is a function of the degree of saturation. The hydro-mechanical behaviour regarding the change in the degree of saturation caused by both suction and net stress changes is also considered, together with the effect of hydraulic hysteresis. Validation of the implemented algorithms is presented through several benchmark problems. Finally, the application and utility of the implemented procedures are illustrated by simulations of two challenging problems of unsaturated geomechanics, including a slope failure due to seepage and rainfall infiltration as well as cone penetration tests in unsaturated soil. A suitable mesh optimisation scheme is also incorporated to handle finite deformations.
Sadeghian, F, Jahandari, S, Haddad, A, Rasekh, H & Li, J 2022, 'Effects of variations of voltage and pH value on the shear strength of soil and durability of different electrodes and piles during electrokinetic phenomenon', Journal of Rock Mechanics and Geotechnical Engineering, vol. 14, no. 2, pp. 625-636.
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Saha, S, Gayen, A, Gogoi, P, Kundu, B, Paul, GC & Pradhan, B 2022, 'Proposing novel ensemble approach of particle swarm optimized and machine learning algorithms for drought vulnerability mapping in Jharkhand, India', Geocarto International, vol. 37, no. 25, pp. 8004-8035.
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Drought, a natural and very complex climatic hazard, causes impacts on natural and socio-economic environments. This study aims to produce the drought vulnerability map (DVM) considering novel ensemble machine learning algorithms (MLAs) in Jharkhand, India. Forty, drought vulnerability determining factors under the categories of exposure, sensitivity, and adaptive capacity were used. Then, four machine learning and four novel ensemble approaches of particle swarm optimized (PSO) algorithms, named random forest (RF), PSO-RF, multi-layer perceptron (MLP), PSO-MLP, support vector regression (SVM), PSO-MLP, Bagging, and PSO-Bagging, were established for DVMs. The receiver operating characteristic curve (ROC), mean-absolute-error (MAE), root-mean-square-error (RMSE), precision, and K-index were utilized for judging the performance of novel ensemble MLAs. The obtained results show that the PSO-RF had the highest performance with an AUC of 0.874, followed by RF, PSO-MLP, PSO-Bagging, Bagging, MLP, PSO-SVM and SVM, respectively. Produced DVMs would be helpful for policy intervention to minimize drought vulnerability.
Sakti, AD, Fauzi, AI, Takeuchi, W, Pradhan, B, Yarime, M, Vega-Garcia, C, Agustina, E, Wibisono, D, Anggraini, TS, Theodora, MO, Ramadhanti, D, Muhammad, MF, Aufaristama, M, Perdana, AMP & Wikantika, K 2022, 'Spatial Prioritization for Wildfire Mitigation by Integrating Heterogeneous Spatial Data: A New Multi-Dimensional Approach for Tropical Rainforests', Remote Sensing, vol. 14, no. 3, pp. 543-543.
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Wildfires drive deforestation that causes various losses. Although many studies have used spatial approaches, a multi-dimensional analysis is required to determine priority areas for mitigation. This study identified priority areas for wildfire mitigation in Indonesia using a multi-dimensional approach including disaster, environmental, historical, and administrative parameters by integrating 20 types of multi-source spatial data. Spatial data were combined to produce susceptibility, carbon stock, and carbon emission models that form the basis for prioritization modelling. The developed priority model was compared with historical deforestation data. Legal aspects were evaluated for oil-palm plantations and mining with respect to their impact on wildfire mitigation. Results showed that 379,516 km2 of forests in Indonesia belong to the high-priority category and most of these are located in Sumatra, Kalimantan, and North Maluku. Historical data suggest that 19.50% of priority areas for wildfire mitigation have experienced deforestation caused by wildfires over the last ten years. Based on legal aspects of land use, 5.2% and 3.9% of high-priority areas for wildfire mitigation are in oil palm and mining areas, respectively. These results can be used to support the determination of high-priority areas for the REDD+ program and the evaluation of land use policies.
Sakti, AD, Rahadianto, MAE, Pradhan, B, Muhammad, HN, Andani, IGA, Sarli, PW, Abdillah, MR, Anggraini, TS, Purnomo, AD, Ridwana, R, Yulianto, F, Manessa, MDM, Fauziyyah, AN, Yayusman, LF & Wikantika, K 2022, 'School Location Analysis by Integrating the Accessibility, Natural and Biological Hazards to Support Equal Access to Education', ISPRS International Journal of Geo-Information, vol. 11, no. 1, pp. 12-12.
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This study proposes a new model for land suitability for educational facilities based on spatial product development to determine the optimal locations for achieving education targets in West Java, Indonesia. Single-aspect approaches, such as accessibility and spatial hazard analyses, have not been widely applied in suitability assessments on the location of educational facilities. Model development was performed based on analyses of the economic value of the land and on the integration of various parameters across three main aspects: accessibility, comfort, and a multi-natural/biohazard (disaster) risk index. Based on the maps of disaster hazards, higher flood-prone areas are found to be in gentle slopes and located in large cities. Higher risks of landslides are spread throughout the study area, while higher levels of earthquake risk are predominantly in the south, close to the active faults and megathrusts present. Presently, many schools are located in very high vulnerability zones (2057 elementary, 572 junior high, 157 senior high, and 313 vocational high schools). The comfort-level map revealed 13,459 schools located in areas with very low and low comfort levels, whereas only 2377 schools are in locations of high or very high comfort levels. Based on the school accessibility map, higher levels are located in the larger cities of West Java, whereas schools with lower accessibility are documented far from these urban areas. In particular, senior high school accessibility is predominant in areas of lower accessibility levels, as there are comparatively fewer facilities available in West Java. Overall, higher levels of suitability are spread throughout West Java. These distribution results revealed an expansion of the availability of schools by area: senior high schools, 303,973.1 ha; vocational high schools, 94,170.51 ha; and junior high schools, 12,981.78 ha. Changes in elementary schools (3936.69 ha) were insignificant, as the current numbe...
Sanahuja-Embuena, V, Lim, S, Górecki, R, Trzaskus, K, Hélix-Nielsen, C & Kyong Shon, H 2022, 'Enhancing selectivity of novel outer-selective hollow fiber forward osmosis membrane by polymer nanostructures', Chemical Engineering Journal, vol. 433, pp. 133634-133634.
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An ideal forward osmosis (FO) membrane module for osmotic membrane bioreactor (OMBR) application would have high packing density, low reverse solute flux and low fouling propensity. Recently, an outer-selective hollow fiber forward osmosis (HFFO) membrane has been developed to simultaneously improve packing density and reduce fouling propensity. However, a high reverse solute flux of the HFFO membrane still generates a salinity build-up in the reactor and remains the main challenge of this technology. To tackle this problem, we successfully improved the selectivity of an outer-selective HFFO membrane by incorporating a prior developed formulation based on Pluronic® nanostructures containing water selective proteins into the active layer of the membrane. The assimilation of these nanostructures in the membrane resulted in a significant decrease of the specific reverse solute flux from 0.36 ± 0.01 gL-1 to 0.12 ± 0.02 gL-1 with no significant decrease in water flux. Also, urea was selected as a challenging solute to investigate the selectivity of the developed membranes. In comparison with the pristine membranes, membranes containing nanostructures presented a superior rejection of urea from 87.7 ± 2.0 % to 95.2 ± 0.9 %. The developed membranes are able to be used for future OMBR application tests to prove feasibility of the process. Thus, this study can lead to the development of new membranes suitable for efficient and long-term operation in OMBR configurations. Additionally, the nanostructures investigated here can be used for different thin-film composite membranes as an additive to improve membrane selectivity.
Santoro, S, Aquino, M, Han Seo, D, Van Der Laan, T, Lee, M, Sung Yun, J, Jun Park, M, Bendavid, A, Kyong Shon, H, Halil Avci, A & Curcio, E 2022, 'Dimensionally controlled graphene-based surfaces for photothermal membrane crystallization', Journal of Colloid and Interface Science, vol. 623, pp. 607-616.
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Membrane-based photothermal crystallization - a pioneering technology for mining valuable minerals from seawater and brines - exploits self-heating nanostructured interfaces to boost water evaporation, so achieving a controlled supersaturation environment that promotes the nucleation and growth of salts. This work explores, for the first time, the use of two-dimensional graphene thin films (2D-G) and three dimensional vertically orientated graphene sheet arrays (3D-G) as potential photothermal membranes applied to the dehydration of sodium chloride, potassium chloride and magnesium sulfate hypersaline solutions, followed by salt crystallization. A systematic study sheds light on the role of vertical alignment of graphene sheets on the interfacial, light absorption and photothermal characteristics of the membrane, impacting on the water evaporation rate and on the crystal size distribution of the investigated salts. Overall, 3D-G facilitates the crystallization of the salts because of superior light-to-heat conversion leading to a 3-fold improvement of the evaporation rate with respect to 2D-G. The exploitation of sunlight graphene-based interfaces is demonstrated as a potential sustainable solution to aqueous wastes valorization via recovery in solid phase of dissolved salts using renewable solar energy.
Saravanakumar, A, Chen, W-H, Arunachalam, KD, Park, Y-K & Chyuan Ong, H 2022, 'Pilot-scale study on downdraft gasification of municipal solid waste with mass and energy balance analysis', Fuel, vol. 315, pp. 123287-123287.
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Sebayang, AH, Milano, J, Shamsuddin, AH, Alfansuri, M, Silitonga, AS, Kusumo, F, Prahmana, RA, Fayaz, H & Zamri, MFMA 2022, 'Modelling and prediction approach for engine performance and exhaust emission based on artificial intelligence of sterculia foetida biodiesel', Energy Reports, vol. 8, pp. 8333-8345.
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Sterculia foetida derived biodiesel is a potential fuel for a diesel engine. The Sterculia foetida biodiesel required a pre-refining process called degumming and an acid pretreatment process before converting them to methyl ester using the transesterification process. This study blended fuel from Sterculia foetida biodiesel and diesel with different volume ratios (5% to 30% of biodiesel blend with 95% to 70% diesel fuel). Sterculia foetida biodiesel and blended fuels met the ASTM D6751 and EN 14214 standards. The blended fuel is examined to obtain its influences on the performance and emission when operating at a diesel engine (1300 rpm to 2400 rpm). From the outcome, the engine performance of the SFB5 blend shows better performance than diesel fuel in terms of BTE (28.84%) and BSFC (5.86%). Artificial neural networks and extreme learning machines were employed to predict engine performance and exhaust emissions. The developed models gave excellent results, where the coefficient of determination is more than 99% and 98% for BSFC and BTE, respectively. When the engine is operated with SFB5, there is a significant reduction in CO, HC, and smoke opacity emissions by 8.26%, 2.08%, and 3.08%, respectively, and at the same time, an increase in CO2 by 3.53% and NOX by 22.39%. The comparison is made with diesel fuel. The extreme learning machine modelling is powerful for predicting engine performance and exhaust emission compared to artificial neural networks in terms of prediction accuracy. Sterculia foetida biodiesel–diesel blends of 5% show its capability to replace diesel fuel by providing engine peak performance than diesel fuel.
Senanayake, S & Pradhan, B 2022, 'Predicting soil erosion susceptibility associated with climate change scenarios in the Central Highlands of Sri Lanka', Journal of Environmental Management, vol. 308, pp. 114589-114589.
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Soil erosion hazard is one of the prominent climate hazards that negatively impact countries' economies and livelihood. According to the global climate index, Sri Lanka is ranked among the first ten countries most threatened by climate change during the last three years (2018-2020). However, limited studies were conducted to simulate the impact of the soil erosion vulnerability based on climate scenarios. This study aims to assess and predict soil erosion susceptibility using climate change projected scenarios: Representative Concentration Pathways (RCP) in the Central Highlands of Sri Lanka. The potential of soil erosion susceptibility was predicted to 2040, depending on climate change scenarios, RCP 2.6 and RCP 8.5. Five models: revised universal soil loss (RUSLE), frequency ratio (FR), artificial neural networks (ANN), support vector machine (SVM) and adaptive network-based fuzzy inference system (ANFIS) were selected as widely applied for hazards assessments. Eight geo-environmental factors were selected as inputs to model the soil erosion susceptibility. Results of the five models demonstrate that soil erosion vulnerability (soil erosion rates) will increase 4%-22% compared to the current soil erosion rate (2020). The predictions indicate average soil erosion will increase to 10.50 t/ha/yr and 12.4 t/ha/yr under the RCP 2.6 and RCP 8.5 climate scenario in 2040, respectively. The ANFIS and SVM model predictions showed the highest accuracy (89%) on soil erosion susceptibility for this study area. The soil erosion susceptibility maps provide a good understanding of future soil erosion vulnerability (spatial distribution) and can be utilized to develop climate resilience.
Senanayake, S, Pradhan, B, Alamri, A & Park, H-J 2022, 'A new application of deep neural network (LSTM) and RUSLE models in soil erosion prediction', Science of The Total Environment, vol. 845, pp. 157220-157220.
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Rainfall variation causes frequent unexpected disasters all over the world. Increasing rainfall intensity significantly escalates soil erosion and soil erosion related hazards. Forecasting accurate rainfall helps early detection of soil erosion vulnerability and can minimise the damages by taking appropriate measures caused by severe storms, droughts and floods. This study aims to predict soil erosion probability using the deep learning approach: long short-term memory neural network model (LSTM) and revised universal soil loss equation (RUSLE) model. Daily rainfall data were gathered from five agro-meteorological stations in the Central Highlands of Sri Lanka from 1990 to 2021 and fed into the LSTM model simulation. The LSTM model was forecasted with the time-series monthly rainfall data for a long lead time period, rainfall values for next 36 months in each station. Geo-informatics tools were used to create the rainfall erosivity map layer for the year 2024. The RUSLE model prediction indicates the average annual soil erosion over the Highlands will be 11.92 t/ha/yr. Soil erosion susceptibility map suggests around 30 % of the land area will be categorised as moderate to very-high soil erosion susceptible classes. The resulted map layer was validated using past soil erosion map layers developed for 2000, 2010 and 2019. The soil erosion susceptibility map indicates an accuracy of 0.93 with the area under the receiver operator characteristic curve (AUC-ROC), showing a satisfactory prediction performance. These findings will be helpful in policy-level decision making and researchers can further tested different deep learning models with the RUSLE model to enhance the prediction capability of soil erosion probability.
Senanayake, S, Pradhan, B, Huete, A & Brennan, J 2022, 'Spatial modeling of soil erosion hazards and crop diversity change with rainfall variation in the Central Highlands of Sri Lanka', Science of The Total Environment, vol. 806, no. Pt 2, pp. 150405-150405.
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The spatial variation of soil erosion is essential for farming system management and resilience development, specifically in the high climate hazard vulnerable tropical countries like Sri Lanka. This study aimed to investigate climate and human-induced soil erosion through spatial modeling. Remote sensing was used for spatial modeling to detect soil erosion, crop diversity, and rainfall variation. The study employed a time-series analysis of several variables such as rainfall, land-use land-cover (LULC) and crop diversity to detect the spatial variability of soil erosion in farming systems. Rain-use efficiency (RUE) and residual trend analysis (RESTREND) combined with a regression approach were applied to partition the soil erosion due to human and climate-induced land degradation. Results showed that soil erosion has increased from 9.08 Mg/ha/yr to 11.08 Mg/ha/yr from 2000 to 2019 in the Central Highlands of Sri Lanka. The average annual rainfall has increased in the western part of the Central Highlands, and soil erosion hazards such as landslides incidence also increased during this period. However, crop diversity has been decreasing in farming systems, namely wet zone low country (WL1a) and wet zone mid-country (WM1a), in the western part of the Central Highlands. The RUE and RESTREND analyses reveal climate-induced soil erosion is responsible for land degradation in these farming systems and is a threat to sustainable food production in the farming systems of the Central Highlands.
Septiadi, WN, Iswari, GA, Sudarsana, PB, Putra, GJP, Febraldo, D, Putra, N & Mahlia, TMI 2022, 'Effect of Al2O3 and TiO2 nano-coated wick on the thermal performance of heat pipe', Journal of Thermal Analysis and Calorimetry, vol. 147, no. 11, pp. 6193-6205.
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A heat pipe is a passive two-phase heat exchanger technology, as a capillary-driven structure that allows heat transport by maintaining temperature difference. Heat pipe performance can be determined from the value of heat resistance, and nanoparticle can be applied to increase heat pipe performance. This research uses Al2O3 and TiO2 as a coating material for the heat pipe. The methods used in this research were by giving the heat pipe a nano-coating treatment using the electrophoretic deposition process and doing a pool boiling experiment by giving the heat pipe some heat loads. The main data of this research are temperature and bubble growth data. Based on the result of the research, the use of nanoparticles can improve heat pipe performance. The temperature difference between the evaporator and condenser area was calculated 2.38 °C on Al2O3 coating and 3.92 °C on TiO2 coating. Al2O3 nanoparticle coating was able to provide a heat transfer coefficient 480% superior to sample without nanoparticle coating, and 174% better than TiO2 nanoparticle coating.
Serbouti, I, Raji, M, Hakdaoui, M, El Kamel, F, Pradhan, B, Gite, S, Alamri, A, Maulud, KNA & Dikshit, A 2022, 'Improved Lithological Map of Large Complex Semi-Arid Regions Using Spectral and Textural Datasets within Google Earth Engine and Fused Machine Learning Multi-Classifiers', Remote Sensing, vol. 14, no. 21, pp. 5498-5498.
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In this era of free and open-access satellite and spatial data, modern innovations in cloud computing and machine-learning algorithms (MLAs) are transforming how Earth-observation (EO) datasets are utilized for geological mapping. This study aims to exploit the potentialities of the Google Earth Engine (GEE) cloud platform using powerful MLAs. The proposed method is implemented in three steps: (1) Based on GEE and Sentinel 2A imagery (spectral and textural features), that cover 1283 km2 area, a variety of lithological maps are generated using five supervised classifiers (random forest (RF), support vector machine (SVM), classification and regression tree (CART), minimum distance (MD), naïve Bayes (NB)); (2) the accuracy assessments for each class are performed, by estimating overall accuracy (OA) and kappa coefficient (K) for each classifier; (3) finally, the fusion of classification maps is performed using Dempster–Shafer Theory (DST) for mapping lithological units of the northern part of the complex Paleozoic massif of Rehamna, a large semi-arid region located in the SW of the western Moroccan Meseta. The results were quantitatively compared with existing geological maps, enhanced color composite and validated by field survey investigation. In comparison of individual classifiers, the SVM yields better accuracy of nearly 88%, which was 12% higher than the RF MLA; otherwise, the parametric MLAs produce the weakest lithological maps among other classifiers, with a lower OA of approximately 67%, 54% and 52% for CART, MD and NB, respectively. Noticeably, the highest OA value of 96% is achieved for the proposed approach. Therefore, we conclude that this method allows geoscientists to update previous geological maps and rapidly produce more precise lithological maps, especially for hard-to-reach regions.
Shafaghat, A & Khabbaz, H 2022, 'Recent advances and past discoveries on tapered pile foundations: a review', Geomechanics and Geoengineering, vol. 17, no. 2, pp. 455-484.
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© 2020, © 2020 Informa UK Limited, trading as Taylor & Francis Group. The growing tendency to study the behaviour of tapered piles in the last two decades has made it necessary to gain a deeper insight into this specific kind of deep foundation. Tapered piles have been investigated through analytical, experimental, and numerical studies. These piles have revealed different behaviour under various loading conditions. Hence, reviewing and assessing these efforts to comprehend their response can be of great significance. In this paper firstly, it is attempted to go over experimental studies, conducted on tapered piles. Then, the proposed mathematical and numerical solutions, employed to calculate the bearing capacity of single tapered piles, are compared to have a better vision of how these piles behave. In the third section, the optimum tapering angles of tapered piles in loose, medium, and dense sand are discussed. All the efforts are investigated technically to find the advantages, disadvantages, and the research gaps for this specific kind of piles. In addition, another section entitled the directions and ideas for future research on tapered piles is provided comprising the most recent achievements in this area. Moreover, the implementation of tapered piles in a significant project as a case study is discussed.
Shafaghat, A, Khabbaz, H & Fatahi, B 2022, 'Axial and Lateral Efficiency of Tapered Pile Groups in Sand Using Mathematical and Three-Dimensional Numerical Analyses', Journal of Performance of Constructed Facilities, vol. 36, no. 1.
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This study presents a new mathematical equation for calculating the pile group efficiency in cohesionless soil under combined axial and lateral loading conditions, considering the tapering angle effect. Based on the mathematical definition of the pile group efficiency, analytical correlations are developed. The tapering effect is considered by developing a new geometry coefficient for efficiency associated with the shaft vertical bearing component of tapered piles. In addition, a simplified mathematical equation is developed for predicting the group interaction factor as a function of pile spacing, number of piles in the group, diameter of the cylindrical reference pile, tapering angle, and pile slenderness ratio. On the other hand, an array of three-dimensional numerical analyses is performed for modeling same-volume single bored piles and pile groups with various arrangements to capture the accuracy of the proposed mathematical equation. The hardening soil constitutive model is adopted for the modeling of piles in loose sand. Subsequently, the load-displacement diagrams of single piles, as well as pile groups, are obtained. The bearing capacities of straight-sided and tapered bored piles are then calculated and compared using a definite settlement criterion. By computing the various bearing-capacity components, group efficiencies can be attained from both numerical and mathematical analyses. The results indicate an acceptable agreement between both analyses. Finally, the developed equation can predict the pile group efficiency incorporating the tapering angle and other influencing parameters as a novel and simple relationship under simultaneous axial and lateral loading conditions.
Shafapourtehrany, M, Yariyan, P, Özener, H, Pradhan, B & Shabani, F 2022, 'Evaluating the application of K-mean clustering in Earthquake vulnerability mapping of Istanbul, Turkey', International Journal of Disaster Risk Reduction, vol. 79, pp. 103154-103154.
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Performing the most up-to-date and accurate vulnerability assessment is key to an effective earthquake disaster management. In cities like Istanbul (Turkey) with a high rate of urban expansion, the safety of the residents must not be neglected. The challenges in such studies are related to the lack of a training dataset. Some areas are highly prone to earthquakes, however, there have been no earthquakes in those areas recently. This research proposes and tests the ability of the k-mean clustering method to create the training dataset for earthquake vulnerability analysis. Subsequently, the derived sample dataset was used in four state-of-the-art models i.e. Decision Tree (DT), Support Vector Machine (SVM), Self-Organizing Map (SOM) and Logistic Regression (LR) for assessing earthquake vulnerability in Istanbul, Turkey. The multicollinearity among the variables was determined using tolerance (TOL) and variance inflation factor (VIF) which revealed no multicollinearity among the variables. The highest VIF belonged to the “distance to faults” factor. Vulnerability related variables were classified, weighed and using k-mean clustering, a training database was constructed. Then, the standardized variables were keyed in as input alongside the training site maps into DT, SVM, SOM and LR to construct an Earthquake Vulnerability Map (EVM). EVMs were created for all the four samples and graded as very-low, relatively-low, moderate, high, or extremely-high. Several statistical metrics such as Area under the ROC curve (AUC), sensitivity (SST), specificity (SPF), root-mean-squared-errors (RMSE), positive predictive value (PPV), and negative predictive value (NPV) were used to evaluate the accuracy of the resultant maps. The highest and lowest AUC prediction rates were 0.962 and 0.912 from the K-means-SOM and K-means-LR models, respectively. The lowest RSME results using the testing dataset (0.329) belonged to K-means-SVM model. The region's most prone vulnerability ...
Shahabuddin, M, Mofijur, M, Rizwanul Fattah, IM, Kalam, MA, Masjuki, HH, Chowdhury, MA & Hossain, N 2022, 'Study on the tribological characteristics of plant oil-based bio-lubricant with automotive liner-piston ring materials', Current Research in Green and Sustainable Chemistry, vol. 5, pp. 100262-100262.
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The development of bio-lubricant is an immerging area of research considering the rapid depletion of petroleum reserve and environmental concern. This study aims to develop non-edible jatropha oil-based bio-lubricant and investigate the tribological properties considering commonly used piston ring-cylinder liner materials of stainless steel and cast iron due to their interaction under lubricated conditions in an internal combustion engine. The bio-lubricant was prepared by blending different percentages of vegetable oil with commercial lubricants. The tribological test was carried out using a Reo-Bicerihigh-frequency reciprocating rig (HFRR) for the duration of 6 h under standard operating conditions. Different properties of bio-lubricants were measured before and after the HFRR test using various analytical instruments. The morphology of the worn material surfaces was examined via Hitachi S-4700 FE-SEM cold field emission high resolution scanning electron microscopy (SEM). The result showed that addition of vegetable oil lubricant up to 7.5% concentration can be compared with commercial lubricant in case of wear rate and coefficient of wear as weight loss reduced significantly. Minimum change in viscosity was observed at the addition of 7.5% bio-lubricant. Surface morphology analysis confirmed less damage of metal surface when tribological analysis were performed at mixed lubricated condition.
Shan, F, He, X, Jahed Armaghani, D, Zhang, P & Sheng, D 2022, 'Success and challenges in predicting TBM penetration rate using recurrent neural networks', Tunnelling and Underground Space Technology, vol. 130, pp. 104728-104728.
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Tunnel Boring Machines (TBMs) have been increasingly used in tunnelling projects. Forecasting future TBM performance would be desirable for project time management and cost control. We aim to use recurrent neural networks to predict the near future TBM penetration rate from historical data. Our datasets are composed of Changsha and Zhengzhou metro lines, with totally different geological conditions. In the experiments, the one-step forecast of TBM penetration rate by the traditional recurrent neural network (RNN) or long short-term memory (LSTM) is relatively accurate, irrespective of the different geological conditions used in training and evaluation. Predicting the next Nth step penetration rate proves to be more challenging and depends on the time to the future or the distance ahead of the TBM cutterhead. There are generally time lags between measured and predicted results. The recursive RNN is then developed to address the lag problems, but to no avail. Alternative methods for predicting future penetration rates are studied, including the penetration rate at the Nth step in the future and the average penetration rate of the next N steps, with the latter being trained by long-input or short-input methods. The average N-step forecast using short inputs provides the best results, and its performance over other alternatives becomes more distinct as the number N increases. We also discuss the possibility of the forecast problem as a quasi-random walk, which means that forecasting penetration rate cannot easily be achieved using low-frequency data with RNNs, and that the accuracy depends on the correlation between the last and predicted steps in the data.
Shanableh, A, Al-Ruzouq, R, Hamad, K, Gibril, MBA, Khalil, MA, Khalifa, I, El Traboulsi, Y, Pradhan, B, Jena, R, Alani, S, Alhosani, M, Stietiya, MH, Al Bardan, M & AL-Mansoori, S 2022, 'Effects of the COVID-19 lockdown and recovery on People's mobility and air quality in the United Arab Emirates using satellite and ground observations', Remote Sensing Applications: Society and Environment, vol. 26, pp. 100757-100757.
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The stringent COVID-19 lockdown measures in 2020 significantly impacted people's mobility and air quality worldwide. This study presents an assessment of the impacts of the lockdown and the subsequent reopening on air quality and people's mobility in the United Arab Emirates (UAE). Google's community mobility reports and UAE's government lockdown measures were used to assess the changes in the mobility patterns. Time-series and statistical analyses of various air pollutants levels (NO2, O3, SO2, PM10, and aerosol optical depth-AOD) obtained from satellite images and ground monitoring stations were used to assess air quality. The levels of pollutants during the initial lockdown (March to June 2020) and the subsequent gradual reopening in 2020 and 2021 were compared with their average levels during 2015-2019. During the lockdown, people's mobility in the workplace, parks, shops and pharmacies, transit stations, and retail and recreation sectors decreased by about 34%-79%. However, the mobility in the residential sector increased by up to 29%. The satellite-based data indicated significant reductions in NO2 (up to 22%), SO2 (up to 17%), and AOD (up to 40%) with small changes in O3 (up to 5%) during the lockdown. Similarly, data from the ground monitoring stations showed significant reductions in NO2 (49% - 57%) and PM10 (19% - 64%); however, the SO2 and O3 levels showed inconsistent trends. The ground and satellite-based air quality levels were positively correlated for NO2, PM10, and AOD. The data also demonstrated significant correlations between the mobility and NO2 and AOD levels during the lockdown and recovery periods. The study documents the impacts of the lockdown on people's mobility and air quality and provides useful data and analyses for researchers, planners, and policymakers relevant to managing risk, mobility, and air quality.
Shao, R, Wu, C & Li, J 2022, 'A comprehensive review on dry concrete: Application, raw material, preparation, mechanical, smart and durability performance', Journal of Building Engineering, vol. 55, pp. 104676-104676.
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Dry concrete, which can be understood literally, is defined as the fresh mixture of concrete having no flowability with a very small slump value. It is a hardened mixture mixed with essentially the same raw materials (cement, aggregate and supplementary cementitious material) but lower water content as compared to conventional concrete. Performance and properties of dry concrete are closely related to the raw materials dosage, preparation technique, curing regimes and curing. At present, the applications of dry concrete products have been expanded to many engineering areas which benefit from their prominent advantages such as fast hardening, high early strength, along with low material and production cost. This paper reviews two most representative dry concrete mixtures, namely roller-compacted concrete (RCC) and dry-cast concrete (DCC), in terms of raw material, preparation method, static/dynamic mechanical behaviour, smart and durability performance, and application. Among them, the static and dynamic mechanical properties, including static strength behaviour and elastic modulus, as well as dynamic responses under seismic and impact loads, are reviewed in detail. In addition, the freeze-thaw resistance, carbonation resistance, permeability, abrasion resistance, fatigue characteristic and volume change which involved in durability investigation of both RCC and DCC are successively elaborated and analysed. Finally, some suggestions and ideas on the further researches of dry concrete are also presented.
Shao, R, Wu, C, Li, J & Liu, Z 2022, 'Development of sustainable steel fibre-reinforced dry ultra-high performance concrete (DUHPC)', Journal of Cleaner Production, vol. 337, pp. 130507-130507.
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Dry concrete technology has been extensively utilized in many engineering fields thanks to its remarkable high early strength, fast construction speed and low production cost. However, its shortcomings such as low flexural tensile strength, poor toughness, and susceptible to crack under stress and temperature also render the safety and service life of concrete structures unable to be effectively ensured. Dry ultra-high performance concrete (DUHPC), a promising building material, has improved mechanical and durability performance, and contributes to economical construction by reducing the cross-section size and improving structural long-term serviceability. In this study, the mechanical performance (such as compressive and indirect tensile behaviour) of fibre-reinforced DUHPC (FR-DUHPC) was experimentally investigated after a benchmark mix proportioning was determined via orthogonal tests. Different steel fibre volume contents (0.5–2.0%) and curing regimes including normal-temperature water curing, moist/steam curing and hot-water bath curing were used to explore their impacts on the mechanical properties of DUHPC. In total, 648 FR-DUHPC samples were fabricated and tested for determining their unit weight, compressive, flexural and split tensile strengths. The samples’ failure modes after bending and split tensile tests were analyzed. The results indicated that the fibre addition exhibited a notable positive effect on the mechanical properties of DUHPC, especially for the enhancement of the flexural and split tensile strengths, along with the improvement of post-cracking behaviour. An evident increase in early strength was found via using moist/steam and hot-water bath curing regime, but the former negatively impacted the development of the long-term strength. 50 °C moist/steam curing temperature was suggested for consolidating the pre-cast DUHPC units based on the microstructure analysis conducted, and the volume content of 1.5% was considered to be the...
Shao, R, Wu, C, Li, J & Liu, Z 2022, 'Investigation on the mechanical characteristics of multiscale mono/hybrid steel fibre-reinforced dry UHPC', Cement and Concrete Composites, vol. 133, pp. 104681-104681.
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Dry ultra-high performance concrete (DUHPC) is a promising building material with better mechanical and durability properties, developed on the basis of retaining the advantages of traditional dry concrete, such as fast hardening speed, high early age strength and rapid demoulding. In the current study, the impacts of multiscale mono and hybrid steel fibre reinforcements on the static mechanical behaviour of DUHPC were further studied based on the benchmark mix ratio and optimal curing regime obtained from the previous study. The experiments carried out included the quasi-static uniaxial compression, four-point bending and split-tensile tests. The mono fibre reinforcement (0.5–2.0 vol. %) comprised of straight steel fibres with the same diameter but different lengths (6, 10 and 13 mm), while the hybrid fibre reinforcement was composed of different combinations of foregoing fibres at a fixed content (1.5 vol. %), which could be further divided into double and ternary hybridization. Test results revealed that compared to control samples without fibre reinforcement, the single addition of any steel fibres improved the static mechanical behaviour of DUHPC, particularly for flexural and split-tensile performance. In the case of fibre hybridization, the replacement of longer fibres with more addition of short (6 mm) ones evidently reduced the flexural toughness and energy absorption capacity of DUHPC upon cracking, whereas the mixtures with hybrid medium (10 mm) and long (13 mm) fibres as well as with hybrid short, medium and long fibres showed better compressive toughness and energy absorption capability. The proposed multivariate regression linear, nonlinear and most of the mixed models could well estimate the compressive, flexural and split-tensile strength values of mono steel fibre-reinforced DUHPC at a given range of fibre length, volume content and curing age. The updated best-fit models containing compressive strength as an additional independent vari...
Sharari, N, Fatahi, B, Hokmabadi, A & Xu, R 2022, 'Seismic resilience of extra-large LNG tank built on liquefiable soil deposit capturing soil-pile-structure interaction', Bulletin of Earthquake Engineering, vol. 20, no. 7, pp. 3385-3441.
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AbstractAssessment of seismic resilience of critical infrastructure such as liquefied natural gas (LNG) storage tanks, is essential to ensure availability and security of services during and after occurrence of large earthquakes. In many projects, it is preferred to build energy storage facilities in coastal areas for the ease of sea transportation, where weak soils such as soft clay and loose sand with liquefaction potential may be present. In this study, three-dimensional finite element model is implemented to examine the seismic response of a 160,000 m3full containment LNG tank supported by 289 reinforced concrete piles constructed on liquefiable soil overlaying the soft clay deposit. The seismic soil-structure interaction analysis was conducted through direct method in the time domain subjected to the 1999 Chi-Chi and the 1968 Hachinohe earthquakes, scaled to Safe Shutdown Earthquake hazard level for design of LNG tanks. The analyses considered different thicknesses of the liquified soil deposit varying from zero (no liquefaction) to 15 m measured from the ground surface. The key design parameters inspected for the LNG tank include the acceleration profile for both inner and outer tanks, the axial, hoop and shear forces as well as the von Mises stresses in the inner tank wall containing the LNG, in addition to the pile response in terms of lateral displacements, shear forces and bending moments. The results show that the seismic forces generated in the superstructure decreased with increasing the liquefied soil depth. In particular, the von Mises stresses in the inner steel tank exceeded the yield stress for non-liquefied soil deposit, and the elastic–plastic buckling was initiated in the upper section of the tank where plastic deformations were detected as a result of excessive von Mises stresses. However, when soil liquefaction occurred, although von Mises stresses in the inner tank shell remai...
Sharari, N, Fatahi, B, Hokmabadi, AS & Xu, R 2022, 'Impacts of Pile Foundation Arrangement on Seismic Response of LNG Tanks Considering Soil–Foundation–Structure Interaction', Journal of Performance of Constructed Facilities, vol. 36, no. 1.
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Sharma, P, Gaur, VK, Gupta, S, Varjani, S, Pandey, A, Gnansounou, E, You, S, Ngo, HH & Wong, JWC 2022, 'Trends in mitigation of industrial waste: Global health hazards, environmental implications and waste derived economy for environmental sustainability', Science of The Total Environment, vol. 811, pp. 152357-152357.
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Majority of industries, in order to meet the technological development and consumer demands generate waste. The untreated waste spreads out toxic and harmful substances in the environment which serves as a breeding ground for pathogenic microorganisms thus causing severe health hazards. The three industrial sectors namely food, agriculture, and oil industry are among the primary organic waste producers that affect urban health and economic growth. Conventional treatment generates a significant amount of greenhouse gases which further contributes to global warming. Thus, the use of microbes for utilization of this waste, liberating CO2 offers an indispensable tool. The simultaneous production of value-added products such as bioplastics, biofuels, and biosurfactants increases the economics of the process and contributes to environmental sustainability. This review comprehensively summarized the composition of organic waste generated from the food, agriculture, and oil industry. The linkages between global health hazards of industrial waste and environmental implications have been uncovered. Stare-of-the-art information on their subsequent utilization as a substrate to produce value-added products through bio-routes has been elaborated. The research gaps, economical perspective(s), and future research directions have been identified and discussed to strengthen environmental sustainability.
Shenbagamuthuraman, V, Patel, A, Khanna, S, Banerjee, E, Parekh, S, Karthick, C, Ashok, B, Velvizhi, G, Nanthagopal, K & Ong, HC 2022, 'State of art of valorising of diverse potential feedstocks for the production of alcohols and ethers: Current changes and perspectives', Chemosphere, vol. 286, pp. 131587-131587.
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Shi, J, Li, X, Zhang, S, Sharma, E, Sivakumar, M, Sherchan, SP & Jiang, G 2022, 'Enhanced decay of coronaviruses in sewers with domestic wastewater', Science of The Total Environment, vol. 813, pp. 151919-151919.
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Recent outbreaks caused by coronaviruses and their supposed potential fecal-oral transmission highlight the need for understanding the survival of infectious coronavirus in domestic sewers. To date, the survivability and decay of coronaviruses were predominately studied using small volumes of wastewater (normally 5-30 mL) in vials (in-vial tests). However, real sewers are more complicated than bulk wastewater (wastewater matrix only), in particular the presence of sewer biofilms and different operational conditions. This study investigated the decay of infectious human coronavirus 229E (HCoV-229E) and feline infectious peritonitis virus (FIPV), two typical surrogate coronaviruses, in laboratory-scale reactors mimicking the gravity (GS, gravity-driven sewers) and rising main sewers (RM, pressurized sewers) with and without sewer biofilms. The in-sewer decay of both coronaviruses was greatly enhanced in comparison to those reported in bulk wastewater through in-vial tests. 99% of HCoV-229E and FIPV decayed within 2 h under either GS or RM conditions with biofilms, in contrast to 6-10 h without biofilms. There is limited difference in the decay of HCoV and FIPV in reactors operated as RM or GS, with the T90 and T99 difference of 7-10 min and 14-20 min, respectively. The decay of both coronaviruses in sewer biofilm reactors can be simulated by biphasic first-order kinetic models, with the first-order rate constant 2-4 times higher during the first phase than the second phase. The decay of infectious HCoV and FIPV was significantly faster in the reactors with sewer biofilms than in the reactors without biofilms, suggesting an enhanced decay of these surrogate viruses due to the presence of biofilms and related processes. The mechanism of biofilms in virus adsorption and potential inactivation remains unclear and requires future investigations. The results indicate that the survivability of infectious coronaviruses detected using bulk wastewater overestimated...
Shi, X, Chen, Z, Liu, X, Wei, W & Ni, B-J 2022, 'The photochemical behaviors of microplastics through the lens of reactive oxygen species: Photolysis mechanisms and enhancing photo-transformation of pollutants', Science of The Total Environment, vol. 846, pp. 157498-157498.
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The photoaging mechanisms of various polymers have been explored based on the basic autoxidation scheme (BAS) before 10 years ago, however current research verified some defects in the BAS in both thermodynamic and dynamics. These defects are troublesome because they are associated with the hydrogen abstraction which is central to continuously perform the photooxidation process of microplastics. These found indicated that we might wrongly inferred photo-oxidation process of some microplastics. In addition, the important role of reactive oxygen species (ROS) in the type-dependent photoaging process of various microplastics has been revealed recently. In this case, fully and accurately understanding the photoaging mechanisms of different microplastics in environment is a priority to further manage the ecological risk of microplastics. Herein, this review aims to revise and update the degradation process of microplastics based on the revised BAS and in the perspective of ROS. Specifically, the modification of BAS is firstly discussed. The photoaging mechanisms of representative microplastics (i.e., polyethylene, polystyrene and polyethylene terephthalate) are then updated based on the corrected BAS. Additionally, the role of ROS in their photolysis process and the possibility of microplastics as photosensitizers/mediators to regulate the fate of co-existent pollutants are also analyzed. Finally, several perspectives are then proposed to guide future research on the photoaging behaviors of microplastics. This review would pave the way for the understanding of microplastic photoaging and the management of plastic pollution in environments.
Shi, X, Wu, L, Wei, W & Ni, B-J 2022, 'Insights into the microbiomes for medium-chain carboxylic acids production from biowastes through chain elongation', Critical Reviews in Environmental Science and Technology, vol. 52, no. 21, pp. 3787-3812.
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Bioconversion of medium-chain carboxylic acids (MCCAs) from biowastes through anaerobic mixed-culture fermentation is undergoing a revolution in terms of mitigating the lower fossil fuels requirement and increasing biowaste treatment capacity. Benefiting from hydrophobicity and high energy density of MCCA, this high-valuable biofuel exhibits easier separation and wider application than traditional volatile fatty acid products. The biggest bottleneck for efficiently and simultaneously producing MCCAs by mixed-culture fermentation is complicated or even entangled microbial interaction. Therefore, this review aimed to supply guidelines to understand and steer these microbiomes toward the controllable ones. The metabolic pathway of chain elongation and associated cooperating and competing pathways were firstly discussed to understand the primary microbial interaction in mixed-culture fermentation. In an attempt to inspect the overall performance of mixed-culture CE reactor, the typical microbial community and its variation influenced by reactor parameters were also identified. The methods of in-line extraction of MCCAs for relieving toxicity inhibition on microbiome were also summarized regarding the difficulties lied in continuous MCCAs production. Finally, the future research directions of MCCAs production via mixed-culture fermentation would be proposed to help steer these novel bioproduction processes toward full-scale applications.
Shi, X, Xia, Y, Wei, W & Ni, B-J 2022, 'Accelerated spread of antibiotic resistance genes (ARGs) induced by non-antibiotic conditions: Roles and mechanisms', Water Research, vol. 224, pp. 119060-119060.
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The global spread of antibiotic resistance genes (ARGs) has wreaked havoc with the treatment efficiency of antibiotics and, ultimately, anti-microbial chemotherapy, and has been conventionally attributed to the abuse and misuse of antibiotics. However, the ancient ARGs have alterative functions in bacterial physiology and thus they could be co-regulated by non-antibiotic conditions. Recent research has demonstrated that many non-antibiotic chemicals such as microplastics, metallic nanoparticles and non-antibiotic drugs, as well as some non-antibiotic conditions, can accelerate the dissemination of ARGs. These results suggested that the role of antibiotics might have been previously overestimated whereas the effects of non-antibiotic conditions were possibly ignored. Thus, in an attempt to fully understand the fate and behavior of ARGs in the eco-system, it is urgent to critically highlight the role and mechanisms of non-antibiotic chemicals and related environmental factors in the spread of ARGs. To this end, this timely review assessed the evolution of ARGs, especially its function alteration, summarized the non-antibiotic chemicals promoting the spread of ARGs, evaluated the non-antibiotic conditions related to ARG dissemination and analyzed the molecular mechanisms related to spread of ARGs induced by the non-antibiotic factors. Finally, this review then provided several critical perspectives for future research.
Shirmard, H, Farahbakhsh, E, Heidari, E, Beiranvand Pour, A, Pradhan, B, Müller, D & Chandra, R 2022, 'A Comparative Study of Convolutional Neural Networks and Conventional Machine Learning Models for Lithological Mapping Using Remote Sensing Data', Remote Sensing, vol. 14, no. 4, pp. 819-819.
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Lithological mapping is a critical aspect of geological mapping that can be useful in studying the mineralization potential of a region and has implications for mineral prospectivity mapping. This is a challenging task if performed manually, particularly in highly remote areas that require a large number of participants and resources. The combination of machine learning (ML) methods and remote sensing data can provide a quick, low-cost, and accurate approach for mapping lithological units. This study used deep learning via convolutional neural networks and conventional ML methods involving support vector machines and multilayer perceptron to map lithological units of a mineral-rich area in the southeast of Iran. Moreover, we used and compared the efficiency of three different types of multispectral remote-sensing data, including Landsat 8 operational land imager (OLI), advanced spaceborne thermal emission and reflection radiometer (ASTER), and Sentinel-2. The results show that CNNs and conventional ML methods effectively use the respective remote-sensing data in generating an accurate lithological map of the study area. However, the combination of CNNs and ASTER data provides the best performance and the highest accuracy and adaptability with field observations and laboratory analysis results so that almost all the test data are predicted correctly. The framework proposed in this study can be helpful for exploration geologists to create accurate lithological maps in other regions by using various remote-sensing data at a low cost.
Shokravi, H, Heidarrezaei, M, Shokravi, Z, Ong, HC, Lau, WJ, Din, MFM & Ismail, AF 2022, 'Fourth generation biofuel from genetically modified algal biomass for bioeconomic development', Journal of Biotechnology, vol. 360, pp. 23-36.
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Biofuels from microalgae have promising potential for a sustainable bioeconomy. Algal strains' oil content and biomass yield are the most influential cost drivers in the fourth generation biofuel (FGB) production. Genetic modification is the key to improving oil accumulation and biomass yield, consequently developing the bioeconomy. This paper discusses current practices, new insights, and emerging trends in genetic modification and their bioeconomic impact on FGB production. It was demonstrated that enhancing the oil and biomass yield could significantly improve the probability of economic success and the net present value of the FGB production process. The techno-economic and socioeconomic burden of using genetically modified (GM) strains and the preventive control strategies on the bioeconomy of FGB production is reviewed. It is shown that the fully lined open raceway pond could cost up to 25% more than unlined ponds. The cost of a plastic hoop air-supported greenhouse covering cultivation ponds is estimated to be US 60,000$ /ha. The competitiveness and profitability of large-scale cultivation of GM biomass are significantly locked to techno-economic and socioeconomic drivers. Nonetheless, it necessitates further research and careful long-term follow-up studies to understand the mechanism that affects these parameters the most.
Shon, HK, Jegatheesan, V, Phuntsho, S, Fujiwara, T, Woo, Y & Yan, B 2022, 'Challenges in environmental science and engineering', Process Safety and Environmental Protection, vol. 168, pp. 300-302.
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Siddiki, SYA, Mofijur, M, Kumar, PS, Ahmed, SF, Inayat, A, Kusumo, F, Badruddin, IA, Khan, TMY, Nghiem, LD, Ong, HC & Mahlia, TMI 2022, 'Microalgae biomass as a sustainable source for biofuel, biochemical and biobased value-added products: An integrated biorefinery concept', Fuel, vol. 307, pp. 121782-121782.
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Microalgal biomass has been proved to be a sustainable source for biofuels including bio-oil, biodiesel, bioethanol, biomethane, etc. One of the collateral benefits of integrating the use of microalgal technologies in the industry is microalgae's ability to capture carbon dioxide during the application and biomass production process and consequently reducing carbon dioxide emissions. Although microalgae are a feasible source of biofuel, industrial microalgae applications face energy and cost challenges. To overcome these challenges, researchers have been interested in applying the bio-refinery approach to extract the important components encapsulated in microalgae. This review discusses the key steps of microalgae-based biorefinery including cultivation and harvesting, cell disruption, biofuel and value-added compound extraction along with the detailed technologies associated with each step of biorefinery. This review found that suitable microalgae species are selected based on their carbohydrate, lipid and protein contents and selecting the suitable species are crucial for high-quality biofuel and value-added products production. Microalgae species contain carbohydrates, proteins and lipids in the range of 8% to 69.7%, 5% to 74% and 7% to 65% respectively which proved their ability to be used as a source of value-added commodities in multiple industries including agriculture, animal husbandry, medicine, culinary, and cosmetics. This review suggests that lipid and value-added products from microalgae can be made more economically viable by integrating upstream and downstream processes. Therefore, a systematically integrated genome sequencing and process-scale engineering approach for improving the extraction of lipids and co-products is critical in the development of future microalgal biorefineries.
Siddiq, A, Shukla, N & Pradhan, B 2022, 'Spatio-temporal modelling of dengue fever cases in Saudi Arabia using socio-economic, climatic and environmental factors', Geocarto International, vol. 37, no. 26, pp. 12867-12891.
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Siddiqi, H-U-R, Qamar, A, Shaukat, R, Anwar, Z, Amjad, M, Farooq, M, Abbas, MM, Imran, S, Ali, H, Khan, TMY, Noor, F, Ali, HM, Kalam, MA & Soudagar, MEM 2022, 'Heat transfer and pressure drop characteristics of ZnO/DIW based nanofluids in small diameter compact channels: An experimental study', Case Studies in Thermal Engineering, vol. 39, pp. 102441-102441.
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This experimental study is focused on heat transfer performance and pressure drop characteristics of ZnO/DIW-based nanofluids (NFs) in horizontal mini tubes of different (1.0-2.0 mm) diameters. Different mass concentrations (0.012-0.048 wt %) of nanoparticles (NPs) were tested with varying fluid flow rates (12-24 ml/min) of NFs. The thermal conductivity (TC) and viscosity (VC) of stable NFs were tested at 20-60 °C, at a fixed temperature (40 °C), and concentration of NPs (0.048 wt%) the maximum rise was 18.27% and 20.31%, respectively. The local and average heat transfer coefficients (HTCs) and the pressure gradient were noticed to be directly proportional to volume flow rate of NFs and the mass concentration of NPs. However, an inverse trend was noticed with the test section's diameter. At 0.048 wt % of NPs and 24.0 ml/min flow rate of NFs, the maximum rise in local and average HTCs and pressure gradient was 17.11-11.61% and 13.05-9.79%, and 29.19-12.25%, respectively, in a tube's diameter of 1.0-2.0 mm. The friction factor increased with NP's loading while the same reduced with the fluid flow rate. The corresponding maximum change in the friction factor was 28.85-12.72% for the tubes with 1.0-2.0 mm diameters, respectively, at a 12.0 ml/min flow rate of NFs. The comparison of experimental findings for the HTCs, pressure gradients and friction factors with the standard Shah and Darcy's correlations showed that the observations are in good agreement with the predicted ones.
Silva, IN, Indraratna, B, Nguyen, TT & Rujikiatkamjorn, C 2022, 'Shear behaviour of subgrade soil with reference to varying initial shear stress and plasticity index', Acta Geotechnica, vol. 17, no. 9, pp. 4207-4216.
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AbstractThe influence of stress anisotropy (K) (i.e. the ratio between effective horizontal and vertical stresses) on the shear behaviour of soils has received significant attention in past studies, but how its influence depends on different values of the plasticity index (PI) has not been properly quantified. In this study, the results of a series of undrained triaxial tests on anisotropically consolidated soil at different values of K are reported, and together with past experimental data, the interactive roles of K and PI on the shear behaviour of soil are rigorously interpreted. The findings indicate that the peak shear strength increases with higher brittleness, whereas the peak excess pore pressure diminishes when the value of K decreases. Moreover, increasing the value of PI up to 35 tends to increase the peak shear strength, but beyond that the influence of PI seems marginal. Based on the findings of this study, empirical equations incorporating PI and K to estimate the undrained shear strength are proposed with acceptable accuracy.
Singh, SK, Taylor, RW, Pradhan, B, Shirzadi, A & Pham, BT 2022, 'Predicting sustainable arsenic mitigation using machine learning techniques', Ecotoxicology and Environmental Safety, vol. 232, pp. 113271-113271.
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This study evaluates state-of-the-art machine learning models in predicting the most sustainable arsenic mitigation preference. A Gaussian distribution-based Naïve Bayes (NB) classifier scored the highest Area Under the Curve (AUC) of the Receiver Operating Characteristic curve (0.82), followed by Nu Support Vector Classification (0.80), and K-Neighbors (0.79). Ensemble classifiers scored higher than 70% AUC, with Random Forest being the top performer (0.77), and Decision Tree model ranked fourth with an AUC of 0.77. The multilayer perceptron model also achieved high performance (AUC=0.75). Most linear classifiers underperformed, with the Ridge classifier at the top (AUC=0.73) and perceptron at the bottom (AUC=0.57). A Bernoulli distribution-based Naïve Bayes classifier was the poorest model (AUC=0.50). The Gaussian NB was also the most robust ML model with the slightest variation of Kappa score on training (0.58) and test data (0.64). The results suggest that nonlinear or ensemble classifiers could more accurately understand the complex relationships of socio-environmental data and help develop accurate and robust prediction models of sustainable arsenic mitigation. Furthermore, Gaussian NB is the best option when data is scarce.
Singhania, RR, Guo, W, de Souza Vendenberghe, LP, Mannina, G & Kim, S-H 2022, 'Bioresource technology for bioenergy, bioproducts & environmental sustainability', Bioresource Technology, vol. 347, pp. 126736-126736.
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Sirivivatnanon, V, Xue, C & Khatri, R 2022, 'Service-Life Design of Low-Carbon Concrete Containing Fly Ash and Slag under Marine Tidal Conditions', ACI Materials Journal, vol. 119, no. 6.
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The use of blended cements enables the production of concretes with low embodied carbon and improved resistance to chloride penetration compared to General Purpose (GP) cement concrete. This paper reports the chloride diffusion characteristics in terms of apparent diffusion coefficient (Da), surface chloride concentration (Cs), and corresponding aging factors (a & b) of these low carbon concrete (LCC) derived from up to 9-year long-term exposure of small reinforced concrete slabs in both laboratory-simulated and field marine tidal conditions. LCC with either 30% fly ash or 50% slag provides slightly to significantly lower 28-day compressive strength than GP cement concrete at the same water/binder ratio but significantly better resistance to chloride penetration. The long-term chloride profile necessary to determine the concrete cover where chloride threshold is reached can be determined with the Da.t0, Cs.t0 and corresponding age factors a and b where t0 is the one-year time of exposure. The improved resistance to chloride penetration by use of fly ash and slag as cement replacement was largely due to their intrinsic influence on the microstructure of the concrete. The results highlight the difference in chloride penetration arises from the change in test methods thus the importance of calibration when data obtained from laboratory concrete were used as input for service life design.
Siwal, SS, Sheoran, K, Saini, AK, Vo, D-VN, Wang, Q & Thakur, VK 2022, 'Advanced thermochemical conversion technologies used for energy generation: Advancement and prospects', Fuel, vol. 321, pp. 124107-124107.
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The commercial conquest of the ethanol industry has raised curiosity within operations that transform biomass into biofuels. The energy production from biomass, bioenergy, is an outlook conception to substitute fossil fuels in the coming days, as it is productive, pure, and carbon dioxide neutral. Biomass may be combusted instantly to cause heat and power and employ advanced thermochemical techniques. It can be restored within bio-fuels in solid, liquid, and gas constitutions that may be utilized additionally towards heat and energy production. Here, in this review article, we have discussed the properties of biomass fuels, sustainability attention towards energy production from biomass along with different types of wastes to energy generation, and the advanced thermochemical conversion technologies that can be used for energy production from wastes. In the last, we have compared the advantages and drawbacks of these technologies and concluded our article with current challenges and future perspectives in this field.
Smit, R, Awadallah, M, Bagheri, S & Surawski, NC 2022, 'Real-world emission factors for SUVs using on-board emission testing and geo-computation', Transportation Research Part D: Transport and Environment, vol. 107, pp. 103286-103286.
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A Portable Emissions Measurement System (PEMS) was used to measure emissions of five sports utility vehicles (SUVs) in a wide range of real-world driving conditions. The program included testing of fuel quality, coast-down and emissions in start, hot running and extended idling conditions. Geo-computation methods were used to add critical information (road gradient) to the PEMS data. Results from this study are generally in good agreement with international PEMS data. Hot running NOx emission factors are on average seven times higher than the type-approval limit for diesel SUVs, and they reach about 2100 and 400 mg/km in urban conditions for NOx and NO2, respectively. They are 7 (NOx) and 4 (NO2) times higher than current emission factors in COPERT Australia. COPERT Australia emission algorithms for CO2 are well behaved and the PEMS data suggest an update is not required. COPERT Australia emission algorithms should be revised for diesel SUVs (NOx, NO2) and petrol SUVs (CO, THC, NO2) to ensure accurate estimation of vehicle emissions at fleet level. Inclusion of logistic regression is proposed for future COPERT updates.
Smit, R, Chu-Van, T, Suara, K & Brown, RJ 2022, 'Comparing an energy-based ship emissions model with AIS and on-board emissions testing', Atmospheric Environment: X, vol. 16, pp. 100192-100192.
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Song, K, Li, Z, Li, L, Zhao, X, Deng, M, Zhou, X, Xu, Y, Peng, L, Li, R & Wang, Q 2022, 'Methane production from peroxymonosulfate pretreated algae biomass: Insights into microbial mechanisms, microcystin detoxification and heavy metal partitioning behavior', Science of The Total Environment, vol. 834, pp. 155500-155500.
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This study investigated the methane production potential of algal biomass by anerobic digestion with the addition of peroxymonosulfate (PMS), the removal of microcystin were analyzed and discussed. The microcystin concentration in the collected algal sludge was 1.20 μg/L in the liquid phase and 1393 μg/g in the algal sludge before anaerobic fermentation. The microcystin concentration decreased to 0.20-0.35 μg/L in the liquid phase and 4.16-11.51 μg/g in the sludge phase after 60 days of digestion. The initial PMS dose and residue microcystin concentration could be simulated with a logarithmic decay model (R2 > 0.87). Anaerobic digestion could recover energy from algal source in the form of methane gas, which was not affected in the presence of microcystin, and the microcystin removal rate was >99%. Digestion decreased the total contents of Cd and Zn in the liquid phase and increased the total contents of Cr and Pb in the liquid phase. The microbial community and function prediction results indicated that the PMS0.1 system had the highest methane production, which was attributed to the high abundance of Mechanosaeta (40.52%). This study provides insights into microbial mechanisms, microcystin detoxification and the heavy metal partitioning behavior of the algal biomass during methane production.
Soomro, MHAA, Indraratna, B & Karekal, S 2022, 'Critical shear strain and sliding potential of rock joint under cyclic loading', Transportation Geotechnics, vol. 32, pp. 100708-100708.
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A new concept of critical shear strain ετcritical of rock joint under cyclic loading is presented, and the role of ετcritical in evaluating the sliding potential of rock joint is highlighted. A series of cyclic triaxial tests was conducted on a cylindrical rock joint specimen with a replicated rough surface representing a joint roughness coefficient JRC value of 12.6 oriented at 60° with respect to the horizontal plane. The experimental results indicate that the onset of instability of rock joint is suppressed with increase in confining pressure and number of loading cycles N until the normalized shear deformation increases beyond a threshold value of ετcritical. Generally, the critical strain of most rock types is considered in the proximity of 1% under small strain conditions [36–37], however, in this study, the critical strain concept is extended to the domain of rock joints, and a semi-empirical model to more rigorously quantify the critical shear strain (ετcritical) of rock joint is suggested considering the effect of joint roughness coefficient JRC, cyclic loading amplitude, and the number of loading cycles N. Also, a rational classification of Joint Sliding Potential (JSP) based on the ετcritical and normalized total shear strain εθN of rock joint is proposed to characterize the cyclic loading induced sliding instability of a rock discontinuity.
Srivastava, A, Yetemen, O, Saco, PM, Rodriguez, JF, Kumari, N & Chun, KP 2022, 'Influence of orographic precipitation on coevolving landforms and vegetation in semi‐arid ecosystems', Earth Surface Processes and Landforms, vol. 47, no. 12, pp. 2846-2862.
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AbstractTopography affects the intensity and spatial distribution of precipitation due to orographic lifting mechanisms and, in turn, influences the prevailing climate and vegetation distribution. Previous modelling studies on the impact of orographic precipitation on landform evolution have considered bare soil conditions. However, research on the effect of changes in precipitation regimes induced by elevation gradients (particularly in aspect‐controlled semi‐arid ecosystems) on landform patterns, trying to understand feedbacks and consequences for coevolving vegetation, has been limited. In this study, the Channel–Hillslope Integrated Landscape Development (CHILD) landscape evolution model coupled with the vegetation dynamics Bucket Grassland Model (BGM) is used to analyse the coevolution of semi‐arid landform–vegetation ecosystems. The CHILD+BGM model is run under different combinations of precipitation and solar radiation settings. Three precipitation settings, including uniform, elevation control, and orographic control on precipitation, are considered in combination with spatially uniform and spatially varied radiation settings. Based on the results, elevation control, aspect, and drainage network are identified as the major drivers of the distribution of vegetation cover on the landscapes. Further, the combination of orographic precipitation and spatially varied solar radiation created the highest asymmetry in the landscape and divide migration due to the emergence of gentler slopes on the windward than the leeward sides of the domain. The modelling outcomes from this study indicate that aspect control of solar radiation in combination with orographic precipitation plays a key role in the generation of topographic asymmetry in semi‐arid ecosystems.
Stewart, MG 2022, 'Reliability-based design and robustness for blast-resistant design of RC buildings', Advances in Structural Engineering, vol. 25, no. 7, pp. 1402-1412.
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Explosive blasts from accidental or malevolent sources constitute an extreme event resulting in abnormal loads on buildings and other structures. A reinforced concrete (RC) multistorey building is assumed to be attacked by a terrorist vehicle-borne improvised device. Structural reliabilities are calculated for each RC column in the multistorey building exposed directly to the blast event. The probability of progressive collapse for the building is then estimated using system reliability analysis comprising of ground floor columns exposed to the explosive blast. The RC columns are designed according to United States blast-resistant design standard based on (i) threat dependent and (ii) alternate path design methods. The effects of threat dependent and alternate path design methods on column sizing, column reliability, and building collapse probability are investigated by conservatively assuming that collapse occurs if one or more columns fail. The robustness is also dependent on the location of the explosive. It was also found that a threat-dependent design appears to be more effective than the alternate path method in reducing building collapse risks.
Stewart, MG 2022, 'Simplified calculation of airblast variability and reliability-based design load factors for spherical air burst and hemispherical surface burst explosions', International Journal of Protective Structures, vol. 13, no. 2, pp. 144-160.
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There can be significant uncertainty and variability with explosive blast loading. Standards and codes of practice are underpinned by reliability-based principles, and there is little reason not to apply these to explosive blast loading. This paper develops a simplified approach where regression equations may be used to predict the probabilistic model of airblast variability and associated reliability-based design load factors (or RBDFs) for all combinations of range, explosive mass and model errors. These models are applicable to (i) hemispherical surface bursts, and (ii) spherical free-air bursts. The benefit of this simplified approach is that the equations can be easily programed into a spreadsheet, computer code or other numerical methods. There is no need for any Monte-Carlo or other probabilistic calculations. Examples then illustrate how model error, range and explosive mass uncertainty and variability affect the variability of pressure and impulse, which in turn affect the damage assessment of residential construction.
Stewart, MG 2022, 'Simplified reliability-based load design factors for explosive blast loading, weapons effects, and its application to collateral damage estimation', The Journal of Defense Modeling and Simulation: Applications, Methodology, Technology, vol. 19, no. 3, pp. 385-401.
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The paper describes a simplified approach to quantifying a reliability-based design load factor (RBDF) for the variability of explosive blast loading. The user can select range and explosive mass variability and model errors to derive RBDFs for pressure and impulse. These algorithms may be easily programmed into a spreadsheet, computer code, or other numerical method. There is a need by military planners to increase the predictive accuracy of collateral damage estimation (CDE) to ensure maximum damage to the target while minimizing harm to nearby civilians. This present paper uses the CDE damage criterion adopted by the USA and NATO to assess damage and safety risks and recommend safe collateral damage distances. Hence, the present paper utilizes RBDFs to simulate collateral damage risks to a hypothetical reinforced concrete residential building from a 2000 lb bomb using the 99th percentile of blast loads, engineering models, and Monte Carlo simulation analysis that considers variabilities of load and resistance. It was found that CDE is sensitive to airblast model errors and variability of structural resistance. It is recommended that these considerations be incorporated into CDE methodology since existing CDE methodology may be non-conservative, resulting in higher risks of collateral damage.
Stewart, MG 2022, 'Systems thinking averts apocalypses now and in the future: why we should always look on the bright side of life', Civil Engineering and Environmental Systems, vol. 39, no. 3, pp. 188-204.
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Systems thinking and analysis from the civil and environmental engineering communities have been highly successful in mitigating the effects of natural and man-made hazards. Not surprisingly, the United Nations Human Development Index shows steady improvement for every nation since its implementation in 1990. The world has never been healthier, wealthier, or more educated than at the present. Climate change and sustainability remain as significant challenges to be faced. It will be shown, though, that economic and life-safety losses from climate change are often exaggerated and do not reflect wealth creation, human capital, and new improved technologies. There is an urgent need for systems-led approaches and there is a proud record of accomplishments in the past that should equally as well translate into the future. This paper will discuss these issues, as well as briefly describe the importance of systems engineering in dealing with new and emerging threats, as well as the political imperative. The paper will also highlight that there is much to be optimistic about the future, and in the ability of systems thinking to meet any challenges. And to quote Monty Python we should try to ‘Always Look on the Bright Side of Life’.
Su, G, Mohd Zulkifli, NW, Ong, HC, Ibrahim, S, Bu, Q & Zhu, R 2022, 'Pyrolysis of oil palm wastes for bioenergy in Malaysia: A review', Renewable and Sustainable Energy Reviews, vol. 164, pp. 112554-112554.
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Su, G, Ong, HC, Cheah, MY, Chen, W-H, Lam, SS & Huang, Y 2022, 'Microwave-assisted pyrolysis technology for bioenergy recovery: Mechanism, performance, and prospect', Fuel, vol. 326, pp. 124983-124983.
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The emergence of bioenergy provides a solution to the environment and energy crises caused by the indiscriminate use of fossil fuels. Pyrolysis technology has broad application prospects in bioenergy production and waste disposal, providing a solid guarantee for the sustainable development of human beings and the environment. As an endothermic process, pyrolysis relies on external heat as an energy source. The introduction of microwave provides a different energy source for the pyrolysis process and exhibits a different pyrolysis performance due to its unique energy transfer mechanism. Conventional pyrolysis is conducive to the formation of bio-oil, whereas microwave-assisted pyrolysis can improve the composition of bio-oil and the surface properties of biochar. This article focuses on the advantages and limitations of microwave-assisted and conventional pyrolysis modes. Special attention is given to the differences in product distribution and properties and the economic feasibility of the two pyrolysis modes.
Su, G, Ong, HC, Fattah, IMR, Ok, YS, Jang, J-H & Wang, C-T 2022, 'State-of-the-art of the pyrolysis and co-pyrolysis of food waste: Progress and challenges', Science of The Total Environment, vol. 809, pp. 151170-151170.
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The continuous growth of population and the steady improvement of people's living standards have accelerated the generation of massive food waste. Untreated food waste has great potential to harm the environment and human health due to bad odor release, bacterial leaching, and virus transmission. However, the application of traditional disposal techniques like composting, landfilling, animal feeding, and anaerobic digestion are difficult to ease the environmental burdens because of problems such as large land occupation, virus transmission, hazardous gas emissions, and poor efficiency. Pyrolysis is a practical and promising route to reduce the environmental burden by converting food waste into bioenergy. This paper aims to analyze the characteristics of food waste, introduce the production of biofuels from conventional and advanced pyrolysis of food waste, and provide a basis for scientific disposal and sustainable management of food waste. The review shows that co-pyrolysis and catalytic pyrolysis significantly impact the pyrolysis process and product characteristics. The addition of tire waste promotes the synthesis of hydrocarbons and inhibits the formation of oxygenated compounds efficiently. The application of calcium oxide (CaO) exhibits good performance in the increment of bio-oil yield and hydrocarbon content. Based on this literature review, pyrolysis can be considered as the optimal technique for dealing with food waste and producing valuable products.
Su, G, Ong, HC, Gan, YY, Chen, W-H, Chong, CT & Ok, YS 2022, 'Co-pyrolysis of microalgae and other biomass wastes for the production of high-quality bio-oil: Progress and prospective', Bioresource Technology, vol. 344, pp. 126096-126096.
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Su, G, Ong, HC, Mofijur, M, Mahlia, TMI & Ok, YS 2022, 'Pyrolysis of waste oils for the production of biofuels: A critical review', Journal of Hazardous Materials, vol. 424, no. Pt B, pp. 127396-127396.
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The application of waste oils as pyrolysis feedstocks to produce high-grade biofuels is receiving extensive attention, which will diversify energy supplies and address environmental challenges caused by waste oils treatment and fossil fuel combustion. Waste oils are the optimal raw materials to produce biofuels due to their high hydrogen and volatile matter content. However, traditional disposal methods such as gasification, transesterification, hydrotreating, solvent extraction, and membrane technology are difficult to achieve satisfactory effects owing to shortcomings like enormous energy demand, long process time, high operational cost, and hazardous material pollution. The usage of clean and safe pyrolysis technology can break through the current predicament. The bio-oil produced by the conventional pyrolysis of waste oils has a high yield and HHV with great potential to replace fossil fuel, but contains a high acid value of about 120 mg KOH/g. Nevertheless, the application of CaO and NaOH can significantly decrease the acid value of bio-oil to close to zero. Additionally, the addition of coexisting bifunctional catalyst, SBA-15@MgO@Zn in particular, can simultaneously reduce the acid value and positively influence the yield and quality of bio-oil. Moreover, co-pyrolysis with plastic waste can effectively save energy and time, and improve bio-oil yield and quality. Consequently, this paper presents a critical and comprehensive review of the production of biofuels using conventional and advanced pyrolysis of waste oils.
Su, G, Ong, HC, Mohd Zulkifli, NW, Ibrahim, S, Chen, WH, Chong, CT & Ok, YS 2022, 'Valorization of animal manure via pyrolysis for bioenergy: A review', Journal of Cleaner Production, vol. 343, pp. 130965-130965.
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Suleman, SB, Hai, FI, Mukhtar, H, Duong, HC & Ansari, AJ 2022, 'Influence of operating parameters and membrane fouling on nutrient transport by FO membrane', Journal of Water Process Engineering, vol. 47, pp. 102699-102699.
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Sulthana, R, Taqui, SN, Syed, UT, Khan, TMY, Khadar, SDA, Mokashi, I, Shahapurkar, K, Kalam, MA, Murthy, HCA & Syed, AA 2022, 'Adsorption of Crystal Violet Dye from Aqueous Solution using Industrial Pepper Seed Spent: Equilibrium, Thermodynamic, and Kinetic Studies', Adsorption Science & Technology, vol. 2022, pp. 1-20.
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The economic viability of adsorbing crystal violet (CV) using pepper seed spent (PSS) as a biosorbent in an aqueous solution has been studied. A parametrical investigation was conducted considering parameters like initial concentration of dye, time of contact, pH value, and temperature variation. The analysis of experimental data obtained was carried out by evaluating with the isotherms of Freundlich, Sips, Tempkin, Jovanovic, Brouers–Sotolongo, Toth, Vieth–Sladek, Radke–Prausnitz, Langmuir, and Redlich–Peterson. The adsorption kinetics were studied by implementing the Dumwald-Wagner, Weber-Morris, pseudo-first-order, pseudo-second-order, film diffusion, and Avrami models. The experimental value of adsorption capacity ([Formula: see text]) was observed to be quite close to the Jovanovic isotherm adsorption capacity ([Formula: see text]) at ([Formula: see text]), coefficient of correlation of 0.945. The data validation was found to conform to that of pseudo-second-order and Avrami kinetic models. The adsorption process was specified as a spontaneous and endothermic process owing to the thermodynamic parametrical values of [Formula: see text], [Formula: see text], and [Formula: see text]. The value of [Formula: see text] is an indicator of the process’s physical nature. The adsorption of CV to the PSS was authenticated from infrared spectroscopy and scanning electron microscopy images. The interactions of the CV-PSS system have been discussed, and the observations noted suggest PSS as a feasible adsorbent to extract CV from an aqueous solution.
Sun, C, Du, Q, Zhang, X, Wang, Z, Zheng, J, Wu, Q, Li, Z, Long, T, Guo, W & Ngo, HH 2022, 'Role of spent coffee ground biochar in an anaerobic membrane bioreactor for treating synthetic swine wastewater', Journal of Water Process Engineering, vol. 49, pp. 102981-102981.
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Using anaerobic membrane bioreactors (AnMBRs) to treat swine wastewater is an effective method to recover bioenergy. However, due to the inhibitory effect of high concentrations of organic matter and ammonia nitrogen on microbial activities in swine wastewater, some problems are evident such as low recovery efficiency and serious membrane fouling. In this study, biochar prepared from spent coffee grounds (SCG-BC) was added to AnMBR to investigate its effect on the operation process. Results reported that methane yield rose from 0.227 LCH4/g-CODremoved to 0.267 LCH4/g-CODremoved along with a reduction in CO2 being produced at 35.25 % after adding SCG-BC. It confirmed that in-situ biogas upgrading was achieved. As well, the total volatile fatty acids declined to a low concentration of 194.87 ± 51.82 mg/L while pH remained steadily at 7.70 ± 0.31. Adding SCG-BC reduced irreversible membrane fouling by 34.69 %. Microbial community analysis showed that SCG-BC increased the relative abundance of methanogenic archaea, especially Methanosarcina (from 1.47 % to 8.03 %). Also, Anaerolinea and Methanosaeta participating in direct interspecies electron transfer were enriched onto biochar. They acted together to enhance the biogas production. It can be concluded that AnMBR with SCG-BC addition has good application prospects in recovering bioenergy from wastewater.
Sun, J, Peng, Z, Zhu, Z-R, Fu, W, Dai, X & Ni, B-J 2022, 'The atmospheric microplastics deposition contributes to microplastic pollution in urban waters', Water Research, vol. 225, pp. 119116-119116.
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Identifying and understanding the potential sources delivering microplastics into the urban water environment is imperative for microplastic pollution control. However, how atmospheric deposition contributes to microplastic pollution in the urban water environment is unclear. Therefore, this study investigated the contribution of atmospheric deposition to microplastic pollution in urban waters based on the analysis of the atmospheric deposition characteristics in the urban area. The results showed that microplastic deposition fluxes during wet weather and dry weather varied from 1.1 × 103±0.06×103 to 3.5 × 103±0.3 × 103 particles/m2/day and 0.91×103±0.09×103 to 1.6 × 103±0.1 × 103 particles/m2/day, respectively. The microplastics deposition flux showed moderate to strong correlations to atmospheric particulate matter concentrations, especially the PM2.5 concentration (R2 = 0.76-0.93), suggesting the regularly monitored PM2.5 concentration might be served as an indicator for microplastics deposition flux estimation. The deposited microplastics were mainly transparent fragments with an average size of 51-67 μm. Polyethylene and polypropylene were the most abundant plastic polymer, followed by polyethylene terephthalate and polyamide. The comparison of microplastics collected during different weather conditions suggested that rain events could increase microplastics deposition fluxes when air quality conditions are similar. Particularly, rains promoted the deposition of fibrous microplastics as well as smaller microplastics. The estimated daily microplastics deposition in the whole city region suggested more microplastics were deposited in summer and winter. The total quantity of microplastics deposited in the urban environment could reach 1.7-12 times of those discharged from treated wastewater. Among them, 10% would directly deposit to urban waters in the studied city region, while the others may also enter the urban waters through runoff. The results of...
Sun, KQ, Zhang, N, Zhu, QX & Liu, X 2022, 'Exact and approximate solutions for free vibrations of continuous partial-interaction composite beams', STEEL AND COMPOSITE STRUCTURES, vol. 44, no. 4, pp. 517-529.
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An exact dynamic analytical method for free vibrations of continuous partial-interaction composite beams is proposed based on the Timoshenko beam theory. The main advantage of this method is that the independent shear deformations and rotary inertia of sub-beams are considered, which is more in line with the reality. Therefore, the accuracy of eigenfrequencies obtained by this method is significantly improved, especially for higher order modes, compared to the existing methods where the rotary angles of both sub-beams are assumed to be equal irrespective of the differences in the shear stiffness of each sub-beam. Furthermore, the solutions obtained by the proposed method are exact owing to no introduction of approximated displacement and force fields in the derivation. In addition, an exact analytical solution for the case of simply supported is obtained. Based on this, an approximate expression for the fundamental frequency of continuous partial-interaction composite beams is also proposed, which is useful for practical engineering applications. Finally, the practicability and effectiveness of the proposed method and the approximate expression are explored using numerical and experimental examples; The influence factors including the interfacial interaction, shear modulus ratio, span-to-depth ratio, and side-to-main span length ratio on the eigenfrequencies are presented and discussed in detail.
Sun, KQ, Zhang, N, Zhu, QX & Liu, X 2022, 'Exact and approximate solutions for free vibrations of continuous partial-interaction composite beams', Steel and Composite Structures, vol. 44, no. 4, pp. 531-543.
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An exact dynamic analytical method for free vibrations of continuous partial-interaction composite beams is proposed based on the Timoshenko beam theory. The main advantage of this method is that the independent shear deformations and rotary inertia of sub-beams are considered, which is more in line with the reality. Therefore, the accuracy of eigenfrequencies obtained by this method is significantly improved, especially for higher order modes, compared to the existing methods where the rotary angles of both sub-beams are assumed to be equal irrespective of the differences in the shear stiffness of each sub-beam. Furthermore, the solutions obtained by the proposed method are exact owing to no introduction of approximated displacement and force fields in the derivation. In addition, an exact analytical solution for the case of simply supported is obtained. Based on this, an approximate expression for the fundamental frequency of continuous partial-interaction composite beams is also proposed, which is useful for practical engineering applications. Finally, the practicability and effectiveness of the proposed method and the approximate expression are explored using numerical and experimental examples; The influence factors including the interfacial interaction, shear modulus ratio, span-to-depth ratio, and side-to-main span length ratio on the eigenfrequencies are presented and discussed in detail.
Sun, N, Dou, P, Zhai, W, He, H, Nghiem, LD, Vatanpour, V, Zhang, Y, Liu, C & He, T 2022, 'Polyethylene separator supported thin-film composite forward osmosis membranes for concentrating lithium enriched brine', Water Research, vol. 216, pp. 118297-118297.
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To extract lithium from salt lake brine involves a process of separation and concentration. After separating lithium from brine, the lithium ion concentration is generally a few hundred mg/L which is far below the required 20-30 g/L (as Li+) before precipitation as lithium carbonate. The concentration step of a lithium enriched brine is crucial but highly energy-intensive. Spontaneous forward osmosis (FO) technology offers the possibility for concentrating lithium ions with low energy. Because the concentrating process involves both feed and draw solution with very high salinity, it is highly desirable to have a high performance FO membrane with a low structural parameter as well as a high rejection to ions. In this work, thin polyethylene separator supported FO (PE-FO) membranes were prepared and post-treated stepwise with benzyl alcohol (BA) and hydraulic compaction. The effect of the post-treatment on the FO performance was systematically analyzed. Excellent FO performance was achieved: the water flux and reverse salt flux selectivity were 66.3 LMH and 5.25 L/g, respectively, when the active layer is oriented towards the 0.5 M NaCl draw solution with deionized water as the feed. To the best of our knowledge, this FO flux is the highest ever reported in the open literature under similar test conditions. Applied in concentrating lithium enriched brine, the membrane showed superior water flux using saturated MgCl2 as draw solution. A new FO model was established to simulate the water flux during the concentration process with good agreement with the experimental results. The promising results using PE-FO membrane for lithium enrichment opens a new frontier for the potential application of FO membranes.
Sun, S, Hou, Y-N, Wei, W, Sharif, HMA, Huang, C, Ni, B-J, Li, H, Song, Y, Lu, C, Han, Y & Guo, J 2022, 'Perturbation of clopyralid on bio-denitrification and nitrite accumulation: Long-term performance and biological mechanism', Environmental Science and Ecotechnology, vol. 9, pp. 100144-100144.
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The contaminant of herbicide clopyralid (3,6-dichloro-2- pyridine-carboxylic acid, CLP) poses a potential threat to the ecological system. However, there is a general lack of research devoted to the perturbation of CLP to the bio-denitrification process, and its biological response mechanism remains unclear. Herein, long-term exposure to CLP was systematically investigated to explore its influences on denitrification performance and dynamic microbial responses. Results showed that low-concentration of CLP (<15 mg/L) caused severe nitrite accumulation initially, while higher concentrations (35-60 mg/L) of CLP had no further effect after long-term acclimation. The mechanistic study demonstrated that CLP reduced nitrite reductase (NIR) activity and inhibited metabolic activity (carbon metabolism and nitrogen metabolism) by causing oxidative stress and membrane damage, resulting in nitrite accumulation. However, after more than 80 days of acclimation, almost no nitrite accumulation was found at 60 mg/L CLP. It was proposed that the secretion of extracellular polymeric substances (EPS) increased from 75.03 mg/g VSS at 15 mg/L CLP to 109.97 mg/g VSS at 60 mg/L CLP, which strengthened the protection of microbial cells and improved NIR activity and metabolic activities. Additionally, the biodiversity and richness of the microbial community experienced a U-shaped process. The relative abundance of denitrification- and carbon metabolism-associated microorganisms decreased initially and then recovered with the enrichment of microorganisms related to the secretion of EPS and N-acyl-homoserine lactones (AHLs). These microorganisms protected microbe from toxic substances and regulated their interactions among inter- and intra-species. This study revealed the biological response mechanism of denitrification after successive exposure to CLP and provided proper guidance for analyzing and treating herbicide-containing wastewater.
Sun, Z, Chen, Y, Zheng, J, Jiang, S, Dong, W, Li, X, Li, Y & E, S 2022, 'Temperature‐Dependent Electromagnetic Microwave Absorbing Characteristics of Stretchable Polyurethane Composite Foams with Ultrawide Bandwidth', Advanced Engineering Materials, vol. 24, no. 7, pp. 2101489-2101489.
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With the rapid development of current electronic equipment, electromagnetic microwave absorption (EMA) materials with higher design requirements under special circumstances have attracted great attention. Herein, a flexible polyurethane composite foam assisted by coral‐like CNT@Fe3O4/graphene nanocomposites is fabricated by a facile solvothermal and moisture self‐foaming method. The composite foam with 15 wt% nanofillers exhibits an outstanding temperature cycle stability with gradually improved EMA performance at elevated temperature and excellent resilience stability with a tensile strength of 4.81 MPa. An enhanced minimum reflection loss (RLmin) of −59.44 dB at 10.38 GHz with a thickness of 2.28 mm is achieved, while the ultrawide absorption bandwidth of 6.09 GHz nearly covers the full X‐band. This benefits from interface impedance matching, dielectric and magnetic dual losses, and multiple reflections depending on the interior open microcellular structures. It is expected to become a promising thermally tunable microwave absorber in harsh environments.
Swain, S, Altaee, A, Saxena, M & Samal, AK 2022, 'A comprehensive study on heterogeneous single atom catalysis: Current progress, and challenges☆', Coordination Chemistry Reviews, vol. 470, pp. 214710-214710.
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Tan, M, Gao, Q, Fu, Y, Xu, Y, Hao, D, Ni, B-J & Wang, Q 2022, 'Fabrication of visible-light-active Fe-2MI film electrode for simultaneous removal of Cr(VI) and phenol', Materials Science in Semiconductor Processing, vol. 151, pp. 107013-107013.
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In this study, a new coordination polymer of Fe-2-methylimidazole (Fe-2MI) was successfully loaded onto F-doped tin oxide (FTO) via a one-pot solvothermal method, using Fe(NO3)3 and 2MI as raw materials. For X-ray diffraction patterns (XRD) and scanning electron microscope (SEM) analysis, it can be deduced that Fe-2MI assembles were evenly dispersed on the surface of FTO, and were partially encapsulated by tiny FeOOH particles. The as-prepared Fe-2MI film electrode was used as photoanode with titanium sheet (Ti) as the cathode. Simultaneous photoelectrocatalytic (PEC) removal of phenol and Cr(VI) can be effortlessly accomplished under noticeable light illumination. Meanwhile, the impact of initial Fe state was also investigated. Fe-2MI prepared with Fe(III) behaved better PEC performance than that with Fe(II). Furthermore, the Fe-2MI photoanodes were optimized by adjusting the initial concentration of Fe(III) and 2MI precursors. Besides, the application conditions were optimized at acidic pHs and 2.5 V bias voltage. Cr(VI) can be completely reduced with 80% removal of phenol after 5 h PEC reaction. After 5 successive cyclic runs, stable photocatalytic performance can still be observed. Therefore, Fe-2MI coordination polymer can be a promising candidate for preparing visible-light-active photoanode in the application of environmental remediation.
Tang, J, Pu, Y, Huang, J, Pan, S, Wang, XC, Hu, Y, Ngo, HH, Li, Y & Abomohra, A 2022, 'Caproic acid production through lactate-based chain elongation: Effect of lactate-to-acetate ratio and substrate loading', Environmental Technology & Innovation, vol. 28, pp. 102918-102918.
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Substrate properties play a key role in promoting the caproate yield through lactate-based carbon chain elongation pathway. In the present study, the effect of lactate-to-acetate (LA/AA) carbon ratio (from 0.5 to 5.0) and substrate loading (in terms of substrate/inoculum ratio within the range 20–180 mmol-C/g-VSS) on caproate fermentation was investigated. Results showed that both caproate content and yield increased by increasing the LA/AA ratio up to 3.0, then decreased at higher ratios due to activation of acrylate pathway and dispersion of carbon flux at elevated lactate content. At the optimal LA/AA carbon ratio of 3.0, substrate loading lower than 100 mmol-C/g-VSS was beneficial for efficient substrate utilization with low caproate selectivity, while higher substrate-to-inoculums (S/I) ratio led to incomplete substrate utilization and dispersed carbon flow, which finally reduced the caproate yield. Thus, the highest caproate yield of 0.42 g-COD/g-COD and selectivity of 49.5% were recorded at LA/AA and S/I ratio ratios of 3.0 and 100 mmol-C/g-VSS, respectively. The present study further depictures the novel approach for caproate production with lactate.
Tang, Z, Li, W, Peng, Q, Tam, VWY & Wang, K 2022, 'Study on the failure mechanism of geopolymeric recycled concrete using digital image correlation method', Journal of Sustainable Cement-Based Materials, vol. 11, no. 2, pp. 113-126.
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In this study, an experimental investigation was conducted to understand the failure mechanism of geopolymeric recycled aggregate concrete (GRAC) under compression. GRAC specimens with different recycled aggregate (RA) replacement ratios were prepared and tested. A digital image correlation (DIC) system was used to monitor the displacement field and strain distribution over the surface of the specimen. The results revealed that RA replacement adversely affected the mechanical properties of geopolymeric concrete, including compressive strength, elastic modulus, and splitting tensile strength. For all the specimens, cracks mainly initiated near the interfacial transition zones, and usually nucleated around natural aggregate (NA) rather than RA. As observed from the final crack patterns, it was more frequent for the RA that cracks passed through the aggregate particles, in comparison with the NA. The location of strain concentration region detected by the DIC method was closely consistent with that of the formed macro cracks.
Tanko, D, Barua, PD, Dogan, S, Tuncer, T, Palmer, E, Ciaccio, EJ & Acharya, UR 2022, 'EPSPatNet86: eight-pointed star pattern learning network for detection ADHD disorder using EEG signals', Physiological Measurement, vol. 43, no. 3, pp. 035002-035002.
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Abstract Objective. The main objective of this work is to present a hand-modelled one-dimensional signal classification system to detect Attention-Deficit Hyperactivity Disorder (ADHD) disorder using electroencephalography (EEG) signals. Approach. A novel handcrafted feature extraction method is presented in this research. Our proposed method uses a directed graph and an eight-pointed star pattern (EPSPat). Also, tunable q wavelet transforms (TQWT), wavelet packet decomposition (WPD), statistical extractor, iterative Chi2 (IChi2) selector, and the k-nearest neighbors (kNN) classifier have been utilized to develop the EPSPat based learning model. This network uses two wavelet decomposition methods (TQWT and WPD), and 85 wavelet coefficient bands are extracted. The proposed EPSPat and statistical feature creator generate features from the 85 wavelet coefficient bands and the original EEG signal. The learning network is termed EPSPatNet86. The main purpose of the presented EPSPatNet86 is to detect abnormalities of the EEG signals. Therefore, 85 wavelet subbands have been generated to extract features. The created 86 feature vectors have been evaluated using the Chi2 selector and the kNN classifier in the loss value calculation phase. The final features vector is created by employing a minimum loss-valued eight feature vectors. The IChi2 selector selects the best feature vector, which is fed to the kNN classifier. An EEG signal dataset has been used to demonstrate the presented model’s EEG signal classification ability. We have used an ADHD EEG dataset since ADHD is a commonly seen brain-related ailment. Main results. Our developed EPSPatNet86 model can detect the ADHD EEG signals with 97.19% and 87.60% accuracy using 10-fold cross and subject-wise validations, respectively. Significance.
Tao, G, Ouyang, Q, Lei, D, Chen, Q, Nimbalkar, S, Bai, L & Zhu, Z 2022, 'NMR-Based Measurement of AWRC and Prediction of Shear Strength of Unsaturated Soils', International Journal of Geomechanics, vol. 22, no. 9.
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Tao, M, Lu, D, Shi, Y & Wu, C 2022, 'Utilization and life cycle assessment of low activity solid waste as cementitious materials: A case study of titanium slag and granulated blast furnace slag', Science of The Total Environment, vol. 849, pp. 157797-157797.
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Taşcı, B, Acharya, MR, Datta Barua, P, Metehan Yildiz, A, Veysel Gun, M, Keles, T, Dogan, S & Tuncer, T 2022, 'A new lateral geniculate nucleus pattern-based environmental sound classification using a new large sound dataset', Applied Acoustics, vol. 196, pp. 108897-108897.
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Tian, Y, Li, Q, Wu, D, Chen, X & Gao, W 2022, 'Nonlinear dynamic stability analysis of clamped and simply supported organic solar cells via the third-order shear deformation plate theory', Engineering Structures, vol. 252, pp. 113616-113616.
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This study presents a semi-analytical framework to explore the nonlinear dynamic buckling characteristics of the imperfect organic solar cell (OSC) with clamped and simply supported restrains grounded on the third-order shear deformation plate theory (TSDT). The exerting axial displacement loading is divided into infinite and finite durations. Moreover, the spatially dependent Winker-Pasternak elastic foundation and damping effect are incorporated in the current analysis. Combining the von Kármán nonlinearity, the governing equations are derived with the aid of the Airy stress function. By applying the Galerkin method and fourth-order Runge–Kutta procedure, the dynamic buckling critical condition of the OSC subjected to these two kinds of loadings is determined by Budiansky–Hutchinson (B-H) criterion. Based on the numerical results, the influence of some critical parameters, including the geometrical dimension, boundary condition, loading configuration, initial imperfection, damping ratio, and elastic foundation coefficient are investigated. Not limited to the solar cell, this method is also suitable to the dynamic buckling behaviours of other laminated plates.
Tian, Z, Li, Y, Li, S, Vute, S & Ji, J 2022, 'Influence of particle morphology and concentration on the piezoresistivity of cement-based sensors with magneto-aligned nickel fillers', Measurement, vol. 187, pp. 110194-110194.
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Cement-based sensors with magneto-aligned nickel fillers have the proven capability to significantly enhance piezoresistivity compared with the sensors with randomized fillers. In this paper, the influence of particle morphology and concentration of nickel particles on the piezoresistive and mechanical properties of cement-based sensors, treated with and without magnetic field intervention, are investigated experimentally. Five categories of nickel particles with different average diameters are type N50 (50 nm), N500 (0.5 μm), F(1 μm × 20 μm flake), T (5 μm) and U (25 μm). The obtained results indicate that the application of magnetic field enhances most of the piezoresistive performance and yields best piezoresistivity for the samples with type T nickel powder. Anisotropic piezoresistivity can be achieved under a very low filler content (0.1 vol%) in N50 nano-scale nickel powder and cement composite, followed by the N500 and T nickel particles in 5 vol% content. Small particles with lower content have similar piezoresistive performance to the samples with large particles and higher concentration. One half of the samples can achieve high giant gauge factor (GF) of over 500, two-thirds of which are aligned by magnetic field with anisotropic piezoresistive property. Samples with 5 vol% type T nickel content has the highest GF value, followed by the sample with 5 vol% type F nickel flakes and 10 vol% type U nickel powder. It is also found that mechanical strength decreases with the increase of particle concentration.
Tong, C-X, Dong, Z-L, Sun, Q, Zhang, S, Zheng, J-X & Sheng, D 2022, 'On compression behavior and particle breakage of carbonate silty sands', Engineering Geology, vol. 297, pp. 106492-106492.
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Tong, C-X, Zhai, M-Y, Li, H-C, Zhang, S & Sheng, D 2022, 'Particle breakage of granular soils: changing critical state line and constitutive modelling', Acta Geotechnica, vol. 17, no. 3, pp. 755-768.
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Truong, DQ, Loganathan, P, Tran, LM, Vu, DL, Nguyen, TV, Vigneswaran, S & Naidu, G 2022, 'Removing ammonium from contaminated water using Purolite C100E: batch, column, and household filter studies', Environmental Science and Pollution Research, vol. 29, no. 12, pp. 16959-16972.
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Tuan Tran, H, Lin, C, Bui, X-T, Ky Nguyen, M, Dan Thanh Cao, N, Mukhtar, H, Giang Hoang, H, Varjani, S, Hao Ngo, H & Nghiem, LD 2022, 'Phthalates in the environment: characteristics, fate and transport, and advanced wastewater treatment technologies', Bioresource Technology, vol. 344, pp. 126249-126249.
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Tucho, A, Indraratna, B & Ngo, T 2022, 'Stress-deformation analysis of rail substructure under moving wheel load', Transportation Geotechnics, vol. 36, pp. 100805-100805.
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Turner, BD & Spadari, M 2022, 'Mass stabilisation and leaching characteristics of organotins from contaminated dredged sediments', International Journal of Environmental Science and Technology, vol. 19, no. 8, pp. 7425-7436.
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Uddin Murad, MA, Cetindamar, D & Chakraborty, S 2022, 'Identifying the Key Big Data Analytics Capabilities in Bangladesh’s Healthcare Sector', Sustainability, vol. 14, no. 12, pp. 7077-7077.
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The study explores the crucial big data analytics capabilities (BDAC) for healthcare in Bangladesh. After a rigorous and extensive literature review, we list a wide range of BDAC and empirically examine their applicability in Bangladesh’s healthcare sector by consulting 51 experts with ample domain knowledge. The study adopted the DEcision MAking Trial and Evaluation Laboratory (DEMATEL) method. Findings highlighted 11 key BDAC, such as using advanced analytical techniques that could be critical in managing big data in the healthcare sector. The paper ends with a summary and puts forward suggestions for future studies.
Ung, HTT, Leu, BT, Tran, HTH, Nguyen, LN, Nghiem, LD, Hoang, NB, Pham, HT & Duong, HC 2022, 'Combining flowform cascade with constructed wetland to enhance domestic wastewater treatment', Environmental Technology & Innovation, vol. 27, pp. 102537-102537.
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This study reports the performance of a new combined flowform cascade (FC) and constructed wetland (CW) system to enhance nitrogen removal and biological degradation of urban wastewater. A series of 8 FC units at the flow rate of 200 L/h could markedly increase the dissolved oxygen level in the wastewater from the initial value of 0.2 mg/L to 5.6 mg/L, thus providing suitable aerobic condition in the front zone of the CW for nitrification and biodegradation of organic contaminants. The results demonstrate that the combined FC/CW system could achieve the sequence of aerobic and anoxic conditions for nitrification and denitrification, respectively. By using a series of FC units for aeration, the CW system could enhance the removal of total nitrogen from 49.4% to 71.2% and biochemical oxygen demand from 80.9% to 86.1% when the hydraulic loading rate was 31.25 m3/m2⋅day. On the other hand, the FC units exerted negligible effects on the phosphate and total suspended solid removals of the CW system. Thus, the combined FC/CW process exhibited phosphate and total suspended solid removals comparable to those of the CW alone.
Van, CN, Tran Thanh, H, Nguyen, TN & Li, J 2022, 'Numerical investigation of the influence of casting techniques on fiber orientation distribution in ECC', Frontiers of Structural and Civil Engineering, vol. 16, no. 11, pp. 1424-1435.
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AbstractEngineered cementitious composites (ECC), also known as bendable concrete, were developed based on engineering the interactions between fibers and cementitious matrix. The orientation of fibers, in this regard, is one of the major factors influencing the ductile behavior of this material. In this study, fiber orientation distributions in ECC beams influenced by different casting techniques are evaluated via numerical modeling of the casting process. Two casting directions and two casting positions of the funnel outlet with beam specimens are modeled using a particle-based smoothed particle hydrodynamics (SPH) method. In this SPH approach, fresh mortar and fiber are discretized by separated mortar and fiber particles, which smoothly interact in the computational domain of SPH. The movement of fiber particles is monitored during the casting simulation. Then, the fiber orientations at different sections of specimens are determined after the fresh ECC stops flowing in the formwork. The simulation results show a significant impact of the casting direction on fiber orientation distributions along the longitudinal wall of beams, which eventually influence the flexural strength of beams. In addition, casting positions show negligible influences on the orientation distribution of fibers in the short ECC beam, except under the pouring position.
Varjani, S, Shahbeig, H, Popat, K, Patel, Z, Vyas, S, Shah, AV, Barceló, D, Hao Ngo, H, Sonne, C, Shiung Lam, S, Aghbashlo, M & Tabatabaei, M 2022, 'Sustainable management of municipal solid waste through waste-to-energy technologies', Bioresource Technology, vol. 355, pp. 127247-127247.
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Increasing municipal solid waste (MSW) generation and environmental concerns have sparked global interest in waste valorization through various waste-to-energy (WtE) to generate renewable energy sources and reduce dependency on fossil-derived fuels and chemicals. These technologies are vital for implementing the envisioned global 'bioeconomy' through biorefineries. In light of that, a detailed overview of WtE technologies with their benefits and drawbacks is provided in this paper. Additionally, the biorefinery concept for waste management and sustainable energy generation is discussed. The identification of appropriate WtE technology for energy recovery continues to be a significant challenge. So, in order to effectively apply WtE technologies in the burgeoning bioeconomy, this review provides a comprehensive overview of the existing scenario for sustainable MSW management along with the bottlenecks and perspectives.
Vasanthkumar, P, Senthilkumar, N, Rao, KS, Metwally, ASM, Fattah, IMR, Shaafi, T & Murugan, VS 2022, 'Improving energy consumption prediction for residential buildings using Modified Wild Horse Optimization with Deep Learning model', Chemosphere, vol. 308, no. Pt 1, pp. 136277-136277.
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The consumption of a significant quantity of energy in buildings has been linked to the emergence of environmental problems that can have unfavourable effects on people. The prediction of energy consumption is widely regarded as an effective method for the conservation of energy and the improvement of decision-making processes for the purpose of lowering energy use. When it comes to the generation of positive results in prediction tasks, the Machine Learning (ML) technique can be considered the most appropriate and applicable strategy. This article presents a Modified Wild Horse Optimization with Deep Learning approach for Energy Consumption Prediction (MWHODL-ECP) model in residential buildings. The MWHODL-ECP method that has been provided places an emphasis on providing an up-to-date and precise forecast of the amount of energy that residential buildings consume. The MWHODL-ECP algorithm goes through several phases of data preprocessing in order to achieve this goal. These steps include merging and cleaning the data, converting and normalising the data, and converting the data. A model known as deep belief network (DBN) is used here for the purpose of predicting energy consumption. In the end, the MWHO algorithm is utilised for the hyperparameter tuning procedure. The results of the experiments demonstrated that the MWHODL-ECP approach is superior to other existing DL models in terms of its performance. The MWHODL-ECP model has improved its performance, with effective prediction results of MSE-1.10, RMSE-1.05, MAE-0.41, R-squared-96.28, and Training time-1.23.
Vayghan, SS, Salmani, M, Ghasemkhani, N, Pradhan, B & Alamri, A 2022, 'Artificial intelligence techniques in extracting building and tree footprints using aerial imagery and LiDAR data', Geocarto International, vol. 37, no. 10, pp. 2967-2995.
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Veza, I, Afzal, A, Mujtaba, MA, Tuan Hoang, A, Balasubramanian, D, Sekar, M, Fattah, IMR, Soudagar, MEM, EL-Seesy, AI, Djamari, DW, Hananto, AL, Putra, NR & Tamaldin, N 2022, 'Review of artificial neural networks for gasoline, diesel and homogeneous charge compression ignition engine', Alexandria Engineering Journal, vol. 61, no. 11, pp. 8363-8391.
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Veza, I, Irianto, Panchal, H, Paristiawan, PA, Idris, M, Fattah, IMR, Putra, NR & Silambarasan, R 2022, 'Improved prediction accuracy of biomass heating value using proximate analysis with various ANN training algorithms', Results in Engineering, vol. 16, pp. 100688-100688.
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The conventional experimental methods to determine biomass heating value are laborious and costly. Numerous correlations to estimate biomass' higher heating values have been proposed using proximate analysis. Recently, the utilisation of artificial neural network (ANN) has been extensively applied to predict HHV. However, most studies of ANN to estimate the biomass’ HHV only use one algorithm to train a small number of biomass datasets. The specific objective of this study is to predict the HHV of 350 samples of biomass from the proximate analysis by developing an ANN model which was trained with 11 different algorithms. This study fills a gap in the research on how to predict the HHV of biomass using numerous ANN training algorithms utilising sizeable biomass datasets. Results show that the ANN trained with Levenberg-Marquardt gave the highest accuracy. The Levenberg–Marquardt algorithm shows the best fit giving the highest R and R2 values and the lowest MAD, MSE, RMSE and MAPE. Compared with previous biomass HHV prediction studies, the ANN model developed in this study provides improved prediction accuracy with higher R2 and lower RMSE. Results from this study have also indicated that the Levenberg-Marquardt should be the first-choice supervised algorithm for feedforward-backpropagation.
Veza, I, Zainuddin, Z, Tamaldin, N, Idris, M, Irianto, I & Fattah, IMR 2022, 'Effect of palm oil biodiesel blends (B10 and B20) on physical and mechanical properties of nitrile rubber elastomer', Results in Engineering, vol. 16, pp. 100787-100787.
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Vo, HNP, Nguyen, TMH, Ngo, HH, Guo, W & Shukla, P 2022, 'Biochar sorption of perfluoroalkyl substances (PFASs) in aqueous film-forming foams-impacted groundwater: Effects of PFASs properties and groundwater chemistry', Chemosphere, vol. 286, no. Pt 1, pp. 131622-131622.
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The widespread use of per- and polyfluoroalkyl substances (PFASs)-related products such as aqueous film-forming foams (AFFF) has led to increasing contamination of groundwater systems. The concentration of PFASs in AFFF-impacted groundwater can be several orders of magnitude higher than the drinking water standard. There is a need for a sustainable and effective sorbent to remove PFASs from groundwater. This work aims to investigate the sorption of PFASs in groundwater by biochar column. The specific objectives are to understand the influences of PFASs properties and groundwater chemistry to PFASs sorption by biochar. The PFASs-spiked Milli-Q water (including 19 PFASs) and four aqueous film-forming foams (AFFF)-impacted groundwater were used. The partitioning coefficients (log Kd) of long chain PFASs ranged from 0.77 to 4.63 while for short chain PFASs they remained below 0.68. For long chain PFASs (C ≥ 7), log Kd increased by 0.5 and 0.8 for each CF2 moiety of PFCAs and PFSAs, respectively. Dissolved organic matter (DOM) was the most influential factor in PFASs sorption over pH, salinity, and specific ultraviolet absorbance (SUVA). DOM contained hydrophobic compounds and metal ions which can form DOM-PFASs complexes to provide more sorption sites for PFASs. The finding is useful for executing PFASs remediation by biochar filtration column, especially legacy long chain PFASs, for groundwater remediation.
Vu, HP, Nguyen, LN, Wang, Q, Ngo, HH, Liu, Q, Zhang, X & Nghiem, LD 2022, 'Hydrogen sulphide management in anaerobic digestion: A critical review on input control, process regulation, and post-treatment', Bioresource Technology, vol. 346, pp. 126634-126634.
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Hydrogen sulphide (H2S) in biogas is a problematic impurity that can inhibit methanogenesis and cause equipment corrosion. This review discusses technologies to remove H2S during anaerobic digestion (AD) via: input control, process regulation, and post-treatment. Post-treatment technologies (e.g. biotrickling filters and scrubbers) are mature with >95% removal efficiency but they do not mitigate H2S toxicity to methanogens within the AD. Input control (i.e. substrate pretreatment via chemical addition) reduces sulphur input into AD via sulphur precipitation. However, available results showed <75% of H2S removal efficiency. Microaeration to regulate AD condition is a promising alternative for controlling H2S formation. Microaeration, or the use of oxygen to regulate the redox potential at around -250 mV, has been demonstrated at pilot and full scale with >95% H2S reduction, stable methane production, and low operational cost. Further adaptation of microaeration relies on a comprehensive design framework and exchange operational experience for eliminating the risk of over-aeration.
Vu, MT, Nguyen, LN, Ibrahim, I, Abu Hasan Johir, M, Bich Hoang, N, Zhang, X & Nghiem, LD 2022, 'Nutrient recovery from digested sludge centrate using alkali metals from steel-making slag', Chemical Engineering Journal, vol. 450, pp. 138186-138186.
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Results in this study highlighted the potential of nutrient recovery from anaerobically digested sludge centrate using calcium and other alkali metals from steel-making slag. Up to 96% phosphate and 71% ammonia could be recovered from sludge centrate at the optimal conditions. Mass balance calculation confirmed precipitation and volatilisation as the main mechanisms for phosphorus and ammonia recovery, respectively. Morphology and elemental analysis of obtained precipitates confirmed that phosphorus was recovered in the form of dicalcium phosphate dihydrate (CaHPO4·2H2O). The results also showed that sludge centrate pre-treatment by sand filtration and forward osmosis (FO) enrichment was essential to achieve high nutrient recovery. Sand filtration pre-treatment decreased the total suspended solid of sludge centrate by eightfold, leading to mitigated membrane fouling and reduced nutrient loss during FO pre-concentration. The production of slag liquor with high calcium and alkaline content from steel-making slag for nutrient recovery was demonstrated. Slag liquor with high pH increased ammonia recovery significantly, but only enhanced phosphate recovery slightly. Phosphate recovery was more dependent on the initial Ca:PO4 molar ratio than the final pH. The process demonstrated in this study has potential and significant practical implications to nutrient recovery from wastewater and beneficial use of steel-making slag.
Vu, MT, Nguyen, LN, Mofijur, M, Johir, MAH, Ngo, HH, Mahlia, TMI & Nghiem, LD 2022, 'Simultaneous nutrient recovery and algal biomass production from anaerobically digested sludge centrate using a membrane photobioreactor', Bioresource Technology, vol. 343, pp. 126069-126069.
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This study aims to evaluate the performance of C. vulgaris microalgae to simultaneously recover nutrients from sludge centrate and produce biomass in a membrane photobioreactor (MPR). Microalgae growth and nutrient removal were evaluated at two different nutrient loading rates (sludge centrate). The results show that C. vulgaris microalgae could thrive in sludge centrate. Nutrient loading has an indiscernible impact on biomass growth and a notable impact on nutrient removal efficiency. Nutrient removal increased as the nutrient loading rate decreased and hydraulic retention time increased. There was no membrane fouling observed in the MPR and the membrane water flux was fully restored by backwashing using only water. However, the membrane permeability varies with the hydraulic retention time (HRT) and biomass concentration in the reactor. Longer HRT offers higher permeability. Therefore, it is recommended to operate the MPR system in lower HRT to improve the membrane resistance and energy consumption.
Wali, SB, Hannan, MA, Ker, PJ, Rahman, MSA, Mansor, M, Muttaqi, KM, Mahlia, TMI & Begum, RA 2022, 'Grid-connected lithium-ion battery energy storage system: A bibliometric analysis for emerging future directions', Journal of Cleaner Production, vol. 334, pp. 130272-130272.
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The lithium-ion battery energy storage systems (ESS) have fuelled a lot of research and development due to numerous important advancements in the integration and development over the last decade. The main purpose of the presented bibliometric analysis is to provide the current research trends and impacts along with the comprehensive review in the field of the grid-connected lithium-ion battery (LIB) ESS within the year 2010–2021. The research has been performed using refined keyword searches on grid-connected LIB ESS in the Scopus database and the data of the top 100 highly cited articles were extracted. The research trend has shown that the grid-connected LIB ESS literature has increased substantially between 2016 and 2021, compared to the period 2010–2015. The bibliometric analysis consists of detailed keyword co-occurrence network analysis, co-authorship map, distribution of articles over countries, journals, research types, and subject categories. The evaluation of highly cited articles identifies numerous aspects, including methodologies and systems, issues, and challenges, to determine existing constraints and research gaps. The process of deciding, developing, and evaluating the highly cited articles, is expected to contribute to a methodical foundation for potential progress of grid-connected LIB ESS, as well as identify emerging pathways for future researchers. This study may act as a guideline providing future directions towards improving energy efficiency, environmental sustainability, reliability, and flexibility of the LIB ESS integrated power system.
Wan Mahari, WA, Kee, SH, Foong, SY, Amelia, TSM, Bhubalan, K, Man, M, Yang, Y, Ong, HC, Vithanage, M, Lam, SS & Sonne, C 2022, 'Generating alternative fuel and bioplastics from medical plastic waste and waste frying oil using microwave co-pyrolysis combined with microbial fermentation', Renewable and Sustainable Energy Reviews, vol. 153, pp. 111790-111790.
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In the present study, microwave co-pyrolysis (MCP) was used to simultaneously convert medical plastic waste (MPW) and waste frying oil (WFO) into liquid oil products. The MCP process demonstrated a faster heating rate (24 °C/min) and shorter process time (20 min) compared to conventional pyrolysis techniques converting MPW and WFO into liquid oil (≥80 wt%). The MCP reduced the oxygen content from 25.7 to 9.82 wt% in liquid oil encompassing light aliphatic hydrocarbons ranging from C10 to C28, generating a novel sustainable liquid fuel. The liquid having a high carbon content (approximately 77.1 wt%) and low carbon to nitrogen ratio (27.9) is a suitable energy feedstock for polyhydroxyalkanoate (PHA) bioplastic production in the form of poly3-hydroxybutyrate [P(3HB)]. The liquid oil acted as an energy source for the growth of Bacillus sp. During microbial fermentation, yielding approximately 11% (w/w) P(3HB). Bioplastics are biodegradable, biocompatible with humans and non-toxic to marine organisms, representing a valuable additive in the production of cosmetics, detergents, and as medical scaffolds for tissue engineering. The results indicate the promising upcycling of waste products by this approach through pyrolytic biorefinery into value-added fuel and bioplastic products, being important for the future sustainable production of renewable resources.
Wang, C, Park, MJ, Gonzales, RR, Phuntsho, S, Matsuyama, H, Drioli, E & Shon, HK 2022, 'Novel organic solvent nanofiltration membrane based on inkjet printing-assisted layer-by-layer assembly', Journal of Membrane Science, vol. 655, pp. 120582-120582.
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Novel layer-by-layer (LBL) organic solvent nanofiltration (OSN) membrane was developed via inkjet printing of polyethyleneimine (PEI) and single walled carbon nanotube (SWCNT) on a polyketone (PK) membrane surface, followed by post-treatment using three different cross-linking agents: glutaraldehyde (GA), (±)-epichlorohydrin (ECH) and trimesoyl chloride (TMC). The effects of PEI and SWCNT concentrations, bilayer numbers, and cross-linking conditions in the formation of the selective layers were evaluated in terms of membrane OSN performances. PEI concentration of 10.0 g/L and SWCNT concentration of 1.0 g/L with eight cycles of printing bilayers were chosen as optimal conditions. GA cross-linking was found to give the best membrane performance, and thus GA was considered as the best cross-linking agent for inkjet-printed LBL membrane modification among the three kinds of cross-linkers. The (PEI/SWCNT)8-GA exhibited Rose Bengal (RB) rejection over 99% with high organic solvent permeances. Compared to the cross-linking time, cross-linking agent concentration was found to have a greater effect on the membrane modification in terms of rejection performance. Moreover, the inkjet-printed LBL membrane showed negligible changes in membrane weight and OSN performance after immersion in different organic solvents over a period of three weeks, indicating its high mechanical and chemical stability. Finally, the possible applications of our printed LBL membranes in the pharmaceutical and hemp industries were evaluated. Overall, our work could further develop inkjet printing method for LBL OSN membrane fabrications.
Wang, C, Park, MJ, Seo, DH, Phuntsho, S, Gonzales, RR, Matsuyama, H, Drioli, E & Shon, HK 2022, 'Inkjet printed polyelectrolyte multilayer membrane using a polyketone support for organic solvent nanofiltration', Journal of Membrane Science, vol. 642, pp. 119943-119943.
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This study investigates the inkjet printing technique as an efficient way to fabricate polyelectrolyte multilayer membranes (PEM) for organic solvent nanofiltrtaion (OSN). Polyethyleneimine (PEI) and poly(sodium 4-styrene sulfonate) (PSS) were used as polycation and polyanion, respectively. Single walled carbon nanotube (SWCNT) was incorporated into membranes to enhance the membrane physical and chemical stability. The polyketone (PK) membrane served as substrate for OSN because of its organic solvent resistance property in nature. The effects of numbers of bilayer, polyelectrolyte concentration, and the cross-linking condition on the membrane OSN performances were evaluated. The best OSN performance was achieved with 10 bilayers of polyelectrolytes printing, noted as (PEI/PSS-CNT)10. The (PEI/PSS-CNT)10 membrane exhibited ethanol, methanol, IPA and acetone permeances of 2.52, 4.21, 1.21 and 4.75 L m−2 h−1 bar−1, respectively, along with good dye rejection rate (Rose Bengal (RB) rejection >98%). Moreover, the inkjet printed OSN membrane was found to be stable after soaking in different organic solvents for two weeks. The membrane weights and the performances exhibited negligible changes. The 12 h continuous filtration tests also confirmed the membrane stability property. Our work broadened the use of inkjet printing technology for membrane fabrication and validated the technology as a promising method for producing multilayer OSN membranes, which may open a new avenue for OSN membrane preparations.
Wang, C, Park, MJ, Yu, H, Matsuyama, H, Drioli, E & Shon, HK 2022, 'Recent advances of nanocomposite membranes using layer-by-layer assembly', Journal of Membrane Science, vol. 661, pp. 120926-120926.
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Layer-by-layer (LBL) assembly is a versatile technology with the ability to produce charged thin film active layers by absorbing oppositely charged polyelectrolytes or nanomaterials through various interactions, which has been proven to be a promising method for preparing separation membranes with desired properties. Recently, nanocomposite membranes fabricated by incorporating various kinds of nanomaterials through the LBL technique have gained increasing interest due to their excellent membrane performances in terms of improved permeability, selectivity, anti-fouling, chlorine resistance, and long-term stability. This review aims to provide a comprehensive investigation of the state-of-the-art achievements of the nanocomposite membranes prepared by LBL assembly. Different LBL assembly methods such as dip coating, spray coating, spin coating, inkjet printing, electric field, and high gravity technologies are introduced. The detailed membrane fabrication processes and their applications in different separation areas including nanofiltration, reverse osmosis, ultrafiltration, microfiltration, pressure retarded osmosis, forward osmosis, pervaporation and organic solvent nanofiltration are summarised and discussed. The advantages and challenges of the LBL nanocomposite membranes are also addressed. Overall, this review provides some fundamental clues for the exploration of LBL assembly techniques for the preparation of separation membranes with preferable performances and applications.
Wang, C, Wei, W, Chen, Z, Wang, Y, Chen, X & Ni, B-J 2022, 'Polystyrene microplastics and nanoplastics distinctively affect anaerobic sludge treatment for hydrogen and methane production', Science of The Total Environment, vol. 850, pp. 158085-158085.
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Microplastics and nanoplastics generally accumulated in waste activated sludge (WAS) after biological wastewater treatment. Currently, researches mainly focused on how plastics affected a particular sludge treatment method, without the comparison of different sludge systems. Herein, distinct responses of hydrogen-producing and methane-producing sludge systems were comprehensively evaluated with polystyrene microplastics (PS-MPs) and nanoplastics (PS-NPs) existence. Experimental results showed that PS particles would stimulate inhibition on anaerobic gas production except that PS-MPs were conducive to hydrogen accumulation, which was caused by the enhanced solubilization. Mechanistic investigation demonstrated that severe inhibition of PS-NPs to hydrogen production was derived from the excessively inhibitory hydrolysis despite of improving solubilization. Varying degrees of inhibition to acidification and methanation collectively contributed to reduced methane accumulation with exposure to PS-MPs and PS-NPs. Excessive oxidative stress would be generated in the presence of PS-MPs or PS-NPs, deteriorating microbial activities and richness of species responsible for hydrogen or methane production.
Wang, C, Wei, W, Dai, X & Ni, B-J 2022, 'Calcium peroxide significantly enhances volatile solids destruction in aerobic sludge digestion through improving sludge biodegradability', Bioresource Technology, vol. 346, pp. 126655-126655.
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This work put up a novel strategy of applying calcium peroxide (CaO2) in aerobic sludge digestion and provided insights into such system. The degradation percentage of sludge and total inorganic nitrogen production in the digesters with CaO2 at 0.02 g/g-VS-WAS increased by 25.8% and 18.8% of control. CaO2 addition allowed various key microbes related to organics degradation to accumulate in the system. Moreover, the modelling and chemical (i.e., excitation emission matrix (EEM) fluorescence and fourier transformation spectroscopy (FTIR)) analyses revealed that CaO2 addition enhanced sludge biodegradability with more release of biodegradable organics and increased degradation of recalcitrant organics, which can be transformed into biodegradable organics with the action of CaO2. Subsequent transformation test indicated that CaO2 enabled to promote hydrolysis and catabolism of biodegradable substrates in sludge. Further investigations on function mechanism suggested that CaO2 carried on positive action for sludge aerobic digestion mainly through the enhancement by ·OH.
Wang, C, Wei, W, Dai, X & Ni, B-J 2022, 'Zero valent iron greatly improves sludge destruction and nitrogen removal in aerobic sludge digestion', Chemical Engineering Journal, vol. 433, pp. 134459-134459.
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Zero-valent iron (ZVI), a low-cost metallic material, has been previously applied in effectively enhancing sewage sludge anaerobic digestion. However, the potential role of ZVI on aerobic digestion of sludge, a completely different sludge treatment method from anaerobic digestion, is still unknown. Herein, the effects of ZVI on the performance of aerobic sludge digestion were systematically studied, focusing on the sludge degradation, nitrogen removal and sludge dewaterability. Results showed ZVI greatly increased the volatile solids (VS) destruction from 27.0 ± 1.3% to 50.0 ± 1.0% and significantly enhanced the TCOD removal from 26.0 ± 1.2% to 47.9 ± 0.9% in aerobic digesters with different ZVI levels (0–20 g/L). The metabolic intermediate transformation steps of solubilization, hydrolysis and catabolism processes in aerobic digestion were all revealed to be enhanced by ZVI. More importantly, the aerobic digesters with higher ZVI levels achieved higher inorganic nitrogen removal, even with higher sludge degradation for ammonium release, due to the occurrence of both chemical and biological denitrification induced by ZVI. Correspondingly, the microbial compositions in the digesters with ZVI shifted towards the direction that was conducive to sludge degradation and nitrogen removal (e.g., aerobic denitrification) compared to control. Further, the dewaterability of the aerobically digested sludge was also improved with ZVI addition, supported by the reducing capillary suction time (CST) and negative surface potential.
Wang, C, Wei, W, Mannina, G, Dai, X & Ni, B-J 2022, 'Unveiling the distinctive role of titanium dioxide nanoparticles in aerobic sludge digestion', Science of The Total Environment, vol. 813, pp. 151872-151872.
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Aerobic digestion is considered to be a common process for the stabilization of waste activated sludge (WAS) in the small-sized wastewater treatment systems, while the broad application of titanium dioxide nanoparticles (TiO2 NPs) results in their unavoidable existence in WAS aerobic digestion, with its role in aerobic sludge digestion being never documented. This study set up a series of aerobic sludge digesters to evaluate the previously unknown role of TiO2 NPs on the performance of the digesters. The volatile solids (VS) degradation percentage increased from 21.9 ± 0.6% to 26.9 ± 0.1% - 30.0 ± 0.3% with the different contents of TiO2 NPs (0, 1, 20 and 50 mg/L). Similarly, the total inorganic nitrogen production increased from 23.1 ± 0.3 to 31.0 ± 0.1 mg N/g VS with the rising TiO2 NPs concentrations from 0 to 50 mg/L. The microbial analysis suggested that TiO2 NPs contributed to the accumulation of specific microbes correlated with the degradation of organic substances and the conversion of nitrogen compounds. Model-based analysis showed the higher biodegradability and hydrolysis rate of sludge with TiO2 NPs. Further mechanistic studies indicated that the enhancement of WAS solubilization and the degradation of recalcitrant substances (e.g., humic acid and cellulose) contributed to the better performance of experimental aerobic digesters, which was confirmed by the fourier transformation infrared spectroscopy (FTIR) indicating the converting of these materials into biodegradable substrates for digestion with TiO2 NPs. It could be inferred from this investigation that aerobic digestion rather than anaerobic digestion would be a more suitable treatment method for sludge containing TiO2 NPs.
Wang, C, Wei, W, Zhang, Y-T & Ni, B-J 2022, 'Evaluating the role of biochar in mitigating the inhibition of polyethylene nanoplastics on anaerobic granular sludge', Water Research, vol. 221, pp. 118855-118855.
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The extensive application of anaerobic granular sludge (AGS) to wastewater treatment for methane recovery has drawn considerable attention to the system performances affected by the presence of emerging contaminants in wastewater such as nanoplastics. However, effective strategies on how to mitigate the inhibition caused by nanoplastics remained unavailable. In this study, a novel strategy using biochar to mitigate the inhibition on the AGS performances caused by polyethylene nanoplastics (PE-NPs) was proposed and the corresponding mitigating mechanisms involved were explored. The PE-NPs solely decreased the level of methane recovery of AGS to 71.3 ± 2.7% of control, which was subsequently increased to 85.6 ± 0.8% of control with the presences of both biochar and PE-NPs, although biochar solely showed no obvious effect on methane production. The addition of biochar also elevated the granule size of AGS, along with AGS integrity based on the morphological observation. Moreover, the distributions of live cells and functional microbes related to acidification and methanation increased with biochar addition compared to sole PE-NPs exposure. More extracellular polymeric substance (EPS) was secreted when biochar was involved in AGS systems, with more protein being detected to maintain the granule structure of AGS. Evaluation of adsorption tests indicated that biochar possessed stronger affinity for PE-NPs than AGS, thus capturing the PE-NPs that would originally contact AGS and posing less toxicity to microorganisms.
Wang, C, Wei, W, Zhang, Y-T, Dai, X & Ni, B-J 2022, 'Different sizes of polystyrene microplastics induced distinct microbial responses of anaerobic granular sludge', Water Research, vol. 220, pp. 118607-118607.
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Recent investigations confirmed the inhibitory effect of microplastics with single sizes on the anaerobic granular sludge (AGS) wastewater treatment system. However, the differences of toxicity from different sizes of microplastics toward AGS and their underlying mechanism are still unclear. In this work, the responds of AGS exposed to different particle sizes of polystyrene microplastics (PS-MPs) were reported. The results showed that the increasing particle sizes (from 0.5 μm to 150 μm) of PS-MPs induced a gradually increasing and distinct inhibitory (from 6.7% to 16.2%) effect on the cumulative methane production by AGS, accompanied by the similar decreasing organic carbon degradation trends. Correspondingly, the integrity and the cell viability of the AGS granules were damaged and the populations of the key acidogens and methanogens were reduced when exposed to PS-MPs, which was particularly evident in the reactors affected by the larger micron-sized PS-MPs. The zeta potential and contact angle indicated that the larger-sized PS-MPs had the stronger dispersive properties and affinity for AGS, causing the higher oxidative stress and leachates toxicity. Further investigation revealed that the tolerance of AGS to PS-MPs toxicity also exhibited size-dependent trend. Larger particles (e.g., 150 μm) of PS-MPs inhibited extracellular polymeric substance (EPS) secretion, while smaller particles (e.g., 0.5 μm) promoted EPS generation with the release of more humic acid, alleviating their toxicity.
Wang, CT, Lan, TH, Chong, WT, Ong, HC & Chen, SX 2022, 'An Optimal Inlet Flow Angle Design of Vascular-type Micromixer', Journal of the Chinese Society of Mechanical Engineers, Transactions of the Chinese Institute of Engineers, Series C/Chung-Kuo Chi Hsueh Kung Ch'eng Hsuebo Pao, vol. 43, no. 1, pp. 57-62.
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Micromixers are important modules in medical applications. Novel and excellent biometric micromixers have been designed with an effective mechanism of flow splitting and recombining (SAR). The aim of this study is to modify the prototype of a biometric micromixer by designing the inlet flow channel and generating a better flow geometry in the blood vessel-micromixer. The blood vessel-micromixer was also investigated with different inlet channel angles and various Reynolds number ratios (ReI2 and Rer) for the estimation of their influence on the mixing performance of the micro-mixer. The ReI2 is the inlet 2 and the Rer is the combination of side flow and middle flow effects during the different flow conditions. Results showed that the blood vessel-micromixer with an inlet channel angle of 30° (Ø =30°) can be optimized for future research works. In addition, optimal performance with a Amixing index of 0.88 would be achieved at a condition of ReI2= 1 and Rer = 0.7. These findings will be definitely useful for the improvement of micromixer applications in the future.
Wang, D, Wang, X, Yang, Q, Zhang, Y & Wu, C 2022, 'Dynamic response analysis of a large commercial aircraft hitting the AP1000 containment vessel', Zhendong yu Chongji/Journal of Vibration and Shock, vol. 41, no. 10.
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Since the event of '9•11', 2001, the protection of nuclear power plants against the impact of large commercial aircraft has been a hot issue in the field of nuclear safety. Using ANSYS/LS-DYNA software, the refinement finite element models of a Boeing 737 MAX 8 and a AP1000 containment vessel were established. The accuracy and validity of the finite element modelling of the plane hitting were validated by using the Riera method. Five different initial impact velocities (100 m/s, 150 m/s, 200 m/s, 250 m/s and 300 m/s) and five different impact heights (39 m, 30 m, 47 m, 54 m and 65 m) in the plane hitting process were taken into account in the numerical simulation. The time history of the impact force and kinetic energy of the aircraft, the dynamic response of the steel containment, the equivalent stress distribution and the local damage of the aircraft were studied and analyzed. The research results show that the engine's contribution to the aircraft impact force is about 3-4 times of that of the front of the fuselage; the peak impact force on the steel tube body in the equivalent beam segment is larger, than that on other segments, the largest one is up to 171% of the latter (at the rate of 300 m/s); the junction part of the containment cylinder body to the dome is the most dangerous position, where the penetrated sizes are greater than those at other locations, the largest penetrated size in ring direction is 29.68 m, and that in vertical direction is 17.86 m. The dome in all conditions are not damaged. The equivalent steel beam segment can withstand the aircraft impact very well. When the impact velocity of the aircraft is greater than 150 m/s, the influence range of the equivalent steel plate stress in the impact area of the containment vessel decreases with the increase of initial impact velocity, and the distribution range of the equivalent steel plate stress in the impact area of the equivalent beam segment is larger than that of the non-equivale...
Wang, D, Zhang, J, Li, J, Wang, W, Shon, HK, Huang, H, Zhao, Y & Wang, Z 2022, 'Inorganic scaling in the treatment of shale gas wastewater by fertilizer drawn forward osmosis process', Desalination, vol. 521, pp. 115396-115396.
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In this study, fertilizer drawn forward osmosis (FDFO) process was applied for the treatment of shale gas wastewater. The forward osmosis (FO) experiments with simulated shale gas wastewater and real shale gas wastewater were carried out, respectively. The effects of reverse salt diffusion on the inorganic fouling to the membrane surface was systematically investigated. Two commercial FO membranes were selected and the optimized operating conditions were evaluated. It was found that calcium sulfate scaling can be alleviated by optimizing the operating parameters, including increasing flow rate and decreasing temperature. Furthermore, the Aquaporin FO membrane, which has lower reverse salt flux and less surface charge potential, exhibited lower fouling tendency. Under the optimal operating conditions, the effects of reverse salt diffusion on the barium sulfate scaling were also analyzed. The presence of calcium ions can alleviate barium sulfate scaling, while sodium chloride will aggravate the barium sulfate scaling. In addition, the scaling behavior of real shale gas wastewater was further explored. Inorganic scaling phenomenon seriously affected the FO membrane performance and lower pH had beneficial effect on recycling the real shale gas wastewater. The present study provided both theoretical fundamentals and industry applicable practices for implementing FO technology in the treatment and resource recovery of shale gas wastewater.
Wang, F, Long, G, Bai, M, Wang, J, Yang, Z, Zhou, X & Zhou, JL 2022, 'Cleaner and safer disposal of electrolytic manganese residues in cement-based materials using direct electric curing', Journal of Cleaner Production, vol. 356, pp. 131842-131842.
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The direct stockpiling of electrolytic manganese residues (EMR) poses a major environmental issue, and more eco-friendly disposal is urgently needed. The combination of cement solidified waste (CSW) and direct electric curing (DEC) provides a potential solution for hazard-free value-added utilization of EMR. The effects of DEC voltages and EMR dosages on mechanical properties, hydrated products, pore structure of mixture were investigated. The influencing mechanism of DEC on the properties of cement hydration was explored in-depth using TG and XRD results. The environmental and economic evolution of DEC was analyzed, and the leaching test was conducted to evaluate the immobilization of heavy metals. Results indicate that cement-EMR pastes cured in higher DEC voltage and reduced EMR dosage increase mechanical strength and improve pore structure and capillary water absorption with respect to indoor curing (IC). The increased cement dosage improves the effectiveness of CSW, while the increased DEC voltage enhances the ionic driving force. The boosted ettringite formation occurs in system after introducing DEC and amplifying the DEC voltage. The improvement of ion concentration in DEC accelerates the formation of hydration products. The CO2-e per MPa (EIF) and cost per MPa (CIF) values of paste DMP-7 cured in 12V-DEC exhibit the lowest values with respect to those cured in other voltages and IC. The decrease in the leaching amount of Mn2+ and NH4+-N as the DEC voltage increases, and the 28-d leaching concentration of Mn2+ and NH4+-N in pastes are in accordance with the national standards. The application of DEC and cement-solidified disposal for EMR could provide a potential solution for high-value and large-capacity disposal of hazardous solid waste.
Wang, F, Long, G, Bai, M, Wang, J, Zhou, JL & Zhou, X 2022, 'Application of electrolytic manganese residues in cement products through pozzolanic activity motivation and calcination', Journal of Cleaner Production, vol. 338, pp. 130629-130629.
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Degradation in grade of manganese ore aggravates the complexity of electrolytic manganese residue (EMR). Calcination is one of the most practical pretreatment methods to improve EMR activity and dispose the hazardous elements. In this paper, the evolution of mineral phase, pozzolanic activity, pore structure and harmful components induced by calcining EMR was investigated. The results show that EMR calcined at 800 °C has the strength activity index (SAI) of 84.79 at 28 d, which is attributed to the decomposition of dihydrate gypsum and the formation of activated calcium, silicon and aluminum oxide. The formation of β-type hemihydrate gypsum increases the pozzolan activity, while the latter is limited by the formation of stable Mn-spinel (Mn3O4) and Mn-hercynite (MnFe2O4). In the EMR-doped mortar matrix, the production of a large amount of ettringite due to the existence of gypsum, as well as common C-S-H, portlandite and AFm, which strongly verify the pozzolanic activity of EMR. Leaching results show that Mn2+ and NH4+-N could not be eliminated completely at low temperature (<600 °C), but could be completely stabilized in the alkaline environment provided by the cement. The Mn2+ and NH4+-N levels in mortar are fully below the regulatory standards when calcinated above 800 °C. All heavy metals are fixed in the cement and calcination process, ensuring the cleaner utilization of EMR in building materials.
Wang, F, Long, G, He, J, Xie, Y, Tang, Z, Zhou, X, Bai, M & Zhou, JL 2022, 'Fabrication of Energy-Efficient Carbonate-Based Cementitious Material Using Sodium Meta-Aluminate Activated Limestone Powder', ACS Sustainable Chemistry & Engineering, vol. 10, no. 20, pp. 6559-6572.
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Limestone powder (LP) and sodium meta-aluminate (SMA) were used to fabricate calcium carbonate-based cementitious material, as a solution to address the solid waste problem. The effects of SMA doses and curing conditions on the hydration properties and mechanical performance of paste were investigated. The results show that the 28-day unconfined compressive strength and flexural strength of the paste with an LP/SMA ratio of 2/1 were 49.7 and 15.9 MPa, respectively. The characterization by scanning electron microscopy, X-ray diffraction, and thermal gravimetry shows that the calcium aluminum carbonate hydroxide hydrate (CACHH) was the predominant hydrated product and had a dense layered double hydroxide structure (LDHs). The microbridge effect developed by LDHs significantly increases the flexural strength of the paste. Meanwhile, the developed paste exhibited an extremely low carbon emission and energy consumption. This study also reveals the mechanism of LP incorporated with SMA to form CACHH. Overall, this work provides an approach of high value-added utilization for LP as a binder without tedious operation, which could address carbon emission reduction and circular economy of LP.
Wang, G, Weng, L, Huang, Y, Ling, Y, Zhen, Z, Lin, Z, Hu, H, Li, C, Guo, J, Zhou, JL, Chen, S, Jia, Y & Ren, L 2022, 'Microbiome-metabolome analysis directed isolation of rhizobacteria capable of enhancing salt tolerance of Sea Rice 86', Science of The Total Environment, vol. 843, pp. 156817-156817.
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Soil salinization has been recognized as one of the main factors causing the decrease of cultivated land area and global plant productivity. Application of salt tolerant plants and improvement of plant salt tolerance are recognized as the major routes for saline soil restoration and utilization. Sea rice 86 (SR86) is known as a rice cultivar capable of growing in saline soil. Genome sequencing and transcriptome analysis of SR86 have been conducted to explore its salt tolerance mechanisms while the contribution of rhizobacteria is underexplored. In the present study, we examined the rhizosphere bacterial diversity and soil metabolome of SR86 seedlings under different salinity to understand their contribution to plant salt tolerance. We found that salt stress could significantly change rhizobacterial diversity and rhizosphere metabolites. Keystone taxa were identified via co-occurrence analysis and the correlation analysis between keystone taxa and rhizosphere metabolites indicated lipids and their derivatives might play an important role in plant salt tolerance. Further, four plant growth promoting rhizobacteria (PGPR), capable of promoting the salt tolerance of SR86, were isolated and characterized. These findings might provide novel insights into the mechanisms of plant salt tolerance mediated by plant-microbe interaction, and promote the isolation and application of PGPR in the restoration and utilization of saline soil.
Wang, L, Tang, S, Chen, TE, Li, W & Gunasekara, C 2022, 'Sustainable High-Performance Hydraulic Concrete', Sustainability, vol. 14, no. 2, pp. 695-695.
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Concrete has always been indispensable as a material for the engineering and construction of hydraulic structures (e [...]
Wang, L, Wu, C, Fan, L & Wang, M 2022, 'Effective velocity of reflected wave in rock mass with different wave impedances of normal incidence of stress wave', International Journal for Numerical and Analytical Methods in Geomechanics, vol. 46, no. 9, pp. 1607-1619.
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AbstractThe effective velocity of the reflected wave in rock mass is of significance to the detection of crustal structure and the geophysical seismic exploration. In this paper, the modified characteristic method was introduced to solve P‐wave reflection in rock mass with different wave impedances on two sides of the joint. Effective velocity was defined to characterize the propagation velocity of the reflected wave in jointed rock mass. The effects of incident frequency, joint stiffness and wave impedance ratio on the effective velocity were discussed. The results show that when the stress wave propagation in 'hard‐to‐soft' rock mass, the effective velocity increases firstly and then decreases as the incident frequency and the joint stiffness increase, while the effective velocity always decreases as the wave impedance ratio increases; when the stress wave propagation in 'soft‐to‐hard' rock mass, the effective velocity decreases as the incident frequency increases, increases as the joint stiffness increases and decreases as the wave impedance ratio increases. The wave impedance ratio has an important influence on the effective velocity. The effective velocity without considering wave impedance ratio is smaller than that of stress wave propagation in 'soft‐to‐hard' rock mass, but larger than that of stress wave propagation in 'hard‐to‐soft' rock mass.
Wang, S-N, Fang, F, Li, K-Y, Yue, Y-R, Xu, R-Z, Luo, J-Y, Ni, B-J & Cao, J-S 2022, 'Sludge reduction and microbial community evolution of activated sludge induced by metabolic uncoupler o-chlorophenol in long-term anaerobic-oxic process', Journal of Environmental Management, vol. 316, pp. 115230-115230.
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Excess sludge management is a restrictive factor for the development of municipal wastewater treatment plants. The addition of metabolic uncouplers has been proven to be effective in sludge reduction. However, the long-term effect of metabolic uncoupler o-chlorophenol (oCP) on the biological wastewater treatment system operated in anaerobic-oxic mode is still unclear. To this end, two parallel reactors operated in anaerobic-oxic mode with and without 10 mg/L of oCP addition were investigated for 91 days. The results showed that 56.1 ± 2.3% of sludge reduction was achieved in the oCP-added system, and the nitrogen and phosphorus removal ability were negatively affected. Dosing oCP stimulated the formation of microbial products and increased the DNA concentration, but resulted in a decrease in the electronic transport activity of activated sludge. Microbial community analysis further demonstrated that a significant reduction of bacterial richness and diversity occurred after oCP dosing. However, after stopping oCP addition, the pollutant removal ability of activated sludge was gradually increased, but the sludge yield, as well as species richness and diversity, did not recover to the previous level. This study will provide insightful guidance on the long-term application of metabolic uncouplers in the activated sludge system.
Wang, W, Zhao, L, Ni, B-J, Yin, T-M, Zhang, R-C, Yu, M, Shao, B, Xu, X-J, Xing, D-F, Lee, D-J, Ren, N-Q & Chen, C 2022, 'A novel sulfide-driven denitrification methane oxidation (SDMO) system: Operational performance and metabolic mechanisms', Water Research, vol. 222, pp. 118909-118909.
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Microbial denitrification is a crucial biological process for the treatment of nitrogen-polluted water. Traditional denitrification process consumes external organic carbon leading to an increase in treatment costs. We developed a novel sulfide-driven denitrification methane oxidation (SDMO) system that integrates autotrophic denitrification (AD) and denitrification anaerobic methane oxidation (DAMO) for cost-effective denitrification and biogas utilization in situ. Two SDMO systems were operated for 735 days, with nitrate and nitrite serving as electron acceptors, to explore the performance of sewage denitrification and characterize metabolic mechanisms. Results showed SDMO system could reach as high as 100% efficiency of nitrogen removal and biogas desulfurization without an external carbon source when HRT was 10 days and inflow nitrogen concentrations were 50-100 mgN·L-1. Besides, nitrate was a preferable electron acceptor for SDMO system. Biogas not only enhanced nitrogen removal but also intensified the DAMO, nitrogen removed through DAMO contribution doubled as original period from 2.9 mgN·(L·d)-1 to 6.2 mgN·(L·d)-1, and the ratio of nitrate removal through AD to DAMO was 1.2:1 with nitrate as electron acceptor. While nitrogen removed almost all through AD contribution and DAMO was weaken as before, the ratio of nitrate removal through AD to DAMO was 21.2:1 with nitrite as electron acceptor. Biogas introduced into SDMO system with nitrate inspired the growth of DAMO bacteria Candidatus Methylomirabilis from 0.3% to 19.6% and motivated its potentiality to remove nitrate without ANME archaea participation accompanying with gene mfnE upregulating ∼100 times. According to the reconstructed genome from binning analysis, the dramatically upregulated gene mfnE was derived from Candidatus Methylomirabilis, which may represent a novel metabolism pathway for DAMO bacteria to replace the role of archaea for nitrate reduction.
Wang, X, Gao, J, Chen, Z, Chen, H, Zhao, Y, Huang, Y & Chen, Z 2022, 'Evaluation of hydrous ethanol as a fuel for internal combustion engines: A review', Renewable Energy, vol. 194, pp. 504-525.
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Ethanol has been extensively used worldwide as a renewable biofuel to partly substitute fossil fuels, aiming to reduce pollutant and greenhouse gas emissions. However, due to the azeotropic points of water and ethanol, the production of anhydrous ethanol is energy intensive as significant energy is consumed in the distillation and dehydration processes. Therefore, the direct use of hydrous ethanol in engines can dramatically conserve energy and reduce costs. Under this background, this review focuses on the direct use of hydrous ethanol in internal combustion engines. This paper begins with a brief description of the fuel physicochemical properties relevant to engine applications. Furthermore, fundamental combustion characteristics, including the laminar burning velocity, ignition delay time and flame instability, are introduced. Then, the applications of hydrous ethanol or its blends with gasoline in spark ignition engines are summarized. Next, compression ignition engines running on hydrous ethanol in blended and dual-fuel modes are described. Subsequently, the use of hydrous ethanol in advanced combustion concepts, such as homogeneous charge compression ignition and thermally stratified compression ignition, is reviewed. Finally, the conclusions are presented and recommendations for future research are proposed.
Wang, X, Li, W, Luo, Z, Wang, K & Shah, SP 2022, 'A critical review on phase change materials (PCM) for sustainable and energy efficient building: Design, characteristic, performance and application', Energy and Buildings, vol. 260, pp. 111923-111923.
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Building construction deserves many attentions due to its huge energy consumption, while Phase Change Materials (PCMs) provide positive solutions for improving energy efficiency and enhancing the thermal properties of construction materials. However, PCMs also present some negative impacts, such as weakening mechanical properties and increasing costs, chemical instability and so on. In this paper, the main characteristics of PCMs, design and incorporating methods, effects on energy consumption and construction reliability are comprehensively reviewed and discussed. Although many materials have the capacity of phase change, some organic PCMs are more suitable due to the higher latent heat and favourable phase change point in buildings, when eutectic PCMs present greater potential to become the optimal one but much effort is required for investigations. Current design methods and application in construction materials can meet the essential requirements, but the effectiveness is inadequate, including low efficiency of phase changing, leading to low energy storage. Subsequently, some promising research direction and critical areas for optimization are also proposed accordingly in this paper. Future development of PCMs, including novel PCM and efficient incorporation, real applications and functions in buildings are proposed. Additionally, multifunctional construction materials combining PCM deserve much attention and possess promising prospect for energy saving in sustainable and energy efficient building construction.
Wang, X, Xie, G-J, Tian, N, Dang, C-C, Cai, C, Ding, J, Liu, B-F, Xing, D-F, Ren, N-Q & Wang, Q 2022, 'Anaerobic microbial manganese oxidation and reduction: A critical review', Science of The Total Environment, vol. 822, pp. 153513-153513.
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Manganese is a vital heavy metal abundant in terrestrial and aquatic environments. Anaerobic manganese redox reactions mediated by microorganisms have been recognized for a long time, which promote elements mobility and bioavailability in the environment. Biological anaerobic redox of manganese serves two reactions, including Mn(II) oxidation and Mn(IV) reduction. This review provides a comprehensive analysis of manganese redox cycles in the environment, closely related to greenhouse gas mitigation, the fate of nutrients, microbial bioremediation, and global biogeochemical cycle, including nitrogen, sulfur, and carbon. The oxidation and reduction of manganese occur cyclically and simultaneously in the environment. Anaerobic reduction of Mn(IV) receives electrons from methane, ammonium and sulfide, while Mn(II) can function as an electron source for manganese-oxidizing microorganisms for autotrophic denitrification and photosynthesis. The anaerobic redox transition between Mn(II) and Mn(IV) promotes a dynamic biogeochemical cycle coupled to microorganisms in water, soil and sediment environments. The discussion of reaction mechanisms, microorganism diversity, environmental influence bioremediation and application identify the research gaps for future investigation, which provides promising opportunities for further development of biotechnological applications to remediate contaminated environments.
Wang, Y, Mukherjee, A & Castel, A 2022, 'Non-destructive monitoring of incipient corrosion in reinforced concrete with top-bar defect using a combination of electrochemical and ultrasonic techniques', Construction and Building Materials, vol. 360, pp. 129346-129346.
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Wang, Y, Wei, W, Dai, X & Ni, B-J 2022, 'Corncob ash boosts fermentative hydrogen production from waste activated sludge', Science of The Total Environment, vol. 807, no. Pt 3, pp. 151064-151064.
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With the increasing demand for sustainable development, the recycling and utilization of wastes has received widespread attention. This study proposed a green method of using one waste, corncob ash, to boost microbial the production of hydrogen from another waste, waste activated sludge, during anaerobic fermentation. The corncob ash dosage and the fermentative hydrogen production was positively correlated, and the maximum production of hydrogen reached up to 46.8 ± 1.0 mL/g VS, which was about 3.5 times that of the control group without corncob ash dosage (17.0 ± 0.9 mL/g VS). Mechanistic studies found that corncob ash was beneficial to the solubilization, hydrolysis and acetogenesis processes involved in fermentative hydrogen production process. The microbial community analysis indicated that corncob ash enriched more hydrolytic microorganisms (e.g., Bacteroides sp. and Leptolinea sp.), and has less impact on acidifying microorganisms, compared to the control group. The strategy of using corncob ash to boost the production of hydrogen during anaerobic waste activated sludge fermentation proposed in this study might provide a new waste-control-waste paradigm, making sludge disposal and wastewater treatment more sustainable.
Wang, Y, Zhuang, J-L, Lu, Q-Q, Cui, C-Z, Liu, Y-D, Ni, B-J & Li, W 2022, 'Halophilic Martelella sp. AD-3 enhanced phenanthrene degradation in a bioaugmented activated sludge system through syntrophic interaction', Water Research, vol. 218, pp. 118432-118432.
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Polycyclic aromatic hydrocarbons (PAHs) are a group of common recalcitrant pollutant in industrial saline wastewater that raised significant concerns, whereas traditional activated sludge (AS) has limited tolerance to high salinity and PAHs toxicity, restricting its capacity to degrade PAHs. It is therefore urgent to develop a bioaugmented sludge (BS) system to aid in the effective degradation of these types of compounds under saline condition. In this study, a novel bioaugmentation strategy was developed by using halophilic Martelella sp. AD-3 for effectively augmented phenanthrene (PHE) degradation under 3% salinity. It was found that a 0.5∼1.5% (w/w) ratio of strain AD-3 to activated sludge was optimal for achieving high PHE degradation activity of the BS system with degradation rates reaching 2.2 mg⋅gVSS-1⋅h-1, nearly 25 times that of the AS system. Although 1-hydroxy-2-naphthoic acid (1H2N) was accumulated obviously, the mineralization of PHE was more complete in the BS system. Reads-based metagenomic coupled metatranscriptomic analysis revealed that the expression values of ndoB, encoding a dioxygenase associated with PHE ring-cleavage, was 5600-fold higher in the BS system than in the AS system. Metagenome assembly showed the members of the Corynebacterium and Alcaligenes genera were abundant in the strain AD-3 bioaugmented BS system with expression of 10.3±1.8% and 1.9±0.26%, respectively. Moreover, phdI and nahG accused for metabolism of 1H2N have been annotated in both above two genera. Degradation assays of intermediates of PHE confirmed that the activated sludge actually possessed considerable degradation capacity for downstream intermediates of PHE including 1H2N. The degradation capacity ratio of 1H2N to PHE was 87% in BS system, while it was 26% in strain AD-3. These results indicated that strain AD-3 contributed mainly in transforming PHE to 1H2N in BS system, while species in activated sludge utilized 1H2N as substrate to grow, thus est...
Wang, Z, Jin, X, Kaw, HY, Fatima, Z, Quinto, M, Zhou, JL, Jin, D, He, M & Li, D 2022, 'Tracing historical changes, degradation, and original sources of airborne polycyclic aromatic hydrocarbons (PAHs) in Jilin Province, China, by Abies holophylla and Pinus tabuliformis needle leaves', Environmental Science and Pollution Research, vol. 29, no. 5, pp. 7079-7088.
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Due to their wide distribution and availability, plant leaves can be considered interesting candidates as biomonitoring substrates for the evaluation of atmospheric pollution. In addition, some species can also retain historical information, for example, related to environmental pollution, due to their leaf class age. In this study, the content of polycyclic aromatic hydrocarbons (PAHs) in Abies holophylla and Pinus tabuliformis needle samples in the function of their class age has been investigated to obtain information regarding the degradation constant for each PAH under investigation (α values ranging from 0.173 to 1.870) and to evaluate the possibility to correlate the presence of PAHs in needles with some important pollution environmental factors. Considering air pollutant variables registered in Jilin Province, interesting correlations (at 95% confidence level) have been found between coal consumption per year and anthracene contents in needles, while fluorene, phenanthrene, and anthracene results correlated with coal consumption. Furthermore, it has been demonstrated that the total PAH concentration in needles, for both species, increased with their age (from 804 to 3604 ng g-1 dry weight), showing a general tendency to accumulate these substances through years. PAH degradation rates increased instead with molecular complexity. This study could be considered a first trial to obtain historical environmental information by pine needles biomonitoring.
Wang, Z, Yuan, B, Cao, J, Huang, Y, Cheng, X, Wang, Y, Zhang, X & Liu, H 2022, 'A new shift mechanism for micro-explosion of water-diesel emulsion droplets at different ambient temperatures', Applied Energy, vol. 323, pp. 119448-119448.
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Wang, Z, Yuan, B, Huang, Y, Cao, J, Wang, Y & Cheng, X 2022, 'Progress in experimental investigations on evaporation characteristics of a fuel droplet', Fuel Processing Technology, vol. 231, pp. 107243-107243.
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Investigating the evaporation characteristics of a fuel droplet is critical for understanding spray and combustion processes, which provides valuable information and guidance for optimizing engine performance. This paper systematically reviews the droplet evaporation characteristics of various fuels. Firstly, experimental methods for fuel droplet evaporation are introduced, including flying droplet, suspension and levitation, of which the latter two are the most widely applied due to their simple setups and convenient measurements. Secondly, droplet evaporation mechanisms of different fuels are comprehensively discussed. The evaporation process of single-component fuel droplets includes transient heating and equilibrium evaporation phases. Miscible and immiscible multi-component fuel droplets could experience puffing and micro-explosion phenomena, which increase droplet surface area and evaporation rate. Droplet evaporation may be the best when light component concentration is around 50% due to the strongest puffing and micro-explosion. The water droplets in emulsified fuel are slightly superheated by 0–30 °C when micro-explosion occurs. Nanoparticles could enhance droplet evaporation at low concentrations (0–1.25%) but inhibit droplet evaporation at higher concentrations. Finally, future research directions of fuel droplets are elaborated. More advanced experimental and numerical methods should be developed. Meanwhile, investigations on droplet evaporation should be combined with spray and combustion.
Wee, CK, Zhou, X, Gururajan, R, Tao, X, Chen, J, Gururajan, R, Wee, N & Barua, PD 2022, 'Notice of Removal: Automated Triaging Medical Referral for Otorhinolaryngology Using Data Mining and Machine Learning Techniques', IEEE Access, vol. 10, pp. 44531-44548.
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Wei, W, Shi, X, Wu, L, Liu, X & Ni, B-J 2022, 'Calcium peroxide pre-treatment improved the anaerobic digestion of primary sludge and its co-digestion with waste activated sludge', Science of The Total Environment, vol. 828, pp. 154404-154404.
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Primary sludge (PS) and Waste activated sludge (WAS) as two main sludge streams in wastewater treatment plants are commonly anaerobically co-digested, which though may be differently affected by pretreatment. Previous work has found that calcium peroxide (CaO2) pretreatment effectively enhanced anaerobic digestion of WAS. However, the feasibilities of this strategy on PS anaerobic digestion and co-digestion of WAS and PS are still unclear. Herein, this work provided new insights into these systems. Biomethane potential test demonstrated that CaO2 pretreatment at 0.02-0.26 g/g-volatile suspended solids (VSS) promoted anaerobic digestion of PS. Then the feasibility of CaO2 pretreatment for improving anaerobic co-digestion of PS and WAS mixture was confirmed, with the highest improvement in methane production, VSS destruction and sludge reduction being approximately 37.4%, 38.9% and 19.9%, achieved at 0.14 g/g-VSS of CaO2. Process modelling analysis revealed that CaO2 pretreatment increased both degradable faction and actually degraded fraction in sludge mixture. The changes of sludge characteristics via pretreatment and key enzyme activity in sludge anaerobic co-digestion system demonstrated that increased CaO2 concentration resulted in increased soluble organics release from sludge mixture in the pretreatment stage and inhibited activity of coenzyme F420 responsible for methanogenesis. Further mechanism investigation disclosed that OH-, O2- and OH were main contribution factors, and the order of their contributions were OH- >O2- >OH. This work laid the theoretical foundation and provided guidance for the practical application of CaO2 pre-treatment technology.
Wei, W, Wang, C, Shi, X, Zhang, Y-T, Chen, Z, Wu, L & Ni, B-J 2022, 'Multiple microplastics induced stress on anaerobic granular sludge and an effectively overcoming strategy using hydrochar', Water Research, vol. 222, pp. 118895-118895.
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Previous studies mostly focused on the responses of anaerobic granular sludge (AGS) to one kind of microplastics during wastewater treatment. However, a wide variety of microplastics has been detected in wastewater. The multiple microplastics induced stress on AGS and the effectively mitigating strategy still remain unavailable. Herein, this work comprehensively excavated the influences of multiple microplastics (i.e., polyethylene terephthalate (PET), polystyrene (PS), polyethylene (PE) and polypropylene (PP)) coexisting in the wastewater on AGS system from macroscopic to microcosmic aspects. Experimental results illustrated that microplastics decreased AGS granule size, increased cell inactivation and caused deteriorative methane recovery from wastewater. As such, this study then put great emphasis on proposing a mitigating strategy using hydrochar and disclosing the role of hydrochar in overcoming the stress induced by coexisting microplastics to AGS system. Physiological characterization and microbial community analysis demonstrated that hydrochar effectively mitigated the reductions in methane production by 50.6% and cell viability by 68.8% of microplastics-bearing AGS and reduced the toxicity of microplastics to microbial community in the AGS. Mechanisms investigation by fluorescence tagging and excitation emission matrix fluorescence spectroscopy with fluorescence regional integration (EEM-FRI) analysis revealed that hydrochar adsorbed/accumulated microplastics and enhanced microplastics-bearing AGS to secrete extracellular polymeric substance (EPS) with more humic acid generation, thus reducing the direct contact between microplastics and AGS. In addition, hydrochar weakened the AGS intracellular oxidative stress induced by microplastics, thereby completely eliminating the inhibition of microplastics on acidification efficiency of AGS, and partially mitigating the suppression on methanation.
Wei, W, Zhang, Y-T, Wang, C, Guo, W, Ngo, HH, Chen, X & Ni, B-J 2022, 'Responses of anaerobic hydrogen-producing granules to acute microplastics exposure during biological hydrogen production from wastewater', Water Research, vol. 220, pp. 118680-118680.
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Anaerobic hydrogen-producing granule (AHPG) has been successfully applied in hydrogen production from wastewater. While various types of microplastics in large amounts are readily detected in both municipal and industrial wastewaters, however, to date the response of AHPG to multiple coexisting microplastics in wastewater is unknown yet. Herein, this study provided a first insight into the acute exposure-response relationship between multiple coexisting microplastics and the AHPG during biological hydrogen production from wastewater. Fluorescence tagging found that many microplastics accumulated and covered on the surface of the whole granule. Morphology and particle size of microplastics-bearing AHPG were characterized by microscopic observation, showing that the shock load of microplastics in the wastewater at the studied concentrations (40 and 80 mg/L) made the granule loose and even break down with the decreased particle size. The visualization of extracellular polymeric substances (EPS) structure revealed that microplastics decreased EPS production by 8.8-16.7%. Microbial community analysis demonstrated that the acute exposure of microplastics did not drive the change in the microbial community diversity and composition. However, toxic leachates and upgraded oxidative stress induced by microplastics increased cell death up to 14.7% and decreased hydrogen production by 18.7%, when the AHPG exposed to 80 mg/L of microplastics. This work gained a new insight into the response of anaerobic microorganisms to coexisting microplastics in the real environment.
Wei, Y, Jiang, W, Liu, Y, Bai, X, Hao, D & Ni, B-J 2022, 'Recent advances in photocatalytic nitrogen fixation and beyond', Nanoscale, vol. 14, no. 8, pp. 2990-2997.
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The traditional synthesis of ammonia is an industrial process with high energy consumption that is not environmentally friendly; thus, it is urgent to develop cost-effective approaches to synthesize ammonia under ambient conditions.
Weidner, E, Karbassiyazdi, E, Altaee, A, Jesionowski, T & Ciesielczyk, F 2022, 'Hybrid Metal Oxide/Biochar Materials for Wastewater Treatment Technology: A Review', ACS Omega, vol. 7, no. 31, pp. 27062-27078.
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This paper discusses the properties of metal oxide/biochar systems for use in wastewater treatment. Titanium, zinc, and iron compounds are most often combined with biochar; therefore, combinations of their oxides with biochar are the focus of this review. The first part of this paper presents the most important information about biochar, including its advantages, disadvantages, and possible modification, emphasizing the incorporation of inorganic oxides into its structure. In the next four sections, systems of biochar combined with TiO2, ZnO, Fe3O4, and other metal oxides are discussed in detail. In the next to last section probable degradation mechanisms are discussed. Literature studies revealed that the dispersion of a metal oxide in a carbonaceous matrix causes the creation or enhancement of surface properties and catalytic or, in some cases, magnetic activity. Addition of metallic species into biochars increases their weight, facilitating their separation by enabling the sedimentation process and thus facilitating the recovery of the materials from the water medium after the purification process. Therefore, materials based on the combination of inorganic oxide and biochar reveal a wide range of possibilities for environmental applications in aquatic media purification.
Wolny, A, Siewniak, A, Zdarta, J, Ciesielczyk, F, Latos, P, Jurczyk, S, Nghiem, LD, Jesionowski, T & Chrobok, A 2022, 'Supported ionic liquid phase facilitated catalysis with lipase from Aspergillus oryzae for enhance enantiomeric resolution of racemic ibuprofen', Environmental Technology & Innovation, vol. 28, pp. 102936-102936.
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Supported ionic liquid phase (SILP) was used as a carrier for lipase from Aspergillus oryzae (LAO) and used as a biocatalyst for enantiomeric resolution of racemic ibuprofen via esterification leading to (S)-(+)-ibuprofen ester. Using native form of lipase, outstanding results were achieved, obtaining (S)-(+)-ibuprofen propyl ester with enantiomeric excess (ee) of 99.9% and high conversion of racemic ibuprofen after 24 h (α=34.8%) and respectively ee = 99.9% with α=45.2% after 48 h. Several hybrid materials composited with silica and metal-based oxides including magnesium, calcium, and zirconia were evaluated as supports for LAO with various surface characteristics. The selected ionic liquid 1-methyl-3-(triethoxysilylpropyl)imidazolium bis(trifluoromethylsulfonyl)imide was immobilized via the covalent bound onto the surface of solid material and in the second step LAO was anchored. Optimized results in enantiomeric resolution of racemic ibuprofen (35.23% conversion of rac-ibuprofen after 7 days with 95% ee of ester) were obtained for SILP biocatalyst based on MgO⋅ SiO2 (1:1) (ionic liquid loading 6.79%, enzyme loading 3.96%). This is proposed as a generic approach to tailoring supported ionic liquids phase biocatalysts for industrially-relevant reactions, to generate both environmentally and economically sustainable processes.
Wong, CM, Yau, YH, Ong, HC & Chin, WM 2022, 'Study of climate change impacts on the lifespan of a bin weather data set in Senai, Malaysia', Urban Climate, vol. 44, pp. 101219-101219.
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Wu, C, Xia, Y & Bi, K 2022, 'Guest editorial', Advances in Structural Engineering, vol. 25, no. 7, pp. 1371-1372.
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Wu, F, Li, F, Zhao, X, Bolan, NS, Fu, P, Lam, SS, Mašek, O, Ong, HC, Pan, B, Qiu, X, Rinklebe, J, Tsang, DCW, Van Zwieten, L, Vithanage, M, Wang, S, Xing, B, Zhang, G & Wang, H 2022, 'Meet the challenges in the “Carbon Age”', Carbon Research, vol. 1, no. 1.
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Wu, H-L, Chong, Y-H, Ong, H-C & Shu, C-M 2022, 'Thermal stability of modified lithium-ion battery electrolyte by flame retardant, tris (2,2,2-trifluoroethyl) phosphite', Journal of Thermal Analysis and Calorimetry, vol. 147, no. 6, pp. 4245-4252.
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With the increasing awareness of green energy, electric vehicles have become the future trend, with lithium-ion batteries (LIBs) regarded as the most suitable energy storage carrier. Therefore, more and more research topics are focused on LIBs, and all parties are working hard to improve the performance of LIBs. Yet, the safety concerns caused by the failure of LIBs cannot be ignored. LIBs themselves are energetic materials, and the causes of accidents often go through multistage irreversible reactions. Several studies have also pointed out that the electrolyte has a significant correlation with the response characteristics because, in the process of LIBs thermal runaway, the electrolyte participating in the oxidation of the entire battery leads to a considerable amount of heat and even runaway reaction as well. Accordingly, it is necessary to obtain a safer electrolyte by modification. In this study, a significant flame retardant (FR) additive, tris (2,2,2-trifluoroethyl) phosphite (TTFP), is used to suppress lithium-ion battery fires or even explosions and maintain typical battery performance. The performance of the electrolyte was tested by differential scanning calorimetry and thermogravimetric analyzer, and the electrolysis was examined on liquid flash point (FP), self-extinguishing time (SET), and conductivity. During the heating process, adding TTFP to the electrolyte effectively delayed the exothermic peak, reduced the amount of heat, improved the FP, and curtailed the SET. The hazard degree of the electrolyte under high-temperature environment was much lower than before adding the additives, and the additives were finally obtained. It can conclusively prove the safety of lithium batteries without lessening the practical performance of the batteries.
Wu, L, Wang, L, Wei, W, Song, L & Ni, B 2022, 'Sulfur‐driven autotrophic denitrification of nitric oxide for efficient nitrous oxide recovery', Biotechnology and Bioengineering, vol. 119, no. 1, pp. 257-267.
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AbstractNitrous oxide (N2O) was previously deemed as a potent greenhouse gas but is actually an untapped energy source, which can accumulate during the microbial denitrification of nitric oxide (NO). Compared with the organic electron donor required in heterotrophic denitrification, elemental sulfur (S0) is a promising electron donor alternative due to its cheap cost and low biomass yield in sulfur‐driven autotrophic denitrification. However, no effort has been made to test N2O recovery from sulfur‐driven denitrification of NO so far. Therefore, in this study, batch and continuous experiments were carried out to investigate the NO removal performance and N2O recovery potential via sulfur‐driven NO‐based denitrification under various Fe(II)EDTA‐NO concentrations. Efficient energy recovery was achieved, as up to 35.5%–40.9% of NO was converted to N2O under various NO concentrations. N2O recovery from Fe(II)EDTA‐NO could be enhanced by the low bioavailability of sulfur and the acid environment caused by sulfur oxidation. The NO reductase (NOR) and N2O reductase (N2OR) were inhibited distinctively at relatively low NO levels, leading to efficient N2O accumulation, but were suppressed irreversibly at NO level beyond 15 mM in continuous experiments. Such results indicated that the regulation of NO at a relatively low level would benefit the system stability and NO removal capacity during long‐term system operation. The continuous operation of the sulfur‐driven Fe(II)EDTA‐NO‐based denitrification reduced the overall microbial diversity but enriched several key microbial community. Thauera, Thermomonas, and Arenimonas that are able to carry out sulfur‐driven autot...
Wu, L, Wang, L-K, Wei, W & Ni, B-J 2022, 'Autotrophic denitrification of NO for effectively recovering N2O through using thiosulfate as sole electron donor', Bioresource Technology, vol. 347, pp. 126681-126681.
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To reclaim nitrous oxide (N2O) as an energy resource economically, this study developed an autotrophic denitrification-based system with thiosulfate (S2O32-) and nitric oxide (NO) as electron donor and acceptor, respectively. NO from flue gases is absorbed on Fe(II)EDTA to overcome its low solubility in liquid phase by forming Fe(II)EDTA-NO. Short-term batch tests and long-term continuous experiments were conducted to investigate the N2O production profile and NO conversion efficiency from thiosulfate-based denitrification under varied Fe (II)EDTA-NO conditions (5-20 mM). Up to 39% of NO was converted to gaseous N2O at 20 mM Fe(II)EDTA-NO amid batch test due to the inhibition of key enzymatic activities by NO and the acidic conditions following thiosulfate oxidation. Higher Fe(II)EDTA-NO levels induced lower enzymatic activities with N2OR being suppressed harder than NOR. Microbial diversity was reduced in the continuous thiosulfate-driven Fe(II)EDTA-NO-based denitrification system. NO-resistant bacteria and sulfide-tolerant denitrifiers were enriched, facilitating NO conversion to N2O thereafter.
Wu, L, Wei, W, Chen, Z & Ni, B-J 2022, 'Medium-chain carboxylate productions through open-culture fermentation of organic wastes', Journal of Cleaner Production, vol. 373, pp. 133911-133911.
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The growing global demand for petroleum-derived products and alarms concerning to depletion of crude oil have encouraged the conversion of organic wastes into medium-chain fatty acids (MCFAs), the precursor molecules biofuels. To this end, anaerobic fermentation-based technology has received a great deal of interests, as such eco-friendly technique can produce these value-added chemicals efficiently and sustainably. Open-culture fermentation is preferred to generate the said carboxylates given to its lower capital and operating costs than axenic systems. However, the underlying microbial pathways and the microbial interactions are not well understood. Therefore, a comprehensive understanding of the MCFAs productions from open-culture fermentation would benefit the valorisation of wastes by forming products with higher commercial value. To this end, this review article firstly covered a systematic introduction regarding the MCFAs formations through open-culture fermentation from the aspects of metabolic platforms and competitive bio-reactions. Suitable operational conditions and challenges are then scrutinized to discuss the feasibility of up-to-date strategies towards higher productivities. The potential opportunities for improving MCFAs productions biologically are finally proposed based on the content of the review.
Wu, L, Wei, W, Liu, X, Wang, D & Ni, B-J 2022, 'Potentiality of recovering bioresource from food waste through multi-stage Co-digestion with enzymatic pretreatment', Journal of Environmental Management, vol. 319, pp. 115777-115777.
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Food waste (FW) is not only a major social, nutritional and environmental issue, but also an underutilized resource with significant energy, which has not been fully explored currently. Considering co-digestion can adjust carbon to nitrogen ratio (C/N) of the feedstock and improve the synergetic interactions among microorganisms, anaerobic co-digestion (AnCoD) is then becoming an emerging approach to achieve higher energy recovery from FW while ensuring the stability of the system. To obtain higher economic gain from such biodegradable wastes, increasing attention has been paid on optimizing the system configuration or applying enzymatic hydrolysis before digesting FW. A better understanding on the potentiality of correlating enzymatic pretreatment and AnCoD operated in various system configuration would enhance the bioresource recovery from FW and increase revenue through treating this organic waste. Specifically, the biobased chemicals outputs from FW-related co-digestion system with different configuration were firstly compared in this review. A deep discussion concerning the challenges for achieving bioresources recovery from FW co-digestion systems with enzymatic pretreatment was then given. Recommendations for future studies regarding FW co-digestion were then proposed at last.
Wu, P, Wu, C, Liu, Z, Xu, S, Li, J & Li, J 2022, 'Triaxial strength and failure criterion of ultra-high performance concrete', Advances in Structural Engineering, vol. 25, no. 9, pp. 1893-1906.
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Over the past few decades, ultra-high performance concrete (UHPC) has been widely studied and applied because of its outstanding mechanical properties. A large number of studies have been conducted on the uniaxial static and dynamic performance of UHPC materials, however, limited investigations exist on the triaxial compression properties of UHPC. In this study, 98 cylindrical samples of UHPC with different steel fiber volumetric ratios (0.0%–1.5%) were tested to investigate the triaxial behavior of UHPC under different confining pressures (0 MPa–40 MPa). The confining pressure and steel fiber contents have clear impact on the triaxial strength, failure mode, crack width, and the angle between the oblique crack and the axial direction. The triaxial compressive strength and compressive toughness of UHPC subjected to various confining pressures are obtained from the tests and discussed in the study. Based on the testing data, the triaxial compression failure criterion of UHPC is established according to the unified strength theory. Finally, the simplified empirical equations for the full stress-strain curves of UHPC specimens subjected to uniaxial and multiaxial loads are derived, and good agreement with the experimental results is achieved.
Wu, S-L, Wei, W, Wang, Y, Song, L & Ni, B-J 2022, 'Transforming waste activated sludge into medium chain fatty acids in continuous two-stage anaerobic fermentation: Demonstration at different pH levels', Chemosphere, vol. 288, no. Pt 1, pp. 132474-132474.
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Bioenergy recovery in the form of medium-chain fatty acids (MCFAs) from waste activated sludge (WAS) is increasingly attractive, which are valuable building blocks for fuel production. This study experimentally demonstrated the long-term MCFAs (C6-C8) production from WAS in two-stage anaerobic sludge fermentation at different pH conditions, using continuously operated bench-scale anaerobic reactors. The WAS was continuously converted to short chain fatty acids (SCFAs, 3500-3800 mg chemical oxygen demand (COD)/L) at the first stage via alkaline anaerobic fermentation, which was directly fed into the second stage as both substrates and inoculum for MCFAs production through chain elongation (CE). The productions of MCFAs at the second stage were continuously studied under three different pH conditions (i.e., 10, 7 and 5.5). The results demonstrated that there was no significant MCFAs production at pH 10 during the steady state, whereas the MCFAs productions were clearly observed at both pH 7 and pH 5.5, with much higher MCFAs production from WAS at pH 7 (i.e., 10.32 g COD/L MCFAs) than that at pH 5.5 (i.e., 8.73 g COD/L MCFAs) during the steady state. A higher MCFAs selectivity of 62.3% was also achieved at pH 7. The relatively lower MCFAs production and selectivity at pH 5.5 was likely due to the higher undissociated MCFAs generated at pH 5.5, which would pose toxicity impact on CE microbes and thus inhibit the CE process. Microbial community analysis confirmed that the relative abundances of CE related microbes (e.g., Clostridium sensu stricto 12 sp. and Clostridium sensu stricto 1) increased at pH 7 compared to those at pH 5.5, which enabled more efficient MCFAs production from WAS.
Wu, Z-Y, Xu, J, Wu, L & Ni, B-J 2022, 'Three-dimensional biofilm electrode reactors (3D-BERs) for wastewater treatment', Bioresource Technology, vol. 344, no. Pt B, pp. 126274-126274.
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Three-dimensional biofilm electrode reactors (3D-BERs) are highly efficient in refractory wastewater treatment. In comparison to conventional bio-electrochemical systems, the filled particle electrodes act as both electrodes and microbial carriers in 3D-BERs. This article reviews the conception and basic mechanisms of 3D-BERs, as well as their current development. The advantages of 3D-BERs are illustrated with an emphasis on the synergy of electricity and microorganisms. Electrode materials utilized in 3D-BERs are systematically summarized, especially the critical particle electrodes. The configurations of 3D-BERs and their integration with wastewater treatment reactors are introduced. Operational parameters and the adaptation of 3D-BERs to varieties of wastewater are discussed. The prospects and challenges of 3D-BERs for wastewater treatment are then presented, and the future research directions are proposed. We believe that this timely review will help to attract more attentions on 3D-BERs investigation, thus promoting the potential application of 3D-BERs in wastewater treatment.
Xie, J, Liu, C-H, Huang, Y & Mok, W-C 2022, 'Effect of sampling duration on the estimate of pollutant concentration behind a heavy-duty vehicle: A large-eddy simulation', Environmental Pollution, vol. 305, pp. 119132-119132.
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Plume chasing is cost-effective, measuring individual, on-road vehicular emissions. Whereas, wake-flow-generated turbulence results in intermittent, rapid pollutant dilution and substantial fluctuating concentrations right behind the vehicle being chased. The sampling duration is therefore one of the important factors for acquiring representative (average) concentrations, which, however, has been seldom addressed. This paper, which is based on the detailed spatio-temporal dispersion data after a heavy-duty truck calculated by large-eddy simulation (LES), examines how sampling duration affects the uncertainty of the measured concentrations in plume chasing. The tailpipe dispersion is largely driven by the jet-like flows through the vehicle underbody with approximate Gaussian concentration distribution for x ≤ 0.6h, where x is the distance after the vehicle and h the characteristic vehicle size. Thereafter for x ≥ 0.6h, the major recirculation plays an important role in near-wake pollutant transport whose concentrations are highly fluctuating and positively shewed. Plume chasing for a longer sampling duration is more favourable but is logistically impractical in busy traffic. Sampling duration, also known as averaging time in the statistical analysis, thus has a crucial role in sampling accuracy. With a longer sampling (averaging) duration, the sample mean concentration converges to the population mean, improving the sample reliability. However, this effect is less pronounced in long sampling duration. The sampling accuracy is also influenced by the locations of sampling points. For the region x > 0.6h, the sampling accuracy is degraded to a large extent. As a result, acceptable sample mean is hardly achievable. Finally, frequency analysis unveils the mechanism leading to the variance in concentration measurements which is attributed to sampling duration. Those data with frequency higher than the sampling frequency are filtered out by moving average in th...
Xing, L, Yang, J, Ni, B-J, Yang, C, Yuan, C & Li, A 2022, 'Insight into the generation and consumption mechanism of tightly bound and loosely bound extracellular polymeric substances by mathematical modeling', Science of The Total Environment, vol. 811, pp. 152359-152359.
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The quantity of tightly bound extracellular polymeric substances (TB-EPS) and loosely bound extracellular polymeric substances (LB-EPS) are recognized to be crucial for activated sludge flocculability and settleability. However, the generation and consumption mechanisms of TB-EPS and LB-EPS are vague, and there is no effective model to quantitatively predict LB-EPS and TB-EPS. In this work, a decrease in LB-EPS and TB-EPS was verified to increase the absolute value of the zeta potential and decrease the sludge settling volume, which affects the flocculation and settling performance of sludge. Hence, we comparatively developed, calibrated and validated two different mathematical model structure (named expanded unified model-TL1 and expanded unified model-TL2), aiming to systematically reveal the generation and consumption mechanism of TB-EPS and LB-EPS and quantitatively predict changes of TB-EPS and LB-EPS. On the basis of microbial physiology and the existing literature, two different mechanisms of the generation and consumption of TB-EPS and LB-EPS are described. According to the validation performed, expanded unified model-TL2 fit better with experimental TB-EPS and LB-EPS, which described with the hypotheses: (i) TB-EPS and LB-EPS are simultaneously generated while activate biomass growth on external substrate, (ii) LB-EPS can also be hydrolyzed by TB-EPS, and (iii) Biomass-associated products (BAP) are hydrolyzed by LB-EPS, and it was further proven to be more realistic from the perspective of microbial physiology. This study systematically revealed the generation and consumption mechanism of TB-EPS and LB-EPS by mathematical modeling, and provides a basis for regulating the concentrations of them to improve sludge settling capacity and system stability.
Xing, L, Yang, J, Zhang, Y, Ni, B-J, Yang, C, Yuan, C & Li, A 2022, 'Model-based evaluation of the impacts of aeration on tightly bound and loosely bound extracellular polymeric substance production under non-steady-state conditions', Science of The Total Environment, vol. 852, pp. 158566-158566.
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Tightly bound extracellular polymeric substances (TB-EPS) and loosely bound extracellular polymeric substances (LB-EPS) affect the flocculability and settleability of sludge and the transfer of oxygen, which are highly related to aeration. In this study, we systemically evaluated the expanded unified model-TL2.1 for its long-term simulation of TB-EPS and LB-EPS. Two different aeration conditions and three different influent carbon sources were used to evaluate the model, and the simulation results fit well with the experimental data. TB-EPS and LB-EPS production increased with aeration intensity. The influence of aeration parameters on TB-EPS and LB-EPS production in a short-term batch system and long-term sequencing batch reactor (SBR) system was compared. The aeration parameters included the total transfer coefficient (kLa) and the concentration of dissolved oxygen at the interface (CS). To ensure a high removal rate of substrates and ammonia nitrogen and achieve a stable active biomass concentration, the following aeration parameters can be adopted to reduce energy wastage during aeration: when CS is 2 mg/L, kLa can be set above 30 h-1 and below 50 h-1; when kLa is 50 h-1, CS can be set above 1 mg/L and below 1.5 mg/L. This study systematically revealed the influence of aeration on TB-EPS and LB-EPS formation in an SBR system through a mathematical model, and it provides a theoretical basis for better understanding aeration.
Xu, B, Qiu, W, Du, J, Wan, Z, Zhou, JL, Chen, H, Liu, R, Magnuson, JT & Zheng, C 2022, 'Translocation, bioaccumulation, and distribution of perfluoroalkyl and polyfluoroalkyl substances (PFASs) in plants', iScience, vol. 25, no. 4, pp. 104061-104061.
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Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are persistent in the environment and have been detected in a variety of plants such as vegetables, cereals, and fruits. Increasing evidence shows that plants are at a risk of being adversely affected by PFASs. This review concludes that PFASs are predominantly absorbed by roots from sources in the soil; besides, the review also discusses several factors such as soil properties and the species of PFASs and plants. In addition, following uptake by root, long-chain PFASs (C ≥ 7 for PFCA and C ≥ 6 for PFSA) were preferentially retained within the root, whereas the short-chain PFASs were distributed across tissues above the ground - according to the studies. The bioaccumulation potential of PFASs within various plant structures are further expressed by calculating bioaccumulation factor (BAF) across various plant species. The results show that PFASs have a wide range of BAF values within root tissue, followed by straw, and then grain. Furthermore, owing to its high water solubility than other PFASs, PFOA is the predominant compound accumulated in both the soil itself and within the plant tissues. Among different plant groups, the potential BAF values rank from highest to lowest as follows: leaf vegetables > root vegetables > flower vegetables > shoot vegetables. Several PFAS groups such as PFOA, PFBA, and PFOS, may have an increased public health risk based on the daily intake rate (ID). Finally, future research is suggested on the possible PFASs degradation occurring in plant tissues and the explanations at genetic-level for the metabolite changes that occur under PFASs stress.
Xu, B-H, Indraratna, B, Rujikiatkamjorn, C & Trung Nguyen, T 2022, 'A large-strain radial consolidation model incorporating soil destructuration and isotache concept', Computers and Geotechnics, vol. 147, pp. 104761-104761.
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Xu, R-Z, Cao, J-S, Feng, G, Luo, J-Y, Feng, Q, Ni, B-J & Fang, F 2022, 'Fast identification of fluorescent components in three-dimensional excitation-emission matrix fluorescence spectra via deep learning', Chemical Engineering Journal, vol. 430, pp. 132893-132893.
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Three-dimensional excitation-emission matrix (3D-EEM) fluorescence spectroscopy has been widely applied to detect the fluorescent components in samples from natural water bodies to wastewater treatment processes. Data interpretation methods such as parallel factor analysis (PARAFAC) are required to decompose the overlapped fluorescent signals in the 3D-EEM spectra. However, strict requirements of data and complicated procedures of the PARAFAC limit the online monitoring and analysis of samples. Here we develop a fast fluorescent identification network (FFI-Net) model based on the deep learning approach to fast predict the numbers and maps of fluorescent components by simply inputting a single 3D-EEM spectrum. Two types of convolutional neural networks (CNN) are trained to classify the numbers of fluorescent components with an accuracy of 0.956 and predict the maps of fluorescent components with the min mean absolute error of 8.9 × 10-4. We demonstrate that the accuracy of the FFI-Net model will be further improved when more 3D-EEM data are available as a training dataset. Meanwhile, a user-friendly interface is designed to facilitate practical applications. Our approach gives a robust way to overcome the shortage of the PARAFAC and provides a new platform for online analysis of the fluorescent components in water samples.
Xu, R-Z, Cao, J-S, Luo, J-Y, Feng, Q, Ni, B-J & Fang, F 2022, 'Integrating Mechanistic and Deep Learning Models for Accurately Predicting the Enrichment of Polyhydroxyalkanoates Accumulating Bacteria in Mixed Microbial Cultures', Bioresour Technol, vol. 344, no. Pt B, pp. 126276-126276.
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The enrichment of polyhydroxyalkanoates (PHA) accumulating bacteria (PAB) in mixed microbial cultures (MMC) is extremely difficult to be predicted and optimized. Here we demonstrate that mechanistic and deep learning models can be integrated innovatively to accurately predict the dynamic enrichment of PAB. Well-calibrated activated sludge models (ASM) of the PAB enrichment process provide time-dependent data under different operating conditions. Recurrent neural network (RNN) models are trained and tested based on the time-dependent dataset generated by ASM. The accurate prediction performance is achieved (R2 > 0.991) for three different PAB enrichment datasets by the optimized RNN model. The optimized RNN model can also predict the equilibrium concentration of PAB (R2 = 0.944) and corresponding time, which represents the end of the PAB enrichment process. This study demonstrates the strength of integrating mechanistic and deep learning models to predict long-term variations of specific microbes, helping to optimize their selection process for PHA production.
Xu, R-Z, Cao, J-S, Ye, T, Wang, S-N, Luo, J-Y, Ni, B-J & Fang, F 2022, 'Automated machine learning-based prediction of microplastics induced impacts on methane production in anaerobic digestion', Water Research, vol. 223, pp. 118975-118975.
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Microplastics as emerging pollutants have been heavily accumulated in the waste activated sludge (WAS) during biological wastewater treatment, which showed significantly diverse impacts on the subsequent anaerobic sludge digestion for methane production. However, a robust modeling approach for predicting and unveiling the complex effects of accumulated microplastics within WAS on methane production is still missing. In this study, four automated machine learning (AutoML) approach was applied to model the effects of microplastics on anaerobic digestion processes, and integrated explainable analysis was explored to reveal the relationships between key variables (e.g., concentration, type, and size of microplastics) and methane production. The results showed that the gradient boosting machine had better prediction performance (mean squared error (MSE) = 17.0) than common neural networks models (MSE = 58.0), demonstrating that the AutoML algorithms succeeded in predicting the methane production and could select the best machine learning model without human intervention. Explainable analysis results indicated that the variable of microplastic types was more important than the variable of microplastic diameter and concentration. The existence of polystyrene was associated with higher methane production, whereas increasing microplastic diameter and concentration both inhibited methane production. This work also provided a novel modeling approach for comprehensively understanding the complex effects of microplastics on methane production, which revealed the dependence relationships between methane production and key variables and may be served as a reference for optimizing operational adjustments in anaerobic digestion processes.
Xu, S, Faust, O, Seoni, S, Chakraborty, S, Barua, PD, Loh, HW, Elphick, H, Molinari, F & Acharya, UR 2022, 'A review of automated sleep disorder detection', Computers in Biology and Medicine, vol. 150, pp. 106100-106100.
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Automated sleep disorder detection is challenging because physiological symptoms can vary widely. These variations make it difficult to create effective sleep disorder detection models which support hu-man experts during diagnosis and treatment monitoring. From 2010 to 2021, authors of 95 scientific papers have taken up the challenge of automating sleep disorder detection. This paper provides an expert review of this work. We investigated whether digital technology and Artificial Intelligence (AI) can provide automated diagnosis support for sleep disorders. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines during the content discovery phase. We compared the performance of proposed sleep disorder detection methods, involving differ-ent datasets or signals. During the review, we found eight sleep disorders, of which sleep apnea and insomnia were the most studied. These disorders can be diagnosed using several kinds of biomedical signals, such as Electrocardiogram (ECG), Polysomnography (PSG), Electroencephalogram (EEG), Electromyogram (EMG), and snore sound. Subsequently, we established areas of commonality and distinctiveness. Common to all reviewed papers was that AI models were trained and tested with labelled physiological signals. Looking deeper, we discovered that 24 distinct algorithms were used for the detection task. The nature of these algorithms evolved, before 2017 only traditional Machine Learning (ML) was used. From 2018 onward, both ML and Deep Learning (DL) methods were used for sleep disorder detection. The strong emergence of DL algorithms has considerable implications for future detection systems because these algorithms demand significantly more data for training and testing when compared with ML. Based on our review results, we suggest that both type and amount of labelled data is crucial for the design of future sleep disorder detection systems because this will steer the choice of...
Xu, S, He, R, Zhao, S, Shon, HK & He, T 2022, 'Is conductivity measurement or inductively coupled plasma-atomic emission spectrometry reliable to define rejection of different ions?', Desalination, vol. 543, pp. 116097-116097.
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Rejection of single salts or ions is a basic and crucial characteristic of nanofiltration (NF) membranes. The simple and most pursued method to quantify the salt concentration has been via conductivity measurement. Pitfalls exist when ions hydrolysis or feed water contains monovalent ions. This could be explained in two possible scenarios: (1) easily hydrolyzed single salts form low charged ions and reduce feed pH, resulting in increased permeate conductivity and low nominal rejection; (2) for membranes with high multivalent ion rejections (>99%) or the concentration of target ions in feed is low, conductivity measurement results in low rejection due to the passage of monovalent ions if deionized water is used for the feed solution. A correction formula by subtracting the concentration of monovalent ions in water to obtain an accurate rejection value is proposed. This work provides an accurate, simple and robust evaluation of rejection for NF membranes, which promotes fair comparison of performance in literature, reliable analysis of separation mechanisms as well as a precise determination of product purity.
Xu, S, Yang, Y, Wu, C & Liu, K 2022, 'Electromagnetic wave absorption performance of UHPC incorporated with carbon black and carbon fiber', Archives of Civil and Mechanical Engineering, vol. 22, no. 2.
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This study focuses on the electromagnetic wave absorption performance (EWAP) of ultra-high-performance concrete (UHPC) incorporated with carbon black (CB) and carbon fiber (CF) in 2–18 GHz frequency range (required for the radar wave absorbing materials). The reflectivity of the traditional UHPC was investigated and compared to the cement-based composites reported in the literatures, so as to illustrate the advantages of novel UHPCs with respect to EWAP. Afterwards, the effect of CB and CF on the compressive strength, complex permittivity and reflectivity of the novel UHPCs was investigated. The microstructure of the novel UHPCs was also explored via scanning electron microscopy to illustrate the mechanism of performance enhancement on incorporating CB and CF. The results indicated that EWAP of the traditional UHPC was similar or inferior (at specific frequencies) to the literature reported cement-based composites. However, EWAP of the novel UHPCs was significantly improved after reinforcing with CB or CF. A positive effect of CB and CF was also observed on the compressive strength of the developed UHPCs. This study provides avenues for the use of UHPCs in protecting structures for absorbing the electromagnetic waves and safeguarding these structures against extreme loads, including blast and penetration.
Xu, T, Yang, G, Li, Y & Lai, T 2022, 'Influence of inerter‐based damper installations on control efficiency of building structures', Structural Control and Health Monitoring, vol. 29, no. 5.
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Xu, X, Xu, G, Chen, J, Liu, Z, Chen, X, Zhang, Y, Fang, J & Gao, Y 2022, 'Multi-objective design optimization using hybrid search algorithms with interval uncertainty for thin-walled structures', Thin-Walled Structures, vol. 175, pp. 109218-109218.
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Xu, X, Zhang, Y, Fang, J, Chen, X, Liu, Z, Xu, Y & Gao, Y 2022, 'Axial mechanical properties and robust optimization of foam-filled hierarchical structures', Composite Structures, vol. 289, pp. 115501-115501.
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Xu, X, Zhang, Y, Wang, X, Fang, J, Chen, J & Li, J 2022, 'Searching superior crashworthiness performance by constructing variable thickness honeycombs with biomimetic cells', International Journal of Mechanical Sciences, vol. 235, pp. 107718-107718.
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Xu, Y, Gao, Y, Wu, C, Fang, J, Sun, G, Steven, GP & Li, Q 2022, 'Concurrent optimization of topological configuration and continuous fiber path for composite structures — A unified level set approach', Computer Methods in Applied Mechanics and Engineering, vol. 399, pp. 115350-115350.
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This study proposes a novel topology optimization approach for design of continuous steering fiber path for composite structures using a level set method. The radial basis function (RBF) is employed to construct the level set function (LSF). Fiber orientations are parameterized by LSF and fiber paths can be determined instinctively for the inherent advantages of the level set approach. Besides, the fast-marching method is employed to extrapolate the primary fiber paths to the secondary fiber paths, which can avoid the manufacturing drawbacks such as gaps and overlaps to a large extent. A detection and filtering technique is proposed here to alleviate the orientation disorder at the intersection of the diffusion surfaces. Two design schemes are developed to optimize both structural topology and fiber path. In a sequential procedure, topology optimization is conducted first with isotropic materials; and then fiber paths are optimized on the basis of fixed topological boundary. In a simultaneous optimization procedure, structural boundaries and fiber paths are optimized alternately through two inner loops. In this study, three numerical examples are presented to demonstrate the effectiveness of the proposed methods, and the results show that optimization of fiber path is beneficial to improvement of structural performance. In general, the simultaneous optimization scheme exhibits better optimal outcome in comparison with the sequential optimization scheme.
Xu, Z, Khabbaz, H, Fatahi, B & Wu, D 2022, 'Real-time determination of sandy soil stiffness during vibratory compaction incorporating machine learning method for intelligent compaction', Journal of Rock Mechanics and Geotechnical Engineering, vol. 14, no. 5, pp. 1609-1625.
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An emerging real-time ground compaction and quality control, known as intelligent compaction (IC), has been applied for efficiently optimising the full-area compaction. Although IC technology can provide real-time assessment of uniformity of the compacted area, accurate determination of the soil stiffness required for quality control and design remains challenging. In this paper, a novel and advanced numerical model simulating the interaction of vibratory drum and soil beneath is developed. The model is capable of evaluating the nonlinear behaviour of underlying soil subjected to dynamic loading by capturing the variations of damping with the cyclic shear strains and degradation of soil modulus. The interaction of the drum and the soil is simulated via the finite element method to develop a comprehensive dataset capturing the dynamic responses of the drum and the soil. Indeed, more than a thousand three-dimensional (3D) numerical models covering various soil characteristics, roller weights, vibration amplitudes and frequencies were adopted. The developed dataset is then used to train the inverse solver using an innovative machine learning approach, i.e. the extended support vector regression, to simulate the stiffness of the compacted soil by adopting drum acceleration records. Furthermore, the impacts of the amplitude and frequency of the vibration on the level of underlying soil compaction are discussed. The proposed machine learning approach is promising for real-time extraction of actual soil stiffness during compaction. Results of the study can be employed by practising engineers to interpret roller drum acceleration data to estimate the level of compaction and ground stiffness during compaction.
Xu, Z, Li, J, Qian, H & Wu, C 2022, 'Blast resistance of hybrid steel and polypropylene fibre reinforced ultra-high performance concrete after exposure to elevated temperatures', Composite Structures, vol. 294, pp. 115771-115771.
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In this study, the blast resistance of fibre reinforced ultra-high performance concrete (UHPC) components after exposure to elevated temperatures was investigated. With a hybrid steel and polypropylene (PP) fibre reinforcement, this fire resistant UHPC maintained approximately 60% of its original compressive strength after exposed to 800 °C temperature. Uniaxial and triaxial material behaviour after exposure to high temperatures was studied experimentally and then incorporated into a plasticity concrete model, i.e. Karagozian & Case Concrete (KCC model) model for the blast induced structural response analysis. Material strength and failure surfaces, volumetric change with pressure, strain rate effect and material damage parameters were updated with consideration of fire hazards. The simulated UHPC uniaxial stress–strain curves after exposure to 200, 400, 600 and 800 °C elevated temperatures, together with the simulated post-fire blast tests results on UHPC members were compared with available experimental results. The reasonable agreement between the tests and simulation results validated the proposed model in both material and structural scopes. The numerical model was further applied to predict the blast response of reinforced UHPC components after exposed to thermal hazards.
Xu, Z, Ma, Y, Li, Y, Li, G, Nghiem, L & Luo, W 2022, 'Comparison between Cold Plasma, Ultrasonication, and Alkaline Hydrogen Peroxide Pretreatments of Garden Waste to Enhance Humification in Subsequent Composting with Kitchen Waste: Performance and Mechanisms', Bioresour Technol, vol. 354, p. 127228.
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This study compared the performance and mechanisms of cold plasma, ultrasonication, and alkali-assisted hydrogen peroxide for garden waste pretreatment to advance humification in composting with kitchen waste. High-throughput sequencing integrated with Functional Annotation of Prokaryotic Taxa was used to relate bacterial dynamics to humification. Results show that all pretreatment techniques accelerated humification by 37.5% - 45.7% during composting in comparison to the control treatment. Ultrasonication and alkalization preferred to decompose lignocellulose to produce humus precursors in garden waste, thereby facilitating humus formation at the beginning of composting. By contrast, cold plasma was much faster and simpler than other pretreatment techniques to effectively disrupt the surface structure and reduce the crystallinity of garden waste to enrich functional bacteria for aerobic chemoheterotrophy, xylanolysis, cellulolysis, and ligninolysis during composting. As such, a more robust bacterial community was developed after cold plasma pretreatment to advance humification at the mature stage of composting.
Xue, C 2022, 'Cracking and autogenous self-healing on the performance of fiber-reinforced MgO-cement composites in seawater and NaCl solutions', Construction and Building Materials, vol. 326, pp. 126870-126870.
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Xue, C 2022, 'Performance and mechanisms of stimulated self-healing in cement-based composites exposed to saline environments', Cement and Concrete Composites, vol. 129, pp. 104470-104470.
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Yadav, S, Ibrar, I, Al-Juboori, RA, Singh, L, Ganbat, N, Kazwini, T, Karbassiyazdi, E, Samal, AK, Subbiah, S & Altaee, A 2022, 'Updated review on emerging technologies for PFAS contaminated water treatment', Chemical Engineering Research and Design, vol. 182, pp. 667-700.
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Yadav, S, Ibrar, I, Altaee, A, Samal, AK & Zhou, J 2022, 'Surface modification of nanofiltration membrane with kappa-carrageenan/graphene oxide for leachate wastewater treatment', Journal of Membrane Science, vol. 659, pp. 120776-120776.
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Yadav, S, Ibrar, I, Altaee, A, Samal, AK, Karbassiyazdi, E, Zhou, J & Bartocci, P 2022, 'High-Performance mild annealed CNT/GO-PVA composite membrane for brackish water treatment', Separation and Purification Technology, vol. 285, pp. 120361-120361.
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Yadav, S, Ibrar, I, Samal, AK, Altaee, A, Déon, S, Zhou, J & Ghaffour, N 2022, 'Preparation of fouling resistant and highly perm-selective novel PSf/GO-vanillin nanofiltration membrane for efficient water purification', Journal of Hazardous Materials, vol. 421, pp. 126744-126744.
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To meet the rising global demand for water, it is necessary to develop membranes capable of efficiently purifying contaminated water sources. Herein, we report a series of novel polysulfone (PSf)/GO-vanillin nanofiltration membranes highly permeable, selective, and fouling resistant. The membranes are composed of two-dimensional (2D) graphite oxide (GO) layers embedded with vanillin as porogen and PSf as the base polymer. There is a growing interest in addressing the synergistic effect of GO and vanillin on improving the permeability and antifouling characteristics of membranes. Various spectroscopic and microscopic techniques were used to perform detailed physicochemical and morphological analyses. The optimized PSf16/GO0.15-vanillin0.8 membrane demonstrated 92.5% and 25.4% rejection rate for 2000 ppm magnesium sulphate (MgSO4) and sodium chloride (NaCl) solutions respectively. Antifouling results showed over 99% rejection for BSA and 93.57% flux recovery ratio (FRR). Experimental work evaluated the antifouling characteristics of prepared membranes to treat landfill leachate wastewater. The results showed 84-90% rejection for magnesium (Mg+2) and calcium (Ca+2) with 90.32 FRR. The study experimentally demonstrated that adding GO and vanillin to the polymeric matrix significantly improves fouling resistance and membrane performance. Future research will focus on molecular sieving for industrial separations and other niche applications using mixed matrix membranes.
Yang, F, Zhang, X, Zhao, Z, Guo, W & Ngo, HH 2022, 'Fate of typical organic halogen compounds in the coexistence of endogenic chlorine atoms and exogenic X-', Chemosphere, vol. 309, pp. 136761-136761.
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Yang, G, Qin, L, Li, M, Ou, K, Fang, J, Fu, Q & Sun, Y 2022, 'Shear-induced alignment in 3D-printed nitrile rubber-reinforced glass fiber composites', Composites Part B: Engineering, vol. 229, pp. 109479-109479.
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Nitrile rubber composite with aligned glass fibers (GFs/NBR composites) were prepared by direct-ink-writing (DIW) technology for application in flexible thermal management of electronic equipment.The alignment and orientation (0°, 45° and 90°) of glass fibers was precisely tuned by shear force field and 3D printing direction. Furthermore, the effect of print direction on the mechanical properties, thermal conductivity and heat dissipation performance were investigated. The tensile strength (1.78 MPa) and thermal conductivity (1.2 W m−1 K−1) of GFs/NBR composites with a 90° orientation was improved to be 149.6% and 300% compared to the composites with disordered orientation, respectively. The temperature of LED device and computer’ CPU covered with GFs/NBR composites with a 90° orientation was reduced by ca. 8.1 °C and 4.1 °C, respectively. The study confirmed the formation of GFs/NBR composites with controlled alignment and orientation for various applications.
Yang, M, Zhang, X, Yang, Y, Liu, Q, Nghiem, LD, Guo, W & Ngo, HH 2022, 'Effective destruction of perfluorooctanoic acid by zero-valent iron laden biochar obtained from carbothermal reduction: Experimental and simulation study', Science of The Total Environment, vol. 805, pp. 150326-150326.
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This study investigated the degradation of perfluorooctanoic acid (PFOA) on zerovalent iron-laden biochar (BC-ZVI) prepared by carbothermal reduction. Results show that over 99% PFOA can be removed by BC-ZVI in hydrothermal conditions under 240 °C within 6 h. The maximum defluorination rate of 63.2% was achieved after 192 h, and this outcome was significantly better than biochar (BC) and zero-valent iron (ZVI) alone. The short-chain perfluorinated compounds (PFCs) and perfluoroheptanal were detected in the liquid phase after degradation, suggesting that the degradation of PFOAs by BC-ZVI followed the Kobel decarboxylation process. XRD and SEM-EDS analyses strongly suggested that carbothermal reduction could avoid the agglomeration of ZVI loaded onto biochar, which helped make the PFOA degradation more efficient. The frontier molecular orbital theory calculated by density functional theory revealed there were two possibilities for ZVI loading on BC (edged or internal loading), while the edge loaded ZVI had a greater tendency to provide electrons for the defluorination of PFOA than internally loaded ZVI.
Yang, T, Xu, S, Liu, Z, Li, J, Wu, P, Yang, Y & Wu, C 2022, 'Experimental and numerical investigation of bond behavior between geopolymer based ultra-high-performance concrete and steel bars', Construction and Building Materials, vol. 345, pp. 128220-128220.
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In this study, a total of twenty groups of specimens were tested to investigate bond behavior between the geopolymer based ultra-high-performance concrete (G-UHPC) and steel bars. The failure modes and bond stress-slip relationships were analyzed and discussed in detail. Subsequently, a detailed 3D numerical model was developed and validated against the experimental findings. The validated numerical model was then employed to perform parametric studies to evaluate the effects of steel strength, bond length, and protective layer thickness on the bond behavior between G-UHPC and the steel bar. It was revealed that the bond strength between the steel bar and G-UHPC was enhanced upon increasing the steel bar strength and protective layer thickness, along with reducing the steel bar diameter. The bond slip decreased with an increase in the steel fiber length and volume fraction. Further, the protective layer thickness exhibited an insignificant effect on the linear ascending stage of the bond stress-slip relationships, but positively impacted the maximum bond strength of the specimen. Finally, a bond stress-slip constitutive model was proposed to precisely predict the bond behavior between G-UHPC and the steel bars.
Yang, X, Hsia, T, Merenda, A, AL-Attabi, R, Dumee, LF, Thang, SH & Kong, L 2022, 'Constructing novel nanofibrous polyacrylonitrile (PAN)-based anion exchange membrane adsorber for protein separation', Separation and Purification Technology, vol. 285, pp. 120364-120364.
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Purification of biopharmaceutical streams is essential for producing high quality therapeutic bioproducts. This work developed a novel polyacrylonitrile (PAN)-based nanofibrous membrane with strong anion exchange functionality via electrospinning. The key material functionality was obtained via RAFT copolymerization of acrylonitrile and dimethylaminoethyl acrylate (pAD), followed by quaternization to form quaternary amine (QA) ligands, namely pAQ, a series of nanofibrous PAN-pAQ membranes were electrospun by blending the pAQ copolymer with PAN homopolymer at varying ratios. The chemistry of the respective pAQ copolymer and resulting membranes was confirmed by NMR and FTIR, evidencing successful functionalization. As compared to the reference pure membrane PAN4 that was negatively charged, the resulting composite membranes showed a positive surface charge. The investigation on surface morphology revealed that the nanofiber diameter increased from 300 nm to 1 μm with an increasing blend ratio from 1:4 to 1:7 for the PAN-pAQ membranes. Such trend in surface micro/nano morphology changes strongly influenced other surface properties such as increased pore size, reduced specific surface area and increased hydrophobicity. The static binding of model protein BSA of PAN-pAQ membranes firstly increased with blend ratio from 1:4 to 1:5, and then decreased at 1:7, which was attributed to the complex trade-off relationship between surface micro/nano-structure and hence distribution/density of quaternary functional groups. The PAN-pAQ membranes showed about a 10-fold increase in static binding capacity compared to PAN4, up to 310–320 mg·g−1 at a blend ratio of 1:5. Thus through this study, we were able to demonstrate a facile route to incorporate pre-functionalized copolymers into conventional polymers to form chromatographic membranes, with many possibilities to tailor membrane functionality for a wide range of applications.
Yang, X, Merenda, A, AL-Attabi, R, Dumée, LF, Zhang, X, Thang, SH, Pham, H & Kong, L 2022, 'Towards next generation high throughput ion exchange membranes for downstream bioprocessing: A review', Journal of Membrane Science, vol. 647, pp. 120325-120325.
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Membrane chromatography is recognised as a potential solution to streamline downstream processing for protein purification, where ion exchange membrane chromatography (IEMC) as a polishing step to remove impurities has been successfully demonstrated in small scales. Despite limited commercial adoption in large-scale production, the concept of IEMC attracts many interests and tremendous progress is made. To fill the review gap for advancements in the last decade, this article provides a timely analysis on key performance-determining aspects in IEMC systems. Modern laboratory-made membranes with polymeric chains of tuneable surface area and charge allow for high binding capacity (up to 10-fold higher than that of traditional resins) while simultaneously mitigating the loss of permeance due to the introduction of grafted layers up to 40%. Nevertheless, robust evaluation are yet to be conducted. Despite making equal contribution to binding, the review on process-related work was supported by only <1/3 of the cited articles, where a transition of empirical to mechanistic models was identified, enabling rationale system design and upscaling. The use of molecular simulation into binding studies reveals the roles of membrane properties but limited work was found. While highlighting disconnection between academic and commercial efforts, research gaps for future work were identified.
Yang, X, Zhang, X, Ngo, HH, Guo, W, Huo, J, Du, Q, Zhang, Y, Li, C & Yang, F 2022, 'Sorptive removal of ibuprofen from water by natural porous biochar derived from recyclable plane tree leaf waste', Journal of Water Process Engineering, vol. 46, pp. 102627-102627.
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To remove ibuprofen (IBP) in water efficiently and economically, plane tree leaf-derived biochar (P-BC) as a new adsorbent was prepared via pyrolysis at 600 °C. Textural characterizations of P-BC exhibited a porous structure and abundant hydroxyl groups. The results of FTIR and XPS indicated that -OH functional groups played a key role in the adsorption process. Batch adsorption studies were carried out at pH values of 2 to 8, adsorbent dosage of 0.1 to 2.0 g/L and initial concentrations of 500 to 5000 μg/L. Adsorption results showed that P-BC (1.0 g/L) could remove as much as 96.34% of ibuprofen (2000 μg/L) in a strong acidic environment (i.e. pH 2). The adsorption of ibuprofen by P-BC was found to be more consistent with the pseudo-second order kinetic model and Langmuir isothermal model with higher correlation coefficients of 0.999 and 0.996, respectively. Its maximum adsorption capacity was up to 10,410 μg/g. A mechanism analysis demonstrated that the -OH functional groups on the surface of P-BC could form hydrogen bonds with IBP as donors and acceptors, respectively. It played a predominant role in removing IBP. In particular the fabricated P-BC is an effective and recyclable sorbent and its efficiency in removing ibuprofen can still reach more than 70% after five regenerations. The total production cost of P-BC is 4.05 USD / kg, which is equivalent to the treatment cost of only 0.004 USD/L wastewater. The results revealed that P-BC is an environment-friendly, low-cost and efficient adsorbent for removing IBP from water.
Yang, Y, Liu, S, Dong, Z, Huang, Z, Lu, C, Wu, Y, Gao, M, Liu, Y & Pan, H 2022, 'Hierarchical conformal coating enables highly stable microparticle Si anodes for advanced Li-ion batteries', Applied Materials Today, vol. 26, pp. 101403-101403.
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Microsized silicon powders have great potential for high capacity anode materials in next-generation lithium ion batteries, because of the high gravimetric and volumetric energy densities, ease of mass production and low costs. However, large volume change and consequently rapid capacity fading upon lithiation and delithiation prevent its practical applications. Herein, we demonstrate an effective hierarchical conformal coating strategy for high-performance microsized Si anodes. The Si-based composites consist of an amorphous Li-Si-O inner coating layer and a graphene outer encapsulation layer, which are prepared by coupling reactive milling with electrostatic self-assembly. This unique hierarchical conformal coating structure not only strengthens the mechanical property (31.8 GPa for the elastic modulus) and promotes the ionic diffusion (2.03 × 10−10 cm2 s−1) of Si anode, but also effectively stabilizes the electrode/electrolyte interfaces and increases the electronic conductivity. As a result, a high reversible capacity (1450 mA⋅h g−1 at 0.1 A g−1), good cycling stability (97.7% of capacity retention from the 2nd to the 310th cycle at 0.5 A g−1), and high rate capability (703 mA⋅h g−1 at 5 A g−1) have been successfully achieved. These findings provide new insights into the improvement of electrochemical properties of microsized Si composite anodes for high-performance Li-ion batteries.
Yang, Y, Phuong Nguyen, TM, Van, HT, Nguyen, QT, Nguyen, TH, Lien Nguyen, TB, Hoang, LP, Van Thanh, D, Nguyen, TV, Nguyen, VQ, Thang, PQ, Yılmaz, M & Le, VG 2022, 'ZnO nanoparticles loaded rice husk biochar as an effective adsorbent for removing reactive red 24 from aqueous solution', Materials Science in Semiconductor Processing, vol. 150, pp. 106960-106960.
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Yang, Y, Wu, C, Liu, Z & Zhang, H 2022, '3D-printing ultra-high performance fiber-reinforced concrete under triaxial confining loads', Additive Manufacturing, vol. 50, pp. 102568-102568.
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3D-printing concrete structural members may experience complex stress states, while external reinforcement (wrapping steel tube or fiber-reinforced polymer) may be one of the effective ways to improve performance. Therefore, triaxial mechanical properties of 3D-printing concrete should be explored. This study presents an experimental investigation of the triaxial behavior of 3D-printing ultra-high performance fiber-reinforced concrete (3DP-UHPFRC) loaded in the Z-direction. Mold-casting ultra-high performance fiber reinforced concrete (MC-UHPFRC) was used as the reference specimen. Based on the test data, the failure mode and mechanical properties of the 3D-printing specimens were analyzed, and the failure criteria were explored. The experimental results showed that 3DP-UHPFRC possessed triaxial failure modes, mechanical properties, and failure criteria as MC-UHPFRC. All 3DP-UHPFRC specimens exhibited oblique shear cracks under triaxial compression. The fitting effect of Mohr-Coulomb failure criterion on 3D-printing specimens without steel fiber is poor (R2 is less than 0.9), which is due to the linear relationship of Mohr-Coulomb failure criterion and the obvious nonlinear increase in strength of 3D-printing specimens without steel fiber with the confining pressure, whereas the Power-law and Willam-Warnke failure criteria were good for all 3D-printing specimens. A modified model was established for predicting the stress-strain curves of 3DP-UHPFRC under triaxial confining pressure.
Yang, Y, Wu, C, Liu, Z, Li, J, Yang, T & Jiang, X 2022, 'Characteristics of 3D-printing ultra-high performance fibre-reinforced concrete under impact loading', International Journal of Impact Engineering, vol. 164, pp. 104205-104205.
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3D-printing concrete exhibits anisotropy under static loads, owing to its unique additive manufacturing process, while its dynamic performance study is still insufficient. In particular, the dynamic properties of 3D-printing ultra-high performance fibre reinforced concrete (3DP-UHPFRC) have not been studied yet. Therefore, this study explores the characteristics of 3DP-UHPFRC under impact loads using the SHPB tests. Three impact velocities of 3.886, 6.026, and 8.538 m/s were studied in the tests. The impact process was recorded by a high-speed camera. The dynamic mechanical characteristics of 3D-printing ultra-high performance concrete (3DP-UHPC) without fibre, 3DP-UHPFRC and reference specimens were investigated in terms of fibre type, fibre content, preparation method, loading direction, and impact velocity. The characteristics of strain rate, dynamic compressive stress, dynamic increase factor (DIF), energy absorption capacity and failure process were evaluated. The findings of this study indicated that the degree of failure of 3DP-UHPC was similar in all directions, while the degree of failure of 3DP-UHPFRC in all directions was different. The degree of failure in the X-direction was the worst, followed in decreasing order by the degrees of failure in the Y- and Z-directions. At the same impact velocity, the elastic modulus and strain rate effect of the 3D-printing specimens exhibited anisotropic characteristics, owing to the different elastic modulus of the 3D-printing specimens in each direction. Furthermore, the specimens were more susceptible to deformation in the X-direction than that in the Y- and Z-directions. As the impact velocity was increased, the dynamic peak stresses for 3DP-UHPFRC were isotropic at the same impact velocity, owing to the strain rate effect. Finally, the DIF of the 3D-printing specimens was observed to be anisotropic, and in the X-direction the specimens exhibited the most significant strain rate sensitivity.
Yang, Y, Wu, C, Liu, Z, Wang, H & Ren, Q 2022, 'Mechanical anisotropy of ultra-high performance fibre-reinforced concrete for 3D printing', Cement and Concrete Composites, vol. 125, pp. 104310-104310.
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Yang, Y, Zhang, X, Ngo, HH, Guo, W, Li, Z, Wang, X, Zhang, J & Long, T 2022, 'A new spent coffee grounds based biochar - Persulfate catalytic system for enhancement of urea removal in reclaimed water for ultrapure water production', Chemosphere, vol. 288, pp. 132459-132459.
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Ye, Y, Hao Ngo, H, Guo, W, Woong Chang, S, Duc Nguyen, D, Fu, Q, Wei, W, Ni, B, Cheng, D & Liu, Y 2022, 'A critical review on utilization of sewage sludge as environmental functional materials', Bioresource Technology, vol. 363, pp. 127984-127984.
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Sewage sludge (SS) is increasingly used as an environment functional material to reduce or control pollution and improve plant growth because of the large amounts of carbon and essential plant nutrients in it. To achieve the best application results, it is essential to comprehensively review recent progress in SS utilization. This review aims to fill the gaps in knowledge by describing the properties of SS, and its usage as adsorbents, catalysts and fertilizers, and certain application mechanisms. Although SS generates several benefits for the environment and humans, many challenges still exist to limit the application, including the risks posed by potentially toxic substances (e.g., heavy metals) in SS. Therefore, future research directions are discussed and how to make SS applications more feasible in terms of technology and economy.
Ye, Y, Ngo, HH, Guo, W, Chang, SW, Nguyen, DD, Varjani, S, Liu, Q, Bui, XT & Hoang, NB 2022, 'Bio-membrane integrated systems for nitrogen recovery from wastewater in circular bioeconomy', Chemosphere, vol. 289, pp. 133175-133175.
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Yin, L, Wang, D, Li, X, He, Y, Liu, X, Xu, Y & Chen, H 2022, 'One-pot synthesis of oxygen-vacancy-rich Cu-doped UiO-66 for collaborative adsorption and photocatalytic degradation of ciprofloxacin', Science of The Total Environment, vol. 815, pp. 151962-151962.
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UiO-66, as one of the most stable metal-organic frameworks (MOFs), has attracted a lot of attention in the field of adsorption and photocatalysis. However, this application of UiO-66 is still limited due to either the low accessibility of micropores or the poor electron-hole charge separation capability. This study aims to promote UiO-66 accessibility of micropores and charge separation through the construction of oxygen vacancies (OVs) and mesopore defects as well as copper incorporation. Herein, mesopore Cu doped UiO-66 with rich OVs was synthesized by a one-pot method and demonstrated high efficiency for the removal of ciprofloxacin (CIP) from the aquatic system. First of all, denatured mesopore defects were produced in Cu doped UiO-66 which possessed a 58% increase in specific surface area compared to UiO-66, facilitating the adsorption of molecular oxygen. Secondly, e- was preferentially trapped by OVs under light irradiation. Electron (e-) reacted rapidly with the surface adsorbed oxygen to generate superoxide radical (O2-). Meanwhile, copper incorporation increased the photocurrent and reduced the interfacial charge transfer resistance, thereby improving the charge separation efficiency. As a result, the adsorption efficiency and photocatalytic performance of mesopore Cu doped UiO-66 with OVs were 8.1 and 3.7 times higher than those of UiO-66, respectively. This study paved a way for the one-step synthesis of MOFs containing OVs and broadened the possibilities of practical applications for photo-induced removal of antibiotics from effluent.
Yousefi, M, Tabatabaei, SH, Rikhtehgaran, R, Pour, AB & Pradhan, B 2022, 'Detection of alteration zones using the Dirichlet process Stick-Breaking model-based clustering algorithm to hyperion data: the case study of Kuh-Panj porphyry copper deposits, Southern Iran', Geocarto International, vol. 37, no. 25, pp. 9788-9816.
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Youssef, AM, Pradhan, B, Dikshit, A & Mahdi, AM 2022, 'Comparative study of convolutional neural network (CNN) and support vector machine (SVM) for flood susceptibility mapping: a case study at Ras Gharib, Red Sea, Egypt', Geocarto International, vol. 37, no. 26, pp. 11088-11115.
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Geohazard risk is high in Arab countries due to ineffective disaster preparedness measures, mismanagement, lack of public awareness, inadequate funding and lack of stakeholder support. One such country is Egypt, which is hit by floods every year that cost lives and bring the economy to a standstill. Moreover, not much has been done to map flood-prone areas. In this paper, flood susceptibility modelling was evaluated in the Ras Gharib region of Egypt using two effective techniques machine learning technique-MLT (Support Vector Machine (SVM)) and deep learning method-DL (Convolutional Neural Networks (CNN)). Thirteen flood related factors and flood inventory layer were prepared to construct these models. Validation was performed with 30% of the flood locations where receiver operating characteristic (ROC) curves showed that the deep learning technique (CNN) gave a prediction accuracy of 86.5% (high performance), while the MLTs (SVM) gave 71.6% (medium performance). The results show that CNN provides 17% better than SVM which indicates a powerful and accurate model in flood susceptibility mapping. Results were confirmed using the Astro Digital images shortly after the 2016 flood, in which the CNN model provides a good agreement.
Youssef, AM, Pradhan, B, Dikshit, A, Al-Katheri, MM, Matar, SS & Mahdi, AM 2022, 'Landslide susceptibility mapping using CNN-1D and 2D deep learning algorithms: comparison of their performance at Asir Region, KSA', Bulletin of Engineering Geology and the Environment, vol. 81, no. 4.
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Yu, H, Naidu, G, Zhang, C, Wang, C, Razmjou, A, Han, DS, He, T & Shon, H 2022, 'Metal-based adsorbents for lithium recovery from aqueous resources', Desalination, vol. 539, pp. 115951-115951.
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The continuous increase of demand for lithium (Li) chemicals in industrial applications calls for exploring affordable Li production and sustainable options beyond land mining. Thus, aqueous resources, such as geothermal brine, salt lake brine, and seawater, play an essential role in continuous Li supply due to abundant storage and low cost. Adsorption technology is promising in Li recovery with the advantages of attaining high selectivity for Li over other major ions present in aqueous resources at low cost and low energy demand with facile synthesis processes that enable practical large-scale production. Metal-based adsorbents are conspicuous among various adsorbents for presenting the visible prospect closest to industrial applications. This review presents a comprehensive summary and critical analysis of the synthesis methods for metal-based adsorbents, the mechanisms for Li selective recovery, and the performance of Li adsorption. The advantages and challenges are discussed for different adsorbents and preparation methods. A specific focused case study on an industrial application of Al-based adsorbent production and Li recovery processes and operations on an engineering and economic scale is discussed in detail to provide a comprehensive overview of the practical industrial application of metal-based adsorbent.
Yu, Y, Liang, S, Samali, B, Nguyen, TN, Zhai, C, Li, J & Xie, X 2022, 'Torsional capacity evaluation of RC beams using an improved bird swarm algorithm optimised 2D convolutional neural network', Engineering Structures, vol. 273, pp. 115066-115066.
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Yu, Y, Rashidi, M, Samali, B, Mohammadi, M, Nguyen, TN & Zhou, X 2022, 'Crack detection of concrete structures using deep convolutional neural networks optimized by enhanced chicken swarm algorithm', Structural Health Monitoring, vol. 21, no. 5, pp. 2244-2263.
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With the rapid increase of ageing infrastructures worldwide, effective and robust inspection techniques are highly demanding to evaluate structural conditions and residual lifetime. The damages on structural surfaces, for example, spalling, crack, rebar buckling and exposure, are important indicators to assess the structural condition. In fact, several state-of-the-art automated inspection techniques using these indicators have been developed to reduce human-conducted onsite inspection activities. However, the efficiency of these techniques is still required to be improved in terms of accuracy and computational cost. In this study, a vision-based crack diagnosis method is developed using deep convolutional neural network (DCNN) and enhanced chicken swarm algorithm (ECSA). A DCNN model is designed with a deep architecture, consisting of six convolutional layers, two pooling layers and three fully connected layers. To enhance the generalisation capacity of trained model, ECSA is introduced to optimize meta-parameters of the DCNN model. The model is trained and tested using image patches cropped from raw images obtained from damaged concrete samples. Finally, a comparative study on different crack detection techniques is conducted to evaluate performance of the proposed method via a group of statistical evaluation indicators.
Yu, Y, Samali, B, Rashidi, M, Mohammadi, M, Nguyen, TN & Zhang, G 2022, 'Vision-based concrete crack detection using a hybrid framework considering noise effect', Journal of Building Engineering, vol. 61, pp. 105246-105246.
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Diagnosing surface cracks of concrete structures has been a critical aspect of assessing structural integrity. Existing diagnosis technologies are time-consuming, subjective, and heavily dependent on the experiences of inspectors, which leads to low detection accuracy. This paper aims to resolve these challenges by proposing a vision-based automated method for surface condition identification of concrete structures, consisting of state-of-the-art pre-trained convolutional neural networks (CNNs), transfer learning, and decision-level image fusion. For this purpose, a total of 41,780 image patches of various concrete surfaces are generated for the development and validation of the proposed method. Each pre-trained CNN is employed to establish the predictive model for the initial diagnosis of surface conditions via transfer learning. Since different CNNs may generate conflicting results due to differences in network architectures, a modified Dempster-Shafer (D-S) algorithm is designed to conduct decision-level image fusion to improve the crack detection accuracy. The superiority of the proposed method is validated via the comparison with single CNN models. The robustness of the proposed method is also verified using the images polluted with various types and intensities of noise, with satisfactory outcomes. Finally, this hybridised approach is applied to the analysis of images of concrete structures captured in the field, through an exhaust search-based scanning window. The results show that it is capable of accurately identifying the crack profile with wrong predictions of limited areas, demonstrating its potential in practical applications.
Yuan, P, Xu, S, Liu, J, Su, Y, Li, J, Qu, K, Liu, C & Wu, C 2022, 'Correction to: Experimental investigation of G-HPC-based sandwich walls incorporated with metallic tube core under contact explosion', Archives of Civil and Mechanical Engineering, vol. 22, no. 4.
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Yuan, P, Xu, S, Liu, J, Su, Y, Li, J, Qu, K, Liu, C & Wu, C 2022, 'Experimental investigation of G-HPC-based sandwich walls incorporated with metallic tube core under contact explosion', Archives of Civil and Mechanical Engineering, vol. 22, no. 4.
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A novel geopolymer-based high-performance concrete (G-HPC) sandwich wall consisting of two G-HPC layers separated by a metallic tube core possessing high strength and lightweight structure was developed in this study. The contact blast tests with 1 kg TNT were subsequently conducted to explore the blast resistance of the developed sandwich walls. For this purpose, three sandwich walls and a C40 reinforced concrete (RC) slab were employed. The superior blast resistance of the sandwich walls was verified based on the experimental results as compared to the RC slab. The sandwich wall with a circular steel tube core exhibited a superior blast resistance than the wall with a circular aluminum alloy tube core, whereas the sandwich wall with a rectangular steel tube core revealed the best performance. The blast resistance and damage mechanism of the sandwich walls were subsequently analyzed. The accuracy of the available empirical formulas was also examined for predicting the damage in the sandwich walls under contact explosion conditions.
Yusoff, MNAM, Zulkifli, NWM, Sukiman, NL, Kalam, MA, Masjuki, HH, Syahir, AZ, Awang, MSN, Mujtaba, MA, Milano, J & Shamsuddin, AH 2022, 'Microwave irradiation-assisted transesterification of ternary oil mixture of waste cooking oil – Jatropha curcas – Palm oil: Optimization and characterization', Alexandria Engineering Journal, vol. 61, no. 12, pp. 9569-9582.
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Zabed, HM, Bankar, SB, Rehan, M, Nizami, A-S, Alam, MA & Mofijur, M 2022, 'Editorial: Design and application of biocatalysts for biofuel and bio-based material production', Frontiers in Energy Research, vol. 10.
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Zahmatkesh, S, Ni, B-J, Klemeš, JJ, Bokhari, A & Hajiaghaei-Keshteli, M 2022, 'Carbon quantum dots-Ag nanoparticle membrane for preventing emerging contaminants in oil produced water', Journal of Water Process Engineering, vol. 50, pp. 103309-103309.
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A polycarbonate copolymer was used to create a novel low-cost microfiltration membrane. Due to their antibacterial properties, carbon quantum dots and silver nanoparticles (CD-Ag NPs) have been synthesized and incorporated into a poly(acrylonitrile-styrene) membrane by the Creighton method. This work examined the membranes using Infrared Vibrational Spectroscopy, Ultraviolet-Visible Spectroscopy, and a Scanning Electron Microscope (SEM). An investigation was conducted to determine the effects of the CDs-Ag NPs amount on the matrix's morphology, pore size, porosity, permeability, and mechanical strength. Also, photobleaching was used to reduce and stabilize CDs-Ag NPs, as reflected by a red shift in the spectra for CDs compared to CDs-Ag NPs from 290 nm to 570 nm in the UV/Vis spectrum, indicating the nanoparticle was generated. Pore size and mechanical strength are reduced when CDs-Ag NPs are added to neat membranes. However, it is followed by a decrease in porosity and mechanical strength. The optimized membrane exhibited a 0.66 pore size. In addition to removing oils and metals from wastewater, they also remove dyes, antibiotics, and other organic and inorganic compounds. The colony forming unit (CFU) test also showed that the percentage of CFU decreased as AgNO3 concentration increased so that at a concentration of 4, the percentage of CFU for E. coli and S. aureus was 5 % and 1.9 % for S. aureus. The Creighton methodology was therefore proven suitable for functionalizing the membrane, and discs-Ag NPs membranes have been demonstrated to be promising wastewater treatment membranes.
Zainal, BS, Gunasegaran, K, Tan, GYA, Danaee, M, Mohd, NS, Ibrahim, S, Chyuan, OH, Nghiem, LD & Mahlia, TMI 2022, 'Effect of temperature and hydraulic retention time on hydrogen production from palm oil mill effluent (POME) in an integrated up-flow anaerobic sludge fixed-film (UASFF) bioreactor', Environmental Technology & Innovation, vol. 28, pp. 102903-102903.
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Zamri, MFMA, Milano, J, Shamsuddin, AH, Roslan, MEM, Salleh, SF, Rahman, AA, Bahru, R, Fattah, IMR & Mahlia, TMI 2022, 'An overview of palm oil biomass for power generation sector decarbonization in Malaysia: Progress, challenges, and prospects', WIREs Energy and Environment, vol. 11, no. 4.
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AbstractWith the ever‐increasing danger of climate change, power plants are shifting from polluting fossil fuels to sustainable bioenergy fuels. As Malaysia continues to pledge to decrease glasshouse gas (GHG) emissions, quick and dramatic action should resolve the reliance on fossil fuel power plants. Furthermore, the coal‐fired power station is Malaysia's biggest supplier of energy and the final power plant to be decommissioned. In Malaysia, a significant portion of palm oil biomass has the potential to replace coal in the generation of renewable energy power. However, the deployment of palm oil biomass as a renewable energy source has not been fully achieved. Furthermore, the surplus of unutilized biomass from the palm oil milling process has emerged as the key talking point leading to environmental concerns. As estimated, this palm oil biomass can generate approximately 5000 MW of electricity under 40% of operation efficiency. This significant power potential has the ability to replace Malaysia's yearly reliance on coal. Nonetheless, the limitations of technological stability, budgetary constraints, and other government policy concerns have prevented the potentials from being fulfilled. This necessitates an integrated framework that synergizes the decarbonization drive in order to realize the primary advantages of energy renewability and carbon neutrality. Among the suggested actions to decarbonize the power generating sector is an integrated scheme of palm oil production, biogas plant for electricity and steam generation, and biofuel pellet manufacture. This review provides an in‐depth overview of palm oil biomass for Malaysian power production decarbonization.This article is categorized under:Sustainable Energy > BioenergyClimate and Environment > Net Zero Planning and Decarbonization
Zdarta, J, Jesionowski, T, Pinelo, M, Meyer, AS, Iqbal, HMN, Bilal, M, Nguyen, LN & Nghiem, LD 2022, 'Free and immobilized biocatalysts for removing micropollutants from water and wastewater: Recent progress and challenges', Bioresource Technology, vol. 344, no. Pt B, pp. 126201-126201.
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Enzymatic conversion of micropollutants into less-toxic derivatives is an important bioremediation strategy. This paper aims to critically review the progress in water and wastewater treatment by both free and immobilized enzymes presenting this approach as highly efficient and performed under environmentally benign and friendly conditions. The review also summarises the effects of inorganic and organic wastewater matrix constituents on enzymatic activity and degradation efficiency of micropollutants. Finally, application of enzymatic reactors facilitate continuous treatment of wastewater and obtaining of pure final effluents. Of a particular note, enzymatic treatment of micropollutants from wastewater has been mostly reported by laboratory scale studies. Thus, this review also highlights key research gaps of the existing techniques and provides future perspectives to facilitate the transfer of the lab-scale solutions to a larger scale and to improve operationability of biodegradation processes.
Zhang, B, Yao, R, Fang, J, Ma, R, Pang, T & Zhou, D 2022, 'Energy absorption behaviors and optimization design of thin-walled double-hat beam under bending', Thin-Walled Structures, vol. 179, pp. 109577-109577.
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Zhang, H, An, N & Zhu, X 2022, 'Structural dynamic reliability analysis of super large-scale lattice domes during earthquakes using the stochastic finite element method', Soil Dynamics and Earthquake Engineering, vol. 153, pp. 107076-107076.
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For large-scale dome structures subjected to earthquake ground motions, the need for accurate and efficient approaches that account for uncertainties in design, material properties, loads, damping, and manufacturing processes has grown significantly. In uncertainty analyses, the theory of probability, uncertainty quantification, and reliability analysis approaches are commonly used. However, because of computing efficiency and capability, the space scale of dome structures is severely limited. As a result, the computational issues of the complex dynamic reliability that super-large-scale dome structures encounter during earthquakes are challenging. The uncertainties of the dynamic demands of a super-large-scale lattice dome with multiple variables are quantified using a stochastic finite element method (SFEM) with nonlinear time-history analysis developed in this paper, and this method can consider the randomness of variables in more detail for a structure. The dynamic reliability is investigated in depth using the efficient Latin hypercube sampling (LHS) technique to reduce the number of repetitive time-consuming calculations. To improve the efficiency and accuracy of the analysis, an optimization approach based on the genetic algorithm (GA) is used to obtain the probability of structural failure and the reliability index. The results show that these methods are highly efficient for super-large-scale structures. Finally, a sensitivity analysis based on variable randomness is conducted to further evaluate the effects of variables on structural performance using various evaluation methods. This paper provides an efficient solution for structural dynamic reliability problems of super-large-scale structures in the SFEM framework.
Zhang, H, Nguyen, H, Bui, X-N, Pradhan, B, Asteris, PG, Costache, R & Aryal, J 2022, 'A generalized artificial intelligence model for estimating the friction angle of clays in evaluating slope stability using a deep neural network and Harris Hawks optimization algorithm', Engineering with Computers, vol. 38, no. S5, pp. 3901-3914.
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In landslide susceptibility mapping or evaluating slope stability, the shear strength parameters of rocks and soils and their effectiveness are undeniable. However, they have not been studied for all-natural materials, as well as different locations. Therefore, this paper proposes a novel generalized artificial intelligence model for estimating the friction angle of clays from different areas/locations for evaluating slope stability or landslide susceptibility mapping, including the datasets from the UK, New Zealand, Indonesia, Venezuela, USA, Japan, and Italy. The robustness and consistency of the model’s prediction were checked by testing with various datasets having different geological and geomorphological setups. Accordingly, 162 observations from different areas/locations were collected from the locations and regions above for this aim. Subsequently, deep learning techniques were applied to develop the multiple layer perceptron (MLP) neural network model (i.e., DMLP model) with the goal of error reduction of the MLP model. Next, Harris Hawks optimization (HHO) algorithm was applied to boost the optimization of the DMLP model for predicting friction angle of clays aiming to get a better accuracy than those of the DMLP model, called HHO–DMLP model. A DMLP neural network without optimization of the HHO algorithm and two other conventional models (i.e., SVM and RF) were also employed to compare with the proposed HHO–DMLP model. The results showed that the proposed HHO–DMLP model predicted the friction angle of clays better than those of the other models. It can reflect the friction angle of clays with acceptable accuracy from different locations and regions (i.e., MSE = 12.042; RMSE = 3.470; R2 = 0.796; MAPE = 0.182; and VAF = 78.806). The DMLP model without optimization of the HHO algorithm provided slightly lower accuracy (i.e., MSE = 15.151; RMSE = 3.892; R2 = 0.738; MAPE = 0.202; and VAF = 73.431). Besides, two other conventional models (i.e., SVM and RF) p...
Zhang, H, Zhang, Y, Zhu, X, Wang, H & Song, Y 2022, 'Time-dependent performance of large-scale dome structures subjected to earthquakes using a machine learning-based evaluation method', Engineering Structures, vol. 273, pp. 115065-115065.
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Zhang, J, Chen, Z, Liu, Y, Wei, W & Ni, B-J 2022, 'Phosphorus recovery from wastewater and sewage sludge as vivianite', Journal of Cleaner Production, vol. 370, pp. 133439-133439.
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Developing feasible techniques to recover phosphorous (P) from wastewater and sewage sludge is urgent work to meet the huge demand for P resources and wastewater/sludge management. Recently, recovering P as value-added vivianite (Fe3(PO4)2·8H2O) has aroused great interest due to the convenient process operation, high recovery efficiency, and wide applications of vivianite. In this review, qualitative and quantitative detection methods of vivianite have been first analyzed, providing reference to test vivianite content and purity. Advanced technologies for P enrichment and vivianite production, including ion exchange, electrodialysis, capacitive de-ionization, membrane bioreactor, anaerobic fermentation, chemical precipitation, electrochemical crystallization, biomineralization, and anaerobic digestion are then comprehensively summarized. Mechanisms and representative applications of each technique are emphasized. Also, critical parameters (e.g., pH, Fe/P molar ratio, sulfate concentration, microorganisms, supersaturation index, organic matters, and seed crystals) affecting vivianite formation have been systematically analyzed. Furthermore, perspectives regarding fast detection of vivianite, strategies optimization, seed application, and vivianite commercialization have been proposed to guide the development of next-generation techniques for P recovery. This review is expected to provide fundamental insights into cleaner technologies synchronous recovering waste P and producing valued vivianite, as well as to stimulate future studies on circular economy-driven wastewater management.
Zhang, K, Fu, Y, Hao, D, Guo, J, Ni, B-J, Jiang, B, Xu, L & Wang, Q 2022, 'Fabrication of CN75/NH2-MIL-53(Fe) p-n heterojunction with wide spectral response for efficiently photocatalytic Cr(VI) reduction', Journal of Alloys and Compounds, vol. 891, pp. 161994-161994.
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In this study, p-type carbon nitride (CN75) nanoparticles were introduced to precursors of NH2-MIL-53(Fe). A CN75 and NH2-MIL-53(Fe) p-n heterojunction was formed by solvothermal reaction. It showed that tiny loading of CN75 onto NH2-MIL-53(Fe) would boost the separation, migration and transfer of photo-induced carriers effectively. Meanwhile, its spectral response was broadened, which draw in efficient photocatalytic performance together. As for photocatalytic reduction of Cr(VI), the rate constant on CN75/NH2-MIL-53(Fe) was ca 1.8 and 25.3 times that by NH2-MIL-53(Fe) and CN75 under visible light (λ ≥ 420 nm), respectively. Reduction rate of CN75/NH2-MIL-53(Fe) (0.1 g/L) reached about 100% within 15 min at pH 2. Good activity could also be observed even under red light (λ: 650–660 nm). Besides, CN75/NH2-MIL-53(Fe) exhibited high stability after 5 cyclic runs, and the leaching of Fe3+ can be greatly suppressed after loading CN75. Structural analysis proved that the MOFs framework was well maintained. Thus, this research paper would provide useful information about the construction and synthesis of efficient and steady Fe-MOFs based photocatalyst for environmental remediation.
Zhang, L, Sun, J, Zhang, Z, Peng, Z, Dai, X & Ni, B-J 2022, 'Polyethylene terephthalate microplastic fibers increase the release of extracellular antibiotic resistance genes during sewage sludge anaerobic digestion', Water Research, vol. 217, pp. 118426-118426.
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Microplastic fibers (MFs), as the most frequently detected microplastic shape in sewage sludge, have posed emerging concern for sludge treatment and disposal. However, the effect of MFs on antibiotic resistance genes (ARGs), especially extracellular ARGs (eARGs) during sludge treatment remains far from explicit. Therefore, this study investigated the potential impact of MFs on eARGs during sludge anaerobic digestion (AD), a commonly used sludge treatment method, through long-term operation. The qPCR results showed that both absolute and relative abundances of eARGs increased with the MFs exposure during sludge AD. The average absolute and relative abundances of eight tested eARGs in the AD reactor with the highest MFs dosage (170 items/gTS) were 1.70 and 2.15 times higher than those in the control AD reactor. The metagenomics results further comfirmed the increase of eARGs abundance during sludge anaerobic digestion after MFs exposure and the enhancement did not show significant selectivity. The identification of the potential hosts of eARGs suggested the host numbers of eARGs also increased with MFs exposure, which may suggest enhanced horizonal transformation as a result of increased eARGs. Further exploring the mechansims showed that the genes involved in type IV secretion system was upregulated after MFs exposure, suggesting the active release of eARGs was enhanced with MFs exposure. In contrast, the MFs may not affect the passive release of eARGs as its impact on cell membrance damage was insignificant. The enhanced eARGs in sludge AD process may further accelerate the transport of ARGs in environment, which should be considered during sludge treatment and disposal.
Zhang, R, Liu, X, Chen, R, Wang, Z, Lin, W, Ngo, HH, Nan, J, Li, G, Ma, J & Ding, A 2022, 'Environmental and economic performances of incorporating Fenton-based processes into traditional sludge management systems', Journal of Cleaner Production, vol. 364, pp. 132613-132613.
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Municipal and industrial wastewater treatment plants produce a tremendous amount of sludge containing organic and toxic components. One of the advanced oxidation processes (AOP) - Fenton process has demonstrated great prospect in reduction of sludge organics and toxicity. Fenton pretreatment could ameliorate the sludge dewaterability and biodegradability for anaerobic digestion (AD) process, and enhance the sludge lower heating value for incineration process, thus stimulating sludge dewatering, reduction and energy recovery. However, doubts remain about whether the incorporation of the Fenton process into the traditional sludge management systems brings environmental benefits. Hence, a life cycle environmental impact calculation model was established for sludge with various organic contents (60%, 70%, 80%) under the effect of Fenton and US/UV/Electro-Fenton processes. Noteworthy mitigation of environmental load was observed for the Fenton process coupled with incineration system, which involves high dewatering demand. Conversely, as for the AD system with high biomass transformation rate, Fenton process failed to attain the assumed promotion of environmental benefit. Hydrogen peroxide (H2O2) prominently attributed to the weakness of Fenton process combined with AD (F-AD) scenario, compared with the AD scenario in terms of environmental impact. Summarily, the F-AD scenario acts as the preponderant system when weighing up the pros and cons of environmental impact, energy balance and life cycle cost. Contrary to the mainstream view, the proven technical advantages of Fenton process cannot compensate for the additional environmental loads in the life cycle of sludge. It provides valuable reflection for environmental managers and scholars that we should be more cautious in the application of cutting-edge technologies.
Zhang, S, Lan, P, Li, H-C, Tong, C-X & Sheng, D 2022, 'Physics-informed neural networks for consolidation of soils', Engineering Computations, vol. 39, no. 7, pp. 2845-2865.
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PurposePrediction of excess pore water pressure and estimation of soil parameters are the two key interests for consolidation problems, which can be mathematically quantified by a set of partial differential equations (PDEs). Generally, there are challenges in solving these two issues using traditional numerical algorithms, while the conventional data-driven methods require massive data sets for training and exhibit negative generalization potential. This paper aims to employ the physics-informed neural networks (PINNs) for solving both the forward and inverse problems.Design/methodology/approachA typical consolidation problem with continuous drainage boundary conditions is firstly considered. The PINNs, analytical, and finite difference method (FDM) solutions are compared for the forward problem, and the estimation of the interface parameters involved in the problem is discussed for the inverse problem. Furthermore, the authors also explore the effects of hyperparameters and noisy data on the performance of forward and inverse problems, respectively. Finally, the PINNs method is applied to the more complex consolidation problems.FindingsThe overall results indicate the excellent performance of the PINNs method in solving consolidation problems with various drainage conditions. The PINNs can provide new ideas with a broad application prospect to solve PDEs in the field of geotechnical engineering, and also exhibit a certain degree of noise resistance for estimating the soil parameters.Originality/valueThis study presents the potential application of PINNs for the consolidation of soils. S...
Zhang, S, Li, X, Shi, J, Sivakumar, M, Luby, S, O'Brien, J & Jiang, G 2022, 'Analytical performance comparison of four SARS-CoV-2 RT-qPCR primer-probe sets for wastewater samples', Science of The Total Environment, vol. 806, no. Pt 2, pp. 150572-150572.
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Current studies have confirmed the feasibility of SARS-CoV-2 RNA detection by RT-qPCR assays in wastewater samples as an effective surveillance tool of COVID-19 prevalence in a community. Analytical performance of various RT-qPCR assays has been compared against wastewater samples based on the positive ratio. However, there is no systematic comparison work has been conducted for both analytical sensitivity and quantitative reliability against wastewater, which are essential factors for WBE. In this study, the detection performance of four RT-qPCR primer-probe sets, including CCDC-N, CDC-N1, N-Sarbeco, and E-Sarbeco, was systematically evaluated with pure synthetized plasmids, spiked wastewater mocks and raw wastewater samples. In addition to confirm RT-qPCR results, Nanopore sequencing was employed to delineate at molecular level for the analytical sensitivity and reproducibility of those primer-probe sets. CCDC-N showed high sensitivity and the broadest linearity range for wastewater samples. It was thus recommended to be the most efficient tool in the quantitative analysis of SARS-CoV-2 in wastewater. CDC-N1 had the highest sensitivity for real wastewater and thus would be suitable for the screening of wastewater for the presence of SARS-CoV-2. When applying the primer-probe sets to wastewater samples collected from different Australian catchments, increased active clinical cases were observed with the augment of SARS-CoV-2 RNA quantified by RT-qPCR in wastewater in low prevalence communities.
Zhang, S, Sun, W-L, Song, H-L, Zhang, T, Yin, M, Wang, Q & Zuo, X 2022, 'Effects of voltage on the emergence and spread of antibiotic resistance genes in microbial electrolysis cells: From mutation to horizontal gene transfer', Chemosphere, vol. 291, no. Pt 1, pp. 132703-132703.
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Microbial electrolysis cells (MECs) are widely considered as promising alternatives for degrading antibiotics. As one of the major operating parameters in MECs, voltage might affect the spread of antibiotic resistance genes (ARGs) given it can affect the physiological characteristics of bacteria. However, little is known about the impacts of voltage on the acceleration of bacterial mutation and the promotion of ARG dissemination via horizontal transfer in MECs. In this study, two voltages (0.9 V and 1.5 V) were applied to identify if electrical stimulation could increase bacterial mutation frequency. Three voltages (0.9 V, 1.5 V, and 2.5 V) were used to evaluate the conjugative transfer frequency of plasmid-encoded the ARGs from the donor (E. coli K-12) to the recipient (E. coli HB101) in MECs. After repeating subculture in MECs for 10 days, the mutation frequency of E. coli K-12 was promoted, consequently, the generated mutants became more resistant against tetracycline. When the voltage was higher than 0.9 V, conjugative ARG transfer frequency was significantly increased in the anode chamber (p < 0.05). The over-production of reactive oxygen species (ROS) (voltage >0.9 V) and cell membrane permeability (voltage >1.5 V) were significantly enhanced under electrical stimulations (p < 0.05). Genome-wide RNA sequencing indicated that the expressions of genes related to oxidative stress and cell membrane were upregulated with exposure to electrical stimulation. Electrical stimulations induced oxidative reactions, which triggered ROS over-production, SOS response, and enhancement of cell membrane permeability for both donor and recipient in the MECs. These findings provide insights into the potential role of voltage in the generation and spread of ARGs in MECs.
Zhang, SS, Ke, Y, Chen, E, Biscaia, H & Li, WG 2022, 'Effect of load distribution on the behaviour of RC beams strengthened in flexure with near-surface mounted (NSM) FRP', Composite Structures, vol. 279, pp. 114782-114782.
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Debonding failures of FRP have been frequently observed in laboratory tests of reinforced concrete (RC) beams flexurally-strengthened with near-surface mounted (NSM) fibre-reinforced polymer (FRP). A number of numerical and theoretical studies have been carried out to predict debonding failures in NSM FRP-strengthened beams, and several strength models have also been proposed. The existing studies, however, were all based on the scenario of a simply supported beam tested under one or two-point loading, while the influence of load distribution has not yet been investigated. This paper presents the first ever study into the effect of load distribution on the behaviour of NSM FRP-strengthened RC beams. A series of large-scale RC beams flexurally-strengthened with NSM FRP strips were first tested under different load uniformities; then a finite element (FE) model, which can give close predictions to the behaviour of such strengthened beams, was developed; finally, the proposed FE model was utilized to investigate the influence of bond length of NSM FRP on the load uniformity effect. It was found that the load uniformity has a significant effect on the beam behaviour, and the degree of this effect varies with the bond length of NSM FRP.
Zhang, W, Dong, T, Ai, J, Fu, Q, Zhang, N, He, H, Wang, Q & Wang, D 2022, 'Mechanistic insights into the generation and control of Cl-DBPs during wastewater sludge chlorination disinfection process', Environment International, vol. 167, pp. 107389-107389.
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Chlorination disinfection has been widely used to kill the pathogenic microorganisms in wastewater sludge during the special Covid-19 period, but sludge chlorination might cause the generation of harmful disinfection byproducts (DBPs). In this work, the transformation of extracellular polymeric substance (EPS) and mechanisms of Cl-DBPs generation during sludge disinfection by sodium hypochlorite (NaClO) were investigated using multispectral analysis in combination with Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). The microorganism Escherichia coli (E. coli) was effectively inactivated by active chlorine generated from NaClO. However, a high diversity of Cl-DBPs were produced with the addition of NaClO into sludge, causing the increase of acute toxicity on Q67 luminous bacteria of chlorinated EPS. A variety of N-containing molecular formulas were produced after chlorination, but N-containing DBPs were not detected, which might be the indicative of the dissociation of -NH2 groups after Cl-DBPs generated. Additionally, the release of N-containing compounds was increased in alkaline environment caused by NaClO addition, resulted in more Cl-DBPs generation via nucleophilic substitutions. Whereas, less N-compounds and Cl-DBPs were detected after EPS chlorination under acidic environment, leading to lower cell cytotoxicity. Therefore, N-containing compounds of lignin derivatives in sludge were the major Cl-DBPs precursors, and acidic environment could control the release of N-compounds by eliminating the dissociation of functional groups in lignin derivatives, consequently reducing the generation and cytotoxicity of Cl-DBPs. This study highlights the importance to control the alkalinity of sludge to reduce Cl-DBPs generation prior to chlorination disinfection process, and ensure the safety of subsequential disposal for wastewater sludge.
Zhang, X & Far, H 2022, 'Effects of dynamic soil-structure interaction on seismic behaviour of high-rise buildings', Bulletin of Earthquake Engineering, vol. 20, no. 7, pp. 3443-3467.
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Zhang, X, Huang, J, Cheng, X, Chen, H, Liu, Q, Yao, P, Ngo, HH & Nghiem, LD 2022, 'Mitigation of reverse osmosis membrane fouling by electrochemical-microfiltration- activated carbon pretreatment', Journal of Membrane Science, vol. 656, pp. 120615-120615.
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Zhang, X, Li, Z-X, Shi, Y, Wu, C & Li, J 2022, 'Fragility analysis for performance-based blast design of FRP-strengthened RC columns using artificial neural network', Journal of Building Engineering, vol. 52, pp. 104364-104364.
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In this paper, fragility analysis for performance-based blast design of FRP-strengthened RC columns is carried out. The blast intensity levels, performance levels and performance objectives of the RC columns are defined. A simplified probabilistic risk assessment framework incorporating the performance-based design concept and fragility analysis is established. Since fragility analysis is the most important but time-consuming process of probabilistic assessment risk, an artificial neural network (ANN) based fragility analysis framework is proposed to improve its computational efficiency. Based on the rapid fragility analysis method, fragility curves of several typical RC columns with or without FRP strengthening are calculated to analyze their damage probabilities. This study provides avenues for engineers to estimate the failure probabilities of RC columns with or without FRP strengthening under blast loads and make decisions quickly.
Zhang, X, Sui, G, Wang, Z, Ngo, HH, Guo, W, Wen, H, Zhang, D, Wang, X & Zhang, J 2022, 'Effective fluorine removal using mixed matrix membrane based on polysulfone: adsorption performance and diffusion behavior', Water Science and Technology, vol. 85, no. 11, pp. 3196-3207.
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Abstract Fluorine is one of the essential trace elements for human life activities, but excessive intake of fluoride poses a great risk to people's health. In this paper, a series of mixed matrix membrane (MMM)-based polysulfone for removing fluoride were prepared by phase inversion, and their properties, adsorption capacity, adsorption isotherms, adsorption kinetics of fluoride ions, and mechanism were all investigated. The results confirmed that the MMM contained a large number of hydroxyl and aluminum functional groups due to resin being added. The MMM exhibited the best fluorine ion adsorption capacity of 2.502 mg/g at a pH of 6 with the initial concentration of 6 mg/L. As well, adsorption kinetics of fluorine ion on MMM followed the pseudo-second-order model, while the adsorption behavior of fluorine ion on MMM was well simulated by the Langmuir isotherm model. The adsorption capacity of MMM remained stable after six cycles and the regeneration efficiency was still above 80%, resulting in a long-term stability adequate for fluorine ion removal. Complexation and ion exchange played a key role in the fluorine ion adsorption of MMM. These results indicated the MMM as novel type of absorbent had an excellent capacity for removing fluoride.
Zhang, X, Wang, Z, Huang, J, Chen, H, Liu, Q, Yao, P, Ngo, HH & Nghiem, LD 2022, 'A novel membrane photo-electro oxidizer for advanced treatment of coal processing wastewater: Fouling control and permeate quality', Journal of Cleaner Production, vol. 378, pp. 134573-134573.
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Zhang, X, Yang, Y, Hao Ngo, H, Guo, W, Long, T, Wang, X, Zhang, J & Sun, F 2022, 'Enhancement of urea removal from reclaimed water using thermally modified spent coffee ground biochar activated by adding peroxymonosulfate for ultrapure water production', Bioresource Technology, vol. 349, pp. 126850-126850.
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Zhang, X, Yang, Y, Hao Ngo, H, Guo, W, Sun, F, Wang, X, Zhang, J & Long, T 2022, 'Urea removal in reclaimed water used for ultrapure water production by spent coffee biochar/granular activated carbon activating peroxymonosulfate and peroxydisulfate', Bioresource Technology, vol. 343, pp. 126062-126062.
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Zhang, X, Zhang, W, Zhang, L, Huang, Z, Hu, J, Gao, M, Pan, H & Liu, Y 2022, 'Single-pot solvothermal strategy toward support-free nanostructured LiBH4 featuring 12 wt% reversible hydrogen storage at 400 °C', Chemical Engineering Journal, vol. 428, pp. 132566-132566.
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Lithium borohydride (LiBH4) exhibits poor hydrogen storage reversibility because of phase separation between LiH and B due to foaming during thermal dehydrogenation. Herein, we report that by synthesizing nanostructured LiBH4 without any supports, the foaming and phase separation can be effectively suppressed, and consequently, the hydrogen storage reversibility of LiBH4 can be considerably improved. Using a facile single-pot solvothermal approach, a hierarchical porous nanostructured LiBH4 composed of 50–60 nm-sized primary nanoparticles is synthesized. The resulting neat nano-LiBH4 reversibly desorbs and absorbs approximately 12 wt% of H at 400 °C and under 100 bar H2. The superior hydrogen storage performance is attributed to the effective inhibition of foaming upon heating. The formation of LiH and B prior to melting, which can be associated with the largely reduced particle sizes and porous agglomeration structure, plays a crucial role in suppressing foaming. Our findings offer a new strategy for the preparation of nanoscaled freestanding borohydrides, and also important insights into the development of highly reversible metal borohydrides for hydrogen storage applications.
Zhang, XL, Zhang, X, Zhang, LC, Huang, ZG, Fang, F, Hu, JJ, Yang, YX, Gao, MX, Pan, HG & Liu, YF 2022, 'Ultrafast hydrogenation of magnesium enabled by tetragonal ZrO2 hierarchical nanoparticles', Materials Today Nano, vol. 18, pp. 100200-100200.
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Transition metal catalysts are particularly effective in improving the reaction kinetics of light metal hydrides for reversible hydrogen storage. Herein, tetragonal ZrO2 hierarchical nanoparticles (nano-ZrO2) composed of primary particles of ∼4 nm in diameter are successfully synthesized by a facile one-pot solvothermal process. The unique hierarchical structure features homogeneous distributions of in situ formed multivalent Zr-based species, which allow superior catalytic activity for hydrogen storage in MgH2. The MgH2+10 wt% nano-ZrO2 starts releasing H2 at 163 °C after one activation, which is 107 °C lower than additive-free MgH2, and 50 °C lower than that of bulk ZrO2-doped MgH2. At 230 °C, 5.9 wt% of H is rapidly liberated within 20 min from the nano-ZrO2-containing MgH2. More importantly, the material shows superior hydrogenation kinetics compared with all reported catalyst-modified MgH2. The nano-ZrO2-containing Mg took up 4.0 wt% of H in only 12 s at 100 °C under 50 bar H2, 400 times faster than the bulk-ZrO2-modified sample. Even at 50 °C, approximately 1.8 wt% H was absorbed within 1 min. Our findings provide useful insights into the design and development of high-performance catalysts toward solid-state hydrogen storage materials.
Zhang, Y, Afroz, S, Nguyen, QD, Kim, T, Nguyen, D, Castel, A, Nairn, J & Gilbert, RI 2022, 'Autogenous shrinkage of fly ash and ground granulated blast furnace slag concrete', Magazine of Concrete Research, pp. 1-13.
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Supplementary cementitious materials (SCMs) are widely used to reduce the cement content to achieve economic and environmental objectives. As a result, understanding the shrinkage of blended cement-based concrete is essential. In total, 21 concrete mixes were produced with type general purpose cement and with cement replacements of 30% by fly ash, 40% and 60% by ground granulated blast furnace slag (GGBFS). The concrete compressive strength ranged from 25 MPa to 100 MPa. Experimental results were also compared with the predictions by models. Additional tests on pastes with the same SCM content were conducted to investigate both autogenous and chemical shrinkage in relation to their time-dependent pore structure refinement. For concretes with strength below 50 MPa, no significant difference in autogenous shrinkage could be observed between the different blends up to 28 days. However, the autogenous shrinkage of GGBFS concrete increased significantly after 28 days, being about 50% higher than all other concretes at 100 days. This late increase in autogenous shrinkage between 28 and 100 days can be attributed to pore refinement processes. No clear difference was observed for GGBFS concretes with strength greater than 50 MPa. Autogenous shrinkage of fly ash concretes was overall equivalent to that of reference concretes.
Zhang, Y, Hu, J, Nomngongo, PN, Wang, Q & Spanjers, H 2022, 'Editorial: Antibiotics in Water: Impacts and Control Technologies', Frontiers in Environmental Science, vol. 10, p. 921651.
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Zhang, Y, Huang, R, Zhou, Y, Zhou, T, Tao, C, Huang, Y & Qian, Y 2022, 'Effects of turbulence intensity and n-pentanol concentration on droplet evaporation and auto-ignition', Fuel, vol. 322, pp. 124177-124177.
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Evaporation and auto-ignition characteristics of an n-pentanol-diesel droplet are investigated under a high-temperature (900 K) and turbulent environment. Turbulence intensity and n-pentanol mass fraction are varied between 0 and 0.527 m/s and 0–50%, respectively. Droplet evaporation is controlled by the gas temperature, which is affected by turbulent transport and chemical reactions. Diesel vapor accumulates around the droplet at all turbulence intensities, whereas strong turbulence facilitates the transport of n-pentanol vapor to far areas. Turbulence intensity has little impact on the droplet temperature and evaporation rate of pure diesel. The addition of n-pentanol reduces both the evaporation rate and droplet temperature at a high turbulence intensity of 0.527 m/s, but it has little influence on droplet temperature in a static environment. The vapor distribution determines the chemical activity of gas phase around the droplet, and consequently the auto-ignition characteristics. With the increase of n-pentanol concentration, the auto-ignition delay firstly decreases and then increases under low turbulence intensities (0–0.264 m/s), while it monotonically increases under a high turbulence intensity (0.395 and 0.527 m/s). The auto-ignition delay firstly decreases and then increases with the increase of turbulence intensity, regardless of n-pentanol concentration.
Zhang, Y, Xu, X, Fang, J, Huang, W & Wang, J 2022, 'Load characteristics of triangular honeycomb structures with self-similar hierarchical features', Engineering Structures, vol. 257, pp. 114114-114114.
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Zhang, Y-T, Wei, W, Wang, C & Ni, B-J 2022, 'Microbial and physicochemical responses of anaerobic hydrogen-producing granular sludge to polyethylene micro(nano)plastics', Water Research, vol. 221, pp. 118745-118745.
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Micro(nano)plastics is an emerging contaminant in wastewater that has showed significant impacts on various biological treatment processes. Nevertheless, the underlying effects of micro(nano)plastics with different concentrations and sizes on the anaerobic hydrogen-producing granular sludge (HPG) were still unclear. This work firstly attempted to illustrate the microbial and physicochemical responses of HPG to a shock load of polyethylene microplastics (PE-MPs) with varied concentrations and sizes. The results revealed that the PE-MPs inhibitory effect on hydrogen production by HPG was both concentration- and size-dependent. Specifically, the increase of PE-MPs concentration and the decline of PE-MPs size to nano-sized plastics (NPs) significantly decreased the hydrogen yield, downgraded to 79.9 ± 2.6% and 63.0 ± 3.9% (p = 0.001, and 0.0002) of control, respectively, at higher MPs concentration and the smaller MPs size (i.e., NPs). The higher PE-MPs concentration and PE-NPs also suppressed extracellular polymeric substances (EPS) generation more severely. The critical bio-processes involved in hydrogen production were disturbed by PE-MPs, with the extent of negative impacts depending on the dosage and size of PE-MPs. These adverse impacts further manifested as granule disintegration and loss of cellular activity. Mechanism analysis highlighted the roles of oxidative stress, leachate released from PE-MPs, interaction between PE-NPs and granules inducing physical crushing of HPG that led to possible direct contact between cells and toxic substances.
Zhang, Y-T, Wei, W, Wang, C & Ni, B-J 2022, 'Understanding and mitigating the distinctive stresses induced by diverse microplastics on anaerobic hydrogen-producing granular sludge', Journal of Hazardous Materials, vol. 440, pp. 129771-129771.
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This work comparatively studied the different stress responses of anaerobic hydrogen-producing granular sludge (HPG) to several typical MPs in wastewater, i.e., polyethylene (PE), polyethylene terephthalate (PET), and polyvinyl chloride (PVC) MPs. A new approach to mitigating the inhibition caused by MPs based on biochar was then proposed. The results displayed that microbe in HPG had diverse tolerances to PE-MPs, PET-MPs and PVC-MPs, with the hydrogen production downgraded to 82.0 ± 3.2 %, 72.3 ± 2.5 % and 66.6 ± 2.3 % (p < 0.05) of control respectively, due to the distinct leachates toxicities and oxidative stress level induced by different MPs. The discrepant mitigation reflected in the hydrogen yields of biochar-based HPGs raised back to 88.7 ± 1.4 %, 85.3 ± 3.8 % and 88.5 ± 3.5 % of control. The MPs induced disintegrated granule morphology, fragile microbial viability and impaired defensive function of extracellular polymeric substances were restored by biochar. The effective mitigation was revealed to be due to the strong adsorption of MPs by biochar, reducing direct contact between microbes and MPs. Biochar addition also enhanced protection for HPG by increasing EPS secretion and weakened the oxidative damage to anaerobes induced by MPs. Biochar manifested the disparate adsorption properties of three MPs. The most superior mitigation in HPG contaminated by PVC-MPs was attributed to the strongest affinity of biochar to PVC-MPs and effective alleviation of PVC leachates toxicity.
Zhang, Z, Li, X, Liu, H, Zamyadi, A, Guo, W, Wen, H, Gao, L, Nghiem, LD & Wang, Q 2022, 'Advancements in detection and removal of antibiotic resistance genes in sludge digestion: A state-of-art review', Bioresource Technology, vol. 344, no. Pt A, pp. 126197-126197.
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Sludge from wastewater treatment plants can act as a repository and crucial environmental provider of antibiotic resistance genes (ARGs). Over the past few years, people's knowledge regarding the occurrence and removal of ARGs in sludge has broadened remarkably with advancements in molecular biological techniques. Anaerobic and aerobic digestion were found to effectively achieve sludge reduction and ARGs removal. This review summarized advanced detection and removal techniques of ARGs, in the last decade, in the sludge digestion field. The fate of ARGs due to different sludge digestion strategies (i.e., anaerobic and aerobic digestion under mesophilic or thermophilic conditions, and in combination with relevant pretreatment technologies (e.g., thermal hydrolysis pretreatment, microwave pretreatment and alkaline pretreatment) and additives (e.g., ferric chloride and zero-valent iron) were systematically summarized and compared in this review. To date, this is the first review that provides a comprehensive assessment of the state-of-the-art technologies and future recommendations.
Zhang, Z, Xu, T & Castel, A 2022, 'Damage of non-steam-cured UHPC under axial compression with and without short-term sustained loading history', Structures, vol. 38, pp. 1066-1078.
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The damage of non-steam-cured ultra-high performance concrete (UHPC) under short-term sustained compression was experimentally investigated. The UHPC specimens were tested under monotonic loading, cyclic loading without a sustained loading history, or cyclic loading with a sustained loading history. The influence of the sustained stress levels and loading age of UHPC was elucidated. The stress-strain history of the specimens was measured. The effect of damage due to the short-term sustained loading history on the mechanical properties of UHPC was analyzed. The fraction of the sustained strains contributing to the damage was calibrated. The micro-cracking propagation within the UHPC is imagined based on non-destructive testing using an ultrasonic wave method and by assessing the nominal Poisson's ratio. The interface between steel fibers and matrix was observed by Scanning Electron Microscope (SEM). The damage occurred for the UHPC specimens under short-term sustained compression when the sustained stress was higher than 0.7fc′. Both the compressive strength and the elastic modulus of the specimens were reduced. When the sustained stress was greater than or equal to 0.8fc′, the elastic modulus of the UHPC specimens measured during the reloading phase was considerably reduced. The specimen group subjected to a sustained stress of 0.9fc′ with a duration of 128 s experienced a reduction of about 30% in elastic modulus. The damage is statistically independent of the loading age of the UHPC. Damage is characterized by micro-cracking propagation within the UHPC specimens. Microstructural analysis of the interface between steel fibers and matrix shows that under high sustained stress, the bond between the steel fibers and the concrete matrix was impaired by the creep effect and could not prevent the propagation of micro-cracks.
Zhao, E, Walker, PD & Surawski, NC 2022, 'Emissions life cycle assessment of diesel, hybrid and electric buses', Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, vol. 236, no. 6, pp. 1233-1245.
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This paper applies a case study approach for Australia and calculates the equipment life cycle assessment of diesel, hybrid and electric buses. This study prepared the assessment according to the procedures and methodologies outlined in the ISO 14040:2006 Environmental Management – Life Cycle Assessment. The authors have chosen three bus models currently in service in the Australian bus fleet to serve as a baseline model for comparison. The amount of greenhouse gas emissions were calculated from the production, assembly, transportation, maintenance and disposal phases. The results in this study show that the electric bus has a higher total environmental impact than the diesel and hybrid bus, mainly due to the manufacturing of the lithium-ion battery. The results also show that the electric bus has a higher environmental impact than the diesel and hybrid bus (18.2% and 14.7% higher, respectively), albeit specific to the product life cycle and without including operation emissions. However, there are many opportunities to reduce product life cycle emissions, such as improvement in manufacturing efficiency, developing new battery technology and production in regions with low carbon-intense grid-mixes.
Zhao, H, Hu, Y, Tang, Z, Wang, K, Li, Y & Li, W 2022, 'Deterioration of concrete under coupled aggressive actions associated with load, temperature and chemical attacks: A comprehensive review', Construction and Building Materials, vol. 322, pp. 126466-126466.
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Concrete infrastructure subjected to mechanical load or surrounding aggressive environments experiences gradual deterioration of performance. Although many studies have conducted on durability of concrete under single aggressive condition, the related research results have already been well-summarized. The concrete deterioration under coupled actions is severer and more complicated than that under single aggressive conditions. However, few studies have reviewed the studies on this topic. This paper comprehensively reviews the research outcomes of the performance of concrete under various coupled aggressive actions, such as high temperature and impact load, freeze–thaw and fatigue loading, alkali-silica reaction and compression, sulfate attack and dry-wet cycling, chloride penetration and carbonation, as well as acid corrosion and high temperature exposure, and so on. The testing methods, interaction of two aggressive conditions, and strengthening measures have been discussed and summarized correspondingly. The results indicate that the performance degradation under the coupled mechanical load and aggressive environments are much severer compared to the single aggressive environment. The properties of concrete are significantly affected by the severity of coupled aggressive actions, and can be improved at the early-age stage. The experimental methods also have higher impact on the performance of concrete due to different mechanisms, but the difference between under and after high temperature exposures is relatively lower. Finally, some enhancement methods proposed in this review, such as adding fly ash, silica fume, slag, fibers or air-entraining agents, are effective in improving the durability of concrete under coupled aggressive environments.
Zhao, S, Dou, P, Sun, N, Shon, HK & He, T 2022, 'Fabrication of dialyzer membrane-based forward osmosis modules via vacuum-assisted interfacial polymerization for the preparation of dialysate', Journal of Membrane Science, vol. 659, pp. 120814-120814.
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Zhao, T, Wang, S, Li, Y, Jia, C, Su, Z, Hao, D, Ni, B, Zhang, Q & Zhao, C 2022, 'Heterostructured V‐Doped Ni2P/Ni12P5 Electrocatalysts for Hydrogen Evolution in Anion Exchange Membrane Water Electrolyzers', Small, vol. 18, no. 40, pp. e2204758-2204758.
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AbstractRegulating the electronic structure and intrinsic activity of catalysts’ active sites with optimal hydrogen intermediates adsorption is crucial to enhancing the hydrogen evolution reaction (HER) in alkaline media. Herein, a heterostructured V‐doped Ni2P/Ni12P5 (V–Ni2P/Ni12P5) electrocatalyst is fabricated through a hydrothermal treatment and controllable phosphidation process. In comparison with pure‐phase V–Ni2P, in/ex situ characterizations and theoretical calculations reveal a redistribution of electrons and active sites in V–Ni2P/Ni12P5 due to the V doping and heterointerfaces effect. The strong coupling between Ni2P and Ni12P5 at the interface leads to an increased electron density at interfacial Ni sites while depleting at P sites, with V‐doping further promoting the electron accumulation at Ni sites. This is accompanied by the change of active sites from the anionic P sites to the interfacial Ni–V bridge sites in V–Ni2P/Ni12P5. Benefiting from the interface electronic structure, increased number of active sites, and optimized H‐adsorption energy, the V‐Ni2P/Ni12P5 exhibits an overpotential of 62 mV to deliver 10 mA cm–2 and excellent long‐term stability for HER. The V–Ni2P/Ni12P5 catalyst is applied for anion exchange membrane water electrolysis to deliver superior performance with a current density of 500 mA cm–2 at a cell voltage of 1.79 V and excellent durability.
Zhao, Y, Ngo, HH & Yu, X 2022, 'Phytohormone-like small biomolecules for microalgal biotechnology', Trends in Biotechnology, vol. 40, no. 9, pp. 1025-1028.
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Microalgae are highly adaptable to abiotic stress and produce valuable metabolites, but microalgal commercialization is still difficult because of minimal yields. The application of phytohormone-like small biomolecules is effective in simultaneously improving the productivity of valuable microalgal biomass-derived metabolites and stress tolerance. This represents a significant opportunity for microalgal biotechnology.
Zhen, J, Zhao, Y, Yu, X, Guo, W, Qiao, Z, Ismail, S & Ni, S-Q 2022, 'Feasibility of Partial Nitrification Combined with Nitrite-Denitrification Phosphorus Removal and Simultaneous Nitrification–Endogenous Denitrification for Synchronous Chemical Oxygen Demand, Nitrogen, and Phosphorus Removal', ACS ES&T Water, vol. 2, no. 6, pp. 1119-1131.
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Zheng, H, Guan, R, Liu, Q, Ou, K, Li, D-S, Fang, J, Fu, Q & Sun, Y 2022, 'A flexible supercapacitor with high capacitance retention at an ultra-low temperature of -65.0°C', Electrochimica Acta, vol. 424, pp. 140644-140644.
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Zhou, F, Li, S, Ouyang, L, Liu, J, Liu, J, Huang, Z & Zhu, M 2022, 'Facile synthesis of black phosphorene via a low melting media assisted ball milling', Chemical Engineering Journal, vol. 444, pp. 136593-136593.
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Few-layer phosphorene (FLP) has attracted strong research interest due to its extraordinary physical and chemical properties. However, an efficient and rapid fabrication of high-quality FLP is still unavailable. Herein, a simple and efficient low melting media-assisted ball milling (LMMBM) approach is developed to prepare FLP in large quantities. The phase change of the LMM at higher temperatures leads to FLP with larger lateral dimensions compared to the ones obtained via dry solid state ball milling. Transmission electron microscope (TEM) studies indicated that liquid facilitates the slipping/curling of black phosphorus (BP) layers under the shearing force generated during ball milling. When used as an anode in Lithium-ion batteries, the FLP-C composite exhibits high initial Coulombic efficiency, stable cycling and rate capacity. This LMMBM approach can be adopted for mass production of other two-dimensional materials from their bulk counterparts.
Zhou, T, Li, X, Zhang, Q, Dong, S, Liu, H, Liu, Y, Chaves, AV, Ralph, PJ, Ruan, R & Wang, Q 2022, 'Ecotoxicological response of Spirulina platensis to coexisted copper and zinc in anaerobic digestion effluent', Science of The Total Environment, vol. 837, pp. 155874-155874.
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Copper ion (Cu2+) and zinc ion (Zn2+) are widely co-existent in anaerobic digestion effluent as typical contaminants. This work aims to explore how Cu2+-Zn2+ association affects physiological properties of S. platensis using Schlösser medium (SM) and sterilized anaerobic digestion effluent (SADE). Microalgae cells viability, biochemical properties, uptake of Cu2+ and Zn2+, and risk assessment associated with the biomass reuse as additives to pigs were comprehensively assessed. Biomass production ranged from 0.03 to 0.28 g/L in SM and 0.63 to 0.79 g/L in SADE due to the presence of Cu2+ and Zn2+. Peak value of chlorophyll-a and carotenoid content during the experiment decreased by 70-100% and 40-100% in SM, and by 70-77% and 30-55% in SADE. Crude protein level reduced by 4-41% in SM and by 65-75% in SADE. The reduction ratio of these compounds was positively related to the Cu2+ and Zn2+ concentrations. Maximum value of saturated and unsaturated fatty acids was both obtained at 0.3 Cu + 2.0 Zn (50.8% and 22.8%, respectively) and 25% SADE reactors (33.8% and 27.7%, respectively). Uptake of Cu in biomass was facilitated by Zn2+ concentration (> 4.0 mg/L). Risk of S. platensis biomass associated with Cu2+ was higher than Zn2+. S. platensis from SM (Cu2+ ≤ 0.3 mg/L and Zn2+ ≤ 4.0 mg/L) and diluted SADE (25% and 50% SADE) reactors could be used as feed additives without any risk (hazard index <1), which provides sufficient protein and fatty acids for pig consumption. These results revealed the promising application of using S. platensis for bioremediation of Cu2+ and Zn2+ in anaerobic digestion effluent and harvesting biomass for animal feed additives.
Zhou, Y, Kumar, V, Harirchi, S, Vigneswaran, VS, Rajendran, K, Sharma, P, Wah Tong, Y, Binod, P, Sindhu, R, Sarsaiya, S, Balakrishnan, D, Mofijur, M, Zhang, Z, Taherzadeh, MJ & Kumar Awasthi, M 2022, 'Recovery of value-added products from biowaste: A review', Bioresource Technology, vol. 360, pp. 127565-127565.
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This review provides an update on the state-of-the art technologies for the valorization of solid waste and its mechanism to generate various bio-products. The organic content of these wastes can be easily utilized by the microbes and produce value-added compounds. Microbial fermentation techniques can be utilized for developing waste biorefinery processes. The utilization of lignocellulosic and plastics wastes for the generation of carbon sources for microbial utilization after pre-processing steps will make the process a multi-product biorefinery. The C1 and C2 gases generated from different industries could also be utilized by various microbes, and this will help to control global warming. The review seeks to expand expertise about the potential application through several perspectives, factors influencing remediation, issues, and prospects.
Zhu, J, Li, J, Chapman, EC, Shi, H, Ciocan, CM, Chen, K, Shi, X, Zhou, J, Sun, P, Zheng, Y & Rotchell, JM 2022, 'Gonadal Atresia, Estrogen-Responsive, and Apoptosis-Specific mRNA Expression in Marine Mussels from the East China Coast: A Preliminary Study', Bulletin of Environmental Contamination and Toxicology, vol. 108, no. 6, pp. 1111-1117.
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AbstractThis preliminary survey analysed mussel atresia incidences, estrogen-responsive and apoptotic-specific molecular end points, and aqueous and gonadal levels of selected estrogens from the East China coast. Estrogen levels were low (e.g. < LOD-28.36 ng/L, < LOD-3.88 ng/g wet weight of tissue for BPA) relative to worldwide freshwater environments, but high oocyte follicle atresia incidences (up to 26.6%) occurred at selected sites. Expression of estrogen-responsive ER2 was significantly increased in males relative to females at sites with high atresia incidences in females. A second estrogen-responsive gene, V9, was significantly increased at two sites in April in females relative to males; the opposite was true for the remaining two sites. Apoptosis-specific genes (Bcl-2, fas) showed elevated expression in males relative to females at the site with the highest atresia incidence. These results provide coastal estrogen levels and the utility of several estrogen-specific molecular-level markers for marine mussels.
Zhu, P, Pan, X, Shen, Y, Huang, X, Yu, F, Wu, D, Feng, Q, Zhou, J & Li, X 2022, 'Biodegradation and potential effect of ranitidine during aerobic composting of human feces', Chemosphere, vol. 296, pp. 134062-134062.
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Ranitidine is widely concerned due to it is mainly related to the transformation into highly toxic carcinogenic products and non-readily biodegradable characteristics in aquatic environment. In this study, biodegradation of ranitidine during rural human feces (HF) aerobic composting was investigated. Results show that both levels of ranitidine are quickly removed in the first-3-day composting. The microorganisms play a vital role in the ranitidine degradation, especially for Firmicutes at the thermophilic period. The effect of ranitidine on the aerobic composting was further analyzed under the normal content (10 mg/kg) and high content (100 mg/kg). The 10 mg/kg ranitidine quickens temperature rise and organic matter degradation of the composting, while the 100 mg/kg ranitidine produces inhibiting effects. However, the effects only occur in the early stage of composting, and then tend to disappear with the removal of ranitidine. Fluorescence spectra confirm that humification and aromatization of dissolved organic matters (DOMs) in the substrates are fastened in 10 mg/kg group, while delayed in 100 mg/kg group. Metagenomic analysis reveals that relative abundances of Firmicutes and sequences related to carbohydrates metabolism increase in the groups mixed with the ranitidine at the early period. The findings provide the first new and systematical insights into degradation characteristics and potential effect of ranitidine during the rural HF composting.
Zhu, P, Shen, Y, Li, X, Liu, X, Qian, G & Zhou, J 2022, 'Feeding preference of insect larvae to waste electrical and electronic equipment plastics', Science of The Total Environment, vol. 807, no. Pt 3, pp. 151037-151037.
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Waste electrical and electronic equipment (WEEE) plastics not only pollute the environment, but are challenging to treat in an environmentally friendly manner. Biodegradation by insect larvae is potentially an eco-friendly method to treat WEEE plastics, but information about the feeding preference of insect larvae to WEEE plastics is lacking. In this study, a total of nine WEEE and pristine plastics were chosen to feed larvae of the following two insect species, i.e. Galleria mellonella and Tenebrio molitor. G. mellonella larvae significantly favor corresponding pristine plastics compared to two types of WEEE plastics, waste rigid polyurethane (RPU) and waste polystyrene (PS). One possible explanation is the increased chlorine or metals in the WEEE plastics measured using X-ray fluorescence spectrometer analysis. Scanning electron microscopy and Fourier transform infrared spectroscopy show that the destruction of physical structures and changes in surface functional groups were found in the two types of WEEE plastics in the larval frass, implying that the larvae partly biodegraded the plastics. Meanwhile, the powdered waste high impact polystyrene plastics (WHIPS) were ingested, but not the lumpy ones, indicating that the consumption by G. mellonella larvae is improved by the WHIPS physical modification. In addition, G. mellonella larvae presented the following decreasing preference for pristine plastics under individual-plastic-fed mode: RPU > phenol-formaldehyde resin > polyethylene (PE) > polypropylene > PS ≈ polyvinyl chloride; this is possibly due to differences in physical properties and chemical structures of the plastics; feeding preference of the larvae under multiple-plastics-fed mode is relatively consistent to that under individual-plastic-fed mode. Interestingly, the consumption by G. mellonella larvae of PE is higher than that of PS, while T. molitor larvae showed the opposite trend, implying that insect larvae have different plastics pref...
Zhu, Y, Shen, S, Ouyang, L, Liu, J, Wang, H, Huang, Z & Zhu, M 2022, 'Effective synthesis of magnesium borohydride via B-O to B-H bond conversion', Chemical Engineering Journal, vol. 432, pp. 134322-134322.
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Magnesium borohydride (Mg(BH4)2) is widely regarded as a promising hydrogen storage material due to its high capacity; however, it is still challenging to synthesize Mg(BH4)2 with low cost. Traditionally, Mg(BH4)2 has been mainly produced using other borohydride as the starting materials via exchange reactions. Herein, we report an economical method to synthesize Mg(BH4)2 by converting B-O bonds in widely available borates or boric acid to B-H. The borates or boric acid is ball-milled with MgH2 under ambient conditions to form Mg(BH4)2 with high yield (>80%). Mg(BH4)2 was also successfully generated by reacting low-cost Mg with boric acid. Compared with previous approaches, this method avoids expensive boron sources such as LiBH4, NaBH4, and B2H6, and does not require high pressure H2 gas and high temperatures, and therefore significantly reduces costs. This method could be an alternative to the current Mg(BH4)2 synthesis processes.
Zhu, Y-Y, Liu, Y, Xu, J & Ni, B-J 2022, 'Three-dimensional excitation-emission matrix (EEM) fluorescence approach to probing the binding interactions of polystyrene microplastics to bisphenol A', Journal of Hazardous Materials Advances, vol. 5, pp. 100046-100046.
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Zhuang, J-L, Sun, X, Zhao, W-Q, Zhang, X, Zhou, J-J, Ni, B-J, Liu, Y-D, Shapleigh, JP & Li, W 2022, 'The anammox coupled partial-denitrification process in an integrated granular sludge and fixed-biofilm reactor developed for mainstream wastewater treatment: Performance and community structure', Water Research, vol. 210, pp. 117964-117964.
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This study describes an integrated granular sludge and fixed-biofilm (iGB) reactor innovatively designed to carry out the anammox/partial-denitrification (A/PD) process for nitrogen removal with mainstream municipal wastewater. The iGB-A/PD reactor consists of anammox granules inoculated in the lower region of reactor and an acclimated fixed-biofilm positioned in the upper region. Compared to the other reported A/PD systems for mainstream wastewater treatment, this iGB-A/PD reactor is notable due to its higher quality effluent with a total inorganic nitrogen (TIN) of ∼3 mg•L-1 and operation at a high nitrogen removal rate (NRR) of 0.8 ± 0.1 kg-N•m-3•d-1. Reads-based metatranscriptomic analysis found that the expression values of hzsA and hdh, key genes associated with anammox, were much higher than other functional genes on nitrogen conversion, confirming the major roles of the anammox bacteria in nitrogen bio-removal. In both regions of the reactor, the nitrate reduction genes (napA/narG) had expression values of 56-99 RPM, which were similar to that of the nitrite reduction genes (nirS/nirK). The expression reads from genes for dissimilatory nitrate reduction to ammonium (DNRA), nrfA and nirB, were unexpectedly high, and were over the half of the levels of reads from genes required for nitrate reduction. Kinetic assays confirmed that the granules had an anammox activity of 16.2 g-NH4+-N•kg-1-VSS•d-1 and a nitrate reduction activity of 4.1 g-N•kg-1-VSS•d-1. While these values were changed to be 4.9 g- NH4+-N•kg-1-VSS•d-1and 4.3 g-N•kg-1-VSS•d-1 respectively in the fixed-biofilm. Mass flux determination found that PD and DNRA was responsible for ∼50% and ∼25% of nitrate reduction, respectively, in the whole reactor, consistent with high effluent quality and treatment efficiency via a nitrite loop. Metagenomic binning analysis revealed that new and unidentified anammox species, affiliated with Candidatus Brocadia, were the dominant anammox organisms. Myx...
Zou, P, Liu, J, Huang, Z, Hu, R & Ouyang, L 2022, 'Phenylphosphonic acid as a grain-refinement additive for a stable lithium metal anode', Chemical Communications, vol. 58, no. 91, pp. 12724-12727.
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The increased overpotential due to the complexation between phenylphosphonic acid and Li ions can reduce the grain size, boost nucleation rates, and prevent the formation of Li dendrites.
Zuo, W, Zhang, Y, E, J, Huang, Y, Li, Q, Zhou, K & Zhang, G 2022, 'Effects of multi-factors on performance of an improved multi-channel cold plate for thermal management of a prismatic LiFePO4 battery', Energy, vol. 261, pp. 125384-125384.
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In this work, an improved multi-channel cold plate is designed based on a traditional multi-channel cold plate for enhancing its performance. Taguchi experimental design, grey relational analysis and analysis of variance are applied to investigate the effects of multi-factors on the performance of the improved multi-channel cold plate. In addition, j/f factor is employed to evaluate the overall performance of the improved multi-channel cold plate. Results suggest that j/f factor of the improved multi-channel cold plate is the highest when the mass flow rate, channel number, ambient temperature and oblique angle are 0.4 g/s, 6, 35 °C and 45°, respectively. Moreover, the impact of multi-factors on the j/f factor is ranked as: ambient temperature > channel number = oblique angle > mass flow rate > numerical error. Finally, mass flow rate, channel number and ambient temperature dominate the pressure drop, heat transfer coefficient and j/f factor of the improved multi-channel cold plate, respectively. This work provides a significant reference and valuable guidance for designing improved multi-channel cold plates.
