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Title: Genetic characterization and population structure of Erysiphe pulchra the causal agent of powdery mildew on Cornus florida in the eastern United States
Author: Wyman, Christopher Robert
Publication Date: 2018-05
Publication Type: masters thesis
Collection: Graduate Theses and Dissertations
PDF: PDF
Abstract: Cornus florida L. (flowering dogwood) is a deciduous understory tree endemic to the eastern United States. Known for its attractive bracts, C. florida is very popular for its ornamental qualities. After 1995, dogwood powdery mildew caused by Erysiphe pulchra Cooke & Peck reached epidemic levels throughout the C. florida growing region. Initially, both sexual and asexual stages of E. pulchra were regularly observed, but in recent years, the teleomorph has not been seen as often. Fifteen microsatellite loci were used to analyze the genetic diversity and population structure of 174 E. pulchra samples from 10 eastern states. The results of this study indicated low genetic diversity, lack of definitive population structure, and significant linkage disequilibrium within the sampled population. Evidence of a recent bottleneck was also observed. Our results suggest that E. pulchra has become clonal in eastern United States and may be an exotic plant pathogen to North America.

Title: Audit Committee Reputation Incentives
Author: Short, Justin Cole
Publication Date: 2018-05
Publication Type: doctoral dissertation
Collection: Graduate Theses and Dissertations
PDF: PDF
Abstract: The demand for qualified directors to serve in audit committee chair and designated financial expert positions has grown in recent years, increasing the number of these directors that serve on multiple audit committees. Past research has examined the effect of these directors holding multiple audit committee seats on audit committee effectiveness, but no studies to date have examined how these directors allocate their monitoring effort across their multiple audit committee seats. Using a sample of audit committee chairs and financial experts that serve on multiple audit committees from 2004-2014, I examine whether the reputation incentives for these directors are associated with audit committee effectiveness at the firms they serve. Reputation incentives theory suggests that these directors will allocate more monitoring effort to the firms in their portfolio that offer them a greater opportunity to enhance their reputation as a monitor (higher reputation incentives). Consistent with this theory, I find that audit committee effectiveness is higher at firms that offer these directors high reputation incentives as compared to firms that do not. My results suggest that these directors exert varying levels of monitoring effort based on the relative importance of any one audit committee to their portfolio of audit committees. My findings should be of interest to boards, investors, and regulators considering the implications of service on multiple audit committees.

Title: Design Space Evaluation for Resonant and Hard-charged Switched Capacitor Converters
Author: Gamble, Jordan Alexander
Publication Date: 2018-08
Publication Type: masters thesis
Collection: Graduate Theses and Dissertations
PDF: PDF
Abstract: USB Power Delivery enables a fixed ratio converter to operate over a wider range of output voltages by varying the input voltage. Of the DC/DC step-down converters powered from this type of USB, the hard-charged Switched Capacitor circuit is of interest to industry for its potential high power density. However implementation can be limited by circuit efficiency. In fully resonant mode, the efficiency can be improved while also enabling current regulation. This expands the possible applications into battery chargers and eliminates the need for a two-stage converter. In this work, the trade-off in power loss and area between the hard-charged and fully resonant switched capacitor circuit is explored using a technique that remains agnostic to inductor technology. The loss model for each converter is presented as well as discussion on the restrained design space due to parasitics in the passive components. The results are validated experimentally using GaN-based prototype converters and the respective design spaces are analyzed.

Title: Candidate Measurement Technique Application as a Method for Materials Accountancy in Electrochemical Reprocessing
Author: Gilliam, Stephen N.
Publication Date: 2018-08
Publication Type: masters thesis
Collection: Graduate Theses and Dissertations
PDF: PDF
Abstract: Electrochemical reprocessing is a promising method to recover useful fissile material from spent nuclear fuel. Due to the recent attention surrounding electrochemical reprocessing as a complement or alternative to aqueous methods, necessary safeguards must be developed. However, the process requires high temperatures and an inert atmosphere thus complicating the prospect of making material accountancy measurements. Thus, to be deployed commercially, viable material accountancy and process monitoring methods must be designed and tested to meet safeguard standards. This work focuses on gamma spectroscopy and total neutron counting methods, which have previously been applied to aqueous reprocessing. These signatures are simulated in a previously developed flowsheet model. By tracking the isotopic mass concentrations at a given time and location, proper emission rates can be calculated that yield accurate representations of the material. Furthermore, notional diversion scenarios were simulated to evaluate the sensitivity of the measurement simulations to slight changes in material mass. Confirmatory measurements at key locations allowed for identification and differentiation of normal and off-normal operating conditions.

Title: Respiratory Structure Morphology, Group Origins, and Phylogeny of Eublastoidea (Echinodermata)
Author: Bauer, Jennifer Elizabeth
Publication Date: 2018-05
Publication Type: doctoral dissertation
Collection: Graduate Theses and Dissertations
PDF: PDF
Abstract: Evolutionary relationships of Paleozoic echinoderms have fostered significant debate over the past century. Many early echinoderms have complexly plated bodies with a variety of morphologies, very unlike modern echinoderms (e.g., sea urchins, sea stars). A major clade, Blastozoa, has been subdivided based on the occurrence of specific respiratory structures but these groups have yet to be fully assessed in a quantitative framework. Phylogenetic inference provides a quantitative means to assess trait evolution, respiratory structure modification, or clade origination. Herein, we assess respiratory morphology, evolution, and group origination of Eublastoidea. The respiratory structures (hydrospires) of eublastoids have been used to separate major subgroups within Eublastoidea but have only been examined externally. Previously only assessed by 2D serial sections of specimens, my research provides 3D detailed anatomical models of these internal structures. Rendering in 3D allows for detailed morphological analysis and functional morphology simulations. Our findings suggest separation by the external expression of hydrospires results in a misleading understanding of evolutionary history. These insights into eublastoid respiratory structures shed light on an ongoing debate regarding the origins of blastoids. Origins of blastoids are unclear and a series of ancestors has been proposed. A single species of blastoid Macurdablastus uniplicatus, was recorded from the Late Ordovician with the next undisputed species in the middle Silurian. We reassessed anatomy and evolutionary relationships through detailed morphological examination, synchrotron imaging, and phylogenetic analyses. Results from our subsequent phylogenetic analyses suggest Macurdablastus is not a true blastoid (eublastoid) but is include in the broadly defined Blastoidea that includes coronoids, eublastoids, Lysocystites. The revival of the term Eublastoidea to include species with recumbent ambulacra and hydrospires provided the basis to explore the evolution of this long-lived clade. Following and expanding upon a proposed homology scheme for echinoderms, I produced a comprehensive character matrix for the external and internal morphology of eublastoids. The phylogeny was used to reassess eublastoid classification and as a framework to address the validity of group separation via the external expression of hydrospires. This work provides the first complete assessment of echinoderm respiratory structures and detailed reassessement of eublastoid morphology.

Title: Traditional Rural Values, Posttraumatic Stress, and Posttraumatic Growth among Rural and Urban Undergraduates
Author: Keller, Emily Molly
Publication Date: 2018-05
Publication Type: masters thesis
Collection: Graduate Theses and Dissertations
PDF: PDF
Abstract: Although rurality is often treated as an aspect of diversity, disagreement appears in the literature regarding whether the traditionally rural values of self-reliance, distrust of outsiders, religiosity, centrality of family, and fatalism continue to differentiate rural versus urban residents. The present study examined whether differences in these values exist between rural and urban residents and whether these values may predict posttraumatic stress symptom (PTSS) severity and posttraumatic growth (PTG). Undergraduates who reported experiencing traumatic and stressful events (N = 213) completed measures of these constructs through an online survey. Over a quarter (n = 56) of participants classified their permanent residences as located in rural areas, primarily in the Southeast. T-test results indicated that rural respondents had significantly higher levels of PTSS severity and distrust of outsiders and significantly lower levels of organized religiosity when compared with urban participants. In predicting stress-related outcomes, a greater emphasis on family, higher distrust toward outsiders, lower levels of intrinsic religious beliefs, and higher levels of fatalism were associated with more severe PTSS. Higher intrinsic religiosity predicted higher levels of PTG. Thus, results suggest that rural and urban undergraduates are becoming more similar with regard to traditionally rural values. Further research is needed to determine if these values continue to apply to rural residents in other generations or regions of the United States, as these values may be important to consider in the context of therapy.

Title: Electromechanical Dynamics of High Photovoltaic Power Grids
Author: You, Shutang
Publication Date: 2017-12
Publication Type: doctoral dissertation
Collection: Graduate Theses and Dissertations
PDF: PDF
Abstract: This dissertation study focuses on the impact of high PV penetration on power grid electromechanical dynamics. Several major aspects of power grid electromechanical dynamics are studied under high PV penetration, including frequency response and control, inter-area oscillations, transient rotor angle stability and electromechanical wave propagation. To obtain dynamic models that can reasonably represent future power systems, Chapter One studies the co-optimization of generation and transmission with large-scale wind and solar. The stochastic nature of renewables is considered in the formulation of mixed-integer programming model. Chapter Two presents the development procedures of high PV model and investigates the impact of high PV penetration on frequency responses. Chapter Three studies the impact of PV penetration on inter-area oscillations of the U.S. Eastern Interconnection system. Chapter Four presents the impacts of high PV on other electromechanical dynamic issues, including transient rotor angle stability and electromechanical wave propagation. Chapter Five investigates the frequency response enhancement by conventional resources. Chapter Six explores system frequency response improvement through real power control of wind and PV. For improving situation awareness and frequency control, Chapter Seven studies disturbance location determination based on electromechanical wave propagation. In addition, a new method is developed to generate the electromechanical wave propagation speed map, which is useful to detect system inertia distribution change. Chapter Eight provides a review on power grid data architectures for monitoring and controlling power grids. Challenges and essential elements of data architecture are analyzed to identify various requirements for operating high-renewable power grids and a conceptual data architecture is proposed. Conclusions of this dissertation study are given in Chapter Nine.

Title: Thermo-mechanical analysis of iron-chromium-aluminum (FeCrAl) alloy cladding for light water reactor fuel elements
Author: Sweet, Ryan Terrence
Publication Type: doctoral dissertation
Collection: Graduate Theses and Dissertations
PDF: PDF
Abstract: Alternative cladding materials have been proposed to replace the currently used zirconium (Zr)-based alloys, in order to improve the accident tolerance of light water reactor (LWR) fuel. Of these materials, there is a particular focus on iron-chromium-aluminum (FeCrAl) alloys that exhibit much slower oxidation kinetics in high-temperature steam than Zr-alloys. This behavior should decrease the energy release due to oxidation and allow the cladding to remain integral longer in the presence of high temperature steam, making accident mitigation more likely. This dissertation documents efforts to develop fuel performance capabilities to assess the behavior of FeCrAl cladding during normal and transient reactor operating scenarios. Within this work, simulations were performed for FeCrAl cladding using constitutive models and representative reactor operating conditions implemented into the finite-element fuel performance code BISON. Simulations were performed targeting the cladding behavior during normal operation of a boiling water reactor using boundary conditions derived from neutronics data. These simulations indicate that the fuel compliance plays a much larger role in the evolution of the cladding stress state after gap closure for the FeCrAl cladding than for Zircaloy. Individual sensitivity analyses of the fuel and cladding creep responses were then performed, which indicated the influence of compliance for each material, separately, on the stress state of the fuel cladding. To improve calculations of the fuel expansion and compliance, an additional investigation was performed to assess the role of creep, relocation, and explicit fracture in the fuel. Fuel rods using each of these models are simulated under representative conditions and compared to test rod measurements. This analysis provides a start toward the development and incorporation of explicit fracture in fuel performance analysis. Additionally, performance and stability under transient conditions must also be demonstrated for FeCrAl cladding. This analysis focused on modeling the integral thermo-mechanical performance of FeCrAl clad uranium dioxide fuel during transient reactor operation. Results from this simple analysis show similar bursting time and temperature between both FeCrAl and Zircaloy cladding, however, beyond cladding burst in these conditions, the superior high temperature oxidation kinetics of the FeCrAl cladding significantly reduce hydrogen gas production and provide longer fuel integrity.

Title: Quantifying Irregular Geographic Exposure on the Internet
Author: Holland, Jordan Alexander
Publication Date: 2018-05
Publication Type: masters thesis
Collection: Graduate Theses and Dissertations
PDF: PDF
Abstract: In this work, we examine to what extent the Internet's routing infrastructure needlessly exposes network traffic to nations geographically irrelevant to packet transmission. We quantify what countries are geographically logical to see on a network path traveling between two nations through the use of convex hulls circumscribing major population centers, and then compare that to the nation states observed in over 14.5 billion measured paths. Our results show that 49% of paths unnecessarily expose traffic to at least one nation. We further explore what nations, regions, and ASes expose and benefit from this geographically illogical traffic. As an example, we see that 23% of source/destination pairs located outside of the United States send their traffic through the US, but only 8% of those paths are geographically logical. Finally, we examine what happens when countries exercise both legal and physical control over ASes transiting traffic, gaining access to traffic outside of their geographic borders, but carried by organizations that fall under a particular country's legal jurisdiction. When considering both the physical and legal countries that a path traverses, our results show that over 57% of paths expose traffic to a geographically irrelevant country.

Title: Prediction of Host-Microbe Interactions from Community High-Throughput Sequencing Data
Author: Stough, Joshua Michael Albert
Publication Date: 2017-12
Publication Type: doctoral dissertation
Collection: Graduate Theses and Dissertations
PDF: PDF
Abstract: Microbial ecology is a diverse field, with a broad range of taxa, habitats, and trophic structures studied. Many of the major areas of research were developed independently, each with their own unique methods and standards, and their own questions and focus. This has changed in recent decades with the widespread implementation of culture-independent techniques, which exploit mechanisms shared by all life, regardless of habitat. In particular, high-throughput sequencing of environmentally isolated DNA and RNA has done much to expand our knowledge of the planet’s microbial diversity and has allowed us to explore the complex interplay between community members. Additionally, metatranscriptomic data can be used to parse relationships between individual members of the community, allowing researchers to propose hypotheses that can be tested in a laboratory or field setting. However, use of this technology is still relatively young, and there is a considerable need for broader consideration of its pitfalls, as well as the development of novel approaches that allow those without a computational background or with fewer resources to navigate its challenges and reap its rewards. To address these needs, we have developed targeted computational approaches that simplify next-generation sequencing datasets to a more manageable size, and we have used these techniques to address specific questions in environmental ecosystems. In a dataset sequenced for the purpose of identifying ecological factors that drive Microcystis aeruginosa to dominate cyanobacterial harmful algal blooms worldwide, we used a targeted approach to predict replication and lysogenic dormancy in bacteriophage. We used RNA-seq data to characterize viral diversity in the Sphagnum peat bog microbiome, identifying a wealth of novel viruses and proposing several host-virus pairs. We were able to assemble and describe the genome of a freshwater giant virus as well as that of a virophage that may infect it, and we used our techniques to describe its activity in publicly available datasets. Lastly, we have extended our efforts into the realm of medicine where we showed the influence exerted by the mouse gut microbiome on the host immune response to malaria, identifying several genes that may play a key role in reducing disease severity.

Title: Demolishing an American Ghetto: How Neoliberalism is Reinventing Life and Labor in Nashville, Tennessee
Author: Walton, Charles Dean
Publication Date: 2017-12
Publication Type: masters thesis
Collection: Graduate Theses and Dissertations
PDF: PDF
Abstract: The purpose of this project is to examine the adverse effects of neoliberal economic development in Nashville, Tennessee. For several years, the city has been widely praised for its rapidly growing economy, especially in industries such as healthcare and entertainment. There is, however, a contradiction built into this growth that is often left out of discussion. National trends related to deindustrialization, offshoring, and automation have left sectors of the population without work, oftentimes forcing them into the informal or underground economy. Tennessee especially fits into the neoliberal paradigm as the state promotes its emphasis on deregulation in its growing medical and manufacturing industries all while having a regressive tax system in place. In addition, wide-scale gentrification in Nashville and cuts to governmental social expenditures have left this population even more vulnerable, fracturing communities and leaving people economically discarded. This project draws on eight months of fieldwork, primarily in East and Northeast Nashville. It provides a framework for explaining the role of the urban poor in a postindustrial economy defined by urban displacement and destitution as a byproduct of neoliberal policies that aim to manage and punish the poor (Piven and Cloward, 1993; Wacquant, 2009). In addition, it works to make sense of how the urban poor situate themselves in a changing social reality defined by displacement and state repression, perpetual surveillance via the dismantling of the welfare state, their declining relevance to the productive economy, and finally the fracturing of physical market spaces and exchange relations by means of the decentralization in the informal economy.

Title: Effects of Acute Lying and Sleep Deprivation on the Behavior and Immune Function of Lactating Dairy cows
Author: Kull, Jessie Ann
Publication Date: 2018-05
Publication Type: masters thesis
Collection: Graduate Theses and Dissertations
PDF: PDF
Abstract: The objective of the study was to determine the effects of sleep or lying deprivation on the behavior, production, metabolism and immune function of dairy cows. Data were collected from 8 multi- and 4 primi-parous cows (DIM = 199 ± 44 (mean ± SD); days pregnant = 77 ± 30). Each cow experienced: 1) 24 h sleep deprivation implemented by noise or physical contact and 2) 24 h lying deprivation imposed by a wooden grid placed on the pen floor that prevented a recumbent position. An 11-d collection period (from 2 d before the first treatment (trt) to 8 d after trt) was followed by 12-d washout periods. Study days were organized from 2100 to 2059. During habituation (d -2 and -1 before trt), baseline (d 0), and trt (d 1), housing was individual stalls (mattress with no bedding). After trt, cows returned to sand-bedded freestalls for a 7-d recovery period (d 2 to 8). Lying behaviors were recorded by accelerometers attached to the hind leg. Milk yield was recorded 2× daily. NEFA and glucose concentrations were evaluated from serum sampled at 0300, 0900, 1500, and 2100 on d 1 and 2. Data were analyzed using a mixed model in SAS including fixed effects of trt, day, and their interaction with significant main effects separated using a PDIFF statement (P ≤ 0.05). Lying time decreased during trt and increased on the first day of recovery for lying deprivation compared to sleep deprivation (d 1: 1.9 vs. 8.4 ± 0.7 h/d (mean ± pooled SE); P < 0.001; d 2: 16.8 vs. 13.6 ± 0.7 h/d; P = 0.002). Milk yield decreased during lying deprivation compared to sleep (P = 0.002). NEFA and glucose varied by time (P ≤ 0.03). IL-1β and TNF-α were higher during trt, compared to baseline for both treatments (day: P = 0.04 and P = 0.004, respectively). Collectively, this suggests, lack of access to resting resources rather than the relative comfort of that resource, may have greater long-term effects on the welfare of dairy cows.

Title: Hungaria Asteroid Region Telescopic Spectral Survey (HARTSS): Establishing Asteroid-Meteorite Connections Between Hungaria Asteroids and Meteorites of the Acapulcoite-Lodranite Clan
Author: Lucas, Michael Peter
Publication Date: 2017-12
Publication Type: doctoral dissertation
Collection: Graduate Theses and Dissertations
PDF: PDF
Abstract: Hungaria region asteroids are survivors of giant planet migration that destabilized a now extinct inner-portion of the primordial asteroid belt. In this scenario, the Hungaria region represents a “purgatory” for the closest, preserved samples of material from which the terrestrial planets accreted. Deciphering the surface composition of these samples may provide constraints on the nature of the primordial building blocks of the terrestrial planets. We carried out a two-phased ground-based observational campaign—Hungaria Asteroid Region Telescopic Spectral Survey (HARTSS)—to record their visible and near-infrared reflectance spectra. We analyzed these spectra to characterize the taxonomy, surface mineralogy, and potential meteorite analogs of Hungaria background and family asteroids. In HARTSS I we found that ~80% of the background population are stony S-types that exhibit spectral and mineralogical diversity. Two main asteroid-meteorite connections exist between background S-types and stony meteorites: unmelted L-/LL-ordinary chondrites, and partially-melted primitive achondrites. To strengthen connections between S-types and partially-melted meteorites, we measured the spectral and cosmochemical properties of 10 acapulcoite-lodranites. We found a well-defined relationship between the ~2 μm band center and ferrosilite (Fs) content of orthopyroxene. Because Fs in orthopyroxene and fayalite (Fa) content in olivine are well-correlated in these meteorites, the derived Fs content can be used to estimate Fa of the co-existing olivine. These relationships help to determine whether S-types are nebular (ordinary chondrites), or have experienced partial melting (primitive achondrites). In HARTSS II, we focus on family members and hypothesize that the Hungaria family is compositionally homogeneous. Surviving fragments of an asteroid collisional family typically exhibit similar taxonomies, albedos, and spectral properties. Measurements of these properties for Hungaria family members are consistent with this scenario. Spectral observations of 92 Hungarias acquired during HARTSS uncover a compositionally heterogeneous background population and a spectrally homogeneous collisional family, implying that the parent body was homogeneous. This parent body was likely consistent in composition with enstatite achondrites (aubrites) and therefore formed under reduced, igneous conditions. If aubrites are truly representative of igneous mantle material, then the Hungaria parent body was itself a collisional fragment that originated on a differentiated, heterogeneous parent body early in Solar System history.

Title: "Our people are warlike": Civil War Pittsburgh and Home-Front Mobilization
Author: York, Allen Christopher
Publication Date: 2018-05
Publication Type: doctoral dissertation
Collection: Graduate Theses and Dissertations
PDF: PDF
Abstract: The Civil War was won by the Union through the effective mobilization of Northern society. Communities across the North were the essential actors in providing troops, producing war materiel, and rendering aid to soldiers. But historians of the Northern home front have primarily focused on dissent and opposition rather than explaining popular support for the war. Scholarship that has concentrated on mobilization has centered on the ideology that influenced it rather than the process by which it was carried out, and historians of the Civil War have largely viewed Northern society as a single entity rather than a conglomerate of individual communities. The Pittsburgh home front connected with and manifested support for the Union war effort in myriad ways that illustrate the importance of regional distinctiveness to understanding the role of Northern society in the war. Ultimately, Pittsburghers were mobilized by a strong sense of localism that made mobilization a matter of honor for the community, by an interpretation of events on the home front that drew parallels with the experience of soldiers on the front line, and by adaptations of existing traditions to promote mobilization. By interpreting the war in ways that fit their existing ideologies and by creating opportunities to directly participate in its prosecution, community leaders and organizers in Pittsburgh enabled the people to engage in the war rather than simply observe it.

Title: Optical Diagnostic Techniques as an Approach to Characterizing Forced and Freestream Disturbances
Author: Harris, Adam Joel
Publication Date: 2018-05
Publication Type: masters thesis
Collection: Graduate Theses and Dissertations
PDF: PDF
Abstract: Two optical techniques are examined for their feasibility to measure laser-induced disturbances and freestream disturbances in supersonic flow. The two techniques examined are laser differential interferometry and time-resolved Schlieren. They provide unique capabilities for measuring these disturbances, and may provide much insight when used simultaneously. Laser differential interferometry can measure broadband noise in a wind tunnel in the < 100kHz range. Focusing laser differential interferometry may be a more appropriate technique to measure laser-induced disturbances, as it can spatially filter regions of little interest. Laser differential interferometry is path-integrated, and measurements can be obscured by dynamic content present in the regions of little interest along the measurement volume; however, it was used to make mean measurements of laser-induced disturbances. Schlieren can make qualitative observations of freestream disturbance levels for a global field of view. Schlieren allows observation of many characteristics of a laser-induced disturbance such as the growth rate and internal spatial frequencies in quiescent air. It was determined that the growth rate of laser-induced disturbances is highly non-linear, of the form D(t) = a(t)^b where t is time in seconds and D is diameter in meters. Mean values of a = 0.0271 and b = 0.171 are observed. Spatial frequencies of the thermal disturbance are typically found to vary between 7 and 15 cm^-1. Turbulent structures are found to evolve within the first 500 us, and diffusion causes the disturbance to continue to expand for the next 10 ms where the disturbances would typically become too diffuse to observe. Internal spatial frequencies are found to be proportional to the diameter of the disturbance by normalizing spectra by the instantaneous diameter. This shows that after the evolution of turbulent structures, diffusion of the forced disturbance becomes the dominant mechanism in the absence of a driving force. The disturbance behaves very similarly in a Mach 2 flow as it does in quiescent air, though the mean diameter is observed to be larger by a ratio of 1.71. This is likely due to the lower density environment.

Title: Expanding the Metabolome with Applications in Neuroscience and Bioremediation
Author: Bourdon, Allen
Publication Date: 2018-05
Publication Type: doctoral dissertation
Collection: Graduate Theses and Dissertations
PDF: PDF
Abstract: The study of small molecules, while not a new concept, is still at its infancy for both detection and structure identification. My work at the University of Tennessee, Knoxville has been focused on the advancement of both analytical detection and identification of novel compounds as potential small molecule targets. Using in vitro and in vivo neurometabolomics on rodents as my foundation, I have been able to identify numerous small molecules for further study in the areas of social defeat stress and across various states of consciousness. Through untargeted metabolomics via liquid chromatography coupled with high-resolution mass spectrometry, this research has provided the additional hurdle of identifying novel targets among the unidentified spectral features, or “unknown” metabolites. In the final chapter of this dissertation, I emphasize my ability to elucidate the structure of a novel cobamide identified as a native prosthetic group in catalytically active tetrachloroethene reductive dehalogenases of Desulfobacterium hafniense. Utilizing stable isotope labeling of microbial cultures, mass spectrometry confirmed the molecular formula, followed by 1D and 2D nuclear magnetic resonance spectroscopy to characterize structural connectivity. The research presented in this dissertation advances the field of novel compound discovery and characterization for the identification of small molecule targets by highlighting unique research within the fields of neurometabolomics and microbiology.

Title: Electrochemically Activated Persulfate for Ciprofloxacin Degradation
Author: Matzek, Laura Whitaker
Publication Date: 2018-05
Publication Type: doctoral dissertation
Collection: Graduate Theses and Dissertations
PDF: PDF
Abstract: Electrochemically activated persulfate (EAP) is a potential point source treatment for wastewater effluents containing high pharmaceutical content. This dissertation explores the fundamental mechanisms of EAP to better understand this technology for practical application. Ciprofloxacin, a fluoroquinolone antibiotic, was chosen as the model compound to assess parameters of EAP. Ciprofloxacin was selected for its high environmental risk factor and prevalence in hospital wastewater, a potential application for EAP. During the evaluation of EAP as a point source treatment, degradation kinetics and pathways of ciprofloxacin were elucidated. In the first stage of this study, persulfate activation by solid iron with and without applied current was characterized and applied to the degradation of ciprofloxacin. It was found that persulfate activation increased with iron surface area and increased to a plateau with increasing current. Ciprofloxacin degraded via first-order kinetics; however, applied current did not affect ciprofloxacin removal. In the second part of this study, electrochemical persulfate activation without iron, using boron-doped diamond (BDD) anodes and graphite or platinum cathodes, was examined. Sulfate radical formation at a BDD anode and persulfate activation at a graphite cathode were elucidated using different electrolytes and electrochemical set-ups. In this system, ciprofloxacin degraded via first order-kinetics, with persulfate electrolyte enhancing ciprofloxacin removal over sulfate or nitrate. In the final phase of this study, parameters such as reactor configuration, electrode surface area, persulfate concentrations and the presence of a complex matrix were examined to determine their impact on contaminant removal. Due to mass transfer limitations and relative cathode sizes, a flow-through reactor was least benefited by persulfate addition while a rotating-disk electrode reactor showed enhanced ciprofloxacin removal with persulfate electrolyte. Ciprofloxacin removal from synthetic hospital effluent using electrochemically activated persulfate was found to be less than that in pure electrolyte but still followed a first-order mechanism. Considerable total organic carbon removal of ciprofloxacin and other organic components of the effluent was achieved. Similar degradation was achieved with persulfate and sulfate electrolyte in the effluent. Chlorate, chlorite and perchlorate were formed in significant amounts during the electrochemical process, with formation independent of the presence of persulfate.

Title: Social Work Practice in Public Defense
Author: Buchanan, Sarah Beck
Publication Date: 2017-12
Publication Type: doctoral dissertation
Collection: Graduate Theses and Dissertations
PDF: PDF
Abstract: Little is known about the collaboration between public defense and social work despite the growing implementation of the approach. This dissertation attempts to better understand the implications for social work practice in the public defense setting by 1) reviewing the literature to gain an understanding of social work roles, services, and practice outcomes, 2) examining demographic characteristics and criminal charges incurred by a group of clients in a public defense setting to better understand the population to develop and tailor interventions, and 3) determining the effect of social work services in terms of the number and severity of criminal charges when statistically controlling for pre-existing criminal history and demographic characteristics. Findings indicate that significant gaps exist in understanding the population of public defense clients served by social workers, making it difficult to understand how to tailor services and target interventions. A clear picture emerged of the typical social work client in one public defense setting: male, European American, unmarried, and around 34 years old at the time he began working with a social worker. Also, two distinct subgroups of social work clients were identified: a smaller group comprised of clients who predominantly incurred low-level misdemeanor charges, and a larger group comprised of clients who incurred a high number of low-level misdemeanors, but incurred a higher number of charges, in general, and were more likely to have incurred some felony charges. When comparing clients who did and did not receive social work services, results indicated that the probability of incurring a misdemeanor charge and the number of misdemeanor charges incurred during a two-year time period were lower for clients who received social work services. The probability of incurring a felony charge was lower for the legal group, but there was not a statistically significant difference between groups in the number of felony charges. Implications for practice and future research are discussed.

Title: Construction Dispute Mitigation: Quantitative and Qualitative Analytic Approach with a Focus on Bidding, Out-of-Sequence Work, and Contract Analysis
Author: Abotaleb, Ibrahim Salah Eldin
Publication Date: 2018-05
Publication Type: doctoral dissertation
Collection: Graduate Theses and Dissertations
PDF: PDF
Abstract: The complexity of today’s construction projects deems conflicts and disputes unavoidable. The mere presence of disputes leads to productivity losses, schedule overruns, cost overruns, and quality decline. Moreover, failure to resolve disputes in a quick manner ripples these impacts and prevents successful completion of projects. Accordingly, preventing disputes prior to taking place is always better than resolving them after the fact. There are several factors that cause disputes. However, this dissertation focuses on those related to bidding, out-of-sequence (OOS) work, and contract administration of owner’s obligations, due to the significant knowledge gaps that were identified in their research streams. The goal of this research is to cover the identified knowledge gaps by providing various effective quantitative and qualitative means of dispute mitigation at the different stages of the project’s lifecycle. To this end, the research has four main objectives; each corresponding to one of the identified major knowledge gaps. The objectives are: (1) develop an advanced model for construction bid price estimation that is able to draw sound statistical inferences even in cases of data incompleteness and dynamic behaviors of competitors; (2) present contract administration guidelines for utilizing employer’s obligations clauses under the most widely used national and international standard forms of design-build contracts; (3) identify the causes and early warning signs of OOS work and their characteristics, as well as the best practices to avoid and mitigate its impacts, and (4) develop an advanced systematic model for analyzing the dynamics of OOS. The objectives were achieved through multiple analytical quantitative and qualitative methods; utilizing Bayesian statistics, decision theory, contractual examinations, surveys and meetings, statistical analysis, decision support systems, and system dynamics simulation. The research has various intellectual merits as it tackles important research areas that have not been explored before and improves areas which needed improvement. The research also has practical merits as it provides project stakeholders with models and tools that are used in multiple stages of the project cycle to mitigate disputes. The intellectual and practical outcomes of this research will partake in further understanding construction projects, minimizing disputes at different stages, and promoting healthier contracting environments.

Title: The Impact of Chemical Additives and Chemical Transformations on Water Quality in Hydraulic Fracturing
Author: Manz, Katherine Elizabeth
Publication Date: 2018-05
Publication Type: doctoral dissertation
Collection: Graduate Theses and Dissertations
PDF: PDF
Abstract: The U.S. Energy Information Administration (EIA) predicts that electricity generation from natural gas will increase by 30 to 40% until 2040 [1]. Natural gas is produced via hydraulic fracturing, which does not come without environmental health and safety concerns. Many of the concerns are due to the insufficient knowledge about what hydraulic fracturing fluids contain pre-and post-fracture and how they impact water quality [2]. Consequently, knowledge gaps remain concerning how the additives transform and how they interact with the geological formations downhole. Failure to address this issue has caused the public to question whether the benefits outweigh the perceived risks as the environmental and ecosystem concerns surrounding hydraulic fracturing are still present [3]. To address these concerns, this research investigates the interactions and transformations of chemical additives used in hydraulic fracturing with one another and with shale rock. Specifically, the adsorption of a surfactant-like chemical, 2-butoxyethanol (2-BE), found in the chemical additive Revert Flow, and a non-surfactant chemical, 3-furaldehyde, found in enzyme breaker additives, will be monitored in shale rock and with granular activated carbon to assess the potential for chemical migration through geological formations. This dissertation will also investigate the reactions between 2-BE, shale rock, and chemical additives, including sodium persulfate and hydrochloric acid. In turn, the changes in shale properties, including particle size and heavy metal leaching, due to contact with chemical additives will be assessed. The organic byproducts produced or metals precipitated in each set of reactions will be used to determine how hydraulic fracturing fluids transform water quality. Hydraulic fracturing transformations must be understood to evaluate how hydraulic fracturing fluids impact water quality. A better understanding of how chemicals interact under hydraulic fracturing conditions will increase awareness and knowledge of what the waste fluids contain, aid in developing environmental policies that protect the ecosystems surrounding a well, and facilitate spill preparedness to mitigate hydraulic fracturing pollution based on the information in this study.

The University of Tennessee, Knoxville

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