Digital Commons Network^™

Structure Analysis Of Soft Energy Materials Using Neutron Scattering, Luke A. Heroux

Doctoral Dissertations

The structure of several materials important in the development of sustainable energy have been determined using multiple neutron scattering methods. Elucidating the structure-property relationships of these conductive polymer blends, microemulsions, and deep eutectic solvents (DES) provides correlation of material assembly to electro-chemical performance.

Conductive films of poly(3,4‑ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) are found to organize into smaller domains with the addition of dimethyl sulfoxide(DMSO) to a pre-deposition solution. Addition of DMSO disrupts the aggregates and large domains within PEDOT:PSS, enabling alignment of the PEDOT fibrils within the PSS domains, and occurs in both spin-coated and spray-coated depositions. The spin-coated films have consistently …

Processing Of Preceramic Polymers For Direct-Ink Writing, James W. Kemp

Doctoral Dissertations

Preceramic polymers are organosilicon polymers that, when pyrolyzed to above 1000°C, convert from a polymer to an amorphous ceramic. These polymers have been used for fiber spinning, polymer infiltration, and casting of materials but have recently gained interest for use as the feedstock material for additive manufacturing techniques. This work explores preceramic polymers being used for direct-ink writing (an additive manufacturing method) and many of the issues that occur with the polymers during curing and pyrolysis.

The first chapter of this dissertation provides a review of preceramic polymers, while the second and third chapters focus on the development of inks …

Sustainable Underground Reactive Barrier To Attenuate Contaminants From Agricultural Drainage, Yuchuan Fan

Doctoral Dissertations

Denitrifying bioreactor (DNBR) has become a popular edge-of-field practice applied to reduce nitrate over the Mississippi river and to prevent a downstream hypoxic zone occurring at the Gulf of Mexico. Despite widespread field and laboratory studies, fewer investigations have been directed toward a systematic means of evaluating the nitrate removal performance achieved by various filling materials, abiotic factors, and other critical parameters. Our ultimate goal is to improve the nitrate removal by choosing the optimum fill materials and operate under optimal conditions, meanwhile, modeling the DNBR by critical variables. This study begins by establishing a global database. Forty filling materials …

Who Mediates Matters: The Impact Of Individual Mediator Competency Skills On Individual And Civil Conflict Mediation, Erin V. Rowland

Doctoral Dissertations

Until this point, research in the field of conflict mediation concerning how third-party entities impact mediation outcomes has largely focused on the macrolevel factors of those entities and the disputing parties – geographic proximity of the mediating states to the disputants, the presence of alliances, the existence of enduring rivalries, etc. However, even when macrolevel factors are relatively similar, differences still exist in mediation outcome. This research proposes that some differences in mediation outcome are due to the impact of individual mediator factors, more specifically individual mediator competency skills in the form of Knowledge, Know-how, and Behavioral competencies. Borrowing from …

Towards Modeling Projectile Penetration In Dry And Multiphase Granular Materials, Mohmad Mohsin Thakur

Doctoral Dissertations

The present work aims at developing and validating numerical modeling strategies in granular materials impacted by a projectile. The focus is on two regions: (a) near-field: region near the tip and along the path of a projectile where comminution of grains is significant, (b) intermediate-field: region far from the projectile where grain-scale interactions are important but stresses are not high enough to cause crushing of the grains.

A novel framework has been introduced and validated wherein particle shape captured using X-ray CT imaging was incorporated in FEM simulations using shell elements for simulating triaxial boundary value problems. The results indicate …

Calmodulin Like 38 Is Required For Autophagy Of Hypoxia-Induced Cytoplasmic Rna Granules In Arabidopsis Thaliana, Sterling Field

Doctoral Dissertations

In response to the energy crisis resulting from submergence stress and hypoxia, the model plant Arabidopsis thaliana limits non-essential mRNA translation, and accumulates cytosolic stress granules. Stress granules are phase-separated mRNA-protein particles that partition transcripts for various fates: storage, degradation, or return to translation after stress alleviation. Another response by the plant cell to low oxygen stress is the induction of the turnover pathway autophagy. Stress granule regulation by autophagy occurs by a ‘granulophagy’ pathway in yeast and mammalian systems through which parts or whole stress granules are degraded. Whether this occurs in plants has not been investigated.

A connection …

Impurity Production And Transport In The Prototype Material Plasma Exposure Experiment, Clyde J. Beers

Doctoral Dissertations

The Prototype Material Plasma Exposure eXperiment (Proto-MPEX) is a linear pulse plasma device at Oak Ridge National Laboratory with the purpose of doing the research and development for the heating concepts on the planned full MPEX device. The goal of MPEX is to perform material studies at fusion relevant conditions. To understand the conditions at the material target for performing plasma-material interaction studies the ion temperature and density, the electron temperature and density, and the particle flux and fluence must be known. Impurities within Proto-MPEX can alter the desired conditions at the material target and need to be understood for …

Assessing Multiple Lines Of Evidence For Gene Flow In Archaeological Contexts, Angela Marie Mallard

Doctoral Dissertations

This multi-study dissertation assesses the ability of two skeletal analysis methods—a model-bound quantitative genetic method (Relethford-Blangero) and a model-free biological distance method (Mahalanobis’ D²)—to evaluate gene flow in the U.S. Southwest and Northwest Mexico based on archaeological models. The first study uses dental metric data from the Sonoran Desert and Mogollon Rim (c. 1600 B.C. to A.D. 1450) to pilot the Relethford-Blangero method in this context. Notably, the method shows that populations from two large sites have less than expected dental variance, failing to support a gene flow event despite material culture pointing to at least two coexisting …

Quantifying And Reversing Compensatory Movements By Persons Post-Stroke In The Ambient Setting, Aaron Miller

Doctoral Dissertations

Nearly 800,000 people in the United States suffer stroke annually. Following the onset of stroke, survivors will exhibit deficits, such as hemiplegia, which will limit their function and ability to perform activities of daily living (ADLs). In order to regain independence, many stroke survivors will employ maladaptive compensatory strategies to help with the completion of tasks. Compensation is generally defined as any performance of a task that is different than the way it may have been performed before the onset of a neurodegenerative disorder. While for some severely impaired individuals, compensation may be necessary, for most these maladaptive strategies ultimately …

Distribution, Ecological Niche, Movement, And Home Range Of The Sickle Darter (Percina Williamsi) In The Upper Tennessee River Basin., Kyler Hecke

Doctoral Dissertations

The Sickle Darter (Percina williamsi) is a rare and imperiled species that is endemic to the upper Tennessee River basin. Over the last ~50 years it has declined across much of its range, and as a result it has been petitioned for federal listing under the Endangered species Act. This species has been relatively understudied, and important questions remain to be addressed: 1.) What is the current distribution of the Sickle darter and how has it varied spatiotemporally? 2.) What is the ecological niche of the Sickle Darter? and 3.) What is the movement capability of the Sickle …

Electroweak Interactions And Fundamental Symmetries In Light Nuclei With Short-Range Effective Field Theories, Zichao Yang

Doctoral Dissertations

Effective field theories(EFTs) are powerful tools to study nuclear systems that display separation of scales. In this dissertation, we present halo EFT results for the $\beta$-delayed proton emission from $^{11}$Be, and pionless EFT results for three-nucleon systems. Halo nuclei are simply described by a tightly bound core and loosely bound valence nucleons. Using the halo EFT, we calculate the rate of the rare decay $^{11}$Be, which is a well-known halo nucleus, into $^{10}\text{Be} + p +e^- + \bar{\nu}_e$. We assume a shallow $1/2 ^+$ resonance in the $^{10}$Be$-p$ system with an energy consistent with a recent experiment by Ayyad {\it …

Sunny Days Ahead: Messages During A Pandemic: Creative Strategies And Themes In Health And Wellness Public Service Ads By The Ad Council, Meenakshi Trichur Venkitasubramanian

Doctoral Dissertations

Public Service Advertising is an essential field of study because of its ability to impact and shape public behavior and community changes. Historically, the advertising industry has come together during the times of world war to form an association, the Ad Council, to help create awareness to the public. Over the past 75 years, the Ad Council has contributed to the various causes by communicating and advertising to encourage better habits and behavior. The Ad Council has collaborated with CDC and COVID Collaborative to communicate the right messages about coronavirus response and COVID-19 vaccine during this pandemic. The purpose of …

Las Almanegras: Trazando Caminos De Territorialidad En La Poética Afrofemenina Colombiana, Maria Catalina Rojas Blanco

Doctoral Dissertations

Within the panorama of black women’s writings in Latin America and the Caribbean, the literary production associated with Colombia has blossomed and currently stands as out as an important artistic expression and literary movement. This literature has an immense aesthetic, vital, social, and political value since it is through such poetics that Afro-descendant women are increasingly prominent globally. My study focuses on the development and trajectory of this writing and seeks to contribute to this process by analyzing the writings of María Teresa Ramírez Nieva, Mary Grueso Romero, and María Elcina Valencia Cordoba, three poets from Cauca recognized as the …

A Systematic And Biogeographic Study Of Trillium (Melanthiaceae), Jayne A. Lampley

Doctoral Dissertations

Trillium (Melanthiaceae, Parideae) has a disjunct distribution occurring in eastern and western North America, and eastern Asia. Past studies have examined the phylogeny and historical biogeography of Melanthiaceae and Parideae, however these studies either did not fully examine these aspects within Trillium or did not employ sufficiently broad taxonomic or character sampling to clarify relationships among taxa. The first phylogenetic analysis presented in this study provides a resolved phylogeny for Trillium s.l. and Paris s.l. by using a dataset of 70 plastid coding genes and by sampling broadly from Trillium s.s., Pseudotrillium, Trillidium, Paris s.s., Daiswa, and Kinugasa. The results …

Auto-Curation Of Large Evolving Image Datasets, Sara Mousavicheshmehkaboodi

Doctoral Dissertations

Large image collections are becoming common in many fields and offer tantalizing opportunities to transform how research, work, and education are conducted if the information and associated insights could be extracted from them. However, major obstacles to this vision exist. First, image datasets with associated metadata contain errors and need to be cleaned and organized to be easily explored and utilized. Second, such collections typically lack the necessary context or may have missing attributes that need to be recovered. Third, such datasets are domain-specific and require human expert involvement to make the right interpretation of the image content. Fourth, the …

The Studies Of Effects Of Vitamin A Status On Type 2 Diabetes In Zucker Diabetic Fatty Rats And Retinoic Acid On Glucose Transporter 4 Expression In L6 Cells, Tiannan Wang

Doctoral Dissertations

The epidemic of metabolic diseases such as diabetes has become a public health concern. Previous research data from our lab have shown that vitamin A (VA) status and retinoic acid (RA), a metabolite of VA, contribute to the glucose and lipid metabolism in the body and cells. As the skeletal muscle contributes to metabolic homeostasis, the effects of VA signaling system on its glucose metabolism are worth to be investigated. Here in this dissertation, the following two projects were carried out to study the VA’s role in the control of metabolism. (1) The effects of VA status on the development …

Erecta Family Genes Regulate The Shoot Apical Meristem And Organ Formation, Daniel A. Degennaro

Doctoral Dissertations

Plants are sessile and must adjust their organ growth to their environments. A reservoir of stem cells in the shoot apical meristem (SAM) supplies cells for differentiation into organs. The SAM must balance organ production with stem cell maintenance. The ERECTA family (ERfs) encodes the leucine-rich repeat receptor-like kinases ERECTA (ER), ERECTA-LIKE 1 (ERL1), and ERL2. ERf signaling regulates organ initiation and stem cell maintenance. Results presented in this work include the following:

1) WUSCHEL (WUS) and CLAVATA3 (CLV3) make up a negative feedback loop to maintain SAM size. WUS and CLV3 expression localization is critical for …

Critical Political Thinking: An Analysis Of Undergraduate Students’ Higher-Order Thinking Skills And Preferred Political Values, Labels, And Leadership Traits, Maya Mingo

Doctoral Dissertations

The current study details the political values of students enrolled in an entry-level, multi-section educational psychology course at a large, southeastern United States university during the fall semester of 2017 (N = 167). Survey data were collected to identify the following: which political values and personality traits undergraduate students give the most priority when making political decisions, whether or not the political labels participants identified as most important to them are consistent with those common to their families, close friends, and childhood geographical regions, the quality of respondents’ self-reported label-value congruence, and the relation between the students’ critical thinking …

Modeling And Control Of Power Electronics Interfaced Load For Transmission Power Network Analysis, Shuyao Wang

Doctoral Dissertations

The penetration level of power electronics (PE) interfaced loads has been gradually increasing in recent years. It is beneficial to equip the electric load with a PE interface since it allows for more advanced control of the load performance. Furthermore, the increasing penetration of PE interfaced loads will bring both challenges and opportunities to power network resilience and reliability.

However, the lack of modeling and control design for PE interfaced load units in the transmission-level power network analysis, especially for these high-penetrated high-power-rating load applications, limits the accuracy of evaluating the dynamic performance and stability status of the power network. …

Federated Agentless Detection Of Endpoints Using Behavioral And Characteristic Modeling, Hansaka Angel Dias Edirisinghe Kodituwakku

Doctoral Dissertations

During the past two decades computer networks and security have evolved that, even though we use the same TCP/IP stack, network traffic behaviors and security needs have significantly changed. To secure modern computer networks, complete and accurate data must be gathered in a structured manner pertaining to the network and endpoint behavior. Security operations teams struggle to keep up with the ever-increasing number of devices and network attacks daily. Often the security aspect of networks gets managed reactively instead of providing proactive protection. Data collected at the backbone are becoming inadequate during security incidents. Incident response teams require data that …

Controversy In The Early Elementary Classroom: A Case Study Of The 2020 Presidential Election, Zachary W. Stumbo

Doctoral Dissertations

This single case study with embedded units of analysis examines how three early elementary teachers in Kentucky public schools taught the 2020 Presidential Election in grades one, two, and three using Scholastic News resources as instructional tools. The research questions focused on how teachers used the materials and the pedagogical strengths of the instructional resources. The three research participants were purposefully selected as early-career, mid-career, and late-career teacher leaders in grades one, two, and three. Data collected included semi-structured interviews, qualitative data analysis of the Scholastic News instructional materials, multi-level policies, and news reports concerning the election. The analysis focused …

A Postfeminist Multimodal Discourse Analysis Of Red Bull Sponsored Female Action Sports Athletes’ Digital Media Representation, Charli Celine Kerns

Doctoral Dissertations

This study applies a multimodal discourse analysis to social media content produced by Red Bull Media House. The aim of the research is to determine what postfeminist sensibilities discourses are used and how in the framing of the female action sports athletes the energy drink company sponsors. Specifically, Instagram posts, YouTube videos, and the biographical web pages about the 23 athletes were analyzed using multimodal discourse analysis. The findings revealed that while action sports have the potential to disrupt dominant discourses around femininity in sports contexts, ultimately Red Bull repackaged the discourses into different narratives.

Identifying An Optimization Technique For Maker Usage To Address Covid-19 Supply Shortfalls, Michael J. Wilson

Doctoral Dissertations

Fused Deposition Modeling (FDM) can be purchased for under five hundred dollars. The availability of these inexpensive systems has created a large hobbyist (or maker) community. For makers, FDM printing is used numerous uses.

With the onset of the COVID-19 pandemic, the needs for Personal Protective Equipment (PPE) skyrocketed. COVID-19 mitigation strategies such as social distancing, businesses closures, and shipping delays created significant supply shortfalls. The maker community stepped in to fill gaps in PPE supplies.

In the case of 3DP, optimization remains the domain of commercial entities. Optimization is, at best, ad-hoc for makers. With the need to PPE …

Evaluating The Impact Of Brief Electronic Professional Development On Emotional Intelligence And Burnout Among In-Service Educators, Michelle Fast

Doctoral Dissertations

To determine the impact of an intervention to improve emotional intelligence (EI) and reduce burnout in educators, 48 in-service educators were randomly assigned to a control or experimental group and administered the Scales of Emotional Functioning: Educators (SEF:ED; McCallum et al., 2019) and the Maslach Burnout Inventory – Educators Survey (MBI-ES; Maslach et al., 2016) before and after intervention. The control group served as a waiting control and completed these instruments again after receiving the intervention. 70% of the participants noted the intervention “helped [them] manage [their] classroom,” though repeated measures ANOVAS yielded little evidence to support this characterization. No …

Local Control Over Education: Perceptions Of Tennessee And Florida County School Board Members, Joseph G. Jarret

Doctoral Dissertations

Historically, local boards of education have been viewed as community stewards who are responsible for providing local children with a quality education that reflects the values and mores of the locality in which they serve (Rice, 2014). However, in recent years, many states have significantly expanded their roles in public education. Quite often, this expansion results in an erosion of local control. For instance, in 2019, the State of Florida, which presently has a mix of elected and appointed school superintendents, considered a state constitutional amendment which would have moved the state to a wholly appointed school superintendent model. In …

Total Internal Reflection: Applications In Nonlinear Microscopy And Fluorescence Anisotropy, Brandon Colon

Doctoral Dissertations

As technology advances to harness new energies and to create new cures, the sophistication of analysis grows not only in depth but in efficiency. Total internal reflection (TIR) has been coupled to microscopy leveraging its unique optical phenomenon on a breadth of topics. In this dissertation, the work presented will show how TIR was applied in two different instrumental analyses to evaluate two unique and complex systems. The first project features TIR paired with the transient absorption microscopy (TAM), a nonlinear optical technique, to gauge solvent mixing and diffusion in microreactors. Microreactors gained acclaim for their ability to produce high …

Instrument Development For High Sensitivity Size Characterization Of Lipid Vesicles And Other Biological Macromolecules Via Taylor Dispersion Analysis, Meagan Moser

Doctoral Dissertations

Just as humans communicate with other humans, the cells in our bodies communicate with each other through various, often complex, mechanisms. Cell-to-cell transmission of small molecules, lipids, proteins, peptides, or nucleic acids can be mediated by extracellular lipid vesicles called exosomes. Exosomes have been found to play a role in the delivery of regulatory molecules from one cell to another, serving as a universal communication mechanism. Currently, there is an emerging focus on characterizing exosome communication dynamics. Understanding exosome mechanisms of cell-to-cell communication requires accurate measurements of the spatiotemporal and chemical dynamics of exosome secretion. No current analytical approach offers …

Beyond ‘Help-Seeking,’ Toward ‘Engagement’: Understanding Barriers To Mental Health Equity Among Sexual Minority Individuals, Elliot Spengler

Doctoral Dissertations

The finding that 57.4% of adults living in the United States with a diagnosable mental health disorder do not receive mental health care (Substance Abuse and Mental Health Services Administration, 2018) opens important questions as to what structural and individual factors contribute to this “treatment gap” and individuals’ willingness and/or ability to seek out traditional mental health care. Sexual minority (SM) individuals experience inequitable mental health outcomes and report more unmet mental health needs and more barriers to health care than heterosexual individuals. Thus, there is a need to understand the process of mental health care engagement (MHCE) for SM …

Forecasting Nigeria's Electricity Demand And Energy Efficiency Potential Under Climate Uncertainty, Olawale Olabisi

Doctoral Dissertations

The increasing population and socio-economic growth of Nigeria, coupled with the current, unmet electricity demand, requires the need for power supply facilities expansion. Of all Nigeria’s electricity consumption by sector, the residential sector is the largest and growing at a very fast rate. To meet this growing demand, an accurate estimation of the demand into the future that will guide policy makers to adequately plan for the expansion of electricity supply and distribution, and energy efficiency standards and labeling must be made. To achieve this, a residential electricity demand forecast model that can correctly predict future demand and guide the …

Synthesis And Characterization Of Metallic Nanostructures Via Pulsed Laser Induced Dewetting And Electron Beam Lithography, David A. Garfinkel

Doctoral Dissertations

Metallic nanostructures have a wide range of applications from high resolution sensing to cancer treatment. Here, these structures are synthesized via a combination of single metal and bi-metal sputtering, in parallel with pulsed laser induced dewetting (PLiD) and electron beam lithography. PLiD is used to generated arrays of spherical caps that can be controlled by initial thin film geometry, namely the thickness. Electron beam lithography is used to produce higher complexity structures such as coupled meta-atoms. By using metallic elements that possess plasmonic (Au and Ag) and magnetic (Ni and Co) properties, tunability that is a function of size, composition, …