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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. …

Non-Destructive Hhxrf Archaeometry For Grouping Individuals Via Trace Element Analysis Of Dental Remains, Griffon G. Binkowski

Graduate Studies Theses and Dissertations 2026

Handheld X-ray fluorescence (HHXRF) spectrometry has been validated as an accurate, non-destructive method for analyzing archaeological osseous materials. This study utilizes HHXRF to address key bioarchaeological questions, including population differentiation, individuation, and the interpretation of bioaccumulated trace elements versus diagenetic impacts. Using dental enamel from the Maya site of Altun Ha, Belize (n=20) and several Roman-Christian sites in the Dakhleh Oasis in Egypt (n=6), the occlusal surface of molar crowns was assayed in air using a Bruker Tracer III- equipped with a 12 mil Al, 1 mil Ti, 6 mil Cu filter. Semi-quantitative trace element ratios (Sr/Ca, Fe/Ca, and Zn/Ca) …

Sensory And Emotional Impacts On Modern Consumer Experiences, Winter E. Bland

Graduate Studies Theses and Dissertations 2026

This dissertation comprises two essays examining how environmental and psychological stimuli shape consumer experience, attitudes, and cognition. The first essay investigates the joint influence of scent temperature (warm versus cool) and scent arousal (stimulating versus relaxing) on experiential attitudes and cognitive performance in digitally mediated consumption environments. Across multiple lab experiments with biometric validation, findings reveal that these two scent dimensions interact to shape downstream outcomes. Warm, low-arousal scents (e.g., vanilla) enhance consumers' experiential evaluations of digital interactions but do not improve task performance, whereas cool, high-arousal scents (e.g., peppermint) boost cognitive efficiency and accuracy but do not elevate experiential …

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 …

An Examination Of The Impact Of School Context And Socioeconomic Status On Agency And Creative Productivity In Gifted High School Students, Elizabeth Bronson

Graduate Studies Theses and Dissertations 2026

This explanatory sequential mixed methods study investigated gifted high school students’ perception of the agency afforded them within school settings, and the relationship between these perceptions and their creative productivity. A sample of 140 students was drawn from a population of 966 identified gifted high school students. These students were contacted via their parents and asked to complete the Agentic Engagement Scale (AES) questionnaire which provided gifted high school students’ perceptions of the agency afforded at school. No significant differences in perceived agency were found across demographic variables, including socioeconomic status and school type. Of the respondents, 10 students were …

A Systematic Review And Characterization Of Privacy Noncompliance In Real-World Applications, Alexander E. Charkiewicz

Graduate Studies Theses and Dissertations 2026

Software applications increasingly rely on user data to provide their functionality, but improper handling of such data can lead to serious privacy noncompliance with applicable regulations and policies. A prominent example is the Facebook–Cambridge Analytica scandal, in which a third-party application collected the personal data of approximately 87 million Facebook users without users' consent. Despite growing attention to privacy compliance, two key challenges hinder the systematic understanding and analysis of privacy noncompliance. First, unlike security vulnerabilities, which have been systematically categorized through taxonomies such as the Common Weakness Enumeration (CWE), privacy noncompliance lacks a technical taxonomy describing how it manifests …

Pioglitazone Uncouples Macrophage Inflammatory Signaling From Epithelial Oxidative Stress During Map Infection Mimicking Crohn’S Disease Treatment, Sabera Akter Bushra

Graduate Studies Theses and Dissertations 2026

Crohn’s disease (CD) is a chronic inflammatory bowel disease characterized by intestinal inflammation, epithelial barrier dysfunction, and abnormal immune signaling. CD pathophysiology is increasingly linked to Mycobacterium avium subspecies paratuberculosis (MAP) infection, which increases chronic macrophage activation and the production of inflammatory mediators that lead to epithelial damage. Among these mediators, CXCL10, TNF-α, and IL-6 contribute in inflammation, while NOX-1 and SERPINE-1 indicate epithelial oxidative stress and damage. Despite the role of macrophage-epithelial interaction in CD, selective pharmaceutical regulation of this axis remains unclear. Pioglitazone, an FDA-approved PPARγ agonist used for type 2 diabetes, is an appealing repurposing candidate, given …

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 …

An Empirical Comparison Of K-Nearest-Neighbors And Logistic Regression Classification Models, Jackson Cushing

Graduate Studies Theses and Dissertations 2026

This thesis presents an empirical comparison of two classification methods: Logistic Regression and K Nearest Neighbors (KNN). The primary objective of this research is to evaluate the strengths and limitations of each method when applied to real-world datasets. Several publicly available datasets on diabetes, breast cancer, heart attack risk, and cardiovascular disease, were analyzed. For each dataset, K Nearest Neighbors models were implemented in the same way logistic regression had already been applied. The results demonstrate that while logistic regression offers interpretable parameter estimates and performs well when the underlying predictor and outcome relationship is approximately linear, however KNN can …

Vaccine Hesitancy In Arabic Discourse: A Multi-Method Social Media Study, Nada Dimashkieh Chehab

Graduate Studies Theses and Dissertations 2026

Vaccine hesitancy — the state of uncertainty about vaccination — poses global public health challenges, undermining efforts to prevent infectious diseases. It is also a contextual phenomenon, shaped by social and political forces. While survey-based research on vaccine hesitancy is abundant both globally and in the Arab world, humanities-oriented approaches using discourse analysis remain limited especially in Arabic on social media: some have tracked trends on Twitter, but virtually none have done so on Facebook. This dissertation addresses these gaps through a multimethod design combining Textual and Trend Analyses and Critical Discourse Study. It examines vaccine-related trends and discourses among …

Non-Gaussian Phenomena In Light Scattering And Applications, Shubham Atul Dawda

Graduate Studies Theses and Dissertations 2026

Physical reality is rarely deterministic; which, when probed by electromagnetic fields that also fluctuate, leads to observables that are most efficiently modelled as statistical processes. At equilibrium, this is usually achieved by invoking the Gaussian statistics of underlying physical processes, however, in practice, one often encounters out-of-equilibrium conditions where Gaussian descriptions may not suffice. Such situations are plentiful in nature– from biology to astronomy. This dissertation addresses several non-Gaussian phenomena associated with light scattering, and includes specific models’ derivations, experimental techniques developments, and demonstrations of potential applications. The systematic presentation will consider circumstances that infringe upon specific assumptions of the …

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 …

Optically-Pumped Semiconductor Optical Amplifiers, Dhruvkumar Desai

Graduate Studies Theses and Dissertations 2026

Semiconductor optical amplifiers (SOAs) offer a low-cost, compact solution for power amplification needs in an optical communication system compared with the dominant erbium-doped fiber amplifiers (EDFAs). They can also provide a wide gain bandwidth. However, conventional electrically-pumped SOAs suffer from larger noise figures, low saturation power, and polarization dependence, in comparison with EDFAs. We propose an optically-pumped SOA (OP-SOA) that will maintain the benefits of conventional SOAs while closing the gaps in other amplifier performance metrics. The underlying reasons for optical pumping are twofold. First, optical pumping allows higher carrier injection and thus "population inversion." Second, optical pumping decouples carrier …

Independent And Interacting Effects Of Co-Presence And Social Media 'Likes' On Online Disinhibition, Margaret M. Doheny

Graduate Studies Theses and Dissertations 2026

Social media platforms have fundamentally transformed interpersonal communication by creating environments in which behaviors are publicly reinforced through visible social feedback systems such as “likes.” Although prior research has linked online environments with increased disinhibition and negative behavior, existing literature has primarily focused on anonymity and invisibility as the primary mechanisms underlying these effects. However, the mechanistic role of physical and psychological co-presence in driving online disinhibition has received little empirical investigation. The central aim of the present study was to determine whether reduced social presence and the selective reinforcement of negative content contribute to online disinhibition and anticipatory reward-seeking …

Detecting Error In Ai-Generated Text: The Effects Of Authorship And Word Presentation Speed, Gabriela Flores Cruz

Graduate Studies Theses and Dissertations 2026

The increased us of artificial intelligent (AI) chatbots powered by Generative Pre-trained Transformers has raised concerns about users’ ability to detect errors of AI-generated text. This dissertation examined how readers identify inconsistencies in AI-generated expository passages using the inconsistency detection paradigm from comprehension monitoring research. Across two experiments, it investigated whether perceived authorship and word presentation speed influenced inconsistency detection. Experiment 1 used a 3 (author: human, AI, no author) × 2 (inconsistency type: internal, external) between-subjects design. Perceived authorship did not significantly affect hit rates, sensitivity, or response bias. Exploratory analyses indicated that reading comprehension and working memory predicted …

Flow Field Characterization Of The Hyperreact Vitiated Hypersonic Wind Tunnel, Erik R. Fernandez

Graduate Studies Theses and Dissertations 2026

Reliable interpretation of hypersonic ground-test data requires knowledge of the thermochemical state delivered to the test section, especially in combustion-heated facilities where the gas is chemically altered before nozzle expansion. This thesis investigates the HyperReact vitiated hypersonic wind tunnel using the effective specific-heat ratio, γeff, as an experimentally inferred indicator of the coupled chemical and gas-dynamic behavior of hydrogen-air vitiated flow. HyperReact produces high stagnation temperatures through hydrogen-air combustion before expanding the mixture through interchangeable converging-diverging nozzles. During this expansion, temperature-dependent specific heats, molecular-weight changes, finite-rate chemistry, and internal energy relaxation can modify the relationship between Mach number, pressure ratio, …

Investigating The Impact Of School Leaders’ Leadership Style And Teachers’ Intrinsic Motivation For Improved Science Instruction In Elementary Schools, Leila M. Greene

Graduate Studies Theses and Dissertations 2026

A report by the National Academies of Sciences, Engineering, and Medicine, determined that 69% of U.S. elementary teachers are not prepared to teach science, especially in the areas of earth/space and physical sciences. As a result, some elementary teachers avoid teaching science. School administrators play a key role in providing a supportive environment to inspire and motivate elementary science teachers. For this reason, the study utilized the Self-Determination Theory (SDT), to examine three types of school leadership styles (Transformational, Transactional, and Laissez-Faire) and how they impact the intrinsic motivation for elementary science teachers in three areas including autonomy, competency, and …

Deciphering Ultrafast Photoinduced And Photocatalytic Reaction Dynamics On Oxide Surfaces: Direct Detection Of Radical Intermediates, Fragment Trapping, And Carbon–Carbon, Carbon–Oxygen, And Carbon–Hydrogen Bond Formation Pathways, Aakash Gupta

Graduate Studies Theses and Dissertations 2026

Understanding photoinduced reactions at solid interfaces is essential for advancing heterogeneous photocatalysis, surface photochemistry, and energy conversion technologies. This dissertation investigates the ultrafast dynamics of reactive intermediates, fragment trapping, and radical-mediated bond formation on oxide surfaces using time-of-flight mass spectrometry in conjunction with femtosecond pump-probe spectroscopy. Various experimental findings are validated through collaborations via density functional theory (DFT). By combining temporal, mass, and energy-resolved measurements, this work provides molecular-level insight into the elementary processes governing light-driven surface reactions. The photodissociation dynamics of CH₃I adsorbed on TiO₂(110), TiO₂(100), and amorphous silicon oxide surfaces are examined …

Minimizing Performance Overheads For Crash-Consistency In Disaggregated Persistent Memory, Khan Shaikhul Hadi

Graduate Studies Theses and Dissertations 2026

Compute express link (CXL) enables persistent memory disaggregation with memory pooling and hardware managed multi-host memory sharing capability, resulting in better resource utilization, increased scalability. Persistency-aware applications need to manage crash consistency across the system which results in significant performance overhead. This dissertation systematically investigates performance overhead to achieve crash consistency in disaggregated persistent memory and proposes solutions to enable persistency-aware application scaling for distributed system. First, we study persistent parallel programming to scale computation capability beyond single processor and determine the underlying hardware limitation to adopt lock-free data structure. We propose hardware support to design durable atomic instruction (DAI) …

Strategic Signaling Or Structural Friction?: How Ai Disclosure Moderates Resource-Performance Dynamics In Hotels And Restaurants, Jaewan Heo

Graduate Studies Theses and Dissertations 2026

Artificial intelligence (AI) has become an increasingly important strategic issue in the hospitality industry. While prior research has primarily examined AI as an operational technology that improves efficiency and service delivery, less attention has been paid to how AI-related disclosures influence investor evaluations of firm resources. This dissertation investigates whether AI-related disclosures moderate the relationship between organizational resources and financial performance in publicly traded hospitality firms.

Drawing on signaling theory and the resource-based view, this study conceptualizes AI disclosures as strategic signals that shape investor perceptions of firm capabilities and future value creation. Firm-level financial data were obtained from Compustat …

A Case Study Examining Organizational Influences On Student Teacher Placement In K-12 Classrooms, Rachel L. Ickes

Graduate Studies Theses and Dissertations 2026

Student teaching is a prominent and required learning experience in most teacher education programs. The learning that takes place in student teaching blends pedagogy with practice. However, not all student teaching placements provide positive learning experiences for student teachers. This descriptive case study examines the organizational factors that affect the process of student teacher placement at K-12 classroom sites by one teacher education program. For this case study, one teacher education program in the southeastern United States was selected as the case site, and the case for this study is the process of student teacher placement. Semi-structured interviews, observation, and …

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 …

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 …

The Odyssey Of Emotion Regulation In Extremis: How Challenges Lead To Team States Through Regulation And Psychological Safety In Ice, Andres Kaosaar

Graduate Studies Theses and Dissertations 2026

Isolated, confined, and extreme (ICE) teams experience challenges that require continuous emotional adaptation. Although emotion regulation (ER) has been recognized as critical for functioning in these contexts, little is known about how specific challenges shape regulatory responses, how team climate influences those responses, and how individual regulation accumulates into team-level outcomes. This dissertation develops and tests a multilevel framework linking challenge exposure, perceived psychological safety, individual ER, team emotions, and team viability in space analog environments. Data were collected from 36 crews (N = 184) participating in two-week missions at two space analog stations, yielding 2,577 daily observations and …

The Impact Of Criminal Justice System Contact On Adolescents In The U.S.: Prescription Drug Misuse, Marijuana Use, Health Outcomes, And Demographic Characteristics, Fadime Gokce Karaaslan

Graduate Studies Theses and Dissertations 2026

Criminal justice system (CJS) contact remains a pervasive feature of social life in the United States, with both direct and indirect consequences for adolescents and their families. Although previous research has explored the consequences of direct CJS contact, less is known about how indirect or vicarious contact affects adolescents’ well-being and substance use. Drawing on data from the Future of Families and Child Wellbeing Study (FFCWS), this study investigates the association between parental incarceration and vicarious police stops, defined as police stops involving parents, siblings, friends, neighbors, or other social ties, and adolescent well-being. Findings indicate that CJS contact is …

Two Studies Exploring Signal-Environment Fit In Ai-Assisted Managerial Decision-Making Under Uncertainty, Oleksandr Kondrachuk

Graduate Studies Theses and Dissertations 2026

This dissertation examines how the fit between the characteristics of artificial intelligence systems and the uncertainty environment shapes managerial reliance on AI advice. Organizations increasingly deploy different AI systems, such as predictive and generative, to support management accounting decisions. However, the accounting literature has mainly treated AI as a single undifferentiated entity. This dissertation addresses this gap through two related studies. In the first study, drawing on signaling theory and ecological rationality, I develop a signal-environment fit framework proposing that the reliance on a certain AI system depends on the match between system characteristics (input, process, output) and uncertainty characteristics. …

Advances In Active And Passive Integrated Photonic Devices On Thin-Film Lithium Niobate, Pooja S. Kulkarni

Graduate Studies Theses and Dissertations 2026

Thin-film lithium niobate (TFLN) has emerged as a powerful platform for integrated photonics, combining the exceptional electro-optic, nonlinear, and optical properties of bulk lithium niobate with the scalability and compactness of planar nanophotonic technologies. Building on these principles, advanced device architectures such as adiabatic dichroic filters have demonstrated exceptional spectral performance spanning over two octaves of bandwidth on the TFLN platform. Beyond reciprocal devices, it also offers promising pathways toward integrated nonreciprocal components. By leveraging broadband filtering structures and advanced nonlinear photonic design strategies, compact and monolithic optical isolators can be envisioned without relying on traditional magneto-optic materials. In the …

Establishment Of An In Vitro Dss-Induced Epithelial Injury Model To Investigate Il-6 Signaling And Microbial Metabolite Mediated Barrier Recovery, Srijal Kunwar

Graduate Studies Theses and Dissertations 2026

Dextran sodium sulphate (DSS) is widely used in vivo to induce epithelial injury; however, the molecular effects of DSS on intestinal epithelial cells, that investigate inflammatory and metabolic repair mechanisms remain unclear. Here, we establish an in vitro DSS-induced epithelial damage model using differentiated Caco-2 cell monolayer. Exposure to 2.5%(w/v) DSS for 24 hours resulted in significant upregulation of pore forming protein Claudin-2(2.677-fold) and oxidative marker, NOX-1(1.866-fold), accompanied by increased ROS production confirmed via DHE staining. Increased epithelial permeability was observed by TEER analysis, without significant cytotoxicity. Surprisingly, ELISA analysis revealed significant downregulation of IL-6 (p-value …

Modeling And Mitigating Atmospheric Degradation In Computer Vision With Application In Renewable Energy Prediction, Sumit Laha

Graduate Studies Theses and Dissertations 2026

Weather-induced variability poses significant challenges to the reliability and performance of modern computational systems, particularly those relying on visual perception and environmental prediction. This dissertation focuses on enhancing computer vision and machine learning based predictive models that operate under varying atmospheric conditions. Two representative weather-impacted applications are investigated: image dehazing and solar photovoltaic (PV) power output forecasting. Image dehazing focuses on the restoration of clear, unobstructed visuals from hazy or foggy images, a task that is vital for various applications. On the other hand, photovoltaic (PV) power forecasting aims to predict future solar energy generation based on historical sky images …