Physical Sciences and Mathematics Commons^™

New Porous Semiconductor Nanocomposites As Dye-Sensitized Photocatalysts, Tahmina Akter

Open Access Theses & Dissertations

The wide band gap layered semiconductors potassium titanium niobium oxide (KTiNbO5) and potassium hexaniobate (K4Nb6O17) along with a metal co-catalyst can be been used to generate hydrogen fuel from water. However, ultraviolet light is required, which limits their utility in solar energy conversion. Modification of these types of semiconductors can sensitize them to visible light, providing a promising way to produce clean, renewable hydrogen (H2) fuel. Many photocatalysts suffer from poor H2 production efficiencies under visible light, due to inadequate and unstable sensitizers, resulting in photocatalysts that fail quickly.

In this research, several new high surface area dye sensitized nanocomposites …

Computer-Aided Classification Of Impulse Oscillometric Measures Of Respiratory Small Airways Function In Children, Nancy Selene Avila

Open Access Theses & Dissertations

Computer-aided classification of respiratory small airways dysfunction is not an easy task. There is a need to develop more robust classifiers, specifically for children as the classification studies performed to date have the following limitations: 1) they include features derived from tests that are not suitable for children and 2) they cannot distinguish between mild and severe small airway dysfunction.

This Dissertation describes the classification algorithms with high discriminative capacity to distinguish different levels of respiratory small airways function in children (Asthma, Small Airways Impairment, Possible Small Airways Impairment, and Normal lung function). This ability came from innovative feature selection, …

Application Of Urinary Metabolites For Cancer Detection, Qin Gao

Open Access Theses & Dissertations

Prostate cancer (PCa) is the 3rd most common cause of male cancer mortality in the US. Early diagnosis and treatment of PCa will improve the quality of care and reduce mortality. The prostate specific antigen (PSA) is commonly used in the current PCa screening, but its limitation has resulted in an intense search for more reliable biomarkers. Studies showed that dogs could differentiate PCa patients from negative control by sniffing their urine. As the odor profiles are generated by volatile organic compounds (VOCs), the finding suggests that particular VOCs could be linked to PCa, PCa risk levels and other cancers. …

Dynamic Triggering Of Earthquakes Within The State Of Utah, Usa, David Lewis Guenaga

Open Access Theses & Dissertations

Understanding the stress state of faults and the stress needed to trigger earthquakes remains a fundamental goal for understanding the earthquake cycle. We focus on deciphering the stress of faults by studying seismic waves from large, distant earthquakes that trigger local seismicity, called remote or dynamic triggering. Utilizing 17 years of waveform and catalog data (2000-2017) from seismic regional networks (i.e., EarthScope USArray Transportable Array, United States Geological Survey, and University of Utah Regional networks), we search for triggered seismicity in the state of Utah following 227 large magnitude (M ≥ 7) distant earthquakes. Utah provides a long-standing regional network …

Cmas/Volcanic Ash Infiltration Performance Of Yttria Rich-Zirconia Thermal Barrier Coatings Produced By Electron Beam Physical Vapor Deposition, Juan Jose Gomez Chavez

Open Access Theses & Dissertations

For many years the use of thermal barrier coatings (TBC) in gas turbine engines has allowed a significant increase in engine operating temperatures which are above the Ni-based super alloys' melting point. The base material for TBCs is the state of the art 7 wt % yttria stabilized zirconia (YSZ) which provides the thermal protection. Current industry demands for increased engine efficiency has pushed TBCs to the limits where significant technological constrains have been identified. One of the main ones represents the high temperature corrosion of the TBC material due to the ingestion of silicate based airborne particles commonly referred …

A Bottom-Up Modeling Methodology Using Knowledge Graphs For Composite Metric Development Applied To Traffic Crashes In The State Of Texas, Daniel Michael Mejia

Open Access Theses & Dissertations

Data is a key factor for understanding real-world phenomena. Data can be discovered and integrated from multiple sources and has the potential to be interpreted in a multitude of ways. Traffic crashes, for example, are common events that occur in cities and provide a significant amount of data that has potential to be analyzed and disseminated in a way that can improve mobility of people, and ultimately improve the quality of life. Improving the quality of life of city residents through the use of data and technology is at the core of Smart Cities solutions. Measuring the improvement that Smart …

Ultrafine Black Carbon: A Cumulative Assessment On The Physiology Of Lung - Derived Cells, M Esther Salinas

Open Access Theses & Dissertations

Combustion-derived nanomaterials are noxious ultrafine (<100 nm) aerosolized by-products generated by human activity. They pose threats to pulmonary health due to their small size, allowing them to penetrate deep into the alveolar regions causing detrimental responses downstream. Indeed, an examination between nanocarbon particle exposure and poor pulmonary health via cellular behavior was needed. I hypothesized that low-dose and long-term administrations of carbonaceous nanoparticles contribute to respiratory conditions by irritating lung-derived cells. Responses to ultrafine black carbon (UBC), a key component of airborne pollutants, by human lung A549 and murine lung LA4 epithelial cells, human peripheral-blood monocytes THP1, and murine macrophages RAW264.7 were investigated. These lines were chosen because epithelial cells and mononuclear cells (monocytes and macrophages) are the first to come in contact with inhaled particulate matter (PM) and contribute to stress and inflammation of pulmonary tissues. The cells were first plated on day zero and fed fresh UBC suspended in culture media on days one, four, and seven. The exposure regimen included three different low-level concentrations of UBC. On day ten, all cells were prepared for subsequent assays. Effects on cellular viability revealed that UBC was modestly cytotoxic while ATPase and esterase activity (termed enzyme vitality for the purpose of this study) were significantly diminished in a dose-dependent manner. Additionally, beta-galactosidase proportionally increased with UBC concentration compared to untreated cells, indicating that cellular senescence was promoted across all cell types. Multiple markers of oxidative stress were subsequently measured, showing non-uniform trends and displaying moderate accumulation of oxidative damage, contingent upon cell line and UBC treatment. However, a significant induction of inner mitochondrial membrane depolarization of human UBC-treated cells was observed; an aberrant cell-cycle progression was found across all cells. The implemented regimen of UBC exposure elicited an imbalance of free (reduced) glutathione, altered mitochondrial potential, and abnormal cell-cycle activity. This method demonstrated that modifications across both species induced changes to cellular fitness overall. The data supported that compounding nanosized black carbon exposure could negatively affect overall pulmonary cell health by distinctively modifying intracellular activity. Additionally, we further surmised that sustained exposure to nanocarbon could impair innate immunity. Therefore, reactive oxygen species (ROS), reactive nitrogen species (RNS), and cytokine levels upon continuous administrations to 3.0 μg/mL UBC after brief challenges to microbial proxies were assessed; on day 9, the cells were succumbed to three different microbial insults (LPS, Poly I:C, and Zymosan). On day 10, measurements demonstrated a moderate accumulation of oxidative stress, conditional to each cell type. Thus, UBC plus microbe approach triggered pro-oxidant levels and cytokine production across different cell types and diminished phagocytic response by murine macrophages. Based on the results, ultrafine-PM exposure may impair inflammatory function in response to pathogenic infections. In summation, our findings indicated that additive nanosized UBC in combination with microbe-like challenges may compromise cellular behavior, suggesting potential ways by which inhalation of ultrafine-PM may contribute to or exacerbate poor pulmonary health.

Earthquake Magnitude Prediction Using Support Vector Machine And Convolutional Neural Network, Esther Amfo

Open Access Theses & Dissertations

A deep learning-based method Convolutional Neural Network (CNN) and Support Vector Machine (SVM) for earthquake prediction is proposed. Large-magnitude earthquakes triggered by earthquakes can kill thousands of people and cause millions of dollars worth of economic losses. The accurate prediction of large-magnitude earthquakes is a worldwide problem.

In recent years, deep learning technology that can automatically extract features from mass data has been applied in image recognition, natural language processing, object recognition, etc., with great success. We explore to apply deep learning technology to earthquake prediction, we propose a deep learning method for continuous earthquake prediction using historical seismic events. …

Study Of Blinking Statistics In Silver Coated Cobalt Ferrite Single Nanoprticle Using Two-Photon Fluorescence Microscopy, Rajen Kumar Goutam

Open Access Theses & Dissertations

Two-photon fluorescence microscopy is a powerful tool to study the molecular and cellular interactions. This technology is a non-invasive approach with the advantage of three-dimensional imaging up to submicron resolution. Two-photon excitation process is the result of simultaneous absorption of two photons that has special features of reduced photodamaged and elongated penetration depth on samples. In this work, blinking statistics of silver-coated Cobalt ferrite (CoFe2O4) single nanocrystal is studied using two-photon fluorescence microscopy. By defining the intensity threshold, the observed fluorescence is divided into two distinct stages: OFF and ON states. Both of these states followed the inverse power law. …

Fault Kinematics Of The Southern Rio Grande Rift: Exploring The Possibility Of Fault Reactivation, Georgina Rodriguez Gonzalez

Open Access Theses & Dissertations

The region in and around the southern Rio Grande rift has experienced a long and complex tectonic history since the Precambrian era. In addition to recording extension directions due to the opening of the Rio Grande rift, faults can also possibly record contractional deformation related to the Laramide orogeny, extension along the boundary of the Mesozoic Chihuahua Trough, and possibly strike - slip movement since the Precambrian related to the Texas Lineament. The northern and central segments of the Rio Grande rift preserve mostly N - S-trending faults, whereas the southern segment preserves NW - SE-trending faults. The main hypoThesis …

Exploring Paths For Water Services And Human Capabilities In U.S.-Mexico Border Colonias, Chilton Tippin

Open Access Theses & Dissertations

This Thesis examines causes and consequences of water insecurity in colonias on the U.S.-Mexico border and explores potential pathways for improving situations wherein low-income households lack reliable access to water and sewer services. Colonias are low-income, rural and/or semi-rural communities that lack basic services, such as paved streets, water, and sewer. Through in-depth interviews, surveys, and ethnographic observations, the research presented here describes needs, desires, and capabilities of residents in two high-needs Texas colonias. First, findings elucidate the lived experiences of water insecurity in colonias households, leading to an argument that lacking water access constitutes a nexus, wherein water insecurity …

Electronic Tuning Of Dimolybdenum Complexes Through Symmetry Manipulation Of Formamidinate Ligands In Their Second Coordination Sphere, Iván Alonso Cervantes Cervantes Martã­Nez

Open Access Theses & Dissertations

Alternative sustainable energy sources are required to decrease our dependence on carbon-based fuels. Small molecule activation is one of the most promising to fulfill global energy demand and maintain a sustainable world. Most of the industrial processes relevant for global energy supply and expenditure involves small molecules and metal catalysts. However, it is still required to gain fundamental insights on how these catalysts achieve such reactions. Dinuclear compounds, namely dimolybdenum complexes, may serve as a good experimental model to understand metal-metal cooperativity and its influence in catalysis.

In Chapter 2, three unsymmetric aryl formamidines were synthesized and characterized through 1H …

Origin And Characterization Of Intrasalt Non-Halite Lithologies Of The Neoproterozoic Patawarta Diapir, Central Flinders Ranges, South Australia, Rachelle A. Kernen

Open Access Theses & Dissertations

Non-halite lithologies in salt diapirs are variously referred to as clasts, chips, rafts, stringers, sutures, and encased minibasins in the literature. Due to the complexities of gathering and processing seismic reflection data within salt bodies, nonhalite intrasalt lithologies, collectively referred to as inclusions here, are often first identified while drilling wells. These wells may penetrate unexpected lithologies of unknown fluid pressure, which can result in economic failure and pose serious drilling hazards and a threat to human life. Therefore, it is imperative to identify and determine the nature of inclusions prior to drilling, and ideally during the well planning process …

Time-Reflective Text Representations For Semantic Evolution Tracking And Trend Analytics, Roberto Camacho Barranco

Open Access Theses & Dissertations

The extraction of significant, relevant, and useful trends from massive document collections, such as a streaming newswire or scientific publications, is a challenging and significant problem in many different fields, including intelligence analysis, recommendation systems, and scientific research. However, techniques that tackle trend analytics of such large text corpora are limited because research that addresses the temporal nature of these publications is still in its early stages. In this work, we first show that it is possible to capture the evolution of a story (or trend) by connecting the dots between different documents in a text corpus. The observed results …

Stratigraphic Response Of The Differential Rise Of The Gypsum Valley Salt Wall, Jurassic Entrada Formation, Paradox Basin, Colorado, Rafael Andres Delfin

Open Access Theses & Dissertations

The effect of halokinetic processes on fluvial and marine depositional environments adjacent to salt diapirs have been well established through extensive research, however eolian systems in similar geologic settings have not been documented. This has left a void in our understanding of eolian depositional environments adjacent to salt diapirs. This study is aimed at providing new knowledge and a solid foundation on eolian systems and diapiric processes. Despite our limited understanding of theses interactions, there has been a recent interest in deep water prospectively in the Gulf of Mexico. Successful tests of the Norphlet Formation prove that eolian sandstones deposited …

Manfreda Maculosa Leaf Extracts And Their Effects On Whole And Selected Myotoxic Components In Crotalid Venom, Charles Steven Gilbert

Open Access Theses & Dissertations

Manfreda spp have been used for the treatment of snakebite by several cultures in North and Central America (Austin & Honychurch, 2004, Johnson, 1999, Moerman, 2008, Verhoek, 1978a). There has been no systematic study of the genus Manfreda for its usefulness in the treatment of snakebite.

While the annual incidence of snakebite in the United States is relatively low (approximately 8,000 - 10,000), with a low mortality rate of 5 - 6 cases per year, there is still significant morbidity associated with snakebite (CDC - NIOSH, 2018, Springhouse Corp (eds), 2005). Worldwide numbers of the cases of snakebite can only …

Phase Diagram Of Nuclear Matter, Adrian Gaytan Terrazas

Open Access Theses & Dissertations

Nowadays it is well known that nuclear matter has a liquid and a gas phase, as well as a coexistence of phases region. Symmetric nuclear matter (same number of protons and neutrons) exhibit phase transitions from the gas phase to a liquid-gas mixture. A useful tool to represent such phases and transitions is through diagrams that show the necessary conditions of density and temperature to be in either of the phases.

Now the question is, what if we extend the traditional phase diagram for symmetric matter to the asymmetric

cases (different number of protons and neutrons)?

This study uses classical …

Modeling Correlated Data Via Copulas, Panfeng Liang

Open Access Theses & Dissertations

Copulas are widely used to model the dependency structure among components of multi- variate data sets. Elliptical copulas, such as Gaussian copula, are most popular copulas being used since many data sets follow elliptical distributions or meta-elliptical distribu- tions (Fang et al. (2002)). However, today's approaches and software packages require us to assume the specific category, such as Gaussian or Student's T, of the elliptical cop- ula before estimating it. In this Thesis, we will propose a Bayesian method using Markov chain Monte Carlo (MCMC) methods to estimate the density function of elliptical copulas without specifying it is the copula …

Combination Of Resampling Based Lasso Feature Selection And Ensembles Of Regularized Regression Models, Abhijeet R. Patil

Open Access Theses & Dissertations

In high-dimensional data, the performance of various classiers is largely dependent on the selection of important features. Most of the individual classiers using existing feature selection (FS) methods do not perform well for highly correlated data. Obtaining important

features using the FS method and selecting the best performing classier is a challenging task in high throughput data. In this research, we propose a combination of resampling based least absolute shrinkage and selection operator (LASSO) feature selection (RLFS)

and ensembles of regularized regression models (ERRM) capable of handling data with the high correlation structures. The ERRM boosts the prediction accuracy with …

Scratching The Surface Of The Isotope Landscape Of An Ore Deposit Molybdenum-Sulfur Isotope Relationships In A Porphyry Copper-Molybdenum Deposit (Santa Rita / Chino Mine, Nm), Joshua Roger Peterson

Open Access Theses & Dissertations

More than 95% of the world's molybdenum (Mo) is mined from porphyry deposits (Sinclair, 2007). Molybdenum is an important component for the metal industry, as a key ingredient in stainless steel alloys and high-speed heat resistant tools. Despite the importance of porphyry deposits for the supply of this industrially important metal, major questions about Mo mineral precipitation remain unresolved and the process of ore body emplacement and formation remains poorly investigated (Cooke et al., 2014a).

Recent observations have revealed a wide range of Mo isotope compositions in porphyry deposits, both globally and locally (Greber et al., 2014a; Shafiei et al., …

Dust Storms And The Dispersal Of Aquatic Invertebrates In The Chihuahuan Desert Ecoregion, Jose Rivas Jr.

Open Access Theses & Dissertations

The Chihuahuan Desert surrounding El Paso, Texas is one of the most intense sources of dust in the Western Hemisphere. Within this vast desert are ephemeral wetlands with micrometazoan propagules contained within their sediment egg banks. Dispersal of aquatic microinvertebrates between habitats is vital for the success of their populations. Passive dispersal of the propagules provides an escape mechanism from unfavorable conditions. Upon desiccation of these habitats, windstorms can potentially transport propagules mixed within entrained sediments across regional scales. To study this process, I collected falling sediment from 91 windstorms, with 59 samples collected at the University of Texas at …

Near Room Temperature Magnetocaloric Materials For Magnetic Refrigeration, Eduardo Martinez Teran

Open Access Theses & Dissertations

Magnetic refrigeration (MR) is a cooling process based on the magnetocaloric effect (MCE) that is present to some extent in all magnetic materials, and the ones in which this effect is more appreciable are called magnetocaloric materials (MCM). The implementation of new designs and materials for the construction of cooling systems is a must do, being essential that these improved designs will reduce the environmental impact and increase the efficiency of their predecessors. In this thesis, the magnetocaloric effect theory is presented from a thermodynamic point of view and also the synthesis and study to a new Heusler alloy (MnFe2Ga) …

Code Smells Quantification: A Case Study On Large Open Source Research Codebase, Swapnil Singh Chauhan

Open Access Theses & Dissertations

Research software has opened up new pathways of discovery in many and diverse disciplines. The research software is developed under unique budgetary and schedule constraints. The developers are often untrained transient workforce of graduate students and postdocs. As a result, the software quality hinders its sustainability beyond the immediate research goals. More importantly, the prevalent reward structures favor contributions in terms of research articles and systematically undervalues research code contributions. As a result, researchers and funding agencies do not allocate appropriate efforts or resources to the development, sustenance, and dissemination of research codebases. At the same time, there are no …

The Rhetoric Of Low Carbon Energy Technology Scientists And Engineers, Nicolas Cesar Hernandez

Open Access Theses & Dissertations

Scholars in the burgeoning field of Energy Communication have successfully contributed to communication studies and environmental communication practice. However, energy communication scholars have largely focused on energy of media coverage, corporate communication and decision making in the context crisis. While rich and informative, this tendency has left quotidian aspects of energy communication rather understudied. As such, this Thesis contributes to the understanding of the internal, non-untechnical rhetoric of low carbon energy technology (LCET) scientists and engineers (herein LCET professionals). Textual analysis was used to examine LCET professionals' internal rhetoric at professional trade conferences and through long form, semi-structured interviews. Wind …

Formulation And Implementation Of Iterative Method For Generating Spatially-Variant Lattices, Manuel Fernando Martinez

Open Access Theses & Dissertations

The use of a matrix-free, memory-efficient approach to generate large-scale spatially variant lattices (SVL) was explored. A matrix-free iterative SVL generation algorithm was formulated and then implemented with a tremendous memory reduction observed. The algorithm consists of solving first-order central finite-differences along the entirety of the problem space point-by-point to obtain the grating phase function Φ(𝑠⃗) to which all desired spatially variant lattice properties are applied to. The algorithm was studied to identify key areas of data and task parallelism to exploit in heterogeneous computing systems consisting of clusters of central processing units (CPU) and graphics processing units (GPU) combinations. …

Precipitation And Transformation Of Iron-Sulfide Nanoparticles In Low-Temperature Aqueous Environment: Effects Of Reactant Iron And Sulfide Sources, Ezequiel A. Moreno Flores

Open Access Theses & Dissertations

Iron sulfide nanoparticles assume an important role within a wide range of geological settings as indicators of redox environmental conditions and elemental cycling mechanisms. Initial precipitates of iron sulfide are exclusively nanoscale sized in low temperature aqueous conditions and have been reported to go through diverse morphological and phase transformations, possibly leading to the ultimate deposits of pyrite in geologic records of various times. A systematic understanding of how the early-stage nanoparticles of iron sulfide may develop into more crystalline iron sulfide forms is still lacking however. The major goal for this study was to illuminate the effects of the …

Seismic Analysis Of The 30 July 1972 Sitka Earthquake Aftershocks, Stress Drop Of Aftershocks In Cook Strait, New Zealand Following The 2013 Cook Strait And Lake Grassmere And 2016 Kaikoura Earthquakes, And 2d Seismic Tomography In The Brady Hot Springs Geothermal Site, Nevada, Juan Alejandro Ochoa Chavez

Open Access Theses & Dissertations

The 1972 Mw 7.6 Sitka earthquake is the largest earthquake to have occurred along the Alaska portion of the Queen Charlotte fault (QCF) in historic time. The QCF system forms the plate boundary between the Pacific and North American plates within southeastern Alaska and has accumulated enough slip since 1972 to produce a comparable sized event in the near future. Thus, it is important to better understand the controls on the rupture process of the 1972 mainshock and its aftershocks. Following the mainshock the U.S. Geological Survey installed a network of 11 portable seismographs that recorded over 200 aftershocks of …

Amplification Vs The Natural Ear: A Test On The Effectiveness Of The Natural Ear On Adults Ability To Match Pitch In Song, Celeste Orozco

Open Access Theses & Dissertations

Background: Singing is a natural enjoyment of life; however, individuals tend to isolate themselves from this enjoyment due to their inability to match pitch accurately. A new technology, the Natural Ear provides altered auditory feedback to the user while singing. It is hypothesized that this feedback may aid in the userâ??s ability to match pitch.

Purpose: The purpose of this study is to compare the effects of the Natural Ear to amplification and no amplification conditions on pitch matching accuracy in song.

Study Design: This study used a complex counterbalance within-subjects design.

Methods: 50 adults from the El Paso Metropolitan …

Zircon (U-Th)/He Thermochronologic Investigation Of The Long-Term Thermal History Of Proterozoic Rocks In West Texas And Southern New Mexico, Nathan Zachary Reade

Open Access Theses & Dissertations

The tectonic history of west Texas and southern New Mexico is well documented, however existing geologic data only provide limited snapshots of the region’s prolonged and complex tectonic evolution. Zircon (U-Th)/He (ZHe) thermochronology is used to examine the long-term thermal history of Proterozoic rocks exposed in the southern Rio Grande rift. ZHe data were collected from the Carrizo Mountains (10 dates), Cookes Range (16 dates), and Franklin Mountains (30 dates) in order to constrain the long-term (>1 Ga) thermal history of rocks in this region and relate this history to known tectonic or climatic events. Individual ZHe dates range …

Synthesis, Characterization And Antibacterial Properties Of Silver(I) N-(4-Pyridyl) Benzamide Complexes With Varying Conterions, Mauro J. Ruiz

Open Access Theses & Dissertations

Organic semiconductor materials composed of - stacking aromatic compounds have been under intense investigation for their potential uses in flexible electronics and other advanced technologies. Herein we report a new family of seven - stacking compounds of Silver(I) N-(4-pyridyl) Benzamide with varying counterions, namely [Ag(NPBA)2]X, where NPBA is N-(4-pyridyl) Benzamine, X = NO3- (1), ClO4- (2), CF3SO3- (3), PF6- (4), BF4- (5), CH3PhSO3- (6), and PhSO3- (7), which form extended - stacking networks in one-dimensional (1D), 2D and 3D directions in the crystalline solid-state via the phenyl moiety, with average inter-ring distances of 3.823 Å. Interestingly, the counterions that contain …