Digital Commons Network^™

Leveraging The Intrinsic Switching Behaviors Of Spintronic Devices For Digital And Neuromorphic Circuits, Steven Pyle

Electronic Theses and Dissertations

With semiconductor technology scaling approaching atomic limits, novel approaches utilizing new memory and computation elements are sought in order to realize increased density, enhanced functionality, and new computational paradigms. Spintronic devices offer intriguing avenues to improve digital circuits by leveraging non-volatility to reduce static power dissipation and vertical integration for increased density. Novel hybrid spintronic-CMOS digital circuits are developed herein that illustrate enhanced functionality at reduced static power consumption and area cost. The developed spin-CMOS D Flip-Flop offers improved power-gating strategies by achieving instant store/restore capabilities while using 10 fewer transistors than typical CMOS-only implementations. The spin-CMOS Muller C-Element developed …

Conceptualization And Fabrication Of A Bioinspired Mobile Robot Actuated By Shape Memory Alloy Springs, Lietsel Richardson

Electronic Theses and Dissertations

This work is an experimental study and fabrication of design concepts to validate the feasibility of smart materials and their applications in bio-inspired robotics. Shape-Memory Alloy (SMA) springs are selected as the smart material actuators of interest to achieve locomotion in the proposed mobile robot. Based on a previous design of the robot, this work focuses on both implementing a new locomotion concept and reducing size and weight of the previous design, both using SMA based actuators. Objectives are met in consideration of the conceptual mechanics of circular robot locomotion. The first prototype is a variation of the original design. …

Characterization Of Florida Landfills With Elevated Temperatures, Ryan Joslyn

Electronic Theses and Dissertations

The occurrence of elevated temperatures within landfills is a very challenging issue for landfill operators to detect and correct. Little is known regarding the causes of elevated temperatures (ETs) and the number of landfills currently operating under such conditions. Therefore, the goal of this research was to determine which landfills within Florida have been impacted by ETs, and to develop a more complete understanding of the factors that may lead to these landfills becoming elevated temperature landfills (ETLFs). Historical landfill gas wellhead data, waste deposition reports, and landfill site geometry were collected for 27 landfill cells through the FDEP OCULUS …

Fluctuations In Walking Speeds And Spatiotemporal Gait Parameters When Walking On A Self-Paced Treadmill At Level, Incline, And Decline Slopes, Cesar Castano

Electronic Theses and Dissertations

On a daily basis, humans walk over a variety of terrains. Studies have shown that spatiotemporal gait parameters, such as stride length, stride frequency, stride variability, etc., change when humans walk down a decline and up an incline compared to level ground. However, these studies have been limited to using fixed speed treadmills or analyzing a small number of strides when conducted over ground. Thus, there is a need to investigate the fluctuations in spatiotemporal gait parameters of humans walking at their self-selected speed, which requires recording hundreds of strides. Here we hypothesized that subjects will walk with a slower …

Quality Diversity: Harnessing Evolution To Generate A Diversity Of High-Performing Solutions, Justin Pugh

Electronic Theses and Dissertations

Evolution in nature has designed countless solutions to innumerable interconnected problems, giving birth to the impressive array of complex modern life observed today. Inspired by this success, the practice of evolutionary computation (EC) abstracts evolution artificially as a search operator to find solutions to problems of interest primarily through the adaptive mechanism of survival of the fittest, where stronger candidates are pursued at the expense of weaker ones until a solution of satisfying quality emerges. At the same time, research in open-ended evolution (OEE) draws different lessons from nature, seeking to identify and recreate processes that lead to the type …

Classification Of The 4 Stages Of Diabetic Retinopathy Using A Low Complexity Convolutional Neural Network., Zeliha Ogur

Electronic Theses and Dissertations

Diabetic Retinopathy is an eye disease that affects the blood vessels of the retina tissue found in the back of the eye. The blood vessels in the retina discharge fluid or cause hemorrhage when affected by diabetic retinopathy. It leads to loss of eye vision with people with diabetics and also among working adults. The disease may advance in four stages which include Mild nonproliferative, moderate nonproliferative, severe nonproliferative and proliferative diabetic retinopathy. In the mild stage also known as background retinopathy, lumps occur in the blood vessel and distort a little amount of blood. At this stage, you are …

Representation And Restraint : Cross-National Analysis Of Fractionalization And State-Building., David Lian

Electronic Theses and Dissertations

This study seeks to understand the relationships between democracy, ethnic-linguistic-religious (ELR) fractionalizations and state-building. The speed of a country’s economic recovery from war is used as proxy to determine the state-building process. Using Cox PH model, I conducted a large sample hazard analysis of 107 conflicts, having polity and ELR as explanatory variables. I found that competitiveness of political participation and executive constraints are associated with state-recovery while ethno-linguistic fractionalizations have the reverse effect. I propose that the institutional feedback process is equal to the product of negative executive power centralization and representation minus fractionalization; as in F = – …

Defects In Fetal Mouth Movement And Pharyngeal Patterning Underlie Cleft Palate Caused By Retinoid Deficiency., Regina Friedl

Electronic Theses and Dissertations

Cleft palate is a common birth defect. Etiologic mechanisms of palate cleft include defects in palate morphogenesis, mandibular growth, or spontaneous fetal mouth movement. Cleft palate linked to deficient fetal mouth movement has been demonstrated directly only in a single experimental model of loss of neurotransmission. Here, using retinoid deficient mouse embryos, we demonstrate directly for the first time that deficient fetal mouth movement and cleft palate occurs as a result of mis-patterned development of pharyngeal peripheral nerves and cartilages. Retinoid deficient embryos were generated by inactivation of retinol dehydrogenase 10 (Rdh10), which is critical for production of …

The Division I Men's Basketball Transfer Redshirt Requirement : Hurting Or Helping Black Student-Athletes?, Sarah B. Williams

Electronic Theses and Dissertations

The following study provided a voice to an otherwise unheard from population of former student-athletes as they explained their transition experiences with the Division I transfer and redshirt year. The purpose of the study was to explore the Black student-athlete’s transition experience through the redshirt year in Division I men’s basketball from a qualitative, phenomenological research perspective. The study used two theories as guiding frameworks: 1) Schlossberg’s (1981) Transition Theory and 2) Critical Race Theory (Calmore, 1992; Tate, 1997). Both Schlossberg’s (1981) Transition Theory and Critical Race Theory were used to examine the transition experience of the Black male basketball …

Doing Place : A Framework For Interpreting Young Adults' Commitments To Appalachian Kentucky., Jeanelle Susanne Sears

Electronic Theses and Dissertations

Confronted with negative consequences of rural youth outmigration, many rural communities are interested in how to recruit and retain young adults. Yet, attention has largely been focused on those who leave. This study thus explores the experiences of young adults who make conscious commitments to improving the communities of Appalachian Kentucky despite many obstacles and pressures to leave. Two aims were established in this pursuit: 1) Understand and provide deep description of young adults’ experience of committing to stay and work in Appalachian Kentucky and the meaning they make of these decisions and 2) Develop a context specific framework for …

Cooking Lessons: Oral Recipe Sharing In The Southern Kitchen, Alana Claxton

Electronic Theses and Dissertations

This study analyzes oral recipe sharing practices as they emerge in Southern cooking. Researcher and participants were immersed in cooking recipes together in a qualitative research method that combined interactive interviewing with sensory ethnography. Findings revealed a category of oral recipe sharing practices that is missing from the literature: cooking lessons. This study identified cooking lessons as a distinct recipe sharing practice and worked to further operationalize and concretize such practices in hopes of spurring further research.

Becoming A Master Manager: An Analysis Of Snap Recipient Stories Of Navigating Government Assistance, Kallie Gay

Electronic Theses and Dissertations

This study examines experiences of utilizing government assistance in the United States. It focuses on the ways in which persons participating in the Supplemental Nutrition Assistance Program (SNAP) communicatively managed their lives in relation to their role in the program. Specifically, the research reveals that SNAP recipients are master managers. After synthesizing the pre-existing body of research concerning social assistance in the U.S. and its effects on those who utilize it, the author argues that sharing the stories of marginalized groups can serve to reduce stigma surrounding government assistance participation. Employing a Feminist Standpoint Theory sensibility to elicit such stories, …

Synthesis And Evaluation Of 1,2,4-Oxadiazolidinones: The Search For A Potential Non-Β-Lactam Β-Lactamase Inhibitors., Chimdi Eke Kalu

Electronic Theses and Dissertations

β-lactam antibiotics have been the most widely used drug of choice to combat infectious disease caused by bacteria. Unfortunately, their effectiveness is drastically threatened by bacterial β-lactamases. β-lactamases is responsible for the resistance to most antibiotic drugs. For decades, β-lactam β-lactamases inhibitors have been used to reduce bacterial resistance; however, in this study 1,2,4-oxadiazolidinone derivatives as a non-β-lactam β-lactamases inhibitor against TEM-1 and P99 β-lactamases. The significance of oxadiazolidinone is the prominent five-membered ring scaffold in its structure, which is configurationally stable and present in other biologically active compounds such as linezolid and avibactam. Oxadiazolidinones were synthesized by treating nitrones …

Treatment Of Electric Utility Wastewaters By Sol-Gel Solidification And Stabilization, Alex Kearns

Electronic Theses and Dissertations

To meet the demands of new regulations on coal-fired power plants, many treatment scenarios require a zero-liquid discharge (ZLD) approach. Two revisions to regulations in 2015, the Effluent Limitations Guidelines (ELG) and Coal Combustion Residuals (CCRs) rule, drastically changed the treatment approach for managing effluents at coal-fired plants. In some scenarios, coal-fired plants retired early deeming the capital cost for maintaining compliance too expensive. Traditionally, stabilization/solidification (S/S) ZLD technologies have fallen in two categories: cementitious and vitrification. However, neither approach offers the ideal solution for coal-fired power plants needing ZLD by S/S methods. In what follows, a novel sol-gel encapsulation …

Capture And Release Gels For Optimized Storage (Cargos), Theodore S. Kalbfleisch Ii

Electronic Theses and Dissertations

Unassisted, the lifetime of many proteins outside their natural environment is very short. Scientists generally need to extract the sample, often in remote locations, and then transport, isolate, and store such biospecimens relatively far from the point of origin in order to study them. Currently, the most commonly used methods for storage of biospecimens are cryopreservation or refrigeration which, though effective, have their fair share of flaws. Cryopreservation and refrigeration-based storage of biospecimens requires a great deal of space and other resources to be effective. Furthermore, the hardware required for cold storage does not transport well. These factors make such …

An Exploration Of Resilience: Evaluating Resilience Scores Among Honors Undergraduates Involved In Leadership Programs, Amy Van Buren

Electronic Theses and Dissertations

Resilience is vital to college and university student success. Furthermore, resilience is necessary for successful leadership. Student leadership programs must consider resilience building as part of successful program development. By considering resilience as a factor in student leadership success and future leadership success, programs may encourage the development of leaders who are highly equipped to lead and continue to lead in the long term. Because of the need to promote resilience building through leadership program development, the researcher sought to explore the potential relationship between participation in leadership activities and student resilience scores.

The purpose of this quantitative research was …

Capability Approach And Teacher Quality: An Analysis Of Female Teacher Experience In A Rural, Malawian Community, Annabelle Hardy

Electronic Theses and Dissertations

This study used the capability approach as a lens to understand teacher quality from both the perspective of educational leaders and practicing teachers in a rural community in central Malawi. The overarching question of this research study was “How can the capability approach inform our understanding of teacher quality from both the perspective of educational leaders and practicing teachers?” The focus questions to guide this research were:

1. What do national educational leaders value in a quality teacher?
2. What do rural, Malawian, female teachers value in teaching?
3. How do these teachers pursue and achieve what they value in teaching?

This study …

Assessment Of Magnetic Resonance Imaging Safety: Allied Health Professional Clinical Competence, Tiffany Houser

Electronic Theses and Dissertations

Magnetic resonance imaging is a major advancement in the diagnostic imaging field. Most patients can tolerate an MRI however, there are some who are unable to complete a lengthy scan while lying completely still without sedatives or anesthesia. Non-MRI healthcare providers are trained to use equipment that is “unsafe” in the MRI suite due to the strong magnetic field. Staff who are not fully knowledgeable and trained in MRI safety measures can endanger staff and patients.

The purpose of this study was to determine the knowledge level of non-MRI healthcare providers regarding safety risks associated with MRI and to determine …

Pocket Ace: Neglect Of Child Sexual Abuse Survivors In The Aces Study Questionnaire, Robyn Dolson

Electronic Theses and Dissertations

In 1998, a seminal study on adverse childhood experiences (ACEs) and subsequent health risks catapulted ACEs and the study questionnaire into the zeitgeist. However, its childhood sexual abuse (CSA) item is problematic as it requires the perpetrator have been 5-years or older than the victim. To assess whether some survivors’ CSA is not identified by the current item, whether their exclusion prevents access to services requiring a four-threshold ACE score, and how their health outcomes compared to other CSA groups and controls, an international sample of 974 women completed an online survey assessing their current health and CSA history using …

Development Of Granulated Adsorbent For Clean-Up Of Water Contaminated By Cesium, Esther Alorkpa

Electronic Theses and Dissertations

A study was conducted on sol-gel synthesis of an adsorbent (phosphotungstic acid embedded in silica gel, H-PTA/SiO­₂) of radioactive cesium. A novelty of this work is covalent bonding of PTA to the surface of solid support that prevents leaching from the surface of the material. The sample was granulated with a binder, aluminium oxide (γ-Al₂O₃). Solid-state NMR and FT-IR spectroscopy were used to confirm the presence of Keggin units of PTA in the bound materials. Thermal analysis of H-PTA/SiO­₂ - γ-Al₂O₃ (50 %) showed that the water content in the …

Ecometric Estimation Of Present And Past Climate Of North America Using Crown Heights Of Rodents And Lagomorphs: With Application To The Middle Miocene Climatic Optimum, Julia Schap

Electronic Theses and Dissertations

Continental scale studies on ungulate crown heights in relation to climate and habitat changes have revealed a correlation between increasing hypsodonty and a shift to more arid environments. Small mammals have been shown to adapt to changing habitats millions of years earlier than larger mammals. In this study I examined fossil localities throughout the last 37 Ma across North America. Diversity of rodents and lagomorphs were analyzed through this time period, with examination of community structure characterized by relative percentages of taxa with different crown heights. Overall, a decrease in precipitation and temperature was found across North America from 37 …

Differentiating Black Bears (Ursus Americanus) And Brown Bears (U. Arctos) Using Linear Tooth Measurements And Identification Of Ursids From Oregon Caves National Monument, Emily Bogner

Electronic Theses and Dissertations

North American black bears and brown bears can be difficult to distinguish in the fossil record due to similar dental and skeletal morphologies. Challenges identifying ursid material from Oregon Caves National Monument (ORCA) called for an accurate tool to distinguish the species. This study utilized a large database of lower tooth lengths and ratios in an attempt to differentiate black and brown bears in North America. Further, this project examined how these linear measurements differ geographically. Analysis of variance (ANOVA) found significant differences between black and brown bears from across North America for every variable studied. Stepwise discriminant analyses (DA) …

Paleoecology And Land-Use Of Quaternary Megafauna From Saltville, Virginia, Emily Simpson

Electronic Theses and Dissertations

Land-use, feeding habits, and response to seasonality by Quaternary megaherbivores in Saltville, Virginia, is poorly understood. Stable isotope analyses of serially sampled Bootherium and Equus enamel from Saltville were used to explore seasonally calibrated (δ¹⁸O) patterns in megaherbivore diet (δ¹³C) and land-use (⁸⁷Sr/⁸⁶Sr). Overall, this dataset suggests an open forest with relatively constant temperatures year round that were similar to modern conditions. Neither Bootherium or Equus individuals spent a significant amount of time at higher elevations in the nearby Blue Ridge geologic province. These analyses provide a unique perspective on long-term response …

Factors Contributing To Low Adequate Prenatal Care Rates In Orange County, Florida, Lauren Daniel

Electronic Theses and Dissertations

In 2017, only 56% of births in Orange County, Florida, received adequate prenatal care - care that has been shown to prevent maternal and infant death. The Florida Department of Health uses the Kotelchuck Index to determine care adequacy. This index rates care adequacy based on when the mother first receives care, and how many recommended appointments she attends. Prenatal care is rated "inadequate" if it starts after the fourth month of pregnancy, and/or if less than half of the recommended appointments are attended. Receiving earlier and consistent prenatal care has been shown to be an effective way to improve …

Biogeochemical Effects Of Sea Level Rise-Induced Transitions Within Coastal Wetlands, Havalend Steinmuller

Electronic Theses and Dissertations

As sea level rise (SLR) affects coastal wetlands, ecosystem responses can include vertical accretion, landward transgression, or submergence. Sea level rise-induced transitions can alter key biogeochemical transformations within wetland soils, impacting the ability of these systems to provide ecosystem services, specifically carbon (C) storage and water quality regulation. Through a series of complementary laboratory and field-based studies, biogeochemical responses to salinity, vegetation shifts, and submergence were investigated. Changes in nutrient dynamics associated with saltwater intrusion were evaluated by artificially adding saline water to different freshwater wetland soil types, indicating that potential exports of critical nutrients (forms of nitrogen, phosphorus, and …

Detection Of Mercury Through Surface Plasmon Resonance Of Immobilized Gold Nanorods, Khang Trieu

Electronic Theses and Dissertations

Mercury is a known environmental pollutant that can damage the brain, heart, kidney and lungs upon exposure. Emissions from fossil fuel plants can release mercury into the air, where it can settle into the water supply and be exposed to human and aquatic life. The use of gold nanorods functionalized on solid substrates as a mercury sensor in tap water samples is investigated herein. The functionalization of the substrates involves the physical immobilization of the nanorods onto the solid surface through the use of (3-mercaptopropyl)trimethoxysilane (MPTMS). The immobilization of the nanorods drastically increases their stability, allowing for use in complicated …

Novel Fuel-Producing Fungi And Methodologies For Increasing Fuel Production, Yuemin Wang Kovaleff

Electronic Theses and Dissertations

An endophytic fungus Hypoxylon sp. (BS15) has recently been isolated and found to produce volatile organic compounds (VOCs) that have potential relevance as hydrocarbon fuels. In the work described here, the traditional refined carbohydrate (e.g., sucrose) diet source was replaced by simple sugars produced using a solvent free green chemistry mechanocatalytic method involving ball milling in the solid. BS15 is able to grow on this degraded cellulose as well as the more traditional potato dextrose broth. The volatile compounds produced from both media were largely the same. Unfortunately, it is observed that long term in vitro growth of BS15 results …

Synthetic Design And Characterization Of Polycyclic Aromatic Compounds In Molecular And Extended System, Gavin Pour

Electronic Theses and Dissertations

The work presented herein focuses on the synthesis and characterization of polycyclic aromatic compounds for a wide variety of toxicological, analytical, and electronic applications. First, the modular synthesis of 12 dibenzo- and naphtho- fluoranthene polycyclic aromatic hydrocarbons (PAHs) via a Pd-catalyzed five-membered ring closing procedure is discussed. By understanding the various modes through which the Pd migrates during transformation, structural rearrangements were bypassed, obtaining regioselectivity through various redesigns in the synthetic route. Each compound in the serious was rigorously characterized via 1D/2D NMR, absorption and emission spectroscopy as well as cyclic voltammetry, which shows vast differences due to small structural …

Living With Cain: Associations Among Sibling Trauma, Sibling Aggression, Social Adaptability, And Risk Taking In College, Chad Collins

Electronic Theses and Dissertations

This study evaluated the relationship between three different dimensions of sibling abuse– verbal, physical, and sexual– and communicative social adaptability and risk-taking outcomes. A quantitative survey (N = 477) explored the frequency of such abuse among college students and self-reported risk-taking behavior, social experience, social wit, appropriate self-disclosure, social confirmation, and social composure. Moreover, participants responded to nominal prompts asking whether they ever reported their sibling abuse. Independent sample t-tests and correlation tests show that survivors of sibling trauma are moee likely to appropriately disclose socially and are more likely to report engaging in an index of various risky behaviors …

Preparation Of A Flavonol Specific Glucosyltransferase Found In Grapefruit And Site-Directed Mutants For Protein Crystallization, Aaron Birchfield

Electronic Theses and Dissertations

This research was designed to determine the conditions necessary to remove c-myc and 6x-His tags from a flavonol specific glucosyltransferase found in grapefruit (CP3GT) using thrombin in preparation for crystallization. X-ray crystallography of CP3GT crystals may elucidate structural features that account for flavonol specificity in some glucosyltransferase enzymes. A thrombin cleavage site was inserted into WT CP3GT and one mutant. Recombinant CP3GT was expressed in yeast and purified. Optimal conditions for thrombin digestion were explored. Digestion with 100U of thrombin for 2 hours at 4^o C was optimal for removing tags from CP3GT. Storage at 4^o C for …