Open Access. Powered by Scholars. Published by Universities.®

Social and Behavioral Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1141 - 1170 of 2936

Full-Text Articles in Social and Behavioral Sciences

Coupled Hydro-Geochemical Modelling Of A Permeable Reactive Barrier For Treating Acidic Groundwater, Buddhima Indraratna, Punyama Pathirage, Kerry Rowe, Laura Banasiak Jan 2014

Coupled Hydro-Geochemical Modelling Of A Permeable Reactive Barrier For Treating Acidic Groundwater, Buddhima Indraratna, Punyama Pathirage, Kerry Rowe, Laura Banasiak

Faculty of Engineering and Information Sciences - Papers: Part A

This study focuses on coupling geochemistry with geo-hydraulics to enable time-dependent modelling of the remediation of acidic groundwater using an alkaline permeable reactive barrier (PRB). Chemical clogging due to secondary mineral precipitates reduces the porosity and hydraulic conductivity of the reactive medium. The governing equations are incorporated into commercial numerical codes, MODFLOW and RT3D. An original algorithm was developed for RT3D to simulate geochemical reactions occurring in the PRB. The results and the model predictions are in agreement, confirming that the hydraulic conductivity reduction due to mineral precipitation occurs at the start of permeation and continues until halfway through the …


Residual Stresses In Rail-Ends From The In-Service Insulated Rail Joints Using Neutron Diffraction, Vladimir Luzin, Chandrahas Rathod, David Wexler, Paul Boyd, Manicka Dhanasekar Jan 2014

Residual Stresses In Rail-Ends From The In-Service Insulated Rail Joints Using Neutron Diffraction, Vladimir Luzin, Chandrahas Rathod, David Wexler, Paul Boyd, Manicka Dhanasekar

Faculty of Engineering and Information Sciences - Papers: Part A

Insulated rail joints (IRJs) are an integral part of the rail track signaling system and pose significant maintenance and replacement costs due to their low and fluctuating service lives. Failure occurs mainly in rail head region, bolt-holes of fishplates and web-holes of the rails. Propagation of cracks is influenced by the evolution of internal residual stresses in rails during rail manufacturing (hot-rolling, roller-straightening, and head-hardening process), and during service, particularly in heavy rail haul freight systems where loads are high. In this investigation, rail head accumulated residual stresses were analysed using neutron diffraction at the Australian Nuclear Science and Technology …


On The Security Of Auditing Mechanisms For Secure Cloud Storage, Yong Yu, Lei Niu, Guomin Yang, Yi Mu, Willy Susilo Jan 2014

On The Security Of Auditing Mechanisms For Secure Cloud Storage, Yong Yu, Lei Niu, Guomin Yang, Yi Mu, Willy Susilo

Faculty of Engineering and Information Sciences - Papers: Part A

Cloud computing is a novel computing model that enables convenient and on-demand access to a shared pool of configurable computing resources. Auditing services are highly essential to make sure that the data is correctly hosted in the cloud. In this paper, we investigate the active adversary attacks in three auditing mechanisms for shared data in the cloud, including two identity privacy-preserving auditing mechanisms called Oruta and Knox, and a distributed storage integrity auditing mechanism. We show that these schemes become insecure when active adversaries are involved in the cloud storage. Specifically, an active adversary can arbitrarily alter the cloud data …


A Model For Acid-Mediated Tumour Growth With Nonlinear Acid Production Term, Andrew B. Holder, Marianito R. Rodrigo, Miguel A. Herrero Jan 2014

A Model For Acid-Mediated Tumour Growth With Nonlinear Acid Production Term, Andrew B. Holder, Marianito R. Rodrigo, Miguel A. Herrero

Faculty of Engineering and Information Sciences - Papers: Part A

This article considers a mathematical model for tumour growth based on an acid-mediated hypothesis, i.e. the assumption that tumour progression is facilitated by acidification of the region around the tumour-host interface. The resulting destruction of the normal tissue environment promotes tumour growth. We will derive and analyse a reaction-diffusion model for tumour progression that includes different aspects of pathological and healthy cell metabolism to check tumour growth. Our results can provide insights into the governing dynamics of invasive processes that may suggest possible intervention strategies, leading to the design of new and better experiments or treatments.


Cellular Automaton Simulation Of Hot Deformation Of Trip Steel, Ying Zhi, Xianghua Liu, Hailiang Yu Jan 2014

Cellular Automaton Simulation Of Hot Deformation Of Trip Steel, Ying Zhi, Xianghua Liu, Hailiang Yu

Faculty of Engineering and Information Sciences - Papers: Part A

The recrystallization process of hot deformed austenite of TRIP steel was predicted using Cellular Automaton (CA) combined with the principles of physical metallurgy. A model was developed for prediction of the dynamic and static recrystallization microstructure evolution and properties of hot deformed austenite for TRIP steel. The theoretical modeling of recrystallization was based on dislocation density. The microstructure evolution of austenite recrystallization of TRIP steel (such as the grain shape and size, volume fraction, kinetics curve of recrystallization) was predicted both visually and quantitatively. The distribution and variation of the dislocation density and flow stress were also obtained, and the …


Approximate Ordinary Differential Equations For The Optimal Exercise Boundaries Of American Put And Call Options, Marianito R. Rodrigo Jan 2014

Approximate Ordinary Differential Equations For The Optimal Exercise Boundaries Of American Put And Call Options, Marianito R. Rodrigo

Faculty of Engineering and Information Sciences - Papers: Part A

We revisit the American put and call option valuation problems. We derive analytical formulas for the option prices and approximate ordinary differential equations for the optimal exercise boundaries. Numerical simulations yield accurate option prices and comparable computational speeds when benchmarked against the binomial method for calculating option prices. Our approach is based on the Mellin transform and an adaptation of the Kármán–Pohlausen technique for boundary layers in fluid mechanics.


Behavior Of Fresh And Fouled Railway Ballast Subjected To Direct Shear Testing: Discrete Element Simulation, B Indraratna, N T Ngo, C Rujikiatkamjorn, J S. Vinod Jan 2014

Behavior Of Fresh And Fouled Railway Ballast Subjected To Direct Shear Testing: Discrete Element Simulation, B Indraratna, N T Ngo, C Rujikiatkamjorn, J S. Vinod

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents the three-dimensional discrete element method (DEM) that was used to study the shear behaviour of fresh and coal fouled ballast in direct shear testing. The volumetric changes and stress-strain behaviour of fresh and fouled ballast were simulated and compared with the experimental results. 'Clump logic' in Particle Flow Code (PFC3D) incorporated in a MATLAB Code was used to simulate irregular shaped particles in which groups of ten to twenty spherical balls were clumped together in appropriate sizes to simulate ballast particles. Fouled ballast with various Void Contaminant Index (VCI), ranging from 20%VCI to 70%VCI, were modelled by …


A Novel Hybrid-Link-Based Container Routing Model, Shuaian Wang Jan 2014

A Novel Hybrid-Link-Based Container Routing Model, Shuaian Wang

Faculty of Engineering and Information Sciences - Papers: Part A

Container routing determines how to transport containers from their origins to their destinations in a liner shipping network. Container routing needs to be solved a number of times as a subproblem in tactical-level decision planning of liner shipping operations. Container routing is similar to the multi-commodity flow problem. This research proposes a novel hybrid-link-based model that nests the existing origin-link-based and destination-link-based models as special cases. Moreover, the hybrid-link-based model is at least as compact as the origin-to-destination-link-based, origin-link-based and destination-link-based models in the literature.


Degradation Trend Estimation And Prognosis Of Large Low Speed Slewing Bearing Lifetime, Prabuono Buyung Kosasih, Wahyu Caesarendra, Kiet Tieu, Achmad Widodo, Craig A. S Moodie Jan 2014

Degradation Trend Estimation And Prognosis Of Large Low Speed Slewing Bearing Lifetime, Prabuono Buyung Kosasih, Wahyu Caesarendra, Kiet Tieu, Achmad Widodo, Craig A. S Moodie

Faculty of Engineering and Information Sciences - Papers: Part A

In many applications, degradation of bearing conditions is usually monitored by changes in time-domain features. However, in low speed (< 10 rpm) slewing bearing, these changes are not easily detected because of the low energy and low frequency of the vibration. To overcome this problem, a combined low pass filter (LPF) and adaptive line enhancer (ALE) signal preconditioning method is used. Time-domain features such as root mean square (RMS), skewness and kurtosis are extracted from the output signal of the combined LPF and ALE method. The extracted features show accurate information about the incipient of fault as compared to extracted features from the original vibration signal. This information then triggers the prognostic algorithm to predict the remaining lifetime of the bearing. The algorithm used to determine the trend of the nonstationary data is auto-regressive integrated moving average (ARIMA).


A New Model For The Prediction Of Earthquake Ground-Motion Duration In Iran, Saman Yaghmaei-Sabegh, Zhila Shoghian, M Neaz Sheikh Jan 2014

A New Model For The Prediction Of Earthquake Ground-Motion Duration In Iran, Saman Yaghmaei-Sabegh, Zhila Shoghian, M Neaz Sheikh

Faculty of Engineering and Information Sciences - Papers: Part A

The paper proposes a new empirical model to estimate earthquake ground-motion duration, which significantly influences the damage potential of an earthquake. The paper is concerned with significant duration parameters that are defined as the time intervals between which specified values of Arias intensity are reached. In the proposed model, significant duration parameters have been expressed as a function of moment magnitude, closest site-source distance, and site condition. The predictive model has been developed based on a database of earthquake ground-motion records in Iran, containing 286 records up to the year 2007, and a random-effect regression procedure. The result of the …


Understanding Demographics Influence On Teleconsultation Acceptance In Hospital: A Mixed-Method Study, Nurazean Maarop, Khin T. Win, Sukdershan Singh Hs Jan 2014

Understanding Demographics Influence On Teleconsultation Acceptance In Hospital: A Mixed-Method Study, Nurazean Maarop, Khin T. Win, Sukdershan Singh Hs

Faculty of Engineering and Information Sciences - Papers: Part A

The aim of this study is to explore and understand the influence of demographic factors on teleconsultation acceptance in Malaysian government hospitals. The materials of this study are based on an exploratory mixed-method study involving semi-structured interviews with key informants and questionnaires survey of health care providers. The prominent influence of demographic aspects over the acceptance of teleconsultation technology from the mixed methods standpoint is further discussed. The findings of both results provide evidence to suggest that teleconsultation acceptance differs across the types of hospital, distance between referring and referral hospital, role of teleconsultation, and user's computer ability. Interestingly, user's …


Removal Of Pharmaceuticals, Steroid Hormones, Phytoestrogens, Uv-Filters, Industrial Chemicals And Pesticides By Trametes Versicolor: Role Of Biosorption And Biodegradation, Luong Nguyen, Faisal Ibney Hai, Shufan Yang, Jinguo Kang, Frederic Leusch, Felicity Roddick, William E. Price, Long D. Nghiem Jan 2014

Removal Of Pharmaceuticals, Steroid Hormones, Phytoestrogens, Uv-Filters, Industrial Chemicals And Pesticides By Trametes Versicolor: Role Of Biosorption And Biodegradation, Luong Nguyen, Faisal Ibney Hai, Shufan Yang, Jinguo Kang, Frederic Leusch, Felicity Roddick, William E. Price, Long D. Nghiem

Faculty of Engineering and Information Sciences - Papers: Part A

This study reports the removal of 30 diverse trace organic contaminants (TrOC) by live (biosorption þ biodegradation), intracellular enzyme-inhibited and chemically inactivated (biosorption only) whole-cell preparations and the fungal extracellular enzyme extract (predominantly laccase) from Trametes versicolor (ATCC 7731). Because phenolic substrates are amenable to degradation by laccase, all 14 phenolic TrOC were readily biodegraded. On the other hand, only eight of the 16 non-phenolic TrOC were readily biodegraded while the removal of hydrophilic TrOC (log D < 3) was negligible. With the exception of diclofenac, no non-phenolic TrOC were degraded by the extracellular enzyme extract. The whole-cell culture showed considerably higher degradation of at least seven compounds, indicating the importance of biosorption and subsequent degradation by intracellular and/or mycelium associated enzymes. Improvement (20e90%) of enzymatic degradation of four phenolic and seven non-phenolic TrOC was achieved in the presence of a redox mediator. Compared with the whole-cell culture, mediator-amended extracellular extract achieved better removal of six TrOC, but lower removal of six others. A particular concern was the increased toxicity of the treated media when the redox-mediator was used. In addition to reporting the white-rot fungal removal of two UV filters, three phytoestrogens and a few other pharmaceutically active TrOC for the first time, this study provides unique insights into their removal mechanisms.


A Comprehensive Tool To Analyse Dynamic Log Files From An Elekta-Synergy Accelerator, Sankar Arumugam, Aitang Xing, Claire Pagulayan, Lois Holloway Jan 2014

A Comprehensive Tool To Analyse Dynamic Log Files From An Elekta-Synergy Accelerator, Sankar Arumugam, Aitang Xing, Claire Pagulayan, Lois Holloway

Faculty of Engineering and Information Sciences - Papers: Part A

This study presents the development of a software tool 'Treat Check' to analyse the dynamic log files from an Elekta - Synergy accelerator. The software generates formatted output in the form of a plot presenting errors in various treatment delivery parameters such as gantry angle, Multi Leaf Collimator (MLC) leaf position, jaw position and Monitor Units (MU) for each of the control-points (CP) of the treatment beam. The plots are automatically saved in Portable Document Format (pdf). The software also has the functionality to introduce these treatment delivery errors into the original plan in the Pinnacle (Philips) treatment planning system …


Preliminary Investigation Of An Soi-Based Arrayed Waveguide Grating Demodulation Integration Microsystem, Hongqiang Li, Wenqian Zhou, Yu Liu, Cheng Zhang, Changyun Miao, Meiling Zhang, Enbang Li, Chunxiao Tang Jan 2014

Preliminary Investigation Of An Soi-Based Arrayed Waveguide Grating Demodulation Integration Microsystem, Hongqiang Li, Wenqian Zhou, Yu Liu, Cheng Zhang, Changyun Miao, Meiling Zhang, Enbang Li, Chunxiao Tang

Faculty of Engineering and Information Sciences - Papers: Part A

No abstract provided.


Toll Pricing Framework Under Logit-Based Stochastic User Equilibrium Constraints, Zhiyuan Liu, Shuaian Wang, Qiang Meng Jan 2014

Toll Pricing Framework Under Logit-Based Stochastic User Equilibrium Constraints, Zhiyuan Liu, Shuaian Wang, Qiang Meng

Faculty of Engineering and Information Sciences - Papers: Part A

This paper addresses the toll pricing framework for the first-best pricing with logit-based stochastic user equilibrium (SUE) constraints. The first-best pricing is usually known as marginal-cost toll, which can be obtained by solving a traffic assignment problem based on the marginal cost functions. The marginal-cost toll, however, has rarely been implemented in practice, because it requires every specific link on the network to be charged. Thus, it is necessary to search for a substitute of the marginal cost pricing scheme, which can reduce the toll locations but still minimize the total travel time. The toll pricing framework is the set …


On-Chip High-Throughput Manipulation Of Particles In A Dielectrophoresis-Active Hydrophoretic Focuser, Sheng Yan, Jun Zhang, Ming Li, Gursel Alici, Haiping Du, Ronald Sluyter, Weihua Li Jan 2014

On-Chip High-Throughput Manipulation Of Particles In A Dielectrophoresis-Active Hydrophoretic Focuser, Sheng Yan, Jun Zhang, Ming Li, Gursel Alici, Haiping Du, Ronald Sluyter, Weihua Li

Faculty of Engineering and Information Sciences - Papers: Part A

This paper proposes a novel concept of dielectrophoresis (DEP)-active hydrophoretic focusing of micro-particles and murine erythroleukemia (MEL) cells. The DEP-active hydrophoretic platform consists of crescent shaped grooves and interdigitated electrodes that generate lateral pressure gradients. These embedded electrodes exert a negative DEP force onto the particles by pushing them into a narrow space in the channel where the particle to groove interaction is intensive and hydrophoretic ordering occurs. Particles passing through the microfluidic device are directed towards the sidewalls of the channel. The critical limitation of DEP operating at a low flow rate and the specific hydrophoretic device for focusing …


An Experimental Investigation On The Deformation And Degradation Behaviour Of Geogrid-Reinforced Ballast, Sd. K Karimullah Hussaini, B Indraratna, J S. Vinod Jan 2014

An Experimental Investigation On The Deformation And Degradation Behaviour Of Geogrid-Reinforced Ballast, Sd. K Karimullah Hussaini, B Indraratna, J S. Vinod

Faculty of Engineering and Information Sciences - Papers: Part A

Railroad ballast, owing to its unbounded granular nature, spreads laterally when subjected to large vertical axle loads, which influences the track stability. In this view, large-scale cyclic tests have been conducted on ballast to explore the role of geogrid in controlling the lateral deformation of ballast and hence improving the track performance. Fresh latite ballast having a mean particle size of 35 mm and geogrids with different aperture sizes was used for the investigations. Tests were conducted using a modified process simulation test (MPST) apparatus at a loading frequency of 20 Hz, with geogrid placed at the subballast-ballast interface and …


Energy-Efficiency Analysis Of Per-Subcarrier Antenna Selection With Peak-Power Reduction In Mimo-Ofdm Wireless Systems, Ngoc Phuc Le, Le Chung Tran, Farzad Safaei Jan 2014

Energy-Efficiency Analysis Of Per-Subcarrier Antenna Selection With Peak-Power Reduction In Mimo-Ofdm Wireless Systems, Ngoc Phuc Le, Le Chung Tran, Farzad Safaei

Faculty of Engineering and Information Sciences - Papers: Part A

The use of per-subcarrier antenna subset selection in OFDM wireless systems offers higher system capacity and/or improved link reliability.However, the implementation of the conventional per-subcarrier selection schememay result in significant fluctuations of the average power and peak power across antennas, which affects the potential benefits of the system. In this paper, power efficiency of high-power amplifiers and energy efficiency in per-subcarrier antenna selection MIMO-OFDM systems are investigated. To deliver the maximum overall power efficiency, we propose a two-step strategy for data-subcarrier allocation.This strategy consists of an equal allocation of data subcarriers based on linear optimization and peak-power reduction via cross-antenna …


Molecular Weight Distribution Of Network Strands In Double Network Hydrogels Estimated By Mechanical Testing, Hai Xin, Hugh Ralph Brown, Geoffrey M. Spinks Jan 2014

Molecular Weight Distribution Of Network Strands In Double Network Hydrogels Estimated By Mechanical Testing, Hai Xin, Hugh Ralph Brown, Geoffrey M. Spinks

Faculty of Engineering and Information Sciences - Papers: Part A

The remarkably high toughness of double network (DN) hydrogels is related to the energy dissipation that occurs due to the scission of network strands in the most tightly crosslinked of its two interpenetrating networks. The loading curve during tensile testing of DN hydrogels usually takes a complex shape and sometimes shows yielding. Wang and Hong recently proposed a model [1] based on the successive scission of the shortest remaining elastically active strands during tensile loading that predicts the shape of the loading curve of one DN hydrogel reasonably well. In the present study, the model was modified slightly and applied …


Colloidal Solitary Waves With Temperature Dependent Compressibility, Amirah Azmi, Timothy Marchant Jan 2014

Colloidal Solitary Waves With Temperature Dependent Compressibility, Amirah Azmi, Timothy Marchant

Faculty of Engineering and Information Sciences - Papers: Part A

Spatial solitary waves which form in colloidal suspensions of dielectric nanoparticles are considered. The interactions, or compressibility, of the colloidal particles, is modelled using a series in the particle density, or packing fraction, where the virial, or series, coefficients depend on the type of particle interaction model. Both the theoretical hard disk and sphere repulsive models, and a model with temperature dependent compressibility, are considered. Experimental results show that particle interactions can be temperature dependent and either repulsive or attractive in nature, so we model the second virial coefficient using a physically realistic temperature power law. One- and two-dimensional semi-analytical …


Improved Workflow Modelling Using Role Activity Diagram-Based Modelling With Application To A Radiology Service Case Study, Nagesh Shukla, John Keast, Darek Ceglarek Jan 2014

Improved Workflow Modelling Using Role Activity Diagram-Based Modelling With Application To A Radiology Service Case Study, Nagesh Shukla, John Keast, Darek Ceglarek

Faculty of Engineering and Information Sciences - Papers: Part A

The modelling of complex workflows is an important problem-solving technique within healthcare settings. However, currently most of the workflow models use a simplified flow chart of patient flow obtained using on-site observations, groupbased debates and brainstorming sessions, together with historic patient data. This paper presents a systematic and semi-automatic methodology for knowledge acquisition with detailed process representation using sequential interviews of people in the key roles involved in the service delivery process. The proposed methodology allows the modelling of roles, interactions, actions, and decisions involved in the service delivery process. This approach is based on protocol generation and analysis techniques …


A Deformation Mechanism Of Hard Metal Surrounded By Soft Metal During Roll Forming, Hailiang Yu, A Kiet Tieu, Cheng Lu, Xiong Liu, Ajit Godbole, Huijun Li, Charlie Kong, Q Qin Jan 2014

A Deformation Mechanism Of Hard Metal Surrounded By Soft Metal During Roll Forming, Hailiang Yu, A Kiet Tieu, Cheng Lu, Xiong Liu, Ajit Godbole, Huijun Li, Charlie Kong, Q Qin

Faculty of Engineering and Information Sciences - Papers: Part A

It is interesting to imagine what would happen when a mixture of soft-boiled eggs and stones is deformed together. A foil made of pure Ti is stronger than that made of Cu. When a composite Cu/Ti foil deforms, the harder Ti will penetrate into the softer Cu in the convex shapes according to previously reported results. In this paper, we describe the fabrication of multilayer Cu/Ti foils by the roll bonding technique and report our observations. The experimental results lead us to propose a new deformation mechanism for a hard metal surrounded by a soft metal during rolling of a …


Shear Strength Of Rock Joints Influenced By Compacted Infill, Buddhima Indraratna, Wuditha N. Premadasa, Edwin T. Brown, Antonio Gens, Ana Heitor Jan 2014

Shear Strength Of Rock Joints Influenced By Compacted Infill, Buddhima Indraratna, Wuditha N. Premadasa, Edwin T. Brown, Antonio Gens, Ana Heitor

Faculty of Engineering and Information Sciences - Papers: Part A

Discontinuities such as fault planes, joints and bedding planes in a rock mass may be filled with different types of fine-grained material that are either transported or accumulated as gouge due to weathering or joint shearing. Previous laboratory studies have mainly examined the role of saturated infill that exhibits the minimum shear strength. However, in practice, the infill materials are often partially saturated generating matric suction within the joint that can contribute to increased shear strength. To the authors' knowledge this is the first study to examine the influence of compacted (unsaturated) infill on the joint shear strength. A series …


Analytical Solutions For Filtration Process Based On The Constriction Size Concept, Buddhima Indraratna, Cholachat Rujikiatkamjorn, Vo Trong Nguyen, Ashok Raut Jan 2014

Analytical Solutions For Filtration Process Based On The Constriction Size Concept, Buddhima Indraratna, Cholachat Rujikiatkamjorn, Vo Trong Nguyen, Ashok Raut

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper, an analytical model was proposed to describe the filtration process applicable to a base soil-filter system. The Navier-Stokes equation for porous media was used to capture the hydrodynamic behavior, while numerically a new algorithm has been proposed to solve the Navier-Stokes equation in non-linear form. The various mixtures of base particles eroded and water flow within the system was computed using the work-energy principle incorporating the constriction size of the filter. The model can assess the filtration process through the flow rate, and the accumulation and erosion of base soil within the filter. By discretising the base …


Role Of The Compaction Energy Level On The Small Strain Stiffness Of A Silty Sand Soil Subjected To Wetting And Drying, A Heitor, B Indraratna, C Rujikiatkamjorn Jan 2014

Role Of The Compaction Energy Level On The Small Strain Stiffness Of A Silty Sand Soil Subjected To Wetting And Drying, A Heitor, B Indraratna, C Rujikiatkamjorn

Faculty of Engineering and Information Sciences - Papers: Part A

The dynamic properties of a soil are routinely quantified to describe its engineering behaviour under repeated loading. While the results of previous research studies indicate that the effect of changes in suction on the dynamic response is significant, only limited research has been engaged in the assessment of post-compacted changes in suction induced by cycles of wetting and drying. In this paper, aspects related to the dynamic properties with special reference to small strain shear modulus behaviour at different compaction energy levels are described and outlined. Particular emphasis is placed on the hysteric behaviour observed (i.e. amplitude of the hysteresis …


Co-Digestion Of Sewage Sludge And Crude Glycerol For On-Demand Biogas Production, Long Nghiem, Thanh Nguyen, Patric Manassa, Shona K. Fitzgerald, Marcia Dawson, Sarah Vierboom Jan 2014

Co-Digestion Of Sewage Sludge And Crude Glycerol For On-Demand Biogas Production, Long Nghiem, Thanh Nguyen, Patric Manassa, Shona K. Fitzgerald, Marcia Dawson, Sarah Vierboom

Faculty of Engineering and Information Sciences - Papers: Part A

Pilot scale experiments, biomethane potential (BMP) evaluation, and BioWin simulations were conducted to evaluate the intermittent co-digestion of sewage sludge and crude glycerol for on-demand biogas production. BMP tests revealed that both pure and crude glycerols were readily biodegradable. BioWin simulations showed that intermittent glycerol injection at a high (3% v/v) dose might lead to an increase in chemical oxygen demand of the digestate. Results from the pilot scale experiments confirmed that intermittent injection of crude glycerol at both low (0.63% v/v) and high (3%v/v) doses could be used for on-demand biogas production to match the daily fluctuation in energy …


Net Section Tension Capacity Of Equal Angle Braces Bolted At Different Legs, Lip H. Teh, Benoit Gilbert Jan 2014

Net Section Tension Capacity Of Equal Angle Braces Bolted At Different Legs, Lip H. Teh, Benoit Gilbert

Faculty of Engineering and Information Sciences - Papers: Part A

This paper points out that, in practice, the two connected ends of an angle brace or bracket may be bolted at different legs due to constructional constraints. However, no design equation for determining the net section tension capacity of such a connection exists, and neither do published laboratory test results. This paper presents a series of laboratory tensile test results involving equal angle braces bolted at different legs, with legs ranging from 50 to 75mm and tension distances ranging from 100 to 300mm. The specimens were composed of 3.0-mm G450 sheet steel, which is among those that have the lowest …


Numerical Analysis Of Spiral Roller Of Chain-Die Former, Shenglan Zhu, Yong Sun, Shichao Ding Jan 2014

Numerical Analysis Of Spiral Roller Of Chain-Die Former, Shenglan Zhu, Yong Sun, Shichao Ding

Faculty of Engineering and Information Sciences - Papers: Part A

Chain-die Forming is a novel sheet metal forming technology developed recently. It effectively minimizes the redundant deformation during forming in order to reduce residual stresses to very small values even to zero in product, which is impossible to be achieved through conventional roll forming. Better quality of products therefore can be expected with the development of this new technology. This article is to use FEM to analyze the stresses developed in the spiral roller which is one of the key elements in a Chain-die former. In order to optimize the design of Chain-die former, the results of equivalent stress have …


Zappa-Szep Products Of Semigroups And Their C*-Algebras, Nathan D. Brownlowe, Jacqueline Ramagge, David I. Robertson, Michael F. Whittaker Jan 2014

Zappa-Szep Products Of Semigroups And Their C*-Algebras, Nathan D. Brownlowe, Jacqueline Ramagge, David I. Robertson, Michael F. Whittaker

Faculty of Engineering and Information Sciences - Papers: Part A

Zappa-Szep products of semigroups provide a rich class of examples of semigroups that include the self-similar group actions of Nekrashevych. We use Li's construction of semigroups C*-algebras to associate a C*-algebra to Zappa-Szep products and give an explicit presentation of the algebra. We then define a quotient C*-algebra that generalises the Cuntz-Pimsner algebras for self-similar actions. We indicate how knowne examples, previously viewed as distinct classes, fit into our unifying framework. We specifically discuss the Baumslag-Solitar groups, the binary adding machine, the semigroup NXNx, and the ax+b semigroup ZXZx.


Impact Of Organic And Colloidal Fouling On Trace Organic Contaminant Rejection By Forward Osmosis: Role Of Initial Permeate Flux, Ming Xie, Long D. Nghiem, William E. Price, Menachem Elimelech Jan 2014

Impact Of Organic And Colloidal Fouling On Trace Organic Contaminant Rejection By Forward Osmosis: Role Of Initial Permeate Flux, Ming Xie, Long D. Nghiem, William E. Price, Menachem Elimelech

Faculty of Engineering and Information Sciences - Papers: Part A

Fouling behaviour and its impact on the rejection of trace organic contaminants (TrOCs) by forward osmosis (FO) were investigated.Membrane fouling was simulated using humic acid and colloidal particles asmodel foulants at different initial permeatewater fluxes.Water flux declinewas insignificant at an initial permeate flux of 9 L/m2h and the fouling layerwas loose and fluid-like. By contrast, thewater flux declinewas substantial at an initial permeate flux of 20 L/m2h, resulting in the formation of a compact fouling layer. Water flux recovery after physical cleaning for both humic acid and colloidal particle fouledmembraneswas consistently higher at an initial permeate flux of 9 L/m2h …