Digital Commons Network^™

Investigation Of The Rupture Initiation And Mechanical Performance Of Alumina Port Covers For Integrated Rocket Ramjet Systems, Haley R. Goldston

Masters Theses

Hypersonic flight is widely considered essential to ensure a competitive defensive capability in the United States. In hypersonic air breathing propulsion, cruise vehicles are a priority research and development area given the ease to which they can be implemented with existing DoD infrastructure. Advancements in ramjet engine systems, including integrated rocket ramjets, play a considerable role in military and space access hypersonic vehicle designs. By design, ramjets cannot produce static thrust. They first need to be brought to operational speeds with the help of a rocket booster. An integrated rocket ramjet (IRR) combines the booster phase and the ramjet phase …

Chemical Elemental Analysis Using Portable X-Ray Fluorescence As A Means Of Sorting Commingled Human Remains, Matthew Mikal Davis

Masters Theses

Anthropological analyses include the examination of individual skeletal elements to estimate the biological profile of an unknown individual (age, sex, stature, and ancestry). Commingled human remains (the remains of multiple individuals mixed together) present a significant challenge to these analyses. Commingled skeletal elements may appear similar in size and color, making visual determinations of which bones belong to a certain person insufficient to ensure accurate sorting. Furthermore, when remains are fragmentary as well as commingled, it is more complicated to re-associate each element with a single individual. Traditional methods of sorting commingled remains include pair matching, osteometrics, taphonomic assessment, and …

Relative Soybean Response To Aminocyclopyrachlor, 2,4-D, Dicamba, And Aminopyralid, Trey I. Clark

Masters Theses

This research compared the visual symptomology of four auxin herbicides applied at three rates to simulate tank contamination on non-auxin tolerant soybeans. The herbicides examined were aminocyclopyrachlor (ACP), 2,4-D, dicamba, and aminopyralid. The standard labeled rates (SLR) used to base the application rates were 0.12 kg ae ha^-1 for ACP and aminopyralid while dicamba and 2,4-D used 1.12 kg ae ha^-1. These four herbicides exhibit similar symptoms on soybeans which is problematic when diagnosing soybean response. One goal of this project was to obtain high-quality images of the four herbicide’s effect on soybeans, with the hope of …

Designing Polymer Materials For Improved Additive Manufacturing, Kaizhong Guan

Masters Theses

Currently, two of the most used additive manufacturing methods for polymers are selective laser sintering (SLS) and fused filament fabrication (FFF). Although at high market size, they both have imperfections. The materials for SLS are limited and the objects manufactured by FFF existing anisotropic behavior. Targeting on these drawbacks, this thesis has proposed a novel method to prepare polypropylene (PP) microsphere which is suitable for SLS with low cost and scalable potential; and a novel material with polycarbonate as matrix that has shown a decrease in anisotropy after FFF printing.

The PP microsphere in this thesis was prepared via liquid-liquid …

Fungicide Sensitivity And Spore Trapping Of Cercospora Sojina, Elias Zuchelli

Masters Theses

Cercospora sojina is the causal agent of frogeye leaf spot disease (FLS) in soybean. FLS management is achieved by resistant varieties, crop rotation and fungicide applications. The use of fungicides may result in the development of fungicide resistance, which has occurred within C. sojina already and in response to the QoI fungicide group. The goal of this project was to investigate any additional loss of fungicide efficacy, using both field and laboratory trials, as well as to develop a threshold for triggering fungicide applications based on inoculum detection using spore traps and molecular tools. The fungicide efficacy of Topguard (Flutriafol), …

The Effect Of Bovine Endometrial Cell Conditioned Media On In Vitro Produced Bovine Embryo Development And Gene Expression, Mary A. Oliver

Masters Theses

In vitro produced (IVP) bovine embryos provide enhanced genetic value and a means for studying early embryonic development. However, IVP embryos are developmentally compromised and are lower quality compared to in vivo derived (IVD) embryos. Consequently, after transfer pregnancy rates from IVP embryos are consistently lower, as they exhibit the highest amounts of pregnancy failure during the early embryonic phase (prior to day 28). Progesterone (P4) has been shown to influence bovine endometrial epithelial (EPI) and stromal fibroblast (SF) cells to secrete developmentally important molecules that promote early embryo development and conceptus elongation. However, IVP embryos are not exposed to …

Feeding Behavior And Influence Of Hemp Varieties And Fertilization Rates On Damage Caused By Corn Earworm, Helicoverpa Zea, Julian Cosner

Masters Theses

Production of industrial hemp, Cannabis sativa L., has increased tremendously in the U.S. after its legalization through the Agricultural Improvement Act of 2018, known as the 2018 Farm Bill, which allowed commercial hemp production. By grower number, in 2020, Tennessee was the nation’s largest hemp program with over 1,800 producers licensed to grow up to 6,500 hectares (16,000 acres) according to the Tennessee Department of Agriculture. Though fiber and seed have a role in the industry, most growers (ca. 98%) concentrate on cannabidiol production because of the expected higher cash value potential per hectare. Introducing hemp as a monocrop system …

Ni De Aquí, Ni De Allá: Constructing National Identity In The Case Of Jonathan González, Arturo Jaime Morales Jr

Masters Theses

First-generation Mexican-Americans who are born in the US to immigrant parents often find themselves at a crossroad constantly negotiating their ethnic identity. One of those junctions where Mexican-Americans often have to navigate their identity is in the world of soccer, in particular when it comes to rooting for the US national team or the Mexican national team. Scholars call this transnational concept Entre Dos Mundos–Between Two Worlds (Bacallao and Smokowski 2005; Campbell 2005; Gutierrez 1996; Menjivar 2002). Jonathan González is one of those Mexican-Americans, who in 2018 announced his decision to play for the Mexican national team instead of …

Assessing Mechanical Performance Of Dissimilar Steel Systems Made Via Wire-Arc Additive Manufacturing, Obed Daniel Acevedo

Masters Theses

Hot stamping is part of a specific type of metalworking procedure widely used in the automotive industry. This research seeks to help make hot stamp tooling component production more cost-effective by using large-scale additive manufacturing. Additive manufacturing can produce dissimilar steel components that can be more cost-effective and time-efficient and allow for complex geometries to be made. A dissimilar steel system consisting of 410 martensitic stainless steel and AWS ER70S-6 mild steel is proposed to make hot stamps, making them more cost-efficient. However, the material interface's mechanical behavior in 410SS-mild steel additively manufactured material systems is not well understood. This …

Pollinator Community Homogenization And Pollination Services In Agroecosystems, Devon S. Eldridge .

Masters Theses

Pollination, or the transfer of pollen to plant stigmas, is an essential part of plant reproduction. The term “pollination system” refers to the floral phenotype and pollinator of a given plant. Although angiosperms exhibit a variety of different pollination systems, most rely partially or completely on animals, particularly insects, to vector their pollen. In agricultural systems, understanding the pollination system of the crop species is necessary to produce an economically valuable yield. Moreover, agricultural management may affect pollination systems by altering the abundance, diversity, or function of the pollinator community. In natural ecosystems, there is a great diversity of pollinating …

Deep Learning Based Prediction Of Clogging Occurrences During Lignocellulosic Biomass Feeding In Screw Conveyors, Yang Li

Masters Theses

Over the last decades, there have been substantial government and private sector investments to establish a commercial biorefining industry that uses lignocellulosic biomass as feedstock to produce fuels, chemicals, and other products. However, several biorefining plants experienced material conveyance problems due to the variability and complexity of the biomass feedstock. While the problems were reported in most conveyance unit operations in the biorefining plants, screw conveyors merit special attention because they are the most common conveyors used in biomass conveyance and typically function as the last conveyance unit connected to the conversion reactors. Thus, their operating status affects the plant …

Vorticity And Kinematic Analysis Of The Cordillera Blanca Shear Zone, Peru, Corey Flynn

Masters Theses

Quantitative vorticity analyses applied to naturally deformed rocks are essential for studying kinematics in shear zones and can be performed using a range of methods, which have been developed over the last two decades. An understanding of vorticity, or the contribution of pure vs. simple shear, can permit for the modeling of shear zone development in a deformed region. Recent (5 Ma-present) deformation in the Cordillera Blanca Shear Zone of the Peruvian Andes has exposed sections of the middle crust at the surface, allowing for observation and analysis of shear zone processes. Oblique grain-shape (OGS) analysis and crystallographic vorticity analysis …

Therapeutic Intervention Or Rider Influence On The Electromyographic Activity And Kinematics Of Horses, Karen L. Shaw

Masters Theses

Core strengthening and postural stability are desired outcomes of certain therapeutic exercises performed in horses. This study aimed to quantify changes in muscle activation at a walk and trot in horses traveling over eight consecutive ground poles evenly spaced (at 30 inches for walk and 48 inches for trot) in parallel fashion in a straight line, and with hindquarter and abdominal elastic resistance bands applied at 25% stretch. Surface electromyography (sEMG) data were collected for the longissimus dorsi and rectus abdominus muscles in six horses. A 2x2 repeated measures ANOVA was performed for each muscle to test for significant differences …

Modeling And Quality Analysis Of Radio Frequency Heating Of Low Moisture Foods, Qianyi Chen

Masters Theses

Low moisture food is usually considered as high safety food. Since its low water activity (aw < 7), this would be a strict environment for pathogen microbes to grow in the low moisture food. However, the recent outbreaks of Salmonella in low moisture foods indicated the possibility of microbiological contamination happened during the harvesting, processing or transportation of food products. Since the bad heat conduction of conventional thermal process on low moisture food, radiofrequency (RF) treatment is a promising technology to improve the heating efficiency with its volumetric heating. Nevertheless, non-uniformity heating is still a challenge in RF technology. There are two research chapters in this study. The first research chapter was to use computer modeling to understand the improvement of applied immersion fluids on the RF heating of the cornflour. The model had a good agreement with the experiment results. The modeling results showed that the soybean oil immersion could reduce the electric field distortion to get the best heating uniformity. Also, the higher sample heating rate caused by soybean oil immersion was mainly because of higher electromagnetic power absorption and lower surface heat loss. The heating efficiency of RF was improved but less study focused on the quality analysis of flour. Therefore, the second research study is to evaluate the effect of RF and extensive hot air oven processing on the quality and functionality of all-purposed flour.

Investigation Of Semiquantitative Marrow Iron Scoring And Reticulocyte Hemoglobin Content (Chr) In Healthy And Ill Canines With And Without Clinical Evidence Of Blood Loss., Grace A. Pawsat

Masters Theses

Background: Insufficient iron for erythropoiesis can occur in multiple conditions, including absolute iron deficiency, which is often caused by chronic external hemorrhage in dogs. Distinguishing this from other causes of iron-restricted erythropoiesis allows appropriate intervention. Decreased marrow iron assessed by Prussian blue staining is considered the gold standard to diagnose absolute iron deficiency but scoring systems are not validated in dogs. The performance of standardized semiquantitative marrow scoring of iron deposits in dogs has not been previously reported or correlated to iron biomarkers in blood.[1-4]

Objectives: Objectives included evaluation of the effects of different staining sequences, evaluation the technical performance …

Decomposition Approach To Parametric Nonconvex Regression; Nuclear Resonance Analysis, Jordan L. Armstrong

Masters Theses

Parameterized nonconvex regression is a difficult problem for any optimization solver packages, often resulting in approximations and linearizations of the problem in order to be able to arrive a solution, if the problem is even solvable at all. These changes to the initial problem are largely dependent upon having appropriate domain knowledge and still often times result in a sizable gap between the achieved solution and the best true solution. We propose a novel method of decomposing the global problem into small, overlapping windows. Thus, the independent windows are now solvable. Subsequently, we offer a novel, sequential method of parameter …

The Desire To Train: A Motivational Profile Of Brazilian Jiu Jitsu Players, Terrance Tarver

Masters Theses

Combat sports, such as Brazilian Jiu Jitsu, require intense physical, mental, and emotional tasking within its training. With the degree of difficulty ingrained within the sport, as well as the performance-focused climate that this sport may be practiced within, many participants that once were intrigued by the sport may lose this interest and enjoyment if their goals are not met. This leads to much interest into what factors drive the motivation of those that continue to participate within Brazilian Jiu Jitsu. The purpose of this study is to develop a motivational profile of Brazilian Jiu Jitsu players. 216 participants from …

Partial Discharge Testing And Detection Under Pwm Voltage, John Meadors

Masters Theses

Partial Discharge detection and measurement is an important part of electric insulation design. However, in PWM (pulse width modulation) voltage source converter environments, the noise resulting from switching voltage (rise and fall times of tens of nanoseconds) makes detection and extraction of partial discharge difficult. Unique methods of partial discharge detection are needed to address and decouple the noise from partial discharge measurements. PWM voltage can feature high switching speeds and high dv/dt during voltage switching. These PWM voltage behaviors are not found in traditional utility high voltage applications, and the effects that this type of voltage has on insulation …

Influence Of Physical Variability Of Highly Weathered Sedimentary Rock On Nitrate In Area 3 Of The Enigma Field Research Site At Y-12, Erin Kelly

Masters Theses

Uranium processing and waste storage in unlined waste ponds leached contaminants into the groundwater at Y-12, Oak Ridge, Tennessee, from the 1950s to 1980s. Groundwater wells near the S-3 ponds have had the highest nitrate concentrations of groundwater anywhere in the world (>10,000 mg/L). For reference, the maximum contaminant level for nitrate in drinking water set by the U.S. Environmental Protection Agency is 10 mg/L. Since 2012, the ENIGMA (Ecosystems and Networks Integrated with Genes and Molecular Assemblies) group has been characterizing, monitoring, and conducting field experiments to understand the interactions between contaminants, microbes, and the subsurface. The goals …

Impacts Of Anthropogenic Change On Plant Reproduction And Fitness, Alexandra S. Faidiga

Masters Theses

Humans are altering natural systems around the globe in myriad ways. For plant species, such anthropogenic changes have resulted in increasingly fragmented populations, desynchronized interactions with mutualists, and shifted geographic ranges, among other effects. However, despite numerous examples of human impacts on plant populations, the consequences of these changes on plant reproduction remain poorly understood. In my thesis, I investigate the impacts of two forms of anthropogenic change–habitat disturbance and climate warming–on plant reproduction and fitness. I take two distinct approaches to address questions posed at local and regional scales. In Chapter I, I ask how inbreeding depression varies across …

Political Attitudes And Behavior In A Pandemic: Factors Affecting Compliance With Covid-19 Policies, Christopher Palmer

Masters Theses

The ongoing COVID-19 public health crisis provides a unique opportunity to examine the role that public opinion plays in policy efficacy. More specifically, what factors contribute to different policy outcomes within the population? Governments and institutions at all levels have sought to incentivize compliance behavior utilizing different approaches. Statistical models were used to examine the relationship between attitudes and behaviors within the United States in this context. Trust is the primary focus in this paper because of its role in a public health crisis with consideration for rules and norms of social interaction. The analysis herein shows that social trust …

Growth, Browsing And Mortality In Mixed Oak And Pine Plantings, Heather Slayton

Masters Theses

The purpose of this project was to determine if different oak/pine arrangements elicited potential beneficial interactions that affected seedling growth, mortality and overall protection from deer browsing. Northern red oak (Quercus rubra L.) and shortleaf pine (Pinus echinata Mill.) were planted together and alone in six different planting patterns and spacings, replicated over three blocks in recent clearcuts in east Tennessee, USA. Each block consisted of two monocultures planted at a 3.0 by 3.0 meter (m) spacing and four multi-cropped treatments planted at varying spatial arrangements (0.3 m, 1.0 m, 1.5 m, and 3.0 m) from neighboring shortleaf …

“The Only Way I Feel Connected Is Through Other Latinx Friends”: Latinx Ethnic Identity, Social Connection, And Sense Of Belonging At A Southeastern Predominantly White Institution, Jasmine M. Koech

Masters Theses

Research demonstrates that Latinx students enrolled in Predominantly White Institutions (PWIs) face challenges in locating a sense of belonging and creating social connections on campus (e.g., Dueñas & Gloria, 2020). A lack of sense of belonging and limited access to affirming social connections can have negative consequences on ethnic identity development (e.g., Jones & Galliher, 2014). Our study sought to further investigate the experiences of Latinx students at a southeastern PWI, their experiences with locating a sense of belonging and social connections on campus, as well as their experiences navigating their ethnic identity development. Focus group data was collected from …

The Factors Influencing The Leader’S Perceptions Of Success Of Dairy Cooperatives: The Case Of Cumbal Nariño’S Dairy Associations, Omar Efren Aza Fuelantala

Masters Theses

During the last few decades, Colombia’s dairy sector has been affected by economic, social, and political conditions, not only endangering it but also putting at risk the long-term sustainability of the dairy industry. To mitigate these conditions, the dairy farmers have joined cooperatives, which enabled them to gain some strategic advantages and reduce the adverse effects of the economic, political, and social conditions. This study evaluates the influence of economic, financial, membership, management and operational characteristics on the presidents’ perceptions of success of the dairy associations in Cumbal-Nariño. To accomplish this objective, we surveyed the presidents of dairy associations in …

Radiation Effects On Lithium Indium Diselenide Semiconductors As Neutron Imaging Detectors, Robert M. Golduber

Masters Theses

The studies presented in this work aim to improve upon the knowledge base of lithium indium diselenide (LISe) semiconductors to understand how the material behaves in high radiation environments and refine the process of turning it into a neutron detector. LISe has great potential as neutron imaging detector because of the high neutron absorption efficiency of its enriched ⁶Li component and its ability to discriminate between gamma-rays and neutrons. Its ability to remain functional after being irradiated with large amounts of neutron fluence has been tested and the change in its electro-optical properties with relation to fluence has been …

Increasing Hydrophilicity And Transparency Of Diamond-Like Carbon Thin Films With Dopants For An Anti-Fogging Laparoscope Coating, Anna Bull

Masters Theses

Laparoscopes are prone to fogging which can lead to a limited field of view during surgical procedures. Current methods of mitigating fogging issues are not efficient or can require costly modification to the laparoscope. Previous studies of diamond-like carbon (DLC) coatings found doping the films improved hydrophilic qualities, suggesting their possible use as antifogging coatings for laparoscopes. For this work, two series of DLC films, doped with either SiO and Al₂O₃ were investigated.

The biocompatibility, transparency, and stability of these films were assessed through cellular assays, spectrophotometry, and simulated body fluid soaking experiments. Contact angle and surface …

Seasonality, Distribution, And Biological Control Of Crapemyrtle Bark Scale, A New Invasive Threat In Tennessee, Amira Cornish

Masters Theses

Crapemyrtle bark scale, Acanthococcus (= Eriococcus) lagerstroemiae (Kuwana), an invasive pest from Asia, is a threat in the United States. to crape myrtles grown in ornamental nurseries and in landscapes. Although mortality to crape myrtles is rare, its negative effects on aesthetics is considerable. It should affect the sale (valued at >$66 million wholesale) and use of crape myrtle in landscapes. This pest species has been found in numerous states, including Tennessee, where little is known about its state-wide distribution, lifecycle, biology, natural enemies, and impact on crape myrtles. The purpose of this two-year study is to gain additional knowledge …

Molecular Markers Within And Beyond Viburnum: A Single Set Of Ssrs For An Immense Genus, Trinity Paige Hamm

Masters Theses

Comprised of more than 160 species, Viburnum is the largest genus in the Viburnaceae (formerly Adoxaceae) alongside Adoxa and Sambucus. The native range of Viburnum species spans much of the Northern Hemisphere and extends into the mountains of South America and Southeastern Asia. Their wide geographic range has made Viburnum particularly interesting to phylogeographers and phylogeneticists. This diverse genus is also horticulturally valuable with varying traits such as fragrance, fruit color, and bud and inflorescence form. There is sufficient morphological diversity in the genus for there to be more than 70 species and intraspecific hybrids in cultivation, and in …

Thermodynamic Analysis Of An Autogenous Pressurization System, Samuel H. Smith

Masters Theses

Pressurized gas feed systems have been vital to spacecraft where a pump-fed design would prove too large, heavy, or complicated to be effective. This project investigates autogenous pressurization – a pressurized feed system where the intentional vaporization of liquid propellant to fill the ever-increasing ullage space with its own warm, low-density gas. Motivation for this research originates from the University of Tennessee Space Institute’s (UTSI) contract with Gloyer-Taylor Laboratories (GTL) to assist the development of an innovative pressurization system.

While other pressurization systems have been studied and used extensively, modeling of an autogenous system is less established. Despite the relative …

Accelerating Dynamical Density Response Code On Summit And Its Application For Computing The Density Response Function Of Vanadium Sesquioxide, Wileam Y. Phan

Masters Theses

This thesis details the process of porting the Eguiluz group dynamical density response computational platform to the hybrid CPU+GPU environment at the Summit supercomputer at Oak Ridge National Laboratory (ORNL) Leadership Computing Center. The baseline CPU-only version is a Gordon Bell-winning platform within the formally-exact time-dependent density functional theory (TD-DFT) framework using the linearly augmented plane wave (LAPW) basis set. The code is accelerated using a combination of the OpenACC programming model and GPU libraries -- namely, the Matrix Algebra for GPU and Multicore Architectures (MAGMA) library -- as well as exploiting the sparsity pattern of the matrices involved in …