Physical Sciences and Mathematics Commons^™

Rare Occurrences Of Free-Living Bacteria Belonging To Sedimenticola From Subtidal Seagrass Beds Associated With The Lucinid Clam, Stewartia Floridana, Aaron M. Goemann

Masters Theses

Lucinid clams and their sulfur-oxidizing endosymbionts comprise two compartments of a three-stage, biogeochemical relationship among the clams, seagrasses, and microbial communities in marine sediments. A population of the lucinid clam, Stewartia floridana, was sampled from a subtidal seagrass bed at Bokeelia Island Seaport in Florida to test the hypotheses: (1) S. floridana, like other lucinids, are more abundant in seagrass beds than bare sediments; (2) S. floridana gill microbiomes are dominated by one bacterial operational taxonomic unit (OTU) at a sequence similarity threshold level of 97% (a common cutoff for species level taxonomy) from 16S rRNA genes; …

Environmental Controls On The Diversity And Distribution Of Endosymbionts Associated With Phacoides Pectinatus (Bivalvia: Lucinidae) From Shallow Mangrove And Seagrass Sediments, St. Lucie County, Florida, Thomas Walters Doty

Masters Theses

Lucinid bivalves are capable of colonizing traditionally inhospitable shallow marine sediments due to metabolic functions of bacterial endosymbionts located within their gills. Because lucinids can often be the dominant sediment infauna, defining their roles in sediment and pore fluid geochemical cycling is necessary to address concerns related to changes in coastal biological diversity and to understanding the sensitivity of threatened coastal ecosystems over time. However, there has been limited research done to understand the diversity and distribution of many lucinid chemosymbiotic systems. Therefore, the goals of this thesis were to evaluate the distribution of Phacoides pectinatus and its endosymbiont communities …

Border-Collision Bifurcations Of Cardiac Calcium Cycling, Jacob Michael Kahle

Masters Theses

In this thesis, we study the nonlinear dynamics of calcium cycling within a cardiac cell. We develop piecewise smooth mapping models to describe intracellular calcium cycling in cardiac myocyte. Then, border-collision bifurcations that arise in these piecewise maps are investigated. These studies are carried out using both one-dimensional and two-dimensional models. Studies in this work lead to interesting insights on the stability of cardiac dynamics, suggesting possible mechanisms for cardiac alternans. Alternans is the precursor of sudden cardiac arrests, a leading cause of death in the United States.

Determination Of Dispersal Patterns And Characterization Of Important Habitats For Lake Sturgeon Restoration In The Upper Tennessee River System, Christina Grace Saidak

Masters Theses

Lake Sturgeon, Acipenser fulvescens, are one of the slowest to reach sexual maturity and longest-lived freshwater fish species in North America. These fish are a species of special concern by the U.S. Fish and Wildlife Service, a vulnerable species by the American Fisheries Society (Jelks et al. 2008), and a threatened species in Tennessee (Chiasson et al. 1997; Williams et al. 1989). They have been reintroduced into the Upper Tennessee River system since 2000.

Since December 2013, 49 Lake Sturgeon have been implanted with ultrasonic acoustic transmitters, and 26 fixed-station receivers installed throughout the Upper Tennessee River System to …

Chemical Investigations Of Diabetes Mellitus, Malaria, And Castrate-Resistant Prostate Cancer, Maggie Sparks Lookadoo

Masters Theses

This work studies a variety of molecules and the systems they are involved in to further understand disease and treatment of diabetes mellitus, malaria, and castrate resistant prostate cancer. The first system studied, diabetes mellitus, involves synthesis of 5 different steroidal compounds, while the other two systems, malaria and castrate-resistant prostate cancer, apply mass spectrometric-based untargeted metabolomics to study both known metabolites and unknown spectral features.

Diabetes mellitus is a result of the dysfunction and death of islet beta cells caused by the transcription of pro-inflammatory cytokines resulting in reduced insulin secretion and uncontrollable blood glucose levels. Glucocorticoids can reduce …

Rapid Dissolution For Destructive Assay Of Nuclear Melt Glass, Jonathan Allen Gill

Masters Theses

This study evaluates four methods for dissolving complex glassy debris resulting from nuclear detonations. The samples of interest simulate the glassy debris generated from a nuclear detonation’s fireball coming in contact with solid masses. Each method attempts to achieve dissolution through different approaches involving either acid digestion, alkaline digestion, or molten salt fusion. Two of the four methods were modified to retain all elements of the debris or surrogate debris. This retention is critical to the proportional relationships used in identifying fuel types and designs of nuclear weapons. Analysis is conducted with an inductively coupled time of flight mass spectrometer …

Hsp-Wrap: The Design And Evaluation Of Reusable Parallelism For A Subclass Of Data-Intensive Applications, Paul R. Giblock

Masters Theses

There is an increasing gap between the rate at which data is generated by scientific and non-scientific fields and the rate at which data can be processed by available computing resources. In this paper, we introduce the fields of Bioinformatics and Cheminformatics; two fields where big data has become a problem due to continuing advances in the technologies that drives these fields: such as gene sequencing and small ligand exploration. We introduce high performance computing as a means to process this growing base of data in order to facilitate knowledge discovery. We enumerate goals of the project including reusability, efficiency, …

Experimental Limestone Dissolution And Changes In Multiscale Structure Using Small- And Ultra Small- Angle Neutron Scattering, Chad Alan Novack

Masters Theses

Small angle neutron scattering (SANS), ultra-small angle neutron scattering (USANS), and backscatter electron (BSE) imaging, along with neutron computed tomography (NCT) were used in this study to experimentally quantify pore size, distribution, and connectivity of dissolved limestone geometries. Eight samples of Indiana limestone of two different initial permeabilities (2-4 mD and 70 mD ) [millidarcy] were reacted with HCl [hydrochloric acid] solutions at differing pH (2 and 4), and flow rates (0.1 and 10 cm³/min) [cubic centimeters per minute] to describe a broad range of parameters that affect limestone dissolution. NCT was first used to image the dissolution …

Testing For The Effects Of Sediment Sorting On Detrital-Zircon Age Spectra By Sampling Multiple Bedforms In Single Fluvial Channels: Case Studies From The Wood Canyon Formation (Terreneuvian) And Stirling Quartzite (Ediacaran), Southeastern Ca, Jason Gerhard Muhlbauer

Masters Theses

Multiple bedforms were sampled from single fluvial channels in the Neoproterozoic (Ediacaran) upper member of the Stirling Quartzite and the Cambrian (Terreneuvian) middle member of the Wood Canyon Formation, southeastern California. Sampling strategy was designed to determine if sorting of detrital zircon populations by their textural properties can affect detrital-zircon age spectra in fluvial sandstones. Four samples derive from the middle member Wood Canyon Formation and two samples come from the upper member Stirling Quartzite. Sandstone samples vary in textural characteristics: grain sizes sampled range from fine to coarse sand, sorting ranges from moderately well to poorly sorted, and sampled …

Preparation And Characterization Of Thermodynamically Controlled Polymer Nanocomposites, Jiadi Hou

Masters Theses

The mechanical and physical properties of polymeric materials can be greatly improved by adding nanoscale additives. To mediate the dispersion of nanoparticles in polymers, it is often necessary to modify their surfaces to prevent aggregation. While polymer nanocomposites system consisting of homopolymer-grafted nanoparticles are well understood, copolymer-functionalized nanoparticles are less well understood but provide additional ways to alter dispersion through the use of chemically different comonomers. In this thesis, polystyrene nanocomposites blended with copolymer-grafted nanoparticles were prepared and studied. The particular comonomers used were methyl methacrylate and cyclohexyl methacrylate, which provides miscibility with polystyrene. Polymers with varying comonomer ratios were …

Long-Term Impacts Of Conservation Management Practices On Soil Carbon Storage, Stability, And Utilization Under Cotton Production In West Tennessee, Candace Brooke Wilson

Masters Theses

Biogeochemical cycling of soil carbon (C) is heavily influenced by conservation agricultural (CA) practices. This study examined SOC stability under three CA practices: reduced nitrogen (N) fertilizer application rate, cover cropping, and zero-tillage implemented for 31 years. Respiration rates measured from a 602-day incubation period were fitted to a double-pool first order exponential model of SOC decomposition. The active [respired] SOC pool showed distinct differences between applications of reduced (34N kg ha^-1 [-1]) and high fertilization rates (101N kg ha^-1) combined with tillage, and suggest that high fertilizer applications with conventional tillage allocated more C into a …

Strontium Monoxide Measurements In Methane-Air Flames, Bobby J. Wimberly

Masters Theses

The spectroscopy of alkaline earth metal compounds has been an area of active research for several decades. This is at least in part stimulated by the application of these compounds to practical areas ranging from technology to medicine. The use of these compounds in the field of pyrotechnics was the motivation for a series of flame emission spectroscopy (FES) experiments with strontium containing compounds. Specifically, strontium monoxide (SrO) is studied as a candidate radiator for the diagnostic of methane-air flames.

SrO emissions have been observed in flames with temperatures in the range of 1200-1600-K for two compounds: strontium hydroxide and …

Late Tertiary Tectonic Uplift In The Southern And Central Appalachians, Mary Sheela Biswal

Masters Theses

The exposed Appalachian Mountains extend about 2500 km from Newfoundland to Alabama with the highest peaks >2000 m above sea level. The last orogeny that affected Appalachian crust was the 325-260 Ma Alleghanian. Even with minimal erosion rates, it is highly unlikely that the Appalachians could have sustained such elevations for over 200 m.y., suggesting that recent tectonic uplift has produced today’s mountainous topography. The multiple phases of Tertiary uplift are related to poorly understood processes, but a large amount of data from today’s mountain chain and the adjacent Coastal Plain indicate the present high topography is anomalous and clearly …

Siloxane And Silane-Functionalized Polynorbornenes As Membranes For Passive Carbon Dioxide Separation, Eunice Koheun Hong

Masters Theses

In 2012, carbon dioxide (CO₂) [carbon dioxide] accounted for approximately 82% [percent] of all U.S greenhouse gas emissions.¹ These excessive CO2 levels have been attributed to climate changes that have a range of negative effects on human health and welfare.1 In an effort to decrease these emissions, polymeric membranes consisting of silane- and siloxane-functionalized norbornene units have been targeted as a potential solution for the passive separation of CO2 from other non-greenhouse gases. These substituted norbornene-based polymers were synthesized via vinyl-addition polymerization. Through a series of catalyst trials, commercially available palladium and nickel catalysts were compared along …

Installation And Alignment Of The N3he Experiment, Eric Lee Plemons

Masters Theses

The n3He experiment is designed to probe the hadronic weak interaction by measuring the parity violating asymmetry between the spin of incoming neutrons and the momentum of outgoing protons following the nuclear break up of a helium three upon absorbing a neutron. Cold neutrons from the SNS are first polarized then allowed to impact a target chamber filled with helium three where the reaction occurs. Energetic particles resulting from the nuclear breakup ionize the helium three gas and are thereby detected as currents by an array of signal wires within the target chamber. In order to make a statistics limited …

Neutrino Signatures In Terrestrial Detectors From Two- And Three-Dimensional Core-Collapse Supernovae Simulations, Tanner Brooks Devotie

Masters Theses

Core-collapse supernovae (CCSNe) are driven by neutrino emission and are the most prodigious sources of neutrinos in the Universe. Importantly, the neutrino radiation from CCSNe is emitted from deep in the explosion and can provide information about physical processes taking place in the newly-born neutron star at the heart of the event. We examine the four-flavor (i.e. ν_e, ν_e, ν_x and ν_x) [electron, muon and tau neutrinos along with their anti-matter counterparts] signature of CCSNe neutrino emission in various neutrino detector types. We use data from the multidimensional Chimera (Lentz et al., 2015) …

Modelling Supercomputer Maintenance Interrupts: Maintenance Policy Recommendations, Jagadish Cherukuri

Masters Theses

A supercomputer is a repairable system with large number of compute nodes interconnected to work in harmony to achieve superior computational performance. Reliability of such a complex system depends on an effective maintenance strategy that involves both emergency and preventive maintenance. This thesis analyzes the maintenance records of four supercomputers operational at The National Institute of Computational Science located at Oak Ridge National Laboratory. We propose to use the generalized proportional intensities model (GPIM) to model the maintenance interrupts as it can capture both the reliability parameters and maintenance parameters and allows the inclusion of both emergency and preventive maintenance. …

American Black Duck Wintering Dynamics And Dabbling Duck Response To Herbicide Application In Western Tennessee Wetlands, Joshua Matthew Osborn

Masters Theses

American black duck (Anas rubripes) populations declined throughout North America in the late 20^th century. Although the breeding population has since stabilized, research investigating habitat use by black ducks in the Mississippi Flyway is scarce. Impacts of wetland management practices in response to invasive species must also be tested to measure responses to habitat quality by black ducks and other waterfowl. During winters 2011-2013 (December-February), I estimated food biomass, diurnal habitat use, and activities of black ducks in 6 cover types at the Duck River Unit of Tennessee National Wildlife Refuge and Cross Creeks National Wildlife Refuge …

Europan Double Ridge Morphology As A Test For Hypothesized Models Of Formation, Ashley Caroline Dameron

Masters Theses

Double ridges on the Jovian satellite Europa consist of two ridges with a central trough. Several hypotheses exist describing their formation. Explosive cryovolcanism would result in granular ice depositing as two self-symmetric ridges flanking a central fracture, lying at or below the angle of repose (AOR). Cryo-sediments deposited by tidal squeezing and low-viscosity cryolavas emplaced by effusive cryovolcanism would likely have shallow slopes, although ridge symmetry is not expected. A second group of hypotheses involves brittle deformation of the crust, namely by diapirism, shear heating, and buckling of the lithosphere due to compression. Because these models involve uplifting vertical fractures, …

Near-Infrared (2 – 4 Micron) Spectroscopy Of Near-Earth Asteroids: A Search For Oh/H2o On Small Planetary Bodies, Nathanael Richard Wigton

Masters Theses

Near-Earth asteroids (NEAs) are not expected to have H₂O [water] ice on their surfaces because a) most accreted dry and therefore never contained H₂O, and b) their relatively high surface temperatures should drive rapid H₂O ice sublimation. However, OH/H₂O has been detected on other anhydrous inner solar system objects, including the Moon and Vesta. Possible sources for OH/H₂O in the inner Solar System might include production via solar wind interactions, carbonaceous chondrite or cometary impact delivery, or native OH/H₂O molecules bound to phyllosilicates. As these processes are active …

Real-Time Spectroscopic Analysis Of Microalgal Adaptation To Changing Environmental Conditions, Robert Ked Byrd

Masters Theses

Increases in anthropogenic pollution are causing many environmental problems; understanding their impact on the environment has become an important issue. Industrialization and the burning of fossil fuels have caused increased levels of carbon dioxide to enter the atmosphere, which is contributing to global warming and ocean acidification. Agricultural runoff has caused levels of inorganic nitrogen and phosphorus to rise, where they have been noted to cause harmful algal blooms. Marine ecosystems have been particularly affected as both of these forms of pollution accumulate in bodies of water. Microalgae are important organisms in these ecosystems because they sequester these pollutants and …

Geostatistical Analysis Of Point Soil Water Retention Parameters For Flint Sand, William Blake Roberts

Masters Theses

Geostatistics were employed to characterize sub-core scale heterogeneity and identify spatial structure in previously published water retention data (Kang et al., 2014) obtained using neutron radiography for Flint sand. The water retention data were parameterized using the Brooks and Corey (BC) model. The BC parameters investigated were: saturated water content (Ѳ_s), residual water content (Ѳ_r), air entry value (ψ_a), and pore size distribution index (λ). Spatial dependency in the BC parameters was identified using semivariograms. Of the four BC parameters analyzed, two were found to be spatially correlated, Ѳ …

Biodegradable Nano-Hybrid Polymer Composite Networks For Regulating Cellular Behavior, Charles Henley Sprague

Masters Theses

Photo-crosslinkable polymeric biomaterials have emerged in the field of biomedical research to promote tissue regeneration. For example, scaffolds that can be crosslinked and hardened in situ have been known to make suitable implant alternatives. Since injectable and photo-crosslinkable biomaterials offer the advantage of being minimally invasive, they have emerged to compete with autografts, a current highly invasive method to repair diseased tissue. A series of novel photo-crosslinkable, injectable, and biodegradable nano-hybrid polymers consisting of poly(ε-caprolactone fumarate) (PCLF) and polyhedral oligomeric silsesquioxane (POSS) has been synthesized in our laboratory via polycondensation. To engineer the material properties of the nano-hybrid networks, varied …

An Examination Of Fertilizer Use Efficiency And Irrigation Management In Tennessee Agricultural Production, Timothy James Grant

Masters Theses

Understanding the effect of supplemental irrigation and timing of nitrogen availability on yield of cotton is pertinent to the success of Tennessee cotton producers. Response to irrigation and nitrogen source is likely to vary across greatly differing soil types. This research indicated the need for higher amounts of water and earlier irrigation initiation to optimize yields in coarse-textured, low water holding capacity soils. Deep silt loam soils did not respond to irrigation in two wet years. Delaying nitrogen availability via use of a polymer coated urea fertilizer generally either lowered or did not affect yield. Delaying nitrogen availability was less …

Correlating Morphology To Performance In Conjugated Polymer Nanocomposite Thin Films, Siddharth Pradhan

Masters Theses

The morphology and performance of thin films that consist of conjugated polymers and nanoparticles are investigated in this thesis. In the first system, the morphology of the nanocomposite that consists of low band gap alternating copolymers with a methano-fullerene are determined by neutron scattering and correlated to their photovoltaic performance as polymer solar cells. These results show that the conjugated alternating copolymers have high miscibility relative to other conjugated polymers. The analysis of the scattering data shows that the morphology of the conjugated polymer-fullerene bulk heterojunction can be described as the formation of aggregates on two length scales. Important parameters …

Survival And Growth Rate Of Translocated Freshwater Mussels Lampsilis Fasciola And Medionidus Conradicus, Laura L. Pullum

Masters Theses

Freshwater mussels (Family Unionidae and Margaritiferidae) are a widely threatened group of bivalve molluscs, particularly in the Southeastern United States. Translocation of freshwater mussels is an increasingly common conservation method. However, there are relatively few studies that quantitatively investigate the factors influencing translocation success or failure. In October 2013, hundreds of Medionidus conradicus and Lampsilis fasciola were translocated to the Pigeon and Nolichucky Rivers in Tennessee, with an interim partial survey (June 2014) and a full survey (October 2014). In this study, I analyze this field-collected data to determine the mechanism(s) that currently influence the outcomes of Tennessee mussel translocation. …

Measurement Of Hysteretic Shale Capillary Pressure – Saturation Relationships Using A Water Activity Meter, Brendan Michael Donnelly

Masters Theses

Capillary pressure is the pressure difference across the interface of two immiscible fluids within a porous medium due to the interfacial tension between fluids and is related to both the properties of the fluids and the porous medium. Capillary pressure within a porous medium will change depending upon its degree of saturation. Understanding the relationship between capillary pressure and saturation for a rock allows for the modeling of multi-phase flow. Many traditional methods of measuring capillary pressure are unsuitable for the characterization of shale due to their inability to measure the high capillary pressures found within the small pores. Furthermore, …

Establishing A Chronology Of Late Quaternary Glacial Advances In The Cordillera De Talamanca, Costa Rica, Rebecca Susan Potter

Masters Theses

Little research has focused on glacial events in the tropics. Providing an absolute glacial chronology in Costa Rica will build a foundation for future glacial chronologies and paleoclimate reconstructions in the highlands of Central America. Evidence of past glaciation, including moraines and glacial lakes, is preserved within formerly glaciated valleys in the Cordillera de Talamanca. Orvis and Horn (2000) constrained deglaciation ages of the most recent glacial event in the Cordillera de Talamanca based on radiocarbon dates of glacial lake sediments. Radiocarbon ages indicated complete deglaciation after 12.4 ka cal BP but before 9.7 ka cal BP (Orvis and Horn, …

Comparison Of Activation Enthalpies For Aminoglycoside Modification Reactions, Brittany Sterling Soto

Masters Theses

At highly elevated temperatures, many biological reactions can proceed spontaneously from the ground state to the transition state. However, due to the long half-life of these reactions, catalysts are required to catalyze these reactions at modern day temperatures by lowering the activation energy. Wolfenden et al. has previously shown that catalysts enhance the rate of the reaction by reducing the enthalpy of activation. Therefore, the activation energies have been determined for three aminoglycoside modifying enzymes, APH(3’)-IIIa, AAC(3)-IIIb, and AAC(3)-VIa, to determine whether these three enzymes distinguish between the two classes of aminoglycoside antibiotics by reducing the enthalpy of activation during …

Mechanisms For Social Influence, Jeremy David Auerbach

Masters Theses

Throughout the thesis, I study mathematical models that can help explain the dependency of social phenomena in animals and humans on individual traits. The first chapter investigates consensus building in human groups through communication of individual preferences for a course of action. Individuals share and modify these preferences through speaker listener interactions. Personality traits, reputations, and social networks structures effect these modifications and eventually the group will reach a consensus. If there is variation in personality traits, the time to reach consensus is delayed. Reputation models are introduced and explored, finding that those who can best estimate the average initial …