Digital Commons Network^™

Communication In Phelan-Mcdermid Syndrome: Assessment And Genotype-Phenotype Correlation, Sarah Quadri

All Dissertations

Phelan McDermid Syndrome (PMS) is a rare genetic disorder caused by deletions or mutations of the SHANK3 gene on chromosome 22q13.3. Language and communication impairment are hallmark features of PMS, and this dissertation aims to address the lack of consensus on appropriate methods for assessing these abilities and genotype-phenotype correlations of language and communication impairments in PMS.

The first chapter introduces PMS and associated language and communication impairment, identifies gaps in the literature, and shows how this research fills those gaps to advance our understanding of this rare genetic disease. The second chapter identifies and analyzes practices for assessing speech, …

Multiparametric Continuous And Mixed-Integer Nonlinear Optimization With Parameters In General Locations, Andrew Pangia

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Convex programming has been a research topic for a long time, both theoretically and algorithmically. Frequently, these programs lack complete data or contain rapidly shifting data. In response, we consider solving parametric programs, which allow for fast evaluation of the optimal solutions once the data is known. It has been established that, when the objective and constraint functions are convex in both variables and parameters, the optimal solutions can be estimated via linear interpolation. Many applications of parametric optimization violate the necessary convexity assumption. However, the linear interpolation is still useful; as such, we extend this interpolation to more general …

Beyond Just Money Transactions: Redesigning Digital Peer-To-Peer Payments For Social Connections, Lingyuan Li

All Dissertations

Financial activities, such as the exchange of money between individuals, have long been considered a crucial aspect of how people build and maintain their interpersonal relationships (i.e., a strong, deep, or close association/acquaintance between two or more people) with individuals they know because money is a sensitive social construct. In particular, over the past decade, how to conduct, manage, and experience money exchanges and processes between individuals has been dramatically transformed due to the increasing popularity of digital peer-to-peer (P2P) payment services (i.e., performing one to one online money transactions via a digital device). In this sense, digital P2P payments …

Deep Reinforcement Learning And Game Theoretic Monte Carlo Decision Process For Safe And Efficient Lane Change Maneuver And Speed Management, Shahab Karimi

All Dissertations

Predicting the states of the surrounding traffic is one of the major problems in automated driving. Maneuvers such as lane change, merge, and exit management could pose challenges in the absence of intervehicular communication and can benefit from driver behavior prediction. Predicting the motion of surrounding vehicles and trajectory planning need to be computationally efficient for real-time implementation. This dissertation presents a decision process model for real-time automated lane change and speed management in highway and urban traffic. In lane change and merge maneuvers, it is important to know how neighboring vehicles will act in the imminent future. Human driver …

Developing A Cultural Management Approach To Bermudagrass Mite (Acari: Eriophyidae) Infestation, Matthew Brown

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Bermudagrass mite (Aceria cynodoniensis Sayed) (Acari: Eriophyidae) infestation stunts bermudagrass growth, leading to thinned turf and lower aesthetic and recreational value. Cultural management practices may impact bermudagrass mite infestation and turfgrass recovery from mite damage. Scalping or mowing shorter may physically remove mites, while drought stress may increase grass susceptibility to mites. Fertilizer application may promote mite infestation by improving plant nutrition. I conducted greenhouse, nursery, and field experiments to evaluate the impact of nitrogen fertility, irrigation rate, mowing height, and scalping on turf health and bermudagrass mite infestation in terms of the densities of witch’s brooms (i.e., stunted …

Elucidating The Mechanical And Transport Properties Of Lignin-Based Hydrogel Composites, Nicholas Gregorich

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The use of lignin in the fabrication of soft composites has become an emerging area of research in polymer science and polymer chemistry. These lignin-based materials present numerous benefits, notably, a reduction in the use of petroleum-based precursor, improved structural benefits to otherwise soft host polymers, as well as the inherent antimicrobial and antioxidant properties of lignin, making it suitable for biomaterials. Herein, we present two chemical reaction pathways of incorporating lignin that was fractionated and cleaned using the Aqueous Lignin Purification with Hot Agents (ALPHA) process into poly(vinyl alcohol) (PVA) hydrogel composites for aqueous-based separations. By leveraging the ALPHA …

Development Of A Novel Predictive Model And Prosthetic System To Assess Dynamic Leg Length Based Gait Biomechanics In Lower Limb Prosthesis Users, Therese Parr

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Individuals with transfemoral amputation often rely on a prosthesis as a replacement for their missing extremity’s structure and function. Lower-limb prosthetic devices are developed with the goal of restoring biomechanical abilities and mitigating secondary health risks for users. However, biomechanical deficits for unilateral transfemoral prosthesis users are very common and are induced by both leg length discrepancy (LLD) and current prosthetic design shortcomings. Lack of push off power as well as difficulty shortening the leg for toe clearance can result in gait compensations that lead to asymmetric limb loading, increased muscle activity, and an increased incidence of falling due to …

Design And Implementation Of High-Efficiency, Lightweight, System-Friendly Solid-State Circuit Breaker, Dehao Qin

All Dissertations

Direct current (DC) distribution system has shown potential over the alternative current (AC) distribution system in some application scenarios, e.g., electrified transportation, renewable energy, data center, etc. Because of the fast response speed, DC solid-state circuit breaker (SSCB) becomes a promising technology for the future power electronics intensive DC energy system with fault-tolerant capability. First, a thorough literature survey is performed to review the DC-SSCB technology. The key components for DC-SSCB, including power semiconductors, topologies, energy absorption units, and fault detection circuits, are studied. It is observed that the prior studies mainly focus on the basic interruption capability of the …

The Erasure Of Rural West Texas Voices In Higher Education Institutions An Autoethnographic Study Of Minoritized Students Of West Texas In Their Journey To Obtain Success In Higher Education Institutions, David Whaley-Weems Sr

All Dissertations

I was once told there is a person in the world who has locked within his or her mind the framework for the cure for cancer or even the ability to create an energy model that will revolutionize how society consumes natural resources. Now imagine if I told you I have seen that person alive and well working as an oil well driller on a rig in Mentone, Texas. The first question most people would ask is, “Why is the person drilling in the middle of nowhere Texas instead of impacting the world by way of displaying his or her …

Women's Advancement To U.S. Higher Education Executive Leadership: An Intersectional, Secondary Data Analysis, Ann Marie Alexander

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This study focused on the issue that women are underrepresented in higher education executive and senior leadership roles at four-year colleges and universities in the United States (Dominici et al., 2009; Ginsberg et al., 2019; Gomez, 2020; Hannum et al., 2015; O’Conner, 2019; Smith, D., 2017; Teague 2015). A theoretical framework of intersectionality was used. Significant literature review findings were that the majority of studies on women in U.S. higher education leadership were qualitative and located at one university or in a single region of the country. Another finding was that more studies examining the races and ethnicity of these …

Acetate Metabolism In The Fungal Pathogen Cryptococcus Neoformans, Oly Ahmed

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Cryptococcus neoformans is an environmental basidiomycetous fungus with a worldwide distribution and a wide range of habitats. Inhalation of the desiccated yeasts or spores of C. neoformans often leads to opportunistic pulmonary infections in immunocompromised individuals, and in severe cases causes lethal meningitis following hematogenous dissemination. During infection, depending on the tissue and disease state, the invading fungi experience a range of nutrient microenvironments within the host body. As a result, rapid metabolic adaptations geared towards efficient utilization of carbon sources alternative to glucose become one of the prime determinants of survival and growth for the pathogen. Incidentally, cryptococcal infection …

The Effects Of Laser Shock Peening On The Fatigue Life Of Additive Manufactured Alsi10mg, Jacob L. Biddlecom

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Additive manufacturing (AM) is becoming a manufacturing process that is well established, even with all the resources and attention that has been brought to it, the field is still lacking some key understandings. Currently, there are certain aspects that are difficult to overcome. Some of the intrinsic obstacles include process-induced defects, such as porosity from lack of fusion and gaseous bubble entrapment, as well as complex thermal gradients. These defects can lead to altered material response especially when looking at the fatigue life. The fatigue behaviors of AM components can change from print to print as well as when compared …

Vanet Applications Under Loss Scenarios & Evolving Wireless Technology, Adil Alsuhaim

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In this work we study the impact of wireless network impairment on the performance of VANET applications such as Cooperative Adaptive Cruise Control (CACC), and other VANET applications that periodically broadcast messages. We also study the future of VANET application in light of the evolution of radio access technologies (RAT) that are used to exchange messages. Previous work in the literature proposed fallback strategies that utilizes on-board sensors to recover in case of wireless network impairment, those methods assume a fixed time headway value, and do not achieve string stability. In this work, we study the string stability of a …

My Superintendent Journey From Educator To Activist: An Autoethnography Across Three Decades, Betty Bagley

All Dissertations

Superintendents rise to the highest level of professional educational leadership within local communities. National statistics show increasing turnover in that district-level position. Superintendents come and go, which means their accomplishments fade in time. Superintendents rarely tell their stories of successes, failures, pressures, expectations, challenges, or any experiences within their highly visible role. This gap shows a lack of access to superintendents’ perspectives, and that gap may affect current and aspiring superintendents’ potential.

Given a two-century historical gap in the literature about educational leadership with few accounts from superintendents’ perspectives, my study described my journey through three superintendencies from 1993 to …

Enhanced Mobile Networking Using Multi-Connectivity And Packet Duplication In Next-Generation Cellular Networks, Prabodh Mishra

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Modern cellular communication systems need to handle an enormous number of users and large amounts of data, including both users as well as system-oriented data. 5G is the fifth-generation mobile network and a new global wireless standard that follows 4G/LTE networks. The uptake of 5G is expected to be faster than any previous cellular generation, with high expectations of its future impact on the global economy. The next-generation 5G networks are designed to be flexible enough to adapt to modern use cases and be highly modular such that operators would have the flexibility to provide selective features based on user …

Instructional Leadership Practices And Problem-Solving Processes Among Secondary School Principals During The Covid-19 Pandemic, Matthew Moore

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The purpose of this study was to explore principals’ reflections on effective instructional leadership problem-solving and practices during the COVID-19 pandemic. Generally, principals have very few evidence-based guidelines for providing instructional leadership during a global pandemic, presumably, improvising solutions to novel instructional challenges. To generate selected secondary principals’ reflections about instructional challenges during COVID-19, I used the Critical Incident Technique (CIT), an open-ended method developed by Flanagan (1954) for ascertaining participants. I selected 10 secondary school principals from the 20-school district region in a single state in the Charlotte-Atlanta corridor. All began their professional careers as teachers and their service …

A Study On Asymmetric Perfect Vortex: Fractional Orbital Angular Momentum And Nonlinear Interaction, Kunjian Dai

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In this work, the manipulation including generation and detection of the asymmetric perfect vortex (APV) carrying fractional orbital angular momentum (OAM) was demonstrated and discussed. All the manipulation of the modes is in real-time which provides a perfect tool for sensing the dynamic properties of complex media. The OAM-involved nonlinear conversion, specifically the second-harmonic generation (SHG) using the APV and asymmetric Bessel-Gaussian (BG) beams was studied in detail.

The generation and detection of the APV are based on the HOBBIT concept which includes acoustic optical deflector (AOD) and log-polar coordinate transformation optics. The RF signal driving the AOD allows the …

Bridging The Gap Between Phase Behavior And Processing For Renewable And Refinable Carbonaceous Precursors, Graham Tindall

All Dissertations

As a category of materials, engineered carbons, specifically carbon fibers, are first-in-class for properties such as modulus, specific strength, and thermal resilience; however, the inability to directly process atomic carbon necessitates the development and optimization of carbonaceous precursors. Because the structure and properties of carbon are highly dependent on the precursors and requisite processing, numerous materials have been investigated as feedstocks for large-scale production. Although cellulose and rayon were among the first investigated, polyacrylonitrile (PAN) is the current hegemon of carbon fiber precursors. PAN feeds 90% of this market, but it is neither inexpensive nor renewable. Because a significant fraction …

Essays On Manufacturing And Growth, Hugo Vaca Pereira Rocha

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The first chapter of this dissertation studies the role of human capital in generating economic convergence through its impact on manufacturing productivity growth and allocation of labor across sectors of the economy. I confirm and extend existing results showing that productivity in manufacturing – unlike its economy-wide counterpart – has exhibited convergence; that is, countries further behind the technology frontier tend to catch up to those on the frontier. I then show that the convergence in manufacturing is (a) somewhat accelerated by countries’ tertiary education levels and (b) faster in high-tech industries. Perhaps surprisingly, this is not driven by tertiary …

Computational Modeling Of Patterned Membranes And Spacers For Improved Hydrodynamics And Fouling Reduction In Reverse Osmosis Water Treatment Processes, Zuo Zhou

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My research goal is to discover ways to improve the hydrodynamics of reverse osmosis (RO) membrane systems through creative membrane surface patterning and spacer designs. Since concentration polarization (CP) usually promotes membrane fouling, improving hydrodynamics would result in reduced fouling and better membrane performance. With computational fluid dynamics (CFD), we can explore dozens or even hundreds of models with different geometries and boundary conditions. Through plotting their velocity profile, streamlines, shear stress, pressure profile, concentration profile, and so on, we can determine which design would lead to the best performance.

At first, patterned membranes were evaluated and compared with flat …

Molecular Dynamics Simulation On Molybdenum Disulfide: Thermal-Mechanical Properties And Phase Transitions Under External Loading, Mahabubur Rahman

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Due to their remarkable properties, transition metal dichalcogenides (TMDs) have received much scientific interest throughout the past decade. Two layers of chalcogen atoms (S, Se, Te) sandwich a layer of transition metal atoms (Mo, W, Ta) to form the three-atom thick unit cell in TMDs. The interaction between TMD "single layers" is mediated by neighboring chalcogen planes and bonded by Van der Waals forces. Due to this weak out-of-plane interaction, bulk samples can be thinned down to a single layer by exfoliation. Among the TMDs, Molybdenum Disulfide (MoS₂) shows promise in the field of electronics, optics, and sensing …

3d Printing With Photopolymerizable Polyester Resins For Resorbable Medical Device Applications, Mathew Murphy Stanford

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In the past decade, the healthcare industry has seen a significant increase in the use of additive manufacturing (AM or “3D printing”) with subsequent improvement in clinical outcomes.As an exceptional AM technology, vat-photopolymerization (VP), often called stereolithography, can create complex structures and has thus been adopted for a range of biomedical applications including surgical guides, temporary implants, and resorbable tissue scaffolds.However, limitations remain in the availability of photopolymerizable resin materials with appropriate mechanical performance, biodegradability, and biocompatibility for application to resorbable medical devices.

The objective of this work was to employ novel photopolymerizable polyester-based macromers in the development of resorbable …

Mesoscale Modeling Of Controlled Degradation In Polymer Networks And Melts, Vaibhav Palkar

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Controlled degradation of polymers finds various applications in fields ranging from the design of functional soft materials to recycling of polymers. In several of these applications, the characteristic length scale at which relevant processes occur ranges from nanometers to microns, typically referred to as the mesoscale. Although analytical models and continuum approaches inform our current understanding, analysis of degradation at the mesoscale is exceptionally limited. For modeling degradation at the mesoscale, we use the Dissipative Particle Dynamics (DPD) technique and the LAMMPS simulation software. Within the DPD framework, we model controlled degradation or the breaking of covalent bonds within a …

Contrasting Public And Private Approaches To Private Land Conservation In The United States: Local Government, Land Trust, And Landowner Viewpoints, Anna Overby

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In the United States (US), low-density, non-contiguous development, termed sprawl, has long been of widespread concern. Since the 1970s, rural residential sprawl, or exurban sprawl, has grown faster than any other development pattern. Exurban sprawl is development beyond the urban/suburban fringe with ties to the urban environment, such as employment and consumption, rather than to rural economies. Exurban sprawl is highly consumptive of land and has implications for conservation, natural resource management, agriculture, and communities. This study explores two main avenues of exurban sprawl prevention in the US: voluntary conservation easements and local government growth management regulations. The use of …

Filth Flies As A Vector For Some Pathogenic Bacteria Transfer, Ahmet Buyukyavuz

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Two separate sets of experiments were conducted to determine the transfer of bacteria by flies. An Escherichia coli ampicillin-resistant strain with a fluorescent gene was used during the experiments. The first set of experiments were divided into two trials to measure the transfer of E. coli by fruit flies to apple slices and bologna during short term exposure. Short time exposure (1, 5 and 15 min) of flies to inoculated apple slices were tested in the first trial to determine the transfer of E. coli to flies. No difference (P>0.05) in the number of bacteria transferred to flies were …

An Experimental And Numerical Investigation Of The In-Plane Shear Behavior Of Cantilever Cross-Laminated Timber Diaphragms, Bibek Bhardwaj

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This research focuses on investigating the behavior of Cross Laminated Timber (CLT) diaphragms under in-plane shear loads through an experimental, analytical, and numerical approach. Full-scale destructive tests were conducted on cantilever CLT diaphragms to measure their response to cyclic loading. The results showed that the ultimate capacity of the diaphragms was primarily influenced by the fasteners used and exceeded the LRFD capacity. The primary energy dissipation mechanism was through the slip of diaphragm components and rotation of CLT panels due to fastener deformations. The strain data revealed that the diaphragms exhibited deep-beam-like behavior, with resistance to tensile and compressive forces …

Rated T For Therapy: How Video Games Portray Mental Illness And Their Effects On Social Stigmas, Christine Wendell

All Theses

Mental illness has always been a tricky subject for us to tackle as a society due to the social stigmas surrounding it. Historically, people with mental illness were seen as violent and unstable and would often need to be committed for public safety; however, a large majority of people with mental illness do not fit that bracket and often don’t reach out for help due to that fear of being “othered” by society. As time went on, these tropes faded to purely entertainment mediums but the stigmas still remain. Many video games specifically hold onto these tropes for shock value …

We Are Gullah: A Community Approach To Preserving Gullah Geechee Historical Sites Of Significance, Peter Gaytan

All Theses

The National Register of Historic Places is an inventory established by the National Historic Preservation Act of 1966 that identifies architectural and archaeological sites significant to American history. The National Register was created to encourage the documentation, evaluation, and protection of America’s historic resources. Over 96,000 historic properties, sites, and structures are currently listed on the National Register. Despite the number of historic places listed on the National Register there is still an overwhelmingly low number of sites listed on the National Register relating to underrepresented communities. This thesis assessed the definition of significance laid out in the National Register …

Apparatus And Instrumentation Design For Investigation Of Surface Impact Effects On Superconductivity, Austin Back

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The effects of ion irradiation on the physical properties of materials make EBITs an invaluable tool for many scientific and engineering fields. Many experiments rely on the use of these lab setups to test for device reliability, explore surface physics phenomena, and replicate the environment for many physical systems that are not readily accessible. We seek to extend the capabilities of these experiments using the CUEBIT and a new sample holder installed in section 3.

This thesis begins by presenting an overview of the CUEBIT and the basic operations of the equipment. This is followed by a brief explanation of …

Impacts Of Preferential Flow On Tc-99and Np-237 Vadose Transport In Soils At The Savannah River Site, Josh Parris

All Theses

Since the 1950s, the United States has produced approximately 90,000 metric tons of spent nuclear fuel (SNF) (Office of Nuclear Energy, 2022); however, no long-term storage solutions are available. Technecium-99 and neptunium-237, two fission products found in SNF, readily form highly mobile species in oxidizing conditions (Hu, 2008; Bondietti, 1979) and have respective half-lives of 2.13 x 10⁵ and 2.14 x10⁶ years (Hu, 2010). Considering these characteristics, ⁹⁹Tc and ²³⁷Np are two risk-driving isotopes found in SNF storage. The process of macropore-facilitated preferential flow, transport through cracks within a soil matrix, has been recognized to increase …