Engineering Commons^™

A Numerical Study Of High Temperature And High Velocity Gaseous Hydrogen Flow In A Cooling Channel Of A Ntr Core, Sajan B. Singh

University of New Orleans Theses and Dissertations

Two mathematical models (a one and a three-dimensional) were adopted to study, numerically, the thermal hydrodynamic behavior of flow inside a single cooling channel of a Nuclear Thermal Rocket (NTR) engine. The first model assumes the flow in the cooling channel to be one-dimensional, unsteady, compressible, turbulent, and subsonic. The working fluid (GH₂) is assumed to be compressible. The governing equations of the 1-D model are discretized using a second order accurate finite difference scheme. Also, a commercial CFD code is used to study the same problem. Numerical experiments, using both codes, simulated the flow and heat transfer …

A Framework To Predict High Risk Roadways For Pedestrians In Tennessee, Zane Hunter Pannell

Masters Theses

Pedestrians and bicyclists are a class of vulnerable road users that are often over-represented in incapacitating injury or fatal crash statistics. Because non-motorized trips are vital to many urban and rural residents for utility or recreation and exercise, it is essential to identify safety deficiencies in our existing transportation infrastructure to address rising injuries and fatalities among this group of road users. As the economy continues to struggle and fuel prices remain high, many cities and rural transportation agencies are seeing large increases in bicycling, walking, and transit ridership. While passenger car fatalities have shown sharp declines in the last …

Development Of A Coupled Fluid And Colloidall Particle Transport Model, Scott Ripplinger

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A colloidal system usually refers to when very small particles are suspended within a solution. The study of these systems encompasses a variety of cases including bacteria in ground water, blood cells and platelets in blood plasma, and river silt transport. Taking a look at these kinds of systems using computer simulation can provide a great deal of insight into how they work. Most approaches to date do not look at the details of the system, however, and are specific to given system. In this study a program called OpenFOAM is used as a basis to build a computer simulation …

Experimental Investigation Of The 100 Kev X-Ray Dose Response Of The High-Temperature Thermoluminescence In Lif: Mg, Ti (Tld-100): Theoretical Interpretation Using The Unified Interaction Model, Jayde Livingstone, Y Horowitz, L Oster, H Datz, Michael Lerch, Anatoly Rosenfeld, A Horowitz

Michael L.F. Lerch

The dose response of LiF:Mg,Ti (TLD-100) chips was measured from 1 to 50 000 Gy using 100 keV X rays at the European Synchroton Radiation Facility. Glow curves were deconvoluted into component glow peaks using a computerised glow curve deconvolution (CGCD) code based on first-order kinetics. The normalised dose response, f(D), of glow peaks 4 and 5 and 5b (the major components of composite peak 5), as well as peaks 7 and 8 (two of the major components of the high-temperature thermoluminescence (HTTL) at high levels of dose) was separately determined and theoretically interpreted using the unified interaction model (UNIM). …

Xpswmm Analysis Of The Ornl Stormwater Collection System Up To Outfall 211, Heidi Belle Henderson

FIU Electronic Theses and Dissertations

The Oak Ridge National Laboratory, Tennessee, was the site for a number of US Government projects during the 1940s and 1950s including the development of thermonuclear weapons. Chemical processes conducted at the site as part of these projects resulted in contamination of certain building areas at the ORNL. The purpose of this study is to develop a hydraulic-hydrologic computer model via XPSWMM to determine surface water flow rates and water stages within the drainage system during rainfall events and introduce a conservative contaminant into the system to trace peak concentrations of contaminants.

The model was calibrated by simulating actual rainfall …

An Adaptive Bilateral Negotiation Model Based On Bayesian Learning, Chao Yu, Fenghui Ren, Minjie Zhang

Dr Fenghui Ren

Endowing the negotiation agent with a learning ability such that a more beneficial agreement might be obtained is increasingly gaining attention in agent negotiation research community. In this paper, we propose a novel bilateral negotiation model based on Bayesian learning to enable self-interested agents to adapt negotiation strategies dynamically during the negotiation process. Specifically, we assume that two agents negotiate over a single issue based on time-dependent tactic. The learning agent has a belief about the probability distribution of its opponent's negotiation parameters (i.e., the deadline and reservation offer). By observing opponent's historical offers and comparing them with the fitted …

Modeling Target Disinfection By-Product Dynamics In Indoor Swimming Pools, Barnard S. Mondal, Cary Troy, Mehrnaz Afifi, Shih-Chi Weng, Ernest R. Blatchley Iii

The Summer Undergraduate Research Fellowship (SURF) Symposium

Chlorination is the primary disinfection method for swimming pools in the United States; however, chlorine also reacts with pollutants (e.g., sweat, urine and anthropogenic compounds) to form disinfection by-products (DBPs). Some DBPs are asthma causing (e.g. nitrogen-trichloride) and even carcinogens (e.g., trihalomethanes and nitrosamines). Consequently, exposure to DBPs poses health risks to patrons and staff in pool environments. Furthermore, volatilization of DBPs is enhanced by bather activity, but the relationship between activity and volatilization has yet been quantified such that the dynamic behavior of DBPs can be predicted. Therefore, the objective of this research is to …

An Investigation On The Impacts Of Density Currents On The Sedimentation In Dam Reservoirs Using Tcm Model; Case Study: Maroon Dam, Farhad Raof, Mohammad Naghshine, Ali Khoshrftar

Farhad Fakheri Raof

Sedimentation in dams' reservoirs is one of the most pressing concerns facing dams today. Maroon reservoir dam, located in Khuzestan Province, is one of the most important dams in this region. Since it is a new constructed dam, numerical simulation of sedimentation trend in its reservoirs could significantly help on a better utilization. To this end, TCM model which is capable to simulate density currents was used. The obtained results show that the dam loses about 91 million m3 of its reservoirs during a 50-year exploitation period.

Protein Structure Validation And Identification From Unassigned Residual Dipolar Coupling Data Using 2d-Pdpa, Arjang Fahim, Rishi Mukhopadhyay, Ryan Yandle, James H. Prestegard, Homayoun Valafar

Faculty Publications

More than 90% of protein structures submitted to the PDB each year are homologous to some previously characterized protein structure. The extensive resources that are required for structural characterization of proteins can be justified for the 10% of the novel structures, but not for the remaining 90%. This report presents the 2D-PDPA method, which utilizes unassigned residual dipolar coupling in order to address the economics of structure determination of routine proteins by reducing the data acquisition and processing time. 2D-PDPA has been demonstrated to successfully identify the correct structure of an array of proteins that range from 46 to 445 …

A Multi-Physics Model For Solid Oxide Iron-Air Redox Flow Battery: Simulation Of Discharge Behavior At High Current Density, Meng Guo, Xuan Zhao, Ralph E. White, Kevin Huang

Faculty Publications

A rigorous physics-based mathematical model for a solid oxide iron-air redox flow battery system is presented in this paper. The modeled flow battery system combines a Fe-FeO redox couple as the energy storage unit and a regenerative solid oxide fuel cell as the electrical functioning unit in a 2D axial symmetric geometry. This model was developed from fundamental theories of reaction engineering in which basic transport phenomena and chemical/electrochemical kinetics are included. The model shows good agreement with the experimental data. Simulation results for the chemical, electrochemical and transport behavior of the battery are discussed.

Finite Element Models Of The Knee & Hip Joints: Using Opensim To Predict Muscle Forces, Kevin S. Jones, Spencer D. Wangerin, Jeffrey D. Pyle, Stephen M. Klisch, Scott J. Hazelwood

STAR Program Research Presentations

Quantitative data of stresses and strains in the cartilage of the knee and hip joints are required to design prostheses and can be used to give accurate advice to patients with cartilage damage as to which activities should be avoided. Instrumented hip implants can only give the overall resultant force in the joint, not the stresses and strains throughout the cartilage. Finite Element (FE) models of the Knee and Hip are being constructed in order to obtain the stresses and strains in articular (of the joint) cartilage. Muscle forces and joint contact forces are required as inputs to these FE …

Nutrient And Carbon-Dioxide Requirements For Large-Scale Microalgae Biofuel Production, Benjamin K. Shurtz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ever-increasing fuel prices and a limited supply of oil worldwide are threatening our economy and way of life in both the near and distant future. In order to reduce oil
dependence, the US Department of Energy (DOE) has established a goal that by the year 2030, 30% of the US transportation fuel will be renewable. The goal equates to
approximately 60 billion gallons per year of renewable fuel.

In an effort to reach the DOE renewable fuel goal, numerous types of plants are being studied, whose oil can be harvested and refined to serve as replacement fuel.
Among the various …

Shear Strength Model For Sediment-Infilled Rock Discontinuities And Field Applications, Buddhima Indraratna, Wuditha N. Premadasa, Jan Anton Nemcik, Mylvaganam Jayanathan

Wuditha N Premadasa

Discontinuities have a great influence on the reduction of rock mass shear strength depending on the geometry, roughness and the nature of infill sediments. These discontinuities are generally filled with different types of sediments. When the infill sediments are saturated, they make a considerable impact on the overall strength of the rock mass. Most infilled discontinuities in the field are overconsolidated due to various factors such as climatic and weathering conditions, as well as hydrothermal alteration. The increase in the thickness of joint infill subdues the otherwise prominent role of joint roughness. This paper presents some of the existing mathematical …

The Rq-Tech Methodology: A New Paradigm For Conceptualizing Strategic Enterprise Architectures, Christine Ann Hoyland

Engineering Management & Systems Engineering Theses & Dissertations

The purpose of this research is to develop and apply a system-theoretic based methodology and corresponding model for Enterprise Architecture development. Enterprise Architectures can assist managers by illustrating the systemic relationships within an organization and the impact changes to the organization could make. Unfortunately, today's modeling practices are proprietary, time-consuming, and generally ineffective as tools for understanding the consequences of strategic-level planning decisions across all levels of the enterprise. This research supports the conclusion that system-specific solutions produce islands of technology and can be prevented by employing better enterprise change planning.

This research combined the practice of Enterprise Architectures with …

Studying The Impact Of The Corner Propagation Model On Vanet Routing In Urban Environments, Abhinay Mukunthan, Craig Cooper, Farzad Safaei, D. Franklin, Mehran Abolhasan

Professor Farzad Safaei

Accurate modelling of the radio channel is often the most difficult aspect of a Vehicular Ad Hoc Network (VANET) simulation due to the large variability present in vehicular terrain. CORNER is a propagation model that calculates path-loss in an urban terrain with a large concentration of buildings, based on the position of the transmitter and receiver on a street map. This paper proposes additions to the CORNER propagation model to take selective multi-path fading into account and investigates the performance of the GPSR routing protocol under the CORNER propagation model in a realistic city environment.

Ignoring A Level In A Multilevel Model: Evidence From Uk Census Data, Mark Tramner, David Steel

Professor David Steel

Because of the inherent multilevel nature of census data, it is often appropriate to use multilevel models to investigate relationships between census variables. For a local population, the data available from the census allow a three-level nested model to be assumed, with an individual level (level 1), an enumeration district (ED) level (level 2), and a ward level (level 3). The consequences of ignoring one of the three levels in this model are assessed here theoretically. Empirical results, based on 1991 UK Census data, are also provided, comparing the variance components estimated from the three-level model with analyses based on …

An Introduction To Model-Based Survey Sampling With Applications, Raymond Chambers, Robert Clark

Robert Clark

No abstract provided.

Supercomputer Design: An Initial Effort To Capture The Environmental, Economic, And Societal Impacts, Marshall T. Mcdonnell

Faculty Publications and Other Works -- Chemical and Biomolecular Engineering

Abstract Currently, the Green500 is possibly the largest effort to direct the evolution of supercomputing towards sustainable design but does not address life-cycle impacts of a supercomputer. Supercomputer assessment with economical, environmental, and societal impacts considered would provide an optimal future supercomputer design that is sustainable. Some of the benefits of such an assessment would help determines the complete impact for bringing a supercomputer online, determine impact “hot spots” in design, and determine optimal locations for construction. By combining process-LCA and EIO-LCA methods, an initial model for in-depth sustainability analysis of supercomputer design has been developed and the results presented. …

Live-Load Test And Finite-Element Model Analysis Of An Integral Abutment Concrete Girder Bridge, Robert W. Fausett

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As part of the Long Term Bridge Performance (LTBP) Program, a single-span, prestressed, integral abutment concrete girder pilot bridge near Perry, Utah was instrumented with different sensors at various locations onto the bridge for long-term monitoring and periodic testing. One of the periodic tests conducted on this bridge was a live-load test. The live-load test included driving trucks across the bridge, as well as parking trucks along different lanes of the bridge, and measuring the deflection and strain. The data collected from these tests was used to create and calibrate a computer model of the bridge. The model was afforded …

Levetiracetam-Loaded Biodegradable Polymer Implants In The Tetanus Toxin Model Of Temporal Lobe Epilepsy In Rats, Amy J. Halliday, Toni E. Campbell, Timothy S. Nelson, Karen J. Mclean, Gordon G. Wallace, Mark J. Cook

Gordon Wallace

Approximately one-third of people with epilepsy receive insufficient benefit from currently available anticonvulsant medication, and some evidence suggests that this may be due to a lack of effective penetration into brain parenchyma. The current study investigated the ability of biodegradable polymer implants loaded with levetiracetam to ameliorate seizures following implantation above the motor cortex in the tetanus toxin model of temporal lobe epilepsy in rats. The implants led to significantly shorter seizures and a trend towards fewer seizures for up to 1 week. The results of this study indicate that drug-eluting polymer implants represent a promising evolving treatment option for …

Simulation Model Of A Grid-Connected Single-Phase Photovoltaic System In Pscad/Emtdc, Brian K. Perera, Sridhar R. Pulikanti, Philip Ciufo, Sarath Perera

Dr Philip Ciufo

In this paper, a complete simulation model of a grid-connected single-phase two-stage photovoltaic (PV) system with associated controllers is presented. The simulation model is developed in PSCAD/EMTDC simulation program. The component models of the grid-connected PV system include a PV array, a dc-dc boost converter, a voltage source converter (VSC) and an LCL filter. Components of the LCL filter, the dc-link capacitor of the VSC and the inductor of the dc-dc boost converter are established theoretically and that are used in modelling the grid-connected PV system. The control architecture of the presented system incorporates a synchronous reference frame phase-locked-loop (s-PLL), …

Integrated Seat And Suspension Control For A Quarter Car With Driver Model, Haiping Du, Weihua Li, Nong Zhang

Professor Weihua Li

In this paper, an integrated vehicle seat and sus pension control strategy for a quarter car with driver model is proposed to improve suspension performance on driver ride comfort. An integrated seat and suspension model that includes a quarter-car suspension, a seat suspension, and a 4-degree-of freedom (DOM) driver body model is presented first. This in1 tegrated model provides a platform to evaluate ride comfort 1performance in terms of driver head acceleration responses under typical road disturbances and to develop an integrated control of seat and car suspensions. Based on the integrated model, an H∞ state feedback controller is designed …

A Microslip Model Of The Bonding Process In Ultrasonic Wire Bonders Part I: Transient Response, C M. Hu, N Guo, H Du, W H. Li, M Chen

Professor Weihua Li

Ultrasonic wire bonders with precision capillary tips are widely used for bonding electrical wires to IC chips and circuits. The industry is driving wire-bonding technology towards increased yields, decreased pitch, and ever decreasing cost. However, many technical and material issues will be involved in achieving these goals, such as bond quality monitoring, new failure modes, reliability problems in new plastic mold compounds, and increasing wire sweep problems, in particular lack of the quantitative understanding and validated mathematical model of the bonding process. In this paper, a microslip model is proposed for the bonding process based on the bonding pattern observed, …

Sector Expansion And Elliptical Modeling Of Blue-Gray Ovoids For Basal Cell Carcinoma Discrimination In Dermoscopy Images, Pelin Guvenc, Robert W. Leander, Serkan Kefel, William V. Stoecker, Ryan K. Rader, Kristen A. Hinton, Sherea Monica Stricklin, Harold S. Rabinovitz, Margaret C. Oliviero, Randy Hays Moss

Chemistry Faculty Research & Creative Works

Background: Blue-gray ovoids (B-GOs), a critical dermoscopic structure for basal cell carcinoma (BCC), offer an opportunity for automatic detection of BCC. Due to variation in size and color, B-GOs can be easily mistaken for similar structures in benign lesions. Analysis of these structures could afford accurate characterization and automatic recognition of B-GOs, furthering the goal of automatic BCC detection. This study utilizes a novel segmentation method to discriminate B-GOs from their benign mimics.

Methods: Contact dermoscopy images of 68 confirmed BCCs with B-GOs were obtained. Another set of 131 contact dermoscopic images of benign lesions possessing B-GO mimics provided a …

Thermomechanical Fatigue Life Prediction Of Notched 304 Stainless Steel, Justin Karl

Electronic Theses and Dissertations

The behavior of materials as they are subjected to combined thermal and mechanical fatigue loads is an area of research that carries great significance in a number of engineering applications. Power generation, petrochemical, and aerospace industries operate machinery with expensive components that undergo repeated applications of force while simultaneously being exposed to variable temperature working fluids. A case of considerable importance is found in steam turbines, which subject blades to cyclic loads from rotation as well as the passing of heated gases. The complex strain and temperature histories from this type of operation, combined with the geometric profile of the …

A Scr Model Based On Reactor And Engine Experimental Studies For A Cu-Zeolite Catalyst, Xiaobo Song

Dissertations, Master's Theses and Master's Reports - Open

A NO_x reduction efficiency higher than 95% with NH₃ slip less than 30 ppm is desirable for heavy-duty diesel (HDD) engines using selective catalytic reduction (SCR) systems to meet the US EPA 2010 NO_x standard and the 2014-2018 fuel consumption regulation. The SCR performance needs to be improved through experimental and modeling studies. In this research, a high fidelity global kinetic 1-dimensional 2-site SCR model with mass transfer, heat transfer and global reaction mechanisms was developed for a Cu-zeolite catalyst. The model simulates the SCR performance for the engine exhaust conditions with NH₃ maldistribution and aging …

A Bi-Level Decision Model For Customer Churn Analysis, Ya Gao, Guangquan Zhang, Jie Lu, Jun Ma

Faculty of Engineering and Information Sciences - Papers: Part A

This paper develops a bi-level decision model and a solution approach to optimizing service features for a company to reduce its customer churn rate. First, a bi-level decision model, together with its modeling approach, are developed to describe the gaming relationship between decision makers in a company (service provider) and its customers. Then, a practical solution approach to reaching solutions for the bi-level-modeled customer churn problem is developed. Finally, experiments and case studies are conducted to illustrate the bi-level decision model and the solution approach.

An Elasto-Plastic Model For Liquefiable Sands Subjected To Torsional Shear Loadings, Gabriele Chiaro, Junichi Koseki, Nalin L. I De Silva

Faculty of Engineering - Papers (Archive)

This paper presents a modeling procedure for simulating the monotonic undrained torsional shear behavior of sands, including stress-strain relationship, and excess pore water pressure generation, while considering the void ratio and stress level dependence of stress-strain-dilatancy behavior of sand. A unique set of soil parameters is required by the model to satisfactorily predict the undrained behavior of loose and dense Toyoura sand over a wide range of initial void ratios and confining pressures, as proven by simulating experimental data produced by the authors and found in the literature.

A General Performance Model For Mac Layer Cooperative Retransmission Contention Protocols, Brett Hagelstein, Mehran Abolhasan, Daniel Franklin, Farzad Safaei

Faculty of Engineering and Information Sciences - Papers: Part A

Cooperative retransmission schemes can significantly improve transmission reliability and performance over high loss and time-varying links. However, analytically comparing performance between retransmission strategies is challenging and generally requires simplistic assumptions. This paper presents a general model for the performance of distributed, slot-based contention algorithms for opportunistic decode and forward retransmission algorithms. The model is independent of specific modulation or coding schemes and may be adapted to suit state-based transmission probability models. The model is validated through QualNet simulations.

Agency In Transport Service: Implications Of Traveller Mode Choice Objective And Latent Attributes Using Random Parameter Logit Model, Ahm Mehbub Anwar, A Kiet Tieu, Peter Gibson, Khin Than Win, Matthew J. Berryman

Faculty of Engineering and Information Sciences - Papers: Part A

This paper explains how principal-agent theory (PAT) can be used as an analytical tool to understand the traveller-Transport for NSW relationship and minimise the agency uncertainty in the relationship by examining traveller preferences for mode choices. The paper emphasises latent variables and objective attributes together during the choice process within the agency relationship, as a method by which the utility of the principal (traveller) can be maximised and evaluated using a discrete choice experiment, i.e. random parameter logit (RPL) model. The probability of car useis significantly higher than public transport, which indicates that an agency uncertainty exists in the relationship …