Digital Commons Network^™

Novel Redox Oxygen Active Materials For Solid Oxide Cells And Thermochemical Hydrogen Production, Jiaxin Lu

Theses and Dissertations

This dissertation investigates novel materials designed to significantly enhance the performance and durability of oxygen electrodes for solid oxide cells and redox active materials for thermochemical hydrogen production. The first part of this work evaluates Ta-doped BaCoO₃₋δ (BCT) and its structural analog SrCoO₃₋δ (SCT), focusing on their catalytic performance in oxygen reduction and evolution reactions. Among BCT compositions (x = 0.1, 0.3, 0.5), the BCT10 (x = 0.1) composition exhibited the highest oxygen vacancy concentration, electronic conductivity, and lowest polarization resistance. However, SCT10 surpassed BCT10 in these critical performance parameters and also demonstrated greater stability over extended operational periods. Notably, …

Knowledge And Ontology Enhanced Approach To Natural Language Understanding (Koe-Nlu) In Computational Social Media And Healthcare, Naga Usha Gayathri Lokala

Theses and Dissertations

Natural Language Understanding (NLU) faces both opportunities and challenges as the amount of social media and healthcare data grows. This is particularly evident in context-sensitive applications such as evaluating cognitive health, identifying mental health symptoms, and monitoring drug abuse. Even though traditional NLU models work well for processing language in a wide range of areas, they often lack the ability to understand language in a specific domain, reason in context, and incorporate structured external knowledge. This dissertation talks about the Knowledge and Ontology Enhanced Approach to Natural Language Understanding (KOE-NLU), a new framework that is meant to make NLU systems …

“Digital Shame Shift”: From Telling The Pain To Recording The Truth — Black Maternal Health And Digital Counter-Narrative Storytelling On Tiktok, Odera Covenant Ezenna

Theses and Dissertations

This dissertation explores how digital storytelling on TikTok is used to challenge medical racism, with a particular focus on Black maternal health. Guided by Critical Race Theory (CRT) and Critical Technocultural Discourse Analysis (CTDA), the study examines how TikTok users—ranging from Black mothers to healthcare professionals—create and circulate counter-narratives through two prominent campaigns: #BlackMaternalHealthWeek and #BlackMamasMatter. These digital stories serve as acts of resistance, disrupting dominant medical discourse and amplifying the lived experiences of Black birthing individuals. The research analyzes over 2900 TikTok videos posted between 2021 and 2024, identifying key themes, storytelling strategies, and rhetorical shifts over time. The …

Optimal Data Splitting Methods, Sujay Mudalgi

Theses and Dissertations

In predictive modeling, effective data splitting is crucial for creating statistically representative training and validation sets. The state-of-the-art data splitting methods are based on minimizing the energy distance between the split subsets. However, there are a number of limitations in the existing methods, which this dissertation aims to address. First, the existing methods were computationally inefficient. Thus, Chapter 2 proposes a method to scale up these approaches for big data. Here, we introduce scalable Twinning (s-Twinning), which significantly improves the execution speed of data splitting without sacrificing accuracy. Second, the existing methods did not consider the predictive relationship in the …

Characterization Of Nanoplastic-Induced Exacerbation Of Asthmatic Pathophysiology In A Murine In Vivo Model, Keith Li

Theses and Dissertations

As global plastic production increases, so does the environmental and biological presence of nanoplastics (NPs), raising growing concerns about their potential impact on human health. These particles have been detected in various organs, including the lungs, yet their role in respiratory inflammation remains largely unexplored. Emerging evidence suggests that NP exposure may influence immune responses in the lungs, particularly in individuals with preexisting conditions such as asthma. However, the specific ways in which these particles interact with allergen driven inflammation are still unclear.

In this study, a murine model of allergic airway inflammation was used to investigate how surface modified …

Intervertebral Lateral Bending Moment Differences In The Lumbar Spine Of Baseball Pitchers Across Throwing Velocities, Justin Humenay

Theses and Dissertations

Introduction Baseball pitching imposes substantial mechanical demands on the lumbar spine, a crucial link in the kinetic chain responsible for transferring energy from the lower body to the upper extremity. While increased pitch velocity is associated with greater trunk forces the specific intervertebral loading patterns during high-velocity pitching remain unclear. This study investigates differences in lateral bending moments across lumbar spinal segments between collegiate pitchers throwing at high versus low velocities.

Methods Twenty right-handed collegiate pitchers were divided into two groups: high-velocity (n = 10, 90.3 ± 1.6 mph) and low-velocity (n = 10, 81.6 ± 1.1 mph). Motion capture …

Automated Treatment Planning Framework For Cervical Cancer In Brachytherapy, Suman Gautam

Theses and Dissertations

Brachytherapy (BT) is a critical treatment modality for cervical cancer that delivers ionizing radiation directly to the tumor using intracavitary (IC) and/or interstitial (IS) applicators. In high dose-rate (HDR) BT, a remote afterloader guides the radioactive source to specific dwell positions for defined durations, known as dwell times, allowing for a conformal dose to the tumor while minimizing exposure to surrounding organs at risk (OAR). However, due to the inherent nature of ionizing radiation, some dose to OARs is unavoidable, creating a fundamentally conflicting objective in treatment planning: maximizing tumor coverage while minimizing OAR dose. This characterizes the problem as …

Bugs In The Flux: Links Between Arthropod Diversity And Spatial Variation Of Soil Respiration In A Temperate Forest, Erin-Darby H. Mcclain

Theses and Dissertations

Soil respiration (Rs) is the largest terrestrial flux of carbon (C) to the atmosphere, with heterotrophic contributions to Rs varying spatially and temporally. While microbes are the primary and most thoroughly studied source of soil heterotrophic respiration (Rh), contributions from higher trophic organisms, including arthropods, are rarely quantified and poorly understood. Arthropod abundance and diversity correspond with variation in soil microclimate, which is influenced by site factors including canopy structure, site productivity, and disturbance. However, the extent to which these site factors influence arthropod abundance and diversity, and consequently, spatial variation in Rs is not known. The objective of our …

Identification Of Mechanisms Associated With Electronic Nicotine Delivery System Use For Weight Control In Young Adults, Gabrielle Maldonado

Theses and Dissertations

Electronic nicotine delivery system (ENDS) use continues to rise among young adults in the United States, raising public health concerns as the harmful effects of ENDS continue to rise while tailored cessation programs lag. Weight control motives may drive ENDS initiation and frequent use, particularly among sexual and gender minority (SGM) populations, who report higher ENDS use, body dissatisfaction, and disordered eating behaviors than those who identify as heterosexual and cisgender. Understanding these behaviors, their mechanisms, and at-risk populations is critical for improving public health. Seven hundred and eight young adults (ages 18–30; M = 26, SD = 3.3) reporting …

Advanced Air Preheater Sealing Systems For Enhanced Efficiency And Reliability In Thermal Power Plants, Pavan Kumar Ravulaparthy

Theses and Dissertations

Global electricity generation still relies heavily on thermal power plants, which consume vast amounts of fuel and emit significant amounts of carbon dioxide. A major but often overlooked source of inefficiency in these plants lies within the rotary regenerative air preheater (RAPH), a critical heat-exchange component where air leakage can exceed 20% in aging units. This leakage increases fuel consumption, parasitic fan power, and CO₂ emissions, while degrading boiler reliability.

This research introduces advanced adaptive sealing systems designed to mitigate these losses by dynamically compensating for rotor eccentricity, thermal distortion, and wear under harsh operating conditions. Brush seals, composed of …

Scopolamine-Induced Modulation Of Serotonin And Dopamine Transporters Activity: Behavioral And Molecular Insights Into Rapid Antidepressant Action, Deepak Karunakaran

Theses and Dissertations

Major depressive disorder (MDD) affects over 350 million individuals worldwide and is characterized by profound dysregulation of serotonin (5-HT) and dopamine (DA) systems that govern mood, reward processing, and motivation. The serotonin transporter (SERT) and dopamine transporter (DAT), both dynamically regulated through phosphorylation, serve as critical determinants of synaptic monoamine signaling. Despite decades of therapeutic development, current antidepressants require 4-6 weeks to achieve efficacy, and approximately one-third to half of patients develop treatment-resistant depression. The emergence of rapid-acting antidepressants like ketamine represents a paradigmatic shift, demonstrating symptom relief within hours; however, ketamine's therapeutic potential remains constrained by abuse liability, dissociative …

We Are Worthy Of Investment: Exploring Forms Of Cultural Capital Among Black American Families, Joyice Robinson Myers

Theses and Dissertations

This three-paper dissertation investigates how the cultural wealth of Black American families functions as a foundation for educational, developmental, and economic outcomes, especially for Black males, across childhood, adolescence, and the transition into adulthood. Grounded in frameworks of the Revised Cultural Wealth Model, African American Male Theory, and the Racial Stratification Model, the research repositions Black families as producers of capital rather than subjects of deficit. In Paper Paper 1, I synthesized scholarship on family structure, educational attainment, and economic standing, framing racial "achievement gaps” as long-standing education debts owed to Black males. In Paper 2, I used longitudinal data …

Therapy-Induced Senescence In Cancer: Developing Senolytic-Based Combination Strategies To Delay Re-Emergence Of Triple-Negative Breast Cancer, Eesha Chakraborty

Theses and Dissertations

Therapy-induce senescence (TIS) represents a major biological outcome of many anticancer treatments and is increasingly recognized as a strategic vulnerability in triple negative breast cancer, which is a highly aggressive subtype with limited therapeutic options and frequent relapse. Here, we probed TIS as a primary cellular response that may ultimately compromise long-term outcomes using standard chemotherapeutic agents in TNBC as well as the antibody-drug conjugate sacituzumab govitecan (SG). Both chemotherapy and SG reliably induced pronounced senescence across TNBC models, yielding durable growth arrest, however, also generating a persistent reservoir of viable tumor cells capable of eventual proliferative recovery, a hallmark …

Unraveling The Reactivity Of Nitrate Ester Explosives: Insights From Femtosecond Time-Resolved Mass Spectrometry And Computational Chemistry, Erica Britt

Theses and Dissertations

This dissertation uncovers the ultrafast molecular mechanisms underlying the decomposition of nitrate ester explosives—nitroglycerin (NG), ethylene glycol dinitrate (EGDN), and amyl nitrate—through the integration of femtosecond time-resolved mass spectrometry and advanced computational chemistry. Although these compounds play fundamental roles in both military and civilian contexts, the precise molecular dynamics governing their pronounced reactivity and impact sensitivity have remained inadequately characterized. Our research establishes that low O–NO2 bond dissociation energies are the primary driver of ultrafast fragmentation and high reactivity in all three esters. The distinctive molecular architectures of these esters dictate their explosive properties: NG’s tri-nitrate configuration leads to exceptional …

Laser Ablation-Induced Corrosion Resistance For Molten Salt Equipment Materials Evaluated Utilizing Electrochemical And Spectroscopic Analysis, Peggy Milota

Theses and Dissertations

Advanced reactors and used nuclear fuel separation (i.e. pyroprocessing technology) utilize high temperature salt as a thermal storage medium as well as an ionic solution for electrochemical processes. The use of these aggressive molten chloride and fluoride mediums requires specific materials or additional system alterations to extend the lifetime and structural integrity of equipment due to corrosion. Some materials, in the presence of inherently impure salt, will corrode and form oxide films in a specific formation that decreases corrosion rate by electrochemically and physically preventing elemental movement to the material surface. This is referred to as a passivation layer. However, …

Relationship Extraction Using Retrieval Augmented Generation For Biomedical Dataset, Jannat Jannat

Theses and Dissertations

With the increasing number of structured and unstructured data, obtaining reliable information effectively has become crucial. In the biomedical domain, extracting information from the scientific papers is crucial in order to stay up-to-date with accurate information, given the increased pace by which new research studies are published. This work focuses on identifying relationships between entities that are extracted from the abstracts and titles of biomedical research papers. In this work, we developed a Retrieval Augmented Generation (RAG) based system to automatically identify relations between biomedical entities. We evaluate multiple open source Large Language Models (LLMs) and the number of examples …

Functional Analysis Of Ligand Binding Domain 2 Of Outer Surface Protein C Of Borreliella Burgdorferi, Gavin Z. Chambers

Theses and Dissertations

Lyme disease, caused by the spirochete Borreliella burgdorferi, is the most common vector-borne infection in North America. A critical determinant of early mammalian infection is outer surface protein C (OspC), a highly variable lipoprotein that is indispensable for spirochete survival but whose precise function remains unresolved. OspC has been proposed to mediate diverse roles, including complement evasion, adhesion, tissue dissemination, and antiphagocytic activity, supporting the view that it is a multifunctional virulence factor. Structural studies have identified two putative ligand-binding domains (LBD1 and LBD2), with LBD2 forming a solvent-exposed crown at the membrane-distal end of the OspC dimer.

To …

Implementation Of Quantized Artificial Neural Networks With Spintronic Stochastic Computing, Saadi Sabyasachi Mr.

Theses and Dissertations

Artificial intelligence or machine learning is going through a rapid expansion. It also incurs significant costs for power and device footprints. Various approaches are being explored to design energy and hardware efficient machine learning models. Stochastic computing has been proposed for efficient machine learning implementation. It requires a source of random number generation which poses some practical challenges. So spintronic solutions such as magnetic tunnel junction has been used for random number generation. Again, spintronic random number generation to implement high precision circuit is prone to device-to-device variations. Hence we designed quantized artificial neural network with spintronic stochastic computing which …

Facile Synthesis Of Gold, Copper, And Silicon Nanostructures By Laser Ablation In Liquid, Nicholas Simpson

Theses and Dissertations

Metal nanoparticle (NP) synthesis is a continually evolving area of research, owing to the widespread application of NPs in fields such as catalysis, drug delivery, and biosensing. Compared to bulk metal material, NPs contain a larger proportion of surface atoms and exhibit unique optical properties, thus making them ideal for applications where maximizing surface interactions is key. Moreover, their compositions can be altered in several different ways, as evidenced by metal alloy, core/shell, supported, and defective NPs. While conventional synthesis methods are capable of producing NPs in large quantities, they often require conditions of high temperature and pressure, strong reducing …

Building A Culture Of Preparedness: Using Community Emergency Response Teams To Promote Preparedness Behavior, Joseph Faulk

Theses and Dissertations

Communities throughout the nation use the Community Emergency Response Team (CERT) program to supplement the disaster response after hazard events as well as help build a culture of preparedness. Currently, practitioners and academics have limited knowledge about how CERTs promote enhanced preparedness postures. To address that knowledge gap, 20 CERT program managers were interviewed in this study to improve the general understanding of how CERTs contribute to developing a preparedness culture. The results identify program activities, objectives, and measures. In addition, this study introduces the Preparedness Behavior Change Model and collects feedback on its usefulness, which suggests it has a …

From Ink To Code, From Binary To Boundless Reality—Until All Returns To Emptiness, Weitong Sun

Theses and Dissertations

This thesis explores the entangled relationship between language, memory, and technology through the lens of immigrant experience. Moving from programming to visual storytelling, I investigate how dyslexia, bilingualism, and cultural displacement have shaped my ways of reading, writing, and coding.

Beginning with personal reflections on switching from computer science to art, I trace how code offered a form of clarity and expression where written language had once failed me. Yet as I ventured into real-time simulation and XR storytelling, I encountered new forms of mistranslation—where narratives dissolved, mutated, or resisted coherence altogether.

Through a series of experiments in code-driven art, …

How To Remain A Stranger / Encountering, In A Basement, Hannah Rotwein

Theses and Dissertations

How to Remain a Stranger / Encountering, in a Basement consists of two parallel essays. On the lefthand side of the page, How to Remain a Stranger explores the ways that the legend of the Wandering Jew, the Tradescantia genus of plants, peddlers, and exile relate to my practice of collecting, sorting, and combining found objects. On the righthand side, Encountering, in a Basement describes my thesis exhibition at the Institute for Contemporary Art at Virginia Commonwealth University. Focusing on the idea of the encounter, I detail the materials, considerations, and processes behind four of the ten sculptures in the …

Dosimetric Validation Of An Electron Monte Carlo (Emc) Algorithm For Small Cutouts And Extended Ssd’S: Assessing Emc In Small Field Dosimetry, Anil Basavaaraju

Theses and Dissertations

This thesis validates the accuracy and limitations of Electron Monte Carlo (eMC) simulations in Eclipse treatment planning systems for small-field electron dosimetry and extended source-to-surface distances (SSDs). Systematic measurements were performed using a microDiamond detector across various electron energies and field sizes. The study examines the discrepancies between measured and calculated (eMC) dose distributions, validating challenges due to lateral scatter disequilibrium and extended air gaps. Our findings provide systematic data for eMC dose calculations and demonstrate that eMC performs within clinical tolerances, with the ultimate goal of enhancing the precision and safety of radiation treatments.

Feeling Foreign / Foreign Feeling: Affect In Southeast Asian Diasporic Short Story Collections, Francys Aerin Fortes

Theses and Dissertations

Affect studies have long been saturated with scholarship investigating the fluidity of emotions, though a larger turn in the field now prioritizes the felt experiences of marginalized peoples. Sianne Ngai’s work is one part of this turn that seeks to unpack the effects of oppressive systemic forces on Black, Brown, and queer bodies. Sianne Ngai reexamined the nature of emotions in her seminal text Ugly Feelings (2005), particularly concerned with how negative feelings are disproportionately felt by marginalized bodies as a result of conditions of obstructed agency, systems of power, and wage labor capitalism. Drawing from Ngai’s writing, this thesis …

Multiphysics Modeling Of Material Response To High-Intensity X-Ray And Laser Pulses: Heating, Ablation, And Plasma Expansion, Youssef Abouhussien

Theses and Dissertations

This dissertation presents a computational framework to investigate material response under high-intensity X-ray fluxes produced by an exo-atmospheric nuclear detonation and laser-material irradiations, with a focus on heating, ablation, and plasma expansion phenomena relevant to satellite vulnerability and high-energy-density environments. A hybrid Monte Carlo and Two-Temperature Model (MC-TTM) was developed to simulate X-ray and laser energy deposition and thermal relaxation in metals and semiconductors across a range of X-ray and laser pulse durations from femtoseconds to nanoseconds. Results demonstrate distinct thermal behavior between materials, with ablation thresholds and phase transitions captured in good agreement with experimental data.

In parallel, a …

Development Of A Mediation Model Of Pain Cognition In Adult Patients With Sickle Cell Disease, Daniel M. Sop

Theses and Dissertations

Pain is a hallmark of Sickle Cell Disease (SCD), a genetic hemoglobinopathy characterized by chronic hemolytic anemia, vaso-occlusion, and organ damage. While acute vaso-occlusive crises (VOC) have been extensively studied, the mechanisms underlying chronic pain and its interplay with brain function remain unclear. This dissertation investigates the relationships between cerebral blood flow (CBF), fluid cognition, and pain sensitivity in adults with SCD, utilizing advanced imaging techniques and validated assessment tools.

Arterial spin labeling (ASL) and functional magnetic resonance imaging (fMRI) were employed to measure CBF and brain activity, respectively. Pain sensitivity was assessed using the Pain Sensitivity Questionnaire (PSQ), and …

Development, Synthesis And Characterization Of Advanced Low- Cobalt And High-Nickel Cathode Materials For Lithium-Ion Batteries, Arjun Patel

Theses and Dissertations

This dissertation focuses on the improvement of structural and electrochemical stability of active materials for lithium-ion batteries. It explores the modification strategies to mitigate the issues related to Ni-rich cathode materials, along with the continuous production of cathode precursors using a slug flow reactor to improve the quality of the product.

The First part of the dissertation examines the effect of substitution of cobalt with aluminum and iron on the electrochemical stability of Ni-rich lithium nickel cobalt manganese oxide (NCM) materials. This study investigates how Al and Fe doping work and how they impact the performance and stability of these …

Immersive Medical Practice And Clinical Training: Virtual And Mixed Reality In Pharmacy And Orthopedic Surgery, Silas Semprini De Toledo Contaifer

Theses and Dissertations

Extended‑reality (XR) technologies including virtual reality (VR) and mixed reality (MR) offer new ways to improve training and surgical precision. This thesis evaluates their educational and clinical impact through two complementary studies.

Specific Aim 1 compared an immersive 360° video VR module with conventional training for teaching USP < 797> sterile‑compounding skills to second‑year PharmD students (N = 36). VR trainees raised their knowledge from 6.14 ± 1.55 to 8.69 ± 1.07, yet the overall post‑test advantage versus control was not statistically significant (U = 71.50, p = 0.21). Item‑level McNemar testing showed significant VR‑exclusive gains on three critical questions (K5, K6, …

Food Waste Renaissance: From The Table, For The Table, Yasamin Shaikhi

Theses and Dissertations

What if waste could be seen as a valuable resource rather than a burden? Food Waste Renaissance (FWR) explores innovative ways to transform excess food and byproducts into sustainable design materials. In Qatar, where food waste constitutes approximately 60% of urban waste, FWR promotes a shift in perception rather than attempting to resolve large-scale waste management issues. By fostering a culture where surplus becomes a resource, it inspires individuals, designers, and communities to embrace and contribute to a circular economy. FWR examines rice and date byproducts as biodegradable raw materials for lamps, bringing material from the table back to the …

Civic Conservation Workshop: A User Manual For Creating A Makerspace Dedicated To Historic Preservation, Building Repair, And Civic Engagement, Madeleine Bean

Theses and Dissertations

Research Abstract:

Democracy depends on citizens’ participation at all levels, from local to national; moreover, engagement in one’s community is directly correlated with greater reported feelings of happiness and trust (Cox et al., 2021). This research examines how makerspaces can act as civic hubs that promote inclusive community interaction, facilitate the exchange of cultural and skills-based knowledge, encourage civic discourse, and serve as sites for political engagement through the provision of tools and resources that focus on historic home repair/preservation and craft-based trades. Specifically, this study proposes the development and design of a preservation-focused makerspace in Jackson Ward, a historically …