Digital Commons Network^™

Cross-Frame Effects And Design Optimization For Skewed Steel I-Girder Bridges, Nisha Sthapit

Theses and Dissertations

Cross-frames are critical for load distribution and stability in steel I-girder bridges with complex geometry, especially during construction. However, they are often designed with standardized cross-sections that are uniform throughout the bridge. This thesis presents an optimization approach for cross-frame cross-sections for skewed steel I-girder bridges with integral and stub abutments with skews ranging from 15⁰-60⁰. This optimization, using Method of Moving Asymptotes (MMA), minimizes girder flange lateral bending stress while maintaining or reducing the total volume of the cross-frames from the original design. Validated 3D finite element models in CSI Bridge showed that the optimization achieved around 20% decrease …

Generalizable Skill Learning In Robotic Agents Using Transformer Models, Erik Enriquez

Theses and Dissertations

This work explores the application of Transformer models to robotic skill learning, aiming to enhance generalization across various physical tasks and environments with continuous control. Despite their success in other domains, our experiments reveal that the utility of Transformers in robotics heavily depends on pretraining strategies. Specifically, Transformers pretrained on reinforcement learning tasks generalized effectively, while those trained with task-agnostic masking strategies did not. These findings challenge assumptions about the universality of Transformer-based methods and underscore the importance of domain-aligned pretraining for developing versatile robotic agents.

Identification Of Cadmium As A Structural And Functional Modulator Of Psd-95 Regulating Nmdars At Postsynaptic Membranes, Claudia Garza

Theses and Dissertations

Postsynaptic density-95 (PSD-95) is an essential scaffolding protein in excitatory neurons. PSD-95’s N-terminal palmitoylation region elicits synaptic plasticity by targeting, anchoring, and trafficking glutamate receptors, such as N-methyl-d-aspartate receptors (NMDAR), to the postsynaptic membrane. The molecular interactions of PSD-95 and its dysregulation in excitatory synapses are currently being explored as primary causes of neurodegenerative diseases and disorders, such as Alzheimer’s disease, Schizophrenia, and Parkinson’s disease. Recent studies demonstrate an overaccumulation of zinc at two cysteines (C3 and C5) and two histidines (H24 and H28) of PSD-95 blocks palmitoylation, causing a loss of NMDAR at the postsynaptic membrane. In addition, exposure …

Evaluating Structural Response Of Steel I-Girder Bridges Under Different Support Conditions: Construction Loading In Skewed Straight And Thermal Loading In Horizontally Curved Configuration, Bikesh Sedhain

Theses and Dissertations

Skewed and horizontally curved steel I-girder bridges are commonly designed and constructed to connect existing roadways and navigate obstacles in densely populated areas. However, these bridges can introduce significant challenges to bridge design and analysis, including complex lateral movements and torsional effects. Simplified support representation techniques that are commonly adopted in analysis and design may not accurately capture these effects, which lead to potential misestimations of bridge responses. This research aims to evaluate skewed and curved steel I-girder bridges for complicated loading and support conditions – skewed integral abutment bridges were studied during pre-composite deck placement and horizontally curved bridges …

Porous Geopolymer Composite For Geotechnical Applications, Karla Viviana Sierra Flores

Theses and Dissertations

This research investigates the development of a porous geopolymer cement grout for soil grouting applications, aiming to reduce carbon emissions associated with Portland cement while maintaining critical performance characteristics such as strength and permeability. Class F fly ash and metakaolin were used as aluminosilicate precursors, activated by sodium silicate and sodium hydroxide solutions. The addition of hydrogen peroxide served as a foaming agent to introduce porosity by creating a thermodynamic reaction that releases oxygen gas during mixing. Compressive strength, porosity, and hydraulic conductivity were evaluated, with results showing that metakaolin significantly increased compressive strength due to its smaller particle size …

Development Of A New Seismic Metamaterial For Passive Vibration Control Of Civil Structures, Shayan Khosravi

Theses and Dissertations

Seismic metamaterials are engineered structures that control mechanical wave propagation through frequency bandgaps, making them useful for structural control and seismic hazard mitigation. This study introduces the Passive Friction Seismic Metamaterial Base Isolation (PFSMBI) system, which combines frequency bandgaps and solid friction energy dissipation to improve the seismic performance of civil structures. The PFSMBI consists of a lattice structure with identical cells connected by springs and dampers, shifting a building’s natural frequency away from earthquake excitations. A dynamic model analyzes the system’s absolute acceleration, drift responses, and base shear force, optimizing parameters such as frequency ratios, mass ratios, and the …

A Modern Prometheus: Frankenstein's Relevance In Our Modern Society, Amanda C. Partida

Theses and Dissertations

For over two hundred years Mary Shelley’s Frankenstein has been in the public consciousness. It took only five years for the first adaptation, Presumption; or the Fate of Frankenstein, to be staged in 1825. Since then, there has been at least one adaptation every decade, with Universal Studios’ 1931 Frankenstein as the most famous adaptation, which shows just how much Shelley’s novel of science and hubris has resonated with audiences for many years.

This thesis aims to connect the ever-changing scientific anxieties of society with the most well-known Frankenstein film adaptations. By focusing on four specific films Frankenstein (1931), …

Two Essays On Finance And Culture, Gia Han Ngoc Doan

Theses and Dissertations

This dissertation consists of two essays on finance and culture. The first essay examines the relationship between corporate quality culture and product recalls. The results show that firms with a stronger quality culture are less likely to have product recalls. This relationship is stronger for firms with more female directors and higher levels of managerial ability. We also find that for firms in high-tech industries, the impact of quality culture on product failure is more profound. The results are robust to various endogeneity tests and alternative models. Our findings support that a firm’s quality culture significantly influences product success and …

Vibration-Based Algorithm For Diagnostic And Prognostic Condition Monitoring Of Railroad Bearings And Wheels, Jeffery Ray Pams

Theses and Dissertations

Bearing and wheel failure accounts for the majority of equipment-related train derailments on US railroads. Current wayside monitoring systems have been insufficient in the prevention of catastrophic derailments prompting the rail industry to explore the possible integration of onboard condition monitoring systems into their rail operations. The University Transportation Center for Railway Safety (UTCRS) in partnership with Hum Industrial Technology, Inc., has developed a wireless onboard system intended for the condition monitoring of railroad bearings and wheels. This thesis presents the development, evaluation, and implementation of an algorithm designed to be used in conjunction with these systems to provide railroad …

Analysis And Modeling Of Porous Media Networks In Petroleum Reservoirs Through Microscale Thermography And Core Flooding, Alan Petrovich-Mar

Theses and Dissertations

Reservoir rocks are porous materials that are an important area of study since they are present in reservoir sites rich in crude oil. It is important to understand the spreading phenomena on the rock surface and through the porous structure during fluid flow through these porous materials. For a complex system like reservoir rocks, factors such as spatially varying chemical composition and topography, multidimensional porosity, temperature, humidity, and existing oil/water in the pores can affect wettability and be a detriment to oil recovery.

The interaction of core samples with different porosity and permeability with water after proper cleaning procedures and …

Synthesis And Characterization Of Composite Hydrogels For Tissue Engineering: An Investigation On Mechanical Properties And Biocompatibility, Ismael Lamas Jr.

Theses and Dissertations

This study investigates the fabrication and characterization of Polyvinyl Alcohol (PVA)/agar double-network (DN) hydrogels for biomedical applications, focusing on mechanical strength, biocompatibility, and tissue engineering potential. Techniques like swelling ratio analysis and Fourier-transform infrared spectroscopy (FTIR), alongside antibacterial and cytotoxicity assays, were employed to evaluate the hydrogels' properties. Results show that increasing agar content enhances mechanical and physical properties, with swelling ratios increasing by 300% when agar makes up 6% of the hydrogel, compared to 140% without agar. A positive correlation was observed between agar concentration and compressive and tensile moduli. Load-relaxation rates, essential for viscoelastic properties, also improved with …

Development And Tribological Characterization Of Uhmwpe-Tin Composite Coatings Deposited By Electrostatic Spraying, Jarrod Keith Perez

Theses and Dissertations

The increasing demand for inert, wear-resistant, cost-efficient, environmentally friendly, and low-friction coatings has driven extensive research into polymer-based solutions. Among these, ultra-high-molecular-weight polyethylene (UHMWPE) has emerged as a strong candidate due to its low density, anticorrosion properties, self-lubricating nature, affordability, and ease of processing. However, its low load-bearing capacity limits its widespread use in high-stress tribological applications. To overcome this limitation, this project investigates the development and characterization of UHMWPE composite coatings reinforced with titanium nitride (TiN) particles at varying concentrations (2.5, 5, and 10 wt%) to enhance their mechanical properties and wear resistance.

The Impact Of Politics On Romantic Relationships: Longevity, Quality, And Political Beliefs Or Candidate Choice?, Jadelyn Lopez

Theses and Dissertations

This project aimed to understand how polarization in the United States affects romantic relationships. Other studies in this area have only gauged samples that were either couples in relationships or singles. This work compared the responses of individuals based on their relationship status (in a relationship or not), to note the differences, if any, between samples. This research was conducted through surveys on The University of Texas Rio Grande Valley student population.

In understanding how political opinions affect relationship longevity, satisfaction, and whether candidate choice or opinions matter more, there were interesting findings. Regarding relationship longevity, there was a significance …

Exploring The Effects Of Serotonin And Selective Serotonin Reuptake Inhibitors On The Neurological, Behavioral, And Cardiovascular Systems Using The Animal Model Of The Syrian Hamster (Mesocricetus Auratus), Ariana Vianey Hinojosa

Theses and Dissertations

Serotonin is a neurotransmitter widely recognized for its role in neuropsychological processes, particularly in regulating mood, cognition, and emotional responses. However, its influence extends beyond the central nervous system (CNS), playing a crucial role in various physiological functions, including metabolism, the gastrointestinal system, reproductive processes, and cardiovascular regulation. As a key modulator of homeostasis, serotonin contributes to maintaining equilibrium within these systems, ensuring proper function and response to environmental stimuli. Despite its well-documented effects on mood and behavior, the broader physiological implications of serotonin remain less understood, particularly in the context of its interactions among neural, behavioral, and cardiovascular systems. …

Carbon Dioxide, Methane, And Nitrous Oxide Fluxes From Managed Aquatic Systems Of The Rio Grande Valley, Siena Rose Stassi

Theses and Dissertations

Greenhouse gas (GHG) dynamics from small-scale inland water remain relatively understudied, with knowledge gaps across ecosystem types and regions. In South Texas, there is a unique system of managed distributaries and their associated ox-bow lakes, commonly known as resacas. Most resacas are artificially managed and considered novel ecosystems, yet their GHG dynamics are unknown. Two resaca systems were monitored throughout one year to understand the magnitude, temporal variation, and environmental drivers of diffusive fluxes of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), along with ebullitive CH4 emissions. Emissions of both CO2 and CH4 peaked in hot summer months, …

P-Adic Quantum Mechanics, Infinite Potential Wells, And Continuous-Time Quantum Walks, Nathaniel P. Mayes

Theses and Dissertations

In this thesis, we introduce a p-adic version of the infinite potential well in quantum mechanics (QM). This model describes the confinement of a particle in a p-adic ball. We rigorously solve the Cauchy problem for the Schrödinger equation and determine the stationary solutions. The p-adic balls are fractal objects. By dividing a p-adic ball into a finite number of sub-balls and using the wavefunctions of the infinite potential well, we construct a continuous-time quantum walk (CTQW) on a fully connected graph, where each vertex corresponds to a sub-ball in the partition of the original ball. …

Territorio Nepantla: A Visual Exploration Of The Matamoros – Brownsville Borderlands, Michel Valeria Flores Tavizón

Theses and Dissertations

This thesis examines the work presented in the MFA exhibition titled Territorio Nepantla. A multidisciplinary exhibition featuring a visual exploration of the Matamoros and Rio Grande Valley borderlands through the perspective of a Mexican transfronteriza traversing the Matamoros – Brownsville border. The feminist Chicana theory of nepantla, a word from Nahuatl origin meaning “in-between” is central to the exhibition. Scholar Gloria Anzaldua defines the borderlands as a nepantla space, a liminal space where art and la frontera intersect. Nepantla represents the in-betweenness beyond physicality. A nepantla space can be emotional, spiritual, sexual, linguistical and more. This body of work …

The Herzog-Takayama Resolution Over A Skew Polynomial Ring, Linoy Utkina

Theses and Dissertations

Let k be a field, and let I be a monomial ideal in the polynomial ring R = k[x1,..., xn]. In her thesis, Taylor introduced a complex that yields a finite free resolution of R/I as an R-module. Building on Taylor’s work, Ferraro, Martin, and Moore extended this construction to monomial ideals in skew polynomial rings. Because the Taylor resolution is typically not minimal, subsequent research efforts went into identifying specific classes of ideals whose minimal free resolutions can be constructed more simply. In 1990, Eliahou and Kervaire devised an approach for handling minimal resolutions of …

Climate Resilience In Texas Assessing The Impact Of Extreme Weather On Energy Poverty And The Mitigating Role Of Tree Canopy Coverage, Yongwen Yang

Theses and Dissertations

Extreme weather events, including severe heat and cold waves —increasingly threaten public health, economic stability, and energy equity. This two-part study examines the interplay between extreme weather, energy poverty, and green infrastructure (tree canopy coverage) in Texas, a state characterized by climatic extremes and socioeconomic diversity.

This study consists of four chapters. The first chapter in the Introduction includes the research background, existing research, research gaps, research questions, and potential contributions. Followed by two core chapters. Chapter II aims to assess the impact of extreme weather on energy poverty at the household level. Chapter III aims to identify whether tree …

Camassa-Holm Type Equations And Multi-Peakon Solutions, Yonghong Chen

Theses and Dissertations

This thesis investigates the multi-peakon solutions of a class of Camassa-Holm type equations with quadratic nonlinearities, specifically focusing on the differential equation mt +θmu+ amxu+bmux = 0, where m = u−uxx, and θ, a, b are arbitrary constants. We derive the nonlocal form of the equation and explore its peakon dynamics, including the well-known Camassa–Holm, Degasperis–Procesi, and Holm–Staley b-family equations. By employing a practical computational approach, we analyze the N-peakon solutions and present the corresponding dynamical systems, particularly focusing on the two-peakon case. The results will …

Survival, Biofilm Formation, And Control Of Foodborne Pathogens In Hydroponic Systems, Sai Rithin Reddy Kothur Thirupathi

Theses and Dissertations

The growing global population and increasingly unpredictable weather patterns have intensified the demand for sustainable food production methods. Hydroponics, a form of Controlled Environment Agriculture (CEA), has gained attention as a viable solution due to its efficient use of resources such as land and water. Although hydroponic systems are perceived as safer alternatives to conventional farming, recent foodborne outbreaks associated with these systems have raised significant public health concerns. This thesis research investigated the food safety risk in hydroponic, particularly the survival and persistence of foodborne pathogens. Chapters I and II provide a comprehensive overview of hydroponics and the microbial …

Unveiling Perspectives: Young Adults Banned Books Critical Content Analysis, Tiffany Ladonna Jarebica

Theses and Dissertations

This dissertation conducts a critical content analysis of seven banned young adult novels—All Boys Aren’t Blue, All the Things We Do in the Dark, Almost Perfect, Ask the Passengers, The Bluest Eyes, The Hate U Give, and The Kite Runner—within one Texas school district. Using intersectionality theory as a lens, the study explores how intersecting identities such as race, gender, sexuality, and trauma are portrayed in these narratives and examines the role these portrayals play in the censorship process. The analysis investigates the socio-cultural, political, and institutional factors that influenced the removal of these texts, considering how their …

Congruences In Arithmetic Progression For Coefficients Of Gaussian Polynomials And Crank Statistics, Joselyne Aniceto

Theses and Dissertations

The study of partition congruences, inspired by Ramanujan’s discoveries for ��(��) over a century ago, remains a central topic in this field. This dissertation examines congruence properties in two restricted partition functions: ��(��,��), which counts partitions of �� into at most �� parts, and ��(��,��,��), which further limits the size of the largest part to be at most ��. Building on Kronholm’s 2007 result, now known as the Interval Theorem, and a recent result by Eichhorn, Engle, and Kronholm, we establish new infinite families of congruences for ��(��,��,��). This dissertation extends not only the recent results of Eichhorn, Engle, …

The Influence Of Solar Energy Infrastructure On Pollinators And Crops, Deisy Garcia

Theses and Dissertations

As the human population grows, demand for agriculture and renewable energy rises. Landuse competition is caused by the expansion of area-intensive solar photovoltaic (PV) facilities. While solar energy is crucial to mitigate climate change, it presents challenges related to land availability and effects on habitats for essential pollinators. In Chapter II, a spatial analysis was conducted to examine the relationship between solar panel density and pollinator diversity, exploring regions with the least interaction between these two factors. Our findings can inform solar siting and management strategies at landscape levels, in conjunction with field studies, that both mitigate potential interaction and …

Implementing And Evaluating An Ai-Powered Visual Decision Support System To Improve Antibiotic Usage Among Physicians With A Built-In Early Warning System, Akua Sekyiwaa Osei-Nkwantabisa

Theses and Dissertations

The widespread misuse and excessive prescription of antibiotics have played a pivotal role in the emergence and proliferation of antibiotic-resistant bacteria, posing a critical global public health crisis. Addressing this challenge necessitates innovative solutions that enhance antimicrobial stewardship. This study presents the development and implementation of a visual decision support system designed to monitor and optimize antibiotic usage among healthcare providers. The proposed system integrates advanced machine learning algorithms with real-time data analytics to provide a dynamic, evidence-based decision support tool. Specifically, a neural network model was developed after evaluating multiple machine learning approaches, including Random Forest, Logistic Regression and …

Spatio-Temporal Pattern Of Nutrient Dynamics In The South Texas Coastal Watershed, Mohammad Sadman Alam

Theses and Dissertations

Eutrophication threatens aquatic ecosystems by altering productivity through excessive nutrient inputs. In some systems, primary productivity is limited by nitrogen (N), phosphorus (P), or both, based on the N:P ratio defined by the "Redfield" ratio. South Texas, facing rapid urban growth and industrialization, is at risk of higher nutrient loads, but research on nutrient dynamics in this region is limited. This study investigates nutrient variations in the freshwater (FW) abandoned distributaries of the Rio Grande and hypersaline saltwater (SW) systems. Results showed a significant decrease in dissolved inorganic nitrogen (DIN) and an increase in dissolved inorganic phosphorus (DIP), shifting the …

Evaluating The Impact Of Reflex Math On Mathematics Achievement In Elementary Schools: A Quasi-Experimental Study In South Texas, Kasey Juarez

Theses and Dissertations

This quantitative, quasi-experimental study examined the impact of Reflex Math, a gamebased instructional program focused on building math fact automaticity, on the achievement of Grade 3-5 students in a South Texas public school district. The study compared a 2023 intervention group that used the program from August to December with a 2022 comparison group that did not. The intervention’s effectiveness varied by grade level, with Grade 3 students showing the most positive gains, no significant effect in Grade 4, and a slight negative difference in Grade 5. Results showed statistically significant, though modest, gains in mathematics achievement among students who …

Other Others At The Border: An Autoethnographic Inquiry, Clover Johnson

Theses and Dissertations

This dissertation critically examines the concept of multiple otherness in online learning environments in Hispanic Serving Institutions. Hispanic Serving Institutions may unintentionally perpetuate practices and curricula that exclude and decenter the needs of older, disabled, or geographically diverse black women who may not identify within the university’s focus. Despite their missions to servingness of a stated population, Hispanic serving institutions must examine existing curricula that primarily cater to the dominant minority group they have tasked themselves to serve. By investigating existing curricular practices, this research seeks to maintain the integrity of minority-serving institutions while encouraging inclusivity for all students. By …

Mitigation Of Droughts And Floods From Conjunctive Water Resource Management Using Managed Aquifer Recharge (Mar): Experiments And Numerical Modeling, Sumiaya Amin Preota

Theses and Dissertations

Water supply of Rio Grande Valley in South Texas has been impacted by intensified climate extremes such as droughts and floods. This research assessed the viability of conjunctive water resource management using Managed Aquifer Recharge (MAR) carbon-modified infiltration basins. Multiple environmental variables in the Arroyo Colorado watershed were investigated, i.e., (i) water availability- quantity of floodwater can be repurposed, (ii) storativity and suitability - capacity within the unsaturated aquifer and ideal locations for building infiltration basins, (iii) water quality- contaminant removal using active carbon/biochar.

Unappropriated flow and high magnitude flow (HMF) analysis indicated that excess floodwater can be a …

Family-Centered Organization Creating “Lazos” To Affix Families And Their Students To Education: A Case Study, Erica Gonzalez

Theses and Dissertations

Historically, parental involvement has alternatively shifted from being a central participant within the United States’ education reform to being a secondary input stakeholder primarily due to the constant attempts to align its purpose, presence, and effects in education initiatives. Additionally, the varied constructs considered by multiple researchers and federal or state education agencies to define ‘parental involvement’, the variety of ‘population descriptors’, and ‘types of communication’ have increased the complexity to address the needs diverse family structures have to successfully build “lazos” to affix themselves and their students to education. This case study explores the perspectives low socioeconomic Hispanic families …