Physical Sciences and Mathematics Commons^™

Heterogeneous And Homogeneous Nickel-Based Electrocatalysts For Oxygen Evolution And Carbon Dioxide Reduction, Meili Sheng

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The growing global energy demand and the increasing concentration of CO₂ in the atmosphere have encouraged the development of renewable energy to replace carbon-based fossil fuels. Electrocatalytic water splitting to form H₂ and O₂ and reduction of CO₂ to CO are appealing processes and we can be directly utilize H₂ and CO as fuels or commodity chemicals in mature industrial processes, which will not alter the current carbon cycle. However, the O₂ evolution reaction of water splitting is a reaction of four-proton and four-electron transfer process, whose kinetics is very sluggish under normal conditions. …

Connection Between The Midlatitude Mesosphere And Sudden Stratospheric Warmings As Measured By Rayleigh-Scatter Lidar, Leda Sox, Vincent B. Wickwar, Chad Fish, Joshua P. Herron

Faculty publications

While the mesospheric temperature anomalies associated with Sudden Stratospheric Warmings (SSWs) have been observed extensively in the polar regions, observations of these anomalies at midlatitudes are much more sparse. The Rayleigh-scatter lidar system, which operated at the Center for Atmospheric and Space Sciences on the campus of Utah State University (41.7°N, 111.8°W), collected a very dense set of observations, from 1993 to 2004, over a 45–90 km altitude range. This paper focuses on Rayleigh lidar temperatures derived during the six major SSW events that occurred during the 11 year period when the lidar was operating and aims to characterize the …

Exploiting Self-Organization In Bioengineered Systems: A Computational Approach, Delin Davis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bio-reactors, also known as microbial factories are used extensively to produce various industrially valuable products. However, scalability and stability of these factories are limited as it is difficult to deliver nutrients and extract product and waste from a large system. Current solution approaches explore changes in the physical configuration of the bio-reactors. Inspired from the nutrient delivery mechanisms of large organisms in nature, this work studies the possibilities of exploiting self-organizing bio-engineered cells which are capable of organizing into a vessel network to support the producer cells in the factory.

Primary goal of this dissertation is to design a proof-of-concept …

Structural And Lithological Influences On The Tony Grove Alpine Karst System, Bear River Range, North-Central Utah, Kirsten Bahr

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Caves are access points into the subsurface for humans, water, and, in many cases, contaminants. Many caves are connected via a series of conduits that carry water from one cave to another and, eventually, to a spring. However, because most of these conduits are inaccessible, it is difficult to determine the pathway groundwater takes on its way to the spring. The primary objective of this study was to examine the effects of folds, fractures, and rock type upon the formation and orientation of cave passages as well as groundwater flow patterns in the Tony Grove alpine karst system.

Although water …

Investigation Into Regional Climate Variability Using Tree-Ring Reconstruction, Climate Diagnostics And Prediction, Daniel A. Barandiaran

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This document summarizes research conducted to develop and apply climate analysis tools toward a better understanding of the past and future of climate variability in the state of Utah. Two pilot studies developed analysis tools through the investigation of natural variability in precipitation systems in Africa, and research into long-term changes and trends in spring rainfall over the U.S. Great Plains. Our third study used tree-ring data to estimate snowpack in the state of Utah to 1850, doubling the length of record and offering a better understanding of the history of snowpack in the state. Our final study looked at …

Aligning Conservation Goals And Management Objectives For Bonneville Cutthroat Trout (Oncorhynchus Clarki Utah) In The Logan River, Utah, Harrison E. Mohn

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Rivers are often managed without informed knowledge of how sportfish use different areas of the river to reproduce, and rarely take into account the relationship between fish movement and how they are distributed within the river when making management decisions. The population of native Bonneville cutthroat trout (Oncorhynchus clarki utah) within the Logan River is the largest documented population remaining for this imperiled species, and still maintains extremely high numbers of fish in the upper river. Currently, fishing is not allowed in the upper 20 kilometers of the Logan River watershed during spawning, based on the assumption that …

Hydra Effects In Stable Communities And Their Implications For System Dynamics, Michael H. Cortez, Peter A. Abrams

Mathematics and Statistics Faculty Publications

A hydra effect occurs when the mean density of a species increases in response to greater mortality. We show that, in a stable multispecies system, a species exhibits a hydra effect only if maintaining that species at its equilibrium density destabilizes the system. The stability of the original system is due to the responses of the hydra-effect species to changes in the other species’ densities. If that dynamical feedback is removed by fixing the density of the hydra-effect species, large changes in the community make-up (including the possibility of species extinction) can occur. This general result has several implications: (1) …

H-Bonding And Stacking Interactions Between Chloroquine And Temozolomide, Okuma Emile Kasende, Vincent De Paul Nzuwah-Nziko, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

The interactions between temozolomide and chloroquine were examined via Dispersion-Corrected Density Functional Theory and MP2 methods. Chloroquine was considered in both its lowest energy structure and in a local minimum where its aromatic system and secondary amine group are free to interact directly with temozolomide. The accessibility of these two components to intermolecular interaction makes the lowest energy dimer of this local monomer minimum competitive in total energy with that involving chloroquine’s most stable monomer geometry. In either case, the most stable heterodimer places the aromatic ring systems of the two molecules parallel and directly above one another in a …

Opal Cubesatellite Flight And Line Of Sight Integration Modeling, Kenneth Zia

Physics Capstone Projects

The Optical Profiling of the Atmospheric Limb (OPAL) mission is funded by NSF to gather global thermosphere temperatures. OPAL will be able to resolve the temperature profiles through observing day-time emissions of O₂ A-band (~760nm) emissions. This is done by using integrated line-of-sight measurements of the A-band through a tangential view of the atmosphere down to 90km and up to 140 km. The OPAL instrument is on a 3U CubeSatellite (30cm×10cm×10cm) and is expected to follow the International Space Station (ISS) orbit (~400km altitude). Having an accurate model of the OPAL CubeSatellite’s position and the attitude of its optical …

Algorithms For The Optical Profiling Of The Atmospheric Limb Radiometry Data Analysis For The Opal Cubesat, Eric D. Ashby

Physics Capstone Projects

The Optical Profiling of the Atmospheric Limb (OPAL) mission is a CubeSat (NSF) project with aims to measure the temperature in the thermosphere between 90 and 140 km. The temperatures are inferred from the characteristic emission lines of molecular oxygen called the O2 A-band (around 760 nm). These temperatures will be used to better understand the evolution of the upper atmosphere during a solar storm and to analyze the temperature signatures of gravity waves. Multiple steps are required to retrieve temperature data from the OPAL satellite. Initially, the data must be deconvoluted from line-of-sight images. Spectral data must then be …

Dynamical Spacetime Symmetry, Benjamin Lovelady, James Thomas Wheeler

Physics Student Research

According to the Coleman-Mandula theorem, any gauge theory of gravity combined with an internal symmetry based on a Lie group must take the form of a direct product in order to be consistent with basic assumptions of quantum field theory. However, we show that an alternative gauging of a simple group can lead dynamically to a spacetime with compact internal symmetry. The biconformal gauging of the conformal symmetry of n-dimensional Euclidean space doubles the dimension to give a symplectic manifold. Examining one of the Lagrangian submanifolds in the flat case, we find that in addition to the expected SO(n) connection …

Temperature Recognition Algorithm For The Opal Mission, Eric Ashby, Ludger Scherliess

Student Research Symposium

The Optical Profiling of the Atmospheric Limb (OPAL) mission is a CubeSat project with aims to measure the temperature in the thermosphere between 90 and 140 km. The temperatures are inferred from the characteristic emission lines of molecular oxygen called the O2 A-band (around 760 nm). These temperatures will be used to better understand the evolution of the upper atmosphere during a solar storm and to analyze the temperature signatures of gravity waves. Multiple steps are required to retrieve temperature data from the OPAL satellite. Initially, the data must be deconvoluted from line-of-sight images. Spectral data must then be converted …

Mineral Physics Modeling Of The Effect Of Water On Crustal Seismic Velocity Ratios, Eric Lyman, Anthony Lowry Phd

Student Research Symposium

This poster presents the relationship between the presence of water (H2O) in the make up of rocks at different levels in the crust. The relationships were calculated using Perple_x software to adjust the level of the different chemical and mineral make up of the rock. The densities were calculated using the velocity of primary waves and shear waves as collected by Tony Lowry. This study focuses primarily on quartz content. There seems to be at least a casual link between water content and quartz content.

Wormholes - Gates To The Stars?, Samuel Shreeve, Jim Wheeler

Student Research Symposium

One of the most consistently fascinating results of Albert Einstein’s theory of general relativity is the prediction of wormholes – astronomical objects which are, among other things, capable of serving as a connection between two distant regions of space. The simplest class of wormholes are Schwarzschild wormholes – wormholes that behave as non-rotating, non-charged black holes, except that the event horizon serves as a connection to another wormhole elsewhere, instead of a point of no return.

This research presentation analyzes the attributes that make a Schwarzschild wormhole unsuitable for human travel, and examines the conditions that would have to hold …

Opal Cubesatellite Flight And Line Of Sight Integration Modeling, Kenneth Zia, Ludger Scherliess

Student Research Symposium

Understanding the lower thermosphere, the range of 90km to 140km above the surface of the Earth, is a growing interest for many areas of research within space weather. The Optical Profiling of the Atmospheric Limb (OPAL) mission is funded by NSF to gather global thermosphere temperatures. OPAL will be able to resolve the temperature profiles through observing day-time emissions of O2 A-band (~760nm) emissions. This is done by using integrated line-of-sight measurements of the A-band through a tangential view of the atmosphere down to 90km. The OPAL instrument is on a 3U CubeSatellite (30cm×10cm×10cm) and is expected to follow the …

Stable Isotope And Radiocarbon Analysis Of Modern Lacustrine Stromatolites Near Great Salt Lake, Utah, Jordan L. Jensen, Dennis L. Newell, W. David Liddell

Student Research Symposium

Stromatolites are accretionary structures that form mainly from bacteria colonization in subaqueous environments and comprise mostly calcium carbonate (CaCO3). They can be found throughout the rock record (Archean-present day) and modern stromatolites are now restricted to areas that have few or no grazing animals. The hypersaline Great Salt Lake in Utah is host to numerous modern stromatolites, which are currently exposed to the air because of low lake levels. Here, we present C and O isotopic data and radiocarbon dates from a transect of a stromatolite dome (SD-1-01). Carbon and oxygen isotopic values covary strongly along the transect and range …

Computational Methods In Modeling Fusion Plasmas, Joseph R. Jepson, Eric D. Held

Student Research Symposium

Fusion provides an attractive potential alternative to using fossil fuels for energy. Fusion requires vastly less fuel resources than does current non-renewable energy processes (virtually a 100% reduction in the required mass of fuel needed). The fuel sources needed (mainly deuterium and lithium) are also highly abundant on the Earth and fusion generates minimal waste products. One of the biggest obstacles to practical fusion energy is how to contain the reactants long enough for energy output to significantly exceed energy input. The equations governing plasma dynamics and confinement are highly nonlinear and do not admit simple analytic solutions in realistic …

Uv Degradation Effects: Terrestrial Versus Space Environment, Katie Gamaunt, Krysta Moser, Alex Souvall, Jr Dennison

Posters

The decrease in visible and ultraviolet transmission spectra of polymeric and glass spacecraft materials has been measured to determine the extent of degradation due to high energy UV radiation similar to the solar spectrum (both above and below the stratosphere). This project looked at the effects that the atmosphere has in regards to blocking UV radiation and thus, slowing down the UV degradation process. Materials such as quartz, borosilicate glass, sodium glasses, polyethylene, polyimide, and polyethylene terephthalate polymers were exposed to radiation from a focused high intensity deuterium lamp source, which generates radiation in the UVA and UVB spectrum. Duplicates …

Dependence Of Electrostatic Field Strength On Voltage Ramp Rate For Spacecraft Materials, Krysta Moser, Allen Andersen, Jr Dennison

Conference Proceedings

This work investigated the dependence of electrostatic field strength for spacecraft materials on voltage ramp rate, by applying an increasing electrostatic field until electrostatic breakdown occurred.

Tests on the polymeric material Kapton ETM found that at ramp rates two or three orders of magnitude lower than the maximum recommended rate, FESD was lower than at rapid rates by a factor or two or more this suggests that tabulated values of FESD which have been used by the spacecraft charging community can substantially overestimate FESD in common slowly evolving spacecraft situations. Similar measurements on other polymeric materials have been performed to …

Absolute Electron Emission Calibration: Round Eobin Tests Of Au And Graphite, Jr Dennison, Justin Christensen, Justin Dekany, Clint Thomson, Neal Nickles, Robert E. Davies, Mohamed Belhaj, Kazuhiro Toyoda, Kazutaka Kawasaki, Isabel Montero, Maria E. Dávil, Leandro Olano, Luis Galán

Conference Proceedings

This study presents a round robin comparison of absolute electron yields of conducting and insulating materials performed in four international laboratories. Measurements are reported for two standard elemental conducting samples with reproducible sample preparation for Au and highly oriented pyrolytic graphite (HOPG). The primary objectives of the study were to determine the consistency and uncertainties of these absolute yields measurements, and to investigate the effects of the similarities and differences of the diverse facilities. In this initial round robin study, HOPG total electron yield results were found to be more reproducible than those for Au. Surface contamination significantly affected the …

Extremely Low Secondary Electron Emission From Metal/Dielectricparticulate Coatings, Isabel Montero, L Aguilera, Leandro Olano, María E. Dávila, V. Nistor, L. Galán, Jr Dennison, Gregory Wilson

Conference Proceedings

We have studied the SEY behaviour of a particulate coating composed of a mixture of a metal (aluminum) in solid state contact with a particulate dielectric material (polyimide thermosetting resin). Surface charging, roughness, and volume fraction are utilized as the main parameters to characterize the electron emission behaviour. Apart from the important role played by surface composition in the SEY, the influence of the dielectric volume fraction has demonstrated to be critical to achieve a significant reduction of SEY. it was found that E1 of the particulate sample increased with increasing dielectric volume fraction. An extremely high first crossover energy, …

Pulsed Electroacoustic System Development For Volume Charge Distribution Measurement In Thin Dielectric Films, Lee H. Pearson, Jr Dennison, Erick W. Griffiths, Anthony C. Pearson

Conference Proceedings

This paper discusses an effort to develop advanced pulsed electroacoustic (PEA) measurement system capabilities that incorporate state-of-the-art hardware and improved signal processing and modeling to characterize embedded charge distributions in thin dielectric films. Objectives in developing this system include: (1) improved spatial resolution, while maintaining reasonable temporal resolution; (2) improved signal processing tools for increased signal/noise ratios; (3) integrated PEA modeling tools; and (4) integrated environmental controls. We emphasize system improvements required to achieve high spatial resolution for in vacuo measurements of thin dielectrics charged using electron beam injection, which are most applicable for spacecraft charging tests. PEA measurement systems …

Temporal And Spatial Correlations In Electron-Induced Arcs Of Adjacent Dielectric Islands, Justin Christensen, Jr Dennison, Justin Dekany

Conference Proceedings

This study investigated coincidence behaviour of a common form of electron-induced light emission [6]. These very short duration(

Synergistic Models Of Electron Emission And Transport Measurements Of Disordered Sio2, Jr Dennison, Jodie Corbridge Gillespie, Allen Andersen, Amberly Evans Jensen, Gregory Wilson, Justin Dekany, Alec Sim, Ryan C. Hoffmann

Conference Proceedings

An important way for the spacecraft charging community to address the expanding necessity for extensive characterization of electron emission and transport properties of materials is to expand the role of more fundamental materials physics. This includes the development of unifying theoretical models of the charge transport equations based on the creation, distribution, and occupancy of defect densities of states. Models that emphasize the synergistic relation between fitting parameters for diverse measurements can also lead to a better understanding of materials and facilitate solutions to spacecraft charging issues. As an example of this approach, we present results of many different measurements …

Perspectives On The Distributions Of Esd Breakdowns For Spacecraft Charging Applications, Allen Andersen, Krysta Moser, Jr Dennison

Posters

Electrostatic discharge (ESD) continues to pose significant risks to space missions despite decades of intense study. We emphasize here the advantages to spacecraft designers and modelers from considering the stochastic distributions of breakdown and how it can be affected by factors including spacecraft environment conditions, design geometries, material temperature, material purity, charging history, and appropriate timescales. Spacecraft charging models and spacecraft designs typically rely on tabulated values or ranges of breakdown strength, often based on cursory measurements with little or no experimental detail. Depending on the timescales and history of environmental and orbital changes or durations of specific missions, it …

Extremely Low Secondary Electron Emission From Metal/Dielectric Particulate Coatings, Isabel Montero, L Aguilera, Leandro Olano, María E. Dávila, Luis Galán, Jr Dennison, Gregory Wilson

Presentations

Research on low secondary electron emission coatings is essential for the design and manufacture of space high-power RF devices without multipactor discharge. This paper discusses some of the factors that reduce secondary electron emission for metal-dielectric surfaces. We have studied the total electron yield (TEY) behavior of a particulate coating composed of a mixture of a metal (aluminum) nanoparticulates in solid state contact with a particulate dielectric material (polyimide thermosetting resin). Surface charging, roughness, and volume fraction are utilized as the main parameters to characterize the electron emission behavior, which can effectively be determined by continuous (total dose 42.5 nC/mm …

Determining Intrinsic Electron Emission Yields Of High Resistivity Ceramic Materials, Jr Dennison, Justin Christensen, Justin Dekany

Presentations

We describe and contrast methods for measuring the intrinsic—or zero-accumulated charge limit—electron emission yields of highly insulating materials with relatively large yields. The intrinsic electron yield is an essential measure of how charge will accumulate in such materials exposed to space environment fluxes and for predicting and mitigating spacecraft charging effects. There are three commonly used methods to determine the intrinsic electron yield: (i) the DC-yield method, which ratios constant incident and emission currents; (ii) the pulsed-yield method, which ratios integrated charge of short-duration, low-current pulses, thereby minimizing the amount of charge being deposited into the material during a measurement, …

The Deep Propagating Gravity Wave Experiment (Deepwave): An Airborne And Ground-Based Exploration Of Gravity Wave Propagation And Effects From Their Sources Throughout The Lower And Middle Atmosphere, David C. Fritts, Ronald B. Smith, Michael J. Taylor, James D. Doyle, Stephen D. Eckermann, Andreas Dörnbrack, Markus Rapp, Bifford P. Williams, Pierre-Dominique Pautet, Katrina Bossert, Neal R. Criddle, Carolyn A. Reynolds, P. Alex Reineke, Michael Uddstrom, Michael J. Revell, Richard Turner, Bernd Kaifler, Johannes S. Wagner, Tyler Mixa, Christopher G. Kruse, Alison D. Nugent, Campbell D. Watson, Sonja Gisinger, Steven M. Smith, James J. Moore, William O. Brown, Julie A. Haggerty, Alison Rockwell, Gregory J. Stossmeister, Et Al. Et Al.

Publications

The Deep Propagating Gravity Wave Experiment (DEEPWAVE) was designed to quantify gravity wave (GW) dynamics and effects from orographic and other sources to regions of dissipation at high altitudes. The core DEEPWAVE field phase took place from May through July 2014 using a comprehensive suite of airborne and ground-based instruments providing measurements from Earth’s surface to ∼100 km. Austral winter was chosen to observe deep GW propagation to high altitudes. DEEPWAVE was based on South Island, New Zealand, to provide access to the New Zealand and Tasmanian “hotspots” of GW activity and additional GW sources over the Southern Ocean and …

Yeast For Mathematicians - A Ferment Of Discovery, Matthew Lewis, James A. Powell

Mathematics and Statistics Faculty Publications

In addition to the memorization, algorithmic skills and vocabulary which are the default focus in many mathematics classrooms, professional mathematicians are expected to creatively apply known techniques, construct new mathematical approaches and communicate with and about mathematics. We propose that students can learn these professional, higher-level skills through Laboratory Experiences in Mathematical Biology which put students in the role of mathematics researcher creating mathematics to describe and understand biological data. Here we introduce a laboratory experience centered on yeast (Saccharomyces cerevisiae) growing in a small capped flask with a jar to collect carbon dioxide created during yeast growth …

Channel Movement, Error Analysis, And Impacts For Neighboring Landowners: A Lower Bear River, Ut Case Study, Russell Babb, Kellie Shawn, Todd Brown, Ayman Alafifi, David Rosenberg

Spring Runoff Conference

The Bear River Fellows program is a unique learning experience for undergraduate students giving hands-on experience in collecting, synthesizing, and analyzing environmental and ecological data. The Bear River is an important resource that provides water to farms, reservoirs, wetlands, wildlife, and hydropower generation. Because of the river’s value, it is important to understand how the Bear River channel moves and how that affects the surrounding landscape, which is a topic of interest for local land owners but especially conservationists in protecting wetlands and river ecology. We collected hydrological, topologic, and vegetative data from three persisting research sites along an 8 …