Engineering Commons^™

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 …

Volumetric Fluorescence Microscopy For High-Throughput And High-Sensitivity Imaging: From Single Molecules To Tissues, Le-Mei Wang

Graduate Studies Theses and Dissertations 2026

Fluorescence microscopy is an indispensable tool in the biological sciences, enabling researchers to investigate intricate subcellular structures, particularly for volumetric studies. However, conventional optical microscopy for volumetric imaging remains fundamentally constrained by imaging speed and throughput. To bypass traditional serial z-scanning, we introduce an axially scan-free method using a phase layer cake to modulate the system's point spread function. This approach projects volumetric information onto a 2D plane in a single shot, offering high flexibility in tuning axial depth alongside simultaneous multicolor imaging with high spatial resolution and sensitivity. This dissertation divides these technical advancements into cellular and tissue imaging …

Advanced Ysz/Si(B)Cn And Bnnt/Si(B)Cn Ceramics Matrix Composites For Extreme Environments In Hydrogen Combustion, Yiting Wang

Graduate Studies Theses and Dissertations 2026

The growing demand for carbon-neutral energy conversion has accelerated the development of hydrogen-fueled gas turbine systems, which operate at significantly higher temperatures and more chemically aggressive environments than conventional natural gas turbines. To meet these stringent requirements, ceramic matrix composite (CMC) materials consisting of yttria-stabilized zirconia (YSZ) fiber reinforced Si(B)CN ceramic matrix were developed. To further enhance in-plane heat dissipation, thermal stability, thermal shock resistance, and thermal cycling performance, a Si(B)CN/Boron Nitride Nanotubes (BNNT) nanocomposite coating was incorporated onto the YSZ/Si(B)CN composites. Microstructural characterization confirmed the formation of a continuous Si(B)CN ceramic matrix reinforced with uniformly distributed BNNTs. The resulting …

Generating Boundary Conditions For Compound Flood Modeling In A Probabilistic Framework, Pravin Maduwantha Mahanthe Gamage

Graduate Studies Theses and Dissertations 2026

Flooding in coastal riverine environments is often driven by the combined influence of multiple hydrometeorological flood drivers, including storm surge, rainfall, waves, and river discharge, which is referred to as compound flooding. A robust flood hazard assessment requires simulation of a wide range of flood driver conditions through dynamic compound flood models to capture the variability in resultant flooding. However, such assessments remain limited by the short length of observational records and the high computational cost of physics-based methods used to generate temporally varying boundary conditions. This dissertation develops a statistical framework to characterize compound flood drivers and generate large …

Performance Analysis Of Labyrinth And Hybrid Seals For Supercritical Co₂ Turbomachinery Applications, Ghanshyam Sarobar Mandal

Graduate Studies Theses and Dissertations 2026

Leaks account for large losses in turbomachinery systems, which has led to research on sealing technologies. The work presented studies the effect of a hybrid seal combining conventional labyrinth geometry and honeycomb structure by simulating supercritical carbon dioxide (sCO₂) flow through this geometry. The CFD solver compares effects such as changes in mass flow rate, formation of vortices, pressure profile, and seal performance as geometry angles of labyrinth teeth and honeycomb walls change at conditions normally found at higher pressures in these seals. Honeycomb walls were placed on the stator, ranging from 125°< θc< 55°. Labyrinth teeth were placed on the rotor at the same degrees. Honeycomb cell diameters were also varied, creating more resistance and turbulence within the flow. It was discovered that the honeycomb angle created stronger effects on vortices and boundary layer formation, while the labyrinth angle mainly affected the throttling of flow and loss generation. Combining all three angles created a relationship dictating the seal leakage. Dimensions of seals were based on gas turbine seals with changes to meet sCO₂ conditions. ANSYS was used to simulate static and rotating conditions until convergence on a specific geometry

Design, Fabrication Modeling, And Optical Metrology Of Mwir Silicon Metalenses, Weiyu Chen

Graduate Studies Theses and Dissertations 2026

Mid-wave infrared (MWIR) optical systems require compact, broadband, manufacturable components whose performance can be predicted and measured reliably. Silicon metalenses are attractive because silicon combines high refractive index, MWIR transparency, and semiconductor-compatible fabrication. This dissertation develops a scale-bridging design–fabrication-modeling–metrology framework for MWIR silicon metalenses.

A shared full-aperture framework connects meta-atom libraries, physical layout generation, angular-spectrum propagation, point-spread-function calculation, and focal-plane energy metrics. Building on this foundation, the Dispersive Sweatt Model (DSM) incorporates meta-atom dispersion into conventional ray-tracing software, enabling broadband co-optimization of metasurfaces and refractive elements. A process-aware design framework then incorporates scanning electron microscopy (SEM)-measured height–radius relationships produced by …

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 …

Timing And Stability Of Uav Operations In Smart City Environments: Experimental Analysis And Design Implications, Rabia Ipek Yasar

Theses and Dissertations

This thesis investigates the deployment and performance of unmanned aerial vehicles (UAVs) within the Virginia Commonwealth University Open Cyber City (OCC) testbed. The study focuses on evaluating real-time indoor positioning performance using the Crazyflie drone platform. High-precision position measurements are obtained using the Vicon motion capture system, enabling analysis of the latency between the drone’s actual position and the system-reported position. In a closed-loop control system, the time difference between the position measurement and the application of the control command is called the system delay. Both stationary (hovering) and trajectory-following experiments are conducted to evaluate system performance. Communication delays in …

Contours Of Duration: Movement Authored Through Form—A Behavior Archive, Jood Senussi Elbeshti

Theses and Dissertations

Insect anatomy offers an elegant example of motion derived from structure. Inspired by insect movement, Contours of Duration employs a cam-and-follower system consisting of moving, leg-like parts, designed to engage a series of rotating cams, such that the shape of each cam’s surface activates the legs in unique ways, generating repetitive movement, and demonstrating how geometry produces distinct motion behaviors over time. Through iterative experimentation and controlled variation, trace emerges as a central methodology, whereby movement, over time, creates a distinct pattern of marks, making motion legible and reflecting how subtle changes to surface and form generate different behavioral outcomes. …

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 …

Machine Learning Modeling Of In-Situ Effective Thermal Conductivities And Ablation Behaviors Of Ceramic Matrix Composites Under Hydrogen Combustion Environments For Gas Turbine Engines, Jayanta Bhusan Deb

Graduate Studies Theses and Dissertations 2026

Through the integration of experimental characterization, machine learning, deep learning, numerical modeling, and physics-informed artificial intelligence, this dissertation explores the thermal performance of polymer-derived ceramic matrix composites (CMCs) for hydrogen combustion environments. The polymer infiltration and pyrolysis (PIP) process was used to create Yttria-stabilized zirconia (YSZ)-fiber-reinforced ceramic matrix composites, which were then experimentally assessed under hydrogen torch and hydrogen combustion conditions typical of next-generation gas turbine and aerospace propulsion systems. Front- and back-surface temperature measurements were used to continually monitor thermal reactions, and post-test microstructural characterization and numerical simulations were carried out to evaluate material integrity and heat-transfer behavior. To …

De Novo Protein Binding To Zinc Oxide Through Biomineralization Pathways, Jean-Mark A. Francis

Theses and Dissertations

De novo proteins are structurally distinct from proteins found in nature and thus capable of having their amino acid sequence modified to accomplish tasks such as increasing protein-nanoparticle binding without unfolding or decomposing. Zinc Oxide nanoparticles are functionally distinct from their bulk counterparts and are widely used as semiconductors in a variety of fields such as medicine and agriculture. With demand for these nanoparticles increasing, environmentally sustainable methods of Zinc Oxide nanoparticle synthesis are being investigated as an eco-friendly alternative to currently utilized but environmentally hazardous chemical and physical techniques. This research investigates the binding characteristics between Zinc Oxide nanoparticles …

Integrated Corridor Management Framework For Severe Freeway Incidents, Sanjida Afroz Iqra

Graduate Studies Theses and Dissertations 2026

Traffic incidents are a major source of non-recurrent congestion on urban freeways, generating substantial mobility, safety, and economic impacts. Severe incidents that block multiple or all travel lanes are particularly disruptive because they degrade freeway operations and propagate congestion onto surrounding arterials. Effective Integrated Corridor Management (ICM) requires the ability to identify severe incidents, estimate their network-wide impacts, and anticipate the traffic conditions and driver behaviors that contribute to instability. This dissertation develops a data-driven ICM framework to address these challenges using real-world incident, crash, detector, and connected vehicle data from major Central Florida corridors, including I-4 and SR-417. The …

Communication-Aware Energy Optimization For Electric Vehicles With Adaptive Cruise Control, Shahriar Shahram

Graduate Studies Theses and Dissertations 2026

This dissertation develops information-driven methods to reduce traction energy in battery electric vehicles during adaptive and cooperative cruise control. Physics-grounded energetics are embedded in a predictive controller that accounts for intermittent V2V preview, sensing noise, packet loss, and powertrain limits. To ensure deployability, the nonconvex traction–power map is replaced by locally convex surrogates so each step solves a small, strictly convex QP in real time (average ≈ 70 ms/step on a desktop CPU: 8 cores/16 threads, 4.2–5.0 GHz), leaving margin at typical sampling rates (Ts =0.05–0.10 s; N=15–25).

Across standardized drive cycles from NREL DriveCAT—including FTP–75 (light duty), NREL Class …

Evaluating The Brain-Muscle Connectivity Of Cyclic Ankle Pedaling Movement In A Clinical Setting, Matthew K. Shanosky

Graduate Studies Theses and Dissertations 2026

Clinical neurorehabilitation requires objective biomarkers to accurately detect and monitor neuromotor impairments. While traditional metrics are favored for their efficiency and minimal equipment demands, they typically rely on subjective observation and lack physiological resolution. High-resolution electrophysiological technologies, such as electroencephalography (EEG) and electromyography (EMG), offer objective insights into nervous system dynamics; however, prolonged data acquisition times have hindered their translation into frontline clinics. To bridge this translational gap, this study developed a time-efficient experimental paradigm designed for rapid clinical deployment. Healthy participants completed two initial resting baseline trials before performing an externally paced, dynamic, cyclic ankle movement task utilizing simulation …

Experimental Demonstration Of A Laboratory Scale Packed Bed Reactor For Thermochemical Energy Storage Using Embedded Heating Elements, Zachary Monem

Graduate Studies Theses and Dissertations 2026

Thermochemical energy storage (TCES) is an emerging technology that is being studied as a carbon-neutral renewable alternative to conventional methods of large-scale power generation, such as the utilization of fossil fuels. TCES makes use of thermochemical materials to store and discharge energy in two-step reversible chemical reactions. Among the most promising TCES materials are metal oxides, which possess significantly higher energy storage densities compared to other TCES materials; consequently, thermochemical reactors are used to store and discharge large amounts of energy during reduction-oxidation cycles using metal oxide materials. The current work focuses on the design and experimental demonstration of a …

Cfd Analysis Of A Full Heat Exchanger Between Ammonia And Supercritical Co2 In Aviation Application, Mairah Ahmed

Graduate Studies Theses and Dissertations 2026

The aviation industry’s transition toward lower-carbon propulsion systems has accelerated interest in alternative fuels, including ammonia–hydrogen fuel blends. In this work, a supercritical CO2 Brayton cycle is integrated with the exhaust stream of a turbofan engine to recover waste heat and utilize it for ammonia preheating and cracking. The recovered thermal energy raises the ammonia temperature to the level required for catalytic decomposition, enabling onboard hydrogen production. The proposed architecture combines ammonia cracking with a high-bypass, two-shaft turbofan engine representative of the propulsion system employed on the Boeing 737 MAX 8. This approach addresses the challenges associated with onboard hydrogen …

Utilizing Coal For Mesophase Pitch-Based Carbon Fiber Production: Precursors, Processes, And Progress, Christina M. Thompson

Theses and Dissertations--Chemistry

Graphitic materials possess unique properties due to the unique combination of layered crystalline structure and carbon’s low atomic weight. High performance carbon fiber is one such example, displaying exceptional strength-to-weight ratios, stiffness, and thermal and chemical resistance. These properties render high performance carbon fiber a critical structural reinforcement material in the manufacture of composites across various industries, such as for automotive and aerospace applications. However, balancing fiber performance with precursor and processing costs remains a challenge. As alternative carbonaceous feedstocks are explored, coal has gained interest for utilization in graphitic products as a relatively abundant and low-cost source of aromatic …

The Effect Of Scanning Strategy And Build Conditions On The Residual Stress Of A Ded System With Realistic Clad Geometry, Christopher Matthew Roeder

Graduate Research Theses & Dissertations

Direct Energy Deposition (DED) is a leading metal additive manufacturing method for fabricating complex parts. However, the high thermal gradients during the process, along with their effects on thermal expansion and shrinkage during heating and cooling cycles, result in significant residual stress that imposes substantial limitations on the building process. These stresses can lead to warpage, cracking, and a reduction in overall mechanical performance, challenges that must be addressed in most manufacturing industries. While scanning patterns and clad geometry have often been studied independently, their interaction may provide deeper insights into the causes and effects of these operating conditions on …

Development And Characterization Of Flat And Flexible Rebco Cables For High-Field Accelerator Magnets, Emily Romancew

Graduate Research Theses & Dissertations

High-Temperature Superconducting (HTS) materials are at the forefront of innovation for fundamental particle physics. The next generation of particle accelerators aims to explore higher mass particles and is dependent on the ability to achieve higher fields in the 20–30 T range to keep machine size within a practical footprint. Current magnet technology relies on low-temperature superconductors (LTS) such as NbTi and Nb₃Sn, which are limited to fields of approximately 8–16 T, while high-temperature superconductors (HTS), particularly Rare-Earth Barium Copper Oxide (REBCO), offer a promising pathway toward higher-field magnets due to their ability to carry large currents at elevated magnetic fields. …

An Integrated Pull System Framework For Disassembly Industries: Bridging The Supply-Demand Mismatch In Duck Meat Processing, Hongchao Yu

Graduate Research Theses & Dissertations

Disassembly-based production systems, such as duck meat processing, face inherent operational challenges due to one-to-many production structures, short product shelf life, and volatile customer demand. A single carcass must be processed into multiple products at largely fixed biological ratios, while demand varies across products and over time. This supply-demand mismatch frequently leads to simultaneous surplus and shortage, resulting in unstable shipment schedules, excess inventory, and unavoidable waste. Traditional order-driven pull systems typically respond to orders independently and are limited in their ability to coordinate these interrelated effects.

This dissertation develops an integrated pull system framework for perishable disassembly processes, using …

Feasibility Of Corn Stover For Biogas Production In Northwestern Illinois: A Case Study Of Jo Daviess And Carroll Counties, Anthony Amotoe-Bondzie

Masters Theses

The growing demand for renewable energy and sustainable waste management has intensified interest in agricultural residues such as bioenergy feedstocks. This study evaluated the feasibility of converting corn stover into biogas through anaerobic digestion (AD) in Jo Daviess and Carroll Counties, Illinois, with consideration of the Savanna Industrial Park as a potential centralized processing hub. Although corn stover represents one of the largest biomass resources in the United States, this research identifies a critical gap between theoretical availability and practically recoverable feedstock. Using a mixed-methods framework, the study integrates biomass quantification, methane yield modeling, economic analysis, and policy assessment. Results …

Design And Validation Of A Novel Patterned Microfluidic Culture Platform For Hipsc-Cm Maturation, Anisia Gabriela Țiplea

Dartmouth College Master’s Theses

Adult cardiomyocytes (CMs) are among the most challenging cells to culture in vitro, given their poor adherence to plastic culture wells and poor maturation outside the native extracellular matrix (Narkar et al., 2022). Human induced pluripotent stem cell-derived CMs (hiPSC-CMs) offer a viable alternative to study heart development and disease progression. While not comparable to adult CMs in their maturity (Narkar et al., 2022), they mimic the clinical phenotypes of heart failure and are more feasible to culture. Nevertheless, hiPSC-CMs require specialized culture conditions that cannot be achieved with 2D static culturing, which fail to replicate native tissue environments (X. …

Lean Service System Optimization In U.S. Automotive Maintenance Centers: A Time Study And Simulation-Based Approach To Reducing Service Cycle Time And Increasing Efficiency, Rakibul Hasan Sarker

All Graduate Theses, Dissertations, and Other Capstone Projects

The primary objective of this study is to measure the current service time at a U.S. automobile service center, with the aim of reducing waste and optimizing service operations through time study and simulation modeling. Inefficiencies in those service centers increase service time and labor costs, reduce service quality, and reduce workshop productivity, thereby increasing customer waiting time. In this study, real-world shop floor data were collected from a single service center, namely Jiffy Lube. Over the course of ten working days, 205 vehicle data points were acquired. Service time, bay time, and overall process time were computed and examined …

Neural Network Transceiver For Ltv Mimo Channels, Iresha Amarasekara

Electronic Theses & Dissertations (2024 - present)

Eigenfunctions are commonly employed to characterize kernels in various data-driven analyses. In machine learning, eigenfunction decomposition typically relies on Mercer's theorem, which assumes kernel symmetry. However, this condition is often unmet in communication systems, where channel kernels are asymmetric due to differences in downlink and uplink propagation environments. The High-Order Generalized Mercer's Theorem (HOGMT) provides a systematic approach for decomposing multidimensional asymmetric kernels into eigenfunctions. To address the complexity of eigen-decomposition, this work introduces a baseline neural network (NN) framework HNET. The HNET framework is further enhanced by incorporating the augmented Lagrangian method (ALM) to explicitly enforce orthogonality constraints. This …

Nanostructured Cathode Catalysts For Aem Electrolysis: From Catalyst Design To Degradation And Hydrogen Dynamics, Yamini Kumaran

Electronic Theses & Dissertations (2024 - present)

Anion exchange membrane water electrolysis (AEMWE) presents a promising pathway toward cost-effective and sustainable hydrogen production by integrating the chemical robustness of alkaline systems with the compact, zero-gap design of proton exchange membrane electrolyzers. However, the widespread implementation of AEMWE is limited by the availability of highly active and durable platinum-group-metal (PGM)-free catalysts and by an incomplete understanding of their degradation behavior under realistic operating conditions.

This dissertation focuses on the development, characterization, and mechanistic investigation of nanostructured MoNi₄–MoO₂-based electrodes for efficient and stable hydrogen generation under alkaline and membrane-integrated environments. MoNi₄–MoO₂ nanorods …