Abdollahi, A & Pradhan, B 2021, 'Integrated technique of segmentation and classification methods with connected components analysis for road extraction from orthophoto images', Expert Systems with Applications, vol. 176, pp. 114908-114908.
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Abdollahi, A & Pradhan, B 2021, 'Integrating semantic edges and segmentation information for building extraction from aerial images using UNet', Machine Learning with Applications, vol. 6, pp. 100194-100194.
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Abdollahi, A & Pradhan, B 2021, 'Urban Vegetation Mapping from Aerial Imagery Using Explainable AI (XAI)', Sensors, vol. 21, no. 14, pp. 4738-4738.
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Urban vegetation mapping is critical in many applications, i.e., preserving biodiversity, maintaining ecological balance, and minimizing the urban heat island effect. It is still challenging to extract accurate vegetation covers from aerial imagery using traditional classification approaches, because urban vegetation categories have complex spatial structures and similar spectral properties. Deep neural networks (DNNs) have shown a significant improvement in remote sensing image classification outcomes during the last few years. These methods are promising in this domain, yet unreliable for various reasons, such as the use of irrelevant descriptor features in the building of the models and lack of quality in the labeled image. Explainable AI (XAI) can help us gain insight into these limits and, as a result, adjust the training dataset and model as needed. Thus, in this work, we explain how an explanation model called Shapley additive explanations (SHAP) can be utilized for interpreting the output of the DNN model that is designed for classifying vegetation covers. We want to not only produce high-quality vegetation maps, but also rank the input parameters and select appropriate features for classification. Therefore, we test our method on vegetation mapping from aerial imagery based on spectral and textural features. Texture features can help overcome the limitations of poor spectral resolution in aerial imagery for vegetation mapping. The model was capable of obtaining an overall accuracy (OA) of 94.44% for vegetation cover mapping. The conclusions derived from SHAP plots demonstrate the high contribution of features, such as Hue, Brightness, GLCM_Dissimilarity, GLCM_Homogeneity, and GLCM_Mean to the output of the proposed model for vegetation mapping. Therefore, the study indicates that existing vegetation mapping strategies based only on spectral characteristics are insufficient to appropriately classify vegetation covers.
Abdollahi, A, Pradhan, B & Alamri, A 2021, 'RoadVecNet: a new approach for simultaneous road network segmentation and vectorization from aerial and google earth imagery in a complex urban set-up', GIScience & Remote Sensing, vol. 58, no. 7, pp. 1151-1174.
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Abdollahi, A, Pradhan, B & Shukla, N 2021, 'Road Extraction from High-Resolution Orthophoto Images Using Convolutional Neural Network', Journal of the Indian Society of Remote Sensing, vol. 49, no. 3, pp. 569-583.
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© 2020, Indian Society of Remote Sensing. Abstract: Two of the major applications in geospatial information system (GIS) and remote sensing fields are object detection and man-made feature extraction (e.g., road sections) from high-resolution remote sensing imagery. Extracting roads from high-resolution remotely sensed imagery plays a crucial role in multiple applications, such as navigation, emergency tasks, land cover change detection, and updating GIS maps. This study presents a deep learning technique based on a convolutional neural network (CNN) to classify and extract roads from orthophoto images. We applied the model on five orthophoto images to specify the superiority of the method for road extraction. First, we used principal component analysis and object-based image analysis for pre-processing to not only obtain spectral information but also add spatial and textural information for enhancing the classification accuracy. Then, the obtained results from the previous step were used as input for the CNN model to classify the images into road and non-road parts and trivial opening and closing operation are applied to extract connected road components from the images and remove holes inside the road parts. For the accuracy assessment of the proposed method, we used measurement factors such as precision, recall, F1 score, overall accuracy, and IOU. Achieved results showed that the average percentages of these factors were 91.09%, 95.32%, 93.15%, 94.44%, and 87.21%. The results were also compared with those of other existing methods. The comparison ascertained the reliability and superior performance of the suggested model architecture for extracting road regions from orthophoto images. Graphic Abstract: [Figure not available: see fulltext.]
Abdollahi, A, Pradhan, B, Sharma, G, Maulud, KNA & Alamri, A 2021, 'Improving Road Semantic Segmentation Using Generative Adversarial Network', IEEE Access, vol. 9, pp. 64381-64392.
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Abeywickrama, A, Indraratna, B, Nguyen, TT & Rujikiatkamjorn, C 2021, 'LABORATORY INVESTIGATION ON THE USE OF VERTICAL DRAINS TO MITIGATE MUD PUMPING UNDER RAIL TRACKS', Australian Geomechanics Journal, vol. 56, no. 3, pp. 117-126.
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The build-up of excess pore water pressure (EPWP) in undrained soft subgrade under repeated rail loads is the key mechanism causing soil to fluidise, consequently yielding slurry tracks (i.e., mud pumping). This issue has substantially reduced transport efficiency associated with immense cost for track maintenance though considerable effort has been made over the past years. Therefore, this study is carried out to investigate how prefabricated vertical drains (PVDs) can be used to mitigate the accumulated EPWP and associated mud pumping. A series of cyclic triaxial tests including undrained (i.e., without PVDs) and PVD-assisted drained soils are conducted, and their results are compared to evaluate the effect of PVDs on cyclic soil behaviour. In this investigation, subgrade soil collected from a mud pumping site is used while loading parameters including the frequency, confining pressure and cyclic stress ratio (CSR) are considered with respect to heavy rail load condition in the field. The results show that PVDs can help dissipate effectively the accumulated EPWP, thus mitigating soil fluidisation. The current study shows that for undrained condition, lower frequency loading (i.e., slower trains) takes a smaller number of cycles to cause soil failure, whereas for drained cases (i.e., PVDs-assisted specimens), an opposite trend is observed. The study proves that installing PVDs into shallow layer (i.e., 3-5 m depth) is an effective approach to stabilise soft subgrade soil under rail tracks.
Abraham, MT, Satyam, N & Pradhan, B 2021, 'Forecasting Landslides Using Mobility Functions: A Case Study from Idukki District, India', Indian Geotechnical Journal, vol. 51, no. 4, pp. 684-693.
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Abraham, MT, Satyam, N, Jain, P, Pradhan, B & Alamri, A 2021, 'Effect of spatial resolution and data splitting on landslide susceptibility mapping using different machine learning algorithms', Geomatics, Natural Hazards and Risk, vol. 12, no. 1, pp. 3381-3408.
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Abraham, MT, Satyam, N, Lokesh, R, Pradhan, B & Alamri, A 2021, 'Factors Affecting Landslide Susceptibility Mapping: Assessing the Influence of Different Machine Learning Approaches, Sampling Strategies and Data Splitting', Land, vol. 10, no. 9, pp. 989-989.
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Data driven methods are widely used for the development of Landslide Susceptibility Mapping (LSM). The results of these methods are sensitive to different factors, such as the quality of input data, choice of algorithm, sampling strategies, and data splitting ratios. In this study, five different Machine Learning (ML) algorithms are used for LSM for the Wayanad district in Kerala, India, using two different sampling strategies and nine different train to test ratios in cross validation. The results show that Random Forest (RF), K Nearest Neighbors (KNN), and Support Vector Machine (SVM) algorithms provide better results than Naïve Bayes (NB) and Logistic Regression (LR) for the study area. NB and LR algorithms are less sensitive to the sampling strategy and data splitting, while the performance of the other three algorithms is considerably influenced by the sampling strategy. From the results, both the choice of algorithm and sampling strategy are critical in obtaining the best suited landslide susceptibility map for a region. The accuracies of KNN, RF, and SVM algorithms have increased by 10.51%, 10.02%, and 4.98% with the use of polygon landslide inventory data, while for NB and LR algorithms, the performance was slightly reduced with the use of polygon data. Thus, the sampling strategy and data splitting ratio are less consequential with NB and algorithms, while more data points provide better results for KNN, RF, and SVM algorithms.
Abraham, MT, Satyam, N, Reddy, SKP & Pradhan, B 2021, 'Runout modeling and calibration of friction parameters of Kurichermala debris flow, India', Landslides, vol. 18, no. 2, pp. 737-754.
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© 2020, Springer-Verlag GmbH Germany, part of Springer Nature. Debris flows account for a substantial economy and property loss in Western Ghats of Kerala, India, especially during monsoon seasons. Wayanad district is an active erosion zone in the plateau margins of Western Ghats, and there is a remarkable rise in the number of debris flows since 2018, due to very high-intensity rainfalls in this region. This study comprises geotechnical investigation, runout modeling, and calibration of friction parameters of Kurichermala debris flow, one of the devastating debris flow events that happened in Wayanad, during the 2018 monsoon. The detailed investigation and back analysis of such events are substantial in calibrating the flow parameters for the region. These parameters can be used for predicting the flow paths of possible debris flows and quantitative risk assessment in the future. The geotechnical investigation provided vital information regarding the soil type and shear strength parameters of the debris flow and has helped in understanding the flow behavior. A dynamic numerical model, rapid mass movements (RAMMS), was used for the back analysis of the debris flow, using the shape information of the flow. For precise calibration using statistical comparison, an image processing tool has been developed, to compare the structural similarity of simulated results with the original shape of debris flow. The dry-Coulomb friction coefficient (μ) was calibrated as 0.01 and turbulent friction coefficient (ξ) as 100 m/s2 for the event, using Voellmy-Salm rheology. The shape predicted by the model had a similarity index of 0.626 with the actual shape of debris flow. The results were found to be in accordance with the field and geotechnical observations. Hence, the results can be used to predict the shape of possible debris flows in the study area. The study is the first of its kind for the region and has significant influence in risk assessment for this highly susceptible l...
Abraham, MT, Satyam, N, Rosi, A, Pradhan, B & Segoni, S 2021, 'Usage of antecedent soil moisture for improving the performance of rainfall thresholds for landslide early warning', CATENA, vol. 200, pp. 105147-105147.
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Landslides triggered by heavy rains are increasing in number and creating severe losses in hilly regions across the world. Rainfall thresholds on regional and local-scales are being used for forecasting such events, for efficient early warning. Empirical and probabilistic approaches for defining rainfall thresholds are traditional tools which are being used as part of the forecasting system for rainfall induced landslides. Such methods are easy-to-use and are based on statistical analyses. They can be derived without looking into the complex hydro-geological processes involved in slope failures, but are often associated with the disadvantage of higher false alarms, limiting their applications in a regional landslide early warning system (LEWS). This study is an attempt to improve the performance of conventional meteorological thresholds by considering the effect of soil moisture, using a probabilistic approach. Idukki district in southern part of India is highly susceptible to landslides and has witnessed major socio-economical setbacks in the recent disasters happened in 2018 and 2019. This tourist hub is now in need of a landslide forecasting system, which can help in landslide risk reduction. This study attempts to understand the effect of averaged soil moisture estimates derived from passive microwave remote sensing data, for improving the performance of conventional empirical and probabilistic thresholds. For defining empirical thresholds, an algorithm-based approach such as Calculation of Thresholds for Rainfall-induced Landslides Tool (CTRL-T) has been used. Probabilistic thresholds were defined using a Bayesian approach, finding the posterior probability of occurrence using the marginal and conditional probabilities of the control parameters along with the prior probability of occurrence of landslide. The derived rainfall thresholds were quantitatively compared with the Bayesian probabilistic threshold derived using rainfall severity and soil we...
Abraham, MT, Satyam, N, Shreyas, N, Pradhan, B, Segoni, S, Abdul Maulud, KN & Alamri, AM 2021, 'Forecasting landslides using SIGMA model: a case study from Idukki, India', Geomatics, Natural Hazards and Risk, vol. 12, no. 1, pp. 540-559.
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Aburas, MM, Ho, YM, Pradhan, B, Salleh, AH & Alazaiza, MYD 2021, 'Spatio-temporal simulation of future urban growth trends using an integrated CA-Markov model', Arabian Journal of Geosciences, vol. 14, no. 2.
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Abuzied, SM & Pradhan, B 2021, 'Hydro-geomorphic assessment of erosion intensity and sediment yield initiated debris-flow hazards at Wadi Dahab Watershed, Egypt', Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards, vol. 15, no. 3, pp. 221-246.
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© 2020, © 2020 Informa UK Limited, trading as Taylor & Francis Group. This study attempts to assess slope and channel erosion for modelling their implications on debris-flow occurrences in Wadi Dahab Watershed (WDW). Remote sensing and Geographic Information System (GIS) were integrated to appraise erosion rates from a hillslope and channel storage throughout WDW. A mass-wasting database was built initially for modelling hazard zones and validating the final map using a bivariate statistical analysis. An Erosion Hazard Model (EHM) was developed to evaluate the erosion intensity and sediment yield throughout WDW and to prognosticate the hazard zones due to debris-flows. The EHM was developed based on hydrological and geomorphic controls which are responsible for disintegrating bedrocks, delivering detritus downslopes, and accelerating debris through channels. Multi-source datasets, including topographic and geologic maps, climatic, satellite images, aerial photographs, and field-based datasets, were used to derive factors associated with the hydro-geomorphic processes. A spatial prediction of erosion intensity was obtained by the integration of both static and dynamic factors generated hazards in GIS platform. The erosion intensity map classifies WDW relatively to five intensity zones in which the most hazardous zones are distributed in steep sloping terrains and structurally controlled channels covered by metamorphic and clastic rocks. The erosion intensity map was correlated and tested against the debris-flows dataset which was not used during the spatial modelling process. The statistical correlation analysis has confirmed that the debris-flow locations increase exponentially in the high erosion intensity zones. The holistic integration approach provides the promising model for forecasting critical zones prone to erosion intensity and their associated hazards in WDW.
Afsari, M, Shon, HK & Tijing, LD 2021, 'Janus membranes for membrane distillation: Recent advances and challenges', Advances in Colloid and Interface Science, vol. 289, pp. 102362-102362.
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© 2021 Elsevier B.V. Membrane distillation (MD) is a promising hybrid thermal-membrane separation technology that can efficiently produce freshwater from seawater or contaminated wastewater. However, the relatively low flux and the presence of fouling or wetting agents in feed solution negate the applicability of MD for long term operation. In recent years, ‘two-faced’ membranes or Janus membranes have shown promising potential to decrease wetting and fouling problem of common MD system as well as enhance the flux performance. In this review, a comprehensive study was performed to investigate the various fabrication, modification, and novel design processes to prepare Janus membranes and discuss their performance in desalination and wastewater treatment utilizing MD. The promising potential, challenges and future prospects relating to the design and use of Janus membranes for MD are also tackled in this review.
Agarwal, A, Foster, SJ & Stewart, MG 2021, 'Model error and reliability of reinforced concrete beams in shear designed according to the Modified Compression Field Theory', Structural Concrete, vol. 22, no. 6, pp. 3711-3726.
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AbstractModel error (or model uncertainty) were probabilistically characterized for modified compression field theory (MCFT) Simplified and General Method approaches using experimental databases that contained reinforced concrete (RC) beams having shear failures with and without stirrups (168 and 368 specimens, respectively). It was found that when compared to the design shear model currently used in ACI‐318, the General Method produced low model error variability indicating better consistency for the determination of shear strength. Structural reliabilities were then calculated for RC beams in shear designed to MCFT General Method (AASHTO LRFD, CSA A23.3‐14, AS3600‐2018) for a live‐to‐dead load ratio between 0 and 5, and for capacity reduction factor ϕ = 0.70, 0.75, and 0.80. It was concluded that the ϕ‐factor for shear failure for Australian standards can be increased from 0.70 to 0.75 for RC beams with stirrups, providing a 7.1% increase in the design shear capacity and contributing to sustainable design and reduction in greenhouse gas emissions due to more efficient usage of materials.
Ahammad, NA, Badruddin, IA, Kamangar, S, Khaleed, HMT, Saleel, CA & Mahlia, TMI 2021, 'Heat Transfer and Entropy in a Vertical Porous Plate Subjected to Suction Velocity and MHD', Entropy, vol. 23, no. 8, pp. 1069-1069.
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This article presents an investigation of heat transfer in a porous medium adjacent to a vertical plate. The porous medium is subjected to a magnetohydrodynamic effect and suction velocity. The governing equations are nondepersonalized and converted into ordinary differential equations. The resulting equations are solved with the help of the finite difference method. The impact of various parameters, such as the Prandtl number, Grashof number, permeability parameter, radiation parameter, Eckert number, viscous dissipation parameter, and magnetic parameter, on fluid flow characteristics inside the porous medium is discussed. Entropy generation in the medium is analyzed with respect to various parameters, including the Brinkman number and Reynolds number. It is noted that the velocity profile decreases in magnitude with respect to the Prandtl number, but increases with the radiation parameter. The Eckert number has a marginal effect on the velocity profile. An increased radiation effect leads to a reduced thermal gradient at the hot surface.
Ahmed, AA, Pradhan, B, Chakraborty, S & Alamri, A 2021, 'Developing vehicular traffic noise prediction model through ensemble machine learning algorithms with GIS', Arabian Journal of Geosciences, vol. 14, no. 16.
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Ahmed, AA, Pradhan, B, Chakraborty, S, Alamri, A & Lee, C-W 2021, 'An Optimized Deep Neural Network Approach for Vehicular Traffic Noise Trend Modeling', IEEE Access, vol. 9, pp. 107375-107386.
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Ahmed, MB, Rahman, MS, Alom, J, Hasan, MDS, Johir, MAH, Mondal, MIH, Lee, D-Y, Park, J, Zhou, JL & Yoon, M-H 2021, 'Microplastic particles in the aquatic environment: A systematic review', Science of The Total Environment, vol. 775, pp. 145793-145793.
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Microplastics (MPs) pollution has become one of the most severe environmental concerns today. MPs persist in the environment and cause adverse effects in organisms. This review aims to present a state-of-the-art overview of MPs in the aquatic environment. Personal care products, synthetic clothing, air-blasting facilities and drilling fluids from gas-oil industries, raw plastic powders from plastic manufacturing industries, waste plastic products and wastewater treatment plants act as the major sources of MPs. For MPs analysis, pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS), Py-MS methods, Raman spectroscopy, and FT-IR spectroscopy are regarded as the most promising methods for MPs identification and quantification. Due to the large surface area to volume ratio, crystallinity, hydrophobicity and functional groups, MPs can interact with various contaminants such as heavy metals, antibiotics and persistent organic contaminants. Among different physical and biological treatment technologies, the MPs removal performance decreases as membrane bioreactor (> 99%) > activated sludge process (~98%) > rapid sand filtration (~97.1%) > dissolved air floatation (~95%) > electrocoagulation (> 90%) > constructed wetlands (88%). Chemical treatment methods such as coagulation, magnetic separations, Fenton, photo-Fenton and photocatalytic degradation also show moderate to high efficiency of MP removal. Hybrid treatment technologies show the highest removal efficacies of MPs. Finally, future research directions for MPs are elaborated.
Ahmed, N, Hoque, MA-A, Pradhan, B & Arabameri, A 2021, 'Spatio-Temporal Assessment of Groundwater Potential Zone in the Drought-Prone Area of Bangladesh Using GIS-Based Bivariate Models', Natural Resources Research, vol. 30, no. 5, pp. 3315-3337.
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Ahmed, N, Howlader, N, Hoque, MA-A & Pradhan, B 2021, 'Coastal erosion vulnerability assessment along the eastern coast of Bangladesh using geospatial techniques', Ocean & Coastal Management, vol. 199, pp. 105408-105408.
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Ahmed, SF, Hafez, MG, Chu, Y-M & Mofijur, M 2021, 'Turbulent energy motion of fiber suspensions in a rotating frame', Alexandria Engineering Journal, vol. 60, no. 3, pp. 3345-3352.
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Turbulent flows play a major role in many fields of science and industry. Noticeable attention is seen on turbulent flows of suspending fibers because of the sensitivity of the electrical, thermal, and mechanical properties of the connecting fiber composites to the spatial configuration and orientation of fibers. The involvement of fibers in the turbulent flow greatly affects the turbulent energy. It is more influenced when the turbulent flow occurs in a rotating system. The effect of fibers on the turbulent energy in the rotating frame must therefore be investigated. For turbulent energy with fiber suspension, a mathematical model can be built in a rotating system that is very important to enhance the quality of industrial goods. This paper, therefore, develops a mathematical model for turbulent energy motion in a rotating frame with a fiber suspension. The model was formulated using the averaging procedure. The momentum equation for incompressible and viscous fluid turbulent flow was considered to develop the model. The turbulent energy motion of the fiber suspensions was presented in the rotating frame in second-order correlation tensors,, and, where all the tensors are the function of time, distance, and space coordinates.
Ahmed, SF, Liu, G, Mofijur, M, Azad, AK, Hazrat, MA & Chu, Y-M 2021, 'Physical and hybrid modelling techniques for earth-air heat exchangers in reducing building energy consumption: Performance, applications, progress, and challenges', Solar Energy, vol. 216, pp. 274-294.
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Noteworthy advancements are seen in developing the earth-air heat exchanger (EAHE) models in the past several decades to reduce building energy consumption. However, it is still an ongoing challenge in selecting and implementing the most suitable and appropriate EAHE modelling technique in buildings based on the climates, performance, and limitations of the techniques. Therefore, this paper aims to review the published research related to the physical, and hybrid EAHE modelling techniques used in buildings, and highlight the prospects, benefits, progress, and challenges of these techniques. This is the first study that comprehensively evidences the prospects and technical challenges caused by unmeasured disturbances, assumptions, or the uncertainties generated in experimental and numerical works of all EAHE modelling techniques. Nevertheless, this study found that hybrid modelling is more effective than physical models for accurate prediction. On the contrary, the hybrid models suffer from high complexity if EAHE operating conditions and all key parameters are considered during the model development. Regarding the generalization capability, the physical models offer improved performance followed by the hybrid models. A minimum number of training data is needed for developing physical models, whereas medium training data is required for the hybrid models. The outcome of this study also provides valuable information regarding the physical and hybrid EAHE modelling techniques to the scientists, researchers, and so on in adopting the most appropriate EAHE modelling technique for their climates.
Ahmed, SF, Mofijur, M, Nuzhat, S, Chowdhury, AT, Rafa, N, Uddin, MA, Inayat, A, Mahlia, TMI, Ong, HC, Chia, WY & Show, PL 2021, 'Recent developments in physical, biological, chemical, and hybrid treatment techniques for removing emerging contaminants from wastewater', Journal of Hazardous Materials, vol. 416, pp. 125912-125912.
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Emerging contaminants (ECs) in wastewater have recently attracted the attention of researchers as they pose significant risks to human health and wildlife. This paper presents the state-of-art technologies used to remove ECs from wastewater through a comprehensive review. It also highlights the challenges faced by existing EC removal technologies in wastewater treatment plants and provides future research directions. Many treatment technologies like biological, chemical, and physical approaches have been advanced for removing various ECs. However, currently, no individual technology can effectively remove ECs, whereas hybrid systems have often been found to be more efficient. A hybrid technique of ozonation accompanied by activated carbon was found significantly effective in removing some ECs, particularly pharmaceuticals and pesticides. Despite the lack of extensive research, nanotechnology may be a promising approach as nanomaterial incorporated technologies have shown potential in removing different contaminants from wastewater. Nevertheless, most existing technologies are highly energy and resource-intensive as well as costly to maintain and operate. Besides, most proposed advanced treatment technologies are yet to be evaluated for large-scale practicality. Complemented with techno-economic feasibility studies of the treatment techniques, comprehensive research and development are therefore necessary to achieve a full and effective removal of ECs by wastewater treatment plants.
Ahmed, SF, Mofijur, M, Tarannum, K, Chowdhury, AT, Rafa, N, Nuzhat, S, Kumar, PS, Vo, D-VN, Lichtfouse, E & Mahlia, TMI 2021, 'Biogas upgrading, economy and utilization: a review', Environmental Chemistry Letters, vol. 19, no. 6, pp. 4137-4164.
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Biogas production is rising in the context of fossil fuel decline and the future circular economy, yet raw biogas requires purification steps before use. Here, we review biogas upgrading using physical, chemical and biological methods such as water scrubbing, physical absorption, pressure swing adsorption, cryogenic separation, membrane separation, chemical scrubbing, chemoautotrophic methods, photosynthetic upgrading and desorption. We also discuss their techno-economic feasibility. We found that physical and chemical upgrading technologies are near-optimal, but still require high energy and resources. Biological methods are less explored despite their promising potential. High-pressure water scrubbing is more economic for small-sized plants, whereas potassium carbonate scrubbing provides the maximum net value for large-sized plants.
Ahmed, SF, Rafa, N, Mofijur, M, Badruddin, IA, Inayat, A, Ali, MS, Farrok, O & Yunus Khan, TM 2021, 'Biohydrogen Production From Biomass Sources: Metabolic Pathways and Economic Analysis', Frontiers in Energy Research, vol. 9.
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The commercialization of hydrogen as a fuel faces severe technological, economic, and environmental challenges. As a method to overcome these challenges, microalgal biohydrogen production has become the subject of growing research interest. Microalgal biohydrogen can be produced through different metabolic routes, the economic considerations of which are largely missing from recent reviews. Thus, this review briefly explains the techniques and economics associated with enhancing microalgae-based biohydrogen production. The cost of producing biohydrogen has been estimated to be between $10 GJ-1 and $20 GJ−1, which is not competitive with gasoline ($0.33 GJ−1). Even though direct biophotolysis has a sunlight conversion efficiency of over 80%, its productivity is sensitive to oxygen and sunlight availability. While the electrochemical processes produce the highest biohydrogen (>90%), fermentation and photobiological processes are more environmentally sustainable. Studies have revealed that the cost of producing biohydrogen is quite high, ranging between $2.13 kg−1 and 7.24 kg−1via direct biophotolysis, $1.42kg−1 through indirect biophotolysis, and between $7.54 kg−1 and 7.61 kg−1via fermentation. Therefore, low-cost hydrogen production technologies need to be developed to ensure long-term sustainability which requires the optimization of critical experimental parameters, microalgal metabolic engineering, and genetic modification.
Ahmed, SF, Saha, SC, Debnath, JC, Liu, G, Mofijur, M, Baniyounes, A, Chowdhury, SMEK & Vo, D-VN 2021, 'Data-driven modelling techniques for earth-air heat exchangers to reduce energy consumption in buildings: a review', Environmental Chemistry Letters, vol. 19, no. 6, pp. 4191-4210.
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Increasing population and urbanization call for smarter cities where the cycles of matter and energy are optimized, notably in buildings which are actually a source of pollution consuming a lot of energy. The efficiency of building energy has been improved by modelling earth-air heat exchangers, yet selecting the suitable models is challenging. Here we review data-driven earth-air heat exchanger models used for buildings. We discuss issues brought about by assumptions, unmeasured disruptions, and uncertainties in numerical and experimental works. We found that high accuracy can be reached if sufficient data is available. Models are appropriate for real-time activity due to their structure simplicity, yet they display a poor generalization capacity. Model development is limited by the constrained parameters and the complex boundary conditions of the heat exchangers.
Ahmed, T, Hossain, SM & Hossain, MA 2021, 'Reducing completion time and optimizing resource use of resource-constrained construction operation by means of simulation modeling', International Journal of Construction Management, vol. 21, no. 4, pp. 404-415.
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© 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group. Traditionally, critical path method (CPM) is widely used with manual resource assignment for planning and scheduling of the construction projects. This is predominant in the construction industry of Bangladesh. Therefore, the industry often faces challenges to complete construction projects in minimum possible time with optimum use of resources. Although, concurrency-based scheduling is an efficient tool to reduce construction completion time, manual formulation of plans for construction operations using the technique is cumbersome (because of complex nature of real-life construction operations, for instance a real-life construction work involves complex interaction between activities, limited number of resources and resource-sharing among activities, etc.) With this viewpoint, the present study aims to introduce computer-aided simulation modelling-based approach to reduce the completion time of a resource-constrained construction operation utilizing the features of concurrency-based scheduling. The study also proposes a method to optimize the resource use of construction operation. A real-life construction work has been considered as the case construction operation for this study. Results indicate that the simulation model developed for the case project can efficiently generate work-flow plans with reduced construction durations compared to the work-flow plan of the actual schedule. The model can also help to optimize the use of resources. Furthermore, the model developed for the case project can easily be reshaped, expanded and applied to other construction operations.
Akbari, M, Meshram, SG, Krishna, RS, Pradhan, B, Shadeed, S, Khedher, KM, Sepehri, M, Ildoromi, AR, Alimerzaei, F & Darabi, F 2021, 'Identification of the Groundwater Potential Recharge Zones Using MCDM Models: Full Consistency Method (FUCOM), Best Worst Method (BWM) and Analytic Hierarchy Process (AHP)', Water Resources Management, vol. 35, no. 14, pp. 4727-4745.
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Akther, N, Kawabata, Y, Lim, S, Yoshioka, T, Phuntsho, S, Matsuyama, H & Shon, HK 2021, 'Effect of graphene oxide quantum dots on the interfacial polymerization of a thin-film nanocomposite forward osmosis membrane: An experimental and molecular dynamics study', Journal of Membrane Science, vol. 630, pp. 119309-119309.
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We report an ultra-low loading of graphene oxide quantum dots (GQDs) into the polyamide (PA) layer of an outer-selective hollow fiber (OSHF) thin-film composite (TFC) membrane using the vacuum-assisted interfacial polymerization (VAIP) technique to improve the water permeability of OSHF TFC membranes without sacrificing membrane selectivity. Experimental results showed that GQD loading in the PA layer influenced membrane performance. The membrane with a GQD loading of 5 mg L (TFN5) demonstrated an optimal water flux of 30.9 L m h and a specific reverse solute flux (SRSF) of 0.12 g L . To investigate the effect of GQDs on the interfacial polymerization (IP) reaction and membrane performance, molecular dynamics (MD) simulation was employed at the water-hexane and water-PA interfaces. The simulation results showed that GQDs decreased the reaction rate during the IP process by reducing the diffusivities of m-phenylenediamine (MPD) and trimesoyl chloride (TMC). Additionally, GQDs reduced water permeability by acting as barriers to water molecules when present at a high concentration near the PA layer surface. At a very high loading, GQDs aggregated at the water-hexane interface and reduced the membrane selectivity by forming non-selective voids at the interface between the PA layer and GQDs. Together with the experimental findings, the MD simulation results delivered a good insight into the GQDs' effect on the TFC membrane's surface and transport properties at both macroscopic and microscopic levels. −1 −2 −1 −1
Akther, N, Lin, Y, Wang, S, Phuntsho, S, Fu, Q, Ghaffour, N, Matsuyama, H & Shon, HK 2021, 'In situ ultrathin silica layer formation on polyamide thin-film composite membrane surface for enhanced forward osmosis performances', Journal of Membrane Science, vol. 620, pp. 118876-118876.
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© 2020 Elsevier B.V. Polyamide (PA) based thin-film composite (TFC) membranes experience a high degree of organic fouling due to their hydrophobic and rough membrane surfaces during forward osmosis (FO) process. In this study, an ultrathin silica layer was grown in situ on the PA surface to enhance the antifouling property of TFC membrane by silicification process. Surface characterization confirmed the development of a silica layer on the PA surface. The superhydrophilic surface of silica-deposited TFC membrane (contact angle of 20°) with 3 h silicification time (STFC-3h) displayed a 53% higher water flux than the pristine TFC membrane without significantly affecting the membrane selectivity. The silica-modified TFC FO membranes also exhibited excellent stability when subjected to long-term cross-flow shear stress rinsing using deionized (DI) water, including exposure to salty, acidic and basic solutions. Moreover, the fouling tests showed that STFC-3h membrane lost only 4.2%, 9.1% and 12.1% of its initial flux with bovine serum albumin (BSA), humic acid (HA) and sodium alginate (SA), respectively, which are considerably lower compared to the pristine TFC FO membrane where flux losses were 18.7%, 23.2% and 37.2%, respectively. The STFC-3h membrane also revealed higher flux recovery ratio (FRR) of 99.6%, 96.9% and 94.4% with BSA, HA and SA, respectively, after physical cleaning than the pristine membrane (91.4%, 88.7%, and 81.2%, respectively). Overall, the in situ formation of an ultrathin hydrophilic silica layer on the PA surface reported in this work shows that the TFC membrane's water flux and antifouling property could be improved without diminishing the membrane selectivity.
Akther, N, Sanahuja-Embuena, V, Górecki, R, Phuntsho, S, Helix-Nielsen, C & Shon, HK 2021, 'Employing the synergistic effect between aquaporin nanostructures and graphene oxide for enhanced separation performance of thin-film nanocomposite forward osmosis membranes', Desalination, vol. 498, pp. 114795-114795.
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Al-Abadi, AM, Fryar, AE, Rasheed, AA & Pradhan, B 2021, 'Assessment of groundwater potential in terms of the availability and quality of the resource: a case study from Iraq', Environmental Earth Sciences, vol. 80, no. 12, pp. 1-22.
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A semi-confined aquifer from Kirkuk Governorate, northern Iraq was taken as a case study to map groundwater potential in terms of both the availability and quality of the resource. In terms of quantity, five machine learning (ML) algorithms were used to model the relationship between locations of 1031 wells with specific-capacity data and nine influential groundwater occurrence factors. The algorithms used were linear discriminant analysis, classification and regression trees, linear vector quantization, random forest, and K-nearest neighbor. The groundwater occurrence factors used were elevation, slope, curvature, aspect, aquifer transmissivity, specific storage, soil, geology, and groundwater depth. Analysis of the worthiness of the factors used in the analysis by the information gain ratio indicated that five out of nine factors were worthy (average merit > 0): groundwater depth, elevation, transmissivity, specific storage, and soil. The remaining factors were non-worthy (average merit = 0) and thus they were removed from the analysis. The performance of the five ML algorithms was investigated using accuracy and kappa as evaluation metrics. Applying the models in the carte package of R software indicated that random forest was the best model. The probability values of this model were used for mapping quantitative groundwater potential after classification into three zones: poor, moderate, and excellent. Groundwater quality for drinking was modeled using the water quality index and the weights of the chemical constituents used (pH, TDS, Ca2+, Mg2+, Na+, SO42-, Cl -, and NO3-) were assigned using entropy information theory. A map of the groundwater quality index revealed five classes: < 50 (excellent), 50–100 (good), 100–150 (moderate), 150–200 (poor), and > 200 (extremely poor). Combining the groundwater quality index map with the groundwater potential map using summation operators revealed three zones of groundwater potential: poor, moderate, and exc...
Alam, MA, Muhammad, G, Khan, MN, Mofijur, M, Lv, Y, Xiong, W & Xu, J 2021, 'Choline chloride-based deep eutectic solvents as green extractants for the isolation of phenolic compounds from biomass', Journal of Cleaner Production, vol. 309, pp. 127445-127445.
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Bioresource valorization to obtain valuable phenolic compounds for medicinal, nutraceutical, food, and cosmetic applications are critical for a current and future sustainable and bio-based economy. Renewable, environmentally friendly, and non-toxic choline chloride-based deep eutectic solvents are the newest and utmost environmentally friendly alternatives to conventional organic solvents for the pretreatment and extraction of phenolic compounds. Recently, numerous studies have focused on phenolic compound extraction using choline chloride-based deep eutectic solvents as solvents or catalysts. Process variable optimization has been reported in terms of kinetic modeling and mechanisms involved in phenolic compounds extraction. This paper describes the cutting-edge methods used to extract phenolic compounds from different bio-based sources using choline chloride-based deep eutectic solvents. In addition, the factors affecting, kinetic models, and mechanisms involved in phenolic compound extraction using choline chloride-based deep eutectic solvents are thoroughly summarized. Moreover, future predictions, challenges, and anticipated growth in this field are addressed and can be used for biomass valorization.
Al-Bawi, AJ, Al-Abadi, AM, Pradhan, B & Alamri, AM 2021, 'Assessing gully erosion susceptibility using topographic derived attributes, multi-criteria decision-making, and machine learning classifiers', Geomatics, Natural Hazards and Risk, vol. 12, no. 1, pp. 3035-3062.
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Gully erosion is an erosive process that contributes considerably to the shape of the earth’s surface and is a major contributor to land degradation and soil loss. This study applied a methodology for mapping gully erosion susceptibility using only topographic related attributes derived from a medium-resolution digital elevation model (DEM) and a hybrid analytical hierarchy process (AHP) and the technique for an order of preference by similarity to ideal solutions (TOPSIS) and compare the results with naïve Bayes (NB) and support vector machine learning (SVM) algorithms. A transboundary sub-basin in an arid area of southern Iraq was selected as a case study. The performance of the developed models was compared using the receiver operating characteristic curve (ROC). Results showed that the areas under the ROC were 0.933, 0.936, and 0.955 for AHP-TOPSIS, NB, and SVM with radial basis function, respectively, which indicated that the performance of simply derived AHP-TOPSIS model is similar to sophisticated NB and SVM models. Findings indicated that a medium resolution DEM and AHP-TOPSIS are a promising tool for mapping of gully erosion susceptibility.
Aldhshan, SRS, Abdul Maulud, KN, Wan Mohd Jaafar, WS, Karim, OA & Pradhan, B 2021, 'Energy Consumption and Spatial Assessment of Renewable Energy Penetration and Building Energy Efficiency in Malaysia: A Review', Sustainability, vol. 13, no. 16, pp. 9244-9244.
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The development of sustainable energy systems is very important to addressing the economic, environmental, and social pressures of the energy sector. Globally, buildings consume up to 40% of the world’s total energy. By 2030, it is expected to increase to 50%. Therefore, the world is facing a great challenge to overcome these problems related to global energy production. Malaysia is one of the top consumers of primary energy in Asia. In 2018, primary energy consumption for Malaysia was 3.79 quadrillion btu at an average annual rate of 4.58%. In this paper, we have carried out a detailed literature review on several previous studies of energy consumption in the world, especially in Malaysia, and how geographical information system (GIS) methods have been used for the spatial assessment of energy efficiency. Indeed, strategies of energy efficiency are essential in energy policy that could be created using various approaches used for energy savings in buildings. The findings of this review reveal that, for estimating energy consumption, exploring renewable energy sources, and investigating solar radiation, several geographic information system techniques such as multiple criteria decision analysis (MCDA), machine learning (ML), and deep learning (DL) are mainly utilized. The result indicates that the fuzzy DS method can more reliably determine the optimal PV farm locations. The 3D models are also regarded as an effective tool for estimating solar radiation, since this method generates a 3D model exportable to software tools. In addition, GIS and 3D can contribute to several purposes, such as sunlight access to buildings in urban areas, city growth prediction models and analysis of the habitability of public places.
Al-Fugara, A, Mabdeh, AN, Ahmadlou, M, Pourghasemi, HR, Al-Adamat, R, Pradhan, B & Al-Shabeeb, AR 2021, 'Wildland Fire Susceptibility Mapping Using Support Vector Regression and Adaptive Neuro-Fuzzy Inference System-Based Whale Optimization Algorithm and Simulated Annealing', ISPRS International Journal of Geo-Information, vol. 10, no. 6, pp. 382-382.
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Fires are one of the most destructive forces in natural ecosystems. This study aims to develop and compare four hybrid models using two well-known machine learning models, support vector regression (SVR) and the adaptive neuro-fuzzy inference system (ANFIS), as well as two meta-heuristic models, the whale optimization algorithm (WOA) and simulated annealing (SA) to map wildland fires in Jerash Province, Jordan. For modeling, 109 fire locations were used along with 14 relevant factors, including elevation, slope, aspect, land use, normalized difference vegetation index (NDVI), rainfall, temperature, wind speed, solar radiation, soil texture, topographic wetness index (TWI), distance to drainage, and population density, as the variables affecting the fire occurrence. The area under the receiver operating characteristic (AUROC) was used to evaluate the accuracy of the models. The findings indicated that SVR-based hybrid models yielded a higher AUROC value (0.965 and 0.949) than the ANFIS-based hybrid models (0.904 and 0.894, respectively). Wildland fire susceptibility maps can play a major role in shaping firefighting tactics.
Ali, SM, Im, S-J, Jang, A, Phuntsho, S & Shon, HK 2021, 'Forward osmosis system design and optimization using a commercial cellulose triacetate hollow fibre membrane module for energy efficient desalination', Desalination, vol. 510, pp. 115075-115075.
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This study is aimed at developing system mathematical design models to simulate and optimize a full scale forward osmosis (FO) for a hollow fibre membrane module for energy efficient desalination. Experimental data from a commercial outer selective CTA hollow fibre FO membrane module was used for validation. Less than 10% difference between the simulation and experimental results were observed which validated the reliability of the models. Simulation and design were performed for a 1000 m3/day FO plant using 0.6 M NaCl as draw solution (DS) (~seawater) and 0.02 M NaCl feed solution (FS) (~MBR effluent) to produce 0.25, 0.2 and 0.15 M NaCl diluted seawater to reduce the energy consumption of downstream pressure driven desalination process. A single element parallel module arrangement was found more suitable for this commercial hollow fibre membrane element. Finally, the numerical simulations revealed that to achieve 0.25, 0.20 and 0.15 M final DS concentrations, the optimum number of modules required were 370, 435 and 555 respectively considering membrane cost and energy consumption. The FO system using the commercial CTA hollow fibre module was found more energy efficient than a commercial TFC spiral wound membrane module.
Ali, SM, Kim, Y, Qamar, A, Naidu, G, Phuntsho, S, Ghaffour, N, Vrouwenvelder, JS & Shon, HK 2021, 'Dynamic feed spacer for fouling minimization in forward osmosis process', Desalination, vol. 515, pp. 115198-115198.
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In this study, a dynamic feed spacer is used to minimize the fouling problem of forward osmosis (FO) membrane process. The conceptual design of the spacer consists of a series of microturbines assembled in ladder type filament cells and termed as turbospacer. It exploits the kinetic energy of the flowing feed solution to rotate the turbines and creates high flow turbulence in the feed channel to prevent the accumulation of foulants and related performance decline. This proof of concept study employed a 3D printed prototype of the proposed spacer in a lab-scale FO experimental setup to compare their performances with a symmetric non-woven spacer of the same thickness under the same operating condition as a reference. Primary effluent from municipal wastewater treatment plant was used as feed solution for a short term (6 days) fouling experiment in this study. Outcomes of the FO fouling experiment revealed that the turbospacer resulted in (i) a factor 2 lower spacer channel pressure drop built-up, and (ii) a 15% reduction in flux decline compared to the reference symmetric spacer. Almost 2.5 times lower foulant resistance was obtained by using the turbospacer at the end of the fouling experiment. In addition, the analysis of the foulant layer growth over a particular position of the membrane surface captured by an optical coherence tomography (OCT) device at different stages of the experiment exhibited that the turbospacer produced a thinner foulant layer. In summary, the turbospacer demonstrated better fouling prevention and control in the FO process.
Alibeikloo, M, Khabbaz, H, Fatahi, B & Le, TM 2021, 'Reliability Assessment for Time-Dependent Behaviour of Soft Soils Considering Cross Correlation between Visco-Plastic Model Parameters', Reliability Engineering & System Safety, vol. 213, pp. 107680-107680.
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An elastic visco-plastic creep model was combined with the Monte-Carlo probabilistic method incorporating multivariate copula and nonlinear analysis to investigate the effects of uncertainties in the elastic visco-plastic model parameters on time-dependent settlement and the distribution of excess pore water pressure in soft soils under applied loads. The elastic-plastic model parameter (λ/V) and creep coefficient (ψ0/V) were considered as random variables with lognormal distribution while considering the cross correlation between these two random variables. When λ/V and ψ0/V were used as random variables, the coefficient of variation of time-dependent deformation gradually decreased approximately 25% over time until reaching an asymptote. By adopting over 50 years of monitoring data from the case study of Väsby test fill and results from the settlement ratio, the most appropriate cross correlation coefficient between selected random variables was introduced. The results revealed that increasing the cross correlation coefficient between λ/V and ψ0/V increased the standard deviation and the coefficient of variation of settlement up to 40%. Meanwhile, the corresponding statistical features for the predicted excess pore water pressure decreased as the cross correlation coefficient increased. This study also provides a practical insight into selecting the most suitable cross correlation coefficient between elastic visco-plastic model parameters, while adopting reliability-based design approach that captures the time-dependent deformation of embankments and structures built on soft soils.
Allioux, F-M, Merhebi, S, Tang, J, Zhang, C, Merenda, A, Cai, S, Ghasemian, MB, Rahim, MA, Maghe, M, Lim, S, Zhang, J, Hyde, L, Mayyas, M, Cunning, BV, Ruoff, RS & Kalantar-Zadeh, K 2021, 'Carbonization of low thermal stability polymers at the interface of liquid metals', Carbon, vol. 171, pp. 938-945.
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Almuntashiri, A, Hosseinzadeh, A, Volpin, F, Ali, SM, Dorji, U, Shon, H & Phuntsho, S 2021, 'Removal of pharmaceuticals from nitrified urine', Chemosphere, vol. 280, pp. 130870-130870.
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In this study, granular activated carbon (GAC) was examined for the removal of five of the most commonly detected pharmaceuticals (naproxen, carbamazepine, acetaminophen, ibuprofen and metronidazole) from a nitrified urine to make the urine-derived fertiliser nutrient safe for food crops. Batch experiments were conducted to investigate the adsorption kinetics that described the removal of micropollutants (equal concentrations of 0.2 mM) from the synthetic nitrified urine at different GAC dosages (10-3000 mg/L). Artificial neural network modelling was also used to predict and simulate the removal of pharmaceuticals from nitrified urine. Langmuir and Freundlich isotherm models described the equilibrium data, with the Langmuir model providing slightly higher correlations. At the highest dose of 3000 mg/L GAC, all the pharmaceuticals showed a removal rates of over 90% after 1 h of adsorption time and 99% removal rates after 6 h of adsorption time. This study concludes that GAC is able to remove the targeted xenobiotics without affecting the concentration of N and P in the urine, suggesting that nitrified urine could be safely used as a nutrient product in future.
Al-Najjar, HAH & Pradhan, B 2021, 'Spatial landslide susceptibility assessment using machine learning techniques assisted by additional data created with generative adversarial networks', Geoscience Frontiers, vol. 12, no. 2, pp. 625-637.
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In recent years, landslide susceptibility mapping has substantially improved with advances in machine learning. However, there are still challenges remain in landslide mapping due to the availability of limited inventory data. In this paper, a novel method that improves the performance of machine learning techniques is presented. The proposed method creates synthetic inventory data using Generative Adversarial Networks (GANs) for improving the prediction of landslides. In this research, landslide inventory data of 156 landslide locations were identified in Cameron Highlands, Malaysia, taken from previous projects the authors worked on. Elevation, slope, aspect, plan curvature, profile curvature, total curvature, lithology, land use and land cover (LULC), distance to the road, distance to the river, stream power index (SPI), sediment transport index (STI), terrain roughness index (TRI), topographic wetness index (TWI) and vegetation density are geo-environmental factors considered in this study based on suggestions from previous works on Cameron Highlands. To show the capability of GANs in improving landslide prediction models, this study tests the proposed GAN model with benchmark models namely Artificial Neural Network (ANN), Support Vector Machine (SVM), Decision Trees (DT), Random Forest (RF) and Bagging ensemble models with ANN and SVM models. These models were validated using the area under the receiver operating characteristic curve (AUROC). The DT, RF, SVM, ANN and Bagging ensemble could achieve the AUROC values of (0.90, 0.94, 0.86, 0.69 and 0.82) for the training; and the AUROC of (0.76, 0.81, 0.85, 0.72 and 0.75) for the test, subsequently. When using additional samples, the same models achieved the AUROC values of (0.92, 0.94, 0.88, 0.75 and 0.84) for the training and (0.78, 0.82, 0.82, 0.78 and 0.80) for the test, respectively. Using the additional samples improved the test accuracy of all the models except SVM. As a result, in data-scarce e...
Al-Najjar, HAH, Pradhan, B, Kalantar, B, Sameen, MI, Santosh, M & Alamri, A 2021, 'Landslide Susceptibility Modeling: An Integrated Novel Method Based on Machine Learning Feature Transformation', Remote Sensing, vol. 13, no. 16, pp. 3281-3281.
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Landslide susceptibility modeling, an essential approach to mitigate natural disasters, has witnessed considerable improvement following advances in machine learning (ML) techniques. However, in most of the previous studies, the distribution of input data was assumed as being, and treated, as normal or Gaussian; this assumption is not always valid as ML is heavily dependent on the quality of the input data. Therefore, we examine the effectiveness of six feature transformations (minimax normalization (Std-X), logarithmic functions (Log-X), reciprocal function (Rec-X), power functions (Power-X), optimal features (Opt-X), and one-hot encoding (Ohe-X) over the 11conditioning factors (i.e., altitude, slope, aspect, curvature, distance to road, distance to lineament, distance to stream, terrain roughness index (TRI), normalized difference vegetation index (NDVI), land use, and vegetation density). We selected the frequent landslide-prone area in the Cameron Highlands in Malaysia as a case study to test this novel approach. These transformations were then assessed by three benchmark ML methods, namely extreme gradient boosting (XGB), logistic regression (LR), and artificial neural networks (ANN). The 10-fold cross-validation method was used for model evaluations. Our results suggest that using Ohe-X transformation over the ANN model considerably improved performance from 52.244 to 89.398 (37.154% improvement).
Alqaisi, R, Le, TM & Khabbaz, H 2021, 'Combined effects of eggshell powder and hydrated lime on the properties of expansive soils', Australian Geomechanics Journal, vol. 56, no. 1, pp. 107-118.
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This study involves the utilization of eggshell powder (ESP) as a supplementary additive to lime stabilization of expansive soil and evaluates its potential in enhancing the performance of expansive soil treated with lime. Eggshell is a waste material obtained from several sources. Some of the challenges associated with dumping eggshell are odour, insect growth, disposal costs and availability of disposal sites. In order to reduce these environmental issues, eggshells can be processed into ESP and play a role as a soil stabilizing agent. Calcium oxide is considered to be the main ingredient of the ESP. Therefore, an experimental program is carried out to test a mixture of kaolinite, bentonite and Sydney fine sand, which is simulated to be as an artificial expansive soil. The eggshell powder was used as an additive to 5% lime in four percentages of 5%, 10%, 15% and 20% by total dry weight of the soil mass. Results of linear shrinkage, proctor compaction, and unconfined compressive strength tests after various curing time are presented in detail and compared with untreated soil samples. The outcomes of these experimental investigations indicated that the combination of eggshell powder and hydrated lime led to a further decrease in linear shrinkage and the maximum dry density of expansive soil samples. It was found that the improved geotechnical characteristics were more pronounced for 5% ESP treated expansive soil. At this percentage, the compressive strength at failure and the corresponding strain increased slightly by 18% and 9%, respectively, compared to the untreated expansive soil after 28 days of curing. Moreover, in comparison with lime (5%) only stabilized expansive soil, the combined lime (5%) and ESP (5%), induced approximately 15% build-up in the compressive strength of samples. Based on the reasonable laboratory test results, this addition is recommended to improve the shrinkage properties and stabilize the expansive soils where the high perfo...
Al-Shetwi, AQ, Hannan, MA, Abdullah, MA, Rahman, MSA, Ker, PJ, Alkahtani, AA, Mahlia, TMI & Muttaqi, KM 2021, 'Utilization of Renewable Energy for Power Sector in Yemen: Current Status and Potential Capabilities', IEEE Access, vol. 9, pp. 79278-79292.
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A severe energy crisis has plagued Yemen for decades, and most of the population lack access to electricity. This has harmed the country’s economic, social, and industrial growth. Yemen generates electricity mainly from fossil fuels, despite having a high potential for renewable energy. Unfortunately, the situation has recently been compounded by the country’s continuing war, which has been ongoing since early 2015. It has impacted the country’s energy infrastructure negatively, resulting in power outages. Therefore, this paper aims to provide an updated perspective on Yemen’s current energy crisis and explain its key issues and potential solutions. Besides, it examines the potential, development, and current state of renewable energy sources, such as solar, wind, geothermal, and biomass. Based on the findings, Yemen is one of the world’s wealthiest countries in terms of sunlight and wind speed, and these two resources are abundant in all regions of the country. In addition, this paper sheds light on the solar energy revolution that has arisen since the war started due to the complete outage of the national electricity. Within a few years, solar energy in Yemen has increased its capacity by 50 times and has recently become the primary source of electricity for most Yemenis. Furthermore, the paper discusses the difficulties and challenges that face the implementation of renewable energy investment projects. Numerous recommendations for potential improvements in Yemen’s widespread use of renewable energy are also provided in this paper. All of the ideas presented in this paper are hoped to increase the efforts to grow renewable energy production in Yemen, thereby solving the issues of energy poverty and reducing environmental effects. The presented analysis can be used as a scientific reference for researchers and industrial companies looking for suitable solutions to advance Yemen’s renewable energy.
AlZainati, N, Saleem, H, Altaee, A, Zaidi, SJ, Mohsen, M, Hawari, A & Millar, GJ 2021, 'Pressure retarded osmosis: Advancement, challenges and potential', Journal of Water Process Engineering, vol. 40, pp. 101950-101950.
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An excessive amount of renewable energy could be possibly produced when solutions of dissimilar salinities are combined simultaneously in a semipermeable membrane. The aforestated energy harnessing for transformation into power could be achieved through the pressure retarded osmosis (PRO) process. The PRO system utilizes a semipermeable membrane for separating a low concentration solution from a pressurized-high concentrated solution. This work examines the recent developments and applications of the PRO process and potential energy that could be conceivably harvested from salinity gradient resources in a single-stage and multi-stage PRO processes. One of the existing challenges for this process is finding a commercial membrane that combines characteristics of the forward osmosis membrane (for reducing the phenomenon of concentration polarization) and the reverse osmosis membrane (to withstand high hydraulic pressure). For addressing this challenge, details about the commercial PRO membranes and the innovative laboratory fabricated PRO membranes are introduced. The potential of the PRO process is presented by elucidating salinity gradient resources, the energy of Pretreatment, the process design, PRO-desalination systems, and dual-stage PRO (DSPRO). It is anticipated that this paper can assist in widely understanding the PRO process and thus deliver important data for activating additional research and development.
An, N, Zhang, H, Zhu, X & Xu, F 2021, 'A Hybrid Approach for the Dynamic Instability Analysis of Single-Layer Latticed Domes with Uncertainties', International Journal of Structural Stability and Dynamics, vol. 21, no. 06, pp. 2150082-2150082.
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Currently, there is no unified criterion to evaluate the failure of single-layer latticed domes, and an accurate nonlinear time-history analysis (NTHA) is generally required; however, this does not consider the uncertainties found in practice. The seismic instability of domes subjected to earthquake ground motions has not been thoroughly investigated. In this paper, a new approach is developed to automatically capture the instability points in the incremental dynamic analysis (IDA) of single-layer lattice domes by integrating different efficient and robust methods. First, a seismic fragility analysis with instability parameters is performed using the bootstrap calibration method for the perfect dome. Second, based on the Sobol sequence, the quasi-Monte Carlo (QMC) sampling method is used to efficiently calculate the failure probability of the dome with uncertain parameters, in which the truncated distributions of random parameters are considered. Third, the maximum entropy principle (MEP) method is used to improve the computational efficiency in the analyses of structures with uncertainties. Last, the uncertain interval of the domes is determined based on the IDA method. The proposed method has been used to investigate the instability of single-layer lattice domes with uncertain parameters. The results show that it can determine the probability of structural failure with high efficiency and reliability. Additionally, the limitations of the proposed method for parallel computation are discussed.
Andaryani, S, Nourani, V, Ball, J, Jahanbakhsh Asl, S, Keshtkar, H & Trolle, D 2021, 'A comparison of frameworks for separating the impacts of human activities and climate change on river flow in existing records and different near‐future scenarios', Hydrological Processes, vol. 35, no. 7.
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AbstractSeparating the effects of human activities/climate change on lotic ecosystems is one of the important components of environmental management as well as water resources maintenance. A Mann–Kendall analysis of hydro‐climatic parameters and vegetation cover (VC), calculated using normalized difference vegetation index (NDVI), during the period 1985–2014 suggested a significant decrease and increase of river flow and temperature at p < 0.01, as well as an insignificant decline and increment of precipitation and VC, respectively within the arid and semi‐arid region, that is, Zilbier River basin in north‐western Iran. A separation of human activities/climate change effects on the reduction of river flow was carried out using three alternative approaches: a simple eco‐hydrological method (coupled water‐energy budget (ECH)), elasticity‐based analysis (Budyko framework (EBA)), and a process‐based watershed model based on the Soil and Water Assessment Tool (SWAT). The efficiency of these approaches was assessed over the periods 1985–1994, 1995–2014, and under five potential near‐future human activities/climate change scenarios (S1–S5) by 2030. The results indicated that the climate change impacts on river flow was more severe than those of human activities. Climate change contributed to an average of 83.6% and 77.0% reduction in river flow in the past and the realistic future scenarios (i.e., S4 and S5), respectively, while human activities accounted for 16.4% and 30%. According to our findings, despite the fact that ECH results are more in line with the SWAT model, in case of physical characterization inaccessibility, ECH and EBA (as simple descriptive and quantitative models, respectively) can be used to separate, simulate and project the impacts of human activities and climate changes on river flow.
Arabameri, A, Chandra Pal, S, Costache, R, Saha, A, Rezaie, F, Seyed Danesh, A, Pradhan, B, Lee, S & Hoang, N-D 2021, 'Prediction of gully erosion susceptibility mapping using novel ensemble machine learning algorithms', Geomatics, Natural Hazards and Risk, vol. 12, no. 1, pp. 469-498.
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Spatial modelling of gully erosion at regional level is very relevant for local authorities to establish successful counter-measures and to change land-use planning. This work is exploring and researching the potential of a genetic algorithm-extreme gradient boosting (GE-XGBoost) hybrid computer education solution for spatial mapping of the susceptibility of gully erosion. The new machine learning approach is to combine the extreme gradient boosting machine (XGBoost) and the genetic algorithm (GA). The GA metaheuristic is being used to improve the efficiency of the XGBoost classification approach. A GIS database has been developed that contains recorded instances of gully erosion incidents and 18 conditioning variables. These parameters are used as predictive variables used to assess the condition of non-erosion or erosion in a given region within the Kohpayeh-Sagzi River Watershed research area in Iran. Exploratory results indicate that the proposed GE-XGBoost model is superior to the other benchmark solution with the desired predictive precision (89.56%). Therefore, the newly built model may be a promising method for large-scale mapping of gully erosion susceptibility.
Arandiyan, H, S. Mofarah, S, Sorrell, CC, Doustkhah, E, Sajjadi, B, Hao, D, Wang, Y, Sun, H, Ni, B-J, Rezaei, M, Shao, Z & Maschmeyer, T 2021, 'Defect engineering of oxide perovskites for catalysis and energy storage: synthesis of chemistry and materials science', Chemical Society Reviews, vol. 50, no. 18, pp. 10116-10211.
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The present work provides a critical review of the science and technological state-of-the-art of defect engineering applied to oxide perovskites in thermocatalytic, electrocatalytic, photocatalytic, and energy-storage applications.
Arivalagan, J, Rujikiatkamjorn, C, Indraratna, B & Warwick, A 2021, 'The role of geosynthetics in reducing the fluidisation potential of soft subgrade under cyclic loading', Geotextiles and Geomembranes, vol. 49, no. 5, pp. 1324-1338.
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The instability of railway tracks including mud pumping, ballast degradation, and differential settlement on weak subgrade soils occurs due to cyclic stress from heavy haul trains. Although geotextiles are currently being used as a separator in railway and highway embankments, their ability to prevent the migration of fine particles and reduce cyclic pore pressure has to be investigated under adverse hydraulic conditions to prevent substructure failures. This study primarily focuses on using geosynthetics to mitigate the migration of fine particles and the accumulation of excess pore pressure (EPP) due to mud pumping (subgrade fluidisation) using dynamic filtration apparatus. The role that geosynthetics play in controlling and preventing mud pumping is analysed by assessing the development of EPP, the change in particle size distribution and the water content of subgrade soil. Using 3 types of geotextiles, the potential for fluidisation is assessed by analysing the time-dependent excess pore pressure gradient (EPPG) inside the subgrade. The experimental results are then used to evaluate the performance of selected geotextiles under heavy haul loading.
Awang, MSN, Mohd Zulkifli, NW, Abbas, MM, Amzar Zulkifli, S, Kalam, MA, Ahmad, MH, Mohd Yusoff, MNA, Mazlan, M & Daud, WMAW 2021, 'Effect of Addition of Palm Oil Biodiesel in Waste Plastic Oil on Diesel Engine Performance, Emission, and Lubricity', ACS Omega, vol. 6, no. 33, pp. 21655-21675.
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Azeez, OS, Pradhan, B & Jena, R 2021, 'Urban tree classification using discrete-return LiDAR and an object-level local binary pattern algorithm', Geocarto International, vol. 36, no. 16, pp. 1785-1803.
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Urban trees have the potential to mitigate some of the harm brought about by rapid urbanization and population growth, as well as serious environmental degradation (e.g. soil erosion, carbon pollution and species extirpation), in cities. This paper presents a novel urban tree extraction modelling approach that uses discrete laser scanning point clouds and object-based textural analysis to (1) develop a model characterised by four sub-models, including (a) height-based split segmentation, (b) feature extraction, (c) texture analysis and (d) classification, and (2) apply this model to classify urban trees. The canopy height model is integrated with the object-level local binary pattern algorithm (LBP) to achieve high classification accuracy. The results of each sub-model reveal that the classification of urban trees based on the height at 47.14 (high) and 2.12 m (low), respectively, while based on crown widths were highest and lowest at 22.5 and 2.55 m, respectively. Results also indicate that the proposed algorithm of urban tree modelling is effective for practical use.
Badeti, U, Pathak, NK, Volpin, F, Dorji, U, Freguia, S, Shon, HK & Phuntsho, S 2021, 'Impact of source-separation of urine on effluent quality, energy consumption and greenhouse gas emissions of a decentralized wastewater treatment plant', Process Safety and Environmental Protection, vol. 150, pp. 298-304.
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The impact of urine diversion on the biological treatment processes at a decentralized wastewater treatment plant (WWTP) was investigated. BioWin software was used for the simulations, and the model was firstly validated with data from a real WWTP. The simulations showed that upto 82 % N, 30 % P, 6% chemical oxygen demand (COD) load to the WWTP can be reduced by complete urine diversion but effluent N reduction was notable up to 75 % urine diversion. Under the current WWTP operating conditions, the simulations suggest that 33 % of aeration energy can be saved by 90 % urine diversion. Direct N2O and CO2 emissions in the treatment processes can also be reduced by 98 % and 25 % respectively. Indirect green house gas emissions can also be reduced by 20 %. Overall, the reduction in the discharge of nutrients and in the operation of blowers was found to contribute to a 22 % reduction in the operating costs (on energy consumption and nutrient discharge).
Bagheri, S, Huang, Y, Walker, PD, Zhou, JL & Surawski, NC 2021, 'Strategies for improving the emission performance of hybrid electric vehicles', Science of The Total Environment, vol. 771, pp. 144901-144901.
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Low emission vehicle technologies need widespread adoption in the transport sector to overcome its significant decarbonisation challenges. Hybrid Electric Vehicles (HEVs) represent an intermediate technology between pure electric vehicles and internal combustion engines that have proven capability in reducing petroleum consumption. HEV customers often cite improved fuel economy as a major benefit from adopting this technology; however, outstanding questions remain regarding their respective emission levels. Through an extensive literature study, we show that several issues remain with HEV emissions performance which stem from frequent high-power cold starts, engine calibration issues and inefficient operating conditions for catalytic converters. HEVs have more NOx, HC, CO and particle number emissions compared to conventional vehicles by up to 21.0, 5.8, 9.0 and 23.3 times, respectively. Improved engine control algorithms, after-treatment design and thermal design of three-way catalysts emerge as research priorities for improving the emissions performance of HEVs.
Bai, X, Hou, S, Wang, X, Hao, D, Sun, B, Jia, T, Shi, R & Ni, B-J 2021, 'Mechanism of surface and interface engineering under diverse dimensional combinations: the construction of efficient nanostructured MXene-based photocatalysts', Catalysis Science & Technology, vol. 11, no. 15, pp. 5028-5049.
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Proposed scheme of the surface and interface engineering to improve the charge separation efficiency of MXene-based photocatalysts.
Bai, X, Jia, T, Wang, X, Hou, S, Hao, D & Bingjie-Ni 2021, 'High carrier separation efficiency for a defective g-C3N4 with polarization effect and defect engineering: mechanism, properties and prospects', Catalysis Science & Technology, vol. 11, no. 16, pp. 5432-5447.
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Different types of defects in g-C3N4 induce polarization effect to promote the separation of charge carriers and improve the photocatalytic efficiency.
Balakrishnan, HK, Badar, F, Doeven, EH, Novak, JI, Merenda, A, Dumée, LF, Loy, J & Guijt, RM 2021, '3D Printing: An Alternative Microfabrication Approach with Unprecedented Opportunities in Design', Analytical Chemistry, vol. 93, no. 1, pp. 350-366.
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In the past decade, 3D printing technologies have been adopted for the fabrication of microfluidic devices. Extrusion-based approaches including fused filament fabrication (FFF), jetting technologies including inkjet 3D printing, and vat photopolymerization techniques including stereolithography (SLA) and digital light projection (DLP) are the 3D printing methods most frequently adopted by the microfluidic community. Each printing technique has merits toward the fabrication of microfluidic devices. Inkjet printing offers a good selection of materials and multimaterial printing, and the large build space provides manufacturing throughput, while FFF offers a great selection of materials and multimaterial printing but at lower throughput compared to inkjet 3D printing. Technical and material developments adopted from adjacent research fields and developed by the microfluidic community underpin the printing of sub-100 μm enclosed microchannels by DLP, but challenges remain in multimaterial printing throughput. With the feasibility of 3D printed microfluidics established, we look ahead at trends in 3D printing to gain insights toward the future of this technology beyond the sole prism of being an alternative fabrication approach. A shift in emphasis from using 3D printing for prototyping, to mimic conventionally manufactured outputs, toward integrated approaches from a design perspective is critically developed.
Balakrishnan, HK, Doeven, EH, Merenda, A, Dumée, LF & Guijt, RM 2021, '3D printing for the integration of porous materials into miniaturised fluidic devices: A review', Analytica Chimica Acta, vol. 1185, pp. 338796-338796.
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Porous materials facilitate the efficient separation of chemicals and particulate matter by providing selectivity through structural and surface properties and are attractive as sorbent owing to their large surface area. This broad applicability of porous materials makes the integration of porous materials and microfluidic devices important in the development of more efficient, advanced separation platforms. Additive manufacturing approaches are fundamentally different to traditional manufacturing methods, providing unique opportunities in the fabrication of fluidic devices. The complementary 3D printing (3DP) methods are each accompanied by unique opportunities and limitations in terms of minimum channel size, scalability, functional integration and automation. This review focuses on the developments in the fabrication of 3DP miniaturised fluidic devices with integrated porous materials, focusing polymer-based methods including fused filament fabrication (FFF), inkjet 3D printing and digital light projection (DLP). The 3DP methods are compared based on resolution, scope for multimaterial printing and scalability for manufacturing. As opportunities for printing pores are limited by resolution, the focus is on approaches to incorporate materials with sub-micron pores to be used as membrane, sorbent or stationary phase in separation science using Post-Print, Print-Pause-Print and In-Print processes. Technical aspects analysing the efficiency of the fabrication process towards scalable manufacturing are combined with application aspects evaluating the separation and/or extraction performance. The review is concluded with an overview on achievements and opportunities for manufacturable 3D printed membrane/sorbent integrated fluidic devices.
Balogun, A-L, Yekeen, ST, Pradhan, B & Wan Yusof, KB 2021, 'Oil spill trajectory modelling and environmental vulnerability mapping using GNOME model and GIS', Environmental Pollution, vol. 268, no. Pt A, pp. 115812-115812.
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This study develops an oil spill environmental vulnerability model for predicting and mapping the oil slick trajectory pattern in Kota Tinggi, Malaysia. The impact of seasonal variations on the vulnerability of the coastal resources to oil spill was modelled by estimating the quantity of coastal resources affected across three climatic seasons (northeast monsoon, southwest monsoon and pre-monsoon). Twelve 100 m3 (10,000 splots) medium oil spill scenarios were simulated using General National Oceanic and Atmospheric Administration Operational Oil Modeling Environment (GNOME) model. The output was integrated with coastal resources, comprising biological, socio-economic and physical shoreline features. Results revealed that the speed of an oil slick (40.8 m per minute) is higher during the pre-monsoon period in a southwestern direction and lower during the northeast monsoon (36.9 m per minute). Evaporation, floating and spreading are the major weathering processes identified in this study, with approximately 70% of the slick reaching the shoreline or remaining in the water column during the first 24 h (h) of the spill. Oil spill impacts were most severe during the southwest monsoon, and physical shoreline resources are the most vulnerable to oil spill in the study area. The study concluded that variation in climatic seasons significantly influence the vulnerability of coastal resources to marine oil spill.
Bao, T, Damtie, MM, Wei, W, Phong Vo, HN, Nguyen, KH, Hosseinzadeh, A, Cho, K, Yu, ZM, Jin, J, Wei, XL, Wu, K, Frost, RL & Ni, B-J 2021, 'Simultaneous adsorption and degradation of bisphenol A on magnetic illite clay composite: Eco-friendly preparation, characterizations, and catalytic mechanism', Journal of Cleaner Production, vol. 287, pp. 125068-125068.
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Excess bisphenol A (BPA) is a pollutant of concern in different water sources. In this work, magnetic illite clay-composite material (Fe3O4@illite) was synthesized via the coprecipitation method by loading Fe3O4 nanoparticles (nano-Fe3O4) onto the surfaces of illite clay. Results from different characterizations showed that nano-Fe3O4 was embedded into illite clay nanosheets and existed on the surfaces of illite clay, thereby reducing the degree of agglomeration and improving dispersibility. The catalytic BPA degradation of Fe3O4@illite and nano-Fe3O4 confirmed the superior performance of Fe3O4@illite compared with that of nano-Fe3O4. The optimum operating parameters for degradation were 0.3 mL of H2O2 at pH of 3 in the presence of Fe3O4@illite, which provided a maximum degradation capacity up to 816, 364, 113, and 68 mg/g for epoxy BPA concentration of resin wastewater (266 mg/L), synthetic wastewater (80 mg/L), Hefei City swan lake (25 mg/L), and Hefei University lake wastewater (14.94 mg/L), respectively, in 180 min reaction time. The degradation data conformed to the pseudo-first-order kinetic model. The degradation pathways and mineralization study revealed that the adsorption-Fenton-like reaction was the principal mechanism that demonstrated 100% degradation efficiency of Fe3O4@illite even after nine successive runs. The regeneration and reusability tendency analysis ensured that Fe3O4@illite can be easily separated by using magnets. Therefore, Fe3O4@illite composite with H2O2 Fenton-like technology was a promising method for BPA degradation.
Baral, P, Indraratna, B, Rujikiatkamjorn, C, Kelly, R & Vincent, P 2021, 'Consolidation by Vertical Drains beneath a Circular Embankment under Surcharge and Vacuum Preloading', Journal of Geotechnical and Geoenvironmental Engineering, vol. 147, no. 8, pp. 05021004-05021004.
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A membrane-type vacuum consolidation system, including surcharge loading and prefabricated vertical drains, was applied to rapidly consolidate soft clay beneath a circular embankment located at the National Field Testing Facility (NFTF) at Ballina, New South Wales (NSW), Australia. Most previous studies were devoted to multidrain systems corresponding to an embankment strip loading in two-dimensional (2D) plane strain. So far, no case study has been investigated using vacuum consolidation via prefabricated vertical drains (PVDs) beneath a circular loaded area, where the system conforms to an axisymmetric problem. This paper outlines the site investigation, construction technique, and installation of a suite of instrumentation on this circular embankment. It also describes and discusses consolidation during and after the construction of this embankment in terms of settlement, excess pore water pressure, lateral deformation, and water flow relationships as they pertain to prediction embankment with vertical drains and surcharge only. The case study demonstrates that a loss of vacuum pressure can be prevented using the proposed approach in a membrane system. Treatment of water extracted using the vacuum consolidation technique, especially in acid-sulfate terrain, is also presented.
Baral, P, Rujikiatkamjorn, C, Indraratna, B, Leroueil, S & Yin, J-H 2021, 'Closure to “Radial Consolidation Analysis Using Delayed Consolidation Approach” by Pankaj Baral, Cholachat Rujikiatkamjorn, Buddhima Indraratna, Serge Leroueil, and Jian-Hua Yin', Journal of Geotechnical and Geoenvironmental Engineering, vol. 147, no. 1, pp. 07020025-07020025.
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Barbieri, DM, Lou, B, Passavanti, M, Hui, C, Hoff, I, Lessa, DA, Sikka, G, Chang, K, Gupta, A, Fang, K, Banerjee, A, Maharaj, B, Lam, L, Ghasemi, N, Naik, B, Wang, F, Foroutan Mirhosseini, A, Naseri, S, Liu, Z, Qiao, Y, Tucker, A, Wijayaratna, K, Peprah, P, Adomako, S, Yu, L, Goswami, S, Chen, H, Shu, B, Hessami, A, Abbas, M, Agarwal, N & Rashidi, TH 2021, 'Impact of COVID-19 pandemic on mobility in ten countries and associated perceived risk for all transport modes', PLOS ONE, vol. 16, no. 2, pp. e0245886-e0245886.
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The restrictive measures implemented in response to the COVID-19 pandemic have triggered sudden massive changes to travel behaviors of people all around the world. This study examines the individual mobility patterns for all transport modes (walk, bicycle, motorcycle, car driven alone, car driven in company, bus, subway, tram, train, airplane) before and during the restrictions adopted in ten countries on six continents: Australia, Brazil, China, Ghana, India, Iran, Italy, Norway, South Africa and the United States. This cross-country study also aims at understanding the predictors of protective behaviors related to the transport sector and COVID-19. Findings hinge upon an online survey conducted in May 2020 (N = 9,394). The empirical results quantify tremendous disruptions for both commuting and non-commuting travels, highlighting substantial reductions in the frequency of all types of trips and use of all modes. In terms of potential virus spread, airplanes and buses are perceived to be the riskiest transport modes, while avoidance of public transport is consistently found across the countries. According to the Protection Motivation Theory, the study sheds new light on the fact that two indicators, namely income inequality, expressed as Gini index, and the reported number of deaths due to COVID-19 per 100,000 inhabitants, aggravate respondents’ perceptions. This research indicates that socio-economic inequality and morbidity are not only related to actual health risks, as well documented in the relevant literature, but also to the perceived risks. These findings document the global impact of the COVID-19 crisis as well as provide guidance for transportation practitioners in developing future strategies.
Barua, PD, Dogan, S, Tuncer, T, Baygin, M & Acharya, UR 2021, 'Novel automated PD detection system using aspirin pattern with EEG signals', Computers in Biology and Medicine, vol. 137, pp. 104841-104841.
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Basack, S, Goswami, G & Nimbalkar, S 2021, 'Analytical and Numerical Solutions to Selected Research Problems in Geomechanics and Geohydraulics', WSEAS TRANSACTIONS ON APPLIED AND THEORETICAL MECHANICS, vol. 16, pp. 222-231.
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Geomechanical and geohydraulic engineering is a promising study area with several emerging research concerns. Most of such problems requires advanced level of mathematics to arrive at specific solutions. A wide range of approaches includes several analytical and numerical techniques for better understanding of such problems. In this paper, a few selected research problems are identified, and their solution techniques are demonstrated. The specific areas relevant to such problems are soil-structure interaction, ground improvement and groundwater hydraulics. This paper presents the problem identification, their mathematical solutions and results as well as pertinent analyses and useful interpretations to practice.
Basaglia, BM, Li, J, Shrestha, R & Crews, K 2021, 'Response Prediction to Walking-Induced Vibrations of a Long-Span Timber Floor', Journal of Structural Engineering, vol. 147, no. 2, pp. 1-15.
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Long-span timber floors are susceptible to annoying floor vibrations caused by human activities, which, in many cases, govern the timber floor design. Consequently, a reliable prediction of floor vibration responses under human activities, which relies on appropriate walking load models, can be crucial in the design to keep timber floors remaining competitive in the commercial building market. Much of the current design guidance for timber floor vibrations have been established from short-span floors in a residential context, and as a result, many designers refer to established design methods formulated for use with concrete and steel-framed buildings. These guidelines predict the floor response based on a deterministic single-person walking load model that differs depending on the classification of the floor as either a high- or low-frequency floor, which are assumed as a transient or resonant floor response, respectively. Recent advances in modeling human walking have been made, including a single footfall trace load that avoids the need to classify the floor, as well as load models that incorporate a probabilistic approach. To date, an investigation on different walking load models to predict the vibration response of long-span timber floors has not been undertaken, partially due to the fact that there are limited examples in practice. This paper presents the results of a recently completed state-of-the-art research project involving full-scale testing of long-span timber floors and the development of novel numerical models to investigate the applicability of the deterministic walking load model used in current floor vibration design guides, as well as two innovative single-person walking load models for predicting the floor responses of a single long-span timber cassette floor. The numerical investigation was carried out with a finite-element model calibrated with experimentally obtained modal properties. The comparison between the predicted respons...
Basha, JS, Jafary, T, Vasudevan, R, Bahadur, JK, Ajmi, MA, Neyadi, AA, Soudagar, MEM, Mujtaba, MA, Hussain, A, Ahmed, W, Shahapurkar, K, Rahman, SMA & Fattah, IMR 2021, 'Potential of Utilization of Renewable Energy Technologies in Gulf Countries', Sustainability, vol. 13, no. 18, pp. 10261-10261.
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This critical review report highlights the enormous potentiality and availability of renewable energy sources in the Gulf region. The earth suffers from extreme air pollution, climate changes, and extreme problems due to the enormous usage of underground carbon resources applications materialized in industrial, transport, and domestic sectors. The countries under Gulf Cooperation Council, i.e., Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, and the United Arab Emirates, mainly explore those underground carbon resources for crude oil extraction and natural gas production. As a nonrenewable resource, these are bound to be exhausted in the near future. Hence, this review discusses the importance and feasibility of renewable sources in the Gulf region to persuade the scientific community to launch and explore renewable sources to obtain the maximum benefit in electric power generation. In most parts of the Gulf region, solar and wind energy sources are abundantly available. However, attempts to harness those resources are very limited. Furthermore, in this review report, innovative areas of advanced research (such as bioenergy, biomass) were proposed for the Gulf region to extract those resources at a higher magnitude to generate surplus power generation. Overall, this report clearly depicts the current scenario, current power demand, currently installed capacities, and the future strategies of power production from renewable power sources (viz., solar, wind, tidal, biomass, and bioenergy) in each and every part of the Gulf region.
Bayazidy-Hasanabad, M, Vayghan, SS, Ghasemkhani, N, Pradhan, B & Alamri, A 2021, 'Developing a volunteered geographic information-based system for rapidly estimating damage from natural disasters', Arabian Journal of Geosciences, vol. 14, no. 17.
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Baygin, M, Dogan, S, Tuncer, T, Datta Barua, P, Faust, O, Arunkumar, N, Abdulhay, EW, Emma Palmer, E & Rajendra Acharya, U 2021, 'Automated ASD detection using hybrid deep lightweight features extracted from EEG signals', Computers in Biology and Medicine, vol. 134, pp. 104548-104548.
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Baygin, M, Yaman, O, Tuncer, T, Dogan, S, Barua, PD & Acharya, UR 2021, 'Automated accurate schizophrenia detection system using Collatz pattern technique with EEG signals', Biomedical Signal Processing and Control, vol. 70, pp. 102936-102936.
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Bhol, P, Yadav, S, Altaee, A, Saxena, M, Misra, PK & Samal, AK 2021, 'Graphene-Based Membranes for Water and Wastewater Treatment: A Review', ACS Applied Nano Materials, vol. 4, no. 4, pp. 3274-3293.
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Bulzinetti, MA, Abraham, MT, Satyam, N, Pradhan, B & Segoni, S 2021, 'Combining rainfall thresholds and field monitoring data for development of LEWS.'.
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<p>Landslide Early Warning Systems (LEWS) can provide enough time to take necessary precautions before the occurrence of landslides and can reduce the risk associated with it. Deriving empirical rainfall thresholds is the conventional approach in developing regional scale LEWS, but the major drawback of this approach is the relatively high number of false alarms. In this study, a prototype method for LEWS is proposed by combining rainfall thresholds and field monitoring data from MicroElectroMechanical Systems (MEMS) units that integrate a tilt sensor, a soil moisture meter and a real-time wireless transmitter. The study was conducted in the Kalimpong district of West Bengal, India. Tilt sensors were installed at different locations on unstable slopes of Kalimpong since July 2017 and the observations from July 2017 to August 2020 were used to enhance the performance of the existing rainfall thresholds.</p><p>During this period, both rainfall thresholds and tilt meters, when used separately, systematically overestimated landslide hazard, producing high false alarm rates. However, it was found that using a decisional algorithm that combines both approaches can reduce the false alarms and improve the overall efficiency of the system from 84 % (based on rainfall thresholds) to 92 % (combined method). The prototype LEWS is found to be promising to be developed as an operational LEWS capable to issue alerts with a lead time of 24 h.&#160;</p><p>The method is simple and can be easy exported to other sites with historical rainfall and landslide data and a network of slope monitoring sensors. Cost of installation of a large number of sensors is a major concern for developing countries like India, hence a cost-effective approach is used in this study: the use of MEMS sensors along with empirical rainfall thresholds is thus a simple and economical approach for the prediction of l...
Cao, D-F, Zhu, H-H, Guo, C-C, Wu, J-H & Fatahi, B 2021, 'Investigating the hydro-mechanical properties of calcareous sand foundations using distributed fiber optic sensing', Engineering Geology, vol. 295, pp. 106440-106440.
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Cao, J, Gowripalan, N, Sirivivatnanon, V & South, W 2021, 'Accelerated test for assessing the potential risk of alkali-silica reaction in concrete using an autoclave', Construction and Building Materials, vol. 271, pp. 121871-121871.
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To rapidly assess the potential risk of alkali-silica reaction (ASR) in concrete, an accelerated test using an autoclave by adopting multi-cycle 80 °C steam warming at atmospheric pressure is proposed. The influence of autoclave steam warming temperature, cycles/duration, and alkali dosage on expansion of mortar bars and concrete prisms was evaluated. Mechanical properties of concrete under accelerated ASR test were investigated. Furthermore, SEM-EDS analysis confirmed ASR products and indicated that the expansion is caused by ASR. The expansion limits considered for classifying aggregates were discussed. The experimental results demonstrated that the period required for assessing the potential risk of ASR in concrete (dacite aggregate in this study) can be shortened to 37 days.
Cao, Y, Sheng, L, Cheng, H, Wang, C, Sun, Y & Fu, Q 2021, 'In situ synthesis of metal‐free N‐GQD@g‐C 3 N 4 photocatalyst for enhancing photocatalytic activity', Micro & Nano Letters, vol. 16, no. 1, pp. 77-82.
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Graphitic carbon nitride modified with N-doped graphene quantum dot (N-GQDs/g-C3N4) was prepared by an in situ method, in which the g-C3N4 was synthesized in the presence of N-GQD. Furthermore, the structure and photocatalytic degradation performance of in situ synthesised N-GQDs/g-C3N4 were investigated and compared with N-GQDs/g-C3N4 prepared by traditional mixing method. The removal efficiency was about 98.0% for the photocatalytic degradation of RhB after 70 min, which was larger comparing with other GQDs/g-C3N4 reported in previous works. The result was attributed to uniform distribution of N-GQDs on surface of g-C3N4, leading to more photogenerated electrons transfer. This work did not only report a new synthesis method of N-GQDs/g-C3N4, but also provided a new method to improve photodegradation performance of photocatalyst based on g-C3N4.
Chakraborty, S, Dann, C, Mandal, A, Dann, B, Paul, M & Hafeez-Baig, A 2021, 'Effects of rubric quality on marker variation in higher education', Studies in Educational Evaluation, vol. 70, pp. 100997-100997.
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Variation among markers has the potential to disadvantage students by contributing to a discrepancy in assessments in higher education settings. In this study, we extended a previous study that analyzed first-year students’ results in a Business Faculty within an Australian university to understand the extent of variation within and between multiple markers and across multiple courses. The study investigated the potential influence of quality of rubrics and associated documentation provided as marker guidance. Results indicated that specific features of rubrics, such as the inclusion of clear indicators of quality, had an observable effect on marker variation.
Chen, C-Y, Chen, W-H, Lim, S, Ong, HC & Ubando, AT 2021, 'Synergistic interaction and biochar improvement over co-torrefaction of intermediate waste epoxy resins and fir', Environmental Technology & Innovation, vol. 21, pp. 101218-101218.
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This study investigated the synergistic effect of co-torrefaction with intermediate waste epoxy resins and fir in a batch-type reactor towards biochar improvement. The synergistic effect ratio was used to judge the interaction between the two materials assisted by statistical tools. The main interaction between the feedstocks was the catalytic reaction and blocking effect. Sodium presented in the intermediate waste had a pronounced catalytic effect on the liquid products during torrefaction. It successfully enhanced the volatile matter emissions and exhibited an antagonistic effect on the solid yield. Different from the catalytic reaction that occurred during short retention time, the blocking effect was more noticeable with a longer duration, showing a synergistic effect on the solid yield. Alternatively, a significantly antagonistic effect was exerted on oxygen content, while the carbon content displayed a converse trend. This gave rise to a major antagonistic effect on the O/C ratio which was closer to coal for pure materials torrefaction. The other spotlight in this study was to reuse the tar as a heating value additive. After coating it onto the biochar, the higher heating value could be increased by up to 5.4%. Although tar is considered as an unwanted byproduct of torrefaction treatment, the presented data show its high potential to be recycled into useful calorific value enhancer. It also fulfills the scope of waste-to-energy in this study.
Chen, J, Indraratna, B, Vinod, JS, Ngo, NT, Gao, R & Liu, Y 2021, 'Stress-dilatancy behaviour of fouled ballast: experiments and DEM modelling', Granular Matter, vol. 23, no. 4.
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This paper presents a study of the mechanical behaviour of ballast contaminated by different fouling agents such as coal and subgrade clay. Large-scale direct shear tests were carried out to examine the strength and deformation properties for coal-fouled and clay-fouled ballast. The experimental results show that fouled ballast (both clay and coal) exhibits a lower peak shear strength and decreased dilation during shearing. The clay-fouled ballast shows higher shear strength and smaller dilation compared to coal-fouled ballast. The relationship between shear stress and dilatancy of ballast under different fouling conditions is reported in this paper, where the numerical predictions are made using the discrete element method (DEM). The DEM simulations show that with the increase of fouling level, the coordination number, the average contact force, the particle rotation and the velocity decrease for ballast aggregates. The results indicate that coal-fouled ballast exhibits a smaller average contact forces with less stress concentrations, less major principal stress orientation and a greater coordination number, leading to less particle rotation and velocity compared to those of clay-fouled ballast for the same degree of fouling. Graphic abstract: [Figure not available: see fulltext.]
Chen, Q, Peng, W, Yu, R, Tao, G & Nimbalkar, S 2021, 'Laboratory Investigation on Particle Breakage Characteristics of Calcareous Sands', Advances in Civil Engineering, vol. 2021, pp. 1-8.
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Many studies have demonstrated the fragility of calcareous sands even under small stresses. This bears an adverse influence on their engineering properties. A series of laboratory tests were carried out on poor-graded calcareous sands to investigate the crushability mechanism. Einav’s relative breakage and fractal dimension were used as the particle breakage indices. The results show that the particles broke into smaller fragments at the low-stress level by attrition which was caused by friction and slip between particles. In contrast, particles broke in the form of crushing at the relatively higher stresses. The evolution of the particle size was reflected by the variation in Einav’s relative breakage and fractal dimension. As testing commenced, the breakage index rapidly increased. When the stress was increased to 400 kPa, the rate of increase in the breakage index was retarded. As the stress was further increased beyond 800 kPa, the rate of increase in the fractal index became much smaller. This elucidated that the well-graded calcareous sands could resist crushing depending on the range of applied stresses. Based on the test findings, a new breakage law is proposed.
Chen, Q, Yu, R, Li, Y, Tao, G & Nimbalkar, S 2021, 'Cyclic stress-strain characteristics of calcareous sand improved by polyurethane foam adhesive', Transportation Geotechnics, vol. 31, pp. 100640-100640.
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Chen, Q, Yu, R, Tao, G, Zhang, J & Nimbalkar, S 2021, 'Shear behavior of polyurethane foam adhesive improved calcareous sand under large-scale triaxial test', Marine Georesources & Geotechnology, vol. 39, no. 12, pp. 1449-1458.
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Chen, Q-S, Peng, W, Tao, G-L & Nimbalkar, S 2021, 'Strength and Deformation Characteristics of Calcareous Sands Improved by PFA', KSCE Journal of Civil Engineering, vol. 25, no. 1, pp. 60-69.
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© 2020, Korean Society of Civil Engineers. Calcareous sand is widely distributed in the islands of the South China Sea, which could be promisingly used as the construction materials. However, particle breakage commonly occurs in calcareous sands, which may significantly influence their mechanical characteristics. To address these issues, an eco-friendly agent, i.e., polyurethane foam adhesive (PFA) is proposed to improve the engineering properties of calcareous sands, compared to the commonly used alkaline stabilizing agents (e.g., lime, cement). The objective of this work is to examine the effectiveness of using PFA in improving the strength-deformation properties of calcareous sand. A series of laboratory tests including direct shear tests, unconfined compression tests, and oedometer tests were performed on the calcareous sands improved by PFA. In addition, A scanning electron microscope (SEM) was conducted to reveal microstructural analysis of using PFA for calcareous sand. The experimental results provided insights into the shear strength, deformation modulus, as well as the micro-structural characteristics of improved calcareous sands with various PFA contents and particle size distributions.
Chen, W-H, Cheng, C-L, Lee, K-T, Lam, SS, Ong, HC, Ok, YS, Saeidi, S, Sharma, AK & Hsieh, T-H 2021, 'Catalytic level identification of ZSM-5 on biomass pyrolysis and aromatic hydrocarbon formation', Chemosphere, vol. 271, pp. 129510-129510.
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Chen, W-H, Chiu, G-L, Chyuan Ong, H, Shiung Lam, S, Lim, S, Sik Ok, Y & E.Kwon, E 2021, 'Optimization and analysis of syngas production from methane and CO2 via Taguchi approach, response surface methodology (RSM) and analysis of variance (ANOVA)', Fuel, vol. 296, pp. 120642-120642.
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Chen, W-H, Du, J-T, Lee, K-T, Ong, HC, Park, Y-K & Huang, C-C 2021, 'Pore volume upgrade of biochar from spent coffee grounds by sodium bicarbonate during torrefaction', Chemosphere, vol. 275, pp. 129999-129999.
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A novel approach for upgrading the pore volume of biochar at low temperatures using a green additive of sodium bicarbonate (NaHCO3) is developed in this study. The biochar was produced from spent coffee grounds (SCGs) torrefied at different temperatures (200-300 °C) with different residence times (30-60 min) and NaHCO3 concentrations (0-8.3 wt%). The results reveal that the total pore volume of biochar increases with rising temperature, residence time, or NaHCO3 aqueous solution concentration, whereas the bulk density has an opposite trend. The specific surface area and total pore volume of pore-forming SCG from 300 °C torrefaction for 60 min with an 8.3 wt% NaHCO3 solution (300-TP-SCG) are 42.050 m2 g-1 and 0.1389 cm3·g-1, accounting for the improvements of 141% and 76%, respectively, compared to the parent SCG. The contact angle (126°) and water activity (0.48 aw) of 300-TP-SCG reveal that it has long storage time. The CO2 uptake capacity of 300-TP-SCG is 0.32 mmol g-1, rendering a 39% improvement relative to 300-TSCG, namely, SCG torrefied at 300 °C for 60 min. 300-TP-SCG has higher HHV (28.31 MJ·kg-1) and lower ignition temperature (252 °C). Overall, it indicates 300-TP-SCG is a potential fuel substitute for coal. This study has successfully produced mesoporous biochar at low temperatures to fulfill '3E', namely, energy (biofuel), environment (biowaste reuse solid waste), and circular economy (bioadsorbent).
Chen, W-H, Lo, H-J, Yu, K-L, Ong, H-C & Sheen, H-K 2021, 'Valorization of sorghum distillery residue to produce bioethanol for pollution mitigation and circular economy', Environmental Pollution, vol. 285, pp. 117196-117196.
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Chen, X, Hu, Z, Xie, H, Ngo, HH, Guo, W & Zhang, J 2021, 'Enhanced biocatalysis of phenanthrene in aqueous phase by novel CA-Ca-SBE-laccase biocatalyst: Performance and mechanism', Colloids and Surfaces A: Physicochemical and Engineering Aspects, vol. 611, pp. 125884-125884.
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Chen, X, Huo, P, Liu, J, Li, F, Yang, L, Li, X, Wei, W, Liu, Y & Ni, B-J 2021, 'Model predicted N2O production from membrane-aerated biofilm reactor is greatly affected by biofilm property settings', Chemosphere, vol. 281, pp. 130861-130861.
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Even though modeling has been frequently used to understand the autotrophic deammonification-based membrane-aerated biofilm reactor (MABR), the relationships between system-specific biofilm property settings and model predicted N2O production have yet to be clarified. To this end, this study investigated the impacts of 4 key biofilm property settings (i.e., biofilm thickness/compactness, boundary layer thickness, diffusivity of soluble components in the biofilm structure, and biofilm discretization) on one-dimensional modeling of the MABR, with the focus on its N2O production. The results showed that biofilm thickness/compactness (200-1000 μm), diffusivity of soluble components in the biofilm structure (reduction factor of diffusivity: 0.2-0.9), and biofilm discretization (12-28 grid points) significantly influenced the simulated N2O production, while boundary layer thickness (0-300 μm) only played a marginal role. In the studied ranges of biofilm property settings, distinct upper and lower bounds of N2O production factor (i.e., the percentage ratio of N2O formed to NH4+ removed, 5.5% versus 2.3%) could be predicted. In addition to the microbial community structure, the N2O production pathway contribution differentiation was also subject to changes in biofilm property settings. Therefore, biofilm properties need to be quantified experimentally or set properly to model N2O production from the MABR correctly. As a good practice for one-dimensional modeling of N2O production from biofilm-based reactors, especially the MABR performing autotrophic deammonification, the essential information about those influential biofilm property settings identified in this study should be disclosed and clearly documented, thus ensuring both the reproducibility of modeling results and the reliable applications of N2O models.
Chen, Y, Wu, D, Yu, Y & Gao, W 2021, 'An improved theory in the determination of aerodynamic damping for a horizontal axis wind turbine (HAWT)', Journal of Wind Engineering and Industrial Aerodynamics, vol. 213, pp. 104619-104619.
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The aerodynamic damping reflects the aero-structure interaction and is intrinsically involved in a fully coupled turbine. However, it is still of great importance to theoretically quantify the aerodynamic damping of a HAWT in some cases. The existing theory can reasonably characterize the aerodynamic damping level of a HAWT with rigid blades, minute shaft tilt and yaw angles, while certain discrepancies were observed when compared with either experimental or numerical damping results of a more realistic turbine. This study aims to provide an improved theory to incorporate more realistic conditions (i.e., blade flexibility, shaft tilt and yaw angle) in aerodynamic damping estimation. Good agreements are found between the proposed theory and numerical results with varied influential factors, upon which modification factors against the original theory are created and discussed. Finally, the aerodynamic damping of tower is determined and included in a decoupled fatigue analysis framework to demonstrate the potential application of this improved aerodynamic damping theory.
Chen, Y, Wu, D, Yu, Y & Gao, W 2021, 'Do cyclone impacts really matter for the long-term performance of an offshore wind turbine?', Renewable Energy, vol. 178, pp. 184-201.
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With the transition on planning and construction of offshore wind turbine (OWT) from North Europe to other regions like America and East Asia, challenges are proposed for the direct application of international OWT experience to these territories due to disparate natural condition like cyclones. This article is intended to evaluate the impact of cyclone on the long-term performance of an OWT to be installed in cyclone-prone regions. To have a comprehensive consideration on the aero-hydro-structural-soil interaction, an improved decoupled method is proposed and validated for an onshore wind turbine before its application to an OWT. Two cyclone models combined with two wave theories are considered in the fatigue evaluation of an OWT under different working status, and their implications on the final estimation of fatigue damage are compared and discussed. The results obtained from this study indicate that the fatigue life reduction which is caused by cyclone, for an OWT can be conspicuous for a reasonable cyclone strength and average recurrence interval. This implies that potential premature failure of an OWT tower and relevant economic losses can be encountered during its service life if the cyclone contribution to fatigue damage is ignored in the initial conceptual design.
Chen, Z, Wei, W & Ni, B-J 2021, 'Cost-effective catalysts for renewable hydrogen production via electrochemical water splitting: Recent advances', Current Opinion in Green and Sustainable Chemistry, vol. 27, pp. 100398-100398.
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Hydrogen, with zero-carbon footprint, high energy density, and earth abundance, is proved as a great energy carrier for a sustainable energy scheme, which is recognized as one key solution to mitigate climate change and reduce air pollution. To achieve this goal, reducing the cost of renewable hydrogen production via electrochemical water splitting is a requisite for supporting a reliable and affordable hydrogen economy. Thus, the development of cost-effective catalysts for water electrolysis is of great significance. In this review, the recent advances in low-cost electrocatalysts for water splitting are summarized, including transition metal–based catalysts and metal-free catalysts. The emphasis is put on the catalyst design strategies and the underlying structure–performance mechanisms. The challenges and perspectives in this booming field are also presented.
Chen, Z, Zheng, R, Deng, S, Wei, W, Wei, W, Ni, B-J & Chen, H 2021, 'Modular design of an efficient heterostructured FeS2/TiO2 oxygen evolution electrocatalyst via sulfidation of natural ilmenites', Journal of Materials Chemistry A, vol. 9, no. 44, pp. 25032-25041.
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Modular design of an efficient FeS2/TiO2 heterostructured OER catalyst from natural ilmenites via a sulfidation process.
Chen, Z, Zheng, R, Graś, M, Wei, W, Lota, G, Chen, H & Ni, B-J 2021, 'Tuning electronic property and surface reconstruction of amorphous iron borides via W-P co-doping for highly efficient oxygen evolution', Applied Catalysis B: Environmental, vol. 288, pp. 120037-120037.
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Designing cost-effective oxygen evolution reaction (OER) electrocatalysts is essential for sustainable water splitting. Recently, amorphous transition metal borides (TMBs) as OER pre-catalysts have acquired growing attention due to their favorable characteristics such as high conductivity, compositional and structural flexibility. Nevertheless, rational design of boride-based OER pre-catalysts remains an ongoing challenge. Herein, an efficient pre-catalyst derived from FeB with accelerated surface reconstruction and regulated intrinsic activity of evolved FeOOH is obtained by W and P co-doping. The obtained catalyst demonstrates an excellent OER activity with a low overpotential of 209 mV at a current density of 10 mA cm−2, and good stability in alkaline electrolyte, which surpasses most of boride-based OER catalysts. Specifically, the anion etching facilitates the surface reconstruction and accelerates the mass/charge transfer. Density functional theory calculations suggest W doping can enhance intrinsic catalytic activity via optimizing the adsorption free energy of reaction intermediates and improving the conductivity. Additionally, the hierarchical structure and amorphous feature also benefit the OER process. This study provides a fundamental insight into the correlation between surface structure and catalytic activity, and a powerful strategy to construct efficient OER pre-catalysts.
Chen, Z, Zheng, R, Zou, W, Wei, W, Li, J, Wei, W, Ni, B-J & Chen, H 2021, 'Integrating high-efficiency oxygen evolution catalysts featuring accelerated surface reconstruction from waste printed circuit boards via a boriding recycling strategy', Applied Catalysis B: Environmental, vol. 298, pp. 120583-120583.
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Converting electronic wastes into high-efficiency energy conversion catalysts is a win-win strategy in addressing the metal resources shortage and sustainable energy challenges. Herein, a facile boriding strategy is developed to directly convert the leachates of waste printed circuit boards into magnetic mixed metal borides (FeNiCuSnBs) for oxygen evolution reaction (OER) catalysts. Via the boriding process, a metal cation recovery rate of 99.78 %, 99.98 %, 99.96 %, and 99.49 % has been attained for Fe, Ni, Cu, and Sn, respectively. The obtained catalysts with a higher ratio of Ni and Fe show better OER performance. The optimal FNCSB-4 attains 10 mA cm−2 at a low overpotential of 199 mV, as well as good stability in alkaline solution. Remarkably, FNCSB-4 represents a record‐high activity among waste-derived OER electrocatalysts. In-depth study suggests that the superior OER performance is mainly owing to accelerated surface self-reconstruction by B/Sn co-etching under OER potential region, and the newly formed multimetal (oxy)hydroxides act as the active species for OER. Additionally, the efficient mass/charge transfer, the amorphous feature, and hierarchical structure also benefit OER. Apart from providing an insight into the correlation between surface self-reconstruction and OER activity of multimetal boride-based catalysts, this study also offers a general strategy for the high-efficiency recovery and advanced energy-driven applications of critical metals from other urban mines in a sustainable and environment-friendly approach.
Chen, Z, Zou, W, Zheng, R, Wei, W, Wei, W, Ni, B-J & Chen, H 2021, 'Synergistic recycling and conversion of spent Li-ion battery leachate into highly efficient oxygen evolution catalysts', Green Chemistry, vol. 23, no. 17, pp. 6538-6547.
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A one-pot synergetic recycling and regeneration strategy to develop highly efficient tri-metal OER electrocatalysts from spent LIB leachates is demonstrated.
Cheng, D, Liu, Y, Ngo, HH, Guo, W, Chang, SW, Nguyen, DD, Zhang, S, Luo, G & Bui, XT 2021, 'Sustainable enzymatic technologies in waste animal fat and protein management', Journal of Environmental Management, vol. 284, pp. 112040-112040.
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Cheng, D, Ngo, HH, Guo, W, Chang, SW, Nguyen, DD, Liu, Y, Liu, Y, Deng, L & Chen, Z 2021, 'Evaluation of a continuous flow microbial fuel cell for treating synthetic swine wastewater containing antibiotics', Science of The Total Environment, vol. 756, pp. 144133-144133.
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Microbial fuel cell (MFC) systems are promising technologies for wastewater treatment and renewable energy generation simultaneously. Performance of a double-chamber microbial fuel cell (MFC) to treat synthetic swine wastewater containing sulfonamide antibiotics (SMs) was evaluated in this study. The MFC was operated in continuous modes at different conditions. Results indicated that the current was successfully generated during the operation. The performance of MFC under the sequential anode-cathode operating mode is better than that under the single continuous running mode. Specifically, higher removal efficiency of chemical oxygen demand (>90%) was achieved under the sequential anode-cathode operating mode in comparison with that in the single continuous mode (>80%). Nutrients were also be removed in the MFC's cathode chamber with the maximum removal efficiency of 66.6 ± 1.4% for NH4+-N and 32.1 ± 2.8% for PO43--P. Meanwhile, SMs were partly removed in the sequential anode-cathode operating with the value in a range of 49.4%-59.4% for sulfamethoxazole, 16.8%-19.5% for sulfamethazine and 14.0%-16.3% for sulfadiazine, respectively. SMs' inhibition to remove other pollutants in both electrodes of MFC was observed after SMs exposure, suggesting that SMs exert toxic effects on the microorganisms. A positive correlation was found between the higher NH4+-N concentration used in this study and the removal efficiency of SMs in the cathode chamber. In short, although the continuous flow MFC is feasible for treating swine wastewater containing antibiotics, its removal efficiency of antibiotics requires to be further improved.
Cheng, D, Ngo, HH, Guo, W, Chang, SW, Nguyen, DD, Nguyen, QA, Zhang, J & Liang, S 2021, 'Improving sulfonamide antibiotics removal from swine wastewater by supplying a new pomelo peel derived biochar in an anaerobic membrane bioreactor', Bioresource Technology, vol. 319, pp. 124160-124160.
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Sulfonamide antibiotics (SMs), as a class of antibiotics commonly used in swine industries, pose a serious threat to animal and human health. This study aims to evaluate the performance of an anaerobic membrane bioreactor (AnMBR) with and without supplying a new pomelo peel derived biochar to treat swine wastewater containing SMs. Results show that 0.5 g/L biochar addition could increase more than 30% of sulfadiazine (SDZ) and sulfamethazine (SMZ) removal in AnMBR. Approximately 95% of chemical oxygen demand (COD) was removed in the AnMBR at an influent organic loading rate (OLR) of 3.27 kg COD/(m3·d) while an average methane yield was 0.2 L/g CODremoved with slightly change at a small dose 0.5 g/L biochar addition. SMs inhibited the COD removal and methane production and increased membrane fouling. The addition of biochar could reduce the membrane fouling by reducing the concentration of SMP and EPS.
Cheng, H, Liu, Y, Huang, D, Cai, B & Wang, Q 2021, 'Rebooting kernel CCA method for nonlinear quality-relevant fault detection in process industries', Process Safety and Environmental Protection, vol. 149, pp. 619-630.
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Process monitoring is essential and important strategy for ensuring process safety and product quality. However, due to the nonlinear characteristics and multiple working conditions in process industries, the traditional process monitoring method cannot be effectively applied. Therefore, we propose a novel process monitoring framework, termed as mixture enhanced kernel canonical correlation analysis framework (M-NAKCCA). The innovations and advantages of M-NAKCCA are as follows: 1). The traditional CCA method is re-boosted as a new method, M-NAKCCA, to better nonlinear fault detection. Also, a matter-element model (MEm) is assimilated into M-NAKCCA to make the information more refined. 2). To overcome the curse of dimensionality that usually occurs in the high-dimensional dataset, M-NAKCCA uses the Nyström approximation technology to compress the kernel matrix. Moreover, the T2 control chart is reconstructed and the corresponding control upper limit is re-configured to improve the method sensitivity and to better the fault detection performance. 3). The proposed M-NAKCCA framework is firstly used to monitor a wastewater treatment plant (WWTP) and chemical plant with diverse process behaviors. The experimental results showed that the M-NAKCCA framework achieved the best performance for both of case studies.
Cheng, H, Wu, J, Huang, D, Liu, Y & Wang, Q 2021, 'Robust adaptive boosted canonical correlation analysis for quality-relevant process monitoring of wastewater treatment', ISA Transactions, vol. 117, pp. 210-220.
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Quality-relevant process monitoring has attracted much attention for its ability to assist in maintaining efficient plant operation. However, when the process suffers from non-stationary and over-complex (with noise, multiplicative faults, etc.) characteristics, the traditional methods usually cannot be effectively applied. To this end, a novel method, termed as Robust adaptive boosted canonical correlation analysis (Rab-CCA), is proposed to monitor the wastewater treatment processes. First, a robust decomposition method is proposed to mitigate the defects of standard CCA by decomposing the corrupted matrix into a low-matrix and a sparse matrix. Second, to further improve the performance of the standard process monitoring method, a novel criterion function and control charts are reconstructed accordingly. Moreover, an adaptive statistical control limit is proposed that can adjust the thresholds according to the state of a system and can effectively reduce the missed alarms and false alarms simultaneously. The superiority of Rab-CCA is verified by Benchmark Simulation Model 1 (BSM1) and a real full-scale wastewater treatment plant (WWTP).
Cheng, H, Yang, G, Li, D, Li, M, Cao, Y, Fu, Q & Sun, Y 2021, 'Ultralow Icing Adhesion of a Superhydrophobic Coating Based on the Synergistic Effect of Soft and Stiff Particles', Langmuir, vol. 37, no. 41, pp. 12016-12026.
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A novel superhydrophobic coating composed of soft polydimethylsiloxane microspheres and stiff SiO2 nanoparticles was developed and prepared. This superhydrophobic coating showed excellent superhydrophobicity with a large water contact angle of 171.3° and also exhibited good anti-icing performance and ultralow icing adhesion of 1.53 kPa. Furthermore, the superhydrophobic coating displayed good icing/deicing cycle stability, in which the icing adhesion was still less than 10.0 kPa after 25 cycles. This excellent comprehensive performance is attributed to stress-localization between ice and the surface, resulting from the synergistic effect of soft and stiff particles. This work thus opens a new avenue to simultaneously optimize the anti-icing and icephobic performance of a superhydrophobic surface for various applications.
Chiniforush, AA, Gharehchaei, M, Akbar Nezhad, A, Castel, A, Moghaddam, F, Keyte, L, Hocking, D & Foster, S 2021, 'Minimising risk of early-age thermal cracking and delayed ettringite formation in concrete – A hybrid numerical simulation and genetic algorithm mix optimisation approach', Construction and Building Materials, vol. 299, pp. 124280-124280.
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Chowdhury, H, Chowdhury, T, Hossain, N, Chowdhury, P, Salam, B, Sait, SM & Mahlia, TMI 2021, 'Exergetic sustainability analysis of industrial furnace: a case study', Environmental Science and Pollution Research, vol. 28, no. 10, pp. 12881-12888.
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Industrial furnaces play a significant role in industrial energy consumption and production. Minimizing losses from these furnaces can contribute to industrial sustainability. Exergy being an optimization tool can reduce energy loss and emission from furnaces and contribute to environmental sustainability. Currently, no exergy-based sustainability analysis has been adopted in the literature. In this analysis, a reheater furnace that is fired by natural gas is analyzed in terms of energy and exergy utilization. To address the sustainability of the furnace, several exergy-based sustainability parameters have been used. The overall energy efficiency of the furnace is 93.40%, while exergy efficiency is only 27.37%. From sustainability analysis, it is found that 72.63% of the fuel is diminished from the furnace, and it contributes to a lower sustainability index of 1.38. Higher exergy losses from this furnace positively affect the environment, which is validated from the higher value of the environmental destruction coefficient, the environmental destruction index, and the lower value of the environmental benign index. The value of the environmental destruction coefficient is 3.65, and the value of the environmental benign index is 0.38. Recovering waste energy and optimizing auxiliary equipment will increase the value of sustainability parameters.
Chowdhury, MA, Shuvho, MBA, Shahid, MA, Haque, AKMM, Kashem, MA, Lam, SS, Ong, HC, Uddin, MA & Mofijur, M 2021, 'Prospect of biobased antiviral face mask to limit the coronavirus outbreak', Environmental Research, vol. 192, pp. 110294-110294.
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The rapid spread of COVID-19 has led to nationwide lockdowns in many countries. The COVID-19 pandemic has played serious havoc on economic activities throughout the world. Researchers are immensely curious about how to give the best protection to people before a vaccine becomes available. The coronavirus spreads principally through saliva droplets. Thus, it would be a great opportunity if the virus spread could be controlled at an early stage. The face mask can limit virus spread from both inside and outside the mask. This is the first study that has endeavoured to explore the design and fabrication of an antiviral face mask using licorice root extract, which has antimicrobial properties due to glycyrrhetinic acid (GA) and glycyrrhizin (GL). An electrospinning process was utilized to fabricate nanofibrous membrane and virus deactivation mechanisms discussed. The nanofiber mask material was characterized by SEM and airflow rate testing. SEM results indicated that the nanofibers from electrospinning are about 15-30 μm in diameter with random porosity and orientation which have the potential to capture and kill the virus. Theoretical estimation signifies that an 85 L/min rate of airflow through the face mask is possible which ensures good breathability over an extensive range of pressure drops and pore sizes. Finally, it can be concluded that licorice root membrane may be used to produce a biobased face mask to control COVID-19 spread.
Cong Nguyen, N, Thi Nguyen, H, Cong Duong, H, Chen, S-S, Quang Le, H, Cong Duong, C, Thuy Trang, L, Chen, C-K, Dan Nguyen, P, Thanh Bui, X, Guo, W & Hao Ngo, H 2021, 'A breakthrough dynamic-osmotic membrane bioreactor/nanofiltration hybrid system for real municipal wastewater treatment and reuse', Bioresource Technology, vol. 342, pp. 125930-125930.
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Consoli, NC, Tonini de Araújo, M, Tonatto Ferrazzo, S, de Lima Rodrigues, V & Gravina da Rocha, C 2021, 'Increasing density and cement content in stabilization of expansive soils: Conflicting or complementary procedures for reducing swelling?', Canadian Geotechnical Journal, vol. 58, no. 6, pp. 866-878.
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The present study makes three contributions to the literature of expansive soils: (i) it proposes equations to predict soil swelling based on dry density and cement content, (ii) it checks the developed general equation by predicting the swelling of different expansive soils from the literature, and (iii) it designs experiments that investigate factors that have a significant influence on swelling. An experimental programme was carried out to analyse the expansion of bentonite–kaolin–cement blends. Different proportions of bentonite–kaolin, cement content, dry density, and moisture content were evaluated. A unique relation of the cement/porosity index was obtained for cement-stabilized expansive soils’ swelling; this index has been used before to portray strength, stiffness, and loss of mass of stabilized soils and is now shown to be applicable to describe swelling of expansive soils treated with Portland cement. In the present research, cement content and dry density are seen as conflicting parameters regarding the swelling of expansive soils, because increasing the amount of Portland cement reduces swelling and increasing the density (through compaction) causes higher expansion. A general swelling model is proposed and successfully checked with data from the literature; it is able to predict the swelling of expansive soils with different densities, expansive mineral, moisture content, and cement content.
Cowled, CJL, Crews, K & Gover, D 2021, 'Influence of loading protocol on the structural performance of timber-framed shear walls', Construction and Building Materials, vol. 288, pp. 123103-123103.
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Dabbaghi, F, Dehestani, M, Yousefpour, H, Rasekh, H & Navaratnam, S 2021, 'Residual compressive stress–strain relationship of lightweight aggregate concrete after exposure to elevated temperatures', Construction and Building Materials, vol. 298, pp. 123890-123890.
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Daly, L, Lee, MR, Darling, JR, McCarrol, I, Yang, L, Cairney, J, Forman, LV, Bland, PA, Benedix, GK, Fougerouse, D, Rickard, WDA, Saxey, DW, Reddy, SM, Smith, W & Bagot, PAJ 2021, 'Developing Atom Probe Tomography of Phyllosilicates in Preparation for Extra‐Terrestrial Sample Return', Geostandards and Geoanalytical Research, vol. 45, no. 3, pp. 427-441.
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Hydrous phyllosilicate minerals, including the serpentine subgroup, are likely to be major constituents of material that will be bought back to Earth by missions to Mars and to primitive asteroids Ryugu and Bennu. Small quantities (< 60 g) of micrometre‐sized, internally heterogeneous material will be available for study, requiring minimally destructive techniques. Many conventional methods are unsuitable for phyllosilicates as they are typically finely crystalline and electron beam‐sensitive resulting in amorphisation and dehydration. New tools will be required for nanoscale characterisation of these precious extra‐terrestrial samples. Here we test the effectiveness of atom probe tomography (APT) for this purpose. Using lizardite from the Ronda peridotite, Spain, as a terrestrial analogue, we outline an effective analytical protocol to extract nanoscale chemical and structural measurements of phyllosilicates. The potential of APT is demonstrated by the unexpected finding that the Ronda lizardite contains SiO‐rich nanophases, consistent with opaline silica that formed as a by‐product of the serpentinisation of olivine. Our new APT approach unlocks previously unobservable nanominerals and nanostructures within phyllosilicates owing to resolution limitations of more established imaging techniques. APT will provide unique insights into the processes and products of water/rock interaction on Earth, Mars and primitive asteroids.
Dang, B-T, Bui, X-T, Itayama, T, Ngo, HH, Jahng, D, Lin, C, Chen, S-S, Lin, K-YA, Nguyen, T-T, Nguyen, DD & Saunders, T 2021, 'Microbial community response to ciprofloxacin toxicity in sponge membrane bioreactor', Science of The Total Environment, vol. 773, pp. 145041-145041.
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Dang, CC, Dang, LC, Khabbaz, H & Sheng, D 2021, 'Numerical study on deformation characteristics of fibre-reinforced load-transfer platform and columns-supported embankments', Canadian Geotechnical Journal, vol. 58, no. 3, pp. 328-350.
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In this investigation, a ground-modification technique utilising a fibre-reinforced load-transfer platform (FRLTP) and columns-supported (CS) embankment constructed on multi-layered soft soils is proposed and investigated. After validating the proposed model with published data in the literature, numerical analysis was firstly conducted on the two-dimensional finite element model of a CS embankment without or with FRLTP to examine the influence of the FRLTP inclusion into the CS embankment system. Secondly, an extensive parametric study was performed to further investigate the effects of the FRLTP essential parameters — including platform thickness, shear strength, and tensile strength properties — and deformation modulus on the embankment performance during the construction and post-construction stages. Additionally, the influence of the embankment design parameters, such as column spacing, column length, and diameter, was examined. The numerical results reveal that the FRLTP inclusion can be effective in enhancing the CS embankment behaviour. It is also found that when increasing the platform thickness, the shear strength properties of FRLTP play a significant role in improving the overall performance of a column embankment with FRLTP.
Dang, KB, Nguyen, TT, Ngo, HH, Burkhard, B, Müller, F, Dang, VB, Nguyen, H, Ngo, VL & Pham, TPN 2021, 'Integrated methods and scenarios for assessment of sand dunes ecosystem services', Journal of Environmental Management, vol. 289, pp. 112485-112485.
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Dang, LC, Khabbaz, H & Ni, B-J 2021, 'Improving engineering characteristics of expansive soils using industry waste as a sustainable application for reuse of bagasse ash', Transportation Geotechnics, vol. 31, pp. 100637-100637.
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Bagasse ash (BA) is an abundant industrial waste of the sugar-cane refining industry, and its improper disposal can result in a detrimental impact on the environment. In this investigation, BA is considered to assess the possible advantages of its pozzolanic component as a novel sustainable waste application for stabilisation of expansive soils. The engineering characteristics of expansive soils were investigated through an array of laboratory experiments on treated and untreated soil specimens mixed with various contents of additive and cured for different times. A comprehensive investigation of the microstructure evolution of soils after treatment was also undertaken using Fourier transform infrared and scanning electron microscopy techniques. The results revealed that addition of BA, lime, and in particular, combined BA-lime (BAL) remarkably improved the maximum strength (815%), the bearing capacity (9.2 times), the compressibility (83%), and the 100% swell properties of stabilised soils due to rich amorphous silica properties of BA waste that promoted higher pozzolanic reactivities of BAL-soil-mixtures and therefore, enhanced the engineering characteristics of treated soils. The findings showed that a proper combination of bagasse ash waste and lime, as a stabilising additive, can effectively enhance the engineering properties of expansive soil while addressing the environmental impact of BA waste disposal. The industrial waste (BA) can be reused as a cost-effective and green construction material for the benefit of sustainable development of civil infrastructure.
Dansana, D, Kumar, R, Parida, A, Sharma, R, Das Adhikari, J, Van Le, H, Thai Pham, B, Kant Singh, K & Pradhan, B 2021, 'Using Susceptible-Exposed-Infectious-Recovered Model to Forecast Coronavirus Outbreak', Computers, Materials & Continua, vol. 67, no. 2, pp. 1595-1612.
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Darabi, H, Torabi Haghighi, A, Rahmati, O, Jalali Shahrood, A, Rouzbeh, S, Pradhan, B & Tien Bui, D 2021, 'A hybridized model based on neural network and swarm intelligence-grey wolf algorithm for spatial prediction of urban flood-inundation', Journal of Hydrology, vol. 603, pp. 126854-126854.
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In regions with lack of hydrological and hydraulic data, a spatial flood modeling and mapping is an opportunity for the urban authorities to predict the spatial distribution and the intensity of the flooding. It helps decision-makers to develop effective flood prevention and management plans. In this study, flood inventory data were prepared based on the historical and field surveys data by Sari municipality and regional water company of Mazandaran, Iran. The collected flood data accompanied with different variables (digital elevation model and slope have been considered as topographic variables, land use/land cover, precipitation, curve number, distance to river, distance to channel and depth to groundwater as environmental variables) were applied to novel hybridized model based on neural network and swarm intelligence-grey wolf algorithm (NN-SGW) to map flood-inundation. Several confusion matrix criteria were used for accuracy evaluation by cutoff-dependent and independent metrics (e.g., efficiency (E), positive predictive value (PPV), negative predictive value (NPV), area under the receiver operating characteristic curve (AUC)). The accuracy of the flood inundation map produced by the NN-SGW model was compared with that of maps produced by four state-of-the-art benchmark models: random forest (RF), logistic model tree (LMT), classification and regression trees (CART), and J48 decision tree (J48DT). The NN-SGW model outperformed all benchmark models in both training (E = 90.5%, PPV = 93.7%, NPV = 87.3%, AUC = 96.3%) and validation (E = 79.4%, PPV = 85.3%, NPV = 73.5%, AUC = 88.2%). As the NN-SGW model produced the most accurate flood-inundation map, it can be employed for robust flood contingency planning. Based on the obtained results from NN-SGW model, distance from channel, distance from river, and depth to groundwater were identified as the most important variables for spatial prediction of urban flood inundation. This work can serve as a basis fo...
Dardor, D, Al Maas, M, Minier-Matar, J, Janson, A, Abdel-Wahab, A, Shon, HK & Adham, S 2021, 'Evaluation of pretreatment and membrane configuration for pressure-retarded osmosis application to produced water from the petroleum industry', Desalination, vol. 516, pp. 115219-115219.
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Daviran, M, Maghsoudi, A, Ghezelbash, R & Pradhan, B 2021, 'A new strategy for spatial predictive mapping of mineral prospectivity: Automated hyperparameter tuning of random forest approach', Computers & Geosciences, vol. 148, pp. 104688-104688.
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Machine learning algorithms (e.g., random forest (RF)) have recently been performed in data-driven mineral prospectivity mapping. These methods are highly sensitive to hyperparameter values, since the predictive accuracy of them can significantly increase when the optimized hyperparameters are predefined and then adjusted to training procedure. The main goal of this contribution is to propose a hybrid genetic-based RF model, namely GRF, which is able to automatically adjust the optimized hyperparameters of RF with the excellent predictive accuracy. Therefore, three primary parameters of RF comprising N , N and d, were well-tuned employing genetic algorithm (GA) in establishing an efficient RF model. The proposed GRF model and also conventional RF were tested on mineralization-related geo-spatial dataset and the predictive models were generated for comparing the accuracy of the proposed GRF model with that of RF. The input dataset (e.g., multi-element geochemical signature, geological-structural layer and hydrothermal alteration evidences) which acquired from Feizabad district, NE Iran, were translated into mappable targeting criteria in the form of four predictor maps. In addition, the locations of 13 known Cu–Au deposits as prospect data and the locations of 13 randomly selected non-prospect data were used as target variables to train the models. Three authentic validation measures, K-fold cross-validation, confusion matrix and success-rate curves, were employed to evaluate the overall performance of two predictive models. Experimental results suggested the superiority of GRF model over the RF, as the favorable areas derived by GRF model occupy only 9% of the study area while predicting 100% of the known deposits. T S
Deepanraj, B, Senthilkumar, N, Ranjitha, J, Jayaraj, S & Ong, HC 2021, 'Biogas from food waste through anaerobic digestion: optimization with response surface methodology', Biomass Conversion and Biorefinery, vol. 11, no. 2, pp. 227-239.
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Deshpande, NM, Gite, S, Pradhan, B, Kotecha, K & Alamri, A 2021, 'Improved Otsu and Kapur approach for white blood cells segmentation based on LebTLBO optimization for the detection of Leukemia', Mathematical Biosciences and Engineering, vol. 19, no. 2, pp. 1970-2001.
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<abstract> <p>The diagnosis of leukemia involves the detection of the abnormal characteristics of blood cells by a trained pathologist. Currently, this is done manually by observing the morphological characteristics of white blood cells in the microscopic images. Though there are some equipment- based and chemical-based tests available, the use and adaptation of the automated computer vision-based system is still an issue. There are certain software frameworks available in the literature; however, they are still not being adopted commercially. So there is a need for an automated and software- based framework for the detection of leukemia. In software-based detection, segmentation is the first critical stage that outputs the region of interest for further accurate diagnosis. Therefore, this paper explores an efficient and hybrid segmentation that proposes a more efficient and effective system for leukemia diagnosis. A very popular publicly available database, the acute lymphoblastic leukemia image database (ALL-IDB), is used in this research. First, the images are pre-processed and segmentation is done using Multilevel thresholding with Otsu and Kapur methods. To further optimize the segmentation performance, the Learning enthusiasm-based teaching-learning-based optimization (LebTLBO) algorithm is employed. Different metrics are used for measuring the system performance. A comparative analysis of the proposed methodology is done with existing benchmarks methods. The proposed approach has proven to be better than earlier techniques with measuring parameters of PSNR and Similarity index. The result shows a significant improvement in the performance measures with optimizing threshold algorithms and the LebTLBO technique.</p> </abstract>
Devda, V, Chaudhary, K, Varjani, S, Pathak, B, Patel, AK, Singhania, RR, Taherzadeh, MJ, Ngo, HH, Wong, JWC, Guo, W & Chaturvedi, P 2021, 'Recovery of resources from industrial wastewater employing electrochemical technologies: status, advancements and perspectives', Bioengineered, vol. 12, no. 1, pp. 4697-4718.
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Dikshit, A & Pradhan, B 2021, 'Explainable AI in drought forecasting', Machine Learning with Applications, vol. 6, pp. 100192-100192.
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Dikshit, A & Pradhan, B 2021, 'Interpretable and explainable AI (XAI) model for spatial drought prediction', Science of The Total Environment, vol. 801, pp. 149797-149797.
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Accurate prediction of any type of natural hazard is a challenging task. Of all the various hazards, drought prediction is challenging as it lacks a universal definition and is getting adverse with climate change impacting drought events both spatially and temporally. The problem becomes more complex as drought occurrence is dependent on a multitude of factors ranging from hydro-meteorological to climatic variables. A paradigm shift happened in this field when it was found that the inclusion of climatic variables in the data-driven prediction model improves the accuracy. However, this understanding has been primarily using statistical metrics used to measure the model accuracy. The present work tries to explore this finding using an explainable artificial intelligence (XAI) model. The explainable deep learning model development and comparative analysis were performed using known understandings drawn from physical-based models. The work also tries to explore how the model achieves specific results at different spatio-temporal intervals, enabling us to understand the local interactions among the predictors for different drought conditions and drought periods. The drought index used in the study is Standard Precipitation Index (SPI) at 12 month scales applied for five different regions in New South Wales, Australia, with the explainable algorithm being SHapley Additive exPlanations (SHAP). The conclusions drawn from SHAP plots depict the importance of climatic variables at a monthly scale and varying ranges of annual scale. We observe that the results obtained from SHAP align with the physical model interpretations, thus suggesting the need to add climatic variables as predictors in the prediction model.
Dikshit, A, Pradhan, B & Alamri, AM 2021, 'Long lead time drought forecasting using lagged climate variables and a stacked long short-term memory model', Science of The Total Environment, vol. 755, pp. 142638-142638.
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Dikshit, A, Pradhan, B & Alamri, AM 2021, 'Pathways and challenges of the application of artificial intelligence to geohazards modelling', Gondwana Research, vol. 100, pp. 290-301.
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© 2020 International Association for Gondwana Research The application of artificial intelligence (AI) and machine learning in geohazard modelling has been rapidly growing in recent years, a trend that is observed in several research and application areas thanks to recent advances in AI. As a result, the increasing dependence on data driven studies has made its practical applications towards geohazards (landslides, debris flows, earthquakes, droughts, floods, glacier studies) an interesting prospect. These aforementioned geohazards were responsible for roughly 80% of the economic loss in the past two decades caused by all natural hazards. The present study analyses the various domains of geohazards which have benefited from classical machine learning approaches and highlights the future course of direction in this field. The emergence of deep learning has fulfilled several gaps in: i) classification; ii) seasonal forecasting as well as forecasting at longer lead times; iii) temporal based change detection. Apart from the usual challenges of dataset availability, climate change and anthropogenic activities, this review paper emphasizes that the future studies should focus on consecutive events along with integration of physical models. The recent catastrophe in Japan and Australia makes a compelling argument to focus towards consecutive events. The availability of higher temporal resolution and multi-hazard dataset will prove to be essential, but the key would be to integrate it with physical models which would improve our understanding of the mechanism involved both in single and consecutive hazard scenario. Geohazards would eventually be a data problem, like geosciences, and therefore it is essential to develop models that would be capable of handling large voluminous data. The future works should also revolve towards interpretable models with the hope of providing a reasonable explanation of the results, thereby achieving the ultimate goal of Explainable AI.
Dikshit, A, Pradhan, B & Huete, A 2021, 'An improved SPEI drought forecasting approach using the long short-term memory neural network', Journal of Environmental Management, vol. 283, pp. 111979-111979.
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Droughts are slow-moving natural hazards that gradually spread over large areas and capable of extending to continental scales, leading to severe socio-economic damage. A key challenge is developing accurate drought forecast model and understanding a models' capability to examine different drought characteristics. Traditionally, forecasting techniques have used various time-series approaches and machine learning models. However, the use of deep learning methods have not been tested extensively despite its potential to improve our understanding of drought characteristics. The present study uses a deep learning approach, specifically the Long Short-Term Memory (LSTM) to predict a commonly used drought measure, the Standard Precipitation Evaporation Index (SPEI) at two different time scales (SPEI 1, SPEI 3). The model was compared with other common machine learning method, Random Forests, Artificial Neural Networks and applied over the New South Wales (NSW) region of Australia, using hydro-meteorological variables as predictors. The drought index and predictor data were collected from the Climatic Research Unit (CRU) dataset spanning from 1901 to 2018. We analysed the LSTM forecasted results in terms of several drought characteristics (drought intensity, drought category, or spatial variation) to better understand how drought forecasting was improved. Evaluation of the drought intensity forecasting capabilities of the model were based on three different statistical metrics, Coefficient of Determination (R2), Root Mean Square Error (RMSE), and Mean Absolute Error (MAE). The model achieved R2 value of more than 0.99 for both SPEI 1 and SPEI 3 cases. The variation in drought category forecasted results were studied using a multi-class Receiver Operating Characteristic based Area under Curves (ROC-AUC) approach. The analysis revealed an AUC value of 0.83 and 0.82 for SPEI 1 and SPEI 3 respectively. The spatial variation between observed a...
Ding, A, Song, R, Cui, H, Cao, H, Ngo, HH, Chang, H, Nan, J, Li, G & Ma, J 2021, 'Presence of powdered activated carbon/zeolite layer on the performances of gravity-driven membrane (GDM) system for drinking water treatment: Ammonia removal and flux stabilization', Science of The Total Environment, vol. 799, pp. 149415-149415.
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Ding, A, Zhang, R, Ngo, HH, He, X, Ma, J, Nan, J & Li, G 2021, 'Life cycle assessment of sewage sludge treatment and disposal based on nutrient and energy recovery: A review', Science of The Total Environment, vol. 769, pp. 144451-144451.
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With the acceleration of urbanization, the production of urban sludge is increasing rapidly. To minimize resource input and waste output, it is crucial to execute analyses of environmental impact and assessments of sustainability on different technical strategies involving sludge disposal based on Life Cycle Assessment (LCA), which is a great potential mean of environmental management adopted internationally in the 21st century. This review aims to compare the environmental sustainability of existing sludge management schemes with a purpose of nutrient recovery and energy saving, respectively, and also to include the substitution benefits of alternative sludge products. Simultaneously, LCA research regarding the emerging sludge management technologies and sludge recycling (cement, adsorbent, bricks) is analyzed. Additionally, the key aspects of the LCA process are worth noting in the context of the current limitations reviewed here. It is worth emphasizing that no technical remediation method can reduce all environmental damage simultaneously, and these schemes are typically more applicable to the assumed local conditions. Future LCA research should pay more attention to the toxic effects of different sludge treatment methods, evaluate the technical ways of adding pretreatment technology to the 'front end' of the sludge treatment process, and further explore how to markedly reduce environmental damage in order to maximize energy and nutrient recovery from the LCA perspective.
Ding, L, Zhou, J, Fu, Q, Bao, G, Liu, Y & Jin, D 2021, 'Triplet Fusion Upconversion with Oxygen Resistance in Aqueous Media', Analytical Chemistry, vol. 93, no. 10, pp. 4641-4646.
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Triplet fusion upconversion (also called triplet-triplet annihilation, TTA) arouses much attention due to its potential in the fields of biological imaging, optogenetics, and light harvesting. However, oxygen quenching remains a challenge ahead, restricting its applications in aqueous media. Previous efforts to realize aqueous TTA with oxygen resistance have been focused on core-shell structures and self-assembly, but tedious processes and complicated chemical modification are required. Here, we report a direct and efficient strategy to realize aqueous TTA by controlling the ionic equilibrium of the TTA dyad. We find that the ionized organic dyad in physiological buffers and electrolyte-based media shows a natural aerotolerance without any complicated structure engineering. In particular, the upconversion intensity of this aqueous TTA in Tris buffer under an air-saturated condition is more than twice that under the deaerated condition. We further demonstrate the TTA system for potential applications in pH and temperature sensing with reversible and sensitive performance. We anticipate this facile approach will inspire the development of practical aqueous TTA and broad applications in biological science.
Ding, W, Jin, W, Zhou, X, Yang, Q, Chen, C & Wang, Q 2021, 'Role of extracellular polymeric substances in anaerobic granular sludge: Assessing dewaterability during Fe(II)-peroxydisulfate conditioning and granulation processes', Journal of Cleaner Production, vol. 286, pp. 124968-124968.
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© 2020 Elsevier Ltd In this study, Fe(II) activated peroxydisulfate (PDS) conditioning and sludge granulation were conducted to investigate the dewaterability of anaerobic granular sludge (AGS). After Fe(II)-PDS conditioning, the dewaterability of three AGS from different sources was enhanced. The specific resistance to filtration (SRF) reduction rates were achieved (98.30% ± 0.19%, 99.51% ± 0.17% and 96.47% ± 1.25%, respectively) under the optimal Fe(II) and PDS additions; And the optimal reductions of capillary suction time (CST) were 93.49% ± 2.49%, 95.33% ± 0.02% and 88.04% ± 2.95%, respectively. The mechanism of improving AGS dewaterability by Fe(II)-PDS conditioning was proposed. The radical SO4⋅−/OH⋅ destroyed the structure of extracellular polymeric substances (EPS) layers and microbial cells, resulting in the bound water released from AGS. Thereafter, the generated Fe(III) facilitated the sludge re-flocculation and decreased the electrostatic repulsion. During a 132-day granulation, the CST value showed a positive correlation with protein (S-EPS), polysaccharide and zeta potential, and a negative correlation with protein (LB-EPS), protein (TB-EPS), particle size and VSS. Collectively, the protein was the primary component in AGS and showed a strong correlation with dewaterability. The variations of protein in TB-EPS during the conditioning and the granulation were consistent with the changes of sludge dewaterability.
Doan, S & Fatahi, B 2021, 'Green’s function analytical solution for free strain consolidation of soft soil improved by stone columns subjected to time-dependent loading', Computers and Geotechnics, vol. 136, pp. 103941-103941.
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This paper proposes an analytical solution in terms of Green's function formulations for axisymmetric consolidation of a stone column improved soft soil deposit subjected to time-dependent loading under free strain condition. The mathematical derivations incorporate the pore water flows in radial and vertical directions in stone column and soft soil synchronously. The capabilities of the proposed analytical solution are evaluated via worked examples investigating the influences of three common time-dependent external surcharges (namely step, ramp and sinusoidal loadings) on consolidation response of the composite ground. The examples show that a faster increase of load from an initial surcharge to an expected loading might generate more significant excess pore water pressure to be dissipated during the early stages of consolidation, but the dissipation rate in soft soil would speed up significantly afterwards. The column and soil settlements along with the differential settlement between them also proceed faster corresponding to the acceleration of loading – unloading processes. Finally, the proposed analytical solution is employed to evaluate the excess pore water pressure dissipation rate at an investigation point in soft clay of a case history foundation. The calculation results exhibit a reasonable agreement with field measurement data when various constant values of stress concentration ratio are substituted into the solution to reflect the increase of stress concentration ratio with consolidation time in real practice.
Dogan, A, Akay, M, Barua, PD, Baygin, M, Dogan, S, Tuncer, T, Dogru, AH & Acharya, UR 2021, 'PrimePatNet87: Prime pattern and tunable q-factor wavelet transform techniques for automated accurate EEG emotion recognition', Computers in Biology and Medicine, vol. 138, pp. 104867-104867.
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Dong, W, Guo, Y, Sun, Z, Tao, Z & Li, W 2021, 'Development of piezoresistive cement-based sensor using recycled waste glass cullets coated with carbon nanotubes', Journal of Cleaner Production, vol. 314, pp. 127968-127968.
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Different from widely exploring the application of waste glass to replace natural aggregate or cement powder, this study firstly utilized waste glass cullets coated with carbon nanotubes (CNTs) as conductive fillers to develop novel self-sensing cement-based sensors. The coating efficiency of CNTs and self-sensing properties were also investigated in terms of workability, water absorption, mechanical properties, electrical resistivity and microstructure. The results show that CNTs are attached to the surfaces of waste glass particles, especially the small-size waste glass particles with high roughness. Workability decreased significantly with the increased waste glass. Cementitious mortar with sand replaced by CNTs-coated waste glass exhibited the highest flowability when the replacement ratio was 25%. Moreover, the water impermeability continuously increased with the content of waste glass. The compressive strength was higher than that of the control mortar, which reached the highest with 50% waste glass content. Additionally, an excellent piezoresistivity was achieved for cement-based sensors with CNTs-coated waste glass particles for the self-monitoring of stress magnitude and failure. The CNTs are uniformly distributed well in the cement matrix by attaching the surfaces of waste glass particles, thus the conductive passages are formed in cement-based sensors for structural health monitoring.
Dong, W, Li, W & Tao, Z 2021, 'A comprehensive review on performance of cementitious and geopolymeric concretes with recycled waste glass as powder, sand or cullet', Resources, Conservation and Recycling, vol. 172, pp. 105664-105664.
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Recycling waste glass for developing cementitious and geopolymeric concretes as sustainable construction materials have recently attracted increasing attentions for the construction industry. There are many previous studies on the effects of waste glass used as powder, sand or cullet based on the various sizes on the fresh and mechanical properties of concrete. However, there are few studies conducted on the durability performance of waste glass concrete. In this paper, in addition to a brief review on the fresh and mechanical properties and microstructure, the durability performance of concrete with waste glass is comprehensively reviewed under various environmental actions, including chemical attacks, chloride transport, high temperature, freeze-thaw cycles, carbonation, efflorescence, abrasion, alkali-silica reaction (ASR), and practical applications. It was found that the type, size and replacement ratio of waste glass significantly affect concrete durability. Compared to the glass cullet, the fine glass powder can usually improve the long-term durability, because the enhanced pozzolanic reactivity can reduce the ASR expansion due to the densified microstructure and reduced porosity. On the other hand, other factors such as mineral additives, mixing and curing methods also potentially affect the durability. Finally, some research perspectives and challenges of concrete with recycled waste glass are also presented and discussed. Considering the potential applications of waste glass concrete, this comprehensive review will provide an insight into an in-depth understanding of the production and performance for promising application.
Dong, W, Li, W, Shen, L, Zhang, S & Vessalas, K 2021, 'Integrated self-sensing and self-healing cementitious composite with microencapsulation of nano-carbon black and slaked lime', Materials Letters, vol. 282, pp. 128834-128834.
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In this paper, multifunctional cementitious composites with integrated self-sensing and self-healing properties are developed using microencapsulation of nano-carbon black (NCB) to enclose slaked lime (SL). The results show that the cracks healing efficiency is strongly improved with NCB enclosed SL. With SL, the self-sensing capacity of NCB-cementitious composite exhibits higher and more stable piezoresistivity before or after self-healing. The NCB enclosing SL particles not only achieve excellent piezoresistivity, but also preserve SL from initial hydration. Furthermore, the remained SL can be released for further reactions in the cracks. The results provide a promising integrated multifunctional self-sensing and self-healing cementitious composite for structural health monitoring application.
Dong, W, Li, W, Vessalas, K, He, X, Sun, Z & Sheng, D 2021, 'Piezoresistivity deterioration of smart graphene nanoplate/cement-based sensors subjected to sulphuric acid attack', Composites Communications, vol. 23, pp. 100563-100563.
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Smart cement-based sensors with self-sensing capacity have been explored for structural health monitoring (SHM) with the intrinsic piezoresistive performance. However, few studies had studied the piezoresistivity degradation of cement-based sensors after exposure to the aggressive environments, especially under sulphate acid attacks. In this study, graphene nanoplate (GNP)/cementitious composites were immersed in sulphuric acid solutions (concentrations of 0, 1%, 2%, and 3%) for 90 and 180 days. Then surface appearance, weight loss, mechanical properties, piezoresistivity and microstructure were investigated and compared before and after sulphuric acid immersion. The results show that after acid immersion, the surface deterioration and mass loss were increased, and the compressive strength was significantly decreased. As for the intact GNP/cementitious composite, the piezoresistivity exhibited excellent linearity and repeatability, demonstrating the great potential to act as intelligent cement-based sensors for SHM. After 90 and 180 days of acid immersion, the piezoresistivity was sensitive to the initial low load initially but then turned less sensitive to the later high load. The highly corroded GNP/cementitious composites exhibited porous microstructures associated with the low compressive strength. The fractional changes to resistivity (FCR) under the low load could be attributed to the compressed pores and voids filled with erosion products that would form conductive passages. In contrast, with the increase of applied load, the intact cement matrix became much denser, which in turn constrained the further development of conductive passages in the GNP/cementitious composites.
Dong, W, Li, W, Wang, K & Shah, SP 2021, 'Physicochemical and Piezoresistive properties of smart cementitious composites with graphene nanoplates and graphite plates', Construction and Building Materials, vol. 286, pp. 122943-122943.
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Graphene nanoplate (GNP) and graphite plate (GP) are promising functional nanofillers for smart self-sensing cementitious composites. The effects of GNP and GP on physicochemical, mechanical and piezoresistive properties of cementitious composite were investigated in this paper. The results show that cement hydration was accelerated with the increased amounts of GNP and GP because of nucleation effect. The electrical resistivity of GNP-cementitious composites was always lower than the counterpart with GP with the same concentration. On the other hand, percolation occurred for the GNP/cementitious composites at the dosages from 2 to 3% (by weight), while it never happens for the GP/cementitious composites. Moreover, the GNP/cementitious composites reached the maximum mechanical strength when the GNP content was 1.0%, while for the GP/cementitious composites, only minor strength improvement was obtained with a dosage of 0.5% GP. As for the piezoresistivity, the cementitious composites with GNP exhibited higher fractional changes of resistivity. Irreversible resistivity happened for 2–3% GP/cementitious composites subjected to cyclic compression, due to the poor and loose microstructures. The outcomes are expected to provide an insight into the application of GNP/cementitious and GP/cement composites as cement-based sensors for the future structural health monitoring.
Dong, W, Li, W, Zhu, X, Sheng, D & Shah, SP 2021, 'Multifunctional cementitious composites with integrated self-sensing and hydrophobic capacities toward smart structural health monitoring', Cement and Concrete Composites, vol. 118, pp. 103962-103962.
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In this study, multifunctional cementitious composites with integrated self-sensing and hydrophobicity capacities were developed and investigated using conductive graphene nanoplate (GNP) and silicone hydrophobic powder (SHP). The mechanical properties, permeability, water contact angle, microstructure and piezoresistivity were studied and compared under different contents of GNP and SHP. The highest compressive and flexural strengths with 1% SHP and 2% GNP reached 62.6 MPa and 8.9 MPa, respectively. The water absorption significantly was decreased with the content of SHP, but was minorly affected by GNP. The water contact angle firstly increased but then decreased with the dosages of GNP and SHP. SHP and GNP could reduce the microscale pores and enhance the density of microstructures. The piezoresistivity under compression firstly exhibited low gauge factor, but then gradually increased to a constant value under high-stress magnitude. Moreover, compared to the conventional cement-based sensors, this piezoresistive cementitious composites containing SHP and GNP as novel cement-based sensors are less sensitive to water content and humidity. The outcomes can provide an insight into promoting the application of multifunctional cement-based sensors toward structural health monitoring under various ambient conditions.
Dorji, U, Tenzin, U, Dorji, P, Pathak, N, Johir, MAH, Volpin, F, Dorji, C, Chernicharo, CAL, Tijing, L, Shon, H & Phuntsho, S 2021, 'Exploring shredded waste PET bottles as a biofilter media for improved on-site sanitation', Process Safety and Environmental Protection, vol. 148, pp. 370-381.
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This study explores an improved alternative on-site treatment for unsewered urban Bhutan. The system combines up-flow anaerobic sludge blanket for blackwater treatment and anaerobic biofilter for a mixture of up-flow anaerobic sludge blanket effluent and greywater. Shredded waste plastic bottles are used as novel biofilter media that provides a large surface area for attached growth while addressing waste plastic problems. A bench-scale up-flow anaerobic sludge blanket (operated at hydraulic retention time or HRT of 1–10 days) and anaerobic biofilter (HRT of 0.25–3 days) study were conducted for 188 days. At 2-d HRT, up-flow anaerobic sludge blanket removed 70–80 % of chemical oxygen demand (COD) while anaerobic biofilter achieved 90–98 % COD removal at eight-hour HRT. Combined up-flow anaerobic sludge blanket and anaerobic biofilter achieved final effluent with COD less than 50 mg/L and turbidity of less than 3 NTU that meets the discharge standard of Bhutan. The study shows that shredded waste plastic bottles can be an effective biofilter support medium for low-cost on-site treatment while helping address waste plastic problems.
Du, M, Liu, X, Wang, D, Yang, Q, Duan, A, Chen, H, Liu, Y, Wang, Q & Ni, B-J 2021, 'Understanding the fate and impact of capsaicin in anaerobic co-digestion of food waste and waste activated sludge', Water Research, vol. 188, pp. 116539-116539.
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Anaerobic co-digestion is an attractive option to treat food waste and waste activated sludge, which is increasingly applied in real-world situations. As an active component in Capsicum species being substantially present in food waste in many areas, capsaicin has been recently demonstrated to inhibit the anaerobic co-digestion. However, the interaction between capsaicin and anaerobic co-digestion are still poorly understood. This work therefore aims to deeply understand the fate and impact of capsaicin in the anaerobic co-digestion. Experiment results showed that capsaicin was completely degraded in anaerobic co-digestion by hydroxylation, O-demethylation, dehydrogenation and doubly oxidization, respectively. Although methane was proven to be produced from capsaicin degradation, the increase in capsaicin concentration resulted in decrease in methane yield from the anaerobic co-digestion. With an increase of capsaicin from 2 ± 0.7 to 68 ± 4 mg/g volatile solids (VS), the maximal methane yield decreased from 274.6 ± 9.7 to 188.9 ± 8.4 mL/g VS. The mechanic investigations demonstrated that the presence of capsaicin induced apoptosis, probably by either altering key kinases or decreasing the intracellular NAD+/NADH ratio, which led to significant inhibitions to hydrolysis, acidogenesis, and methanogenesis, especially acetotrophic methanogenesis. Illumina Miseq sequencing analysis exhibited that capsaicin promoted the populations of complex organic degradation microbes such as Escherichia-Shigella and Fonticella but decreased the numbers of anaerobes relevant to hydrolysis, acidogenesis, and methanogenesis such as Bacteroide and Methanobacterium.
Duong, HC, Cao, HT, Hoang, NB & Nghiem, LD 2021, 'Reverse osmosis treatment of condensate from ammonium nitrate production: Insights into membrane performance', Journal of Environmental Chemical Engineering, vol. 9, no. 6, pp. 106457-106457.
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Ammonium nitrate is an important fertilizer and industrial explosive. The production of ammonium nitrate entails the generation of a large volume of condensate laden with nitrogen that must be treated before environment discharge. Results in this study show that through appropriate membrane selection, over 90% rejection of ammonium nitrate can be achieved by reverse osmosis (RO) filtration. Using RO (which is highly compact and efficient) to enrich ammonium nitrate in the condensate would significantly reduce the size of the evaporation separator for ammonia recovery. The results also highlight the importance of membrane selection for this application. Results reported here suggest that a low pressure RO membrane (e.g. ESPA2) is more suitable for the dilute condensate while a high pressure RO membrane (e.g. SW30) is recommended for the concentrated condensate to ensure adequate ammonia and nitrate rejection. Ammonia and nitrate rejections were dependent on key operating parameters including applied pressure (or water flux), temperature, feed solution pH, and initial ammonium nitrate concentration in the condensate. The impact of operating conditions on ammonia and nitrate rejections was more profound for low pressure (thus high flux) than high pressure RO membrane. An extended filtration experiment shows no evidence of membrane fouling. Results from this study are useful to the integration of a compact RO system to ammonium nitrate manufacturing for pollution prevention and improving product yield.
Duong, HC, Tran, LTT, Vu, MT, Nguyen, D, Tran, NTV & Nghiem, LD 2021, 'A new perspective on small-scale treatment systems for arsenic affected groundwater', Environmental Technology & Innovation, vol. 23, pp. 101780-101780.
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This work provides a new perspective on small-scale treatment systems to remove arsenic from groundwater for potable applications in low-income communities. Data corroborated from the literature highlight a significant challenge to providing potable water in a financially sustainable manner in arsenic affected areas. Analysis of the literature also reveals notable deficiency in the current practice, especially the overfocus on household-scale treatment systems for arsenic affected groundwater without adequate maintenance, monitoring, and a systematic cost–benefit analysis. Accurate and reliable analysis of arsenic in water samples at relevant health guideline values is costly and technologically demanding for low-income communities. Significant discrepancy in the performance of household-scale treatment systems can be attributed to the lack of maintenance and systematic monitoring. Moreover, data on the maintenance and compliance monitoring cost of small-scale arsenic treatment systems are very limited in the literature, and the available data show an exponential increase in maintenance cost per treatment capacity unit as the treatment size decreases. On the other hand, significant opportunities exist to increase performance reliability and reduce water treatment cost by taking advantage of the current digital transformation of the water sector. The analysis in this work suggests the need to reframe current practice towards commune-scale treatment systems as an interim step before centralised water supply is available.
Dzaklo, CK, Rujikiatkamjorn, C, Indraratna, B & Kelly, R 2021, 'Cyclic behaviour of compacted black soil-coal wash matrix', Engineering Geology, vol. 294, pp. 106385-106385.
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Eager, D, Chapman, C, Qi, Y, Ishac, K & Hossain, MI 2021, 'Additional Criteria for Playground Impact Attenuating Sand', Applied Sciences, vol. 11, no. 19, pp. 8805-8805.
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Falls within children’s playgrounds result in long bone and serious injuries. To lower the likelihood and severity of injury, impact attenuating surfaces (IAS) are installed within the impact area (fall zone). There are three primary IAS materials used, namely: granulated rubber products, wood fibre products, and sand. There is a deficiency with existing IAS test methods in that they do not take account of sand degradation over time. When children use the playground, sand degradation can occur when sand produces fines and smaller particles with low sphericity and angular which fill the voids between the sand particles. These fines and smaller particles tend to bind the sand and lower its impact attenuating performance. This paper proposes an additional IAS test to eliminate sands that degrade above an established threshold rate after installation due to normal usage. IAS degradation properties of fifteen IAS sands were tested including sand particle shape, sand particle distribution, percentage fines and sand particle degradation. This accelerated ageing test method is applicable only to sands and not rubber or wood fibre IAS products. The best IAS sands were sourced from quarries located on rivers that had eroded volcanic outcrops. These sands were shown to degrade the least and had little to no fines, and their particle shape was rounded to well-rounded. The most reliable source for good quality IAS sands on these rivers was on specific bends. The sand mined at these locations consistently had a tight particle size distribution.
Ebrahimi, A, Sivakumar, M, McLauchlan, C, Ansari, A & Vishwanathan, AS 2021, 'A critical review of the symbiotic relationship between constructed wetland and microbial fuel cell for enhancing pollutant removal and energy generation', Journal of Environmental Chemical Engineering, vol. 9, no. 1, pp. 105011-105011.
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Ejaz, A, Babar, H, Ali, HM, Jamil, F, Janjua, MM, Fattah, IMR, Said, Z & Li, C 2021, 'Concentrated photovoltaics as light harvesters: Outlook, recent progress, and challenges', Sustainable Energy Technologies and Assessments, vol. 46, pp. 101199-101199.
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Concentrated photovoltaics (CPV) is a dawn technology in the field of photovoltaic that helps in escalating the effective use of solar energy. Nowadays, applications of photovoltaic solar cells are catching attention due to the better utilization of solar energy. A huge amount of solar energy is received by the earth from the sun, but a barrier to the large-scale use of photovoltaic solar cells is their higher initial cost and lower conversion compared to other non-renewable energy systems. Concentrated Photovoltaics (CPV) is one of the vital tools that focus solar radiation on the small area of solar cells using optical devices to maximize solar to thermal conversion. Low cost, high efficiency, and climate-friendly are the main advantages of concentrated photovoltaics. The review study presents the outlook of work conducted worldwide on the different types of concentrated photovoltaics. In addition, the effect of various performance affecting parameters, challenges, and recent progress is also part of the study. Most of the CPV have efficiency up to 15% while some have an efficiency range of 25–28% which is still very low. It was found that the CPV gave maximum efficiency of up to 38.5% at optimal solar radiation. The focus of sunlight on a small area of solar cell increases the temperature of concentrated photovoltaic allegedly pernicious for electrical efficiency and the life of CPV. Factors like direct normal irradiance, high cell temperature, soiling, optical design, reliability, and durability are considered as challenges and a concise summary of various studies on these challenges is presented. In this regard, various cooling techniques have been investigated by different researchers for thermal management of CPV systems which are discussed in detail. As CPV technology is still in the development phase, various new optical designs emphasizing novel designs and materials are also summarized in the current study. Finally, some recommendations are o...
Ejeian, M, Grant, A, Shon, HK & Razmjou, A 2021, 'Is lithium brine water?', Desalination, vol. 518, pp. 115169-115169.
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With the development of light and rechargeable batteries for electric vehicles, global demand for lithium has increased considerably in recent years. This has drawn more attention to how lithium is produced, especially on primary extraction operations such as those at the Salar de Atacama in Northern Chile. There are concerns that brine extraction at the Atacama could irreversibly damage the basin's complex hydrological system. However, differing opinions over the definition of water have frustrated basic action measures for minimizing impacts of operations like these. Some lithium industry stakeholders have historically described brine as a mineral, while others emphasize that brine is also a type of water in a complex network of different water resources. In this communication, we show that brines are undeniably a type of water. We support this position by investigating brine's water molecular structure using molecular dynamics simulations and comparing Gibbs formation energy of the brine using thermodynamic principles. Molecular dynamics show that the structure of water molecules in brine is similar to the structure of molecules in pure water at a pressure of 1.2 atm. The analysis of Gibbs formation energy shows that more than 99% of the brine's formation energy is directly from water, not dissolved minerals.
Ekanayake, D, Loganathan, P, Johir, MAH, Kandasamy, J & Vigneswaran, S 2021, 'Enhanced Removal of Nutrients, Heavy Metals, and PAH from Synthetic Stormwater by Incorporating Different Adsorbents into a Filter Media', Water, Air, & Soil Pollution, vol. 232, no. 3.
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Stormwater harvesting and reuse is an attractive option to lower the demand placed on other sources of water supply. However, it contains a wide range of pollutants that need to be removed before it can be reused or even discharged to the waterways and receiving waters. An experimental protocol to estimate the efficiency of a soil-based-filter medium for the treatment of stormwater pollutants from 1 to 3 years rainfall experienced in the field was developed using a laboratory column-set-up over short-term duration. The filter removed substantial amounts of PO -P and NH -N for up to 8 h at a flow velocity of 100 mm/h which is a 1-year time-equivalent of rainfall at a locality in Sydney, Australia. An addition of 10% zeolite to the soil-based filter extended the column saturation period to 24 h. The breakthrough data for PO -P and NH -N were satisfactorily described by the Thomas model. The majority of the nine heavy metals tested were removed by more than 50% for up to 4 h in the soil-based filter. This level of removal increased to 16 h when 10% zeolite was added to the filter. The column with the soil-based filter + 10% zeolite had higher affinity for Pb, Cu, Zn, and As than Ni, with Pb having the highest percentage removal. Soil-based filter + 10% zeolite removed considerable amounts of 3 polycyclic aromatic hydrocarbons (PAHs) (30–50%), while soil-based filter + 10% zeolite + 0.3% granular activated carbon removed 65 to > 99% of the PAHs at 24-h operation. 4 4 4 4
Ekanayake, UGM, Barclay, M, Seo, DH, Park, MJ, MacLeod, J, O'Mullane, AP, Motta, N, Shon, HK & Ostrikov, KK 2021, 'Utilization of plasma in water desalination and purification', Desalination, vol. 500, pp. 114903-114903.
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© 2020 Elsevier B.V. Supplying fresh drinking water to the world population is a persistent global challenge. Therefore, effective and efficient desalination processes are becoming increasingly important. Oceans account for most of the water on Earth and the presence of salts and other contaminants in seawater prevents them from being used as a source of drinking water. Owing to this challenge, non-thermal plasma can be utilized in order to enhance the existing desalination processes via membrane or material modification while it can also be used as a direct tool for seawater desalination leading to significant process improvements. A direct non-thermal plasma-based desalination process is a new emerging area of research and recent efforts have shown its promise with many unexplored mechanisms, providing benefits that conventional desalination processes cannot offer. Here we critically review the use of plasma technologies in water desalination including membrane modification by plasma for pressure, thermal, photothermal processes and direct plasma-based desalination process. We also address the use of plasmas in water purification. Finally, the existing challenges and future prospects are outlined.
El-Haddad, BA, Youssef, AM, Pourghasemi, HR, Pradhan, B, El-Shater, A-H & El-Khashab, MH 2021, 'Flood susceptibility prediction using four machine learning techniques and comparison of their performance at Wadi Qena Basin, Egypt', Natural Hazards, vol. 105, no. 1, pp. 83-114.
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Floods represent catastrophic environmental hazards that have a significant impact on the environment and human life and their activities. Environmental and water management in many countries require modeling of flood susceptibility to help in reducing the damages and impact of floods. The objective of the current work is to employ four data mining/machine learning models to generate flood susceptibility maps, namely boosted regression tree (BRT), functional data analysis (FDA), general linear model (GLM), and multivariate discriminant analysis (MDA). This study was done in Wadi Qena Basin in Egypt. Flood inundated locations were determined and extracted from the interpretation of different datasets, including high-resolution satellite images (sentinel-2 and Astro digital) (after flood events), historical records, and intensive field works. In total, 342 flood inundated locations were mapped using ArcGIS 10.5, which separated into two groups; training (has 239 flood locations represents 70%) and validating (has 103 flood locations represents 30%), respectively. Nine themes of flood-influencing factors were prepared, including slope-angle, slope length, altitude, distance from main wadis, landuse/landcover, lithological units, curvature, slope-aspect, and topographic wetness index. The relationships between the flood-influencing factors and the flood inventory map were evaluated using the mentioned models (BRT, FDA, GLM, and MDA). The results were compared with flood inundating locations (validating flood sites), which were not used in constructing the models. The accuracy of the models was calculated through the success (training data) and prediction (validation data) rate curves according to the receiver operating characteristics (ROC) and the area under the curve (AUC). The results showed that the AUC for success and prediction rates are 0.783, 0.958, 0.816, 0.821 and 0.812, 0.856, 0.862, 0.769 for BRT, FDA, GLM, and MDA models, respectively. Subseque...
El-Magd, SAA, Pradhan, B & Alamri, A 2021, 'Machine learning algorithm for flash flood prediction mapping in Wadi El-Laqeita and surroundings, Central Eastern Desert, Egypt', Arabian Journal of Geosciences, vol. 14, no. 4.
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Enfrin, M, Wang, J, Merenda, A, Dumée, LF & Lee, J 2021, 'Mitigation of membrane fouling by nano/microplastics via surface chemistry control', Journal of Membrane Science, vol. 633, pp. 119379-119379.
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Nano/microplastic materials fouling across filtration membranes can impact the performance of filtration systems, which constitutes a critical challenge for water facilities operation. In this study, plasma surface modifications aiming at reducing nano/microplastic materials adsorption on ultrafiltration membranes were investigated. Hydrophilic acrylic acid and cyclopropylamine plasma coatings caused a water flux decline of less than 8% after 6 h of crossflow filtration. Both hydrophilic coatings reduced the percentage of nano/microplastics adsorbed on the membranes by more than 60%. On the contrary, the hydrophobic hexamethyldisiloxane layer had no impact on the cumulative percentage of adsorbed nano/microplastics compared to that of the pristine poly(sulfone) membranes, which culminated at 40%, resulting in a water flux decline of 40% upon filtration for both membranes. The extended Derjaguin–Landau–Verwey–Overbeek (XDLVO) theory was then applied to the system particle-membrane, which identified polar forces as the predominant intermolecular interactions contributing to membrane fouling. Tuning the hydrophilicity of the membranes was, therefore, a more efficient strategy to reduce nano/microplastic materials adsorption during filtration than tailoring the surface charge of the membranes, showing potential for complex water matrices remediation.
Fadillah, G, Fatimah, I, Sahroni, I, Musawwa, MM, Mahlia, TMI & Muraza, O 2021, 'Recent Progress in Low-Cost Catalysts for Pyrolysis of Plastic Waste to Fuels', Catalysts, vol. 11, no. 7, pp. 837-837.
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The catalytic and thermal decomposition of plastic waste to fuels over low-cost catalysts like zeolite, clay, and bimetallic material is highlighted. In this paper, several relevant studies are examined, specifically the effects of each type of catalyst used on the characteristics and product distribution of the produced products. The type of catalyst plays an important role in the decomposition of plastic waste and the characteristics of the oil yields and quality. In addition, the quality and yield of the oil products depend on several factors such as (i) the operating temperature, (ii) the ratio of plastic waste and catalyst, and (iii) the type of reactor. The development of low-cost catalysts is revisited for designing better and effective materials for plastic solid waste (PSW) conversion to oil/bio-oil products.
Fang, C, Liu, W, Zhang, P, Rajabzadeh, S, Kato, N, Sasaki, Y, Shon, HK & Matsuyama, H 2021, 'Hollow fiber membranes with hierarchical spherulite surface structure developed by thermally induced phase separation using triple-orifice spinneret for membrane distillation', Journal of Membrane Science, vol. 618, pp. 118586-118586.
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© 2020 Elsevier B.V. Polyvinylidene fluoride (PVDF) hollow fiber membranes were developed by the thermally induced phase separation (TIPS) process using a triple-orifice spinneret with solvent co-extrusion at the outermost channel for applications in membrane distillation (MD). The polymer surface concentration during membrane preparation was controlled by exploiting the interfacial interactions of the diluent and polymer at the extruded solvent surface. The membrane surface was controlled from a dense to a porous structure with a large pore size and a high porosity, which considerably enhanced the membrane water vapor permeability to 13.5 L m−2 h−1. Furthermore, the solvent co-extrusion was responsible for the formation of surface spherulites with different shapes, such as contacted spherulites, isolated spherulites, and isolated spherulites with humps. The spherulites with humps constructed a novel hierarchical structure, which created a superhydrophobic surface that conferred upon the PVDF membrane a remarkable wetting resistance in the MD process toward low-surface-tension saline water. More significantly, all the unique structures were achieved using the one-step membrane fabrication process of solvent co-extrusion without additional processes and materials. Thus, this work provides a new, simple, and useful alternative for the preparation of hollow fiber membranes with high performances for MD desalination.
Fang, C, Liu, W, Zhang, P, Yao, M, Rajabzadeh, S, Kato, N, Kyong Shon, H & Matsuyama, H 2021, 'Controlling the inner surface pore and spherulite structures of PVDF hollow fiber membranes in thermally induced phase separation using triple-orifice spinneret for membrane distillation', Separation and Purification Technology, vol. 258, pp. 117988-117988.
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© 2020 Elsevier B.V. In this study, we controlled the inner surface structures of polyvinylidene fluoride (PVDF) hollow fiber membranes via a thermally induced phase separation process using a triple-orifice spinneret for direct-contact membrane distillation (DCMD). The coextrusion of propylene carbonate (PC) through the outermost channel of the spinneret led to porous outer surfaces with similar pore sizes and spherulitic structures for all the PVDF hollow fiber membranes. In the innermost channel, the extrusion of solvents having different compatibilities with PVDF and the diluent (PC) as the bore liquids controlled the inner surface pore sizes and spherulite structures, and the effects of these inner surface structures on the DCMD performance were investigated in detail. Increasing the compatibility of the bore liquids toward the diluent led to an increase in the inner surface pore size because of the formation of loose, isolated spherulites, which remarkably enhanced the water vapor permeability from 4 to 8.3 L m−2 h−1, while reducing the membrane hydrophobicity, liquid entry pressure, and salt rejection. When increasing the bore liquid compatibility with the polymer, the surface pore size decreased because of the tight spherulite contact, enhancing membrane salt rejection and wetting resistance. Given the significance of bore liquid compatibility with the diluent and the polymer in controlling the inner surface structures, a useful guideline is presented for selecting the appropriate bore liquids to prepare hollow fiber membranes with the desired inner surface structures for high MD performance.
Fang, F, Xu, R-Z, Huang, Y-Q, Luo, J-Y, Xie, W-M, Ni, B-J & Cao, J-S 2021, 'Exploring the feasibility of nitrous oxide reduction and polyhydroxyalkanoates production simultaneously by mixed microbial cultures', Bioresource Technology, vol. 342, pp. 126012-126012.
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Nitrous oxide (N2O), as a powerful greenhouse gas, has drawn increasing attention in recent years and different strategies for N2O reduction were explored. In this study, a novel strategy for valuable polyhydroxyalkanoates (PHA) production coupling with N2O reduction by mixed microbial cultures (MMC) using different substrates was evaluated. Results revealed that N2O was an effective electron acceptor for PHA production. The highest PHA yield (0.35 Cmmol PHA/Cmmol S) and PHA synthesis rate (227.47 mg PHA/L/h) were obtained with acetic acid as substrate. Low temperature (15℃) and pH of 8.0 were beneficial for PHA accumulation. Results of the thermogravimetric analysis showed that PHA produced with N2O as electron acceptor has better thermal stability (melting temperature of 99.4℃ and loss 5% weight temperature of 211.4℃). Our work opens up new avenues for simultaneously N2O reduction and valuable bioplastic production, which is conducive to resource recovery and climate protection.
Fang, J, Wu, C, Rabczuk, T, Wu, C, Sun, G & Li, Q 2021, 'Correction to: Phase field fracture in elasto-plastic solids: a length-scale insensitive model for quasi-brittle materials', Computational Mechanics, vol. 67, no. 6, pp. 1769-1770.
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The original article contained typographical errors that a number of double brackets.
Far, H & Nejadi, S 2021, 'Experimental investigation on flexural behaviour of composite PVC encased macro-synthetic fibre reinforced concrete walls', Construction and Building Materials, vol. 273, pp. 121756-121756.
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Composite PVC encased concrete walls provide substantial advantages in terms of structural strength and durability enhancement, ultraviolet radiation and pest infestation resistance, design flexibility, ease of construction and excellent resistance to impact. In this study, the effects of using macro-synthetic fibre reinforced concrete on flexural behaviour of composite PVC encased walls in comparison with composite PVC encased walls filled with conventional plain concrete and reinforced concrete have been experimentally investigated. Fifteen composite PVC encased concrete wall specimens were cast and tested using three-point bending test. Based on the load-deflection curves resulting from the three-point bending tests, flexural parameters including ultimate loads, ultimate flexural strengths, stiffness and flexural rigidity values for cracked and uncracked conditions were determined for three different cases including i) test specimens filled with plain concrete, ii) test specimens filled with macro-synthetic fibre reinforced concrete, and iii) test specimens filled with reinforced concrete. The determined parameters as well as the measured load-deflection curves for the three cases were compared and the final findings have been discussed. Based on this study, it has become apparent that using BarChip 48 macro-synthetic fibre reinforced concrete in composite PVC encased walls instead of plain concrete can lead to 43.5% flexural strength improvement and 25% stiffness enhancement at the age of 28 days. Based on the experimental measurements and theoretical comparison in this study, it has been concluded that composite PVC encased walls filled with BarChip 48 macro-synthetic fibre reinforced concrete, without steel reinforcement, are deemed suitable for sway-prevented structures such as retaining walls. If using steel reinforcement in composite PVC encased retaining walls is not an option due to high-risk of steel corrosion in harsh environment; it is hig...
Far, H & Nejadi, S 2021, 'Experimental investigation on interface shear strength of composite PVC encased macro-synthetic fibre reinforced concrete walls', Structures, vol. 34, pp. 729-737.
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Over the past decade, Polyvinyl Chloride (PVC) stay-in-place formwork has become a popular alternative for conventional formwork in concrete construction industry due to its relatively lower cost of construction and ease of assembly. The PVC panels are joined using connectors and serve as a permanent formwork into which fresh concrete is poured to form composite PVC encased concrete walls. This study has experimentally investigated the effects of using macro-synthetic fibre reinforced concrete on the interface shear strength of composite PVC encased walls in comparison with composite PVC encased walls filled with conventional plain concrete and reinforced concrete. Nine composite PVC encased concrete wall specimens were cast and tested using direct shear tests. Based on the load–deflection curves obtained from the direct shear tests, the maximum shear loads and interface shear strength values were determined for three different cases including i) test specimens filled with plain concrete, ii) test specimens filled with macro-synthetic fibre reinforced concrete, and iii) test specimens filled with reinforced concrete. The determined parameters as well as the measured load–deflection curves for the three cases were compared and the final findings have been discussed. Based on the outcomes of this study, it has become apparent that the tested composite PVC encased macro-synthetic fibre reinforced concrete wall specimens can noticeably exhibit higher interface shear strength values compared to the tested wall specimens filled with plain concrete. Since AS 3600 (2018) does not prescribe the shear plane surface coefficients for determining the interface shear strength of composite PVC encased concrete walls, in order to enable structural designers to determine the interface shear strength for those panels using AS 3600 (2018), those coefficients have been extracted from the test results for the three mentioned cases and proposed for practical applications.
Far, H, Nejadi, S & Aghayarzadeh, M 2021, 'Experimental investigation on in‐plane lateral stiffness and degree of ductility of composite PVC reinforced concrete walls', Structural Concrete, vol. 22, no. 4, pp. 2126-2137.
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AbstractThis study investigates the in‐plane lateral stiffness and ductility of composite PVC encased concrete walls subject to the lateral loads using pushover tests to determine lateral strength and ductility characteristics of composite PVC encased walls filled with plain concrete, macro‐synthetic fiber reinforced concrete (RC), and steel RC. Eighteen concrete wall specimens were cast and subjected to pushover test to determine the load‐deflection curves. Based on the capacity curves resulting from the pushover tests, the yield and maximum displacements and subsequently structural ductility and performance factors according to Australian Standard for seismic design of buildings have been determined. The determined parameters as well as the initial and effective lateral stiffness values measured from the load‐deflection curves for all three cases were compared and the final findings have been discussed. Based on the outcomes of this study, it has become apparent that the tested composite PVC encased macro‐synthetic fiber RC walls can exhibit superior performance in terms of ductility when compared to the unreinforced concrete specimens. In addition, the results indicated that the initial in‐plane lateral stiffness values of the tested composite PVC encased macro‐synthetic fiber RC walls increased by 25% compared to the tested walls filled with plain concrete. In order to enable structural designers to design composite PVC encased concrete walls, ductility factors for this type of walls have been extracted from the test results for the three mentioned cases and proposed for practical applications. It has been concluded that all the PVC encased concrete walls evaluated in this study can be categorized as fully ductile structures.
Farooq, MA, Nimbalkar, S & Fatahi, B 2021, 'Three-dimensional finite element analyses of tyre derived aggregates in ballasted and ballastless tracks', Computers and Geotechnics, vol. 136, pp. 104220-104220.
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Scrap tyres are a significant source of pollution and pose a grave threat to the environment and human health. The present study aims to examine the application of Tyre Derived Aggregate (TDA) in a concrete slab track and ballasted track and compare its performance in both track forms. In this study, long-term performance of slab track and ballasted track subjected to train induced loading is demonstrated based on the three-dimensional finite element modelling. The most suitable constitutive hyperelastic model for TDA has been identified. Subsequently, the most suitable position for the location of TDA is determined for both track types. A comparative analysis between slab track and ballasted track, with and without TDA, is presented in terms of stress transfer, vibration reduction and displacement (elastic and plastic). It is shown that TDA helps in reducing up to 50% vibration levels of both track types. The influence of train speed and axle load on the vertical and horizontal displacement and stress response of both track forms is shown for a large number of load cycles. Overall, it is observed that the long-term performance of TDA is better in slab track compared to ballasted track.
Feng, S, Hao Ngo, H, Guo, W, Woong Chang, S, Duc Nguyen, D, Cheng, D, Varjani, S, Lei, Z & Liu, Y 2021, 'Roles and applications of enzymes for resistant pollutants removal in wastewater treatment', Bioresource Technology, vol. 335, pp. 125278-125278.
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Resistant pollutants like oil, grease, pharmaceuticals, pesticides, and plastics in wastewater are difficult to be degraded by traditional activated sludge methods. These pollutants are prevalent, posing a great threat to aquatic environments and organisms since they are toxic, resistant to natural biodegradation, and create other serious problems. As a high-efficiency biocatalyst, enzymes are proposed for the treatment of these resistant pollutants. This review focused on the roles and applications of enzymes in wastewater treatment. It discusses the influence of enzyme types and their sources, enzymatic processes in resistant pollutants remediation, identification and ecotoxicity assay of enzymatic transformation products, and typically employed enzymatic wastewater treatment systems. Perspectives on the major challenges and feasible future research directions of enzyme-based wastewater treatment are also proposed.
Feng, Y, Wang, Q, Wu, D, Luo, Z, Chen, X, Zhang, T & Gao, W 2021, 'Machine learning aided phase field method for fracture mechanics', International Journal of Engineering Science, vol. 169, pp. 103587-103587.
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Fonseka, C, Ryu, S, Choo, Y, Mullett, M, Thiruvenkatachari, R, Naidu, G & Vigneswaran, S 2021, 'Selective Recovery of Rare Earth Elements from Mine Ore by Cr-MIL Metal–Organic Frameworks', ACS Sustainable Chemistry & Engineering, vol. 9, no. 50, pp. 16896-16904.
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Rare earth elements (REEs) have become a strategic resource extensively used in renewable energy technologies and modern electronic devices. Depletion of natural REE-bearing mineral deposits has made selective recovery of REEs from alternative sources crucial in meeting the rising global demand. A chromium-based metal–organic framework was synthesized and modified with N-(phosphonomethyl)iminodiacetic acid (PMIDA) in this study to selectively recover REEs (europium, Eu) from chemically complex zinc ore leachate. The adsorbent was characterized and comprehensively examined for Eu uptake as a function of adsorbate concentration, contact time, and pH of the solution. Cr-MIL-PMIDA showed a maximum adsorption capacity of 69.14 mg/g at pH 5.5 while adsorption kinetics best fitted the pseudo-second-order model. Furthermore, Cr-MIL-PMIDA showed exceptional selectivity (88%) toward Eu over competing transitional metal ions (Na, Mg, Al, Ca, Mn, Fe, Ni, Cu, Co, and Zn) found in the dissolved mine ore. High selectivity toward REEs was attributed to the formation of coordinative complexes with grafted carboxylate, phosphonic, and residual amine functional groups. Cr-MIL-PMIDA demonstrated excellent structural stability over multiple regeneration cycles, highlighting its potential for industrial application for REE recovery.
Freguia, S, Sharma, K, Benichou, O, Mulliss, M & Shon, HK 2021, 'Sustainable engineering of sewers and sewage treatment plants for scenarios with urine diversion', Journal of Hazardous Materials, vol. 415, pp. 125609-125609.
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Fu, Q, Wang, D, Li, X, Yang, Q, Xu, Q, Ni, B-J, Wang, Q & Liu, X 2021, 'Towards hydrogen production from waste activated sludge: Principles, challenges and perspectives', Renewable and Sustainable Energy Reviews, vol. 135, pp. 110283-110283.
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Hydrogen production from waste activated sludge (WAS) was widely considered and intensively investigated as a promising technology to recover energy from wastewater treatment plants. To date, no efforts have been made on either systematic summarization or critical thinking of the application niche of hydrogen production from WAS treatment. It is therefore time to evaluate whether and how to recover hydrogen in a future paradigm of WAS treatment. In this critical review, the principles and potentials, microorganisms, possible technologies, and process parameters of hydrogen generation were analyzed. Microbial electrolysis cell shows high theoretical hydrogen yield and could utilize a variety of organic compounds as substrates, which is regarded as a prospective technology for hydrogen production. However, the poor organics utilization and rapid consumptions of produced hydrogen hindered hydrogen recovery from WAS. Based on the analysis of the current state of the literatures, the opportunities and challenges of hydrogen production from WAS are rethought, the detailed knowledge gaps and perspective of hydrogen production from WAS were discussed, and the probable solutions of hydrogen recovery from WAS treatment are figured out. To guide the application and development of hydrogen recovery, a more promising avenue through rational integration of the available technologies to form a hybrid process is finally proposed. The integrated operational paradigm of WWTPs could achieve substantial technical, environmental and economic benefits. In addition, how this hybrid process works is illustrated, the challenges of this hybrid process and future efforts to be made in the future are put forward.
Gan, YY, Chen, W-H, Ong, HC, Lin, Y-Y, Sheen, H-K, Chang, J-S & Ling, TC 2021, 'Effect of wet torrefaction on pyrolysis kinetics and conversion of microalgae carbohydrates, proteins, and lipids', Energy Conversion and Management, vol. 227, pp. 113609-113609.
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Gao, C, Huang, L, Yan, L, Kasal, B, Li, W, Jin, R, Wang, Y, Li, Y & Deng, P 2021, 'Compressive performance of fiber reinforced polymer encased recycled concrete with nanoparticles', Journal of Materials Research and Technology, vol. 14, pp. 2727-2738.
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Nanomaterials have been used in improving the performance of construction materials due to their compacting micro-structure effect and accelerating cement hydration reaction. Considering the brittle characteristic of fiber reinforced polymer (termed as FRP) tube encased concrete and inferior properties of recycled concrete, nanoparticles were used in FRP tube encased recycled aggregate concrete. The axial compressive performance of FRP tube used in recycled concrete treated with nanoparticles strengthening, termed as FRP-NPRC, were investigated by axial compression experiments and theoretical analysis. Five experimental variables were considered including (1) the dosages and (2) varieties of nanoparticles (i.e. 1% and 2% of nanoSiO2, 1% and 2% of nanoCaCO3), (3) replacement ratios of recycled coarse aggregates (termed as RCAs) (0%, 50%, 70% and 100%) the RCAs were mainly produced from the waste cracked bricks, (4) the number of glass FRP (GFRP) tube layers (2, 4 and 6-layer) and (5) the mixing methods of concrete. Results indicate that the combination of FRP confinement and nanoparticle modification in recycled concrete exhibited up to 76.2% increase in compressive strength and 7.62 times ductility improvement. Furthermore, a design-oriented stress–strain model on the basis of the ultimate condition analysis were executed to evaluate the stress–strain property of this strengthened component.
Gao, F, He, X & Zhang, S 2021, 'Pumping effect of rainfall-induced excess pore pressure on particle migration', Transportation Geotechnics, vol. 31, pp. 100669-100669.
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Gao, K, Liu, Z, Wu, C, Li, J, Liu, K, Liu, Y & Li, S 2021, 'Effect of low gas concentration in underground return tunnels on characteristics of gas explosions', Process Safety and Environmental Protection, vol. 152, pp. 679-691.
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This study numerically investigated the effect of a very low gas concentration on a gas explosion's performance numerically using OpenFOAM. The use of the Harten–Lax–van Leer–Contact (HLLC) approximation algorithm based on the density-based solver was proposed to capture the shock wave. The process variable in XiFOAM of the OpenFOAM toolbox was used for the deflagration reaction. A gas explosion test was performed, and the numerical model with OpenFOAM was validated using the testing data. Based on the numerical investigation, the influence of a very low methane concentration on the flame and shock wave propagation law of a gas explosion was analyzed. It showed that the flame initially accelerated, followed by deceleration, and then accelerated again before slowing down. An increase in the methane concentration had an enhanced effect on the maximum overpressure ratio, which increased linearly with an increase in the methane concentration from 0 vol. % to 3.0 vol. % in the return tunnels. Increasing the explosive methane volume and concentration caused a significant increase in the flame spread distance. It was also noted that increasing the methane concentration caused a linear increase in the maximum overpressure ratio, and the methane volume and concentration both had a sensitive effects on the maximum overpressure ratio and average overpressure rising rate. The results clarified how the gas explosion law was affected by a very low gas concentration and provided theoretical support for controlling gas explosion disasters.
Gao, L, Liu, G, Zamyadi, A, Wang, Q & Li, M 2021, 'Life-cycle cost analysis of a hybrid algae-based biological desalination – low pressure reverse osmosis system', Water Research, vol. 195, pp. 116957-116957.
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To fully understand the economic viability and implementation strategy of the emerging algae-based desalination technology, this study investigates the economic aspects of algae-based desalination system by comparing the life-cycle costs of three different scenarios: (1) a multi-stage microalgae based desalination system; (2) a hybrid desalination system based on the combination of microalgae and low pressure reverse osmosis (LPRO) system; and (3) a seawater reverse osmosis (SWRO) desalination system. It is identified that the capital expenditure (CAPEX) and operational expenditure (OPEX) of scenario 1 are significantly higher than those of scenarios 2 and 3, when algal biomass reuse is not taken into consideration. If the revenues obtained from the algal biomass reuse are taken into account, the OPEX of scenario 1 will decrease significantly, and scenarios 2 and 3 will have the highest and lowest OPEX, respectively. However, due to the high CAPEX of scenario 1, the total expenditure (TOTEX) of scenario 1 is still 27% and 33% higher than those of scenarios 2 and 3, respectively. A sensitivity study is undertaken to understand the effects of six key parameters on water total cost for different scenarios. It is suggested that the electricity unit price plays the most important role in determining the water total cost for different scenarios. An uncertainty analysis is also conducted to investigate the effects and limitations of the key assumptions made in this study. It is suggested that the assumption of total dissolved solids (TDS) removal efficiency of microalgae results in a high uncertainty of life-cycle cost analysis (LCCA). Additionally, it is estimated that 1.58 megaton and 0.30 megaton CO2 can be captured by the algae-based desalination process for scenarios 1 and 2, respectively, over 20 years service period, which could result in approximately AU $18 million and AU $3 million indirect financial benefits for scenarios 1 and 2, respectively. When...
Gao, X, Xu, Z, Li, Y, Zhang, L, Li, G, Nghiem, LD & Luo, W 2021, 'Bacterial dynamics for gaseous emission and humification in bio-augmented composting of kitchen waste', Science of The Total Environment, vol. 801, pp. 149640-149640.
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Gao, Y, Sun, S, Zhang, X, Liu, Y, Hu, J, Huang, Z, Gao, M & Pan, H 2021, 'Amorphous Dual‐Layer Coating: Enabling High Li‐Ion Conductivity of Non‐Sintered Garnet‐Type Solid Electrolyte', Advanced Functional Materials, vol. 31, no. 15, pp. 2009692-2009692.
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AbstractGarnet‐type oxide Li6.4La3Zr1.4Ta0.6O12 (LLZTO) has attracted considerable attention as a highly promising solid state electrolyte. However, its high ionic conductivity is achievable only after high temperature sintering (≈1200 °C) to form dense pellets but with detrimental brittleness and poor contact with electrodes. Herein, a novel strategy to achieve high Li+ ion conductivity of LLZTO without sintering is demonstrated. This is realized by ball milling LLZTO together with LiBH4, which results in a LLZTO composite with unique amorphous dual coating: LiBO2 as the inner layer and LiBH4 as the outer layer. After cold pressing the LLZTO composite powders under 300 MPa to form electrolyte pellets, a high Li+ ion conductivity of 8.02 × 10–5 S cm–1 is obtained at 30 °C, which is four orders of magnitude higher than that of the non‐sintered pristine LLZTO pellets (4.17 × 10–9 S cm–1). The composite electrolyte displays an ultrahigh Li+ transference number of 0.9999 and enables symmetric Li–Li cells to be cycled for 1000 h at 60 °C and 300 h at 30 °C. The significant improvements are attributed to the continuous ionic conductive network among LLZTO particles facilitated by LiBH4 that is chemically compatible and electrochemically stable with Li metal electrode.
Gao, Y, Sun, S, Zhang, X, Liu, Y, Hu, J, Huang, Z, Gao, M & Pan, H 2021, 'Solid State Electrolytes: Amorphous Dual‐Layer Coating: Enabling High Li‐Ion Conductivity of Non‐Sintered Garnet‐Type Solid Electrolyte (Adv. Funct. Mater. 15/2021)', Advanced Functional Materials, vol. 31, no. 15, pp. 2170100-2170100.
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Gaur, VK, Sharma, P, Gaur, P, Varjani, S, Ngo, HH, Guo, W, Chaturvedi, P & Singhania, RR 2021, 'Sustainable mitigation of heavy metals from effluents: Toxicity and fate with recent technological advancements', Bioengineered, vol. 12, no. 1, pp. 7297-7313.
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Increase in anthropogenic activities due to rapid industrialization had caused an elevation in heavy metal contamination of aquatic and terrestrial ecosystems. These pollutants have detrimental effects on human and environmental health. The majority of these pollutants are carcinogenic, neurotoxic, and are very poisonous even at very low concentrations. Contamination caused by heavy metals has become a global concern for which the traditional treatment approaches lack in providing a cost-effective and eco-friendly solution. Therefore, the use of microorganisms and plants to reduce the free available heavy metal present in the environment has become the most acceptable method by researchers. Also, in microbial- and phyto-remediation the redox reaction shifts the valence which makes these metals less toxic. In addition to this, the use of biochar as a remediation tool has provided a sustainable solution that needs further investigations toward its implementation on a larger scale. Enzymes secreted by microbes and whole microbial cell are considered an eco-efficient biocatalyst for mitigation of heavy metals from contaminated sites. To the best of our knowledge there is very less literature available covering remediation of heavy metals aspect along with the sensors used for detection of heavy metals. Systematic management should be implemented to overcome the technical and practical limitations in the use of these bioremediation techniques. The knowledge gaps have been identified in terms of its limitation and possible future directions have been discussed.
Gavhane, RS, Kate, AM, Soudagar, MEM, Wakchaure, VD, Balgude, S, Rizwanul Fattah, IM, Nik-Ghazali, N-N, Fayaz, H, Khan, TMY, Mujtaba, MA, Kumar, R & Shahabuddin, M 2021, 'Influence of Silica Nano-Additives on Performance and Emission Characteristics of Soybean Biodiesel Fuelled Diesel Engine', Energies, vol. 14, no. 5, pp. 1489-1489.
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The present study examines the effect of silicon dioxide (SiO2) nano-additives on the performance and emission characteristics of a diesel engine fuelled with soybean biodiesel. Soybean biofuel was prepared using the transesterification process. The morphology of nano-additives was studied using scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS). The Ultrasonication process was used for the homogeneous blending of nano-additives with biodiesel, while surfactant was used for the stabilisation of nano-additives. The physicochemical properties of pure and blended fuel samples were measured as per ASTM standards. The performance and emissions characteristics of different fuel samples were measured at different loading conditions. It was found that the brake thermal efficiency (BTE) and brake specific fuel consumption (BSFC) increased by 3.48–6.39% and 5.81–9.88%, respectively, with the addition of SiO2 nano-additives. The carbon monoxide (CO), hydrocarbon (HC) and smoke emissions for nano-additive added blends were decreased by 1.9–17.5%, 20.56–27.5% and 10.16–23.54% compared to SBME25 fuel blends.
Ghanbari, F, Wang, Q, Hassani, A, Wacławek, S, Rodríguez-Chueca, J & Lin, K-YA 2021, 'Electrochemical activation of peroxides for treatment of contaminated water with landfill leachate: Efficacy, toxicity and biodegradability evaluation', Chemosphere, vol. 279, pp. 130610-130610.
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Contaminated water with landfill leachate (CWLL) with high salinity and high organic content (total organic carbon (TOC) = 649 mg/L and Chemical Oxygen Demand (COD) = 1175 mg/L) is a toxic and non-biodegradable effluent. The present research aimed to assess the treatment effectiveness of CWLL by electrocoagulation (EC)/oxidant process. The ferrous ions generated during the process were employed as coagulant and catalyst for the activation of different oxidants such as peroxymonosulfate (PMS), peroxydisulfate (PDS), hydrogen peroxide (HP), and percarbonate (PC) to decrease TOC in CWLL. Removal of ammonia, color, phosphorous, and chemical oxygen demand (COD) from CWLL effluent was explored at various processes. EC/HP had the best performance (∼73%) in mineralization of organic pollutants compared to others under the condition of pH 6.8, applied current of 200 mA, oxidant dosage of 6 mM, and time of 80 min. The oxidation priority was to follow this order: EC/HP > EC/PMS > EC/PDS > EC/PC. These processes enhanced the biodegradability of CWLL based on the average oxidation state and biochemical oxygen demand (BOD)/COD ratio. SUVA254 and E2/E3 indices were also investigated on obtained effluents. The phytotoxicity evaluation was carried out based on the germination index, indicating that the electro-activated oxidant was an effective system to reduce the toxicity of polluted waters. EC/HP showed supremacy compared to others in terms of efficiency, cost, and detoxification. Therefore, the electro-activated oxidant system is a good means for removing organic pollutants from real wastewater.
Ghobadi, R, Altaee, A, Zhou, JL, Karbassiyazdi, E & Ganbat, N 2021, 'Effective remediation of heavy metals in contaminated soil by electrokinetic technology incorporating reactive filter media', Science of The Total Environment, vol. 794, pp. 148668-148668.
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Soil contamination is increasingly a global problem with serious implications for human health. Among different soil decontamination approaches, electrokinetic (EK) remediation is a relatively new technology for treating organic and inorganic contaminants in soil. This research aims to develop an enhanced EK treatment method incorporating a compost-based reactive filter media (RFM) with the advantages of low-cost and strong affinity for heavy metals and test and improve the treatment efficiency for multiple heavy metals in natural soil. A series of EK operations were performed to investigate the performance of EK-RFM under different operating conditions such as the electric current and voltage, processing time, and the amount of RFM. The electric current and treatment time demonstrated a significant positive impact on removing Zn, Cd and Mn ions while changing the amount of RFM had an insignificant impact on the efficiency of heavy metals removal. Overall, 51.6%–72.1% removal of Zn, Cd, and Mn was achieved at 30.00 mA of electric current and 14 days of treatment duration. The energy consumption of the EK process was 0.17 kWh kg−1. The soil organic matter adversely affected the mobilization and migration of heavy metals such as Cu and Pb during EK treatment. The results are valuable in optimizing the design of the EK-RFM system, which will extend its application to field-scale soil decontamination practices.
Ghobadi, R, Altaee, A, Zhou, JL, McLean, P, Ganbat, N & Li, D 2021, 'Enhanced copper removal from contaminated kaolinite soil by electrokinetic process using compost reactive filter media', Journal of Hazardous Materials, vol. 402, pp. 123891-123891.
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Ghosh, B, Fatahi, B, Khabbaz, H, Nguyen, HH & Kelly, R 2021, 'Field study and numerical modelling for a road embankment built on soft soil improved with concrete injected columns and geosynthetics reinforced platform', Geotextiles and Geomembranes, vol. 49, no. 3, pp. 804-824.
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Gite, S, Pradhan, B, Alamri, A & Kotecha, K 2021, 'ADMT: Advanced Driver’s Movement Tracking System Using Spatio-Temporal Interest Points and Maneuver Anticipation Using Deep Neural Networks', IEEE Access, vol. 9, pp. 99312-99326.
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Assistive driving is a complex engineering problem and is influenced by several factors such as the sporadic nature of the quality of the environment, the response of the driver, and the standard of the roads on which the vehicle is being driven. The authors track the driver's anticipation based on his head movements using Spatio-Temporal Interest Point (STIP) extraction and enhance the anticipation of action accuracy well before using the RNN-LSTM framework. This research tackles a fundamental problem of lane change assistance by developing a novel model called Advanced Driver's Movement Tracking (ADMT). ADMT uses customized convolution-based deep learning networks by using Recurrent Convolutional Neural Network (RCNN). STIP with eye gaze extraction and RCNN performed in ADMT on brain4cars dataset for driver movement tracking. Its performance is compared with the traditional machine learning and deep learning models, namely Support Vector Machines (SVM), Hidden Markov Model (HMM), Convolutional Neural Networks (CNN), Recurrent Neural Networks (RNN), Long Short-Term Memory (LSTM), and provided an increment of almost 12% in the prediction accuracy and 44% in the anticipation time. Furthermore, ADMT systems outperformed all of the models in terms of both the accuracy of the system and the previously mentioned time of anticipation that is discussed at length in the paper. Thus it assists the driver with additional anticipation time to access the typical reaction time for better preparedness to respond to undesired future behavior. The driver is then assured of a safe and assisted driving experience with the proposed system.
Gonzales, RR, Abdel-Wahab, A, Adham, S, Han, DS, Phuntsho, S, Suwaileh, W, Hilal, N & Shon, HK 2021, 'Salinity gradient energy generation by pressure retarded osmosis: A review', Desalination, vol. 500, pp. 114841-114841.
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Pressure retarded osmosis (PRO) has gained attention due to its use as a salinity gradient energy-generating membrane process. This process can convert difference in salinity between two streams into energy as it allows water transport through a semi-permeable membrane against the application of hydraulic pressure. This review provides a comprehensive look at the history and latest developments in preparation of membranes and modules for the PRO process, as well as the various applications of PRO. This review also explored the influence of feed characteristics and pretreatment strategies on water permeation and power generation during PRO operation. The current status and technological advancements of PRO as a process were reviewed, revealing how PRO can be operated as a stand-alone process or in integration with other hybrid processes. Despite the recent advancements in material and process development for PRO, membrane performance, wide-scale implementation, and commercialization efforts still leave much to be desired. Recognizing the current challenges facing the PRO technology, the advancements in PRO membrane and module development, and the various applications of the process, this review also draws out the future direction of PRO research and generation of osmotic salinity gradient energy as a viable energy source.
Gonzales, RR, Abdel-Wahab, A, Han, DS, Matsuyama, H, Phuntsho, S & Shon, HK 2021, 'Control of the antagonistic effects of heat-assisted chlorine oxidative degradation on pressure retarded osmosis thin film composite membrane surface', Journal of Membrane Science, vol. 636, pp. 119567-119567.
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During pressure retarded osmosis (PRO) operation, thin film composite (TFC) membranes are continuously exposed to chemicals present in the stream that can deteriorate the membrane's selective layer with exposure time. Following this observation, TFC membranes are placed in controlled oxidative degradation conditions using aqueous NaOCl solutions. Active chlorine, along with heat, can thin out the dense layer and, when controlled and optimized, can tune the membrane surface properties and separation efficiency as desirable for specific applications. The chlorine oxidative degradation is optimized in terms of chlorine exposure (a factor of both exposure time and chemical dosage), solution pH, and the subsequent heating time. After the chemical modification process, the membrane surface properties were characterized and the PRO performance as well as the osmotic energy harvesting capability were determined. The modified membranes exhibited different levels of polyamide degradation and increase in water permeability, which came along with decrease in selectivity. Optimization of the chlorine oxidative degradation using response surface methodology was performed to maximize the water permeability and extractable osmotic power while keeping salt rejection satisfactory. After performing chlorine oxidation at the following optimized conditions: 3025 ppm Cl2·h, pH 10.72, and 3 min heating time, initial non-pressure retarded water flux of 73.2 L m−2 h−1, specific reverse solute flux of 1.17 g L−1, and power density of 18.71 W m−2 (corresponding to water flux of 56.1 L m-2 h-1) at 12 bar were obtained using 0.6 M NaCl as draw and deionized water as feed.
Gonzales, RR, Zhang, L, Guan, K, Park, MJ, Phuntsho, S, Abdel-Wahab, A, Matsuyama, H & Shon, HK 2021, 'Aliphatic polyketone-based thin film composite membrane with mussel-inspired polydopamine intermediate layer for high performance osmotic power generation', Desalination, vol. 516, pp. 115222-115222.
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Gonzales, RR, Zhang, L, Sasaki, Y, Kushida, W, Matsuyama, H & Shon, HK 2021, 'Facile development of comprehensively fouling-resistant reduced polyketone-based thin film composite forward osmosis membrane for treatment of oily wastewater', Journal of Membrane Science, vol. 626, pp. 119185-119185.
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© 2021 Forward osmosis (FO) has proven to be a suitable process for treatment of problematic oily wastewater, due to its relatively higher water recovery rate and lower energy requirement, as opposed to pressure-driven membrane processes. Despite the lower membrane fouling propensity during FO operation, the development of comprehensively fouling-resistant membranes is further desired in FO as a suitable oily wastewater treatment process. In this current work, reduced aliphatic polyketone (rPK)-based thin film composite (TFC) membranes were developed. Reduction conditions using NaBH4 were tested, and the suitability of reduction was evaluated with membrane morphology, water wettability, and resistance to oil. The resultant rPK-TFC membrane, whose substrate was reduced with 0.5% (w/w) NaBH4 for 10 min, exhibited 37.8 L m−2 h−1 water flux in PRO mode. Using a foulant solution containing 1% (v/v) soybean oil, and 100 ppm humic acid, sodium alginate, and bovine serum albumin, the resultant rPK-TFC membrane maintained an outstanding 95% average flux recovery ratio, while the pristine PK-TFC membrane achieved an average flux recovery ratio of 67%. The results indicate that reduction of aliphatic polyketone is a facile method to develop membranes with outstanding water permeability and fouling resistance.
Gooch, LJ, Masia, MJ & Stewart, MG 2021, 'Application of stochastic numerical analyses in the assessment of spatially variable unreinforced masonry walls subjected to in-plane shear loading', Engineering Structures, vol. 235, pp. 112095-112095.
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This paper develops a modelling strategy for the finite element analysis of perforated (arched) unreinforced masonry walls subjected to in-plane shear loading. An experimental baseline was used to facilitate an accurate calibration and assessment of the chosen modelling strategy. This study provides the procedure and the results relevant to a stochastic assessment of unreinforced masonry shear walls. These results may be used in future studies of the reliability of these structures and may be applied in the calibration of reliability-based design practices. Utilising a two-dimensional micro-modelling approach, the capacity of a monotonic loading scheme to capture the envelope of a cyclically applied load was examined. It was found that, while the elastic stiffness of the laboratory specimens was overestimated by the finite element models, the peak load and global response was accurately recreated by the monotonically loaded models. Once the applicability of this procedure had been established, a series of spatially variable stochastic finite element analyses were created by considering the stochastic properties of key material parameters. These analyses were able to estimate the mean load resistance of the experimentally tested walls with a greater accuracy than a deterministic model. Furthermore, these analyses produced an accurate estimate of the variability of shear capacity of and the observed damage to the laboratory specimens. Due to the fact that the tested walls failed almost exclusively in a rocking mode, a failure mechanism highly dependent upon the structures’ geometry, the variability of the peak strength was minimal. However, the observed damage and presence of some sliding and stepped cracking indicates that the proposed methodology is likely to capture more variable and unstable failure modes in shear walls with a smaller height-to-length ratio or those more highly confined.
Graś, M, Kolanowski, Ł, Chen, Z, Lota, K, Jurak, K, Ryl, J, Ni, B-J & Lota, G 2021, 'Partial inhibition of borohydride hydrolysis using porous activated carbon as an effective method to improve the electrocatalytic activity of the DBFC anode', Sustainable Energy & Fuels, vol. 5, no. 17, pp. 4401-4413.
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Utilization of activated carbons from coffee waste in the complex borohydride electrooxidation process has great potential in increasing the efficiency of an anode based on the AB5-hydrogen storage alloy, as well as in proper management of waste.
Gravina da Rocha, C, Marin, EJB, Quiñónez Samaniego, RA & Consoli, NC 2021, 'Decision-Making Model for Soil Stabilization: Minimizing Cost and Environmental Impacts', Journal of Materials in Civil Engineering, vol. 33, no. 2, pp. 06020024-06020024.
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Gudigar, A, Nayak, S, Samanth, J, Raghavendra, U, A J, A, Barua, PD, Hasan, MN, Ciaccio, EJ, Tan, R-S & Rajendra Acharya, U 2021, 'Recent Trends in Artificial Intelligence-Assisted Coronary Atherosclerotic Plaque Characterization', International Journal of Environmental Research and Public Health, vol. 18, no. 19, pp. 10003-10003.
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Coronary artery disease is a major cause of morbidity and mortality worldwide. Its underlying histopathology is the atherosclerotic plaque, which comprises lipid, fibrous and—when chronic—calcium components. Intravascular ultrasound (IVUS) and intravascular optical coherence tomography (IVOCT) performed during invasive coronary angiography are reference standards for characterizing the atherosclerotic plaque. Fine image spatial resolution attainable with contemporary coronary computed tomographic angiography (CCTA) has enabled noninvasive plaque assessment, including identifying features associated with vulnerable plaques known to presage acute coronary events. Manual interpretation of IVUS, IVOCT and CCTA images demands scarce physician expertise and high time cost. This has motivated recent research into and development of artificial intelligence (AI)-assisted methods for image processing, feature extraction, plaque identification and characterization. We performed parallel searches of the medical and technical literature from 1995 to 2021 focusing respectively on human plaque characterization using various imaging modalities and the use of AI-assisted computer aided diagnosis (CAD) to detect and classify atherosclerotic plaques, including their composition and the presence of high-risk features denoting vulnerable plaques. A total of 122 publications were selected for evaluation and the analysis was summarized in terms of data sources, methods—machine versus deep learning—and performance metrics. Trends in AI-assisted plaque characterization are detailed and prospective research challenges discussed. Future directions for the development of accurate and efficient CAD systems to characterize plaque noninvasively using CCTA are proposed.
Gudigar, A, Raghavendra, U, Nayak, S, Ooi, CP, Chan, WY, Gangavarapu, MR, Dharmik, C, Samanth, J, Kadri, NA, Hasikin, K, Barua, PD, Chakraborty, S, Ciaccio, EJ & Acharya, UR 2021, 'Role of Artificial Intelligence in COVID-19 Detection', Sensors, vol. 21, no. 23, pp. 8045-8045.
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The global pandemic of coronavirus disease (COVID-19) has caused millions of deaths and affected the livelihood of many more people. Early and rapid detection of COVID-19 is a challenging task for the medical community, but it is also crucial in stopping the spread of the SARS-CoV-2 virus. Prior substantiation of artificial intelligence (AI) in various fields of science has encouraged researchers to further address this problem. Various medical imaging modalities including X-ray, computed tomography (CT) and ultrasound (US) using AI techniques have greatly helped to curb the COVID-19 outbreak by assisting with early diagnosis. We carried out a systematic review on state-of-the-art AI techniques applied with X-ray, CT, and US images to detect COVID-19. In this paper, we discuss approaches used by various authors and the significance of these research efforts, the potential challenges, and future trends related to the implementation of an AI system for disease detection during the COVID-19 pandemic.
Gul, M, Zulkifli, NWM, Kalam, MA, Masjuki, HH, Mujtaba, MA, Yousuf, S, Bashir, MN, Ahmed, W, Yusoff, MNAM, Noor, S, Ahmad, R & Hassan, MT 2021, 'RSM and Artificial Neural Networking based production optimization of sustainable Cotton bio-lubricant and evaluation of its lubricity & tribological properties', Energy Reports, vol. 7, pp. 830-839.
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Gunawan, Y, Putra, N, Hakim, II, Agustina, D & Mahlia, TMI 2021, 'Withering of tea leaves using heat pipe heat exchanger by utilizing low-temperature geothermal energy', International Journal of Low-Carbon Technologies, vol. 16, no. 1, pp. 146-155.
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Abstract The volume of Indonesian tea exports to the European Union (EU) decreased by 43% in 2014 because of the EU setting a maximum residue limit of anthraquinone (AQ) for tea as 0.02 mg/kg. The content of AQ in tea leaves increases when there is incomplete combustion in the combustion of firewood for the energy source of withering and drying of tea leaves. This study aims to develop and test a new concept for the direct use of low-temperature geothermal energy with a heat pipe heat exchanger (HPHE) for the withering of tea leaves as a solution for energy sources free from AQ. The geothermal fluid simulators use water, which is heated by heater and flowed by a pump. The HPHE used consists of 42 heat pipes and 181 fins. The heat pipe used has a length of 700 mm with an outer diameter of 10 mm. Each fin is made of aluminum with a thickness of 0.105 mm and a size of 76 × 345 mm2. The results show that the effectiveness of the HPHE varies from 66% to 79.59%. For 100 g of fresh tea leaves, the heating energy produced ranges from 15.21 W to 45.07 W, meaning it can wither tea leaves from 80% (w.b.) to 54% (w.b.) in a variety of 11 h 56 min to only 49.6 min. The Page mathematical model is the best model to represent the behavior of the tea leaves with this HPHE system.
Guo, W, Ngo, HH, Surampalli, RY & Zhang, TC 2021, 'Preface', Sustainable Resource Management: Technologies for Recovery and Reuse of Energy and Waste Materials, pp. xix-xx.
Hafiz, M, Alfahel, R, Hawari, AH, Hassan, MK & Altaee, A 2021, 'A Hybrid NF-FO-RO Process for the Supply of Irrigation Water from Treated Wastewater: Simulation Study', Membranes, vol. 11, no. 3, pp. 191-191.
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Municipal treated wastewater could be considered as a water source for food crop irrigation purposes. Enhancing the quality of treated wastewater to meet irrigation standards has become a necessary practice. Nanofiltration (NF) was used in the first stage to produce permeate at relatively low energy consumption. In the second stage, two membrane combinations were tested for additional water extraction from the brine generated by the NF process. The simulation results showed that using a hybrid forward osmosis (FO)–reverse osmosis (RO) system is more efficient than using the RO process alone for the further extraction of water from the brine generated by the NF process. The total specific energy consumption can be reduced by 27% after using FO as an intermediate process between NF and RO. In addition, the final permeate water quality produced using the hybrid FO-RO system was within the allowable standards for food crops irrigation.
Hafiz, M, Hawari, AH, Alfahel, R, Hassan, MK & Altaee, A 2021, 'Comparison of Nanofiltration with Reverse Osmosis in Reclaiming Tertiary Treated Municipal Wastewater for Irrigation Purposes', Membranes, vol. 11, no. 1, pp. 32-32.
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This study compares the performance of nanofiltration (NF) and reverse osmosis (RO) for the reclamation of ultrafiltered municipal wastewater for irrigation of food crops. RO and NF technologies were evaluated at different applied pressures; the performance of each technology was evaluated in terms of water flux, recovery rate, specific energy consumption and quality of permeate. It was found that the permeate from the reverse osmosis (RO) process complied with Food and Agriculture Organization (FAO) standards at pressures applied between 10 and 18 bar. At an applied pressure of 20 bar, the permeate quality did not comply with irrigation water standards in terms of chloride, sodium and calcium concentration. It was found that nanofiltration process was not suitable for the reclamation of wastewater as the concentration of chloride, sodium and calcium exceeded the allowable limits at all applied pressures. In the reverse osmosis process, the highest recovery rate was 36%, which was achieved at a pressure of 16 bar. The specific energy consumption at this applied pressure was 0.56 kWh/m3. The lowest specific energy of 0.46 kWh/m3 was achieved at an applied pressure of 12 bar with a water recovery rate of 32.7%.
Halat, DM, Snyder, RL, Sundararaman, S, Choo, Y, Gao, KW, Hoffman, ZJ, Abel, BA, Grundy, LS, Galluzzo, MD, Gordon, MP, Celik, H, Urban, JJ, Prendergast, D, Coates, GW, Balsara, NP & Reimer, JA 2021, 'Modifying Li+ and Anion Diffusivities in Polyacetal Electrolytes: A Pulsed-Field-Gradient NMR Study of Ion Self-Diffusion', Chemistry of Materials, vol. 33, no. 13, pp. 4915-4926.
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Han, C, Wang, X, Peng, J, Xia, Q, Chou, S, Cheng, G, Huang, Z & Li, W 2021, 'Recent Progress on Two-Dimensional Carbon Materials for Emerging Post-Lithium (Na+, K+, Zn2+) Hybrid Supercapacitors', Polymers, vol. 13, no. 13, pp. 2137-2137.
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The hybrid ion capacitor (HIC) is a hybrid electrochemical energy storage device that combines the intercalation mechanism of a lithium-ion battery anode with the double-layer mechanism of the cathode. Thus, an HIC combines the high energy density of batteries and the high power density of supercapacitors, thus bridging the gap between batteries and supercapacitors. Two-dimensional (2D) carbon materials (graphite, graphene, carbon nanosheets) are promising candidates for hybrid capacitors owing to their unique physical and chemical properties, including their enormous specific surface areas, abundance of active sites (surface and functional groups), and large interlayer spacing. So far, there has been no review focusing on the 2D carbon-based materials for the emerging post-lithium hybrid capacitors. This concept review considers the role of 2D carbon in hybrid capacitors and the recent progress in the application of 2D carbon materials for post-Li (Na+, K+, Zn2+) hybrid capacitors. Moreover, their challenges and trends in their future development are discussed.
Han, DS, Solayman, KMD, Shon, HK & Abdel-Wahab, A 2021, 'Pyrite (FeS2)-supported ultrafiltration system for removal of mercury (II) from water', Emergent Materials, vol. 4, no. 5, pp. 1441-1453.
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AbstractThis study investigated the Hg(II) removal efficiencies of the reactive adsorbent membrane (RAM) hybrid filtration process, a removal process that produces stable final residuals. The reaction mechanism between Hg(II) and pyrite and the rejection of the solids over time were characterized with respect to flux decline, pH change, and Hg and Fe concentration in permeate water. Effects of the presence of anions (Cl−, SO42−, NO3−) or humic acid (HA) on the rejection of the Hg(II)-contacted pyrite were studied. The presence of both HA and Hg(II) increased the rate of flux decline due to the formation of irreversible gel-like compact cake layers as shown in the experimental data and modeling related to the flux decline and the SEM images. Stability experiments of the final residuals retained on the membrane using a thiosulfate solution (Na2S2O3) show that the Hg(II)-laden solids were very stable due to little or no detection of Hg(II) in the permeate water. Experiment on the possibility of continuously removing Hg(II) by reusing the Hg/pyrite-laden membrane shows that almost all Hg(II) was adsorbed onto the pyrite surface regardless of the presence of salts or HA, and the Hg(II)-contacted pyrite residuals were completely rejected by the DE/UF system. Therefore, a membrane filter containing pyrite-Hg(II) could provide another reactive cake layer capable of further removal of Hg(II) without post-chemical treatment for reuse.
Han, R, Diao, J, Kumar, S, Lyalin, A, Taketsugu, T, Casillas, G, Richardson, C, Liu, F, Yoon, CW, Liu, H, Sun, X & Huang, Z 2021, 'Boron nitride for enhanced oxidative dehydrogenation of ethylbenzene', Journal of Energy Chemistry, vol. 57, pp. 477-484.
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Hannan, MA, Al-Shetwi, AQ, Ker, PJ, Begum, RA, Mansor, M, Rahman, SA, Dong, ZY, Tiong, SK, Mahlia, TMI & Muttaqi, KM 2021, 'Impact of renewable energy utilization and artificial intelligence in achieving sustainable development goals', Energy Reports, vol. 7, pp. 5359-5373.
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Hannan, MA, How, DNT, Lipu, MSH, Mansor, M, Ker, PJ, Dong, ZY, Sahari, KSM, Tiong, SK, Muttaqi, KM, Mahlia, TMI & Blaabjerg, F 2021, 'Deep learning approach towards accurate state of charge estimation for lithium-ion batteries using self-supervised transformer model', Scientific Reports, vol. 11, no. 1, p. 19541.
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AbstractAccurate state of charge (SOC) estimation of lithium-ion (Li-ion) batteries is crucial in prolonging cell lifespan and ensuring its safe operation for electric vehicle applications. In this article, we propose the deep learning-based transformer model trained with self-supervised learning (SSL) for end-to-end SOC estimation without the requirements of feature engineering or adaptive filtering. We demonstrate that with the SSL framework, the proposed deep learning transformer model achieves the lowest root-mean-square-error (RMSE) of 0.90% and a mean-absolute-error (MAE) of 0.44% at constant ambient temperature, and RMSE of 1.19% and a MAE of 0.7% at varying ambient temperature. With SSL, the proposed model can be trained with as few as 5 epochs using only 20% of the total training data and still achieves less than 1.9% RMSE on the test data. Finally, we also demonstrate that the learning weights during the SSL training can be transferred to a new Li-ion cell with different chemistry and still achieve on-par performance compared to the models trained from scratch on the new cell.
Hannan, MA, Wali, SB, Ker, PJ, Rahman, MSA, Mansor, M, Ramachandaramurthy, VK, Muttaqi, KM, Mahlia, TMI & Dong, ZY 2021, 'Battery energy-storage system: A review of technologies, optimization objectives, constraints, approaches, and outstanding issues', Journal of Energy Storage, vol. 42, pp. 103023-103023.
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Due to urbanization and the rapid growth of population, carbon emission is increasing, which leads to climate change and global warming. With an increased level of fossil fuel burning and scarcity of fossil fuel, the power industry is moving to alternative energy resources such as photovoltaic power (PV), wind power (WP), and battery energy-storage systems (BESS), among others. BESS has some advantages over conventional energy sources, which include fast and steady response, adaptability, controllability, environmental friendliness, and geographical independence, and it is considered as a potential solution to the global warming problem. This paper provides a comprehensive review of the battery energy-storage system concerning optimal sizing objectives, the system constraint, various optimization models, and approaches along with their advantages and weakness. Furthermore, for better understanding, the optimization objectives and methods have been classified into different categories. This paper also provides a detailed discussion on the BESS applications and explores the shortages of existing optimal BESS sizing algorithms to identify the gaps for future research. The issues and challenges are also highlighted to provide a clear idea to the researchers in the field of BESS. Overall, this paper conveys some significant recommendations that would be useful to the researchers and policymakers to structure a productive, powerful, efficient, and robust battery energy-storage system toward a future with a sustainable environment.
Hao, D, Chen, Z-G, Figiela, M, Stepniak, I, Wei, W & Ni, B-J 2021, 'Emerging alternative for artificial ammonia synthesis through catalytic nitrate reduction', Journal of Materials Science & Technology, vol. 77, pp. 163-168.
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Artificial catalytic synthesis of ammonia has become a hot research frontier in recent years. It is regarded as a promising approach that may replace the Haber-Bosch process and reduce global carbon dioxide emission. However, it is extremely difficult for the cleavage of nitrogen molecules under ambient conditions. Thus the ammonia yield rate is still low and the study is still limited in lab scale. If nitrites or nitrates are used as nitrogen sources, rather than nitrogen gas, the catalytic efficiency can be significantly improved, and the residual nitrate and nitrite contaminations in water systems can be efficiently eliminated and converted to energy sources at the same time. It is an emerging alternative for artificial ammonia synthesis, while there is not enough focus on the reduction of nitrate and nitrite. Herein, we systematically compared the differences between the reduction of nitrogen and nitrates, as well as listed the challenges in this area. The total conversion rate and energy efficiency of catalytic nitrate reduction are much higher than nitrogen gas reduction due to the much higher solubility and better converting pathway, which might be further enhanced by employing catalysts improvement strategies. Further, we also proposed suitable materials as well as a few future researches needs that may help boost the development of artificial ammonia synthesis using nitrate.
Hao, D, Huang, Q, Wei, W, Bai, X & Ni, B-J 2021, 'A reusable, separation-free and biodegradable calcium alginate/g-C3N4 microsphere for sustainable photocatalytic wastewater treatment', Journal of Cleaner Production, vol. 314, pp. 128033-128033.
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Graphitic carbon nitride (g-C3N4) is a metal-free photocatalyst with the advantages of facile preparation, low cost and good photocatalytic performance. However, as an extensively studied powder catalyst, it is though difficult to be recycled and reused which requires attention urgently. In this study, we report a facile preparation of g-C3N4 hydrogel microspheres with the cross-link reactions between sodium alginate and calcium ions, which can be simply removed from liquid for reuse. The hydroxyl of calcium alginate enabled to boost the adsorption of organic pollutants as well as to boost the transfer and separation of photogenerated charge carriers. The g-C3N4 hydrogel microspheres showed remarkable performance in the control of organic pollutant contamination. The sample 25%-SACN had the best photocatalytic activity, which can remove 80.94% MB in 42 h. The total removal is 1.77 times as that of 0%-SACN. Meanwhile, it had good cycle stability and the catalytic performance did not decrease after 5-time usage. The used g-C3N4 hydrogel microspheres were also demonstrated to be biodegraded anaerobically to produce methane for energy recovery and recycling. The results and outcome of this paper might bring new inspiration for the study of easily reusable and sustainable photocatalysts for wastewater treatment.
Hao, D, Liu, Y, Gao, S, Arandiyan, H, Bai, X, Kong, Q, Wei, W, Shen, PK & Ni, B-J 2021, 'Emerging artificial nitrogen cycle processes through novel electrochemical and photochemical synthesis', Materials Today, vol. 46, pp. 212-233.
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The nitrogen cycle is an important part of the global biogeochemical cycle, while the human activities have already caused a severe imbalance of the global nitrogen cycle. In this review, we proposed a new generation of artificial nitrogen cycle via electrochemical and photocatalytic reactions. In details, the N2 from the air, NO3−/NO2− containing wastewater, nitrogen oxides from vehicle emission are all able to be utilized as a nitrogen source for the synthesis of NH3 under ambient conditions. The oxidation of NH3, N2 and nitrogen oxides can all achieve the aim of obtaining NO3−. Hydrazine can also be synthesized electrochemical and photochemical reactions. Utilizing electrochemical and photocatalytic processes enables to eliminate the hazardous of nitrogen-containing organic chemicals, and some inorganic nitrogen polluted wastewater. More importantly, coupling N-based reaction with other reaction like CO2 reduction enables to synthesize some high-value chemicals such as urea. Then we highlighted some recent achievements in these reactions and proposed some future potential developing directions. The results and funding of this work may help us develop highly efficient catalysts and strategies for the artificial nitrogen cycle, repairing the broken nitrogen cycle balance.
Hao, D, Ren, J, Wang, Y, Arandiyan, H, Garbrecht, M, Bai, X, Shon, HK, Wei, W & Ni, B-J 2021, 'A Green Synthesis of Ru Modified g-C 3 N 4 Nanosheets for Enhanced Photocatalytic Ammonia Synthesis', Energy Material Advances, vol. 2021, pp. 1-12.
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Nitrate is a crucial environmental pollutant, and its risk on ecosystem keeps increasing. Photocatalytic conversion of nitrate to ammonia can simultaneously achieve the commercialization of environmental hazards and recovery of valuable ammonia, which is green and sustainable for the planet. However, due to the thermodynamic and kinetic energy barriers, photocatalytic nitrate reduction usually involves a higher selectivity of the formation of nitrogen that largely limits the ammonia synthesis activity. In this work, we reported a green and facile synthesis of novel metallic ruthenium particle modified graphitic carbon nitride photocatalysts. Compare with bulk graphitic carbon nitride, the optimal sample had 2.93-fold photocatalytic nitrate reduction to ammonia activity (2.627 mg/h/g cat ), and the NH 3 selectivity increased from 50.77% to 77.9%. According to the experimental and calculated results, the enhanced photocatalytic performance is attributed to the stronger light absorption, nitrate adsorption, and lower energy barrier for the generation of ammonia. This work may provide a facile way to prepare metal modified photocatalysts to achieve highly efficient nitrate reduction to ammonia.
Harari, PA, Banapurmath, NR, Yaliwal, VS, Khan, TMY, Badruddin, IA, Kamangar, S & Mahlia, TMI 2021, 'Effect of Injection Timing and Injection Duration of Manifold Injected Fuels in Reactivity Controlled Compression Ignition Engine Operated with Renewable Fuels', Energies, vol. 14, no. 15, pp. 4621-4621.
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In the current work, an effort is made to study the influence of injection timing (IT) and injection duration (ID) of manifold injected fuels (MIF) in the reactivity controlled compression ignition (RCCI) engine. Compressed natural gas (CNG) and compressed biogas (CBG) are used as the MIF along with diesel and blends of Thevetia Peruviana methyl ester (TPME) are used as the direct injected fuels (DIF). The ITs of the MIF that were studied includes 45° ATDC, 50° ATDC, and 55° ATDC. Also, present study includes impact of various IDs of the MIF such as 3, 6, and 9 ms on RCCI mode of combustion. The complete experimental work is conducted at 75% of rated power. The results show that among the different ITs studied, the D+CNG mixture exhibits higher brake thermal efficiency (BTE), about 29.32% is observed at 50° ATDC IT, which is about 1.77, 3.58, 5.56, 7.51, and 8.54% higher than D+CBG, B20+CNG, B20+CBG, B100+CNG, and B100+CBG fuel combinations. The highest BTE, about 30.25%, is found for the D+CNG fuel combination at 6 ms ID, which is about 1.69, 3.48, 5.32%, 7.24, and 9.16% higher as compared with the D+CBG, B20+CNG, B20+CBG, B100+CNG, and B100+CBG fuel combinations. At all ITs and IDs, higher emissions of nitric oxide (NOx) along with lower emissions of smoke, carbon monoxide (CO), and hydrocarbon (HC) are found for D+CNG mixture as related to other fuel mixtures. At all ITs and IDs, D+CNG gives higher In-cylinder pressure (ICP) and heat release rate (HRR) as compared with other fuel combinations.
Hasan, MH, Mahlia, TMI, Mofijur, M, Rizwanul Fattah, IM, Handayani, F, Ong, HC & Silitonga, AS 2021, 'A Comprehensive Review on the Recent Development of Ammonia as a Renewable Energy Carrier', Energies, vol. 14, no. 13, pp. 3732-3732.
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Global energy sources are being transformed from hydrocarbon-based energy sources to renewable and carbon-free energy sources such as wind, solar and hydrogen. The biggest challenge with hydrogen as a renewable energy carrier is the storage and delivery system’s complexity. Therefore, other media such as ammonia for indirect storage are now being considered. Research has shown that at reasonable pressures, ammonia is easily contained as a liquid. In this form, energy density is approximately half of that of gasoline and ten times more than batteries. Ammonia can provide effective storage of renewable energy through its existing storage and distribution network. In this article, we aimed to analyse the previous studies and the current research on the preparation of ammonia as a next-generation renewable energy carrier. The study focuses on technical advances emerging in ammonia synthesis technologies, such as photocatalysis, electrocatalysis and plasmacatalysis. Ammonia is now also strongly regarded as fuel in the transport, industrial and power sectors and is relatively more versatile in reducing CO2 emissions. Therefore, the utilisation of ammonia as a renewable energy carrier plays a significant role in reducing GHG emissions. Finally, the simplicity of ammonia processing, transport and use makes it an appealing choice for the link between the development of renewable energy and demand.
Hazrat, MA, Rasul, MG, Khan, MMK, Mofijur, M, Ahmed, SF, Ong, HC, Vo, D-VN & Show, PL 2021, 'Techniques to improve the stability of biodiesel: a review', Environmental Chemistry Letters, vol. 19, no. 3, pp. 2209-2236.
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He, D, Xiao, J, Wang, D, Liu, X, Fu, Q, Li, Y, Du, M, Yang, Q, Liu, Y, Wang, Q, Ni, B-J, Song, K, Cai, Z, Ye, J & Yu, H 2021, 'Digestion liquid based alkaline pretreatment of waste activated sludge promotes methane production from anaerobic digestion', Water Research, vol. 199, pp. 117198-117198.
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This work proved an efficient method to significantly increase methane production from anaerobic digestion of WAS. This method is to reflux proper of digestion liquid into waste activated sludge pretreatment unit (pH 9.5 for 24 h). The yield of maximum methane improved between 174.2 ± 7.3 and 282.5 ± 14.1 mL/g VSS with the reflux ratio of digestion liquid increasing from 0% to 20%. It was observed that the biodegradable organics in the digestion liquid did not affect the biological processes related to anaerobic digestion but increased methane production through reutilization. The ammonium in the digestion liquid was the main contributor to the increase in methane production via promoting sludge solubilization, but refractory organics were the major inhibitors to anaerobic digestion. It should be emphasized that the metal ions present in the digestion liquid were beneficial rather than harmful to the biological processes in the anaerobic digestion, which may be connected with the fact that certain metal ions were involved in the expression and activation of key enzymes. In addition, it was found that anaerobes in digestion liquid were another potential contributor to the enhanced anaerobic digestion.
He, D, Xiao, J, Wang, D, Liu, X, Li, Y, Fu, Q, Li, C, Yang, Q, Liu, Y & Ni, B-J 2021, 'Understanding and regulating the impact of tetracycline to the anaerobic fermentation of waste activated sludge', Journal of Cleaner Production, vol. 313, pp. 127929-127929.
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Tetracycline (TC), a widely used antibiotic, was enriched in waste activated sludge (WAS) at significant levels. However, the TC impact on WAS anaerobic fermentation are still poorly understood. This work aims to analyze the effect of TC to the WAS anaerobic fermentation by investigating the differences of sludge properties, short-chain fatty acids (SCFAs) production and microbial community abundance. The results showed that the environmental level of TC had no effect on the SCFAs production, but with the further increase of the content of TC to 60 mg/kg TSS, the maximum SCFAs yield decreased from 125.1 ± 3.2 to 90.8 ± 1.7 mg COD/g VSS. Mechanism exploration indicated that TC had no significant effect on solubilization, hydrolysis and homoacetogenesis processes, but severely inhibited acidogenesis, acetogenesis and methanogenesis processes. Microbial analysis showed that the presence of TC reduced the diversity of microbial communities and the abundance of functional microorganisms relevant to SCFAs production and complex organic degradation, such as Proteiniclasticun and Novosphingobium. This negative effect was persistent because only a small amount of TC can be degraded in the anaerobic fermentation process. Hence, CaO2 was proposed and studied as a regulation strategy that can reduce the toxicity of TC on anaerobic fermentation.
He, M, Zhang, X, Huang, J, Li, J, Yan, C, Kim, J, Chen, Y, Yang, L, Cairney, JM, Zhang, Y, Chen, S, Kim, J, Green, MA & Hao, X 2021, 'High Efficiency Cu2ZnSn(S,Se)4 Solar Cells with Shallow LiZn Acceptor Defects Enabled by Solution‐Based Li Post‐Deposition Treatment', Advanced Energy Materials, vol. 11, no. 13, pp. 2003783-2003783.
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AbstractLithium incorporation in kesterite Cu2ZnSn(S,Se)4 (CZTSSe) materials has been experimentally proven effective in improving electronic quality for application in photovoltaic devices. Herein, a feasible and effective solution‐based lithium post‐deposition treatment (PDT), enabling further efficiency improvement on the high‐performance baseline is reported and the dominant mechanism for this improvement is proposed. In this way, lithium is uniformly incorporated into grain interiors (GIs) without segregation at grain boundaries (GBs), which can occupy the Zn sites with a high solubility in the CZTSSe matrix, producing high density of LiZn antisites with shallower acceptor levels than the intrinsic dominant defect (CuZn antisites). As a result, CZTSSe absorber with better p‐type doping is obtained, leading to a pronounced enhancement in fill factor and a corresponding gain in open‐circuit voltage and short‐circuit current and consequently a significant efficiency boost from 9.3% to 10.7%. This work provides a feasible alternative alkali‐PDT treatment for chalcogenide semiconductors and promotes a better understanding of the mechanism of Li incorporation in kesterite materials.
He, X, Wang, F, Li, W & Sheng, D 2021, 'Efficient reliability analysis considering uncertainty in random field parameters: Trained neural networks as surrogate models', Computers and Geotechnics, vol. 136, pp. 104212-104212.
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This paper presents an efficient reliability analysis framework, by using trained artificial neural networks (ANNs) as surrogate models, for geotechnical problems where the random field parameters like the mean and standard deviation are themselves uncertain. Random field theory has been extensively used to model soil uncertainty and spatial variability. However, due to limited availability of data, random field parameters can rarely be estimated accurately, often estimated in confidence intervals (uncertain parameters). Monte Carlo based reliability analysis is computationally extremely demanding because the function to map outcomes of random fields to structural response can only be calculated via numerical simulations. The authors have used trained ANNs as surrogate models in reliability analysis. However, these ANNs are specific for random fields with deterministic parameters. This paper presents a new framework in which trained ANN models are for random fields with variable parameters. A key component is the design of experiments – generating representative outcomes. In the prediction of the bearing capacity for strip footings, the efficiency and accuracy of this framework are successfully demonstrated. This framework is also efficient in reliability sensitivity studies. One main finding is that ignoring random field parameter uncertainty could lead to underestimated failure probability and hence unsafe design.
Hembram, TK, Saha, S, Pradhan, B, Abdul Maulud, KN & Alamri, AM 2021, 'Robustness analysis of machine learning classifiers in predicting spatial gully erosion susceptibility with altered training samples', Geomatics, Natural Hazards and Risk, vol. 12, no. 1, pp. 794-828.
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Hoang, AT, Nizetic, S, Ong, HC, Chong, CT, Atabani, AE & Pham, VV 2021, 'Acid-based lignocellulosic biomass biorefinery for bioenergy production: Advantages, application constraints, and perspectives', Journal of Environmental Management, vol. 296, pp. 113194-113194.
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The production of chemicals and fuels from renewable biomass with the primary aim of reducing carbon footprints has recently become one of the central points of interest. The use of lignocellulosic biomass for energy production is believed to meet the main criteria of maximizing the available global energy source and minimizing pollutant emissions. However, before usage in bioenergy production, lignocellulosic biomass needs to undergo several processes, among which biomass pretreatment plays an important role in the yield, productivity, and quality of the products. Acid-based pretreatment, one of the existing methods applied for lignocellulosic biomass pretreatment, has several advantages, such as short operating time and high efficiency. A thorough analysis of the characteristics of acid-based biomass pretreatment is presented in this review. The environmental concerns and future challenges involved in using acid pretreatment methods are discussed in detail to achieve clean and sustainable bioenergy production. The application of acid to biomass pretreatment is considered an effective process for biorefineries that aim to optimize the production of desired products while minimizing the by-products.
Hoang, AT, Nižetić, S, Ong, HC, Mofijur, M, Ahmed, SF, Ashok, B, Bui, VTV & Chau, MQ 2021, 'Insight into the recent advances of microwave pretreatment technologies for the conversion of lignocellulosic biomass into sustainable biofuel', Chemosphere, vol. 281, pp. 130878-130878.
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The utilization of renewable lignocellulosic biomasses for bioenergy synthesis is believed to facilitate competitive commercialization and realize affordable clean energy sources in the future. Among the pathways for biomass pretreatment methods that enhance the efficiency of the whole biofuel production process, the combined microwave irradiation and physicochemical approach is found to provide many economic and environmental benefits. Several studies on microwave-based pretreatment technologies for biomass conversion have been conducted in recent years. Although some reviews are available, most did not comprehensively analyze microwave-physicochemical pretreatment techniques for biomass conversion. The study of these techniques is crucial for sustainable biofuel generation. Therefore, the biomass pretreatment process that combines the physicochemical method with microwave-assisted irradiation is reviewed in this paper. The effects of this pretreatment process on lignocellulosic structure and the ratio of achieved components were also discussed in detail. Pretreatment processes for biomass conversion were substantially affected by temperature, irradiation time, initial feedstock components, catalyst loading, and microwave power. Consequently, neoteric technologies utilizing high efficiency-based green and sustainable solutions should receive further focus. In addition, methodologies for quantifying and evaluating effects and relevant trade-offs should be develop to facilitate the take-off of the biofuel industry with clean and sustainable goals.
Hoang, AT, Ong, HC, Fattah, IMR, Chong, CT, Cheng, CK, Sakthivel, R & Ok, YS 2021, 'Progress on the lignocellulosic biomass pyrolysis for biofuel production toward environmental sustainability', Fuel Processing Technology, vol. 223, pp. 106997-106997.
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The increasing energy demand and diminishing fossil fuel sources have called for the exploration of new energy sources. To satisfy growing global energy demand and accomplish sustainable energy development goals, biomass plays an essential role in present and future energy. Pyrolysis holds considerable potential approaches among biomass conversion technologies. This study presents a critical review of the effect of the key pyrolysis parameters from lignocellulosic biomass to product distribution. The lignocellulosic biomass composition and pyrolysis conversion behavior of every single component was discussed in detail. On top of that, CO2-based benefits, economic assessment, and technical orientation for biofuel production from biomass are included. The carbon and hydrogen content of biomass is critical for producing high-quality bio-oil. When compared to other energy crops and agricultural residues, pyrolysis of clean wood and polar demonstrated the best bio-oil production. The increased cellulose and hemicellulose content aiding in the synthesis of bio-oil, but the high concentration of lignin results in more biochar. The article delves into product upgrading via several routes such as physical, chemical, and catalytic. From the review, considering factors such as pyrolysis technologies, energy demand, and bio-oil yields, greenhouse potential benefits needs to be evaluated, and this needs to be done on an individual basis. In terms of production cost, the current cost of biomass feedstock can range between $50 to $97/ton, which is approximately 30−54% of the liquid fuel production cost. A wide range of studies covering different aspects of biomass pyrolysis technology, from reactor configuration and the heating source to single and poly-step pyrolysis processes, have been carried out in the search for solutions in optimizing the current technologies. Thus, expanding and improving awareness of the lignocellulosic biomass in the pyrolysis technology wou...
Hoang, AT, Sandro Nižetić, Olcer, AI, Ong, HC, Chen, W-H, Chong, CT, Thomas, S, Bandh, SA & Nguyen, XP 2021, 'Impacts of COVID-19 pandemic on the global energy system and the shift progress to renewable energy: Opportunities, challenges, and policy implications', Energy Policy, vol. 154, pp. 112322-112322.
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Being declared a global emergency, the COVID-19 pandemic has taken many lives, threatened livelihoods and businesses around the world. The energy industry, in particular, has experienced tremendous pressure resulting from the pandemic. In response to such a challenge, the development of sustainable resources and renewable energy infrastructure has demonstrated its potential as a promising and effective strategy. To sufficiently address the effect of COVID-19 on renewable energy development strategies, short-term policy priorities should be identified, while mid-term and long-term action plans should be formulated in achieving the well-defined renewable energy targets and progress towards a more sustainable energy future. In this review, opportunities, challenges, and significant impacts of the COVID-19 pandemic on current and future sustainable energy strategies were analyzed in detail; while drawing from experiences in identifying reasonable behaviors, orientating appropriate actions, and policy implications on the sustainable energy trajectory were also mentioned. Indeed, the question is that whether the COVID-19 pandemic will kill us or provide us with a precious lesson on future sustainable energy development.
Hoang, H-G, Lin, C, Chiang, C-F, Bui, X-T, Lukkhasorn, W, Bui, T-P-T, Tran, H-T, Vo, T-D-H, Le, V-G & Nghiem, LD 2021, 'The Individual and Synergistic Indexes for Assessments of Heavy Metal Contamination in Global Rivers and Risk: a Review', Current Pollution Reports, vol. 7, no. 3, pp. 247-262.
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Hoque, MA-A, Pradhan, B, Ahmed, N & Sohel, MSI 2021, 'Agricultural drought risk assessment of Northern New South Wales, Australia using geospatial techniques', Science of The Total Environment, vol. 756, pp. 143600-143600.
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Hoque, MA-A, Pradhan, B, Ahmed, N, Ahmed, B & Alamri, AM 2021, 'Cyclone vulnerability assessment of the western coast of Bangladesh', Geomatics, Natural Hazards and Risk, vol. 12, no. 1, pp. 198-221.
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Coastal Bangladesh is one of the hotspots of tropical cyclone’s landfall in South Asia. A spatial vulnerability assessment is required to formulate disaster risk reduction strategies. This study develops a comprehensive tropical cyclone vulnerability mapping approach by applying Fuzzy Analytical Hierarchy Process (FAHP) and geospatial techniques and examines the spatial distribution of tropical cyclone vulnerability in the western coastal region of Bangladesh. We have selected 18 spatial criteria under the physical, social, and mitigation capacity categories as the components of vulnerability. Results indicate that the southern and south-eastern peripheral areas exhibit higher vulnerability to tropical cyclones since these areas comprise low elevation, gentle slope, closeness to the sea, a high number of historical cyclone tracks, vulnerable land cover classes (settlements and crops land), and poor socio-economic structures. These areas cover most of the Barguna, Khulna, Bagerhat, Jhalokati, and southern parts of Satkhira, and Pirojpur districts. The existing mitigation capacity measures, for example, the construction of cyclone shelters, embankments, road networks, and effective warning systems in these areas are not adequate levels. The findings would be useful for policymakers and local authorities in formulating appropriate cyclone risk mitigation plans in coastal Bangladesh.
Horry, MJ, Chakraborty, S, Pradhan, B, Fallahpoor, M, Chegeni, H & Paul, M 2021, 'Factors determining generalization in deep learning models for scoring COVID-CT images', Mathematical Biosciences and Engineering, vol. 18, no. 6, pp. 9264-9293.
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<abstract> <p>The COVID-19 pandemic has inspired unprecedented data collection and computer vision modelling efforts worldwide, focused on the diagnosis of COVID-19 from medical images. However, these models have found limited, if any, clinical application due in part to unproven generalization to data sets beyond their source training corpus. This study investigates the generalizability of deep learning models using publicly available COVID-19 Computed Tomography data through cross dataset validation. The predictive ability of these models for COVID-19 severity is assessed using an independent dataset that is stratified for COVID-19 lung involvement. Each inter-dataset study is performed using histogram equalization, and contrast limited adaptive histogram equalization with and without a learning Gabor filter. We show that under certain conditions, deep learning models can generalize well to an external dataset with F1 scores up to 86%. The best performing model shows predictive accuracy of between 75% and 96% for lung involvement scoring against an external expertly stratified dataset. From these results we identify key factors promoting deep learning generalization, being primarily the uniform acquisition of training images, and secondly diversity in CT slice position.</p> </abstract>
Hossain Lipu, MS, Hannan, MA, Karim, TF, Hussain, A, Saad, MHM, Ayob, A, Miah, MS & Indra Mahlia, TM 2021, 'Intelligent algorithms and control strategies for battery management system in electric vehicles: Progress, challenges and future outlook', Journal of Cleaner Production, vol. 292, pp. 126044-126044.
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Globally, the research on battery technology in electric vehicle applications is advancing tremendously to address the carbon emissions and global warming issues. The effectiveness of electric vehicles depends on the accurate assessment of key parameters as well as proper functionality and diagnosis of the battery storage system. However, poor monitoring and safety strategies of the battery storage system can lead to critical issues such as battery overcharging, over-discharging, overheating, cell unbalancing, thermal runaway, and fire hazards. To address these concerns, an effective battery management system plays a crucial role in enhancing battery performance including precise monitoring, charging-discharging control, heat management, battery safety, and protection. The goal of this paper is to deliver a comprehensive review of different intelligent approaches and control schemes of the battery management system in electric vehicle applications. In line with that, the review evaluates the intelligent algorithms in battery state estimation concerning their features, structure, configuration, accuracy, advantages, and disadvantages. Moreover, the review explores the various controllers in battery heating, cooling, equalization, and protection highlighting categories, characteristics, targets, achievements, benefits, and shortcomings. The key issues and challenges in terms of computation complexity, execution problems along with various internal and external factors are identified. Finally, future opportunities and directions are delivered to design an efficient intelligent algorithm and controller toward the development of an advanced battery management system for future sustainable electric vehicle applications.
Hossain, MJ, Chowdhury, UN, Islam, MB, Uddin, S, Ahmed, MB, Quinn, JMW & Moni, MA 2021, 'Machine learning and network-based models to identify genetic risk factors to the progression and survival of colorectal cancer', Computers in Biology and Medicine, vol. 135, pp. 104539-104539.
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Colorectal cancer (CRC) is one of the most common and lethal malignant lesions. Determining how the identified risk factors drive the formation and development of CRC could be an essential means for effective therapeutic development. Aiming this, we investigated how the altered gene expression resulting from exposure to putative CRC risk factors contribute to prognostic biomarker identification. Differentially expressed genes (DEGs) were first identified for CRC and other eight risk factors. Gene set enrichment analysis (GSEA) through the molecular pathway and gene ontology (GO), as well as protein-protein interaction (PPI) network, were then conducted to predict the functions of these DEGs. Our identified genes were explored through the dbGaP and OMIM databases to compare with the already identified and known prognostic CRC biomarkers. The survival time of CRC patients was also examined using a Cox Proportional Hazard regression-based prognostic model by integrating transcriptome data from The Cancer Genome Atlas (TCGA). In this study, PPI analysis identified 4 sub-networks and 8 hub genes that may be potential therapeutic targets, including CXCL8, ICAM1, SOD2, CXCL2, CCL20, OIP5, BUB1, ASPM and IL1RN. We also identified seven signature genes (PRR5.ARHGAP8, CA7, NEDD4L, GFR2, ARHGAP8, SMTN, OIP5) in independent analysis and among which PRR5. ARHGAP8 was found in both multivariate analyses and in analyses that combined gene expression and clinical information. This approach provides both mechanistic information and, when combined with predictive clinical information, good evidence that the identified genes are significant biomarkers of processes involved in CRC progression and survival.
Hossain, N, Hoong, LL, Barua, P, Soudagar, MEM & Mahlia, TMI 2021, 'The effect of enzymatic hydrolysis of pretreated wastepaper for bioethanol production', Korean Journal of Chemical Engineering, vol. 38, no. 12, pp. 2493-2499.
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Enzymatic hydrolysis of waste biomass for bioethanol production is considered a decades old traditional, inexpensive, and energy-effective approach. In this study, waste office paper was pretreated with diluted sulfuric acid (H2SO4) and hydrolyzed with one of the most available and cost-effective enzymes, cellulase derived from Trichoderma reesei, under submerged static condition. Three different pretreatment approaches—cut into 2 cm2, blended with distilled water, and pretreated with diluted H2SO4—have been implemented, and pretreatment with diluted H2SO4 was the most effective. Hydrolysis with different concentrations—0.5 M, 1.0 M, 1.5 M, 2.0 M of H2SO4—was performed. The maximum glucose content was obtained at 2.0 M H2SO4 at 90 min reaction time, and glucose yield was 0.11 g glucose/g wastepaper. The cut paper, wet-blended, and acid-treated wastepaper was hydrolyzed with cellulase enzyme for 2, 4, and 5 consecutive days with 5 mg, 10 mg, 15 mg, and 20 mg enzyme loadings. The maximum glucose content obtained was 9.75 g/l from acid-treated wastepaper, after 5 days of enzymatic hydrolysis with 20 mg enzyme loading and a glucose yield of a 0.5 g glucose/g wastepaper. The wastepaper hydrolysate was further fermented for 6, 8, and 10 hours continuously with Saccharomyces cerevisiae (yeast), and at 10 hours of fermentation, the maximum glucose consumption was 0.18 g by yeast. Further, HPLC analysis of the fermented medium presented a strong peak of bioethanol content at 16.12 min. The distillation of bioethanol by rotary evaporator presented 0.79 ml bioethanol/fermented solution, which indicated the conversion efficiency of 79%.
Hossain, N, Mahlia, TMI, Miskat, MI, Chowdhury, T, Barua, P, Chowdhury, H, Nizamuddin, S, Ahmad, NB, Zaharin, NAB, Mazari, SA & Soudagar, MEM 2021, 'Bioethanol production from forest residues and life cycle cost analysis of bioethanol-gasoline blend on transportation sector', Journal of Environmental Chemical Engineering, vol. 9, no. 4, pp. 105542-105542.
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Hossain, SM, Park, H, Kang, H-J, Mun, JS, Tijing, L, Rhee, I, Kim, J-H, Jun, Y-S & Shon, HK 2021, 'Facile synthesis and characterization of anatase TiO2/g-CN composites for enhanced photoactivity under UV–visible spectrum', Chemosphere, vol. 262, pp. 128004-128004.
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© 2020 Elsevier Ltd For the purpose of atmospheric NO removal, anatase TiO2/g-CN photocatalytic composites were prepared by using a facile template-free calcination route in atmospheric conditions. Considerably fiscal NP400 and laboratory-grade melamine were used as the precursor of the composites. Additionally, samples were prepared with different wt. ratios of TiO2 and melamine by using two distinct calcination temperatures (550 °C/600 °C). The morphological attributes of the composites were assessed with X-ray diffraction, scanning and transmission electron microscopy, infrared spectroscopy, and X-ray photoelectron spectroscopy. Additionally, the optical traits were evaluated and compared using UV–visible diffuse reflectance spectroscopy and photoluminescence analysis. Finally, the photodegradation potentials for atmospheric NO by using the as-prepared composites were assessed under both UV and visible light irradiation. All the composites showed superior NO oxidation compared to NP400 and bulk g-CN. For the composites prepared by using the calcination temperature of 550 °C, the maximum NO removal was observed when the NP400 to melamine ratio was 1:2, irrespective of the utilized light irradiation type. Whereas for increased calcination temperature (600 °C), the maximum NO removal was observed at the precursor mix ratio of 1:3 (NP400:melamine). Successfully narrowed energy bandgaps were perceived in the as-prepared composites. Moreover, a subsequent drop in NO2 generation during NO oxidation was observed under both UV and visible light irradiation. Interestingly, higher calcination temperature during the synthesis of the catalysts has shown a significant drop in NO2 generation during the photodegradation of NO.
Hossain, SM, Park, H, Kang, H-J, Mun, JS, Tijing, L, Rhee, I, Kim, J-H, Jun, Y-S & Shon, HK 2021, 'Synthesis and NOx removal performance of anatase S–TiO2/g-CN heterojunction formed from dye wastewater sludge', Chemosphere, vol. 275, pp. 130020-130020.
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In this study, sludges generated from Ti-based flocculation of dye wastewater were used to retrieve photoactive titania (S-TiO2). It was heterojunctioned with graphitic carbon nitride (g-CN) to augment photoactivity under UV/visible light irradiance. Later the as-prepared samples were utilized to remove nitrogen oxides (NOx) in the atmospheric condition through photocatalysis. Heterojunction between S-TiO2 and g-CN was prepared through facile calcination (@550 °C) of S-TiO2 and melamine mix. Advanced sample characterization was carried out and documented extensively. Successful heterojunction was confirmed from the assessment of morphological and optical attributes of the samples. Finally, the prepared samples' level of photoactivity was assessed through photooxidation of NOx under both UV and visible light irradiance. Enhanced photoactivity was observed in the prepared samples irrespective of the light types. After 1 h of UV/visible light-based photooxidation, the best sample STC4 was found to remove 15.18% and 9.16% of atmospheric NO, respectively. In STC4, the mixing ratio of S-TiO2, to melamine was maintained as 1:3. Moreover, the optical bandgap of STC4 was found as 2.65 eV, where for S-TiO2, it was 2.83 eV. Hence, the restrained rate of photogenerated charge recombination and tailored energy bandgap of the as-prepared samples were the primary factors for enhancing photoactivity.
Hosseini, MR, Jupp, J, Papadonikolaki, E, Mumford, T, Joske, W & Nikmehr, B 2021, 'Position paper: digital engineering and building information modelling in Australia', Smart and Sustainable Built Environment, vol. 10, no. 3, pp. 331-344.
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PurposeThis position paper urges a drive towards clarity in the key definitions, terminologies and habits of speech associated with digital engineering and building information modelling (BIM). The ultimate goal of the paper is to facilitate the move towards arriving at an ideal definition for both concepts.Design/methodology/approachThis paper takes the “explanation building” review approach in providing prescriptive guidelines to researchers and industry practitioners. The aim of the review is to draw upon existing studies to identify, describe and find application of principles in a real-world context.FindingsThe paper highlights the definitional challenges surrounding digital engineering and BIM in Australia, to evoke a debate on BIM and digital engineering boundaries, how and why these two concepts may be linked, and how they relate to emerging concepts.Originality/valueThis is the first scholarly attempt to clarify the definition of digital engineering and address the confusion between the concepts of BIM and digital engineering.
Hosseinzadeh, A, Najafpoor, AA, Navaei, AA, Zhou, JL, Altaee, A, Ramezanian, N, Dehghan, A, Bao, T & Yazdani, M 2021, 'Improving Formaldehyde Removal from Water and Wastewater by Fenton, Photo-Fenton and Ozonation/Fenton Processes through Optimization and Modeling', Water, vol. 13, no. 19, pp. 2754-2754.
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This study aimed to assess, optimize and model the efficiencies of Fenton, photo-Fenton and ozonation/Fenton processes in formaldehyde elimination from water and wastewater using the response surface methodology (RSM) and artificial neural network (ANN). A sensitivity analysis was used to determine the importance of the independent variables. The influences of different variables, including H2O2 concentration, initial formaldehyde concentration, Fe dosage, pH, contact time, UV and ozonation, on formaldehyde removal efficiency were studied. The optimized Fenton process demonstrated 75% formaldehyde removal from water. The best performance with 80% formaldehyde removal from wastewater was achieved using the combined ozonation/Fenton process. The developed ANN model demonstrated better adequacy and goodness of fit with a R2 of 0.9454 than the RSM model with a R2 of 0. 9186. The sensitivity analysis showed pH as the most important factor (31%) affecting the Fenton process, followed by the H2O2 concentration (23%), Fe dosage (21%), contact time (14%) and formaldehyde concentration (12%). The findings demonstrated that these treatment processes and models are important tools for formaldehyde elimination from wastewater.
Hosseinzadeh, A, Zhou, JL, Navidpour, AH & Altaee, A 2021, 'Progress in osmotic membrane bioreactors research: Contaminant removal, microbial community and bioenergy production in wastewater', Bioresource Technology, vol. 330, pp. 124998-124998.
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Renewable energy, water conservation, and environmental protection are the most important challenges today. Osmotic membrane bioreactor (OMBR) is an innovative process showing superior performance in bioenergy production, eliminating contaminants, and low fouling tendency. However, salinity build-up is the main drawback of this process. Identifying the microbial community can improve the process in bioenergy production and contaminant treatment. This review aims to study the recent progress and challenges of OMBRs in contaminant removal, microbial communities and bioenergy production. OMBRs are widely reported to remove over 80% of total organic carbon, PO43-, NH4+ and emerging contaminants from wastewater. The most important microbial phyla for both hydrogen and methane production in OMBR are Firmicutes, Proteobacteria and Bacteroidetes. Firmicutes' dominance in anaerobic processes is considerably increased from usually 20% at the beginning to 80% under stable condition. Overall, OMBR process has great potential to be applied for simultaneous bioenergy production and wastewater treatment.
Huang, J, Li, S, Zhou, Y, Xu, T, Li, Y, Wang, H & Wang, S 2021, 'A heavy-duty magnetorheological fluid mount with flow and squeeze model', Smart Materials and Structures, vol. 30, no. 8, pp. 085012-085012.
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Huang, L, Liu, Z, Wu, C & Liang, J 2021, 'Interaction between a tunnel and alluvial valley under plane SV waves of earthquakes by IBIEM', European Journal of Environmental and Civil Engineering, vol. 25, no. 12, pp. 2217-2235.
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© 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group. This paper investigates the dynamic interaction between a lined tunnel and an alluvial valley under plane SV waves with the indirect boundary integral equation method (IBIEM). The impact of different parameters on the displacement of sedimentary valley and the dynamic stress concentration factors (DSCF) of the lining inner and outer walls are studied. The dynamic response of a tunnel embedded in an alluvial valley is considerably different from that of a tunnel not embedded in an alluvial valley. Numerical results indicate that under the same frequency, different buried depths can change the distribution of displacement in the sedimentary area. The deeper the tunnel is buried, the more resonance points the response spectrum curve has. In general, the DSCF on the inner surfaces of the tunnels embedded in the sedimentary valley is obviously greater than that of the tunnels in the half space. However, the DSCF on the outer surfaces of the former is smaller than that of the latter. The results reported here will provide a quantitative basis to the security assessment and seismic design of lined tunnels.
Huang, Q, Wang, C, Hao, D, Wei, W, Wang, L & Ni, B-J 2021, 'Ultralight biodegradable 3D-g-C3N4 aerogel for advanced oxidation water treatment driven by oxygen delivery channels and triphase interfaces', Journal of Cleaner Production, vol. 288, pp. 125091-125091.
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The development of highly efficient and separation-free, low-cost photocatalysts have crucial prospect for sustainable wastewater treatment, because it is able to eliminate the hazards of organic pollutant with facile operation. However, the relatively high cost of previous photocatalysts highly obstructs the application of these materials. Herein, we report a cost-effective and distinct konjac/graphitic carbon nitride (KCN) aerogel, which has superior performance for advanced oxidation water treatment. The abundant porous structure of the ultralight aerogel ensures the rapid adsorption of pollutants, which is much helpful for the further photodegradation process. During the working process, the aerogel is half submerged in pollutant solution and half exposed in air, forming a distinctive gas-solid-liquid triphase system, where oxygen can be rapidly delivered into the solution via the porous channels, boosting the generation of hydroxyl and superoxide radicals. Meanwhile, the aerogel structure can separate the g-C3N4, obstruct its stacking, as well as improve the light absorption rate. The synthesis, utilization and readily biodegradable treatment of the KCN aerogels are all green and eco-friendly, which is extremely constructive for strategies to develop novel highly efficient photocatalytic materials.
Huang, Q-S, Wei, W & Ni, B-J 2021, 'Catalysts derived from Earth-abundant natural biomass enable efficient photocatalytic CO2conversion for achieving a closed-loop carbon cycle', Green Chemistry, vol. 23, no. 23, pp. 9683-9692.
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A one-pot, facile, sulfuric-acid-assisted carbonization method was developed to fabricate a series of biomass-derived metal-free carbonaceous photocatalysts for high performance CO2conversion, which satisfied a closed-loop carbon cycle.
Huang, S, Samali, B & Li, J 2021, 'Numerical and experimental investigations of a thermal break composite façade mullion under four-point bending', Journal of Building Engineering, vol. 34, pp. 101590-101590.
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© 2020 Elsevier Ltd This paper presents numerical and experimental investigations on a typical thermal break composite façade profile under four-point bending. The purpose of this study is to gain the knowledge of the interfacial behaviour between aluminum extrusion and polyamide insert beyond elastic range. Understanding the behaviour of this energy efficient façade profile within plastic range is important for the design under extreme loading, such as earthquakes, strong wind conditions and even blast loads. The experimental investigation was carried out on four types of beam specimens. The specimens were grouped by their span lengths with three specimens for each span length. As the specimens’ geometry and composite action are complicated, seven strain gauges were used per specimen including small strain gauges to fit in the limited space of the thermal break section. A three stage failure process was observed during the experiments. A numerical investigation was carried out by using Finite Element modelling to simulate behaviour of the thermal break composite façade profile under similar loading condition in order to compare with the testing results as well as to capture the corresponding failure mechanisms. Numerical simulations were setup by applying a proposed partitioned multi-phase failure model to simulate three stage failure process discovered by experiments. The results from FE models were compared and discussed with experimental counterparts. In summary, FE models showed consistent results to the experimental counterparts and it also provided the insight and more details of failure mechanism and stress distribution including interfacial condition details. Behaviour of the thermal break façade profile in the plastic range displayed excellent ductility and high strength capacity of this type of thermal break section in the plastic range after slip.
Huang, Y, Lei, C, Liu, C-H, Perez, P, Forehead, H, Kong, S & Zhou, JL 2021, 'A review of strategies for mitigating roadside air pollution in urban street canyons', Environmental Pollution, vol. 280, pp. 116971-116971.
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Urban street canyons formed by high-rise buildings restrict the dispersion of vehicle emissions, which pose severe health risks to the public by aggravating roadside air quality. However, this issue is often overlooked in city planning. This paper reviews the mechanisms controlling vehicle emission dispersion in urban street canyons and the strategies for managing roadside air pollution. Studies have shown that air pollution hotspots are not all attributed to heavy traffic and proper urban design can mitigate air pollution. The key factors include traffic conditions, canyon geometry, weather conditions and chemical reactions. Two categories of mitigation strategies are identified, namely traffic interventions and city planning. Popular traffic interventions for street canyons include low emission zones and congestion charges which can moderately improve roadside air quality. In comparison, city planning in terms of building geometry can significantly promote pollutant dispersion in street canyons. General design guidelines, such as lower canyon aspect ratio, alignment between streets and prevailing winds, non-uniform building heights and ground-level building porosity, may be encompassed in new development. Concurrently, in-street barriers are widely applicable to rectify the poor roadside air quality in existing street canyons. They are broadly classified into porous (e.g. trees and hedges) and solid (e.g. kerbside parked cars, noise fences and viaducts) barriers that utilize their aerodynamic advantages to ease roadside air pollution. Post-evaluations are needed to review these strategies by real-world field experiments and more detailed modelling in the practical perspective.
Huang, Y, Ng, ECY, Zhou, JL, Surawski, NC, Lu, X, Du, B, Forehead, H, Perez, P & Chan, EFC 2021, 'Impact of drivers on real-driving fuel consumption and emissions performance', Science of The Total Environment, vol. 798, pp. 149297-149297.
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Eco-driving has attracted great attention as a cost-effective and immediate measure to reduce fuel consumption significantly. Understanding the impact of driver behaviour on real driving emissions (RDE) is of great importance for developing effective eco-driving devices and training programs. Therefore, this study was conducted to investigate the performance of different drivers using a portable emission measurement system. In total, 30 drivers, including 15 novice and 15 experienced drivers, were recruited to drive the same diesel vehicle on the same route, to minimise the effect of uncontrollable real-world factors on the performance evaluation. The results show that novice drivers are less skilled or more aggressive than experienced drivers in using the accelerator pedal, leading to higher vehicle and engine speeds. As a result, fuel consumption rates of novice drivers vary in a slightly greater range than those of experienced drivers, with a marginally higher (2%) mean fuel consumption. Regarding pollutant emissions, CO and THC emissions of all drivers are well below the standard limits, while NOx and PM emissions of some drivers significantly exceed the limits. Compared with experienced drivers, novice drivers produce 17% and 29% higher mean NOx and PM emissions, respectively. Overall, the experimental results reject the hypothesis that driver experience has significant impacts on fuel consumption performance. The real differences lie in the individual drivers, as the worst performing drivers have significantly higher fuel consumption rates than other drivers, for both novice and experienced drivers. The findings suggest that adopting eco-driving skills could deliver significant reductions in fuel consumption and emissions simultaneously for the worst performing drivers, regardless of driving experience.
Huang, Y, Surawski, NC, Zhuang, Y, Zhou, JL & Hong, G 2021, 'Dual injection: An effective and efficient technology to use renewable fuels in spark ignition engines', Renewable and Sustainable Energy Reviews, vol. 143, pp. 110921-110921.
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Modern spark ignition engines mostly use one injection system to deliver gasoline into the combustion chamber, using either direct injection or port fuel injection. Both technologies have their respective advantages. To integrate their advantages and to promote the use of renewable fuels, dual injection engines are in development in recent years. Dual injection represents an advanced combustion system and is a novel technology to address the urgent issues of sustainability and environmental protection. This study reviews the state-of-the-art research on dual injection spark ignition engines with a focus on renewable fuels, their advantages and engine performance. The main advantages of dual injection include greater control flexibility, enhanced cooling effect, knock mitigation, engine downsizing, extended lean-burn limits, higher thermal efficiency and reductions of several emission species. The most promising renewable fuels for dual injection are ethanol, methanol and hydrogen. Each renewable fuel is aimed at different advantages of dual injection. Alcohol-gasoline dual injection provides great anti-knock ability by taking advantage of alcohols' large enthalpies of vaporisation and high octane numbers, while hydrogen-gasoline dual injection provides extended lean-burn limits by taking advantage of hydrogen's low ignition energy, wide flammability limit and high flame speed. Direct injection of renewable fuels is the optimal injection strategy because it effectively utilises the strong cooling effect of alcohols or avoids the volumetric efficiency reduction and pre-ignition of hydrogen. Dual injection generally demonstrates higher thermal efficiency than single injection. In addition, dual injection effectively reduces particulate emissions while there are usually trade-offs among gaseous emissions.
Ibrahim, I, Bhoopal, V, Seo, DH, Afsari, M, Shon, HK & Tijing, LD 2021, 'Biomass-based photothermal materials for interfacial solar steam generation: a review', Materials Today Energy, vol. 21, pp. 100716-100716.
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Ibrahim, I, Seo, DH, Angeloski, A, McDonagh, A, Shon, HK & Tijing, LD 2021, '3D microflowers CuS/Sn2S3 heterostructure for highly efficient solar steam generation and water purification', Solar Energy Materials and Solar Cells, vol. 232, pp. 111377-111377.
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Solar-driven interfacial steam generation is a promising method to produce potable water using renewable energy and help solve global clean water scarcity problems. However, the design of photothermal materials (PTMs) with excellent light absorption that can localize heat at the air/water interface, and facilitate water vapor generation remains a key challenge for its practical implementation. In this work, we demonstrate the synthesis of heterostructure microflowers composed of vertically aligned CuS/Sn2S3 nanosheets (3D CSS-NS MF) using a single-step solvothermal method for solar steam generation application. The microflower structures and the abundant nanocavities between the vertically aligned nanosheets resulted in significant sunlight harvesting over the solar spectrum, excellent heat localization through trapping and re-absorbing the heat, and fast escape of water vapor. Under 1 sun (1 kW m-2) illumination, a high water evaporation rate of 1.42 kg m-2 h-1, corresponding to an efficiency of 82.93% was obtained. The 3D CSS-NS MF based solar evaporator exhibited remarkable salt ions rejection efficiency and good reusability over 10 cycles. Furthermore, efficient removal of organic dyes was observed in application geared towards wastewater treatment with a rejection ∼99.9%. Our work demonstrates the potential of using novel semiconductor-based nanocomposites as effective photothermal materials for high-performance solar steam generation in water desalination and wastewater treatment applications.
Ibrahim, I, Seo, DH, McDonagh, AM, Shon, HK & Tijing, L 2021, 'Semiconductor photothermal materials enabling efficient solar steam generation toward desalination and wastewater treatment', Desalination, vol. 500, pp. 114853-114853.
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© 2020 Elsevier B.V. Water scarcity issues around the world have renewed interest in the use of solar water evaporation as a means of providing fresh water. Advances in photothermal materials and thermal management, together with new interfacial system designs, have considerably improved the overall efficiency of solar steam generation (SSG) for desalination and wastewater treatment. Several classes of rationally-designed photothermal materials (PTMs) and nanostructures have enabled effective absorption of broad solar spectrum resulting in improved solar evaporation efficiency. Among several classes of PTMs, semiconductor-based PTMs have demonstrated great potential for SSG. In this review, we highlight the progress and prospects in SSG with emphasis on the use and evolution of advanced semiconductor materials for PTMs and their various designs and engineered architectures. Applications and future prospects for desalination and wastewater treatment are also discussed.
Ibrar, I, Yadav, S, Ganbat, N, Samal, AK, Altaee, A, Zhou, JL & Nguyen, TV 2021, 'Feasibility of H2O2 cleaning for forward osmosis membrane treating landfill leachate', Journal of Environmental Management, vol. 294, pp. 113024-113024.
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Ideris, F, Shamsuddin, AH, Nomanbhay, S, Kusumo, F, Silitonga, AS, Ong, MY, Ong, HC & Mahlia, TMI 2021, 'Optimization of ultrasound-assisted oil extraction from Canarium odontophyllum kernel as a novel biodiesel feedstock', Journal of Cleaner Production, vol. 288, pp. 125563-125563.
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In this novel study, oil was extracted from the kernel of an exotic indigenous species known as Canarium odontophyllum via an ultrasound-assisted process. The extraction process was optimized using response surface methodology (RSM) based on the Box-Behnken experimental design (BBD). The optimal conditions for the investigated parameters were determined as ultrasound amplitude level: 38.30%, ratio of n-hexane to kernel powder: 50:1 in mL/g, extraction time: 45.79 min, resulting in an oil extraction yield of 63.48%. For verification purposes, experiments were conducted using the same optimized values of the investigated parameters which resulted in the average oil yield of 63.27% and this prove the reliability of the regression model. The extracted oil's fatty acid composition was obtained using a gas chromatograph (GC) equipped with flame-ionization detection (FID). The low acid value of the extracted oil is another interesting finding. This is important because it circumvents pretreatment processes such as degumming and esterification prior to the transesterification process. Biodiesel was produced from the oil via ultrasound-assisted transesterification, with a yield of 95.2%. Physiochemical properties of the C. odontophyllum biodiesel were determined, and it was found that all the tested properties comply with fuel specifications based on ASTM D6751 and EN 14214 standards. Significant savings of 52.3% and 80.9% in energy consumption and extraction time, respectively were achieved via ultrasound-assisted extraction compared with the conventional Soxhlet extraction. This study establishes the foundation and the need to further explore the usage of C. odontophyllum as a potential feedstock for biodiesel production.
Inamdar, MA, Raghavendra, U, Gudigar, A, Chakole, Y, Hegde, A, Menon, GR, Barua, P, Palmer, EE, Cheong, KH, Chan, WY, Ciaccio, EJ & Acharya, UR 2021, 'A Review on Computer Aided Diagnosis of Acute Brain Stroke', Sensors, vol. 21, no. 24, pp. 8507-8507.
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Amongst the most common causes of death globally, stroke is one of top three affecting over 100 million people worldwide annually. There are two classes of stroke, namely ischemic stroke (due to impairment of blood supply, accounting for ~70% of all strokes) and hemorrhagic stroke (due to bleeding), both of which can result, if untreated, in permanently damaged brain tissue. The discovery that the affected brain tissue (i.e., ‘ischemic penumbra’) can be salvaged from permanent damage and the bourgeoning growth in computer aided diagnosis has led to major advances in stroke management. Abiding to the Preferred Reporting Items for Systematic Review and Meta–Analyses (PRISMA) guidelines, we have surveyed a total of 177 research papers published between 2010 and 2021 to highlight the current status and challenges faced by computer aided diagnosis (CAD), machine learning (ML) and deep learning (DL) based techniques for CT and MRI as prime modalities for stroke detection and lesion region segmentation. This work concludes by showcasing the current requirement of this domain, the preferred modality, and prospective research areas.
Inayat, A, Shahbaz, M, Khan, Z, Inayat, M, Mofijur, M, Ahmed, SF, Ghenai, C & Ahmad, AA 2021, 'Heat integration modeling of hydrogen production from date seeds via steam gasification', International Journal of Hydrogen Energy, vol. 46, no. 59, pp. 30592-30605.
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The purpose of the current study is to identify the potential of energy-efficient hydrogen (H2) production from date seeds as biomass via steam gasification process along with heat integration in Gulf countries. A reaction kinetics model has been established for steam gasification with in-situ carbon dioxide (CO2) capture of date seeds using MATLAB software. The kinetics of reactions involved in the gasification process was calculated using the optimization parameters fitting approach. The heat integration model has been developed via mixed integer nonlinear programming (MINLP) in MATLAB. In the parametric study, temperature and steam/biomass ratio considered their impact on syngas composition and energy recovery. Results showed that both variables have a strong positive effect on H2 production and depicted maximum production of 68 mol% at a temperature of 750 °C with steam/biomass ratio of 1.2. Methane (CH4) and CO2 production were low in the product gas, which showed the activity of water gas shift reaction, methanation reaction, and carbonation reaction. Utilization of waste heat via process heat integration within the system reduced system's external heat load. More than 70% of energy recovered, which could be utilized for gasification and steam production. Energy analysis and process heat integration proved a prospective approach for energy-efficient and sustainable hydrogen production from date seeds.
Indraratna, B, Ngo, T, Ferreira, FB, Rujikiatkamjorn, C & Tucho, A 2021, 'Large-scale testing facility for heavy haul track', Transportation Geotechnics, vol. 28, pp. 100517-100517.
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Given the substantially increased demand for increased axle loads of heavy haul trains, there is an imperative need to develop sustainable track infrastructure. When subjected to heavy axle loading, ballast aggregates rapidly break down, compromising the particle friction and associated load bearing capacity. Therefore, understanding the deformation and degradation (breakage) of ballast subjected to various boundary and loading conditions is crucial for improved track design and performance monitoring. Ideally, field testing should be carried out in real-life tracks to avoid laboratory scale and boundary effects, but field tests are often expensive, time-consuming and may disrupt rail traffic, hence not always feasible. A prototype test facility that can simulate appropriate axle loading and boundary conditions for standard gauge heavy haul tracks is presented in this paper. In collaboration with more than a dozen Universities and Industry organisations, Australia's first and only National Facility for Heavy-haul Railroad Testing (NFHRT) has recently been constructed and is now fully operational. This new facility enables a real-size (1:1 scale) instrumented track section to be subjected to continuous cyclic loading simulated via two pairs of dynamic actuators in synchronized operation. The results of a typical test are presented in this paper including the measured track settlement and lateral deformation, transient vertical and lateral stresses, rail and sleeper accelerations, resilient modulus and breakage of ballast. The test results show that an average track settlement of about 14 mm and lateral displacements up to 9 mm are recorded after 500,000 load cycles. Subjected to a 25-tonne axle load, the maximum vertical stress measured at the sleeper-ballast interface is about 225 kPa and this attenuates with depth. The test results of this iconic facility are generally consistent with actual field measurements obtained in heavy-haul tracks located in t...
Indraratna, B, Nguyen, TT, Singh, M, Rujikiatkamjorn, C, Carter, JP, Ni, J & Truong, MH 2021, 'Cyclic loading response and associated yield criteria for soft railway subgrade – Theoretical and experimental perspectives', Computers and Geotechnics, vol. 138, pp. 104366-104366.
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Indraratna, B, Phan, NM, Nguyen, TT & Huang, J 2021, 'Simulating Subgrade Soil Fluidization Using LBM-DEM Coupling', International Journal of Geomechanics, vol. 21, no. 5, pp. 1-14.
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The loss of effective stress due to increasing excess pore pressure that results in the upward migration of soil particles, that is, subgrade fluidization and mud pumping, has been a critical issue for railways over many years. Traditional methods such as experimental and analytical approaches can capture macroscopic quantities such as the hydraulic conductivity and critical hydraulic gradient, but they have many limitations when microscopic and localized behavior must be captured. This paper, therefore, presents a novel numerical approach where the microscopic properties of fluid and particles can be better captured when the soil is subjected to an increasing hydraulic gradient. While particle behavior is simulated using the discrete element method (DEM), the fluid dynamics can be described in greater detail using the lattice Boltzmann method (LBM). The mutual LBM-DEM interaction is carried out, so the particle and fluid variables are constantly updated. To validate this numerical method, laboratory testing on a selected subgrade soil is conducted. The results show that the numerical method can reasonably predict the coupled hydraulic and soil fluidization aspects, in relation to the experimental data. Microscopic properties such as the interstitial fluid flowing through the porous spaces of the soil are also captured well by the proposed fluid-particle coupling approach.
Indraratna, B, Qi, Y, Jayasuriya, C, Rujikiatkamjorn, C & Arachchige, CMK 2021, 'Use of recycled rubber inclusions with granular waste for enhanced track performance', Transportation Engineering, vol. 6, pp. 100093-100093.
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Indraratna, B, Rujikiatkamjorn, C, Kelly, R, Kianfar, K & Sloan, LS 2021, 'COLLABORATIONS IN GEOTECHNICAL ENGINEERING: LESSONS FROM THE BALLINA BYPASS AND THE NATIONAL SOFT SOIL FIELD TESTING FACILITY', Australian Geomechanics Journal, vol. 56, no. 2, pp. 85-93.
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Collaboration assists both academics and industry partners to achieve innovations, scientific advancement, and maintain technical competencies. The Ballina Bypass is used here to demonstrate collaboration via an Australian Research Council (ARC) Linkage project on vacuum consolidation, and to discuss how the lessons learned from the Ballina Bypass led to establishing a national facility in Ballina to field test soft soils. The outcomes of the work at the field testing facility have been transferred back to the industry via an international numerical prediction symposium. The project background, roles, and responsibilities of researchers and industry members are discussed and explained, as are the innovative outcomes, stakeholder benefits, and cultural impacts.
Indraratna, B, Singh, M, Nguyen, TT, Leroueil, S, Abeywickrama, A, Kelly, R & Neville, T 2021, 'Correction: Laboratory study on subgrade fluidization under undrained cyclic triaxial loading', Canadian Geotechnical Journal, vol. 58, no. 11, pp. 1790-1790.
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In the Acknowledgements section, “(ITTC),” should be replaced with “(ITTC-Rail) at the”; and “ARTC (Australian Rail Track Corpora-tion)” should be replaced with “ACRI (Australasian Centre for Rail Innovation)”. The corrected text of the Acknowledgements section is as follows: This research was supported by the Australian Government through the Australian Research Council’s Linkage Projects funding scheme (project LP160101254) and the Industrial Transformation Training Centre for Advanced Technologies in Rail Track Infrastructure (ITTC-Rail) at the University of Wollongong. The financial and technical support from SMEC-Australia and ACRI (Australasian Centre for Rail Innovation) is acknowledged.
Indraratna, B, Soomro, MHAA & Rujikiatkamjorn, C 2021, 'Semi-empirical analytical modelling of equivalent dynamic shear strength (EDSS) of rock joint', Transportation Geotechnics, vol. 29, pp. 100569-100569.
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A systematic dynamic triaxial series of tests on replicated rough rock joints were carried out, and results clearly highlight the strength attenuation as a function of joint degradation with respect to the number of loading cycles. A novel semi-empirical mathematical model to evaluate the equivalent dynamic shear strength (EDSS) of rock joint is proposed and validated with experimental results based on two sets of rock joints using rough (JRC = 12.6) and relatively smoother (JRC = 7.2) joint specimens.
Iqbal, J 2021, 'Landslide susceptibility assessment along the Dubair-Dudishal section of the Karakoram Highway, Northwestern Himalayas, Pakistan', Acta Geodynamica et Geomaterialia, pp. 137-155.
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The primary objective of this study is to analyze and characterize landslides in North Pakistan along Karakoram Highway (KKH) to produce a landslide susceptibility map using GIS and remote sensing technology. Using satellite images followed by field investigations, spatial distribution of landslide database was generated. Next, an integrated study was undertaken in the study area to perform the landslide susceptibility mapping. Dubaur-Dudishal section of KKH (about 150 km) which is a part of Kohistan Island Arc, is investigated in this study with a buffer zone of about 8 km along both sides of the KKH. Several thematic maps, e.g., lithology, distance to faults, distance to streams, distance to roads, normalized difference vegetation index (NDVI), slope, aspect, elevation, relative relief, plan-curvature and profile-curvature were prepared. Subsequently, these thematic data layers were analyzed by frequency ratio (FR) model and weights-of-evidence (WoE) model to generate the landslide susceptibility maps. In order to check the accuracy of the models, the area under the curve (AUC) was to quantitatively compare the two models used in this study. The predictive ability of AUC values indicate that the success rates of FR model and WoE model are 0.807 and 0.866, whereas the prediction rates are 0.785 and 0.846, respectively. Both methods show that nearly 50 % landslides in the study area fall in either high or very high susceptibility zones. The landslide susceptibility maps presented in this study are of great importance to the policy makers and the engineers for highway construction as well as the mega dams construction projects (Dasu dam and Bhasha dam which lie within the vicinity of the study area); so that proper prevention as well as mitigation could be done in advance to avoid the possible economic as well as the human loss in future.
Isfeld, AC, Stewart, MG & Masia, MJ 2021, 'Stochastic finite element model assessing length effect for unreinforced masonry walls subjected to one-way vertical bending under out-of-plane loading', Engineering Structures, vol. 236, pp. 112115-112115.
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The strength of unreinforced masonry (URM) walls subjected to one-way vertical bending under out-of-plane loading (no pre-compression) is known to be affected by the tensile bond strength. Factors such as batching, workmanship, and environmental exposure alter the strength of this bond, resulting in spatial variability for any URM assembly. In narrow wall panels a single weak joint may dictate the failure load of a masonry wall, whereas for longer walls there is higher potential for weak joints to occur and load redistribution. This paper focuses on a stochastic assessment of clay brick URM walls with spatially variable tensile bond strength subjected to uniformly distributed out-of-plane loads in one-way vertical bending and assessing the effect of wall length on the ultimate failure load. Stochastic computational modelling combining 3D non-linear Finite Element Analysis (FEA) and Monte Carlo Simulation (MCS) is used to account for bond strength variability when estimating the walls ultimate failure loads. For this assessment FEA MCS has been applied to a set of existing test data for walls 1, 2, 4, and 10 units long, by ten different masons. Models were also developed to consider walls in the intermediate length range, 7 units long, and walls outside of this range, 15 units long. For each set of simulations the peak pressure and load–displacement data was extracted and analysed, showing agreement with the results of wall test data. The panel strength is shown to increase with wall length from 1 to 4 units, then stabilize with further length increase. The variability of the failure load is shown to decrease with increasing wall length.
Islam, A, Kalam, MA, Sayeed, MA, Shano, S, Rahman, MK, Islam, S, Ferdous, J, Choudhury, SD & Hassan, MM 2021, 'Escalating SARS-CoV-2 circulation in environment and tracking waste management in South Asia', Environmental Science and Pollution Research, vol. 28, no. 44, pp. 61951-61968.
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Islam, MB, Chowdhury, UN, Nain, Z, Uddin, S, Ahmed, MB & Moni, MA 2021, 'Identifying molecular insight of synergistic complexities for SARS-CoV-2 infection with pre-existing type 2 diabetes', Computers in Biology and Medicine, vol. 136, pp. 104668-104668.
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Jacob, A, Ashok, B, Alagumalai, A, Chyuan, OH & Le, PTK 2021, 'Critical review on third generation micro algae biodiesel production and its feasibility as future bioenergy for IC engine applications', Energy Conversion and Management, vol. 228, pp. 113655-113655.
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Jahirul, MI, Rasul, MG, Brown, RJ, Senadeera, W, Hosen, MA, Haque, R, Saha, SC & Mahlia, TMI 2021, 'Investigation of correlation between chemical composition and properties of biodiesel using principal component analysis (PCA) and artificial neural network (ANN)', Renewable Energy, vol. 168, pp. 632-646.
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© 2020 Elsevier Ltd Biodiesel will provide a significant renewable energy source for transportation in the near future. In the present study, principal component analysis (PCA) has been used to understand the relationship between important properties of biodiesel and its chemical composition. Finally, several artificial intelligence-based models were developed to predict specific biodiesel properties based on their chemical composition. The experimental study was conducted in order to generate training data for the artificial neural network (ANN). Available (experimental) data from the literature was also employed for this modeling strategy. The analytical part of this study found a complex multi-dimensional correlation between chemical composition and biodiesel properties. Average numbers of double bonds in the chemical structure (representing the unsaturated component in biodiesel) and the poly-unsaturated component in biodiesel had a great impact on biodiesel properties. The simulation result in this study demonstrated that ANN is a useful tool for investigating the fuel properties from its chemical composition which eventually can replace the time consuming and costly experimental test.
Jain, K & Pradhan, B 2021, 'Editorial', Journal of the Indian Society of Remote Sensing, vol. 49, no. 3, pp. 461-462.
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Jamil, S, Loganathan, P, Kandasamy, J, Ratnaweera, H & Vigneswaran, S 2021, 'Comparing nanofiltration membranes effectiveness for inorganic and organic compounds removal from a wastewater-reclamation plant’s micro-filtered water', Materials Today: Proceedings, vol. 47, pp. 1389-1393.
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Jamil, S, Loganathan, P, Khan, SJ, McDonald, JA, Kandasamy, J & Vigneswaran, S 2021, 'Enhanced nanofiltration rejection of inorganic and organic compounds from a wastewater-reclamation plant’s micro-filtered water using adsorption pre-treatment', Separation and Purification Technology, vol. 260, pp. 118207-118207.
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© 2020 Elsevier B.V. Adsorption pre-treatment to enhance the nanofiltration (NF) removal of inorganic ions, dissolved organic carbon (DOC) and organic micropollutants (OMP) from microfiltered (MF) wastewater was investigated using NF 90 membrane (contact angle 79% and molecular weight cut off value of 90–200 Da). The NF showed greater rejection for divalent cations (Ca2+, Mg2+) and anions (SO42−) compared to monovalent cations (Na+, K+) and anions (Cl−, NO3−). The degree of total DOC removal was: GAC adsorption + NF (86%) > an ion exchange resin (Purolite) adsorption + NF (81%) > NF operation alone (72%). GAC + NF removed biopolymers and hydrophobic substances almost completely and the highest percentage of LMW neutral substances. In contrast, Purolite + NF almost completely removed humic substances. The degree of membrane fouling order was: LMW neutrals > building blocks > biopolymers > hydrophobics > humics. Adsorption pre-treatment reduced membrane fouling and increased solution flux, the outcome being better with GAC compared to Purolite. Of the 10 MOPs in the MF water, seven were rejected > 90% by NF without any pre-treatment. Conversely, Purolite and GAC pre-treatments rejected > 90% of all OMPs.
Jayathilaka, P, Indraratna, B & Heitor, A 2021, 'Influence of Salinity-Based Osmotic Suction on the Shear Strength of a Compacted Clay', International Journal of Geomechanics, vol. 21, no. 5, pp. 04021041-04021041.
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Jeffry, L, Ong, MY, Nomanbhay, S, Mofijur, M, Mubashir, M & Show, PL 2021, 'Greenhouse gases utilization: A review', Fuel, vol. 301, pp. 121017-121017.
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The excessive global emission of greenhouse gases (mainly carbon dioxide, CO2 and methane, CH4), especially due to the burning of fossil fuel for energy and power generation, is the main cause to the air pollution and greenhouse effect. This has eventually brought many issues, such as climate change and global warming, that will affect the standard life of human beings. Many strategies have been proposed to further reduce the excessive emission of greenhouse gases, including CO2 and CH4 utilization. This method not only reduce the CO2 concentration in the atmosphere, but also producing renewable energy (syngas) at the same time. Hence, CO2 and CH4 utilization is also a promising approach to assist in overcoming the energy crisis due to the increasing population in time. Basically, the utilization of CO2 and CH4 system can be categorized into four: (i) electrochemical reduction, (ii) advanced catalyst system, (iii) photocatalytic reduction, and (iv) plasma technology. In this review paper, the mechanism implemented on the four abovementioned categories and their respective limitations are presented. Besides, future recommendations to optimize the greenhouse gases utilization system for up-scaling purpose is also highlighted.
Jena, R, Ghansar, TAA, Pradhan, B & Rai, AK 2021, 'Estimation of fractal dimension and b-value of earthquakes in the Himalayan region', Arabian Journal of Geosciences, vol. 14, no. 10.
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Jena, R, Naik, SP, Pradhan, B, Beydoun, G, Park, H-J & Alamri, A 2021, 'Earthquake vulnerability assessment for the Indian subcontinent using the Long Short-Term Memory model (LSTM)', International Journal of Disaster Risk Reduction, vol. 66, pp. 102642-102642.
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Earthquakes are one of the most destructive and unpredictable natural hazards with a long-term physical, psychological, and economic impact to the society. In the past century, more than 1100 destructive earthquakes occurred, and caused around 1.5 million deaths worldwide. Some recent studies have suggested that a future earthquake in the Himalayan region of magnitude range MW 7.5–8 can cause more than 0.2 million human lives and around 150 billion dollar financial loss. Deep learning methods in recent studies proved very useful in natural hazards forecasting and prediction modelling. Long Short-Term Memory (LSTM) model has been particularly popular in several natural hazard forecasting. In this research, for the first time, LSTM model is implemented with suitable Geospatial Information Systems (GIS) techniques to assess the earthquake vulnerability for whole of India. In India, most of the seismic vulnerability assessment available are at city level or state level using traditional techniques. Several factors such as land use, geology, geomorphology, fault distribution, transportation facility, population density were all used to develop the social, structural, and geotechnical vulnerability maps. The results show that the areas around Delhi, NE region of India, major parts of Gujrat, West Bengal plain exhibit high to very-high seismic vulnerability. This model achieved an accuracy of 87.8%, sensitivity (90%) and specificity (84.9%). The present analysis can be helpful towards prioritization of regions which are in higher need of risk reduction interventions. Also, based on this vulnerability index map, the risk metrics can be attenuated.
Jena, R, Pradhan, B, Naik, SP & Alamri, AM 2021, 'Earthquake risk assessment in NE India using deep learning and geospatial analysis', Geoscience Frontiers, vol. 12, no. 3, pp. 101110-101110.
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Jiang, J, Phuntsho, S, Pathak, N, Wang, Q, Cho, J & Shon, HK 2021, 'Critical flux on a submerged membrane bioreactor for nitrification of source separated urine', Process Safety and Environmental Protection, vol. 153, pp. 518-526.
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Membrane fouling is the biggest challenge in membrane based technology operation. Studies on critical flux mainly focused on membrane bioreactor for municipal wastewater and/or greywater treatment, which can significantly differ from the ultrafiltration membrane bioreactor (UF-MBRs) to treat source separated urine. In this work, the inhibitory factors on nitrifying bacteria activity were investigated for fast acclimation of nitrifying bacteria with high ammonium concentration and optimization of a high-rate partial nitrification MBR. The maximum nitrification rate of 447 ± 50 mgN L–1 d–1 was achieved when concentration of ammonia in feed urine is approximately 4006.3 ± 225.8 mg N L–1 by maintaining desired pH around 6.2 and FA concentrations below 0.5 mgL−1. Furthermore, for the first time, the impact of different operational and filtration conditions (i.e. aeration intensity, filtration method, imposed flux, intermittent relaxation, biomass concentration) on the reversibility of membrane fouling was carried out for enhancement of membrane flux and fouling mitigation. Fouling mechanisms for minor irreversible fouling observed under sub-critical condition were pore blocking and polarization. To mitigate membrane fouling, the UF module with effective membrane surface area of 0.02 m2 is recommended to be operated at the aeration intensity of 0.4 m3 h−1, intermittent relaxation of 15 min, biomass concentration of 3.5 g L−1.
Jiang, S, Shen, L & Li, W 2021, 'An experimental study of aggregate shape effect on dynamic compressive behaviours of cementitious mortar', Construction and Building Materials, vol. 303, pp. 124443-124443.
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An experimental investigation is conducted to study the effect of aggregate shape on mortar dynamic failure behaviours. Split Hopkinson bar device is employed to compress cylindrical mortar samples containing irregular glass aggregates and rounded glass aggregates under high strain rates from 1000 s−1 to 2500 s−1. A new insight into the aggregate shape effect on the mortar cracking mechanisms is presented at the microscale using micro-CT. The cracking characteristics are found to be highly dependent on the aggregate shape, where more rounded aggregates in mortar are less likely to possess transgranular cracks after the initiation of intergranular cracks in the weak interfacial transition zone. These microscopic cracking mechanisms are validated by the cumulative distribution evolutions of particle size and morphological parameters (elongation and flatness), which are further manifested by the dynamic compressive strength. The results demonstrate that mortar with more regular aggregates exhibits higher dynamic compressive strength and strain rate sensitivity.
Kalam, MA, Davis, TP, Islam, MA, Islam, S, Kittle, BL & Casas, MP 2021, 'Exploring behavioral determinants of handwashing with soap after defecation in an urban setting in Bangladesh: findings from a barrier analysis', Journal of Water, Sanitation and Hygiene for Development, vol. 11, no. 6, pp. 1006-1015.
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Abstract Social and behavior change (SBC) has long been recognized as a necessary step in the promotion of handwashing with soap (HHWS), and identifying the barriers and enablers of this behavior are key to increasing its adoption. Based on the health belief model (HBM), the theory of reasoned action (TRA) and other behavioral models, this barrier analysis study was conducted to identify the barriers and enablers of HWWS after defecation in an urban setting in Bangladesh. We conducted interviews with 45 adults who washed their hands with soap after defecation (doers) and compared them to 45 adults who did not (non-doers). The analysis showed that the main barriers of HWWS after defecation were related to perceived self-efficacy, difficulty to remember to buy soap, access to low-cost soap, low perceived severity of diarrhea, and not believing that HWWS would reduce diarrhea. Believing that it is Allah's will when one gets diarrhea was mentioned more frequently by the non-doers, while feeling clean and keeping free from illness were reported as benefits of HWWS significantly by the doers. The results suggest that an SBC strategy that addresses these key barriers and enablers would be more effective in promoting the adoption of HWWS.
Kan, ME, Indraratna, B & Rujikiatkamjorn, C 2021, 'On numerical simulation of vertical drains using linear 1-dimensional drain elements', Computers and Geotechnics, vol. 132, pp. 103960-103960.
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Kan, WH, Huang, S, Man, Z, Yang, L, Huang, A, Chang, L, Nadot, Y, Cairney, JM & Proust, G 2021, 'Effect of T6 treatment on additively-manufactured AlSi10Mg sliding against ceramic and steel', Wear, vol. 482-483, pp. 203961-203961.
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Kaw, HY, Jin, X, Liu, Y, Cai, L, Zhao, X, Wang, J, Zhou, JL, He, M & Li, D 2021, 'Gas-liquid microextraction coupled with magnetic-assisted dispersive solid-phase extraction clean-up for multi-residue pesticide analysis in fatty foods of animal origin', LWT, vol. 137, pp. 110448-110448.
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An effective sequential clean-up method by coupling gas-liquid microextraction (GLME) and magnetic-assisted dispersive solid phase extraction (d-SPE) termed as GLME-MA-d-SPE has been developed for multi-residue pesticide analysis in different fatty foods of animal origin. GLME is applied as a primary clean-up step to remove low-volatile interferences, followed by a secondary clean-up technique through adsorptive removal using d-SPE to eliminate other co-extracts like organic acids in fatty biological samples. As much as 99.3% of lipid substances were effectively eliminated by this powerful clean-up method, and the chromatographic analysis by GC-MS showed at least two orders of magnitude reduction for peaks of interference. Analytical results verified the accuracy and precision of this method with recoveries of 50 pesticides ranged from 60.5% to 119.7%, and RSDs of less than 20%. Permethrin was present in salmon, pork and egg samples, but the concentrations were within the maximum residue levels (MRLs) permitted by both national and international regulations. The GLME-MA-d-SPE technique minimizes matrix effects, and it exhibits significant potential as an analytical technique of food safety control systems for broad-spectrum screening trace-level environmental pollutants in complex biological matrices.
Kelly, R, Huang, J, Poulos, H & Stewart, MG 2021, 'Geotechnical and Structural stochastic analysis of piled solar farm foundations', Computers and Geotechnics, vol. 132, pp. 103988-103988.
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Development of large scale solar farms supported by large numbers of short piles has created new challenges for engineers to address. Solar arrays are highly flexible structures and the piles can be designed to move to enable more cost effective design. The structural reliability of the above-ground pile can be assessed and probabilities of failure for different section sizes calculated. Economic analysis incorporating capital cost and whole-of-life maintenance cost can be performed to work out whether adopting smaller section sizes provide the best cost outcome. Assessment of pile movements using Monte-Carlo calculations, unsaturated soil mechanics and updating material parameters with suction have been performed. The results show that soil movements are typically larger than pile movements and that soil can slip past the pile with no pile movement when the limiting conditions occur. The results also highlight that the largest soil and pile movements occur infrequently as a result of extreme wetting or drying conditions. Structural reliability analyses showed that correlating wind speed and direction results in a lower probability of failure than if wind load is considered to be uncorrelated with wind direction. The outcomes of the assessment were sensitive to the adopted probabilistic model for pile durability. The main limitation of the analyses is that there is limited information in the literature relating to the types of probability distributions and their input parameters. This adds uncertainty to the stochastic analysis.
Khade, S, Gite, S, Thepade, SD, Pradhan, B & Alamri, A 2021, 'Detection of Iris Presentation Attacks Using Hybridization of Discrete Cosine Transform and Haar Transform With Machine Learning Classifiers and Ensembles', IEEE Access, vol. 9, no. 99, pp. 169231-169249.
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Iris biometric identification allows for contactless authentication, which helps to avoid the transmission of diseases like COVID-19. Biometric systems become unstable and hazardous due to spoofing attacks involving contact lenses, replayed video, cadaver iris, synthetic Iris, and printed iris. This work demonstrates the iris presentation attacks detection (Iris-PAD) approach that uses fragmental coefficients of transform iris images as features obtained using Discrete Cosine Transform (DCT), Haar Transform, and hybrid Transform. In experimental validations of the proposed method, three main types of feature creation are investigated. The extracted features are utilized for training seven different machine learning classifiers alias Support Vector Machine (SVM), Naive Bayes (NB), Random Forest (RF), and decision tree(J48) with ensembles of SVM+RF+NB, SVM+RF+RT, and RF+SVM+MLP (multi-layer perceptron) for proposed iris liveness detection. The proposed iris liveness detection variants are evaluated using various statistical measures: accuracy, Attack Presentation Classification Error Rate (APCER), Normal Presentation Classification Error Rate (NPCER), Average Classification Error Rate (ACER). Six standard datasets are used in the investigations. Total nine iris spoofing attacks are getting identified in the proposed method. Among all investigated variations of proposed iris-PAD methods, the 4 ×4 of fragmental coefficients of a Hybrid transformed iris image with RF algorithm have shown superior iris liveness detection with 99.95% accuracy. The proposed hybridization of transform for features extraction has demonstrated the ability to identify all nine types of iris spoofing attacks and proved it robust. The proposed method offers exceptional performances against the Synthetic iris spoofing images by using a random forest classifier. Machine learning has massive potential in a similar domain and could be explored further based on the research requirements.
Khan, AUH, Liu, Y, Naidu, R, Fang, C, Dharmarajan, R & Shon, H 2021, 'Interactions between zinc oxide nanoparticles and hexabromocyclododecane in simulated waters', Environmental Technology & Innovation, vol. 24, pp. 102078-102078.
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The zinc oxide nanoparticles (ZnO-NPs) have been increasingly applied in industries and consumer products, causing release of these nanoparticles in environments. The behaviour of ZnO-NPs in the water systems is complicated due to the presence of different cations, anions, organic substances (e.g. humic acid HA) and other organic pollutants (e.g. commonly used brominated flame retardant, BFR). In particular, the aggregation and alteration of these nanoparticles can be influenced by co-existence contaminants. In this study, the interactions between hexabromocyclododecane (HBCD) and ZnO-NPs were investigated for the physicochemical properties and colloidal stability changes in various simulated waters. This is significant to understand the fate and behaviour of ZnO-NPs at environmental relevant conditions. The surface chemistry and particle size distribution (PSD) of ZnO-NPs with and without the existence of HBCD, HA and electrolytes (NaCl, CaCl2 and MgCl2) after different periods (1 and 3 weeks) were investigated at pH 7.00 ± 0.02. The size of the ZnO-NPs increased from nanometres to micrometres with the addition of numerous concentrations of HBCD, HA, and cations and their mixtures. The zeta potential of ZnO-NPs increased upon addition of HBCD, HA and electrolytes indicating a more stable agglomeration form while less agglomeration was observed in the ZnO-NPs and HA suspension after 3 weeks. Hydrophobic and electrostatic interactions, van der Waals forces, including hydrogen bonding and cation bridging could be potential interactive driving forces. The results indicated agglomeration of ZnO-NPs in the existence of organic substances, salts and contaminants, thus sedimentation and precipitation are promising under salty surface water/sea water.
Khan, HM, Iqbal, T, Mujtaba, MA, Soudagar, MEM, Veza, I & Fattah, IMR 2021, 'Microwave Assisted Biodiesel Production Using Heterogeneous Catalysts', Energies, vol. 14, no. 23, pp. 8135-8135.
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As a promising renewable fuel, biodiesel has gained worldwide attention to replace fossil-derived mineral diesel due to the threats concerning the depletion of fossil reserves and ecological constraints. Biodiesel production via transesterification involves using homogeneous, heterogeneous and enzymatic catalysts to speed up the reaction. The usage of heterogeneous catalysts over homogeneous catalysts are considered more advantageous and cost-effective. Therefore, several heterogeneous catalysts have been developed from variable sources to make the overall production process economical. After achieving optimum performance of these catalysts and chemical processes, the research has been directed in other perspectives, such as the application of non-conventional methods such as microwave, ultrasonic, plasma heating etc, aiming to enhance the efficiency of the overall process. This mini review is targeted to focus on the research carried out up to this date on microwave-supported heterogeneously catalysed biodiesel production. It discusses the phenomenon of microwave heating, synthesis techniques for heterogeneous catalysts, microwave mediated transesterification reaction using solid catalysts, special thermal effects of microwaves and parametric optimisation under microwave heating. The review shows that using microwave technology on the heterogeneously catalysed transesterification process greatly decreases reaction times (5–60 min) while maintaining or improving catalytic activity (>90%) when compared to traditional heating.
Khan, HM, Iqbal, T, Yasin, S, Irfan, M, Kazmi, M, Fayaz, H, Mujtaba, MA, Ali, CH, Kalam, MA, Soudagar, MEM & Ullah, N 2021, 'Production and utilization aspects of waste cooking oil based biodiesel in Pakistan', Alexandria Engineering Journal, vol. 60, no. 6, pp. 5831-5849.
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Excessive fuel demand thrusts the Pakistani government to import large volumes of fuel from foreign sources, creating adverse effects on the country's economy. Therefore, exploring an alternative to fossil fuels is unavoidable. The option of environmentally friendly fuel like biodiesel produced from indigenous waste is an additional bonus for the populous developing country like Pakistan where likelihood of waste generation is huge. There exists a potential option for sustainable biodiesel production utilizing excessive waste cooking oil available in the country which otherwise is an ecological burden. The present work is focused to sturdily vindicate the appropriateness of waste cooking oil-based biodiesel generation and utilization in Pakistan through SWOT-AHP, TOWS and PESTLE analysis. The prioritization of SWOT through AHP in view of experts’ perception displayed the strengths and opportunities in highest group priority values (Strengths: 0.51, Opportunities: 0.29). Furthermore, TOWS analysis suggests promising strategies for the sustainable implementation of commercial aspect of waste oil-based biodiesel in Pakistan. Political, Economic, Social, Technological, Legal and Environmental (PESTLE) analysis favors the strengths and opportunities factors of SWOT and TOWS strategies for the application of waste cooking oil based biodiesel in country. At the end, regional recommendations have been provided for the implementation of biodiesel production scenario in country.
Khan, T, Bari, G, Kang, H-J, Lee, T-G, Park, J-W, Hwang, H, Hossain, S, Mun, J, Suzuki, N, Fujishima, A, Kim, J-H, Shon, H & Jun, Y-S 2021, 'Synthesis of N-Doped TiO2 for Efficient Photocatalytic Degradation of Atmospheric NOx', Catalysts, vol. 11, no. 1, pp. 109-109.
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Titanium oxide (TiO2) is a potential photocatalyst for removing toxic NOx from the atmosphere. Its practical application is, however, significantly limited by its low absorption into visible light and a high degree of charge recombination. The overall photocatalytic activity of TiO2 remains too low since it can utilize only about 4–5% of solar energy. Nitrogen doping into the TiO2 lattice takes advantage of utilizing a wide range of solar radiation by increasing the absorption capability towards the visible light region. In this work, N-doped TiO2, referred to as TC, was synthesized by a simple co-precipitation of tri-thiocyanuric acid (TCA) with P25 followed by heat treatment at 550 degrees C. The resulting nitrogen doping increased the visible-light absorption and enhanced the separation/transfer of photo-excited charge carriers by capturing holes by reduced titanium ions. As a result, TC samples exhibited excellent photocatalytic activities of 59% and 51% in NO oxidation under UV and visible light irradiation, in which the optimum mass ratio of TCA to P25 was found to be 10.
Khanafer, D, Ibrahim, I, Yadav, S, Altaee, A, Hawari, A & Zhou, J 2021, 'Brine reject dilution with treated wastewater for indirect desalination', Journal of Cleaner Production, vol. 322, pp. 129129-129129.
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Khanafer, D, Yadav, S, Ganbat, N, Altaee, A, Zhou, J & Hawari, AH 2021, 'Performance of the Pressure Assisted Forward Osmosis-MSF Hybrid Desalination Plant', Water, vol. 13, no. 9, pp. 1245-1245.
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An osmotically driven membrane process was proposed for seawater pretreatment in a multi-stage flashing (MSF) thermal plant. Brine reject from the MSF plant was the draw solution (DS) in the forward osmosis (FO) process in order to reduce chemical use. The purpose of FO is the removal of divalent ions from seawater prior the thermal desalination. In this study, seawater at 80 g/L and 45 g/L concentrations were used as the brine reject and seawater, respectively. The temperature of the brine reject was 40 °C and of seawater was 25 °C. Commercial thin-film composite (TFC) and cellulose triacetate (CTA) membranes were evaluated for the pretreatment of seawater in the FO and the pressure-assisted FO (PAFO) processes. Experimental results showed 50% more permeation flux by increasing the feed pressure from 1 to 4 bar, and permeation flux reached 16.7 L/m2h in the PAFO process with a TFC membrane compared to 8.3 L/m2h in the PAFO process with CTA membrane. TFC membrane experienced up to 15% reduction in permeation flux after cleaning with DI water while permeation flux reduction in the CTA membrane was >6%. The maximum recovery rate was 11.5% and 8.8% in the PAFO process with TFC and CTA membrane, respectively. The maximum power consumption for the pretreatment of seawater was 0.06 kWh/m3 and 0.1 kWh/m3 for the PAFO process with a TFC and CTA membrane, respectively.
Khanh Nguyen, V, Kumar Chaudhary, D, Hari Dahal, R, Hoang Trinh, N, Kim, J, Chang, SW, Hong, Y, Duc La, D, Nguyen, XC, Hao Ngo, H, Chung, WJ & Nguyen, DD 2021, 'Review on pretreatment techniques to improve anaerobic digestion of sewage sludge', Fuel, vol. 285, pp. 119105-119105.
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Anaerobic digestion (AD) of sewage sludge is one of the most efficient, effective, and environmentally sustainable remediation techniques; however, the presence of complex floc structures, hard cell walls, and large amounts of molecular organic matter in the sludge hinder AD hydrolysis. Consequently, sewage sludge pretreatment is a prerequisite to accelerate hydrolysis and improve AD efficiency. This review focuses on pretreatment techniques for improving sewage sludge AD, which include mechanical, chemical, thermal, and biological processes. The various pretreatment process effects are discussed in terms of advantages and disadvantages, including their effectiveness, and recent achievements are reviewed for improved biogas production.
Khosravi, K, Bordbar, M, Paryani, S, Saco, PM & Kazakis, N 2021, 'New hybrid-based approach for improving the accuracy of coastal aquifer vulnerability assessment maps', Science of The Total Environment, vol. 767, pp. 145416-145416.
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Khosravi, K, Miraki, S, Saco, PM & Farmani, R 2021, 'Short-term River streamflow modeling using Ensemble-based additive learner approach', Journal of Hydro-environment Research, vol. 39, pp. 81-91.
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Kolekar, S, Gite, S, Pradhan, B & Kotecha, K 2021, 'Behavior Prediction of Traffic Actors for Intelligent Vehicle Using Artificial Intelligence Techniques: A Review', IEEE Access, vol. 9, pp. 135034-135058.
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Intelligent vehicle technology has made tremendous progress due to Artificial Intelligence (AI) techniques. Accurate behavior prediction of surrounding traffic actors is essential for the safe and secure navigation of the intelligent vehicle. Minor misbehavior of these vehicles on the busy roads may lead to an accident. Due to this, there is a need for vehicle behavior research work in today's era. This research article reviews traffic actors' behavior prediction techniques for intelligent vehicles to perceive, infer, and anticipate other vehicles' intentions and future actions. It identifies the key strategies and methods for AI, emerging trends, datasets, and ongoing research issues in these fields. As per the authors' knowledge, this is the first systematic literature review dedicated to the vehicle behavior study examining existing academic literature published by peer review venues between 2011 and 2021. A systematic review was undertaken to examine these papers, and five primary research questions have been addressed. The findings show that using sophisticated input representation that includes traffic rules and road geometry, artificial intelligence-based solutions applied to behavior prediction of traffic actors for intelligent vehicles have shown promising success, particularly in complex driving scenarios. Finally, the paper summarizes the most widely used approaches in behavior prediction of traffic actors for intelligent vehicles, which the authors believe serves as a foundation for future research in behavior prediction of surrounding traffic actors for secure and accurate intelligent vehicle navigation.
Kolekar, SS, Gite, SS & Pradhan, B 2021, 'Demystifying Artificial Intelligence based Behavior Prediction of Traffic Actors for Autonomous Vehicle- A Bibliometric Analysis of Trends and Techniques', Library Philosophy and Practice, vol. 2021, pp. 1-25.
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Background: The purpose of this study is to examine, using bibliometric methods, the work done on behavior prediction of traffic actors for autonomous vehicles using various artificial intelligence algorithms from 2011 to 2020. Methods: Using one of the most common databases, Scopus, numerous papers on behavior prediction of traffic actors for autonomous vehicles were retrieved. The research papers are being considered for the period from 2011 to 2020. The Scopus analyzer is used to obtain some results of the study, such as documents by year, source, and country and so on. VOSviewer Version 1.6.16 is used for the analysis of different units such as co-authorship, co-occurrences, citation analysis etc. Results: In our study, a database search outputs a total of 275 articles on behavior prediction for autonomous vehicle from 2011 to 2020. Statistical analysis and network analysis shows the maximum articles are published in the years 2019 and 2020 with United State contributed the largest number of documents. Network analysis of different parameters shows a good potential of the topic in terms of research. Conclusions: Scopus keyword search outcome has 272 articles with English language having the largest number. Authors, documents, country, affiliation etc are statically analyzed and indicates the potential of the topic. Network analysis of different parameters indicates that, there is a lot of scope to contribute in the further research in terms of advanced algorithms of computer vision, deep learning, machine learning and explainable artificial intelligence.
Kumar, A, Kim, Y, Su, X, Fukuda, H, Naidu, G, Du, F, Vigneswaran, S, Drioli, E, Hatton, TA & Lienhard, JH 2021, 'Advances and challenges in metal ion separation from water', Trends in Chemistry, vol. 3, no. 10, pp. 819-831.
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Technologies for selective metal ion separation from water and wastewater are currently attracting strong research interest as a pathway to greater sustainability. The chemistry of metal ion separation processes is critical for understanding the mechanisms of selectivity and making the technologies viable. This paper discusses current advances and challenges in metal ion separation technologies from chemical points of view and proposes how they should be approached in the future.
Kumar, A, Naidu, G, Fukuda, H, Du, F, Vigneswaran, S, Drioli, E & Lienhard, JH 2021, 'Metals Recovery from Seawater Desalination Brines: Technologies, Opportunities, and Challenges', ACS Sustainable Chemistry & Engineering, vol. 9, no. 23, pp. 7704-7712.
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The urgent need for environmental sustainability has increasingly prompted policy makers to emphasize resource recovery from desalination brine streams. Recent research on resource recovery from waste streams has shown rising momentum with near term viability for several new technologies. In this perspective, we focus on new opportunities for metal resource recovery from seawater desalination brine, while outlining associated sustainability challenges and opportunities. The potential of metals recovery is discussed.
Kumari, P, Bahadur, N, Cretin, M, Kong, L, O'Dell, LA, Merenda, A & Dumée, LF 2021, 'Electro-catalytic membrane reactors for the degradation of organic pollutants – a review', Reaction Chemistry & Engineering, vol. 6, no. 9, pp. 1508-1526.
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Electro-catalytic membrane reactor exhibiting electro-oxidation degradation of organic pollutants on anodic membrane.
Kumari, P, Bahadur, N, O'Dell, LA, Kong, L, Sadek, A, Merenda, A & Dumée, LF 2021, 'Nanoscale 2D semi-conductors – Impact of structural properties on light propagation depth and photocatalytic performance', Separation and Purification Technology, vol. 258, pp. 118011-118011.
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The performance of photocatalytic materials are largely dictated by the crystalline and optical properties of the semi-conductors. The density of photo-generated electron and hole pairs is greatly influenced by the light penetration in photocatalytic material, leading to specific degradation kinetics. In this work, the relationship between the metal oxide film thickness and the overall materials optical and photocatalytic performances are systematically established for the first time. Thin films of semiconductor metal oxides such as TiO2 and ZnO were prepared by atomic layer deposition (ALD) on stainless steel sputtered silicon wafers. The thickness of the metal oxide thin films was controlled by varying the number of deposition cycles (50–1000 cycles). The fabricated films were fully characterized to examine the change in morphology, roughness, crystallinity, optical and structural properties with varying thickness by several techniques such as Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), X-Ray Diffraction (XRD), Diffuse Reflectance Spectroscopy (DRS) and X-Ray Photo-electro Spectroscopy (XPS). The films were generated to yield very consistent crystallinity, roughness and light absorption properties. Critical thicknesses were observed when a plateau in photocatalytic efficiency was reached at the thickness of 31 nm in the case of the TiO2 and 89 nm thickness for ZnO films. The dependency of the thickness of nanometric ALD films on their photocatalytic efficiency results from the light diffusion and penetration within the material which was investigated through fundamentals and modelling of light-matter interaction in photocatalytic processes. This work establishes a new fundamental understanding of the operation and performance of photocatalysts for further development of advanced reactors and their scale-up.
Kundariya, N, Mohanty, SS, Varjani, S, Hao Ngo, H, W. C. Wong, J, Taherzadeh, MJ, Chang, J-S, Yong Ng, H, Kim, S-H & Bui, X-T 2021, 'A review on integrated approaches for municipal solid waste for environmental and economical relevance: Monitoring tools, technologies, and strategic innovations', Bioresource Technology, vol. 342, pp. 125982-125982.
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Rapid population growth, combined with increased industrialization, has exacerbated the issue of solid waste management. Poor management of municipal solid waste (MSW) not only has detrimental environmental consequences but also puts public health at risk and introduces several other socioeconomic problems. Many developing countries are grappling with the problem of safe disposing of large amounts of produced municipal solid waste. Unmanaged municipal solid waste pollutes the environment, so its use as a potential renewable energy source would aid in meeting both increased energy needs and waste management. This review investigates emerging strategies and monitoring tools for municipal solid waste management. Waste monitoring using high-end technologies and energy recovery from MSW has been discussed. It comprehensively covers environmental and economic relevance of waste management technologies based on innovations achieved through the integration of approaches.
Kute, DV, Pradhan, B, Shukla, N & Alamri, A 2021, 'Deep Learning and Explainable Artificial Intelligence Techniques Applied for Detecting Money Laundering–A Critical Review', IEEE Access, vol. 9, pp. 82300-82317.
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Money laundering has been a global issue for decades, which is one of the major threat for economy and society. Government, regulatory and financial institutions are combating it together in their respective capacity, however still billions of dollars in fines by authorities make the headlines in the news. High-speed internet services have enabled financial institutions to deliver better customer experience through multi-channel engagements, which has led to exponential growth in transactions and new avenues for laundering the money for fraudsters. Literature shows the usage of statistical methods, data mining and Machine Learning (ML) techniques for money laundering detection, but limited research on Deep Learning (DL) techniques, primarily due to lack of model interpretability and explainability of the decisions made. Several studies are conducted on application of ML for Anti-Money Laundering (AML), and Explainable Artificial Intelligence (XAI) techniques in general, but lacks the study on usage of DL techniques together with XAI. This paper aims to review the current state-of-the-art literature on DL together with XAI for identifying suspicious money laundering transactions and identify future research areas. Key findings of the review are, researchers have preferred variants of Convolutional Neural Networks, and AutoEncoder; graph deep learning together with natural language processing is emerging as an important technology for AML; XAI use is not seen in AML domain; 51% ML methods used in AML are non-interpretable, 58% studies used sample of old real data; key challenges for researchers are access to recent real transaction data and scarcity of labelled training data; and data being highly imbalanced. Future research directions are, application of XAI techniques to bring-out explainability, graph deep learning using natural language processing (NLP), unsupervised and reinforcement learning to handle lack of labelled data; and joint research progra...
Labeeuw, L, Commault, AS, Kuzhiumparambil, U, Emmerton, B, Nguyen, LN, Nghiem, LD & Ralph, PJ 2021, 'A comprehensive analysis of an effective flocculation method for high quality microalgal biomass harvesting', Science of The Total Environment, vol. 752, pp. 141708-141708.
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Lee, A, Mondon, J, Merenda, A, Dumée, LF & Callahan, DL 2021, 'Surface adsorption of metallic species onto microplastics with long-term exposure to the natural marine environment', Science of The Total Environment, vol. 780, pp. 146613-146613.
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Microplastics are ubiquitous in most biomes and environments, representing one of the most pressing global environmental challenges. This study investigated the ability of pre-production microplastic pellets to accumulate metals from the marine environment. An accidental ocean discharge of poly(propylene) pellets occurred via a wastewater treatment centre at the coastal city of Warrnambool, Victoria - Australia. These pellets were collected routinely from Shelly Beach, adjacent to the ocean discharge site over a period of 16-months following the spill. This collection formed a unique time-series that accurately represented the degree to which metal ions in the coastal marine environment accumulate on plastic debris. Elemental analysis indicated an increase in concentration over time of rare earth elements and a selection of other metals supporting the hypothesis that microplastics selectively adsorb metals from the environment. A subset of the poly(propylene) pellets contained a surfactant coating which significantly increased the adsorption capacity. The surface properties in relation to adsorption were further explored with surface imaging and these results are also discussed. This study shows how microplastics act as nucleation points and carriers of trace metal ions in marine environments.
Lee, XJ, Ong, HC, Gao, W, Ok, YS, Chen, W-H, Goh, BHH & Chong, CT 2021, 'Solid biofuel production from spent coffee ground wastes: Process optimisation, characterisation and kinetic studies', Fuel, vol. 292, pp. 120309-120309.
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Lei, B, Li, W, Luo, Z, Li, X, Tam, VWY & Tang, Z 2021, 'Performance deterioration of sustainable recycled aggregate concrete under combined cyclic loading and environmental actions', Journal of Sustainable Cement-Based Materials, vol. 10, no. 1, pp. 23-45.
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The effects of strength grades, loading modes, and stress levels on the performance deterioration of sustainable recycled aggregate concrete (RAC) subjected to mechanical loading or coupled mechanical loading and environmental actions are investigated in this study. Comparison analysis of residual properties of RAC suffered from single mechanical loading, coupled actions of mechanical loading, and salt-solution freeze-thaw cycles, as well as the combined actions of mechanical loading and salt-solution corrosion were experimentally studied. The results indicate that the stress level is the most influential factor affecting the durability of RAC followed by the RAC strength grade and the number of times the alternating load applied. Moreover, applying novel intermittent loading mode to simulate the durability of RAC under the coupled actions of sustained loading and environmental factors is feasible and reasonable. Additionally, the fitting equations were proposed to discuss the effects of number of times the alternating load applied, stress level, and mechanical strength on the mechanical strength loss and durability of RAC.
Lei, F, Lv, X, Fang, J, Li, Q & Sun, G 2021, 'Nondeterministic multi-objective and multi-case discrete optimization of functionally-graded front-bumper structures for pedestrian protection', Thin-Walled Structures, vol. 167, pp. 106921-106921.
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Pedestrian lower-leg protection and lower-speed crashworthiness often present two important yet competing criteria on the design of front-bumper structures. Conventional design optimization is largely focused on a single loading condition without considering multiple impact cases. Furthermore, design of front-bumper structures is usually discrete in engineering practice and impacting conditions are commonly random. To cope with such a sophisticated nondeterministic design problem, this study aimed to develop a successive multiple attribute decision making (MADM) algorithm for optimizing a functionally graded thickness (FGT) front-bumper structure subject to multiple impact loading cases. The finite element (FE) model of front-end vehicle was constructed and validated with the in-house experimental tests under the loads of both Flexible Pedestrian Legform Impactor (Flex-PLI) impact and lower-speed impact. In the proposed successive MADM algorithm, the order preference by similarity to ideal solution (TOPSIS) based upon relative entropy was coupled with the analytic hierarchy process (AHP) to develop a MADM model for converting multiple conflicting objectives into a unified single cost function. The presented optimization procedure is algorithmically iterated using the successive Taguchi method to deal with a large number of design variables and design levels. The results showed that not only the algorithm enabled to generate an optimal design efficiently, but also the robustness of Flex-PLI impact is significantly enhanced. The proposed algorithm can be potentially used for other engineering design problems with similar complexity.
Lei, F, Lv, X, Fang, J, Pang, T, Li, Q & Sun, G 2021, 'Injury biomechanics-based nondeterministic optimization of front-end structures for safety in pedestrian–vehicle impact', Thin-Walled Structures, vol. 167, pp. 108087-108087.
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Lower extremity is the most frequently injured body region in a pedestrian–vehicle impact. To evaluate lower extremity injuries, both the Flexible Pedestrian Legform Impactor (FlexPLI) and the Flexible Pedestrian Legform Impactor with Upper Body Mass (FlexPLI-UBM) have been used in practice. In general, UBM would have considerable influence on the design of front-end structures. In this study, a sedan was used to perform the experimental tests first for evaluating the effects of different lower extremities. The experimental results indicated that placement of UBM can lead to a higher risk evaluation of knee ligament damage and a more significant increase in femur bending moment than that in tibia bending moment. Second, a new multiobjective discrete robust optimization (MODRO) algorithm was developed to optimize front-end structures subject to FlexPLI-UBM impact involving uncertainties. In the proposed MODRO algorithm, the order preference by similarity to ideal solution (TOPSIS) was coupled with the fuzzy approach for developing a fuzzy multiple attribute decision making (MADM) model for converting multiple conflicting objectives into a single unified cost function. The presented optimization procedure is iterated using the successive orthogonal experiment to deal with a large number of design variables and design levels. The optimal results showed that in contrast to the structures subject to the FlexPLI impact, the front-end structures under FlexPLI-UBM impact require a higher stiffness of tibia contact area but a lower stiffness of knee and femur contact area. This study provides automotive engineers with new insights into the injury biomechanics-based design of frontal structure from a road safety perspective.
Leng, D, Zhu, Z, Xu, K, Li, Y & Liu, G 2021, 'Vibration control of jacket offshore platform through magnetorheological elastomer (MRE) based isolation system', Applied Ocean Research, vol. 114, pp. 102779-102779.
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With high flexibility and low damping, offshore wind turbines (OWTs) are prone to external vibrations such as wind, wave and earthquake, either attacked individually or as combined loading cases. This study proposes a semi-active variable-stiffness tuned mass damper (VSTMD) with magnetorheological elastomer (MRE) materials to mitigate undesired dynamic responses of OWT. A jacket supported OWT with MRE-TMD installed at the top of the tower is adopted as an example to demonstrate the effectiveness of the proposed design under multiple hazards. A semi-active frequency tracing algorithm is proposed through which the current-dependent stiffness of MRE-TMD is controlled by tracking the acceleration of OWT tower. The numerical results demonstrate that the semi-active MRE-TMD can effectively attenuate the dynamic responses of OWT under multi-hazard loadings, and it outperforms the passive TMD in reducing the peak and RMS displacements of tower structure. Robustness analysis of semi-active MRE-TMD is also validated by considering OWT sudden loss of partial stiffness under multiple-loadings.
Leng, D, Zhu, Z, Xu, K, Li, Y & Liu, G 2021, 'Vibration control of jacket offshore platform through magnetorheological elastomer (MRE) based isolation system', Applied Ocean Research, vol. 114.
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Undesirable vibrations in offshore platforms due to ocean loadings may reduce platform productivity and increase the fatigue failure. This study proposes a magnetorheological elastomer (MRE) based isolation system to control the jacket platform oscillations and its effectiveness is numerically evaluated. The working principle and design method of MRE-based isolation system are proposed, and MRE materials with high magnetorheological effects are conceptually designed. Practical jacket offshore platforms are selected for case studies. Semi-active fuzzy controller (SFC) is utilized to achieve real-time non-resonance vibration control. The proposed fuzzy core is constructed conceptually by the dynamic analysis of object structure. Numerical results demonstrate that MRE isolation system with SFC significantly reduces the maximum, minimum and RMS of the deck displacement and acceleration under realistic irregular waves at different sea states. MRE system could also reduce the response spectrum peaks and present robustness under various deck's mass. The present study proves the feasibility of MRE isolation systems in the application of vibration control for marine structures.
Li, H, Askari, M, Li, J, Li, Y & Yu, Y 2021, 'A novel structural seismic protection system with negative stiffness and controllable damping', Structural Control and Health Monitoring, vol. 28, no. 10.
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In this paper, an innovative controllable negative stiffness system (CNSS) integrating adaptive negative stiffness and controllable damping characteristics is proposed to realise desirable vibration protection and improve adaptability, hence being effective to various earthquakes. The force-displacement relationship of the CNSS is derived as the forward model to describe its nonlinear properties. Three representative control algorithms, i.e., Linear Quadratic Regular (LQR) control, H∞ control and Sliding Mode (SM) control, are utilised for the CNSS to attain optimal control force. Based on the Takagi-Sugeno-Kang (TSK) Fuzzy inference system optimised by Non-Dominated Sorted Genetic Algorithm II (NSGAII), a novel inverse model is proposed accordingly to obtain input current according to the required control force and real-time system responses. To demonstrate the feasibility and efficiency of the CNSS for structural seismic protection, a numerical case study is conducted on a three-storey building model with CNSS installed on its first floor. Four scaled benchmark earthquakes are employed as excitations for the case study. Ten evaluation criteria are adopted to assess and verify the performance of the CNSS, and comparisons are made with that of uncontrolled and passive controlled systems. The numerical results indicate that the proposed CNSS can significantly improve the vibration control performance on all evaluation criteria simultaneously in comparison with the other two conventional systems. In addition to having good suppression effects on peak floor displacement and peak inter-storey drift, the CNSS with the SM controller demonstrates superior performance on mitigating peak structure shear and peak acceleration response of the first floor.
Li, H, Yu, Y, Li, J & Li, Y 2021, 'Analysis and optimization of a typical quasi-zero stiffness vibration isolator', Smart Structures and Systems, vol. 27, no. 3, pp. 525-536.
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To isolate vibration at a low-frequency range and at the same time to provide sufficient loading support to the isolated structure impose a challenge in vibration isolation. Quasi-zero stiffness (QZS) vibration isolator, as a potential solution to the challenge, has been widely investigated due to its unique property of high-static & low-dynamic stiffness. This paper provides an in-depth analysis and potential optimization of a typical QZS vibration isolator to illustrate the complexity and importance of design optimization. By carefully examining the governing fundamentals of the QZS vibration isolator, a simplified approximation of force and stiffness relationship is derived to enable the characteristic analysis of the QZS vibration isolator. The explicit formulae of the amplitude-frequency response (AFR) and transmissibility of the QZS vibration isolator are obtained by employing the Harmonic Balance Method. The transmissibility curves under force excitation with different values of nonlinear coefficient, damping ratio, and amplitude of excitation are further investigated. As the result, an optimization of the structural parameter has been demonstrated using a comprehensive objective function with considering multiple dynamic characteristic parameters simultaneously. Finally, the genetic algorithm (GA) is adopted to minimise the objective function to obtain the optimal stiffness ratios under different conditions. General recommendations are provided and discussed in the end.
Li, H, Yu, Y, Li, J, Li, Y & Askari, M 2021, 'Multi-objective optimisation for improving the seismic protection performance of a multi-storey adaptive negative stiffness system based on modified NSGA-II with DCD', Journal of Building Engineering, vol. 43, pp. 103145-103145.
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Installing adaptive negative stiffness devices (ANSD) on multiple storeys of a building structure to develop a smart seismic protection system, namely multi-storey adaptive negative stiffness system (MANSS), is an effective approach to mitigate the structural responses under earthquake events. However, like other base isolators, the MANSS cannot reach its full potential to address the contradiction between effective vibration isolation and suppression, due to improper setting of structural parameters. In this paper, a comprehensive multi-objective nonlinear optimisation for obtaining the optimal structural parameters of the ANSD is conducted to effectively improve the performance of MANSS on seismic protection. After the characteristic analysis of the ANSD, six optimisation variables and one constraint are determined. Four objective functions are defined by considering the two adverse requirements simultaneously, i.e. enhancing vibration isolation and improving vibration suppression. The highly nonlinear optimisation problem can be adequately resolved by the modified non-dominated sorting genetic algorithm type II (NSGA-II) with dynamic crowding distance (DCD) algorithm, which generates a series of Pareto front, hence obtaining the optimal parameter combination. Furthermore, to verify and evaluate the feasibility and capacity of the proposed optimisation method, a numerical case study is conducted based on a five-storey benchmark building model subjected to six different earthquakes. Four systems, including bare building, bare building with ANSD on the first floor, bare building with dampers on each floor and preliminarily designed MANSS are also investigated to conduct comparative analysis. The results demonstrate that the optimised MANSS can largely reduce both peak and root mean square (RMS) values of inter-storey drift, acceleration, and displacement responses of the benchmark building under all six earthquakes, which proves the effectiveness and su...
Li, J, Guo, J & Zhu, X 2021, 'Time-Varying Parameter Identification of Bridges Subject to Moving Vehicles Using Ridge Extraction Based on Empirical Wavelet Transform', International Journal of Structural Stability and Dynamics, vol. 21, no. 04, pp. 2150046-2150046.
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For a vehicle moving over a bridge, the vehicle-bridge interaction (VBI) embraces the time-varying modal parameters of the system. The identification of non-stationary characteristics of bridge responses due to moving vehicle load is important and remains a challenging task. A new method based on the improved empirical wavelet transform (EWT) along with ridge detection of signals in time-frequency representation (TFR) is proposed to estimate the instantaneous frequencies (IFs) of the bridge. Numerical studies are conducted using a VBI model to investigate the time-varying characteristics of the system. The effects of the measurement noise, road surface roughness and structural damage on the bridge IFs are investigated. Finally, the dynamic responses of an in-situ cable-stayed bridge subjected to a passing vehicle are analyzed to further explore the time varying characteristics of the VBI system. Numerical and experimental studies demonstrate the feasibility and effectiveness of the proposed method on the IF estimation. The identified IFs reveal important time-varying characteristics of the bridge dynamics that is significant to evaluating the actual performance of operational bridges in operation and may be used for structural health assessment.
Li, M, Chen, Q, Wen, K, Nimbalkar, S & Dai, R 2021, 'Improved Vacuum Preloading Method Combined with Sand Sandwich Structure for Consolidation of Dredged Clay-Slurry Fill and Original Marine Soft Clay', International Journal of Geomechanics, vol. 21, no. 10, pp. 04021182-04021182.
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Li, P, Li, W, Sun, Z, Shen, L & Sheng, D 2021, 'Development of sustainable concrete incorporating seawater: A critical review on cement hydration, microstructure and mechanical strength', Cement and Concrete Composites, vol. 121, pp. 104100-104100.
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Many countries are experiencing freshwater crises due to the increasing growth of the population together with the infrastructure construction that is aligned with the needs of freshwater for concrete production. There are also deficiencies in freshwater in many coastal areas where seawater is more accessible. To reduce unnecessary resource-wasting and meanwhile drive sustainable development in the construction industry, great efforts have been made to utilize seawater as the alternative mixing water for concrete casting, which presents potential economical and environmental benefits in the coastal and island regions. This paper comprehensively reviews the current studies on the predominant performance differences between seawater-mixed and conventional concretes with freshwater. Particular attention is paid to the chloride-induced hydration mechanism due to the chloride ions in seawater. The main findings of this review reveal that although harmful ingredients in seawater may weaken some of the concrete performances, applying proper curing conditions and adding moderate additives and admixtures could significantly and effectively mitigate these defects in properties. However, the unstable chloride binding ability in cement hydrates cannot eliminate the risk of rebar corrosion caused by chlorides in seawater, resulting in a limited scope of practical application. Finally, some trade-offs are recommended in using seawater in concrete, suggesting prospects of applications in the future construction industry. This study guides for the safer use of seawater in sustainable concrete through reviewing the advanced research progress.
Li, Q, Tian, Y, Wu, D, Gao, W, Yu, Y, Chen, X & Yang, C 2021, 'The nonlinear dynamic buckling behaviour of imperfect solar cells subjected to impact load', Thin-Walled Structures, vol. 169, pp. 108317-108317.
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Solar cells are becoming a strong competitor in the new energy market due to their superior ability to generate electricity in an environmentally friendly and sustainable manner. The present study is devoted to presenting a theoretical framework for nonlinear dynamic buckling behaviours of imperfect multilayer solar cells subjected to impact loading resting on the elastic foundation. Two types of solar cell models, namely, organic solar cell (OSC) and perovskite solar cell (PSC), with simply supported and clamped boundary conditions are investigated. Sinusoidal, exponential, rectangular, and damping pulse functions are considered Based on the first-order shear deformation plate theory, the nonlinearity are introduced with the aid of von Kármán theory. The equations of the dynamic system of the plate with the consideration of large-deflection are derived by the Galerkin method and then solved by the fourth-order Runge–Kutta methods. After validation, some parametric experiments are performed to explore the influences of the pulse duration, pulse function pulse amplitude, initial imperfection, boundary conditions, Winkler–Pasternak elastic foundation coefficients, and damping ratios on the dynamic stability of the structures.
Li, W, Dong, W, Castel, A & Sheng, D 2021, 'Self-sensing cement-based sensors for structural health monitoring toward smart infrastructure', Journal and Proceedings of the Royal Society of New South Wales, vol. 154, pp. 24-32.
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Since its first appearance more than 100 years ago, concrete has had a significant impact on urban development — buildings, roads, bridges, ports, tunnels, railways and other structures. While traditional concrete is a structural material without any function, a new branch of concrete technology has produced smart (or intelligent) concrete, with superior self-sensing capabilities that can detect stress, strain, cracks and damage, and monitor temperature and humidity. With the incorporation of functional conductive fillers, traditional concrete can exhibit electrical conductivity with intrinsic piezoresistivity. This piezoresistivity means that the electrical resistivity of concrete is synchronously altered under applied load or environmental factors. The self-sensing electrical resistivity thus obtained can be an index or parameter to detect stress or strain changes in concrete, or cracks and damage to concrete. On the other hand, because of the relationship between electrical resistivity, temperature and humidity, self-sensing concrete can also monitor environmental factors. This smart self-sensing concrete can therefore be a promising alternative to conventional sensors for monitoring structural health and detecting traffic information from concrete roads, all of which are critical to achieving smart automation in concrete infrastructures.
Li, W, Luo, Z, Gan, Y, Wang, K & Shah, SP 2021, 'Nanoscratch on mechanical properties of interfacial transition zones (ITZs) in fly ash-based geopolymer composites', Composites Science and Technology, vol. 214, pp. 109001-109001.
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Interfacial transition zones (ITZs) of cementitious concrete are highly heterogeneous, which cause many challenges in accurately obtaining their properties. In this paper, regular aggregates were applied to prepare modelled geopolymer composites, in which ITZs exhibited neat boundaries. Nanoscratch technique with the ability to quickly scan a long distance was adopted to investigate mechanical properties of ITZ and geopolymer paste. To compare the properties of the ITZs and paste, abundant scratch data were analyzed in the form of histograms and Gaussian mixture models. The results showed that the ITZs in geopolymer with silica modulus of 1.5 presented similar properties with the paste, while the ITZs in geopolymer with silica modulus of 1.0 showed significantly higher scratch hardness but lower scratch friction coefficient than paste. Deconvolution analysis revealed that the abnormal hardness and friction coefficient of the paste in geopolymer with silica modulus of 1.0 could be caused by the defects related points. Compared with the traditional scratch scheme, the parallel scratch scheme based on modelled ITZ gave more stable results with a given number of test data, which can provide in-depth information for comparative studies.
Li, X, Guan, R, Ou, K, Fu, Q, Yang, G & Sun, Y 2021, 'Ultra-high stability and magnetic response of magnetorheological fluids based on magnetic ionic liquids and carbonyl iron fibers', Journal of Rheology, vol. 65, no. 6, pp. 1347-1359.
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Li, X, Kulandaivelu, J, Zhang, S, Shi, J, Sivakumar, M, Mueller, J, Luby, S, Ahmed, W, Coin, L & Jiang, G 2021, 'Data-driven estimation of COVID-19 community prevalence through wastewater-based epidemiology', Science of The Total Environment, vol. 789, pp. 147947-147947.
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Wastewater-based epidemiology (WBE) has been regarded as a potential tool for the prevalence estimation of coronavirus disease 2019 (COVID-19) in the community. However, the application of the conventional back-estimation approach is currently limited due to the methodological challenges and various uncertainties. This study systematically performed meta-analysis for WBE datasets and investigated the use of data-driven models for the COVID-19 community prevalence in lieu of the conventional WBE back-estimation approach. Three different data-driven models, i.e. multiple linear regression (MLR), artificial neural network (ANN), and adaptive neuro fuzzy inference system (ANFIS) were applied to the multi-national WBE dataset. To evaluate the robustness of these models, predictions for sixteen scenarios with partial inputs were compared against the actual prevalence reports from clinical testing. The performance of models was further validated using unseen data (data sets not included for establishing the model) from different stages of the COVID-19 outbreak. Generally, ANN and ANFIS models showed better accuracy and robustness over MLR models. Air and wastewater temperature played a critical role in the prevalence estimation by data-driven models, especially MLR models. With unseen datasets, ANN model reasonably estimated the prevalence of COVID-19 (cumulative cases) at the initial phase and forecasted the upcoming new cases in 2-4 days at the post-peak phase of the COVID-19 outbreak. This study provided essential information about the feasibility and accuracy of data-driven estimation of COVID-19 prevalence through the WBE approach.
Li, X, Li, M, Mei, Q, Niu, S, Wang, X, Xu, H, Dong, B, Dai, X & Zhou, JL 2021, 'Aging microplastics in wastewater pipeline networks and treatment processes: Physicochemical characteristics and Cd adsorption', Science of The Total Environment, vol. 797, pp. 148940-148940.
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Despite a wealth of information on removal of the microplastics (MPs) in wastewater treatment plants (WWTPs), little attention has been paid to how wastewater treatment process affect the MP physicochemical and adsorption characteristics. In this study, changes in physicochemical property of three MPs, i.e. polyamide (PA), polyethylene (PE) and polystyrene (PS) through the wastewater pipeline, grit and biological aeration tanks were investigated. The results show that compared with virgin MPs, the treated MPs have higher specific surface area and O content, and lower C and H contents, and glass transition temperature, implying that the three treatments cause the chain scission and oxidation of the MPs. Cd adsorption capacities of the MPs are higher than the corresponding virgin MPs after sulfidation in the pipeline (SWPN) and biological treatment in aeration tank (BTAT). Pearson correlation analysis shows that the increase is mainly resulted from the enhancement of the O-containing groups on the MPs. However, Cd adsorption capacities of the MPs decrease after mechanical abrasion in grit tank (MAGT), corresponding to the decrease in carbonyl index. Two dimensional FTIR correlation spectroscopy demonstrates that the NH bond in the PA plays a more important role than CH bond in the adsorption of Cd, but only change of the CH bond is found in the PE and PS. The findings provide new insights into the effect of WWTPs on the MP aging and physicochemical characteristics.
Li, X, Zhang, J, Shen, L, Qin, L, Fu, Q, Sun, Y & Liu, Y 2021, 'Magnetoresistive micro-displacement sensor based on magnetorheological fluid', Smart Materials and Structures, vol. 30, no. 4, pp. 045025-045025.
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Abstract A novel magnetoresistance material based on magnetorheological fluid (MRF) was developed for applications in micro-displacement sensor. The MRF samples were fabricated by dispersing carbonyl iron particles (CIP) into a magnetic ion liquid (MIL) composed of 1-methylethyl ether-3-butylimidazole cation and [Fe2Cl7]− anions. The magnetoresistance characteristics were also systematically tested. It was found that the resistance value of MRF with a CIP content of 20 vol% decreased from 125 to 24.4 KΩ when increasing the magnetic field from 0 to 0.2 T. A sensor device was developed to study the displacement sensing characteristics of MRF, and found that the sensor had a high sensitivity of 0.1 Ω μm−1 and a high resolution of 10.0 μm. The excellent performance can be attributed to the low modulus and good stability of the MIL matrix, allowing for easy change of the resistance by controlling the magnetic field or displacement. In summary, these unique characters make the present MRF a promising magnetoresistance material with potential applications in displacement sensor.
Li, X, Zhang, S, Shi, J, Luby, SP & Jiang, G 2021, 'Uncertainties in estimating SARS-CoV-2 prevalence by wastewater-based epidemiology', Chemical Engineering Journal, vol. 415, pp. 129039-129039.
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Wastewater-based epidemiology (WBE) is a promising approach for estimating population-wide COVID-19 prevalence through detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in wastewater. However, various methodological challenges associated with WBE would affect the accuracy of prevalence estimation. To date, the overall uncertainty of WBE and the impact of each step on the prevalence estimation are largely unknown. This study divided the WBE approach into five steps (i.e., virus shedding; in-sewer transportation; sampling and storage; analysis of SARS-CoV-2 RNA concentration in wastewater; back-estimation) and further summarized and quantified the uncertainties associated with each step through a systematic review. Although the shedding of SARS-CoV-2 RNA varied greatly between COVID-19 positive patients, with more than 10 infected persons in the catchment area, the uncertainty caused by the excretion rate became limited for the prevalence estimation. Using a high-frequency flow-proportional sampling and estimating the prevalence through actual water usage data significantly reduced the overall uncertainties to around 20-40% (relative standard deviation, RSD). And under such a scenario, the analytical uncertainty of SARS-CoV-2 RNA in wastewater was the dominant factor. This highlights the importance of using surrogate viruses as internal or external standards during the wastewater analysis, and the need for further improvement on analytical approaches to minimize the analytical uncertainty. This study supports the application of WBE as a complementary surveillance strategy for monitoring COVID-19 prevalence and provides methodological improvements and suggestions to enhance the reliability for future studies.
Li, Y, Huang, C, Ngo, HH, Yin, S, Dong, Z, Zhang, Y, Chen, Y, Lu, Y & Guo, W 2021, 'Analysis of event stratigraphy and hydrological reconstruction of low-frequency flooding: A case study on the Fenhe River, China', Journal of Hydrology, vol. 603, pp. 127083-127083.
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Li, Y, Wang, D, Yang, G, Yuan, X, Li, H, Wang, Q, Ni, B, He, D, Fu, Q, Jiang, L, Tang, W, Yang, F & Chen, H 2021, 'Comprehensive investigation into in-situ chemical oxidation of ferrous iron/sodium percarbonate (Fe(II)/SPC) processing dredged sediments for positive feedback of solid–liquid separation', Chemical Engineering Journal, vol. 425, pp. 130467-130467.
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Before disposal of dredged sediments (DS), filtrating DS is commonly used for their volume reduction. The work, for the first time, investigated Fe(II)/SPC processing DS to advance their solid–liquid separation from filtering feasibility, operational mechanism, technic reinforcement to potential implication. 16 mg Fe(II)/TSS & 60 mg SPC/TSS treatment elevated solid content of DS from 25.7% to 55.7% (vacuum filtration for 10 min), along with filtrate volume increased from 45.0 mL to 77.5 mL. •OH and Fe(III) with their hydrolyzed polymers, from Fe(II)/SPC system, are mainly lying behind the improved solid–liquid separation. Detailedly, the dilapidation of extracellular polymeric substances (EPS) with the destruction of biomolecules in EPS was completed by •OH invasion, which might rearrange the extracellular/intracellular protein configuration, with the increments of β-sheet & random coil but the decrement of α-helices. Simultaneously, Fe(III) and their hydrolyzed polymers promoted the relief of electrostatic repulsive-forces and the squeezing of double-electric layers, and the gathered DS could be held by integration of Fe(III) with –COOH and –OH. Additionally, CaO strengthened the filtering velocity/extent of Fe(II)/SPC-treated DS. After 70 mg/g CaO treatment, its solid content further elevated to 61.7% after vacuum filtration for 5.5 min, mainly resulting from skeleton construction by CaO, charge neutrality by released Ca2+, bridging cell debris and biopolymers by released Ca2+, compression of colloids double layers by released Ca2+, and binding PO43- in outer centrate liquid by released Ca2+.
Li, Y, Wang, D, Yang, G, Yuan, X, Yuan, L, Li, Z, Xu, Q, Liu, X, Yang, Q, Tang, W, Jiang, L, Li, H, Wang, Q & Ni, B 2021, 'In-depth research on percarbonate expediting zero-valent iron corrosion for conditioning anaerobically digested sludge', Journal of Hazardous Materials, vol. 419, pp. 126389-126389.
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Anaerobically digested sludge (ADS) is commonly hard to dewater for the presence of extracellular polymeric substances (EPS) and the liberation of glutinous soluble microbic products during anaerobic digestion. Sodium percarbonate (SPC) expediting zero-valent iron (ZVI) corrosion (SPC/ZVI) process firstly conditioned ADS to amend its dewaterability. Results showed that SPC/ZVI conditioning decreased moisture content of dewatered cake from 90.5% (control) to 69.9% with addition of 0.10 g/g TS SPC and 0.20 g/g TS ZVI. Mechanistic research indicated that the enhanced ADS dewaterability mainly resulted from •OH and Fe(III)/iron polymers yielded in SPC/ZVI. •OH disrupted EPS, damaged cytoderm & cytomembrane, and lysed intracellular substances, unbinding the bound water. Meanwhile, the breakage and inactivation of microbe by •OH prompted the production of macro-pores in ADS. •OH adjusted the conformation of extracellular/intracellular proteins by intervening in the H-bonds and S-S bonds, availing the hydrophobicity and slight flocculation of ADS. •OH further facilitated the despiralization of α-helical to β-sheet structure in ADS pellets, benefiting cell-to-cell aggregation. Additionally, Fe(III)/iron polymers from ZVI corrosion accelerated to gather ADS and maintained its floc structure. Consequently, SPC/ZVI conditioning not only adjusted the natures of ADS and its EPS but also the features of residual pellets, which further induced the advancement of ADS dewaterability. In addition, SPC/ZVI conditioning possibly surmounts some limitations existing in ZVI/Peroxide or ZVI/Persulfate technique.
Li, Y, Zeng, X, Zhou, J, Shi, Y, Umar, HA, Long, G & Xie, Y 2021, 'Development of an eco-friendly ultra-high performance concrete based on waste basalt powder for Sichuan-Tibet Railway', Journal of Cleaner Production, vol. 312, pp. 127775-127775.
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Generally, tunnel waste is stacked in the slag field nearby for landfilling, which is harmful to sustainable development. The broken rocks and rock powder among the tunnel waste can be recycled to produce machine-made sand, producing many by-products calling rock powder. Based on the practical project, three types of waste basalt powder (BP), from tunnel excavation waste and by-products (rock powder) of machine-made sand producing from tunnel excavation waste in Sichuan-Tibet railway construction sites, was used to prepare an eco-friendly UHPC. The BP is used to replace the cement and is included in the design UHPC based on Modified Andreasen &Andersen particle packing model (MAA). Moreover, the chemical and physical behaviors and ecological evaluation of the designed UHPC and UHPC pasted were discussed. The results showed that when BP (Specific surface area 4.6582 m2/g) replaces up to 15%, the highest compressive strength of designed UHPC (220 MPa) was obtained. Compared with quartz powder, the pozzolanic activity of BP was generally low and increased with the increase of reaction temperature. However, the presence of BP and its fineness in UHPC pastes increased the values of the total autogenous shrinkage and decreased the total heat release at an early age of designed UHPC pastes, this effect is more pronounced with temperature increasing. Based on a quartering method with embodied carbon dioxide emissions and the compressive strength, UHPC with waste BP reduced embodied carbon dioxide and possessed higher compressive strength and lower environmental impact than the control samples of UHPC.
Li, Z-X, Zhang, X, Shi, Y, Wu, C & Li, J 2021, 'Finite element modeling of FRP retrofitted RC column against blast loading', Composite Structures, vol. 263, pp. 113727-113727.
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Fiber-reinforced polymer (FRP) wrap could considerably improve the shear capacity and ductility of RC columns. FRP is therefore considered a potential material to strengthen the RC column against blast loading. Due to the high expense and safety concern of field blast tests, a very limited number of explosion tests on FRP retrofitted RC columns have been conducted, which hinders the understanding of the response of FRP retrofitted RC columns against blast loading. With advanced computational technology, it is convenient to develop a Finite Element (FE) model that can accurately capture the structural response of FRP retrofitted columns under blast loading. In this paper, a refined FE model was established to simulate the FRP retrofitted RC columns under blast loading. Strain rate effects on the concrete and steel reinforcing bar as well as the FRP composite of which the strain rate effect was commonly ignored, were all considered in the model. Comprehensive modifications were made to the Karagozian and Case concrete (KCC) model to accurately capture the mechanical properties of FRP-confined concrete. Finally, the FE model was validated with several available experimental tests. The developed FE model could capture the blast response of FRP retrofitted columns with good accuracy.
Li, Z-X, Zhang, X, Shi, Y, Wu, C & Li, J 2021, 'Predication of the residual axial load capacity of CFRP-strengthened RC column subjected to blast loading using artificial neural network', Engineering Structures, vol. 242, pp. 112519-112519.
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In this study, two genetic algorithm optimized backpropagation neural networks (GA-BPNN) were established to predict the ratio of residual axial load capacity to the maximum axial load capacity (referred to as RCI hereafter) of the non- and CFRP-strengthened RC columns based on a huge amount of simulation data. The first one can be used to predict the residual axial load capacity of the damaged non- and CFRP-strengthened RC columns induced by blast load with the input of several parameters including column dimensions, concrete strength, transverse reinforcement ratio, longitudinal reinforcement ratio, axial load ratio, CFRP stiffness, carbon fiber strength, peak pressure and impulse of the blast load. Therefore it can be used for the blast-resistant design of non- and CFRP-strengthened RC columns. The input variables of the second GA-BPNN were changed to be the ratio of residual mid-height deflection to the column height after the explosion, column dimensions, concrete strength, transverse reinforcement ratio, longitudinal reinforcement ratio, CFRP stiffness and carbon fiber strength. Since the input variables of the second GA-BPNN could be easily derived after the explosion, thus it could be used for the rapid damage assessment of RC columns. Damage assessments for three non- and CFRP-strengthened columns were also conducted using the first GA-BPNN.
Lim, JHK, Gan, YY, Ong, HC, Lau, BF, Chen, W-H, Chong, CT, Ling, TC & Klemeš, JJ 2021, 'Utilization of microalgae for bio-jet fuel production in the aviation sector: Challenges and perspective', Renewable and Sustainable Energy Reviews, vol. 149, pp. 111396-111396.
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Aviation sector discharges approximately 2% of the global anthropogenic CO2, and the proportion is growing. The search for cost-effective and environmental-friendly bio-jet fuels derived from natural resources is gaining momentum. The microalgae cultivation conditions including temperature, pH, light intensity and nutrients have shown significant influence on the microalgae growth rate and chemical composition, which create the opportunities to enhance the yield and quality of microalgae bio-jet fuel. This review is focused on the hydroprocessing method for converting microalgae oil into bio-jet fuel, as well as the novel conceptual approaches for bio-jet fuel production such as gasification with Fischer-Tropsch and sugar-to-jet. Fischer-Tropsch synthesis of biomass is one of the best alternative ways to replace natural aviation fuel due to the high maximum energy efficiency and low emission of greenhouse gas. In addition, hydroprocessing with the aid of Ni and zeolites catalysts has successfully converted the microalgae biodiesel to bio-jet fuel with high yield and alkane selectivity. Among these techniques, hydroprocessing used the lowest production cost with the longest duration, whereas the bio-jet fuel with high selectivity (C8–C16) could be produced by using gasification with the Fischer-Tropsch process. Consequently, gasification and Fischer-Tropsch and sugar-to-jet can become the future alternative process to convert microalgae to bio-jet fuel. The development of microalgae bio-jet fuel will increase the security of energy supply and reduce the fuel expenses in aviation industry.
Ling, Y, Wang, K, Wang, X & Li, W 2021, 'Prediction of engineering properties of fly ash-based geopolymer using artificial neural networks', Neural Computing and Applications, vol. 33, no. 1, pp. 85-105.
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© 2019, Springer-Verlag London Ltd., part of Springer Nature. Fly ash-based geopolymer has been studied extensively in recent years due to its comparable properties to Portland cement and its environmental benefits. However, the uncertainty and complexity of design parameters, such as the SiO2/Na2O mole ratio in alkaline solution, the alkaline solution concentration in liquid phase, and the liquid-to-fly ash mass ratio (L/F), have made it very difficult to create a systematic approach for geopolymer mix design. These mix design parameters, along with fly ash properties and curing conditions (temperature and time), significantly influence key properties of the material, such as setting time and compressive strength. In this study, an artificial neural network (ANN) was used to develop models for predicting the key properties of high-calcium fly ash-based geopolymer according to its mix design parameters. The correlations between experimental measurements and ANN model predictions of setting time, compressive strength, and heat of geopolymerization were established based on the results of tests on 36, 273, and 72 geopolymer mixes, respectively. The results show that the correlations between the experimental measurements and ANN model predictions of the properties studied are all strong. ANN modeling was found to be a suitable computing method to analyze the effects of design parameters on geopolymer properties and showed that L/F exhibited the greatest effect on setting time, alkaline solution concentration had the greatest influence on compressive strength, and a mole ratio larger than 1.5 significantly impacted heat at the geopolymerization peak. The developed ANN models can be used as guidance for mix design of high-calcium fly ash geopolymer in engineering applications.
Liu, C, Indraratna, B & Rujikiatkamjorn, C 2021, 'An analytical model for particle-geogrid aperture interaction', Geotextiles and Geomembranes, vol. 49, no. 1, pp. 41-44.
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© 2020 The shear strength of geogrid-reinforced ballast is often dependent on the aperture size of geogrids and the nominal size of ballast. This paper presents a theoretical analysis based on probabilistic mechanics of how aperture size affects the interaction between particles and geogrid. Unlike past literature, in this study, the properties of the particle size distribution is analysed using a Weibull distribution. The probability of grain interlock is proposed to describe the interactive mechanisms between particles and geogrids based on the relative particle size, which is defined as the ratio of particle size to aperture size. The mathematical model is calibrated by a set of large-scale direct shear tests with almost single-size (highly uniform) ballast aggregates, and then validated by independent set of data taken from both literature and current study. The study concludes that more uniform particle size distribution increases the probability of grain interlock at the optimum aperture size but decreases it at non-optimum aperture sizes.
Liu, F, Han, R, Naficy, S, Casillas, G, Sun, X & Huang, Z 2021, 'Few-Layered Boron Nitride Nanosheets for Strengthening Polyurethane Hydrogels', ACS Applied Nano Materials, vol. 4, no. 8, pp. 7988-7994.
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Two-dimensional hexagonal boron nitride nanosheets (BNNS) are an outstanding filler and additive, since they are transparent, thermally stable, and chemically inert. However, it is difficult to obtain few-layered BNNS with large lateral sizes in an efficient way due to the strong interlayer interactions in h-BN. Herein, a facile and efficient molten salt-assisted synthesis has been developed to prepare few-layered BNNS with a few microns in lateral size. Ammonia borane was mixed with KCl and NaCl and then heated to 1000 °C and held for 2 min, and the resultant powders were sonicated in water to produce hydroxylated BNNS. Used as an additive with 0.066 wt % loading, the functionalized BNNS can effectively improve the mechanical modulus of polyurethane (PU) hydrogels from 1635 to 2776 kPa, and the optical property of the hydrogel is not compromised. The BNNS-reinforced PU hydrogel with significantly improved mechanical properties can be highly useful in the application of printed electronics.
Liu, F, Han, R, Nattestad, A, Sun, X & Huang, Z 2021, 'Carbon- and oxygen-doped hexagonal boron nitride for degradation of organic pollutants', Surface Innovations, vol. 9, no. 4, pp. 222-230.
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Carbon- and oxygen-doped hexagonal boron nitrides (BCNOs) with good chemical stability and photoresponsiveness to visible light are found to be promising metal-free catalysts for degradation of Rhodamine B (RhB). By doping with heteroatoms of carbon and oxygen, insulating hexagonal boron nitride was transformed into semiconducting BCNO. The BCNO photocatalyst presents photodegradation performance towards RhB, with degradation rates up to 1.39 h−1 (0.05 wt% catalyst loading). The active species involved in the photoreaction were demonstrated to be superoxide anion radical (˙O2 −) and holes (h+), as opposed to ˙OH in the most studied titanium dioxide. The stability of BCNO in highly acidic environments was exploited for catalyst regeneration, as is necessary after long-term use and poisoning. This work demonstrates that BCNO is a promising low-cost and metal-free photocatalyst for environmental pollution remediation.
Liu, H, Li, X, Zhang, Z, Nghiem, LD, Gao, L & Wang, Q 2021, 'Semi-continuous anaerobic digestion of secondary sludge with free ammonia pretreatment: Focusing on volatile solids destruction, dewaterability, pathogen removal and its implications', Water Research, vol. 202, pp. 117481-117481.
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Our previous work has reported the pretreatment of secondary sludge with free ammonia (NH3, FA) enhanced the methane production in batch biochemical methane potential tests. However, the batch biochemical methane potential test could only provide conservative results compared to continuous/semi-continuous anaerobic digestion. Also, the impacts of FA pretreatment on the key anaerobic digestion parameters, including volatile solids (VS) destruction, sludge dewaterability and pathogen removal, are still unknown. This study for the first time investigated these impacts using semi-continuous anaerobic digestion systems for 130 days. Pretreatment of secondary sludge for 24 h at an FA concentration of 560 mg NH3-N/L improved VS destruction by 26.4% (from 22.0 to 27.8%), supported by a similar increase of 28.6% in methane production (from 126.7 to 162.9 ml CH4/g VSfed). Model based analysis revealed that FA pretreatment improved the sludge degradability extent, which may be the reason for the enhanced VS destruction. Equally importantly, the dewaterability of the digested sludge with FA pretreatment was also enhanced by 9.2% (from 12.0 to 13.1% in solids content of the dewatered digested sludge), which could be partly attributed to the increased zeta potential from -16.7 to -14.5 mV. Anaerobic digestion with FA pretreatment enhanced the removals of Fecal Coliform and E. Coli by 1.3 and 1.4 log MPN/g TS (MPN: Most Probable Number; TS: Total Solids), indicating FA pretreatment was effective in enhancing pathogen removal. With inorganic solids representing 21% of the sludge used, the volume of dewatered sludge to be disposed of was reduced by 14.5% via FA pretreatment. This will substantially decrease the cost as evaluated by economic analysis. In brief, this study provides a promising strategy to enhance sludge reduction in anaerobic digestion and is of great significance in promoting the application of FA pretreatment strategy in the real world.
Liu, H, Wang, Z, Nghiem, LD, Gao, L, Zamyadi, A, Zhang, Z, Sun, J & Wang, Q 2021, 'Solid-Embedded Microplastics from Sewage Sludge to Agricultural Soils: Detection, Occurrence, and Impacts', ACS ES&T Water, vol. 1, no. 6, pp. 1322-1333.
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Liu, J, Wu, C, Li, J, Liu, Z, Xu, S, Liu, K, Su, Y, Fang, J & Chen, G 2021, 'Projectile impact resistance of fibre-reinforced geopolymer-based ultra-high performance concrete (G-UHPC)', Construction and Building Materials, vol. 290, pp. 123189-123189.
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This paper describes the mix design of geopolymer-based ultra-high performance concrete (G-UHPC) with the compressive strength from 100 to 150 MPa. Projectile impact tests at two striking velocities of ~550 m/s and ~800 m/s were then performed to explore the impact resistance of G-UHPC targets. G-UHPC without the addition of fibres yielded better impact resistance than Ordinary Portland Cement (OPC) concrete regarding crater damage and crack propagation, but inferior performance on reducing depth of penetration (DOP). The addition of fibres in G-UHPC effectively helped reduced DOP, crater damage and crack propagation. Steel fibres with a length of 10 mm and a volumetric fraction of 2% were most effective in resisting projectile impact compared with other G-UHPC specimens. To further comprehend the projectile impact performance of G-UHPC, a calibrated Karagozian and Case Concrete (KCC) model accounting for the strain rate effect was successfully used for G-UHPC in projectile analysis. Numerical results including single element and full-scale quasi-static tests, deceleration-time histories of projectiles during penetration and DOP of G-UHPC targets were obtained to validate the numerical models. After that, trendlines were regressed to predict DOP of G-UHPC at two striking velocities of ~550 m/s and ~800 m/s. Perforation limits of G-UHPC were also proposed for the design of both safe and cost-effective protective structures against projectile impact, in which the perforation limits of G-UHPC were taken as 1.1 times of DOP.
Liu, J, Wu, C, Liu, Z, Li, J, Xu, S, Liu, K, Su, Y & Chen, G 2021, 'Investigations on the response of ceramic ball aggregated and steel fibre reinforced geopolymer-based ultra-high performance concrete (G-UHPC) to projectile penetration', Composite Structures, vol. 255, pp. 112983-112983.
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This paper presents experimental and numerical studies on projectile impact resistance of ceramic ball aggregated and steel fibre reinforced geopolymer-based ultra-high performance concrete (G-UHPC) targets. Compared with plain G-UHPC, ceramic ball aggregated G-UHPC enhanced projectile impact resistance regarding crack propagation, crater damage and depth of penetration (DOP). A further improvement of projectile impact resistance was observed if a combined addition of steel fibres and ceramic balls was used. Numerical simulations were then performed to further comprehend the projectile impact on G-UHPC targets using the HJC constitutive model in the finite element software LS-DYNA. Numerically simulated DOP, projectile velocity and displacement histories were obtained and then validated through comparing with the existing models. The numerical perforation limits for 20 vol-% ceramic ball aggregated and 1.5 vol-% steel fibre reinforced G-UHPC were 240 mm at 568 m/s and 380 mm at 798 m/s, respectively.
Liu, K, Wu, C, Li, X, Liu, J, Tao, M, Fang, J & Xu, S 2021, 'The influences of cooling regimes on fire resistance of ultra-high performance concrete under static-dynamic coupled loads', Journal of Building Engineering, vol. 44, pp. 103336-103336.
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Liu, M, Xie, K, Nothling, MD, Zu, L, Zhao, S, Harvie, DJE, Fu, Q, Webley, PA & Qiao, GG 2021, 'Ultrapermeable Composite Membranes Enhanced Via Doping with Amorphous MOF Nanosheets', ACS Central Science, vol. 7, no. 4, pp. 671-680.
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Thin-film composite (TFC) polymeric membranes have attracted increasing interest to meet the demands of industrial gas separation. However, the development of high-performance TFC membranes within their current configuration faces two key challenges: (i) the thickness-dependent gas permeability of polymeric materials (mainly poly(dimethylsiloxane) (PDMS)) and (ii) the geometric restriction effect due to the limited pore accessibility of the underlying porous substrate. Here we demonstrate that the incorporation of trace amounts (∼1.8 wt %) of amorphous metal-organic framework (MOF) nanosheets into the gutter layer of TFC assemblies can simultaneously address these two limitations by the creation of rapid, transmembrane gas diffusion pathways. The resultant PDMS&MOF membrane displayed excellent CO2 permeance of 10450 GPU and CO2/N2 selectivity of 9.1. Leveraging this strategy, we successfully fabricate a novel TFC membrane, consisting of a PDMS&MOF gutter and an ultrathin (∼54 nm) poly(ethylene glycol) top selective layer via surface-initiated atom transfer radical polymerization. The complete TFC membrane exhibits excellent processability and remarkable CO2/N2 separation performance (1990 GPU with a CO2/N2 ideal selectivity of 39). This study reveals a strategy for the design and fabrication of a new TFC membrane system with unprecedented gas-separation performance.
Liu, X, Chen, Z, Tian, K, Zhu, F, Hao, D, Cheng, D, Wei, W, Zhang, L & Ni, B-J 2021, 'Fe3+ Promoted the Photocatalytic Defluorination of Perfluorooctanoic Acid (PFOA) over In2O3', ACS ES&T Water, vol. 1, no. 11, pp. 2431-2439.
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Liu, X, Fu, Q, Liu, Z, Zeng, T, Du, M, He, D, Lu, Q, Ni, B-J & Wang, D 2021, 'Alkaline pre-fermentation for anaerobic digestion of polyacrylamide flocculated sludge: Simultaneously enhancing methane production and polyacrylamide degradation', Chemical Engineering Journal, vol. 425, pp. 131407-131407.
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The residual Polyacrylamide (PAM) in sewage sludge might cause severe disturbance in anaerobic digestion, and appropriate solutions to alleviate such situation are urgently required. In present study, alkaline pre-fermentation was proposed for PAM-flocculated sewage sludge (PFS) pretreatment, by which both PFS methane production and PAM degradation were remarkably enhanced. Under the optimal alkaline pre-fermentation condition (pH 10 for 12 d), the biochemical methane potential of PFS (12 g PAM/kg TS) increased from 107.2 to 246.6 mL/g VS, the hydrolysis rate increased from 0.109 to 0.197 d−1, and the degradation efficiency of PAM increased from 30.6% to 80.1%. Mechanism analysis indicated that the alkaline pre-fermentation broke the large “PAM-sludge” floccules, decreased the molecular weight of PAM, which alleviated the disturbance situation of PAM-present digester and made PAM more available for microbes to be biodegraded. Moreover, PFS hydrolysis and acidification were simultaneously accelerated by alkaline pre-fermentation, thereby providing more bioavailable carbon substrates for subsequent methane producing and PAM co-metabolism. Microbial community analysis demonstrated syntrophic bacteria such as Petrimonas and Sedimentibacter, which had ability to degrade an extensive range of various types of organics including carbohydrates and PAM, were enriched in alkaline pre-fermenter, and the acetotrophic methanogen Methanosaeta, were elevated in anaerobic digester. This work provides an effective microbial based strategy to improve the efficiency of anaerobic digestion of PFS.
Liu, X, Ren, Z, Ngo, HH, He, X, Desmond, P & Ding, A 2021, 'Membrane technology for rainwater treatment and reuse: A mini review', Water Cycle, vol. 2, pp. 51-63.
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Because of the current situation of global water shortage, finding strategies that can effectively guarantee water safety and sustainable use has become an urgent problem that needs to be solved at present. Rainwater is a type of clean energy and the method of the treatment and reuse of rainwater has become a pivotal problem that is worthy of consideration. Membrane technology has become the preferred method in the field of wastewater treatment due to its small footprint, good treatment effect, and low cost, and has also received increasing attention in rainwater treatment field. This review aims to retrospect the existing research technology of rainwater treatment with membrane technology and seek out the most critical research gaps to meet future research needs and technological exploration. The characteristics of different types of membrane technologies in rainwater treatment were summarized, the water quality after treatment and the feasibility in practical applications was analyzed. Membrane fouling has been identified as the main challenge. Nowadays, the research on membrane surface modification and membrane process optimization is gradually deepening, and the exploration and synthesis of new membrane materials and the process of treating rainwater with various technology combinations are still under research. The future application prospects are worth looking forward to.
Liu, X, Wu, Y, Xu, Q, Du, M, Wang, D, Yang, Q, Yang, G, Chen, H, Zeng, T, Liu, Y, Wang, Q & Ni, B-J 2021, 'Mechanistic insights into the effect of poly ferric sulfate on anaerobic digestion of waste activated sludge', Water Research, vol. 189, pp. 116645-116645.
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Poly ferric sulfate (PFS), one of the typical inorganic flocculants widely used in wastewater management and waste activated sludge (WAS) dewatering, could be accumulated in WAS and inevitably entered in anaerobic digestion system at high levels. However, knowledge about its impact on methane production is virtually absent. This study therefore aims to fill this gap and provide insights into the mechanisms involved through both batch and long-term tests using either real WAS or synthetic wastewaters as the digestion substrates. Experimental results showed that the maximum methane potential and production rate of WAS was respectively retarded by 39.0% and 66.4%, whereas the lag phase was extended by 237.0% at PFS of 40 g per kg of total solids. Mechanism explorations exhibited that PFS induced the physical enmeshment and disrupted the enzyme activity involved in anaerobic digestion, resulting in an inhibitory state of the bioprocess of hydrolysis, acidogenesis, and methanogenesis. Furthermore, PFS's inhibition to hydrogenotrophic methanogenesis was much severer than that to acetotrophic methanogenesis, which could be supported by the elevated abundances of Methanosaeta sp and the dropped abundances of Methanobacterium sp in PFS-present digester, and probably due to the severe mass transfer resistance of hydrogen between the syntrophic bacteria and methanogens, as well as the higher hydrogen appetency of PFS-induced sulfate reducing bacteria. Among the derivatives of PFS, 'multinucleate and multichain-hydroxyl polymers' and sulfate were unveiled to be the major contributors to the decreased methane potential, while the 'multinucleate and multichain-hydroxyl polymers' were identified to be the chief buster to the slowed methane-producing rate and the extended lag time.
Liu, X, Xu, B, Duan, X, Hao, Q, Wei, W, Wang, S & Ni, B-J 2021, 'Facile preparation of hydrophilic In2O3 nanospheres and rods with improved performances for photocatalytic degradation of PFOA', Environmental Science: Nano, vol. 8, no. 4, pp. 1010-1018.
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This study used metal–organic-framework (MOF) derived In2O3 for the photocatalytic degradation of PFOA for the first time. MOF derived In2O3 demonstrated significantly enhanced performance for PFOA decomposition compared to commercial In2O3.
Liu, Y, Ma, C, Zhang, X, Ngo, HH, Guo, W, Zhang, M & Zhang, D 2021, 'Role of structural characteristics of MoS2 nanosheets on Pb2＋ removal in aqueous solution', Environmental Technology & Innovation, vol. 22, pp. 101385-101385.
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In this study, ultrasonic-assisted liquid-phase stripping and hydrothermal synthesis were used to prepare the two structural types of MoS2 nanosheets, namely u-MoS2 and h-MoS2, respectively. The u-MoS2 and h-MoS2 were characterized by various techniques, and the profound relationship between the structure and preparation method was also identified. Results indicated that adsorptions of Pb2＋ onto both u-MoS2 and h-MoS2 nanosheets reached equilibrium after 30 min at higher rates. The removal efficiencies of Pb2＋ by h-MoS2 and u-MoS2 nanosheets were 98.4% and 20.6% under the condition of low dosage (60 mg/L). The Pb2＋ by h-MoS2 adsorption fitted well to the Langmuir adsorption isotherm with the adsorption capacity of 174.0 mg/g while the Pb2＋ adsorption by u-MoS2 fitted well to the Freundlich isotherm (n=1). The obvious discrepancy suggested that the adsorption performance was directly associated with their structural properties, which were induced by two different synthesis methods. Based on these results, the effects of operational parameters (pH, dosage and existing ions) on Pb2＋ adsorption using h-MoS2 were further investigated. The dosage greatly affected the adsorption capacity and removal efficiency, while pH and coexisting ions had small effects on adsorption performance. In short, this study could help to better understand the role of MoS2 nanosheets’ structures obtained by different preparation methods for adsorption of heavy metal ions in aqueous solution.
Liu, Z, Gao, Y, Yang, J, Xu, X, Fang, J & Xu, Y 2021, 'Effect of discretized transfer paths on abnormal vibration analysis and door structure improvement to reduce its vibration in the door slamming event', Applied Acoustics, vol. 183, pp. 108306-108306.
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Liu, Z, Gao, Y, Yang, J, Xu, X, Fang, J, Duan, Y & Ma, C 2021, 'Transfer path analysis and its application to diagnosis for low-frequency transient vibration in the automotive door slamming event', Measurement, vol. 183, pp. 109896-109896.
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Liu, Z, Liu, J, Pei, Q, Yu, H, Li, C & Wu, C 2021, 'Seismic response of tunnel near fault fracture zone under incident SV waves', Underground Space, vol. 6, no. 6, pp. 695-708.
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This study investigated the impact of a non-causative fault on the dynamic response of a nearby lined tunnel under the incidence of plane SV waves using the indirect boundary element method. The effects of several critical parameters, such as the incident frequency, the inclination degree of the fault, the distance between the fault and the tunnel on the hoop stress of the lined inner and outer walls, were explored intensively. The numerical results indicated that the non-causative fault could significantly change the hoop stress distribution of inner and outer surfaces of the tunnels. In general, for the vertically incident seismic waves, when the tunnel was located in the foot wall (under the fault), the hoop stress within the tunnel was significantly greater than that of the tunnels in the non-fault half space, with an amplification factor of up to 117%. The amplification effect became more pronounced as the fault dip angle increased. However, when the tunnel was located in the hanging wall (above the fault), the non-causative fault could produce a significant shielding effect on the dynamic response of the tunnel under high frequency wave incidence, with the reduction of hoop stress being up to 81%. For low-frequency waves, though, the fault could lead to an increase of the hoop stress of the tunnel of up to 152%. The research results will provide a reference for the seismic design and safety protection of underground structures in non-causative fault sites.
Liu, Z, Yang, M, Cheng, J, Wu, D & Tan, J 2021, 'Meta-model based stochastic isogeometric analysis of composite plates', International Journal of Mechanical Sciences, vol. 194, pp. 106194-106194.
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A stochastic isogeometric analysis approach (SIGA) is presented for functionally graded porous plates with graphene platelets reinforcement (FGP-GPLs). Different kinds of random fields and variables are applied to describe the uncertain system inputs which are including material properties of the FGP matrix and graphene platelets, magnitudes and directions of applied loads. A Nyström based Karhunen-Loève expansion is presented for random field discretization within the IGA scheme. The arbitrary polynomial chaos-Kriging (aPCK) method is presented for uncertainty quantification. To sustain the robustness of the aPCK approach for engineering problems involving high-dimension of uncertainty, a new Dagum kernel function is introduced in Kriging. The mean, standard deviation, probability density function (PDF) and cumulative distribution function (CDF) of structural outputs can be effectively estimated. Three illustrative examples are investigated to assess the performance of the proposed method for mathematical and engineering applications.
Lu, Z-H, Wu, S-Y, Tang, Z, Zhao, Y-G & Li, W 2021, 'Effect of chloride-induced corrosion on the bond behaviors between steel strands and concrete', Materials and Structures, vol. 54, no. 3.
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The corrosion of steel strands due to the chloride contamination is one of the most common causes for the degradation of prestressed concrete infrastructure. In this paper, an experimental study was performed to investigate the bond behaviors between steel strands and concrete after suffered the chloride corrosion. Total twenty central and off-center pull-out specimens with different corrosion levels were prepared and tested, in which the electrochemical acceleration method was employed to induce various corrosion levels. The effects of corrosion rate, stirrup configuration and holding condition of concrete to the steel strands on the bond behaviors of steel strands were studied and compared, in terms of the failure mode, bond-slip relationship, bond strength, and bond toughness. The results show that both the ultimate bond strength and characteristic bond strength decreased with the increase of corrosion degree. The presence of stirrups can significantly enhance the bond performance, indicating the more ductile failure characteristic and increased bond toughness. Moreover, the prediction results using empirical and analytical models are also compared with the experimental results to verify their applicability and accuracies in predicting the bond strength of steel strands after corrosion.
Luo, J, Zhou, C, Li, W, Chen, S, Habibnejad Korayem, A & Duan, W 2021, 'Using graphene oxide to improve physical property and control ASR expansion of cement mortar', Construction and Building Materials, vol. 307, pp. 125006-125006.
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Alkali-silica reaction (ASR) is a slowly occurring reaction in concrete between alkaline pore solution and reactive non-crystalline silica in aggregates, which is a challenge to physical property and durability of concrete. The oxygen-containing functional groups coupled with large surface area of graphene oxide (GO) nanomaterial renders highly reactive interaction with cement-based composite. Here, the physical properties and ASR expansion test of cement mortars modified with varied loadings of GO (wGO) or/and Pyrex glass (GOPM) were implemented after optimizing GO dispersion efficiency in water. The water absorption and microstructures of GOPM were observed to figure out the mechanism of GO's effect on mechanical strength, permeability, and ASR expansion of GOPM. Results show, 15 kJ is the optimal sonication energy for the dispersion of 300 mL pristine GO-water suspension with 0.04% wGO; the effect of GO on improving the flexural and compressive strength of GOPM is remarkable, the maximal amplitude is up to 24.16%, 43.03% compared with the baseline, respectively; GO has great influence on long-term anti-permeability and controlling expansion, the nano-nucleation and interlocking effect of GO render the expansion rate of GOPM be well below 0.1% threshold.
Luo, Z, Li, W, Gan, Y, He, X, Castel, A & Sheng, D 2021, 'Nanoindentation on micromechanical properties and microstructure of geopolymer with nano-SiO2 and nano-TiO2', Cement and Concrete Composites, vol. 117, pp. 103883-103883.
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Fly ash-based geopolymers incorporated with 2% nano-SiO2 (NS)/nano-TiO2 (NT) particles were subjected to microstructural and statistical nanoindentation analysis. With the addition of both types of nanoparticles, the compressive strength of geopolymer and the micromechanical properties of N-A-S-H gel were increased. NS exhibited higher reinforcement effect than NT on macro-strength. However, NT more significantly enhanced gel micromechanical properties. NT and especially the NS were found to have a positive effect on the early reaction rate of geopolymer. After 28 days, the gel proportion obtained by Backscattered electron (BSE) images analysis was close values of 49.16%, 55.69% and 54.02% for reference sample and NS, NT reinforced geopolymer, which were more than two times of that from the statistical nanoindentation. The effects of NS and NT on microstructure, gel proportion and gel micromechanical properties were discussed to reveal the macro-strength reinforcement mechanism. The results obtained from different techniques were also compared and discussed.
Luo, Z, Li, W, Li, P, Wang, K & Shah, SP 2021, 'Investigation on effect of nanosilica dispersion on the properties and microstructures of fly ash-based geopolymer composite', Construction and Building Materials, vol. 282, pp. 122690-122690.
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Nanosilica-geopolymer composites with different dispersion levels of nanoparticles were investigated on the physical properties and gel properties. The results indicated that compared with the nanosilica-geopolymer composites without ultrasonic dispersion, the 20 and 120 min of sonication brought 3.88% and 13.59% of additional strength enhancement, respectively. For the micromechanical properties of N-A-S-H gel, the better dispersed samples exhibited higher elastic modulus. In comparison to the reference sample, the elastic modulus was increased by 15.18% and 29.93% respectively for samples with 20 and 120 min of sonication. The better dispersed nanoparticles exhibited smaller sizes and increased the physical filling effect which could result in densified microstructures, better bonding behaviors and the both improved micro and macro mechanical properties.
Luo, Z, Li, W, Wang, K, Castel, A & Shah, SP 2021, 'Comparison on the properties of ITZs in fly ash-based geopolymer and Portland cement concretes with equivalent flowability', Cement and Concrete Research, vol. 143, pp. 106392-106392.
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This paper aims to compare the properties of interfacial transition zones (ITZs) in Portland cement (PC) concrete and geopolymer concrete. Portland cement and geopolymer pastes were designed with the equivalent flowability to provide similar mix and casting condition of ITZs. Two types of modelled ITZs were prepared to facilitate the nanoindentations across ITZs, microstructural characterization, and comparison on the properties of ITZs with less influential factors. The results showed that the interfacial bonding of ITZs between geopolymer matrix and aggregate is relatively stronger than the counterpart in the PC concrete. There is a high amount of crystalline hydration products in the ITZs of PC concrete, but a layer gel-rich paste with denser microstructures in the ITZs of geopolymer concrete. Additionally, the interface morphology and nanoindentation analysis indicate that the property of ITZs in the modelled geopolymer concrete is not poorer than that of the corresponding geopolymer paste.
Ma, C, Zhang, J, Wang, J, Yang, N, Liu, Q, Zuo, S, Wu, X, Wang, P, Li, J & Fang, J 2021, 'Analytical Model of Open-Circuit Air-Gap Field Distribution in Interior Permanent Magnet Machines Based on Magnetic Equivalent Circuit Method and Boundary Conditions of Macroscopic Equations', IEEE Transactions on Magnetics, vol. 57, no. 3, pp. 1-9.
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To accurately and quickly predict the open-circuit air-gap magnetic field in interior permanent magnet synchronous machines (IPMSMs), an analytical model based on magnetic equivalent circuit (MEC) method is proposed. The analytical model can provide radial and tangential components of open-circuit magnetic field in the slotless air gap. The radial component is obtained from the MEC model, and the tangential component is obtained from boundary conditions of macroscopic equations. Then, a complex relative air-gap permeance is applied to take the effect of slots into account. As a result, an accurate solution of both radial and tangential components of the flux density in the slotted air gap is obtained. Additionally, the no-load back electromotive force (EMF) and cogging torque are calculated based on the open-circuit air-gap magnetic field. All the analytical results are verified by the finite element (FE) analysis and they are well matched. In the end, a direct measurement experiment of open-circuit air-gap magnetic field is proposed to verify the validity of both radial and tangential open-circuit air-gap magnetic fields.
Ma, M, Liu, Y, Wei, Y, Hao, D, Wei, W & Ni, B-J 2021, 'A facile oxygen vacancy and bandgap control of Bi(OH)SO4·H2O for achieving enhanced photocatalytic remediation', Journal of Environmental Management, vol. 294, pp. 113046-113046.
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The development of highly efficient photocatalysts is crucial for the remediation of organic pollutants. Herein, we reported a facile synthesis of oxygen vacancy rich Bi(OH)SO4·H2O photocatalyst by the control of precursor. The samples were characterized by XRD, scanning electron microscope, electron paramagnetic resonance, X-ray photoelectron spectroscopy etc. With more oxygen vacancies introduced, the photocatalytic activity on the degradation of RhB and tetracycline was significantly boosted. Density functional theory calculation was used to further reveal the influence of oxygen vacancy on the band structure of Bi(OH)SO4·H2O. The results and finding of this work are helpful for the development of sustainable environmental protection.
Mahlia, TMI & Fattah, IMR 2021, 'Energy for Sustainable Future', Energies, vol. 14, no. 23, pp. 7962-7962.
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Energy and the environment are interrelated, and they are critical factors that influence the development of societies [...]
Mahmood, AH, Babaee, M, Foster, SJ & Castel, A 2021, 'Continuous Monitoring of the Early-Age Properties of Activated GGBFS with Alkaline Solutions of Different Concentrations', Journal of Materials in Civil Engineering, vol. 33, no. 12.
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Mahmood, AH, Foster, SJ & Castel, A 2021, 'Effects of mixing duration on engineering properties of geopolymer concrete', Construction and Building Materials, vol. 303, pp. 124449-124449.
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Mahmudul, HM, Rasul, MG, Akbar, D, Narayanan, R & Mofijur, M 2021, 'A comprehensive review of the recent development and challenges of a solar-assisted biodigester system', Science of The Total Environment, vol. 753, pp. 141920-141920.
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The extensive use of fossil fuels and the environmental effect of their combustion products have attracted researchers to look into renewable energy sources. In addition, global mass production of waste has motivated communities to recycle and reuse the waste in a sustainable way to lower landfill waste and associated problems. The development of waste to energy (WtE) technology including the production of bioenergy, e.g. biogas produced from various waste through Anaerobic Digestion (AD), is considered one of the potential measures to achieve the sustainable development goals of the United Nations (UN). Therefore, this study reviews the most recent studies from relevant academic literature on WtE technology (particularly AD technology) for biogas production and the application of a solar-assisted biodigester (SAB) system aimed at improving performance. In addition, socio-economic factors, challenges, and perspectives have been reported. From the analysis of different technologies, further work on effective low-cost technologies is recommended, especially using SAB system upgrading and leveraging the opportunities of this system. The study found that the performance of the AD system is affected by a variety of factors and that different approaches can be applied to improve performance. It has also been found that solar energy systems efficiently raise the biogas digester temperature and through this, they maximize the biogas yield under optimum conditions. The study revealed that the solar-assisted AD system produces less pollution and improves performance compared to the conventional AD system.
Maina, JW, Merenda, A, Weber, M, Pringle, JM, Bechelany, M, Hyde, L & Dumée, LF 2021, 'Atomic layer deposition of transition metal films and nanostructures for electronic and catalytic applications', Critical Reviews in Solid State and Materials Sciences, vol. 46, no. 5, pp. 468-489.
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Atomic layer deposition (ALD) has emerged as the technique of choice in the microelectronics industry, owing to its self-limiting nature, that allows conformal film deposition in highly confined spaces. However, while the ALD of metal oxide has developed dramatically over the past decade, ALD of pure metal, particularly the transition metals has been developing at a very slow pace. This article reviews the latest development in the ALD of pure transition metals and alloys, for electronic and catalytic applications. In particular, the article analyzes how different factors, such as the substrate properties, deposition conditions, precursor and co-reactant properties, influence the deposition of the metal films and nanostructures, as well as the emerging applications of the ALD derived transition metal nanostructures. The challenges facing the field are highlighted, and suggestions are made for future research directions.
Mallick, SK, Das, P, Maity, B, Rudra, S, Pramanik, M, Pradhan, B & Sahana, M 2021, 'Understanding future urban growth, urban resilience and sustainable development of small cities using prediction-adaptation-resilience (PAR) approach', Sustainable Cities and Society, vol. 74, pp. 103196-103196.
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Rapid urban proliferation is an indispensable and reciprocal issue in contemporary urban planning and development. This study envisages the prediction-adaptation-resilience (PAR) approach to analyze the future urban landscape resilience and sustainable development goals (SDGs). We have selected a small, unplanned growing up city, namely, Krishnanagar urban agglomeration (KUA), in India, to apply the PAR approach. Therefore, land use land cover map has been prepared for 2000, 2010, and 2020. The result shows the built-up area has been increased most in past 20 years, from 6.36 km2 to 13.23 km2. Then, the cellular automata-Markov chain model is applied to predict the future potential urban development surface for 2030 and 2040. The receiver operating characteristic (ROC) curve shows 83.6% success rate between the predicted and actual map of CA-Markov. The prediction map of 2030 and 2040 shows that the built-up area continuously expands (13.23 km2 to 16.52 km2) towards KUA's surrounding regions. Consequently, other decreasing land classes will be a threat to SDGs and urban resilience. So, people of KUA are adopting the changing hostile nature of urbanisation and urban vulnerability. Hence, this study will help the local administration to make a proper urban planning and adaptation strategies by maintaining good urban governance to achieve 8 SDGs of UN's 2030 Agenda in future.
Mannina, G, Alliet, M, Brepols, C, Comas, J, Harmand, J, Heran, M, Kalboussi, N, Makinia, J, Robles, Á, Rebouças, TF, Ni, B-J, Rodriguez-Roda, I, Victoria Ruano, M, Bertanza, G & Smets, I 2021, 'Integrated membrane bioreactors modelling: A review on new comprehensive modelling framework', Bioresource Technology, vol. 329, pp. 124828-124828.
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Integrated Membrane Bioreactor (MBR) models, combination of biological and physical models, have been representing powerful tools for the accomplishment of high environmental sustainability. This paper, produced by the International Water Association (IWA) Task Group on Membrane Modelling and Control, reviews the state-of-the-art, identifying gaps for future researches, and proposes a new integrated MBR modelling framework. In particular, the framework aims to guide researchers and managers in pursuing good performances of MBRs in terms of effluent quality, operating costs (such as membrane fouling, energy consumption due to aeration) and mitigation of greenhouse gas emissions.
Marks, NA, Stewart, MG, Netherton, MD & Stirling, CG 2021, 'Airblast variability and fatality risks from a VBIED in a complex urban environment', Reliability Engineering & System Safety, vol. 209, pp. 107459-107459.
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Explosive blasts and prediction of fatality risks in urban environments is a complicated task due to the variability in blast wave reflection and propagation. The terrorist threats considered in this paper are vehicle-borne improvised explosive devices (VBIED) containing 225 kg or 450 kg of TNT or ammonium nitrate fuel oil (ANFO) detonated in an open street. This paper uses Viper::Blast CFD software to estimate the variability of explosive blast loads using Monte-Carlo sampling. To probabilistically model the blast wave, the paper takes into consideration the variability of explosive charge mass, detonation location, height of detonation, net equivalent quantity, atmospheric pressure and temperature, and model errors. The fatality risk assessment combines lung-rupture, whole-body displacement and skull fracture dependant on the pressure and impulse. It was found that the mean fatality risk for a 450 kg home-made ANFO explosive device detonated at a road T-intersection is 16% for people exposed in the street. If bollards were placed 10 m from the main street then fatality risk for people in the main street is reduced by over 90%. It was found that a deterministic analysis yielded fatality risks 10–60% higher than a probabilistic analysis, leading to an overly conservative assessment of safety risks.
Mayya, V, Kamath Shevgoor, S, Kulkarni, U, Hazarika, M, Barua, PD & Acharya, UR 2021, 'Multi-Scale Convolutional Neural Network for Accurate Corneal Segmentation in Early Detection of Fungal Keratitis', Journal of Fungi, vol. 7, no. 10, pp. 850-850.
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Microbial keratitis is an infection of the cornea of the eye that is commonly caused by prolonged contact lens wear, corneal trauma, pre-existing systemic disorders and other ocular surface disorders. It can result in severe visual impairment if improperly managed. According to the latest World Vision Report, at least 4.2 million people worldwide suffer from corneal opacities caused by infectious agents such as fungi, bacteria, protozoa and viruses. In patients with fungal keratitis (FK), often overt symptoms are not evident, until an advanced stage. Furthermore, it has been reported that clear discrimination between bacterial keratitis and FK is a challenging process even for trained corneal experts and is often misdiagnosed in more than 30% of the cases. However, if diagnosed early, vision impairment can be prevented through early cost-effective interventions. In this work, we propose a multi-scale convolutional neural network (MS-CNN) for accurate segmentation of the corneal region to enable early FK diagnosis. The proposed approach consists of a deep neural pipeline for corneal region segmentation followed by a ResNeXt model to differentiate between FK and non-FK classes. The model trained on the segmented images in the region of interest, achieved a diagnostic accuracy of 88.96%. The features learnt by the model emphasize that it can correctly identify dominant corneal lesions for detecting FK.
Mazaheri, H, Ong, HC, Amini, Z, Masjuki, HH, Mofijur, M, Su, CH, Anjum Badruddin, I & Khan, TMY 2021, 'An Overview of Biodiesel Production via Calcium Oxide Based Catalysts: Current State and Perspective', Energies, vol. 14, no. 13, pp. 3950-3950.
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Biodiesel is a clean, renewable, liquid fuel that can be used in existing diesel engines without modification as pure or blend. Transesterification (the primary process for biodiesel generation) via heterogeneous catalysis using low-cost waste feedstocks for catalyst synthesis improves the economics of biodiesel production. Heterogeneous catalysts are preferred for the industrial generation of biodiesel due to their robustness and low costs due to the easy separation and relatively higher reusability. Calcium oxides found in abundance in nature, e.g., in seashells and eggshells, are promising candidates for the synthesis of heterogeneous catalysts. However, process improvements are required to design productive calcium oxide-based catalysts at an industrial scale. The current work presents an overview of the biodiesel production advancements using calcium oxide-based catalysts (e.g., pure, supported, and mixed with metal oxides). The review discusses different factors involved in the synthesis of calcium oxide-based catalysts, and the effect of reaction parameters on the biodiesel yield of calcium oxide-based catalysis are studied. Further, the common reactor designs used for the heterogeneous catalysis using calcium oxide-based catalysts are explained. Moreover, the catalytic activity mechanism, challenges and prospects of the application of calcium oxide-based catalysts in biodiesel generation are discussed. The study of calcium oxide-based catalyst should continue to be evaluated for the potential of their application in the commercial sector as they remain the pivotal goal of these studies.
Mazlan, M, Najafi, G, Hoseini, SS, Mamat, R, Alenzi, RA, Mofijur, M & Yusaf, T 2021, 'Thermal efficiency analysis of a nanofluid-based micro combined heat and power system using CNG and biogas', Energy, vol. 231, pp. 120870-120870.
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In the present study, a micro combined heat and power (micro-CHP) system using compressed natural gas (CNG) and biogas fuels, was developed. The objective of this research study was to investigate the utilization of nanofluids as a working fluid to improve thermal performance of the micro-CHP system. Three different nanofluids based on the CNT, Al2O3, and SiO2 have been investigated. The nanofluids was used as the circulating fluid to recover the heating power from the micro-CHP system. Three different concentration of nanoparticles (25, 50 and 100 ppm) have been used. The efficiency of separated heat and power (SHP) system was 27.6% while using combined heat and power, the total efficiency increased up to 65.3%. The results showed that by using CNG gas thermal efficiency of micro-CHP improve compared to the biogas. The result of the present study showed that nanofluids enhances the thermal efficiency of the micro-CHP system. By using the Al2O3 nanofluid the efficiency of micro-CHP efficiency is 73%. While by using the SiO2 and CNTs nanofluids the efficiency of micro-CHP efficiency is 70% and 66.3% respectively. So, we can coclude that by using the Al2O3 nanofluid thermal performance of micro-CHP systems improves.
Mazlan, M, Rahmani-dehnavi, M, Najafi, G, Ghobadian, B, Hoseini, SS, Fayyazi, E, Mamat, R, Alenezi, RA & Mofijur, M 2021, 'Thermal efficiency analysis of the phase change material (PCM) microcapsules', Sustainable Energy Technologies and Assessments, vol. 48, pp. 101557-101557.
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The aim of the present study is to evaluate the thermal behavior of cylindrical modules in a thermal energy storage unit as a combined sensible and latent heat. A thermal energy storage unit is designed, fabricated, and connected to a cold and hot water supply at constant temperatures to monitor the performance of the storage unit. The thermal energy storage unit contains the cylindrical microcapsules containing paraffin waxes as a phase change material which is located inside an insulating cylinder storage tank. Water is used as a heat transfer fluid to transfer heat from a hot water reservoir to the thermal energy storage unit during the phase change material charging process and also during the discharging process water receives heat from the thermal energy storage unit. Charge tests are carried out at the constant temperature. Moreover, the effect of different inlet flow on storage unit performance is investigated. Data were analyzed using Design Expert software and regression analysis which indicated that the increase of charge inlet temperature and charge inlet flow leads to the increase of heat power, thermal performance of thermal energy storage unit, and output variables. In comparison to the heat storage system without phase change material, microcapsules phase change material can improve the heat power of the heat storage system. Also, based on the optimization process, the maximum thermal performance of 96.4% and the maximum heat power level of 1.7 kW can be achieved in the optimized condition of the charging inlet temperature of 75 °C, charging inlet flow of 1.8−4 m3/s, and discharging inlet temperature of 35 °C.
Mehrabi, P, Shariati, M, Kabirifar, K, Jarrah, M, Rasekh, H, Trung, NT, Shariati, A & Jahandari, S 2021, 'Effect of pumice powder and nano-clay on the strength and permeability of fiber-reinforced pervious concrete incorporating recycled concrete aggregate', Construction and Building Materials, vol. 287, pp. 122652-122652.
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Mei, C, Zhang, Y, Wang, D, Wu, C & Xu, Y 2021, 'Parameter optimal investigation of modular prefabricated two-side connected buckling-restrained steel plate shear wall', Structures, vol. 29, pp. 2028-2043.
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This paper research the optimal scope of width-to-thickness ratio α1 of connection steel plate (CSP), thickness ratio α2 between CSP and inner steel plates (ISP), and width-to-thickness ratio α3 between the width of CSP and the thickness of the ISP of modular fabricated two-side connected buckling-restrained steel plate (MTBSP) shear wall. The finite element model (FEM) of the MTBSP shear wall is established based on the ABAQUS platform, which, considering the plastic-damage constitutive model of both concrete and steel materials. Through the result of a comparison between the test and FEM, it can be concluded that the FEM can effectively reflect the mechanical behavior of the MTBSP shear wall. Based on the verified FEM, the mechanical behavior of 93 computational cases with different ratios of α1, α2, and α3 of MTBSP shear wall is investigated and the corresponding optimal scope of α1, α2, and α3 are explored in detail. The results show that the mechanical performance of the MTBSP shear wall can be ensured effectively when the ratio α1, α2, and α3 is in the scope from 10 to 20, from 3 to 5, and from 60 to 80, respectively. Research of this study can be provided supporting the reliable design of the MTBSP shear wall.
Mei, C, Zhao, Z, Zhang, Y, Wang, D & Wu, C 2021, 'Performance Evaluation and Shear Resistance of Modular Prefabricated Two-Side Connected Composite Shear Walls', KSCE Journal of Civil Engineering, vol. 25, no. 8, pp. 2936-2950.
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This paper investigates the impact of configuration parameters on the seismic performance of the modular prefabricated two-side connected composite shear wall. Firstly, the finite element model of the modular prefabricated two-side connected composite shear wall was established and validated by Xu’s experimental results. Secondly, three aspects of parameter investigations were discussed in detail based on the validated numerical technology, namely the design parameter of ISP, design parameter of the stud, and design parameter of reinforced concrete faceplate (RCF). Then, the computation formula of shear capacity is deduced on the basis of the finite element model for reference to structural design. The results of parameter analysis displayed that the seismic performance of the modular prefabricated two-side connected composite shear wall has excellent seismic performance with the array studs of the length-diameter ratio of 4 which the center distance of 150 mm, and RCF with the thickness of 75 mm. A satisfactory but unadventurous estimation of the shear capacity of a modular prefabricated two-side connected composite shear wall is supplied by the advised technique.
Meilianda, E, Lavigne, F, Pradhan, B, Wassmer, P, Darusman, D & Dohmen-Janssen, M 2021, 'Barrier Islands Resilience to Extreme Events: Do Earthquake and Tsunami Play a Role?', Water, vol. 13, no. 2, pp. 178-178.
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Barrier islands are indicators of coastal resilience. Previous studies have proven that barrier islands are surprisingly resilient to extreme storm events. At present, little is known about barrier systems’ resilience to seismic events triggering tsunamis, co-seismic subsidence, and liquefaction. The objective of this study is, therefore, to investigate the morphological resilience of the barrier islands in responding to those secondary effects of seismic activity of the Sumatra–Andaman subduction zone and the Great Sumatran Fault system. Spatial analysis in Geographical Information Systems (GIS) was utilized to detect shoreline changes from the multi-source datasets of centennial time scale, including old topographic maps and satellite images from 1898 until 2017. Additionally, the earthquake and tsunami records and established conceptual models of storm effects to barrier systems, are corroborated to support possible forcing factors analysis. Two selected coastal sections possess different geomorphic settings are investigated: (1) Lambadeuk, the coast overlying the Sumatran Fault system, (2) Kuala Gigieng, located in between two segments of the Sumatran Fault System. Seven consecutive pairs of comparable old topographic maps and satellite images reveal remarkable morphological changes in the form of breaching, landward migrating, sinking, and complete disappearing in different periods of observation. While semi-protected embayed Lambadeuk is not resilient to repeated co-seismic land subsidence, the wave-dominated Kuala Gigieng coast is not resilient to the combination of tsunami and liquefaction events. The mega-tsunami triggered by the 2004 earthquake led to irreversible changes in the barrier islands on both coasts.
Meng, Q, Wu, C, Li, J, Wu, P, Xu, S & Wang, Z 2021, 'A study of pressure characteristics of methane explosion in a 20 m buried tunnel and influence on structural behaviour of concrete elements', Engineering Failure Analysis, vol. 122, pp. 105273-105273.
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With increasing use of natural gas in urban metropolitan areas, utility tunnels that contain utility and gas lines have become critical infrastructure. A leak within a gas pipe may cause methane-air explosions in the tunnel, leading to structural damage and casualties. Thus, it is necessary to investigate the response of structural members against explosion loads in the tunnel. Few studies in the open literature have studied the effects of a methane-air explosion in a full-scale concrete tunnel. This study presents two 9.5% methane-air explosions in a tunnel with a dimension of 20000 mm × 1800 mm × 600 mm. The pressure characteristics are summarized and compared with existing pressure–time curve of the methane-air explosion in typical vented containers. Similarities of pressure characteristics between the current study and previous studies avaliable from the literature are identified. Apart from explosion pressure characteristics, concrete structural specimens with a dimension of 1800 mm × 400 mm × 90 mm are also investigated. Geopolymer concrete, ultra high performance concrete (UHPC) and conventional concrete with compressive strength of approximately 70 MPa, 150 MPa and 30 MPa, respectively, were used to manufacture the testing specimens subjected to the methane-air explosions in the tunnel. In this study, the cracks were observed on all specimens. Due to large size of the tunnel and gas leakage during blast, the pressure distribution in the tunnel is not as uniform as observed in methane-air explosion chamber from the previous literatures. The conventional concrete specimen positioned between two pressure sensors is selected to validate the numerical model in the present study. The calibrated numerical model is then used to study the structural responses of concrete specimen subjected to the captured pressure.
Meng, Q, Zhang, X, Hao, H, James, I & Beel, M 2021, 'An investigation of impact resistance capacity of polypropylene (PP) added plasterboard subjected to soft-body impact', Composite Structures, vol. 275, pp. 114370-114370.
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Plasterboard is one of the most-commonly used construction materials because of its low cost and easy installation characteristics. Although the low strength and fragility make plasterboard functioned as non-load-bearing components. Plasterboard walls are always required to satisfy impact resistance against impact from accidental body strike, hard-body impact from wheelchair, etc. during its usage. This study investigates the impact resistance capacity of plasterboards being subjected to soft-body impact load. Laboratory sandbag impact tests are conducted to examine the responses of plasterboard and PP fibre strengthened plasterboard system at different velocities. Detailed numerical models of plasterboards are also generated to assist the analysis. Different damage and failure modes are observed on the plasterboards when subjected to impactor strike at different velocities. It is found that the coupled deformation of plasterboard and sandbag leads to different impact load time histories from sandbag soft impact, which results in the different failure modes. The PP fibre strengthened board exhibits better impact resistance than conventional plasterboard. Parametric study is then conducted to quantify the peak central deflections under different strength and thickness variances on plasterboard. An empirical formula is then derived based on the parametric results for preliminary assessment of the plasterboard impact resistance capacity.
Merenda, A & Dumée, LF 2021, 'Virus remediation in water engineering: Are our current technologies up to the challenge?', Journal of Water Process Engineering, vol. 44, pp. 102370-102370.
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Merenda, A, Bortolassi, ACC, Rodriguez-Andres, J, Al-Attabi, R, Schütz, JA, Kujawski, W, Shon, HK & Dumée, LF 2021, 'Hybrid polymer/ionic liquid electrospun membranes with tunable surface charge for virus capture in aqueous environments', Journal of Water Process Engineering, vol. 43, pp. 102278-102278.
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Mirzaei, S, Vafakhah, M, Pradhan, B & Alavi, SJ 2021, 'Flood susceptibility assessment using extreme gradient boosting (EGB), Iran', Earth Science Informatics, vol. 14, no. 1, pp. 51-67.
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Flood occurs as a result of high intensity and long-term rainfalls accompanied by snowmelt which flow out of the main river channel onto the flood prone areas and damage the buildings, roads, and facilities and cause life losses. This study aims to implement extreme gradient boosting (EGB) method for the first time in flood susceptibility modelling and compare its performance with three advanced benchmark models including Frequency Ratio (FR), Random Forest (RF), and Generalized Additive Model (GAM). Flood susceptibility map is an efficient tool to make decision for flood control. To do this, the altitude, slope degree, profile curvature, topographic wetness index (TWI), distance from rivers, normalized difference vegetation index, plan curvature, rainfall, land use, stream power index, and lithology were fed to the models. To run the models, 243 flood locations were detected by field surveys and national reports. The same number of locations were randomly created in the study regions and considered as non-flood locations. The flood and non-flood locations were split in 70% ratio for the training dataset and 30% ratio for the testing dataset. Both flood and non-flood locations were fed into the models and output flood susceptibility maps were produced. In order to evaluate the performance of the algorithms, receiver operating characteristics (ROC) curve was implemented. The results of the current research show that the RF model and EGB have the best performances with the area under ROC curve (AUC) of 0.985, and 0.980, followed by the GAM and FR algorithms with AUC values of 0.97, and 0.953, respectively. The results of variable importance by the RF model show that distance from rivers has an important influence on flood susceptibility mapping (FSM), followed by profile curvature, slope, TWI, and altitude. Considering the high performances of the RF and EGB models in flood susceptibility modelling, application of these models is recommended for such studies.
Mofijur, M, Ahmed, SF, Rahman, SMA, Arafat Siddiki, SKY, Islam, ABMS, Shahabuddin, M, Ong, HC, Mahlia, TMI, Djavanroodi, F & Show, PL 2021, 'Source, distribution and emerging threat of micro- and nanoplastics to marine organism and human health: Socio-economic impact and management strategies', Environmental Research, vol. 195, pp. 110857-110857.
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The nature of micro- and nanoplastics and their harmful consequences has drawn significant attention in recent years in the context of environmental protection. Therefore, this paper aims to provide an overview of the existing literature related to this evolving subject, focusing on the documented human health and marine environment impacts of micro- and nanoplastics and including a discussion of the economic challenges and strategies to mitigate this waste problem. The study highlights the micro- and nanoplastics distribution across various trophic levels of the food web, and in different organs in infected animals which is possible due to their reduced size and their lightweight, multi-coloured and abundant features. Consequently, micro- and nanoplastics pose significant risks to marine organisms and human health in the form of cytotoxicity, acute reactions, and undesirable immune responses. They affect several sectors including aquaculture, agriculture, fisheries, transportation, industrial sectors, power generation, tourism, and local authorities causing considerable economic losses. This can be minimised by identifying key sources of environmental plastic contamination and educating the public, thus reducing the transfer of micro- and nanoplastics into the environment. Furthermore, the exploitation of the potential of microorganisms, particularly those from marine origins that can degrade plastics, could offer an enhanced and environmentally sound approach to mitigate micro- and nanoplastics pollution.
Mofijur, M, Fattah, IMR, Alam, MA, Islam, ABMS, Ong, HC, Rahman, SMA, Najafi, G, Ahmed, SF, Uddin, MA & Mahlia, TMI 2021, 'Impact of COVID-19 on the social, economic, environmental and energy domains: Lessons learnt from a global pandemic', Sustainable Production and Consumption, vol. 26, pp. 343-359.
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COVID-19 has heightened human suffering, undermined the economy, turned the lives of billions of people around the globe upside down, and significantly affected the health, economic, environmental and social domains. This study aims to provide a comprehensive analysis of the impact of the COVID-19 outbreak on the ecological domain, the energy sector, society and the economy and investigate the global preventive measures taken to reduce the transmission of COVID-19. This analysis unpacks the key responses to COVID-19, the efficacy of current initiatives, and summarises the lessons learnt as an update on the information available to authorities, business and industry. This review found that a 72-hour delay in the collection and disposal of waste from infected households and quarantine facilities is crucial to controlling the spread of the virus. Broad sector by sector plans for socio-economic growth as well as a robust entrepreneurship-friendly economy is needed for the business to be sustainable at the peak of the pandemic. The socio-economic crisis has reshaped investment in energy and affected the energy sector significantly with most investment activity facing disruption due to mobility restrictions. Delays in energy projects are expected to create uncertainty in the years ahead. This report will benefit governments, leaders, energy firms and customers in addressing a pandemic-like situation in the future.
Mofijur, M, Fattah, IMR, Kumar, PS, Siddiki, SYA, Rahman, SMA, Ahmed, SF, Ong, HC, Lam, SS, Badruddin, IA, Khan, TMY & Mahlia, TMI 2021, 'Bioenergy recovery potential through the treatment of the meat processing industry waste in Australia', Journal of Environmental Chemical Engineering, vol. 9, no. 4, pp. 105657-105657.
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The farm animal and meat processing industry generate waste, including manure, fat, blood, sludge, bones, and wastewater, which create environmental problems worldwide. The effluents generated by this industry are rich in proteins, lipids, fibres, and carbohydrates. All these pollutants have the potential to be used as a resource for energy recovery. The organic matters obtained from the farm animal and meat processing industry are critical sources for biogas production via anaerobic digestion. This process leads to the production of energy-rich biogas, reducing greenhouse gas emissions. This study attempts to determine biogas amount and the energy value produced from the farm animal and meat processing industry in Australia. Australia's livestock population mainly consists of dairy cattle, meat cattle, sheep and lambs, pigs, layers, and meat chickens. Results show a potential biogas amount of 23,874,165 million m3 (Mm3), 215,670 Mm3, 288,228 Mm3, 18,430 Mm3, and 392,284 Mm3 can be obtained from cattle, lamb, sheep, pig, and poultry annually, respectively. The methane generated from slaughterhouse waste and wastewater is estimated to provide 4.52E+ 14 MJ/yr of heat energy with total electricity generation potential from livestock wastes of 4.4E+ 13 kWh/yr. About half of the electricity can be generated in Queensland State. Finally, the present study suggests farm animal and meat processing industry effluent as a potential sustainable energy source in Australia.
Mofijur, M, Siddiki, SYA, Shuvho, MBA, Djavanroodi, F, Fattah, IMR, Ong, HC, Chowdhury, MA & Mahlia, TMI 2021, 'Effect of nanocatalysts on the transesterification reaction of first, second and third generation biodiesel sources- A mini-review', Chemosphere, vol. 270, pp. 128642-128642.
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Biodiesel is a fuel that has numerous benefits over traditional petrodiesel. The transesterification process is the most popular method for biodiesel production from various sources, categorized as first, second and third generation biodiesel depending on the source. The transesterification process is subject to a variety of factors that can be taken into account to improve biodiesel yield. One of the factors is catalyst type and concentration, which plays a significant role in the transesterification of biodiesel sources. At present, chemical and biological catalysts are being investigated and each catalyst has its advantages and disadvantages. Recently, nanocatalysts have drawn researchers' attention to the efficient production of biodiesel. This article discusses recent work on the role of several nanocatalysts in the transesterification reaction of various sources in the development of biodiesel. A large number of literature from highly rated journals in scientific indexes is reviewed, including the most recent publications. Most of the authors reported that nanocatalysts show an important influence regarding activity and selectivity. This study highlights that in contrast to conventional catalysts, the highly variable surface area of nanostructure materials favours interaction between catalysts and substrates that efficiently boost the performance of products. Finally, this analysis provides useful information to researchers in developing and processing cost-effective biodiesel.
Mohanty, SS, Koul, Y, Varjani, S, Pandey, A, Ngo, HH, Chang, J-S, Wong, JWC & Bui, X-T 2021, 'A critical review on various feedstocks as sustainable substrates for biosurfactants production: a way towards cleaner production', Microbial Cell Factories, vol. 20, no. 1, p. 120.
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AbstractThe quest for a chemical surfactant substitute has been fuelled by increased environmental awareness. The benefits that biosurfactants present like biodegradability, and biocompatibility over their chemical and synthetic counterparts has contributed immensely to their popularity and use in various industries such as petrochemicals, mining, metallurgy, agrochemicals, fertilizers, beverages, cosmetics, etc. With the growing demand for biosurfactants, researchers are looking for low-cost waste materials to use them as substrates, which will lower the manufacturing costs while providing waste management services as an add-on benefit. The use of low-cost substrates will significantly reduce the cost of producing biosurfactants. This paper discusses the use of various feedstocks in the production of biosurfactants, which not only reduces the cost of waste treatment but also provides an opportunity to profit from the sale of the biosurfactant. Furthermore, it includes state-of-the-art information about employing municipal solid waste as a sustainable feedstock for biosurfactant production, which has not been simultaneously covered in many published literatures on biosurfactant production from different feedstocks. It also addresses the myriad of other issues associated with the processing of biosurfactants, as well as the methods used to address these issues and perspectives, which will move society towards cleaner production.
Mojiri, A, Zhou, JL, Ratnaweera, H, Ohashi, A, Ozaki, N, Aoi, Y, Vakili, M & Kindaichi, T 2021, 'Performance optimization of a chitosan/anammox reactor in nitrogen removal from synthetic wastewater', Journal of Environmental Chemical Engineering, vol. 9, no. 3, pp. 105252-105252.
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Anaerobic ammonia oxidation (anammox) is an environmentally friendly, cost-effective, and biological method for nitrogen treatment from aqueous solutions. However, slow growth rate, negative effects of high concentration of nitrite, ammonia and other pollutants (such as metals) on anammox activity are the main drawbacks of using anammox. Thus, in this study, anammox was attached on chitosan to improve anammox performance. Two reactors comprising chitosan and anammox bacteria (first reactor, chitosan/anammox) and solely anammox (second reactor, control) were run for 73 d. The nitrogen loading rate (NLR) varied from 2 to 14 (gN/L/d), while the nitrogen concentration varied from 80 to 700 mg/L. The chitosan/anammox reactor showed a better performance than the sole anammox (control), with respective maximum abatement values of ammonia (NH4+), nitrite (NO2-), and total nitrogen (TN) of 90.8%, 83.5%, and 81.7% on days 20-25 under a NLR of 8-10 kgTN/(m3 d). Response surface methodology (RSM) was employed to optimize the performance of both reactors, and a reasonable R2 value showed that the RSM well optimized the performance of the reactors. After finding the optimum performance conditions for both reactors, Fe and Cu (0.5-7.0 mg/L) were added to the influent to monitor the effects of metals on the performance of both reactors. The performance of both reactors decreased to 0% following the addition of 7.0 (first reactor) and 6.5 (second reactor) mg/L Cu and Fe, respectively. This indicated that chitosan not only enhanced nitrogen removal by anammox but also improved the resistance of anammox to metals.
Mojiri, A, Zhou, JL, Ratnaweera, H, Ohashi, A, Ozaki, N, Kindaichi, T & Asakura, H 2021, 'Treatment of landfill leachate with different techniques: an overview', Journal of Water Reuse and Desalination, vol. 11, no. 1, pp. 66-96.
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AbstractLandfill leachate is characterised by high chemical and biological oxygen demand and generally consists of undesirable substances such as organic and inorganic contaminants. Landfill leachate may differ depending on the content and age of landfill contents, the degradation procedure, climate and hydrological conditions. We aimed to explain the characteristics of landfill leachate and define the practicality of using different techniques for treating landfill leachate. Different treatments comprising biological methods (e.g. bioreactors, bioremediation and phytoremediation) and physicochemical approaches (e.g. advanced oxidation processes, adsorption, coagulation/flocculation and membrane filtration) were investigated in this study. Membrane bioreactors and integrated biological techniques, including integrated anaerobic ammonium oxidation and nitrification/denitrification processes, have demonstrated high performance in ammonia and nitrogen elimination, with a removal effectiveness of more than 90%. Moreover, improved elimination efficiency for suspended solids and turbidity has been achieved by coagulation/flocculation techniques. In addition, improved elimination of metals can be attained by combining different treatment techniques, with a removal effectiveness of 40–100%. Furthermore, combined treatment techniques for treating landfill leachate, owing to its high chemical oxygen demand and concentrations of ammonia and low biodegradability, have been reported with good performance. However, further study is necessary to enhance treatment methods to achieve maximum removal efficiency.
Moldovan, D, Choi, J, Choo, Y, Kim, W-S & Hwa, Y 2021, 'Laser-based three-dimensional manufacturing technologies for rechargeable batteries', Nano Convergence, vol. 8, no. 1, p. 23.
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AbstractLaser three-dimensional (3D) manufacturing technologies have gained substantial attention to fabricate 3D structured electrochemical rechargeable batteries. Laser 3D manufacturing techniques offer excellent 3D microstructure controllability, good design flexibility, process simplicity, and high energy and cost efficiencies, which are beneficial for rechargeable battery cell manufacturing. In this review, notable progress in development of the rechargeable battery cells via laser 3D manufacturing techniques is introduced and discussed. The basic concepts and remarkable achievements of four representative laser 3D manufacturing techniques such as selective laser sintering (or melting) techniques, direct laser writing for graphene-based electrodes, laser-induced forward transfer technique and laser ablation subtractive manufacturing are highlighted. Finally, major challenges and prospects of the laser 3D manufacturing technologies for battery cell manufacturing will be provided.
Mondal, BK, Sahoo, S, Paria, P, Chakraborty, S & Alamri, AM 2021, 'Multi-sectoral impact assessment during the 1st wave of COVID-19 pandemic in West Bengal (India) for sustainable planning and management', Arabian Journal of Geosciences, vol. 14, no. 23.
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Mong, GR, Chong, CT, Ng, J-H, Chong, WWF, Ong, HC & Tran, M-V 2021, 'Multivariate optimisation study and life cycle assessment of microwave-induced pyrolysis of horse manure for waste valorisation and management', Energy, vol. 216, pp. 119194-119194.
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Mosiman, DS, Chen, Y, Yang, L, Hawkett, B, Ringer, SP, Mariñas, BJ & Cairney, JM 2021, 'Atom Probe Tomography of Encapsulated Hydroxyapatite Nanoparticles', Small Methods, vol. 5, no. 2, pp. 2000692-2000692.
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AbstractHydroxyapatite nanoparticles (HAP NPs) are important for medicine, bioengineering, catalysis, and water treatment. However, current understanding of the nanoscale phenomena that confer HAP NPs their many useful properties is limited by a lack of information about the distribution of the atoms within the particles. Atom probe tomography (APT) has the spatial resolution and chemical sensitivity for HAP NP characterization, but difficulties in preparing the required needle‐shaped samples make the design of these experiments challenging. Herein, two techniques are developed to encapsulate HAP NPs and prepare them into APT tips. By sputter‐coating gold or the atomic layer deposition of alumina for encapsulation, partially fluoridated HAP NPs are successfully characterized by voltage‐ or laser‐pulsing APT, respectively. Analyses reveal that significant tradeoffs exist between encapsulant methods/materials for HAP characterization and that selection of a more robust approach will require additional technique development. This work serves as an essential starting point for advancing knowledge about the nanoscale spatiochemistry of HAP NPs.
Mueller, J & Stewart, MG 2021, 'Terrorism and Bathtubs: Comparing and Assessing the Risks', Terrorism and Political Violence, vol. 33, no. 1, pp. 138-163.
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The likelihood that anyone outside a war zone will be killed by an Islamist extremist terrorist is extremely small. In the United States, for example, some six people have perished each year since 9/11 at the hands of such terrorists—vastly smaller than the number of people who die in bathtub drownings. Some argue, however, that the incidence of terrorist destruction is low because counterterrorism measures are so effective. They also contend that terrorism may well become more frequent and destructive in the future as terrorists plot and plan and learn from experience, and that terrorism, unlike bathtubs, provides no benefit and exacts costs far beyond those in the event itself by damagingly sowing fear and anxiety and by requiring policy makers to adopt countermeasures that are costly and excessive. This article finds these arguments to be wanting. In the process, it concludes that terrorism is rare outside war zones because, to a substantial degree, terrorists don’t exist there. In general, as with rare diseases that kill few, it makes more policy sense to expend limited funds on hazards that inflict far more damage. It also discusses the issue of risk communication for this hazard.
Muhammad, G, Alam, MA, Mofijur, M, Jahirul, MI, Lv, Y, Xiong, W, Ong, HC & Xu, J 2021, 'Modern developmental aspects in the field of economical harvesting and biodiesel production from microalgae biomass', Renewable and Sustainable Energy Reviews, vol. 135, pp. 110209-110209.
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Microalgae have been widely explored because of the diverse number of their worthwhile applications and potential as a source biomass for the production of biofuels and value-added materials. However, downstream techniques have yet to be fully developed to overcome techno-economic barriers. Flocculation is a superior method for harvesting microalgae from growth medium because of its harvesting efficiency, economic feasibility. Various kind of bio-flocculation harvesting methods are consider as attractive low cost and environmentally friendly options and able to harvest >90% biomass. Lipid recovery from microalgal cells is a major barrier for the biofuel industry because of process complexity and algae cell structure. Thus, the pretreatment method is necessary to disrupt the cell walls of microalgae and enhance lipid extraction. Many techniques, including dry methods of extraction, are already being implemented but found out that they are not efficient and cost-effective. Various new wet harvesting strategies have been claimed to extract major lipids in cost-efficient (30% less than conventional) way as wet technologies can eliminate the cost of cell drying and associated instruments. It is necessary to develop new methods which are energy and cost-effective, and environmentally friendlier for the commercialization of biofuels. Therefore, this review presents the advances in the progress of various flocculation harvesting methods with special emphasis on innovative bio-flocculation, the underlying mechanism of microalgae and flocculation. In this study also summarize the recent progress on microalgal oil extraction processes, and comparison was made between the processes in terms of sustainability, technology readiness, and applications in larger scales.
Mujtaba, MA, Kalam, MA, Masjuki, HH, Razzaq, L, Khan, HM, Soudagar, MEM, Gul, M, Ahmed, W, Raju, VD, Kumar, R & Ong, HC 2021, 'Development of empirical correlations for density and viscosity estimation of ternary biodiesel blends', Renewable Energy, vol. 179, pp. 1447-1457.
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This study aims to investigate the density and viscosity of ternary biodiesel blends. Fuel density and viscosity play an important role in the fuel injection system, flame propagation, and combustion process in compression ignition engine. The density and viscosity of biodiesel are higher than high-speed diesel which is an implication in the commercialization of biodiesel. In the present study, palm oil has been used for the production of biodiesel through the ultrasound-assisted transesterification process. Three different types of fuel additives including butanol, dimethyl carbonate, and plastic oil have been used for the preparation of nine ternary biodiesel blends. The density and viscosity of individual fuels and ternary biodiesel were measured experimentally in a temperature range of 281.51 K–348.15 K. For the prediction of density and viscosity of ternary biodiesel blends, four density and viscosity models were developed. The prediction accuracy of these developed models was assessed by a statistical tool absolute percentage error (APE). Newly proposed exponential regression models predicted well compared to experimental data for density and viscosity values with high regression coefficient 0.9995 and 0.9841 and lower mean absolute percentage of error 0.012 % and – 0.516 % at (348.15 K) temperature respectively. These correlations are significant for the automobile industry in developing fuel pipeline and transport equipment where additives would be present in diesel-biodiesel fuel blends.
Mujtaba, MA, Muk Cho, H, Masjuki, HH, Kalam, MA, Farooq, M, Soudagar, MEM, Gul, M, Ahmed, W, Afzal, A, Bashir, S, Raju, VD, Yaqoob, H & Syahir, AZ 2021, 'Effect of alcoholic and nano-particles additives on tribological properties of diesel–palm–sesame–biodiesel blends', Energy Reports, vol. 7, pp. 1162-1171.
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N.Usefi, Sharafi, P, Mortazavi, M, Ronagh, H & Samali, B 2021, 'Structural performance and sustainability assessment of hybrid-cold formed modular steel frame', Journal of Building Engineering, vol. 34, pp. 101895-101895.
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© 2020 Elsevier Ltd Hybrid cold-formed steel (HCFS) structures are new structural systems in the light steel construction industry offering new possibilities, in particular with regard to the applications in mid-rise construction. The structural performance, sustainability as well as the economic and social costs of these structures are of great importance for decision-makers when it comes to deciding on employing these systems and comparing them with their conventional counterparts. In this study, the HCFS systems are evaluated with respect to sustainability, structural performance, economic cost, and social impacts. The results then are compared with those of Ordinary Moment Resisting Frames (OMRF), as the most popular conventional HRS framed system. The methodology consists of both qualitative and quantitative analyses that include the overview of the positive and negative points of each construction method in the form of a comparative study. The results of the structural analysis of the two construction systems show that the hybrid system exhibits better structural performance with regard to the storey shear and drift. It is also shown that in terms of most environmental performance indicators, HCFS framed structures can lead to less environmental impact than OMRF systems. Moreover, the economic assessment demonstrates that HCFS framed structures can save up to the 23% in framing costs, compared to OMRF systems, primarily owing to the fact that lightweight flooring system can be easily incorporated to the design of HCFS structure. Their great potential for prefabrication, on the other hand, makes HCFS a better option with respect to many social compact indicators such as noise, air, vibration and dust pollution and traffic.
Naghibi, SA, Hashemi, H & Pradhan, B 2021, 'APG: A novel python-based ArcGIS toolbox to generate absence-datasets for geospatial studies', Geoscience Frontiers, vol. 12, no. 6, pp. 101232-101232.
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Naji, O, Al-juboori, RA, Khan, A, Yadav, S, Altaee, A, Alpatova, A, Soukane, S & Ghaffour, N 2021, 'Ultrasound-assisted membrane technologies for fouling control and performance improvement: A review', Journal of Water Process Engineering, vol. 43, pp. 102268-102268.
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Naveed, M, Arslan, A, Javed, HMA, Manzoor, T, Quazi, MM, Imran, T, Zulfattah, ZM, Khurram, M & Fattah, IMR 2021, 'State-of-the-Art and Future Perspectives of Environmentally Friendly Machining Using Biodegradable Cutting Fluids', Energies, vol. 14, no. 16, pp. 4816-4816.
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The use of cutting fluids has played a vital role in machining operations in lubrication and cooling. Most cutting fluids are mineral oil-based products that are hazardous to the environment and the worker, cause severe diseases and pollute the environment. In addition, petroleum resources are becoming increasingly unsustainable. Due to environmental and health issues, legislations have been established to ensure that the consumption of mineral oil is reduced. Consequently, researchers are making efforts to replace these mineral oil-based products. Vegetable oils are grasping attention due to their better lubricating properties, ease of availability, biodegradability, low prices, and non-toxicity. In this study, a detailed review and critical analysis are conducted of the research works involving vegetable oils as cutting fluids keeping in view the shortcomings and possible solutions to overcome these drawbacks. The purpose of the review is to emphasise the benefits of vegetable oil-based cutting fluids exhibiting comparable performance to that of mineral oil-based products. In addition, an appropriate selection of non-edible vegetable oil-based cutting fluids along with optimum cutting parameters to avoid a scanty supply of edible oils is also discussed. According to this research, vegetable oils are capable of substituting synthetic cutting fluids, and this option might aid in the successful and cost-efficient implementation of green machining.
Ng, ECY, Huang, Y, Hong, G, Zhou, JL & Surawski, NC 2021, 'Reducing vehicle fuel consumption and exhaust emissions from the application of a green-safety device under real driving', Science of The Total Environment, vol. 793, pp. 148602-148602.
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Vehicle emissions have a significantly negative impact on climate change, air quality and human health. Drivers of vehicles are the last major and often overlooked factor that determines vehicle performance. Eco-driving is a relatively low-cost and immediate measure to reduce fuel consumption and emissions significantly. This paper reports investigation of the effects of an on-board green-safety device on fuel consumption and emissions for both experienced and inexperienced drivers. A portable emissions measurement system (PEMS) was installed on a diesel light goods vehicle (LGV) to measure real-driving emissions (RDE), including total hydrocarbons (THC), CO CO2, NO, NO2 and particulate matter (PM). In addition, driving parameters (e.g. vehicle speed and acceleration) and environmental parameters (e.g. ambient temperature, humidity and pressure) were recorded in the experiments. The experimental results were evaluated using the Vehicle Specific Power (VSP) methodology to understand the effects of driving behavior on fuel consumption and emissions. The results indicated that driving behavior was improved for both experienced and inexperienced drivers after activation of the on-board green-safety device. In addition, the average time spent was shifted from higher to lower VSP modes by avoiding excessive speed, and aggressive accelerations and decelerations. For experienced drivers, the average fuel consumption and NO, NO2 and soot emissions were reduced by 5%, 56%, 39% and 35%, respectively, with the on-board green-safety device. For inexperienced drivers, the average reductions were 6%, 65%, 50% and 19%, respectively. Moreover, the long-term formed habits of experienced drivers are harder to be changed to accept the assistance of the green-safety device, whereas inexperienced drivers are likely to be more receptive to change and improve their driving behaviors.
Nghiem, LD, Iqbal, HMN & Zdarta, J 2021, 'The shadow pandemic of single use personal protective equipment plastic waste: A blue print for suppression and eradication', Case Studies in Chemical and Environmental Engineering, vol. 4, pp. 100125-100125.
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Ngo, MTT, Ueyama, T, Makabe, R, Bui, X-T, Nghiem, LD, Nga, TTV & Fujioka, T 2021, 'Fouling behavior and performance of a submerged flat-sheet nanofiltration membrane system for direct treatment of secondary wastewater effluent', Journal of Water Process Engineering, vol. 41, pp. 101991-101991.
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Nguyen, AQ, Vu, HP, Nguyen, LN, Wang, Q, Djordjevic, SP, Donner, E, Yin, H & Nghiem, LD 2021, 'Monitoring antibiotic resistance genes in wastewater treatment: Current strategies and future challenges', Science of The Total Environment, vol. 783, pp. 146964-146964.
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Antimicrobial resistance (AMR) is a growing threat to human and animal health. Progress in molecular biology has revealed new and significant challenges for AMR mitigation given the immense diversity of antibiotic resistance genes (ARGs), the complexity of ARG transfer, and the broad range of omnipresent factors contributing to AMR. Municipal, hospital and abattoir wastewater are collected and treated in wastewater treatment plants (WWTPs), where the presence of diverse selection pressures together with a highly concentrated consortium of pathogenic/commensal microbes create favourable conditions for the transfer of ARGs and proliferation of antibiotic resistant bacteria (ARB). The rapid emergence of antibiotic resistant pathogens of clinical and veterinary significance over the past 80 years has re-defined the role of WWTPs as a focal point in the fight against AMR. By reviewing the occurrence of ARGs in wastewater and sludge and the current technologies used to quantify ARGs and identify ARB, this paper provides a research roadmap to address existing challenges in AMR control via wastewater treatment. Wastewater treatment is a double-edged sword that can act as either a pathway for AMR spread or as a barrier to reduce the environmental release of anthropogenic AMR. State of the art ARB identification technologies, such as metagenomic sequencing and fluorescence-activated cell sorting, have enriched ARG/ARB databases, unveiled keystone species in AMR networks, and improved the resolution of AMR dissemination models. Data and information provided in this review highlight significant knowledge gaps. These include inconsistencies in ARG reporting units, lack of ARG/ARB monitoring surrogates, lack of a standardised protocol for determining ARG removal via wastewater treatments, and the inability to support appropriate risk assessment. This is due to a lack of standard monitoring targets and agreed threshold values, and paucity of information on the ARG-pat...
Nguyen, HC, Pan, J, Su, C, Ong, HC, Chern, J & Lin, J 2021, 'Sol‐gel synthesized lithium orthosilicate as a reusable solid catalyst for biodiesel production', International Journal of Energy Research, vol. 45, no. 4, pp. 6239-6249.
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SummaryLithium orthosilicate (Li4SiO4) is a promising solid catalyst for biodiesel synthesis. However, Li4SiO4 is traditionally prepared by a solid‐state reaction, which results in the unstable activity for the reaction. In the present study, Li4SiO4 was successfully prepared using a simple sol‐gel method and employed as an efficient solid alkali catalyst for biodiesel synthesis. The molar ratio of precursors and calcination temperature were optimized for the synthesis of Li4SiO4 by using the sol‐gel method. The physical and chemical properties were determined using X‐ray diffraction, scanning electron microscopy, laser diffraction particle size, and thermogravimetric analysis. The as‐prepared Li4SiO4 catalyst had much smaller particle size, pore volume, and pore size, but higher surface area and basicity than Li4SiO4 catalyst prepared by the solid‐state reaction. It was then used to transesterify methanol and soybean oil into biodiesel. The effect of reaction factors (reaction time from 1 to 3 hours, catalyst concentration from 3 to 9%; molar ratio of methanol to oil from 6:1 to 18:1, and temperature from 55°C to 75°C) on the Li4SiO4‐catalyzed transesterification was systematically examined. The highest biodiesel conversion of 91% was reached under the following conditions: reaction time of 2 hours, Li4SiO4 concentration of 6%, 12:1 methanol:oil molar ratio, and temperature of 65°C. Notably, Li4SiO4 could be efficiently reused for at least 10 times without significant loss of its activity; this suggests that the sol‐gel synthesized Li4
Nguyen, HT, Yoon, Y, Ngo, HH & Jang, A 2021, 'The application of microalgae in removing organic micropollutants in wastewater', Critical Reviews in Environmental Science and Technology, vol. 51, no. 12, pp. 1187-1220.
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© 2020, © 2020 Taylor & Francis Group, LLC. Micropollutants have become a serious environmental problem with several negative outcomes for human health and ecosystems. Many efforts have been made to remove micropollutants using a variety of physical, chemical and biological methods. By far, the most attention has been paid to microalgae-based technologies for wastewater treatment in order to obtain high-quality effluents, recover algal biomass for fertilizers, protein-rich feed, biofuel, and put them to other practical use. This paper reviews the potential of microalgae-based systems for the removal of organic micropollutants from open ponds to closed photobioreactors coupled by suspended microalgal cells, immobilized cells, or microalgae-microbial consortia. The inhibition of micropollutants on microalgae growth as well as micropollutant removal mechanisms performed by microalgae-based systems are also discussed. Other treatment methods for the removal of micropollutants are analyzed to show the advantages and limitations of microalgae-based treatment strategies, from which some possible combined systems can be suggested. Finally, some recommendations for future studies on this topic are proposed. (Figure presented.).
Nguyen, KT, Ahmed, MB, Mojiri, A, Huang, Y, Zhou, JL & Li, D 2021, 'Advances in As contamination and adsorption in soil for effective management', Journal of Environmental Management, vol. 296, pp. 113274-113274.
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Arsenic (As) is a heavy metal that causes widespread contamination and toxicity in the soil environment. This article reviewed the levels of As contamination in soils worldwide, and evaluated how soil properties (pH, clay mineral, organic matter, texture) and environmental conditions (ionic strength, anions, bacteria) affected the adsorption of As species on soils. The application of the adsorption isotherm models for estimating the adsorption capacities of As(III) and As(V) on soils was assessed. The results indicated that As concentrations in contaminated soil varying significantly from 1 mg/kg to 116,000 mg/kg, with the highest concentrations being reported in Mexico with mining being the dominating source. Regarding the controlling factors of As adsorption, soil pH, clay mineral and texture had demonstrated the most significant impacts. Both Langmuir and Freundlich isotherm models can be well fitted with As(III) and As(V) adsorption on soils. The Langmuir adsorption capacity varied in the range of 22-42400 mg/kg for As(V), which is greater than 45-8901 mg/kg for As(III). The research findings have enhanced our knowledge of As contamination in soil and its underlying controls, which are critical for the effective management and remediation of As-contaminated soil.
Nguyen, LN, Kumar, J, Vu, MT, Mohammed, JAH, Pathak, N, Commault, AS, Sutherland, D, Zdarta, J, Tyagi, VK & Nghiem, LD 2021, 'Biomethane production from anaerobic co-digestion at wastewater treatment plants: A critical review on development and innovations in biogas upgrading techniques', Science of The Total Environment, vol. 765, pp. 142753-142753.
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Anaerobic co-digestion (AcoD) can utilise spare digestion capacity at existing wastewater treatment plants (WWTP) to generate surplus biogas beyond the plant's internal energy requirement. Data from industry reports and the peer-reviewed literature show that through AcoD, numerous examples of WWTPs have become net energy producers, necessitating other high-value applications for surplus biogas. A globally emerging trend is to upgrade biogas to biomethane, which can then be used as town gas or transport fuel. Water, organic solvent and chemical scrubbing, pressure swing adsorption, membrane separation, and cryogenic technology are commercially available CO2 removal technologies for biogas upgrade. Although water scrubbing is currently the most widely applied technology due to low capital and operation cost, significant market growth in membrane separation has been seen over the 2015-2019 period. Further progress in materials engineering and sciences is expected and will further enhance the membrane separation competitiveness for biogas upgrading. Several emerging biotechnologies to i) improve biogas quality from AcoD; ii) accelerate the absorption rate, and iii) captures CO2 in microalgal culture have also been examined and discussed in this review. Through a combination of AcoD and biogas upgrade, more WWTPs are expected to become net energy producers.
Nguyen, LN, Vu, MT, Abu Hasan Johir, M, Pernice, M, Ngo, HH, Zdarta, J, Jesionowski, T & Nghiem, LD 2021, 'Promotion of direct interspecies electron transfer and potential impact of conductive materials in anaerobic digestion and its downstream processing - a critical review', Bioresource Technology, vol. 341, pp. 125847-125847.
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Nguyen, MK, Tran, VS, Pham, TT, Pham, HG, Hoang, BL, Nguyen, TH, Nguyen, TH, Tran, TH & Ngo, HH 2021, 'Fenton/ozone-based oxidation and coagulation processes for removing metals (Cu, Ni)-EDTA from plating wastewater', Journal of Water Process Engineering, vol. 39, pp. 101836-101836.
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Wastewater containing heavy metals has caused many serious problems to land and marine environments. These heavy metal-laden wastewaters containing organic complexing agents are the consequence of using large-scale industrial applications for dissolving metals. Ethylenediaminetetraacetate (EDTA) is a widely used complexing agent in plating, metal finishing and chemical cleaning industries. However, due to the dramatic increase in the solubility of metal ions, EDTA has negative impact on heavy metals removed in wastewaters by conventional precipitation processes. This study aims to find the optimal conditions of combined/hybrid process of advanced oxidation and coagulation to treat metals-EDTA containing Cu, Ni plating wastewater from an electroplating manufacturer in Vietnam. The effects of pH, H2O2 dose, Fe2+ dose, ozone, reaction time and poly acrylic acid (PAA) dose were investigated. Results indicated that the 3-stage treatment process at the optimal conditions could remove 99.7 % of Ni and 99.72 % of Cu. The effluent of wastewater after the whole treatment process met the Vietnamese national regulation on industrial wastewater (QCVN 40:2011/BTNMT) for NH4+, Cu and Ni at column A and COD at column B. In short, the combined advanced oxidation processes and coagulation/flocculation could successfully be applied for plating wastewater treatment.
Nguyen, P-D, Tran, N-ST, Nguyen, T-T, Dang, B-T, Le, M-TT, Bui, X-T, Mukai, F, Kobayashi, H & Ngo, HH 2021, 'Long-term operation of the pilot scale two-stage anaerobic digestion of municipal biowaste in Ho Chi Minh City', Science of The Total Environment, vol. 766, pp. 142562-142562.
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A pilot-scale two-stage anaerobic digestion system, which includes a feed tank (0.4 m3), a hydrolysis reactor (1.2 m3) followed by a methane fermenter (4.0 m3) was set up and run at the municipal solid waste landfill located in Ho Chi Minh City (HCMC), Vietnam. The feed that was separated from urban organic solid waste was collected at households and restaurants in District 1, HCMC. This study aimed to investigate the resource recovery performance of the pilot two-stage anaerobic digestion system, in terms of carbon recovery via biogas production and nutrient recovery from digestate. The average organic loading rate (OLR) of the system was step increased from 1.6 kg volatile solids (VS)·m-3·d-1, 2.5 kg VS·m-3·d-1 and 3.8 kg VS·m-3·d-1 during 400 days of operation. During the long-term operation at three OLRs, pH values and alkalinity were stable at both hydrolysis and methanogenesis stages without any addition of alkalinity for the methanogenesis phase. High buildup of propanoic acid and total volatile fatty acid concentrations in the fermenter did not drop pH values and inhibit the methanogenic process at high OLRs (2.5-3.8 kg VS m-3·d-1). The obtained total chemical oxygen demand (tCOD) removal performance was 83-87% at the OLRs ranging from 2.5 kg VS·m-3·d-1 and 3.8 kg VS·m-3·d-1, respectively. The highest biogas yield of 263 ± 64 L·kg-1 tCOD removed obtained at OLR of 2.5 kg VS·m-3·d-1. It is expected that a full scale 2S-AD plant with capacity of 5200 tons day-1 of biowaste collected currently from municipal solid waste in HCMC may create daily electricity of 552 MWh, thermal energy of 630 MWh, and recovery of 16.1 tons of NH4+-N, 11.4 tons of organic-N, and 2.1 tons of TP as both organic liquid and solid fertilizers.
Nguyen, QD, Castel, A, Kim, T & Khan, MSH 2021, 'Performance of fly ash concrete with ferronickel slag fine aggregate against alkali-silica reaction and chloride diffusion', Cement and Concrete Research, vol. 139, pp. 106265-106265.
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Ferronickel slag (FNS) is an industrial by-product of ferronickel alloy production at a high temperature which can be a promising potential to be used as fine aggregate to produce more sustainable concrete. In this study, the performance of concrete containing ferronickel slag sand and fly ash relating to alkali-silica reaction (ASR) and chloride contamination was investigated. ASR-induced expansion, chloride diffusion resistance, and chloride binding capacity of FNS concrete were determined through concrete prism tests (CPT), accelerated diffusion test, and bulk diffusion test. Thermogravimetric analysis (TGA) was conducted to measure the amount of Portlandite and Friedel's salt in concrete. Concrete with 50 wt% FNS sand as fine natural aggregate replacement and 25 wt% of cement replacement by fly ash showed a remarkable potential to be used not only as a low-carbon concrete with comparable mechanical properties to conventional concrete but also with a better performance against ASR and chloride contamination.
Nguyen, TH, Nguyen, AT, Loganathan, P, Nguyen, TV, Vigneswaran, S, Nguyen, THH & Tran, HN 2021, 'Low-cost laterite-laden household filters for removing arsenic from groundwater in Vietnam and waste management', Process Safety and Environmental Protection, vol. 152, pp. 154-163.
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Nguyen, TKL, Ngo, HH, Guo, W, Nghiem, LD, Qian, G, Liu, Q, Liu, J, Chen, Z, Bui, XT & Mainali, B 2021, 'Assessing the environmental impacts and greenhouse gas emissions from the common municipal wastewater treatment systems', Science of The Total Environment, vol. 801, pp. 149676-149676.
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This study measured the environmental impacts from three same-size wastewater treatment systems, specifically activated sludge, a constructed wetland, and a high rate algal pond. Detailed data inventories were employed using SimaPro 9 software to calculate the entire consequences by ReCiPe 2016 and Greenhouse Gas Protocol method. The environmental outcomes caused by substance emissions and resource extraction are presented in several impact categories at the endpoint level. For a better comparison, the single score tool was applied to aggregate all factors into three areas of protection: human health, ecosystem, and resource shortage. Results showed that concrete and steel are the main contributors to the construction phase, while electricity is responsible for the operation stage. The single score calculation indicates that the proportion of construction activities could be equal to or even higher than the operation stage for a small capacity plant. The total environmental impact of the conventional system was 2.3-fold and 3-fold higher than that of constructed wetland and high rate algal pond, respectively. High rate algal pond has the best environmental performance when generating the least burdens and greenhouse gas emissions of 0.72 kg CO2 equivalent per m3. Constructed wetland produces 5.69 kg CO2, higher than an algal pond but much lower than activated sludge plant, emitting 11.42 kg CO2 per m3.
Nguyen, TKL, Ngo, HH, Guo, W, Nguyen, TLH, Chang, SW, Nguyen, DD, Varjani, S, Lei, Z & Deng, L 2021, 'Environmental impacts and greenhouse gas emissions assessment for energy recovery and material recycle of the wastewater treatment plant', Science of The Total Environment, vol. 784, pp. 147135-147135.
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Nguyen, T-T, Bui, X-T, Ngo, HH, Nguyen, T-T-D, Nguyen, K-Q, Nguyen, H-H, Huynh, K-P-H, Némery, J, Fujioka, T, Duong, CH, Dang, B-T & Varjani, S 2021, 'Nutrient recovery and microalgae biomass production from urine by membrane photobioreactor at low biomass retention times', Science of The Total Environment, vol. 785, pp. 147423-147423.
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Urine has been considered as an ideal nutrient source for microalgae cultivation thanks to its composition containing the high concentrations of nitrogen and phosphorus. Herein, the microalgae growth in urine was evaluated in a lab-scale membrane photobioreactor (MPBR) system. This work aimed to validate the influence of low biomass retention times (BRT) (10, 7, 5, 3, 2 d) on nutrient remediation and biomass productivity. It revealed that BRT of 7 d resulted in synergistically high biomass production (biomass productivity of 313 mg/L.d) and removal rates (TN of 90.5 mg/L.d and TP of 4.7 mg/L.d). Notably, the short BRT of 2–5 d was not sufficient to trigger actively growing microalgae and thus reduced biomass production rate. In addition, as operated at a low flux of 2 L/m2.h, MPBR system required no physical cleaning for 100 days of operation. The BRT-dependent biomass concentration played a pivotal role in changing the fouling rate of MPBR; however, the fouling is reversible in the MPBR system under the low flux condition.
Nguyen, TT, Indraratna, B & Singh, M 2021, 'Dynamic parameters of subgrade soils prone to mud pumping considering the influence of kaolin content and the cyclic stress ratio', Transportation Geotechnics, vol. 29, pp. 100581-100581.
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Nguyen, TTQ, Loganathan, P, Dinh, BK, Nguyen, TV, Vigneswaran, S & Ngo, HH 2021, 'Removing arsenate from water using batch and continuous-flow electrocoagulation with diverse power sources', Journal of Water Process Engineering, vol. 41, pp. 102028-102028.
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Nguyen, XC, Ly, QV, Li, J, Bae, H, Bui, X-T, Nguyen, TTH, Tran, QB, Vo, T-D-H & Nghiem, LD 2021, 'Nitrogen removal in subsurface constructed wetland: Assessment of the influence and prediction by data mining and machine learning', Environmental Technology & Innovation, vol. 23, pp. 101712-101712.
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Nguyen, XC, Ly, QV, Peng, W, Nguyen, V-H, Nguyen, DD, Tran, QB, Huyen Nguyen, TT, Sonne, C, Lam, SS, Ngo, HH, Goethals, P & Le, QV 2021, 'Vertical flow constructed wetlands using expanded clay and biochar for wastewater remediation: A comparative study and prediction of effluents using machine learning', Journal of Hazardous Materials, vol. 413, pp. 125426-125426.
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Nguyen, XC, Nguyen, TTH, Bui, X-T, Tran, XV, Tran, TCP, Hoang, NTT, La, DD, Chang, SW, Ngo, HH & Nguyen, DD 2021, 'Status of water use and potential of rainwater harvesting for replacing centralized supply system in remote mountainous areas: a case study', Environmental Science and Pollution Research, vol. 28, no. 45, pp. 63589-63598.
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The failure of the centralized water supply system forced XY community to become more dependent on uncertain and unstable water sources. The results of surveying 50 households showed that 89.18% of total households depended on water collected from rivers, which contributed 58.3% of the total water volume used for the domestic demands. The average water volume consumed was 19.5 liters/person/day (l/p/d), and 86.5% of households used more than one source; 13.5% of households collected water only from rivers, and 45.94% of families had rainwater harvesting (RWH) for their activities (domestic water demand); however, RWH only provided 9.9% of total water consumption. In this study, basic methods were applied to calculate the storage tanks necessary to balance the water deficit created by drought months. Three levels of water demand (14, 20, and 30 l/p/d) can be the best choices for RWH; for a higher demand (40 and 60 l/p/d), small roof area (30-40 m2), and many people (six to seven) per family, RWH might be impractical because of unsuitable rainfall or excessively large storage tanks.
Nikraftar, Z, Mostafaie, A, Sadegh, M, Afkueieh, JH & Pradhan, B 2021, 'Multi-type assessment of global droughts and teleconnections', Weather and Climate Extremes, vol. 34, pp. 100402-100402.
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Noushini, A, Nguyen, QD & Castel, A 2021, 'Assessing alkali-activated concrete performance in chloride environments using NT Build 492', Materials and Structures, vol. 54, no. 2.
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The production of Portland cement is responsible for approximately 5–7% of the worldwide CO2 emission. Geopolymer concrete (GPC) presents potential to become a more sustainable alternative to Portland cement and reduce the environment impact of the concrete industry. Marine environment is one of the most corrosion issues for reinforced concrete structures. Chloride migration test (Nordtest NT Build 492) and bulk diffusion chloride test (ASTM C1556) has been widely used to assess chloride diffusion resistance of Portland cement concrete. NT Build 492, involving externally applied electrical voltage, provides fast and adequate assessment of chloride penetration resistance of Portland cement concrete. However, the utilization of NT Build 492 for GPCs requires recalibration due to their different microstructure and pore solution composition compared to Portland cement concrete. This study aims to establish performance-based criteria for GPCs in marine environments using NT Build 492 and ASTM C1556 test protocols. Experimental results revealed a good correlation between chloride migration coefficients (NT Build 492) and chloride diffusion coefficients (ASTM C1556). In addition, chloride concentration at the colour change boundary used to calculate the chloride migration coefficients in NT Build 492 has been recalibrated for the chemistry of GPCs pore solution.
Obeid, F, Van, TC, Guo, B, Surawski, NC, Hornung, U, Brown, RJ, Ramirez, JA, Thomas-Hall, SR, Stephens, E, Hankamer, B & Rainey, T 2021, 'The fate of nitrogen and sulphur during co-liquefaction of algae and bagasse: Experimental and multi-criterion decision analysis', Biomass and Bioenergy, vol. 151, pp. 106119-106119.
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The removal of nitrogen (N) and sulphur (S) from biocrude oil produced using hydrothermal liquefaction (HTL), is important for the production of high quality renewable fuels. Here the effect of co-liquefaction of bagasse and algae was analysed. Algae (Chlorella vulgaris and Cyanobacteria) were mixed with bagasse (1:1) subjected to HTL at 250–350 °C for 10–60 min. Higher HTL temperatures had a positive effect in increasing the biocrude yield and slightly reduced N content; S did not show a consistent trend. Most of the nitrogen (~66%) and sulphur (~80%) were recovered in the aqueous phase rather than in the biocrude phase, opening the opportunity to recycle these nutrients for algae cultivation. Co-liquefying bagasse with algae improved the biocrude yield (54 wt%) compared to pure Cyanobacteria (47.5 wt%). It also reduced N content from 7 wt% (Cyanobacteria biocrude) to 4.2 wt% (Cyanobacteria: Bagasse) and S from 0.7 wt% to 0.4 wt%. Principal Component Analysis (PCA) analysis identified that biocrude yield is positively correlated with the initial lipid content and anti-correlated with the carbohydrates fraction. Biocrude N content is closely related to the initial amount of proteins in the algae. The Preference Ranking Organization METHod for Enrichment of Evaluations and its descriptive complement Geometrical Analysis for Interactive Aid (PROMETHEE and GAIA) analysis ranked the co-liquefaction of Chlorella vulgaris and bagasse (1:1) at 350 °C and 60 min as one of the best overall combination in terms of biocrude yield, N and S content.
Ong, HC, Tiong, YW, Goh, BHH, Gan, YY, Mofijur, M, Fattah, IMR, Chong, CT, Alam, MA, Lee, HV, Silitonga, AS & Mahlia, TMI 2021, 'Recent advances in biodiesel production from agricultural products and microalgae using ionic liquids: Opportunities and challenges', Energy Conversion and Management, vol. 228, pp. 113647-113647.
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© 2020 Elsevier Ltd Biodiesel is considered as a potential substitute for petroleum-based diesel fuel owing to its comparable properties to diesel. Biodiesel is generally produced from renewable sources such as agricultural products and microalgae in the presence of a suitable catalyst. Recently ionic liquid (IL) catalyzed synthesis of biodiesel has become a promising pathway to an eco-friendly production route for biodiesel. This review focuses on the use of ILs both as solvents as well as catalysts for sustainable biodiesel production from agricultural feedstocks and microalgae with high free fatty acid content. Reactions catalyzed by ILs are known to render high reactivity under the mild condition and high selectivity of ester product with simple separation steps. The article first discusses the state of the art of biodiesel production using ILs along with the physicochemical properties of the produced biodiesel. Then, current IL technologies were elucidated in terms of the categories such as acidic and basic ILs. The use of more advanced ILs such as supported ionic liquids and ionic liquid-enzyme catalysts on different biodiesel feedstocks were also discussed. Furthermore, the role of IL catalyst in intensified biodiesel production methods such as microwave and ultrasound technologies were also discussed. Finally, the prospects and challenges of IL catalyzed biodiesel production are discussed in this article. The review shows that ILs with brønsted acidity or basicity not only pose a low risk to the environment but also result in high biodiesel yields with mild reaction conditions in a short time. Brønsted acidic ILs can convert free fatty acids as well as triglycerides to biodiesel without the need for pretreatment, which facilitates in reducing the production cost of biodiesel. From the review, it can be concluded that ILs present great potential as catalysts for biodiesel production.
Ong, HC, Yu, KL, Chen, W-H, Pillejera, MK, Bi, X, Tran, K-Q, Pétrissans, A & Pétrissans, M 2021, 'Variation of lignocellulosic biomass structure from torrefaction: A critical review', Renewable and Sustainable Energy Reviews, vol. 152, pp. 111698-111698.
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Orwa, JO, Reiner, J, Juma, A, Stacey, A, Sears, K, Schütz, JA, Merenda, A, Hyde, L, Guijt, R, Adineh, VR, Li, Q, Naebe, M, Kouzani, AZ & Dumée, LF 2021, 'Growth of diamond coating on carbon fiber: Relationship between fiber microstructure and stability in hydrogen plasma', Diamond and Related Materials, vol. 115, pp. 108349-108349.
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Stability of carbon fiber in hydrogen plasma during chemical vapor deposition growth of diamond film was investigated for a range of carbon fiber samples with different physical properties. Morphological studies using scanning electron microscopy and focused ion beam showed that pre-growth seeding with nanodiamonds was necessary both to protect the carbon fiber from atomic hydrogen attack and to promote diamond growth. Microstructural studies using Raman spectroscopy indicated that carbon fibers with larger crystallite size, which correspond to high and ultra-high modulus fibers, were less susceptible to etching compared to carbon fibers with smaller crystallite size, corresponding to intermediate modulus fibers. A model was developed to predict the diamond film coverage, following pre-seeding of the carbon fibers with nanodiamonds. Compared to larger seeds, a dense seeding with smaller sized nanodiamonds resulted in faster coalescence, which provides significant benefits as the diamond layer protects the carbon fiber from hydrogen plasma attack. The results of this study will facilitate the integration of diamond and carbon fiber into a versatile hybrid material and, in particular, pave the way towards development of novel biocompatible diamond-coated carbon fiber micro-electrodes with long-term efficacy.
Ottenhaus, L-M, Jockwer, R, van Drimmelen, D & Crews, K 2021, 'Designing timber connections for ductility – A review and discussion', Construction and Building Materials, vol. 304, pp. 124621-124621.
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Pan, S, Chen, X, Cao, C, Chen, Z, Hao Ngo, H, Shi, Q, Guo, W & Hu, H-Y 2021, 'Fluorescence analysis of centralized water supply systems: Indications for rapid cross-connection detection and water quality safety guarantee', Chemosphere, vol. 277, pp. 130290-130290.
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Park, MJ, Nisola, GM, Seo, DH, Wang, C, Phuntsho, S, Choo, Y, Chung, W-J & Shon, HK 2021, 'Chemically Cross-Linked Graphene Oxide as a Selective Layer on Electrospun Polyvinyl Alcohol Nanofiber Membrane for Nanofiltration Application', Nanomaterials, vol. 11, no. 11, pp. 2867-2867.
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Graphene oxide (GO) nanosheets were utilized as a selective layer on a highly porous polyvinyl alcohol (PVA) nanofiber support via a pressure-assisted self-assembly technique to synthesize composite nanofiltration membranes. The GO layer was rendered stable by cross-linking the nanosheets (GO-to-GO) and by linking them onto the support surface (GO-to-PVA) using glutaraldehyde (GA). The amounts of GO and GA deposited on the PVA substrate were varied to determine the optimum nanofiltration membrane both in terms of water flux and salt rejection performances. The successful GA cross-linking of GO interlayers and GO-PVA via acetalization was confirmed by FTIR and XPS analyses, which corroborated with other characterization results from contact angle and zeta potential measurements. Morphologies of the most effective membrane (CGOPVA-50) featured a defect-free GA cross-linked GO layer with a thickness of ~67 nm. The best solute rejections of the CGOPVA-50 membrane were 91.01% for Na2SO4 (20 mM), 98.12% for Eosin Y (10 mg/L), 76.92% for Methylene blue (10 mg/L), and 49.62% for NaCl (20 mM). These findings may provide one of the promising approaches in synthesizing mechanically stable GO-based thin-film composite membranes that are effective for solute separation via nanofiltration.
Park, MJ, Wang, C, Seo, DH, Gonzales, RR, Matsuyama, H & Shon, HK 2021, 'Inkjet printed single walled carbon nanotube as an interlayer for high performance thin film composite nanofiltration membrane', Journal of Membrane Science, vol. 620, pp. 118901-118901.
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Inkjet printing process enables rapid deposition of inks with precise amount and location. Moreover, the process can be automated and provide control such as repetitive printing of the inks. Utilizing the advantageous features of the inkjet printing process, we demonstrate the synthesis of thin film composite (TFC) flat-sheet membrane for NF application where single walled carbon nanotube (SWCNT) was deposited via an inkjet printing process, acting as an interlayer between the polyamide (PA) selective layer and polyethersulfone (PES) MF membrane support. By controlling the number of SWCNT printings on the PES membrane, we investigated how the SWCNT interlayer thickness influences the formation of PA selective layer. The best membrane performance was achieved from the TFC membrane synthesized using 15 cycles of SWCNT printing, where both high water flux (18.24 ± 0.43 L m−2 h−1 bar−1) and the high Na2SO4 salt rejection (97.88 ± 0.33%) rates were demonstrated. SWCNT interlayer provided highly porous, interconnected structure with uniform pore size distribution which led to the formation of a defect-free ultrathin PA selective layer. Designing of TFC membrane using the SWCNT deposition via inkjet printing is the new approach and successfully demonstrated the significant improvement in the NF membrane performances.
Parvin, K, Lipu, MSH, Hannan, MA, Abdullah, MA, Jern, KP, Begum, RA, Mansur, M, Muttaqi, KM, Mahlia, TMI & Dong, ZY 2021, 'Intelligent Controllers and Optimization Algorithms for Building Energy Management Towards Achieving Sustainable Development: Challenges and Prospects', IEEE Access, vol. 9, pp. 41577-41602.
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Paryani, S, Neshat, A & Pradhan, B 2021, 'Improvement of landslide spatial modeling using machine learning methods and two Harris hawks and bat algorithms', The Egyptian Journal of Remote Sensing and Space Science, vol. 24, no. 3, pp. 845-855.
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Paryani, S, Neshat, A & Pradhan, B 2021, 'Spatial landslide susceptibility mapping using integrating an adaptive neuro-fuzzy inference system (ANFIS) with two multi-criteria decision-making approaches', Theoretical and Applied Climatology, vol. 146, no. 1-2, pp. 489-509.
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Landslide is a type of slope process causing a plethora of economic damage and loss of lives worldwide every year. This study aimed to analyze spatial landslide susceptibility mapping in the Khalkhal-Tarom Basin by integrating an adaptive neuro-fuzzy inference system (ANFIS) with two multi-criteria decision-making approaches, i.e., the best-worst method (BWM) and the stepwise weight assessment ratio analysis (SWARA) techniques. For this purpose, the first step was to prepare a landslide inventory map, which was then divided randomly into the ratio of 70/30% for model training and validation. Thirteen conditioning factors were selected based on the previous studies and available data. In the next step, the BWM and the SWARA methods were utilized to determine the relationships between the sub-criteria and landslides. Finally, landslide susceptibility maps were generated by implementing ANFIS-BWM and ANFIS-SWARA ensemble models, and then several quantitative indices such as positive predictive value, negative predictive value, sensitivity, specificity, accuracy, root-mean-square-error, and the ROC curve were employed to appraise the predictive accuracy of each model. The results indicated that the ANFIS-BWM ensemble model (AUC = 75%, RMSE = 0.443) has better performance than ANFIS-SWARA (AUC = 73.6%, RMSE = 0.477). At the same time, the ANFIS-BWM model had the maximum sensitivity, specificity, and accuracy with values of 87.1%, 54.3%, and 40.7%, respectively. As a result, the BWM method was more efficient in training the ANFIS. Evidently, the generated landslide susceptibility maps (LSMs) can be very efficient in managing land use and preventing the damage caused by the landslide phenomenon.
