Digital Commons Network^™

Representativeness And Sensitivity Analysis Of Accident Tolerant Fuel Cladding Behavior In Reactivity-Initiated Accidents, Melissa Andrea Moreno

Nuclear Engineering ETDs

Accident Tolerant Fuels (ATFs) such as FeCrAl are being developed to enhance safety margins in light water reactors during transients like Reactivity Initiated Accidents (RIAs). This dissertation evaluates the accuracy and representativeness of TRACE thermal hydraulic models for predicting FeCrAl C36M cladding behavior under steady state and transient flow boiling conditions. Benchmarking against University of New Mexico separate effects experiments shows that TRACE reproduces key thermal trends but underpredicts cladding temperatures near CHF by approximately 25 to 30%. A calibrated uncertainty and global sensitivity analysis, using Sobol indices, demonstrates that CHF and cladding temperature variability are dominated by mass flux, …

The Role Of Cumulative Usage In Language Learning And Language Variation: Evidence From Spanish Voiced Stops, Sarah Lease

Linguistics ETDs

This dissertation investigates the cumulative repercussions of a word’s typical context of use on lexical representations and speech production, both in cases of language learning and language variation, through the lens of Usage-Based Linguistics. The data come from sociolinguistic interviews with Spanish-speaking children and adults of Mexican heritage living and working in the Pacific Northwestern United States. Each study examines Spanish word-initial /bdɡ/ productions using a myriad of statistical approaches. The dissertation adds to our understanding of the long-term storage of variation in lexical representations, as well as its nuanced impact on children’s and adults’ speech production. The dissertation also …

From Sparse To Precise: Modeling Beam Profiles Using Wavelet-Based Implicit Neural Network (Winn) For Linear Accelerator Commissioning And Quality Assurance, Maryam Ali Albuainin

Computer Science ETDs

Commissioning and routine quality assurance (QA) in radiotherapy require extensive measurements using bulky water tank systems, making the process time-consuming and costly. This research proposes an efficient framework for radiotherapy commissioning and QA by generating complete LINAC physics data from sparse measurements and developing a portable solid-water detector with embedded diodes for high-resolution dosimetry.

At the core of the framework is a Wavelet-based Implicit Neural Network (WINN) that reconstructs full measurement datasets from limited inputs while maintaining clinical accuracy. The model achieves gamma passing rates above 95% (1%/1 mm) and mean absolute errors below 0.5%, while reducing parameters by 99.46% …

The Drive Diaries: How Motivation Shapes Work And Performance, Christian D. Diaz

Masters Theses, 2020-current

Employee motivation remains central to organizational research, yet less is known about how employees personally experience the relationship between intrinsic and extrinsic motivation and performance. Grounded in Self-Determination Theory and Expectancy Theory, this qualitative narrative inquiry examined how employees describe their motivational experiences and their influence on workplace effectiveness. Semi-structured interviews were conducted with 3 employees across diverse industries and analyzed using thematic analysis.

Four themes emerged: (1) autonomy as a primary driver of sustained performance, (2) recognition as a reinforcing factor, (3) organizational culture as either amplifying or diminishing motivation, and (4) motivation as evolving across career stages. Findings …

The Motivation Tapes: Employee Narratives Of Leadership That Matters, Jessica Gray

Masters Theses, 2020-current

This qualitative phenomenological study explored how employees describe their lived experiences at work. The purpose of the research was to understand the relational, emotional, and developmental dimensions that shape employees’ day-to-day workplace realities and the meanings they assign to those experiences. Four participants from diverse occupational backgrounds were interviewed using semi-structured protocols designed to elicit rich, descriptive accounts of their work environments, relationships, and sense-making processes. The findings reveal that participants shared experiences of supportive and hands-on leadership, opportunities for autonomy and ownership, and moments of connection, meaning, and long-term growth. Participants also described disruptions to these experiences. The implications …

Amplifying Strengths: A Phenomenological Exploration Of Elementary Teachers’ Culturally Proficient Practices With Newcomer Students Through An Appreciative Inquiry Lens, Mary Elizabeth Bradford

Teacher Education, Educational Leadership & Policy ETDs

This qualitative study explored the lived experiences of elementary educators working with newcomer students in a Southwest urban school district, with the purpose of identifying culturally proficient strengths that support student belonging and learning. Guided by an interpretive (hermeneutic) phenomenological approach and informed by Appreciative Inquiry, the study centered educators’ meaning-making rather than deficit-oriented perspectives. Data were collected through in-depth, semi-structured interviews with five elementary educators serving newcomer students across kindergarten through fifth grade. Analysis followed van Manen’s phenomenological methods and resulted in six interrelated themes: belonging before language; school as a cultural system; language as agency and identity; cultural …

Write To Lead: A Document Analysis Of Leadership Communication, Rosenda B. Minella

Teacher Education, Educational Leadership & Policy ETDs

This qualitative study examined how executive leaders at an urban community college in the Southwestern United States used motivating language in written communication. Community colleges face increasing complexity, including enrollment declines, limited resources, and heightened expectations for student success. In this context, written leadership communication helps align organizational goals, build trust, and reinforce institutional values. Motivating Language Theory served as the primary coding framework, with findings interpreted through the lens of Authentic Leadership and informed by AACC Leadership Competencies. Using qualitative document analysis and an AI-assisted workflow to support coding consistency, the study analyzed publicly available executive communications produced over …

Heavy Metal And Metalloid Accumulation In The Gallinas River Following The Hermit's Peak / Calf Canyon Wildfire, Olivia A. Kelly

Geography ETDs

This study evaluates the persistence and bioavailability of heavy metals and metalloids in the Gallinas River three years after the Hermit’s Peak/Calf Canyon Wildfire of 2022 using a multicompartment sampling framework that includes water, sediment, and benthic macroinvertebrate tissue analysis via inductively coupled plasma optical emission spectrometry (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS). Results indicate that the Hermit’s Peak/Calf Canyon Fire continues to influence the hydrogeochemical condition of the Gallinas River. Sediments contain elevated concentrations of several metals and metalloids, and these same elements are detectable in macroinvertebrate tissues, linking sediment contamination to biological uptake. Zinc (Zn), silicon …

Statistical And Spectral Theory For Spatially Correlated Random Aperiodic Antenna Arrays, Thomas Edward Christian Jr

Electrical and Computer Engineering ETDs

Aperiodic phased arrays enable beam steering, interference suppression, and spectrum efficiency for 6G, radar, biomedical imaging, and distributed sensing. Minimum inter-element spacing and keep out zones induce spatial correlation, violating the i.i.d. element-position assumption behind classical probabilistic random array theory. This dissertation develops a unified probabilistic spectral framework for correlated (non-i.i.d.) arrays. Second moment power pattern analysis incorporates the pair-correlation function  and structure factor , recovering the i.i.d. limit when  and accommodating unequal excitations. Side lobe and main lobe fields deviate from Rayleigh/Exponential and are modeled by weighted Nakagami and Gamma-mixture distributions, parameterized via Monte Carlo. The blue noise spectral …

A Constructional Approach To Multimodal Linguistic Analysis, Fredy A. Mendieta Rodriguez

Spanish and Portuguese ETDs

This dissertation investigates the systematic organization of co‑speech gestures in referential communication, using data from Spanish‑speaking monolinguals and Spanish–English bilinguals. While traditional gesture research treats pointing as a universal phenomenon, the current analyses show that gestural productions display internal phonological patterning and context‑conditioned variability that parallels spoken constructions. Quantitative results demonstrate how referential distance and communicative context (find‑it versus misunderstanding situations) shape the selection of embodied phonological features—handshape, orientation, movement, and beats—revealing consistent associations between form and interactional demands. Qualitative analyses trace how gestural realizations reduce across discourse as shared understanding emerges. A new complexity metric, based on token frequency …

Realizing The Long Wavelength Array Swarm, Craig Anthony Taylor

Physics & Astronomy ETDs

Sensitive modern radio interferometers are costly to build and operate at the university level. The `swarm telescope' concept addresses this challenge by enabling the collaborative use of individual telescope systems, overseen by separate institutions, that come together to form a more powerful and manageable facility. This dissertation focuses on demonstrating this concept using the Long Wavelength Array (LWA) by commissioning an aperture synthesis telescope consisting of interconnected LWA stations, called the LWA Swarm. The presented work details building a cost-efficient prototype LWA platform -- the LWA--North Arm station -- to enable synthesis imaging using the 3-element interferometer comprised of LWA1, …

A Multi-Frequency Investigation Of Compact Symmetric Objects, Evan E. Sheldahl

Physics & Astronomy ETDs

Some of the brightest objects in the radio sky are jetted active galactic nuclei (AGN), supermassive black holes in the centers of galaxies that accelerate relativistic electrons into twin radio jets. One of the biggest questions surrounding AGN is how they produce radio jets in the first place. We search for an answer to this question by exploring a class of AGN that have uniquely well-constrained physical properties and are thought to be in an early stage of AGN development: compact symmetric objects (CSOs). Throughout our journey with these remarkable sources, we quantify their efficacy as calibrator sources for radio …

Examining The Glat As A Measure Of Ai Literacy, Hunter R. Castleton

Masters Theses, 2020-current

The current study examined the Generative AI Literacy Assessment Test (GLAT) as a promising test of AI literacy due to its content, which is grounded in relevant AI literacy theory, and its design as a cognitive measure of AI literacy. To examine the GLAT, data were collected from a sample of 543 graduating seniors at James Madison University (JMU) who took the GLAT as part of a longer series of tests. Their responses were first analyzed to assess the test’s item characteristics and internal structure. Following this initial analysis, a final item set was established to ensure that low-quality items …

Using Behavior Skills Training To Shape Paraprofessional Fidelity And Reduce Student Latency To Begin Non-Preferred Academic Tasks During Transitions, Maria C. Cole

Masters Theses, 2020-current

The purpose of this study was to investigate the use of behavior skills training (BST) to improve a paraprofessional’s implementation fidelity of evidence-based strategies targeting transition-related behaviors in a student with autism spectrum disorder (ASD). A changing criterion design was used to evaluate whether a functional relation between BST and the implementation of a task-analyzed transition protocol existed. The staff participant was assessed across baseline, three phases of BST intervention, and a mini-reversal phase included to further assess experimental control. Student data were collected tangentially in further evaluating experimental control. The paraprofessional participant demonstrated improving implementation fidelity trends within and …

The Effects Of Behavior Skills Training To Teach A Clinician To Implement A Structured Work System, Megan E. Bowling

Masters Theses, 2020-current

Many children with autism spectrum disorder present with deficits in completing daily living tasks, which may be due to the sequencing of information required to complete these skills. Structured work systems present a support for children to visually organize and sequence events, though they are most used in the classroom setting. The study tested the effectiveness of behavior skills training to teach a behavior support clinician to implement a structured work system via least-to-most prompting. Data was collected on the clinician’s percent of accurate implementation, which was then analyzed across three daily living behaviors in a multiple probe design. Results …

Interprofessional Collaboration: A Survey Study Focusing On Pre-Service Professionals, Megan L. Bell

Masters Theses, 2020-current

Board certified behavior analysts (BCBAs) are bound by an ethical code to engage in appropriate means of interprofessional collaboration for the best interest of their clients. Training in this has been increased during graduate coursework to ensure BCBAs are intentionally following through on this notion to allow for stronger professional relationships with other related service providers and are holistically providing the best care possible for their clients. The goal of this survey was to better understand how these changes compares to other related services providers and their goals of collaboration, when working with individuals with disabilities. A survey was disseminated …

A Colonial Past Revisited: An Authethnography Of Outsider And Insider Identities In Indigenous Education Communities, Tara L. Deyoung

Teacher Education, Educational Leadership & Policy ETDs

In the late 90s, at Rehoboth Christian school, a small private boarding school in northwest New Mexico, I had four different English teachers in my four years of high school. All but two of my teachers at that time would be considered outsiders to the community in which they taught. Teacher outsiders leave schools and districts at higher rates than insiders to a community; this is especially true for rural and remote areas (Hudson et al., 2020). The purpose of this autoethnographic study is to analyze my history as a cultural outsider and insider in relation to my core beliefs …

Success By Design? A Combined Outcome And Process Program Evaluation Of California’S Early And Middle College High Schools, Brooke N. Martin-Gill

Education Dissertations

Early and Middle College High Schools (EMCHS) expand college access for

underrepresented students by integrating high school and college coursework within

community college settings. Despite strong reported outcomes, some EMCHS face

substantial student attrition. Limited research examines how EMCHS organizational

structures influence student persistence. This mixed methods outcome and process

evaluation seeks to address this research gap. Quantitative analysis (paired samples-t-

tests) examined statewide enrollment data (2017-2025) to determine whether significant

differences exist between Year 1 and Year 4 cohort enrollment. Qualitative analysis was

conducted through a deductive discourse analysis of Western Association of Schools and

Colleges (WASC) Self-Study reports …

Millimeter-Wave Antenna Gain Enhancement Through Stacked Planar Substrates, Zachary Bergstedt

Electrical and Computer Engineering ETDs

This work presents a new wideband millimeter-wave (mmWave) and sub-terahertz antenna design with flexible directivity through the integration of stepped horn antennas and transverse substrate integrated waveguide (SIW) slots for radar and communication applications. The work gives a theoretical and analytical basis for this filter-inspired approach to improving bandwidth and directivity, and presents design and results for a standalone stepped horn, a Ka-band antenna with a solid stepped horn and SIW feed, and W-band antennas with empty SIW feeds and stepped horns manufactured out of multiple planar layers. The realized antennas show bandwidth up to 40% and gain up to …

Calibration Methodology, Diagnostic Performance, And Redesign Of The Current Monitors On The Z Machine At Sandia National Laboratories, Stacie Hernandez

Electrical and Computer Engineering ETDs

A proper evaluation of the current diagnostics fielded in the inner-MITL region of the Z facility in 3D simulation models had not been performed until now. The evaluation of the current monitors has brought insight to their performance in a new view that has led to discoveries. The B-dot probe was the current diagnostic-of-choice since before the refurbishment of the Z facility [1] and until the development of the Inductively Driven Transmission Line (IDTL) current diagnostic [2]. Experimental data has shown that the IDTL can produce cleaner signals and it is more robust than conventional B-dots. Simulation (modeled using COMSOL …

Hierarchical Safe Reinforcement-Learning Framework For Mission-Aware, Edge-Enabled Multi-Uav Iot Networks, Abee F. Alazzwi

Electrical and Computer Engineering ETDs

This Ph.D. dissertation presents a unified Hierarchical Safe Reinforcement Learning (HSRL) framework for mission-aware, edge-enabled multi-UAV Internet of Things (IoT) networks. The work addresses the need for autonomous aerial infrastructures capable of delivering low-latency communication, scalable edge computation, and provably safe operation in dynamic environments. The dissertation develops three primary contributions. First, it formulates longhorizon drone base station placement and load balancing as a strategic actor–critic learning problem, enabling proactive adaptation to spatiotemporal demand variations. Second, it introduces a mission-aware multi-agent reinforcement learning controller for coordinated mobility, sensing, and computation offloading under latency and energy constraints. Third, it integrates a …

Technical Advancements In Single-Molecule Spectroscopy For High-Throughput Measurement Of Long-Time Dynamics, Quyen B. Le

Chemical and Biological Engineering ETDs

Single-molecule fluorescence spectroscopy is a powerful technique for resolving transient biomolecular dynamics and quantifying free energy landscapes, kinetics, and binding interactions. However, two fundamental limitations restrict its broader application: slow, labor-intensive data acquisition and the limited observation time imposed by fluorophore photobleaching. These limitations hinder its use in drug discovery and biomedical engineering applications that require both high-throughput and access to long-time dynamics. In this work, both challenges are addressed through technical advancements. First, a simple, generalizable approach is introduced to automate data acquisition, eliminating manual intervention during experiments. This increases the acquisition rate by more than an order of …

Nuclear Deterrence: Enhancing The Mission Through Smart Factory Predictive Solutions, Jarrod Matthew Ronquillo

Chemical and Biological Engineering ETDs

To meet the stewardship and modernization initiatives set by the Department of Energy new technologies must enter the manufacturing facilities within the nuclear deterrent complex. Predictive solutions begin with collecting data. An equipment health monitoring device was created to streamline data collection and organization for equipment and processes. A predictive and process performance dashboard was developed for a deionized water system. The dashboard used Western Electric statistical process rules and a machine learning regression algorithm to predict when the resistivity would fall out of specification. Lastly, a remaining useful life calculation was developed for all equipment related to nuclear deterrent …

Practitioners’ Experiences Of Developmental, Individual Differences, Relationship-Based (Dir) Approach In Their Professional Practice With Neurodivergent Clients: A Hermeneutic Phenomenological Study, Ekaterina Sidor

Educational Studies Dissertations

This phenomenological study explores how professionals experience integrating the developmental, individual-differences, and relationship-based (DIR) framework in their work with neurodivergent clients. Although DIR is recognized as an evidence-based developmental approach in the field of autism support, little is known about how its integration affects practitioners themselves. Grounded in relational-cultural theory and transformative learning theory, the study examines how engagement with DIR influences practitioners’ professional practice and development. Using a qualitative, hermeneutic phenomenological design, data were collected through open-ended questionnaires and in-depth interviews with multidisciplinary professionals from diverse international contexts who completed DIRFloortime training and actively implement DIR in their work. …

Becoming Restorative: An Exploration Of Individual Journeys And The Professional Learning That Supports Them, Jessica Rae Madden-Fuoco

Educational Studies Dissertations

Restorative practices in K-12 schools have been studied primarily for their impact on school climate and discipline outcomes, yet little empirical or conceptual guidance exists for the professional learning that supports educators in becoming restorative. This study investigated three interconnected questions: How do individuals experience the process of becoming more restorative in their personal and professional lives? What key qualities characterize effective andragogy in the teaching of restorative practices? And how do educators perceive the impact of these qualities on their professional learning, development, and ability to use restorative practices in their classroom or school? This study employed two complementary …

The Efficacy Of Emotional Reframing As An Intervention To Promote Adult Transformational Growth, Linda Rossetti

Educational Studies Dissertations

This study investigates the underexplored relationship between adult developmental growth and emotions. Developmental growth requires an individual to respond to self-concept instability by adopting new meaning structures and navigating oppositional emotions. This quantitative study examined the relationship between an emotional reframing intervention and perspective shifts, an indicator of developmental progression. Data collected on three college campuses in the 2024-2025 academic year revealed a strong positive relationship between the intervention and perspective shifts, as evidenced by differences in pre- and post-assessment responses within the studied population, both in aggregate and in specific use cases. The findings contribute to three academic arenas: …

Enacting Leadership And Transforming The World: Hannah Arendt, The Private, The Public, And Transfigurations In Between, Xochitl Mendez

Educational Studies Dissertations

In this dissertation I propose a framework that emphasizes transitions between Private and Public. I argue that individuals can consciously reshape and reformulate these transitions to assert themselves in the world. How can the individual’s own internal realities, ventures, projects and selfhood assert themselves in a fraught world as an act of self-affirmation, leadership, and transformation? New approaches to this question can all be revealed by using transitions between Private and Public as actionable strategies. I re-interpret Hannah Arendt’s Private and Public as she presented them in The Human Condition (1958). I turn these into multivalent and multilayered spaces of …

We Need To Do Better: Exploring Educators’ Perspectives Of Transformative Trauma-Informed Social-Emotional Learning, Heather Stay

Education Doctorate Dissertations

This qualitative, descriptive case study examined educators’ understandings, enactment, and professional learning related to transformative, trauma-informed social-emotional learning (SEL) practices in a center-based emotional support school setting. Data were collected through semi-structured educator interviews and classroom observations to capture a holistic view of pedagogical practices. Guided by the theoretical frameworks of Dis/Crit, Transformative Learning Theory, and Foucault’s Theory of Power, the findings illuminate how educators leverage trauma-informed SEL strategies to support students affected by trauma as they navigate structural and systemic constraints within a normative educational system. Results highlight both effective cultural-sustaining and trauma-responsive practices already in place, as well …

Leadership Regarding The Support And Implementation Of Collaborative Teacher Teams To Advance District Equity Goals, Deborah Holman

Educational Studies Dissertations

Educational leaders increasingly prioritize equity reform processes; however, many struggle to enact sustainable change that addresses persistent disparities in student outcomes. Existing research on district effectiveness identifies key improvement practices but offers less insight into how leaders operationalize these practices effectively. The growing body of research on professional learning communities (PLCs) offers emerging evidence that job-embedded, focused PLCs are a mechanism that can positively impact student outcomes. This study addressed the connection between the improvement practices and PLCs by exploring how school and district leaders leverage collaborative teacher teams as a mechanism for equity-minded reform. Using a constructivist grounded theory …

Trauma Sensitivity In Rural Education: A Teacher-Centric Analysis Grounded In Bronfenbrenner’S Ecological Systems Theory, Karie L. Williams

Educational Studies Dissertations

This qualitative case study examines the ways rural teachers implement trauma-sensitive practices despite having few resources and little institutional support. There is a lack of research regarding what teachers in these settings think about trauma-sensitive practice, how teachers implement trauma-sensitive practice within their classrooms, and what ecological factors contribute to the sustainability of trauma-sensitive practice. The primary question driving this research is “How do K–5 public school teachers in a rural-distant district in Virginia implement trauma-sensitive practices within the ecological systems that shape their professional roles, instructional decisions, and relational work with students?”  This question reflects the study’s purpose to …