Digital Commons Network^™

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 …

Performing The Digital Identity: A Media Discourse Analysis Of Online Identity Construction, Dalya Qasem

Graduate Studies Theses and Dissertations 2026

This dissertation investigates how news media construct narratives about TikTok and its role in shaping digital identity. While existing scholarship has examined issues such as privacy, marketing, and entertainment, less attention has been given to how identity is represented, negotiated, and understood within public discourse. Using Critical Discourse Analysis (CDA) combined with computational text analysis through Voyant Tools, this study analyzes a corpus of 111 news articles published between 2020 and 2025 that explicitly reference TikTok and identity. The analysis identifies prominent keywords, topics, and rhetorical patterns across media texts. Furthermore, the research demonstrates a critical analysis of popular understandings …

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 …

Integrated Design And Trade Study Of A Sub-Ambient Ammonia Fuel Storage And Delivery System For Narrow-Body Commercial Aircraft, Ethan Taylor

Graduate Studies Theses and Dissertations 2026

This study develops an integrated design framework for a sub-ambient anhydrous-ammonia fuel storage and delivery system for narrow-body commercial aircraft, using the Boeing 737 MAX 8 as the baseline platform. Ammonia was selected because it contains no carbon in its molecular structure, benefits from an established global production and distribution infrastructure, and offers more practical storage conditions than several alternative carbon-free energy carriers. However, its relatively low energy density, toxicity, material-compatibility requirements, and combustion hazards require substantial modifications to power conventional commercial aircraft fuel storage and delivery systems.

The study proposes an integrated design and initial analysis of a sub-ambient …

“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 …

Specters, Fred Lambert

Graduate Studies Theses and Dissertations 2026

Specters is a collection of interconnected short fiction that explores the lives of various characters affected by the Iraq War. Touching upon themes of mortality, dehumanization, guilt, and the trauma inflicted by senseless violence, the stories in this collection aim to blur the line between the concrete and the phantasmagoric. The titular story follows a young Marine whose grip on reality is called into question during the Second Battle of Fallujah. In “Demons,” a recruit undergoing the chaotic and brutal grind of Parris Island begins to wonder if his drill instructors are possessed. “Kill Bodies” chronicles the repeated killing of …

Reliability Of Staged Maximal Aerobic Capacity Protocol Using A Combined Upper- And Lower-Body Air-Braked Ergometer, Jack J. Livingston

Graduate Studies Theses and Dissertations 2026

Maximal oxygen uptake (VO₂max) is widely recognized as the preeminent measure of aerobic capacity and is typically assessed using graded exercise testing (GXT). This study examined the test–retest reliability of VO₂peak and associated physiological responses during a staged GXT performed on a combined upper- and lower-body air-braked ergometer. Fifteen recreationally active adults (9 males, 6 females; age: 26.9 ± 7.2 years; body mass: 75.1 ± 11.0 kg) completed one familiarization session and two trials separated by ≥72 hours. Participants performed a staged GXT (40 RPM start, +3 RPM every 3 min to exhaustion) on a combined upper- and lower-body air-braked …

The Development Of An Experimental Chemical Reactor Network Facility For Power Generation And Aviation Gas Turbines, Kesly Lubin

Graduate Studies Theses and Dissertations 2026

Gas turbines are the backbone of power generation globally; however, they are also one of the largest contributors to greenhouse gases and harmful emissions. Advanced combustion strategies, when applied to energy generation, can offer increased optimization of the combustion process with more complete and efficient combustion. With global efforts to reduce NOx formation in energy generation, combustion staging strategies like Rich Quench Lean (RQL), Lean-Premixed (LPM), and Exhaust Gas Recirculation (EGR) have gained more attention in research. The major challenge that exists in the research sector is the ability to evaluate and further develop these techniques at a fundamental level. …

Computational Regolith Mechanics And Instrumentation Development For Lunar Exploration And Resource Utilization, Jared M. Long-Fox

Graduate Studies Theses and Dissertations 2026

Sustained exploration of the Moon requires quantitative understanding of lunar regolith properties to support scientific investigation, in situ resource utilization, excavation, and infrastructure development. This dissertation examines the mechanical interaction between robotic excavation systems and lunar regolith, emphasizing how regolith behavior both enables and constrains exploration-focused and exploration-enabled science. Computational excavation models were compared to laboratory data to evaluate prediction of excavation forces and to develop metrics of excavation efficiency. Laboratory experiments using high-fidelity lunar regolith simulants were conducted to characterize pressure-sinkage behavior, shear strength, and angle of repose across a range of material states. Common analytical excavation and terramechanics …

Angular And Geometric Dependence Of Single-Event Effects In Gallium Nitride Hemts, Patrick Maloney

Graduate Studies Theses and Dissertations 2026

Gallium nitride (GaN) high electron mobility transistors (HEMTs) have become popular in commercial and space applications due to their desirable material properties compared to silicon. However, their susceptibility to radiation-induced single-event effects (SEE) remains a critical reliability concern. This work investigates on permanent SEE in GaN-based power devices, including single-event leakage current (SELC) and single-event burnout (SEB). The dependence of SEE susceptibility on electric field, ion angle of incidence, current rating, and metallization layers is investigated and conclusions are presented. Heavy-ion irradiation experiments demonstrate that the worst-case condition occurs at near-normal incidence (0°–15°), where charge deposition most effectively overlaps high-field …

Exploring The Temporal Dynamics Of Gaming-The-System And Self-Regulated Learning Behaviors Within A Game-Based Learning Environment, Cameron E. Marano

Graduate Studies Theses and Dissertations 2026

Consistently monitoring and regulating cognitive and metacognitive skills during learning is difficult. As a result, game-based learning environments (GBLEs) have been designed to provide richer learning experiences. They foster self-regulated learning (SRL) skills and offer a way to study learners' interactions within complex environments. Although SRL in GBLEs has been widely studied, large gaps remain. For example, it is unclear how improper or maladaptive regulation in GBLEs signals gaming-the-system, in which learners manipulate features to avoid authentic learning. This phenomenon is widely studied in intelligent tutoring systems (ITSs). Limited research has examined how and when both gaming-the-system and SRL behaviors …

Characterization And Experimental Study Of Ammonia-Hydrogen Flames Inside A Toroidal Jet-Stirred Reactor At Atmospheric Conditions, Oli Marquez Valenzuela

Graduate Studies Theses and Dissertations 2026

Due to rising concerns about global surface temperatures and carbon emissions, there has been an increased interest in studying alternative fuels. Ammonia and hydrogen are fuels with the potential to replace general biofuels, hydrocarbons, and sustainable aviation fuels, as they do not contain any carbon, eliminating carbon emissions. However, they are both difficult to work with. Hydrogen has great combustion characteristics such as low ignition energy, high flame speed and lower heating value. However, it is volatile and difficult to store, requiring it to be compressed to high pressure or cooled to incredibly low temperatures. Ammonia can be used as …

Structural Design And Development Of Deployable Propeller Blade, Annan Mashin

Graduate Studies Theses and Dissertations 2026

Aerospace systems frequently face competing requirements between compact packaging and high aerodynamic performance. Large propellers improve efficiency and thrust generation, yet launch constraints and confined storage volumes limit their maximum span. Conventional deployable solutions rely on hinges, locking mechanisms, and external actuation, increasing mechanical complexity and reducing reliability. This dissertation investigates an alternative approach in which elastic instabilities in thin composite shells are deliberately harnessed to enable rapid, mechanism- free deployment of aerodynamic structures. This work harnesses propagating instability in open- section thin-walled airfoil geometries to enable reversible transformation between compact stowed and stiff deployed configurations. By tailoring structural architecture, …

Temporal Patterns Of Storm Surges: Event-Identification, Clustering, And Count Modeling, Ariadna Martin Oliva

Graduate Studies Theses and Dissertations 2026

Coastal regions face compounding risks when extreme events strike in rapid succession, yet most statistical frameworks treat such events as independent, a simplification that can critically underestimate hazard. This thesis addresses that gap through three interconnected contributions focused on the temporal clustering of storm surges at the global scale. A new automated method is developed to extract independent storm surge events from continuous tide gauge records. By leveraging event correlations and a soft-margin approach that accounts for local variability, the method identifies characteristic event durations across 1,485 global tide gauge stations, revealing the influence of both local site conditions and …

The Revelations, Lily Mckenna

Graduate Studies Theses and Dissertations 2026

The Revelations is a self-actualization in the form of a poetry collection. The speaker’s realization that reality is relative arrives through a Title IX case against an abusive boyfriend and former bandmate. Poems such as “Complainant / Respondent” use rigid legal structures to investigate the fluidity of truth and perception and how they can be manipulated. With her band on hiatus and the case propelling her into a new world, the speaker starts running DIY shows alongside a cast of characters with a shared love of music. She interrogates their realities in the character studies “On The Relative Reality Of…,” …

Deceptive Design And Disability: How Dark Patterns Affect Users With Visual Impairments, Konstantin Metz

Graduate Studies Theses and Dissertations 2026

Dark patterns are deceptive interface designs that steer users toward unintended actions, often at financial or privacy cost. This thesis examines how those that are vision impaired are at greater risk of these dark patterns given their visual acuity deficit. We conducted semi structured interviews with nine participants across common contexts including e-commerce checkout, subscription and cancellation flows, software download pages, and mobile permission prompts. The data show recurring exposure to dark patterns such as hidden or de-emphasized fees, pre-selected add-ons, deceptive advertising and fake download buttons along with unequal consent paths, repeated permission nagging, and cancellation friction. Participants reported …

Cfd Investigation Of Heat Transfer Enhancement In Pipes Using Gyroid Tpms Structures For Industrial Steam Generation, Alejandro Moreno Escribano

Graduate Studies Theses and Dissertations 2026

Industrial heating processes account for nearly 28\% of global CO2 emissions, and fossil fueled boilers predominate in high temperature applications. Industrial electrification can be an effective solution when combined with renewable energy sources. Increasing steam generation efficiency and at the same time maintaining system compactness is a significant challenge in industrial thermal processes. Traditional smooth pipes offer limited heat transfer surface area, which constrains boiling heat transfer performance and reduces the overall efficiency of steam generation systems. Advanced internal geometries have the potential to significantly enhance heat transfer by increasing surface area and promoting fluid mixing. This work presents a …

Ignition Delay Time Measurements Of Natural Gas/Ammonia Mixtures At Gas Turbine Operating Conditions, Zachary A. Morris

Graduate Studies Theses and Dissertations 2026

Natural Gas/Ammonia (NG/NH₃) fuel blends are a promising route to reduce CO₂ emissions from gas turbines while leveraging existing NG infrastructure, but their autoignition behavior at elevated pressures is not yet well constrained. This work reports high-pressure shock tube ignition delay time (IDT) measurements for NG/NH₃/Air mixtures at gas turbine-relevant conditions. Experiments were performed at pressures of 5, 10, and 25 bar, temperatures from 1500 to 2100 K, with equivalence ratios of Φ = 1.0, 1.2, and 1.4, and argon-diluted fuel compositions spanning pure NH₃ to NG-rich blends. Experiments were carried out in two …

Revolution In The Age Of Social Media: A Mathematical Model For Information, Dissent, And Stability, Killian Muollo

Graduate Studies Theses and Dissertations 2026

Revolutions, defined by Skocpol as rapid transformations in class, state, and/or social structures, are important world events that can cause civil wars, spark international trends, and result in transitions toward democratic and autocratic regimes alike. They are characterized largely by the mechanism of mass mobilization, which is increasingly facilitated by online networks and digital communication. In this dissertation, we investigate such means and outcomes of revolutions as dynamical systems. We construct three models describing separate but complementary aspects of revolution, beginning at the smallest unit of analysis and then moving outward in scope. First, we construct a graph-based model to …

Study Of Compressibility Of Flames In Scramjet Combustors, Anirudh Ranganathan

Graduate Studies Theses and Dissertations 2026

Viable forms of propulsion for practical hypersonic flight are of great interest in modern times, of which supersonic combustion ramjets(scramjets) are a very advantageous option. Compared to ramjets, which are severely limited by increasing total pressure loss and dissociation effects, scramjets offer a much more efficient form of propulsion in the Mach 6 – 8 regime. Despite this, a common and unmitigated issue facing scramjet technology is scramjet unstart.

Prior investigations researching scramjet unstart have elucidated global heat release considerations in relation to total fueling or combustion modes as a result of global heat release . Minimal work has been …

Multibody Acausal Framework For Structural Dynamics Of Offshore Support Structures With Hydroelasticity And Soil-Structure Interaction, Saad Rahman

Graduate Studies Theses and Dissertations 2026

Offshore energy systems present significant challenges in support structure design due to their scale and the strong coupling between aerodynamic, hydrodynamic, and structural subsystems. These interactions make traditional sequential modeling approaches inefficient for design exploration. Acausal modeling frameworks address this limitation by enabling direct integration of coupled subsystems without reformulating governing equations, improving computational efficiency while preserving physical fidelity. This supports rapid exploration of large design spaces, accelerates iteration cycles, and shortens the path from concept to deployment.

This thesis develops and validates an acausal multibody elastodynamics model for offshore support structures. The framework includes structural flexibility to capture member-level …

Design And Characterization Of A Jet Nozzle Using Particle Image Velocimetry, Valerie K. Rodriguez

Graduate Studies Theses and Dissertations 2026

This paper presents the design and experimental characterization of the jet exit velocity from a supersonic nozzle injecting into a low-pressure vacuum chamber using Particle Image Velocimetry (PIV). The PIV method is employed to overcome limitations encountered in prior experiments characterizing a jet-in-crossflow, such as qualitative shock visualization and insufficient data on jet exit properties. The previous set of experiments used Classical Schlieren to visualize the flow as well as emission measurement with IR detectors. For the fuel injection cases, particular emphasis is placed on preventing condensation within the injection line and at the nozzle exit due to under expanded …