Engineering Commons^™

Diagnosing Growth In Low-Grade Gliomas With And Without Longitudinal Volume Measurements: A Retrospective Observational Study., Hassan M Fathallah-Shaykh, Andrew Deatkine, Elizabeth Coffee, Elias Khayat, Asim K Bag, Xiaosi Han, Paula Province Warren, Markus Bredel, John Fiveash, James Markert, Nidhal Carla Bouaynaya, Louis B Nabors

Henry M. Rowan College of Engineering Departmental Research

BACKGROUND: Low-grade gliomas cause significant neurological morbidity by brain invasion. There is no universally accepted objective technique available for detection of enlargement of low-grade gliomas in the clinical setting; subjective evaluation by clinicians using visual comparison of longitudinal radiological studies is the gold standard. The aim of this study is to determine whether a computer-assisted diagnosis (CAD) method helps physicians detect earlier growth of low-grade gliomas.

METHODS AND FINDINGS: We reviewed 165 patients diagnosed with grade 2 gliomas, seen at the University of Alabama at Birmingham clinics from 1 July 2017 to 14 May 2018. MRI scans were collected during …

Transferring Power Through A Magnetic Couple, Nickolas Cruz Villalobos Jr.

Senior Theses

Properties of several working magnetic coupled rotors have been measured and their performance compared to theoretical models. Axial magnetic couplers allow rotors to work within harsh environments, without the need for seals, proper alignment, or overload protection on a motor. The influence of geometrical parameters, such as distance from the center of the rotors, polarity arrangement, and the number of dipole pairs were experimentally tested. These results can be used to improve rotor designs, to increase strength and efficiency.

Exploring The Electrical Properties Of Twisted Bilayer Graphene, William Shannon

Senior Theses

Two-dimensional materials exhibit properties unlike anything else seen in conventional substances. Electrons in these materials are confined to move only in the plane. In order to explore the effects of these materials, we have built apparatus and refined procedures with which to create two-dimensional structures. Two-dimensional devices have been made using exfoliated graphene and placed on gold contacts. Their topography has been observed using Atomic Force Microscopy (AFM) confirming samples with monolayer, bilayer, and twisted bilayer structure. Relative work functions of each have been measured using Kelvin Probe Force Microscopy (KPFM) showing that twisted bilayer graphene has a surface potential …

The Rock 2019, School Of Engineering And Computer Science

The Rock

No abstract provided.

Calculation And Tabulation Of Efficiencies For Tungsten Foil Positron Moderators, R. Alsulami, M. Albarqi, S. Jaradat, Shoaib Usman, Joseph T. Graham

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

Monte Carlo radiation transport simulations were used to calculate the positron stopping profiles in tungsten positron moderator foils. Stopping profiles were numerically integrated with efficiency kernels derived from Green's function solutions of the 3D diffusion equation to determine the moderation efficiency in both the backscattering and transmission geometries. Stopping profiles and efficiencies were calculated for positron energies from 10 keV to 10 MeV and incident angles from 0° to 75°. The resulting efficiencies agreed with other calculated and measured values in the literature, especially when similar values of the positron diffusion length and surface emission branching ratio were used. Large …

Normally-Off Computing Design Methodology Using Spintronics: From Devices To Architectures, Arman Roohi

Electronic Theses and Dissertations

Energy-harvesting-powered computing offers intriguing and vast opportunities to dramatically transform the landscape of Internet of Things (IoT) devices and wireless sensor networks by utilizing ambient sources of light, thermal, kinetic, and electromagnetic energy to achieve battery-free computing. In order to operate within the restricted energy capacity and intermittency profile of battery-free operation, it is proposed to innovate Elastic Intermittent Computation (EIC) as a new duty-cycle-variable computing approach leveraging the non-volatility inherent in post-CMOS switching devices. The foundations of EIC will be advanced from the ground up by extending Spin Hall Effect Magnetic Tunnel Junction (SHE-MTJ) device models to realize SHE-MTJ-based …

Public Utilities' Disaster Response And Management Plans: An Evaluation Of National Grid And New York State Electric & Gas, Taylor N. Vishion

Public Administration Master’s Projects

Societal dependence on electricity has rapidly increased as technological advancement has occurred, thus requiring electric utilities to advance their emergency response and repair procedures. Disaster management and response is a relatively new field for electric utilities, and despite the adoption of the Incident Command System created by FEMA, there are still opportunities for all utilities to improve. This project aims to assess the disaster response and management procedures of National Grid U.S. and NYSEG and identify opportunities for improvement. This study interviewed emergency management professionals experienced with electric utilities and found both National Grid U.S. and NYSEG can improve in …

Autonomous Boat Control Software Design Using Model-Based Systems Engineering, Noah Nelson

Electrical Engineering Undergraduate Honors Theses

While there is considerable buzz about self-driving cars, self-driving boats are actually more fully developed. The Boat Hardware Control Platform Team was tasked with developing a fleet of small autonomous boats that travel to a destination while avoiding obstacles and staying in formation. The author’s specific task was to develop software used by the boats to detect obstacles and plan a route to a destination. This was done using a method inspired by self-driving cars, which shows promise, but is still being tested at the time of writing. The entire project incorporated model-based systems engineering, which proved to be useful.

Optimization Of Ultra-Low Power Application-Specific Asynchronous Deep Learning Integrated Circuit Design, Cole Sherrill

Computer Science and Computer Engineering Undergraduate Honors Theses

The Internet of Things (IoT) consists of all devices connected to the internet, including battery-powered devices like surveillance cameras and smart watches. IoT devices are often idle, making leakage power a crucial design constraint. Currently, there are only a few low-power application-specific processors for deep learning. Recently, the Trustable Logic Circuit Design (TruLogic) laboratory at the UofA designed an asynchronous Convolutional Neural Network (CNN) system. However, the original design suffered from delay-sensitivity issues undermining its reliable operation. The aim of this thesis research is to modify the existing CNN circuit to achieve increased reliability and to optimize the improved design …

Designing A Solar Pv System To Power A Single-Phase Distribution System, Ana Guerra Vega

Electrical Engineering Undergraduate Honors Theses

Over the last decade, the costs of PV system components have dropped more than 70%. Additionally, green energy incentives like the 30% tax credit have been pushed forward. PV solar systems have become accessible to the general public. Companies are pledging to reduce their carbon emissions.

As part of their green initiative, the City of Fayetteville has requested a feasibility study for a PV system to be installed on the rooftop of the Facilities Management building, 115 S. Church Ave, Fayetteville, AR, 72701. This thesis shows the design process of this PV system and the return on investment estimation. While …

How Moisture Content Levels And Packing Density In Soil Affect Crude Oil Spreads, Shaylin N. Williams

Venture: The University of Mississippi Undergraduate Research Journal

Crude oil spills are one of the most destructive disasters that can occur, and they are extremely difficult to recover from. Many studies focus on what can be done to clean these crude oil spills, but more research should be focused on means of prevention. Currently, very little is known about how the moisture content levels and the packing efficiency of soil can affect an oil spill. These two factors alone can offer a variety of information to environmental agencies, manufacturers, and refineries. Through utilization of a chemical engineering lab, a recording mechanism, and ImagePro software, data was collected and …

A State-Of-The-Art Review Of Bending And Shear Behaviors Of Corrosion-Damaged Reinforced Concrete Beams, Mahmoodreza Soltani, Amir Safiey, Almarie Brennan

Publications

Steel corrosion is mainly at fault for the trend of deterioration among U.S. infrastructure—namely, bridges, pipelines, and wharves. Reinforced concrete (RC) is used as the primary construction material worldwide. Reinforcement corrosion can significantly impair mechanical properties of RC members, including shear and bending capacities. In the past decades, several attempts have been made to investigate the impacts of corrosion on the mechanical behavior of RC members. It can be observed that the number of research programs conducted on this topic has rapidly increased in recent years. Therefore, there is a need in the body of knowledge to encapsulate the relevant …

Energy Expenditure And Stability During Self-Paced Walking On Different Slopes, Alanna Raffaelli

Electronic Theses and Dissertations

Metabolic power and cost of transport (COT) are common quantifiers for effort when performing tasks including walking and running. Most studies focus on using a range of normal walking speeds over level ground or varied slopes. However, these studies use fixed-speed conditions. Fatigue, stability, metabolic expenditure, heart rate, and many other factors contribute to normal walking speed varying over time. This study aimed to show that allowing a subject to walk with a self-paced speed should correlate to a minimum COT at a given slope. This study also aimed to determine if a preferred slope exists based on minimizing metabolic …

Development Of Daily, Monthly, Inter-Annual, And Mean Annual Hydrological Models Based On A Unified Runoff Generation Framework, Marwan Kheimi

Electronic Theses and Dissertations

The main goal of this dissertation develops a unified model structure for runoff generation based on observations from a large number of catchments. Furthermore, obtaining a comprehensive understanding of the physical controlling factors that control daily, monthly, and annual water balance models. Meanwhile, applying the developed Unified model on different climate conditions, and comparing it with different well-known models. The proposed model was compared with a similar timescale model (HyMOD, and abcd) and applied on 92 catchments from MOPEX dataset across the United States. The HyMOD and abcd are a well-known daily and monthly hydrological model used on a variety …

A Method For The Measurement Of The Latency Tolerance Range Of Western Musicians, Jorge Medina Victoria

PhDs

This thesis presents a new systematic method to measure the ability of western musicians to cope with latency. The core of the method is a listening test and the development of a measure. The viability of the method is statistically tested with an empirical observation of 31 test subjects performing on 17 different musical instruments.

The primary goal of the investigation is the development of a systematic, reliable and replicable method that can be applied to different western music instruments, in order to provide data for analysis on latency issues while performing music in non-collaborative performances. In addition, a measure …

Predicting The Mechanical Properties Of Nanocomposites Reinforced With 1-D, 2-D And 3-D Nanomaterials, Scott Edward Muller

Graduate Theses and Dissertations

Materials with features at the nanoscale can provide unique mechanical properties and increased functionality when included as part of a nanocomposite. This dissertation utilizes computational methods at multiple scales, including molecular dynamics (MD) and density functional theory (DFT), and the coupled atomistic and discrete dislocation multiscale method (CADD), to predict the mechanical properties of nanocomposites possessing nanomaterials that are either 1-D (carbyne chains), 2-D (graphene sheets), or 3-D (Al/amorphous-Si core-shell nanorod).

The MD method is used to model Ni-graphene nanocomposites. The strength of a Ni-graphene nanocomposite is found to improve by increasing the gap between the graphene sheet and a …

Fault Adaptive Workload Allocation For Complex Manufacturing Systems, Charlie B. Destefano

Graduate Theses and Dissertations

This research proposes novel fault adaptive workload allocation (FAWA) strategies for the health management of complex manufacturing systems. The primary goal of these strategies is to minimize maintenance costs and maximize production by strategically controlling when and where failures occur through condition-based workload allocation.

For complex systems that are capable of performing tasks a variety of different ways, such as an industrial robot arm that can move between locations using different joint angle configurations and path trajectories, each option, i.e. mission plan, will result in different degradation rates and life-expectancies. Consequently, this can make it difficult to predict when a …

The Role Of Inter-Particle Behavior In Iron Oxide Nanoparticle Induction Heating, Hayden Seth Carlton

Graduate Theses and Dissertations

Due to their multi-functional nature, iron oxide nanoparticles present themselves in a myriad of scientific disciplines, but perhaps the most interesting property of these nanomaterials can be seen in their immense thermal response under the influence of alternating magnetic fields. Currently popularized as an alternative cancer treatment through localized hyperthermia, iron oxide nanoparticle induction heating presents an interesting physical phenomenon that distinguishes itself from macroscopic induction heating. Understanding how a single spherical particle behaves is relatively simple and remains well documented; however, magnetic interactions of a single particle often extend over many length scales, affecting numerous neighboring particles in the …

Auto-Calibration Of Wim Using Traffic Stream Characteristics, Johnson Baker

Graduate Theses and Dissertations

This project evaluates the performance of Weigh-in-Motion (WIM) auto-calibration methods used by the Arkansas Department of Transportation (ARDOT). Typical auto-calibration algorithms compare the WIM measured weights of vehicles from the traffic stream to reference values, using five-axle tractor-trailer configured trucks for comparisons, e.g. Federal Highway Administration (FHWA) Class 9. Parameters of the existing algorithms including the Front Axle Weight (FAW) reference value, the sampling frequency required to update the calibration factor, and thresholds for Gross Vehicle Weight (GVW) bins were evaluated. The primary metric used to estimate algorithm performance was Mean Absolute Percent Error (MAPE) between the WIM and static …

Motor Control Systems Analysis, Design, And Optimization Strategies For A Lightweight Excavation Robot, Austin Jerold Crawford

Graduate Theses and Dissertations

This thesis entails motor control system analysis, design, and optimization for the University of Arkansas NASA Robotic Mining Competition robot. The open-loop system is to be modeled and simulated in order to achieve a desired rapid, yet smooth response to a change in input. The initial goal of this work is to find a repeatable, generalized step-by-step process that can be used to tune the gains of a PID controller for multiple different operating points. Then, sensors are to be modeled onto the robot within a feedback loop to develop an error signal and to make the control system self-corrective …

Manufacturing And Testing The Permanent Magnet Linear Motor, Renjie Kang

Senior Theses

Controlled mechanical motion is vital in many useful applications in technology. Among them, linear motors have advantages over traditional rotating motors. In this work, we built a permanent magnet linear motor to test and measure its energy efficiency. A maximum 29% total energy efficiency, and 67% energy transfer rate, were detected. In addition, a C-shape support structure was added to the moving part in order to increase the moving accuracy. The tests show that, with the support structure, the fluctuation in the vertical direction decreases significantly, but the friction of the system slightly increases.

Investigation Of The Surface Topology Changes Associated With Fatigue, Randall D. Kelton

Material Science and Engineering Dissertations - Archive

Metals have long been known to change their surface topology when subjected to a plastic strain. Given that a plastic zone exists at the tip of a propagating crack, it would seem natural to quantitatively study surface topology changes associated with nucleating and propagating fatigue cracks. So far the workers in this study have only found one measurement of the surface topology changes associated with a nucleating crack. The current research seeks to study and refine, a possible correlation between crack growth and surface topology changes, with the object to develop a damage index for fatigue cracking from surface topology …

Electrochemical Energy Storage Integration Challenges Within High Voltage Distributed Generation Power System Architectures, Charles N. Nybeck

Electrical Engineering Dissertations - Archive

Future stationary and mobile microgrids may be deployed with a number of high power electrical loads that operate transiently. The transient nature of the loads will impart high stress on a microgrid’s power system, possibly pushing it outside of the acceptable power quality standards. To restore power quality and increase system reliability, it is being proposed that electrochemical energy storage systems be used as a buffer. Energy storage systems that store a great deal of energy and could be used with open circuit potentials (OCPs) as high as 1 kV. Since size and weight on a mobile microgrid is limited, …

Wearable Biomedical Sensors, Wenyuan Shi

Electrical Engineering Dissertations - Archive

Focusing on current major research interests about the wearable biomedical sensors, numerous achievements contributed by researchers and engineers are reviewed in chapter 1. Development and research trends, as well as challenges of the wearable technologies are discussed. In chapter 2, a new double-resonance sensor was presented for monitoring body dehydration with two resonant frequencies. Using the waveguide method and the finite-element simulations, the sensor was designed with optimal parameters. Electromagnetic field distributions, Q factors, and sensitivities of the sensor are analyzed. The sensor’s equivalent circuit was deduced. The finite-element model and the equivalent circuit model were simulated for identifying various …

Real-Time Multi-Pulse Rectifier Models For Power Hardware-In-The-Loop Implementation In Medium Voltage Dc Microgrid Applications, Brian J. Mcree

Electrical Engineering Dissertations - Archive

Microgrids have proliferated the landscape of the world’s power systems as distributed energy generation, energy storage, and evolving electrical loads become more abundant. Microgrids offer many advantages to the end user of electrical power over traditional power distribution networks that rely on exceedingly large rotating machines producing power for a large group of electrical loads over long physical distances. Microgrids provide a unique benefit to smaller electrical networks that may be isolated, may have unique electrical loads, or may have a network of energy storage devices that can be utilized to serve the microgrid in particular operational scenarios. With the …

Production Of Liquid Fuels From Natural Gas: Simulation Of Synthesis Gas And Fischer-Tropsch Reactors, Saiedeh Arabi Bolaghi

Mechanical and Aerospace Engineering Dissertations - Archive

Gas to Liquid (GTL) processes chemically convert natural gas to valuable liquid hydrocarbon products. The GTL process considered in this research is comprised of three phases: 1) syngas production, 2) Fischer-Tropsch synthesis (FTS), and 3) product separation. This study focuses on the simulation and optimization of a GTL process to convert natural gas to more valuable liquid fuels. In syngas production, steam methane reforming (SMR) is typically used although it requires an external heat source due to the endothermic nature of the reaction. In addition, the SMR approach produces syngas with a hydrogen to carbon monoxide ratio that is not …

Gasdynamic Phenomena And Propulsive Performance Of Pulse Detonation Engines, James T. Pearce

Mechanical and Aerospace Engineering Dissertations - Archive

The pulsed detonation engine (PDE) is an advanced propulsion system that makes use of intermittent detonations to provide thrust. In recent decades, the PDE has been at the center of various propulsion research efforts focused on practical implementation of a reliable detonation-based engine for aerospace propulsion applications. However, many design challenges remain to be solved due to the PDEs unsteady operating characteristics. In particular, the unsteady nature of the thrust chamber flow field inherent to the PDE operation makes the design of nozzles aimed at adequately expanding the burned detonation products especially difficult. In order to address this design challenge, …

Onboard Payload Mass Estimation And Electric Propulsion Modeling For Multicopters With Application In Unmanned Aerial Systems, Abel Martinez Martinez Martinez

Mechanical and Aerospace Engineering Theses - Archive

Unmanned vehicles are the future. The aim of the future online retailers, delivery and transportation companies would be air delivery using unmanned aerial vehicles. Multicopters are becoming rapidly famous because they o er a relatively easy-to-fly platform that is also very stable, and their mechanical simplicity. The possibility of estimating the weight of the multicopter in real time is really useful. A weight estimation system that could be implemented in multicopters with cable suspended payloads without using any extra sensors is presented in this thesis. The weight estimation system uses a functional relationship that correlates Pulse Position Modulation (PPM) signal …

Experimental Analysis For Optimization Of Thermal Performance Of A Server In Single Phase Immersion Cooling, Pravin Ashok Shinde

Mechanical and Aerospace Engineering Theses - Archive

Liquid immersion cooling of servers in synthetic dielectric fluids is an emerging technology which offers significant cooling energy saving and increased power densities for data centers. A noteworthy advantage of using immersion cooling is high heat dissipation capacity which is roughly 1200 times greater than air. Other advantages of dielectric fluid immersion cooling include high rack density, better server performance, even temperature profile, reduction in noise. The enhanced thermal properties of oil lead to the considerable saving of both upfront and operating cost over traditional methods. In this study, a server is completely submerged in a synthetic dielectric fluid. Experiments …

Onboard Payload Mass Estimation And Electric Propulsion Modeling For Multicopters With Application In Unmanned Aerial Systems, Abel Martinez Martinez

Mechanical and Aerospace Engineering Theses - Archive

Unmanned vehicles are the future. The aim of the future online retailers, delivery and transportation companies would be air delivery using unmanned aerial vehicles. Multicopters are becoming rapidly famous because they o er a relatively easy-to-fly platform that is also very stable, and their mechanical simplicity. The possibility of estimating the weight of the multicopter in real time is really useful. A weight estimation system that could be implemented in multicopters with cable suspended payloads without using any extra sensors is presented in this thesis. The weight estimation system uses a functional relationship that correlates Pulse Position Modulation (PPM) signal …