Physical Sciences and Mathematics Commons^™

Topological Properties Of A 3-Rung Möbius Ladder, Rebecca Woods

Electronic Theses and Dissertations

In this work, we discuss the properties of the 3-rung Möbius ladder on the torus. We also prove ℤ₂ is an orientation preserving topological symmetry group of the 3-rung Möbius ladder with sides and rungs distinct, embedded in the torus.

Italian Domination On Ladders And Related Products, Bradley Gardner

Electronic Theses and Dissertations

An Italian dominating function on a graph $G = (V,E)$ is a function such that $f : V \to \{0,1,2\}$, and for each vertex $v \in V$ for which $f(v) = 0$, we have $\sum_{u\in N(v)}f(u) \geq 2$. The weight of an Italian dominating function is $f(V) = \sum_{v\in V(G)}f(v)$. The minimum weight of all such functions on a graph $G$ is called the Italian domination number of $G$. In this thesis, we will consider Italian domination in various types of products of a graph $G$ with the complete graph $K_2$. We will find the value of the Italian domination …

Extraction And Purification Of Biologically Active Metabolites From Rhodococcus Sp. Mtm3w5.2, Mohrah Alenazi

Electronic Theses and Dissertations

Rhodococcushas been recognized as a potential antibiotic producer. Recently, a strain of Rhodococcussp. MTM3W5.2 was isolated from a soil sample collected in Morristown, Tennessee and was found to produce an inhibitory compound which is active against other related species. The purpose of this research is to extract, purify and analyze the active metabolite. The compound was extracted from RM broth cultures and purified by preliminary fractionation of crude extract through a Sephadex LH-20 column. Further purification was completed using semi-preparative reversed phase column chromatography. Final purification was obtained using multiple rounds of an analytical C18 HPLC column. Based …

Improving Sinkhole Mapping Using Lidar Data And Locating Sinkhole Hotspots In Johnson City, Tn, Kingsley Fasesin

Electronic Theses and Dissertations

Predicting infrastructure damage and economic impact of sinkholes requires high accuracy mapping distribution and development. The study mapped sinkholes and sinkhole hotpsots in Johnson City, TN using LiDAR-derived Digital Elevation Model (DEM) and a database of known sinkholes which were matched to LiDAR-derived depressions. For all matched depressions (n = 404), three metrics were calculated: circularity index, ratio of length to width of the Minimum Bounding Rectangle (MBR) and percent coverage of the MBR by the depression, and 3,634 new sinkholes were identified. Newly developed hotspots were identified in north Johnson City and other areas in the south near the …

The Ecology Of Fecal Indicators, Dennis A. Gilfillan

Electronic Theses and Dissertations

Animal and human wastes introduce pathogens into rivers and streams, creating human health and economic burdens. While direct monitoring for pathogens is possible, it is impractical due to the sporadic distribution of pathogens, cost to identify, and health risks to laboratory workers. To overcome these issues, fecal indicator organisms are used to estimate the presence of pathogens. Although fecal indicators generally protect public health, they fall short in their utility because of difficulties in public health risk characterization, inconsistent correlations with pathogens, weak source identification, and their potential to persist in environments with no point sources of fecal pollution. This …

Performance Assessment Of The Extended Gower Coefficient On Mixed Data With Varying Types Of Functional Data., Obed Koomson

Electronic Theses and Dissertations

Clustering is a widely used technique in data mining applications to source, manage, analyze and extract vital information from large amounts of data. Most clustering procedures are limited in their performance when it comes to data with mixed attributes. In recent times, mixed data have evolved to include directional and functional data. In this study, we will give an introduction to clustering with an eye towards the application of the extended Gower coefficient by Hendrickson (2014). We will conduct a simulation study to assess the performance of this coefficient on mixed data whose functional component has strictly-decreasing signal curves and …

Dreadd Targeting Projections From The Nucleus Accumbens To The Ventral Pallidum With Nicotine Self-Administration, Amanda Smith

Electronic Theses and Dissertations

Projections from the Nucleus Accumbens (NAc) to the Ventral Pallidum (VP) play a critical role in motivation and reward. Rewards and reward-associated cues are thought to alter this pathway by suppressing GABA release to the VP, however, the role of the NAc to VP pathway has never been investigated with regard to nicotine self-administration. We hypothesized that increasing GABAergic signaling from the NAc to the VP would decrease the reinforcing effects of nicotine. To increase GABA release, CRE dependent DREADD was expressed in the NAc of male rats. Administration of low dose clozapine activated the DREADD receptor and showed a …

An Outcrop Based Study Of The Weches Formation In Sabine County, Texas: Investigating Its Unconventional Resource Potential Through The Study Of Stratigraphy, Sedimentology, Petrology, And Geochemistry, Talban Kantala

Electronic Theses and Dissertations

Fresh Weches Formation (Middle Eocene) exposures found in aggregate quarries in Sabine County, Texas, were sampled, measured, and logged with gamma-ray spectrometry (GRS). Sedimentology and petrology characteristics of Weches samples were analyzed through thin section, scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction, and GRS Th/K ratios analyses. The source rock quality of the Weches was evaluated with geochemical techniques involving total organic carbon (TOC), Rock-Eval pyrolysis, and GRS Th/U ratios.

The Weches, in the study area, is 27.4 meters thick, and delineated into three major stratigraphic facies: an upper marginal marine prodeltaic facies (Therrill Member) comprised of silty claystones and …

Electrochemical And Morphological Properties Of Chloride-Doped Lithium Argyrodite Solid Electrolytes., William Richard Arnold

Electronic Theses and Dissertations

Recently, much attention has been devoted to the development of solid electrolytes to be used in all-solid-state-batteries. One group of promising solid electrolyte (SE) materials are lithium argyrodites, a class of superconductors which are noted for their high ionic conductivities. In particular, halogen doping has been shown to increase both conductivity and stability. The majority of research has focused on material synthesis through solid state reactions, but a novel liquid synthesis method for the preparation of Cl-doped Li7PS6 solid electrolyte provides the advantages of a homogenous product and a rapid, economic synthesis. Here this thesis focuses on the liquid synthesis …

Application Of Silicon Nanohair Textured P-N Junctions In A Photovoltaic Device, Michael Small

Electronic Theses and Dissertations

The goal of this project is to design and develop a fabrication process for a silicon photovoltaic device which incorporates a nanohair textured p-n junction. The silicon nanowires are etched into a silicon wafer, comprising an epitaxial p-layer on n-substrate, via metal-assisted chemical etching (MACE). The resulting nanowires contain p-n junctions that lie along the length of the vertical nanowires. This construct has the potential to increase the optical bandwidth of a silicon photovoltaic device by allowing a greater amount of short wavelength light to reach the junction. In addition, the MACE method of nanofabrication has the potential for decreasing …

Groundwater Hydrogeolgy And Hydrochemistry Of Karst Springs In The Eastern Peninsula Of Fort Hood Military Installation, William Scribner Welles

Electronic Theses and Dissertations

The eastern peninsula of Fort Hood Military Installation is underlain by a complex karst spring network. These springs are a primary water source in a protected habitat for endangered songbirds, which has only recently begun to be fully investigated. These Fredericksburg Group springs express both epigenetic and hypogenetic karst signatures. The study area is part of a paleo reef trend, a hydraulically disconnected segment of the northern section of the Edwards Aquifer. This study utilized standard ion index values, repeated measures, and principal component analyses on the chemical profiles of six perennial springs to classify spring water sources and their …

Computational Quantum Chemistry Studies Of The Interactions Of Amino Acids Side Chains With The Guanine Radical Cation., Edward Acheampong

Electronic Theses and Dissertations

Guanine is generally accepted as the most easily oxidized DNA base when cells are subjected to ionizing radiation, photoionization or photosensitization. At pH 7, the midpoint reduction potential is on the order of 0.2 – 0.3 V higher than those of the radicals of e.g. tyrosine, tryptophan cysteine and histidine, so that the radical “repair” (or at least, a thermodynamically favorable reaction) involving these amino acids is feasible. Computational quantum studies have been done on tyrosine, tryptophan, cysteine and histidine side chains as they appear in histones. Density functional theory was employed using B3LYP/6-31G+ (d, p) basis set to study …

Imidacloprid Persistence, Mobility, And Effect On Ecosystem Function, Joanna Hardin

Electronic Theses and Dissertations

Imidacloprid is a neonicotinoid pesticide used to protect against biting and sucking insects. Land managers rely on its systemic properties, however long-term studies investigating imidacloprid effects on ecosystem function are limited. This study investigated imidacloprid applications to Tsuga caroliniana and Tsuga canadensis over time and compared concentrations to measures of ecosystem function including soil respiration, microbial function, and invertebrate density. Results indicate that imidacloprid is persistent (p0.5). Microbial function and invertebrate density were not significantly different between control and treatment locations nor did imidacloprid concentrations correlate with ecosystem functional indicator activity (p>0.05). It is evident that imidacloprid does not …

A Normal Form For Words In The Temperley-Lieb Algebra And The Artin Braid Group On Three Strands, Jack Hartsell

Electronic Theses and Dissertations

The motivation for this thesis is the computer-assisted calculation of the Jones poly- nomial from braid words in the Artin braid group on three strands, denoted B3. The method used for calculation of the Jones polynomial is the original method that was created when the Jones polynomial was first discovered by Vaughan Jones in 1984. This method utilizes the Temperley-Lieb algebra, and in our case the Temperley-Lieb Algebra on three strands, denoted A3, thus generalizations about A3 that assist with the process of calculation are pursued.

Effectiveness Of Prescribed Fire On Meeting Fuel Load And Wildlife Habitat Management Objectives In East Texas National Forests, Trey Wall

Electronic Theses and Dissertations

Using standardized methodology outlined by the United States Forest Service and the National Forests and Grasslands in Texas’ Fire Monitoring Program for data collection, the efficacy of current Forest Service prescribed burn regimes were analyzed for 24 study sites in East Texas National Forests. Study sites were located within Sam Houston, Davy Crockett, and Angelina/Sabine National Forests. Efficacy was determined by comparing defined management objectives established by the Forest Service to the data collected at the study sites. The results conclude that most objectives, as outlined by the Forest Service, are not being met with the current practices. Re-visitation of …

A Transfer Learning Approach For Sentiment Classification., Omar Abdelwahab

Electronic Theses and Dissertations

The idea of developing machine learning systems or Artificial Intelligence agents that would learn from different tasks and be able to accumulate that knowledge with time so that it functions successfully on a new task that it has not seen before is an idea and a research area that is still being explored. In this work, we will lay out an algorithm that allows a machine learning system or an AI agent to learn from k different domains then uses some or no data from the new task for the system to perform strongly on that new task. In order …

Framing Climate Change As National Security: A Survey-Experiment On Climate Change Perceptions., Adam Lyons

Electronic Theses and Dissertations

The issues surrounding climate change continue to have polarizing effects on many Americans. In this thesis I offer a potential bridge to this divide with a comprehensive study on how issue frames can impact how individuals shape their opinions on environmental issues. Focusing on a national security frame, I ask the central research “Will the public perceive issues of climate change differently when they are framed as threats to national security?” For this thesis I design an original experimental survey to measure the impact security framing has on participants’ perception of both climate change and environmental policy options. The survey …

Computational Prediction, Characterization, And Methodology Development For Two-Dimensional Nanostructures: Phosphorene And Phosphide Binary Compounds., Congyan Zhang

Electronic Theses and Dissertations

In this thesis, a comprehensive computational simulation was carried out for predicting, characterizing, and applications of two-dimensional (2D) materials. The newly discovered GaP and InP layers were selected as an example to demonstrate how to explore new 2D materials using computational simulations. The performance of phosphorene as the anode material of Lithium-ion battery was discussed as the example of the application of 2D material. Furthermore, the semi-empirical Hamiltonian for phosphorous and lithium elements have been developed for our future work on the application of phosphorus and lithium-based systems. The novel 2D materials of GaP and InP binary compounds were found …

The Regional Distribution And Molecular Interactions Of Phospholipids And Glucose In Mammalian Vitreous Humors., Abigail Nicole Schnepf

Electronic Theses and Dissertations

The vitreous humor (VH) is located in between the lens and the retina. It is composed of 98% water, hyaluronan (HA), collagen, proteins, phospholipids (PLs), and other metabolites. With aging, the VH undergoes liquefaction, a process that causes the gel-like structure of the VH to turn into a liquid and can lead to serious ocular diseases, including retinal detachment, vitreal detachment, and macular hole formation. The liquefaction process is expedited in diabetic VHs. This project focuses on understanding the molecular changes that lead to liquefaction and the reasons for which this process is accelerated with diabetes. Matrix-assisted laser desorption ionization/mass …

Innate Immunity, The Hepatic Extracellular Matrix, And Liver Injury: Mathematical Modeling Of Metastatic Potential And Tumor Development In Alcoholic Liver Disease., Shanice V. Hudson

Electronic Theses and Dissertations

The overarching goals of the current work are to fill key gaps in the current understanding of alcohol consumption and the risk of metastasis to the liver. Considering the evidence this research group has compiled confirming that the hepatic matrisome responds dynamically to injury, an altered extracellular matrix (ECM) profile appears to be a key feature of pre-fibrotic inflammatory injury in the liver. This group has demonstrated that the hepatic ECM responds dynamically to alcohol exposure, in particular, sensitizing the liver to LPS-induced inflammatory damage. Although the study of alcohol in its role as a contributing factor to oncogenesis and …

Investigating The Unique Reactivity Of Novel Hx (X=Cl, Br) Reagents With Alkenes And Alkynes., Rene E. Ebule

Electronic Theses and Dissertations

The addition of hydrogen halides to carbon-carbon unsaturated systems is a classic synthetic transformation that gives rise to a variety of halogenated products as well as building blocks.¹ The different routes to achieve hydrohalogenation make use of the hydrogen halides either in the gaseous form² or in solution³, or their surrogates⁴. Only second to dihalogens, hydrogen halides are the most atom efficient source of halogenation. However, hydrogen halides are reactive gases at ambient temperature, posing a major challenge in their application. Handling gaseous hydrogen halide reagents requires expert knowledge and specialized equipment. We have …

Relative Permittivity As A Function Of Co-Solvent And Impedance Spectroscopy For Quantifying Anions In Solution, Yahya Sami Alseiha

Electronic Theses and Dissertations

This work measured relative permittivity from 15.0 to 55.0 °C of aqueous solutions containing acetone or tetrahydrofuran using a BI 870 dielectric meter. A cubic polynomial fit resulted in coefficients for calculating permittivity as a function of temperature and mole fraction. Literature values for other co-solvent system resulted in similar polynomial coefficients. Using BI 870, permittivity measurements of ionic solutions were not possible because of high conductivity. A simple method using impedance spectroscopy measured these solutions. Impedance decreases with increasing temperature and decreases with increasing ionic strength. Due to the temperature dependence of impedance, all measurements were at 25.0 °C. …

The Effects Of Seasonal Variations In Chemistry And Hydrology On The Microbial Community And Its Sulfide Oxidation Potential In A Naturally Acidic Maine Stream, Raymond C. Kahler Iii

Electronic Theses and Dissertations

Sulfide minerals oxidize through interaction with water and oxygen, releasing hydrogen ions. The process often occurs naturally near metal sulfide deposits, and can be accelerated through mining. Microorganisms accelerate the rate of sulfide oxidation. Acidified streams typically contain high metal concentrations (e.g. aluminum) and microbes in these systems may develop resistances to metal toxicity. Stream flow can affect sulfide oxidation and microbial community structure. Baseflow can influence stream chemistry from interactions with the surrounding bedrock, while stormflow affects stream chemistry and the local microbial community through dilution and addition of microbes transported by runoff. Microbial community composition is affected by …

Depositional Environment And Facies Analyses Of The Owl Mountain Province, Fort Hood Military Installation, Bell And Coryell Counties, Texas, Jacob Meinerts

Electronic Theses and Dissertations

The Owl Mountain Province is a plateaued, karst landscape located in the eastern section of the Fort Hood Military Installation and is characterized by Lower Cretaceous Fredericksburg Group carbonates. The topography is capped by thick sequences of the Edwards limestone; steep scarps and incised valleys along the edges of the plateaus host inter-fingering outcrops of the Edwards and Comanche Peak limestones, and the lower valleys are covered by alluvial sediments and intermittent outcrops of the Walnut Clay. These formations were deposited to the north and west of the main Edwards trend, and are thought to be part of a series …

Three-Dimensional Bedrock Channel Evolution With Smoothed Particle Hydrodynamics, Nick Richmond

Electronic Theses and Dissertations

Bedrock channels are responsible for balancing and communicating tectonic and climatic signals across landscapes, but it is difficult and dangerous to observe and measure the flows responsible for removing weakly-attached blocks of bedrock from the channel boundary. Consequently, quantitative descriptions of the dynamics of bedrock removal are scarce. Detailed numerical simulation of violent flows in three dimensions has been historically challenging due to technological limitations, but advances in computational fluid dynamics aided by high-performance computing have made it practical to generate approximate solutions to the governing equations of fluid dynamics. From these numerical solutions we gain detailed knowledge of the …

Modern And Paleoecological Perspectives On A Terrestrial-Marine Linkage In The Falkland Islands, Dulcinea V. Groff

Electronic Theses and Dissertations

The Falkland Islands are a biodiversity hotspot in the South Atlantic Ocean, with some of the world’s most important populations of seabirds and seals. The impact of climate change on these marine populations and their coastal breeding habitat in the Falklands is unknown. Coastal grasslands of Poa flabellata (tussac grass) form critical breeding habitat for wildlife, but have been heavily degraded by the introduction of livestock in the 17^th century. This dissertation investigates the impacts of global change (climate change, grazing) on P. flabellata and its sensitivity to the fecal nutrient subsidies provided by marine wildlife. Chapter 1 provides …

Late Holocene Spit Evolution On Centennial Timescales In The Southeast Delaware Bay, Usa, Ryan Eli Phillip

Electronic Theses and Dissertations

The relationship between barrier spit growth and longshore drift is well established. However, the role of storm activity in spit evolution on an intermediate (centennial) timescale is more of a mystery due to a knowledge gap between decadal-scale shoreline processes and millennial-scale stratigraphic data. Recent studies in the northwestern Atlantic basin using ground-penetrating radar (GPR) and optically-stimulated luminescence (OSL) are providing the opportunity to study centennial-scale shoreline evolution and examine similar age storm activity. Cape Henlopen, Delaware exhibits preserved remnants of a long-term northward-growing spit coastline that evolved from a recurved spit complex, to a cuspate spit, to the present-day …

An Evaluation Of Geotagged Twitter Data During Hurricane Irma Using Sentiment Analysis And Topic Modeling For Disaster Resilience, Ike Robert Vayansky

Electronic Theses and Dissertations

Disasters require quick response times, thought-out preparations, overall community, and government support. These efforts will ensure prevention of loss of life and reduce possible damages. The United States has been battered by multiple major hurricanes in the recent years and multiple avenues of disaster response efforts were being tested. Hurricane Irma can be recognized as the most popular hurricane in terms of social media attention. Irma made landfall in Florida as a Category 4 storm and preparation measures taken were intensive thus providing a good measure to evaluate in terms of efficacy. The effectiveness of the response methods utilized are …

Thermochemical Conversion Of Guaiacol Over Unsupported Tungsten Oxide And Nickel Supported Catalysts, Pamela Ruiz Martinez

Electronic Theses and Dissertations

Interest in conversion of biomass into renewable fuels has motivated development of thermochemical methods for production of bio-oil and development of hydrodeoxygenation catalysts for upgrading the oil. Two types of catalysts were investigated. The catalytic activity of unsupported tungsten oxide bronze catalysts for the conversion of guaiacol was explored as a representative compound from bio-oil. The reactions were carried out in a trickle bed reactor at various concentrations of the reactant and hydrogen pressure, as well as varying catalyst activation and reaction temperatures. The reaction pathway from guaiacol to phenol by demethoxylation, followed by hydrogenation to cyclohexanol, and finally dehydration …

Physical And Chemical Response Of Small, North Temperate Lakes To Recovery From Acidification And Climate Change, Amanda Gavin

Electronic Theses and Dissertations

As the rate of sulfate (SO42-) deposition continues to decline and climate is trending towards warmer and wetter conditions, the biogeochemical and physical response of small, north temperate lakes is variable. In this study, we observed long-term chemical trends combined with seasonal water temperature patterns in the context of climate change and recovery from acidification in two remote lake populations in Maine: 29 high elevation lakes and eight low elevation lakes. Small, temperate lakes are the most abundant type of lake, making them a widely representative study sample to consider. Maine’s high elevation lakes (>600m) could potentially provide unique …