Digital Commons Network^™

Improving The Flexibility And Robustness Of Machine Tending Mobile Robots, Richard Ethan Hollingsworth

Theses and Dissertations

While traditional manufacturing production cells consist of a fixed base robot repetitively performing tasks, the Industry 5.0 flexible manufacturing cell (FMC) aims to bring Autonomous Industrial Mobile Manipulators (AIMMs) to the factory floor. Composed of a wheeled base and a robot arm, these collaborative robots (cobots) operate alongside people while autonomously performing tasks at different workstations. AIMMs have been tested in real production systems, but the development of the control algorithms necessary for automating a robot that is a combination of two cobots remains an open challenge before the large scale adoption of this technology occurs in industry. Currently popular …

Treatment Access And Outcomes For Craniofacial Care: Patient And Parent Perspectives, Benjamin F. Lowe Iii

Theses and Dissertations

Objective: The purpose was to evaluate whether craniofacial patients and their parents have adequate access to care, perceive this care as high quality, and believe that the incorporation of telehealth visits would benefit their current system of craniofacial care. Methods: An original survey was developed and sent to families in treatment with the Virginia Commonwealth University craniofacial team. The tool was used to gather demographic information and assess opinions toward access to, outcomes of, and telehealth services for craniofacial care. Patients 18 years and older took the survey for themselves, while patients under 18 years old had a parent/guardian take …

Youth And Caregivers' Perceptions Of Racial Socialization: Examining The Interactive Role Of Risk And Cultural Resilience Factors As Predictors And Mental Health As Outcomes, Arlenis Santana

Theses and Dissertations

Black families' mental health, including that of the children and caretakers, is a persistent public health concern. Existing work documents that parental racial socialization messages are a protective process for the psychological well-being of Black children, youth, and emerging adults (Bannon et al., 2009). The majority of work to date has focused on youth, and we have limited information about the effects of racial socialization on caregivers’ mental health outcomes. It is also essential to examine the relation between racial socialization and outcomes among caregivers because, aside from their identity as parents, caregivers have other identities and experiences that deserve …

Effect Of Apical Preparation Size On Endodontic Treatment Outcomes, Joseph Vaughn

Theses and Dissertations

Objective: Previous authors have attempted to identify the ideal apical preparation size needed to achieve endodontic treatment objectives. Despite vast literature on the topic, there exists a lack of consensus on ideal apical enlargement, with few studies discussing the effect of apical prep enlargement on clinical outcomes. The purpose of this retrospective study was to evaluate the effect of final apical preparation size on endodontic outcomes in maxillary and mandibular molars treated in both a graduate endodontic clinic and a private practice.

Methods: A chart review was conducted for patients seen at the VCU graduate endodontic clinic as well as …

Utilization Of Occupational Therapy Services For Patients With Cancer In Acute Care Settings, Christine Mcnichols

Theses and Dissertations

For patients with cancer diagnoses, effects from the disease or as a result of cancer treatments can cause profound impairments impeding patient functioning and independence. These assaults to the independent achievement of activities have far reaching implications and linkages to a patient’s length of stay and their likelihood of a hospital readmission. Unfortunately, occupational therapy services have frequently been found not to be ordered for patients with cancer, even when there have been demonstrated functional deficits and needs. Through the analysis of patient records from a National Cancer Institute hospital over 5 years, the current study investigated occupational therapy services …

How Do Cultural Norms Shape Healthy Eating In African Americans? The Role Of Cultural Congruence And Mindsets Of Health In Healthy Eating Intentions Among African American College Students, Danyel Smith

Theses and Dissertations

Targeting dietary behaviors is a predominant strategy to reduce rates of obesity among African Americans, across the lifespan. Notably, dietary behaviors are shaped by social, cultural and environmental affordances. This study integrated Theory of planned behavior (TPB), identity-based motivation, and mindset theory to unearth cultural mechanisms that inform motivations to eat healthy among African American college students. This project employed a cross-sectional (Study 1) and experimental design (Study 2) to contextualize the antecedents of intentions to eat healthy among African American college students. Recruitment occurred via university-wide digital channels. Eligible participants: were 18+ years; Black/African American; were undergraduate students; and …

Evaluating How Acidic Solutions Affect The Microhardness Of Bioceramic Sealers, Colton Fischer

Theses and Dissertations

Introduction: With growing use of bioceramic sealers (BCS) in root canal therapy, there have been challenges when retreating BCS cases. Weak acids may be effective in removing BCS and their efficacy as a solvent can be measured by their influence on the microhardness of BCS. Microhardness can be used as an indirect measurement of material hardness. The purpose of this study was to investigate the microhardness of BCS when placed in contact with various acidic solutions to assess their potential use as a solvent for retreatment procedures.

Methods: EndoSequence BC Sealer (Brasseler USA) was injected into four 10 × 3mm …

Emergent Trends Of Contemporary Dramatic Recontextualization: An Exploration Utilizing Eugene O'Neill's Mourning Becomes Electra, Cameron M. Nickel

Theses and Dissertations

The art of adaptation in the realm of drama has undergone an easily recognizable evolution in the past couple of decades, from the work of Sarah Ruhl to Branden Jacobs-Jenkins. This evolution has opened doors to an altogether new form of adaptation in the theatre: dramatic recontextualization. While the two forms are built upon a foundation of shared aspects, there are certain observable and quantifiable delineations between the two artistic forms. As this trend continues to grow exponentially in the world of theatre, it is important to further research the origins and methodologies of contemporary dramatic recontextualization, both to provide …

Dental Treatment Planning: Decisions With Interdisciplinary Cases, William W. Porzio

Theses and Dissertations

Purpose: To explore the variance in treatment planning options with interdisciplinary cases that involve a combination of endodontic, periodontic, and prosthodontic factors.

Methods: A REDCap survey was emailed to Virginia based American Academy of Periodontology (AAP) members, American College of Prosthodontists (ACP) members, and periodontal residents to assessing various treatment planning options for six interdisciplinary cases.

Results: A total of 56 individuals responded to the survey; 10 periodontal residents, 35 practicing periodontists, 11 practicing prosthodontists. Response rate was not able to be evaluated based on the fact that third-party organizations were used to disseminate the survey in …

Exploring The Impact Of Covid-19 On Adults With Intellectual And Developmental Disabilities In The United States, Sarah Lineberry

Theses and Dissertations

Like most disasters, the COVID-19 pandemic has disproportionately impacted people from historically marginalized communities. People with intellectual and developmental disabilities (IDD) have faced higher rates of infection, hospitalization, and death compared to people without disabilities, as well as significant disruptions to the services that support them to participate in the community. A relative lack of research about the experiences of people with IDD may have contributed to this risk and continues to limit our understanding of the impacts of COVID-19. This three-paper dissertation is guided by the theory of epistemic injustice (Fricker, 2007) to understand the impacts of COVID-19 on …

Dune Building Dynamics Impact Cross-Island Connectivity And Barrier Island Characteristics, Alexander Sabo

Theses and Dissertations

Located at the land-sea interface, barrier islands are important protective features that reduce wave energy and erosion from mainland areas. Further, barrier islands provide habitat for many different organisms and serve as popular areas for recreation and tourism. As sandy landforms, barrier islands are easily disturbed, but often recover after disturbance as a result of island plant communities, specifically dune building grasses. Disturbance on barrier islands is driven by storms, tides, and overwash events. After disturbance has occurred, dune grasses colonize the dunes allowing for dune building and habitat restoration. On the Virginia barrier islands, there are three dominant dune …

A Methodology Of Paradoxes: Investigating Authenticity In The Representation Of Queerness On The Contemporary Stage, Kendall C. Walker

Theses and Dissertations

In my experience as a queer theatre practitioner, performer, and student, I have always had questions of ownership and authenticity when it comes to LGBTQIA+ narratives on the contemporary theatre stage. The question of: “Who is allowed to tell what story?” and the many complex ideas that this leads to, is what has inspired this thesis and my own pedagogy of intersectionality and inclusivity.

The purpose of this thesis is to investigate the relationship between authenticity and queerness on the contemporary stage in order to develop a methodology for how all theatre practitioners—no matter their identity—can effectively tell queer-identifying stories …

Acculturative Stress And Quality Of Life Among Older Korean Immigrants: Do Religiosity And Resilience Matter?, Sunghwan Cho

Theses and Dissertations

The impact of acculturative stress on the quality of life among older adults has been widely acknowledged in previous literature. However, few studies have explored the role of religiosity and resilience in this relationship among older Korean immigrants. This dissertation explores the relationships between acculturative stress, religiosity, resilience, and quality of life among 300 older adults aged 65 years and over who live in an ethnic Korean enclave of Queens, New York. The study employs path analysis and multiple regression analyses to test hypothesized relationships among these variables.

The key findings of the study are as follows: (1) higher acculturative …

Wifi Sensing At The Edge Towards Scalable On-Device Wireless Sensing Systems, Steven M. Hernandez

Theses and Dissertations

WiFi sensing offers a powerful method for tracking physical activities using the radio-frequency signals already found throughout our homes and offices. This novel sensing modality offers continuous and non-intrusive activity tracking since sensing can be performed (i) without requiring wearable sensors, (ii) outside the line-of-sight, and even (iii) through the wall. Furthermore, WiFi has become a ubiquitous technology in our computers, our smartphones, and even in low-cost Internet of Things devices. In this work, we consider how the ubiquity of these low-cost WiFi devices offer an unparalleled opportunity for improving the scalability of wireless sensing systems. Thus far, WiFi sensing …

The Type Iv Pilus Secretin Bfpb: Structural Analysis And Binding Interactions, Janay I. Little

Theses and Dissertations

Enteropathogenic Escherichia coli (EPEC) causes severe diarrhea in young children. The type IV pilus (T4P) of EPEC, known as the bundle-forming pilus (BFP), plays an important role in EPEC pathogenesis. T4Ps are a family of surface appendages that are important for adhesion, colonization, biofilm formation, virulence, twitching motility and many other functions. One essential component of the BFP system is the secretin, BfpB. Secretins are a large family of integral outer membrane proteins found in T4Ps as well as type II and type III secretion systems, and filamentous phages. Details of the secretin structure have been limited to the overall …

Romantic Nostalgia: Examining The Motivational And Relational Outcomes, Margaret Kneuer

Theses and Dissertations

Romantic nostalgia, or the sentimental longing and wistful affection towards a romantic partner (Evans et al., in press), is a type of nostalgia pertaining to relationships that has not been addressed widely in the current literature. The goal of this research is to investigate whether romantic nostalgia buffers against conflict and promotes motivational benefits to the relationship. I extend the work on the restorative nature of nostalgia to close relationships and explore cognitive, motivational, and behavioral relationship maintenance strategies. Study 1 sampled university students currently in romantic relationships to examine the association between romantic nostalgia proneness and compassionate goals. Romantic …

Using A Single Measure To Assess Adherence And Differentiation In Family Therapy For Adolescent Externalizing Problems, Stephanie Violante

Theses and Dissertations

Family therapy is considered a well-established treatment approach for adolescent externalizing problems; however, research examining its effectiveness when delivered in routine practice settings has produced mixed results. The accurate interpretation of these inconsistent results requires an understanding of what therapeutic techniques were delivered, including those that were prescribed (i.e., adherence) and those that were non-prescribed (i.e., differentiation), suggesting the need for a measure that can concurrently assess treatment adherence and differentiation. The current study examined the extent to which an observational measure of an array of therapeutic techniques for youth emotional and behavioral problems (the Therapy Process Observational Coding System …

Aerosol Synthesis Of Tungsten Bronze Particles For Nir Shielding, Hao Tu

Theses and Dissertations

This dissertation emphasizes the need for efficient energy use in buildings and transportation due to global warming and the energy crisis. It suggests that improving energy efficiency can help reduce energy consumption and emissions and support sustainability. The dissertation introduces various transparent materials that can block near-infrared (NIR) radiation from solar radiation to save energy and money, and it highlights the growing market value of such products. The dissertation compares tungsten bronze with other NIR shielding materials and shows its advantages. The dissertation introduces a cheap and environmentally friendly method for continuously producing tungsten bronze particles via aerosol synthesis. Particle …

A Longitudinal Analysis Of Academic Self-Concept Among Preclinical Medical Students, Meagan Rawls Lewis

Theses and Dissertations

Medical school plays a pivotal role in the training of future physicians. Academic Self-Concept (ASC) represents a person’s beliefs about their academic ability, and it has been documented across educational contexts as an important factor in relation to academic performance. Despite decades of research into the relationship between ASC and academic performance, this relationship remains underexplored in medical education. The purpose of this study was to examine the ASC of preclinical medical students using longitudinal data to explore both the relationship between ASC and performance and ASC throughout the preclinical phase of medical school. Survey data from three cohorts of …

Access To Hiv Prevention, Care, And Treatment Services In The Us: The Role Of Primary Care, Jessica S. Kiernan

Theses and Dissertations

This dissertation examines the role of access to primary care in benefitting HIV outcomes through increased access to HIV prevention, care, and treatment services, among populations disproportionately affected by HIV in the US. Over 30,000 individuals are newly diagnosed with HIV annually in the US and diagnoses are concentrated in specific populations. At an individual-level, ~ 70% of new diagnoses are among gay and bisexual men and of those diagnoses, 70% are among Non-Hispanic Black and Hispanic gay and bisexual men. At a community-level, over 50% of new HIV diagnoses occur in less than 2% of US counties (48), Washington, …

Natural Hazard Uncertainty Characterization And Risk Assessment For Pressurized Water Reactor Safety Based On System Level Reactor Safety Analysis Models, Tao Liu

Theses and Dissertations

Natural hazard accidents, especially the Fukushima Daiichi accident that occurred in 2011, have brought up significant safety concerns regarding the nuclear power plant (NPP) under external natural hazards. As a result, external natural hazards have been identified as one of the potentially most significant risk contributors to the core damage frequency of the NPPs, highlighting the need for a better understanding of the natural hazards and their associated uncertainties for probability risk assessments (PRAs). However, there are limited computational models and analysis tools to support the probabilistic evaluation of external hazards in PRAs, especially for natural hazards such as floods …

I. Preparation Of Strategic Synthetic Building Blocks For World Health Organization Essential Medicines. Ii. Applying The Principles Of Process Intensification To The Synthesis Of Fluoroquinolone Antibiotics., Jeffrey M. Noble

Theses and Dissertations

The synthesis of active pharmaceutical ingredients is often a time-consuming and expensive process. Due to the nature of pharmaceutical manufacturing, these costs are carried forward to the final purchase price by the consumer. Although there are many factors which are involved in the final costing of a pharmaceutical, the cost associated with the synthesis is the primary one which can be managed by chemists and engineers.

This work discusses the synthetic routes of four active pharmaceutical ingredients as well as the synthetic techniques and equipment used with an emphasis on how the application of specific techniques can be applied to …

Material Extrusion-Based Additive Manufacturing: G-Code And Firmware Attacks And Defense Frameworks, Haris Rais

Theses and Dissertations

Additive Manufacturing (AM) refers to a group of manufacturing processes that create physical objects by sequentially depositing thin layers. AM enables highly customized production with minimal material wastage, rapid and inexpensive prototyping, and the production of complex assemblies as single parts in smaller production facilities. These features make AM an essential component of Industry 4.0 or Smart Manufacturing. It is now used to print functional components for aircraft, rocket engines, automobiles, medical implants, and more. However, the increased popularity of AM also raises concerns about cybersecurity. Researchers have demonstrated strength degradation attacks on printed objects by injecting cavities in the …

Variability In Causal Effects On A Binary Outcome And Noncompliance In A Multisite Randomized Trial, Xinxin Sun

Theses and Dissertations

Noncompliance to treatment assignment is widespread in randomized trials and presents challenges in causal inference. In the presence of noncompliance, the most commonly estimated effect of treatment assignment, also known as intent-to-treat (ITT) effect, is biased. Of interest in this setting is the complier average causal effect (CACE), the ITT effect among compliers. Further complication arises when the outcome variable is partially observed.

My research focuses on estimating the distribution of a site-specific CACE in a multisite randomized controlled trial (MRCT) by maximum likelihood (ML). Assuming compliance missing at random (MAR). We express the likelihood as an integral with respect …

Exploring The Role Of Institutional Culture In Student Affairs Assessment Practitioners’ Experiences Implementing Equity-Centered Assessment, Jaime L. Williams

Theses and Dissertations

Student affairs assessment is a field in higher education that emphasizes the measurement of effectiveness and student learning in student serving programs that take place outside of the classroom. Outcomes-based assessment is the basis of most assessment practices in student affairs, and focuses on the continuous improvement of out-of-classroom programs, services, and student learning. Many assessment practices stem from traditional research methods, which have been developed by people who hold mostly majority identities. These methods were not created with the rapidly changing demographics of today’s college-going students in mind. To help address the increasing diversity of college students and the …

Quantifying Insect Emergence In Tidal Freshwaters And The Importance Of Aquatic Prey In Wetland-Dependent Songbird Diet, Samantha L. Rogers

Theses and Dissertations

Insectivorous birds and their arthropod prey are experiencing widespread population declines, driven largely by anthropogenic disturbance and climate change. For wetland-dependent insectivores that consume a mixture of terrestrial and aquatic insects, understanding the availability, consumption, and nutritional qualities of aquatic diet subsidies is important for conservation. I use prothonotary warblers (Protonotaria citrea) as a model species throughout this work, because their breeding season aligns with aquatic insect emergence and they include aquatic insects when provisioning nestlings. In the first chapter, I estimate aquatic insect emergence from tidal freshwaters, which are understudied compared to nontidal systems. Using continuous field …

Modulation Of Opioid-Induced Respiratory Depression By Stimulants And Their Associated Monoaminergic Receptor Mechanisms In Mice Using Whole Body Plethysmography, Harrison J. Elder

Theses and Dissertations

Opioid overdose and associated deaths involving opioid-induced respiratory depression (OIRD) began to accelerate beginning in 2015 with the emergence of illicitly manufactured fentanyl and its analogs and currently represents one of the most significant public health challenges in the United States. The increases in overdose deaths have occurred despite the increased availability of the opioid overdose reversal agent, naloxone, to first responders and the public. This new phase of the opioid epidemic has been paralleled by substantial growth in the co-use of opioids with stimulants, particularly methamphetamine. The objective of this dissertation is to ascertain whether fentanyl is particularly resistant …

Black Racial Identity And Externalizing Symptoms: The Regulatory Role Of Dyadic Relationships, Sultan A. Hubbard

Theses and Dissertations

This study explored caregiver impact on Black racial identity (BRI) and externalizing through the integration of BRI, racial socialization (RS), and social support theoretical frameworks. The study used 85 Black undergraduates (Mean age =19.3, SD=3.43) who rated three caregivers, respectively. Restricted maximum likelihood estimation was conducted to estimate variance components. BRI, RS, internalizing, and externalizing variables reflected significant trait effects and dyadic effects. However, racial centrality and public regard did not reflect significant dyadic effects. Participant burden due to randomization of caregivers and items likely suppressed dyadic effects. Moreover, caregivers who evoked private regard were perceived as having high cultural …

Investigating The Dynamics And Fragmentation Of Nitroaromatic Radical Cations Through Femtosecond Time-Resolved Mass Spectrometry And Computational Chemistry, Hugo Andres Lopez Pena

Theses and Dissertations

Chemists have sought to control molecular dissociation with lasers for decades. Effective control of unimolecular dissociation was only achieved with the development of high-intensity ultrashort pulsed lasers and coherent control techniques that operate on timescales faster than vibrational energy redistribution. In view of this, our lab has specialized in the study of polyatomic radical cations using femtosecond time-resolved mass spectrometry (FTRMS). The interest in radical cations stems from the fact that they are highly reactive species that contribute to many physical, chemical, and biological processes. For instance, radical cations participate in shock initiation of detonated energetic materials used as explosives …

District-Level Supervisors: Leaders And Advocates For School Counseling, Thomas M. Mitchell

Theses and Dissertations

All school counselors are expected to serve as leaders and advocates in their school communities. However, many are underprepared for the work after they complete graduate-level training. The present study explored the experiences of district- level school counseling supervisors in facilitating leadership development with professional school counselors. District-level supervisors are ideally placed to support school counselors in their leadership development and advocacy work. Through a semi- structured interview process, eight district-level school counseling supervisors provided information about their leadership development experiences. Data analysis yielded four themes in this descriptive phenomenological study involving social justice, role advocacy, barriers to effective leadership, …