Digital Commons Network^™

Dynamic Optimization Of Directed Energy Deposition Build Conditions Using Real-Time Monitoring Via Closed-Loop Control, Callan Herberger

Open Access Theses & Dissertations

Directed Energy Deposition (DED) is an additive manufacturing process that is being rapidly adopted by industry and is well suited for the fabrication of complex components in various metal alloys. DED provides unique benefits such as design flexibility, the potential for in-situ alloying, and an open environment that allows for unobstructed monitoring within the build chamber. Despite these benefits, fully exploiting additive manufacturing's (AM) potential remains a complex task for designers. This dissertation presents a framework for controlling Directed Energy Deposition process variables through in-situ monitoring. An exploration into modifying AM build conditions through the development and implementation of a …

Vertically Aligned Nickel Cobalt Molybdenum Copper Oxide Nanotubes For High Performance Asymmetric Supercapacitors, Ricardo Herrera Aguirre

Open Access Theses & Dissertations

Designing materials having novel multi metal oxide electrodes with controlled structure and composition is a critical technological challenge for high performance supercapacitor applications. Quaternary metal oxides have attracted considerable attention in this field, where many methods have been used to improve their performance. In the present work, the nickel cobalt molybdenum copper oxide (NCMCuO2) has been synthesized using a hydrothermal method. The effect of different concentrations of Cu doping (0.5%,1.0% and 2.0%) on the NCM frame and structural and electrochemical properties of the quaternary metal oxide (NCMCuO2) are studied thoroughly. The XRD pattern of synthesized NCMCuO2 exhibited predominant (002) orientation …

Critical Analysis Of Archival Data: The Alvarado V. Episd Case, Mauro Alfredo Hinojosa

Open Access Theses & Dissertations

This research analyses the Alvarado vs. El Paso Independent School District legal files, housed at the Sonnichsen Special Collections Department, The University of Texas at El Paso Library. This dissertation explored the following questions: Research question 1 (RQ1): What are the political and social-cultural contexts of the Alvarado case based on the Archives?; and Research Question 2 (RQ2): impact on school education, to include themes in policy and leadership. A qualitative research approach framed through Latino Critical Race Theory exposes how the U.S. education system has historically reinforced White perspectives and marginalized Latino groups, specifically focusing on Mexican-American students in …

Chipless 3d Microfluidic Rf Sensing, Sheikh Dobir Hossain

Open Access Theses & Dissertations

Effective management of the cold chain is essential to uphold the quality and safety of products vulnerability to physical factors like temperature, humidity, pressure, etc., including perishable foods, pharmaceuticals, and vaccines. Chipless Radio Frequency Identification (RFID) sensors have become increasingly favored as a viable technology for tracking, inventory, and sensing industries due to their wireless and non-line of sight (NLOS) situations, straightforward fabrication, cost efficiency, and adaptability to challenging environmental conditions. However, there is still a need for advancements in RFID sensors to make them promise for cold chain applications. Integration of flexibility and non-volatile memory into the existing RFID …

Environmental Change As A Driver Of The Evolution Of Migratory Behavior In Suboscine Birds, Emily Johns

Open Access Theses & Dissertations

Avian migration, particularly long-distance seasonal migratory movement, has long captured the attention of researchers and the public alike. However, the evolutionary origins of migratory behavior are poorly understood, in part due to limited understanding of the full range of migratory strategies including short-distance and intra-tropical movements. We examine the climatic drivers of migration across suboscine birds, a group of roughly 1,300 primarily Neotropical species with a complex array of migratory strategies. Our reconstructions of the evolutionary history of suboscine migration reveal that migratory behavior is labile and is lost approximately twice as often as it is gained. We find that …

A Qualitative Study Of School Resource Officers In A Borderland School, Myrna Lozano

Open Access Theses & Dissertations

In recent years, there has been growing concern over the role of school resource officers (SROs) in enforcing discipline in K-12 public schools. This qualitative study aims to explore the experiences of SROs involved with discipline issues at schools. By conducting interviews with SROs and examining official school documents, this study will shed light on how these officers navigate the complexities of the job while balancing the need for security with the goal of promoting positive outcomes for students. It is crucial to explore the perspectives and experiences of SROs to better understand their involvement with the K-12 public school …

Thermal Analysis Of Combustion Synthesis Of Fealxoy Catalysts For Dehydrogenation Of Fossil Fuels, Laura Alejandra Martinez Espinoza

Open Access Theses & Dissertations

The growing demand for hydrogen as a clean energy carrier highlights the need for its alternative production method with reduced CO₂ emissions. Microwave-assisted thermocatalytic dehydrogenation of fossil fuels offers a promising solution for clean hydrogen production, with FeAlxOy nanocomposites acting as efficient catalysts due to their thermal stability, catalytic activity, and microwave-absorption properties. FeAlxOy nanocomposites, fabricated by solution combustion synthesis (SCS), have shown good microwave-absorption and catalytic properties. However, the effects of synthesis parameters such as fuel type and Fe:Al molar ratio on the SCS process and properties of the final material are not well understood. The SCS process involves …

Efficient Anomaly Detection Driven By Different Machine Learning Architectures And Models, William Marfo

Open Access Theses & Dissertations

The rapid growth and ubiquitous adoption of the internet and cyber-physical systems (CPS) have fundamentally transformed modern communication, work, and human-system interactions. While networks now form the backbone of critical digital ecosystems, enabling seamless data transmission across diverse, interconnected systems, this increased connectivity also expands the attack surface, making real-time detection of network intrusions and anomalies a pressing challenge. Detecting unusual activities within network infrastructure requires advanced data traffic analysis to differentiate between legitimate and malicious interactions. Traditional approaches to network anomaly detectionâ??such as rule-based and signature-based systemsâ??often depend on predefined patterns to identify known anomalies, limiting their effectiveness against …

Elucidating The Effect Of Milled Glass And Graphite Fiber On The Quasi-Static Properties Of Vinyl Ester Resin Composites, Sarahi Mendivil

Open Access Theses & Dissertations

Composite materials can be tailored to various applications, making them one of the most conventional materials. Their ability to enhance desired characteristics enables higher strength while maintaining light weight. However, understanding defects and manufacturing limitations is crucial for optimizing their fabrication processes. This paper focuses on the manufacturing processes of open molding with controlled variations to establish an optimal technique aimed at minimizing defects, such as bubble formation where the focus is on mitigating defects and ensuring uniform dispersion of fiber in fiber-reinforced composites. After refining the manufacturing process, composites with varying resin-to-fiber concentration ratios were manufactured using glass and …

The New Anthropocentrism: The Problem Of Water Conservation And Water Justice, Benjamin Stuart Milam

Open Access Theses & Dissertations

My objective with my thesis is to argue for and reinforce a type of anthropocentrism that is both environmentally conscious and consumable for an audience that is not necessarily well versed in philosophical literature. In the first chapter I go over philosophical frameworks, such as Anthropocentrism and Biocentrism, and why I believe they do not meet both of those criteria listed. After that I discuss New Anthropocentrism, coined by Clive Hamilton, and why I believe that a slightly modified version possesses qualities that I believe are needed for the crisis at hand. In chapter 2 I use that framework and …

Ultra-High Temperature Ceramics: Materials, Manufacturing, And Machine Development, Joseph Matthew Munoz

Open Access Theses & Dissertations

This research aimed to advance the 3D printing of ultra-high-temperature ceramic matrix composites (UHTCMCs) and develop a custom Direct Ink Writing (DIW) system with multimaterial and in-line mixing capabilities. The study first focused on creating ZrB₂–SiC composites reinforced with aligned silicon carbide fibers (SiCf) using paste extrusion. By formulating suspensions with a preceramic polymer (SMP-10), ZrB₂, and SiCf, the study assessed how fiber alignment influenced key properties such as thermal and electrical conductivity and mechanical strength. Green curing and pyrolysis transformed the printed parts into UHTCMCs, with results showing substantial improvements in thermal conductivity—nearly double that of non-aligned parts—and a …

Production Of Labiodental Fricative /V/ In Heritage Speakers Of Spanish, Andrea Michelle Nunez

Open Access Theses & Dissertations

AbstractThe present study investigates the factors that influence Heritage Spanish speakersâ?? production of the allophone [v]â??namely its corresponding orthography ( vs. ), the phonological context in which it is produced (VCV vs. NCV, where V = vowel, C = consonant, N = /n/), and participantsâ?? language dominance (Spanish vs. English). More specifically, this study seeks to determine whether, for these Spanish speakers, [v] contrasts with /b/ (hence, /v/) or is an allophone of /b/. Standard Spanish does not have /v/, but it has â??an orthographic form of /b/, which in turn has (at least) two allophonic realizations: [b] after nasals …

Navigating Social And Academic Spaces As A Non-Traditional Student In A Doctoral Program: An Autoethnography, Luz Elena Nieto

Open Access Theses & Dissertations

This autoethnography examines my personal, professional, and academic experiences throughout my educational journey, aiming to address gaps in scholarly literature relevant to non-traditional students at all educational levels, particularly at the doctoral level. As a non-traditional student, I have encountered significant challenges during my academic career. I have often felt like an outsider due to my age, generational gap, and educational background. The impostor phenomenon has intensified my feelings of being an outcast, even though I have had a prosperous professional career. I have drawn upon my memories, reflections, narratives, scholarly literature, documents, and personal artifacts to provide a comprehensive …

Investigating A Study Abroad Program As A Reflective Development Of Intercultural Competence For Students In A Hispanic-Serving University, Akindele Ogunleye

Open Access Theses & Dissertations

This dissertation project investigates the broad problem of evaluation and effectiveness that have diminished the opportunities that study abroad can potentially offer as part of higher education in the U.S. The research aim was to develop a reflective plan of implementing study abroad to achieve the transformation of intercultural competence of students of higher education in a Hispanic university. The research questions were deduced from a combination of views from literature since the 1920s affirming study abroad as elitist endeavor, female, liberal arts and academically weak. Using a quantitative data methodology, the study were collected data from students who participated …

The United States National Security And Policy Implications Of Desertification, Eric Olvera

Open Access Theses & Dissertations

Contemporary climate security literature reveals that desertification appears to be overlooked as a climate change security threat to the United States (US). This investigation demonstrates that an inequity exists between sea-level-rise- and desertification-based climate security literature. This inequity may reveal that the US may be ignoring desertification at a time when land use in some dryland areas is reaching a critical point where it can no longer support human activity. Due to the interdisciplinary nature (science and security) of this work, a review of the terminology used in the article is provided to establish a baseline understanding of “desertification” and …

The Influence Of Pitch Type (Fastball, Curveball, And Change-Up) On The Contralateral Trunk Tilt In Adolescent Pitchers, Arlene Nichole Perez

Open Access Theses & Dissertations

Baseball participation has grown, with over 15.59 million players aged six and older in 2021. Pitching relies on effective coordination of the kinetic chain to transfer forces and generate ball velocity. While trunk rotation during pitching has been studied, contralateral trunk tilt across pitch types remains underexplored. This study investigated differences in hand velocity, stride length, and contralateral trunk tilt between fastball, curveball, and change-up pitches in 16 adolescent pitchers ages 15-18. Motion data were collected using a seven-camera system interfaced with Theia 3D. Repeated measures ANOVA revealed a significant difference in hand velocity between fastball and change-up (p = …

Unpacking Exclusion: A Narrative Literature Review And Discrete Analysis Of Preschool Suspension And Expulsion, Megan Pheterson

Open Access Theses & Dissertations

This thesis explores exclusionary disciplinary practices in preschool settings, where children from marginalized groups, particularly racial minorities and those with disabilities, face a higher risk of suspension and expulsion. This thesis provides a qualitative overview and interpretation of existing literature, pointing trends and gaps in research and highlighting four main themes: (1) Navigating the layers of exclusionary practices: From policy to practice; (2) Exclusionary practices: An adult decision with complex consequences; (3) Exclusive education: Who is left out and why in early childhood settings; and (4) Resistance as a tool for inclusion. Through a Disability Critical Race Theory framework, this …

Ni Uno Mas: A Critical Examination Of Zero Tolerance Policies, Marcos Eduardo Peã±A

Open Access Theses & Dissertations

This study investigates the impact of zero-tolerance policies on minority students, emphasizing the school-to-prison pipeline (STPP). Using a qualitative methodology and testimonios, the study reveals how these policies, initially aimed at severe offenses, have disproportionately targeted minor infractions among ethnic minority students, exacerbating systemic inequities. Through a comprehensive literature review and personal narratives, the research highlights the cultural mismatch between strict disciplinary measures and the lived realities of these students, shedding light on the profound consequences these policies have on their educational journey and personal development. The findings underscore the urgent need for policy reform, advocating for restorative justice practices …

Computational Investigation Of Boundary-Layer Transition Mechanisms In A Blunt Cone, Arturo Rodriguez

Open Access Theses & Dissertations

In this study, we have performed two-dimensional steady-state hypersonic CFD and one-and-two-dimensional steady-state heat conduction numerical simulations. We are using them to guide and study hypersonic boundary-layer transition ground testing physical experiments to be performed at Holloman High-Speed Test Track. We use surface heat transfer and fluid flow spot signatures to identify fluid flow regimes using laminar and turbulent numerical simulation solvers to understand boundary-layer transition thermocouple temperatures and fluid flow-forming structures. We have also analyzed the fluid flow in the geometries to be inviscid. We passed the CFD solution into the boundary-layer Harris code developed by NASA to explore …

Development Of A Novel Autoantibody Panel For Prostate Cancer Detection Based On Immunoproteomic Profiling And Cancer Driver Genes, Cuipeng Qiu

Open Access Theses & Dissertations

Prostate cancer (PCa) is the second most frequent cancer in males with 1.47 million new cases and 396,700 deaths worldwide in 2022. It is the second leading cause of cancer-related deaths among males in the United States with over 35,000 estimated deaths in 2024. PCa is a type of indolent cancer that can progress to an advanced metastatic castration-resistant (mCRPC) stage if not detected and treated early. Screening precancerous lesions or early tumor detection is an effective strategy to reduce the mortality of cancer. Despite the development of effective screening methods, such as the prostate-specific antigen (PSA) test, the specificity …

A Blue Hydrogen Framework For Regional Energy Resiliency, Safwan Shafquat

Open Access Theses & Dissertations

High-pressure gasification is gaining attention as an emerging solution for sustainable energy production due to its potential to achieve higher efficiencies, improved syngas quality and smaller equipment footprints. High operating pressures and temperatures can increase the synergistic reactivity of biomass and organic materials, consequently enabling higher in situ tar reformation and ultimately reducing the number of gas treatment requirements. Additionally, higher operating pressures result in a more concentrated CO2 stream and reduce the amount of post-gasification compression requirements in the carbon capture and storage (CCS) unit, improving overall system efficiency. Plus, pressurized CO2 streams from the gasifier also provides routes …

Novel Therapuetic Approaches For Chagas Disease, Juan Carlos Silva

Open Access Theses & Dissertations

Chagas disease (CD) is caused by the hemoflagellate protozoan Trypanosoma cruzi. This disease is considered one of the 20 neglected tropical diseases (NTD), and it is estimated that 6 to 8 million people worldwide are diagnosed with CD. In the United States, Chagas infection is not reported in all states; however, most reported CD cases are chronic infections. Chagas infection is characterized by two phases: an acute and a chronic phase. Until this present moment, no prophylactic or therapeutic human vaccine is available. However, in a recent study in a murine model, our group showed that the synthetic 20-merpeptide (DAENPGGEVFNDNKKGLSRV) …

Blood And Ink: Revenge In Contemporary Fiction, Shadia Sobers

Open Access Theses & Dissertations

They say that revenge is a dish best served cold and that it is sweet, but what about the flavors in between? It is sweet at times, with a hint of saltiness following close behind as you pucker your lips and swish your tongue around. Soon after, a sour taste comes out of nowhere before a tang of umami hits you at the end. The flavor varies from person to person, just as if seeking revenge in and of itself is morally correct.

We’ve seen revenge in countless forms of media: books, movies, and plays. Each takes a slightly different …

Bloc 27, Makani Speier-Brito

Open Access Theses & Dissertations

Bloc 27 is set in the early 22nd century in a severely overpopulated and competitive world. The society is run by OX, a highly controlled powerhouse government. OX controls the citizens through hierarchy and a vast divide between the rich and the poor. The poor citizens, derogatorily termed "roaches," are controlled not through currency but by a highly specialized points system. This system is tracked through body tech called "Seed Trackers," implanted at birth and operated through the wrist. All data is tracked through these embedded devices, including their currency mode. Citizens gain points for fulfilling monthly initiatives, and points …

Assessing Sedimentation Impact Through Dem, Point Cloud, And Discharge Analysis, Shandell Thomas

Open Access Theses & Dissertations

This study focused on five arroyos flowing into the Rio Grande, in the stretch between Caballo Dam and Las Cruces, New Mexico. Drone imagery was acquired from study areas in each arroyo. Photogrammetry was used to create high-resolution digital elevation models (DEMs), point clouds, drone imagery and potential discharges were acquired for each arroyo. Investigation of seven different methods resulted in the selection of the Terrain Ruggedness Map (TRM) as a predictor of surface roughness, along with high-resolution DEMâ??s to illustrate small and low-relief channel features. The five arroyos with varying sediment sizes and characteristics were studied to understand how …

Constructing A Discourse Model Across Modalities In Bilinguals, Diana Uribe

Open Access Theses & Dissertations

The present study aimed to explore whether discourse integration is affected by differences in modalities, and if the magnitude of the effect is modulated by language dominance for bilingual readers. Spanish-English bilinguals read and listened to pairs of passages describing two fake science facts, one of which was repeated across passages and the other revised in the second passage. The pair of passages were either in the dominant or less dominant language. The modality (audio or text) of each member of the passage pair was manipulated across four within-subject conditions. After the second passage of each pair, participants verbally recalled …

Rockets, Rovers, And Rocks, Oh My!, Tara Lynn Sweeney

Open Access Theses & Dissertations

This body of work undertakes three distinct projects, all with the ultimate goal of improving the future efforts of human space exploration.Chapter 2 is a seismic analysis of rocket launch and landing operations. Being able to identify and understand anthropogenically induced seismic signals in comparison to naturally occurring seismic signals is an important step in characterizing and monitoring both types of signals on the Moon. Relatively few terrestrial studies have been performed to explore this, but there is a growing opportunity to record, discern, and understand the differences between anthropogenic and naturally occurring seismic signals due to the increasing pace …

Tracking - Uh - Attention: Examining The Influence Of Filled Pauses During Speech Comprehension, Rachel Lynn Williams

Open Access Theses & Dissertations

In this study, we investigated the temporal dynamics of attention during comprehension and the subsequent effects of changes in attention on speech production manipulated via the filled pause uh. Participants orally described a series of pictures (pretest description phase), then listened to a short informational passage and answered comprehension questions about the passage, and then orally described another series of pictures (posttest description phase). Participants completed this twice: the first passage included a dative structure alternation, and the second passage included a passive structure alternation. For each passage, half of the participants heard a passage with filled pauses included (present) …

Understanding The Factors Associated With The Targeting Of Prison Gangs By Specialized Gang Units (Sgus) In The United States, Bruno Aldair Zapata

Open Access Theses & Dissertations

Specialized gang units (SGUs) are prominent in police departments in the United States with their sole purpose to respond to gang activity across the country. SGUs vary in the types of gangs they target, resources available, officer composition, and the types of enforcement activities they use. SGUs have encountered various controversies such as exaggerating the gang problem in the media, for distorted intelligence in their gang databases, and for racial stereotyping and harassment among Hispanics in particular. Research regarding SGUs is limited in general, but even fewer studies exist on the targeting efforts of prison gangs by SGUs. Prison gang …

Enhancing Predictive Accuracy In Noisy Data: A Robust Gradient Boosting Approach, Gabriela Alexa Acuna

Open Access Theses & Dissertations

This thesis aims to enhance the gradient boosting technique, a well-known machine learning method, in a regression setup. Gradient boosting techniques implement sequential weak learners, in this case, shallow trees that contribute to the model with a small percentage. The traditional gradient boosting approach uses regression trees that choose thresholds based on minimizing variance and makes predictions based on the mean of the target variable for the observations contained within each node. The residual sum of squares (RSS) and mean metrics are sensitive to outliers, which makes the model's predictions less robust. Outliers influence the predictions, resulting in a model …