Digital Commons Network^™

Persistence And Lived Experiences Of Doctoral Students At A Hispanic Serving Institution, Jacob Michael Camacho

Theses and Dissertations

The purpose of this study was to examine the factors that influence the completion of PhD degrees and identify obstacles to completion at a Hispanic Serving Institution. Low completion rates are a national and global problem predicted to generate a critical shortage of professionals needed by society. The researcher utilized a phenomenological qualitative study to research the phenomenon through the interpretation of an individual's experiences in various situations (Stake, 2010). This research is important as it aims to analyze programs with high completion rates to find the factors that contribute to or impede dissertation completion. This project will focus on …

Variational Bias Sampling For Collaborative Filtering Recommender Systems, Prisca Stephens

Theses and Dissertations

Advancements in digitalization has yielded enormous growth of data on online platforms, overwhelming users with multitude of options to choose from. Recommender systems narrow down these options to a few relevant ones thereby facilitating the decision-making processes for users. This study presents a framework for integrating variational bias sampling into model-based collaborative filtering techniques for recommender systems. Variational bias sampling is a novel and unique way to account for random factors that affect explicit ratings in collaborative filtering recommender systems. A Gaussian distribution is used to model all the possible random factors that could affect ratings. Sampling user and item …

Mitigation Methods For Instrumental Artifacts In Gravitational Wave Data, Raghav Girgaonkar

Theses and Dissertations

Strain data from ground-based gravitational wave detectors are regularly affected by instrumental artifacts known as glitches. Such glitches form the background of false alarms in the detection of gravitational waves from compact binary coalescences, in-turn reducing search sensitivity. If left unaccounted, these glitches along with other non-stationarity may also contribute towards a corrupted representation of the statistical properties of detector noise, subsequently affecting parameter estimation for detected gravitational wave candidates. Therefore, effective data analysis methods to veto glitches and identify non-stationarities in detector data are crucial to enhancing the sensitivity of a gravitational wave search. In this thesis, we …

Sensemaking Of The Unexpected: A Qualitative Study In Understanding The Actions Of South Texas School Board Members To The Covid-19 Pandemic, Angel Magallanes

Theses and Dissertations

The purpose of the study was to gather knowledge of how school board presidents make sense of unexpected situations and what influences, informs, or impacts their decision-making during situations void of information and filled with uncertainty for decision-making in the midst of an imminent crisis. The research was focused on the lived experiences of three school board presidents in South Texas during the COVID-19 pandemic in 2020. Utilizing an interpretive phenomenological analysis, I analyzed interviews and observations of recorded school board meetings as data sources that I could triangulate about the COVID-19 phenomenon for understanding how …

Conditional Constrained And Unconstrained Quantization For A Uniform Distribution On A Hexagon, Christina Hamilton

Theses and Dissertations

In this thesis, we have considered a uniform distribution on a regular hexagon and the set of all its six vertices as a conditional set. For the uniform distribution under the conditional set first, for all positive integers n ≥ 6, we obtain the conditional optimal sets of n-points and the nth conditional quantization errors, and then we calculate the conditional quantization dimension and the conditional quantization coefficient in the unconstrained scenario. Then, for the uniform distribution on the hexagon taking the same conditional set, we investigate the conditional constrained optimal sets of n-points and the conditional constrained quantization errors …

Soil Carbon Sequestration Efforts In Arid And Semi-Arid Climates Under Conservation Agriculture And Reforestation, Samantha Lynn Colunga

Theses and Dissertations

Soil organic carbon (SOC) plays a vital role in the global carbon cycle and aids in climate change mitigation. However, deforestation and intensive agricultural practices threaten topsoil and carbon (C) pools through soil disturbances releasing vast amounts of carbon dioxide (CO2) by enhancing the decomposition of organic materials. Degraded soils typically lack stable aggregates, nutrient and water retention, and overall low fertility. In arid and semi-arid regions, soils are in an even more dire situation, as low precipitation and high temperatures slow down the accumulation of SOC. This thesis has two objectives: 1) to evaluate whether conservation tillage practices increase …

A Descriptive Exploration Of Selected Employment Barriers And Supports For Individuals With Visual Impairments In Bangladesh, Mohammed Mozadded Hossen

Theses and Dissertations

Employment is crucial for individuals with disabilities, including those with visual impairments, as it facilitates financial independence, promotes social inclusion, enhances the quality of life, and enables the utilization of valuable job-related skills. However, some barriers obstruct opportunities for employment for individuals with visual impairments, which affect different areas of their lives. This dissertation investigated the employment barriers, supports, and outcomes for individuals with visual impairments in Bangladesh, with an aim to understanding the factors that impacted employment outcomes for individuals with visual impairment, including access to education and training, availability of employment supports …

How Mathematics Instructors Foster The Development Of Black Students' Mathematics Identity In Undergraduate Active Learning Mathematics Courses, Ashly J. Olusanya

Theses and Dissertations

Black students must overcome unique challenges to succeed in mathematics. Educators are tasked with identifying equitable teaching practices to support these students. Active learning (AL) is a teaching pedagogy that engages students in rigorous mathematical activities and encourages student participation. This research study will explore the professors’ beliefs about how students learn mathematics and why they use active learning in their collegiate mathematics courses. The study explores the connections between these beliefs and their reported use of instructional practices. The study also identifies the instructors’ beliefs about developing students’ mathematics identities, particularly their Black …

Exploring Equity In Biliteracy Development In A Two-Way Dual Language Program, Dalila Ochoa

Theses and Dissertations

This qualitative exploratory study aimed to better understand how biliteracy is conveyed to native English speakers in order for them to acquire a second language, Spanish in a two-way dual language program. The study uses the theoretical framework of Jose Medina’s C6 Biliteracy Framework (2019) and research from Kathy Escamilla (2014). The research questions that guided this study were: (1) What type of instructional methods are the bilingual certified teachers utilizing to support Spanish development for native English students in a two-way dual language program? (2) How are bilingual teachers tracking the progress …

A Multivariate Analysis Of The Gravitational Wave Signal Landscape From Core Collapse Supernovae, Raul Alberto Espinosa Perez

Theses and Dissertations

Core collapse supernovae (CCSN) are highly anticipated sources of gravitational waves (GW) during the on-going fourth observation run (O4) of GW detectors like LIGO and the future observation runs. The GW signal from the CCSN cannot be modeled mathematically. Several groups around the world have engaged in simulation of the predicted GW signals from CCSN sources. These simulations are carried out in supercomputers, and they incorporate general relativity, hydrodynamics, neutrino physics, mass and angular momentum of the stellar progenitor and nuclear equations of state (EoS). The output consists of simulated signals with varying duration, peak frequency, GW energy and time-frequency …

Escúchame, Mi Ciencia Cuenta: Leveraging Cultural Ways Of Knowing To Increase Chicana Stem Engagement, Patricia Ramirez-Biondolillo

Theses and Dissertations

This paper is about leveraging cultural ways of knowing such as ethnobotany in order to increase STEM engagement in Chicanx populations. The conceptual framework utilized in this study combines social justice, Chicana feminist epistemology, land-based pedagogy, critical place-based pedagogy, pedagogical praxis, pluralism and ecological sustainability to achieve this end. Four pre-service Chicana science teachers provided testimonio from their elder assignment and engaged in two focus groups in order to identify relevant themes that impact Chicana engagement in STEM. Major themes identified were challenges in bilingual education, elder knowledge as a form of pedagogy, stagnation in common science teaching practices, tensions …

A Study On A Vector Complex Modified Korteweg-De Vries Equation, Changyan Shi

Theses and Dissertations

In this thesis, we systematically study a vector complex modified Kordeweg-de Vries equation by combining Hirota's bilinear method and the the Kadomtsev–Petviashvili (KP) reduction method. This vector nonlinear equation is a multi-component generalization of the well-known modified Kordeweg-de Vries (mKdV) equation and can be reduced to the known Hirota equation, Sasa-Satsuma (SS) equation, Sasa-Satsuma-mKdV equation as well as coupled Sasa-Satsuma equation. First, we bilinearize the vector complex mKdV equation under both the zero and nonzero boundary conditions by introducing auxiliary tau functions. Then, starting from two sets of bilinear equations of multi-component KP hierarchy and single-component KP-Toda …

Uncovering Insights On Remote Learning Through A Critical Discourse Analysis Of Tweets At The Start Of The Pandemic In The United States, Douglas Wayne Bridges

Theses and Dissertations

This dissertation examines the discourses surrounding remote learning during the initial stages of the COVID-19 pandemic through Twitter conversations. Employing a Critical Discourse Analysis informed by Michel Foucault’s theories of discourse and power, this study explores how the pandemic has transformed educational interactions over social media platforms. It particularly focuses on the relationships between language, power, and social structures, highlighting the transformative potentials of remote learning amidst a global crisis.

The research reveals how discourse on Twitter reflects broader societal and cultural dynamics, serving as a microcosm of the shifts within the educational sector. Analysis of Twitter threads, retweets, and …

The Perspectives Of Using Desmos For Students’ Conceptual Understanding And Procedural Fluency To Solve Linear Equations, Larmel Dimatulac Madrilejos

Theses and Dissertations

The study examines the perspectives of using the Desmos calculator of Algebra I students' conceptual understanding and procedural fluency to write, graph, and solve linear equations in Algebra I STAAR. While the students have continuously used technology for mathematics assessment, emergent bilingual students in South Texas still need help passing high-stakes testing. The framework of the study is grounded in the theory of mathematical education (knowledge of mathematics educators to teach), the theory of mathematical learning (understanding how students learn mathematics), and social constructivism. The study seeks ways to teach all students, mainly the minority, to learn …

Exploring Chicana Preservice Teachers’ Conscientizing Processes: Introducing An Array Of Criticalities In An Elementary Social Studies Methods Course, Raul Garza

Theses and Dissertations

Recognizing that our preservice teachers are experiencing a euro-centered teacher preparation curriculum, this study aimed to explore Chicana preservice teachers' interactions with an array of criticalities focused on a bioregional context that highlighted critical and resistant resources.

Chapter 1 surveyed the literature on growing critically conscious teachers of color and posed the following research questions: How do critical place-based pedagogies impact Chicana preservice teachers’ experiences in a social studies methods course? How do Chicana preservice teachers respond to a broad array of criticalities? How do the critical and democratic pedagogies experienced in the social studies methods …

Studies Of Novel And Well-Defined Dinickel Architectures Utilizing An N-Atom Bridge, David Anthony De Los Santos

Theses and Dissertations

There has been a growing interest in organometallic chemistry to utilize late Earth-abundant metals towards challenging molecular functionalization of abundant feedstocks to value-added products. There is precedent of utilizing cooperativity to try and address some of the shortcomings of traditional mononuclear complexes by integrating metal-metal and or metal-ligand cooperativity to facilitate multi-electron transformations. The utility of a redox-noninnocent scaffold allows for the metal centers to be stable over a range of oxidation states, using the ligand to store electrons. Despite recent progress, complexes harnessing cooperative states towards challenging transformations is still an emerging field. Our group has synthesized a multinucleating …

Synthesis Of Nano-Microstructured Barium Titanate (Batio3) Incorporated In Pvdf-Hfp/Peo For Sustainable And Green Energy Generation, Rigobert Ybarra Jr.

Theses and Dissertations

The global reliance on fossil fuels and natural gas, has largely dominated the energy production field, but due to finite resource depletion and escalating greenhouse gas emissions, the immediate exploration of sustainable energy alternatives to mitigate climate change and ensure resource security has been a major concern. There has been extensive research into other more renewable methods of energy production such as wind and hydropower. Of these current energy generation types there are many areas of untapped potential from the mechanical movements generated ambiently not only in the large scale of power generation but also on a smaller scale. The …

Affective Life, Mobility And Unity In U.S.-Mexico Transborder Families, Aaron A. Adame Sosa

Theses and Dissertations

There has been abundant research on transnational families and their lived realities, but most of this research focuses on analyzing family relations across long distances. This thesis examines transnational life at the borderlands and develops new frameworks for understanding family unity and separation. Using concepts from the sociology of emotions, I find that economic and opportunity inequalities structure much of transborder life and that the emotional work different family members do for the sake of their family unity is largely based on mobility privilege and the idea that the U.S. is economically better off, even as the relative poverty between …

Ecologies Of Teaching With Bilingual Students: Connecting Identity, Agency, And Assessment In First-Year Writing Class, Sumantha Nikole Zapata

Theses and Dissertations

As many students who graduate from high school transition into applying for college or university, they are not aware of the drastic changes that come with it. For bilingual students, this transition can be much more challenging due to their language barrier and the lack of support they may receive. The intersection of demographics, pedagogy, and linguistic agency led to the research question for this study: how can pedagogies in first-year writing classes be adjusted or developed to justly educate and assess bilingual students who are still working toward competence in English? The history of bilingual education …

Tarnished Glory: The Exclusion Of Buffalo Soldiers In World War I, David Michael Barron

Theses and Dissertations

This thesis examines the exclusion of the Buffalo Soldier regiments during World War I. Due to the rise of racial discrimination in the early twentieth century, the Buffalo Soldier regiments experienced violence with civilians while stationed in the United States. The violence experienced by African American soldiers would shape decisions that would ultimately impact their involvement in World War I. By examining evidence from their war record in previous conflicts and evidence from the racial violence that occurred while stationed in the US, this thesis will show that their exclusion in World War I was due to poor conduct perpetrated …

A Statistical Fetch Model For Water Wave Glint Correction Using Worldview-3 Imagery, Amanda Jade Quintanilla

Theses and Dissertations

Sun glint in satellite imagery of the water surface contaminates the upwelling signal received by a detector. Many models exist that attempt to correct for this wave facet effect and phenomena. In this work a model for sun glint correction is created using the comparison of image transects between two nearly simultaneously collected images of the same area, although with differing sensor geometry. One image utilized in this research is almost entirely glint free while the other is contaminated by water wave facet glint. Although many models for removing sun glint exist based on various techniques, none are completely accurate, …

Development Of A Model To Predict Maximum Crack Width And Spacing In Reinforced Concrete Beams Under Flexural Stress, Saeed Alghamdi

Theses and Dissertations

Cracking in reinforced concrete structures is unavoidable due to the low tensile strength of concrete. Even though minimizing cracks on exposed concrete surfaces is significantly important from the aesthetics point of view, it is also very important for the durability and overall performance of the structure.

Flexural members must be designed to minimize cracking that may occur during the structure's service life. Even though there has been a lot of experimental work on crack width over the last several decades, a literature review reveals that researchers still can't agree on which variables are most important. Part of the reason for …

Organizational Cultural Entrenchment: Exploring Cultural Antecedents Of Actively Destructive Employee Behaviors As A Manifestation Of Voice In Mergers And Acquisitions, Keith Dellano Holloway

Theses and Dissertations

Mergers and acquisitions are frequently leveraged as a vehicle for company growth. However, many of these transactions fail to yield a positive result and often cause a net loss of shareholder value.

There are many interrelated factors at work within a merger or acquisition. Structure, leadership, finances, strategic fit, market, and price are just a few variables to consider. However, the factor of culture, and the failure of cultural integration, has surfaced in literature as a significant contributor to losses within mergers and acquisitions.

This study built on the work of Harris, Hirschman, Kotter, and Schlesinger and examined the deleterious …

Test And Evaluation Model For Midwater Docking Of Autonomous Underwater Vehicles, Parker Baillon

Theses and Dissertations

This research created a Test and Evaluation (T&E) model for midwater Autonomous Underwater Vehicle (AUV) capture. The creation of this model will allow for a better assessment of the feasibility of midwater AUV capture. To achieve this, the T&E model was exposed to various flow conditions to assess stability. Capturing an AUV in midwater, the area below the wave-affected zone to the sea floor, has many benefits for an AUV and its mission. AUVs basing missions from a midwater dock will not be affected by wave motions. A midwater dock can be transported to any mission site and deployed with …

Optimization Of Coral Restoration Along The Florida Reef Tract, Raymond Barry Banister

Theses and Dissertations

Historically, the reefs of Florida were dominated by two framework-building corals, Acropora cervicornis and A. palmata. However, these two populations have declined by 95% since the 1970s. The predominant contributors to the coral decline have been ocean warming and disease. In response to the decline, restoration organizations were established to improve survival, growth, and reproduction. Yet, there are gaps in current restoration practices and our knowledge of effective restoration techniques. This study uses large datasets to develop models that predict the most optimal locations for coral restoration in Florida and examines the relationships between the occurrence of wild acroporids …

Improving Static Cold Storage Life Of The Human Heart Before Transplant, Juan Sebastian Rodriguez Paez

Theses and Dissertations

Organ storage and transportation are critical steps for the success of organ transplantation. Static cold storage (SCS) of hearts for heart transplantation (HTx) remains the standard approach. However, SCS may involve damage to the tissue resulting from extended hypothermic preservation, potentially affecting organ viability. More over, the temperature distribution on and within the heart is unknown during heart transplantation. Therefore, there is an interest to study different stages of the heart transplantation process towards determining the 3D temperature distribution on and within the heart. There could be a possibility of having a hypothermic injury in different parts of the heart …

Amazon Fba Vs Fbm; A Strategic Approach To Determine Which Method Can Effectively Utilize Project Management Principles To Enhance Your Success As A New Amazon Seller., Tiffany Renee White

Theses and Dissertations

Navigating the complexities of a platform such as Amazon demands a strategic approach guided by project management principles. A comparative analysis of Fulfillment by Amazon (FBA) and Fulfillment by Merchant (FBM) methods were completed by focusing on how project management principles optimize product acquisition, supply chain management, and shipping methods for Amazon sellers. The objectives of this study included the identification of top product acquisition tools, the evaluation of inventory management software, assessing shipping methods, and determining the most effective fulfillment process for Amazon seller success. A mixed-methods approach was applied, involving an Amazon seller survey, literature review, data analysis, …

Utilization Of Confined Concrete In The Bottom Slab Of Double Composite Box Girder Bridges, Harry Craik

Theses and Dissertations

A mathematical model is proposed for the confinement of rectangular confined reinforced concrete elements under compression. The model was modified from existing models applied to rectangular confined concrete specimens. The present model applies to rectangular reinforced concrete cross-sections with a core aspect ratio of at least 2.0 and a high effective confinement index. The model applies to normal and high-strength concrete and incorporates the spacing of the transverse reinforcing hoops, the strength of the reinforcing bars, the reinforcing quantity, and the core aspect ratio of the section. The proposed model was verified against extensive experimental data, and there was a …

Methodologies For Optimization And Surface Heat Flux Estimation For Hybrid Thermal Protection Systems, Syed Arafun Nabi

Theses and Dissertations

Thermal protection system (TPS) plays a pivotal role in safeguarding space vehicles from extreme aerothermal heating during atmospheric entry. To ensure effective thermal management, Hybrid Thermal Protection seamlessly integrating both active and passive TPS is an innovative solution. The passive TPS consists of an insulative layer on vehicle skin to counteract the aerothermal heat. Although a thicker layer enhances insulation, a trade-off arises between the thickness of the passive layer and the spacecraft’s weight. Beneath the passive TPS layer lies the active TPS functioning as a heat exchanger where the vehicle fuel liquid is considered as coolant. The effectiveness of …

Investigating The Relationship Between Metacognition, Motivation, Self-Regulation Strategy Usage, And Physical Activity Participation, Kay Sharon Stanfield

Theses and Dissertations

There are numerous benefits associated with physical activity. Unfortunately, few people participate in enough daily activity to reap the rewards. Health professionals have explored ways to promote adherence to physical activity and healthy behavior. Evidence shows self-regulation to be a determinant of physical activity. This study investigated the relationship between self-regulation strategy usage and levels of physical activity participation. Additionally, the study examined how motivation (through the perspective of Self-Determination theory) impacts physical activity. Six behavior regulation styles correspond to the degree of motivation (from low to high) on the Self-Determination continuum. A comparison of behavior regulation styles to physical …