Physical Sciences and Mathematics Commons^™

Investigations Of Sulfurized Polymers For Their Use In Lithium-Sulfur Cells, Alan M. Rowland

All Theses

With the invention of the Lithium-Ion cell in the latter half of the 20th century, there has been a continued endeavor for innovation in compact energy-storage. Combined with the ever-growing need to move away from fossil fuels, electrochemical energy storage has seen a myriad of research projects in the pursuit of finding the ‘beyond-lithium’ cell. One of these projects that I personally assisted with was lithium-sulfur cells, which allow for a significantly greater energy storage capacity when compared to lithium-ion cells. In investigating a popular cathode in lithium-sulfur cells, sulfurized polyacrylonitrile (SPAN), it was hinted that there may be more …

Cohen-Macaulay Type Of Open Neighborhood Ideals Of Unmixed Trees, Jounglag Lim

All Theses

Given a tree T and a field k, we define the open neighborhood ideal N(T) of T in k[V] to be the ideal generated by the open neighborhoods of all vertices in the graph. If T is unmixed with respect to the total domination problem, then it is known that N(T) is Cohen-Macaulay. Our goal is to compute the (Cohen-Macaulay) type of k[V]/N(T) using graph theoretical properties of T. We achieve this by using homological algebra and properties of monomial ideals. Along the way, we also provide a different characterization of unmixed trees and a generalization of the total dominating …

Evaluation Of Future Sea-Level Impacts Using A Sharp Interface Saltwater Intrusion Model, Caroline Hiott

All Theses

Saltwater intrusion is a growing problem that is being exacerbated by climate change. Saltwater intrusion is the process by which saltwater moves towards freshwater supplies driven by saltwater’s greater density compared to freshwater. Saltwater intrusion can contribute to the salinization of freshwater resources, degradation of underground storage tanks, communication systems, and pipelines, as well as lead to groundwater flooding (Ketabchi et al., 2016). Numerical modeling can be used to simulate saltwater intrusion along coastal areas. One of the more computationally efficient modeling tools is the sharp interface approach, SWI2, that is a part of the MODFLOW 2005 suite (Werner et …

Training Uav Teams With Multi-Agent Reinforcement Learning Towards Fully 3d Autonomous Wildfire Response, Bryce Hopkins

All Theses

As climate-exacerbated wildfires increasingly threaten landscapes and communities, there is an urgent and pressing need for sophisticated fire management technologies. Coordinated teams of Unmanned Aerial Vehicles (UAVs) present a promising solution for detection, assessment, and even incipient-stage suppression – especially when integrated into a multi-layered approach with other recent wildfire management technologies such as geostationary/polar-orbiting satellites and CCTV detection networks. However, there remains significant challenges in developing the necessary sensing, navigation, coordination, and communication subsystems that enable intelligent UAV teams. Further, federal regulations governing UAV deployment and autonomy pose constraints on real-world aerial testing, creating a disconnect between theoretical research …

Extraction Of Neutron-Gamma Irradiated Diffusion Pump Oils, Cooper L. Tillman

All Theses

This work successfully demonstrates solvent extraction methods for separation of oil from the by-products when two commercially available vacuum pump oils were exposed to an intense neutron and gamma-ray radiation environment. Nuclear fusion power at a commercial scale has accelerated the need for radiation resistant vacuum technology, such as oil-based diffusion pumps. Polyphenyl ether and aromatic silicone oils were irradiated at the Rhode Island Nuclear Science Center (RINSC) up to MGy absorbed doses with neutron and gamma-ray radiation. Solvent extractions were performed using hexane and isopropanol to characterize the oil extraction as a function of total absorbed dose. The by-products …

Evolution Mechanism Of Organic Macromolecular Structure During Lignite Pyrolysis, Ying Shi, Yanming Zhu, Zhenjiang You, Wu Li, Yang Wang, Yu Song

Research outputs 2022 to 2026

Understanding the mechanisms governing coal pyrolysis reactions, particularly in relation to the coal macromolecular structure, is crucial for improving energy efficiency and facilitating the transition of coal into a clean energy source. This study employs cutting-edge techniques, such as High-Resolution Transmission Electron Microscopy (HRTEM) and Thermogravimetric Analysis coupled with Fourier Transform Infrared Spectroscopy and Mass Spectrometry (TG–FTIR–MS), to analyze lignite and its residual solid samples subjected to pyrolysis across a range of temperatures from 300 °C to 1100 °C. The variational characteristics of the macromolecular structure during coal pyrolysis are examined. Utilizing molecular dynamics simulations, we analyze the evolution mechanism …

Exploring Overbank Sediment Deposition Variation In Heavily Modified Floodplains Of The Lower Mississippi River: A Sedimentological And Geophysical Analysis, Seth Fradella

Master's Theses

Since the 1930s, the Lower Mississippi River (LMR) has experienced large-scale modifications to the channel profile and surrounding floodplains through dams, dikes, revetments, dredging, and channel cutoffs. Although these changes have improved navigation and reduced flood risk, unanticipated changes to the major flood return period, individual flood severity and duration, and sediment regime have become increasingly apparent and sometimes problematic, such as the 2011 and 2018-2020 floods. Flood control levees along the LMR have reduced the natural floodplain area by 70-90%, resulting in heavily restricted overbank storage capacity of water and sediment. For the same flood events in recent history, …

Observation Of Gravitational Waves From The Coalescence Of A 2.5–4.5 M⊙ Compact Object And A Neutron Star, A. Abac, R. Abbott, I. Abouelfettouh, F. Acernese, Teviet Creighton, Mario C. Diaz, Francisco Llamas, Soma Mukherjee, Volker Quetschke, Wenhui Wang

Physics and Astronomy Faculty Publications and Presentations

We report the observation of a coalescing compact binary with component masses 2.5–4.5 M⊙ and 1.2–2.0 M⊙ (all measurements quoted at the 90% credible level). The gravitational-wave signal GW230529_181500 was observed during the fourth observing run of the LIGO–Virgo–KAGRA detector network on 2023 May 29 by the LIGO Livingston observatory. The primary component of the source has a mass less than 5 M⊙ at 99% credibility. We cannot definitively determine from gravitational-wave data alone whether either component of the source is a neutron star or a black hole. However, given existing estimates of the maximum neutron star mass, we find …

Robust Hydropower Planning Balances Energy Generation, Carbon Emissions And Sediment Connectivity In The Mekong River Basin, M. Tangi, Rafael Schmitt, Rafael M. Almeida, S. Bossi, Alexander S. Flecker, F. Sala, A. Castelletti

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

We present a framework for strategic dam planning under uncertainty, which includes GHG emissions mitigation as a novel objective. We focus on the Mekong River Basin, a fast‐developing region heavily relying on river‐derived ecosystem services. We employ a multi‐objective evolutionary algorithm to identify strategic dam portfolios for different hydropower expansion targets, using process‐related and statistical models to derive indicators of sediment supply disruption and GHG emissions. We introduce a robust optimization approach that explores variations in optimal portfolio compositions for more than 5,000 state‐of‐ the‐world configurations, regarding sediment origins and trapping and GHG emissions. Thus, we can rank dam projects' …

A Comprehensive And Interactive Visualization Tool To Support Equitable Adoption Of Electrified Transportation, Aashay Maheshwarkar

All Graduate Theses and Dissertations, Fall 2023 to Present

As urban areas continue to grow, the deployment of electric vehicle (EV) charging infrastructure becomes crucial for sustainable development. This study is focused on the development of a data visualization tool that integrates diverse datasets, including traffic patterns, Points of Interest (POI), pollution levels, and socioeconomic indicators, to analyze the current state and potential expansion of EV charging stations. Our visualization tool highlights the significant impact of EV infrastructure on reducing urban pollution and improving socioeconomic outcomes. Areas with a higher density of charging stations show significantly lower levels of unemployment and pollution, emphasizing the dual benefits of EV adoption. …

Implementing General Moment Equations For Parallel Closures In Nimrod, Hankyu Lee

All Graduate Theses and Dissertations, Fall 2023 to Present

Understanding how magnetic fields impact plasma transport is essential for improving the efficiency of thermonuclear fusion power plants. To address the transport problem, both plasma fluid equations and Maxwell’s equations must be solved. To solve these equations, it is necessary to derive closure relations that allow the system to be closed. Previous closure models are useful for describing the behavior of high-collisionality plasma but are not effective at low collisionality. To obtain closure relations valid for low collisionality, the first-order drift kinetic equation must be solved.

This study presents methods for numerically obtaining parallel closures for NIMROD code by deriving …

Soil Additives And Alternative Crops For Drought Defense In The Intermountain West, Tina M. Sullivan

All Graduate Theses and Dissertations, Fall 2023 to Present

The Western U.S. looks for water optimization and conservation as agriculture is the largest water diverter, and resources are pressured by urban growth, winter snowpack instability, and drought persistence. Agricultural producers have several potential options to optimize water use with different investments associated with them. Options with varying levels of risks and known management practices include alternative crops, soil wetting agents, and crop biologicals.

An alternative crop that grew incredibly fast in popularity was industrial hemp (Cannabis sativa) despite limited agronomic knowledge for best management practices. Field trials occurred (2020-2022) near Logan, UT to test a total of …

Dynamics Of Climate And Tectonics On Surface Processes And Their Sedimentary Archives In The Colorado Plateau And Basin And Range, Usa And The Calabrian Forearc, Sicily, Natalie M. Tanski

All Graduate Theses and Dissertations, Fall 2023 to Present

Landscapes change over time in response to movements of the Earth’s crust and the effects of climate. This dissertation examines how these factors shape different landscapes, focusing on erosion of river canyons in elevated plateaus, how the transport history in quartz sand may be encoded in its properties, and how a paleo-delta has formed in response to sea-level change and fault displacement. I use dating techniques, field methods, and topographic analyses to offer insight into erosional patterns and rates in different landscapes.

Rivers can take a long time to adjust to changes in boundary conditions, even after those changes have …

Hydrogen Stable Isotope Constraints On Hydration Of Colorado Plateau Lower Crust From Oligocene-Miocene Navajo Volcanic Field Xenoliths, Shelby Dianne Litton

All Graduate Theses and Dissertations, Fall 2023 to Present

Understanding flat-slab subduction is crucial as it involves the horizontal movement of an oceanic plate beneath a continental margin over a long distance. This tectonic process is widespread yet not fully understood, particularly regarding how it influences the chemical makeup of the continental plate and recycling in the hydrosphere. By analyzing isotopes, which are variations of certain elements found in minerals and water, we can gain insights into the sources of chemicals and geological processes at play. Our study area included six locations within the Navajo volcanic field (NVF), a region in the Colorado Plateau. We analyzed 23 lower crustal …

Informed Intervention Design, Deployment, And Analysis For The Computer Science Classroom, Jaxton J. Winder

All Graduate Theses and Dissertations, Fall 2023 to Present

Improving the teaching of computer science is a challenging task. Educators and computing education researchers devote large amounts of time, energy, and resources towards doing so effectively. One of the ways this is done is through research-informed design, deployment, and analysis of targeted interventions to the classroom. This thesis will detail research conducted at Utah State University targeting classroom interventions: centered around their design, deployment, and analysis.

One of these interventions aims to tackle student procrastination through the offering of “grace points”–forgiving a small amount of mistakes on a student’s assignment–for analyzing a homework assignment early. Through studying this intervention, …

Fishing Vessel Detection In Exclusive Economic Zones From Low Earth Orbit Satellites With Power And Computational Constraints, Kyler E. Nelson

All Graduate Theses and Dissertations, Fall 2023 to Present

Illegal fishing activities pose a significant threat to the sustainability of marine ecosystems and the economies and societies which rely on them. Detection of fishing vessels engaging in illegal activity is difficult, as many ships engaging in such activity actively avoid detection through radio systems used for maritime traffic monitoring. Satellite imagery provides a promising means for detecting fishing vessels, though designing an effective system is difficult due to limited availability of labeled image datasets of fishing vessels. This research proposes a system to detect illegal fishing activity through the use of a low-power ship detection satellite and proposes a …

Md Simulations Of Collision Effects For A Strongly Coupled Plasma, Jawon Jo

All Graduate Theses and Dissertations, Fall 2023 to Present

Studying strongly coupled plasmas can be effectively accomplished using molecular dynamics (MD) simulations. We have developed an advanced MD simulation code that can analyze plasmas with various coupling parameters. This code employs a spherically symmetric cut-off Coulomb force verified through convergence tests by modulating the cut-off and minimum force ranges. Additionally, it incorporates a new algorithm for optimizing the initial positions of particles at a given temperature. This method maintains the temperature constant and the velocity distribution unchanged. As a result, we eliminate the unphysical initial rises and oscillations in temperature that a random distribution of positions causes. The code …

Using Digitized Building And Weather Records To Improve The Accuracy Of Ground To Roof Snow Load Ratio Estimations, Gideon Parry

All Graduate Theses and Dissertations, Fall 2023 to Present

Reliability target loads refer to the amount of accumulated snow a roof needs to be able to support to ensure that the probability of collapse is sufficiently low. Since ground snow weight, or load, is much easier to measure than roof snow load, models for roof snow loads rely on ground snow load measurements along with a statistical model that estimates roof snow retention as a ratio of the measured ground snow load. This thesis focuses on improving the roof snow retention model using data from Canadian case studies that include information about building geometry and local wind speeds. This …

Shaking Off The Rust: Unraveling The Depositional And Diagenetic History Of Enigmatic Ferroan Dolostones In The Cambrian Bright Angel Formation, Tonto Group, Grand Canyon, Joseph J. Clevenger

All Graduate Theses and Dissertations, Fall 2023 to Present

Within the siliciclastic-sediment-dominated Bright Angel Formation (BAF) of the iconic Cambrian sedimentary strata (Tonto Group) in Grand Canyon National Park, Arizona, workers have identified and named prominent reddish-brown cliffs breaking up the generally slope-forming unit near, but separated from, its upper contact with the limestone-dominated Muav Formation, the "Rusty Brown Dolostones" (RBDs). Previous hypotheses suggest that the RBDs are chemically and physically altered tongues of the Muav Formation intercalated with the BAF at increasingly higher stratigraphic positions from west to east within the Canyon. A genetic association between the Muav Formation and the RBDs, as well as between the RBDs …

Characterizing Gsk3Β Interaction And Kinetics Via Isothermal Titration Calorimetry, W A Bhagya De Silva

UNLV Theses, Dissertations, Professional Papers, and Capstones

Glycogen synthase kinase 3β (GSK3β) is a multifunctional serine/threonine kinase involved in several key signaling pathways, including glycogen metabolism, WNT/β-catenin, and Hedgehog signaling. Hyperactivity of GSK3β has been linked to Alzheimer’s disease, bipolar disorder, type II diabetes, and some cancers. Therefore, GSK3β is of interest as a target for therapeutics. Lithium ion (Li+) is a classical inhibitor of GSK3β. Structurally similar beryllium ion (Be2+) is ~1000-fold more potent. Lithium and beryllium have demonstrated pathway-specific and cell type-specific inhibition of GSK3β, prompting an investigation into the inhibitory mechanisms and thermodynamic characteristics of the metal-enzyme interaction.Isothermal titration calorimetry (ITC) is a label-free …

New Insights Into The Diverse Intraplate Volcanism Present Within The Howland And Baker Island United States Exclusive Economic Zone, Nicholas Foresta

UNLV Theses, Dissertations, Professional Papers, and Capstones

The origin of oceanic volcanism has been attributed to various mechanisms, such as upwelling mantle plumes, lithospheric extension driven decompression melting, and small-scale convective cells in the asthenosphere. Discovering the range of magmatic drivers present in the ocean basins aids in understanding mantle geodynamics and tectonic processes. A recent seafloor exploration campaign within the Howland and Baker Island (HBI) U.S. Exclusive Economic Zone (EEZ; approximately near the equator and the International Date Line) resulted in the collection of multiple lava flow samples, which offer valuable insights into the complex origins and dynamics of intraplate seamounts. According to current absolute plate …

Image Processing Techniques For Water Droplet Penetration Time And Contact Angle Estimation, Sai Balaji Jai Kumar

UNLV Theses, Dissertations, Professional Papers, and Capstones

Water droplet behavior on soil surfaces plays a critical role in numerous environmental processes, including soil erosion, hydrological dynamics, and ecosystem health. Accurate characterization of soil water repellency, quantified by parameters such as water droplet penetration time (WDPT) and contact angles (WDCA), is essential for informed decision-making in agricultural management, forestry practices, and land-use planning. Despite the significance of these parameters, challenges exist in reliably estimating them due to the complex and dynamic nature of soil-water interactions. This thesis address challenges in estimating WDPT and WDCA, by leveraging state-of-the-art image processing techniques and machine learning algorithms. The research focuses on …

Scoring Single-Sample Pathway Expression Level Using Graph Autoencoder, Eunyoung Jang

UNLV Theses, Dissertations, Professional Papers, and Capstones

Single-sample pathway analysis (ssPA) is a bioinformatics technique used to assess the activity of biological pathways in individual samples, rather than relying on aggregated data from multiple samples. This approach allows for the detection of pathway activation or suppression in single samples, making it a valuable approach in research and clinical applications where individual variability is critical. In this paper, we propose a deep-learning method that scores individual pathway expression levels using a graph autoencoder. The proposed method provides insights into the biological processes and leverages the high dimensionality of gene expression data by setting the nodes in the neural …

Evaluation Of Electrochemical Corrosion, Electrodeposition, And Other Electroanalytical Methods As Investigative Forensic Techniques For Advancing Metal Substrate Analysis, Crystal C. Kitanovski

UNLV Theses, Dissertations, Professional Papers, and Capstones

Friction ridge skin, bearing unique patterns of epidermal ridges commonly known as fingerprints, has served as a crucial tool for identification since ancient times, with its utilization dating back to Chinese culture around 221 B.C. Today, friction ridge skin impressions remain vital evidence in forensic investigations, aiding in the identification of suspects. While fingerprints, palm prints, and footprints can all serve as identifying markers, this dissertation focuses specifically on fingerprints, broadly classified as visible or latent. Latent fingerprints, though invisible to the naked eye, constitute the majority of prints collected from crime scenes, necessitating physical, chemical, or physicochemical processing for …

Implementing Radformation At Personalized Radiation Oncology: Enhancing Efficiency And Precision, Devin J. Peart

UNLV Theses, Dissertations, Professional Papers, and Capstones

RadMachine is a data quality management application implemented at Personalized Radiation Oncology (PRO) to streamline quality assurance (QA) tests. It offers various functions assisting medical physicists in a radiation oncology clinic, including inputting, analyzing, managing, exporting, and monitoring QA data. Physicists create test lists following the recommendations provided by the American Association of Medical Physics (AAPM). These lists track results for units such as the Varian Edge, Varian BRAVOS, and Siemens SOMATOM go.Open Pro CT scanner. Ancillary equipment used for testing also has assigned test lists to store calibration factors and receive calibration expiration reminders. The primary goal of utilizing …

A Heuristic Approach To Operations And Control Of Btm-Ders For Bill Management And Grid Services, Md Arshad Rashid Shaon

UNLV Theses, Dissertations, Professional Papers, and Capstones

Behind-The-Meter (BTM) distributed energy resources (DERs) have emerged as a critical and transformative force within the energy sector. These decentralized energy assets, which include solar photovoltaic (PV) systems, battery energy storage systems (BESS), and thermostatically controlled loads (TCLs), are increasingly essential for empowering customers by granting them greater control over their energy production and consumption, thereby reducing reliance on centralized power sources. Additionally, they have the potential to play a pivotal role in enhancing grid resilience by providing grid services. This study investigates the management of customer electricity bills and grid services through the integration of various BTM-DERs, particularly solar …

Effects Of Climate Change On (Semi)-Arid Ecosystems In The Southwestern United States, Charlotte Van Der Nagel

UNLV Theses, Dissertations, Professional Papers, and Capstones

Climate change is considered amongst the most severe threats to terrestrial and aquatic ecosystems globally. Ecosystems in the southwestern United States have specifically been impacted by intense drought conditions since 2000. Higher temperatures combined with altered precipitation stresses many ecosystems; however, ecosystem specific responses to such stressors may vary. Here, the effects of climate change on semi-arid ecosystems are analyzed for some of the most vulnerable ecosystems in the southwestern United States: lacustrine, riparian, and dryland ecosystems.

Lakes and reservoirs in arid environments often serve as drinking water sources and recreational areas where high water quality is essential. Climate change …

First Diffusion Course: "The Structure Of Language As A Connection Between Artificial Intelligence, Information And Ethics", Dioneia Monte-Serrat

Journal of Humanistic Mathematics

From August 22nd to November 21st, the first Diffusion Course on “The structure of language as a connection between artificial intelligence, information and ethics” will take place on a Thursday of each month, in Ribeirao Preto, Brazil. You are cordially invited to sign up for in-person classes and join other researchers and students on this course.

7th International Conference On Creative Mathematical Sciences Communication (Cmsc`24), Frances A. Rosamond

Journal of Humanistic Mathematics

The 7th International Creative Mathematical Sciences Communication (CMSC) conference is scheduled for October 2024 in Trier, Germany. Initiated in Darwin, Australia in 2013, CMSC aims to explore novel methods of imparting computational thinking to diverse audiences including non-specialists, modern citizens, and children. Participants from around the world and from various and interdisciplinary disciplines such as science, education, dance, drama, and visual arts convene to exchange ideas, present experimental approaches, and collaborate on engaging children in the exploration of ongoing, unresolved research challenges.

Oh Statistics!, Heather L. Cook

Journal of Humanistic Mathematics

This poem was written about statistics and the usefulness thereof.