Physical Sciences and Mathematics Commons^™

Noncovalent Interactions Involving Microsolvated Networks Of Trimethylamine N-Oxide, Kristina Andrea Cuellar

Electronic Theses and Dissertations

This thesis research focuses on the effects of the formation of hydrogen-bonded networks with the important osmolyte trimethylamine N-oxide (TMAO). Vibrational spectroscopy, in this case Raman spectroscopy, is used to interpret the effects of noncovalent interactions by solvation with select hydrogen bond donors such as water, methanol, ethanol and ethylene glycol in the form of slight changes in vibrational frequencies. Spectral shifts in the experimental Raman spectra of interacting molecules are compared to the results of electronic structure calculations on explicit hydrogen bonded molecular clusters. The similarities in the Raman spectra of microsolvated TMAO using a variety of hydrogen bond …

Structural Analysis Of Bulky Thiolate-Protected Gold Nanomolecules, David Walton Crasto

Electronic Theses and Dissertations

Routine preparation of thiolate-protected gold nanomolecules involves, most commonly, straight-chain organic thiolate ligands for which the sulfhydryl `head' group is bound to a primary carbon atom. The primary connectivity of these sulfur atoms, such as for the case of n-hexanethiol and phenylethanethiol, allows for even packing, and the relative ease of formation of gold-thiolate oligomers about the surface monolayer in the formation of Au-SR bonds. Moreover, these straight-chain ligands routinely support the formation of an icosahedron-based series of core-size gold nanomolecules. Within this series of nanoparticles, Au25(SR)18 and Au38(SR)24 are among the most commonly studied core-sizes; Au25(SR)18 is situated upon …

Impact Of Thread Scheduling On Modern Gpus, Orevaoghene Addoh

Electronic Theses and Dissertations

The Graphics Processing Unit (GPU) has become a more important component in high-performance computing systems as it accelerates data and compute intensive applications significantly with less cost and power. The GPU achieves high performance by executing massive number of threads in parallel in a SPMD (Single Program Multiple Data) fashion. Threads are grouped into workgroups by programmer and workgroups are then assigned to each compute core on the GPU by hardware. Once assigned, a workgroup is further subgrouped into wavefronts of the fixed number of threads by hardware when executed in a SIMD (Single Instruction Multiple Data) fashion. In this …

The Characterization Of Graphs With Small Bicycle Spectrum, Bette Catherine Putnam

Electronic Theses and Dissertations

Matroids designs are defined to be matroids in which the hyperplanes all have the same size. The dual of a matroid design is a matroid with all circuits of the same size, called a dual matroid design. The connected bicircular dual matroid designs have been characterized previously. In addition, these results have been extended to connected bicircular matroids with circuits of two sizes in the case that the associated graph is a subdivision of a 3-connected graph. In this dissertation, we will use a graph theoretic approach to discuss the characterizations of bicircular matroids with circuits of two and three …

Characterizing Non-Covalent Interactions And Peptide Bond Formation With Electronic Structure Theory, Eric Van Dornshuld

Electronic Theses and Dissertations

The development and application of quantum mechanics has exploded in the past century. The rules of classical mechanics were found to be completely insufficient when applied to a universe that operates on the scale of atomic and subatomic particles. The advancement of quantum theory and computer technology has driven quantum mechanical analyses toward routine in the chemist's laboratory. Chapter 1 briefly outlines some comfailures of classical mechanics from a historical standpoint. Chapter 2 provides a mathematical overview to quantum chemistry including a brief presentation of the analytic solutions to the schrã¶dinger equation for some model systems. Chapter 3 and chapter …

An Efficient Storage And Retrieval Mechanism For Large Unstructured Grids, Oyindamola Akande

Electronic Theses and Dissertations

The size of spatial scientific datasets is steadily increasing due to improvements in instruments and availability of computational resources. Scientific datasets today are often far too large to fit into a single machine's memory or even a single disk. However, much of the research on efficient storage and access to spatial datasets has focused on large multidimensional arrays. In contrast, unstructured grids consisting of collections of implices (e.g. triangles or tetrahedra) present special challenges that have received less attention. Data values found at the vertices of the simplices may be dispersed throughout a datafile, producing especially poor disk locality. Partitioning …

Rank-Based Two Sample Tests Under A General Alternative, Jamye Curry

Electronic Theses and Dissertations

The problem of testing whether two samples come from the same or different population is a classical one in statistics. In this dissertation, I first study rank based formulation of univariate two-sample distribution-free tests. One form of the test statistic is the average of between-group distances of ranks. The other form of the test statistic is the difference between the average of between-group distances of ranks and the average of within-group distances of ranks. Although they are different in formulation, they are closely related to the two-sample Cramer-von Mises criterion. The first one is a linear transformation of Cramer-von Mises …

The Impact Of Ph On The Structure And Function Of Neural Cadherin, Jared Michael Jungles

Electronic Theses and Dissertations

Neural (N-) cadherin is a transmembrane protein within adherens junctions that mediates cell-cell adhesion. It has 5 modular extracellular domains (EC1-EC5) that bind 3 calcium ions between each of the modules. Calcium binding is required for dimerization. N-cadherin is involved in diverse processes including tissue morphogenesis, excitatory synapse formation and dynamics, and metastasis of cancer. During neurotransmission and tumorigenesis, fluctuations in extracellular pH occur, causing tissue acidosis with associated physiological consequences. Studies reported here aim to determine the effect of pH on the dimerization properties of EC1-EC2 N-cadherin in vitro. Since N-cadherin is an anionic protein, we hypothesized that acidification …

Fluctuations In Resistivity In The Tuscaloosa Marine Shale, Southwest Mississippi And Southeast Louisiana, Thomas Hetherington Story

Electronic Theses and Dissertations

The Tuscaloosa Marine Shale in southwest Mississippi and Southeast Louisiana's Florida Parishes has become an unconventional target for the exploration and production of oil. Spurred by early estimates of over 7 billion barrels of oil in place, the target region for this production is the basal portion of the shale where a continuous increase in resistivity greater than 5 Ohmm can be observed. This increase was originally attributed solely to the generation of hydrocarbons from the organic matter contained within the shale, with the presence of the oil and gas impeding the flow of electrons through what would normally be …

(Visible) Tilings Of Squares And Hypercubes, John Randall Burt

Electronic Theses and Dissertations

More than eighty years ago, Erdos considered sums of the side lengths of squares packed into a unit square.Here we consider various classes of tilings , this is, packings where there is no empty space inside the unit square. Several types of questions will be explored here. Various construction techniques are introduced, especially methods of generating tilings from tilings with fewer tiles. For some small values of n, I determine all tilings of the unit square with n tiles. I have found a best possible upper bound for a visible tiling, that is a tiling which every tile shares a …

Location, Location: Factors Influencing Greenhouse Gas Fluxes From The Mississippi Delta Agricultural Region, Michael P. Keating

Electronic Theses and Dissertations

Methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2) fluxes from agricultural landscapes may contribute significantly to regional greenhouse gas budgets due to stimulation of soil microbial activity through fertilizer application. Few studies have made measurements of CH4, N2O, and CO2 from the dominant landscape features of the agricultural landscape: farmland, riparian zone, and wetland habitat. This study assessed gas emission variability from the Mississippi Delta agricultural landscape and explored the effects of hydrology and hydrophytic vegetation on gas emissions.

Gas collection chambers were utilized to make gas measurements from soybean and corn farmland, vegetated riparian buffer, and two vegetated …

Group Velocity Of Acoustic Waves In Plates Of Electronic Materials, Saminda Adikaram

Electronic Theses and Dissertations

In this study the propagation and dispersion characteristics of plate acoustic waves (PAW) in electronic materials are investigated experimentally. Plate acoustic waves are elastic waves that travel along a plate with thickness comparable to the wavelength of the waves. Lamb waves, a type of plate acoustic wave, have particle motion in the direction of propagation and normal to the plate. Unlike an infinite medium, plates support two sets of Lamb wave modes (symmetric and anti-symmetric) with unique velocities which depend on the relationship between the wavelength and the thickness of the plate. Out of this, two zero order modes (so …

The Behavior Of A Macroscopic Granular Material In Vortex Flow, Asami Nishikawa

Electronic Theses and Dissertations

A granular material is defined as a collection of discrete particles such as powder and grain. Granular materials display a large number of complex behaviors. In this project, the behavior of macroscopic granular materials under tornado-like vortex airflow, with varying airflow velocity, was observed and studied. The experimental system was composed of a 9.20-cm inner diameter acrylic pipe with a metal mesh bottom holding the particles, a PVC duct, and an airflow source controlled by a variable auto-transformer, and a power-meter. A fixed fan blade was attached to the duct's inner wall to create a tornado-like vortex airflow from straight …

Spectroscopic Analyses Of Factors Affecting Formation And Stability Of I-Motif Dna, Samantha Michelle Reilly

Electronic Theses and Dissertations

The four-stranded i-motif (iM) conformation of DNA has importance to a variety of biochemical systems that include nanomaterials and oncogene regulation. Fundamental studies to understand iM formation and its structure in solution still remain to be done. In this dissertation, we will discuss the use of the fluorescent base analog tC° to determine the structural state of DNA in solution. We will also demonstrate the use of tC° to determine both the hydrodynamic properties and the folding mechanism of an iM. We also determined the loop length dependence on iM formation and stability. Our hydrodynamic studies show that the iM …

Random Forests Based Rule Learning And Feature Elimination, Sheng Liu

Electronic Theses and Dissertations

Much research combines data from multiple sources in an effort to understand the underlying problems. It is important to find and interpret the most important information from these sources. Thus it will be beneficial to have an effective algorithm that can simultaneously extract decision rules and select critical features for good interpretation while preserving the prediction performance. We propose an efficient approach, combining rule extraction and feature elimination, based on 1-norm regularized random forests. This approach simultaneously extracts a small number of rules generated by random forests and selects important features. To evaluate this approach, we have applied it to …

Higgs Effects In Neutrino Physics And Heavy Quark Systems, Ahmed Rashed

Electronic Theses and Dissertations

This work presents a study of the effects of multi-Higgs doublets on the properties of neutrino sector and heavy quark systems. The phenomenological implications of multi-Higgs models, which contain multi-Higgs doublets, in the neutrino and quark sector are discussed in this dissertation. The two-Higgs-doublet model (2HDM), in which two Higgs doublets are introduced, is the simplest extension to the scalar sector of the standard model (SM). A new boson state was recently seen in the CMS (Compact Muon Solenoid) and ATLAS (A Toroidal LHC Apparatus) experiments at the LHC (Large Hadron Collider). We investigate the multi-Higgs models contributions in understanding …

Moments Of Products Of L-Functions, Caroline Laroche Turnage-Butterbaugh

Electronic Theses and Dissertations

We first consider questions on the distribution of the primes. Using the recent advancement towards the Prime k-tuple Conjecture by Maynard and Tao, we show how to produce infinitely many strings of consecutive primes satisfying specified congruence conditions. We answer an old question of Erdös and Turán by producing strings of consecutive primes whose successive gaps form an increasing (respectively decreasing) sequence. We also show that such strings exist whose successive gaps follow a certain divisibility pattern. Finally, for any coprime integers a and D ≥ 1, we refine a theorem of D. Shiu and find strings of consecutive primes …

Atmospheric Mercury Species In Northern Mississippi: Concentrations, Sources, Temporal Patterns, And Soil-Air Exchange, Yi Jiang

Electronic Theses and Dissertations

Mercury is a highly toxic element that is found both naturally and as an introduced contaminant in the environment. The majority of Mercury released to the environment is into the atmosphere, where because of its high volatility and long residence time is dispersed globally. In order to better understand the factors controlling the distribution and temporal patterns of atmospheric Mercury species, as well as the sources of airborne Mercury in the mid-south region, concentrations of gaseous elemental mercury (gem), gaseous oxidized mercury (gom), and particulate-bound mercury (pbm), along with meteorological parameters and other ancillary data, were collected for more than …

Probing New Physics Through Third Generation Leptons, Preet Sharma

Electronic Theses and Dissertations

This dissertation is a study of beyond standard model physics or new physics. The third generation charged lepton -the τ -is an excellent probe of new physics (NP) because of it being the heaviest lepton. As the heaviest lepton, it has the largest coupling ( among the leptons) to the Higgs boson in the Standard Model (SM). New physics contributions to the tau-neutrino nucleon scattering were considered. Charged Higgs and W' effects to the deep inelastic scattering ντ ( [special character omitted]τ) + N → τ− (τ+) + X in the neutrino-nucleon interactions has been studied. The neutrino detection process …

Segmentation And Spatial Depth Ridge Detection Of Unorganized Point Cloud Data, James Clark Church

Electronic Theses and Dissertations

Visual 3D data are of interest to a number of fields: medical professionals, game designers, graphic designers, and (in the interest of this paper) ichthyologists interested in the taxonomy of fish. Since the release of the Kinect for the Microsoft XBox, game designers have been interested in using the 3D data returned by the device to understand human movement and translate that movement into an interface with which to interact with game systems. In the medical field, researchers must use computer vision tools to navigate through the data found in CT scans and MRI scans. These tools must segment images …

Exploration Into The Performance Of Asymmetric D-Ary Heap-Based Algorithms For The Hsa Architecture, Stephen Adams

Electronic Theses and Dissertations

No abstract provided.

Raptorqp2p: Maximize The Performance Of P2p File Distribution With Raptorq Coding, Zeyang Su

Electronic Theses and Dissertations

BitTorrent is the most popular Peer-to-Peer (P2P) file sharing system widely used for distributing large files over the Internet. It has attracted extensive attentions from both network operators and researchers for investigating its deployment and performance. For example, recent studies have shown that under steady state, its rarest first scheme with the tit-for-tat mechanism can work very effectively and make BitTorrent near optimal for the generic file downloading process. However, in practice, the highly dynamic network environment, especially the notorious user churns prevalently existing in most peer-to-peer systems, can severely degrade the downloading performance. In this thesis, we first study …

Synthesis, Characterization And Electrochemical Properties Of Gold Nanomolecules, Vijay Bhaskar Reddy Jupally

Electronic Theses and Dissertations

Chapter 1 gives a brief introduction to the field of gold nanomolecules. Various synthetic protocols and analytical techniques used through out this dissertation are discussed in detail. Size dependent properties of the gold nanomolecules are described. The structure of gold nanomolecules is explained based on the crystal structure of Au25(SCH2CH2Ph)18. The theoretical basis for the stability of the gold nanomolecules is explained using the super atom complex model and geometric parameters. Chapter 2 includes ligand exchange experiments on gold nanomolecules. Ligand exchange experiments are used to modify the monolayer of nanomolecules after synthesis. Ligand exchange reactions are monitored by mass …

Elemental Fingerprinting Using Inductively Coupled Plasma Mass Spectrometry And Chemometrics: Application To Environmental Science And Provenance Studies, Lorlyn Paquibot Reidy

Electronic Theses and Dissertations

No abstract provided.

Emplacement Of Pleistocene Basalt Flows Near Mccoy, Colorado, Andrea Bowen

Electronic Theses and Dissertations

No abstract provided.

Cosmological And Astrophysical Tests Of Modified Gravity, Caixia Gao

Electronic Theses and Dissertations

Three alternative theories to general relativity will be studied. The aim is to test these theories by applying them to astronomical objects or the cosmological background. The first one is unimodular relativity. The cosmological perturbation theory of this model is studied and the predictions on temperature fluctuations of the cmb are found. The second one is drgt massive gravity. In this theory a charged black hole solution is found and compared to those in gr, folloby constraints on the parameter space. The third one is a general massive gravity theory which shares the same background equation with the massless case …

Ramsey Theory Using Matroid Minors, Dixie Smith Horne

Electronic Theses and Dissertations

This thesis considers a Ramsey Theory question for graphs and regular matroids. Specifically, how many elements N are required in a 3-connected graphic or regular matroid to force the existence of certain specified minors in that matroid? This question cannot be answered for an arbitrary collection of specified minors. However, there are results from the literature for which the number N exists for certain collections of minors. We first encode totally unimodular matrix representations of certain matroids. We use the computer program MACEK to investigate this question for certain classes of specified minors.