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Full-Text Articles in Physical Sciences and Mathematics

Ocr Post-Processing Using Large Language Models, Mahdi Hajiali Aug 2023

Ocr Post-Processing Using Large Language Models, Mahdi Hajiali

UNLV Theses, Dissertations, Professional Papers, and Capstones

Optical Character Recognition (OCR) technology transforms textual visuals into an electronically readable, non-graphical format of the text. This allows the editing and other text manipulation of the content by language technology software such as machine translation, text comprehension, query-answering systems, and search engines. While Optical Character Recognition (OCR) systems continually progress towards greater precision, several complications persist when dealing with low-resolution source images or those with multicolored backgrounds. Consequently, the text derived from OCR necessitates additional refinement to optimize accuracy, beneficial for various subsequent applications. It is recognized that the character accuracy of OCR-generated text may influence certain natural language …

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The Transaction Costs Of Federal Environmental Policy Changes: The Effects Of The Temporary Covid-19 Cwa Rollback On Local Water Systems, Jesse Lee Barnes May 2023

The Transaction Costs Of Federal Environmental Policy Changes: The Effects Of The Temporary Covid-19 Cwa Rollback On Local Water Systems, Jesse Lee Barnes

UNLV Theses, Dissertations, Professional Papers, and Capstones

An institutional dilemma exists between the Clean Water Act (CWA) and the Safe Drinking Water Act (SDWA). US surface waters are protected from point-source pollution by the CWA. Community Water Systems (CWSs) that draw from these surface waters for potable purposes are required to treat that water to a level that meets SDWA health standards. Therefore, decreases in CWA regulations could lead to surface water quality declines and, thus, higher SDWA compliance costs for CWSs. This area of inquiry has become increasingly relevant due to Trump-era executive actions to try to decrease the federal government's role in multiple environmental policies, …

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Trajectory Analysis For Driving Safety Quantification, Michael I. Chang May 2023

Trajectory Analysis For Driving Safety Quantification, Michael I. Chang

UNLV Theses, Dissertations, Professional Papers, and Capstones

In order to evaluate the efficacy of the skid recovery exercise in the Driver’s Edge teenage driving program, a process is established to determine the trajectories of vehicles from recorded videos, compare them in terms of similarity through dynamic time warping (DTW), and then analyze the similarity measurements to assess whether the program has a significant effect on driving ability by repeated measures analysis of variance (rANOVA). The video is analyzed by Harris corner detection and Lucas-Kanade optical flow method to ascertain the vehicle trajectories. A homography is then estimated to translate coordinates from video into real-world. The instructor and …

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The Response Of Atomic-To-Molecular Hydrogen Transition Points In Photodissociation Regions Due To A Hard X-Ray Spectrum, Gregory Joseph Colarch May 2023

The Response Of Atomic-To-Molecular Hydrogen Transition Points In Photodissociation Regions Due To A Hard X-Ray Spectrum, Gregory Joseph Colarch

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation develops a model for the response of the transition points in the density profiles from atomic (H0) to molecular (H2) hydrogen in a photodissociation region (PDR) due to a hard X-ray flux (HXR). A model for a steady-state PDR due to the photodissociation of H2 by the far-ultraviolet (FUV) Lyman-Werner radiation band is presented both analytically and computa- tionally. A steady state X-ray dissociation region (XDR) from an HXR in the 1 - 100 keV energy range is also developed both analytically and computationally. An analytic model is then developed by combining these two different steady state models. …

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On Outflows Due To Radiation, Randall Cody Dannen May 2023

On Outflows Due To Radiation, Randall Cody Dannen

UNLV Theses, Dissertations, Professional Papers, and Capstones

Observations of ionized AGN outflows have provided compelling evidence that the radiation field transfers both momentum and energy to the plasma. At parsec scale distances in AGN, energy transfer can dominate, in which case the only force needed to launch an outflow is due to gas pressure. Much closer to the black hole, gravity dominates thermal energy due to insufficient heating by the radiation and the gas is in the so-called ’cold wind solution’ regime. Only magnetic or radiation forces can lead to outflow, but it is unclear how these forces depend on the spectral energy distribution (SED) and the …

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Outside, Looking In: A Dissertation On Mindful Walking And How Green Exercise Affects State Mindfulness And Connectedness To Nature, Dustin Wyatt Davis May 2023

Outside, Looking In: A Dissertation On Mindful Walking And How Green Exercise Affects State Mindfulness And Connectedness To Nature, Dustin Wyatt Davis

UNLV Theses, Dissertations, Professional Papers, and Capstones

INTRODUCTION: Mindfulness, green exercise, and connectedness to nature are increasingly popular topics among academics and the public. These three topics overlap in the underexplored area called mindful green exercise. Mindful green exercise is a blend of mindful exercise and green exercise. Mindful exercise is physical exercise during which people pay attention on purpose without judgment to each new present moment. The person applies an accepting awareness to internal phenomena (thoughts, emotions, and bodily sensations) and external phenomena (objects and events in the environment). Green exercise is exercise performed outdoors in natural environments. Despite its name, green exercise does not only …

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Response Of The Isothermal Mode Grüneisen Tensor Across Phase Boundaries, Jasmine K. Hinton May 2023

Response Of The Isothermal Mode Grüneisen Tensor Across Phase Boundaries, Jasmine K. Hinton

UNLV Theses, Dissertations, Professional Papers, and Capstones

The assumptions for the 1912 Grüneisen parameter are reviewed, particularly in the cases of anisotropy, high temperatures, and across phase boundaries. Two main case studies are shown: β-Sn, and Cd. The main techniques of this work involve resistively heated diamond anvil cells with both optical Raman spectroscopy and x-ray diffraction. It is found in Sn that the isothermal mode Grüneisen tensor along increasing isotherms diverges from the single-valued temperature aggregate at the onset of melt, and this is proposed to use as a method of exploring melt phase boundaries in other systems. This method is examined once again on another …

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Applying Instrumental Neutron Activation Analysis To Assess Air Pollution With Spanish Moss As A Bioindicator In The Low Country Of The Savannah River Basin, Christina Jiang May 2023

Applying Instrumental Neutron Activation Analysis To Assess Air Pollution With Spanish Moss As A Bioindicator In The Low Country Of The Savannah River Basin, Christina Jiang

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Savanah River Basin is an area of 9,850 square miles that stretches from the border between South Carolina and Georgia, which empties into the Atlantic Ocean near Savannah, Ga. This area is home to surrounding cities, industrial sites, and the Savanah River Site. It is well documented that traffic, industrial operations, and agriculture contribute to worsening air pollution that needs to be monitored. While Tillandsia usneoides (Spanish moss) has been used in previous studies that prove it to be an effective biomonitor for air pollution and an accumulator of heavy metals, there have been no biomonitoring studies in the …

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Study Of Trace Elements In Southern Nevada Spring Waters And Lakes, Hyejeong Lee May 2023

Study Of Trace Elements In Southern Nevada Spring Waters And Lakes, Hyejeong Lee

UNLV Theses, Dissertations, Professional Papers, and Capstones

Comprehending the natural water resource is imperative for the entire state of Nevada and of particular significance for Southern Nevada, where rapid population growth and climate change are placing significant strain on supplies. This research underscores the significance of water chemistry in identifying potential water source areas through trace elements. For the first time, the study proposed measuring the compositions of the entire suite of metal elements, ranging from Li to U, in over 40 springs in the Moapa Valley and its upper gradient valleys, utilizing the iCAP Qc ICP-MS (Inductively Coupled Plasma Mass Spectrometer) at UNLV. The research evaluated …

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Enhanced Iot-Based Electrocardiogram Monitoring System With Deep Learning, Jian Ni May 2023

Enhanced Iot-Based Electrocardiogram Monitoring System With Deep Learning, Jian Ni

UNLV Theses, Dissertations, Professional Papers, and Capstones

Due to the rapid development of computing and sensing technologies, Internet of Things (IoT)-based cardiac monitoring plays a crucial role in providing patients with cost-efficient solutions for long-term, continuous, and pervasive electrocardiogram (ECG) monitoring outside a hospital setting. In a typical IoT-based ECG monitoring system, ECG signals are picked up by sensors located on the edge, and then uploaded to the remote cloud servers. ECG interpretation is performed for the collected ECGs in the cloud servers and the analysis results can be made instantly available to the patients as well as their healthcare providers.In this dissertation, we first examine the …

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Simulating Radial Ring Structure With An Ambipolar Elsasser (Am) Bump In Non-Ideal Magnetohydrodynamics Of Protoplanetary Disks, Aleksey S. Mohov May 2023

Simulating Radial Ring Structure With An Ambipolar Elsasser (Am) Bump In Non-Ideal Magnetohydrodynamics Of Protoplanetary Disks, Aleksey S. Mohov

UNLV Theses, Dissertations, Professional Papers, and Capstones

Rings are one of the most ubiquitous substructures observed in protoplanetary disks. They are known to be a robust site for planetesimal formation; thus we look for mechanisms that can originate stable rings. From chemical modelling of snow lines, we expect a bump in the Ambipolar Diffusion (AD) Elssaser number (Am) in the radial direction. We use the Athena++ code to model the non-ideal Magentohydrodynamics (MHD) behavior of an Am bump. We explore a parameter space of Gaussian bumps with Am = 5, 1, 0.5 peak strength and σ = 0.25, 1, 5. The Gaussian profile is inserted into the …

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Exploration Of H2o Ice At Extreme Conditions, Zachary M. Grande May 2023

Exploration Of H2o Ice At Extreme Conditions, Zachary M. Grande

UNLV Theses, Dissertations, Professional Papers, and Capstones

Static compression experiments on water ice are needed for precise characterization and discovery of new ice phases near room temperature. Here I present my efforts and the developments that have been made to reduce detrimental effects found in high-pressure experiments in order to acquire precise measurements on ice approaching 3 Mbar. Several key observations are made, relating to the phase transition of ice-VII to X, an intermediate phase I have named ice-VIIt and evidence of a post ice X phase. Some of these experiments have been replicated using D2O ice as well, in order to gain insight into nuclear quantum …

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Characterization Of Hematite Coated Bedrock Fault Scarps In The Northern Colorado River Extensional Corridor Near Lake Mead, Nevada, Molly E. Pickerel May 2023

Characterization Of Hematite Coated Bedrock Fault Scarps In The Northern Colorado River Extensional Corridor Near Lake Mead, Nevada, Molly E. Pickerel

UNLV Theses, Dissertations, Professional Papers, and Capstones

Fault mirrors are reflective, thin, typically <1 mm thick, fault slip surfaces in exhumed fault zones that can provide a record of thermal, chemical, and rheological changes to fault materials during deformation. This study investigates a series of hematite coated fault mirrors along bedrock fault scarps in Miocene volcanic rocks near Lake Mead, Nevada. The studied faults are located in a structurally complex area that includes NE-SW trending left-lateral strike-slip faults of the Lake Mead fault system, NW-SE right-lateral strike-slip faults of the Las Vegas Shear Zone, and N-S striking extensional faults of the Northern Colorado River Extensional Corridor.New zircon U-Pb ages from fault scarp host rocks 21-BC-03 and 21-BC-05 are and 13.86 ± 0.27 Ma and 12.90 ± 0.31 Ma (2σ standard error), respectively. New apatite (U-Th)/He dates range from 5.64 ± 0.46 Ma to 12.4 ± 0.36 Ma (2σ standard error) and are interpreted to be partially reset after eruption due to reheating. Inverse thermal history modeling in HeFTy of apatite He dates indicates a thermal history of reheating to ~65 °C which is interpreted as shallow burial around ~11 - 5 Ma followed by cooling to the surface, interpreted as exhumation between ~4.5 - 2 Ma. The zircon U-Pb ages, apatite He dates, and inverse thermal history models indicate the fault host rocks were erupted to the surface and stayed within the upper ~2 km of the crust since the Miocene. Nearly vertical fault scarps that host the fault mirror surfaces exhibit two sets of slickenlines, indicating oblique and strike-slip motion, with different orientations indicating that there have been multiple episodes of deformation along the surfaces. Three of the five studied fault scarps have E-W orientations, and one scarp is NW-SE, and one is NE-SW striking. The studied faults are interpreted to have been active during deformation associated with the Lake Mead Fault System and the Las Vegas Valley Shear Zone at 13 – 9 Ma and record both strike slip and oblique slip events in the complex strain field during this time. Micro-nano scale texture and grain morphology analysis of the hematite fault mirror volumes shows extreme strain localization along the fault mirror surface. Some fault mirrors exhibit multiple domains separated by discrete slip surfaces. Comminution and cataclasis appear to be the dominant deformation mechanisms in the fault mirror volume. Hematite textures and morphologies are consistent with observations from other fault systems that are interpreted to record aseismic to sub-seismic slip rates, and relatively low coseismic temperature rise. Fluid injection veins and post-deformation FeO mineralization in fractures are interpreted as evidence of high fluid pressures during slip and fluid circulation postdeformation. The new geochronologic and microstructural data inform on the processes operating along discrete fault surfaces in the shallow crust since the Miocene in the Lake Mead region.

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Morphologic Comparisons Of Recrystallized And Neocrystallized Fibrous Amphibole Asbestos: Implications For Corresponding Health Risk Potential, Natalie G. Renkes May 2023

Morphologic Comparisons Of Recrystallized And Neocrystallized Fibrous Amphibole Asbestos: Implications For Corresponding Health Risk Potential, Natalie G. Renkes

UNLV Theses, Dissertations, Professional Papers, and Capstones

The presence of naturally-occurring asbestos (NOA) is increasingly concerning for scientists, health and regulatory agencies, and citizens living in impacted areas. It is commonly believed that fibrous amphibole asbestos can only form through neocrystallization. In southern Nevada, NOA occurs as a result of hydrothermal alteration of granitic rock producing fibrous amphibole both as cross-cutting neocrystallized veins and via recrystallization of original magmatic hornblende crystals. Fibers with a greater aspect ratio are known to have increased toxicity. This study measured the maximum length and average width of both neocrystallized and recrystallized fibers to see if the morphologies were similar. Neocrystallized and …

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A One-Dimensional Analysis Of A Microbial Fuel Cell For Efficient Acetate Removal And Power Density Output, David Rouhani May 2023

A One-Dimensional Analysis Of A Microbial Fuel Cell For Efficient Acetate Removal And Power Density Output, David Rouhani

UNLV Theses, Dissertations, Professional Papers, and Capstones

Microbial fuel cells (MFCs) are electrochemical devices that utilize microorganisms to convert organic matter into electrical energy. MFCs have been discussed to have potential application for sustainable wastewater treatment due to their ability to generate electricity while simultaneously treating contaminated water. To optimize MFC performance, numerical models can be used to understand the complex electrochemical and biological processes occurring in the system. In this study, a numerical model was developed to simulate the performance of MFCs under varying operating conditions and to investigate the performance of a MFC for treating wastewater fuel. More specifically, the MFC was modeled to oxidize …

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Inferring The Compositions And Interior Structures Of Small Planets, David R. Rice May 2023

Inferring The Compositions And Interior Structures Of Small Planets, David R. Rice

UNLV Theses, Dissertations, Professional Papers, and Capstones

Although there are now over 10,000 confirmed and candidate extrasolar planets, accurate masses and radii have been determined for around 200 planets of less than 10 Earth-masses. This number will grow exponentially over the next decade as extreme precision radial velocity spectrographs see first light. The densities of small planets hint at a diverse range of compositions for terrestrial worlds from super-Mercuries to super-Ganymedes. Uncertainty in density is as low as 3% in the Trappist-1 system. To determine composition from observed parameters, the community uses a variety of interior structure models. Underlying these models are multiple computational techniques, numerous experimental …

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Stoichiometric Determination Of Hydride Materials At Extreme Conditions, Gregory Alexander Smith May 2023

Stoichiometric Determination Of Hydride Materials At Extreme Conditions, Gregory Alexander Smith

UNLV Theses, Dissertations, Professional Papers, and Capstones

Hydrogen was predicted to be a high-temperature superconductor at near-megabar conditions in 1968,[1] but only recently was been experimentally observed.[2] This is due to the extraneous metrological constraint of requiring 5 megabars of pressure to stabilize. A more practical approach for synthesis of high-temperature superconductors has been pro-posed through the use of hydride compounds. Recently, a surge of rare earth hydrides have achieved critical superconducting transition temperatures (T_C ) close to room temperature.[3, 4, 5, 6] However, due to limitations of the necessary instrumentation to achieve megabar pressures, many techniques traditionally used to measure stoichiometry are unavailable.Three works presented in …

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The Effects Of Habitat Isolation On Fine-Scale Genetic And Geographic Structure Of Populations Of Two Threatened Endemic Insects In Southern Nevada, Pseudocotalpa Giulianii And Icaricia Shasta Charlestonensis, Kristen Tovar May 2023

The Effects Of Habitat Isolation On Fine-Scale Genetic And Geographic Structure Of Populations Of Two Threatened Endemic Insects In Southern Nevada, Pseudocotalpa Giulianii And Icaricia Shasta Charlestonensis, Kristen Tovar

UNLV Theses, Dissertations, Professional Papers, and Capstones

Assessing the role geographic isolation and ecological specialization have on phylogeographic patterns contributes to our understanding of the evolutionary history of a species and the processes that erode genetic diversity. I used mitochondrial and nuclear genomic sequences to assess whether habitat isolation has shaped the fine-scale patterns of present-day genetic structure and diversity in two threatened insect species endemic to southern Nevada. Pseudocotalpa giulianii (Coleoptera; Scarabaeidae) is a dune obligate scarab beetle endemic to only two small, isolated sand dunes in Nye County, Nevada, with a usable habitat of less than 4.2 km sq that is impacted by on-going degradation. …

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High Clearance Collision-Free Paths, Barun Thapa May 2023

High Clearance Collision-Free Paths, Barun Thapa

UNLV Theses, Dissertations, Professional Papers, and Capstones

Path Planning is one of the widely investigated research areas in computational geometry and robotics. Given a set of polygonal obstacles inside a rectangular box, and start & goal points, the path planning problem is to construct a collision-free path connecting the start point to the goal point. We review existing well known algorithms for solving the path planning problem. We propose new approaches for constructing a collision-free path with high clearance from obstacles. The main idea of the proposed algorithm is the appropriate generation free-region nodes which can be processed to construct high clearance paths. Neighbors of free-region nodes …

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Dea2uth: A Decentralized Authentication And Authorization Scheme For Secure Private Data Transfer, Phillipe Austria May 2023

Dea2uth: A Decentralized Authentication And Authorization Scheme For Secure Private Data Transfer, Phillipe Austria

UNLV Theses, Dissertations, Professional Papers, and Capstones

The sharing of private information is a daunting, multifaceted, and expensive undertaking. Furthermore, identity management is an additional challenge that poses significant technological, operational, and legal obstacles. Present solutions and their accompanying infrastructures rely on centralized models that are susceptible to hacking and can hinder data control by the rightful owner. Consequently, blockchain technology has generated interest in the fields of identity and access control. This technology is viewed as a potential solution due to its ability to offer decentralization, transparency, provenance, security, and privacy benefits. Nevertheless, a completely decentralized and private solution that enables data owners to control their …

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Information-Theoretic Model Diagnostics (Infomod), Armin Esmaeilzadeh May 2023

Information-Theoretic Model Diagnostics (Infomod), Armin Esmaeilzadeh

UNLV Theses, Dissertations, Professional Papers, and Capstones

Model validation is a critical step in the development, deployment, and governance of machine learning models. During the validation process, the predictive power of a model is measured on unseen datasets with a variety of metrics such as Accuracy and F1-Scores for classification tasks. Although the most used metrics are easy to implement and understand, they are aggregate measures over all the segments of heterogeneous datasets, and therefore, they do not identify the performance variation of a model among different data segments. The lack of insight into how the model performs over segments of unseen datasets has raised significant challenges …

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Desert Spring Prokaryotes And Benthic Macroinvertebrates: Geological And Ecological Controls, Ariel D. Friel May 2023

Desert Spring Prokaryotes And Benthic Macroinvertebrates: Geological And Ecological Controls, Ariel D. Friel

UNLV Theses, Dissertations, Professional Papers, and Capstones

Desert springs are aquatic oases, being considered among the most diverse and imperiled ecosystems on Earth. Despite the ecological significance and threatened status of desert springs, few studies have surveyed the microorganisms in these systems or their interactions with other community members. The primary goal of this dissertation was to describe the major controls influencing the community ecology of prokaryotic and BMI communities in cold- and moderate-temperature desert springs of the southern hydrographic Great Basin. Chapter 1 provides a broad overview of spring ecosystems and of each chapter included in this dissertation. Chapter 2 documents the first-ever, regional-scale survey of …

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Solving Boundary Value And Initial Boundary Value Problems Of Partial Differential Equations Using Meshless Methods, Adam Johnson May 2023

Solving Boundary Value And Initial Boundary Value Problems Of Partial Differential Equations Using Meshless Methods, Adam Johnson

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this dissertation, the methods of fundamental solutions (MFS) and the methods of particular solutions (MPS) are used to solve the boundary value problems of the Poisson and Helmholtz equations, where the particular solutions of the Poisson and Helmholtz equations in [13, 14] are used. Then the initial boundary value problems of the diffusion and wave equations are discretized into a sequence of boundary value problems of the Helmholtz equation by using either the Laplace transform or time difference methods along the lines of [8]. The Helmholtz problems are solved consequently in an iterative manner which leads to the solution …

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Joint Constraints On Kepler-36 From Kepler And New Keck-Hires Data, Nicholas Juliano May 2023

Joint Constraints On Kepler-36 From Kepler And New Keck-Hires Data, Nicholas Juliano

UNLV Theses, Dissertations, Professional Papers, and Capstones

I analyze new HIRES Radial Velocity (RV) data in conjunction with transit mid-times and uncertainties from the full 17 quarters of Kepler data to reassess the orbital parameters of the Kepler-36 system. Six additional RV measurements were taken by the Keck-HIRES spectrograph from September 21, 2021 to October 11, 2021. I carry out a differential evolution Markov Chain Monte Carlo-based (DEMCMC) analysis to infer improved orbital elements for the two known planets in the system. Leveraging additional information provided by the new RV measurements, I extend this DEMCMC analysis to a possible three-planet configuration. I explore the likelihood of a …

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Critical Metals: From Granitic Pegmatites To The Anthropogenic Cycle, Dalton Mccaffrey May 2023

Critical Metals: From Granitic Pegmatites To The Anthropogenic Cycle, Dalton Mccaffrey

UNLV Theses, Dissertations, Professional Papers, and Capstones

Critical metals are vital to the functionality of the modern world. The increased diversity and usage intensity of these commodities in defense-related and strategic technologies (e.g., jet engines, rocket assemblies), modern infrastructure and products (e.g., high-strength steel, cellular phones, laptop computers), and energy-related, low-emissions technologies (e.g., nuclear reactors, solar panels, wind turbines, hybrid and electric vehicles) has drastically increased our reliance on critical metals and, thus, the United States (and global) exposure to supply restrictions. Granitic pegmatites are unique mineral deposits that represent a past, present and future resource for many (approximately half) of these critical resources. Even with the …

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Metastability And Degradation In Cu(In,Ga)Se2 Thin-Film Solar Cells, Mohsen Jahandardoost May 2023

Metastability And Degradation In Cu(In,Ga)Se2 Thin-Film Solar Cells, Mohsen Jahandardoost

UNLV Theses, Dissertations, Professional Papers, and Capstones

Cu(In,Ga)(S,Se)2 or CIGS is a thin-film semiconductor that has shown a device efficiency of 23.35% and 24.2% for single-junction and perovskite/CIGS tandem solar cells, respectively. CIGS offers promising properties such as tunable bandgap and ease of processing making them great candidates for thin-film tandem devices. However, knowledge of the effect of material defects, buffer materials, and post-deposition treatment (PDT) on degradation and metastability behavior in these devices is not well understood.In this dissertation, metastability and long-term degradation of CIGS thin-film solar cells have been investigated under combinatorial stress factors of heat, light, and voltage bias to systematically understand the effect …

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A Generalized Family Of Exponentiated Composite Distributions With Applications To Insurance And Survival Data, Bowen Liu May 2023

A Generalized Family Of Exponentiated Composite Distributions With Applications To Insurance And Survival Data, Bowen Liu

UNLV Theses, Dissertations, Professional Papers, and Capstones

The concept of composite distributions was proposed in the early 2000s as a good parametric solution to model the data with heavy tails. Since the concept was proposed, it has been widely used in different areas, such as modeling insurance claim size data, predicting the risk measures in insurance data analysis, fitting survival time data, and modeling precipitation data. While a lot of the composite distributions demonstrated great performances in real applications, many commonly used composite distributions such as the inverse gamma-Pareto (IGP) or exponential-Pareto (EP), did not demonstrate great performances when fitting to several particular data sets. In order …

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Investigating Haloacetonitrile (Han) Formation Potential From Nitrogenous Antibiotics And Agrochemicals, Kazi Shafayet Haider May 2023

Investigating Haloacetonitrile (Han) Formation Potential From Nitrogenous Antibiotics And Agrochemicals, Kazi Shafayet Haider

UNLV Theses, Dissertations, Professional Papers, and Capstones

Disinfection can promote safe drinking water. Chlorine and chloramines are the two most used disinfectants. While these disinfectants are effective in inactivating disease-causing pathogens, they also produce hazardous byproducts when they react with organic compounds (precursors). Nitrogenous disinfection byproducts (N-DBPs) are more toxic than their counterparts. The increased use of nitrogen-based agrochemicals and antibitics has led to their detection in different water sources. The presence of secondary amine and aniline in these compounds can act as a source of reactive nitrogen to form N-DBPs. In addition, the increased concentration of bromide in water systems due to anthropogenic activities can enhance …

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Identification Of Factors Contributing To Traffic Crashes By Analysis Of Text Narratives, Cristian D. Arteaga-Sanchez Dec 2022

Identification Of Factors Contributing To Traffic Crashes By Analysis Of Text Narratives, Cristian D. Arteaga-Sanchez

UNLV Theses, Dissertations, Professional Papers, and Capstones

The fatalities, injuries, and property damage that result from traffic crashes impose a significant burden on society. Current research and practice in traffic safety rely on analysis of quantitative data from crash reports to understand crash severity contributors and develop countermeasures. Despite advances from this effort, quantitative crash data suffers from drawbacks, such as the limited ability to capture all the information relevant to the crashes and the potential errors introduced during data collection. Crash narratives can help address these limitations, as they contain detailed descriptions of the context and sequence of events of the crash. However, the unstructured nature …

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Age And Genesis Of W-Mo-Cu Mineralization, Gold Hill, Utah, Nathan J. Carey Dec 2022

Age And Genesis Of W-Mo-Cu Mineralization, Gold Hill, Utah, Nathan J. Carey

UNLV Theses, Dissertations, Professional Papers, and Capstones

Utah's Gold Hill mining district hosts a Jurassic felsic pluton (~80 km^2) that was emplaced into a Mississippian to Pennsylvanian carbonate-dominated sedimentary sequence and is spatially associated with numerous polymetallic mineral deposits. This study focuses on W-Mo-Cu mineralization at the Lucy L., Doctor, Yellow Hammer, Reaper, and Rustler deposits within the district. The new, detailed petrographic observations, mineral chemistry (on scheelite, molybdenite, chalcopyrite, magnetite, garnet, and pyroxene), and Re-Os molybdenite geochronological data presented here allows for the determination of key mineral associations and paragenesis, the characterization of deposit types and their evolution, and the constraining of the relative and absolute …

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