Bowman, JC, Zhou, JL & Readman, JW 2002, 'Sediment–water interactions of natural oestrogens under estuarine conditions', Marine Chemistry, vol. 77, no. 4, pp. 263-276.
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The natural human female hormones oestrone and 17β-oestradiol have been implicated in the disruption of endocrine systems in some wildlife adjacent to sewage effluents. The sorption behaviour of these two compounds under estuarine conditions was studied by spiking either 2.55 μg of oestrone or 2.65 μg of 17β-oestradiol in kinetic experiments. In equilibrium experiments, 3 ng of oestrone or 3.2 ng of 17β-oestradiol was added in each of the centrifuge tubes. Sorption onto sediment particles was relatively slow, with sorption equilibrium being reached in about 70 and 170 h for oestrone and 17β-oestradiol, respectively. The effects of a variety of environmental parameters on sorption were studied including salinity, sediment concentration (SC), the presence of a third phase, particle size and, also, surfactant concentrations. Results show that although salinity did not induce any statistically significant effect on the sorption of 17β-oestradiol, it did statistically enhance the sorption of oestrone, and a salting constant of 0.3 1 mol-1 was derived. The partition coefficient for both compounds decreased with increasing sediment concentration, a phenomenon that has been widely reported and attributed to the presence of colloids (which could enhance dissolved concentrations). In this paper, the true partition coefficients for sediment particles (Kptrue) and colloidal particles (Kctrue) have been calculated, and a Kptrue value of 141 and 102 ml g-1 was obtained for oestrone and 17β-oestradiol, respectively. In addition, Kctruevalues for oestrone (222 × 102 ml g-1) and 17β-oestradiol (135 × 102 ml g-1) were two orders of magnitude higher than their respective Kptrue values, suggesting that the colloidal particles are significantly stronger sorbents for natural oestrogens than sediment particles. Particles of different sizes were found to have different partition coefficients due to the strong relationships between partition coefficients for the two compounds a...
Bowman, JC, Zhou, JL & Readman, JW 2002, 'Sorption and desorption of benzo(a)pyrene in aquatic systems', Journal of Environmental Monitoring, vol. 4, no. 5, pp. 761-766.
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The sorptive behaviour of polycyclic aromatic hydrocarbons (PAHs) is critical to controlling their transport, fates and effects in the environment. Experiments are described which detail the behaviour of a model compound (benzo(a)pyrene) under simulated aquatic conditions. The kinetics of sorption were comparable to those of other PAH compounds. The sorption equilibrium was extensively studied and found to be affected by several key parameters, notably sediment concentration. The sorption coefficient decreased substantially with the sediment concentration, from 9580 ml g-1 at a sediment concentration of 0.067 g 1-1 to 1110 ml g-1 at a sediment concentration of 9.8 g 1-1. The results are consistent with previous reports and often explained by the presence of colloids. In this paper the dry weight concentration of colloids was determined and used for deriving the true sorption coefficient, which is up to an order of magnitude higher than the observed partition coefficient. The sorption of benzo(a)pyrene was also dependent on some of the particle properties, and the sorption coefficient was found to increase with the organic carbon content and specific surface area of sediment particles. The desorption of benzo(a)pyrene from sediment was shown to be relatively rapid, with implications for the potential remobilisation of benzo(a)pyrene and similar compounds.
Brown, LD, Ray, AS, Thomas, PS & Guerbois, JP 2002, 'Thermal characteristics of Australian sedimentary opals', JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY, vol. 68, no. 1, pp. 31-36.
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Naturally occurring opals from three different regions in Australia were studied for their thermal characteristics. All the opals showed initial expansion followed by contraction in thermomechanical analysis (TMA) although the temperature at which the change from expansion to contraction occurred depended on their provenance. Thermogravimetric analysis (TG) revealed different rates and temperatures of dehydration for these opals. A general correlation between the temperature at which there was a zero thermal expansion and that of the maximum rate of dehydration was observed. A dehydrationsintering mechanism is proposed with the effect of sintering being more pronounced following total dehydration.
Castel, A, François, R & Arliguie, G 2002, 'Modèle de comportement mécanique du béton armé corrodé', Comptes Rendus. Mécanique, vol. 330, no. 1, pp. 45-50.
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Chapman, H, Vigneswaran, S, Ngo, HH, Dyer, S & Ben Aim, R 2002, 'Pre-flocculation of secondary treated wastewater in enhancing the performance of microfiltration', DESALINATION, vol. 146, no. 1-3, pp. 367-372.
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In this study, a new design of static floating medium flocculator was examined for its ability to remove suspended solids, organics and phosphorus. The floating medium flocculator also produced uniform microflocs, which could be removed easily by cross flow microfiltration. Flocs formed enhanced the permeate flux of microfiltration. The floating medium flocculator was able to be operated at high velocities of up to 40 m/h, producing filterable flocs of around 20 μm. Using a filter bed depth of 1m, the floating medium flocculator was able to remove 45% of suspended solids, to as low as 1.3 mg/L; 83% of turbidity, achieving values <1 NTU; 97% of phosphorus, reducing orthophosphate to 0.07 mg/L and 45% of organics, to as low as 1.02 ppm C total organic carbon (TOC). A periodic backwash for duration of 1 min every 90 min enabled the floating medium flocculator to run continuously without termination. A series of experiments was conducted with a combined system of flocculation-microfiltration to assess its capability in removing solids and organics. The improvement of flux by the pre-flocculation was also investigated. The purpose of the floating medium flocculator was to produce filterable flocs and also removal of solids and organics. The critical flux of kaolin clay suspension of 10-100 mg/L was measured with a 0.2 μm membrane, in the presence of 0-4 mg/L of fulvic acid. The pretreatment of flocculation leads to 50% removal of organics, while producing uniform microflocs of 13-16 μm. It enhanced the critical flux by 70% and resulted in a further 30-70% removal of organics by microfiltration.
Choi, K-S & Ball, JE 2002, 'Parameter estimation for urban runoff modelling', Urban Water, vol. 4, no. 1, pp. 31-41.
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Accurate estimation of the control parameters for spatially distributed physically based catchment modelling systems requires considerable work to establish credibility. Presented in this paper is a methodology for estimation of control parameter values based on the application of a decision support system within a hydroinformatic system. The proposed methodology uses information contained within a GIS database together with optimisation techniques to infer spatially variable control parameters for utilisation with a catchment modelling system such as the Stormwater Management Model (SWMM). A case study application of the proposed methodology was undertaken using the Musgrave Avenue Stormwater System in Centennial Park, Sydney. Results from this application suggest that the proposed approach is capable of providing accurate spatially distributed control parameters for implementation with physically based catchment modelling systems. © 2002 Published by Elsevier Science Ltd.
Dharmappa, H, Corderoy, RM & Hagare, P 2002, 'Teaching water treatment processes: Using multimedia and simulation', Water, vol. 29, no. 4, pp. 49-54.
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Teaching and learning environments which use multimedia based resources have the potential to greatly improve the effectiveness and efficiency of learning by engaging students at a deeper level than may otherwise be possible. The presentation media and teaching methods work together to enrich the experience, providing the students with a greater opportunity to explore their own 'mental pictures', develop understanding and revise it as necessary. This is particularly so in situations where 'real world' phenomena and processes are being taught. Using such a multimedia package in teaching pollution control processes is novel. This paper reports on the successful development of a multimedia package dealing with several pollution control processes and its evaluation. The pollution control processes illustrated in the multi-media software are physico-chemical processes which are widely used in both water and wastewater treatment. Teaching the design concepts for these processes in a conventional classroom setting is challenging because students have difficulty in visualising the techniques and processes involved. This difficulty is compounded by the fact that many of the processes occur naturally over longer time periods and so cannot be easily be integrated into normal teaching environments. The software package incorporates several different media modes including text, drawings, photographs, animation, and simulation. A pilot evaluation of this package using third year engineering students indicated that it supported the development of greater insight and understanding of the complex treatment processes being taught. On the teaching side, it was possible to adopt 1 hour lecture and 3 hours tutorial format against the traditional 2 hours each of lecture and tutorial.
Djajakesukma, SL, Samali, B, Li, J & Nguyen, H 2002, 'MODELLING AND IDENTIFICATION OF MR DAMPER FOR SEMIACTIVE STIFFNESS DAMPER', The Proceedings of the International Conference on Motion and Vibration Control, vol. 6.2, no. 0, pp. 1197-1202.
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Epaarachchi, DC, Stewart, MG & Rosowsky, DV 2002, 'Structural Reliability of Multistory Buildings during Construction', Journal of Structural Engineering, vol. 128, no. 2, pp. 205-213.
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The paper develops a probabilistic model to estimate the probability of structural collapse (system risk) during the construction of typical multistory reinforced concrete buildings. The influence of the number of levels of shoring/reshoring, construction cycle and concreting workmanship (curing and compaction), concrete grade, and number of floors of the building on system risk is included in the analysis. It was found that poor concreting workmanship is more detrimental to system risk than reducing the construction cycle by a few days. It was found also that if the design process ignores construction loading on the slab during construction, then a dramatic loss of structural safety can occur.
Hao, H, Wu, C & Seah, CC 2002, 'Numerical Analysis of Blast-Induced Stress Waves in a Rock Mass with Anisotropic Continuum Damage Models Part 2: Stochastic Approach', Rock Mechanics and Rock Engineering, vol. 35, no. 2, pp. 95-108.
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Hao, H, Wu, C & Zhou, Y 2002, 'Numerical Analysis of Blast-Induced Stress Waves in a Rock Mass with Anisotropic Continuum Damage Models Part 1: Equivalent Material Property Approach', Rock Mechanics and Rock Engineering, vol. 35, no. 2, pp. 79-94.
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Hossain, NB & Stewart, MG 2002, 'Serviceability Reliability and Expected Costs of RC Beams Designed to Serviceability Specifications of AS3600', Australian Journal of Structural Engineering, vol. 4, no. 1, pp. 17-27.
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Indraratna, B & Radampola, S 2002, 'Analysis of Critical Hydraulic Gradient for Particle Movement in Filtration', Journal of Geotechnical and Geoenvironmental Engineering, vol. 128, no. 4, pp. 347-350.
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Indraratna, B & Salim, W 2002, 'Modelling of particle breakage of coarse aggregates incorporating strength and dilatancy', Proceedings of the Institution of Civil Engineers - Geotechnical Engineering, vol. 155, no. 4, pp. 243-252.
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The degradation of coarse aggregates under shear stresses and its influence on the shear strength is studied, considering the energy consumption by particle breakage during shearing. An analytical model is developed relating the deviator stress ratio, dilatancy, friction angle and particle breakage under triaxial loading. Large-scale triaxial testing of latite basalt has been conducted, and the extent of particle breakage during shearing has been quantified. The breakage of particles under monotonic triaxial loading has been considered within the scope of this paper, and the modelling of particle breakage of aggregates under cyclic loading will be presented in a follow-up paper. The results show that the breakage of particles continues to increase beyond the peak deviator stress. The energy consumption by particle breakage is non-linearly related to the particle breakage index. The model also evaluates the effect of particle breakage on the friction angle of ballast. This study sheds further light on the basic angle of friction, which is independent of the breakage of particles during shearing.
Indraratna, B, Glamore, WC & Tularam, GA 2002, 'The effects of tidal buffering on acid sulphate soil environments in coastal areas of New South Wales', Geotechnical and Geological Engineering, vol. 20, no. 3, pp. 181-199.
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One-way floodgates installed on flood mitigation drains in regions affected by acid sulphate soils restrict carbonate bicarbonate buffering, thereby creating reservoirs of acid water (pH < 4.5) that discharge during the ebb tide. The drain water quality and hydrodynamic conditions prior to and following floodgate modifications that allowed for controlled saline intrusion are described with reference to data collected from intensively drained and floodgated coastal lowlands located in southeastern New South Wales, Australia. CI:SO4 ratios taken from ground-water samples depicted an acidic environment with little soil buffering capacity. Prior to modification, water quality upstream of the one-way floodgate was consistently acidic (average pH 4.6) with high concentrations of aluminum and iron that fluctuated with precipitation. Over a two-week period before modifications, floodgate leakage permitted alkaline water to intrude upstream of the floodgate and react with H+ ions. This period showed the strongest supporting field evidence for tidal buffering via modified floodgates. After installing vertical lifting, two-way floodgates average drain water pH increased to 5.89 and aluminum and iron concentrations decreased by more than 30%. A large rainfall (131.8 mm) during the post-modification period caused acidic groundwater flushing, however, in comparison to the pre-modification period, recovery time and average pH were markedly improved. Preliminary investigations of ground-water salinity in response to tidal intrusion has shown that electrical conductivity fluctuates with rainfall and it is predominately limited to 10 m perpendicular to the drain.
Indraratna, B, Price, J, Ranjith, P & Gale, W 2002, 'Some aspects of unsaturated flow in jointed rock', International Journal of Rock Mechanics and Mining Sciences, vol. 39, no. 5, pp. 555-568.
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Jegatheesan, V, Lamsal, PR, Visvanathan, C, Ngo, HH & Shu, L 2002, 'Effect of natural organic compounds on the removal of organic carbon in coagulation and flocculation processes', Water Supply, vol. 2, no. 5-6, pp. 473-479.
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Natural organic matter (NOM) in water contains organic compounds that are both hydrophobic and hydrophilic with a wide range of molecular weights. It is composed of non-homogeneous organic compounds such as humic substances, amino acids, sugars, aliphatic and aromatic acids, and other chemical synthetic organic matters. NOM in water is a major concern not only because of its contribution to the formation of disinfection by-products (DBPs) and taste and odor, but also its influence on the demand for coagulants and disinfectants, the removal efficiency of water treatment processes, etc. This research aims at identifying the influence of NOM in coagulation and flocculation processes in order to optimize the coagulation and flocculation conditions. In this study, pretreated pond water was used as the source water. It was observed from the experimental results that:The optimum pH for coagulation to remove NOM is around 7.The optimum alum dose at this pH can vary from 125-1,225 mgl-1 when the TOC is increased from 4 to 25 mgl-1.The presence of secondary compounds such as Ca2+, Mg2+ divalent cations had no significant effect on the removal of organic matter.The presence of clay increased the organic removal by 15%.The organic compound with higher molecular weight has higher removal affinity in coagulation process.Floc size and settling velocity of floc and sludge production all increased with the increase in NOM concentration. From the results of Capillary Suction Time (CST) tests, the floc formed with lower TOC readily released the water to make the dewatering process easier.The organic removal efficiency was significantly different for natural water containing non-homogeneous organic compounds compared to the synthetic water containing humic acid only (homogeneous organic matter). For example, the NOM removal efficiency was 80% for the synthetic water containing humic acid with TOC of 7 mgl-1 at pH 7; but the NOM remov...
Kalam, MA & Majsuki, HH 2002, 'Use of an additive in biofuel to evaluate emissions, engine component wear and lubrication characteristics', Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, vol. 216, no. 9, pp. 751-757.
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This paper presents the results of experiments carried out to evaluate the effect of adding an anticorrosion additive to blended biofuel and lubricating oil on emissions, engine component wear and lubrication characteristics. The blended biofuels consist of 7.5 and 15 per cent palm olein (PO) with ordinary diesel oil (OD). Pure OD was used for comparison purposes. Exhaust emission gases such as NOx, CO and hydrocarbons (HCs) were measured by an exhaust emission analyser for engine operation on 50 per cent throttle at speeds of 800-3600 r/min. To measure engine component wear and lubricating oil characteristics, the engine was operated at 50 per cent throttle at a speed of 2000 r/min for a period of 100 h with each of the fuel samples. The same lubricating oil, conventional SAE 40, was used in all the fuels. A multielement oil analyser (MOA) was used to measure the increase in wear of metals (Fe, Cu, Al, Pb) and the decrease in lubricating oil additives (Zn, Ca) in the lubricating oil used. An ISL automatic Houillon viscometer (ASTM D445) and potentiometric titration (ASTM D2896) were used to measure viscosity and total base number (TBN) respectively. The results show that the addition of anticorrosion additive with biofuel and lubricating oil improves the emission and engine wear characteristics; both the exhaust emission gases (NOx, CO and HCs) and the wear of metals (Fe, Cu, Al and Pd) decrease with the blended fuels in comparison with the base fuel OD. Detailed results, including engine brake power, are discussed.
Kalam, MA & Masjuki, HH 2002, 'Biodiesel from palmoil—an analysis of its properties and potential', Biomass and Bioenergy, vol. 23, no. 6, pp. 471-479.
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Kim, SH, Ngo, HH, Chaudhary, D, Kim, JC, Vigneswaran, S & Moon, H 2002, 'Characterization procedure for adsorption of DOC (Dissolved Organic Carbon) from synthetic wastewater', KOREAN JOURNAL OF CHEMICAL ENGINEERING, vol. 19, no. 5, pp. 888-894.
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Li, J, Samali, B, Ye, L & Bakoss, S 2002, 'Behaviour of concrete beam–column connections reinforced with hybrid FRP sheet', Composite Structures, vol. 57, no. 1-4, pp. 357-365.
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Locke, M & Indraratna, B 2002, 'Filtration of broadly graded soils: the reduced PSD method', Géotechnique, vol. 52, no. 4, pp. 285-287.
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Mahlia, TMI 2002, 'Emissions from electricity generation in Malaysia', Renewable Energy, vol. 27, no. 2, pp. 293-300.
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Mahlia, TMI, Masjuki, HH & Choudhury, IA 2002, 'Development of energy labels for room air conditioner in Malaysia: methodology and results', Energy Conversion and Management, vol. 43, no. 15, pp. 1985-1997.
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Mahlia, TMI, Masjuki, HH & Choudhury, IA 2002, 'Potential electricity savings by implementing energy labels for room air conditioner in Malaysia', Energy Conversion and Management, vol. 43, no. 16, pp. 2225-2233.
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Mahlia, TMI, Masjuki, HH & Choudhury, IA 2002, 'Theory of energy efficiency standards and labels', Energy Conversion and Management, vol. 43, no. 6, pp. 743-761.
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Mahlia, TMI, Masjuki, HH, Choudhury, IA & Ghazali, NNN 2002, 'Economical and environmental impact of room air conditioners energy labels in Malaysia', Energy Conversion and Management, vol. 43, no. 18, pp. 2509-2520.
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Masjuki, HH, Mahlia, TMI, Choudhury, IA & Saidur, R 2002, 'Potential CO2 reduction by fuel substitution to generate electricity in Malaysia', Energy Conversion and Management, vol. 43, no. 6, pp. 763-770.
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Maskaoui, K, Zhou, JL, Hong, HS & Zhang, ZL 2002, 'Contamination by polycyclic aromatic hydrocarbons in the Jiulong River Estuary and Western Xiamen Sea, China', Environmental Pollution, vol. 118, no. 1, pp. 109-122.
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The distribution of 16 polycyclic aromatic hydrocarbons (PAHs) was determined in water, sediment and pore water of the Jiulong River Estuary and Western Xiamen Sea, China. Total PAH concentrations varied from 6.96 to 26.9 μg/l in water, 59-1177 ng/g dry weight in surficial sediments, and 158-949 μg/l in pore water. The PAHs were present in higher levels in pore water than in surface water, due possibly to higher concentrations of dissolved organic carbon or colloids with which the hydrophobic pollutants were strongly associated. Such a concentration gradient implies a potential flux of pollutants from sediment pore water to overlying water. The levels of PAHs in water and pore water were significantly higher than those found in 1998, suggesting recent inputs of these compounds into the area and re-working of sediment phase. The composition pattern of PAHs in the three phases was dominated by high molecular weight PAHs, in particular 5-ring PAHs. The salinity profile of dissolved PAHs suggested that they all behaved non-conservatively due to deviation from the theoretical dilution line. No correlation was found between PAH concentrations in sediment and those in pore water, and the correlation between the partition coefficients of PAHs and sediment organic carbon content was not significant, suggesting the complexity of the partition behaviour of PAHs. As a result of high PAH concentrations in water and pore water, it is likely that they may have caused mortality to certain exposed organisms. © 2002 Elsevier Science Ltd. All rights reserved.
Ngo, HH, Vigneswaran, S, Hu, JY, Thirunavukkarasu, O & Viraraghavan, T 2002, 'A comparison of conventional and non-conventional treatment technologies on arsenic removal from water', Water Supply, vol. 2, no. 5-6, pp. 119-125.
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In this study, four treatment methods were used to remove arsenic from water, namely: (i) chemical precipitation, (ii) arsenic adsorption onto iron-oxide-coated sand, (iii) high-rate saturated floating-medium flocculator/filter and (iv) membrane hybrid system (adsorption-microfiltration). The results indicated that more than 90% of total arsenic was removed by using FeCl3 (40 mg/L) as coagulant. The removal efficiency was 10% lower when polysilicato-iron (PSI, 2.5 mg/L) was used as a flocculant. The results of both the batch and column adsorption studies showed that iron-oxide-coated sand can effectively be used to achieve very high levels of arsenic removal (less than 5 μm/L as As in drinking water). Arsenic was removed up to 78% from the packed polystyrene beads filter with in-line FeCl3 addition at a high loading rate of 30 m3/m2.h. When powder activated carbon (PAC) was used in the membrane hybrid system, 87% removal of arsenic was achieved. A mixing time of 2.7 min with the mixing intensity of 87.8 s-1 were used. A very high filtration (permeate flux of 760 L/m2.h) was observed with a membrane of pore size of 0.2 μm.
Nicoletti, MDC & Brennan, J 2002, 'Learning spatial relations using an inductive logic programming system', Computing and Informatics, vol. 21, no. 1, pp. 17-36.
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The ability to learn spatial relations is a prerequisite for performing many relevant tasks such as those associated with motion, orientation, navigation, etc. This paper reports on using an Inductive Logic Programmming (ILP) system for learning function-free Horn-clause descriptions of spatial knowledge. Its main contribution, however, is to show that an existing relation between two reference systems - the speaker-relative and the absolute - can be automatically learned by an ILP system, given the proper background knowledge and positive examples.
Ponval, S, Pradhan, BK, Sharma, JK & Jain, SC 2002, 'Search and Render Algorithm for Three-dimensional Terrain Visualisation of Large Dataset', Defence Science Journal, vol. 52, no. 3, pp. 277-284.
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Thiruvenkatachari, R, Ngo, HH, Hagare, P, Vigneswaran, S & Aim, RB 2002, 'Flocculation—cross-flow microfiltration hybrid system for natural organic matter (NOM) removal using hematite as a flocculent', Desalination, vol. 147, no. 1-3, pp. 83-88.
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TULARAM, GA 2002, 'A Cylindrical Model of Pyrite Oxidation in Coastal Acidic Soils with Michaelis-Menten Uptake Kinetics', Environmental and Engineering Geoscience, vol. 8, no. 4, pp. 329-334.
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Val, DV & Stewart, MG 2002, 'Safety Factors for Assessment of Existing Structures', Journal of Structural Engineering, vol. 128, no. 2, pp. 258-265.
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Current structural codes have been developed mainly for new design and are not efficient for assessment because of significant differences between these situations. One of the main differences is the possibility to update information about an existing structure. This paper proposes a way in which updating can be taken into account when developing code safety formats (partial factor and load and resistance factor design). Updating information about individual structural properties such as material strengths by carrying out on-site inspections is discussed. Uncertainties associated with on-site testing including 'model' uncertainty are considered and a method for treating these uncertainties in the context of the partial factor format is described. Results indicate that 'model' uncertainty may have a significant effect on partial factors. Furthermore, we consider updating information about the resistance of the whole structure by proof load testing or by taking into account the previous safe performance of a structure. Results show that to increase the resistance reduction factor, the level of proof load needs to be high, resulting in a rather high risk of failure during the test. Satisfactory past performance does not have any noticeable effect on resistance factor, but it does have a more significant effect on probability of failure.
Wu, C & Hao, H 2002, 'Statistical analyses of RQD versus initial damage relationship of Singapore granite', Geotechnical Engineering, vol. 33, no. 3, pp. 103-112.
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This paper carries out statistical analysis of RQD, and correlates RQD with initial damage of the Bukit Timah granite in Singapore. RQDs are obtained by direct measurements of cores and boreholes and indirect measurements using P wave velocity on cores and seismic survey on the boreholes. Based on these data, it is found that RQDs measured both from the direct and indirect methods follow exponential distribution. The relationship of RQD and crack spacing is also derived. The initial damage of the rock mass, which models naturally existing geological discontinuities in a rock mass, is estimated using either the field-measured longitudinal and transverse elastic wave velocities or a damage tensor which is directly related to the discontinuities of the rock mass. By using Monte-Carlo simulation method, a relationship between the initial damage and RQD is derived.
Zhang, X 2002, 'Prediction of short fatigue crack propagation behaviour by characterization of both plasticity and roughness induced crack closures', International Journal of Fatigue, vol. 24, no. 5, pp. 529-536.
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Zhang, Z, Dai, M, Hong, H, Zhou, JL & Yu, G 2002, 'Dissolved insecticides and polychlorinated biphenyls in the Pearl River Estuary and South China Sea', Journal of Environmental Monitoring, vol. 4, no. 6, pp. 922-928.
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Persistent organic pollutants (POPs) such as organochlorine (OCl) insecticides and polychlorinated biphenyls (PCB), together with the new generation of organophosphorus (OP) insecticides, are of global concern, due to their widespread occurrence, persistence, bioaccumulation and hormone disruption potential. This paper represents an attempt to study the source and transportation of such pollutants in estuarine and coastal environments as an integrated ecosystem, by determining the levels of 18 OCl insecticides, 21 PCB congeners, and 17 OP insecticides in the Pearl River Estuary and South China Sea. The total concentrations varied from 126-1198 ng 1-1 for OCl insecticides, 33.38-1064 ng 1-1 for PCB congeners, and 4.44-6356 ng 1-1 for OP insecticides in the Pearl River Estuary. In comparison, their levels in the South China Sea were significantly lower, varying from 57.09-202 ng 1-1 for OCl insecticides, 21.72-144 ng 1-1 for PCBs, and 1.27-122 ng 1-1 for OP insecticides, respectively. The predominance of β-HCH in HCHs, and DDE in DDTs in all water samples was clearly observed, suggesting β-HCH and DDE's resistance to further degradation. The PCBs were dominated by those with 3-6 chlorines. The distribution characteristic of OP insecticides shows that five compounds (methamidophos, dimethoate, malathion, dichlorvos and omethoate) accounted for 56% and 72% of the total OP insecticide concentration. The relationship between pollutant concentrations and salinity in the estuary showed that they were all removed during the mixing process, therefore behaving non-conservatively.
Zhang, Z, Hong, H, Zhou, JL, Yu, G, Chen, W & Wang, X 2002, 'Transport and fate of organochlorine pesticides in the River Wuchuan, Southeast China', Journal of Environmental Monitoring, vol. 4, no. 3, pp. 435-441.
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Persistent organic pollutants (POPs) such as chlorinated pesticides are of global concern due to their widespread occurrence, persistence, bioaccumulation and toxicity to animals and human. This paper summarises recent research on 18 chlorinated pesticides in an important catchment in China, by determining their concentrations and behaviour in water, sediment, soil and plants. The concentrations of the total pesticides were in the ranges 187-893 ng 1-1 in river water, 8.53-210 ng g-1 dry weight in soil, 2.66-13.45 ng g-1 dry weight in river sediment, and 651-2823 ng g-1 dry weight in plants. The predominance of β-HCH as the major isomer of HCHs in all water, soil, sediment and plant samples was clearly observed, due to β-HCH's resistance to biodegradation. On average β-HCH accounted for 44%, 53%, 50%, and 46% of the total HCH concentration in water, soil, sediment and plant, respectively. Of the DDTs, DDE accounted for 48%, 43%, 53%, 55% of the total DDT, which suggested that DDT had been transformed to its metabolites, DDE and DDD, of which DDE was the more stable. The chlorinated pesticide levels in the River Wuchuan were generally below the guideline values in China, but some sites displayed levels in excess of EC Environmental Quality Standards for HCHs and DDTs. The results therefore provide important information on the current contamination status of a key agricultural watershed in China, and point to the need for urgent actions to evaluate the long-term fate and toxicity of such persistent compounds and an appropriate remediation strategy.
Zhang, ZL, Hong, HS, Zhou, JL & Yu, G 2002, 'Occurrence and behaviour of organophosphorus insecticides in the River Wuchuan, southeast China', Journal of Environmental Monitoring, vol. 4, no. 4, pp. 498-504.
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Organophosphorus (OP) insecticides are used worldwide, yet their persistence in the environment is not well understood. This paper summarises recent research on 17 OP insecticides in the River Wuchuan, an important catchment in China, by determining their concentrations in water, soil, sediment and plants by gas chromatography with flame photometric detection (GC-FPD). The concentrations of the total OP insecticides ranged from 92.77 to 229 ng 1-1 in river water, 1.61 to 9.93 ng g-1 dry weight in soil, 1.24 to 7.56 ng g-1 dry weight in sediment and 75.28 to 326 ng g-1 dry weight in plants. There was a relatively high abundance of methamidophos, dichlorvos, malathion, omethoate and dimethoate in all water, soil, sediment and plant samples. On average, these five compounds collectively accounted for 64%, 71%, 71% and 54% of the total OP insecticide concentration in water, soil, sediment and plants, respectively, which was similar to the composition of OP insecticides in application formulations used in our study area and in China as a whole. The results therefore reflect the application pattern to some extent, and suggest that the sources of the OP insecticides are mainly from current usage. When compared with other areas, the levels of OP insecticides in the River Wuchuan were moderate. The animal and human risks from exposure to OP insecticides in water and plants were evaluated against relevant threshold values. The results therefore provide important information on the current contamination status of a key agricultural watershed in China, and point to the need for urgent action to control the use of some excessively applied and potentially persistent agrochemicals, such as methamidophos, omethoate and dimethoate.
Zhang, ZL, Hong, HS, Zhou, JL, Dai, MH, Maskaouib, K & Chen, WQ 2002, 'Contamination by organochlorine pesticides in the estuaries of southeast China', Chemical Research in Chinese Universities, vol. 18, no. 2, pp. 153-160.
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Persistent organic pollutants (POPs) such as organochlorine pesticides are of global concern due to their widespread occurrence and persistence. This paper reports recent research studying the distribution and fate of organochlorine pesticides in the Jiulong River, the Minjiang River and the Pearl River estuaries in Southeast China. Eighteen organochlorine pesticides were extracted from water, pore water and sediment samples, followed by analysis by GC-ECD. The results showed that the contamination levels were similar in these three estuaries. The levels of the total organochlorine pesticides in porewater were significantly higher than those in surface water, due to the high affinity of these hydrophobic compounds for sediment phase. Among the hexachlorocy-clohexane (HCH) compounds, β-HCH was found to be the most important isomer. The analysis of 1, 1, 1-trichloro-2, 2-bis-chlorophyenyl-ethane (DDT) and its metabolites showed that 1, 1-dichloro-2 [o-chloropheny1]-2 [p-chlorophenyl]-ethylene (DDE) was dominant in the group.
ZHU, XQ & LAW, SS 2002, 'DYNAMIC LOAD ON CONTINUOUS MULTI-LANE BRIDGE DECK FROM MOVING VEHICLES', Journal of Sound and Vibration, vol. 251, no. 4, pp. 697-716.
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Zhu, XQ & Law, SS 2002, 'Moving Loads Identification Through Regularization', Journal of Engineering Mechanics, vol. 128, no. 9, pp. 989-1000.
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ZHU, XQ & LAW, SS 2002, 'PRACTICAL ASPECTS IN MOVING LOAD IDENTIFICATION', Journal of Sound and Vibration, vol. 258, no. 1, pp. 123-146.
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Several methods have been developed in recent years to identify moving loads on top of a continuous beam using measured vibration responses. The methods can identify the forces with some accuracy, but they have not been tested under field measurement conditions with a bridge-vehicle system. This paper discusses the weaknesses and merits of two methods when applied to a single-span bridge deck. The influence, on the moving load identification, of practical aspects such as measurement noise, sampling frequency, a small number of measured response modes, a small number of measuring points, road surface roughness and non-uniform velocity or braking of vehicle is studied in simulations and experiment. Results show that finite element approach with orthogonal function approximation of the responses give more accurate results, in general, than the exact solution approach for all the studies presented in this paper. The road surface roughness and a large variation in the speed are identified as the two main obstacles leading to erroneous results. © 2002 Elsevier Science Ltd. All rights reserved.
Brennan, J & Martin, E 1970, 'Foundations for a Formalism of Nearness', Lecture Notes in Artificial Intelligence (Subseries of Lecture Notes in Computer Science), Springer Berlin Heidelberg, pp. 71-82.
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Reasoning about your spatial environment can be a challenging task, especially when you are a robot trying to rely solely on quantitative measures. With nearness being such a vague concept, a qualitative representation is an obvious choice offering a wider range of possible values. This paper introduces a qualitative representation for spatial proximity that accounts for absolute binary nearness relations. The formalism is based on the notion of perceived points, called sites, in a point based universe. Proximity concepts are determined by the parameters of distance between two sites and weight of each of those sites. These parameters were drawn from the concept of Generalised Voronoi Diagrams. Cognitively useful models and interpretations of our formalism are shown in both a navigation and a natural language context.
Choi, K & Ball, JE 1970, 'A Generic calibration approach: Monitoring the calibration', Proc. 2002 Hydrology and Water Resources Symposium, Hydrology and Water Resources Symposium, The Institution Engineers, Australia, Melbourne.
Choi, K-S & Ball, JE 1970, 'Investigation of Model Complexity and Structure on the Calibration Process', Global Solutions for Urban Drainage, Ninth International Conference on Urban Drainage (9ICUD), American Society of Civil Engineers, Portland, Oregon, USA, pp. 1-9.
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Inference models for estimation of the parameters necessary to implement the Stormwater Management Model (SWMM) were developed and implemented using the Centennial Park Catchment in Sydney, Australia as a test catchment. A number of alternative inference models were developed to assess the influence of inference model complexity and structure on the calibration of the catchment modelling system. These inference models varied from the assumption of a spatially invariant value (catchment average) to spatially variable with each subcatchment having its own unique values. Furthermore, the influence of different measures of deviation between the recorded information and simulation predictions were considered. Presented herein is the results of these investigations into the complexity and structure of models used in the calibration process.
Jegatheesan, V, Lamsal, PR, Visvanathan, C, Ngo, HH & Shu, L 1970, 'Effect of natural organic compounds on the removal of organic carbon in coagulation and flocculation processes', Water Science and Technology: Water Supply, 3rd World Water Congress of the International-Water-Association, I W A PUBLISHING, MELBOURNE, AUSTRALIA, pp. 473-479.
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Natural organic matter (NOM) in water contains organic compounds that are both hydrophobic and hydrophilic with a wide range of molecular weights. It is composed of non-homogeneous organic compounds such as humic substances, amino acids, sugars, aliphatic and aromatic acids, and other chemical synthetic organic matters. NOM in water is a major concern not only because of its contribution to the formation of disinfection by-products (DBPs) and taste and odor, but also its influence on the demand for coagulants and disinfectants, the removal efficiency of water treatment processes, etc. This research aims at identifying the influence of NOM in coagulation and flocculation processes in order to optimize the coagulation and flocculation conditions. In this study, pretreated pond water was used as the source water. It was observed from the experimental results that: (1) The optimum pH for coagulation to remove NOM is around 7. (2) The optimum alum dose at this pH can vary from 125-1,225 mgl-1 when the TOC is increased from 4 to 25 mgl-1. (3) The presence of secondary compounds such as Ca2+, Mg2+ divalent cations had no significant effect on the removal of organic matter. (4) The presence of clay increased the organic removal by 15%. (5) The organic compound with higher molecular weight has higher removal affinity in coagulation process. (6) Floc size and settling velocity of floc and sludge production all increased with the increase in NOM concentration. From the results of Capillary Suction Time (CST) tests, the floc formed with lower TOC readily released the water to make the dewatering process easier. (7) The organic removal efficiency was significantly different for natural water containing non-homogeneous organic compounds compared to the synthetic water containing humic acid only (homogeneous organic matter). For example, the NOM removal efficiency was 80% for the synthetic water containing humic acid with TOC of 7 mgl-1 at pH 7; but the NOM removal for the pret...
LI, J & SAMALI, B 1970, 'VARIABLE STRUCTURE CONTROL OF SEISMICALLY EXCITED STRUCTURE WITH SHAPE MEMORY ALLOY ACTUATORS', Applied Mechanics, Proceedings of the Third Australasian Congress on Applied Mechanics, WORLD SCIENTIFIC, Sydney, Australia, pp. 665-670.
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Li, J, Samali, B & Chapman, C 1970, 'Experimental realisation of active control of a five storey building model using SMA actuators', Advances in Mechanics of Structures and Materials, The 17th Australasian Conference on the Mechanics of Structures and Materials, A.A. Balkema Publishers, Gold Coast, Australia, pp. 699-704.
Li, JC, Samali, B & Ha, G 1970, 'FUZZY SLIDING MODE CONTROL OF A FIVE STOREY BENCHMARK MODEL EQUIPPED WITH ACTIVE MASS DRIVER (AMD)', The Proceedings of the International Conference on Motion and Vibration Control, International Conference on Motion and Vibration Control, Japan Society of Mechanical Engineers, Saitama Japan, pp. 172-177.
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Ngo, HH, Vigneswaran, S, Hu, JY, Thirunavukkarasu, O & Viraraghavan, T 1970, 'A comparison of conventional and non-conventional treatment technologies on arsenic removal from water', Water Science and Technology: Water Supply, 3rd World Water Congress of the International-Water-Association, I W A PUBLISHING, MELBOURNE, AUSTRALIA, pp. 119-125.
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In this study, four treatment methods were used to remove arsenic from water, namely: (i) chemical precipitation, (ii) arsenic adsorption onto iron-oxide-coated sand, (iii) high-rate saturated floating-medium flocculator/filter and (iv) membrane hybrid system (adsorption-microfiltration). The results indicated that more than 90% of total arsenic was removed by using FeCl3 (40 mg/L) as coagulant. The removal efficiency was 10% lower when polysilicato-iron (PSI, 2.5 mg/L) was used as a flocculant. The results of both the batch and column adsorption studies showed that iron-oxide-coated sand can effectively be used to achieve very high levels of arsenic removal (less than 5 μm/L as As in drinking water). Arsenic was removed up to 78% from the packed polystyrene beads filter with in-line FeCl3 addition at a high loading rate of 30 m3/m2.h. When powder activated carbon (PAC) was used in the membrane hybrid system, 87% removal of arsenic was achieved. A mixing time of 2.7 min with the mixing intensity of 87.8 s-1 were used. A very high filtration (permeate flux of 760 L/m2.h) was observed with a membrane of pore size of 0.2 μm.
Samali, B, Al Dawod, M & Li, JC 1970, 'PERFORMANCE OF AN ACTIVE MASS DRIVER SYSTEM ON A FIVE STOREY BENCHMARK MODEL', The Proceedings of the International Conference on Motion and Vibration Control, Japan Society of Mechanical Engineers, Japan, pp. 166-171.
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SAMALI, B, AL-DAWOD, M & LI, J 1970, 'PERFORMANCE OF A FIVE STOREY BENCHMARK MODEL USING AN ACTIVE MASS DRIVER AND A FUZZY CONTROLLER', Applied Mechanics, Proceedings of the Third Australasian Congress on Applied Mechanics, WORLD SCIENTIFIC, Gold Coast, Australia, pp. 647-652.
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Samali, B, Wu, Y & Li, J 1970, 'Torsional response of a base-isolated eccentric building model', Advances in Mechanics of Structures and Materials, The 17th Australasian Conference on the Mechanics of Structures and Materials, A.A. Balkema Publishers, Gold Coast, Australia, pp. 769-774.
Thiruvenkatachari, R, Ngo, HH, Hagare, P, Vigneswaran, S & Ben Aim, R 1970, 'Flocculation-cross-flow microfiltration hybrid system for natural organic matter (NOM) removal using hematite as a flocculent', DESALINATION, International Congress on Membranes and Membrane Processes (ICOM), ELSEVIER SCIENCE BV, TAULOUSE, FRANCE, pp. 83-88.
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Thomas, P & Stuart, BH 1970, 'Crystalline morphology of PEEK in PEEK-PTFE blends', 8th Symposium on Thermal Analysis and Calorimetry Abstracts Book, 8th Symposium on Thermal Analysis and Calorimetry, Barcelona.
Umakhanthan, K & Ball, JE 1970, 'Estimation of Rainfall Heterogeneity across Space and Time Scale', Global Solutions for Urban Drainage, Ninth International Conference on Urban Drainage (9ICUD), American Society of Civil Engineers, Portland, Oregon, pp. 1-16.
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Over the last decade, it has been recognized that the spatial and temporal variability of rainfall is a significant influence on the robustness of predictions from catchment modelling systems. However, there have been few, if any, attempts to differentiate storm events occurring on urban catchments according to their variability in both the space and time dimensions. Presented in this paper will be a technique for assessing the spatial and temporal heterogeneity of individual storm events. Also presented will be the application of this technique for the analysis of storm events occurring over urban catchments within the Sydney urban area. This analysis will be based on five-minute rainfall records extracted from the 14 pluviometers within Upper Parramatta River (110 km 2 ) and from the 6 pluviometers in and around the Centennial Park (1.3km 2 ) catchments within Sydney, Australia. As a result of the analysis, storms were categorized as being â¦High spatial and high temporal variability (HS-HT), â¦High spatial and low temporal variability (HS-LT), â¦Low spatial and high temporal variability (LS-HT), and â¦Low spatial and low temporal variability (LS-LT). This categorization was undertaken as part of an investigation into the importance of alternate rainfall models for application in Catchment Modelling Systems.
Umakhanthan, K & Ball, JE 1970, 'Estimation of Spatio-temporal heterogeneity of rainfall and its importance towards a more robust catchment simulation', Proceedings of the International Conference on Urban Hydrology for the 21st Century - Urban Problems in the New Millennium, International Conference on Urban Hydrology for the 21st Century, Water Resources Centre for Southeast Asia and the Pacific, HTC Kuala Lumpur, Malaysia, pp. 1-16.
Umakhanthan, K & Ball, JE 1970, 'Importance of rainfall models in catchment simulation', ADVANCES IN HYDRAULICS AND WATER ENGINEERING, VOLS 1 AND 2, PROCEEDINGS, 13th Congress of the Asia/Pacific Division of the International-Association-of-Hydraulic-Engineering-and-Research, WORLD SCIENTIFIC PUBL CO PTE LTD, SINGAPORE, SINGAPORE, pp. 551-556.
WU, YM, SAMALI, B & LI, J 1970, 'EARTHQUAKE RESISTANT PERFORMANCE OF LAMINATED AND LEAD CORE RUBBER BEARINGS', Applied Mechanics, Proceedings of the Third Australasian Congress on Applied Mechanics, WORLD SCIENTIFIC, Sydney, Australia, pp. 659-664.
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