Engineering Commons^™

Thermal And Mechanical Properties Of Novel Carbide Materials, Evan Charles Schwind

Doctoral Dissertations

"This research focuses on studying the thermal and mechanical properties of novel carbide materials at room and elevated temperatures. The novel carbide materials investigated include zeta phase tantalum carbide (ζ-Ta₄C_3-x) and a high entropy (Ta,Hf,Nb,Zr)C carbide. The electrical resistivity and thermal conductivity of zeta phase tantalum carbide (~96 wt.%) were measured as 160 ± 4.2 μΩ-cm and 9.6 W/m•K. These are higher and lower (respectively) than for cubic tantalum carbide, most likely due to planes of carbon vacancies present in the ζ-Ta₄C_3-x crystal structure. The thermal conductivity of (Ta,Hf,Nb,Zr)C was lower than any …

Prediction Of Battery Health Dynamics, Damola Martins Ajiboye

Doctoral Dissertations

"The successful market penetration of lithium-ion batteries in the last 30 years has ushered in a new dawn in energy applications. Notwithstanding their widespread use, lithium-ion batteries are affected by a plethora of fundamental issues — safety, cycle life, performance, and cost. In this work, advanced modeling techniques are developed to tackle some of these issues. This dissertation is subdivided into four parts, the first is introduction while the remaining are dedicated to the development of computational techniques for predicting battery health dynamics.

In the second part of this work, we developed fast and accurate algorithms for modeling essential battery …

Assessment Of Rib Failure Mechanisms Using Discontinuum Mechanics Based Modeling Approach, Maurice Nuonituo Sunkpal

Doctoral Dissertations

"Coal mine rib failures are major safety and health challenge for coal mines worldwide. The need for clear procedures to evaluate mine rib behavior and to provide an efficient, reliable, and consistent rib control protocol is needed. Understanding coal rib geomechanics is essential for improving rib stability and eliminating fatality and injury trends due to rib failures. This knowledge is also vital to determine support requirements.

The rib control practices used in the 21st Century in most countries originated in roof control techniques. Understandably, applying roof control methods to coal rib does not yield desirable results. The geology of structures …

Studying The Effects Of New Additive Materials For The Improvement Of The Capacity And Cycle Life Performance Of The Lead-Acid Battery, Julian Kosacki

Doctoral Dissertations

"Lead-acid batteries are an established technology with nearly 99% recyclability; however, lead-acid batteries produce only 40% of their theoretical capacity due to poor active mass utilization and PbSO4 pore blockage, and the longevity of the batteries is hampered by secondary reactions during the cycle life such as corrosion and gassing.

Lead-acid batteries were investigated and improved through several different approaches: an alternative electrolyte to mitigate secondary reactions, graphite additives to improve positive active mass (PAM) utilization, and dispersant additives to help the industrial pasting process.

The thermodynamics and chemical reactions of a commercial electrolyte replacement called Tydrolyte^TM were investigated …

Hydromechanical Stress And Internal Erosion Under Earthen Structures, Kerry Allen Magner

Doctoral Dissertations

"Dam failures by seepage and internal erosion have reportedly been attributed to up to 40% of all dam failures in the United States. Backwards piping erosion either through the embankment or foundation soils has been reported to be the major contributing method to seepage and internal erosion dam failures. This proposed research is motivated by the lack of understanding of the complex stress regimes associated with internal erosion in cohesionless soils under earthen structures. The overall goal of this research is to provide a fundamental understanding of internal erosion and the hydromechanical stress conditions necessary for the initiation and continuation …

Sources Of Quality Uncertainty In Laser Powder Bed Fusion Metal Additive Manufacturing, Zachary Young

Doctoral Dissertations

"Powder based additive manufacturing (AM) exhibits tremendous uncertainties, where variations in build quality is present despite utilizing similar build processing parameters. First, this work reports the features and formation mechanisms of five unique types of spatter during the LPBF process by in-situ high-speed, high-energy x-ray imaging. The unique physical characteristics of spatter are determined. The effect of laser scan speed and laser power on spatter formation, ejection, and mitigation are determined. Second, this work addresses the uncertainty challenge by identifying the sources of uncertainty in SLM by in-situ characterization due to variations from the additive manufacturing processing parameters needed for …

Investigating The Impact Of Rock Bridges On The Mechanical Behavior Of Jointed Rock Mass Using Lattice Spring-Based Synthetic Rock Mass (Ls-Srm) Approach, Mariam Salem Alebayat

Doctoral Dissertations

"Rock bridges were defined as a segment of intact rock that separates from discontinuities. Numerous studies are focused on developing methods to quantify their significance in rock mass strength and deformability behavior. This thesis aimed to enhance understanding of the effect of rock bridges on jointed rock masses in both laboratory and slope scales. For this purpose, the lattice spring base Synthetic Rock Mass (LS-SRM) method was adopted to conduct the numerical models, distinguished in computational efficiency, and simulates the brittle failure and roughness of discontinuities.

A robust approach was developed to optimize the calibration procedure to avoid the complex …

In Situ Recrystallization Of Co-Evaporated Cu(In,Ga)Se2 Thin Films By Copper Chloride Vapor Treatment Towards Solar Cell Applications, Deewakar Poudel, Benjamin Belfore, Tasnuva Ashrafee, Elizabeth Palmiotti, Shankar Karki, Grace Rajan, Thomas Lepetit, Angus Rockett, Sylvain Marsillac

Applied Research Center Publications

Cu(In,Ga)Se₂ (or CIGS) thin films and devices were fabricated using a modified three-stage process. Using high deposition rates and a low temperature during the process, a copper chloride vapor treatment was introduced in between the second and third stages to enhance the films properties. X-ray diffraction and scanning electron microscopy demonstrate that drastic changes occur after this recrystallization process, yielding films with much larger grains. Secondary ion mass spectrometry shows that the depth profile of many elements is not modified (such as Cu, In and Se) while others change dramatically (such as Ga and Na). Because of the competing …

Effect Of Random Pinning On Nonlinear Dynamics And Dissipation Of A Vortex Driven By A Strong Microwave Current, W.P.M.R. Pathirana, Alex Gurevich

Physics Faculty Publications

We report numerical simulations of a trapped elastic vortex driven by a strong ac magnetic field H(t)=Hsinωt parallel to the surface of a superconducting film. The surface resistance and the power dissipated by an oscillating vortex perpendicular to the film surface were calculated as functions of H and ω for different spatial distributions, densities, and strengths of pinning centers, including bulk pinning, surface pinning, and cluster pinning. Our simulations were performed for both the Bardeen-Stephen viscous vortex drag and the Larkin-Ovchinnikov (LO) drag coefficient η(v) decreasing with the vortex velocity v. The local residual surface resistance R_i(H) …

Effect Of Hearing And Head Protection On The Localization Of Tonal And Broadband Reverse Alarms, Chantal Laroche, Christian Giguère, Véronique Vaillancourt, Claudia Marleau, Marie-France Cadieux, Karina Laprise-Girard, Emily Gula, Véronique Carroll, Manuelle Bibeau, Hugues Nélisse

Études primaires

Objective

This study explored the effects of hearing protection devices (HPDs) and head protection on the ability of normal-hearing individuals to localize reverse alarms in background noise.

Background

Among factors potentially contributing to accidents involving heavy vehicles, reverse alarms can be difficult to localize in space, leading to errors in identifying the source of danger. Previous studies have shown that traditional tonal alarms are more difficult to localize than broadband alarms. In addition, HPDs and safety helmets may further impair localization.

Method

Standing in the middle of an array of eight loudspeakers, participants with and without HPDs (passive and level-dependent) …

Uncertainty Estimation For Stereo Visual Odometry, Derek W. Ross

Graduate Theses, Dissertations, and Problem Reports (ETD)

Over the past few decades, unmanned aerial vehicles (UAVs) have been increasingly popular for use in locations that are lacking, or have unreliable global navigation satellite system (GNSS) availability. One of the more popular localization techniques for quadrotors is the use of visual odometry (VO) through monocular, RGB-D, or stereo cameras. With primary applications in the context of Simultaneous Localization And Mapping (SLAM) and indoor navigation, VO is largely used in combination with other sensors through Bayesian filters, namely Extended Kalman Filter (EKF) or Particle Filter. This work investigates the accuracy of two standard covariance estimation techniques for a feature-based …

Evaluation Of Various Separation Techniques For The Removal Of Actinides From A Rare Earth-Containing Solution Generated From Coarse Coal Refuse, Deniz Talan

Graduate Theses, Dissertations, and Problem Reports (ETD)

Rare earth elements have emerged as a vital commodity due to their significance in the production of high-tech devices as well as their utilization in defense and military systems. They are deemed critical due to potential scarcity, supply constraints, and the lack of minable concentrations. Therefore, alternative sources are needed to meet the demand and continue manufacturing rare earth-required products. Coal and coal by-products, in that regard, have presented a significant opportunity and proven to contain a considerable amount of rare earths. However, toxic elements such as thorium and uranium are frequently seen in the same mineralization as rare earths. …

Investigating Nox Vs Co2 Tradeoff In Heavy Duty Emissions Through The Years Under The Scope Of Carb’S 3-Bin Moving Average Window Method, Ghadi Sadek

Graduate Theses, Dissertations, and Problem Reports (ETD)

With the rise in urban pollution level over the last few years, regulatory agencies around the world have taken multiple steps to ensure engine exhaust pollutant are well monitored and properly regulated. Yet there exists a significant difference in emissions rates in various operating conditions between US and European products which currently uses a Moving average window (MAW) approach for their in-use compliance testing and certification program. Using WVU’s vehicle data collected using PEMS devices, this study aims at investigating the NOx versus CO2 tradeoff found in heavy duty diesel engines equipped with different aftertreatment technologies, under the scope of …

An Equest Based Building Energy Modeling Analysis For Energy Efficiency Of Buildings, Saroj Lamichhane

Graduate Theses, Dissertations, and Problem Reports (ETD)

Building energy performance is a function of numerous building parameters. In this study, sensitivity analysis on twenty parameters is performed to determine the top three parameters which have the most significant impact on the energy performance of buildings. Actual data from two fully operational commercial buildings were collected and used to develop a building energy model in eQUEST. The model is calibrated using Normalized Mean Bias Error (NMBE) and Coefficient of Variation of Root Mean Square Error (CV(RMSE)) method. The model satisfies the NMBE and CV(RMSE) criteria set by the American Society of Heating, Refrigeration, and Air-Conditioning (ASHRAE) Guideline 14, …

Identification Of Crash Contributing Factors In Av Involved Crashes, Md Tanvir Ashraf

Graduate Theses, Dissertations, and Problem Reports (ETD)

Autonomous Vehicles (AVs) can dramatically reduce the number of traffic crashes and associated fatalities by eliminating the avoidable human-errors related crash contributing factors. Many companies have been conducting pilot tests on public roads in several states in the United States and other countries to accelerate AV mass deployment. AV pilot operations on California public roads saw 251 AV-involved crashes (as of February 2020). These AV-involved crashes provide a unique opportunity to investigate AV crash risks in a mixed traffic environment. This study collected the AV crash reports from the California Department of Motor Vehicles and applied the Decision Tree (DT), …

Productivity Index For Unconventional Gas Wells, Yousef Khajah

Graduate Theses, Dissertations, and Problem Reports (ETD)

Productivity Index reflects the ability of a well to produce hydrocarbons and is often used to analyze the well's performance. Productivity Index is the ratio of the flow rate to the drawdown pressure under pseudo-steady state flow conditions. The unconventional gas formation such as shale are the main target of the gas exploration and production. The application of horizontal drilling and hydraulic fracturing technologies have been instrumental in development of shale gas resources. The evaluation of the productivity index for unconventional gas wells is however challenging because the production mainly occurs under the transient conditions.

This research aims to evaluate …

Telehealth Optimization – Role Of Clinical Athletic Trainers In Orthopedic/Sports Medicine Practice, Katie Harbacheck, Laura Grambo, Shaun Keefer, Eric Klein, Christine Boyd, Carolyn Ford-Hemann, Cameron D’Alpe, Steve Frick, Kevin Shea

Clinical Practice in Athletic Training

Background: Prior to COVID-19, telehealth (TH) implementation in most health systems was minimal. The transition to high rates of TH was dramatic in response to COVID-19, and many health systems struggled to develop optimal, efficient TH workflows. Hypothesis/Purpose: The primary purpose of this study was to evaluate the role of clinically integrated athletic trainers (ATs) into the TH transition of a major orthopedic academic center through growth of TH visits as well as physician satisfaction. Methods: Workflows and tip sheets were designed to include considerations of TH visit increases, adoption of appropriate technology platforms and optimal staff models. The rapid …

Experimental And Numerical Investigation Of Naca Airfoil Wing With Winglets, Courtney Danielle Bachmann

College of Graduate Studies: Theses & Dissertations

This research was performed in order to study wingtip devices and, in particular, winglets. Winglets are attached to commercial aircraft for the purpose of reducing induced drag caused by wake vortices on the wingtip. A winglet device can save an aircraft anywhere from 3-7% in fuel consumption. Over the course of a year, this can add up to hundreds of thousands of dollars saved. This research consisted of two parts: one part experiment and one part equipment design. The latter phase of this research examined various methods of testing in a subsonic wind tunnel laboratory setting. Experimental results found with …

Development Of A Mathematical Model For Galvanic Cells, Joshua C. Johnson

College of Graduate Studies: Theses & Dissertations

It is possible to utilize principles of equilibrium thermodynamics to model the voltage a battery renders as it powers a load in time and discharges. Similarly, consideration of the internal chemistry inside a battery, or galvanic cell, enables modeling thereof. This paper builds upon these principles and presents a derivation of the Nernst equation that utilizes this result to model discharge curves in time for different types of batteries. The Nernst equation relates chemical activity of the reagents inside a battery to the open circuit voltage rendered by the system. By combining the Nernst equation with Faraday's laws of electrolysis, …

Facilitating Veteran And Adult Students' Learning And Retention In Engineering: Faculty-Student Partnership - A Model Of An Evidence-Based Practice, Kim E. Bullington, Anthony Dean, Cynthia Tomovic, Vukica M. Jovanović, Rafael E. Landaeta

Engineering Technology Faculty Publications

With the growing number of adult and military veterans entering higher education, it is important to understand and incorporate the basics of andragogy in curriculum, course development, and the learning environment to facilitate learning and degree completion. Researchers in this S-STEM project funded by the NSF share observations of a student-faculty partnership that resulted from the development of a formal learning community. A series of targeted seminars were conducted that appear to have increased adult and military veteran engineering and technology students’ levels of connectedness and self-efficacy. Results of this pilot study are shared as an evidence-based practice to enhance …

Reducing Environmental Impacts Of Natural Gas Compressor Stations And Applicability Of The Current Regulatory Framework, Scotty Joel Moates

All ETDs from UAB

The natural gas pipeline system is an integral part of the energy structure and critical to meeting energy demand in the United States. Natural gas compressor stations are the heart of the natural gas pipeline industry. Compressor stations compress the gas coming into the station and increase the pressure of the gas to ensure movement down the pipeline at the right operating pressure. This compression process is performed through natural-gas fire engines, such as reciprocating engines and turbines. Natural gas compressor station operations are subject to a wide range of environmental regulations. These regulations seek to mitigate the environmental impacts …

Low Illumination Video Enhancement Based On Machine Learning, Mohsine Taarji

All ETDs from UAB

ow-brightness and image noise are common problems in computer vision that prohibit useful information extraction from video sequences. This problem is caused by insufficient illumination, low-quality cameras, external disturbances, and other factors. Dark image enhancement requires improvement of intensity and saturation; the missing data could be replaced by matching image regions using image feature detector-descriptor pairs. We proposed new metrics for evaluating image descriptors with regard to their uniqueness. Also, we developed new image enhancement techniques based on HSV color space. The idea behind the first contribution of our dissertation is to find the best descriptor that match pixels from …

Impact Evaluation Of Major Hurricanes On Designated Southeast Coast Counties Of Usa Using Multivariate Analysis And Forecasting, Mukti Patel

All ETDs from UAB

The study includes four major analyses. Each analysis has its own uniqueness. The Temporal analysis intended to track the economic effect trends of major storms in small counties and large metro regions as well as compare how the percent GDP loss in these locations has affected. The study shows that unfavorable impacts of major storms of the same scale and intensity stood the greatest shift in GDP growth rate percentage along with greatest damage in terms of GDP particularly in the smaller counties during and after major storm event. In addition to that percentage change in population growth rate, personal …

Model Invariant Visual Tracking Using Deep Learning Of Trajectories, Pravinkumar G. Kandhare

All ETDs from UAB

A target tracking is a well-known computer vision problem due to its wide range of applications in industrial and biomedical domains, such as traffic planning and management, surveillance, robotics, economics, human-computer interaction prediction, and electrode tracking for surgical planning. A significant amount of research has been done to tackle the problem. However, it is still challenging to design a robust tracking system that can provide solutions for many real-world tracking applications and prediction. Most of the proposed tracking solutions are complex due to many model parameters. The overarching goal of this dissertation is to develop predictors and trackers that would …

De Novo Generation Of Cardiomyocytes For Regenerative Medicine Treatment, Yawen Tang

All ETDs from UAB

Cardiovascular disease, till now, is still the leading cause of death in the United States. As a consequences of heart attack event, cardiomyocytes death is an irreversible process accompanied with scar formation and loss of heart function. As mammalian cardiomyocytes exit cell cycle shortly after birth, with no replacement of the necrotic cardiomyocytes, the damages caused by heart attack often progress into more severe symptoms such as heart failure. To replenish damaged cardiomyocytes (CMs), many therapies, such as differentiate the induced pluripotent stem cells (iPSCs) into cardiomyocytes and direct reprogram fibroblasts into CMs, have been developed. During this dissertation study, …

Dynamic Biomechanical Characteristics Of The Optic Nerve Head By Oct Imaging, Jihee Kim

All ETDs from UAB

Approximately 80 million people in the world were estimated to suffer from glaucoma in 2020. To date, lowering intraocular pressure (IOP) is the only clinical treatment to delay or prevent the development and progression of glaucomatous vision loss. However, many glaucoma patients have IOP in the normal range, while some people with abnormally high pressure do not develop neuropathy. This indicates that biomechanical responses of the optic nerve head (ONH) to changes in IOP can vary significantly among individuals. This study investigated acute IOP-induced compliance in the ONH via SDOCT imaging, using computer vision, and deep learning networks to improve …

Applying Inverse Dynamics To A Biomechanical Model To Determine The Safety Of The Motogaitor, Ezzuddin Abuhussein

All ETDs from UAB

People with mobility impairments caused by conditions such as cerebral palsy (CP),stroke, and spina bifida have difficulty achieving high levels of exercise. The lack of exercise can lead to secondary conditions such as diabetes, obesity, and cardiovascular diseases. Gait-training devices are already commercially available; however, they are not fit for home use and are expensive. Therefore, there exists a need for an affordable gaittraining device that is compact and promotes exercise and rehabilitation in a home-setting. A motorized gait-training elliptical dubbed the “Motogaitor,” was designed by students to address the needs of people with mobility impairments. In this present study, …

Studies On The Influence Of Non-Equilibrium Plasma Irradiation On Polyester Scaffolds: Characterization And Evolution Of New Surface Properties Toward Potential Biomedical Applications, Bernabe Samuel Tucker

All ETDs from UAB

A great need exists for innovative, functional materials. Specifically, functional materials must meet the necessary mechanical and interfacial properties for successful bio-integration for end goals such as medical implants. A gap in the knowledge existed before this work. This work addressed that gap through an experimental approach that employed low-temperature plasma (LTP) processing of fibrous, polyester constructs to produce functional materials. First, atmospheric-pressure plasma processing of electrospun polyester fibers, in a tubular geometry, was reported. Characterization of that system was conducted. Next, the effects of magnetized plasmas were reported. That report was a novel application of magnetized plasma and showed …

Choking Under Pressure Detection Model Based On Expert System Foundation Using Tennis Performance Variables For Individual Performance Enhancement, Stepan Vancurik

All ETDs from UAB

Choking under pressure is a phenomenon understood as underperformance or suboptimal performance in a particular task or an action that occurs due to the presence of pressure situations. The phenomenon is feared by many people, especially athletes. Choking has been heavily addressed and studied in psychology and behavioral science research. Research works addressing the phenomenon have also been occasionally published in scientific literature; however, a structural approach to objectively measure, analyze, identify, and define its determinants is absent. Therefore, this dissertation study attempts to add to the existing choking research by proposing a novel approach for choking identification, analyzing domain …

Miniaturization Of The Network Analyzer As An Interface Circuit For Wearable Resonance-Based Sensors, Fan Wu

All ETDs from UAB

Readout interface circuits are the essential part of all sensor units. Miniaturing such circuits is a challenging design issue for the future of the Internet of Things, wearable and implantable biomedical devices, sensors for harsh environments, etc. For developing wireless telemetry sensors, Vector Network Analyzer (VNA) is a powerful measurement instrument that can measure scattering parameters (S-Parameters) of single and dual-port networks, as well as Y- and Z-parameters. However, VNAs are expensive and bulky and cannot be carried around, and therefore, they can’t be used as a sensor interface. This thesis aims to design, develop, and implement a miniaturized data …