Engineering Commons^™

A Maximum Energy Release Rate Computational Framework For Fatigue Crack Trajectory And Life Prediction Under Mixed-Mode Proportional And Nonproportional Loading, Nahla Helmy Matar

Theses and Dissertations

The problem of mixed-mode fatigue crack growth has been a persistent research challenge. The determination of fatigue crack propagation direction directly impacts the safety and integrity of components and structures, making it crucial in various industrial applications, including welded drilling pipes, aerospace, and automotive engineering. Unlike uniaxial loading, mixed-mode cracks tend to change direction frequently (kinking), and nonproportional loading adds to the complexity of the problem. This research aims to estimate the crack propagation direction and fatigue crack life in linear elastic materials subjected to mixed-mode (I+II) loading conditions under proportional or non-proportional cyclic loading. Numerical software was developed based …

Simulation-Based Assessment Of Operational And Retrofit Solutions For Effluent Compliance Of A Capacity-Limited Oxidation Ditch Wwtp, Ahmed Sameh Harash

Theses and Dissertations

Oxidation-ditch wastewater treatment plants (WWTPs) across Egypt's Nile Delta are increasingly carrying hydraulic and organic loads beyond what they were designed for. This work can be considered pioneering as this work compared operational and structural retrofit alternatives for such a plant within a single verified simulation framework. The present study fills that gap by building a digital twin of the Qaha WWTP, a dual-train Carrousel oxidation ditch in Qalyubia Governorate, calibrated to a baseline flow of 7,420 m³/day in the SUMO24 platform (a third-generation, open-source wastewater treatment process simulation software) using the SUMO2c biokinetic model (a simplified variant of Activated …

Dynamic Baseline Schedule Updates Using Digital Twinning: A Case Study On Aluminum Formwork Construction, Ahmed Hamdi Sweilam

Theses and Dissertations

Repetitive high-rise construction using aluminum formwork couples consecutive floor cycles through a reused panel set and a floor-level inspection and pour barrier, so productivity loss compounds upward rather than being absorbed locally. The baseline schedule is nevertheless fixed before execution and is not revised as evidence of realized productivity accumulates. This thesis develops a simulation-based digital twin that updates the baseline from observed as-built durations and acts on its own forecast. A discrete-event simulation of a ten-story residential tower is built in AnyLogic® and verified analytically at 180.00 hours per floor. After each completed floor the twin infers activity productivity …

Sustainable – Low-Cost - Upgrade Of Activated Sludge Process For Nitrogen And Phosphorus (N&P) Removal From Wastewater, Abanoub N. Basta

Theses and Dissertations

Many municipal wastewater treatment plants (WWTPs) in developing countries were designed primarily for organic matter and suspended solids removal and therefore face increasing difficulty in meeting modern nitrogen (N) and phosphorus (P) discharge requirements. Conventional biological nutrient removal upgrades commonly require additional reactor volume, recirculation systems, aeration energy, and capital investment. Accordingly, sustainable retrofit strategies that improve nutrient removal within existing treatment footprints are increasingly needed, particularly in water-scarce and land-constrained regions.

This study investigated the integration of water hyacinth (Eichhornia crassipes) into the aeration stage of an activated sludge process as a hybrid nature-based enhancement for nitrogen and phosphorus …

A Comparative Study: Force Majeure And The Theory Of Unforeseen Circumstances Across Different Jurisdictions In The Middle East, Omar Hamed Sawan

Theses and Dissertations

The motivation behind this study stems from recent global disruption events that impact construction projects worldwide. These events vary across a wide spectrum, whether they are political events such as the Russo-Ukraine war or the war in the Middle East, economic events such as inflation or currency devaluations; or environmental events such as climate change and the emergence of public health crises like the Covid-19 pandemic. These series of events underscore the growing importance of understanding how the different legal frameworks address unforeseeable events in the construction industry. In this context, force majeure and the theory of unforeseen circumstances (also …

Comparative Performance Of Physiological Vital-Sign Forecasting Under Random And Patient-Wise Splitting Using Deep Learning, Lavanya Vasavi Chittem Reddy

Theses and Dissertations

Physiological vital-sign forecasting estimates future measurements based on recent temporal patterns and can support analysis of continuously recorded monitoring data. This study comparatively evaluated deep feedforward, recurrent, bidirectional recurrent, long short-term memory, and bidirectional long short-term memory architectures for one-step-ahead forecasting of peripheral oxygen saturation, heart rate, and pulse rate. Each model received consecutive observations of peripheral oxygen saturation, heart rate, pulse rate, respiratory rate, and age, while separate single-output models predicted the next value of the selected target.

Random and patient-wise data splitting were compared using identical input definitions, preprocessing procedures, model architectures, and training hyperparameters. The strongest architecture …

A Data-Driven Koopman Framework For Station-Keeping On Near Rectilinear Halo Orbit, Anusha Sharma Malladi

Theses and Dissertations

Cislunar missions have gained significant attention in recent decades, motivating the need for efficient modeling and reliable control. In this work a Koopman operator based framework is developed for approximating the error dynamics around a reference Near Rectilinear Halo Orbit (NRHO) in the Earth-Moon Circular Restricted Three-Body Problem (CR3BP). A decoder free neural network is used to learn a lifted linear representation of the nonlinear CR3BP dynamics and a residual based approach is used to identify the corresponding control input matrix. The model is then implemented in a receding-horizon target point controller and compared with uncontrolled propagation and a State …

Extending Geometric Acoustic Ray Tracing To Multi-Room Environments: A Case Study On Gunshot Sound Transmission Between Adjacent Rooms, Tyler Ton

Theses and Dissertations

Accurate localization of gunshots in multi-room building environments remains a challenging problem in acoustic forensics and public safety applications. Existing approaches model sound propagation within a single room, neglecting the transmission of acoustic energy through walls and other building materials. This thesis presents a study on modeling multi-room gunshot acoustic transmission, combining geometric ray tracing with structural acoustic transmission-loss modeling to generate impulse responses for two horizontally adjacent rooms separated by a shared wall, providing a foundation for future inter-room gunshot localization work. The proposed system uses GSound-SIR, a geometric acoustics engine, to simulate sound propagation in both of the …

Polymer Nanocomposite Dielectrics For High-Temperature Superconducting Cables: Cryogenic Characterization And Testing Environment Development, Jared R. Ericksen

Theses and Dissertations

High-temperature superconducting (HTS) cables require dielectric insulation materials that can withstand cryogenic operating environments while maintaining electrical reliability, mechanical stability, and manufacturing compatibility. This thesis investigates polyamide-based polymer nanocomposites as candidate HTS cable insulation materials and develops cryogenic testing platforms for evaluating thin-film dielectrics at reduced temperatures. Two silicon-based filler systems are studied: sol-gel-derived silicon dioxide (SiO 2 ) nanoparticles and polyhedral oligomeric silsesquioxane (POSS). Dielectric breakdown behavior is evaluated under DC and AC high-potential testing, while mechanical behavior is assessed through tensile testing. The results show that PA/SiO 2 nanocomposites provide the strongest overall balance of mechanical reinforcement and …

A Framework For Automated Quantity Extraction From .Ifc Models And Normalized Bid Comparison, Asmaa Mohamed Farouk

Theses and Dissertations

Accurate bid comparison remains a major challenge in construction tendering due to

differences in Bill of Quantities formats, item naming conventions, and pricing methods across

contractor submissions. These variations require time-consuming manual work and often lead to

subjective decisions. This research presents a computational framework that uses Building

Information Modeling through the .ifc file format, combined with text analysis techniques for

automated bid normalization.

The developed system uses a dual-component approach. Phase 1 extracts quantities from .ifc

model files using 3D geometric calculations, automated element classification. Phase 2 uses text

mining with a domain-specific dictionary of construction terms to interpret …

Dual-Polymer Concrete With Recycled Pet And Hdpe Aggregates: Mechanical And Durability Performance Assessment, Omar Abd El Mageed Hammouda

Theses and Dissertations

This study investigates the fresh, mechanical, durability, thermal, performance as well as preliminary financial aspects of dual-polymer concrete incorporating recycled polyethylene terephthalate (PET) as a partial replacement for fine aggregate and recycled high-density polyethylene (HDPE) as a partial replacement for coarse aggregate, with silica fume as a supplementary cementitious material held constant at 10% by weight of cement. The study responds to the convergence of two pressing challenges in the Egyptian context: the scale of plastic waste mismanagement, which results in widespread informal open burning and environmental contamination, and the high operational energy demand of residential buildings in Egypt's hot …

Actionable Hydrologic Data To Information With National Water Model-Based Derived Dataset, Cutting-Edge Data Services, And Agentic Ai System, Sujan Chandra Mondol

Theses and Dissertations

Hydrologic data are the cornerstone of many complex hydrologic research and operational workflows that produce useful hydrologic information for water resources decision-making, flood risk communication, and water availability implications. The National Water Model (NWM) is a valuable source of hydrologic data, particularly for its extended coverage of unmonitored streams and the large-scale continuity of hydrologic processes. Precomputed secondary datasets derived from this simulated data, such as streamflow indices, can improve operational efficiency through thresholding. Disseminating the data through modern technologies, such as application programming interfaces, is required for ready integration into applications. However, if extraction requires an intermediate service, there …

Comparing Principal Component Analysis And Sequential Fusion Deeponet With Varying Dataset Size For Design Space Exploration Of Hypersonic Flow, J. Dallan Trentman

Theses and Dissertations

Design space exploration and optimization of hypersonic vehicles is costly due to the difficulty of producing high fidelity CFD simulations in the hypersonic domain. Reduced order modeling can allow for design optimization at a fraction of the computational cost. This paper investigates the amount of training data required to produce an accurate Reduced Order Model. A PCA based ROM is developed and compared to a Sequential Fusion DeepONet by comparing model prediction accuracy, training time, and prediction time, across dataset sizes from 25 samples to 1024 samples. These models are applied to 2D hypersonic CFD simulations of the Orion reentry …

Resonant Shock Plate Simulation And Prediction Using Modal Substructuring, Harrison C. Denning

Theses and Dissertations

Aerospace structures such as rockets can experience various shock events during flight, such as stage separation or impacts. These shock events can expose components inside the rocket to large accelerations and stresses which in turn can damage the parts. Shocks are often simulated in the lab using a resonant shock plate test. Resonant shock plate testing is often used to qualify aerospace parts, as it can mimic the shocks experienced during launch and stage separations. However, during the course of development, both the definition of the shock environment and the design of the subcomponent tend to change, so that multiple …

Rfsoc Based Ground Penetrating Radar For Detection And Avoidance Of Underground Utilities, Brady Bowerbank

Theses and Dissertations

Preexisting underground utilities present a considerable danger to underground boring projects. Gas and electrical lines can be damaged, leading to major economic impact and even loss of life. While maps of underground utilities exist, they are not always accurate and gas and electrical lines can shift over time, necessitating tools to accurately detect utilities so that crews can steer the machines away from any possible danger. In this thesis, the design of a new frequency-modulated continuous-wave (FMCW) ground penetrating radar (GPR) is outlined. The design of a lightweight, flexible radar is demonstrated using the CASPER FPGA framework with an operating …

Isoperimetric Soft Robots, Mihai Stanciu

Theses and Dissertations

This thesis presents two advances in isoperimetric soft robotic trusses that improve their performance, modularity, and configurability. The first contribution introduces a large-scale modular robotic truss designed as a lightweight, reconfigurable structure for lunar applications. The system consists of inflatable fabric tubes routed through motorized roller units and interconnected by a newly developed spherical joint that enables multiple robotic triangles to connect at a common vertex. The resulting truss can be assembled into structures beyond a single octahedron while retaining compact stowage when deflated and untethered operation after initial inflation. Experimental validation demonstrates modular assembly, long-term pressure retention, load-bearing capabilities …

Thermophysical Property Studies: 1. Thermodynamic Consistency For Associating Compounds 2. Autoignition Temperature, Cassandra Jane Guffey

Theses and Dissertations

Accurate thermophysical property data are essential for the design, optimization, and safe operation of chemical processes. Properties such as vapor pressure, enthalpy of vaporization, heat capacity, density, and autoignition temperature--which are among the properties studied in this work--are required for equipment sizing, process simulation, hazard assessment, and economic evaluation. A major focus of this dissertation is the application of multi-property thermodynamic consistency techniques to compounds that exhibit strong vapor-phase association. These methods improve confidence in recommended property values by enforcing rigorous thermodynamic relationships among ideal-gas heat capacity, liquid heat capacity, vapor and liquid densities, vapor pressure, and enthalpy of vaporization. …

The Influence Of Rainfall And Land Cover Change On Streamflow Variability In Eastern Florida Watersheds, Brynn Romberger

Theses and Dissertations

Streamflow in Florida watersheds is influenced by both land cover change and rainfall variability, but separating their contributions is difficult because both have changed over recent decades. This study evaluated rainfall trends and land cover change to determine which better explains flood and drought threshold exceedance across 27 USGS streamflow gauges within the St. Johns River Water Management District (SJRWMD) from 1985 to 2025. Streamflow was characterized using change-point, trend, and variability analyses with a six-threshold exceedance framework. Land cover was quantified using the National Land Cover Database (NLCD), rainfall characteristics were derived from the Analysis of Records for Calibration …

Color-Coding: An Aid Or Hindrance In A Multi-Unmanned Aerial Vehicle Supervisory Control Task, Austin Daniel Wood

Theses and Dissertations

The purpose of the current study was to investigate the effect of coding types (i.e., alphanumeric coding, color-coding, and redundant color + alphanumeric coding) for vehicle identification and status information on pilots’ recognition performance, situational awareness (SA), and workload for a multi-vehicle operations ground control station (GCS) supervisory control task. With the aviation industry's push towards operators supervising and controlling multiple vehicles, it is pertinent to identify design features that support the capabilities and limitations of human operators. The current study employed a within-subjects, repeated-measures experimental design, in which a sample of 33 students with aviation experience performed three trials, …

Helicopter Pilots’ Safety Behaviors: Identifying Factors That Affect Risk Perception Among Helicopter Pilots, Khaled J. Alzaabi

Theses and Dissertations

Helicopter operations frequently take place in complex, high-risk environments, where pilots continuously assess hazards and make critical decisions under pressure. Despite standardized procedures, regulations, and training designed to enhance safe operations, helicopter pilots may perceive risk differently when encountering similar flight situations. Understanding the factors that influence helicopter pilots’ perception of risk is essential for improving helicopter operation safety.

The purpose of this study was to investigate the effect of various factors on risk perception among helicopter pilots. Using an explanatory correlational design, the study assessed whether helicopter pilots’ demographics, flight experience, and affective domain factors explain differences in their …

Understanding The Correlation Between Prediction Performance And Trust In Ai Through Scenario-Based Tasks, Likhitha Kammara

Theses and Dissertations

Trust in artificial intelligence is commonly assessed through self-reported scales or behavioral reliance, yet behavioral reliance is retrospective and can only be observed after a decision has already been made. This thesis examines whether prediction accuracy — a user's ability to predict what an AI system will recommend before its output is revealed — can serve as a prospective correlate of trust in the same empirical sense as behavioral reliance. The study was conducted in two phases using scenario-based AI decision tasks across disaster response, healthcare, and infrastructure restoration contexts, employing a between-group design in which participants either predicted AI …

Radiation Testing And Failure Analysis Of A Complex Heterogeneous Soc, Garrett Smith

Theses and Dissertations

Heterogeneous System on Chips (SoCs) provide a robust platform that can flexibly handle different applications. Their small form factor and low power consumption for their performance have made SoCs an attractive option for space applications. However, SoCs are sensitive to the ionizing radiation found in space. We need to understand how an SoC will behave in the high radiation found in space. This requires us to perform radiation testing of the SoCs on Earth to understand their behavior. The radiation testing and analysis of a heterogeneous SoC is complex as it contains multiple different processing cores, memories, and other system …

System Design And Validation Of Radio Astronomy Phased Arrays, Rebecca Shiu Haymore

Theses and Dissertations

Modern radio astronomy instruments require a wide field of view and high sensitivity. To this effect, BYU and Cornell University have developed the Advanced L-band Phased Array Camera for Astronomy (ALPACA), a fully cryogenic 69 dual-pol dipole array that produces 80 beams on the sky with 305 MHz instantaneous bandwidth centered on 1500 MHz. Integration testing has demonstrated proper beamforming and calibration, and ALPACA has been commissioned as an all-sky monitor to search for bright transients. Commissioning testing for ALPACA measured an element system noise temperature of 24 K and a beamformed system noise temperature of 17 K, making ALPACA …

Radiation Effects On The Amd Versal Running An Automatic Modulation Classification Model, Allan D. Howe

Theses and Dissertations

With the recent increase of interest into artificial intelligence (AI), graphics processing units (GPUs) have been used as the main hardware architecture for AI computation. Because of their high power consumption and large size, it is necessary to consider other architectures to perform AI computing in outer-space where size, weight, power, and cost (SWaP-C) are tightly constrained. One such architecture is the Advanced Micro Devices (AMD) Versal Adaptive Compute Acceleration Platform (ACAP), which can achieve acceptable AI throughput at a lower power and size compared to a GPU. As the Versal ACAP gets used in space applications, it is necessary …

Equivocation Analysis Across Continuous And Discrete Memoryless Channels, Md Munibun Billah

Theses and Dissertations

Physical-layer security uses the noise already present in the channel to keep a message secret without making any assumption about the eavesdropper's computing power. In Wyner's wiretap channel model, coset coding uses randomness to map the message to many codewords and protects against information leakage from an active eavesdropper. The secrecy provided by such codes is measured by their equivocation, which is the eavesdropper's remaining uncertainty about the message after she observes her channel. So computing equivocation is an important aspect of analyzing the wiretap channel model. Many channels of practical interest have no closed-form expression for equivocation, and exact …

Identifying Failure Behaviors In Stereolithography From Varied Print Orientations, Kevin Veltre

Theses and Dissertations

Stereolithography (SLA) is an additive manufacturing (AM) technique that utilizes photopolymerization to create three-dimensional shapes by strategically printing layers of material. Printing parameters such as layer orientation, print resolution and post cure can affect a specimen’s homogeneity, longevity and mechanical characteristics. Because of this variability, print parameters must be carefully considered when designing products and print processes for desired components, as manufacturers often fail to include all relevant print settings when advertising mechanical properties. For this study, 130 SLA-printed specimens were created with 100-micron print layer thickness and print orientations varying between 0 and 90, including intermediate orientations, to observe …

Policy Analysis Of The Inclusion Of Mitigation Measures In The Re-Design And Construction Of The New Frances Scott Key Bridge, Patrick John O'Connor

Theses and Dissertations

This thesis discusses the tragic event of the container ship MV Dali impacting the Francis Scott Key Bridge on March 26, 2024, leading to the collapse of the structure and killing six people despite having collision mitigation protections in place. This research examines how late twentieth-century structures are inadequate for current shipping demands and emphasizes that updated mitigation design criteria must accommodate larger modern vessels as governments replace or upgrade these structures. This paper will examine four case studies of different collisions that have similar circumstances to the Francis Scott Key Bridge collapse and review National Transportation Safety Board reports …

Fatigue And Healing Performance Of Asphalt Materials Modified With Nanomaterials And High-Polymer Asphalt Binders, Samuel M. Addai

Theses and Dissertations

Fatigue cracking is one of the primary distress mechanisms affecting asphalt pavement durability under repeated traffic loading and environmental aging. Although asphalt binders possess an inherent ability to heal micro-damage during rest periods, this healing capacity is often insufficient to fully counter progressive fatigue damage under field conditions. This thesis investigates the fatigue and self-healing behavior of asphalt binders and mixtures modified with nanomaterials and advanced polymer-based systems. Nanomodified binders were evaluated using Linear Amplitude Sweep (LAS) and Linear Amplitude Sweep with Healing (LASH) tests within the VECD framework to quantify fatigue resistance and healing behavior under different rest periods …

Transport Properties And Microstructural Development Of Co₂-Cured, Co₂-Infused, And Cold-Weather Concrete, Arlene Jane Looc

Theses and Dissertations

This research aims to advance the understanding of durability and transport behavior in emerging CO₂-cured and cold-weather concrete technologies. Limited work has examined long-term durability indicators such as permeability, resistivity, and pore connectivity in these types of concrete. To bridge this gap, the study evaluates transport properties alongside microstructural changes that govern the progression of hydration and the evolution of pore structure. This study measures transport properties, determines correlations between resistivity and fluid ingress, and analyzes the evolution of pore structure. To achieve this, the experimental program evaluated three concrete mixtures for external CO₂ exposure, nine for dry ice infusion, …

Vibro-Seismic Approach For Remediation Of Near-Wellbore Damage, Mounira Ahmed Abdallah

Theses and Dissertations

The research highlights the importance of vibro-seismic technology in the oil and gas industry. The primary objective of this study is to demonstrate how the vibro-seismic method enhances formation properties which are porosity, and permeability. Ultimately, this will lead to improved productivity and its application to remove the wellbore damage.

The research discusses whether or not the formation properties will be enhanced by the optimized acoustic vibration formation parameters. The thesis details laboratory experiments on core plugs, and four key findings are presented. The experimental work first showed that the use of the proper and optimum parameters enhanced the porosity …