Digital Commons Network^™

A Numerical Method For The Navier Stokes Equations In A Velocity-Vorticity Form, Liang Zhao

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In physics, the Navier-Stokes equations (NSE) describe Newtonian fluid flows. Instead of focusing on the standard NSE with velocity and pressure as primary variables, we are interested in the Navier Stokes equations in a velocity-vorticity form (NSE-VV). In NSE-VV, vorticity is included in the system as an independent variable so that it can be computed directly. The main contribution of this thesis is proposing a numerical method for solving NSE-VV, which includes an efficient solver, an adaptive mesh refinement strategy and error analysis. A nested solver plays a fundamental role in the numerical method of NSE-VV. Similar to how it …

Building A Model Of Black Women's Confidence In Campus Sexual Assault Resources: A Critical Race Feminist Quantitative Study, Jimmy Lee Howard, Jr.

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The United States’ evolving federal regulations and laws are doing little to disrupt systemic sexual violence, and more narrowly, are doing very little to protect Black women (Dunn, 2014; Harris, 2017; Harris & Linder, 2017; Konradi, 2016; O’Toole et al., 2015; Yung, 2015). Further, Black women are underrepresented in college sexual assault literature and little is known about how Black women perceive campus sexual violence resources and policy (Crosby, 2015; Tillman et al., 2010). The purpose of this study is to create a model to explore Black women’s confidence in sexual assault resources. In order for institutions of higher education …

Surface Functionalized Organic/Inorganic Colloids: Imaging And Spectroscopy With X-Ray And Optical Excitation, Mary Burdette

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Nanoparticles continue to be studied for their properties as carriers for small molecules, such as bio-imaging agents, biologically relevant targeting ligands, and therapeutic drugs as tethering these small molecules to a larger particle provides stability to the molecule and lessens the probability that the system is cleared prematurely from the body. However, the body suffers from intense auto-fluorescence, so one way to improve imaging agents to combat the auto-fluorescence issue is to create a system that is fluorescence activatable; the activation must occur when the system is only in the intended environment. Additionally, intense light scattering occurs at the blue …

The Effects Of Various Retort Motions On The Rate Of Heat Penetration Of A Food Simulant In Pouches, Mollye Macnaughton

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Processing foods in a retort is a reliable and established method of creating sterile and shelf stable products. The formula of the product and the package size dictates the processing time. Rotary retorts were invented to agitate cans to reduce the processing times and create uniform heating within the can. Recently, horizontal reciprocating agitation has become a feature of retorts referred to as Gentle Motion® and Shaka®. Oscillating agitation is an even newer possible retort motion. This research experiment was designed to (1) determine the effects of oscillating continuously and oscillating-dwell time on the rate of heat penetration in a …

Understanding The Interactions Of Anions With Lewis Acids And Π-Acids To Develop Efficient Ion-Pair Receptors, Krishnendu Maity

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Anions play vital roles in many industrial, environmental, chemical, and biological processes. Due to their adverse effects on our health and ecosystem, precise regulation of toxic anions and ion-pairs are of prime importance. A majority of anion receptors rely on subtle supramolecular forces like electrostatic interactions and hydrogen bonding to bind anions, and the main source of selectivity comes from the shape and size complementarity of the receptors and guest anions. In aprotic solvents, interactions of anions with π-acidic receptors such as naphthalenediimides (NDIs) and perylenediimides (PDIs), and Lewis acids, such as silver ion, depend on their electron donating ability, …

Influence Of Consumer Involvement In Tourist Information Search: Application Of Economics Of Information Theory In A Destination, Peter Judca Mkumbo

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In the modern digital world, it is increasingly challenging for destination marketers to design integrated marketing communication (IMC) strategies. The spectrum of information sources has become broader, serving for wider market interests. The importance of information in the modern world is increasing exponentially, and the tourism industry is traditionally information intense. There is an endless list of information outlets, and it is impossible to be present in all the information platforms. The spectrum of outlets includes old-school prints like magazines and newsletters on the one hand, while on the other hand there are modern advanced Web 2.0 technologies like social …

Experiences Of Upstate South Carolina Historical Preservationists: Wisdom For Cultivating Future Advocates, Steven Clay Pruitt

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Current literature has suggested that despite scholars in other fields gleaning vast amounts of experimental data to use to hone curriculum decisions and support their disciplines, researchers in social studies education have failed to look at Significant Life Experiences (SLEs) of Historical Preservationists (HPs) for the same benefit. The American Historical Association (AHA) cited a twenty-one percent dip in history majors since 2012 (Townsend, 2017), historic sites like Colonial Williamsburg have been hit by a lack of interest and visitation from the public (Tiedemann & Marsico, 2017), and many local historical associations and community museums have uncertain futures due to …

Tunneling Transport Phenomena In Topological Systems, Christopher Moore

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Originally proposed in high energy physics as particles, which are their own anti-particles, Majorana fermions have never been observed in experiments. However, possible signatures of their condensed matter analog, zero energy, charge neutral, quasiparticle excitations, known as Majorana zero modes (MZMs), are beginning to emerge in experimental data. The primary method of engineering topological superconductors capable of supporting MZMs is through proximity-coupled semiconductor nanowires with strong Rashba spin-orbit coupling and an applied magnetic field. Recent tunneling transport experiments involving these materials, known as semiconductor-superconductor heterostructures, were capable for the first time of measuring quantized zero bias conductance plateaus, which are …

Trust-Based Control Of Robotic Manipulators In Collaborative Assembly In Manufacturing, Behzad Sadrfaridpour

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Human-robot interaction (HRI) is vastly addressed in the field of automation and manufacturing. Most of the HRI literature in manufacturing explored physical human-robot interaction (pHRI) and invested in finding means for ensuring safety and optimized effort sharing amongst a team of humans and robots. The recent emergence of safe, lightweight, and human-friendly robots has opened a new realm for human-robot collaboration (HRC) in collaborative manufacturing. For such robots with the new HRI functionalities to interact closely and effectively with a human coworker, new human-centered controllers that integrate both physical and social interaction are demanded. Social human-robot interaction (sHRI) has been …

Framework For Lifecycle Enrichment Of Hpc Applications Towards Exascale Heterogeneous Architectures, Karan Sapra

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With the advent of accelerators and architectures, researchers are faced with a daunting task to port their existing applications and algorithms to the optimal architecture and programming language. Porting existing applications or a new algorithm is both demanding and time-consuming due to the sheer number of accelerators and architectures plus the number of programming models available per architecture. This problem is further compounded for heterogeneous systems with wide availability of resources and complexity of scientific applications. In this dissertation, we focus on enriching the lifecycle of applications by providing an application to optimal architecture mapping and framework to assist in …

Modelling The Effects Of Disease-Associated Single Amino Acid Variants And Rescuing The Effects By Small Molecules, Yunhui Peng

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Single nucleotide polymorphism (SNP) is a variation of a single nucleotide in the genome. Some of these variations can cause a change of single amino acid in the corresponding protein, resulting in single amino acid variation (SAV). SAVs can lead to profound alterations of the corresponding biological processes and thus can be associated with many human diseases. This dissertation focuses on integration of existing and development of new computational approaches to model the effects of SAVs with the goal to reveal molecular mechanism of human diseases. Since proton transfer and pKa shifts are frequently attributed to disease causality, the proton …

Hydrothermal Crystal Growth Of Tetrahedral Framework Oxides For Optical Applications, Rylan James Terry

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In our modern world, lasers are used every day, from the mundane task of playing a DVD to the innovative implementation of laser surgery. Nonlinear optical (NLO) crystals are crucial to laser technology for their ability to modify the frequency of a beam. The development of new NLO crystals is necessary for the advancement of laser technology, in order to reach wavelengths that are not currently accessible due to the limitations of current materials. Of particular importance to semiconductor photolithography, laser micromachining, and scientific instrumentation are the ultra-violet (UV, 200 nm > λ > 400 nm) and deep-UV (λ < 200 nm) portions of the optical spectrum. This dissertation delves into the synthesis of new potential NLO materials by means of hydrothermal crystal growth. In this study, tetrahedral oxides are utilized due to their likelihood of producing noncentrosymmetric (NCS) crystals, a necessity for NLO materials. Silicates are also employed in this study due to their particularly deep absorption edge into the UV. The addition of a spectroscopically silent rare earth ion which is capable of being doped with a lasing ion into a NCS crystal may lead to a single crystal that is both capable of lasing and frequency doubling. In the pursuit of such a crystal, the novel syntheses of Cs3YSi6O15 and LiRESiO4 (RE = Er, Tm, Yb, Lu) were established. Although these materials proved not to be NCS, their structures proved very intriguing and in the case of Cs3YSi6O15 is the parent structure to a family of structures that otherwise exhibits structural disorder or modulation. In expanding the range of mixed oxoanion species, the rare earth ion was replaced with a tetrahedral trivalent oxoanion. The appeal of a series with the general formula ABCO4, (A = alkali ion, B = trivalent metal, and C = tetravalent metal) is its prevalence to produce NCS crystals, notably having a tridymite-type framework. Tridymite is a high temperature variant of quartz that forms six-membered rings propagating through the structure, creating vacant channels. In a stuffed variation of this structural type, rings having negative charge are balanced by the “stuffing” of an alkali or alkaline earth cation into the vacant channels. While the archetype of the stuffed tridymites forms in the centrosymmetric (CS) space group setting of P63/mmc, there are four degrees of freedom that evolve as small variations in the structure are made, often leading to the removal of the inversion center. With the synthesis of a wide array of crystals in this family, those that were found to be NCS were analyzed for their potential use as NLO materials.

High-Throughput Polygenic Biomarker Discovery Using Condition-Specific Gene Coexpression Networks, William Louis Poehlman

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Biomarkers can be described as molecular signatures that are associated with a trait or disease. RNA expression data facilitates discovery of biomarkers underlying complex phenotypes because it can capture dynamic biochemical processes that are regulated in tissue-specific and time-specific manners. Gene Coexpression Network (GCN) analysis is a method that utilizes RNA expression data to identify binary gene relationships across experimental conditions. Using a novel GCN construction algorithm, Knowledge Independent Network Construction (KINC), I provide evidence for novel polygenic biomarkers in both plant and animal use cases.

Kidney cancer is comprised of several distinct subtypes that demonstrate unique histological and molecular …

Role Of The Physical Environment On Team-Based Primary Care In The Military Health System, William B. Lewis

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Primary care in the United States has shifted from a physician-centered care approach to a multidisciplinary, team-based care approach. This shift has resulted in many day-to-day changes in the care delivery process including how clinical staff collaborate; interact with patients; and use space, equipment, and various technologies. Team-based approaches, such as the Patient-Centered Medical Home (PCMH) model, are demonstrating improvements in patient health outcomes. The U.S. Military Health System, one of the largest healthcare organizations in the world, has adopted the PCMH model for primary care clinics. To support this new care model, a team-based clinical module is emerging as …

Magnolia: Impact Of Interspecific Hybridization On Genetic Variation And Ongoing Breeding Initiatives, James Kevin Parris

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The genus Magnolia comprises over 250 species naturally occurring in Eastern North America, Central America, South America, islands of the Gulf of Mexico, and Eastern Asia. A long history of cultivation and breeding going back to the early nineteenth century reveals a common trend of reproductive compatibility throughout this group of basal angiosperms. Interspecific hybridization has led to plethora of ornamental cultivars that have proven adaptable to natural and cultivated habitats beyond the range of each species. Understanding of taxonomic relationships between species has evolved as observations of morphological characteristics and genetic analyses have been more thoroughly investigated. The objectives …

Development Of A Biomimetic, Collagen-Based Scaffold For The Repair And Regeneration Of The Annulus Fibrosus, Ryan Borem

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Annually, over 5.7 million Americans are diagnosed with two IVD-associated pathologies: IVD herniation (IVDH- a mechanical disruption of the concentric fibrous layers of the annulus fibrosus (AF)) and/or degeneration (IVDD- a multifactorial process which initiates within the inner gelatinous core (NP), and results in a biochemical degradation of NP tissue), with over 2.7 million requiring surgical interventions. Although both underlying pathologies are different, quite often they both lead to a decrease in IVD height, impaired mechanical function, and increased pain and disability. These pain symptoms affect approximately 80% of the adult population during their lifetime with estimated expenditures exceeding $85.9 …

Polymer Injection Forming: A New Age Technology For Manufacturing Polymer-Metal Hybrids, Saeed Farahani

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Due to global competition, manufacturing firms in high-wage countries must target innovation in production processes and technologies that allow the mass manufacturing of customized products through highly efficient processes. Motivated by the concept of the integrative production systems, hybrid process of polymer injection molding and sheet metal forming, known as polymer injection forming (PIF), has been introduced to manufacture sheet metal-polymer components using a single tooling, machinery, and operating system. During this process, the sheet metal blank inside the injection mold is deformed by means of tool movement and/or by pressure of the polymer melt. As the melt cools, the …

Investigating The Use Of Streaming And Robotic Dielectrophoresis To Enable Continuous Cell Sorting And Automatic Cell Transfer In Sample Preparation, Rucha Natu

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The sorting of targeted cells or particles from a sample is a crucial step in the sample preparation process used in medical diagnosis, environmental monitoring, bio-analysis and personalized medicine. Current cell sorting techniques can be broadly classified as label based or label-free. Label-based techniques mostly rely on fluorophores or magnetic nanoparticles functionalized to bind with targeted cells. Although highly specific, this approach can be expensive and suffers from limitations in the availability of suitable markers. Label-free techniques exploit properties inherent to the cell, such as density and size, to simplify the sorting protocol and reduce cost by eliminating the need …

Tissue Engineering Platforms For Cardiac Pathology In Diabetes: In Vitro And In Vivo Studies, Laura Elizabeth Mccallum

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425 million people have diabetes worldwide, and by 2045 this number is estimated to increase to 629 million. The risk for cardiovascular diseases such as cardiomyopathy, hypertension, and atherosclerosis increase 5 and 2-fold for diabetic women and men respectively. Diabetic cardiomyopathy (DCMP) is a ventricular dysfunction that occurs in patients with diabetes independent of coronary artery disease, hypertension or valvular abnormalities. Hyperglycemia and dyslipidemia cause metabolic disturbances that adversely affect myocardial cells and extracellular matrix. These modifications alter overall myocardial structure and cardiac function, which can lead to heart failure.

As of now there is no specific marker for this …

Situational Intelligence For Improving Power System Operations Under High Penetration Of Photovoltaics, Yawei Wei

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Nowadays, power grid operators are experiencing challenges and pressures to balance the interconnected grid frequency with rapidly increasing photovoltaic (PV) power penetration levels. PV sources are variable and intermittent. To mitigate the effect of this intermittency, power system frequency is regulated towards its security limits. Under aforementioned stressed regimes, frequency oscillations are inevitable, especially during disturbances and may lead to costly consequences as brownout or blackout. Hence, the power system operations need to be improved to make the appropriate decision in time. Specifically, concurrent or beforehand power system precise frequencies simplified straightforward-to-comprehend power system visualizations and cooperated well-performed automatic generation …

Taxonomic, Genetic And Functional Diversity Of Symbionts Associated With The Coastal Bivalve Family Lucinidae, Jean S. Lim

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Extant bivalve members from the family Lucinidae harbor chemosynthetic gammaproteobacterial gill endosymbionts capable of thioautotrophy. These endosymbionts are environmentally acquired and belong to a paraphyletic group distantly related to other marine chemosymbionts. In coastal habitats, lucinid chemosymbionts participate in facilitative interactions with their hosts and surrounding seagrass habitat that results in symbiotic sulfide detoxification, oxygen release from seagrass roots, carbon fixation, and/or symbiotic nitrogen fixation. Currently, the structural and functional complexity of whole lucinid gill microbiomes, as well as their interactions with lucinid bivalves and their surrounding environment, have not been comprehensively characterized. This dissertation focuses on the taxonomic, genetic, …

Phylogenetic, Genomic And Morphological Investigations Of Three Lance Nematode Species (Hoplolaimus Spp.), Xinyuan Ma

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Lance nematodes (Hoplolaimus spp.) are migratory ecto-endo plant-parasitic. They have been found from a wide range of the world that feed on the roots of a diversity of monocotyledonous and dicotyledonous plants, and have caused a great agricultural damage. Since more taxonomic knowledge and molecular references are demanded for the lance nematode phylogeny and population study, four chapters of lance nematode researches on three species were presented here: (1) A new species, Hoplolaimus smokyensis n. sp., was discovered from a mixed forest sample of maple (Acer sp.), hemlock (Tsuga sp.) and silverbell (Halesia carolina) from …

Fabrication And Mechanical Properties Of Micro-Architectured 3d Scaffolds, Pooya Niksiar

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Freeze casting is a physical process for the fabrication of porous anisotropic materials. In this method, an aqueous slurry of ceramic particles is frozen directionally, creating lamellar columns of ice that push particles between the growing crystals. Then, the frozen material is lyophilized to remove the ice and sintered to densify the ceramic. Scaffolds made by freeze casting often have significant strength in the solidification direction, while they lack sufficient strength in the transverse direction. To enhance strength in the transverse direction, magnetite particles are added to a slurry of paramagnetic particles, and an external magnetic field is applied during …

Chemically Active Rheological Modifiers For The Improved Clinical Use Of Cyanoacrylates, Kyle Joseph Garcia

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Over 100 million surgical incisions, 50 million traumatic wounds, and 20 million minor lacerations from cuts and grazes are treated globally each year. One study determined that globally internal and external wounds occur for 40% and 37% of cases respectively for a total of 111 million patients that were treated for wounds. The remaining 23% of patients were treated for minor lacerations and trauma in the emergency room. These wounds require immediate medical attention including pressure application, sutures, clips, tissue cautery, and/or topical hemostatic agents to cease hemorrhage or the exit of other bodily fluids. With blood flow ceased, wound …

Characterization And Modeling Of The High Strain Rate Response Of Advanced High Strength Steels, Rakan Alturk

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The push for lightweighting in the automotive industry has motivated metallurgist and steel manufacturers to produce new generations of steel that provide significant improvements over the conventional steels to allow them to compete with the introduction of low-density materials into the industry. To achieve this goal, metallurgist introduced different (stronger and more ductile) phases into the ferrite-dominant microstructure of conventional steels. This has led for generations of AHSSs with significantly improved properties. However, the complex microstructure led to increased complexities and unpredictability in the behavior of these materials, especially in their response to variations in the strain rate. This is …

An Interpretative Phenomenological Study Of College Women Who Participate In High-Risk Drinking, Their Perceptions Of Drinking Norms, And The Influence Of Those Norms On Their Drinking Behaviors, Elizabeth Leeman Carter

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High-risk alcohol use on college campuses is associated with several negative consequences for students. Social norms campaigns are a widely used intervention aimed at decreasing high-risk alcohol use in a university population but their efficacy can vary based on students’ peer groups and gender. Research on gendered drinking norms for college students tends to focus on men, as they are usually identified as more likely to drink alcohol overall and to drink in high-risk ways. Additionally, social norms campaigns implemented in a small group setting, which aim to correct misperceptions of students who may not initially identify with norms of …

Tight Representations Of Specially-Structured 0-1 Linear, Quadratic, And Polynomial Programs, Audrey N. Devries

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This research derives improved mathematical representations for various expressions of binary variables. There are three main efforts, consisting of: the Target Visitation Problem (TVP), the Quadratic Linear Ordering Problem (QLOP), and a special family of monomials of binary variables. For the first two efforts, which are known in the literature to be (mixed) 0-1 programs, we derive new families of valid inequalities that tighten existing forms and lead to superior performance. We give computational experience to show the advantages of our approaches. For the third effort, we provide an explicit convex hull representation for special forms of monomials of binary …

Development Of A New Electron Spin Resonance Spectroscopy, Zhe Chen

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The dissertation focuses on the development of a novel electron spin resonance (ESR) spectroscopy based on an RF interferometer. The ESR spectroscopy is broadband and quantitative which is tunable over a wide frequency range, in which the RF interferometer is used to remove radio-frequency (RF) probing signals at the detector. With a planar microwave resonator (MR) the ESR spectroscopy is able to measure as low as 0.2 µg (2.8×1014 spins) DPPH (2,2-diphenyl-1-picrylhydrazyl) sample at a signal-to-noise ratio (SNR) of ~ 121 at room temperature. The broadband ESR operation capability is investigated with a broadband meander micro-strip line (MML) by measuring …

Effects Of Lmx And External Environmental Factors On Creativity Among Faculty In Higher Education, Timothy Allen Dupont

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Recent articles in the news clearly indicate that changes are occurring in American higher education requiring universities to rely on faculty who can initiate change through creativity and innovation (Zhou & George, 2001). Creativity is generally defined as the generation of products or ideas that are both novel and appropriate (Hennessey & Amabile, 2010). Institutional theory, leader-member exchange theory (LMX), and the componential theory of creativity provide the theoretical framework for this study. This study explores the effects of faculty perceptions of external environmental pressures in higher education on faculty perceptions of their creativity. This study also examines: (a) the …

Computational Approaches To Understanding Structure-Function Relationships At The Intersection Of Cellular Organization, Mechanics, And Electrophysiology, Tyler George Harvey

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The heart is a complex mechanical and electrical environment and small changes at the cellular and subcellular scale can have profound impacts at the tissue, organ, and organ system levels. The goal of this research is to better understand structure-function relationships at these cellular and subcellular levels of the cardiac environment. This improved understanding may prove increasingly important as medicine begins shifting toward engineered replacement tissues and organs. Specifically, we work towards this goal by presenting a framework to automatically create finite element models of cells based on optical images. This framework can be customized to model the effects of …