Digital Commons Network^™

Developing A Multimetric Index To Assess Resaca Ecosystem Health, Buford J. Lessley

Theses and Dissertations

As the only freshwater ecosystem in the lower Rio Grande Valley aside from the Rio itself, resacas are critical habitat for many species of flora and fauna. Old distributaries of the Rio Grande, resacas provided conveyance routes moving floodwater to the Laguna Madre. Today these wetlands are novel ecosystems and are artificially maintained. Urbanization and agriculture have lead to sedimentation, habitat loss, contaminants, poor water quality, and invasive species. The objective of this study was to assess and monitor resaca pools and to compose the Resaca Health Index (RHI) from selected indicators of ecosystem structure and function including leaf litter …

Love Sex God, Magdiel G. Alfonso

Theses and Dissertations

As a result of the absence of a father-figure and the repulsion of machismo, a love for that masculinity and a void within grew from the missing father-son/male-male interaction; this is the drive to codify my work with homoerotic imagery bathed with guilty religiosity through a torturous sadomasochist context to display a life-mirrored desire to punish and love the male simultaneously while feeling guilty doing it. The work is inspired by homoerotic and religious art history and at times the blending of the two.

The purpose of this work is not only to show the love for the celebration of …

Low Temperature Flexible Perovskite Solar Cell With Mesoporous Tio2 Electron Transport Layer In High Humidity Environment, Felipe De La Torre

Theses and Dissertations

Perovskite solar cells are the fastest advancing solar technology to date with efficiencies increasing from 3.9% to more than 21% within a few years. They have emerged as a possible alternative to silicon photovoltaics due to their exceptional photovoltaic performance, light absorbing properties, and low-cost fabrication with methylammonium lead iodide (CH3NH 3PbI3) getting considerable interest in research and development. However, there are still many challenges that must be addressed for perovskite solar cells to replace contemporary solar cells, such as improving their stability, making them nonhazardous, further increasing their efficiency, and developing better techniques for large scale fabrication. In this …

From A Long Line Of Thieves, Lucinda Zamora-Wiley

Theses and Dissertations

This is a work of original creative writing, containing works of poetry, prose poems, flash non-fiction, and personal essays. The primary subject areas include family relations after PTSD, love, interracial struggles within marriage and family, pride of place--including Texas and the United States, and poetic/artistic inspirations that influenced the author.

Optical Method For High Magnification Imaging And Video Recording Of Live Cells At Sub-Micron Resolution, Jaime E. Romo Jr.

Theses and Dissertations

Optical microscopy, the most common technique for viewing living microorganisms, is limited in resolution by Abbe’s criterion. Recent microscopy techniques focus on circumnavigating the light diffraction limit by using different methods to obtain the topography of the sample. Systems like the AFM and SEM provide images with fields of view in the nanometer range with high resolvable detail, however these techniques are expensive, and limited in their ability to document live cells. The Dino-Lite digital microscope coupled with the Zeiss Axiovert 25 CFL microscope delivers a cost-effective method for recording live cells. Fields of view ranging from 8 microns to …

Using Machine Learning To Predict Student Achievement On The State Of Texas Assessment Of Academic Readiness Examination In Charter Schools, Christopher D. Gonzalez

Theses and Dissertations

The purpose of this study was to research and develop a way to use machine learning algorithms (MLAs) to predict student achievement on the State of Texas Assessment of Academic Readiness (STAAR), specifically in the charter school setting. Charter schools have the disadvantage of a constant influx in students, so providing historical student data in order to analyze trends proves difficult. This study expands on previous research done on students in secondary and post-secondary school and determining features that indicate success in these settings. The data used is from the district of IDEA Public Schools who focuses on providing education …

Forcespinning®: An Alternative Method To Fabricate Metal Oxide/Carbon Composite Nanofiber Anodes For Li-Ion Batteries, Luis Zuniga

Theses and Dissertations

Metals and their respective oxides have been highly regarded as next generation anode materials for lithium-ion batteries (LIBs). In this research work the electrochemical performance of Sn, SnO2, and TiO2. With the advantages of nanotechnology and the Forcespinning® method of fabricating micro and nanofibers, binder-free anodes are produced from metal or metal oxide/carbon composite microfibers. Through these microfibers the electrochemical performance of the above mentioned materials are significantly improved due to the increased surface area per volume providing a large number of reaction sites for the anode materials. Further performance enhancement was achieved by also modifying the fiber microstructure to …

The Subjugation Of The Texas Indians From The 17th–19th Centuries, Erhard M. Vandeventer

Theses and Dissertations

The Americas have long been a center of conflict as European powers competed for control of the resources of these untapped lands. Spain, France, and England contributed to the turbulent era of colonization. Each left their mark on the Western Hemisphere. Spain couldn’t know that an Independent Mexico would emerge from the actions of the first Spanish conquistadors. The Republic of Texas was actually a stepchild of Spain created through its Mexican land grants and missions. The lands they colonized were not empty. Spain, Mexico and the Texas Republic, found their new holdings populated by Native Americans who were not …

Router Security Effect On Performance Of A Network, David L. Leal

Theses and Dissertations

Recently many of the devices that create a computer network offer security to help protect networks from hackers, such as computers, servers, firewalls and even routers. In most cases when protecting a network from hackers having more security is not always the best, because the more resources of the device is used by the security in inspecting connections, and it can compromise performance of the network.

This thesis investigates performance benefit of having security on a router and its impact on the connection rate of the network when it is under security attacks. In this thesis, different security features and …

Discriminacion A Un Martir: The Ballad Of Felix Longoria, Cristobal A. Carrizales

Theses and Dissertations

This thesis looks at how the Felix Longoria Affair propelled Hector P. Garcia, Lyndon B. Johnson and the American G.I. Forum into the national limelight, while also leaving the Longorias, Three Rivers and Texas in a state of disrepair. The affair in general helped expose injustices that were occurring to Mexicans American in Texas at the time, but left the family, Three Rivers and Texas in a battle over the legacy of how each would be seen in the annals of history.

False Positives On Neuropsychological Measures Of Effort Among Bilingual Neurologically Intact Mexican Americans, Arnoldo Amador Jr.

Theses and Dissertations

The present study examines the performance of bilingual Mexican Americans on neuropsychological measures of effort in language and visual-perceptual formats. Optimal/suboptimal effort cutoff scores derived from monolingual English Speakers were used to test participants divided by language of administration and bilingual groupings based upon Spanish-English difference scores on the Woodcock Munoz Language Survey-Revised Picture Vocabulary subtest. Participants produced more false positives (misidentification of suboptimal effort) on the Reliable Digit Span, a language formatted measure, and similar rates of false positives on visual-perceptual effort measures: Test of Memory Malingering and the Dot Counting Test as compared to established rates using monolingual …

Academic Relationships Between At-Risk High School Students And Teachers Within An Alternative School Setting: "It Is More Than Just Academics, It's Attitude", Daniel R. Galdeano

Theses and Dissertations

The first public schools in the United States were originally created to give all school-aged children the opportunity to gain access to a well-rounded education (Cable, Plucker & Spradlin, 2009). Options in public schools, preparation for high-stakes standardized tests, and graduation requirements are among the many educational reform policies that have been implemented in hopes of enabling students to reach their academic potential (Lange & Sletten, 2002). As a substitute to dropping out, alternative schools are among the leaders in the charge to try to curb the dropout problem that schools are facing. Alternative schools have existed since the civil …

A Journey To Understand Dual Language And The Bilingual World: An Autoethnography Of A Bilingual Program Director In An Urban District, Olivia Hernandez

Theses and Dissertations

This research represents a personalized account of the complexities, interpretations, and reflections on the life-long epistemological development of a bilingual program director currently implementing a dual language program in an urban school district. Using myself as a subject and a researcher in cultural, personal, and professional contexts provided the impetus for this self-study. Through the lens of a mother, daughter, sister, teacher, principal, and bilingual program director, I have chronicled and traced the epistemological conception of the assets that guide my advocacy in the academic realm of bilingual education. As an autoethnography, this study invites the reader to experience the …

Multivariate Calibration Of A Load Sensor For Dynamic And Static Freight Railcar Applications, Dylan Michael Blackwell

Theses and Dissertations

Determination of the load carried by each bearing in a railcar system is crucial to the integrity of the railroad industry. With accurate load measurement, the process of filling a railcar with its specified cargo can be optimized to provide the maximum amount of cargo without exceeding the upper weight limits imposed by the Associations of American Railroads (AAR). An accurate load measurement will additionally make it possible to identify any load imbalance that occurs during periods of travel which result in having a detrimental effect on the health of the bearing. Previous work conducted with a strain-gauge load sensor …

Avian Communities In An Urbanizing Region: Abundance Patterns And Effects Of Local Habitat Features, John S. Brush

Theses and Dissertations

The Lower Rio Grande Valley of Texas has experience rapid population growth and increase of urban area since the mid-20th century. The goal of this thesis were to: 1) explore patterns of avian communities in suburban and remnant urban woodlands, with particular interest in native forest species, and 2) to assess how local habitat variables, such as number of native trees, affect avian communities in suburban habitats, and 3) provide recommendations to municipalities and homeowners to enhance urban habitats for birds. Results indicated that remnant urban woodlands provided habitat for common native forest bird species that otherwise avoided suburban habitats, …

Calculating Evapotranspiration Of Arundo Donax Along The Rio Grande, Jose R. Escamilla Jr.

Theses and Dissertations

Invasive species have been recorded to cause large economic and ecological impacts on various ecosystems and their services. Locally, giant reed (Arundo donax L.), a woody grass native to the Mediterranean, adversely impacts riparian ecosystems in southwestern United States by aggressively displacing their native flora and fauna. Giant reed also has become a cause of concern for national water security, especially in water-limited areas of the arid southwestern United States. The main objective of this study is to provide the first, landscape-level estimates of water use by giant reed in the United States. Evapotranspiration was monitored using the eddy …

Mobile Appointment Reminders In Patient-Centered Care: Design And Evaluation, Ying Wang

Theses and Dissertations

Reminder systems have great potential to enhance healthcare outcome if it can facilitate collaborative appointment management with accessible mobile communication technology in patient-centered care. Yet, Current appointment reminder systems are effective but not optimal (McLean, et al. 2016). Following the design science process delineated by Peffers et al. (2007) and other requirements, this study proposes a design of reciprocal reminder system that automates the process of appointment rescheduling for healthcare providers and patients in addition to confirmation and cancellation. Based on the premises of media synchronicity theory, media naturalness theory and stakeholder theory as kernel theories, this study develops a …

Numerical Simulations Of Shock Waves Reflection And Interaction, Ligang Sun

Theses and Dissertations

The main objective of this dissertation is to detect and study the phenomena of reflection of one shock wave and interaction of two shock waves using numerical methods. In theory, solutions of non-linear Euler equations of compressive inviscid gas dynamics in two dimensions can display various features including shock waves and rarefaction waves. To capture the shock waves properly, highly accurate numerical schemes are designed according to second order Lax-Wendroff method. In this thesis, three numerical experiments were designed to show the reflection and interaction phenomena. Firstly, one shock was formed due to the encounter of two high speed gas …

The Gratitude Questionnaire And Mindful Attention Awareness Scale For Use With Latina/O College Students: A Confirmatory Factor Analysis, Dion B. Smith

Theses and Dissertations

Interventions based on positive psychology constructs have become increasingly popular over the past two decades, necessitating validation of instruments for use with underrepresented populations (Pawelski, 2016; Vela, Lerma, & Ikonomopoulos, 2016). This study reports an evaluation of the Mindful Attention Awareness Scale (MAAS; Brown & Ryan, 2003) and the Gratitude Questionnaire (GQ-6; McCullough, Emmons, & Tsang, 2002) for use with Latina/o college students. Sample sizes used in this study are N = 207 (99 women and 104 men; 4 did not identify) for the MAAS and N = 127 (84 women and 38 men; 5 did not identify) for the …

Boricua Type: Intersectional Hybrid Transcultural Art Concepts And Illustrations, Isaac Santiago

Theses and Dissertations

The concepts and artworks contained in this thesis embodies most of the research that I did in and outside the University. My particular experiences as a Puerto Rican, born and raised, and as a migrant artist in Mexico and Texas. Most of the research was made by trail and error independently or with little to no guidance. In conclusion I found my artistic self: technically, personally, and reached a high level of commitment to our community as a prepared professional.

Sequencing Of The Complete Mitochondrial Genome Of Anastrepha Species, Francisco C. Rugama Ii

Theses and Dissertations

Several members of fruit flies in the vastly diverse Anastrepha (Schinner) genus (family Tephritidae), considered to be among the most important and devastating pests of vegetable and fruit crops, are distributed widely throughout the Americas. They attack several different kinds of fruit including citrus, which is of great economical importance in South Texas. The identification of these flies is based primarily on wing pattern and characteristics of the female genitalia, contrary to males, which cannot be distinguished at all. Misidentification of adults is a widespread problem, while identification at the larval stage is practically impossible. Currently, there are no published …

Optimizing Border Security With Stochastic And Deterministic Strategies, Gabriel A. Rueda

Theses and Dissertations

International trade and border security have always been linked together, and so has the need to find ways to improve security decisions. The United States and bordering countries benefit from the North American Free Trade Agreement (NAFTA), but amongst the positive effects of NAFTA there is a looming drug threat that effects the bi-national supply chains. In 2015 Customs and Border Protections (CBP) processed over 72,000 trucks, rail, and sea containers a day. CBP also seized 3.4 million pounds of narcotics, the majority of them at the ports of entry. With unknown threats using commercial vehicles to transport their illicit …

Ethnicity And Poetry: A Systems Theory Approach To Contemporary African American And Mexican American Poetry, Antonio Paniagua Guzman

Theses and Dissertations

Given the ongoing ethnic transformation of the current society of the United States, contemporary sociologists have extensively studied ethnic relations from diverse theoretical and methodological approaches. Despite the vast sociological research recently developed, the literary-based methodological approach remains partially uncultivated. This study explores motivations and patterns of minority groups’ ethnic performance in contemporary poetry by analyzing inter and intra-group similarities and differences of diverse linguistic and cultural traits. From secondary data analysis, this study examines four hundred poems authored by forty contemporary African American and Mexican American writers experientially connected to the state of Texas. Grounded in systems theory, this …

Evaluating Practicum Student's' Therapeutic Effectiveness Using Solution Focused Brief Therapy With Mexican American Clients: A Single Case Design, Krystle L. Ortega

Theses and Dissertations

The purpose of this study is to examine the effectiveness of a practicum counseling experience on client therapeutic outcomes using Solution Focused Brief Therapy with Mexican American clients. We implemented a small series (N = 3) single-case research design to assess the effectiveness of SFBT for increasing hope and decreasing clinical symptoms. Clients’ clinical areas of functioning and clinically significant change will be evaluated using the Outcome Questionnaire -45.2 whereas hope will be assessed using The Trait Hope Scale. The results of this study will ultimately help researchers in counseling education, counselors, supervisors, and students by providing an outcome …

Knee Joint Internal Forces During Squat Jump Exercise, Ricardo Moreno

Theses and Dissertations

The purpose of this research is to investigate muscular ligament and joint contact forces produced during squat jump exercise. An inverse dynamics, two dimensional, leg model is used to describe the motion in the sagittal plane. The lower extremity model includes two bones, tibia and femur, tibio-femoral ligaments, and muscles such as quadriceps, hamstrings, and gastrocnemius. The ligaments are anatomically modeled as nonlinear strings, but the femoral condyle is modeled as a circle and the tibial plateau as a straight line. Experimental squat jump exercises are conducted to obtain the ground reaction forces, the angular accelerations, and centroid linear acceleration …

Study Of Selective Laser Remelting Of 316l S.S. To Reduce Roughness On Inclined Surface, Jafar Ghorbani

Theses and Dissertations

Additive manufacturing (AM) technologies are increasingly competing with subtractive methods, and there are promising applications for additive technologies that are hybrid with traditional manufacturing methods. Poor surface roughness of additive manufactured parts continues to be a major challenge especially for advanced functional parts. In this study, effect of processing parameters are evaluated, optimized and verified by using the Box–Behnken design of experiment method. The results, for the first time, reveal that surface remelting has the potential to become a high speed approach for improving the roughness of non-horizontal surface of additive manufactured parts.

Carbon And Nitrogen Dynamics Of Anthropogenically Disturbed Seagrass Ecosystems, Alison Shepherd

Theses and Dissertations

As atmospheric CO2 concentrations continue to rise, understanding factors that influence size and longevity of carbon (C) pools within coastal and marine ecosystems (i.e., “blue carbon”) is critical. In 2013, the global average atmospheric CO2 concentration reached 396 ppm, which was the highest recorded level in the last 800,000 years. Recent research acknowledges the importance of “blue carbon” in the global C cycle, finding that these ecosystems capture up to 70% of organic C in the marine realm, rendering them one of the most efficient C sinks on the planet. Specifically, seagrass ecosystems are critically important to the global C …

The Artists Journey- Strolling The Edges Of The Universe, Mary P. Williams

Theses and Dissertations

Space exploration has always fascinated me, and so has the idea ( so far fictional) that humankind may someday encounter extraterrestrial life. My series of paintings and prints are a visual expression of the awe and wonder I feel as I follow our species’s unending drive to expand the boundaries of its known world.

But the unknown is not just out there in interstellar space. And there are other lifeforms to encounter right here on our own planet. Another series of my paintings documents Earth’s flora. Our ties to the microorganisms, animals, and plants on our planet, and the life …

If This Heart Had A Mouth: A Forbidden Romance Narrated Through Mimesis: Poems, Julieta V. Corpus

Theses and Dissertations

If This Heart Had a Mouth consists of forty-two poems where love is the catalyst for a multitude of emotions, ranging from falling in love, to hopelessness, to a begrudging kind of acceptance at losing the beloved to somebody else. To create all forty-two poems, 23 written in Spanish, and 19 poems written in English, I employed the literary device called Mimesis which entails deriving an original poem from someone else's work.

To create each poem, I followed another poet’s original work, line by line. I imitated that poet’s rhythm through their use of meter. I counted the number of …

Lipan Apache Tribe Of Texas: Ethnic And Racial Identity, Ashley S. Leal

Theses and Dissertations

The findings presented in this study are based on a series of semi-structured interviews, focused on racial, ethnic and cultural identity, with 20 registered members of the Lipan Apache Tribe of Texas. Analysis of the interviews show that while members are spread across the country the basic cultural identity still remains the same: they are all cultural and tribal ambassadors to future generations and the world around them. Results indicate that interviewed members share the same aspirations of becoming federally recognized by the United States government, not for any type of benefits but to be seen as real Indians through …