Engineering Commons^™

Fused Filament Fabrication Additive Manufacturing Of 17-4 Ph Stainless Steel: Process–Structure–Property Relationships In Magnetic Materials, Maanav Patel

Theses and Dissertations

Additive manufacturing (AM) enables the fabrication of complex metallic components through layer-by-layer processing directly from digital models. Among AM techniques, material extrusion–based processes such as fused filament fabrication (FFF) provide an accessible method for producing metal parts using filament feedstocks composed of metal powders and polymer binders. When applied to precipitation-hardening stainless steels such as 17-4 PH, the processing route and heat treatments can influence the resulting microstructure and functional properties. This work investigates the magnetic behavior of 17-4 PH stainless steel fabricated using FFF and evaluates how heat treatment conditions influence measured magnetic properties. Samples were produced and analyzed …

A Quantitative Analysis Of Burrowing And Subterranean Locomotion In The Sand Lance Using A Transparent Sediment, Issei Fujita, Makoto Tomiyasu, Jun Yamamoto, Yasuzumi Fujimori

Journal of Marine Science and Technology–Taiwan

Sand lances (Ammodytes spp.) rely on rapid burrowing into sediment for predator avoidance. Although their sediment grain-size preferences are well documented, the biomechanics underlying burrowing success remain unclear because natural substrates are opaque. Using a transparent-sediment system, we directly visualized and quantified burrowing kinematics to: (1) test the effect of body size (total length, TL) on burrowing success; (2) examine entry mechanisms (e.g., swimming speed, entry angle); and (3) describe locomotion within sediment. Logistic regression on the full dataset (N = 28 fish) identified TL as the primary determinant of success, with larger individuals exhibiting significantly higher success …

Cruise Network Design Under Sequential Duopolistic Entry, Ta-Hui Yang, Ching-Hui Tang, Wan-Tien O

Journal of Marine Science and Technology–Taiwan

This study addresses the network design for international cruise services in a duopolistic market, where carriers enter and make decisions sequentially. The leader, who makes the first move, makes decisions as there is no competitor in the market. The follower, who makes decisions later, has to design their network considering the existing leader’s network. The leader’s model is a mixed integer linear problem while the follower’s model is a mixed integer nonlinear problem. Therefore, a heuristic is proposed to solve the problem. The commercially available general algebraic modeling system is used in conjunction with its different solvers to solve the …

Effect Of Heat Treatment On The Corrosion And Wear Behavior Of 17-4 Ph Stainless Steel For Marine Applications, Syuan Tai, I-Kon Lee, Ming-Yuan Lin, Kang-Yu Liao, Chin-Chun Chang, Hung-Bin Lee

Journal of Marine Science and Technology–Taiwan

This study explores the tribocorrosion behavior of conventionally cast 17-4 PH stainless steel under real seawater conditions, focusing on the effects of three heat treatments (Solution, H900, H1100). Electrochemical tests, tribocorrosion experiments, SEM, XPS, and quantitative analysis were used to establish a three-stage tribocorrosion mechanism. Results show that H900 exhibits superior corrosion and wear resistance, while H1100 suffers increased material loss and surface cracking at high potentials. Elemental analysis revealed NbC migration forming third-body particles, which, although briefly reducing friction, induced local stress concentration and crack initiation. The findings highlight the critical influence of microstructure, passive film stability, and third-body …

Enhancing Underwater Imagery And Organism Detection Using Reinforcement Learning, K. Arul Deepa, P. Ramya, Karpaga Vinodha, Dharmaraja C

Journal of Marine Science and Technology–Taiwan

Underwater environments pose significant challenges in assessing image quality and organism detection due to light scattering and absorption, which limits visibility and color fidelity. Existing solutions often fail to effectively address these challenges, resulting in suboptimal image quality and hindering organism identification. This paper examines the problem through a dual-focused approach: enhancing underwater images and detecting organisms using the Underwater Image Enhancement Benchmark (UIEB) dataset. The first step introduces a state-of-the-art method for image enhancement by applying reinforcement learning (RL) principles. By formulating the enhancement process as a Markov Decision Process (MDP)—where states are represented by image features and actions …

Development Of An Adhesive Emulsion Hydrogel For Soft Tissue Reconstruction, David J. Alpert

Dissertations and Theses

Soft tissue filling materials are most commonly associated with various aesthetic, cosmetic procedures, primarily using lightly cross-linked hyaluronic acid to fill wrinkles and give facial features a more youthful appearance. These natural materials are biocompatible but degrade over time while more persistent synthetic fillers may provoke a chronic inflammatory response. Migration from the injection site is also a key factor as this may not only render the implant non- functional but necessitate further procedures for removal of the foreign material. Such concerns are more pronounced for soft tissue reconstruction procedures (e.g., to treat congenital defects or traumatic injuries), which require …

Design, Testing And Controls For Air Source Heat Pump System In Cold Climates Using Natural & Conventional Refrigerants, S M Abdur Rob

Dissertations and Theses

Fossil-fuel based heating systems used in the residential buildings in northeastern U.S region are not only inefficient but also largely responsible for the greenhouse gas emissions in U.S. Electrification of the buildings has been proved to be the most efficient way to reduce the greenhouse gas emissions where Heat Pumps can be the best alternative to replace the natural gas based heating system to accelerate the electrification process. Among different types of heat pumps, the Air Source Heat Pump (ASHP) system is widely used due to the easy installation and energy efficiency. Conventional heat pump technologies use various types of …

Climate Change Impacts On Hydrology In The Upper James Watershed, Imiya Mudiyanselage Chathuranika, Dalya Ismael

Engineering Technology Faculty Publications

Hydrological modeling of the Upper James Watershed (UJW), Virginia, is critical for predicting water availability, flood management, agriculture, ecosystem protection, and hydropower production under increasing climate change. The Hydrologic Engineering Center-Hydrologic Modeling System (HEC-HMS) is applied to evaluate climate change impacts on key hydrological components within the watershed. Future climate conditions were assessed for the near (NF: 2026-2050), mid (MF: 2051-2075), and far (FF: 2076-2100) periods using three Global Climate Models (GCMs) under Shared Socioeconomic Pathways SSP 2-4.5 and SSP 5-8.5. Climate data were bias-corrected using the Linear Scaling Method (LSM) and used to drive the HEC-HMS model. Results project …

Improving Medical Diagnostics With Vision-Language Models: Convex Hull-Based Uncertainty Analysis, Ferhat Ozgur Catak, Murat Kuzlu, Taylor Patrick, Michel Audette

Engineering Technology Faculty Publications

In recent years, vision-language models (VLMs) have been applied to various fields, including healthcare, education, finance, and manufacturing, with remarkable performance. However, concerns remain regarding VLMs’ consistency and uncertainty, particularly in critical applications such as healthcare, which demand a high level of trust and reliability. This paper proposes a novel approach to evaluate uncertainty in VLMs’ responses using a convex hull approach on a healthcare application for visual question answering (VQA). For any VLM, temperature refers to a sampling parameter used in probabilistic generation, which controls the randomness of the model’s output. The LLM-CXR model is selected as the medical …

Challenges And Best Practices For The Development Of Coastal Hazard Decision Support Tools, Noah Hallisey

Open Access Dissertations

There is growing interest in developing Decision Support Tools (DSTs) supporting emergency managers and other decision-makers during coastal storm events. Yet many tools fail to inform decision-making due to challenges associated with their development and transition into operational tools for real-time decision-making. This dissertation investigates these challenges and offers best practices for their development and implementation for real-world decision-making through a literature review, interviews with subject matter experts in the United States, and a real-world case study.

Manuscript 1 reviews existing published literature to understand whether and how tool developers are incorporating emergency managers in the development of DSTs and …

Scalable Single-Erbium Telecom Qudits With Record Room-Temperature Quantum Coherence In Silicon-Based Nanostructures, Alexander Kaloyeros

Electronic Theses & Dissertations (2024 - present)

Advancing quantum information science demands solid-state quantum systems that maintain long quantum coherence at elevated temperatures while supporting scalable, CMOS-compatible fabrication and telecom C-band operation. No existing platform has simultaneously achieved these requirements, as state-of-the-art demonstrations of coherent control of erbium ions, with an intrinsic telecom-band optical transition, have been confined to cryogenic temperatures below < 10 K under controlled vacuum conditions. This thesis introduces a new paradigm in which materials science and engineering provides the enabling pathway to quantum coherence.

A foundry-compatible nanofabrication approach, paired with targeted materials engineering, is developed to realize a new class of CMOS-scalable quantum system: arrays of spatially isolated single-erbium-ion qudits (five-level systems) embedded in silicon-based (e.g., silicon carbide (SiC) and SiC_xO_y) hollow nanopillars (HNPs). Non-lithographically …

Development And Analysis Of An Embedded Hardware Platform For Low-Power Rram–Based In-Memory Computing And Neural Network Applications, Jeelka Solanki

Electronic Theses & Dissertations (2024 - present)

Conventional computing architectures are based on repeated data transfer between memory and the compute unit; however, artificial neural network applications rely on data-intensive vector-matrix multiplication as a mathematical operation, where data movement from memory to compute processor results in increased power consumption and reduced performance. Possible solutions to this problem include in-memory computing, which addresses the data transfer bottleneck by computing directly within the memory. To demonstrate the potential of this approach, our research group fabricated hafnium oxide-based resistive random-access memory (RRAM) arrays using a 65nm CMOS technology for in-memory compute operations. This work demonstrates the design and development of …

Regulation Of Tgf-Β1–Induced Epithelial–Mesenchymal Transition By Integrin Inhibition, Wesam Elhawabri

Theses and Dissertations

Epithelial–mesenchymal transition (EMT) is a critical process underlying cancer progression, fibrosis, and tissue remodeling, characterized by coordinated changes in cell morphology, nuclear structure, and extracellular matrix (ECM) organization. Transforming growth factor beta 1 (TGF-β1) is a primary inducer of EMT; however, the extent to which integrin-mediated signaling and ECM remodeling regulate these structural changes remains incompletely understood. In this study, we quantitatively investigated EMT-associated remodeling in A549 lung carcinoma cells and MCF10A epithelial cells following TGF-β1 stimulation. Cells were cultured on ECM-coated substrates and treated with TGF-β1 in the presence or absence of integrin-targeting inhibitors (ATN-161, 28-G11, and STX-100). Im …

Nanomagnet Based Reservoir Computing And Quantum Control, Fahim F. Chowdhury

Theses and Dissertations

Conventional CMOS scaling has driven remarkable advances in computing but faces increasing physical and energy constraints, motivating alternative computing paradigms that integrate memory and computation while improving energy efficiency. Nanoscale magnetic systems offer a promising platform for such approaches because their intrinsic nonlinear dynamics and localized magnetic fields can support both classical and quantum information processing. This thesis investigates nanomagnetic systems for physical reservoir computing and, with primary emphasis, for localized quantum control of spin qubits.

The first part explores dipole-coupled nanomagnet arrays as physical reservoirs. Micromagnetic simulations demonstrate nonlinear dynamical behavior with high short-term memory and parity-check capacity, enabling …

Empirical Dynamical Modeling Of Cortico-Hippocampal Information Transfer During Memory Encoding, Sam Y. Cole

Theses and Dissertations

Understanding how brain dynamics support successful memory formation remains a central challenge in neuroscience. This dissertation applies tools from empirical dynamical systems theory to investigate the neural mechanisms underlying episodic encoding, with a focus on cortico-hippocampal interactions. Using stereoelectroencephalography (sEEG) data recorded during a delayed free recall of word lists task, this work reveals nonlinear, state-dependent shifts in directed information flow between cortex and hippocampus that distinguish successful from unsuccessful encoding. To further characterize these dynamics, state-space trajectories are reconstructed using time-delay embedding and recurrence-based methods, and features derived from these trajectories are used to classify memory outcomes. By integrating …

Modeling Of Laser-Produced Plasma Plumes: Expansion, Chemistry, And Thin-Film Deposition, Edmund Tsiri Semaha, Edmund Tsiri Semaha

Theses and Dissertations

Abstract

Laser-assisted material processing involves coupled plasma expansion, chemical reactions, and particle transport that govern the quality of thin-film deposition. This dissertation presents a comprehensive computational investigation of these processes using the OpenFOAM framework. First, the performance of the twoPhaseEulerFoam (tPEF), rhoCentralFoam (rCF), and sonicFoam (sF) solvers is evaluated for modeling laser-produced plasma plume expansion under atmospheric conditions, demonstrating that tPEF accurately captures shock-wave propagation, hydrodynamic behavior, and multispecies interactions. Building on this validation, the reactingFoam (rF) solver is employed to investigate the chemistry of aluminum plasma expanding into an air environment (Al–N₂–O₂). The model incorporates appropriate thermodynamic, transport, and …

Evaluation Of Chromium-Crosslinked Amps-Hpam Copolymer Gels: Effects Of Key Parameters On Gelation Time And Strength, Maryam Sharifi Paroushi, Baojun Bai, Thomas P. Schuman, Yin Zhang, Mingzhen Wei

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Controlling CO₂ channeling in heterogeneous reservoirs remains a major challenge for both enhanced oil recovery (EOR) and secure geological storage. AMPS-HPAM copolymers exhibit high-temperature resistance and brine tolerance compared with conventional HPAM gels, making them well suited for the harsh environments associated with CO₂ injection. Chromium-based crosslinkers (CrAc and CrCl₃) were investigated because sulfonic acid groups in AMPS can coordinate with trivalent chromium ions, enabling dual ionic crosslinking and the formation of a robust gel network. While organic crosslinked AMPS-HPAM gels have been widely studied, the behavior of chromium-crosslinked AMPS-containing systems, particularly their gelation kinetics under …

Effect Of Ionic Strength On Gelation Time And Strength Of Amps-Based Polymer Gels, Maryam Sharifi Paroushi, Xuyang Tian, Baojun Bai, Thomas P. Schuman, Yin Zhang, Mingzhen Wei

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Polymer gel treatment has been widely applied for improving sweep efficiency and controlling excessive water and gas production. Their performance depends on gelation time and final gel strength. In most studies, brine salinity is used to describe the effect of formation water on gel behavior. However, changing salinity also changes ionic strength and ion composition at the same time. Because of this coupling, it is difficult to identify the mechanisms controlling gelation, which has led to inconsistent trends in the literature. Increasing salinity has been reported to either slow or accelerate gelation and to weaken or strengthen gels depending on …

Carbon Nanotube/ Thermoplastic Polyurethane (Cnt/Tpu)-Based Triboelectric Nanogenerator With Self-Charge Pumping For Implantable Knee Load Sensing And Energy Harvesting, Osama Abdalla, Maryam Hosseini, Milad Azami, Amir Ameli, Emre Salman, Milutin Stanacevic, Ryan Willing, Shahrzad Towfighian

Mechanical Engineering Faculty Scholarship

Aseptic loosening and joint instability remain the primary modes of failure in total knee arthroplasty (TKA). To provide real-time biomechanical load monitoring, this study presents a triboelectric nanogenerator (TENG) utilizing a carbon nanotube/foamed thermoplastic polyurethane (CNT/TPU) composite dielectric layer paired with a Kapton tape between dual electrodes. By leveraging the triboelectric effect, the device functions simultaneously as an energy harvester and a self-powered load sensor. To overcome power density limitations, a self-charge pumping mechanism via a multi-stage voltage multiplier circuit (VMC) was integrated and evaluated under physiological cyclic loading (2100 N at 1 Hz). The system’s charge dynamics were further …

Eco-Friendly Solvent-Based Fabrication Of Single-Layer And Polydopamine-Modified Bilayer Pvdf-Hfp Membranes, Eesh M. Kulshrestha

Theses and Dissertations--Chemical and Materials Engineering

The growing global demand for clean drinking water has intensified the need for advanced water treatment technologies capable of efficiently removing contaminants while maintaining environmental sustainability. Polymeric membrane systems have emerged as an effective approach for water separations due to their high separation efficiency, simplicity, and adaptability to a wide range of water treatment applications. However, traditional membrane fabrication processes often rely on toxic organic solvents, such as N-methyl-2-pyrrolidone (NMP) and diemethylacetamide (DMAc), which pose environmental and health risks. These concerns have led to an increase in regulatory restrictions, primarily through the Registration, Evaluation, Authorisation, and Restriction of Chemicals (REACH) …

Investigation Of Succinylated Zwitterionic Polyethylenimine/Dna Complexes: Performance In Serum, Internalization, And Intracellular Fate, Levi Lampe

Theses and Dissertations--Chemical and Materials Engineering

Gene therapy has promised to revolutionize medicine since the earliest clinical trials, but a lack of delivery methods that are both safe and efficient has hampered progress. Gene therapy with viral vectors is effective at delivering nucleic acids to cells, but is associated with dangerous immunogenic responses and cancer-causing insertions into the genome. Viral vectors are also among the most prohibitively costly therapeutics in medicine. Polymeric vectors avoid these dangers and are made from inexpensive, off-the- shelf materials, but have been hindered by poor efficiency compared to viral vectors.

A benchmark polymer for in vitro nucleic acid delivery has been …

Aqueous Synthesis Of Luminescent Semiconductors For Opto-Electronic Applications, Saurabh Singh

Theses and Dissertations--Chemical and Materials Engineering

The advancement of opto-electronic and scintillation technologies relies heavily on developing low-temperature, eco-friendly, and scalable synthesis routes for high performance luminescent halide-based semiconductor materials. However, traditional synthesis methods for halide-based semiconductors, including hot-injection, solvothermal, solid-state reactions, Ligand-Assisted Reprecipitation (LARP), microwave-assisted synthesis, and thin film deposition techniques (spin coating, physical vapor deposition (PVD), chemical vapor deposition (CVD), etc.), often demand toxic organic/inorganic solvents, elevated processing temperatures, and high vacuum/inert environments. Such constraints limit their scalability, raise environmental concerns, and impede their commercial-level device integration. This research overcomes these long-standing challenges by employing water as a powerful crystallization-directing, and environmentally benign medium …

Anaerobic Digestion Of Food Waste Components: Modeling Biogas Production, Opeyemi E. Adelegan

Civil Engineering Dissertations

Food waste constitutes the single largest component of municipal solid waste landfilled in the United States — approximately 22% of 292.4 million tons generated in 2018 — and its anaerobic decomposition releases methane, a greenhouse gas with global warming potential approximately 27–30 times that of carbon dioxide over a 100-year horizon (IPCC, 2021). Anaerobic digestion (AD) offers an alternative management pathway that recovers energy and produces nutrient-rich digestate, but AD performance varies by as much as five-fold across food waste streams (130–630 m³ CH₄ per Mg VS added), and existing predictive tools either treat food waste as a …

Nanosecond Pulsed Electric Fields For Extracellular Vesicle Engineering: From Electro-Exocytosis To Cargo Modulation, Art Neal, Teresa Graham, Mohamadmahdi Samandari, Arash Ghorbannia, Anca Dobrian, Stephen J. Beebe, Ruben M. L. Colunga-Biancatelli

Bioelectrics Publications

Extracellular vesicles (EVs), including small extracellular vesicles (sEVs) and medium/large extracellular vesicles (MVs), have emerged as promising therapeutic vectors and diagnostic biomarkers across various branches of biomedicine. However, the clinical translation of EV-based technologies remains constrained by persistent challenges in manufacturing: insufficient yield from primary cell sources, limited control over cargo composition, and the absence of scalable, standardized production platforms. Nanosecond pulsed electric fields (nsPEF) represent an emerging biophysical approach that can address several of these limitations. Unlike conventional electroporation, which targets the plasma membrane using microsecond-to-millisecond pulses, nsPEF delivers ultrashort (1–300 ns), high-amplitude (10–300 kV/cm) pulses that penetrate intracellularly …

Beyond The Square Pulse: Waveform Shape, Eeg Correlates, And The Pursuit Of Natural Sensation In Tens, Jason Whitson

Honors Undergraduate Theses

This study investigates the relationship between electrical stimulus characteristics of shape and charge on evoked sensations and electroencephalogram (EEG) data during multi-waveform transcutaneous electrical nerve stimulation (TENS) of the median nerve. Neuromodulation methods have traditionally had little control over the location and quality of their associated evoked sensation (e.g., electric, vibration, touch). This experiment utilized five unique stimulus waveforms during TENS stimulation. EEG data were collected concurrently to provide an introductory objective measure of the neural responses underlying these sensory changes. Eleven participants completed three tasks (thresholding, super-threshold stimulation, two-alternative forced choice) using a two-electrode TENS approach. Stimulus waveforms were …

Artificial Intelligence In Cybersecurity: Applications, Threats, And Implications, Brandon A. Rodriguez

Honors Undergraduate Theses

The point of this thesis is to analyze the growth of artificial intelligence in the world of cyber security, highlighting the specific impacts it has in the use of defense and offensive misuse. The way that this research was done was by using three main methods, those being interviewing cybersecurity specialists, testing the uses of public AI models and by reviewing peer-reviewed studies. Some of the findings that were discovered with the research were that AI can be a great asset in supporting defensive systems with such things as assisting in the creation of scripts, but there are also negatives …

A Chicken Model For Non-Invasive Diagnosis Of Infant Developmental Dysplasia Of The Hip (Ddh) Using Acoustic Transmission Measurements, Aliza Shah

Honors Undergraduate Theses

Developmental dysplasia of the hip (DDH) is a condition characterized by abnormal development and stability of the hip joint. In a healthy infant, the femoral head (ball) fits securely within the acetabulum (socket of the pelvis), allowing for proper joint function. In DDH, the relationship is disrupted, ranging from mild acetabular dysplasia to partial (subluxation) or complete dislocation of the femoral head. This condition represents a range of structural abnormalities that develop during early growth. The integrity of the hip joint is essential for physical mobility, and disruption of this structure can lead to significant functional impairment. DDH may result …

Effect Of Inter Electrode Distance On Electrochemical Mineralization Of Calcium Carbonate In Mildly Acidic Environments, Irene Walker, Ivy Wu, Steven Decaluwe, Robert Bell, Kerry Rippy

Reviews, Analyses, and Instructional Studies in Electrochemistry (RAISE)

The effect of inter electrode distance (IED) on electrochemical mineralization in a parallel plate cell with a stainless-steel working electrode is presented. Three IEDs were tested, 6.5 mm, 15.5 mm, and 22.0 mm, for their water reduction effectiveness to create a region of local alkalinity that stimulates calcium carbonate precipitation in mildly acidic conditions. Chronoamperometry at -1.6 V for 30 minutes with ex-situ optical microscopy and scanning electron microscopy (SEM) were used. At the smallest IEDs, crystal clusters formed in growth-favored regimes as compared to the largest IED, where nucleation dominated, leading to encasement of the SS mesh. Rapid precipitation …

Cfd-Coupled Multi-Objective Optimization Of A Solid Oxide Electrolysis Cell Stack, Erin Webb

Theses, Dissertations and Capstones

Solid oxide electrolysis cells (SOECs) can convert steam into hydrogen with lower electrical demand than lower-temperature electrolysis technologies. Their performance depends on coupled fluid flow, heat transfer, species transport, and electrochemical behavior, which makes optimization difficult because improving one response can negatively affect another. Detailed computational fluid dynamics (CFD) can capture these interactions, but the computational cost makes trial-and-error design impractical. This thesis develops a three-dimensional model of a two-cell planar SOEC stack in ANSYS Fluent and couples it directly to a customized NSGA-II in MATLAB. Each candidate design is evaluated using the CFD model rather than a surrogate. Eight …

Public Preferences And Trade-Offs In Critical Mineral Mining Development In The United States, Bamidele Joseph Ajiga

Masters Theses

Rising demand for battery-critical minerals has increased U.S. mining efforts, but projects often face public opposition. There is limited work on how individuals in affected regions evaluate trade-offs between economic and environmental risks.

This research applies a discrete choice experiment to examine individual preferences for proposed battery-critical minerals mining projects in Missouri, Minnesota, and Idaho. 1908 respondents evaluated hypothetical mining projects defined by jobs, state tax revenue, the proportion of tailings reprocessed, groundwater impacts, and surface water impacts, under gold and silver versus battery-critical mineral framings.

Conditional and mixed logit models were used to assess the importance of attributes, demographic …