Physical Sciences and Mathematics Commons^™

Improving Scalability And Usability Of Parallel Runtime Environments For High Availability And High Performance Systems, Thara Angskun

Doctoral Dissertations

The number of processors embedded in high performance computing platforms is growing daily to solve larger and more complex problems. Hence, parallel runtime environments have to support and adapt to the underlying platforms that require scalability and fault management in more and more dynamic environments. This dissertation aims to analyze, understand and improve the state of the art mechanisms for managing highly dynamic, large scale applications.

This dissertation demonstrates that the use of new scalable and fault-tolerant topologies, combined with rerouting techniques, builds parallel runtime environments, which are able to efficiently and reliably deliver sets of information to a large …

Total Synthesis Of An Analog Of Hydramycin And Derivatization Of Thiol-Terminated Carbohydrates And Development Of A Glycoconjugate Too Set For The Assembly And Presentation Of Carbohydrate Ligands On Surfaces, Medhanit Woldeghiorghis Bahta

Doctoral Dissertations

2-(1,2-Dihydroxy-1-(oxiran-2-yl)ethyl)-11-hydroxy-5-methyl-1Hnaphtho[ 2,3-h]chromene-4,7,12-trione (1), a pyranoanthraquinone isolated from Streptomyces violaceus P950-4, showed a potent antibacterial and cytotoxic activity. A model synthesis for analogs 2-(1,2-dihydroxy-1-(oxiran-2-yl)ethyl)-4H-chromen- 4-one (2) and2-(1-hydroxy-1-(oxiran-2-yl)ethyl)-1H-naphtho[2,3- h]chromene-4,7,12-trione (3) was developed by Dr. David White and Dr. Sarah Headrick. A new analog, 2-(1,2-dihydroxy-1-(oxiran-2-yl)ethyl)-1H-naphtho[2,3- h]chromene-4,7,12-trione (4), was designed to be structurally more similar to hydramycin with –CH2OH functionality on the pyranone ring and anthraquinone skeleton. Therefore, it is expected to have greater anticancer activity than either analogs 2 or 3. This dissertation will cover developments, challenges and solutions in …

Fabrication And Analysis Of Polymeric Nanocomposites From Cellulose Fibrils, Qingzheng Cheng

Doctoral Dissertations

A novel process using high-intensity ultrasonication (HIUS) was developed to isolate fibrils from cellulose fibers. The geometrical characteristics of the fibrils were investigated using polarized light microscopy (PLM), scanning electron microscopy (SEM) and atomic force microscopy (AFM). Results show that small fibrils with diameter ranging from about thirty nanometers to several micrometers were peeled from the fibers. The degree of fibrillation of the fibers was significantly increased. The crystallinities or molecular structures of most of the cellulose materials were changed by HIUS treatment.

To evaluate the fibrils degradation by HIUS, a method using AFM was modified and developed to measure …

Electroanalysis Of Metals In Biological And Environmental Samples At Bismuth Electrodes, Kristie Carter Armstrong

Doctoral Dissertations

An Advanced Oxidation Process (AOP) was designed for the decomposition of organic material in blood as a pretreatment for chromium analysis. Acidified porcine blood was treated with hydrogen peroxide and UV light for 60 min. The rate of decomposition was studied using UV/Vis spectroscopy. It was found that the order of the photolytic reaction with respect to hydrogen peroxide was 0.35. The pretreated blood was subsequently analyzed for chromium content by catalytic adsorptive stripping voltammetry at a bismuth film electrode. The concentration of chromium was determined to be 6.0 " 0.3 parts per billion (ppb). A bismuth bulk electrode was …

Statistical And Machine Learning Techniques Applied To Algorithm Selection For Solving Sparse Linear Systems, Erika Fuentes

Doctoral Dissertations

There are many applications and problems in science and engineering that require large-scale numerical simulations and computations. The issue of choosing an appropriate method to solve these problems is very common, however it is not a trivial one, principally because this decision is most of the times too hard for humans to make, or certain degree of expertise and knowledge in the particular discipline, or in mathematics, are required. Thus, the development of a methodology that can facilitate or automate this process and helps to understand the problem, would be of great interest and help. The proposal is to utilize …

Parametric And Non-Parametric Regression Tree Models Of The Strength Properties Of Engineered Wood Panels Using Real-Time Industrial Data, Timothy Mark Young

Doctoral Dissertations

The forest products industry is undergoing unprecedented change from international competition, increasing fiber costs, rising energy prices and falling product prices. Competitive businesses have the key ability to adapt quickly to change through improved knowledge. Among adaptations to change are better product development, improved process efficiency and superior product quality. This dissertation is directly related to improving the knowledge of forest products manufacturers by investigating data mining (DM) methods that improve the ability to quantify causality of sources of variation. A contemporary DM method related to decision theory is decision trees (DTs). DTs are designed for heterogeneous data and are …

Physical Properties Of Unconventional Superconductors, Valentina Anatolyevna Kuznetsova

Doctoral Dissertations

In the following development, we attempt to obtain basic physical properties of majority of unconventional superconductors through a Bardeen-Cooper-Schrieffer-type weak-coupling approach. The method we adopted in our study is model-independent. The weak-coupling approach depends only on the symmetry of the coupling, not on its origin. It is known that a general analysis of physical properties of unconventional superconductors is possible, but has not been done yet. The goal of our work is to develop and test such analysis, using available experimental data.

Since paramagnetic limiting for spin-singlet superconductors can be suppressed in superconductors with broken inversion symmetry of crystal lattice, …

Towards Automatic And Adaptive Optimizations Of Mpi Collective Operations, Jelena Pjesivac-Grbovic

Doctoral Dissertations

Message passing is one of the most commonly used paradigms of parallel programming. Message Passing Interface, MPI, is a standard used in scientific and high-performance computing. Collective operations are a subset of MPI standard that deals with processes synchronization, data exchange and computation among a group of processes. The collective operations are commonly used and can be application performance bottleneck. The performance of collective operations depends on many factors, some of which are the input parameters (e.g., communicator and message size); system characteristics (e.g., interconnect type); the application computation and communication pattern; and internal algorithm parameters (e.g., internal segment size). …

Characterization Of The Temperature Dependence Of Optical Components In A Cryo-Vacuum Chamber Used For Space Sensor Testing, Jesse M. Labello

Masters Theses

The space sensor cryo-vacuum chambers at Arnold Air Force Base are world class sensor characterization and calibration facilities. The chambers provide a simulated deep space background and accurate infrared projections. Several large optical systems are used within the chambers to accomplish this. Calibration of the chambers requires the use of a database of the measured optical properties of these components to simulate the output. However, as the information in the database is room temperature information and the chambers run near 20K, some discrepancies exist between the actual output and the model output. The purpose of this work is to translate …

Impact Of The Equation Of State In Core-Collapse Supernovae, Mark Lewis Baird

Masters Theses

One of the key ingredients to the core collapse supernova mechanism is the physics of matter at or near nuclear density. Included in simulations as part of the Equation of State (EoS), nuclear repulsion experienced at high densities is responsible for the bounce shock, which initially causes the outer envelope of the supernova to expand, as well as determining the structure of the newly formed proto-neutron star. Recent years have seen renewed interest in this fundamental piece of supernova physics, resulting in several promising candidate EoS parameterizations. We will present the impact of several of their variations in the nuclear …

Alkoxide Routes To Inorganic Materials, George Harrison Thomas

Doctoral Dissertations

An all alkoxide solution chemistry utilizing metal 2-methoxyethoxide complexes in 2-methoxyethanol was used to deposit thin-films of metal oxides on single-crystal metal oxide substrates and on biaxially textured metal substrates. This same chemistry was used to synthesize complex metal oxide nanoparticles. Nuclear Magnetic Resonance spectroscopy was used to study precursor solutions of the alkaline niobates and tantalates. Film crystallization temperatures were determined from X-ray diffraction patterns of powders derived from the metal oxide precursor solutions. Film structure was determined via X-ray diffraction. Film morphology was studied using scanning electron microscopy (SEM) and atomic force microscopy (AFM).

Epitaxial thin-films of strontium …

Design Construction And Use Of A Thermomechanical Detwinning Apparatus: Detwinning Of Orthorhombic Nb2bacu2o3, Chad J. Bircher

Masters Theses

In this thesis I will describe a device designed and built for thermo- mechanically detwinning crystals. Twinning is a process in which a crys- talline structrure with two different axes of nearly equal length alternate directions throughout the material, effectively generating a single bulk material with two or more distinct internal crystals. This structure defect can lead to many other effects in the crystal, and it is useful to elimi- nate twinning in many materials in order to determine which properties are fundamental properties of the crystal, and which properties are ar- tifacts of the structural imperfections. The apparatus described …

Impact Of Crop Rotations And Winter Cover Crops On Vegetative Cover, Aboveground Biomass, And Soil Organic Matter Under No-Till In Western Tennessee, Nicholas Phillip Ryan

Masters Theses

We investigated, under long-term no-till in western Tennessee, the effects of rotating the low-input crops cotton and soybeans with the high-input crop corn, compared to continuous monocultures of cotton and soybeans, and of using the winter cover crops (WCCs) winter wheat and hairy vetch, compared to winter fallow, on key indicators of soil health concerning vegetative cover and labile SOM. The line-transect method was used to measure percent vegetative cover. Dry weight of surface crop residue and aboveground living plant biomass (WCCs and winter weeds) was obtained. The living plant biomass was analyzed for carbon (C) and nitrogen (N) by …

Effects Of Environmental Stress On Growth, Yield, And Flavonolignan Content In Milk Thistle Silybum Marianum L. Gaertn, Amy Renae Belitz

Masters Theses

Four experiments were performed in a greenhouse or growth chamber to study the quantity and quality of flavonolignans in response to environmental stress in milk thistle (Silybum marianum L., Gaertn.). A preliminary experiment was conducted in spring 2004 to study effects of leaf harvests on growth, development, and flavonolignan content in milk thistle seeds. Taxifolin, a component of silymarin and precursor to flavonolignans, was significantly reduced due to leaf harvest treatments.

The weedy nature (sporadic germination) of Silybum made germinating enough plants for experimentation problematic. Initial germination studies to determine imbibition and pre-chilling requirements were inconclusive due to heavy …

Reduction Of Human Factors-Related Accidents During The Flight Test Of Homebuilt Aircraft Through The Application Of Professional Flight Test Practices, Justin Samuel Garr

Masters Theses

Homebuilt aircraft have a high accident rate during the flight test period, particularly during their first and second flights. For the 2002-2004 period, over 1.0% of homebuilt aircraft were involved in an accident on their first flight, and 3.3% were involved in accidents in the first 40 hours of operation. Untrained, low time in aircraft type amateur flight test participants, unorthodox flight test procedures, and lack of clear guidance as to who should and how to conduct safe and effective flight test lead to unsafe conditions and the accident statistics support this hypothesis. In the accidents analyzed, lack of experience …

Major And Trace-Element Chemistry Of Minerals In Lithologies A And B In Martian Meteorite Eeta79001: Petrogenesis Revisited, Michael Joseph Mellin

Masters Theses

EETA79001 is a unique shergottite composed of two mafic lithologies (termed LithA and LithB) that are separated by an igneous contact. Both lithologies have basaltic compositions; however, LithA contains megacrysts of olivine, orthopyroxenes, and chromite whereas LithB does not; also, LithA is finer-grained than LithB. Currently, the literature is in disagreement regarding the formation of this unique meteorite, especially regarding LithA. Different formational theories (e.g. fractional crystallization, magma mixing, assimilation, and impact melting) have their own constraints (chemical, thermal, or petrographic). This study uses petrographic observations combined with major- and trace- element compositions within minerals to investigate the petrogenesis of …

Bacterial Source Tracking In An Eastern Tennessee Stream Using Bacteroides Host Associated Real-Time Polymerase Chain Reaction Assays, Ryan Michael Ragsdale

Masters Theses

A bacterial source tracking study using Bacteroides host associated real-time PCR assays was performed to determine the sources of fecal contamination in Pond Creek (HUC 06010201013). Pond Creek, located in the Ridge and Valley physiographic region in Eastern Tennessee, is a 303(d) listed stream that fails to meet water quality standards for pathogens. Water samples and discharge were measured monthly at eight locations from November 2005 to November 2006. Grab samples were analyzed for several chemical parameters and for microbial fecal indicator organisms, namely Bacteroides spp., Escherichia coli, and Enterococcus. The objectives of the study were to quantify total, …

Stream Restoration Assessment Of Abrams Creek In The Great Smoky Mountains National Park: Management Implications And Comparison Of Empirical And Analytical Physical Assessment Approaches, Daniel L. Carter

Masters Theses

Natural resource managers in the Great Smoky Mountains National Park requested the assistance of the University of Tennessee Department of Civil and Environmental Engineering to assess Abrams Creek for potential stream restoration needs. A presumed, unstable study reach and a stable reference reach were identified on Abrams Creek in Cades Cove. Chemical, biological and physical assessments were completed on Abrams Creek in order to evaluate ecological health and channel stability of the stream. Water quality and ecological (fish and habitat surveys) data acquired by National Park Service, Tennessee Valley Authority and the University of Tennessee were assessed. The physical assessment …

Cross Sections Fall 2007, Department Of Physics And Astronomy

Cross Sections

No abstract provided.

Boron And Metal Halides In Organic Synthesis, Scott T. Borella

Doctoral Dissertations

This dissertation summarizes the recent use of organoboron and metal halides to form new carbon-carbon bonds. Several novel reactions have been discovered. These include the halovinyl alkenylation of alkoxides with alkenylboron dihalides; alkynylation of alkoxides with alkynylboron dihalides; boron trichloride and ferric chloride-mediated allylation of alkoxides. The results of these studies strongly imply a cationic mechanism, and prompted a reinvestigation of the boron trihalide mediated alkyne-aldehyde coupling reaction. The olefin stereochemistry of the resultant 1,5-dihalo-1,4-pentadienes can be influenced by controlling the reaction temperature and the sequence of reagent addition. The reaction methodology of the research described herein can be characterized …

Synthesis And Reactivity Of Titanium Amido Complexes With Relevance To Olefin Polymerization, Michael A. Blanchard

Doctoral Dissertations

Ziegler-Natta catalysts are well known in the chemical industry. They are responsible for the production of more than half of the HDPE and HDPP worldwide annually. Ziegler-Natta catalysts exist in many forms, both in homogeneous and heterogeneous types as well as both with early and late transition metal basis. While Ziegler-Natta catalysts can exist in various forms, all polymerize via the same general mechanism. Dissecting the known mechanism(s) results in three items that must be in place for polymerization to occur. First, the active metal center must be highly Lewis acidic, enough to allow coordination of approaching olefins. Second, a …

Past Fire Regimes Of Table Mountain Pine (Pinus Pungens L.) Stands In The Central Appalachian Mountains, Virginia, U.S.A., Georgina Deweese

Doctoral Dissertations

Table Mountain pine is an Appalachian endemic that occurs in a patchy distribution from Georgia to Pennsylvania and is prolific at sites with a history of fire disturbance. The purpose of this dissertation was to reconstruct the fire regimes of Table Mountain pine stands in the Jefferson National Forest, Virginia. Sections from firescarred Table Mountain pines were collected at four sites to analyze fire history, while increment cores and stand composition information were collected from macroplots within each fire history site to investigate the possible influence of fires that were more ecologically severe. Results show that fire was frequent before …

A Team-Based Approach To Social Learning Research In Natural Resource Management, Jonah Malachai Fogel

Doctoral Dissertations

This thesis responds to the need to quantify social learning and its outcomes as it relates to natural resource management. Social learning enables individuals engaging in collective action to understand each other’s perspectives, encourages integration of diverse knowledge bases, and the creation of new knowledge (Keen, Brown, & Dyball, 2005). However, the concept currently lacks a clear operational definition in natural resource management. The lack of an operational definition for social learning has stymied attempts to validate its espoused ability to improve civic discourse and, ultimately, resource governance (Pahl-Wostl & Hare, 2004). This report is composed of three papers that …

Novel Approaches To Metal Ion Sensing, Nathan Allen Carrington

Doctoral Dissertations

The primary focus of this dissertation is the development of new chemical analyses for metal ions. Approaches combining electrochemical, spectroscopic, analytical, inorganic, and materials chemistry have been used to investigate novel methods for metal ion sensing. Topics discussed in this dissertation include pyridinium-functionalized sol-gel films for the enhanced electrochemical analysis of Cr(VI), pyridinium-functionalized sol-gel monoliths for the optical determination of Cr(VI), the use of the electrochemical quartz crystal microbalance for the determination of Pd(II), novel electrochemical and spectroscopic approaches to Fe(III) sensing, and the electrochemical quartz crystal microbalance investigation of the Cr(III)-DTPA complex.

A Multi-Scale Analysis Of Disturbance Dynamics In Hardwood Forest Communities On The Cumberland Plateau, U.S.A., Justin L. Hart

Doctoral Dissertations

The purpose of this research was to quantify forest disturbance processes and evaluate the influence of these processes on secondary hardwood forest communities on a section of the Cumberland Plateau in Tennessee. The specific objectives of this study were to: (1) reconstruct the disturbance history of a secondary hardwood forest using species composition, stand structure, tree-ring data, and soil charcoal analyses, (2) quantify canopy gap formation mechanisms, (3) document canopy gap characteristics, and (4) determine the forest response to small-scale disturbance events. This information is useful to understand the importance of localized disturbances on stand development and forest successional patterns. …

Optimization Of Interfacial Interactions To Achieve The Nanoscale Dispersion Of Clay In Polymer/Clay Nanocomposites, Deepali Kumar

Doctoral Dissertations

Polymer clay nanocomposites are a promising class of multicomponent systems where incorporation of small amount of clay results in dramatic improvement of mechanical, thermal and barrier properties. However, accomplishment of these properties necessitates molecular level dispersion of the clay platelets in the polymer matrix. This thesis presents the guidelines for obtaining thermodynamically stable nanocomposites where strong specific interactions such as hydrogen bonding between the polymer and the clay can be utilized to achieve the desired goal of nanoscale dispersion of clay sheets.

In first part of the dissertation, optimization of intermolecular hydrogen bonding between the polymer and clay is carried …

Mapping The Martian Geologic Record: Studies Of The Gusev Crater Spirit Landing Site And Plagioclase Feldspar Compositions On Mars, Keith Alan Milam

Doctoral Dissertations

The flurry of activity involved in the scientific study of Mars has resulted in multiple new data sets from several missions (Mars Global Surveyor (MGS), Mars Odyssey (MO), Mars Exploration Rovers (MER), Mars Reconnaissance Orbiter (MRO), and Mars Express) that provide information for unlocking the planet’s geologic and climatic history.

This three part study utilized both orbital data and laboratory experiments to examine Mars for morphologic and mineralogic evidence of aqueous activity and magmatic evolution.

The first study examined Gusev Crater, landing site for the Spirit MER rover. This work began during final landing site selection and was published just …

Molecular Anion Spectroscopy And Stability, Jeffrey Daniel Steill

Doctoral Dissertations

A detailed and thorough computational investigation of the SF ₆ anion is undertaken, with additional calculations of other stable SF _n anions. The calculations are used to in- terpret recent infrared multi-photon dissociation (IRMPD) experiments of SF ₆ and SF ₅ anions done with the FELIX free electron tunable infrared laser in the spectral range of 450-850 cm^-1. The vibrational spectroscopy of negative molecular ions is crucial towards understanding the dynamics of electron transfer processes, as well as providing experimental validation for computational models of molecular bonding in anions. Many molecular negative ions have been shown to exhibit …

Synthesis Of Novel Boronated Amino Acids For Bnct An Alternate Cancer Therapy And Use Of Microwaves In Organic Synthesis, Abhijit Achyut Naravane

Doctoral Dissertations

Boron neutron capture therapy (BNCT) is a binary form of cancer treatment wherein ¹⁰B nuclei, when irradiated with thermal neutrons, produce high energy transfer particles. These particles, due to their size and energy, are confined to a radius of 9-10μm, which is comparable to the size of single cell. Potential BNCT agents reported in the literature include boron-containing amino acids, nucleic acids, nucleosides, antibodies, and other biomolecules.

In recent years, microwaves have gained importance in organic chemistry. Microwave induced reactions are energy efficient, often enhance reaction rates, and generally lead to enhanced product yields. Recent studies have …

Tectonics Of The Northeastern Inner Piedmont, Northwestern Nc, From Detailed Geologic Mapping, Geochronologic, Geochemical, And Petrologic Studies With Structural Analyses Of Ductile Fault Zones, Matthew Patrick Gatewood

Masters Theses

New field and laboratory data collected for the northeastern Inner Piedmont (IP) reveal the structure and composition of a portion of the southern Appalachian crystalline core, delimited the timing of orogenesis, and provide new insight into the nature of deep crustal processes during orogenesis. Previously recognized lithologies are continuous throughout the study area and comprise two distinct crystalline thrust sheets: the Marion and Brindle Creek thrust sheets, or eastern Tugaloo and western Cat Square terranes, respectively. Western IP Precambrian- Cambrian(?) metasedimentary lithologies and Ordovician metaigneous lithologies make up the Marion thrust sheet northwest of a Neoacadian suture, the Brindle Creek …