Physical Sciences and Mathematics Commons^™

Substituting Failure Avoidance For Redundancy In Storage Fault Tolerance, Christopher David Brumgard

Doctoral Dissertations

The primary mechanism for overcoming faults in modern storage systems is to introduce redundancy in the form of replication and error correcting codes. The costs of such redundancy in hardware, system availability and overall complexity can be substantial, depending on the number and pattern of faults that are handled. This dissertation describes and analyzes, via simulation, a system that seeks to use disk failure avoidance to reduce the need for costly redundancy by using adaptive heuristics that anticipate such failures. While a number of predictive factors can be used, this research focuses on the three leading candidates of SMART errors, …

Synthesis, Reactivity, And Nmr Trends Of Early Transition Metal Compounds, Tabitha Marie Cook

Doctoral Dissertations

This dissertation focuses of three different subjects. The first is the synthesis and characterization of heptacoordinate amidinate compounds. Heptacoordinate compounds are not common, but their structures have been studied. Group 4 amidinate compounds have been used as precursors in the CVD/ ALD processes. Ancillary ligands, such as amidinates, have been used to reduce air-sensitivity of complexes. Reactions of these complexes with water have been used to make metal oxide thin films.

In the first study, the complexes Zr[MeC(NⁱPr)₂]₃Cl [zirconium trisamidinate chloride], Hf[MeC(NⁱPr)₂]₃Cl [hafnium trisamidinate chloride], Zr[MeC(NⁱPr) …

Beta-Delayed Neutron Data And Models For Scale, Kemper Dyar Talley

Doctoral Dissertations

Recent advancements in experimental and theoretical nuclear physics have yielded new data and models that more accurately describe the decay of fission products compared to historical data currently used for many applications. This work examines the effect of the adopting the Effective Density Model theory for beta-delayed neutron emission probability on calculations of delayed-neutron production and fission product nuclide concentrations after fission bursts as well as the total delayed neutron fraction in comparison with the Keepin 6-group model. We use ORIGEN within the SCALE code package for these calculations. We show quantitative changes to the isotopic concentrations for fallout nuclides …

Large Scale Brownian Dynamics Simulation Of Dilute And Semidilute Polymeric Solutions, Amir Saadat

Doctoral Dissertations

Excluded Volume (EV) and Hydrodynamic Interactions (HI) play a central role in static and dynamic properties of macromolecules in solution under equilibrium and nonequilibrium settings. The computational cost of incorporating HI in mesoscale Brownian dynamics (BD) simulations, particularly in the semidilute regime has motivated significant research aimed at development of high-fidelity and efficient techniques.

In this study, I have developed several algorithms for the mesoscale bead-spring representation of a macromolecular solution in dilute and semidilute regimes. The Krylov subspace method enables fast calculation of single chain dynamics with simulation time scaling of O(N_b²) [order N …

The Effect Of Illumination On The Conformation And Thermodynamics Of Conjugated Polymers, Brian Frank Morgan

Doctoral Dissertations

This dissertation explores the effects which illumination has on the structure and conformation of conjugated polymers, both in solution and the bulk. Conjugated polymers are an important class of optoelectronic polymeric materials which make up the active layer of key organic electronic devices such as organic photovoltaics, transistors, and light emitting diodes. Considering the strong link between polymer chain structure and device efficiency in these materials, a comprehensive understanding of certain experimental conditions which may influence this conformation and thusly alter the functionality of the devices predicated upon them is of vital importance.

The first part of this dissertation provides …

Context-Sensitive Auto-Sanitization For Php, Jared M. Smith, Richard J. Connor, David P. Cunningham, Kyle G. Bashour, Walter T. Work

Chancellor’s Honors Program Projects

No abstract provided.

Optical Spectroscopy And The Contruction Of An Optimal Wannier Basis With Application To The Development Of Ab Initio Models, Robert Gerard Van Wesep

Doctoral Dissertations

Understanding the role of local orbital degrees of freedom in the behavior of solid state systems has long been understood as a key to unraveling the mysteries presented by complex transition metal compounds. A general approach to the many-body problem is density functional theory (DFT) and its time-dependent extension (TDDFT), which provide a realistic representation of the material-dependent symmetry and chemistry of a compound. Calculation of quantities in (TD)DFT are most often performed using the basis of Bloch states, which is not natural for investigating local degrees of freedom. The Wannier basis provides localized orbitals that retain all of the …

Development And Validation Of The Statistics Assessment Of Graduate Students, Dammika Lakmal Walpitage

Doctoral Dissertations

This study developed the Statistics Assessment of Graduate Students (SAGS) instrument, and established its preliminary item characteristics, reliability, and validity evidence. Even though there are limited number of assessments available for measuring different aspects of statistical cognition, these previously available assessments have numerous limitations. The SAGS instrument was developed using Rasch modeling approach to create a new measure of statistical research methodology knowledge of graduate students in education and other behavioral and social sciences. Thirty-five multiple-choice questions were written with stems representing applied research situations and response options distinguishing between appropriate use of various statistical tests or procedures. A focus …

Design And Synthesis Of Lipid Probes Used For Membrane Derivatization And Fusion, Stuart Allen Whitehead

Doctoral Dissertations

Lipids control a variety of complex biological processes. Bulk lipids such as phosphatidylcholine (PC), phosphatidylserine (PS), and phosphatidylethanolamine (PE) represent the major components of cellular membranes. In addition, unilamellar vesicles composed of lipids (liposomes) are valuable for delivery applications since they can encapsulate and transport drugs and other agents. In order to maximize delivery efficiency and target specific membranes, the ability to trigger and control vesicle-vesicle fusion is desirable. Such approaches generally seek to mimic the membrane fusion machinery present in nature while imparting specificity in the membranes that undergo fusion. The goal of this work is selective drug delivery …

Development Of An F-Element Separation Chemistry Using Solid Electrolytes, Kristian Guy Myhre

Doctoral Dissertations

The f‒elements (lanthanides and actinides) have numerous applications and are critically important to many industries, including the energy, security, and medical industries. One of the barriers to increased use and availability of the f‒elements is the difficulty in separating them from each other due to their similar chemistries. This is especially true of the trivalent f‒elements (lanthanides and minor actinides). The development of separation techniques that maximize the differences in the physicochemical properties of the f‒elements is therefore an important area of research. For these reasons, an effort was undertaken to explore the use of solid …

Catalytic Aziridination With A Borate-Containing N-Heterocyclic Tetracarbene Iron Complex, Preeti Pradip Chandrachud

Doctoral Dissertations

Aziridines, the nitrogen analog of epoxides, are an important class of compounds. They are present in many biologically active compounds having antibacterial and antitumor properties. Along with biological significance, it can also be considered as a synthetic tool for various functional group transformations. Being an important functional group we focused on the development of synthetic methodology using alkenes as substrates and organic azides as the nitrene source [C₂ (carbon2)+ N₁ (nitrogen1) addition reaction].

For the potential use as an aziridination catalyst a macrocyclic N-heterocyclic tetracarbene (NHC) ligand system was developed. First, the neutral NHC ligand was used …

Kinematic, Metamorphic, And Geochronologic Constraints On The Evolution Of The Lhagoi Kangri Gneiss Dome, Southern Tibet: Insight Into Mid-Crustal Processes During Himalayan Orogenesis, Timothy Francis Diedesch

Doctoral Dissertations

The north Himalayan gneiss domes are a series of isolated structures in southern-central Tibet that expose middle crust and record an early history of deformation, metamorphism, and partial melting. The domes are windows into the processes and physical conditions that promoted growth and uplift of the Himalaya during the early stage of collision (Eocene to Miocene) between India and Asia. Mechanisms responsible for creating the north Himalayan gneiss domes are crucial to understanding the early tectonic evolution of large orogens, such as the Himalaya, particularly with respect to crustal rheology and how middle crust is exhumed in collisional settings. Models …

Synthesis And Behavior Of Stimuli-Responsive Shape-Changing Linear Molecular Bottlebrushes, Daniel Mark Henn

Doctoral Dissertations

Molecular bottlebrushes are composed of polymer side chains densely grafted to a macromolecular backbone. The main focus of this dissertation work is the synthesis and behavior of linear molecular brushes that can undergo unimolecular size and shape changes in response to environmental stimuli in dilute aqueous solution. Chapter 1 provides an introduction to molecular bottlebrushes and stimuli-responsive polymers.

Chapter 2 presents the development of a robust method for the synthesis of well-defined molecular brushes by a “grafting to” approach using copper-catalyzed azide-alkyne cycloaddition “click” reactions. Well-defined, new azide-containing backbone polymers with different lengths and high degrees of azide functionality were …

Geomorphology, Stratigraphy, And Paleohydrology Of The Aeolis Dorsa Region, Mars, With Insights From Modern And Ancient Terrestrial Analogs, Robert Eric Jacobsen Ii

Doctoral Dissertations

Ancient fluvial features on Mars evidence past episodes of hydrologic activity and paleoclimate conditions suitable for liquid water. The Aeolis Dorsa region preserves the most numerous and diverse assemblage of fluvial features yet observed on Mars and many of these features have experienced a history of burial, exhumation, and topographic inversion. This dissertation describes analyses of visual images and topography of Mars and complementary analyses of fluvial analogs on Earth. These analyses provide information about the styles of fluvial activity, magnitudes of paleodischarge, changes in slope, and inferences about Martian paleoclimate conditions. Results indicate that the Aeolis Dorsa deposits encapsulate …

On The Quantification Of Complexity And Diversity From Phenotypes To Ecosystems, Zachary Harrison Marion

Doctoral Dissertations

A cornerstone of ecology and evolution is comparing and explaining the complexity of natural systems, be they genomes, phenotypes, communities, or entire ecosystems. These comparisons and explanations then beget questions about how complexity should be quantified in theory and estimated in practice. Here I embrace diversity partitioning using Hill or effective numbers to move the empirical side of the field regarding the quantification of biological complexity.

First, at the level of phenotypes, I show that traditional multivariate analyses ignore individual complexity and provide relatively abstract representations of variation among individuals. I then suggest using well-known diversity indices from community ecology …

Assessing Tennessee Landowners' Attitudes Toward Wild Hogs And Support For Control Options, Carlotta Anne Caplenor

Masters Theses

Wild hogs (Sus scrofa) are an invasive species with destructive habits, particularly rooting and wallowing, which can directly impact agricultural crops, pasture land, and water quality. Considering wild hogs are widely dispersed across the landscape, it is extremely difficult to control them. Moreover, disagreements can arise among different stakeholders over whether and how their population should be managed. The purpose of this study was to examine Tennessee landowners’ attitudes toward wild hogs, to compare acceptability of control methods, and to evaluate the factors significantly influencing public support for wild hog control regulations. Logistic regression was used to analyze …

Preliminary Investigation For The Development Of Surrogate Debris From Nuclear Detonations In Marine-Urban Environments, Adam G. Seybert

Masters Theses

No nuclear weapon has ever been detonated in a United States city. However, this also means the nuclear forensic community has no actual debris from which to develop analytical methods for source attribution, making the development of surrogate nuclear debris a vital undertaking. Moreover, the development of marine-urban debris presents an unusual challenge because unlike soil and urban structures, which remain compositionally consistent, the elemental composition of harbor and port waters fluctuates considerably due to natural phenomenon and human activity. Additionally, marine vessel composition and cargo can vary dramatically. While early US nuclear tests were carried out in shallow-water coastal …

Tagamajig: Image Recognition Via Crowdsourcing, Gregory Martin Simpson

Masters Theses

The University of Tennessee, Knoxville (UTK) Library possesses thousands of unlabeled gray-scale photographs from the Smoky Mountains circa the 1920s - 1940s. Their current method of identifying and labeling attributes of the photographs is to do so manually. This is problematic both because of the scale of the collection as well as the reliance on an individual's limited knowledge of the area's numerous landmarks.

In the past few years, similar dilemmas have been tackled via an approach known as crowd computing. Some examples include Floating Forests, in which users are asked to identify and mark kelp forests in satellite images, …

Three Body Interactions Of Rare Gas Solids Calculated Within The Einstein Model, Dan D'Andrea

Masters Theses

Three body interactions can become important in solids at higher pressures and densities as the molecules can come into close contact. At low temperatures, accurate studies of three body interactions in solids require averaging the three-body terms over the molecules' zero point motions. An efficient, but approximate, averaging approach is based on a polynomial approximation of the three-body term. The polynomial approximation can be developed as a function of the symmetry coordinates of a triangle displaced from its average geometry and also as a function of the Cartesian zero point displacements from each atom’s average position. The polynomial approximation approach …

Synthesis And Characterization Of Novel Ligand For Use On Rhodium Paddlewheel Complexes, Gavin J. Rustin

Masters Theses

Dirhodium (II) paddlewheel complexes have proven to be useful catalysts in many transformations including C-H insertions, cyclopropanation, and silane insertion reactions. One deficiency of these catalysts is the inability to modulate the enantioselectivity with reactive diazo compounds. One avenue for potential improvement of paddlewheel complexes is coordinating ligands in the axial site to increase enantioselectivity. The axial site has been occupied by various ligands including Nheterocyclic carbenes, nitrogen compounds, and phosphorous compounds. This work examines compounds that can be used as ligands on dirhodium complexes that have a pendant chain containing a dibenzyl phosphite and dibenzyl phosphate, both of which …

Mathematics Education From A Mathematicians Point Of View, Nan Woodson Simpson

Masters Theses

This study has been written to illustrate the development from early mathematical learning (grades 3-8) to secondary education regarding the Fundamental Theorem of Arithmetic and the Fundamental Theorem of Algebra. It investigates the progression of the mathematics presented to the students by the current curriculum adopted by the Rhea County School System and the mathematics academic standards set forth by the State of Tennessee.

Development, Analysis, And Optimization Of A Swirl-Promoting Mean Flow Solution For Solid Rocket Motors, Andrew Steven Fist

Masters Theses

This work demonstrates and analyses a new flow candidate for describing the internal gaseous motion in simulated rocket motors. The fundamental features of this solution include the conservation of key system properties also incorporated in the classic Taylor-Culick (TC) system (i.e. inviscid, axisymmetric, steady and rotational properties), while allowing for the development of a swirling velocity component. The work compares the new solution to the development and formulation of the classic TC system, ultimately identifying that both the new and classic solutions are special cases of the Bragg-Hawthorne equation. Following this development, the text then explores the development of energy-optimized …

Understanding Stakeholder Attitudes And Involvement In Habitat Conservation Plans And The Endangered Species Act, Kyle Andrew Rodgers

Masters Theses

The Endangered Species Act (ESA), established in 1973, was a landmark piece of environmental legislation and remains the standard for endangered species conservation. Implementation of the ESA has often been framed as pitting economic development against species conservation, inciting passions for and against endangered species conservation. The strength of opposing public opinions is highlighted by high-profile controversies such as those around the snail darter, northern spotted owl and the greater sage grouse. In an attempt to reduce conflict, the US Fish and Wildlife Service (USFWS) increasingly seeks to utilize collaborative, stakeholder-based processes that address stakeholder interests, attitudes, and values.

In …

Experimental Study On The Production Of Negative Ion Copper Clusters And Applications, Ran Chu

Masters Theses

At the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratories (ORNL), we investigated the formation, production and potential application of negative-ion copper clusters using mass distributions of negative-ion copper clusters obtained by bombarding various copper samples with Cs ions. The Cu samples – in very large mass-selected clusters Cu (e.g. n=54) – included natural Cu, isotopically enriched copper-63 and copper-65, and electroformed ultra-clean Cu. Mass spectra of negative copper cluster produced by Cs sputter source size up to 50 are shown for the first time.

Three main features were observed for all four copper samples: the intensity …

Correction To Luminosity Measurement For The Pixel Luminosity Telescope At Cms, Krishna Thapa

Masters Theses

The search for and detailed study of new particles and forces with the Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC) of CERN is fundamentally dependent on the precise measurement of the rate at which proton-proton collisions produce any particles, the so-called luminosity. Therefore, a new detector, the Pixel Luminosity Telescope (PLT), dedicated to measure the luminosity at high precision was added to the CMS experiment in 2015. It measures the inclusive charged particle production from each collision of proton bunches in the LHC. Additional charged particles which are observed by the instrument but produced from sources …

Lattice Boltzmann Methods For Wind Energy Analysis, Stephen Lloyd Wood

Doctoral Dissertations

An estimate of the United States wind potential conducted in 2011 found that the energy available at an altitude of 80 meters is approximately triple the wind energy available 50 meters above ground. In 2012, 43% of all new electricity generation installed in the U.S. (13.1 GW) came from wind power. The majority of this power, 79%, comes from large utility scale turbines that are being manufactured at unprecedented sizes. Existing wind plants operate with a capacity factor of only approximately 30%. Measurements have shown that the turbulent wake of a turbine persists for many rotor diameters, inducing increased vibration …

Synthesis And Characterization Of New Multifunctional Initiators For Anionic Polymerization And The Use Of Poly(4-Hydroxystyrene) As A Template For New Polymers, Christopher Michael Hurley

Doctoral Dissertations

This dissertation explores the synthesis and use of multifunctional anionic polymerization initiators for the purpose of opening the gateway to the synthesis of polymer architectures of greater complexity. First the multifunctional oxyanion initiator generated by reacting poly(4-hydroxystyrene) with sodium hydride was used to synthesize a previously unknown polymer containing an aryl halide functional group. The homopolymer solution self-assembly behavior of poly(4-hydroxystyrene) and the newly synthesized poly (4-bromo-phenyloxystyrene) were both investigated. This is followed by the synthesis and characterization of multifunctional alkyne core molecules and random copolymers of polystyrene-co-poly(4-hydroxystyrene) which served as templates for the synthesis of new random copolymers of …

The Effect Of Attractive Polymer-Nanoparticle Interactions On The Local Segmental Dynamics Of Polymer Nanocomposites, Adam Prillaman Holt

Doctoral Dissertations

Considerable progress has been made in understanding the miscibility and morphology of polymer nanocomposites (PNCs). However, to date, there is little understood concerning the modification of segmental mobility at the polymer-nanoparticle interface, which due to prevalence of interfaces in PNCs, will predominately control the viscoelastic and mechanical properties of these materials.

In this dissertation, static and dynamic experimental techniques are combined to identify the specific parameters controlling the modification of segmental dynamics at the polymer-nanoparticle interface in the model system of poly(2-vinyl pyridine)/silica nanocomposites. In general, the experimental results clearly demonstrate that the segmental dynamics at the polymer-nanoparticle interface are …

Achieving High Reliability And Efficiency In Maintaining Large-Scale Storage Systems Through Optimal Resource Provisioning And Data Placement, Lipeng Wan

Doctoral Dissertations

With the explosive increase in the amount of data being generated by various applications, large-scale distributed and parallel storage systems have become common data storage solutions and been widely deployed and utilized in both industry and academia. While these high performance storage systems significantly accelerate the data storage and retrieval, they also bring some critical issues in system maintenance and management. In this dissertation, I propose three methodologies to address three of these critical issues.

First, I develop an optimal resource management and spare provisioning model to minimize the impact brought by component failures and ensure a highly operational experience …

Reducing Power Consumption And Latency In Mobile Devices Using A Push Event Stream Model, Kernel Display Server, And Gui Scheduler, Stephen Gregory Marz

Doctoral Dissertations

The power consumed by mobile devices can be dramatically reduced by improving how mobile operating systems handle events and display management. Currently, mobile operating systems use a pull model that employs a polling loop to constantly ask the operating system if an event exists. This constant querying prevents the CPU from entering a deep sleep, which unnecessarily consumes power.

We’ve improved this process by switching to a push model which we refer to as the event stream model (ESM). This model leverages modern device interrupt controllers which automatically notify an application when events occur, thus removing the need to constantly …