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Dynamic Interactions Of The Compressible Reacting Flow With A Morphing Wall In A Supersonic Combustor, Mason R. Thornton

Graduate Studies Theses and Dissertations 2026

The influence of compressibility on supersonic reacting flows is explored by varying the area expansion ratio in a supersonic cavity combustor using a moving wall. In principle, this design allows on-the-fly adjustment of the combustor aft wall expansion ratio to accommodate variable inlet conditions and fueling rates. The variable back pressure broadens the operability envelope and ensures greater pressure rise recovery compared with a constant geometry combustor. The results demonstrate that modulating area expansion alters the combustor pressure distribution and can influence cavity flame dynamics. At sufficiently high equivalence ratios and compression levels, the back pressure induced by the moving …

Watch Your Step, Mind The Crowd: Socially Compliant Navigation In Unstructured Environments, Jack Vice

Graduate Studies Theses and Dissertations 2026

Autonomous mobile robots increasingly operate in complex real-world environments characterized by uneven terrain, dynamic obstacles, and human presence. This dissertation addresses the fundamental challenge of developing adaptive navigation strategies that enable robots to safely and effectively traverse unstructured outdoor environments including construction sites, agricultural fields, and disaster areas while maintaining social compliance around people. We advance this capability through five complementary contributions that collectively target dynamic, unstructured, human-occupied environments. First, we demonstrate evolutionary optimization of legged mobility for uneven terrain. Second, we propose using a spatiotemporal autoencoder to learn the temporal dynamics of moving people and objects. Third, we introduce …

Oblique Detonation Waves In Internal Axisymmetric Converging Flow, Zachary P. White

Graduate Studies Theses and Dissertations 2026

Detonative combustion offers significant thermodynamic advantages for high‑speed propulsion, motivating the development of detonation‑based combustors for hypersonic flight. Among these, oblique detonation wave (ODW) engines require extremely high combustor velocities to achieve steady wave stabilization. While most prior experimental and numerical studies have focused on planar two‑dimensional geometries, axisymmetric combustors offer practical benefits for hypersonic vehicle integration and may influence achievable pressure gain. However, the effects of inward‑turning axisymmetric compression on ODW formation and performance remain largely unexplored. This work presents an experimentally stabilized ODW formed on an internal axisymmetric converging ramp. Experiments were conducted in a high‑enthalpy blowdown wind …

Bowtie Antenna-Coupled Bi₂Te₃–Sb₂Te₃ Thermoelectric Detector For Millimeter-Wave Radiation, Rumana Zahir

Graduate Studies Theses and Dissertations 2026

We explore the development of antenna-coupled thermoelectric detectors for long-wavelength radiation using sputtered bismuth telluride (Bi₂Te₃) and antimony telluride (Sb₂Te₃) thin films. Detection in the infrared, millimeter-wave, and terahertz regimes is critical for sensing, imaging, and energy applications; however, many existing detectors rely on cryogenic operation, exhibit narrow spectral response, or require complex material systems. In this work, we investigate the feasibility of reliable, room-temperature long-wavelength detection using microfabricated thermoelectric thin films integrated with antenna structures. A systematic full-factorial experimental approach was employed to determine how sputtering parameters and post-deposition annealing influence …

Photothermal Excitation And Optical Interferometric Readout Of Mos2 Nanomechanical Resonators, Sadia Afrin

Graduate Studies Theses and Dissertations 2026

Two-dimensional (2D) materials have emerged as promising candidates for nanoelectromechanical systems (NEMS) due to their exceptional mechanical, optical, and electrical properties. Among these materials, molybdenum disulfide (MoS2) has attracted considerable interest for nanomechanical resonator applications because of its low mass density, high mechanical strength, and semiconducting nature. This thesis presents the fabrication, theoretical modeling, and experimental characterization of suspended MoS2 drumhead resonators. The devices were fabricated by mechanically exfoliating MoS2 flakes from bulk MoS2 crystals and transferring selected flakes onto pre-patterned substrates using a dry-transfer process. Mechanical resonance was excited through photothermal actuation using a modulated blue laser, while device …

Pseudo-Boiling Of Supercritical Co2 In A Parallel-Flow Microchannel And A Micro-Jets Impingement Device And Single-Phase And Two-Phase Heat Transfer Of Subcritical Co2 Jets, Pranzal Ahmed

Graduate Studies Theses and Dissertations 2026

Carbon dioxide (CO2) is gaining attention as a low-toxicity, zero-ozone-depletion refrigerant with a global warming potential of 1, making it an attractive alternative to synthetic HFCs/HFOs. Near its critical point, CO2's thermophysical properties change sharply with small shifts in temperature and pressure — a behavior that can be exploited to enhance heat transfer in trans-critical power cycles and electronics cooling. This dissertation experimentally investigates heat transfer during the pseudo-boiling of supercritical CO2 in a parallel-flow microchannel and a micro-jet impingement device, alongside CO2 flow boiling and single-phase water heat transfer in micro-jet impingement. Using microfluidic devices instrumented with embedded resistance …

Charge Transport Modeling Of Multifunctional Molecular Transistors, Romena Akter

Graduate Studies Theses and Dissertations 2026

Distinguishing between the current–voltage characteristic curves associated with different transport mechanisms in a molecular electronic device and an artifact arising from device-level disorder is a central challenge in the study of molecular electronics. Characterizing these mechanisms and connecting them qualitatively to molecular-level orbital alignment, electrode coupling, voltage division, energetic disorder, and reorganization energy requires not only experimental data but also a rigorous theoretical framework for extracting physically meaningful parameters from measured transfer characteristics. This dissertation addresses this challenge in Chapters 2, 3, and 4 by developing and applying four complementary transport models —Simmons tunneling, single-level Landauer, Marcus hopping, and McConnell …

Effects Of Back-Pressure On Pseudo-Shock Systems, Emil C. Alunno

Graduate Studies Theses and Dissertations 2026

The isolator of a scramjet engine houses a pseudo-shock, a compressive flow structure that raises the static pressure and decelerates the incoming supersonic flow for efficient combustion while shielding the inlet from the elevated pressure downstream. Under sufficient back pressure the leading shock bifurcates and forms a shock train followed by a shockless mixing region, and the resulting system oscillates even under nominally steady conditions; this unsteadiness distorts the flow, can drive the pseudo-shock out of the isolator and unstart the inlet. This thesis experimentally examines how a pseudo-shock in a constant-area isolator at a measured entrance Mach number of …

Soil Texture And Organic Matter Influence Hydraulic Performance Of Stormwater Infiltration Systems Across Antecedent Moisture Conditions, Laura E. Andrade Barron

Graduate Studies Theses and Dissertations 2026

Stormwater infiltration systems are widely used to improve urban stormwater management by promoting drainage and groundwater recharge while treating nonpoint source pollution such as nutrients in surface runoff. Nutrient removal and hydrologic performance of these systems are closely coupled and both are dependent on characteristics of underlying soils. In this study, laboratory flow-through experiments were conducted using 30 intact cores taken from six soil types with different textures (0.99-16.63% clay content) and organic matter contents (OMC 0.44-93.3%). Measured cumulative fluxes from laboratory experiments were used to calibrate numerical models simulating flow through porous media (HYDRUS-1D). Calibrated models were used to …

Making Unsafe Sequences Unexecutable: Formal Protocol Enforcement For Cyber-Physical Systems, Arthur Amorim

Graduate Studies Theses and Dissertations 2026

Cyber-physical systems execute physical actions in response to software commands, making their communication protocols a primary attack surface. A stealthy attack is a sequence of individually valid messages that violates a required ordering, driving the system into an unsafe state without malware or protocol violation. Existing defenses examine messages or physical state in isolation, not protocol level sequences, and cannot prevent them. Preventing them requires enforcement that makes unsafe sequences unexecutable at the communication boundary.

Formal methods offer a principled path to enforcement, but no tool spans specification to safe deployed hardware. Model checking automates proofs but has no certified …

Numerical Investigation Of Reacting Flow In Pmma-Fueled Solid Fuel Scramjet Combustors Under Experimental Test Conditions, Hunter Bassett

Graduate Studies Theses and Dissertations 2026

A simplified steady RANS-based numerical study of reacting flow in solid-fuel scramjet combustors is presented to evaluate the ability of commercial CFD frameworks to reproduce key features observed in experimental test sections. The work focuses on solid PMMA fuel in two supersonic combustor configurations: a cavity-assisted flameholding combustor and a variable-angle diverging combustor. The cavity combustor is analyzed as a baseline case and results are compared directly with experimental data. Three combustor geometry states corresponding to ignition, early-burning, and steady-burning conditions are investigated. Meshes are assessed through a systematic grid refinement method to establish grid independence. A novel variable-angle diverging …

Connecting The Existing Fiber Infrastructure To The Future With Antiresonant Hollow Core Fibers, Timothy Bate

Graduate Studies Theses and Dissertations 2026

Optical fiber systems based on solid-core silica waveguides underpin modern telecommunications, high-power laser delivery, precision sensing, and coherent optical systems. However, nonlinear effects, material absorption, and thermal limitations within silica increasingly constrain further scaling in both optical power and transmission performance. Antiresonant hollow-core fibers provide a promising alternative by guiding light predominantly in air, substantially reducing nonlinear interactions, latency, and optical damage while enabling transmission regimes inaccessible to conventional solid-core fibers. Despite rapid advances in antiresonant hollow-core fiber attenuation and power handling, one of the largest remaining barriers to widespread adoption is reliable integration with the existing solid-core fiber ecosystem. …

Integrated Optical Probes For Confocal Scanning Imaging And Adjustable Coherent-Gated Dynamic Sensing, Yonglin Huang

Graduate Studies Theses and Dissertations 2026

Optics and photonics have been one of the most important sciences and technologies that impact modern human life in a big way. For example, fiber-optics for communications and artificial intelligence. Optical probes are critical components for optical imaging and optical sensing technologies that have been actively researched and developed in the past decades. Advanced fiber-optic sensor probes with smaller size, better performance, lower noise, higher photon efficiency, rapid sensing time, and lower cost are needed in many applications, such as nanoscale material science, chemistry, and biomedical fields, etc.  In this project, new fiber-optic sensor probe technologies and integrated micro-optic devices …

Genuine And Meaningful Black Character Narratives In Video Games, Derek L. Manns

Graduate Studies Theses and Dissertations 2026

The lack of Black representation in video games reflects stereotypes and hollow narratives. Authentic and meaningful design of Black characters allows Black players a reflection of emotional attachments everyone wants when playing a game. Examining racial identities through avatars, critiquing the notion that customization equates to racial inclusivity, limited options and predominant, white-coded protagonists reinforce systemic biases in games (Dietrich, 2013). My Afrofuturistic content analysis framework explores Black culture with a future of speculative fiction. Reimagining the past, present, and future through Black narratives for alternate futures (Womack). Integrating these ideas enhance culture and aesthetics in this dissertation to highlight …

Experimental And Computational Characterization Of A Rotorcraft-Tiltrotor Model Using Morphing Wings For Whirl Flutter Instability, Darrell Nieves Lugo

Graduate Studies Theses and Dissertations 2026

Tiltrotor rotorcraft configurations combine the capabilities of vertical and forward flight, offering a crucial and advantageous design for maximizing the operational flight envelope. This versatility enables broad adaptability across numerous designs and platforms, including unmanned aerial vehicles (UAVs), micro-air vehicles (MAVs), and vertical take-off and landing (VTOLs) aircraft. However, propeller-based aircraft are susceptible to an aeroelastic instability at high flight speeds known as whirl flutter. This instability phenomena is a crucial research task and problem to investigate, as with advances in manufacturing and vehicle designs, these can yield new rotorcraft formats capable of advancing the flight envelopes at higher cruise …

Two-Phase Transcritical Carbon Dioxide Flow At The Microscale For Thermal Management Applications, Soroush Niazi

Graduate Studies Theses and Dissertations 2026

High-power electronic and power-conversion devices now generate heat fluxes that exceed what conventional air- and single-phase-liquid cooling can dissipate, motivating the search for more capable coolants and cooling mechanisms. Carbon dioxide is an attractive candidate for this role: it is inexpensive, non-toxic, and environmentally friendly, and near its critical point its thermophysical properties change rapidly, which raises the heat-transfer coefficient. In addition, a large pressure drop produces strong cooling through the Joule–Thomson effect and phase change, so that the throttling element itself becomes a source of cooling. This dissertation studies the throttling, phase change, and choking of high-pressure carbon dioxide …

Hidden Gem, Fraught Liability, Or Visible Asset? The Museum Of Contemporary Art Jacksonville, Keidra D. Navaroli

Graduate Studies Theses and Dissertations 2026

This dissertation utilizes a combination of archival research, qualitative interviews, and data-driven analyses to examine how the Museum of Contemporary Art (MOCA) Jacksonville came under the governance of the University of North Florida (UNF). Founded in 1924, MOCA became a cultural institute of UNF in 2009 during the Great Recession. Tracing MOCA’s reinventions and geospatial movements across Jacksonville, this study considers the ideologies that informed the museum’s development, the locations that defined its service to Northeast Florida, and the financial conditions that necessitated its eventual rescue by a public university. The museum’s challenges are reflective of larger tensions in the …

Discrete Element Modeling Of Granular Soils: Critical State Behavior Applied To Impact Pile Driving, Esteban Patino Marin

Graduate Studies Theses and Dissertations 2026

This thesis investigates the use of the Discrete Element Method (DEM) to study two complementary aspects of granular soil mechanics: critical state behavior of granular materials and dynamic response of driven piles in sand, both of which are governed by the same particle-scale mechanisms of dilation, contraction, and fabric evolution.

The first examines the critical state behavior and fabric anisotropy of granular soils through DEM simulations of direct shear, direct simple shear, and true triaxial tests. Sphere-cluster particles representative of a uniform sand are used in two assemblages of approximately twenty-five thousand and one hundred twenty-five thousand spheres to evaluate …

Advancing Cyber-Physical Security And Resilience Of Modern Power Systems: Intelligent Monitoring, Secure Operation, And Resilient Recovery, Md Moshiur Rahman

Graduate Studies Theses and Dissertations 2026

Modern power distribution systems are rapidly evolving into cyber-physical, DER-rich, and data-driven networks that rely on extensive sensing, communication, automation, grid-edge intelligence, and operator decision support. While this transformation improves flexibility, observability and controllability, it also expands the cyber-attack surface and increases the risk that cyber intrusions can propagate into physical disturbances, compromised DER operation, degraded situational awareness, and interrupted service continuity. This dissertation advances the cyber-physical security and resilience of modern distribution systems by developing a high-fidelity real-time cyber-physical hardware-in-the-loop testbed using OPAL-RT, EXata CPS, industrial relays, SCADA/RTAC, HMI, and grid-edge devices to emulate realistic DER-integrated distribution grid operation. …

Mathematical Modeling And Characterization Of A Variable Stiffness Ankle-Foot-Orthosis, David E.L. Richards

Graduate Studies Theses and Dissertations 2026

Conventional ankle–foot orthoses (AFOs) typically employ static stiffness profiles that do not replicate the dynamic quasi-stiffness of the human ankle during gait. Variable stiffness mechanisms (VSMs) offer a promising alternative solution for gait pathologies, such as foot drop and post-stroke hemiparesis; however, their implementation is limited by the lack of accurate mathematical models capable of predicting force and stiffness characteristics. The objective of this thesis is to develop and validate comprehensive mathematical models describing the kinematics and kinetics of a novel variable stiffness ankle–foot orthosis (VS-AFO). This study derives governing equations to characterize how mechanical adjustments influence the force transmission …

On Performance And Applications Of A Liquid Fueled Pulsed Flame Jet Igniter, Gerardo A. Rodriguez

Graduate Studies Theses and Dissertations 2026

As global demands for supersonic and hypersonic flight heighten, high-speed air breathing propulsion technologies stand out as a worthwhile direction to overcome many of the limitations that turbomachinery-based engines face at supersonic speeds. Air breathing propulsion concepts are attractive for their geometrical simplicity, using supersonic incoming air to provide compression. Scramjet flight vehicles operate within the hypersonic flight regime and have been a global research topic, especially in the 21st century, for defense and combined cycle engine architectures. As scramjet technology continues maturing towards widespread use, efforts have converged on liquid hydrocarbon fuels for storage, range, and operational benefits. Flight …

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 …

Study On Fracture Toughness Under Different Modes Through Continuum Damage Mechanics Based Fracture Locus, Yeting Sun

Graduate Studies Theses and Dissertations 2026

Traditional elastic-plastic fracture mechanics (EPFM) relies on crack-tip analysis, whereas continuum damage mechanics (CDM) is typically calibrated from uncracked bodies. This dissertation aims to bridge the gap between these two fundamental branches by explicitly linking fracture toughness with ductile damage models. Based on the assumptions regarding Mode I crack deformation, analytical solutions are derived to establish a novel relationship among Mode I fracture toughness, CDM-based ductile fracture strain, and material strain hardening capability. This theoretical framework is subsequently extended to encompass Mode II and Mode III loading conditions. To validate the proposed relationships, finite element (FE) models are developed in …

“I Call For The Resurgence And Reclamation Of Our Indigenous Ways”: Institutional Landscapes, Resistance, And The Experiences Of Mmir Advocates, Sara Tehrani

Graduate Studies Theses and Dissertations 2026

Indigenous Peoples across Turtle Island experience disproportionately high rates of violence and homicide compared to other racial groups. Rooted in coloniality and sustained by Western institutions, this epidemic is recognized as the Missing and Murdered Indigenous Relatives (MMIR) crisis. In response, Indigenous women have mobilized the MMIR Movement to raise awareness and advocate for institutional change. Although scholarship on MMIR has expanded, limited research has explored the experiences of MMIR advocates. This study interrogates the institutional landscapes that shape MMIR advocacy and explores the resistance strategies advocates employ to address the crisis. Using reflexive thematic analysis, this study examines semi-structured …

Memory-Efficient Acceleration For Emerging Applications Via Hardware/Software Co-Design, Shilin Tian

Graduate Studies Theses and Dissertations 2026

Emerging artificial-intelligence and data-intensive scientific workloads increasingly face a memory wall: irregular access patterns and large intermediate data volumes make data movement, rather than arithmetic, the primary constraint on performance and energy efficiency. This dissertation develops a memory-centric hardware/software co-design methodology that jointly reshapes algorithms, architectures, and dataflows to retain frequently reused data on chip. The methodology is demonstrated through three accelerators and an RTL design tool. VITA replaces multi-head attention in vision-transformer-based 3D human mesh recovery with hardware-friendly average pooling and maps the resulting operators to a reconfigurable datapath, achieving 5.05-fold and 69.12-fold speedups over a state-of-the-art GPU and …

Human And Ai Support In Business Simulations: A Quasi-Experimental Mixed Methods Study Of Performance At Scale, Sara Willox

Graduate Studies Theses and Dissertations 2026

Large classes change what instruction looks like. In hybrid business courses with high enrollment, it becomes harder to respond to individual students, and performance can suffer as a result. This study looked at what happens when that gap is addressed in different ways during an eight-week business simulation at the University of Central Florida. Six course sections were divided into three study groups. One group worked without support, one received instructor guidance, and one used AI tools that included a course search system and generative responses. Student outcomes were based on weekly profit and loss recorded in Sim Companies. The …

Two Dogmas Of Free Speech Doctrine, David R. Dow

Oklahoma Law Review

No abstract provided.

The Best Of Both Worlds: How Artificial Intelligence Can Balance Precision And Flexibility In Article 9 Search Logic, Lindsay Martin Mayes

Oklahoma Law Review

No abstract provided.

Reward-Based Gamification: Evaluating Game Mechanics That Promote The Implementation Of Personal Device Security Measures, Leah Lynne Branstetter

Dartmouth College Master’s Theses

Many everyday computer users lack the cybersecurity knowledge and motivation necessary to secure their personal devices. To better understand these barriers, we conducted an initial study with nine participants who were asked to complete simple laptop security tasks, such as reviewing firewall settings. We found two primary challenges: participants were unfamiliar with basic security features, and many expressed low motivation to engage in security practices even after learning about them. To address the motivational barrier, we developed a beginner-friendly cybersecurity game designed to reward users for completing real device security tasks. We compared this reward-based game to a version of …

Lens: Llm-Enabled Narrative Synthesis For Mental Health By Aligning Multimodal Sensing With Language Models, Wenxuan Xu

Dartmouth College Master’s Theses

Multimodal health sensing offers rich behavioral signals for assessing mental health, yet translating these numerical time-series measurements into natural language remains challenging. Current LLMs cannot natively ingest long-duration sensor streams, and paired sensor–text datasets are scarce. To address these challenges, we introduce LENS, a framework that aligns multimodal sensing data with language models to generate clinically grounded mental-health narratives. LENS first constructs a large-scale dataset by transforming Ecological Momentary Assessment (EMA) responses related to depression and anxiety symptoms into natural-language descriptions, yielding over 100,000 sensor–text QA pairs from 258 participants. To enable native time-series integration, we train a patch-level encoder …