Physical Sciences and Mathematics Commons^™

Colorado River Basin Water Accounts: 1-Page Summary, David E. Rosenberg

Civil and Environmental Engineering Faculty Publications

26 Colorado River managers and experts constructively improved basin water accounts as a framework to transition emergency reservoir operations into more sustainable, equitable, and adaptive water uses.

Effects Of Exposure To Atmospheric Humidity On Breakdown Field Strength Measurements Of Polymers, Megan Loveland Dewaal

Physics Capstone Projects

This study investigates the effects of absorbed water introduced via exposure to atmospheric humidity on electrostatic breakdown field strength measurements of polymers. Conducting breakdown tests under sample conditions appropriate for different applications is essential. If the breakdown field strength is overestimated for an application, an insulator may be used inappropriately in high electric fields where they are more likely to break down. Comparisons are made between: sets of pristine samples, samples that underwent a thorough vacuum bake out to remove absorbed water, and samples subject to subsequent incremental prolonged atmospheric exposure. These investigated the effects of absorbed water and determined …

Examining Cultural And Chemical Treatments To Fusarium Bulb Rot In Onions, Tim Miller

Fall Student Research Symposium 2022

Onions are grown in 1,500 acres in northern Utah and are a large part of growers' income. In the fall of 2021, 30% of a grower's onion yield was affected by Fusarium bulb rot (caused by a fungus known as Fusarium proliferatum) and the onions were unmarketable. The literature surrounding this pathogen is sparse and losses of this magnitude could cause growers to lose between six and seven thousand dollars per acre. Samples of the fungus were plated onto potato dextrose agar at half strength and maintained fresh throughout the winter. In vitro experiments were performed with various fungicides at …

Assessing The Impact Of Storage Time And Shape Of The Block On The Slicability Of Commercial Cheddar Cheese, Nathan Pace

Fall Student Research Symposium 2022

Cheddar cheese is one of the world's most popular cheeses and is consumed in blocks and slices. The slicability of cheddar cheese can depend on textural and rheological properties. Understanding these characteristics can enhance desirability and reduce material loss occurring during slicing. In this study, we focused on four main parameters: slice thickness, cheese shape, storage period, and cheese type. Four thicknesses (0.5, 1.0, 1.5, and 2.0 mm) and two shapes (triangular and square) of mild, medium, sharp, and extra sharp were selected. Cheeses were purchased from Walmart and the Utah State University creamery. At first, cheese blocks were cut …

Why America Should Switch To Nuclear Energy As Its Primary Power Source, William Fike

Fall Student Research Symposium 2022

While nuclear waste and public fear hurt the image of nuclear energy, I believe that nuclear energy should be used instead of alternative power sources because it is safe, carbon-free, and more fuel efficient than alternative energy sources. Nuclear power is the process of using uranium 235 to make energy. Nuclear energy is a very clean and safe energy producer. My target audience would be someone who does not know a lot about nuclear power. Or they are possibly scared because of past nuclear disasters. My goal in this poster is to convince you that nuclear power is safe and …

Electron Yield Measurements Of Highly Insulating Granular Samples Related To Charging Of Dusty Plasmas, Heather Allen

Fall Student Research Symposium 2022

Reliable electron yield (EY) measurements of highly insulating granular particles have long been considered too difficult to collect due the many experimental complexities that arise from the nature of the granular materials. This has led to a critical knowledge gap for both engineering strategies and basic science issues essential for myriad important space applications. This talk will emphasize the preliminary EY measurements of highly insulting granular samples we have collected, including a range of samples with typical particle size ranging from ~1 μm to ~100 μm, samples with cubical, spherical and highly angular particle shapes, studies of highly angular Al2O3 …

Effects Of Exposure To Atmospheric Humidity On Breakdown Field Strength Measurements Of Polymers, Megan Loveland Dewaal

Fall Student Research Symposium 2022

This study investigates the effects of absorbed water introduced via exposure to atmospheric humidity on electrostatic breakdown field strength measurements of polymers. Conducting breakdown tests under sample conditions appropriate for different applications is essential. If the breakdown field strength is overestimated for an application, an insulator may be used inappropriately in high electric fields where they are more likely to break down. Comparisons are made between: sets of pristine samples, samples that underwent a thorough vacuum bake out to evaporate absorbed water, and samples subject to subsequent incremental prolonged atmospheric exposure. These investigated the effects of absorbed water and determined …

Light Scattering From Periodic Conducting Nanostructures, Wesley Mills

Fall Student Research Symposium 2022

Carbon nanotube (CNT) forests are roughly vertically aligned carbon tubes with a diameter of a few nanometers, and a height of hundreds of micrometers. CNT forests of proper densities and heights can be excellent absorbers of visible light, so a lot of interest has been generated in their application in optical calibration, energy conversion, antireflection, and radiometry. Unfortunately, reflectance from CNTs rises quickly above the mid-infrared range, limiting their present use. Improving a CNT-based broadband absorber requires understanding why the forests have almost zero visible-light reflectance, as well as a strategy to extend that low reflectance into longer wavelengths. Since …

How Does Perceived Human Instability Affect One's Own Stability?, Madi Braunersrither

Fall Student Research Symposium 2022

Participants were prompted to evaluate the stability of pictured human postures while standing on a force plate. We measured irregularity by analyzing the presence of patterns in the sequential center of pressure values. To measure the presence of patterns, sample entropy, a time series statistic, was developed and we utilized it on the force plate data. Does one's own stability change when viewing a posture deemed unstable? Is Sample Entropy (SampEn) an effective tool to determine stability? This relationship could have implications for modeling the progression of motor skills, understanding human development, and the design of environments for rehabilitation.

The Stigma Against Elderly Drivers And An Analysis Of The Effects Of Age On Driving Ability, Alexander Lee

Fall Student Research Symposium 2022

Elderly drivers are not as big of a danger on the road as the general population believes. This was preliminary research into the significance of elderly drivers on the road and the statistical data on whether they are a hazard on the road. They are among the minority of people that are in car accidents and most elderly people still on the road are more experienced and drive safer to compensate for ailments they may experience from their age. Elderly that can not drive safely or can pose a hazard on the road usually remove themselves from driving or are …

Investigating The Color-Changing Properties Of Poly-Phenyl Sulfide, Dallen Dewaal

Fall Student Research Symposium 2022

Investigating the Color-Changing Properties of Poly-Phenyl Sulfide Dallen DeWaal, Megan Loveland DeWaal, Heather Allen, JR DennisonMaterials Physics Group, Physics Department, Utah State UniversityAbstractWhile preparing samples of FortronTM PPS (poly-phenyl sulfide) for spacecraft charging testing, it was discovered that the polymeric dielectric material exhibits color-changing properties from mechanical forces while shearing and bending. Given enough time, PPS reverts from blue-green back to its original tan color. PPS samples were characterized by the magnitude of color change and recovery time. PPS samples were subjected to multiple tests to discover which forms of energy input activate the color change, and which (if any) …

The Effect Of The Plant-Based Diet On Athletes And Its Limitations, Dylan Hill

Fall Student Research Symposium 2022

In this study, I was hoping to learn more about the differences between the omnivore diet and plant-based diet in relation to the effects on an athlete. Research was conducted using library and internet resources to locate both primary and secondary research. For this study, personal accounts and experiences of athletes who had experimented with a plant based diet were examined. Research showed that although a very enticing option for a healthy diet for athletes, the plant-based diet is just as effective as a balanced omnivore diet but much more difficult to do properly and is much less accessible to …

Spacecraft Charging Test Considerations For Composite Materials, Allen Andersen, Wousik Kim, J. R. Dennison, Brian Wood, Todd A. Schneider, Jason Vaughn, Kenneth H. Wright Jr., Nelson W. Green, Eric Suh, Joel Schwartz, Abdul-Majeed Azad

Journal Articles

Composite materials present a growing challenge for spacecraft charging assessments. We review some recent lessons learned for charging tests of composite materials using both parallel-plate and electron beam test geometries. We also discuss examples of materials that exhibit significant variations between samples, despite them all having the same trade name.

A Study Of Electron Plasma Oscillations Using The Nimrod Code, Mckay Murphy

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

A plasma, whether ”hot” or ”cold,” magnetized or unmagnetized, electrostatic or electromagnetic, exhibits normal modes of oscillation. Critical to understanding the stability of a plasma is the study of these normal modes. Waves originate from the long-range electric interactions between charged particles. This work will consider a class of waves known as Langmuir waves. These waves occur when a group of electrons are displaced with respect to the ions, with the electric Coulomb force playing the role of the restoring force of the oscillation [1]. Since the mass of ions is much greater than that of electrons, we can approximate …

Graviweak Theory In Bicomformal Space, Mubarak Ukashat

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

There are four basic forces in nature: the electromagnetic force, which accounts for interactions of particles with charges; the weak force, which is responsible for radioactive decay; the strong force, which holds the particles inside a nucleus tightly bound together; and the gravitational force, which is responsible for keeping us on our beautiful planet, Earth and holding together our entire solar system. Physicists have been on the hunt for a theory that can single-handedly explain all these forces under the same underlying mathematical formulation. So far, physicists have suceeded in unifying the electromagnetic and weak forces in what is called …

Power Approximations For Generalized Linear Mixed Models In R Using Steep Priors On Variance Components, Sydney Geisler

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

When designing an experiment, researchers often want to know how likely they are to detect statistically significant effects in the resulting data, i.e., they want to estimate their statistical power. The probability distribution method is a flexible way to do this, and it is currently implemented in the statistical software package SAS. This method requires a hypothetical data set (showing the magnitude of hypothesized effects) and constant values of variance components, which are critical elements of the statistical models used. The statistical software package R is increasingly popular, but the probability distribution method has not yet been implemented in R, …

Human Appropriation Of Net Primary Production Through Crops, Grazing, And Forestry In The U.S. From 1997 To 2012, Suman Paudel

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This dissertation conducts a county-level analysis of human appropriation of net primary production (HANPP) harvested from crops, timber and grazing in the conterminous United States in the years 1997, 2002, 2007 and 2012. This study consists of three manuscripts (Chapters 2, 3, and 4). The first study quantifies net primary production in US counties in 1997, 2002, 2007 and 2012. The detailed HANPP study conducted concludes that HANPP is a valuable footprint tool for analyzing land use intensity and agricultural ecosystems. The second manuscript shows how HANPP is an improved or modernized ecological footprint and is a sustainable indicator as …

Data Visualization, Dimensionality Reduction, And Data Alignment Via Manifold Learning, Andrés Felipe Duque Correa

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The high dimensionality of modern data introduces significant challenges in descriptive and exploratory data analysis. These challenges gave rise to extensive work on dimensionality reduction and manifold learning aiming to provide low dimensional representations that preserve or uncover intrinsic patterns and structures in the data. In this thesis, we expand the current literature in manifold learning developing two methods called DIG (Dynamical Information Geometry) and GRAE (Geometry Regularized Autoencoders). DIG is a method capable of finding low-dimensional representations of high-frequency multivariate time series data, especially suited for visualization. GRAE is a general framework which splices the well-established machinery from kernel …

Investigations Of Prokaryotic Defense Systems, Hannah Domgaard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bacteria are constantly threatened with infection by mobile genetic elements (MGE) such as bacteriophage and plasmids. Bacteriophage and plasmids require the bacteria's cellular infrastructure to replicate their genomes. Rampant replication can lead to cell death which is one reason why bacteria have developed a diverse array of immune systems to prevent or limit infection. This thesis studies three types of bacterial immune systems, type IV-A CRISPR-Cas (Clustered Regularly Interspaced Short Palindromic Repeat –CRISPR associated), type V-A2 CRISPR-Cas systems, and Wadjet systems.

The type IV-A system lies adjacent to a dinG-like helicase gene. Research has shown that this system can target …

River Response To Sediment Supply: The Sand Bed Case, Christina M. Leonard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Effective management of in-channel and floodplain habitat requires an ability to forecast river response to changes in water and sediment supply. These changes may result from dam construction/decommissioning, changes in reservoir operations, or changes in grazing or forestry practices. If a change in water and sediment supply causes sediment to be delivered faster than the channel’s capacity to transport it, sediment will accumulate in the reach, leading to changes in channel form and increasing the potential for flooding. A decrease in sediment supply relative to transport capacity can lead to channel incision. The extent and timing of sediment accumulation or …

Investigating Atmospheric Gravity Waves Using 3-Dimensional Spectral Analysis, Kenneth I. Zia

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Atmospheric gravity waves (GW) are generated from the ground and go into the upper layers of the atmosphere where space begins. These waves have strong effects on the temperature and circulation of the Earth’s atmosphere. The temperature changes caused by these waves are observed through special cameras looking at light that the Earth’s atmosphere naturally emit at night. One of these cameras is placed at McMurdo Station, Antarctica where the long nights are used to see these waves longer than anywhere else. The images captured there are automatically analyzed to determine wave properties to better understand how often they are …

Old-Growth Forest Dynamics After Fire And Drought In The Sierra Nevada, California, Usa, Kendall M.L. Becker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Understanding forest ecosystems is important because forests cover approximately one-third of Earth’s land area, store half of Earth’s carbon, shelter half of Earth’s species, and absorb a quarter of new anthropogenic carbon emissions, slowing climate change. This dissertation provides insight into future forest habitat, fuels, species composition, and structure by investigating what happens to snags, seedlings, and trees in an old-growth forest after a low- to moderate-severity fire.

Chapter II explores how low- to moderate-severity fire changes snag fall rates. Predicting how long snags will remain standing after fire is essential for managing habitat, understanding chemical cycling in forests, and …

Bedrock Geology Map Of The Naomi Peak 7.5' Quadangle, Cache County, Utah And Novel Age Constraints On Its Cambrian Strata, Hannah R. Cothren

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Geologists use various “rock-clocks” in order to interpret the timing and tempo of events in Earth’s history. These include global geochemical events in the oceans (chemostratigraphy), the evolution of certain fossil species (trilobite biostratigraphy), and the radiogenic decay of uranium to lead in certain mineral such as zircon (U-Pb geochronology). Integrating these methods in the stratigraphic record in one location can provide a well-constrained timeline for a select part of the Geologic, or Deep Time, record. This technique is especially important in the Cambrian Period (538.8 to 486.9 million years; Ma), which sets the stage for life today with the …

Temperature Dependent Density Of States Models And Compiled Data For Radiation Induced Conductivity, Jodie Gillespie

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Radiation Induced Conductivity (RIC) is the change in conductivity of a material due to bombardment from incident high energy radiation. RIC has consistently been found to follow a standard power law relation, 𝜎_𝑅𝐼𝐶(𝑇) = 𝑘_𝑅𝐼𝐶(𝑇)Ḋ^∆(𝑇), between conductivity, 𝜎_𝑅𝐼𝐶 and adsorbed dose rate, Ḋ. 𝑘_𝑅𝐼𝐶(𝑇) and ∆(𝑇) are material dependent parameters. Previous RIC models were developed in the 𝑇 → 0 limit. Now expanded models are developed in the low temperature limit (within a few 𝑘_𝐵𝑇 of the effective Fermi level) by approximating the Fermi-Dirac equation within a …

Development Of In Situ Second-Order Nonlinear Optical Scatterings For Molecular Behaviors At Aerosol Surfaces, Yuqin Qian

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Aerosol particles are one of the most important components of the atmosphere. During the growth of aerosol particles, they directly or indirectly affect air quality, human health, and environmental chemistry. Therefore, understanding the chemical and physical properties of such particles is an important scientific, engineering, and medical issue. The growth of aerosol particles in the atmosphere is closely related to the chemical structure at its surface, as well as the heterogeneous reactions which take place at and below the particle’s surface. However, there is a lack of suitable surface-specific analytical techniques which directly measure the chemical structure of aerosol particle …

Normative Evaluations Of Resource Conditions: The Influence Of Visitor Characteristics And Implications For Recreation Management In Urban-Proximate Parks, Jordan E. Nesbitt

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Urban-proximate parks and protected areas provide a unique recreation landscape to individuals living in and near urban centers. They have been shown to provide similar recreation experiences to traditionally studied parks and protected areas such as National Parks, National Forests and Wilderness areas. This study takes place in a set of four urban-proximate parks in Orange County, California, USA. These parks are designated as urban-proximate because they are located within 100 miles of an urban center with 1 million or more people. Using norm theory, a well vetted social science theory, this work sought to identify thresholds of acceptability for …

Design Of Environment Aware Planning Heuristics For Complex Navigation Objectives, Carter D. Bailey

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A heuristic is the simplified approximations that helps guide a planner in deducing the best way to move forward. Heuristics are valued in many modern AI algorithms and decision-making architectures due to their ability to drastically reduce computation time. Particularly in robotics, path planning heuristics are widely leveraged to aid in navigation and exploration. As the robotic platform explores and navigates, information about the world can and should be used to augment and update the heuristic to guide solutions. Complex heuristics that can account for environmental factors, robot capabilities, and desired actions provide optimal results with little wasted exploration, but …

Investigating The Use Of Quartz Luminescence And Rock-Color Alteration To Characterize Wildfire Exposure; Applied To The 2020 Mangum Fire, Kaibab Plateau, Arizona, April I. Phinney

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wildfires appear to be increasing in size, severity, and frequency. Land managers need information on past wildfire behavior to make effective and adaptive land management plans. However, there are only a few techniques and data sources that provide information on past fire heating. This study aims to provide new methods to equip managers with a more robust understanding of historic and modern fire behavior. Fire behavior is assessed using novel methods that can assess soil and rock response to past wildfire heat exposure.

This study examined samples from the 2020 Mangum Fire, in northern Arizona. Sediment and rock were gathered …

Statistical Challenges And Methods For Missing And Imbalanced Data, Rose Adjei

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Missing data remains a prevalent issue in every area of research. The impact of missing data, if not carefully handled, can be detrimental to any statistical analysis. Some statistical challenges associated with missing data include, loss of information, reduced statistical power and non-generalizability of findings in a study. It is therefore crucial that researchers pay close and particular attention when dealing with missing data. This multi-paper dissertation provides insight into missing data across different fields of study and addresses some of the above mentioned challenges of missing data through simulation studies and application to real datasets. The first paper of …

Bifurcations And Hysteresis In The Dynamics Of Small Populations Of Spherical Magnets, Peter T. Haugen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

If you heat up some kinds of metals and then cool them down next to a magnet, they will be a magnet when they cool, but if they cool down away from a magnet, they will just be a lump of metal. This is an example of hysteresis and it’s very important for lots of technology. Another example of hysteresis might be a water tower pump that turns on when the tower is nearly empty and keeps going until the tower is nearly full. Whether or not the pump is on when the tower is half full depends on what …