Engineering Commons^™

Development Of Sediment-Infilled Rock Joint Models And Implications On Rockmass Stability, Buddhima Indraratna, Wuditha N. Premadasa, David Oliveira, H S. Welideniya

Buddhima Indraratna

Soil-infi lled discontinuities adversely infl uence the stability of rockmass, because, the infi ll materials especially when saturated, drastically reduce the shear strength. The angle of shearing resistance of a discontinuity decreases signifi cantly for increasing infi ll thickness. Once it reaches a critical thickness, the shear strength of the discontinuity will be governed only by the infi ll material and the rock-walls effect becomes negligible. Owing to the lack of research on the shear behavior of infi lled rock joints, it has been common practice to assume that the shear strength of the joint is that of the infi …

Development Of A New Detector Module For Use In Positron Emission Tomography, Michael Lerch, Robert Ward, Philip Simmonds, Steven Meikle, Anatoly Rosenfeld, George Takacs, V Pervertailo, G Taylor

George Takacs

No abstract provided.

Development Of Functional Indices Of Facility Occurrence Towards The Distribution Of Social Services In Lagos Island Nigeria., Augustus O. Atubi

Confluence Journal Environmental Studies (CJES), Kogi State University, Nigeria

Proper coordination of transport and public facilities provision is vital to any balanced regional development strategy. The central aim of this study, therefore, is to find out what the relationship is between access to the transport network and the provision of functional indices of facility occurrence towards the distribution of social services in Lagos Island, Nigeria. In particular it seeks to find out areas that have below or above average level of facility occurrences relative to the level of accessibility. However, a pair wise correlation matrix of the eleven (11) variables employed in the index construction was carried out. The …

Slides: Collaborative Planning And Lessons Learned, Matt Sura

Best Management Practices (BMPs): What? How? And Why? (May 26)

Presenter: Matt Sura, University of Colorado Law School

48 slides

Statistical Analysis When The Data Is An Image: Eliciting Student Thinking About Sampling And Variability., Margaret A. Hjalmarson, Tamara J. Moore, Robert Delmas

School of Engineering Education Faculty Publications

Results of analysis of responses to a first-year undergraduate engineering activity are presented. Teams of students were asked to develop a procedure for quantifying the roughness of a surface at the nanoscale, which is typical of problems in Materials Engineering where qualities of a material need to be quantified. Thirty-five teams were selected from a large engineering course for analysis of their responses. The results indicate that engagement in the task naturally led teams to design a sampling plan, use or design measures of center and variability, and integrate those measures into a model to solve the stated problem. Team …

Theme-Based Comprehensive Evaluation In New Product Development Using Fuzzy Hierarchical Criteria Group Decision-Making Method, Jie Lu, Jun Ma, Guangquan Zhang, Yijun Zhu, Xianyi Zeng, Ludovic Koehl

Faculty of Engineering and Information Sciences - Papers: Part A

One of the features of the digital ecosystem is the integration of human cognition and socio-economic themes into the process of new product development (NPD). In a socio-economic theme-based NPD, ranking a set of product prototypes that have been designed always requires the participation of multiple evaluators and consideration of multiple evaluation criteria. Using the well-being theme-based garment NPD as a background, this paper first presents a fuzzy hierarchical criteria group decision-making (FHCGDM) method which can effectively calculate final ranking results through fusing all assessment data from human beings and machines. It then presents a garment NPD comprehensive evaluation model …

Development Of A Dc-Lsnd Welding Process For Gmaw On Dh-36 Steel, Raymond Holder, Nathan Larkin, Huijun Li, Lenka Kuzmikova, Zengxi Pan, John Norrish

Faculty of Engineering and Information Sciences - Papers: Part A

Weld induced distortion correction is a major cost within the shipbuilding industry. This paper investigates the use of an active cooling process known as Dynamically Controlled - Low Stress No Distortion (DC-LSND) Welding on DH-36 steel. Thermal profiles are obtained and distortion measurements are also achieved. Results show that the application of a localised cryogenic cooling source trailing the welding arc can significantly reduce weld induced distortion using the GMAW process. The effect of forced cooling on the weld microstructure is also observed.

Development Of A Lifetime Model For Vrla Batteries Used In Wind Turbine Generators, Xiaolin Wang, Stephen Choi, Tieling Zhang, K J. Tseng

Faculty of Engineering and Information Sciences - Papers: Part A

An approach to predict the remaining lifetime of lead-acid battery is described. The battery is used to provide back-up power to keep essential devices within wind turbine generators operational under emergency conditions. The approach is developed from a circuit model of the battery. From the results of laboratory tests, changes in the model parametric values due to ambient temperature variations, battery aging effects as well as discharge current level have been quantified. Through a developed computational method, the terminal voltage and state of charge of the battery at any other discharging conditions can then be calculated. The discharge profile allows …

Development Of Fully 3d Image Reconstruction Techniques For Pinhole Spect Imaging, Xuezhu Zhang, Yujin Qi

Faculty of Engineering and Information Sciences - Papers: Part A

The purpose of this study was to develop fully 3D image reconstruction techniques for pinhole SPECT imaging with our Micro-SPECT system. Our studies involve in the derivation of projection operators, analysis of the sampling characteristics of pinhole SPECT imaging in Radon space, development of effective geometric calibration method for system misalignment, and 3D image reconstruction development and implementation with quantitative degrading compensation for pinhole SPECT with both circular and helical scan. The performances of pinhole SPECT imaging were evaluated using computer simulations and experiments with the Ultra-Micro Hot-Spot phantom, Ultra-Micro Defrise phantom and small-animal imaging. The results from the computer …

Research To Establish A Systematic Approach To Safe Welding Procedure Development Using Austenitic Filler Material For Fabrication Of High Strength Steel, Lenka Kuzmikova, John Norrish, Huijun Li, Mark Callaghan

Faculty of Engineering and Information Sciences - Papers: Part A

High strength, thermo-mechanically treated steels often require very careful control of welding procedures to ensure freedom from hydrogen assisted cold cracking (HACC) in the weld metal and heat affected zone (HAZ) whilst avoiding undue loss of heat affected zone strength. In practice this leads to restricted operating envelopes and the requirement for rigorous procedure management. An alternative approach is the use of austenitic welding consumables but whilst this may be expected to expand the process parameter envelope its use is often restricted by adherence to procedures previously developed for ferritic consumables. The current paper describes the research undertaken to establish …

Development Of Sediment-Infilled Rock Joint Models And Implications On Rockmass Stability, Buddhima Indraratna, Wuditha N. Premadasa, David Oliveira, H S. Welideniya

Faculty of Engineering - Papers (Archive)

Soil-infi lled discontinuities adversely infl uence the stability of rockmass, because, the infi ll materials especially when saturated, drastically reduce the shear strength. The angle of shearing resistance of a discontinuity decreases signifi cantly for increasing infi ll thickness. Once it reaches a critical thickness, the shear strength of the discontinuity will be governed only by the infi ll material and the rock-walls effect becomes negligible. Owing to the lack of research on the shear behavior of infi lled rock joints, it has been common practice to assume that the shear strength of the joint is that of the infi …

Development And Validation Of Calibration Methods For Discrete Element Modelling, Andrew Grima, Peter W. Wypych

Faculty of Engineering - Papers (Archive)

Discrete element method (DEM) is proving to be a reliable and increasingly used tool to study and predict the behaviour of granular materials. Numerous particlescale mechanisms influence the bulk behaviour and flow of bulk materials. It is important that the relevant measurable input parameters for discrete element models bemeasured by laboratory equipment or determined by physical calibration experiments for rational results. This paper describes some of the bench-scale experiments that have been developed to calibrate the DEM simulations to reflect actual dynamic behaviour. Relevant parameters such as static and rolling coefficients of friction, coefficient of restitution and interparticle cohesion forces …

Development Of A Web-Based Underground Coal Mining Information Management System, Ian Porter, Ernest Y. Baafi, Raymond J. Stace

Faculty of Engineering - Papers (Archive)

The development of the Australian Coal Association Research Program (ACARP) funded “one stop shop” information management system for the coal mining industry is described. The site www.undergroundcoal.com.au went live on 28 August 2009 with various sub-modules including an introduction to underground coal mining practices and a handbook of roadway development practice. The site also includes presentations from ACARP six-monthly workshops on current roadway development practice. These workshops provide an invaluable opportunity to share state of the art knowledge in roadway development practice, to learn of emerging Research and Development (Rand D) programs and development of equipment and technology by Original …

Development Of A Water-Mist Based Venturi System For Dust Control From Maingate Chocks And Bsl, Ting Ren, Graeme Cooper, Srinivasa Yarlagadda

Faculty of Engineering - Papers (Archive)

Advances in modern longwall (LW) technology have resulted in high production faces with more powerful chocks and shearers that can advance at faster rates. As longwall chocks (supports) advance, crushed roof coal and/or rock can fall from the top of the chock canopy into the face ventilation airflow. Dust survey showed that chock movement is a significant source of dust exposure for shearer operators, accounting for about 47% of total LW face dust make during the cutting cycle. 3D CFD models have been developed to understand the behaviour of longwall dust particles from various sources including maingate (MG) chocks and …

Bauschinger Effect In Microalloyed Steels: Part Ii. Influence Of Work Softening On Strength Development During Uoe Line-Pipe Forming, Andrii Kostryzhev, Martin Strangwood, Claire L. Davis

Faculty of Engineering and Information Sciences - Papers: Part A

The Bauschinger effect (a reduced yield stress at the start of reverse deformation following forward prestrain) is an important factor of strength development for cold metal forming technology. In steels, the magnitude of the Bauschinger effect depends on composition, through the presence of microalloy precipitates, and prior processing, through the size and distribution of the microalloy precipitates and the presence of retained work hardening. In this article, the parameters of the Bauschinger effect and work hardening (coefficient and exponent) in forward and reverse deformations were quantitatively related to the particle number density and dislocation density for two high-strength low-alloy (HSLA) …

Knowledge Sharing Through Virtual Layers In Regional Sustainable Development Networks, Rosemary A. Van Der Meer, Luba Torlina, Jamie Mustard

Faculty of Engineering and Information Sciences - Papers: Part A

Our research examines how the organisational structure facilitates knowledge sharing within the group. This case study examines a Victorian regional sustainable group using interviews and social network analysis to identify the group's organisational structure and its effect on knowledge sharing between the members. Our findings indicate that while the mixed membership, lack of hierarchy and layered structure are complex, these elements work together to provide members with a rich body of knowledge. The diversity and differences in membership are complimentary and combined can provide a more in-depth understanding of the regional sustainable development issues.

Comprehensive Model Of Oxygen Steelmaking Part 1: Model Development And Validation, Neslihan Dogan, Geoffrey A. Brooks, Akbar Rhamdhani

Faculty of Engineering - Papers (Archive)

A comprehensive model of oxygen steelmaking that includes the kinetics of scrap melting, flux dissolution, slag chemistry, temperature profile of the system, formation and residence of metal droplets in the emulsion, and kinetics of decarburization reaction in different reaction zones was developed. This paper discussed the development and the application of the model into an industrial practice. The results from the model were consistent with the plant data from the study of Cicutti et al. The model suggested that 45% of the total carbon was removed via emulsified metal droplets and the remaining was removed from the impact zone during …

The Development And Manufacture Of Ultra-Thin Cast Strip Steel Products With High Residual Element Levels Via The Castrip® Process, Daniel G. Edelman, Peter C. Campbell, Chris R. Killmore, Kristin R. Carpenter, Harold R. Kaul, James G. Williams, Walter N. Blejde

Faculty of Engineering and Information Sciences - Papers: Part B

A range of Ultra-Thin Cast Strip (UCS) sheet steels with elevated residual levels was produced via the CASTRIP twin drum casting method at Nucor Steel, Indiana. This paper examines the influence of elevated levels of copper, chromium, nickel, and phosphorous on mechanical properties, surface quality, processing, and weldability of UCS sheet steel products produced by the CASTRIP process. Increased levels of copper and phosphorous were found to strengthen UCS sheet steel due to solid solution strengthening but chromium and nickel did not. At lower coiling temperatures and low hot reductions, where processing conditions promote microstructural strengthening, copper and chromium further …

V1-Derived Renshaw Cells And Ia Inhibitory Interneurons Differentiate Early During Development, Ana Benito González

Browse all Theses and Dissertations

Locomotor development is dependent on the maturation of spinal cord circuits controlling motor output, but little is known about the development of the spinal interneurons that control motoneuron activity. This study focused on the development of Renshaw cells (RCs) and Ia inhibitory interneurons (IaINs), which mediate recurrent and reciprocal inhibition, respectively, two basic inhibitory circuits for motorneuron control. Both interneurons originate from the same progenitor pool (p1) giving rise to ventral spinal embryonic interneurons denominated V1. V1-derived interneurons (V1-INs) establish local inhibitory connections with ipsilateral motoneurons and express the transcription factor engrailed-1. This characteristic permitted the generation of transgenic mice …