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Full-Text Articles in Engineering
Normalized Confinement Stiffness Approach For Modeling Frp-Confined Concrete, Veysel Yazici, Muhammad N. S Hadi
Normalized Confinement Stiffness Approach For Modeling Frp-Confined Concrete, Veysel Yazici, Muhammad N. S Hadi
Faculty of Engineering - Papers (Archive)
Passive confinement provided by fiber-reinforced polymer (FRP) jackets increases the compressive strength and axial deformation capacity of concrete. This study explains a normalized confinement stiffness approach to quantify the strength and strain increase of FRP confined concrete using a previously proposed and most widely-used model for both active and passive confinement of concrete, and claims that these equations can still be used for FRP-confined concrete with very simple modifications. A comparison of the proposed model's accuracy to American Concrete Institute guidelines was made using experimental results reported in the literature. The proposed modified model was shown to be quite effective …
Electron Contamination Modeling And Skin Dose In 6 Mv Longitudinal Field Mrigrt: Impact Of The Mri And Mri Fringe Field, Bradley Oborn, Peter E. Metcalfe, Martin Butson, Anatoly B. Rosenfeld, P J. Keall
Electron Contamination Modeling And Skin Dose In 6 Mv Longitudinal Field Mrigrt: Impact Of The Mri And Mri Fringe Field, Bradley Oborn, Peter E. Metcalfe, Martin Butson, Anatoly B. Rosenfeld, P J. Keall
Faculty of Engineering - Papers (Archive)
PURPOSE: In recent times, longitudinal field MRI-linac systems have been proposed for 6 MV MRI-guided radiotherapy (MRIgRT). The magnetic field is parallel with the beam axis and so will alter the transport properties of any electron contamination particles. The purpose of this work is to provide a first investigation into the potential effects of the MR and fringe magnetic fields on the electron contamination as it is transported toward a phantom, in turn, providing an estimate of the expected patient skin dose changes in such a modality. METHODS: Geant4 Monte Carlo simulations of a water phantom exposed to a 6 …
Business Modeling With The Support Of Multiple Notations In Requirements Engineering, Mohammad Moshiur Bhuiyan, Aneesh Krishna
Business Modeling With The Support Of Multiple Notations In Requirements Engineering, Mohammad Moshiur Bhuiyan, Aneesh Krishna
Faculty of Engineering - Papers (Archive)
Requirements specification should not be concerned only with the software specification, but should also be able to integrate with the organizational models describing the environment in which the system will function. Agent–oriented conceptual modeling notations such as i* represents an interesting approach for modeling early phase requirements which includes organizational contexts, stakeholder intentions and rationale. Business Process Modeling notations such as BPMN are used to effectively conceptualize and communicate important process characteristics to relevant stakeholders. On the other hand, Unified Modeling Language (UML) is suitable for later phases of requirement capture which usually focus on completeness, consistency, and automated verification …
Evolutionary Modeling For Streamflow Forecasting With Minimal Datasets: A Case Study In The West Malian River, China, Qingwei Ni, Li Wang, Renzhen Ye, Fenglin Yang, Muttucumaru Sivakumar
Evolutionary Modeling For Streamflow Forecasting With Minimal Datasets: A Case Study In The West Malian River, China, Qingwei Ni, Li Wang, Renzhen Ye, Fenglin Yang, Muttucumaru Sivakumar
Faculty of Engineering - Papers (Archive)
A large data set is generally needed when modeling hydrological processes. However, for developing countries such as China, data sets are often unavailable in remote areas. An attempt to apply a novel genetic programming (GP) technique was made to model the relationship between streamflow of the West Malian River and the impact of climate change in the northeastern part of China. Available annual streamflow and climatic data were used for training and testing of the GP model. Data from the years between 1982 and 2002 were used for automatic selection of the model relationship. Prediction of the model was undertaken …
Modeling Of Strip Shape During Cold Rolling Of Thin Strip, Zhengyi Jiang, Xiaozhong Du, Yi Du, Dongbin Wei, M Hay
Modeling Of Strip Shape During Cold Rolling Of Thin Strip, Zhengyi Jiang, Xiaozhong Du, Yi Du, Dongbin Wei, M Hay
Faculty of Engineering - Papers (Archive)
Strip shape is an important factor affecting the strip quality significantly during cold rolling of thin strip. In the paper, finite element simulation models of the strip shape in cold rolling for both symmetrical and asymmetrical rolling cases were successfully developed. The strip edge drop and the effect of the rolling force on the strip shape (the thickness distribution along the strip width) have been obtained. The developed finite element model has been verified with the experimental value, which shows they are in good agreement. The obtained results are applicable to control the rolled thin strip shape during cold rolling …
Characterization And Modeling Of Conjugated Polymer Sensors, Yang Fang, Xiaobo Tan, Andrew Temme, Gursel Alici
Characterization And Modeling Of Conjugated Polymer Sensors, Yang Fang, Xiaobo Tan, Andrew Temme, Gursel Alici
Faculty of Engineering - Papers (Archive)
In this paper the behavior of conjugated polymers as mechanical sensors is experimentally characterized and modeled. A trilayer conjugated polymer sensor is considered, where two polypyrrole (PPy) layers sandwich an amorphous polyvinylidene fluoride (PVDF) layer, with the latter serving as an electrolyte tank. A theory for the sensing mechanism is proposed by postulating that, through its influence on the pore structure, mechanical deformation correlates directly to the concentration of ions at the PPy/PVDF interface. This provides a key boundary condition for the partial differential equation (PDE) governing the ion diffusion and migration dynamics. By ignoring the migration term in the …
Modeling Of Viscoelastic Turbulent Flow In Channel And Pipe, Shuqing Yang, G Dou
Modeling Of Viscoelastic Turbulent Flow In Channel And Pipe, Shuqing Yang, G Dou
Faculty of Engineering - Papers (Archive)
This paper investigates turbulent flows with or without polymer additives in open channels and pipes. Equations of mean velocity, root mean square of velocity fluctuations, and energy spectrum are derived, in which the shear stress deficit model is used and the non-Newtonian properties are represented by the viscoelasticity α*. The obtained results show that, with α* increment, (1) the streamwise velocity fluctuations is increased, (2) the wall-normal velocity fluctuation is attenuated, (3) the Reynolds stress is reduced, and (4) there is a redistribution of energy from high frequencies to the low frequencies for the streamwise component, but …
General Methodology For Analysis And Modeling Of Trust Relationships In Distributed Computing, Weiliang Zhao, Vijay Varadharajan, George Bryan
General Methodology For Analysis And Modeling Of Trust Relationships In Distributed Computing, Weiliang Zhao, Vijay Varadharajan, George Bryan
Faculty of Engineering - Papers (Archive)
In this paper, we discuss a general methodology for analysis and modeling of trust relationships in distributed computing. We discuss the classification of trust relationships, categorize trust relationships into two layers and provide a hierarchy of trust relationships based on a formal definition of trust relationship. We provide guidelines for the analysis and modeling of trust relationships. We review operations on trust relationships and relative types of trust relationships in our previous work. We provide a set of definitions for the properties of direction and symmetry of trust relationships. In order to analyze and model the scope and diversity of …
Kinetics Of The Peritectic Phase Transformation: In-Situ Measurements And Phase Field Modeling, Dominic J. Phelan, Mark H. Reid, Rian J. Dippenaar
Kinetics Of The Peritectic Phase Transformation: In-Situ Measurements And Phase Field Modeling, Dominic J. Phelan, Mark H. Reid, Rian J. Dippenaar
Faculty of Engineering - Papers (Archive)
An experimental study has been conducted into the role of cooling rate on the kinetics of the peritectic phase transformation in a Fe-C alloy. The interfacial growth velocities of the peritectic phase transformation were measured in situ for cooling rates of 100, 50, and 10 K/min. In-situ observations were obtained using high-temperature laser scanning confocal microscopy (HTLSCM) in a concentric solidification configuration. The experimentally measured interface velocities of the liquid/austenite (L/γ) and austenite/delta-ferrite (γ/δ) interphase boundaries were observed to increase with higher cooling rates. A unique finding of this study was that as the cooling rate increased, there was a …
Modeling The Effect Of P53 On Tumor Heterogeneity And The Mutator Phenotype, Melissa Ryan, Matthew J. Berryman, Derek Abbott
Modeling The Effect Of P53 On Tumor Heterogeneity And The Mutator Phenotype, Melissa Ryan, Matthew J. Berryman, Derek Abbott
Faculty of Engineering - Papers (Archive)
p53 is an important gene, involved in apoptosis (programmed cell death), DNA repair, and cell cycle progression. We explore the selective advantages and disadvantages of mutations in the p53 gene on tumor cells, and the heterogeneity of tumor cell populations. Based on an evolutionary computational approach, our model considers changes in mutation rate caused by lack of DNA repair processes, and the lack of apoptosis caused by mutations in p53. We find that the degree of robustness of p53 to mutations has a significant effect on the tumor heterogeneity and “fitness”, with clinical consequences for people who inherit p53 mutations.
Numerical Modeling Of Flow At An Open-Channel Confluence, Muttucumaru Sivakumar, Kalyani Dissanayake, Ajit Godbole
Numerical Modeling Of Flow At An Open-Channel Confluence, Muttucumaru Sivakumar, Kalyani Dissanayake, Ajit Godbole
Faculty of Engineering - Papers (Archive)
This paper presents the first part of a 3D numerical simulation of a horizontal-bed open-channel water flow with a 90° equal-width junction. A commercially available CFD package is used. The results of the numerical simulations are compared with the experimental data published by previous researchers. The numerical simulation was carried out in two steps: (a) using a Cartesian mesh to determine the shape of the free surface, and (b) using a body-fitted mesh conforming to the free-surface shape. The first step yielded a fair comparison between simulated and experimentally determined free-surface profiles. Further work on the simulation in the second …
Modeling Of Contaminant Transport In On-Site Waste Disposal Systems, Thidarat Bunsri, Dharmappa Hagare, Muttucumaru Sivakumar
Modeling Of Contaminant Transport In On-Site Waste Disposal Systems, Thidarat Bunsri, Dharmappa Hagare, Muttucumaru Sivakumar
Faculty of Engineering - Papers (Archive)
One of the most common problems of septic systems is poor drainage in the field. Septic systems release number of organic contaminants that cause groundwater pollution, especially organic substances, nutrients and pathogenic microorganisms. However, there are mechanisms that operate between soil and contaminants, which can purify the septic tank effluent. Below the drainage field, soil is separated into two zones; unsaturated and saturated zone, which provide the water movement mainly in vertical and horizontal direction, respectively. The purpose of this paper is to develop a conceptual model and to define governing equations for the transport of septic tank effluent in …
Modeling Of Acid Generation In Pyritic Estuarine Soils, Buddhima Indraratna, Bruce G Blunden
Modeling Of Acid Generation In Pyritic Estuarine Soils, Buddhima Indraratna, Bruce G Blunden
Faculty of Engineering - Papers (Archive)
The effective management of acid sulfate or pyritic soils is a major issue for many coastal regions in Australia. Drainage and subsequent aeration of potential acid sulfate soils often leads to pyrite oxidation and the acidification of the soil and groundwater. A numerical model has been developed to calculate the rate and magnitude of pyrite oxidation in acid sulfate soils, and the distribution of oxidation products such as H+, SO4 2- and Fe3+ within the soil profile. The pyrite oxidation model includes vertical diffusion of oxygen from the atmosphere through soil macropores, lateral diffusion of dissolved oxygen from the macropores …
Modeling Of Bolted Joint Behaviour Under Constant Normal Stiffness Conditions - Laboratory Study, Buddhima Indraratna, Najdat I. Aziz, A Dey
Modeling Of Bolted Joint Behaviour Under Constant Normal Stiffness Conditions - Laboratory Study, Buddhima Indraratna, Najdat I. Aziz, A Dey
Faculty of Engineering - Papers (Archive)
The shear behaviour of grouted joints has been studied in the recent past using the conventional direct shear apparatus, where the normal load on the joint plane is kept constant during testing. The Constant Normal Stiffness (CNS) condition is adopted in this study of shear behaviour of bolted joints, as the CNS condition represents a better approximation of the deformation behaviour of grouted joints in underground excavations as compared to the conventional Constant Normal Load (CNL) condition. A series of tests were conducted to study the behaviour of these stabilised joints under constant normal stiffness condition at an initial normal …
Experimental And Numerical Modeling Of Shear Behaviour Of Rock Joints, Buddhima Indraratna, A Haque
Experimental And Numerical Modeling Of Shear Behaviour Of Rock Joints, Buddhima Indraratna, A Haque
Faculty of Engineering - Papers (Archive)
The shear behaviour of soft rock joints is investigated in laboratory under both Constant Normal Load (CNL) and Constant Normal Stiffness (CNS) conditions. The laboratory behaviour is modelled numerically using the Universal Distinct Element Code (UDEC). The predicted shear stress, normal stress and dilation behaviour with shear displacements are compared with the laboratory results. It is observed that UDEC can predict the peak shear stress of unfilled joints under CNS, however, it overestimates the joint dilation as well as the normal stress. The maximum peak shear stress in UDEC is attained at a greater shear displacement in contrast to the …