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Self-Consistent Effects Of The Recirculating Plasmapshere On The Development Of Storm Time Dynamics In The Inner Magnetosphere., Christian-Andrew Bagby-Wright

Physics Dissertations - Archive

The near Earth space environment is a highly coupled system. The Interplanetary Magnetic Field (IMF) interacts with the magnetosphere in myriad ways depend on the orientation of the IMF to the magnetosphere. The magnetic fields of the magnetosphere and the IMF trap plasma and carry the plasma with it as both magnetic fields evolve over time. This plasma can in turn interact with other plasmas, carried by other field lines, affecting the dynamics of the other population and the magnetic field lines of both populations. The nature, frequency, and importance of interactions between different plasma, or magnetic fields, varies greatly …

The Quantum Computational Utility Of Symmetry-Protected Topological Order: From Near-Term Advantages To Universal Measurement-Based Quantum Computing, Austin Kevin Daniel

Physics & Astronomy ETDs

Quantum computers offer new avenues to approach difficult problems by taking advantage of the strange and often nonintuitive phenomena present in quantum physics. Though many quantum algorithms are believed or known to outperform the best known classical algorithms, the fundamental mechanism granting them their power remains elusive. In measurement-based quantum computation (MBQC), two key resources have been show to enable universal and provably nonclassical quantum computations, respectively. These are symmetry-protected topological order (SPTO), a notion describing a class of quantum magnets with hidden long-range correlations in their entanglement structure, and quantum contextuality, the fact that a quantum measurement outcome inherently …

Assessment Of Bridge Pier Response To Fire, Vehicle Impact, And Air Blast, Chen Fang, Qusai Alomari, Daniel G. Linzell

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Highway bridges exposed to intentional or unintentional fire followed by combined vehicle impact and air blast are at risk of significant damage and, possibly, collapse. Limited studies examining the complex effects of these extreme demands on bridge support elements and parametrizing their response and damage are found in the open literature. Research that is presented is part of an ongoing numerical investigation examining round, multi-column, reinforced concrete (RC), bridge pier behavior subject to multi-hazard scenarios involving fire, vehicle impact, and air blast. Detailed nonlinear finite element analysis models of single columns and multi-column piers supported by a pile foundation system …

Quantum Phases Of Lattice Dipolar Bosons Coupled To A High-Finesse Cavity, Yaghmorassene Hebib, Chao Zhang, Jin Yang, Barbara Capogrosso-Sansone

Physics

Two types of long-range interactions, dipolar interaction and cavity-mediated interaction, lead to exotic quantum phases. Both interactions were realized and observed in optical lattice setups. Here, we study quantum phases of dipolar bosons trapped in optical lattices and coupled to a high-finesse cavity where both dipolar interaction and cavity-mediated interaction coexist. We perform quantum Monte Carlo simulations and find that the checkerboard solid is enhanced and the checkerboard supersolid phase can exist in a wide range of densities (e.g., 0.27≲n≲0.73). Our unbiased numerical results suggest that both solid and supersolid phases can be achieved experimentally with magnetic atoms coupled to …

Photon Correlation Measurements And Second Harmonic Generation Using Pulsed Lasers, Apoorva Bisht

Physics Undergraduate Honors Theses

Correlation measurements are one of the fundamental ways to understand the photon statistics/distribution for a source of light. It is also an important method to confirm single photon sources by confirming the anitbunching nature. This project developed a correlation measurement system, utilized field programmable gate arrays, and non-linear crystals for processes like second harmonic generation and down conversion.

First-Principal Investigations Of The Electronic, Magnetic, And Thermoelectric Properties Of Crtirhal Quaternary Heusler Alloy, Shuruq Alsayegh

Graduate Theses and Dissertations

Density functional theory calculations are performed to investigate the electrical electronic, magnetic, and thermoelectric properties of CrTiRhAl quaternary Heusler alloy (QHA). The type-I atomic configuration is found to be the most stable structure of this alloy. The CrTiRhAl QHA exhibits a half-metallic ferromagnetic structure with a narrow band gap at one spin channel (semiconductor), and a metallic behavior at the other spin channel. This corresponds to a 100% spin-polarization, making it ideal for potential spintronic applications. Applying the semi-classical Boltzmann theory, the Seebeck coefficient, electrical conductivity, and electronic thermal conductivity of CrTiRhAl alloy were calculated. The predicted figure of merit …

Boundaries And Currents Of The Dayside Magnetosphere: Mhd Simulations And Observations, Pauline Marie Dredger

Physics Dissertations - Archive

The solar wind streams through space at supersonic speeds, carrying plasma and the interplanetary magnetic field (IMF) from the sun. Earth’s magnetosphere presents a magnetosonic obstacle to the solar wind flow, which slows down suddenly, creating a bow shock. Between the bow shock and Earth’s magnetic field is the region of space called the magnetosheath, which contains the dense plasma and turbulent IMF of the shocked solar wind. The magnetopause is the boundary between the magnetosheath and the region of near-Earth space dominated by the terrestrial magnetic field; its location is determined by the competing pressures of the plasma in …

Investigation Of Optical And Electrical Properties Of Noble Metal And Superconducting Thin Films And Design And Fabrication Of Metamaterial Solar Absorbers, Vivek Khichar

Physics Dissertations - Archive

An extensive study of light-matter interactions leading to the generation of photon drag voltage under surface plasmon resonance conditions in noble metal thin films was undertaken by performing a series of experimental measurements and numerical simulations. The drag voltage originates from a force that arises because of the transfer of momentum from incident light to electrons. This transfer of photon momentum leads to an electric current, which in turn results in the generation of drag voltage. The effect is particularly enhanced under surface plasmon resonance conditions and thereby reinforces the interaction between light and collective oscillations of the surface charges. …

Exploring Ferroelectric Phenomena In Batio3, Linbo3, And Liznsb: From Extended Oxygen Vacancies To Tri-Stable Polarization And Giant Hyperferroelectricity, Shaohui Qiu

Graduate Theses and Dissertations

This dissertation presents three projects that investigate the complex phenomena of ferroelectricity under different conditions in BaTiO3, LiNbO3, and LiZnSb using first-principles density functional calculations. Extended defects in ferroelectric solids play a crucial role in reducing the lifetime and performance of ferroelectric devices by causing fatigue, domain pinning, and aging. Thus, understanding their impact is of critical importance for the development of reliable and high-performance ferroelectric devices. In addition, hyperferroelectricity is an intriguing phenomenon that has attracted much attention in recent years. Despite the existence of depolarization field, spontaneous polarization persists under an open-circuit boundary condition (OCBC), making hyperferroelectric materials …

What Does The Geometry Of The Hβblr Depend On?, Lizvette Villafaña, Peter R. Williams, Tommaso Treu, Brendon J. Brewer, Aaron J. Barth, Vivian U, Vardha N. Bennert, Hengxiao Guo, Misty C. Bentz, Gabriela Canalizo, Alexei V. Filippenko, Elinor Gates, Michael D. Joner, Matthew A. Malkan, Jong-Hak Woo, Bela Abolfathi, Thomas Bohn, K. Azalee Bostroem, Goni Halevi, Carol E. Hood, J. Chuck Horst, Maxime De Kouchkovsky, Benjamin Kuhn, Douglas C. Leonard, Raúl Michel, Melanie Kae B. Olaes, Daeseong Park, Jordan N. Runco, Remington O. Sexton, Isaac Shivvers, Chance L. Spencer, Benjamin E. Stahl, Samantha Stegman, Jonelle L. Walsh, Weikang Zheng

Physics

We combine our dynamical modeling black-hole mass measurements from the Lick AGN Monitoring Project 2016 sample with measured cross-correlation time lags and line widths to recover individual scale factors, f, used in traditional reverberation-mapping analyses. We extend our sample by including prior results from Code for AGN Reverberation and Modeling of Emission Lines (CARAMEL) studies that have utilized our methods. Aiming to improve the precision of black-hole mass estimates, as well as uncover any regularities in the behavior of the broad-line region (BLR), we search for correlations between f and other AGN/BLR parameters. We find (i) evidence for a …

Exploration Of H2o Ice At Extreme Conditions, Zachary M. Grande

UNLV Theses, Dissertations, Professional Papers, and Capstones

Static compression experiments on water ice are needed for precise characterization and discovery of new ice phases near room temperature. Here I present my efforts and the developments that have been made to reduce detrimental effects found in high-pressure experiments in order to acquire precise measurements on ice approaching 3 Mbar. Several key observations are made, relating to the phase transition of ice-VII to X, an intermediate phase I have named ice-VIIt and evidence of a post ice X phase. Some of these experiments have been replicated using D2O ice as well, in order to gain insight into nuclear quantum …

Applying Instrumental Neutron Activation Analysis To Assess Air Pollution With Spanish Moss As A Bioindicator In The Low Country Of The Savannah River Basin, Christina Jiang

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Savanah River Basin is an area of 9,850 square miles that stretches from the border between South Carolina and Georgia, which empties into the Atlantic Ocean near Savannah, Ga. This area is home to surrounding cities, industrial sites, and the Savanah River Site. It is well documented that traffic, industrial operations, and agriculture contribute to worsening air pollution that needs to be monitored. While Tillandsia usneoides (Spanish moss) has been used in previous studies that prove it to be an effective biomonitor for air pollution and an accumulator of heavy metals, there have been no biomonitoring studies in the …

Joint Constraints On Kepler-36 From Kepler And New Keck-Hires Data, Nicholas Juliano

UNLV Theses, Dissertations, Professional Papers, and Capstones

I analyze new HIRES Radial Velocity (RV) data in conjunction with transit mid-times and uncertainties from the full 17 quarters of Kepler data to reassess the orbital parameters of the Kepler-36 system. Six additional RV measurements were taken by the Keck-HIRES spectrograph from September 21, 2021 to October 11, 2021. I carry out a differential evolution Markov Chain Monte Carlo-based (DEMCMC) analysis to infer improved orbital elements for the two known planets in the system. Leveraging additional information provided by the new RV measurements, I extend this DEMCMC analysis to a possible three-planet configuration. I explore the likelihood of a …

Stoichiometric Determination Of Hydride Materials At Extreme Conditions, Gregory Alexander Smith

UNLV Theses, Dissertations, Professional Papers, and Capstones

Hydrogen was predicted to be a high-temperature superconductor at near-megabar conditions in 1968,[1] but only recently was been experimentally observed.[2] This is due to the extraneous metrological constraint of requiring 5 megabars of pressure to stabilize. A more practical approach for synthesis of high-temperature superconductors has been pro-posed through the use of hydride compounds. Recently, a surge of rare earth hydrides have achieved critical superconducting transition temperatures (T_C ) close to room temperature.[3, 4, 5, 6] However, due to limitations of the necessary instrumentation to achieve megabar pressures, many techniques traditionally used to measure stoichiometry are unavailable.Three works presented in …

Analysis And Application Of Finite Element And High-Order Finite Difference Methods For Maxwell’S Equations In Complex Media, Li Zhu

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Perfectly Matched Layer (PML) technique is an effective tool introduced by B´erenger [13] to reduce the unbounded wave propagation problem to a bounded domain problem. This dissertation focuses on two different PML models and their applications to wave propagation problems with Maxwell’s equation in complex media. We investigate these models using two popular numerical methods: the Finite Difference Method (FDM) in Chapters 2 and 3, and the Finite Element Method (FEM) in Chapters 4 and 5.In Chapter 2, we focus on analyzing the stability of a PML developed by B’ecache et al. [10] for simulating wave propagation in the …

Spatial Metabolomics Reveals Glycogen As An Actionable Target For Pulmonary Fibrosis, Lindsey R. Conroy, Harrison A. Clarke, Derek B. Allison, Samuel Santos Valenca, Qi Sun, Tara R. Hawkinson, Lyndsay E. A. Young, Juanita E. Ferreira, Autumn V. Hammonds, Jaclyn B. Dunne, Robert J. Mcdonald, Kimberly J. Absher, Brittany Dong, Ronald C. Bruntz, Kia H. Markussen, Jelena A. Juras, Warren J. Alilain, Jinze Liu, Matthew S. Gentry, Peggi M. Angel, Christopher M. Waters, Ramon C. Sun

Saha Cardiovascular Research Center Faculty Publications

Matrix assisted laser desorption/ionization imaging has greatly improved our understanding of spatial biology, however a robust bioinformatic pipeline for data analysis is lacking. Here, we demonstrate the application of high- dimensionality reduction/spatial clustering and histopathological annotation of matrix assisted laser desorption/ionization imaging datasets to assess tissue metabolic heterogeneity in human lung diseases. Using metabolic features identified from this pipeline, we hypothesize that metabolic channeling between glycogen and N-linked glycans is a critical metabolic process favoring pulmonary fibrosis progression. To test our hypothesis, we induced pulmonary fibrosis in two different mouse models with lysosomal glycogen utilization deficiency. Both mouse models displayed …

Representations Of Time In Time-Based Media: An Exploration Of The Human Experience Of Temporality In Film And Tv, Nelea Fong

Honors Thesis

Time is an aspect of the human experience that fascinates us but eludes our understanding. Humans have turned to science, philosophy, and theology in our endeavor to understand time, but our shared love and history of storytelling drives us to explore temporality through visual medias that have a structural foundation in time. Expanding our understanding of the human experience of time through time-based media such as movies and TV can point us toward comprehending various forms of time and how each person can perceive said time differently. Using film and TV theory, informed by scientific and philosophical explorations in the …

College Of Natural Sciences Newsletter, March - May 2023, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

Volume 4, Issue 2

Page 1 Dean's Message
Page 2-7 Awards and Recognition
Page 8 March 3rd Corothers Seminar
Page 9 54th Geography Convention
Page 10 Spring 2023 Day of Scholars
Page 11 2023 URSCAD Snaps
Page 12-14 Media Coverage of CNS
Page 15 Open PRAIRIE Data

Extending The Lifetime Of Optically Stimulated Dosimeters For Use In Output Checks At Iroc- Houston, Hayden Scott

Dissertations and Theses (Open Access)

Purpose: Optically Stimulated Luminescent Dosimeters (OSLDs) are a prominent form of in-vivo dosimeter used both in clinics as well as for the audits of radiological
equipment at the Imaging and Radiation Oncology Core (IROC)-Houston. These
dosimeters have a recommended dose limit of 10 Gy due to a change in signal response with dose. To assist with the OSLD operation at IROC-Houston, evaluating the signal response of these dosimeters with IROC’s methodologies offers the potential to extend the dose limit past 10 Gy, improve the efficiency of handling OSLDs, and reduce the cost and time spent on commissioning OSLDs.
Methods: The …

Determination Of Effective Index Of Refraction Of Structured Materials (Photonic Crystals), Md Arafat Hossain

Theses and Dissertations

Photonic crystals have been widely studied by researchers due to their ability to control light propagation in all spatial directions. For example, 2D photonic crystals can be made of dielectric rods arranged in a square lattice. When light propagates through 2D photonic crystals, it experiences multiple scatterings by the crystal centers. The superposition of all scattered waves forms the transmitted field largely dependent upon the effective index of refraction of the structured material. We propose a method to determine the effective index of refraction through such materials with the Finite-Difference Time-Domain (FDTD) model. We set up the interface of two …

Magnetic Properties Of Polycrystalline Spinel Oxides From Solid State Reaction, Camden Olds

Honors Program: Senior Projects (Public)

Spinel crystal materials of nickel, cobalt, and iron oxides have seen abundant research for their strong conductivity, ferromagnetic and ferroelectric properties, and their catalytic uses. These can be synthesized by a number of means. This project explores the use of the solid state synthesis method, which benefits from simplicity, of this family of materials, looking for interesting phase shift lines in the triangle between of varying compositions of these three metals.

Nickel cobaltite and other related spinels were synthesized from two different solid state approaches and characterized using XRD and SQUID magnetometry. The range 0.5-0.6 of molar ratios of nickel …

Tdcosmo - Xii. Improved Hubble Constant Measurement From Lensing Time Delays Using Spatially Resolved Stellar Kinematics Of The Lens Galaxy, Anowar J. Shajib, Pritom Mozumdar, Geoff C.-F. Chen, Tommaso Treu, Michele Cappellari, Shawn Knabel, Sherry H. Suyu, Vardha N. Bennert, Joshua A. Frieman, Dominique Sluse, Simon Birrer, Frederic Courbin, Christopher D. Fassnacht, Lizvette Villafaña, Peter R. Williams

Physics

Strong-lensing time delays enable the measurement of the Hubble constant (H₀) independently of other traditional methods. The main limitation to the precision of time-delay cosmography is mass-sheet degeneracy (MSD). Some of the previous TDCOSMO analyses broke the MSD by making standard assumptions about the mass density profile of the lens galaxy, reaching 2% precision from seven lenses. However, this approach could potentially bias the H₀ measurement or underestimate the errors. For this work, we broke the MSD for the first time using spatially resolved kinematics of the lens galaxy in RXJ1131−1231 obtained from the Keck Cosmic …

Modeling Accuracy Matters: Aligning Molecular Dynamics With 2d Nmr Derived Noe Restraints, Milan Patel

Honors Scholar Theses

Among structural biology techniques, Nuclear Magnetic Resonance (NMR) provides a holistic view of structure that is close to protein structure in situ. Namely, NMR imaging allows for the solution state of the protein to be observed, derived from Nuclear Overhauser Effect restraints (NOEs). NOEs are a distance range in which hydrogen pairs are observed to stay within range of, and therefore experimental data which computational models can be compared against. To that end, we investigated the effects of adding the NOE restraints as distance restraints in Molecular Dynamics (MD) simulations on the 24 residue HP24stab derived villin headpiece subdomain to …

The Safe And Effective Clinical Deployment Of Artificial Intelligence To Ols, Kelly Nealon

Dissertations and Theses (Open Access)

18 million new cancer cases are diagnosed each year. Roughly half of these patients will be treated with radiation therapy, a complex technique that requires an interdisciplinary team of clinical staff and expensive equipment to be delivered safely. Cancer centers in Low- and Middle-Income Countries (LMIC) have an especially difficult time meeting the demands of radiation therapy as the complexity of treatment techniques increase, with only 37% of patients in these regions having access to the care they need. Artificial Intelligence (AI) based tools are being developed to simplify the treatment planning and quality assurance processes to increase the number …

Effect On Focusing Fields By Ferromagnetic Cell Cores In Linear Induction Accelerators, Cooper Guillaume

Senior Honors Theses

In the Los Alamos National Laboratories DARHT facility, there are two perpendicular linear induction accelerators, LIAs. The LIAs’ solenoids produce magnetic fields which focus the electron beam. Simultaneously, the accelerating pulse creates a magnetic field. These two field intensities act upon a ferromagnetic material in the cells to enhance magnetic flux density. Due to the nonlinearity of the material, this flux density will reach a saturation point. In turn, the magnetic field intensity of the axial solenoidal magnetic field will be affected and slightly altered. The width of the electron beam will increase, causing a decrease in effectiveness. Through simulation, …

Treatment Planning Automation For Rectal Cancer Radiotherapy, Kai Huang

Dissertations and Theses (Open Access)

Background

Rectal cancer is a common type of cancer. There is an acute health disparity across the globe where a significant population of the world lack adequate access to radiotherapy treatments which is a part of the standard of care for rectal cancers. Safe radiotherapy treatments require specialized planning expertise and are time-consuming and labor-intensive to produce.

Purpose:

To alleviate the health disparity and promote the safe and quality use of radiotherapy in treating rectal cancers, the entire treatment planning process needs to be automated. The purpose of this project is to develop automated solutions for the treatment planning process …

Apparatus And Instrumentation Design For Investigation Of Surface Impact Effects On Superconductivity, Austin Back

All Theses

The effects of ion irradiation on the physical properties of materials make EBITs an invaluable tool for many scientific and engineering fields. Many experiments rely on the use of these lab setups to test for device reliability, explore surface physics phenomena, and replicate the environment for many physical systems that are not readily accessible. We seek to extend the capabilities of these experiments using the CUEBIT and a new sample holder installed in section 3.

This thesis begins by presenting an overview of the CUEBIT and the basic operations of the equipment. This is followed by a brief explanation of …

The Characterization Of Atmospheric Turbulence And Its Effect On Laser Beam Propagation, Michael Cox

All Theses

Having a controlled environment to measure atmospheric turbulence is essential to understanding its effects on different laser beam characteristics. The Clemson Variable Turbulence Generator (VTG) has the capability to propagate a laser beam up to 100 m and be able to dial many turbulence settings up to a heat flux of 357 W/m². A high-speed camera, power detector, and high-resolution temperature probes characterize the VTG with theoretical turbulence spectrums. The exponent associated with the Rayleigh-Bénard (RB) temperature structure constant equation is studied. Two different laser beam profiles are used throughout this work: Gaussian and Asymmetric Perfect Vortex (APV). …

An Investigation On The Effect Of Conserved Hinge Histidine On Influenza Hemagglutinin(Ha2) Protein Conformation Using Md Simulations, Nada Tolba

Chemistry & Biochemistry Undergraduate Honors Theses

Hemagglutinin is a protein on the surface of Human Influenza Viruses.¹ It is composed of two glycopolypeptide domains, the HA1 and HA2 domains. Previous studies have found that across different strains of Influenza viruses, HIS435 residues remain conserved.⁴ In studies where mutations occurred in hinge-site histadine residues, the Influenza virus was inactive.⁴ These investigations indicated a significant role of HIS435 (hinge-site histadines) in virulence. Four systems were created using Molecular dynamics (MD) simulations. Each system was composed of an Isolated HA2 trimer solvated in a 150 mM NaCl rectangular water box at 310 K under isobaric and …

Sexual Dimorphism Of Glomerular Capillary Morphology In Rats, Zackarias Coker

Undergraduate Honors Theses

Chronic kidney disease (CKD) progresses faster in males than females; however, the underlying mechanisms remain poorly understood. Sex differences in glomerular capillary morphology has been hypothesized to contribute, in part, to the increased susceptibility to hypertension-induced renal injury and CKD progression in males, but this has not been investigated. The goal of the present study was to assess glomerular capillary morphology in male vs. female rats with intact kidneys and after uninephrectomy (UNX). We hypothesized that glomerular capillary radii (R_CAP) and length (L_CAP) would be greater in male rats.

Male (n=4) and female (n=4) with intact …