Physical Sciences and Mathematics Commons^™

Electromagnetic Transitions And Beta Decays In Nuclei From The Ab Initio Symmetry-Adapted No-Core Shell Model, Grigor Sargsyan

LSU Doctoral Dissertations

Nuclear physics today is a diverse field, involving research that extends from the minus- cule scales of neutrons and protons to the colossal dimensions of astrophysical objects in the universe. And since the ab initio methods in nuclear physics use realistic internucleon interactions, nuclear modeling has gained predictive capabilities that enable us to probe ever more deeply into the fundamental nature of matter. One of these models – the symmetry- adapted no-core shell model (SA-NCSM) – is capable of reaching the medium-mass region of the chart of the nuclides, by exploiting the emergent symmetries of nuclei, and is therefore well-suited …

Error Estimates For Discrete Approximations Of Game Options With Multivariate Diffusion Asset Prices, Yuri Kifer

Journal of Stochastic Analysis

No abstract provided.

Laser Surface Treatment And Laser Powder Bed Fusion Additive Manufacturing Study Using Custom Designed 3d Printer And The Application Of Machine Learning In Materials Science, Hao Wen

LSU Doctoral Dissertations

Selective Laser Melting (SLM) is a laser powder bed fusion (L-PBF) based additive manufacturing (AM) method, which uses a laser beam to melt the selected areas of the metal powder bed. A customized SLM 3D printer that can handle a small quantity of metal powders was built in the lab to achieve versatile research purposes. The hardware design, electrical diagrams, and software functions are introduced in Chapter 2. Several laser surface engineering and SLM experiments were conducted using this customized machine which showed the functionality of the machine and some prospective fields that this machine can be utilized. Chapter 3 …

Effects Of Structure, Crystallographic Orientation, And Dimensionality On Emergent Properties Of Transition Metal Oxide Thin Films, Prahald Siwakoti

LSU Doctoral Dissertations

SrRuO₃ is the only example of ferromagnetic perovskite oxide of a 4d transition metal, wherein the electron -electron correlation is still relevant while the heavier 4d ion (Ru) gives it a larger spin-orbit coupling strength which makes it an interesting material to study. In this thesis, we present our investigation of the structure and properties of SrRuO₃ thin films of varying thickness grown on [001] and [111] crystallographic orientation of the SrTiO3 substrate. For SrRuO₃(001), we present microscopically the presence of 90◦ in-plane rotated structural domains that are identified by the difference in octahedral rotations and …

Hessian Formulas And Estimates For Parabolic Schrödinger Operators, Xue-Mei Li

Journal of Stochastic Analysis

No abstract provided.

Remembering Kunita-San, Ken-Iti Sato

Journal of Stochastic Analysis

No abstract provided.

Indicators Of Senescence And Their Relationship With The Antioxidant Response Element In Ovarian Cancer Cells—Toward A More Encompassing View Of Enzyme Activity Levels In Cells, Shaniqua Analycia Hayes

LSU Doctoral Dissertations

Enzymes and other related proteins are promising targets as biomarkers for cancer diagnostics, and it is therefore important to be able to quantify intracellular enzyme activity levels, not just presence of enzyme. Thus, there is a great need for the development of methods that offer spatiotemporal quantification of intracellular enzyme activity levels in respiring 2- and 3-dimensional cultures or their sample-processed variants. Previous studies have demonstrated that ß-gal is upregulated in senescence and in select ovarian cancers, and its expression/activity is upregulated when cells are under oxidative stress conditions. To that end, the primary goal of this work was to …

Learning To Interpret Fluid Type Phenomena Via Images, Simron Thapa

LSU Doctoral Dissertations

Learning to interpret fluid-type phenomena via images is a long-standing challenging problem in computer vision. The problem becomes even more challenging when the fluid medium is highly dynamic and refractive due to its transparent nature. Here, we consider imaging through such refractive fluid media like water and air. For water, we design novel supervised learning-based algorithms to recover its 3D surface as well as the highly distorted underground patterns. For air, we design a state-of-the-art unsupervised learning algorithm to predict the distortion-free image given a short sequence of turbulent images. Specifically, we design a deep neural network that estimates the …

Dirac-Born-Infeld Warm Inflation Realization In The Strong Dissipation Regime, Meysam Motaharfar, Rudnei O. Ramos

Faculty Publications

We consider warm inflation with a Dirac-Born-Infeld (DBI) kinetic term in which both the non-equilibrium dissipative particle production and the sound speed parameter slow the motion of the inflaton field. We find that a low sound speed parameter removes, or at least strongly suppresses, the growing function appearing in the scalar of curvature power spectrum of warm inflation, which appears due to the temperature dependence in the dissipation coefficient. As a consequence of that, a low sound speed helps to push warm inflation into the strong dissipation regime, which is an attractive regime from a model building and phenomenological perspective. …

The Life And Scientific Work Of Hiroshi Kunita, Yasushi Ishikawa

Journal of Stochastic Analysis

No abstract provided.

Palynology And Paleoclimatology Of The Chicxulub Impact Crater In The Early Paleogene, Vann Smith

LSU Doctoral Dissertations

At the end of the Cretaceous Period, a large bolide impacted the Earth and formed the Chicxulub impact crater in the Yucatán Peninsula, Mexico. In 2016, International Ocean Discovery Program (IODP) Expedition 364 Site M0077 drilled into the buried peak ring of the crater, recovering a marine Paleocene to early Eocene post-impact section deposited on top of the impact breccia. Palynological analysis of 195 samples from the post-impact section has yielded the first pre-Holocene vegetational record from inside the Chicxulub impact crater and the first palynological record of the recovery of life following the end-Cretaceous mass extinction from inside the …

Memories Of Professor Hiroshi Kunita, Ichiro Shigkeawa

Journal of Stochastic Analysis

No abstract provided.

On The Works Of Hiroshi Kunita In The Sixties, Masatoshi Fukushima

Journal of Stochastic Analysis

No abstract provided.

Personal Memories Of Hiroshi Kunita, David Elworthy

Journal of Stochastic Analysis

No abstract provided.

Preface, Shigeki Aida, David Applebaum, Yasushi Ishikawa, Arturo Kohatsu-Higa, Nicolas Privault

Journal of Stochastic Analysis

No abstract provided.

Spatiotemporal Trends And Variability In The Centroid Of The Northern Hemisphere's Circumpolar Vortex, Nazla Bushra, Robert V. Rohli

Faculty Publications

Recent previous research has established the "sharpest gradient" approach to defining the circumpolar vortex and has identified correlations of the area and circularity of the Northern Hemisphere's circumpolar vortex (NHCPV) to important atmospheric-oceanic teleconnections. However, because geographical shifts in the NHCPV, independent of area or circularity changes, could affect surface environmental conditions, this research addresses the question of the extent to which the NHCPV centroid undergoes such shifts, both intra- and inter-annually. Results show that during the 1979-2017 period, the centroid has moved less on a daily basis in more recent years, perhaps indicative of a stabilization in circulation, with …

Phragmites Australis Dieback In The Mississippi River Delta: Chemical Profiles Of Soil Types And Restoration Potential, Herie Lee

LSU Master's Theses

Since 2016, there has been widespread dieback of P. australis in the Lower Mississippi River Delta (hereafter referred to as Lower MRD, which is defined as the Birds Foot Delta) with relatively little to no signs of recovery. The cause of the current dieback is not fully understood. This thesis explores P. australis with emphasis on chemical profile characterization of different soil types and its effects on plant growth and the potential for restoration in the Lower MRD.

In chapter 2, I characterized the chemical profiles of soils collected from healthy and dieback stands of Phragmites, and from newly …

Degumming Of Hemp Fibers Using Combined Microwave Energy And Deep Eutectic Solvent, Bulbul Ahmed

LSU Master's Theses

Hemp is considered as one of the sustainable agricultural fiber materials. Degumming or surface modification of hemp bast is needed to produce single fibers for ensuing textile and industrial applications. The traditional degumming process necessitates a high amount of alkali, which causes detrimental environmental pollution. This study offers a new method to degum hemp fibers with reduced use of harmful alkali and precious water resources. In this work, hemp bast fibers were degummed by using combined microwave energy and deep eutectic solvent (DES). The properties of hemp fibers manufactured by this method were investigated and compared with the traditional alkali …

Algorithms Related To Triangle Groups, Bao The Pham

LSU Doctoral Dissertations

Given a finite index subgroup of $\PSL_2(\Z)$, one can talk about the different properties of this subgroup. These properties have been studied extensively in an attempt to classify these subgroups. Tim Hsu created an algorithm to determine whether a subgroup is a congruence subgroup by using permutations \cite{hsu}. Lang, Lim, and Tan also created an algorithm to determine if a subgroup is a congruence subgroup by using Farey Symbols \cite{llt}. Sebbar classified torsion-free congruence subgroups of genus 0 \cite{sebbar}. Pauli and Cummins computed and tabulated all congruence subgroups of genus less than 24 \cite{ps}. However, there are still some problems …

Causes And Characteristics Of Electrical Resistivity Variability In Shallow (<4 M) Soils In Taylor Valley, East Antarctica, William S. Gutterman

LSU Master's Theses

The McMurdo Dry Valleys are the largest ice-free region in Antarctica and are characterized as a polar desert environment. Soils in the region are typically very dry (<1% soil water by weight) and remain frozen for most of the year. Increases in air temperature and incoming solar radiation during the austral summer generate meltwater from glaciers, ground ice, and snow patches supplying moisture to soils and altering the physical and chemical makeup of the subsurface. Previous studies have utilized airborne electromagnetic surveys (AEM) to analyze groundwater systems in the deep subsurface but have not yet examined soil moisture in the shallow (<4 m) subsurface. Here, I used electrical resistivity data from two AEM surveys (2011 and 2018) and soil geochemical data from three transects to characterize the spatial heterogeneity of soil properties in the near-subsurface of lower Taylor Valley. Soil resistivities from 2011 and 2018 range from 33.2 Ωm to 3535 Ωm with low elevations of <100 meters above sea level (masl) typically displaying the lowest resistivities and high elevations displaying greater resistivities. Liquid brine fractions were empirically estimated from electrical resistivity values using Archie’s Law and range from 0.3% to 68.2% for soils with resistivities <200 Ωm. Additionally, soil transect data show greater percentages of fine-grained sediments (<63 µm) exist at elevations <100 masl where soil resistivities begin decreasing. Resistivity variability in the subsurface is ultimately controlled by the site history, local and regional climate, soil salinity, soil moisture, soil lithology.

Late Miocene Unroofing Of The Inner Lesser Himalaya Recorded In The Nw Himalaya Foreland Basin, Elise Marie Exnicios

LSU Master's Theses

Testing models that link climate and solid Earth tectonics requires independent erosional, structural and climatic histories. Two well preserved stratigraphic sections of the Himalayan foreland basin are exposed in NW India. The Jawalamukhi (13–5 Ma) and Joginder Nagar sections (21–13 Ma) are dated by magnetostratigraphy and span a period of significant climate change and tectonic evolution. We use detrital zircon U-Pb dating and apatite fission track analyses to reconstruct changes in the patterns of erosion and exhumation in this area from the Early Miocene to Pliocene. The provenance of the foreland sediments shows that since at least ~21 Ma the …

An Analysis Of Effort, Success, And Attitudes Of Louisiana Hunters By Email And Mixed-Mode Surveys, Michael Sullivan

LSU Master's Theses

ABSTRACT

Louisiana surveys waterfowl hunters every 5 years to assess harvest, harvest practices, demographics, and specific management objectives, as well as to research hypotheses derived from previous surveys of waterfowl hunters. In the 2020 survey, research hypotheses addressed hunter perceptions of changing waterfowl migration patterns, satisfaction, and relationships between perceptions and avidity with survey distribution waves and sample coverage. I surveyed a stratified census of 68,578 Louisiana waterfowl hunters by email following the 2019–2020 season, and asked 31 questions about waterfowl-hunting effort, success, satisfaction, regulatory alternatives, and demographics. I used generalized linear models to test hypotheses about hunters’ perception of …

Computer Simulations Of Diffusional Isotope Effects And Dynamical Properties Of Silicate Melts, Haiyang Luo

LSU Doctoral Dissertations

Silicate melts have served as transport agents in the chemical and thermal evolution of Earth. Diffusional isotope effect in silicate melts is the key to interpret isotope variations in lots of geological samples. Isotopic mass dependence of diffusion is commonly expressed as (Di/Dj)=(mj/mi)^β, where Di and Dj are diffusion coefficients of two isotopes whose masses are mi and mj. However, how the dimensionless empirical parameter β depends on temperature, pressure, and composition remains poorly constrained. Viscosity and electrical conductivity are two fundamental dynamical properties of silicate melts needed to constrain melt distribution in Earth's interior but remain unclear for most …

Modeling Of Island Block Scatter For Intensity Modulated Bolus Electron Conformal Therapy, Joseph G. Scotto

LSU Master's Theses

Purpose: Bolus electron conformal therapy (BECT) benefits treatment of the post-mastectomy chest wall, head and neck, paraspinal muscles, and extremities. Patient dose heterogeneities caused by bolus can be reduced through intensity modulation (IM) across the incident electron beam. This requires passive radiotherapy intensity modulation for electrons (PRIME) devices, which utilize tungsten pins (island blocks) imbedded in machinable foam. IM-BECT treatment planning requires accurate dose calculation using the pencil beam redefinition dose algorithm (PBRA). Currently, the PBRA models island blocks as perfect collimators. This work explores models to account for electrons scattering into and out of the sides of island blocks. …

Effect Of Forage Management Strategies And Land Use Change On Nitrogen Budget And Soil Health Parameters In Pasture Systems, Yili Meng

LSU Doctoral Dissertations

Pastures produce hay for livestock, and they conserve soil, water, and air resources. However, high nitrogen (N) fertilizer demands in pasture production have significant implication on greenhouse gas emission and environmental pollution. Appropriate forage management strategies can reduce environmental N loss and improve soil health, to enhance the long-term pasture productivity. Therefore, this study was carried out to investigate the effects of management strategies on N budgets and soil health parameters in subtropical pastures. Both field and laboratory experiments were conducted to evaluate the effects of N stabilizers including urease inhibitor and nitrification inhibitor on pasture yield, greenhouse gas emission, …

Structural Shielding Considerations For Vmat, Ana Lucia Dieguez

LSU Master's Theses

Introduction: As noted in National Council on Radiation Protection and Measurements (NCRP) Report 151, the medical physicist or other qualified expert has the responsibility to keep abreast of any new technology or treatment method that could potentially impact structural shielding design. Volumetric arc therapy (VMAT) became prevalent after the publication of Report 151 and thus was not explicitly addressed in Report 151. If the shielding-related characteristics of VMAT differ enough from the expectations of Report 151, especially in the circumstance of a vault utilized exclusively for VMAT, a shielding design based on Report 151 could potentially be inadequate. The …

Numerical And Field Study Of Tidal And Subtidal Dynamics In A Bar-Built Estuary: Barataria Bay, Gulf Of Mexico, Ali Reza Payandeh

LSU Doctoral Dissertations

This study investigated tidal and subtidal dynamics of water level, currents, and suspended sediment concentration (SSC) in Barataria Bay, a shallow bar-built estuary of the Northern Gulf of Mexico. First, the local and remote wind forcing contribution on subtidal water level and current variability were examined using three different methods: (i) statistical analysis of observed data, (ii) an analytical model and (iii) a 2-D barotropic numerical model. Results suggested that the remote and local wind effects were equally important at the bay mouth, however local winds were the dominant forcing driver inside the bay. The amplitudes of subtidal fluctuations induced …

An Analysis Of The Presence Of Dialogic Communication Features On Indiana Environmental Organizations' Websites, Jessica Moon

LSU Master's Theses

Dialogic communication is a two-way form of communication that allows entities such as organizations and their publics to share their viewpoints and contribute to decision-making processes openly and equally. The Five Dialogic Principles of Public Relations (ease of use of the interface, usefulness of information, conservation of visitors, generation of return visits, and dialogic loop) is a framework that has been used to examine this form of communication online. Research has shown that organizations’ websites have a generally low presence of features related to the Five Dialogic Principles. The goal of the present study was to determine the …

Electrochemical Reduction Of Hexavalent Chromium In Acetonitrile Using Glassy Carbon Electrodes, Temitope Jegede

LSU Master's Theses

Hexavalent chromium Cr(VI), a form of chromium mainly generated through industrial processes, has attracted great research interests due to its severe toxicity to biological systems. A common way to remove hexavalent chromium from industrial wastes is through reduction to the non-toxic trivalent state. To this end, methods such as chemical reduction, chemical precipitation and coagulation have been used. However, these methods are limited by poor removal efficiency, formation of secondary pollutants (sludge), and are mostly applicable to aqueous solutions. Recently, electrochemical methods have been investigated for reducing hexavalent chromium, but there is a lack of data on the reduction of …

"Super Gzk" Particles In A Classic Kramers' Diffusion-Over-A-Barrier Model. I. The Case Of Protons, S. T. Alnussirat, A. F. Barghouty, G. M. Webb, P. L. Biermann

Faculty Publications

In interactions of ultra-high-energy cosmic ray (UHECR) protons with cosmic microwave background photons, we focus in this work on photopion production reactions and the effects of the measured, broad, energy-loss distributions in these reactions on the evolution of the protons' density functions in energy space. We rely on a Fokker-Planck transport equation in energy space whose transport coefficients are calculated using laboratory measurements. We also derive a Fokker-Planck potential that accounts for both systematic (drift) and stochastic (dispersive) energy losses due to photopion production reactions. Our results show that dispersive energy losses have significant effects on estimating the protons' horizon …