Physical Sciences and Mathematics Commons^™

Statistical Modeling, Exploration, And Visualization Of Snow Water Equivalent Data, James Beguah Odei

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Due to a continual increase in the demand for water as well as an ongoing regional drought, there is an imminent need to monitor and forecast water resources in the Western United States. In particular, water resources in the Intermountain West rely heavily on snow water storage. Thus, the need to improve seasonal forecasts of snowpack and considering new techniques would allow water resources to be more effectively managed throughout the entire water-year. Many available models used in forecasting snow water equivalent (SWE) measurements require delicate calibrations.

In contrast to the physical SWE models most commonly used for forecasting, we …

Landscape Evolution Of The Needles Fault Zone, Utah, Investigated Through Chronostratigraphic And Terrain Analyses, Faye L. Geiger

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Arcing eastward from the deep gorge of Cataract Canyon on the Colorado River is a series of aligned valleys (graben) and ridges (horst). This unusual landscape has formed as subsurface salt deforms toward the river and dissolves away, causing the overlying rocks to fault, slide, and subside. Geologists have long been interested in this actively evolving area they call the Needles fault zone, because understanding its mechanics and origin may shed light on how faults work in general and similar, yet inaccessible places like offshore rift zones or even the surface of the Moon. Despite this interest, the timing and …

Modeling The Defect Density Of States Of Disordered Sio2 Through Cathodoluminescence, Amberly Evans Jensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Spacecraft charging is the accumulation of an electrical charge on orbiting spacecraft induced by the space plasma environment and has harmful effects on the electrical functionality of a spacecraft. This is studied extensively, particularly in the Materials Physics Group (MPG) at Utah State University (USU). During charging studies performed by the MPG, another potentially problematic effect of the space plasma environment on spacecraft was observed: light emanating from the sample undergoing electron beam bombardment. Space-based observatories are one type of spacecraft on which this luminescence may occur. If the luminescence from the material caused by the space plasma is within …

Information And Hardness Quantification Of Graphs: A Computational Study, Brent Dutson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

New techniques to measure the information contained within a network of interconnected nodes (such as links between computers in the Internet) have recently been developed. This work studies the relationship between the computer time needed to solve a common network problem and the information contained within the given network.

In Situ Stress And Geology From The Mh-2 Borehole, Mountain Home, Idaho: Implications For Geothermal Exploration From Fractures, Rock Properties, And Geomechanics, James Andrew Kessler

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Geothermal energy is being explored as a supplement to traditional fossil fuel resources to meet growing energy demand and reduce carbon emissions. Geothermal energy plants harvest heat stored in the Earth’s subsurface by bringing high temperature fluids to the surface and generating steam to produce electricity. Development of geothermal resources is often inhibited by large upfront risk and expense. Successful mitigation of those costs and risks begins with efficient characterization of the resource before development. A typically successful geothermal reservoir consists of a fractured reservoir that conducts hydrothermal fluids and a cap rock seal to limit convective heat loss through …

Multiplicity Results Of Periodic Solutions For Two Classes Of Nonlinear Problems, Kazuya Hata

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

We investigate the existences and qualitative properties of periodic solutions of the following two classes of nonlinear differential equations:

I) (Special) Relativistic Pendulum Equations (RPEs);

II) (2-coupled) Gross-Pitaevskii Equations (GPEs).

The pendulum equation describes the motion of a pendulum. According to Special Relativity, which was published by A. Einstein in 1905, causality is more fundamental than constant time-space, thus time will flow slower and space will distort to keep causality if the speed of motion is near the speed of light. In such high speed situations, the pendulum equation needs to be revised due to Special Relativity. The revised equation …

Family-Wise Error Rate Control In Quantitative Trait Loci (Qtl) Mapping And Gene Ontology Graphs With Remarks On Family Selection, Garrett Saunders

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

One of the great aims of statistics, the science of collecting, analyzing, and interpreting data, is to protect against the probability of falsely rejecting an accepted claim, or hypothesis, given observed data stemming from some experiment. This is generally known as protecting against a Type I Error, or controlling the Type I Error rate. The extension of this protection against Type I Errors to the situation where thousands upon thousands of hypotheses are examined simultaneously is known as multiple hypothesis testing. This dissertation presents an improvement to an existing multiple hypothesis testing approach, the Focus Level method, specific to gene …

Substrate Binding And Reduction Mechanism Of Molybdenum Nitrogenase, Zhiyong Yang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As a key constituent of proteins, nucleic acids, and other biomolecules, nitrogen is essential to all living organisms including human beings. Dinitrogen represents the largest pool of nitrogen, about 79% of the Earth’s atmosphere, yet it is unusable by most living organisms due to its inertness. There are two ways to fix this inert dinitrogen to usable ammonia. One is the industrial Haber-Bosch process, which needs to be conducted at high temperature and pressure. This process uses a lot of the non-renewable fossil fuel as the energy source. The other major pathway is the biological nitrogen fixation carried out by …

Alluvial Geochronology And Watershed Analysis Of The Golo River, Northeastern Corsica, France, Emilee M. Skyles

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Golo River in Corsica, France, is a short, steep river (~95 km, 2706 m relief) in the Western Mediterranean with formerly glaciated headwaters. The small size and location of the Golo River make this system ideal for observing the influence of climate and sea-level change on river dynamics over the 100,000 years. A rapidly advancing dating technique, optically stimulated luminescence, was utilized to determine the timing of these river deposits on the coastal plain in order to frame them in the context of previous glacial and interglacial episodes. Climate fluctuations in the headwaters supplied the vast majority of sediment …

Unified Model Of Charge Transport In Insulating Polymeric Materials, Alec Sim

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Charge transport, charging, and subsequent electrostatic discharge due to interactions with the space environment are primary concerns of spacecraft designers. Developing a physical understanding of the interactions of charge with the multitude of materials that spacecraft are composed of is a critical step in understanding and mitigating both short-term and long-term spacecraft degradation. In particular, the study of charge transport in highly insulating materials is critical as they store charge longer, with higher capacity, and with greater destructive capability than other materials.

The Utah State University Materials Physics Group, with the funding of the NASA James Webb Space Telescope project …

Effective Graph-Based Content--Based Image Retrieval Systems For Large-Scale And Small-Scale Image Databases, Ran Chang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Digital imaging was a great invention in the last century. Since digital cameras became popular in the public, a large amount of digital images emerged in the late of the twentieth century. How to manage the huge amount of images and find desired images among them became an urgent issue during the same period.

Techniques of retrieving a desired image are generally categorized into two basic classes. One relies on text-based key words to retrieve desired images in the image
database. The other one relies on image-based queries to retrieve desired images in the image database. The second technique is …

Mechanisms Of Vegetation-Induced Channel Narrowing On An Unregulated Canyon-Bound River, Rebecca Blanche Manners

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The accurate prediction of river channel width remains a fundamental area of investigation in the field of geomorphology. River managers and scientists are interested in understanding how a channel will respond to environmental perturbations such as altered runoff patterns from climate change, a new dam, or a pulse of sediment from a landslide. Increasingly, studies that focus on this question acknowledge the importance of accounting for the vegetation that lines the river banks. For this dissertation, I strove to identify some of the primary ways by which vegetation affects channel width.

At a fundamental level, vegetation influences the size of …

Modeling Habitat Use Of A Fringe Greater Sage-Grouse Population At Multiple Spatial Scales, Anya Cheyenne Burnett

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Greater sage-grouse (Centrocercus urophasianus; hereafter sage-grouse) are a prominent bird species of sagebrush-dominated landscapes across the western United States. Over the past 15 years, sage-grouse have gained international attention due to decreasing population trends despite management efforts. In 2010 the U.S. Fish and Wildlife Service designated this species as warranted for listing under the Endangered Species Act, but the listing was precluded by other species at higher conservation risk. Habitat loss, degradation, and fragmentation have been implicated as primary sources of declines in sage-grouse distribution and abundance. The Bald Hills population in southwestern Utah occupies an area with …

Two Scenes From Utah's Stratigraphic Record: Neoproterozoic Snowball Earth, Before And After, Dawn Schmidli Hayes

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research is focused on rock units deposited in northern Utah before and after global glacial events of unprecedented magnitude, commonly referred to as
“Snowball Earth” glaciations. The rock units deposited prior to the beginning of these glaciations (~770 to 740 million years ago) include the Uinta Mountain Group in Utah’s Uinta Mountains. Rock units deposited after the glaciations (either ~665 or ~635 million years ago) include parts of the Kelley Canyon Formation on Antelope Island in the Great Salt Lake. These rocks, deposited in shallow ocean environments, record the history of life and ocean chemistry just before and after …

Formation, Deformation, And Incision Of Colorado River Terraces Upstream Of Moab, Utah, Andrew P. Jochems

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The history of rivers is laid down as sediment in all landscapes, typically as a function of climate, geologic structures, and/or changes in sea level. When a river abandons its floodplain, this sediment collectively constitutes a landform called a fluvial terrace. Terraces are used to unlock prior characteristics of a river flowing through a given area at both local and regional scales. Dating terrace sediment allows comparison to known changes in climate and geologic deformation, two significant controls on the hydraulics of rivers and the deposition of their sediment loads.

The importance of terraces lies in their utility as markers …

Constraining Ice Advance And Linkages To Paleoclimate Of Two Glacial Systems In The Olympic Mountains, Washington And The Southern Alps, New Zealand, Cianna E. Wyshnytzky

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis investigates glacial sediments in the South Fork Hoh River Valley, Washington and the Lake Hawea Valley, New Zealand that were deposited during the last glacial period. Research objectives were to reconstruct the style and timing of glacier advance and retreat in both areas and to assess the viability of luminescence dating of sediments in glacial environments.

Glaciers are influenced primarily by temperature and precipitation. Valley glaciers, like those in the Olympics Mountains and Southern Alps, are thought to respond relatively rapidly to climate fluctuations in comparison to continental ice sheets. Understanding how these glacial systems responded to past …

Enhanced Structural Support Of Metal Sites As Nodes In Metal-Organic Frameworks Compared To Metal Complexes, Sanjit Das

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Crystalline porous materials have gained long-standing interest for their application in gas storage, separation and catalysis. These materials have been useful for domestic, scientific and industrial purposes for many decades. Zeolites are a well known example of such materials.

Metal-organic frameworks are a new class of crystalline porous materials. They have many advantages over the more widely known zeolites. Though metal-organic frameworks are relatively new, their basic structure, known as the secondary building unit, very closely resembles the structure of metal complexes. Such metal complexes have been characterized in chemistry for more than a century.

Chemical catalysis is a process …

Bear River Heritage Area: A Study Of Recreation Specialization And Importance-Performance, Tyler A. Baird

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Heritage tourism is a fast growing sector in the recreation arena. Research into multiple aspects of heritage tourism has increased during the last few decades as it has been recognized as a distinct form of tourism and promoted around the globe. This study was conducted in an effort to better understand multiple aspects of heritage tourism in the Bear River Heritage Area of northern Utah and southeastern Idaho. The following aims to provide Bear River Heritage Area leadership with baseline data on their visitors and build upon the base of literature in the areas of recreation specialization, and importance-performance analysis. …

Weyl Gravity As A Gauge Theory, Juan Teancum Trujillo

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A gauge theory is a theory in which the governing functional, known as the action, remains invariant under a continuous group of local transformations that form its symmetry. Each of the known fundamental interactions in the universe, such as electricity and magnetism, can be explained as arising from a particular gauge theory. Gravitation is no exception. Just as calculus can be used to find the value of a variable that maximizes or minimizes a function, calculus of variations can be used to find the equations, known as the field equations, that extremize the action, and these are the main equations …

Oxidative Aliphatic Carbon-Carbon Bond Cleavage Reactions, Caleb J. Allpress

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The work presented in this dissertation has focused on the activation and cleavage of chemical bonds between two carbon atoms. The selective oxidative activation of carbon-carbon bonds is important due to potential applications in the utilization of biomass for fuel production, applications in wastewater treatment and bioremediation, and in developing new reactions for organic synthesis of fine chemicals including pharmaceuticals. Ideally these reactions would be carried out with high atom economy at low temperatures and pressures, and using earth-abundant elements as reagents and catalysts. With these points in mind, nature provides an ideal model framework, carrying out its chemistry at …

Colorado River Cutthroat Trout Habitat Resistance And Resilience To Climate Change, Kate H. Olsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Government agencies and private organizations spend large amounts of public money attempting to return ecosystems to a more natural state, which have often been harmed or even destroyed as a result of modern development. Colorado River cutthroat trout, Oncorhyncus clarki pleuriticus, are a subspecies of cutthroat trout. Cutthroat trout live in the Rocky Mountains of the western United States. The population of this particular subspecies has been severely reduced by human actions, and currently only 12% of its historic populations still exist. To improve the condition of cutthroat trout, fisheries professionals and biologists are working to restore natural populations. …

Empirical Properties Of Functional Regression Models And Application To High-Frequency Financial Data, Xi Zhang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Functional data analysis (FDA) has grown into a substantial field of statistical research, with new methodology, numerous useful applications and interesting novel theoretical developments. My dissertation focuses on the empirical properties of functional regression models and their application to financial data. We start from testing the empirical properties of forecasts with the functional autoregressive models based on simulated and real data. We define intraday returns and consider their prediction from such returns on a market index. This is an extension to intraday data of the Capital Asset Pricing model. Finally we investigate multifactor functional models and assess their suitability for …

Carrier Dynamics In Ingaas/Gaas Quantum Dots Excited By Femtosecond Laser Pulses, Kripa Nidhan Chauhan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In semiconductors, everything is becoming smaller day by day; quantum dots are the smallest nanomaterials available today. Typical sizes of these quantum dots are in the range of 5 to 30 nm in diameter. Variations in size changes many material properties, such as electrical and nonlinear optical properties, making them very different from bulk semiconductors. The size of the QDs results in new quantum phenomena, which yield some extraordinary properties. Material properties change dramatically because quantum effects arise from the confinement of electrons and holes in the material. Hence, semiconductor quantum dots play an important role in designing new devices …

Existence And Multiplicity Results On Standing Wave Solutions Of Some Coupled Nonlinear Schrodinger Equations, Rushun Tian

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Coupled nonlinear Schrodinger equations (CNLS) govern many physical phenomena, such as nonlinear optics and Bose-Einstein condensates. For their wide applications, many studies have been carried out by physicists, mathematicians and engineers from different respects. In this dissertation, we focused on standing wave solutions, which are of particular interests for their relatively simple form and the important roles they play in studying other wave solutions. We studied the multiplicity of this type of solutions of CNLS via variational methods and bifurcation methods.

Variational methods are useful tools for studying differential equations and systems of differential equations that possess the so-called variational …

Parallel Heat Transport In Magnetized Plasma, Mukta Sharma

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A huge global increase in energy use is inevitable, so there is an urgent need to seek cleaner ways of producing energy on large scales. Fusion is the energy source of the universe and a promising way to fulfill energy needs of mankind for many centuries to come. It offers important advantages as a safe, sustainable, and environmentally friendly source of energy. The International Thermonuclear Experimental Reactor (ITER) aims to demonstrate magnetic fusion is an energy source of the future. The goal of ITER is to produce 500 MW of fusion power given 50 MW of input power—or ten times …

Statistical Algorithms For Optimal Experimental Design With Correlated Observations, Chang Li

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The first part of my dissertation demonstrates that a modified simulated annealing algorithm can successfully determine highly efficient D-optimal designs for second order polynomial regression for a variety of correlated error structures.

In the second part, I solved weak universal optimal block designs for the nearest neighbor correlation structure and multiple block sizes, for the hub correlation structure with any block size, and for circulant correlation with odd block size.

In the third part, we propose an improved Particle Swarm Optimization (PSO) algorithm with time varying parameters. Then combining the theorem of decision making and PSO, we innovated nested PSO …

A Numerical Algorithm For Simulating Two Species Plasma, Richard F. Datwyler

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In our ever-growing technology-dependent society, a great need for cleaner, more lucrative energy sources is being sought out. Nuclear fission power plants have been used to help provide energy for many years now. More recently, fusion test reactors have been built and planned as another means to fill the energy quota. A large part of understanding the fundamental principles in a fusion reactor focuses on the principles of plasma physics. This topic of plasma physics has been studied for many decades and much progress has been made in its understanding.

More recently, computers have become larger and faster allowing for …

Cougar Predation Behavior In North-Central Utah, Dustin L. Mitchell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Today’s ability to apply global positioning systems (GPS) collars to wild animals and track their movements, without inadvertently disrupting their daily routine, is a major benefit to wildlife research. Cougars are carnivorous predators that have been identified as being one of several possible causes for recent mule deer population declines throughout the Western United States. Past cougar predation studies have relied on snow tracking, radio-collar tracking, and modeling techniques to estimate cougar prey use and predation rates. These methods rely heavily on weather conditions, logistical availabilities, and broad assumptions, which have led to a wide range of predation rate estimates. …

Study Of Genes Relating To Degradation Of Aromatic Compounds And Carbon Metabolism In Mycobacterium Sp. Strain Kms, Chun Zhang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Polycyclic aromatic hydrocarbons are produced from incomplete combustion of organic materials by human or natural activities. These polycyclic aromatic hydrocarbons are classified as pollutants because of their toxic, mutagenic, and carcinogenic characteristics. Mycobacterium sp. strain KMS, isolated from a contaminated soil, grows on the model polycyclic aromatic hydrocarbon, pyrene, with its degradation to water and carbon dioxide. This study locates genes on the chromosome and plasmids of isolate KMS relating to pyrene degradation, elucidates the influence of other carbon sources available in the habitats of isolate KMS on degradation of pyrene, and deduces possible metabolic pathways used by isolate …

Particle Dynamics And Resistivity Characteristics In Bifurcated Current Sheets, Tushar Andriyas

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Charged particle chaos and its collective effects in different magnetic geometries are investigated in a sequence of various numerical experiments. The fields generated by the particles as a result of interaction with the background electric and magnetic fields is not accounted for in the simulation. An X-line is first used to describe the geometry of the magnetotail prior to magnetic reconnection and a study of the behavior of charged particles is done from a microscopic viewpoint. Another important geometry in the magnetotail prior to substorm onset is Bifurcated Current Sheet. The same analysis is done for this configuration. The existence …