Digital Commons Network^™

Towards Improving Computational Modeling Of The Lumbar Spine - Impact Of Material Properties And Laminotomy On Spinal Biomechanics, Isaac K. Kumi

Mechanical & Aerospace Engineering Theses & Dissertations

Spinal ligaments play a crucial role in maintaining the mechanical stability of the lumbar spine. These dense, collagenous tissues not only resist excessive motion but also distribute loads between spinal components to protect neural structures. Traditionally, the mechanical response of ligaments has been modeled using linear elastic assumptions, which treat the tissue as having a constant stiffness regardless of loading history. While this simplifies analysis, it fails to capture the time-dependent behaviors, such as creep, stress relaxation, and hysteresis, that are characteristic of biological tissues.

Viscoelastic modeling may provide a more physiologically accurate representation by incorporating both elastic and viscous …

Toward More Challenge-Engaging Stem Students: A Narrative Inquiry Into Student Persistence In The Face Of Failure, Stephanie R. Fahey

Educational Leadership & Workforce Development Theses & Dissertations

Science, Technology, Engineering, and Mathematics (STEM) postsecondary graduates greatly contribute to advances in technology and research, and STEM fields promise graduates careers with positive long-term outcomes. Many postsecondary students initially choose STEM majors; however, less than half of those students graduate with a STEM degree. High STEM attrition is a problem that continues to vex educators and researchers. One attributable factor to high STEM attrition is students adversely reacting to initial academic failure in challenging STEM educational contexts. However, there are a lack of studies that investigate the individual experiences of students who persist despite academic failure to better understand …

Systems Statistical Engineering – Hierarchical Fuzzy Constraint Propagation, Hengameh Fakhravar

Engineering Management & Systems Engineering Theses & Dissertations

Driven by the growing need in the 21st century for integrating rigorous statistical analysis into engineering research, there is a movement to develop an integrated statistical engineering science within statistics and quality communities (Hoerl & Snee, 2010; Anderson-Cook et al., 2012). Systems Statistical Engineering research seeks to integrate the Causal Bayesian hierarchical modeling (Pearl, 2009) and cybernetic control theory within Beer’s Viable System Model (1972, 1979, 1985) and the Complex Systems Governance framework (Keating, 2014; Keating & Katina, 2015, 2016) to produce multivariate systemic models for robust dynamic systems mission performance. Cotter & Quigley (2018) set forth the Bayesian systemic …

Complex System Governance And Cyber Operations, Willie Gernard Mccallister

Engineering Management & Systems Engineering Theses & Dissertations

This dissertation examines the potential integration of Complex System Governance (CSG) within cybersecurity, emphasizing the development of a reference model for Cybersecurity Infrastructures. Traditional strategies for securing digital environments have struggled to address the intricate and dynamic layers inherent in modern cybersecurity systems. The purpose of this research is to explore the applicability of CSG as a framework to assess cybersecurity infrastructure using a case study research design. The research addresses two key questions: (1) How can the CSG reference model be adapted to explore cybersecurity infrastructure? (2) What results from CSG based exploration of cybersecurity infrastructure through a case …

Effects Of Sediment Composition On Spartina Alterniflora And Juncus Roemerianus Productivity In Coastal Virginia: A Thin-Layer Sediment Placement Experiment, Caitlin Hemphill

Biological Sciences Theses & Dissertations

Climate change poses a major threat to the health of estuaries and their coastal wetland systems. The Chesapeake Bay’s coastal salt marshes are at high risk of inundation due to sea-level rise and land subsidence. Restoration techniques for maintaining coastal marsh resistance to sea-level rise are being developed and refined, with thin layer placement (TLP) emerging as a feasible solution in many areas of the United States. Despite TLPs use across the country, additional research is needed on species-specific responses, sediment types, and geographically focused studies in the lower Chesapeake Bay. My research addresses these gaps by combining both greenhouse …

Analysis On Plasma Propulsion Thruster Material Reconfiguration For Thrust Stabilization, Chinedumu Chidiebere Okafo

Mechanical & Aerospace Engineering Theses & Dissertations

Rocket propulsion has been a primary focus for scientific and technical advancement supporting space exploration. For long-duration, low-thrust space missions, propulsion systems designed with plasma energy as the primary source for generating thrust are of high interest. Plasma energy, like electric propulsion, involves the excited state of ionized atoms, where the ionized particles are separated and then act as a propellant to push a spacecraft in the intended direction for flight. Although more energy efficient compared to traditional rocket systems, plasma propulsion has the deficiency of consistent erosion of the metallic containment substrate, as plasma is being generated and released …

Good And Safe: Exploring The Impact Of Mindfulness And Primal World Beliefs On Psychological Well-Being, Katelyn J. Haschke

Psychology Theses & Dissertations

Dispositional mindfulness refers to the ability to intentionally focus on the present moment, which positively affects psychological well-being (PWB). Mindfulness can be practiced through formal interventions—such as meditation or body scan, where individuals engage in structured activities to cultivate awareness—or informal practices, such as focusing on one task at a time where mindfulness is integrated into routine activities. A person’s phenomenological perspective, shaped by their core beliefs about the world (primals), also influences PWB. For instance, those who view the world as mostly safe or good may be more likely to form close relationships and engage more deeply with their …

A Strict Physicality-Preserving Scheme For A 2d Q-Tensor Flow With A Singular Potential, Md Mashud Parvez

Mathematics & Statistics Theses & Dissertations

Nematic liquid crystals are a state of matter that exhibit properties between those of conventional liquids and solid crystals. Their unique ability to align molecules in specific directions makes them essential in various applications, including display technologies and advanced materials. To model their complex behavior, mathematical frameworks such as the Q-tensor model are used to describe the orientation and degree of molecular order. In this work, we introduce a numerical scheme for a two-dimensional (2D) dynamic Q-tensor model, which is formulated as an L²-gradient flow driven by the liquid crystal free energy and incorporates a singular potential to …

Analysis Of Multi Grade Deep Learning, Ronglong Fang

Mathematics & Statistics Theses & Dissertations

Multi-Grade Deep Learning (MGDL) is a training framework that incrementally builds deep neural networks. It does this by dividing the training process into multiple “grades,” where each grade sequentially trains a shallow neural network to learn the residue from the previous one, using the outputs of prior grades as input. This approach progresses from shallow to deep architectures. This dissertation offers a comprehensive theoretical and numerical analysis of the MGDL methodology.

We first demonstrate that MGDL can effectively learn target functions within the sum-composition learning format. In this context, MGDL approximates high-frequency components by composing multiple low-frequency functions. This unique …

Enhancing Non-Visual Interaction With Online User-Generated Content, Mohan Krishna Sunkara

Computer Science Theses & Dissertations

The Web has become the dominant medium for our everyday activities, including communication, business, e-commerce, news, and entertainment. Consequently, the online world is experiencing an explosion of User-Generated Content (UGC), particularly on social media platforms and online review systems. To facilitate convenient interaction with UGC, web platforms have adopted various presentation strategies that enable users to efficiently browse and contribute to the UGC. However, these user interfaces are primarily designed for sighted individuals, so they do little to assist blind users who rely predominantly on audio-based screen reader assistive technology. The extant efforts to improve web interaction for blind users …

From First-Generation To Flourishing: Exploring The Influence Of Academic, Social, And Deeper Life Interactions In Higher Education, Melissa Jean Overton

Educational Leadership & Workforce Development Theses & Dissertations

Despite comprising half of all undergraduate students (RTI International, 2024) and being widely studied in higher education literature, first-generation students experience many barriers to success and are less likely to graduate than continuing-generation students (Engle & Tinto, 2008; Fry, 2021; Kezar et al., 2023). Social science and higher education scholars have identified flourishing, the presence of complete mental health and holistic well-being (Keyes & Haidt, 2003), as an important outcome of higher education beyond more traditional success metrics, with the thought that flourishing promotes success in other areas.

This study explored how first-generation students’ academic, social, and deeper life interactions …

Testing An Ironic Process Model Of Emotion Expression In Daily Life, Laura B. Kenneally

Psychology Theses & Dissertations

Expressive suppression, or suppressing the expression of an emotion, is a common emotion regulation approach that has been found to have substantial negative implications for one’s mental health, physical health, and relationship functioning. However, expression of emotion, and of negative emotion in particular, has not consistently been found to be beneficial for mood or relationships. Moreover, the social expression of emotion that is culturally valued among Black-identifying Americans is different in White-identifying Americans, particularly in regard to expression of negative affect. However, it is unknown whether this cultural context mitigates the potential consequences of expressive suppression and emotion expression.

Expressive …

School Counselor Burnout And Self-Efficacy And Their Impact On The Degree Of Implementation Of A Comprehensive School Counseling Program, Rebecca Pierre-Louis

Counseling & Human Services Theses & Dissertations

School Counselors are educators who are vital in supporting students’ educational development. School Counselors do this by delivering a comprehensive, developmentally appropriate, and prevention-oriented school counseling programs that provide direct, indirect, and responsive services to support students’ career, academic, and social/emotional development. School Counselors do this while often experiencing an expanded definition of their role within a school building. While research supports the benefits of comprehensive school counseling programs to schools and students, school counselors often face large student caseloads. As well, they are tasked with many non-school counseling duties, which hampers the delivery of a comprehensive school counseling program. …

Inter-Cellular Forces Modulate Cell-Ecm Traction Forces, Zaria Booth

Mechanical & Aerospace Engineering Theses & Dissertations

Epithelial cells are among the most abundant cell types in the human body, making up sheets of epithelial tissues that cover the linings of organs and body cavities. Cellular adhesion and force transmission across epithelial tissues are crucial in maintaining tissue integrity and ensuring proper tissue regeneration. Defects in cellular force transmission have been found in various diseases, including cancer. Force transmission at cell-cell and cell-ECM junctions drive cell survival and development. It has been previously shown that changes in cell-ECM traction directly modulates forces at cell-cell contacts. In this study, we aim to determine the effects of perturbations in …

Reproductive Redlining: Unraveling Historical Disparities And Facility Placement In Distance To Licensed Childcare Facilities, Reproductive Health Clinics, & Crisis Pregnancy Centers For Women In The Southern Region Of The United States, Mackenzie A. Kibler

Sociology & Criminal Justice Theses & Dissertations

This dissertation investigates how historical and structural inequalities shape contemporary access to reproductive health services, licensed childcare facilities, and crisis pregnancy centers across Mississippi, Virginia, and Maryland. Using feminist geography, reproductive justice theory, and historical trauma theory, this research develops the concept of reproductive redlining to explore how race, policy, and space intersect to produce health disparities. By combining GIS mapping with multivariate statistical analysis and redlining data from the Home Owners’ Loan Corporation (HOLC), the study evaluates spatial distributions and demographic correlates of facility access before and after the Dobbs decision. Findings reveal enduring spatial inequities that disproportionately impact …

'Managed Hearts’ In Helper-Education: Gender Non-Binary Helper-Educators’ Experiences Of Emotional Labor, Jordan Pearce

Counseling & Human Services Theses & Dissertations

The unique experiences of people who identify with a gender beyond the binary paradigm dominant in the Global West are not well understood. The literature provides little insight into the experiences and perspectives of these individuals in a variety of contexts, including in their workplaces. As various social movements collide, they bring amplified attention to the mental health of marginalized communities and to workers, as well as the dynamics of modern work environments, and the specific needs of certain individuals doing certain types of work. The current study explored the experiences of gender non-binary individuals (GNI) working as helper-educators engaged …

Valorizing Cement Kiln Dust And Glass Powder: A Binder Study On Sustainable Partial Cement Replacement, Sai Kiran Simhadri

Civil & Environmental Engineering Theses & Dissertations

The production of cement ranks as a major source of global CO₂ emissions because of the high energy requirements needed to create clinker. The construction industry is actively seeking ways to reduce its carbon footprint. Utilizing industrial waste materials to partially replace cement can lower emissions. This research evaluates a ternary binder system which uses Cement Kiln Dust (CKD) and Glass Powder (GP) to replace a portion of Type IL (Portland Limestone) cement. The mixes were made with a fixed water-to-binder ratio of 0.44 and contained 15% GP by mass while the CKD content ranged from 0% to 10%. The …

Enhancing The Design Of Strained Superlattice Gallium Arsenide Based Photocathodes With Distributed Bragg Reflector, Adam D. A. Masters

Electrical & Computer Engineering Theses & Dissertations

Particle accelerators play a crucial role in our understanding of matter and the universe and have numerous practical applications in various fields. These devices enable scientists to examine the smallest components of matter, study the forces that govern their interactions, and probe conditions from the early universe. Moreover, accelerators are valuable in medicine, industry, and research, enhancing imaging methods, cancer therapies, and manufacturing techniques. As the experiments conducted at these facilities evolve and require higher precision, improved particle sources must continue to advance to keep up with their requirements. To do that, we enhanced the design of spin polarized electron …

An Optimized Generalized Multi-Color Point Implicit Solver For Intel Gpus Using Intel Oneapis Esimd, Joseph Wassell

Computer Science Theses & Dissertations

The growing popularity of Computational Fluid Dynamics (CFD) simulations among engineers necessitates the use of GPU acceleration for increased efficiency. NASA FUN3D offers GPU accelerated CFD simulations using unstructured grids across the speed regime from incompressible to hypersonic flows involving reentry. This work focuses on the generalized multi-color point implicit solver used in FUN3D, accounting for roughly half of the run time. Specifically, this work focuses on developing three optimized multi-color linear-solver kernels for the Intel Data Center Max 1550 GPU that is available on the Argonne Leadership Computing Facility’s (ALCF) exascale machine, Aurora. These optimized kernels work for a …

Language Barriers In Accessing Healthcare Services For Refugees In The United States, Sadaf Khuram

Communication & Theatre Arts Theses

Accessing healthcare is a pivotal aspect of refugees' integration into their host countries and significantly impacts their long-term health outcomes. The literature emphasizes the critical role of language proficiency in overcoming communication barriers within healthcare settings. This thesis, however, challenges the assumption that addressing language barriers alone is universally sufficient. It argues that the importance of language solutions is context-dependent, varying with the design of healthcare systems and the diverse needs and backgrounds of refugees. In some cases, focusing primarily on language barriers can divert resources from other critical areas, particularly when healthcare facilities have limited capacities or when services …

“We Are Trans, But We’Re Not Transitional”: Exploring Safety, Place, And Space In The Lives Of Transgender Individuals In Southeastern Virginia, Susana Avalos

Sociology & Criminal Justice Theses & Dissertations

In general, little research exists on trans people’s spatial experiences despite space being highly relevant to their experiences of violence and perceptions of safety. To date, two criminological studies have examined LGBTQ people’s fear of crime in relation to public or private places and spaces. This is in stark contrast to the sizable place and space literature on cisgender men and women. These topics from the perspectives of trans people are underexplored primarily because most criminological research has historically upheld binarized understandings of gender. Safety should not be privileged or limited to certain groups, individuals, or spaces. Instead, safety should …

Persistence And Completion Rates Of Community College Students: The Impact Of Receptivity To Social Engagement Scores Compared To Recorded Cocurricular Activity, Nancy Wagner Boylan

Educational Leadership & Workforce Development Theses & Dissertations

This study examined the relationship between Ruffalo Noel Levitz College Student Inventory Receptivity to Social Engagement scores and the persistence and completion of community college students. The Ruffalo Levitz College Student Inventory assesses student receptivity to institutional support services. Receptivity scores indicate a student's willingness to accept help in areas such as academic support and social engagement as well as career and financial guidance.

This research explored the impact of documented cocurricular involvement, measured through student activities indicators, on persistence and completion outcomes. Using ex post facto data and binary logistic regression analyses, the research focused on three populations at …

Effect Of Moderate Decrease In Contractility On Epithelial Cell-Cell Contacts Under External Stretch, Saika Sharmin

Mechanical & Aerospace Engineering Theses & Dissertations

Epithelial tissues are characterized by extensive cell–cell contacts and often subject to stretch during normal function. Cell-cell contact adhesion strength maintains mechanical continuity from cell to cell. Mechanical forces exerted by cells via actomyosin contractility are known to strengthen cell-cell adhesions to a certain extent. While it is known that a large decrease in contractility causes cell-cell contact rupture due to weakened adhesions, it is unclear how a moderate reduction in contractility affects cell-cell junction stability. Here, we studied how a moderate inhibition of non-muscle myosin II (NMII) affects the integrity of epithelial cell-cell contacts, especially when subject to the …

Flux Trapping Sensitivity On The Metallurgical State Of Superconducting Radio Frequency Niobium, Bashu Dev Khanal

Physics Theses & Dissertations

Trapped magnetic flux in superconducting radio-frequency (SRF) niobium cavities due to the incomplete Meissner effect is a significant source of rf losses. The relationship between flux expulsion and flux trapping sensitivity to the metallurgical state of 1.3 GHz and 3.0 GHz SRF niobium cavities fabricated from standard and cold-worked Nb sheets and subjected to various heat treatments has been studied. Flux expulsion increased with higher heat treatment temperature in all cavities. Nb cavities made from cold-worked sheets showed better flux expulsion after 800 ◦C/3 h compared to the standard SRF-grade Nb cavities. Similar flux expulsion was observed after annealing at …

Exploring The Relationship Between Cannabis Use Motives And Readiness To Change Among Young Adult College Students, Emma Kathryn Rawls

Psychology Theses & Dissertations

Cannabis use among young adult college students has risen steadily over the past decade, raising concerns about the associated health, academic, and psychological consequences. While cannabis use motives and readiness to change have each been linked to use patterns and outcomes, limited research has examined how these factors interact. The current study investigated whether readiness to change, based on the Transtheoretical Model (TTM), moderates the relationship between cannabis use motives and cannabis-related consequences as well as past-30-day use frequency. A sample of 100 college students 18-25 years old (M_age = 20.08, SD = 2.12; 67% female; 55.0% Black or …

Computational Investigation Of Energetic Materials: Influence Of Electronic And Steric Properties On Sensitivity And Decomposition Mechanisms, Elizabeth Ruth Zengel

Chemistry & Biochemistry Theses & Dissertations

Developing novel high energy density materials (HEDMs) requires knowledge of the causes and mechanisms of detonation. These chemical events are almost instantaneous and involve the release of a large amount of energy, which limits the experimental studies that can be performed on them. Computational methods including density functional theory (DFT) and molecular dynamics (MD) simulations have been used to investigate trigger bonds, those which break to initiate detonation. These bonds are commonly found within explosophores, substituents that increase the explosive potential of a molecule.

The Wiberg bond index (WBI) is an estimation of orbital overlap and bond strength between two …

Service With A Smile Or Salesperson Mirroring? Understanding The Flow Of Emotional Contagion In Sales Encounters, Vinh Quoc Trong Luong

Theses and Dissertations in Business Administration

This study examines the directionality of emotional contagion in sales interactions, addressing a critical gap in understanding whether emotions flow primarily from the salesperson to the customer, from the customer to the salesperson, or bidirectionally. While prior research emphasizes customer-driven emotional flow or bidirectional alignment, this study challenges these assumptions by employing categorical Cross-Recurrence Quantification Analysis (CRQA) to assess temporal emotional synchronization in sales dialogues. Leveraging automated sentiment analysis and multi-agent AI evaluation for performance metrics, the research analyzes 166 sales interactions to quantify emotional influence dynamics. Results reveal that salespeople predominantly lead emotional exchanges, exhibiting stronger and more stable …

Explanations For Racial Inequality In America; Effects Of Protestant Beliefs, Behaviors And Region, Qurshonda Shannae Lomans

Sociology & Criminal Justice Theses & Dissertations

The founder of the Center for the Study of Social Policy in Washington DC, Tom Joe (1987) released an article examining economic disparities between Black and White Americans. Across the measures of income, poverty and unemployment rates, Black Americans were found to be at an economic disadvantage. According to current data published by the U.S. Department of Commerce (2018), the economic wealth gap has remained unequal. Prior research examining racial inequality has found Protestantism to be a foundation from which Americans form their ideologies about social issues (Hunt, 2007; Edgell & Tranby, 2007; Taylor & Merino, 2011). Data provided by …

The Effects Of The Chief Information Officer’S Presence And Tenure On Financial Performance, Xuemei Li

Theses and Dissertations in Business Administration

CIOs should be at the core of the organization. They play more and more critical roles in organizations. However, CIOs have not been paid enough attention in many firms. This can be partially observed in a lack of studies about CIOs, for instance, how CIOs influence the organizations, and how organizations' settings influence the CIOs. Technical initiatives or innovations may be the bridge between CIOs and firm performance. Different theories have been employed concerning CIOs, innovations, and firm performance. For instance, the resource-based view (RBV) has served as a theoretical foundation in related studies.

Drawing on RBV, attention-based view (ABV), …

Examining How Self-Regulated Learning Professional Development Affects Teacher Srl Knowledge, Beliefs, And Practices, Stephanie Greenquist-Marlett

STEMPS Theses & Dissertations

Self-regulated learning (SRL) strategies promote valuable student learning outcomes including academic achievement and lifelong learning (EU Council, 2002). Teachers have an opportunity to cultivate student SRL development within their classrooms (Azevedo et al., 2008). While teachers believe in the benefits associated with SRL promotion (Spruce & Bol, 2014), their positive attitudes are not often supported by adequate knowledge of SRL strategies. This leads to a lack of self-efficacy for developing SRL instruction in classrooms (Dignath & Büttner, 2018; Zimmerman et al., 1996). SRL-based professional development (PD) interventions have demonstrated their effectiveness for increasing teacher SRL instruction and implementation (Cleary et …