Digital Commons Network^™

Products Of Laser Ablated Actinides And Actinide Comparators In The Presence Of Carbonyl Sulfide Characterized By Rotational Spectroscopy, Joshua Edward Isert

Doctoral Dissertations

As the consumption of energy continues to rise globally, so too has interest in alternative energy sources such as nuclear power. However, a fundamental understanding of the actinide series is needed in order to safely and efficiently utilize these elements. Rotational or microwave spectroscopy, depending on if one is speaking of the physical outcome of the experiment or the region of the electromagnetic spectrum being operated in, is a gas phase molecular study utilized for structural determination. This technique can be utilized to gain an in depth understanding of bonding within the actinide series. However, when studying species that are …

Advancements In Signal Processing And Image Reconstruction For Active Microwave Thermographic Measurements, Logan Martin Wilcox

Doctoral Dissertations

Active microwave thermography, or AMT, is a coupled electromagnetic-thermographic nondestructive testing and evaluation technique. AMT has found success in a variety of inspection needs in the aerospace, space, and infrastructure fields due to its unique type of thermal excitation. During an AMT inspection, a specimen is exposed to microwave energy from a radiating source (i.e., an antenna). This exposure to microwave energy results in dielectric/magnetic heating, which causes an increase in temperature and potential defect indications to manifest on an inspection surface (which is measured via an infrared camera). Due to the use of an antenna, there is a spatially …

Machine Learning Models For Location Prediction, Message Routing And Path Planning For Rescue Of Underground Miners, Abhay Goyal

Doctoral Dissertations

Self-rescue during underground mine disasters is vital for miner safety. Evolving hazards and post-disaster conditions demand solutions that enable navigation under severe communication and computational constraints. Centralized systems often fail in such rugged settings, while decentralized methods—particularly Delay Tolerant Networks (DTNs), proven in battlefields and space missions—offer distinct advantages for underground applications. This research addresses five core challenges: (i) predicting miners’ next locations on low-power devices using points of interest and movement sequences; (ii) delivering timely updates on safe routes, evacuation zones, and hazardous areas; (iii) evaluating energy efficiency and comparing graph-based approaches to existing methods; (iv) enabling edge-ready frameworks, …

Investigating The Effects Of Fly Ash On The Properties Of Silica-Deficient High Alumina Materials, Sai Akshay Ponduru

Doctoral Dissertations

This research is made up of five studies mainly focused on attaining sustainability in high alumina cements like calcium aluminate cement (CAC) and calcium sulfoaluminate belite cements (CSAB) by partially replacing them with additives and supplementary cementitious materials (SCMs) like fly ash (FA). The first study focused on understanding the reaction kinetics of CAC and FA binders at different replacement levels (i.e. between 10%-to-50% by mass) and their effect on mechanical properties. It was also shown that the reactive nature of FAs can be determined by calculating a single parameter called number of constraints (nc) derived from topological constraint theory. …

Generalizations Of Finiteness Conditions And Extension Monads In Algebras With Infinitely Many Or Infinitary Operations, Danielle Christienne Bowerman

Doctoral Dissertations

In this work, we extend the results of finiteness conditions and extension monads found in Insall from finitely many finitary operations to infinitely many finitary operations, as well as touching on infinitary operations. We also examine varieties of algebras, including the notion of strong varieties introduced in Insall, and common constructions of extension monads in varieties of algebras. We see that for finite collections of algebras of the same signature, the extension monad operation on a variety of algebras commutes with the direct product operation, and all retractions from an enlargement or extension monad are trivial. We also see that …

Identification Of Corrosion Damage, Vibration, And Loose Conections In Aircraft Data Transmission Lines Using Reflected And Transmitted Signals; Formulation Of Vegetable Oil-Based Nanofluids As Cutting Fluids For Mql Machining, Saidanvardzhon Valiev

Doctoral Dissertations

This research presents a novel Frequency Domain Transmitometry (FDT) method that uses transmitted signals (S21) to detect and characterize aircraft data transmission lines (ADTL) corrosion damage without additional reflectometry circuitry. Corrosion experiments were conducted according to ASTM G85-A5 over 14 weeks. Combined FDT and reflected signals (S11) analyses revealed distinct three-peak signatures associated with damage and corrosion. The square root of the Area Under the Curve (AUC) of the FDT damage peak and the Full Width at Three-Quarter Maximum (FW3QM) of the S11 damage peak is correlated with corrosion propagation depth and width. S11 signals were further used for vibration …

Mindfulness Matters: Addressing Anxiety And Navigating Toward Wellbeing Through Miea Mindfulness Practices, A Mixed-Methods Study Of Lgbtiq Graduate Writing Students, Kim Westerman

Doctoral Dissertations

ABSTRACT

Mindfulness Matters: Addressing Anxiety and Navigating Toward Wellbeing Through MIEA Mindfulness Practices, a Mixed-Methods Study of LGBTIQ Graduate Writing Students

Anxiety has always been a part of the human experience, even before the phenomenon was conceptualized in the 17^th century and named by Freud in the 19th. And human beings have devised many strategies for addressing anxiety: reducing it, ignoring it, distracting oneself from it, despairing over it, medicating it, engaging with it, moving through it, co-existing with it. The current zeitgeist, more than four years into the COVID-19 global pandemic, situates anxiety as a central facet of …

The Nature Of Students' Justifications In Geometry: The Impact Of Using Dynamic Geometry Software, Anek Janjaroon

Doctoral Dissertations

Mathematical justification is a process that reflects how students demonstrate and accept the truth of mathematical statements. The purpose of this study was to investigate the nature of students’ justifications when allowed to use dynamic geometry software in the justification process. The justifications of 18 preservice teachers in response to two geometric conjectures were analyzed to identify characteristics of justifications based on Harel and Sowder’s (1998) framework of proof schemes. The results inform us of the impact of the dynamic software in students’ justifications and the overall nature of students’ work when they use the software to learn geometric ideas. …

Global Imaging Of The Magnetoshpere: An In-Depth Analysis Of The Magnetosphere-Ionosphere Coupling, Mayowa Adewuyi

Doctoral Dissertations

Magnetosphere – Ionosphere (MI) coupling plays an important role in Earth’s overall space environment. MI coupling influences ion dynamics in the plasma sheet, the evolution of ring current ions, and field aligned currents during storm time events. The coupling of these two regions makes it important to understand both as a whole, rather than individually. Understanding the importance of the magnetosphere-Ionospheric system and how the coupling affects earth’s space environment is made difficult due to the reliance on localized in-situ measurements and the spacecraft being at the right location at the right time.

The Two Wide-Angle Imaging Neutral-Atom Spectrometers (TWINS), …

12-Year Full Solar Cycle Maps Of Interstellar Neutral Atoms By Ibex-Lo And The Observation Of Elastic Scattering Of Primary Helium By Solar Wind Particles, Hafijul Islam

Doctoral Dissertations

The Interstellar Boundary Explorer (IBEX) mission is playing a pivotal role in advancing our understanding of the interaction between the very local interstellar medium (VLISM) and the heliosphere. By sampling interstellar neutral (ISN) atoms and energetic neutral atoms (ENA), IBEX has provided over 15 years of continuous data over a range of energy from 15 eV to 6 keV, offering an invaluable opportunity to study these interactions across various phases of solar activity. The IBEX-Lo instrument, which detects lower-energy ISNs, has been particularly useful in exploring the properties of hydrogen and helium in the interstellar medium, as well as their …

The Genomic Basis Of Adaptation In Salt-Marsh-Breeding Sparrows, Jonathan David Clark

Doctoral Dissertations

Salt marshes are an ecotone between terrestrial and marine environments characterized byshort, graminoid vegetation and periodic tidal inundation with saline water. Despite the generally inhospitable conditions salt marshes present for terrestrial vertebrate life—principally, exposure to heat, salinity, and flooding—several terrestrial vertebrate species have adapted to, or are capable of inhabiting salt marshes. Notably, species of passerine birds that have adapted to salt marshes have repeatedly evolved a similar suite of adaptations, which has been named the “saltmarsh syndrome,” including larger bills, darker plumage, and an increased tolerance of salt.

The myriad species of New World sparrows (Passerellidae) that breed in …

A Physics-Based Material Model Incorporating Strain Gradient Plasticity Formulations In A Mean-Field Framework To Predict Spatial Fluctuation Of Material Properties, Zhangxi Feng

Doctoral Dissertations

With the market expansions and increasing number of scientific explorations, the demands for manufacturing metallic parts to satisfy specific requirements continue to increase. A slight improvement in the manufacturing process can result in great cost savings in time and energy. The research and development time to identify these areas of improvements can be greatly reduced using numerical models. One such model is the mean-field elastoplastic self-consistent (EPSC) framework studied extensively and advanced in this dissertation. In the past two decades, many material behavior formulations were implemented in EPSC, and the model has shown versatility and accuracy in predicting a wide …

“Why You Understand The Why”: A Qualitative Characterization Of The Metacognitive Competence Of Introductory Stem Peer Coaches, Jonathan Kustina

Doctoral Dissertations

The processes of metacognition are vital for students’ development of critical thinking skills and productive learning mindsets, yet many students never receive the direct instruction that would allow them to formally develop their metacognition. As instructors are typically not providing this instruction, there may be an alternate source to facilitate the learning of metacognition to students. This research study will investigate the viability of having peer coaches, undergraduate peer educators who help facilitate learning and problem solving in introductory STEM courses, facilitate metacognition to their students. Specifically, this research study aims to understand and characterize the metacognitive competence of the …

Engineer-Friendly Synergetic Methodology For Surrogate Modeling Of Complex Connections By Modal-Based Low-Fidelity Finite Element Model Updating Approach, Milad Mehrkash

Doctoral Dissertations

Finite element models are widely used to simulate the behavior of structures. They can also be utilized for structural condition assessment and health monitoring. However, due to software limitations, simplifying assumptions, and lack of knowledge about the system properties, the predictions of the numerical models may deviate from laboratory or field measurements of the actual structure. This issue may be further exacerbated by the simplifications applied in modeling complex connections, which is a common practice in numerical modeling to save time and effort. While finite element model updating improves the accuracy of numerical models, physics-based surrogate modeling of connections balances …

Artificial Intelligence Driven Magnetic Materials Discovery: From Data Extraction To Property Prediction, Yibo Zhang

Doctoral Dissertations

This dissertation presents an integrated artificial intelligence framework aimed at accelerating magnetic materials discovery by addressing key challenges in materials science: improving experimental characterization techniques, efficiently extracting structured data from scientific literature, developing comprehensive materials databases, and creating reliable predictive models.

We first develop a UNet-enhanced vector field electron tomography (VFET) approach for three-dimensional magnetic structure reconstruction. This method addresses the missing wedge problem in experimental data collection while maintaining computational efficiency, providing reliable experimental data crucial for materials research.

We introduce GPTArticleExtractor, a novel workflow leveraging large language models to automatically extract key information from scientific literature. Applied to …

Functional Characterization Of Copper Tolerance In The Atypical Microsymbiont Pseudofrankia Inefficax, Megan Paige Garcia

Doctoral Dissertations

Bacterial species in the family Frankiaceae are soil-dwelling microsymbionts that form a mutualistic symbiosis, termed the actinorhizal symbiosis, with over 220 species of woody dicots. In this relationship, frankia fix atmospheric nitrogen to ammonia, a form usable by plants, while the bacteria benefit from the carbon sources exuded by their actinorhizal hosts. Since nitrogen is typically a limiting nutrient for growth in degraded and contaminated soils, actinorhizal plants establish at these sites as pioneer plant species, initiating a path for phytoremediation. Likely due to their association with plant hosts in contaminated soils, most frankia strains have evolved above average tolerances …

Improving Understanding Of Fluvial Reach-Scale Solute Transport And Uptake Using A Particle Tracking Model And Random Forest Machine Learning Model, Jiaying Liu

Doctoral Dissertations

In addition to transporting flowing water, river systems carry dissolved nutrients and pollutants, which can experience chemical reactions, biological uptake, or retention in surface or hyporheic zones. This dissertation enhances our understanding of solute transport and uptake in river reaches through three main components. The first component involves the development of a novel curve-fitting model designed to capture the characteristics of pulse-release breakthrough curves (BTCs) from tracer studies with conservative solutes. The model, which was found to be applicable to a wide range of field studies, enables the rapid comparison of transport parameters among diverse field studies obtained under a …

Deformation-Induced Bonding Of Glassy Polymeric Films And The Diluent Effect, Ajay Vallabh

Doctoral Dissertations

Bonding between two polymer films can be achieved through various heat- or chemical-based methods. Recently, our group has discovered the novel phenomenon of deformation-induced bonding (DIB) for solid-state glassy polymers in time on the scale of a fraction of a second at ambient temperatures substantially below the bulk glass transition temperatures (T_g). DIB is achieved by bulk plastic compression, which triggers the molecular mobility of polymer chains to cause interpenetration across the interface even in a glassy regime.

First, we performed a series of experiments to evaluate solid-state, deformation-induced bonding in organic polymer blends composed of films of hydroxypropyl methylcellulose …

Challenge, Hindrance, Or Both: Exploring The Relationship Between Motivational State And Employee Experience Of Job Demands, Leonard Hudson Taylor

Doctoral Dissertations

One of the most common typologies of workplace stressors is the challengehindrance framework (Cavanaugh et al., 2000). Challenge stressors are job demands that are perceived by employees as obstacles to be overcome to learn and achieve (LePine et al., 2005). Conversely, hindrance stressors are job demands that are perceived by employees as unnecessarily thwarting personal growth and goal attainment (LePine et al., 2005). While useful, Cavanaugh et al.’s tendency to label stressors as one or the other categorically was later disputed, in that there is more variability in how stressors are experienced than Cavanaugh et al. described (Webster et al., …

Simulations, Modeling And Data Analysis Of Parity Violating Electron Scattering Experiments, Yufan Chen

Doctoral Dissertations

In the Standard Model (SM) of nuclear and particle physics, parity violation is incorporated through the representation of the weak interaction as a chiral gauge interaction. Only the left-handed components of particles and right-handed components of antiparticles participate in weak interactions in the Standard Model. This implies that parity is asymmetric for the weak interaction. Parity violating electron scattering (PVES) experiments are designed to probe the physics parameters related to the SM, with the possibility to discover physics beyond the SM (BSM) by measuring the parity violating asymmetry 𝐴𝑃𝑉 of longitudinally polarized electrons scattered off unpolarized targets with high precision. …

Attachment Styles As Moderators Of Loneliness In Remote Work, Brody Tj Loughlin

Doctoral Dissertations

This dissertation investigates the role of attachment styles in moderating the relationship between remote work and loneliness. Drawing on attachment theory, which posits that early life experiences shape attachment styles and influence social interactions, the study examines whether attachment styles (anxious, avoidant, and secure) moderate the association between remote work and feelings of loneliness. The research targets 394 remote workers, using a quantitative, cross-sectional survey design with proportional stratified sampling to reflect the distribution of hybrid and fully remote work arrangements in the U.S. workforce. The Extent of RemoteWork measure, the Three-Item Loneliness Scale, and the Adult Attachment Scale assess …

How Helpless Are You? The Need For Closure And The Need For Cognitive Preferences As A Moderating Effect In The Relationship Between Perceived Self-Efficacy And Learned Helplessness, Aungelique Renea Sledge

Doctoral Dissertations

A substantial amount of research has been shown that the impact of self-efficacy has shown positive and negative effects. Additionally, the need for closure defined as an individual's motivational degree to reach firm answers, as opposed to ambiguity has also been shown to have diverse effects for individuals when their closure needs are threatened or unobtained. Research has posited that to successfully obtain and/or avoid reaching closure in various situations, an individual must be able to process information in a way that is quick, heuristic, and stereotypical (e.g., cognitive structuring) or in a way that is much slower, effortful, and …

Float: A Multi-Scale Flood Loss Assessment Tool Developed From Experimentally Derived Material Damage, Anna Katya Opel

Doctoral Dissertations

Current practice of flood loss prediction presents limitations in accurately predicting building flood losses at multiple scales. While whole-building estimates can more accurately predict high-level losses (i.e., large groups of buildings), a significant analysis error is revealed with small-scale (i.e., individual, or small groups of buildings) investigation. The novel approach of collecting experimental flood data to support damage estimation has provided sufficient evidence that current damage models can and do under or overestimate loss. This research has developed a multi-scale approach to assessing flood losses based on experimentally derived material damage. The methodology is stored and accessible in a multi-scale …

Measurement Of Multi-Jet Ratios In The Atlas Experiment, Zahra Farazpay

Doctoral Dissertations

This dissertation presents a comprehensive study of multi-jet cross-section ratios using proton-proton collision data collected by the ATLAS detector during Run 2 of the Large Hadron Collider (LHC) at a center-of-mass energy of √ s = 13TeV. By examining these ratios across different energy scales, the analysis provides valuable insights into the running of the strong coupling constant, αs, a fundamental parameter in Quantum Chromodynamics (QCD) that dictates the strength of the strong interaction. The running of αs—its variation with energy—is crucial for understanding QCD, yet it remains one of the least precisely known aspects of the theory. In this …

Computational Design Of Complex Concentrated Alloys, Hamid Sharifi

Doctoral Dissertations

A high-throughput parameterization of modified embedded atom model (MEAM) interatomic potentials for combinations of Cu, Ti, Ni, Cr, Co, Al, Fe, and Mn was carried out using a genetic algorithm. Unary systems were parameterized based on DFT calculations and experimental results. MEAM potentials for 28 binary and 56 ternary combinations of the elements were parameterized to DFT results that were carried out with semi-automated frameworks. Specific attention was made to reproduce properties that impact compositional segregation, material strength, and mechanics. Utilizing the MEAM interatomic potentials and a Monte Carlo scheme, phase segregation in the CrNiCo, CuNiCr and CuNiCo fcc alloys …

Effectiveness Of Virtual Reality Training Environments, Lindsay Kristina Gouedy

Doctoral Dissertations

As technology has evolved so has training methodology in many applied fields. Training of aviation professionals is adapting by including technology features that allow for safer and less costly training methods. Pilot training is expensive given the number of flight hours and all that is included in the cost of flying an airplane. The main goal of this project is to assess the efficacy of the use of virtual reality environments as a valid training tool. Based on our literature review, we hypothesized that trainees perform simulated flight tasks more efficiently, with fewer errors, when trained using VR technology. The …

An Evaluation Of Self-Monitoring For Increasing Physical Activity, Holly Wiggins

Doctoral Dissertations

There are numerous benefits to engaging in daily moderate-to-vigorous physical activity, including improved bone health, better academic performance, and reduced symptoms of depression (CDC, 2016). Given the importance of increasing exercise for improved health outcomes, behavior analysts should consider increased physical activity as a therapeutic goal. Although self-monitoring has been demonstrated to be effective at increasing physical activity within a multicomponent intervention, the relative efficacy of self-monitoring alone for increasing physical activity is unknown. The purpose of this study was to extend the self-monitoring and physical activity literature by evaluating a component analysis of self-monitoring for increasing physical activity engagement …

Land Conservation Planning For Flood Resilience In New Hampshire's Coastal Watershed, Michal Zahorik

Doctoral Dissertations

Land conservation plays an important role in managing flood risk. It enhances community resilience and supports multiple ecosystem functions. This qualitative study investigates how local and regional land conservation strategies advance flood resilience in New Hampshire’s coastal watershed. Focusing on the institutional context, this thesis analyzes the effectiveness of local land conservation planning efforts, explores cross-scale interactions between local and regional planning, and identifies barriers and opportunities for flood-focused conservation projects. The data for this research were collected through semi-structured interviews with representatives of municipalities, public and private conservation organizations, regional planning commissions, partnership organizations, and landowners. The secondary data …

Neural Retrieval Through Entities And Text Understanding, Pooja Himanshu Oza

Doctoral Dissertations

For various artificial intelligence systems, automatic text understanding algorithms that go beyond mere pattern recognition are helpful. For instance, understanding web pages is beneficial for Information Retrieval (IR) systems to retrieve relevant information. In the most common form, IR systems retrieve relevant information as entities or documents in response to keywords-based queries. Traditional IR models use lexical matching between the query terms and document terms to identify relevant documents. With the emergence of neural networks, Neural IR approaches utilize deep learning techniques to learn high-dimensional representations of documents and queries that go beyond term matching.

On the other hand, with …

Three Essays On Disability Policy And Employment Of People With Disabilities, Xueting Sun

Doctoral Dissertations

The employment of people with disabilities is substantially and persistently lower than the employment of people without disabilities (Burkhauser et al., 2002; Houtenville & Bach, 2024; Livermore & Honeycutt, 2015). In 2022, using American Community Survey data, the employment-to-population ratio of people with disabilities ages 18-64 was 44.5 percent, compared to 78.9 percent for their counterparts without disabilities (Houtenville & Bach, 2024). This dissertation consists of three essays on disability policy and employment of people with disabilities. The first essay (Chapter 2) explores the effect of the Medicaid expansion, authorized by the Patient Protection and Affordable Care Act, on employment …