Engineering Commons^™

Improving And Supporting Flight Instructor’S Decisions For First Solo, Isabella Piasecki

Theses and Dissertations

Flight instructors have the burden of determining when a student is ready for their first solo flight, and many have expressed uncertainty over their own decision-making skills during this phase of a student’s training. Prior studies have examined flight instructors’ pre-solo decisions in other countries, but no such study has been conducted with American flight instructors. For this study, current flight instructors with multiple prior endorsements for a student pilot’s first solo were interviewed to identify the more abstract concepts they use to guide their decision. Qualitative themes were identified from their experiences. Using this information, a checklist was developed …

The Effects Of Experiential Learning On Engineering Self-Efficacy: A Study Of The Impact Of Inperson And Virtual Internships, Co-Ops, And Research Experiences, Sunny Bharat Patel

Theses and Dissertations

This dissertation examined the relationship between participation in Engineering Learning Experiences (ELEs) and engineering self-efficacy, with particular attention to differences among ELE types (internships, cooperative education, and undergraduate research) and delivery modalities (in-person versus hybrid/virtual). Grounded in social cognitive theory, this study sought to better understand how work-related experiential formats influence students’ confidence in their ability to succeed in engineering tasks and professional contexts. As engineering programs and industry increasingly adopt flexible and technology-mediated environments, examining how these experiences shape beliefs about engineering capability is both timely and necessary. Using a mixed-methods approach, quantitative analyses compared self-efficacy outcomes across students …

A Cradle To Grave Life Cycle Assessment Of Captured Landfill Methane Abatement Strategies, Joshua Caleb Richard

Theses and Dissertations

Landfill methane mitigation strategies are commonly evaluated using percentage-based leakage assumptions and linear scaling models. These approaches may misrepresent system performance at varying throughput levels and real-world operating scenarios. This thesis develops a system-level life cycle assessment framework that incorporates both fixed infrastructure losses and employs sensitivity analysis to more accurately characterize emissions from landfill gas management pathways. Three scenarios are evaluated: methane capture and flare, methane capture and combustion for electricity generation, and methane upgrading with pipeline injection as renewable natural gas. Results demonstrate that emissions models over- dependance on static factors may inadvertently lead to under-reporting and provide …

Development Of Carbon-Fiber-Reinforced Composite Rotor Sleeves For High-Speed, Multi-Layer Ferrite-Based Interior Permanent-Magnet Motors, Andrew Walters

Theses and Dissertations

This research investigated whether a non-wound carbon fiber reinforced composite (CFRC) sleeve could serve as an effective retention mechanism for a high-speed, multi-layer ferrite-based interior permanent magnet motor. Material characterization testing was conducted on IM7/CYCOM-5320 and IM7/8552, with IM7/8552 selected due to its superior commercial availability. Experimentally obtained properties for both materials fell within acceptable tolerances of published values. Sleeves were manufactured to rotor design specifications (50-mm width, 1.2-mm thickness, 88.6-mm diameter) and tested per ASTM D2290 Procedure A to determine apparent hoop-failure stress. These experimental results validated a finite element model of the D2290 test, confirming realistic strain patterns …

Experimental Investigation Of The Effectiveness Of Various Stitching Methods On Arresting Mode-Ii Interlaminar Damage Propagation In Geometrically-Scaled Stitched Resin-Infused Composites, Allison Jean White

Theses and Dissertations

This thesis presents an experimental and analytical investigation of mode-II interlaminar fracture in geometrically-scaled quasi-isotropic resin-infused composites, with emphasis on through-thickness stitching as reinforcement. A global-local framework integrating load-displacement response, size effect fracture energy analysis, and digital image correlation-based separation measurements enabled direct comparison between unstitched and stitched configurations. Unstitched laminates exhibited pseudo-ductile behavior but significant post-peak load drops (16.7–26.8%) and a small fracture process zone (FPZ) of 0.73 mm, limiting stable crack growth. Stitching preserved pre-peak stiffness while reducing post-peak load drops by 43–95%, increasing effective fracture energy by 39.7% (to 2.413 N/mm), and expanding the FPZ to 2.85 …

Feasibility-Aware Deep Reinforcement Learning For Sustainable Timber Procurement Under Hurricane Demand Uncertainty, Jarod Wright

Theses and Dissertations

The timber supply chain connects landowners and mills to provide wood products but faces challenges from stochastic demand, seasonal variations, and disruptions such as hurricanes. Fur- thermore, sustainability concerns like transportation emissions create trade-offs in procurement. This study proposes a feasibility-aware Deep Reinforcement Learning framework for sustainable timber procurement and inventory control under joint demand–hurricane uncertainty. We develop a stochastic mathematical model capturing mill-landowner interactions, seasonal demand, hurricane- driven pricing, and carbon emissions. The problem is formulated as a constrained Markov decision process and solved using Proximal Policy Optimization with a feasibility-enforcing layer. A Mississippi-based case study with 2,100 landowners …

A Study & Comparison Of Lift Boosters For An Unmanned Aerial Vehicle, Trevor Sean Dady

Theses and Dissertations

Unmanned aerial vehicles are becoming increasingly prevalent in modern society for tasks, such as package delivery, defense, and cinematography. Due to this surge in applications, many researchers have begun to search for improvements to unmanned aerial vehicles for their lift and thrust properties. Potential solutions to magnify an unmanned aerial vehicle’s thrust capability are the implementation of Coanda surfaces, nozzles, or bowl-shaped structures on each propeller. Coanda surfaces provide additional lift force by creating a vacuum in response to the adhesion of fluid to the smooth surface. Nozzles can constrict the flow of air, while also increasing its velocity. The …

Engagement Modeling And Inference For Risk-Aware Path Planning Under Adversarial Uncertainty, Grant Stagg

Theses and Dissertations

This dissertation develops methods for planning safe and efficient trajectories for autonomous vehicles operating in environments containing adversarial and environmental threats with uncertain parameters. The central objective is to quantify and control the risk of adverse events--such as interception or detection--when threat characteristics are imperfectly known. To address this challenge, probabilistic weapon engagement zone (PEZ) models are introduced to estimate the likelihood of violating adversarial engagement constraints under uncertainty in pursuer state and capabilities. Multiple computational strategies are developed for PEZ evaluation, including first-order sensitivity-based approximations, Monte Carlo estimation, and neural-network surrogate models. These approaches enable rapid engagement-probability assessment and …

A New Approach To Generate Combinatorial Patterns In Logical Analysis Of Data And Its Application To Predict College Retention, Salihah Ahmed E. Jaafari

Theses and Dissertations

Student retention and degree completion remain central challenges for higher-education institutions, with significant implications for student success, institutional effectiveness, and public accountability. While advances in predictive analytics have enabled earlier identification of students at risk of withdrawal, many commonly used machine learning approaches suffer from limited interpretability, constraining their practical usefulness for advising, intervention, and policy decision making. This dissertation addresses the problem of predicting student persistence by developing and evaluating optimization based, interpretable classification models within the Logical Analysis of Data (LAD) framework. Building on existing LAD formulations, this research introduces two novel pattern generation models, the Best Term …

Aircraft Fault Detection Via Weight And Bias Analysis Of A Custom First Neural Network Layer, George Harrison Chen

Theses and Dissertations

Fault detection in aircraft is traditionally handled through redundant hardware and comparison algorithms to detect failures. Alternatives like model-based residual generation and data-driven approaches such as supervised fault classification and unsupervised anomaly detection have been explored, but they suffer from practical limitations; model-based methods require accurate system models, and data-driven methods have large constraints on the data limiting scalability and adaptability. This work presents a purely data-driven neural network architecture featuring a custom first layer designed for real-time fault detection where the weights and biases of this layer are used to detect faults. The network requires zero supervision and complements …

Moon Adaptive Technology For Extraterrestrial Architectural Robotics (Matear), Candela Noemi Solis Zampini

Theses and Dissertations

The Moon Adaptive Technology for Extraterrestrial Architectural Robotics (MATEAR) focuses on the development of an autonomous robotic system capable of providing structural building blocks directly from lunar regolith. As a sustained human presence on the Moon becomes a necessity, the costly and limited payload capacity associated with transporting construction goods from Earth creates a critical challenge. MATEAR addresses this problem through in-situ resource utilization (ISRU), integrating a regolith processing system onto a remote operated vehicle. The proposed system is designed to collect lunar dust, mechanically compact the material, and apply thermal treatment to enhance cohesion through sintering. These regolith-made bricks …

Learning Adaptive Control For Safe Collaborative Autonomous Driving, Fabian Alexis Hernandez

Theses and Dissertations

Connected autonomous vehicles improve urban driving through collaborative perception via Vehicle-to-Everything (V2X) communication. Frameworks such as V2Xverse leverage this collaboration for planning and perception, yet their controllers rely on fixed parameters that cannot adapt to varying traffic. Control Barrier Functions (CBFs) enforce safety by constraining actions within a safe set, but a fixed barrier gain imposes a single operating point: conservative settings reduce throughput while permissive settings under-react to hazards.

This research proposes an adaptive CBF framework that learns state-dependent, class-specific barrier gains via constrained Reinforcement Learning (RL). A compact policy outputs separate gains for vehicles, pedestrians, and bicycles, parameterizing …

Exit Topology Effects On Low-Mach Jet Impingement, Alejandro Garcia

Theses and Dissertations

Planar PIV characterizes a low‑Mach (M = 0.05) air jet impinging normally on a plate at fixed spacing H/D = 4.0. Four nozzles of equal hydraulic diameter (D = 50.8 mm) are compared: circular, rectangular (AR 3), diamond, and elliptical (AR 2); asymmetric exits are tested in major and minor orientations. Mean velocity, azimuthal vorticity, and turbulence kinetic energy reveal that exit topology strongly modulates the stagnation footprint and shear‑layer growth. The circular jet forms the canonical toroidal wall jet and a narrow stagnation core (dₛ = 0.9D). Orienting the rectangular major axis toward the plate elongates the core to …

The Role Of Operational Context In Shaping Energy Management Portfolios: A Comparative Case Study Of Two Manufacturing Facilities, Cynthia Aranda

Theses and Dissertations

Using two facilities as illustrative examples, this research investigates how a manufacturing plant's operational and financial context may influence its investment decisions in energy-efficiency measures. This challenges the primacy of the simple payback period (SPP) as a screening tool and instead demonstrates the role of operational context in investment decision-making. To this extent, this study is anchored to a qualitative comparative case study analysis of two ITAC energy assessments for two manufacturing plants in Texas: a higher value-added aerospace MRO plant (GE Aerospace, TR0060) versus a cost-sensitive automotive stamping plant (UMP Metal Stamping, TR0061). The two cases illustrate two different …

Sub-Ghz Propagation Along Freight Trains For Wireless Onboard Communications, Dario Hinojosa

Theses and Dissertations

With the increasing length of freight trains, maintaining reliable wireless communication for onboard sensors has become increasingly challenging. Sub-GHz communication bands are a promising solution due to their long-range capability and suitability for rural railway environments. This study analyzes radio wave propagation around freight railcars to evaluate path loss and determine how antenna polarization affects wireless communication performance.

Time-domain full-wave electromagnetic simulations were performed using simplified railcar models and later validated through field testing using a vector signal generator, vector network analyzer (VNA), and spectrum analyzer. Various antenna polarization configurations were evaluated within the Sub-GHz Long Range (LoRa) frequency band …

Hdra-Fusion: Hybrid Detection With Routed Architecture For Manipulation-Aware Ai Face Forgery Detection, Omar Ebeid

Theses and Dissertations

With the rapid advancements in artificial intelligence-based image generation and manipulation tools, it is extremely difficult to detect if an image is genuine or artificially crafted. Despite extensive research in this area, existing image detection systems suffer from three major problems: suboptimal cross-dataset generalization due to shortcut learning of dataset-specific patterns, unreliable probability estimates due to domain shift, particularly in cross-manipulation evaluation settings, and an inability to detect images manipulated by multiple types of manipulations within a single detection framework. To address these limitations, we propose HDRA-Fusion (Hybrid Detection with Routed Architecture), a framework built on the conclusion that different …

Decomposition And Spectral Characterization Of Unsteady Loads In Pulse-Jet Propulsion Testing, Cesar Benitez

Theses and Dissertations

Pulsed jet propulsion systems produce inherently unsteady forces whose time-resolved characterization is essential for performance assessment, yet the measured load signal conflates aerodynamic forcing with the dynamic response of the measurement balance itself. This thesis develops a load centered framework for the dynamic characterization of a pulsed jet system, treating the measured load fluctuation as the primary physical observable rather than attempting full true-thrust reconstruction. A single-degree-of-freedom balance model identified through ringdown testing provides the structural reference scale, yielding a natural frequency of 8.5 Hz and damping ratio of 18%. Power spectral density, phase-averaging, and synchronous–residual decomposition is applied uniformly …

Examining The Effects Of Lateral Loading On Railroad Tapered Roller Bearings, Abel David Sanchez Trinidad

Theses and Dissertations

The loading conditions experienced by freight railcar bearings vary as a function of vehicle operating conditions. Under static conditions, bearings are primarily subjected to radial loads transmitted through the wheelset. During operation, however, track irregularities, braking events, railcar load imbalances, and curving introduce complex impact, longitudinal, and lateral forces in addition to the normal radial loading. These lateral forces increase friction within the bearing raceways, which could accelerate wear and potentially lead to premature spall initiation and propagation. While prior research at the University Transportation Center for Railway Safety (UTCRS) has demonstrated that vibration signatures can be used to detect …

Electrical Resilience In Water Treatment Plants: An Extreme Weather And Lightning Protection Study, Genesis Martinez

Theses and Dissertations

Water treatment plants (WTPs) are vital infrastructure systems that depend on sensitive electrical, electronic, and control equipment to ensure the continuous supply of safe drinking water and effective wastewater treatment. As global temperatures rise and climate change accelerates, the frequency and intensity of extreme weather events—such as hurricanes, flooding, and increased lightning activity—are becoming more pronounced. These events pose significant risks to the electrical resilience of water treatment facilities, often leading to power outages, equipment failures, grid instability, and prolonged service disruptions. This report explores the impacts of extreme weather, with a particular focus on lightning and electrical surges, on …

Adaptive Artificial Potential Field Guidance And Control For Autonomous Docking With Uncooperative And Unknown Spacecraft, Steven Holmberg

Theses and Dissertations

The increasing demand for on-orbit servicing (OOS), active debris removal (ADR), and space domain awareness (SDA) missions has increased the need for autonomous spacecraft rendezvous and proximity operations (RPO) with uncooperative and unknown targets. Traditional guidance and control methods are typically designed for cooperative systems with known geometry and state information. This work builds on previous research to develop and evaluate an artificial potential field (APF)-based control framework capable of autonomous operation with minimal prior target knowledge and applicability to both relatively static and tumbling spacecraft.

The proposed APF formulation incorporates established safety constructs from cooperative docking systems, including an …

Moodify: A Mood-Based Music Recommendation System, Meghana Kagitha

Theses and Dissertations

Music has long been recognised as a powerful tool for emotional regulation, yet existing music streaming platforms often fail to align song recommendations with a user's current emotional state. Moodify is a mood-based music recommendation system designed to bridge this gap by delivering personalised playlists that reflect how a user feels in real time.

This project presents the design, development, and evaluation of Moodify, a mobile application that leverages the Circumplex Model of Emotion to capture user mood through an intuitive two-dimensional valence-arousal interface. Rather than relying on text input or manual search, users plot their emotional state directly onto …

Porous Hydrophobic Adsorbent Coatings For Carbon Dioxide Capture, Samuel Babatunde Olushola

Theses and Dissertations

This work presents the development of a porous, hydrophobic zeolite 13X coating for the separation of carbon dioxide (CO₂) from flue gas or natural gas. Zeolite 13X was combined with yeast, glucose, and sodium alginate as pore-forming agents, and with polytetrafluoroethylene (PTFE) and Polydimethylsiloxane (PDMS) as hydrophobicity-inducing agents to enhance water resistance while maintaining CO₂ access to the adsorbent. The study explored PTFE/13X mass ratios ranging from 0 to 2.33 to investigate the interplay between hydrophobicity and CO₂ uptake. The wettability of the coating was characterized by using a temporal water contact angle (WCA) measurement. Increasing …

Manned Exploration Of Satellites Of The Outer Planets: An Analysis Of Current Technologies And A Discussion Of Advancements Required, Joshua Carson Meador

Theses and Dissertations

The Solar System’s outer planets have many satellites, some of which are known to be the most likely places to find extraterrestrial life in our celestial backyard. Multiple scientific missions have been sent to glean information from these satellites, yet the possibility of a manned expedition has long been exclusive to science fiction stories. This paper intends to collect and analyze the current state of space travel technology to explore the feasibility of such a mission with modern technology and to discuss which future advancements should be the focal point for making such missions a reality. To begin, data on …

Range Extension Of Electric Propulsion General Aviation Aircraft Using Solar Technology, Mary Kathryn Shultz

Theses and Dissertations

Alternative propulsion technologies in aviation have been a long-time topic of interest as operators aim to bypass growing fuel prices and meet environmental sustainability requirements set globally. Research regarding alternative propulsion technologies is primarily centered around marginally improving efficiency of combustion systems or large-scale implementation of novel technologies. This research evaluates the feasibility of implementing solar-integrated propulsion for general aviation aircraft to extend range through a comparison of full-electric, hybrid solar, and internal combustion engine propulsion systems. This evaluation of existing technology by range analysis indicates that hybrid solar‑electric propulsion is viable primarily for short‑range training and recreational aircraft, rather …

An Experimental Study On Turbine-Based Energy Harvesters For Thermal Underwater Gliders, Stephen Edward Coster

Theses and Dissertations

Buoyancy-driven underwater gliders have been optimized for long-duration missions primarily for continual monitoring of the ocean’s water column. However, longer missions and higher-powered sensors have increased the energy requirements of gliders. While current solutions aim to increase battery capacity, the development of energy-harvesting systems (EHMs) could greatly improve mission capabilities in both ability and duration. This thesis discusses the experimental testing of an underwater glider with an EHM as detailed in the theoretical study, “Development of a Turbine-Based Ocean Thermal Energy Harvesting Mechanism Applied to the Underwater Glider” by Hongbo Hou, PhD. The rear-mounted turbine captures energy using the kinetic …

Design And Simulation Of Anti-Resonant Hollow-Core Fiber For Sensing Applications, Pravallika Kante

Theses and Dissertations

This thesis presents the design and simulation of an 8-tube single-ring anti-resonant hollow-core fiber for sensing applications, with particular emphasis on methane gas detection at the fundamental absorption wavelength of 3.3 µm. Conventional solid-core silica optical fibers exhibit strong multi-phonon material absorption beyond 2.5 µm, rendering them fundamentally unsuitable for efficient light guidance and direct gas sensing at mid-infrared wavelengths. Anti-resonant hollow-core fibers overcome this limitation by guiding light predominantly through an air-filled hollow core via the anti-resonant reflecting optical waveguide mechanism, in which the thin silica glass walls of the cladding tubes act as Fabry-Pérot etalons that confine the …

Advanced Studies In Characterization Of Pyrolysis Products From Live Vegetation, Mahsa Alizadeh

Theses and Dissertations

Fire is a naturally occurring element in many ecosystems which can have both positive and negative effects. However, in recent years the frequency of the fires and the area they affect has increased. The rapid spread of wildland fires coupled with the limited resources available to forest services to manage wildland fires highlights the urgency for accurate prediction of fire spread. Fire prediction models enable the fire management services to predict the spread of fire and prioritize firefighting efforts more effectively. Understanding reactions and mechanisms occurring during wildland fires improves the fire prediction models. During wildland fires, the biomass covering …

Improving Electrochemical Measurements And Informing Future Reprocessing Of Advanced Nuclear Fuels, J. Marvin Torrie

Theses and Dissertations

This research promotes the application of molten salts through developing analytical tools in electroanalytical studies and in the data analysis of vapor pressure data. The electrochemical community lacks standardized, stable, and repeatable reference electrode designs which threaten the reliability of measured thermophysical properties and repeatability of published studies. This work confirms the application of a saturated reference electrode design for molten chlorides systems that outperforms traditional Ag+/Ag reference electrodes. In the field of thermal physical property measurements, vapor pressure data for chloride salts are diffused throughout the literature, uncertainty quantification is absent or limited, and all previous studies rely on …

Mild Thermal Treatment Of Lithium-Ion Batteries To Optimize Black Mass Production, Brooke Lillie

Theses and Dissertations

This thesis explains the design of equipment and the experimental procedure for thermal treatment of lithium-ion batteries for the purpose of low-cost materials recycling. Conditions used were between 150 ℃ and 425 ℃, involving different atmospheric conditions and treatment durations. The battery samples were processed through a sieve shaker device. Mass loss during the heat treatment, and separation of the battery through sieving was used to analyze the effect of the treatments on separability of black mass from the batteries. Additionally, internal battery temperature was measured and compared to real average furnace temperature to monitor thermal runaway. Testing showed minimal …

Biomass Fuel Processing, Mineral Matter Engineering, And Ash Phase Equilibria For Deposition Control In Coal To Biomass Boiler Conversion, Spencer Bandi

Theses and Dissertations

As the conversion of coal utility boilers to 100% biomass combustors gains traction, understanding the interconnected impacts of harvesting and storage methods, fuel preparation, and thermochemical ash behavior is critical. This study evaluates miscanthus, switchgrass, and corn stover, targeting a < 1000 µm particle size through minimal (shredders/hammer mills) and heavy (pelletizing) pre-treatment. While heavy pre-treatment failed in a coal mill, minimal pre-treatment succeeded. Miscanthus (forage-harvested/silage-bagged) proved optimal, exhibiting minimal exogenous mineral accumulation up to (1.26 w%) and the smoothest mechanical feeding (deviation < 9%) due to its low particle aspect ratio. Conversely, baled switchgrass and corn stover accumulated up to 9.23 w% mineral matter and exhibited severe feeding resistance (>17% deviation) driven by fibrous, high-aspect-ratio morphologies. During combustion, agricultural residues yield low ash fusion temperatures (AFTs), generating deposits two to three times stronger than coal. To mitigate this severe fouling, mineral additives (coal fly ash, lime, and cement kiln dust) were injected. These additives effectively raised bulk AFTs and reduced deposit tenacity by up to 73%. Specifically, 2 w% …