Engineering Commons^™

The Dropbot: Design And Development Of A Custom Drone For Precision Water Drop Penetration Time (Wdpt) Testing, Mugundan Prakash

UNLV Theses, Dissertations, Professional Papers, and Capstones

Assessing the hydrophobic characteristics of soil is vital for understanding soil wettability or soil-water interactions, particularly in post-wildfire environments where water repellency can significantly impact ecosystem recovery, water infiltration, and erosion control. One key metric in soil wettability studies is the Water Drop Penetration Time (WDPT) test, which evaluates the hydrophobicity of soil and guides land treatment strategies. This thesis presents the design and development of DropBot, a custom-built drone platform engineered for the precise delivery and analysis of water droplets in WDPT tests.The DropBot, a custom drone, integrates a lightweight, 3D-printed frame with a self-leveling platform, enabling consistent droplet …

Improving Particle-Phase Nitrate Measurement In Pm2.5 Filter Sampling: Evaluation Of A Denuder–Nylon Filter Modification In The Spartan Network, Wenyu Liu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Accurate measurement of PM_2.5 composition is of global importance. Evaporation-induced mass loss introduces potential bias in filter-based PM_2.5 measurements, with ammonium nitrate volatilization from Teflon filters being a major contributor to negative mass artifacts. Previous studies have demonstrated that using an acid gas denuder in combination with nylon filters can help recover the nitrate mass. This study evaluates design modifications to the AirPhoton sampling station setup within the globally distributed Surface Particulate Matter Network (SPARTAN) incorporating an additional acid gas denuder upstream and a nylon filter downstream of the existing Teflon filter.

Two co-located AirPhoton Sampling stations were …

Safe Real-Time Obstacle Detection And Navigation Using Cbf–Clf And Cbf–Pid Control, Nicolas M. Hernandez

McKelvey School of Engineering Graduate Student Theses & Dissertations

Traditional robotic navigation pipelines typically follow a three stage architecture: obstacle detection, path planning, and low-level control for trajectory tracking. While effective in static environments, these methods often introduce latency and lack formal guarantees of safety in dynamic or unplanned for scenarios. Our work addresses these limitations by developing a real-time controller grounded in Control Barrier Functions (CBFs) and Control Lyapunov Functions (CLFs), unified through a Quadratic Program (QP). We first investigate a hybrid CBF-PID-QP controller on a 1/10 scale car, where the CBF serves as a real-time safety filter, modifying the PID output to prevent constraint violations. While this …

Orbital Maneuvers And Interplanetary Trajectory Design Via Reinforcement Learning, Roberto Cuéllar Rangel

Doctoral Dissertations and Master's Theses

This dissertation investigates the application of reinforcement learning (RL) to the design and optimization of low-thrust spacecraft trajectories, with an emphasis on autonomy, adaptability, and robustness in the presence of system uncertainties and unmodeled perturbations. Classical approaches to low-thrust trajectory design are predominantly grounded in optimal control theory, which relies on the availability of precise dynamical models and often requires problem-specific reformulation and solver tuning. While optimal control methods offer high accuracy under deterministic conditions, their sensitivity to stochastic disturbances and computational limitations in highly nonlinear or uncertain environments pose significant challenges for future autonomous space missions.

To address these …

Understanding And Evaluating Genomic Language Models, Aadit Kapoor

Master's Theses

Large Language Models (LLMs) have shown remarkable capabilities in interpreting complex patterns across various domains, yet their application to genomic data remains limited. We see great potential in leveraging LLMs for vital biological tasks, such as predicting transcription factor binding sites and identifying antibiotic-resistant genes. This emergent behavior positions LLMs as powerful tools for enhancing our understanding of intricate biological language. LLMs trained specifically on genomic data, such as DNA sequences, operate distinctly compared to those trained on natural language. This difference is evident not only in the architectural landscape of the models but also in the methodologies employed by …

Characterizing And Modeling The Nonlinear Behavior Of Additively Manufactured Trapped-Powder Dampers, Jonathan Knight Black

Theses and Dissertations

Laser Powder Bed Fusion (LPBF) can be used to create metal parts with pockets of retained, unfused powder that serve as mechanical dampers. These trapped-powder dampers show promise for reducing the amplitude of vibrations at resonance by orders of magnitude. However, little is currently understood about the nonlinearity and repeatability of trapped-powder dampers, meaning that the design process currently consists of expensive trial-and-error prototyping and iteration. The present work contributes a corpus of experimental measurements for rectangular beams with trapped-powder dampers of various dimensions and locations. Preliminary testing revealed the presence of a memory effect which we hypothesize to be …

Investigating Radiation Induced Rowhammer And Retention Failures In Dram, Tyler Ricks

Theses and Dissertations

It is desirable for DRAM devices to be used in harsh radiation environments. Exposure to radiation causes DRAM cells to lose their retention time as their ability to store charge effectively declines. Exposure also worsens the effect of disturbance that causes neighboring cells to flip when a row is opened multiple times: an effect known as the Row Hammer Effect. This thesis evaluates the impact of radiation-induced memory cell degradation by comparing memory cell's retention time and their resilience to the row hammer vulnerability. Three generations of DRAM were placed under a neutron radiation beam. Sections of the irradiated devices …

Accelerating Gnn Inference On Multi-Core Systems, Binglin Ji

McKelvey School of Engineering Graduate Student Theses & Dissertations

Graph Neural Networks (GNNs) are becoming increasingly popular, with their applications expanding across diverse domains. As the scale of graph data continues to grow, including larger numbers of nodes, edges, and higher embedding dimensions, standardized libraries such as DGL and PyG have been developed to facilitate GNN computation. However, with the rapid increase in the number of processor cores and the evolution of multi-core architectures, these libraries often show poor scalability and fail to execute GNN inference efficiently on the latest multi-core systems, particularly those with upwards of a hundred cores. To address this limitation, we present FGI, a Fast …

Compact Heterogeneous Architectures And Algorithmic Methods For Enhanced Real-Time Digital True Time Delay Beamforming And Radar Applications, Nathan Lynn Burnett

Theses and Dissertations

Modern radar and signal processing systems require efficient computational architectures to handle increasing data rates while still being able to maintain dynamic configurability and complex tasks. This thesis presents and explores hardware and algorithmic approaches addressing these demands across several different applications. First, a low-cost tracking platform and architecture for unmanned aerial vehicles (UAVs) is developed, which provides detection and tracking capabilities, compliant with new FAA remote ID regulations. Second, a GPU-FPGA based digital true time delay beamformer is implemented to achieve real-time wideband radio frequency interference (RFI) mitigation. Specifically this beamformer explores weight calculation and calibration through particle swarm …

Versatile Waveform Generation And Clocking Techniques For Rfsoc-Based Digital Designs, Michael David Jones

Theses and Dissertations

Within an ever-evolving radio-frequency (RF) environment, designers are required to adapt systems to increasingly constricted parameters. The available tools continually grow to match this need, but so does the complexity in using them. The radio-frequency system-on-chip (RFSoC) is an innovation that combines a field-programmable gate array (FPGA) with an integrated RF chain. Designing with an RFSoC allows for high-precision data transmission, sampling, and processing, but it can be difficult and time-consuming to develop specialized circuits. The open-source CASPER project aims to provide a library of abstracted block-design components to simplify the design process. An arbitrary waveform generator (AWG) is created …

Wear Of High Entropy Alloys: Understanding Effects Of Cryogenic Temperatures And Surface Nitriding On Wear Behavior, Aubrey Yu Tang

Dartmouth College Ph.D Dissertations

Cryogenic tribological applications have become increasingly important with the development and innovation of advanced equipment in aerospace, polar regions, superconductivity, and more. Traditional lubrication methods are not viable under these harsh environments, so metallic materials must be able to maintain excellent mechanical properties and withstand the constant impact and wear alone. High entropy alloys (HEAs) have emerged as potential candidates for these applications because of their wide variety of excellent room temperature properties and apparent improvement of mechanical properties of some HEAs at extremely low temperatures. Despite their promising nature, very limited work has been done on understanding the wear …

Development Of Numerical Tools And Performance Metrics For Analysis Of Optical Particle Counters, Doug Webb

Theses and Dissertations

Monitoring air quality is essential for understanding and mitigating the health impacts of airborne particulate matter (PM), which is linked to respiratory and cardiovascular disease. Optical particle counters (OPCs) are widely used for air quality monitoring, yet their precision and accuracy remain uncertain due to inconsistent performance evaluations. In this thesis, performance metrics are developed that can be used to assess the accuracy of OPCs in measuring PM concentrations and size distributions. Computational fluid dynamics (CFD) simulations are employed to analyze the behavior of particle-laden air streams through representative OPC models. The impact of design parameters is quantified using newly …

Scalable And Adaptive Agile Framework For Semiconductor Foundry: Advanced Packaging And Heterogeneous Integration Perspective, Pravin Thorat

Harrisburg University Dissertations and Theses

This research addressed the critical requirement for a scalable and adaptive agile framework specifically designed for the unique demands of semiconductor foundries specializing in advanced packaging and heterogeneous integration (HI). The semiconductor industry was encountering growing pressure to innovate and respond quickly to rapidly evolving demands, yet traditional manufacturing processes often struggled to adapt. Existing agile frameworks, mainly developed for the software industry, lacked the necessary adaptations to address the complexities of semiconductor manufacturing, including extended lead times, high capital investment, rigorous quality requirements, and the integration of various technologies. This research gap hindered the ability of semiconductor foundries to …

Exploring The Role Of Accessibility In Enhancing User Experience: Trends, Challenges, And Opportunities Across Digital Platforms, Adiba Khan

Harrisburg University Dissertations and Theses

Accessibility was a fundamental aspect of enhancing user experience (UX) across digital platforms, ensuring equitable access to information and services for a diverse range of users, including individuals with visual, auditory, cognitive, or motor impairments. As digital products became increasingly central to education, commerce, and communication, the need for inclusive design grew. This study explored the intersection of accessibility and UX, with a specific focus on how accessibility-driven design improved usability, user satisfaction, engagement, and the overall quality of digital interactions. Grounded in Agile project management principles, the research examined how early integration of accessibility into the software development lifecycle …

Tracing Tremor: From Upper-Limb Neuromusculoskeletal Dynamics To Movement Signatures In Essential Tremor, Landon J. Beutler

Theses and Dissertations

Tremor is a common neurological condition that significantly impairs the quality of life for millions. Despite this prevalence, the underlying mechanisms of its propagation remain poorly understood, and current treatment options often rely on trial-and-error methods. Moreover, the most common type, Essential Tremor (ET), presents a unique challenge due to its heterogeneity--patients exhibit a wide range of symptoms, severities, and responses to treatment. This thesis primarily advances tremor understanding through computational modeling, with a secondary focus on data-driven subtyping of ET via cluster analysis. These parallel paths aim to improve both mechanistic insight and clinical classification. Tremor propagation refers to …

Design Of A Fan-Based Test Stand For Evaluating Multicopter Handling In Turbulent Flow, Salim Roig

Doctoral Dissertations and Master's Theses

With the innovation of eVTOL rotorcraft the need to analyze how turbulence-induced disturbances from orthogonal flow affect various rotorcraft configurations outside of simulations have grown significantly. To investigate the behavior of this type of flow and how it interacts with various rotorcraft configurations, a turbulent inducing test stand was designed and constructed. The test stand will have two walls of computer fans arranged in an L-shape frame, creating wind gusts that simulate the non-linear turbulent wind experienced by eVTOL. This also aids the Eagle Flight Research Center (EFRC) in their efforts to better understand how disturbances affect the handling qualities …

Development Of Low-Cost Small-Batch Flibe Filtration, And A Comparison Of Uranium Tetrafluoride And Ionic Oxygen Oxidation In Flibe, Jacob D. Christensen

Theses and Dissertations

Low-cost benchtop-scale molten fluoride salt cleaning was investigated in FLiBe (LiF-BeF2), focusing on electrochemical cleaning and filtration. FLiBe filtration was demonstrated using both pressurized and open filtration systems. Copper and 400 Monel meshes were effective and reusable. Wetting appears to be the primary obstacle to FLiBe filtration. Oxygen oxidation behavior in FLiBe was examined using cyclic voltammetry (CV) and cyclic square wave voltammetry (CSWV) techniques. Standard addition height measurement was used to determine electrode surface area. Results support a single-step 2-electron process, matching observations in literature. Pt electrodes may be prone to oxidative side reactions, although more investigation is required. …

Effect Of Arm Movement On Lower Body Muscle Contributions To Standing Long Jump Performance, Abigail Douglas

Masters Theses

Previous jumping studies have proven that jumping with arm motion enhances performance compared to jumping without arm motion. The purpose of this study was to investigate the effect of arm motion on the muscle contributions of the lower extremities during the standing long jump using muscle-actuated modeling informed by experimental data. Specifically investigating how arm motion enhances performance at the muscle level and how the muscle contributions of the lower extremities differ in jumps with and without arm motion. Three male and three female participants performed three jumps with arms and three jumps without arms. The longest jumps with and …

The Effect Of Wall Temperature And Transpiration On Görtler Vortices In High-Speed Boundary Layers, Asmaa Ahaggach

Theses and Dissertations

Görtler vortices are counterrotating flow structures generated as a result of the imbalance between the wall radial pressure gradients and the centrifugal forces in a boundary layer developing on a curved surface. Their presence leads to secondary instabilities and increases the wall shear stress as they accelerate the transition from laminar to turbulent flow. These secondary instabilities can be mitigated using control techniques aimed at decreasing the energy and the wall shear stress. In this thesis, the combined effect of wall temperature and transpiration on Görtler vortices developing in supersonic and hypersonic boundary layers is investigated. Görtler vortices are excited …

Load Balancing For Stream Processing In Edge Computing, Faiza Akram

Theses and Dissertations

Unlike cloud-based systems, where resources are centralized for data processing and located at a distance from the source, leading to an increase in the response time, edge computing emerges as a transformative paradigm that processes the data closer to the sources to meet the application’s service requirements. Since the resources in edge computing are distributed and limited, load balancing is crucial. To ensure the prevention of bottlenecks and failures in resource-constrained environments, load balancing is an important aspect of edge computing as it optimizes resource utilization while maintaining the requirements of low-latency applications, improved fault tolerance, energy efficiency, adaptability, scalability, …

Optical Trapping For The Study Of The Chemical And Physical Dynamics Of Single Particles, Yukai Ai

Theses and Dissertations

This dissertation explores the combined technique of optical trapping and Raman spectroscopy (OT-RS) to study the physical and chemical properties, as well as the dynamic surface changes, of single aerosol particles in air. The study covers a wide range of aerosol types, including bioaerosols (such as pollen, bacteria, and fungi), dust particles (such as black carbon, terrestrial, and extraterrestrial materials), and liquid droplets (such as sea-spray aerosols). The optical trapping system used in this work is based on the universal optical trap (UOT), which is capable of trapping and manipulating a wide variety of particle types. These include both transparent …

Calibration And Validation Of The Thermal Finite Element Model For Er120s-G Wire Arc Directed Energy Deposition Using Infrared Cameras And Thermocouples, Joshua Mykl Bassett

Theses and Dissertations

Wire Arc Directed Energy Deposition (WA-DED) is a promising additive manufacturing method for producing large metallic components with high deposition rates and low costs. However, its rapid heat input can lead to residual stress, microstructural changes, and dimensional inaccuracies. Accurate thermal modeling is essential to mitigate these effects. This study presents a thermal calibration of a finite element model (FEM) for ER120S-G using thermocouples and infrared (IR) imaging. Thermal data were gathered from three experiments to complete the calibration of the FEM . Calibration focused on tuning the Goldak heat source parameters, power efficiency, and heat transfer coefficients to minimize …

Towards Applying Artificial Intelligence To Solve Np-Complete Problems Using Quantum Computing, Andrew Robert Haverly

Theses and Dissertations

This dissertation explores the methodology for more thoroughly entangling artificial intelligence and quantum computing. This is explored through a background search of problems solved using Grover’s quantum algorithm, a new quantum protein folding and drug discovery algorithm, using Grover’s algorithm to train quantum artificial neural networks, using quantum artificial neural networks for reinforcement learning, mapping classical assembly instructions to quantum circuits to make quantum programming easier, and using prompt engineering to get a classical artificial intelligence agent to solve an NP-Complete problem using a Grover’s algorithm. This method not only simplifies the creation of algorithms but also opens new avenues …

Spray Characterization And Fuel Property Analysis Of Tier 3 Gasoline In A Gdi System Using Machine Learning, Kyungwon Lee

Theses and Dissertations

This study investigates the spray behavior of Tier 3 gasoline in gasoline direct injection engines using experimental methods. Tier 3 gasoline, formulated with lower sulfur content, enhances aftertreatment system efficiency and supports cleaner combustion. A comparative fuel property analysis between Tier 3 gasoline and PACE-20, surrogate fuel, was conducted to understand compositional effects on spray. A constant volume spray chamber and optical diagnostics, including diffuse back-illumination extinction, Schlieren, microscopic, and 3D CT reconstruction imaging, were used to examine spray morphology under varying injection conditions. Key spray parameters such as liquid volume fraction, projected liquid volume, droplet size, and cone angle …

Transforming Movement Assessment In Physical Therapy Through Subaquatic Data Collection, Kaitlyn Mcdonald

Theses and Dissertations

This study explored the interest and perceived barriers to integrating subaquatic diagnostic technologies (SDTs) into hydrotherapy among licensed physical therapists. Seventeen semi-structured interviews were conducted using a mixed-methods design, with 15 interviews included in the final analysis. Quantitative data were analyzed using chi-square tests, while qualitative responses were coded thematically. Results indicated no statistically significant relationships between SDT interest and career stage or hydrotherapy access, though qualitative data highlighted concerns about cost, limited access, and usability. Despite mixed interest in adoption, participants identified several potential benefits of SDTs, including improved treatment tailoring, increased patient buy-in, and enhanced outcome monitoring. Functional …

Neural Architecture Search-Driven Unsupervised Domain Adaptation For Enhanced Wood Chip Quality Evaluation In Forest Industries, Abdur Rahman

Theses and Dissertations

Reliable and efficient measurement of wood chip moisture content is crucial for forest-reliant industries, including biofuel production, pulp and paper manufacturing, and bio-refineries, as it directly influences product quality and energy output. Traditional methods like the oven-drying technique, despite their widespread use, are time-consuming and impractical for real-time applications, while modern alternatives such as NIR spectroscopy, electrical capacitance, and microwave analysis are often costly, less portable, and require specialized expertise. This dissertation addresses these limitations by leveraging deep learning and machine vision to develop a scalable, accurate, and portable method for moisture content measurement using RGB images of wood chips. …

Thermo-Mechanical Advancements For Very High Strength And Ultra High Performance Concretes, Lana Grayson Brown Sisung

Theses and Dissertations

Interest in the use of high-strength concrete (HSC) has increased in recent years with demand for improved concrete performance. HSCs are widely associated with high heat of hydration and elusive behavior when exposed to high temperatures commonly occurring in mass structures. The optimization of HSC mixture proportioning is difficult due to a wide variety of constituents that influence thermal and mechanical properties. Additionally, determining in-place properties of mass concrete placements is elusive, and there are currently minimal to no test methods available that are both predictive and a direct measurement of mechanical properties. The objective of this dissertation is to …

Non-Thermal Dbd Plasma-Induced Co₂ Capture And Conversion To Value Added Chemicals, Chinwendu Theresa Umeojiakor

Theses and Dissertations

Electrified CO2 conversion via nonthermal dielectric-barrier discharge (DBD) plasma presents a promising pathway for integrating renewable energy into the carbon cycle, addressing the dual challenges of CO2 reduction and sustainable fuel generation. In this research, DBD plasma technology was integrated with a sorbent material and/or catalytic materials for CO2 desorption and conversion. Specifically, with Ni/Al2O3 as the catalyst, we investigated CO2 splitting (CO2 to CO and 0.5O2) and hydrogenation (CO2 and H2 to CO and H2O) under adiabatic and subcooled conditions. We find that CO2 splitting shows higher efficiency than hydrogenation, particularly at relatively lower power inputs. While CO2 hydrogenation …

Interatomic Potential Of Multiphase Materials Using Modified Embedded Atom Method (Meam) And Artificial Neural Network (Rann), Henan Zhou

Theses and Dissertations

There is a significant need for computer simulations to explore multiphase materials because of their significance in both industry and research. These simulations are both more efficient and less expensive than many experimental approaches, making them an ideal choice for this purpose. It is possible to use molecular dynamics simulations that make use of the MEAM and RANN interatomic potentials in order to comprehend and characterize the properties, performance, and behavior of materials at the atomic scale of different material phases. In the realms of elements, alloys, and impurities, MEAM can be utilized in a wide variety of applications. Through …

Reactive Molecular Dynamics And Method Development For Applications In Renewable Energy And Sorption Equilibria, Woodrow Wilson

Theses and Dissertations

It is crucial to harness energy from sustainable sources to combat the dwindling nonrenewable feedstocks used to produce everyday commodities and fuels. Liquid-phase heterogeneous catalysis has demonstrated remarkable product selectivity and yields for reactions relevant to biomass valorization under mild operating conditions. However, active site characterization is challenging due to the complex solvated environment and interface. Ground-state first-principles (FP) molecular simulations have provided insights into reactive systems in catalysis. These calculations, however, scale poorly with the number of electrons. Observing atomic motion with molecular dynamics (MD) or sampling static properties with Monte Carlo (MC) simulations at statistically relevant lengths- and …