Digital Commons Network^™

Structural And Optical Investigations Of Rbxcs1-Xh2po4, Alex D. Price

Open Access Theses & Dissertations

Proton conductor solid acid electrolytes RbxCs1-xH2PO4 (0≤x≤1) have been investigated using second harmonic generation and powder x-ray diffraction. Second harmonic generation is an optical technique which can be used to study the structural properties of materials. Microscopes of this nature have the ability to image objects with a variable penetration depth in a non-destructive manner, allowing for great potential to be used for in situ observations of the electrolyte’s structure when in a fuel cell under operating conditions.

X-ray powder diffraction was carried out on the series of samples and found for values of 0≤x≤0.5 the structure of the material …

A Narrative Inquiry Of Experiences Of Validation Of Graduate Students In Economics, Eva Ximena Quintana

Open Access Theses & Dissertations

The purpose of this study was to understand the experiences of students in a graduate Economics program located at a predominantly Hispanic-serving institution using narrative research design, a methodology that is not used in economics literature. The research question that guided the study was: How are graduate students validated throughout the process of their graduate education at a Master's in Economics program at a predominantly Hispanic-serving institution? The researcher interviewed 3 graduate women economics students, and 3 graduate men economics students to ensure triangulation of data. After conducting the study it became apparent that graduate women economics students and graduate …

Drug-War Violence, Mental Health, And Coping Mechanisms Among Mexican-Origin Women In El Paso, Texas, Nora Angelica Benavides

Open Access Theses & Dissertations

This Thesis examines how the drug-war violence in Mexico from 2006 to 2012 shaped the experiences of migrant women who were adapting to life in El Paso, TX (USA) after leaving Ciudad Juarez, Mexico. This study is oriented through a testimonio approach, which involves telling the stories of ten Mexican origin women interviewed between 2012 and 2014. It focuses on their narratives about their traumatic experiences with drug-war related violence in Juarez and forced migration to El Paso, TX and how they coped with the challenges to achieve resilience after arriving in the US. I also report on their mental …

Clashes In The Contact Zone: Student, Faculty, And Administrative Resistance To Intersectional Pedagogies In The Writing Classroom, Gina Marie Lawrence

Open Access Theses & Dissertations

This Dissertation is a study of rhetoric and composition instructors around the country who use intersectional pedagogy as a way to introduce students to issues of class, race, sexuality, and gender in order to work toward a more just society. Instructors using this approach often encounter resistance from students and administrators, and this project will help instructors respond to this resistance in thoughtful, rather than reactionary, ways.

Empowerment Or Threat: Perceptions Of Childhood Sexual Abuse In The #Metoo Era, Melissa Samantha De Roos

Open Access Theses & Dissertations

Most victims of Childhood Sexual Abuse (CSA) will not disclose the abuse until they reach adulthood. When victims do disclose, they often face negative responses such as disbelief or blame. The specifics of both the individual and the abuse can create barriers for individual victims to disclose the abuse (i.e. gender of the perpetrator or age of the victim at the time of abuse). These situational and individual differences create societal expectations and stereotypical beliefs about CSA that further complicate the disclosure process for the victim. The aim of these studies is to explain why men tend to be less …

Technical Project Management: Union Of Systems Engineering Processes With Project Management Processes, Deyaaldeen M. Abusal

Open Access Theses & Dissertations

Today, most projects in technical fields utilize project management to complete projects as planned, and some of the projects utilize system engineering to cover the project in both technically and commercially. This Thesis investigates the relationship between Project Management (PM) and Systems Engineering (SE) to determine if a suitably professional level of management and level of quality can be achieved. When studying PM and SE separately and make a comparison between both, there is much overlap between these two mature fields. The project could be planned and completed solely by either process. This study combines both fields of Project Management …

An Integrated Machine Learning Geological Field Tool In The Age Of Big Data And Drones, Guillermo Vargas

Open Access Theses & Dissertations

Unmanned aerial vehicles (UAVs) and machine learning are relatively new research tools in the geosciences that can be used to collect and analyze large data sets rapidly. We combine the power of rapid data collection using unmanned aerial vehicles with machine learning algorithms to develop a field-based system to identify targeted geological features. For data collection, we have used a commercial-grade UAV which carried visible-wavelength and multispectral (visible- infrared) cameras. We analyzed the data with machine learning and machine vision algorithms that can classify rock units exposed in a field area. We have identified algorithms that in previous literature have …

Hybrid 3d Printing Demonstrated By Arbitrary 3d Meandering Transmission Lines, Ubaldo Robles

Open Access Theses & Dissertations

This Dissertation focuses on the automation of multi-material direct write three-dimensional (3D) manufacturing of arbitrary metal-dielectric structures. The technology was demonstrated by manufacturing 3D meandering interconnects and transmission lines (TLs). Manufacturing 3D functional electronics with multiple materials required pushing the current state of 3D printing (3DP) technology to utilize simultaneous multi-material processes combined with sophisticated slicing and bonding under one process. Multi material 3DP is known as hybrid 3DP. This research pioneered the process for producing meandering transmission lines, starting with design and manufacturing, using hybrid 3DP through micro-dispensing and fuse deposition modeling. The research starts by 3DP magnetic and …

Electrocatalysts Based On Organic Macrocycles For Electrochemical Water Splitting, Yanyu Wu

Open Access Theses & Dissertations

Water splitting, which is the dissociation of water into hydrogen and oxygen gases, can be separated into two half reactions corresponding to the hydrogen evolution reaction and oxygen evolution reaction (HER and OER, respectively). Both reactions offer a promising way for storing energy into the form of chemical bonds, which is an important strategy for the development of clean-energy technologies. A main area of interest while studying HER and OER is to design effective and robust electrocatalysts made from earth-abundant materials. This dissertation describes several homogeneous and heterogeneous systems for the electrocatalytic generation of hydrogen and oxygen gases.

In Chapter …

Testing Of A 1n Af-M315e Thruster, Daniela Ivette Aguilar

Open Access Theses & Dissertations

The Center for Space Exploration and Technology Research (cSETR) at the University of Texas at El Paso (UTEP) is currently pursuing various space propulsion and small satellite projects. One of these projects is called Orbital Factory X (OFX), which mission is to design a 2U Cube-Satellite (Cube Sat) with 4 green mono-propellant thrusters along with multiple micro-cathode arc thrusters. A CubeSat is a small-scale version of a satellite that is usually placed in orbit for near earth missions. However, they have a relative short life and limited maneuverability due to their limited source of power and restricted payload. Now, technologies …

Language Attitudes Toward Mexican Spanish-Accented And Standard Varieties Of English, Michelle Aguilar

Open Access Theses & Dissertations

The unique demographics of El Paso, Texas show that it is a site with intense Mexican-American ethnolinguistic contact that creates a co-existence of different English and Spanish varieties. In El Paso, approximately 80 percent of the population identifies as Hispanic or Latino and approximately 95 percent of that group has reported to be of Mexican ancestry (Statistical Atlas, 2015). As a result, Spanish is spoken by 68 percent of the population (United States Census Bureau, 2016). Yet, particular Hispanic-accented English varieties spoken in the region, (Chicano English and Mexican Spanish-accented English), are stigmatized. The focus of this study will be …

Does A Family History Of Type 2 Diabetes Affect Exercise Induced Improvements In Insulin Sensitivity, Metabolic Flexibility, And Myokine Expression In Mexican-American Males?, Manuel Amador

Open Access Theses & Dissertations

A family history of diabetes (FH+) is considered a risk factor for the development of insulin resistance and type 2 diabetes. However, it is not known whether exercise induced improvement in insulin sensitivity (IS) and metabolic flexibility (MF) are impacted by a FH+. Purpose: To determine if a FH+ limits exercise induced improvements in Insulin sensitivity, MF, body composition, and strength following an 8-week combined aerobic and resistance training intervention compared to those without a family history of diabetes (FH-). Methods: 19 (FH- n=9, age 21.89 ± 0.60 years, BMI 27.51 ± 1.68 kg/m2; FH+ n=10, age 23.41 ± 0.86 …

Geostatistical And Geospatial Distribution Of Multiple Metallic Elements In Agricultural Regions Of The Mid-Continental Usa, Najwah Alssaeidi Ahmed Almesleh

Open Access Theses & Dissertations

Regional geochemical mapping constitute the chemistry of the surface of the earth in a large scale and relatively low sample density. It is widely accepted scientific activity and man uses some cases to identify contamination. In the present study, data present in national geochemical survey database was used to investigate the chemical loading loading of the agricultural soil. In the mid-continent region of the United States. Several traditional parameters were used mainly the enrichment factor (EF), and geoaccumulation index (I geo). Total chemical influence (TCI) maps were used to guide sampling. In addition, regional trace element chemistry of bedrock was …

Forecasting Space Weather Using Deep Learning Techniques, Sumi None Dey

Open Access Theses & Dissertations

Solar activity gives rise to various kinds of space weather among which solar flares have serious detrimental eects on both near-Earth space and our upper atmosphere that will have consequent influence in our lives. For example, solar flares can damage satellite infrastructure, hinder power grids, disrupt Global Positioning Systems (GPS) and disrupt long-distance communication. Airplane pilots, cabin crew and astronauts can be aected by the harmful radiation released from the Sun. As a result, there is a need of a methodology to forecast space weather accurately. In this work, we have developed a deep learning architecture to do the short-range …

Comparison Of Stride Length And Stride Frequency Patterns Of Sprint Performance In Overground Vs Motorized Treadmill Sprinting., Fayon Kamieka Gonzales

Open Access Theses & Dissertations

The purpose of this study was to investigate the relationship between different kinematic parameters when maximal effort sprints are performed overground and on a motorized treadmill by recreationally trained and collegiate level sprinters. To accomplish the goals of this study, we measured stride length, stride frequency, contact time, and flight time overground and on a motorized treadmill to determine what differences or similarities can be identified. Anthropometric measurements such as the height, body weight, lower limb length, and lower limb circumference were also recorded. Subjects' performance of a 60 meter sprint (50 meter acceleration, 10 meter maximal velocity) was measured …

Detection Of Pharmaceuticals And Personal Care Products In The Rio Grande And Their Effects On A Model Aquatic Invertebrate (Rotifera, Monogononta: Plationus Patulus), Enrique David Garcia

Open Access Theses & Dissertations

Rivers, including the Rio Grande, receive discharges from urban, agricultural, and industrial areas. These discharges have potentially harmful contaminants that may affect life span, fecundity, and/or behaviors of aquatic organisms. In this project, water quality was analyzed near a discharge point source and impacts of pharmaceuticals and personal care products (PPCPs) on a non-target organism (Plationus patulus) were investigated. Long-term and integrative organic samplers (POCIS) were left in situ for about 1 month near a wastewater treatment plant that discharges effluent into the Rio Grande. Over 40 PPCPs, including carbamazepine (ranging from 17.50 to 584.29 ng/L), erythromycin (ranging from 0.51 …

Regional Differences In Feto-Infant Mortality In The U.S. - Mexico Border Region: Using The Perinatal Period Of Risk (Ppor) Approach, Dyanne G. Herrera

Open Access Theses & Dissertations

Introduction. Infant mortality (IM) is a critical indicator of the health of communities because societal factors that affect population health directly impact the mortality rate of infants. There is limited infant mortality data for the U.S. side of the U.S.-Mexico Border Region, defined as the areas within 100 km north of the border. Data from 2005-2007 show that the average IM rate for the border states combined was 5.8 infant deaths per 1,000 live births; for the border counties, the rate was 5.4 per 1,000. Although IM rates were lower in the border counties than in the border states, risk …

Environmental Injustice And Racial/Ethnic Heterogeneity In Houston, Texas, Michel G. Loustaunau Garcia

Open Access Theses & Dissertations

This Thesis seeks to contribute to distributive environmental justice (EJ) research by analyzing racial/ethnic and intra-ethnic disparities in potential health risks from exposure to hazardous air pollutants (HAPs) in Harris County, the most populous county in Texas. Previous EJ research in this urban area has not examined intra-ethnic heterogeneity in exposure to air pollutants or attempted to compare social disparities in exposure to air pollution caused by vehicular (mobile) and point (stationary) sources. The goal of this study is to determine how the EJ implications of cancer risks from inhalation exposure to HAPs from mobile and stationary sources differ across …

Geospatial Relationship Of Intelligent Compaction Measurement Values With In-Situ Testing For Quality Assessment Of Geomaterials, Luis Alberto Lemus

Open Access Theses & Dissertations

The implementation of Intelligent Compaction (IC) in the construction of transportation infrastructure as a tool for quality control of compacted geomaterials has attracted the attention of a number of highway agencies. Compaction quality has been conventionally assessed using density, and to a less extent, modulus-based spot measurements at selected locations along the roadway section. While spot measurements do not provide a thorough rendition of the level of compaction of the roadway, IC technology is effective in meeting full coverage requirements. IC roller measurements are accelerometer-based measurements recording machine-ground interaction assumed to be indicative of the stiffness of the compacted geomaterial. …

Magnetotelluric Analysis Of Central Kenya Kenyan Rift Volcanoes For Geothermal Development, Anna Wairimu Mwangi

Open Access Theses & Dissertations

Abstract

High temperature geothermal resources are vast along rift margins because of emplacement of magma in shallow crust. This is the case along the Kenyan Rift valley also known as the Gregory Rift. It is the Eastern arm of the East African rift and a chain of volcanoes along the rift graben characterizes it. We use (MT) magnetotelluric method to image beneath the peralkaline province of the Kenya Rift i.e. Olkaria, Eburru, Badlands, and Longonot volcanoes. The resistivity structure shows active geothermal activity happening at the upper 3km from the subsurface as evidenced by low resistivity cap rock comprised of …

Juggernaut: A Memoir In Pieces, Leeann Olivier

Open Access Theses & Dissertations

This experimental memoir is a collection of lyric essays that address the link between place (bodies of water in particular) and identity. They also examine my experiences being married to (and eventually divorcing) a man with a traumatic brain injury that led to drug addiction, domestic violence, and a diagnosis of bipolar disorder.

Evolving Identity: A Case Study Of Mentor Science Teachers, Melissa N. Ortega

Open Access Theses & Dissertations

This dissertation is a case study of how mentor science teachers understood and presented their experiences, challenges they faced, and learning of being and becoming a mentor teacher while they participated in a year-long district mentoring program. The purpose of this study is to examine what science teachers learn in their experiences as mentors and the role this learning played on their identities as professional educators. According to Bullough (1997), teacher identity is of vital concern to teacher education as it is the “basis of meaning making and decision making” (p. 21). Existing research on science teacher identity indicate that …

Determing Fault Location Within An Active Rift Basin Using Gravity Analysis To Determine Fault Movemnet And Effect On Water Recharge, Mark Andrew Ornelas

Open Access Theses & Dissertations

The growth of the El Paso, TX and Ciudad Juárez, Chihuahua, metropolitan area has increased reliance of groundwater pumping from the Hueco Bolson. With growing demands for water and recharge of the bolson not occurring at a fast enough rate, water storage within the bolson is beginning to diminish. My study focuses on locating and understanding how faults interact with water flow into the basin and how they aid in storing water on the northwestern side of the bolson. Previous studies in the northernmost part of my study area have delineated a series of faults that predominantly trend northwest-southeast. In …

Extraction Of Fiber Morphology From Sem Images For Quality Control Of Fiber Reinforced Composites Manufacturing, Md Fashiar Rahman

Open Access Theses & Dissertations

The morphology of fibers (e.g. spatial uniformity, orientation, and length) plays a decisive role in determining the material properties or fabrication quality of fiber-reinforced nanocomposites. Hence, determining the morphology becomes a very critical issue in the field of nanocomposite quality control. The conventional way of quality inspection is to take the scanning electron microscopic (SEM) images of the cross-section of composite material and do the visual checking of these SEM images to evaluate the nanofiber alignment and length distribution. But this type of inspection is often subjective, inaccurate and time consuming. Moreover, the extremely small size of nanofibers makes the …

A Leveling Production Strategy To Automotive Assembly Using Queuing Systems Software Through Simio Simulation, Ivan Arturo Renteria Marquez

Open Access Theses & Dissertations

The automotive manufacturing industry is challenged with an unpredictable costumer demand with considerable fluctuation. In addition, the number of products (vehicles) and the complexity of them are constantly growing. These characteristics make very difficult to plan and schedule production. This Thesis presents a methodology to model with a high degree of accuracy the production floor, warehouse and material handling system of an automotive assembly facility through Simio simulation software; resulting in a dynamic model that combines all the critical variables of the system. The presented methodology includes an algorithm developed with the goal of modeling the automotive facility Kanban system. …

Characterization And Geochemistry Of Carbonate Caprock Associated With The Gypsum Valley Salt Wall, Paradox Basin, Colorado: Implications For Understanding Lateral Caprock Emplacement, Piper Lee Poe

Open Access Theses & Dissertations

On the northeastern side of Gypsum Valley salt wall in the Paradox Basin of Colorado, discontinuous exposures of layered gypsum and carbonate rocks were previously mapped as the contact between diapiric Paradox Formation and marine limestone of the Pennsylvanian Honaker Trail Formation. Utilizing new and existing mapping, petrographic and isotopic geochemical analyses, this study reinterprets this zone to represent lateral gypsum and carbonate caprock that formed in the Triassic during passive rise of the Gypsum Valley salt wall. Gypsum Valley lateral carbonate caprock can be distinguished from Pennsylvanian and Permian depositional carbonate strata exposed elsewhere on the salt wall by …

Geophysical Investigations Of Southcentral Alaska, Felix Dziedzorm Ziwu

Open Access Theses & Dissertations

The Castle Mountain Fault (CMF) is the closest (<50 km) active fault to Anchorage, Alaska and is known to be capable of producing earthquakes of magnitude 7.0 â?? 7.1. While several mapping and trenching studies have been conducted along the CMF, geophysical investigations along the fault zone have been limited. We use over 700 recently collected, closely spaced gravity observations, in addition to existing regional gravity, aeromagnetic, seismic reflection, well log data, and geologic information, to develop new 2D models of the deeper structure of the CMF system. We developed four 2D integrated forward models across the Castle Mountain Fault. These models indicate differences between the western and eastern segments of the Castle Mountain Fault. The models show a thick sequence of Tertiary to Mesozoic sediments overlying the Peninsular terrane basement at varying depths within the area. We identified two main intrusive granitic rocks based on the varying susceptibilities. These granitic rocks share a possible fault contact with the Mesozoic sedimentary rocks. The model also shows that the CMF cuts through the Mesozoic sediments at depth. These rocks can create strong coupling along the fault and with the decreasing eastward angle of subduction, it is highly for fluid migration to the eastern edge of the subducting Yakutat microplate. Seismic events plotted along the profiles supports the Holocene motion along the western CMF (WCMF) and indicates a deeper extent of the CMF into the crust. The eastern CMF shows high rate of deformation based on the structures associated with the Mesozoic rocks.

On Numerical Stochastic Optimal Control Via Bellman's Dynamic Programming Principle, Prince Osei Aboagye

Open Access Theses & Dissertations

In this work, we present an application of Stochastic Control Theory to the Merton's portfolio optimization problem. Then, the dynamic programming methodology is applied to reduce the whole problem to solving the well-known HJB (Hamilton-Jacobi-Bellman) equation that arises from the Merton's portfolio optimization problem subject to the power utility function. Finally, a numerical method is proposed to solve the HJB equation and the optimal strategy. The numerical solutions are compared with the explicit solutions for optimal consumption and investment control policies.

Impact Of Patient Demographics And Health Insurance On Hospital Discharge, Ana Acosta

Open Access Theses & Dissertations

Based on discharge data collected with 241 patients who received medical care from a fall injury between 2014 and 2015 at the emergency room in a general hospital in El Paso, Texas, I will examine whether individuals over age 55 have health insurance and the type of care that is recommended to patients after being discharged. In particular, I will examine demographics, including ethnicity, age, and language on whether the patient paid with insurance and the disposition of discharge from the emergency department after a fall. Additionally, I will examine which demographic factors are associated with disposition of discharge- facility, …

Effects Of Increasing Deciduous Shrub Litter On Ecosystem Functioning In Alpine Tundra, Alejandro Emmanuel Benhumea

Open Access Theses & Dissertations

Rising temperatures due to global warming have resulted in rapid environmental changes in northern environments, resulting in an increase in deciduous shrub growth which has the potential to alter soil ecosystem properties and processes. In order to address some potential mechanisms by which shrubs alter ecosystem properties and processes, we designed an experiment which separated the effects of physical shrub presence and the effects of litter quantity in a fully factorial experiment on a north facing alpine plateau in the southwest Yukon, Canada. Specifically, we asked the following questions: What are effects of shrub litter, independent of shrub presence, on …