Engineering Commons^™

Continuous Electrospinning Prototype Development For Spider Silk, Justin A. Jones

Funded Research Records

No abstract provided.

Inter-Joint Coordination Deficits Revealed In The Decomposition Of Endpoint Jerk During Goal-Directed Arm Movement After Stroke, Jozsef Laczko, Robert A. Scheidt, Lucia Simo, Davide Piovesan

Biomedical Engineering Faculty Research and Publications

It is well documented that neurological deficits after stroke can disrupt motor control processes that affect the smoothness of reaching movements. The smoothness of hand trajectories during multi-joint reaching depends on shoulder and elbow joint angular velocities and their successive derivatives as well as on the instantaneous arm configuration and its rate of change. Right-handed survivors of unilateral hemiparetic stroke and neurologically-intact control participants held the handle of a two-joint robot and made horizontal planar reaching movements. We decomposed endpoint jerk into components related to shoulder and elbow joint angular velocity, acceleration, and jerk. We observed an abnormal decomposition pattern …

Speech Based Machine Learning Models For Emotional State Recognition And Ptsd Detection, Debrup Banerjee

Electrical & Computer Engineering Theses & Dissertations

Recognition of emotional state and diagnosis of trauma related illnesses such as posttraumatic stress disorder (PTSD) using speech signals have been active research topics over the past decade. A typical emotion recognition system consists of three components: speech segmentation, feature extraction and emotion identification. Various speech features have been developed for emotional state recognition which can be divided into three categories, namely, excitation, vocal tract and prosodic. However, the capabilities of different feature categories and advanced machine learning techniques have not been fully explored for emotion recognition and PTSD diagnosis. For PTSD assessment, clinical diagnosis through structured interviews is a …

Virtual Substrate Synthesis For Low-Cost High Efficiency Iii-V, Sean J. Babcock

Electrical & Computer Engineering Theses & Dissertations

The use of the low-cost thin-film vapor-liquid-solid (TF-VLS) method in the manufacturing of III-V solar cell substrates has the potential to provide a lightweight, flexible, and cheaper alternative to traditional III-V substrates typical of state-of-the- art power generation technology. The TF-VLS process has been shown to produce high optoelectronic quality polycrystalline InP on lightweight flexible metal foils. In this work, this novel method is applied to the growth of binary and ternary III-V materials which include: InP, InAs, and InGaP on Mo foils and/or sputtered Mo on Si wafers.

As a result of InP trials, powder XRD measurements have identified …

Improved Ballistic Wind Prediction Using Projectile Tracking Data, William Arthur Kenney

Computational Modeling & Simulation Engineering Theses & Dissertations

The United States Air Force AC-130 gunships have been in operation since the Vietnam War and have seen frequent use during recent conflicts. They are able to employ gun weapon systems from above a target in a way that maximizes possible time on target. When firing, the gun operators must deal with miss distances caused by winds acting on the projectile in flight. Operators currently perform a “tweak” to predict a ballistic wind affecting fired rounds which is then used in the fire-control to correct for the real winds and bring shots onto target. This correction, a single-point wind prediction, …

Efficient Algorithms For Solving Size-Shape-Topology Truss Optimization And Shortest Path Problems, Gelareh B. Sanjabi

Civil & Environmental Engineering Theses & Dissertations

Efficient numerical algorithms for solving structural and Shortest Path (SP) problems are proposed and explained in this study. A variant of the Differential Evolution (DE) algorithm for optimal (minimum) design of 2-D and 3-D truss structures is proposed. This proposed DE algorithm can handle size-shape-topology structural optimization. The design variables can be mixed continuous, integer/or discrete values. Constraints are nodal displacement, element stresses and buckling limitations.

For dynamic (time dependent) networks, two additional algorithms are also proposed in this study. A heuristic algorithm to find the departure time (at a specified source node) for a given (or specified) arrival time …

Design Of A Virtual Laboratory For Automation Control, Zelin Zhu

Computational Modeling & Simulation Engineering Theses & Dissertations

In the past, only students who studied on campus were able to access laboratory equipment in traditional lab courses; distance learning students, enrolled in online courses, were at a disadvantage for they could learn basic lab experiment principles but could never experience hands-on learning. Modeling and simulation can be a powerful tool for generating virtual laboratories for distance learning students. This thesis describes the design and development of a virtual laboratory for automation control using mechanical, electrical, and pneumatic components for an automation and control course at Old Dominion University. This virtual laboratory application was implemented for two platforms — …

Investigation, Modeling And Validation Of Digital Bridge For A New Generation Hot-Wire Anemometer, Karthik Kamalakar Joshi

Mechanical & Aerospace Engineering Theses & Dissertations

The Digital Bridge Thermal Anemometer (DBTA) is a new generation anemometer that uses advanced electronics and a modified half-Wheatstone bridge configuration, specifically a sensor and a shunt resistor in series. This allows the miniaturization of the anemometer and the communication between host computer and anemometer is carried out using serial or ethernet which eliminates the noise due to the use of long cables in conventional anemometer and the digital data sent to host computer is immune to electrical noise. In the new configuration the potential drop across a shunt resistor is used to control the bridge.

This thesis is confined …

A Low Cost Inflatable Cubesat Drag Brake Utilizing Sublimation, Adam Charles Horn

Mechanical & Aerospace Engineering Theses & Dissertations

The United Nations Inter-Agency Debris Coordination Committee has adopted a 25-year post-mission lifetime requirement for any satellite orbiting below 2000 km in order to mitigate the growing orbital debris threat. Low-cost CubeSats have become important satellite platforms with startling capabilities, but this guideline restricts them to altitudes below 600 km because they remain in orbit too long. In order to enable CubeSat deployments at higher release altitudes, a low-cost, ultra-reliable deorbit device is needed.

This thesis reports on efforts to develop a deployable and passively inflatable drag brake that can deorbit from higher orbital altitudes, thereby complying with the 25-year …

Simulated Dynamics Of Soil Water And Pore Vapor In A Semi-Arid Sandy Ecosystem, Shohreh Pedram

Civil & Environmental Engineering Theses & Dissertations

Understanding dynamics of soil water content (SWC) and pore air relative humidity (RHpa), as influenced by wetting-drying cycles, is crucial for sustaining fragile ecosystems of desert lands across the world and needed for improving the prediction accuracy of global climate change. However, to date, such an understanding is still incomplete. The objective of this dissertation was to examine such dynamics at a typical desert site within the Horqin Sandy Land, located in Mongolian Plateau of north China. The examination was done by using a HYDRUS-1D computer simulation model and the continuous sensor-based soil water data for two calendar years. HYDRUS-1D …

A Hilbert Space Geometric Representation Of Shared Awareness And Joint Decision Making, Mustafa Canan

Engineering Management & Systems Engineering Theses & Dissertations

Two people in the same situation may ascribe very different meanings to their experiences. They will form different awareness, reacting differently to shared information. Various factors can give rise to this behavior. These factors include, but are not limited to, prior knowledge, training, biases, cultural factors, social factors, team vs. individual context, time, resources, and technology. At the individual level, the differences in attaining separate actions by accessing shared information may not be considered as an anomaly from the perspective of rational decision-making. But for group behavior, reacting differently to the shared information can give rise to conflicts and deviations …

Investigating Physical Processes Associated With Chesapeake Bay And Changjiang Estuary, Arash Niroomandi

Civil & Environmental Engineering Theses & Dissertations

Coastal and estuaries are landforms that not only have great impacts on large marine ecosystem, but also play a significant role in moderating or aggravating natural hazards and erosion risks that are expected to increase with climate change. This dissertation explores some of the concerns associated with coasts and coastal systems. In the second chapter, a thirty seven year wave hindcast (1979-2015) in Chesapeake Bay using NCEP's Climate Forecast System Reanalysis (CFSR) wind is presented. The long-term significant wave heights are generated by the third-generation nearshore wave model SWAN, which is validated using the wave height measurements at buoy stations …

The Effect Of Bone And Ligament Morphology Of Ankle Joint Loading In The Neutral Position, Jinhyuk Kim

Mechanical & Aerospace Engineering Theses & Dissertations

Computational modeling of joints is used to investigate the effect of injuries, to plan surgeries, and to answer questions about joints that cannot be answered experimentally. Existing models of the ankle joint are moving toward being able to model specific patients, however, they do not include all of the anatomy (e.g., bones and/or ligaments) and have restrictive boundary conditions. These simplification in anatomy are made to minimize pre-processing and computation time. Because biomechanical modeling is increasingly focused on the implementation of patient specific cases, the effects of including more anatomical structures and determining how they affect the model results is …

Development Of The Compact Jet Engine Simulator From Concept To Useful Test Rig, Henry H. Haskin

Mechanical & Aerospace Engineering Theses & Dissertations

NASA had a goal to develop a set of modeling tools for designing next generation civil transport aircraft with reduced noise, emissions and increased fuel efficiency by 2016. To verify the models, a database of aerodynamic and acoustic data was needed for an unconventional flying wing design that was predicted to meet the goals. A Compact Jet Engine Simulator (CJES) was needed as the jet source for the 5.8% scale model. Ultra-Compact Combustor Technology from the Air Force Research Laboratory was used to reduce the conventional burner acoustic test rigs down to the required scale size. The Air Force design …

Initiating Event Analysis Of A Lithium Fluoride Thorium Reactor, Nicholas Charles Geraci

Engineering Management & Systems Engineering Theses & Dissertations

The primary purpose of this study is to perform an Initiating Event Analysis for a Lithium Fluoride Thorium Reactor (LFTR) as the first step of a Probabilistic Safety Assessment (PSA). The major objective of the research is to compile a list of key initiating events capable of resulting in failure of safety systems and release of radioactive material from the LFTR.

Due to the complex interactions between engineering design, component reliability and human reliability, probabilistic safety assessments are most useful when the scope is limited to a single reactor plant. Thus, this thesis will study the LFTR design proposed by …

Itsblue: A Distributed Bluetooth-Based Framework For Intelligent Transportation Systems, Ahmed Awad Alghamdi

Computer Science Theses & Dissertations

Inefficiency in transportation networks is having an expanding impact, at a variety of levels. Transportation authorities expect increases in delay hours and in fuel consumption and, consequently, the total cost of congestion. Nowadays, Intelligent Transportation Systems (ITS) have become a necessity in order to alleviate the expensive consequences of the rapid demand on transportation networks. Since the middle of last century, ITS have played a significant role in road safety and comfort enhancements. However, the majority of state of the art ITS are suffering from several drawbacks, among them high deployment costs and complexity of maintenance.

Over the last decade, …

The Efficacy Of Programming Energy Controlled Switching In Resistive Random Access Memory (Rram), David Malien Nminibapiel

Electrical & Computer Engineering Theses & Dissertations

Current state-of-the-art memory technologies such as FLASH, Static Random Access Memory (SRAM) and Dynamic RAM (DRAM) are based on charge storage. The semiconductor industry has relied on cell miniaturization to increase the performance and density of memory technology, while simultaneously decreasing the cost per bit. However, this approach is not sustainable because the charge-storage mechanism is reaching a fundamental scaling limit. Although stack engineering and 3D integration solutions can delay this limit, alternate strategies based on non-charge storage mechanisms for memory have been introduced and are being actively pursued.

Resistive Random Access Memory (RRAM) has emerged as one of the …

Multi-Material Mesh Representation Of Anatomical Structures For Deep Brain Stimulation Planning, Tanweer Rashid

Computational Modeling & Simulation Engineering Theses & Dissertations

The Dual Contouring algorithm (DC) is a grid-based process used to generate surface meshes from volumetric data. However, DC is unable to guarantee 2-manifold and watertight meshes due to the fact that it produces only one vertex for each grid cube. We present a modified Dual Contouring algorithm that is capable of overcoming this limitation. The proposed method decomposes an ambiguous grid cube into a set of tetrahedral cells and uses novel polygon generation rules that produce 2-manifold and watertight surface meshes with good-quality triangles. These meshes, being watertight and 2-manifold, are geometrically correct, and therefore can be used to …

Investigation And Analysis Of The Fluctuating Brominated To Total Trihalomethane Ratio In The Virginia Beach Distribution System, Christopher Steven Mihalkovic

Civil & Environmental Engineering Theses & Dissertations

An increasing trend in the brominated-trihalomethane to total-trihalomethane concentration ratio from 2001 to 2016 in the Virginia Beach water distribution system was established and investigated. This study aimed at identifying factors contributing to fluctuations in trihalomethane speciation in finished water. Reservoir management practices, treatment processes, and source water conditions were examined to quantitatively and qualitatively discern the impact of their variations on finished water THM speciation. Data on water quality constituents and parameters from the Moore’s Bridges Treatment Facility and within the Virginia Beach distribution system were examined to interpret spatial and temporal relationships with trihalomethane concentrations using established research …

A Comparative Study Of The Effects Of External Selection On Settleability And Formation Of Aerobic Granular Sludge, Tyler A. Brickles

Civil & Environmental Engineering Theses & Dissertations

Aerobic granular sludge (AGS) has shown much promise in the advancement of the wastewater treatment industry. AGS has been studied intensely since the early 1990’s due to highly desirable characteristics of nutrient removal efficiency, low footprint, and abnormally faster settling rates than conventional activated sludge. With the exception of a few on-going research projects, all AGS systems have been studied and implemented through the use of sequencing batch reactors (SBR). Recently, a novel approach to developing AGS and improving settling characteristics of activated sludge within conventional activated sludge (CAS) processes has being attempted through the use of external selection.

Activated …

Diversity Team Building: Impact On Virtual Team Performance, Nina C. Magpili-Smith

Engineering Management & Systems Engineering Theses & Dissertations

Although organizations have addressed diversity issues at the organizational-level with resulting positive employee outcomes, lack of scholarly attention to team-level interventions remain. Team-level interventions would benefit organizations more directly as they address issues directly related to task accomplishment. Since diversity may lead to negative performance results for teams, a team building intervention based on the latest empirical research was developed and tested to address the potential performance losses associated to diversity in decision-making teams. The team building intervention provides six crucial elements, namely (1) direct experience of how deep-level team diversity affect team dynamics, (2) diversity education, (3) cultivation of …

Inertization, Utilization, And Safe Disposal Of Incineration Residues, Anil Mehrotra

Civil & Environmental Engineering Projects for D. Eng. Degree

Combustion of coal or Municipal Solid Waste (MSW) caused air pollution and produces solid residues which contain high levels of toxic elements. The toxic characteristics of residues generated from combustion of MSW in waste-to-energy plants are strictly controlled by Federal and State Waste Management Regulations. According to Resource Conservation and Recovery Act (RCRA), residue generated from combustion of MSW is considered hazardous and must be tested according to EPA Toxic Characteristics Leaching Procedure (TCLP) Method 1311 and suitably treated for its safe disposal to landfills. Experiments with various treatment chemicals as primary independent variable had earlier been conducted by several …

Human Factors For Small Net Habitable Volume: The Case For A Close-Quarter Space Habitat Analog, Victor Kitmanyen, Timothy J. Disher, Ryan L. Kobrick, Jason P. Kring

Publications

Increasing efforts in sending humans to Mars calls for greater considerations of the ways in which vehicle and habitat design can influence crew performance and behavioral health.

Fuzzy Color Clustering For Melanoma Diagnosis In Dermoscopy Images, Haidar A. Almubarak, R. Joe Stanley, William V. Stoecker, Randy Hays Moss

Electrical and Computer Engineering Faculty Research & Creative Works

A fuzzy logic-based color histogram analysis technique is presented for discriminating benign skin lesions from malignant melanomas in dermoscopy images. The approach extends previous research for utilizing a fuzzy set for skin lesion color for a specified class of skin lesions, using alpha-cut and support set cardinality for quantifying a fuzzy ratio skin lesion color feature. Skin lesion discrimination results are reported for the fuzzy clustering ratio over different regions of the lesion over a data set of 517 dermoscopy images consisting of 175 invasive melanomas and 342 benign lesions. Experimental results show that the fuzzy clustering ratio applied over …

Investigation Of Passengers’ Intentions To Use High-Speed Rail And Low-Cost Carriers In China, Jing Yu Pan

Doctoral Dissertations and Master's Theses

With a large population, China is an ideal market for high-speed rail (HSR) and low-cost carrier (LCC) services. While HSR has gained substantial market share in China over the past decade, LCCs have achieved only limited market penetration. The potential growth of LCCs in China, however, is promising given the growing travel demand and government policy support. As LCCs expand their service in the domestic market, they are likely to become a strong competitor of HSR. The potential competition between LCCs and HSR justifies the research of passengers’ behavioral intentions to use HSR and LCCs in China.

This research focused …

Design Of Variable Stiffness Composite Panels For Maximum Strength, Joel P. Hurley

Doctoral Dissertations and Master's Theses

The purpose of this research is to explore the design of variable stiffness composites and develop an automated framework to model, analyze and optimize these structures. Variable stiffness composites have been shown to exhibit increased strength and stiffness over traditional constant stiffness composites by tailoring fiber orientations for specific load conditions. This is achieved by allowing the fiber orientation to vary spatially across the design domain. Motivation for new design methods is driven by the recent advancements in composite additive manufacturing, such as automated fiber placement machines, which allow fiber reinforcements to be placed along prescribed trajectories during manufacturing. Through …

Numerical Study Of Mixing Of A Supercritical Jet In A Supercritical Environment, Neil Sullivan

Doctoral Dissertations and Master's Theses

A numerical simulation campaign is conducted to better elucidate flow physics and modeling requirements of a supercritical (SC) nitrogen jet injected into a tank of quiescent SC nitrogen. The goals of this work are twofold: to inform the design of injectors and combustion chambers for use in the direct-fired supercritical CO2 (s-CO2) power generation cycle and cryogenic liquid propellant rockets, and to investigate the extent to which meaningful flow characterization can be achieved with computationally expedient methods, using commercial software. Reynolds-Averaged Navier-Stokes (RANS) and Large Eddy Simulation (LES) approaches are used in STAR-CCM+ versions 10.06.010 and 12.02.011. Jet disintegration is …

Metallographic Analysis And Electrical Resistivity Of The 1045 Steel After Being Heat-Treated, M Quiroga Agurto, E Medrano Atencio, F Américo Reyes Navarro, J G Miranda Ramos

Journal of Metals, Materials and Minerals

Herein, it was studied the structural evolution of the AISI 1045 steel water-quenched and oilquenched, respectively, from a temperature higher than the critical to various temperatures between 800 and 820°C. The two quenching media were used at 16.5°C. Microstructural variations occurred in the quenched 1045 steel. Also, by using the four-terminal sensing, it was measured the evolution of the electrical resistivity of the quenched samples; it was found that quenching at different temperatures provoked a complex behavior. It was noticed a major increase in the electrical resistivity in the case of water-quenched samples. Besides, when compared samples before and after …

Reply To Comment By Fred L. Ogden Et Al. On "Beyond The Scs-Cn Method: A Theoretical Framework For Spatially Lumped Rainfall-Runoff Response", Mark Bartlett, Anthony J. Parolari, Jeffrey Mcdonnell, Amilcare Porporato

Civil and Environmental Engineering Faculty Research and Publications

Though Ogden et al. list several shortcomings of the original SCS-CN method, fit for purpose is a key consideration in hydrological modelling, as shown by the adoption of SCS-CN method in many design standards. The theoretical framework of Bartlett et al. [2016a] reveals a family of semidistributed models, of which the SCS-CN method is just one member. Other members include event-based versions of the Variable Infiltration Capacity (VIC) model and TOPMODEL. This general model allows us to move beyond the limitations of the original SCS-CN method under different rainfall-runoff mechanisms and distributions for soil and rainfall variability. Future research should …

Development Of Adjustment Factors For Mepdg Pavement Responses Utilizing Finite-Element Analysis, Osman Erman Gungor, Imad L. Al-Qadi, Angeli Gamez, Jaime Hernandez

Civil and Environmental Engineering Faculty Research and Publications

The Mechanistic-empirical pavement design guide (MEPDG) provides theoretically superior methodology, as compared with its predecessor, for the design and analysis of pavement structures. The mechanistic part refers to simulating pavement–tire interaction to calculate critical responses within pavement. The empirical part means prediction of pavement distress propagation over time using transfer functions that link a critical pavement response to a particular pavement distress. The mechanistic part of MEPDG simulates tire–pavement interaction in three steps: subdivision of pavement layers; complex modulus calculation at the middepth of each sublayer, considering velocity and temperature; and running the multilayered elastic theory (MLET) software, …