Physical Sciences and Mathematics Commons^™

A Method For Achieving Analytic Formulas For Three Body Integrals Consisting Of Powers And Exponentials In All Three Interparticle Hyllerass Coordinates, Chris M. Keating

Dissertations and Theses

After an introduction to the variational principle of three body systems via the Helium atom, we present general analytical formulas for the radial parts of integrals that occur when three body systems are described using wave functions that consist of powers and exponentials in all three interparticle Hylleraas coordinates [Hylleraas1929]. This work is an extension of integrals given by Harris, Frolov and Smith, Jr. [Harris2004]. Specifically included are radial integrals encountered in calculations involving the dipole moment matrix element in Hylleraas coordinates that contain a function f(kr₁) (such as a spherical Bessel function) in addition to …

Evolutionary Dynamics Of Speciation And Extinction, Dawn Michelle King

Dissertations

Presented here is an interdisciplinary study that draws connections between the fields of physics, mathematics, and evolutionary biology. Importantly, as we move through the Anthropocene Epoch, where human-driven climate change threatens biodiversity, understanding how an evolving population responds to extinction stress could be key to saving endangered ecosystems. With a neutral, agent-based model that incorporates the main principles of Darwinian evolution, such as heritability, variability, and competition, the dynamics of speciation and extinction is investigated. The simulated organisms evolve according to the reaction-diffusion rules of the 2D directed percolation universality class. Offspring are generated according to one of three reproduction …

Analysis Of Capillary Flow In Interior Corners : Perturbed Power Law Similarity Solutions, Joshua Thomas Mccraney

Dissertations and Theses

The design of fluid management systems requires accurate models for fluid transport. In the low gravity environment of space, gravity no longer dominates fluid displacement; instead capillary forces often govern flow. This thesis considers the redistribution of fluid along an interior corner. Following a rapid reduction of gravity, fluid advances along the corner measured by the column length z = L(t), which is governed by a nonlinear partial differential equation with dynamical boundary conditions. Three flow types are examined: capillary rise, spreading drop, and tapered corner. The spreading drop regime is shown to exhibit column length growth L ~ …

Computation Of A Virtual Tide Corrector To Support Vertical Adjustment Of Autonomous Underwater Vehicle Multibeam Sonar Data, Lawrence H. Haselmaier

University of New Orleans Theses and Dissertations

One challenge for Autonomous Underwater Vehicle (AUV) multibeam surveying is the limited ability to assess internal vertical agreement rapidly and reliably. Applying an external ellipsoid reference to AUV multibeam data would allow for field comparisons. A method is established to merge ellipsoid height (EH) data collected by a surface vessel in close proximity to the AUV. The method is demonstrated over multiple collection missions in two separate areas. Virtual tide corrector values are derived using EH data collected by a boat and a measured ellipsoid to chart datum separation distance. Those values are compared to measurements by a traditional tide …

Postural Responses To Perturbations Of The Vestibular System During Walking In Healthy Young And Older Adults, Jung Hung Chien

Theses & Dissertations

It has been shown that approximate one-third of US adults aged 40 years and older (69 million US citizens) have some type of vestibular problems. These declining abilities of the vestibular system affect quality of life. Difficulties in performing daily activities (dressing, bathing, getting in and out of the bed and etc.) have been highly correlated to loss of balance due to vestibular disorders. The exact number of people affected by vestibular disorders is still difficult to quantify. This might be because symptoms are difficult to describe and differences exist in the qualifying criteria within and across studies. Thus, it …

Parameterized Spectral Bathymetric Roughness Using The Nonequispaced Fast Fourier Transform, David H. Fabre

University of New Orleans Theses and Dissertations

The ocean and acoustic modeling community has specifically asked for roughness from bathymetry. An effort has been undertaken to provide what can be thought of as the high frequency content of bathymetry. By contrast, the low frequency content of bathymetry is the set of contours. The two-dimensional amplitude spectrum calculated with the nonequispaced fast Fourier transform (Kunis, 2006) is exploited as the statistic to provide several parameters of roughness following the method of Fox (1996). When an area is uniformly rough, it is termed isotropically rough. When an area exhibits lineation effects (like in a trough or a ridge line …

Developing And Testing An Anguilliform Robot Swimming With Theoretically High Hydrodynamic Efficiency, John B. Potts Iii

University of New Orleans Theses and Dissertations

An anguilliform swimming robot replicating an idealized motion is a complex marine vehicle necessitating both a theoretical and experimental analysis to completely understand its propulsion characteristics. The ideal anguilliform motion within is theorized to produce ``wakeless'' swimming (Vorus, 2011), a reactive swimming technique that produces thrust by accelerations of the added mass in the vicinity of the body. The net circulation for the unsteady motion is theorized to be eliminated.

The robot was designed to replicate the desired, theoretical motion by applying control theory methods. Independent joint control was used due to hardware limitations. The fluid velocity vectors in the …

Momentum Of Particles From Time-Of-Flight Measurements, Joseph Best

Senior Theses

In order to find the momentum of particles from time of flight measurements, I used a program called Geant4 to simulate experiments. I made a simple two detector setup, and I recreated a real world experiment. I spent a lot of time learning to code in C++ so I could use Geant4 correctly. I simulated these experiments shooting electrons, muons, and pions through the geometry and measured the time at two points in their flight. Subtracting the second time from the first gave me the time of flight distribution for each particle. I used ROOT to draw histograms of the …

Molecules And Metals In The Distant Universe: Sub-Mm And Optical Spectroscopy Of Quasar Absorbers, Sean Stephen Morrison

Theses and Dissertations

In order to gain a complete understanding of galaxy formation and evolution, knowledge of the atomic and molecular gas in the interstellar medium (ISM) is required. Absorption-line spectroscopy of quasars offers a powerful and luminosity independent probe of gas in distant galaxies. The Damped Lyman- systems (DLAs; 20.3 . log NHI ), are the highest neutral hydrogen column density quasar absorbers and contain a substantial fraction of the neutral gas available for star formation in the high-redshift Universe. This thesis presents a study of the metal content in some DLAs, based on optical spectroscopy, and a search for molecules based …

Optical Second Harmonic Generation In The Batio3 Phase On Magnetically Aligned Multiferroic Nanofibers, Katia Gasperi

Theses and Dissertations

Multiferroic materials enable the exploration of electrical control of magnetic properties and vice versa. Their increasing interest is especially due to their potential applications in the industry of information storage. Thanks to recent progress in nanotechnology, they have also been found to have many other applications such as transducers and sensors, and they already occupy a unique place in the biomedical field. The objective of this project is to study multiferroic nanofibers made of cobalt ferrite CoFe2O4 (CFO) and barium titanate BaTiO3 (BTO) with a specific focus in the characterization of the ferroelectric phase. We researched the state of knowledge …

Methodology For Generating Simplified Cross Section Data Sets For Neutron Transport Calculations, Thomas Jay Harrison

Doctoral Dissertations

Neutron shielding problems involve radiation transport calculations over a wide range of energies. Fission neutrons have initial energy on the order of MeV, fusion neutrons have initial energy on the order of 10s of MeV, and space-origin neutrons have initial energy on the order of 100s of MeV or higher. Shielding calculations must track the neutrons from their initial energies until they are no longer of interest; for deep-penetration neutrons, this final energy can be on the order of eV before the neutron is no longer tracked. Thus, for deep-penetration space radiation shielding problems, the calculation may require tracking the …

Terahertz Radiation From High-Temperature Superconducting Bscco Mesas Of Various Geometries, Daniel P. Cerkoney

HIM 1990-2015

The purpose of this thesis is to examine the radiation from high-temperature superconducting mesas of Bi2Sr2CaCu2O8+ (BSCCO). This is motivated by the need for coherent sources of continuous wave terahertz (THz) emission capable of radiating practically in the THz frequency band. As BSCCO has been shown to be tunable from 0.5–2.4 THz (i.e., through the entire socalled terahertz gap centered about 1 THz), and has a higher peak operating temperature near 1 THz than most alternative sources, it is a good candidate for imaging and spectroscopy device applications [1]. When a static DC voltage is applied to a BSCCO mesa, …

Spontaneously Generated Inhomogeneous Phases Via Holography, Kübra Yeter Aydeniz

Doctoral Dissertations

We discuss a holographic model consisting of a U(1) gauge field and a scalar field coupled to a charged AdS (anti-de Sitter) black hole under a spatially homogeneous chemical potential. By turning on a higher-derivative interaction term between the U(1) gauge field and the scalar field, a spatially dependent profile of the scalar field is generated spontaneously. We calculate the critical temperature at which the transition to the inhomogeneous phase occurs for various values of the parameters of the system. We solve the equations of motion below the critical temperature, and show that the dual gauge theory on the boundary …

Effective Field Theory Approach To Collective Motion In Atomic Nuclei, Eduardo Antonio Coello Perez

Doctoral Dissertations

Collective motion in heavy nuclei has been studied within collective and algebraic models, and within density functional theory. While they reproduce the energy spectra of these systems, their predictions for some electromagnetic transitions and moments do not lie within experimental uncertainty; in other words, these predictions are inconsistent with experimental data. An effective field theory approach to collective motion in heavy nuclei solves this long standing problem. Based on symmetry arguments only, the effective field theories, constructed as expansions in powers of a small parameter, consistently describe the energy spectra of nuclei exhibiting collective motion at low order in the …

Solar Modulation Of The Cosmic Ray Intensity And The Measurement Of The Cerenkov Reemission In Nova’S Liquid Scintillator, Philip James Mason

Doctoral Dissertations

The NOνA (NuMI Off-axis electron neutrino Appearance) experiment is a long baseline neutrino oscillation experiment at Fermi National Accelerator Laboratory. Its purpose is to observe the oscillation of ν_μ (muon neutrino) to ν_e (electron neutrino) and to investigate the neutrino mass hierarchy and CP violation in the neutrino sector. Two detectors have been built for this purpose, a Near Detector 300 feet underground at Fermilab, and a Far Detector, on the surface at Ash River, Minnesota.

The completion of NOνA’s Far Detector in October 2014 enabled not only the recent measurement of neutrino oscillations, but an array of …

The Effect Of Composition And Architecture On Polymer Behavior In Homopolymer Blends And Inter-Filament Bonding In 3d Printed Models, Edward Roy Duranty

Doctoral Dissertations

This dissertation presents work that increases our understanding of the effects of composition and architecture on copolymer structure and dynamics and how they affect material diffusion between filaments in a 3D printed model. Copolymers are polymer chains made up of at least two different monomers. The ordering and arrangement of the two monomer species within a copolymer can have drastic effects on the behavior and properties of the copolymer.

The first chapter of this dissertation examines how the copolymer composition affects the structure and dynamics of the chain in a homopolymer blend. This study used a modified Monte Carlo BFM …

High Pressure X-~Ray Absorption Spectroscopy Studies Of Heavy-~Fermion Cerium And Uranium Compounds, Daniel Antonio

UNLV Theses, Dissertations, Professional Papers, and Capstones

Investigations into f- electron heavy-fermion materials have revealed a wide range of novel behavior. Hydrostatic pressure is a valuable "clean" non-thermal parameter that can be used to systematically study them by tuning their ground state properties. The rare earth compound CeCu2Ge2 shows an unusual two-domed region of unconventional superconductivity under pressure, similar to its isostructural counterpart CeCu2Si2. While the lower pressure dome at about 10 GPa is caused by a magnetic quantum critical point (QCP), the higher one at about 16 GPa is less well understood. Previous structural measurements have indicated that it may be caused by critical valence fluctuations, …

Theoretical Investigation Of Interactions And Relaxation In Biological Macromolecules, Koki Yokoi

Theses and Dissertations

One of the major challenges posed to our quantitative understanding of structure, dynamics, and function of biological macromolecules has been the high level of complexity of biological structures. In the present work, we studied interactions between G protein-coupled receptors (GPCRs), and also introduced a theoretical model of relaxation in complex systems, in order to help understand interactions and relaxation in biological macromolecules.

GPCRs are the largest and most diverse family of membrane receptors that play key roles in mediating signal transduction between outside and inside of a cell. Oligomerization of GPCRs and its possible role in function and signaling currently …

Scalable Synthesis And Energy Applications Of Defect Engineered Nano Materials, Mehmet Karakaya

All Dissertations

Nanomaterials and nanotechnologies have attracted a great deal of attention in a few decades due to their novel physical properties such as, high aspect ratio, surface morphology, impurities, etc. which lead to unique chemical, optical and electronic properties. The awareness of importance of nanomaterials has motivated researchers to develop nanomaterial growth techniques to further control nanostructures properties such as, size, surface morphology, etc. that may alter their fundamental behavior. Carbon nanotubes (CNTs) are one of the most promising materials with their rigidity, strength, elasticity and electric conductivity for future applications. Despite their excellent properties explored by the abundant research works, …

Dark Matter Halo Concentration And The Evolution Of Spiral Structure In N-Body, Barred Spiral Galaxies, Jazmin Esmeralda Berlanga Medina

Graduate Theses and Dissertations

Motivated by the evidence of relationships between pitch angle (the tightness of spiral arm structure in the disk), P, and various indicators of central mass concentration, as well as the theoretical relationship between halo mass concentration and the density of visible matter in the central part of the galaxy, we look at a possible relationship between P and cvir (the virial concentration of the dark matter halo) in N-body simulations of barred, spiral galaxies. We also look at the evolution of pitch angle over time in higher temporal resolution than any data currently available in the literature. We find that …

Time-Resolved, Near Atomic Resolution Structural Studies At The Free Electron Laser, Jason James Tenboer

Theses and Dissertations

Time-resolved serial femtosecond crystallography (TR-SFX) employs X-ray free electron lasers (XFELs) to provide X-ray pulses of femtosecond (fs) duration with 1012 photons per pulse. These XFELs are more than a billion times more brilliant than 3rd generation synchrotron X-ray sources. For structure determination, protein crystals on the micrometer length scale (microcrystals) are injected into the X-ray beam and the resulting diffraction patterns are recorded on fast-readout pixel detectors. Although these intense pulses deposit enough energy to ultimately destroy the protein, the processes that lead to diffraction occur before the crystal is destroyed. This so-called diffraction-before-destruction principle overcomes radiation damage, which …

Deposition And Characterization Of Carbon Nanotubes (Cnts) Based Films For Sensing Applications, Amila C. Dissanayake

Dissertations

The advent of carbon nanotubes (CNTs) has opened up lot of novel applications because of their unique electrical and mechanical properties. CNTs are well known material for its exceptional electrical, mechanical, optical, thermal and chemical properties. A single-wall nanotube (SWNT) can be either semiconducting, metallic or semi-metallic, based on its chirality and diameter. SWNTs can be used in transistor device as active channels due to high electron mobility (~10000 cm2/(V s), electrical interconnects, nano-scale circuits, field-emission displays, light-emitting devices and thermal heat sinks due to low resistivity, high current density (~109A cm-2) and high thermal conductivity (~3500 W m-1). Further, …

Experimental Investigation Of Interaction Between Proteins And Carbon Nanomaterials, Bishwambhar Sengupta

All Theses

The global market for nanomaterials based products is forecasted to reach $1 trillion per annum per annum for 2015. Engineered nanomaterials (ENMs) exhibit unique physicochemical properties with potential to impact diverse aspects of society through applications in electronics, renewable energy, and medicine. While the research and proposed applications of ENMs continue to grow rapidly, the health and safety of ENMs still remains a major concern to the public as well as to policy makers and funding agencies. It is now widely accepted that focused efforts are needed for identifying the list of physicochemical descriptors of ENM before they can be …

Predictive Modeling Of Terrestrial Radiation Exposure From Geologic Materials, Daniel A. Haber

UNLV Theses, Dissertations, Professional Papers, and Capstones

Aerial gamma ray surveys are an important tool for national security, scientific, and industrial interests in determining locations of both anthropogenic and natural sources of radioactivity. There is a relationship between radioactivity and geology and in the past this relationship has been used to predict geology from an aerial survey. The purpose of this project

is to develop a method to predict the radiologic exposure rate of the geologic materials in an area by creating a model using geologic data, images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), geochemical data, and pre-existing low spatial resolution aerial surveys …

Optimization Of The Development Process For Air Sampling Filter Standards, Rajah Marie Mena

UNLV Theses, Dissertations, Professional Papers, and Capstones

Air monitoring is an important analysis technique in health physics. However, creating standards which can be used to calibrate detectors used in the analysis of the filters deployed for air monitoring can be challenging. The activity of a standard should be well understood, this includes understanding how the location within the filter affects the final surface emission rate. The purpose of this research is to determine the parameters which most affect uncertainty in an air filter standard and optimize these parameters such that calibrations made with them most accurately reflect the true activity contained inside. A deposition pattern was chosen …

Construction Of A 408 Nm Laser System For Use In Ion Interferometry, Lawrence Archibald

Theses and Dissertations

This work reports on the construction of a 408 nm laser system designed to drive stimulated Raman transitions between the F = 4 and F = 5 2 S 1/2 states of 87 Sr + using the 2 P 3/2 state as the intermediate state. This laser system will be used as part of a 87 Sr + ion interferometer. This work also includes a discussion of relevant theory describing the interaction of the ions and laser, along with a calculation of the transition rates as a function of laser power and detuning.

Hydrogen Bond-Mediated Structural Order In Hydroxylated Bis-Mpa Dendritic Polymers: Experimental And Molecular Dynamics Simulation Study, Maliha N. Syed

Dissertations

Dendritic architectures are echoed throughout nature. While the significance of these pervasive patterns is not entirely clear, connections between their structures and physical properties are fascinating to contemplate. Particular interest has been paid to a family of synthetically manufactured and commercially available dendritic polymers based on 2,2-bis(hydroxymethyl) propionic acid (bis-MPA) as a monomer. Composed of two hydroxyls and a carboxyl group, bis-MPA based structures hydrogen bond (H-bond) profusely. Given the high concentration and unique spatial orientation of end-groups, as well as the multitude of carbonyl, ester, and ether interior H-bond acceptors, a set of distinct H-bond organizations may be observed …

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 …

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 …

Voxel-Level Absorbed Dose Calculations With A Deterministic Grid-Based Boltzmann Solver For Nuclear Medicine And The Clinical Value Of Voxel-Level Calculations, Justin Mikell

Dissertations & Theses (Open Access)

Voxel-level absorbed dose (VLAD) is rarely calculated for nuclear medicine (NM) procedures involving unsealed sources or 90Y microspheres (YM). The current standard of practice for absorbed dose calculations in NM utilizes MIRD S-values, which 1) assume a uniform distribution in organs, 2) do not use patient specific geometry, and 3) lack a tumor model. VLADs overcome these limitations. One reason VLADs are not routinely performed is the difficulty in obtaining accurate absorbed doses in a clinically acceptable time. The deterministic grid-based Boltzmann solver (GBBS) was recently applied to radiation oncology where it was reported as fast and accurate for both …