Physical Sciences and Mathematics Commons^™

Study Of 2,5-Diaminoimidazolone, A Mutagenic Product Of Oxidation Of Guanine In Dna, Hannah Catherine J. Pollard

Electronic Theses and Dissertations

2,5-diaminoimidazolone (Iz) is an important product of a 4-electron oxidation of guanine. The present research focuses on the mechanisms of formation of Iz via pathways initiated by guanine oxidation by one-electron oxidants (OEOs) generated by X-ray radiolysis in aqueous solutions. The kinetics of formation and yields of Iz in reactions of native highly polymerized DNA with different OEOs have been compared using an HPLC-based quantitative analysis of low-molecular products generated from the reaction of DNA-bound Iz with primary amines. Mechanisms of Iz formation in DNA have been investigated including oxygen and superoxide dependence as well as the hypothesis that 8-oxo-G, …

Only The Earth Remains: Exploring The Machine In Selected Lyric Poetry Of Robinson Jeffers, Mark Hutton

Electronic Theses and Dissertations

In The Machine in the Garden: Technology and the Pastoral Idea in America, Leo Marx “evaluates the uses of the pastoral ideal in the interpretation of American experience” (Marx 4). While Marx explores ways that pastoralism has been impacted by factors such as industrialism, it is the purpose of this project to explore Marx’s assertion regarding the presence of the figurative and literal machine within the poetry of Robinson Jeffers.

Jeffers’ poetry is generally located within the landscapes of California. His lyric poetry has a distinct connection to the land and is driven by inhumanism, which works to shift …

Graph Analytics Methods In Feature Engineering, Theophilus Siameh

Electronic Theses and Dissertations

High-dimensional data sets can be difficult to visualize and analyze, while data in low-dimensional space tend to be more accessible. In order to aid visualization of the underlying structure of a dataset, the dimension of the dataset is reduced. The simplest approach to accomplish this task of dimensionality reduction is by a random projection of the data. Even though this approach allows some degree of visualization of the underlying structure, it is possible to lose more interesting underlying structure within the data. In order to address this concern, various supervised and unsupervised linear dimensionality reduction algorithms have been designed, such …

An X-Ray Study Of Two B+B Binaries: Ah Cep And Cw Cep, Richard Ignace, K. T. Hole, Lidia M. Oskinova, J. P. Rotter

ETSU Faculty Works

AH Cep and CW Cep are both early B-type binaries with short orbital periods of 1.8 days and 2.7 days, respectively. All four components are B0.5V types. The binaries are also double-lined spectroscopic and eclipsing. Consequently, solutions for orbital and stellar parameters make the pair of binaries ideal targets for a study of the colliding winds between two B stars. Chandra ACIS-I observations were obtained to determine X-ray luminosities. AH Cep was detected with an unabsorbed X-ray luminosity at a 90% confidence interval of erg s−1, or , relative to the combined Bolometric luminosities of the two components. While formally …

Evaluating And Improving The Effectiveness Of Vehicle Inspection And Maintenance Programs: A Cost-Benefit Analysis Framework, Ying Li

ETSU Faculty Works

Motor vehicle inspection and maintenance (I/M) programs are designed to identify high-emitting vehicles and mitigate their impacts on air quality and climate. I/M programs have been traditionally ranked superior among various vehicle emission control measures by the results of cost-benefit analysis, based on the assumption that these programs will achieve the targeted emission reduction outcomes. However, the actual effects of I/M programs may be greatly uncertain and when this uncertainty is taken into account, these programs may become suboptimal. This study develops a new a cost-benefit analysis framework that links various program design consideration, such as program participation rate, identification …

Effects Of Global Warming On Work-Rest Routines For Crop Workers In Appalachia, Ken Silver, Ying Li, Emmanuel Odame, Yuqiang Zhang

ETSU Faculty Works

Background: Workers in outdoor occupations are expected to be at high risk of increased morbidity and mortality, and diminished productivity, as a result of global warming in the 21st century. A previous modelling study of geographic variations in heat-related mortality risk in projected U.S. populations mid-century showed the states of Tennessee, Kentucky and North Carolina to be highly vulnerable. Methods: Under both the RCP4.5 and RCP8.5 emissions scenarios of IPCC AR5, we evaluate the effect of future warming on estimated Wet Bulb Globe Thermometer (WBGT) temperatures using model-simulated future climate variables that were dynamically downscaled by a regional meteorology model …

Comparing Urban And Rural Vulnerability To Heat-Related Mortality: A Systematic Review And Meta-Analysis, Ying Li, Emmanuel A. Odamne, Ken Silver, Shimin Zheng

ETSU Faculty Works

Studies of the adverse impacts of high temperature on human health have primarily focused on urban areas, due in part to urban centers generally having higher population density and often being warmer than surrounding rural areas (the “urban heat island” effect). As a result, urban areas are often considered to be more vulnerable to summer heat. However, heat vulnerability may not only be determined by heat exposure, but also by other population characteristics such as age, education, income, baseline health status, and social isolation. These factors are likely to increase vulnerability among rural populations compared to urban populations. In this …

Limb Darkening And Planetary Transits: Testing Center-To-Limb Intensity Variations And Limb-Darkening Directly From Model Stellar Atmospheres, Hilding R. Neilson, Joseph T. Mcneil, Richard Ignace, John B. Lester

ETSU Faculty Works

The transit method, employed by Microvariability and Oscillation of Stars (MOST), Kepler, and various ground-based surveys has enabled the characterization of extrasolar planets to unprecedented precision. These results are precise enough to begin to measure planet atmosphere composition, planetary oblateness, starspots, and other phenomena at the level of a few hundred parts per million. However, these results depend on our understanding of stellar limb darkening, that is, the intensity distribution across the stellar disk that is sequentially blocked as the planet transits. Typically, stellar limb darkening is assumed to be a simple parameterization with two coefficients that are derived …

On The Binary Nature Of Massive Blue Hypergiants: High-Resolution X-Ray Spectroscopy Suggests That Cyg Ob2 12 Is A Colliding Wind Binary - Iopscience, Lidia M. Oskinova, David P. Huenemoerder, Wolf-Rainer Hamann, Tomer Shenar, A. A.C. Sander, Richard Ignace, H. Todt, R. Hainich

ETSU Faculty Works

The blue hypergiant Cyg OB2 12 (B3Ia+) is a representative member of the class of very massive stars in a poorly understood evolutionary stage. We obtained its high-resolution X-ray spectrum using the Chandra observatory. PoWR model atmospheres were calculated to provide realistic wind opacities and to establish the wind density structure. We find that collisional de-excitation is the dominant mechanism depopulating the metastable upper levels of the forbidden lines of the He-like ions Si xivand Mg xii. Comparison between the model and observations reveals that X-ray emission is produced in a dense plasma, which could reside only at the photosphere …

Investigating Genetic Algorithm Optimization Techniques In Video Games, Nathan Ambuehl

Undergraduate Honors Theses

Immersion is essential for player experience in video games. Artificial Intelligence serves as an agent that can generate human-like responses and intelligence to reinforce a player’s immersion into their environment. The most common strategy involved in video game AI is using decision trees to guide chosen actions. However, decision trees result in repetitive and robotic actions that reflect an unrealistic interaction. This experiment applies a genetic algorithm that explores selection, crossover, and mutation functions for genetic algorithm implementation in an isolated Super Mario Bros. pathfinding environment. An optimized pathfinding AI can be created by combining an elitist selection strategy with …

Groundwater Flow Tracing In Carter Saltpeter Cave And Toll Branch, Carter County, Tn, Aaron G. Doyka

Electronic Theses and Dissertations

Groundwater tracing studies have shown a well-developed conduit system in the karst aquifer beneath the Buffalo Creek Watershed of Carter County, TN. Groundwater can quickly travel beneath topographic divides, transporting contaminants. Using GIS and field reconnaissance, two sites were selected for a two phase dye trace study. In May-June 2016 groundwater resurgences were located using activated carbon samplers, and in October-December 2016 flow velocities were measured using ISCO automatic water samplers. In study 1, a stream sinking in the back of Carter Saltpeter Cave was traced to its resurgence at Cave Springs Cave. In study 2, the dye mass centroid …

Ecological Informatics: An Agent Based Model On Coexistence Dynamics, Shiva Thapa

Electronic Theses and Dissertations

The coexistence of species is probably one of the most interesting and complex phenomenon in nature. We constructed an agent based model to study the coexistence dynamics of prey - predator populations by varying productivity levels of producers in fragmented and connected habitats along with different levels of quality of predators. Our results indicated that productivity levels of producers in fragmented and connected habitats along with levels of predator quality are significantly responsible for overall predator - prey population size and survivorship. In the absence of predation, competition between identical prey populations is more probable in connected habitats than in …

Vulnerability Assessment Of Groundwater To No3 Contamination Using Gis, Drastic Model And Geostatistical Analysis, Adela Beauty Adu Agyemang

Electronic Theses and Dissertations

The study employed Geographical Information System (GIS) technology to investigate the vulnerability of groundwater to NO₃ content in Buncombe County, North Carolina in two different approaches. In the first study, the spatial distribution of NO₃ contamination was analyzed in a GIS environment using Kriging Interpolation. Cokriging interpolation was used to establish how NO₃ relates to land cover types and depth to water table of wells in the county. The second study used DRASTIC model to assess the vulnerability of groundwater in Buncombe County to NO₃ contamination. To get an accurate vulnerability index, the DRASTIC parameters were …

Vertex Weighted Spectral Clustering, Mohammad Masum

Electronic Theses and Dissertations

Spectral clustering is often used to partition a data set into a specified number of clusters. Both the unweighted and the vertex-weighted approaches use eigenvectors of the Laplacian matrix of a graph. Our focus is on using vertex-weighted methods to refine clustering of observations. An eigenvector corresponding with the second smallest eigenvalue of the Laplacian matrix of a graph is called a Fiedler vector. Coefficients of a Fiedler vector are used to partition vertices of a given graph into two clusters. A vertex of a graph is classified as unassociated if the Fiedler coefficient of the vertex is close to …

A Novel Method For Synthesis Of Hydroxytyrosol, Emmanuel Onobun

Electronic Theses and Dissertations

Hydroxytyrosol, 3,4-dihydroxyphenolethanol, a naturally occurring polyphenol most common in olive tree (Olea europaea), is one of the most effective member of the polyphenols family, because of its remarkable antioxidant activity, its ability to inhibit oxidation of low density lipids (LDL), and its protection against DNA oxidative damage. Hydroxytyrosol, which is widely used in cosmetics and food supplements industries, can be purchased as an olive oil extract that contains low concentration of hydroxytyrosol besides other polyphenols. The price and low natural abundance of hydroxytyrosol make alternative synthetic sources very attractive. In this research, a novel method for the synthesis of pure …

Application Of Symplectic Integration On A Dynamical System, William Frazier

Electronic Theses and Dissertations

Molecular Dynamics (MD) is the numerical simulation of a large system of interacting molecules, and one of the key components of a MD simulation is the numerical estimation of the solutions to a system of nonlinear differential equations. Such systems are very sensitive to discretization and round-off error, and correspondingly, standard techniques such as Runge-Kutta methods can lead to poor results. However, MD systems are conservative, which means that we can use Hamiltonian mechanics and symplectic transformations (also known as canonical transformations) in analyzing and approximating solutions. This is standard in MD applications, leading to numerical techniques known as symplectic …

Performance Of Imputation Algorithms On Artificially Produced Missing At Random Data, Tobias O. Oketch

Electronic Theses and Dissertations

Missing data is one of the challenges we are facing today in modeling valid statistical models. It reduces the representativeness of the data samples. Hence, population estimates, and model parameters estimated from such data are likely to be biased.

However, the missing data problem is an area under study, and alternative better statistical procedures have been presented to mitigate its shortcomings. In this paper, we review causes of missing data, and various methods of handling missing data. Our main focus is evaluating various multiple imputation (MI) methods from the multiple imputation of chained equation (MICE) package in the statistical software …

Denoising Tandem Mass Spectrometry Data, Felix Offei

Electronic Theses and Dissertations

Protein identification using tandem mass spectrometry (MS/MS) has proven to be an effective way to identify proteins in a biological sample. An observed spectrum is constructed from the data produced by the tandem mass spectrometer. A protein can be identified if the observed spectrum aligns with the theoretical spectrum. However, data generated by the tandem mass spectrometer are affected by errors thus making protein identification challenging in the field of proteomics. Some of these errors include wrong calibration of the instrument, instrument distortion and noise. In this thesis, we present a pre-processing method, which focuses on the removal of noisy …

A Distribution Of The First Order Statistic When The Sample Size Is Random, Vincent Z. Forgo Mr

Electronic Theses and Dissertations

Statistical distributions also known as probability distributions are used to model a random experiment. Probability distributions consist of probability density functions (pdf) and cumulative density functions (cdf). Probability distributions are widely used in the area of engineering, actuarial science, computer science, biological science, physics, and other applicable areas of study. Statistics are used to draw conclusions about the population through probability models. Sample statistics such as the minimum, first quartile, median, third quartile, and maximum, referred to as the five-number summary, are examples of order statistics. The minimum and maximum observations are important in extreme value theory. This paper will …

An Investigation Into The Performance Evaluation Of Connected Vehicle Applications: From Real-World Experiment To Parallel Simulation Paradigm, Md Salman Ahmed

Electronic Theses and Dissertations

A novel system was developed that provides drivers lane merge advisories, using vehicle trajectories obtained through Dedicated Short Range Communication (DSRC). It was successfully tested on a freeway using three vehicles, then targeted for further testing, via simulation. The failure of contemporary simulators to effectively model large, complex urban transportation networks then motivated further research into distributed and parallel traffic simulation. An architecture for a closed-loop, parallel simulator was devised, using a new algorithm that accounts for boundary nodes, traffic signals, intersections, road lengths, traffic density, and counts of lanes; it partitions a sample, Tennessee road network more efficiently than …

On T-Restricted Optimal Rubbling Of Graphs, Kyle Murphy

Electronic Theses and Dissertations

For a graph G = (V;E), a pebble distribution is defined as a mapping of the vertex set in to the integers, where each vertex begins with f(v) pebbles. A pebbling move takes two pebbles from some vertex adjacent to v and places one pebble on v. A rubbling move takes one pebble from each of two vertices that are adjacent to v and places one pebble on v. A vertex x is reachable under a pebbling distribution f if there exists some sequence of rubbling and pebbling moves that places a pebble on x. A pebbling distribution where every …

Synthesis And In-Vitro Cell Viability/Cytotoxicity Studies Of Novel Pyrrolobenzodiazepine Derivatives, John M. Jarrett

Undergraduate Honors Theses

Pyrrolobenzodiazepines (PBDs) are a group of naturally occurring compounds that were discovered in the cultures of Streptomyces in the 1960s. Some natural PBDs discovered in these cultures, such as anthramycin and sibiromycin, were shown to possess a broad spectrum of anti-tumor activity. Since cancer is still a leading cause of death globally, the development of novel anti-proliferative derivatives of PBDs is essential for human welfare worldwide. Further synthesis and structure-activity relationship (SAR) studies of the parent natural products and their tetracyclic analogs will lead to the discovery of drug candidates. In this work, thirteen PBD analogues were synthesized using no …

Hydrogen Molybdenum Bronze Catalyzed Hydrolysis Of Cellulose, Claire O. Baker

Undergraduate Honors Theses

In recent years, there has been increasing concern with respect to the large dependence across the globe on nonrenewable energy sources, such as fossil fuels. Ethanol has been explored, however, in alleviating this problem; cellulose, a polymer of glucose molecules, is a precursor to this potentially useful biofuel. However, the strength and rigidity of the cellulose structure has proven to be a difficult obstacle to overcome in this multistep synthesis. Harsh conditions are required, often including concentrated sulfuric acid and extremely high temperatures, to complete hydrolysis to a useful extent. In this work, the hydrolysis of cellulose was performed with …

Elucidating The Effects Of Thiamethoxam Neonicotinoid On Honey Bee Learning Using The Proboscis Extension Response, David J. Shepherd

Undergraduate Honors Theses

In this study, the effects of the neonicotinoid pesticide, thiamethoxam, are examined through the Proboscis Extension Response (PER) in honey bees (Apis mellifera). PER is a form of classical conditioning applied to honey bees through scent and reward association which quantifies learning rates. Results between groups treated with thiamethoxam did not differ significantly from untreated control groups. Potential reasons for these results are discussed. The method and experimental apparatus for testing the PER assay are also discussed.

Electrodynamical Modeling For Light Transport Simulation, Michael G. Saunders

Undergraduate Honors Theses

Modernity in the computer graphics community is characterized by a burgeoning interest in physically based rendering techniques. That is to say that mathematical reasoning from first principles is widely preferred to ad hoc, approximate reasoning in blind pursuit of photorealism. Thereby, the purpose of our research is to investigate the efficacy of explicit electrodynamical modeling by means of the generalized Jones vector given by Azzam [1] and the generalized Jones matrix given by Ortega-Quijano & Arce-Diego [2] in the context of stochastic light transport simulation for computer graphics. To augment the status quo path tracing framework with such a modeling …

Fullerenes In Solar Energy Cells, Fletcher G. Griffitts

Undergraduate Honors Theses

This project involves controlling and characterizing the morphology of the active layer in a special type of organic photovoltaics (OPVs), consisting of porphyrin-fullerene composites, with emphasis on electron exchange interactions between the two components. The Vienna Ab Initio Simulation Package (VASP) is applied to model a variety of donor-acceptor complexes containing fullerene and porphyrin in terms of their stabilities as well as their geometric, electronic, and charge transfer features. The goal is to identify supramolecular chain structures with highest occupied molecular orbitals (HOMOs) and lowest unoccupied molecular orbitals (LUMOs) that may serve as electron (hole) transfer channels in a photovoltaic …

Phosphomolybdic Acid Catalysis Of Cellulose Hydrolysis, Troy R. Dolmetsch

Undergraduate Honors Theses

Renewable sources such as cellulose derived biofuels are sought after in order to replace fossil fuel sources that are currently used to meet energy demands. Cellulose is a biological polymer composed of a chain of glucose molecules. Hydrolysis of cellulosic materials then has potential to serve as a source of renewable energy in the form of biofuels. The crystalline structure of cellulose is very stable, and current methods of catalyzed hydrolysis are inefficient for industrial application. This project explores the use of phosphomolybdic acid (PMA) in water to catalyze hydrolysis of microcrystalline cellulose. Temperature of hydrolysis was varied from 40 …

Role Of Nanoparticles In Voltammetric Signal Enhancement Exhibited By Layer-By-Layer (Lbl) Gold Nanoparticle-Modified Screen-Printed Carbon Electrodes (Spces), Ben K. Ahiadu

Electronic Theses and Dissertations

Screen-printed electrodes (SPEs) have found wide use as sensing platforms due to their simple fabrication, customizability in terms of geometry and composition, and relatively low cost of production. Nanoparticles have been incorporated in or interfaced with SPEs in order to improve sensor response or provide electrocatalytic capabilities. Though nanomaterial-modified SPEs are becoming increasingly common sensing platforms, the benefits provided by nanomaterials are often determined through voltammetric studies with common redox probes, such as ferricyanide. However, recent reports have documented the ferri-/ferrocyanide redox couple to be an unreliable system for characterizing some carbon-based electrodes due to the dependence of its electrochemical …

Functionalized Silica Gel For Adsorption Of Cesium From Solution, Kenneth Marshall Seaton Iii

Electronic Theses and Dissertations

Mesoporous silica gel containing embedded phosphotungstic acid (PTA) was synthesized by sol-gel co-condensation of tetraethyl orthosilicate with PTA in acidic media. The obtained material had high Brunauer-Emmett-Teller Theory (BET) surface area and pore volume. A characteristic band of the Keggin structure of PTA was present in its FT-IR spectrum while its X-ray diffraction patterns were absent. This proved the embedding of PTA on a sub-molecular level and not as a second phase. Acidic sites were determined by neutralization with base in aprotic solvent, followed by titration of the remaining base with an acid. The material demonstrated high adsorption capacity of …

Inventory Optimization Using A Simpy Simulation Model, Lauren Holden

Electronic Theses and Dissertations

Existing multi-echelon inventory optimization models and formulas were studied to get an understanding of how safety stock levels are determined. Because of the restrictive distribution assumptions of the existing safety stock formula, which are not necessarily realistic in practice, a method to analyze the performance of this formula in a more realistic setting was desired. A SimPy simulation model was designed and implemented for a simple two-stage supply chain as a way to test the performance of the safety stock formula. This implementation produced results which led to the conclusion that the safety stock formula tends to underestimate the level …