Engineering Commons^™

Rigid Pavement Analysis System (Rpas): An Enhanced Graphical User Interface, Samina Samrose

Open Access Theses & Dissertations

In recent decades there has been a significant interest among researchers in developing pavement analysis tools that will work with high efficiency and provide accurate results within a short timeframe. The University of Texas at El Paso (UTEP) has developed a finite element-based pavement analysis software named â??Rigid Pavement Analysis Systemâ?? (RPAS) capable of analyzing Jointed PCC pavements of any number of PCC and soil layers. The processing core of this software was developed in MATLAB with a pre- and post-processing user interface developed in C++. The MATLAB code is compiled into an executable and together with the C++ interface …

Biomass-Mediated Metastable Zinc(Ii) Oxide Nanoparticles And Its Nanocomposites For Sustainable Water Treatment, Kazi Afroza Sultana

Open Access Theses & Dissertations

Water is undeniably the most crucial resource that allows all living entities to thrive and survive. Due to a continuously growing population and the expansion of industrial sectors, water pollution has emerged as a global issue. Consequently, people face challenges in obtaining the required quantity and quality of water for their daily activities such as drinking, cooking, hygiene, and agriculture. Hence, there is a compelling need to develop an effective and environmentally friendly approach to eliminate harmful pollutants in water, promoting the establishment of a sustainable society with widespread access to clean and safe water resources. Although there are a …

Distinct Modes Of Aged Soil Carbon Export In A Large Tropical Lake Basin Identified Using Bulk And Compound-Specific Radiocarbon Analyses Of Fluvial And Lacustrine Sediment, Wesley G. Parker, Jason M.E. Ahad, Jonathan Obrist-Farner, Benjamin Keenan, Peter M.J. Douglas

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The 14C content of sedimentary organic matter (OM) and specific organic molecules provide valuable information on the source and age of OM stored in sediments, but these data are limited for tropical fluvial and lake sediments. We analyzed 14C in bulk OM, palmitic acid (C16), and long-chain n-alkanoic acids (C24, C26, and C28), within fluvial and lake sediments in the catchment of Lake Izabal, a large tectonic lake basin in Guatemala. We combined these measurements with bulk and compound-specific δ13C measurements, as well as sediment organic carbon to nitrogen (OC:N) ratios, to understand the source and age of sedimentary OM …

Road Map Of Semiconductor Metal-Oxide-Based Sensors: A Review, Taposhree Dutta, Tanzila Noushin, Shawna Tabassum, Satyendra K. Mishra

Electrical Engineering Faculty Publications and Presentations

Identifying disease biomarkers and detecting hazardous, explosive, flammable, and polluting gases and chemicals with extremely sensitive and selective sensor devices remains a challenging and time-consuming research challenge. Due to their exceptional characteristics, semiconducting metal oxides (SMOxs) have received a lot of attention in terms of the development of various types of sensors in recent years. The key performance indicators of SMOx-based sensors are their sensitivity, selectivity, recovery time, and steady response over time. SMOx-based sensors are discussed in this review based on their different properties. Surface properties of the functional material, such as its (nano)structure, morphology, and crystallinity, greatly influence …

Analyzing The Labor Shortage In The Construction Industry And The Best Practices To Increase Worker Satisfaction, Cade Batchman

Construction Management

The construction industry is facing a significant labor shortage, which has far-reaching implications for the industry and the economy. This paper explores the causes of the shortage and the practices being implemented to address it. Economic changes, technological advancements, union/open shop dynamics, educational shifts, and the industry's image all contribute to the shortage. The economic rebound from the 1980s recession and the lack of new entrants into the field have created a demand-supply gap. Additionally, slow adoption of technology and the perception of construction work as physically demanding and risky have deterred potential workers. The decline in union membership has …

Electrosteric Control Of The Aggregation And Yielding Behavior Of Concentrated Portlandite Suspensions, Sharu Bhagavathi Kandy, Narayanan Neithalath, Mathieu Bauchy, Aditya Kumar, Edward Garboczi, Torben Gaedt, Samanvaya Srivastava, Gaurav Sant

Materials Science and Engineering Faculty Research & Creative Works

Portlandite (calcium hydroxide: CH: Ca (OH)2) suspensions aggregate spontaneously and form percolated fractal aggregate networks when dispersed in water. Consequently, the viscosity and yield stress of portlandite suspensions diverge at low particle loadings, adversely affecting their processability. Even though polycarboxylate ether (PCE)-based comb polyelectrolytes are routinely used to alter the particle dispersion state, water demand, and rheology of similar suspensions (e.g., ordinary portland cement suspensions) that feature a high pH and high ionic strength, their use to control portlandite suspension rheology has not been elucidated. This study combines adsorption isotherms and rheological measurements to elucidate the role of PCE composition …

Data-Driven Predictive Modeling To Enhance Search Efficiency Of Glowworm-Inspired Robotic Swarms In Multiple Emission Source Localization Tasks, Payal Nandi

Mechanical & Aerospace Engineering Theses & Dissertations

In time-sensitive search and rescue applications, a team of multiple mobile robots broadens the scope of operational capabilities. Scaling multi-robot systems (< 10 agents) to larger robot teams (10 – 100 agents) using centralized coordination schemes becomes computationally intractable during runtime. One solution to this problem is inspired by swarm intelligence principles found in nature, offering the benefits of decentralized control, fault tolerance to individual failures, and self-organizing adaptability. Glowworm swarm optimization (GSO) is unique among swarm-based algorithms as it simultaneously focuses on searching for multiple targets. This thesis presents GPR-GSO—a modification to the GSO algorithm that incorporates Gaussian Process Regression (GPR) based data-driven predictive modeling—to improve the search efficiency of robotic swarms in multiple emission source localization tasks. The problem formulation and methods are presented, followed by numerical simulations to illustrate the working of the algorithm. Results from a comparative analysis show that the GPR-GSO algorithm exceeds the performance of the benchmark GSO algorithm on evaluation metrics of swarm size, search completion time, and travel distance.

Evaluating Direct Filtration As An Alternative To Conventional Carbon-Based Advanced Treatment For Indirect Potable Reuse, Savannah M. Flemmer

Civil & Environmental Engineering Theses & Dissertations

Hampton Roads Sanitation District (HRSD) is recharging purified wastewater into the Potomac Aquifer via the Sustainable Water Initiative for Tomorrow (SWIFT) project. Conventional SWIFT treatment applies coagulation, flocculation, sedimentation, ozonation, biofiltration, granular activated carbon (GAC) adsorption, and ultraviolet disinfection to secondary effluent to produce water that meets drinking water standards for managed aquifer recharge. HRSD is considering implementing direct filtration as an alternative to conventional treatment for two additional SWIFT facilities. Direct filtration presents an opportunity for significant cost savings by eliminating sedimentation, shortening flocculation detention time, and reducing coagulant usage. Without upstream removal of solids and organics, however, biofilters …

An Advanced Simulation Architecture For Testing Autonomous And Connected Vehicles Enabled By Virtual Reality, Defu Cui

Electrical & Computer Engineering Theses & Dissertations

With the advancement of intelligent transportation systems, autonomous driving and connected driving are seen as potential solutions to alleviate traffic congestion, enhance traffic safety, and improve efficiency. Extensive testing and validation of autonomous vehicles (AVs) and connected vehicles (CVs) including connected autonomous vehicles are crucial to ensure their safety and reliability. However, testing and validating AVs and CVs on public roads faces challenges such as high costs, inadequate support from transportation infrastructure with communication technologies, and safety concerns, among others. Simulations have become essential tools for testing autonomous driving and connected driving. As mixed traffic involves multiple domains including traffic …

Study Of Microphonic Effects On The C100 Cryomodule For High Energy Electron Beam Accelerators, Caleb James Hull

Mechanical & Aerospace Engineering Theses & Dissertations

The Continuous Electron Beam Accelerator Facility (CEBAF) at Thomas Jefferson National Laboratory (JLab) is a particle accelerator which can accelerate an electron beam to relativistic speeds and apply the beam onto target samples. The C100 superconducting radio frequency (SRF) cavity is the primary accelerating structure of the C100 cryomodule, one of the many cryomodules which compose the CEBAF linear accelerator. SRF cavities are particularly sensitive to internal and external vibrations that can result in a phenomenon called microphonics which degrade the operational stability of a cryomodule.

The purpose of this thesis is to investigate the significance of mechanical disturbances on …

Biocrude Production From Lignin In Hydrothermal Medium: Effect Of Rapid Heating And Short Residence Time, Kyoko Hirayama

Civil & Environmental Engineering Theses & Dissertations

This study aims to address knowledge gaps in the production of valuable products from waste streams generated during lignocellulosic biofuel production. The primary objective is to develop a process that converts lignin, a byproduct of bioethanol refineries, into a sustainable biolubricant.

The first chapter examines recent advancements in synthesizing biolubricants and investigates their scalability. It explores innovative materials, catalysts, chemical modification approaches, and additives that have emerged in the field. A particular hurdle is the oxidative stability of biolubricants derived from plant oils, which are prone to autooxidation due to their C=C bonds. To overcome this, the study aims to …

Localization And Identification Of Emi Sources In Shielding Enclosures Based On A Two-Step Source Reconstruction Method, Zi An Wang, Jun Fa Mao, Li (Lijun) Jun Jiang, Ping Li

Electrical and Computer Engineering Faculty Research & Creative Works

Localization and identification of unknown electromagnetic interference (EMI) sources in shielding enclosures is a great challenge due to the complex electromagnetic environment. In this work, a two-step source reconstruction method is proposed to address this issue. The actual EMI sources are initially modeled by equally distributed equivalent electric dipoles in the shielding enclosure. Effects of surrounding environments are rigorously incorporated using the numerical Green's function which bridges between the equivalent dipoles and planar scanned tangential magnetic near-field. Next, the initial equivalent sources are downsized via evaluating the contribution of each equivalent dipole. The parameters of remaining equivalent dipoles are updated …

Ultrasensitive Tapered Optical Fiber Refractive Index Glucose Sensor, Erem Ujah

Biomedical Engineering Theses & Dissertations

Refractive index (RI) sensors are of great interest for label-free optical biosensing. A tapered optical fiber (TOF) RI sensor with micron-sized waist diameters can dramatically enhance sensor sensitivity by reducing the mode volume over a long distance. Here, a simple and fast method is used to fabricate extremely sensitive refractive index sensors based on localized surface plasmon resonance (LSPR). Two TOFs (l = 5 mm) with waist diameters of 5 µm and 12 µm demonstrated sensitivity enhancement at λ = 1559 nm for glucose sensing (5–45 wt%) at room temperature. The optical power transmission decreased with increasing glucose concentration due …

Oxidation Of Hafnium Diboride—Silicon Carbide At 1500 °C In Air; Effect Of Compressive Stress, Anthony J. Degregoria, Marina B. Ruggles-Wrenn, Glen E. Pry

Faculty Publications

The long-term oxidation behavior of HfB₂ and of HfB₂-20 vol.% SiC was studied. Test samples of each material were oxidized at 1500 °C in air using a box furnace. The exposure times were 0, 0.5, 1, 2, 3, 6, 9, 12, 15, 30, 45 and 90 h. Weight gain, oxide scale composition and oxide scale thickness were characterized for both materials. Crystal structure of the surface scales was analyzed using x-ray diffraction. Oxide scales were further characterized via scanning electron microscopy with energy dispersive spectroscopy analysis. For HfB₂ the oxide scale consists predominantly of porous HfO …

Silicon Carbide-Based Dna Sensing Technologies, Abdulla Al Mamun, Mason Mcgarrity, Jong Hoon Kim, Feng Zhao

Electrical and Computer Engineering Faculty Research & Creative Works

DNA sensing is critical in various applications such as the early diagnosis of diseases and the investigation of forensic evidence, food processing, agriculture, environmental protection, etc. As a wide-bandgap semiconductor with excellent chemical, physical, electrical, and biocompatible properties, silicon carbide (SiC) is a promising material for DNA sensors. In recent years, a variety of SiC-based DNA-sensing technologies have been reported, such as nanoparticles and quantum dots, nanowires, nanopillars, and nanowire-based field-effect-transistors, etc. This article aims to provide a review of SiC-based DNA sensing technologies, their functions, and testing results.

Measurement Of Vapour Pressure, Miscibility And Thermal Conductivity For Binary And Ternary Refrigerant Lubricant Mixtures In The Context Of Heat Pump Tumble Dryers, Katharina Stockel, Ramona Nosbers, Riley Barta, Christiane Thomas

School of Mechanical Engineering Faculty Publications

Household appliances need to be both efficient and cost-effective. As a result, electrically driven tumble dryers were converted to heat pump driven ones several years ago in order to comply with energy directives, in this case in Germany. In order to increase the efficiency of heat pumps of different performance classes, the use of zeotropic refrigerant mixtures can be useful, since the temperature glide during the phase change of the refrigerant mixture can be adapted to the temperature gradients of the secondary fluids. In order to take advantage of this unique property, a refrigerant mixture selection was carried out by …

Investigation Of Possible Inflammatory Response After Ultrasound And Microbubble Procedure In The Spinal Cord., Jenna Wilkerson

Electronic Theses and Dissertations

The purpose of this experiment is to explore the inflammatory effects of focused ultrasound paired with intravenously delivered microbubbles when used in the lumbar spinal cord. There are currently very few pharmaceuticals that can successfully enter the blood spinal cord barrier (BSCB). This technique used at the lumbar enlargement might allow targeted treatment of pathologies involving the spinal cord.

To test the possible inflammatory response of this technique, an animal experiment was performed. 15 animals were given a T12 laminectomy and allowed to fully recover. Once recovered, all animals received FUS+MB at L2 and were euthanized in groups of five …

Development And Application Of A Microfluidic Platform For Quantifying Intra-Tumoral Compressive Stress., Zachary P. Fowler

Electronic Theses and Dissertations

Cancer progression is linked to the emergence of aberrant mechanical signaling in the tumor microenvironment. Modulation of extrinsic signals, such as ECM stiffness and composition, have been thoroughly explored. However, the development of solid stresses within the tumor remains poorly understood. To address this, we have developed a microfluidic platform that generates deformable alginate microbeads that allow for the quantification of compressive stresses generated within a growing glioblastoma (GBM) tumorsphere. PDMS microfluidic devices were fabricated via SU-8 mold with channels ranging from 10µm-40µm in diameter. Fluorescently labeled sodium alginate underwent a cross-linking reaction within the device to generate monodisperse beads …

Addition Of Process Control Experiment To Unit Operations Ii Laboratory., Bradley Esselman

Electronic Theses and Dissertations

Process control is an essential aspect of manufacturing, contributing to improved process safety, efficiency, product consistency, and energy optimization. Chemical engineers are often responsible for ensuring the safe, efficient, and cost-effective operation of industrial processes, and process control plays a pivotal role in accomplishing this.

Chemical engineering students at the University of Louisville complete the course, Elements of Process Control, during the second semester of their fourth year. This lecture-based course offers limited hands-on, practical experience. To supplement the lack of hands-on experience in the classroom, a new process control experiment was designed and implemented into the Unit Operations …

Design And Evaluation Of A Multi-Functional Surgical Device For Microgravity Surgeries., Sienna Shacklette

Electronic Theses and Dissertations

No abstract provided.

Investigation Of Cyclic Gaseous Solvent Injection For Enhanced Oil Recovery In Unconventional Formations, Samuel Asante Afari

Theses and Dissertations

Unconventional resources have been known to hold vast quantities of hydrocarbons. However, exploiting the oil and gas they hold was previously challenging due to their low permeabilities. Recent advances in horizontal well drilling and hydraulic fracturing have enabled oil and gas production from these reservoirs, leading to significant increases in energy supply to meet the growing energy demand. However, despite the relative technological success, considerable obstacles persist; oil production from unconventional wells often declines by more than 20% of their initial production rate within the first two years, leaving significant volumes of residual oil trapped in the formations. This overarching …

Performance Evaluation Of A Coupled Photovoltaic-Thermal Solar Powered Desalination Pilot System, Martin Chavarin

Open Access Theses & Dissertations

A pilot scale coupled photovoltaic-thermal solar powered desalination system was evaluated at the Brackish Groundwater National Desalination Research Facility (BGNDRF). The pilot system consisted of a 3-kW photovoltaic-thermal (PVT) solar panel array and a 2.3 kW photovoltaic (PV) array coupled with a 4 gal/min single-stage 4 membrane reverse osmosis (RO) desalination system. A heat exchange system was in place to provide simultaneous cooling for the PVT system and heating to the RO system feed water. This system was evaluated with three objectives in mind. The first objective was to identify whether cooling of the PVT panels resulted in a significant …

A Novel Approach For Defect Detection Of Wind Turbine Blade Using Virtual Reality And Deep Learning, Md Fazle Rabbi

Open Access Theses & Dissertations

Wind turbines are subjected to continuous rotational stresses and unusual external forces such as storms, lightning, strikes by flying objects, etc., which may cause defects in turbine blades. Hence, it requires a periodical inspection to ensure proper functionality and avoid catastrophic failure. The task of inspection is challenging due to the remote location and inconvenient reachability by human inspection. Researchers used images with cropped defects from the wind turbine in the literature. They neglected possible background biases, which may hinder real-time and autonomous defect detection using aerial vehicles such as drones or others. To overcome such challenges, in this paper, …

Electrochemical Approaches To Life-Support Resources In Space Missions And Nuclear Technologies: Hydrogen Peroxide And Uranium Films, Armando Manuel Pena-Duarte

Open Access Theses & Dissertations

Space race has developed several technological advances that have achieved and continue to achieve the success of space missions in the aerospace timeline. Currently, the number of space technical and scientific innovations is still growing––demanding new materials and developments for extreme performing applications of fuel cells, batteries, supercapacitors, and systems of nuclear energy. Space missions require life-support solutions, auto-sustainable closed-loop living environments, cleaning and sanitizing solutions against pathogens, and safe nuclear-based resources of energy––with fissile materials with well-controlled dimensions within the core fuel elements. Likewise, to guarantee safety conditions, reduce costs, and facilitate operational logistics, space missions must reduce their …

The Genetic And Non-Genetic Factors For Impulsivity, Erick Benjamin Saldes

Open Access Theses & Dissertations

Inhibitory control is an executive function suppressing inappropriate actions or thoughts and inhibitory control dysfunction leads to impulsivity. Impulsivity is associated with wide-ranging brain disorders including attention deficit hyperactivity disorder, autism spectrum disorder, substance use disorder, and dementia. The genetic and non-genetic factors contributing to impulsivity are poorly understood. This dissertation aims to begin closing this knowledge gap by identifying the genetic and non-genetic factors for impulsivity and the underlying mechanism in the model organism Drosophila melanogaster. For this task, we developed a new Go/No-Go test, which measures the fly's ability to suppress movements in situations that can endanger its …

Effect Of Heat Treatment On The Mechanical And Corrosion Properties Of The Cocrnifeal Heas, Ahmed Korra

Masters Theses and Doctoral Dissertations

High entropy alloys (HEAs) are a relatively new class of metallic materials that have shown great potential for use in extreme environments, such as high temperatures and corrosive conditions. Among the different types of HEAs, CoCrNiFeAl HEAs are potential materials for a wide range of applications, including aerospace, biomedical, and energy storage. This work focused on the effects of heat treatment temperatures from 800 °C to 1100 °C on the microstructure and mechanical properties of these alloys, as well as their electrochemical corrosion behavior. A thermodynamic model was implemented to predict the performance of the material. The results of this …

Integrating Human Psychology Into Car-Following Models For Accurate Response Prediction: A Realistic Approach, Faiza Khan

Masters Theses and Doctoral Dissertations

Car-following models traditionally focus on vehicle kinematics or dynamics parameters without considering human psychology. However, recent research has attempted to incorporate psychology into car-following models. Despite these efforts, there are limitations in understanding the psychological triggers that influence individual drivers' responses. To address this gap, we propose a new car-following model based on the Theory of Planned Behavior (TPB), which incorporates a human element by utilizing concepts of psychology. To gather the data pertaining to human input a questionnaire was carefully developed utilizing the Theory of Planned Behavior. Data collection and analysis were done through a survey using google forms. …

Subject-Specific Human Knee Fea Models For Transtibial Amputees Vs Control Tibial Cartilage Pressure In Gait, Cycling And Elliptical Training, Ali Yazdkhasti

Master's Theses

Millions of individuals around the globe are impacted by osteoarthritis, which is the prevailing type of arthritis. This condition arises as a result of gradual deterioration of the protective cartilage that safeguards the ends of the bones. This is especially true of transtibial amputees, who have a significantly higher incidence of osteoarthritis of the knee in their intact limb than non-amputees. Engaging in regular physical activity, managing weight effectively, and undergoing specific treatments can potentially slow down the advancement of the disease and enhance pain relief and joint function. Nevertheless, the relationship between the type of exercise and its impact …

Performance Improvements Of Hot Mix Asphalt Concrete Using Carbon-Based Fillers, Leonardo A. Ortega Ruiz

Theses and Dissertations

To further advance the state of the art on the performance improvements of hot mix asphalt concrete, this paper investigates the improvements to cracking damage of hot mix asphalt concrete by the addition of carbon-based fillers. There have been various studies dedicated to measuring the strength performance of asphalt mixtures modified with non-traditional fillers, but many of the current studies seem to have varying success with their results or have results that are not statistically significant. In this research, carbon black and F-516 graphite in various percentages were added into asphalt mixtures as a replacement of the traditionally used hydrated …

Simple Mechanically Reconfigurable Patch Antennas, Luis Alonso Hernandez Galvan

Theses and Dissertations

Reconfigurable antennas form an active subdivision of antenna and communications research primarily targeted at achieving reconfigurability in the RF, microwave, and millimeter-wave frequency regimes. Mechanical, all-electronic, material based, and optical methods are the most common approaches to achieve reconfigurability. Each method can overlap to create new and innovative approaches to enable device tunability. The sub-class of reconfigurable antennas are antennas that dynamically achieve an adaptable transformation of their frequency, radiation-pattern, polarization, and/or bandwidth characteristics to enable multiple dynamic functionalities.

In this thesis, we designed new rectangular and triangular microstrip patch array antennas operating in the 5G midband at 5GHz. These …