UTSA Runner Research Press (Univ. of Texas at San Antonio)
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Evaluating TikTok and Short Form Media as a Supplemental Tool to Address Post-Pandemic Gaps in High School Mathematics
Full text linkThe Covid-19 pandemic drastically altered educational delivery and exposed significant learning gaps in fundamental mathematics, particularly revealing amongst high school students. This thesis explores the potential of TikTok – a high visual and short form video platform- as a supplemental tool to support the ideologies of microlearning in mathematics. This study examines how curated TikTok videos can be meaningfully evaluated and integrated as instructional tools to support 9th grade Algebra students’ understanding of rounding decimals—a foundational skill that is often underemphasized in secondary mathematics education. Using primarily a Qualitative approach, the research incorporates a student-selected and teacher-curated video playlists along with interviews coded using thematic framework and small quantitative breakdown on pre to post assessment results. Analysis of the curated TikTok videos revealed that features such as clarity, visual appeal, and brevity were key contributors to student engagement and comprehension; these findings align with the observed growth among students who interacted with the evaluated content. This thesis proposes a rubric-based evaluation method for short form educational videos and argues for sustained integration of microlearning strategies in the evolving mathematics classroom. TikTok may not be sustained in the coming years, but short form media platforms of similar style are a part of the future and educators can find means to bridge persistent achievement gaps in math education using alike applications as a vehicle akin to our students.Mathematic
Chemical Manipulation of the Collective Superspin Dynamics in Heat-Generating Superparamagnetic Fluids: An AC-Susceptibility Study
Full text linkWe use Co doping to alter the magnetic relaxation dynamics in superparamagnetic nanofluids made of 18 nm average diameter Fe<sub>3</sub>O<sub>4</sub> nanoparticles immersed in Isopar M. Ac-susceptibility data recorded at different frequencies and temperatures, &chi;&Prime;vs. T|<sub>f</sub>, reveals a major (~100 K) increase in the superspin blocking temperature of the Co<sub>0.2</sub>Fe<sub>2.8</sub>O<sub>4</sub>-based fluid (CFO) compared to its Fe<sub>3</sub>O<sub>4</sub> counterpart (FO). We ascribe this behavior to the strengthening of the interparticle magnetic dipole interactions upon Co doping, as demonstrated by the relative &chi;&Prime;-peak temperature variation per frequency decade <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi mathvariant="sans-serif">&Phi;</mi><mo>=</mo><mstyle scriptlevel="0" displaystyle="true"><mfrac><mrow><mo>&#8710;</mo><mi mathvariant="normal">T</mi></mrow><mrow><mi mathvariant="normal">T</mi><mo>&middot;</mo><mo>&#8710;</mo><mi mathvariant="normal">l</mi><mi mathvariant="normal">o</mi><mi mathvariant="normal">g</mi><mo>(</mo><mi mathvariant="normal">f</mi><mo>)</mo></mrow></mfrac></mstyle></mrow></semantics></math></inline-formula>, which decreases from &Phi;~0.15 in FO to &Phi;~0.025 in CFO. In addition, &chi;&Prime;vs. T|<sub>f</sub> datasets from the CFO fluid reveal two magnetic events at temperatures T<sub>p1</sub> = 240 K and T<sub>p2</sub> = 275 K, both above the fluid&rsquo;s freezing point (T<sub>F</sub> = 197 K). We demonstrate that the physical rotation of the nanoparticles within the fluid, the Brown mechanism, is entirely responsible for the collective superspin relaxation observed at T<sub>p1</sub>, whereas the N&eacute;el mechanism, the superspin flip across an energy barrier within the particle, is dominant at T<sub>p2</sub>. We confirm this finding through fits of models that describe the temperature dependence of the relaxation time via the two mechanisms: <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi mathvariant="sans-serif">&tau;</mi></mrow><mrow><mi mathvariant="normal">B</mi></mrow></msub><mo stretchy="false">(</mo><mi mathvariant="normal">T</mi><mo stretchy="false">)</mo><mo>=</mo><mstyle scriptlevel="0" displaystyle="true"><mfrac><mrow><mn>3</mn><msub><mrow><mi mathvariant="sans-serif">&eta;</mi></mrow><mrow><mn>0</mn></mrow></msub><msub><mrow><mi mathvariant="normal">V</mi></mrow><mrow><mi mathvariant="normal">H</mi></mrow></msub></mrow><mrow><msub><mrow><mi mathvariant="normal">k</mi></mrow><mrow><mi mathvariant="normal">B</mi></mrow></msub><mi mathvariant="normal">T</mi></mrow></mfrac></mstyle><mrow><mrow><mi mathvariant="normal">exp</mi></mrow><mrow><mfenced open="[" close="]" separators="|"><mrow><mstyle scriptlevel="0" displaystyle="true"><mfrac><mrow><msup><mi mathvariant="normal">E</mi><mo>&prime;</mo></msup></mrow><mrow><msub><mrow><mi mathvariant="normal">k</mi></mrow><mrow><mi mathvariant="normal">B</mi></mrow></msub><mfenced separators="|"><mrow><mi mathvariant="normal">T</mi><mo>&minus;</mo><msup><msub><mrow><mi mathvariant="normal">T</mi></mrow><mrow><mn>0</mn></mrow></msub><mo>&prime;</mo></msup></mrow></mfenced></mrow></mfrac></mstyle></mrow></mfenced></mrow></mrow></mrow></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi mathvariant="sans-serif">&tau;</mi></mrow><mrow><mi mathvariant="normal">N</mi></mrow></msub><mfenced separators="|"><mrow><mi mathvariant="normal">T</mi></mrow></mfenced><mo>=</mo><msub><mrow><mi mathvariant="sans-serif">&tau;</mi></mrow><mrow><mn>0</mn></mrow></msub><mrow><mrow><mi mathvariant="normal">exp</mi></mrow><mrow><mfenced open="[" close="]" separators="|"><mrow><mstyle scriptlevel="0" displaystyle="true"><mfrac><mrow><msub><mrow><mi mathvariant="normal">E</mi></mrow><mrow><mi mathvariant="normal">B</mi></mrow></msub></mrow><mrow><msub><mrow><mi mathvariant="normal">k</mi></mrow><mrow><mi mathvariant="normal">B</mi></mrow></msub><mfenced separators="|"><mrow><mi mathvariant="normal">T</mi><mo>&minus;</mo><msub><mrow><mi mathvariant="normal">T</mi></mrow><mrow><mn>0</mn></mrow></msub></mrow></mfenced></mrow></mfrac></mstyle></mrow></mfenced></mrow></mrow></mrow></semantics></math></inline-formula>. The best fits yield <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi mathvariant="sans-serif">&gamma;</mi></mrow><mrow><mn>0</mn></mrow></msub><mo>=</mo><mstyle scriptlevel="0" displaystyle="true"><mfrac><mrow><mn>3</mn><msub><mrow><mi mathvariant="sans-serif">&eta;</mi></mrow><mrow><mn>0</mn></mrow></msub><msub><mrow><mi mathvariant="normal">V</mi></mrow><mrow><mi mathvariant="normal">H</mi></mrow></msub></mrow><mrow><msub><mrow><mi mathvariant="normal">k</mi></mrow><mrow><mi mathvariant="normal">B</mi></mrow></msub></mrow></mfrac></mstyle><mtext>&nbsp;</mtext></mrow></semantics></math></inline-formula>= 1.5 &times; 10<sup>&minus;8</sup> s&middot;K, E&prime;/k<sub>B</sub> = 7 03 K, and T<sub>0</sub>&prime; = 201 K for the Brown relaxation, and E<sub>B</sub>/k<sub>B</sub> = 2818 K and T<sub>0</sub> = 143 K for the N&eacute;el relaxation.Physics and Astronom
Electrical Resistivity in Inkjet-Printed Metal Nanoparticle Films: Percolation Behavior and Finite Element Simulation
Full text linkInkjet printing of metal nanoparticle inks has emerged as a critical technology for additive manufacturing of electronics, yet the fundamental relationship between printing parameters and electrical performance remains poorly understood. This research investigates the resistivity-drop spacing relationship in inkjet-printed gold nanoparticle films to establish predictive models for electrical conductivity in printed electronics applications. The purpose of this study was to quantify how percolation network formation and droplet overlap geometry control electrical transport in printed conductive films. Gold nanoparticle films were fabricated using drop-on-demand inkjet printing with systematically varied drop spacings from 20 to 80 micrometers. Electrical characterization employed both van der Pauw and four-point probe techniques to measure sheet resistance, while scanning electron microscopy and atomic force microscopy provided morphological analysis. COMSOL Multiphysics simulations were developed to model electrical measurements and validate experimental scaling relationships under various percolation conditions. The research revealed dual-regime electrical transport behavior controlled by distinct physical mechanisms. Near the percolation threshold, connectivity-limited transport follows classical percolation scaling with critical exponent t ≈ 1.3, consistent with two-dimensional percolation theory. In the conductive regime, geometry-limited transport exhibits universal scaling with exponent α ≈ 0.5, representing intrinsic geometric scaling for discrete droplet contact resistance. A critical transition occurs at approximately 60 micrometers drop spacing, marking the boundary between percolation-dominated and geometry-dominated regimes. These quantitative scaling relationships provide fundamental design principles for optimizing electrical performance in inkjet-printed electronics, enabling predictive control of resistivity through printing parameter selection.Electrical and Computer Engineerin
Enhanced SWAP Model for Simulating Evapotranspiration and Cotton Growth Under Mulched Drip Irrigation in the Manas River Basin
No full textModel-based simulation of farmland evapotranspiration and crop growth facilitates precise monitoring of crop and farmland dynamics with high efficiency, real-time responsiveness, and continuity. However, there are still significant limitations in using crop models to simulate the dynamic process of evapotranspiration and cotton growth in mulched drip-irrigated cotton fields under different irrigation gradients. The SWAP crop growth model effectively simulates crop growth. However, the original SWAP model lacks a dedicated module to consider the impact of mulching on cotton field evapotranspiration and cotton dry matter mass. Therefore, in this study, the source codes of the soil moisture, evapotranspiration, and crop growth modules of the SWAP model were improved. The evapotranspiration and cotton growth data of the mulched drip-irrigated cotton fields under three irrigation treatments (W1 = 3360 m<sup>3</sup>&middot;hm<sup>&minus;2</sup>, W2 = 4200 m<sup>3</sup>&middot;hm<sup>&minus;2</sup>, and W3 = 5040 m<sup>3</sup>&middot;hm<sup>&minus;2</sup>) in 2023 and 2024 at the Xinjiang Modern Water-saving Irrigation Key Experimental Station of the Corps were used to verify the simulation accuracy of the improved SWAP model. Research shows the following: (1) The average relative errors of the simulated evapotranspiration, leaf area index, and dry matter weight of cotton in the improved SWAP crop growth model are all &lt;20% compared with the measured values. The root means square errors of the three treatments (W1, W2, and W3) ranged from 0.85 to 1.38 mm, from 0.03 to 0.18 kg&middot;hm<sup>&minus;2</sup>, and 55.01 to 69 kg&middot;hm<sup>&minus;2</sup>, respectively. The accuracy of the improved model in simulating evapotranspiration and cotton growth in the mulched cotton field increased by 37.49% and 68.25%, respectively. (2) The evapotranspiration rate of cotton fields is positively correlated with the irrigation water volume and is most influenced by meteorological factors such as temperature and solar radiation. During the flowering stage, evapotranspiration accounted for 62.83%, 62.09%, 61.21%, 26.46%, 40.01%, and 38.8% of the total evapotranspiration. Therefore, the improved SWAP model can effectively simulate the evaporation and transpiration of the mulched drip-irrigated cotton fields in the Manas River Basin. This study provides a scientific basis for the digital simulation of mulched farmland in the arid regions of Northwest China.Earth and Planetary Science
Texans One and All: Introduction Packet
No full textThe Texans One and All curriculum at the Institute of Texan Cultures examines the migration, settlement patterns, cultural traditions, and lasting contributions of diverse ethnic groups to Texas. The curricula in this series was originally intended to supplement a guided tour through the comprehensive exhibits featuring over 20 cultural communities—including Native American, African American, European, Asian, and Middle Eastern groups— which documents the multicultural foundations of Texas. These curricula provide insights into how various peoples have collectively shaped the state's identity and heritage. This packet includes introductory information about the curriculum, as well as instructions and worksheets for three activities: "Why Do People Move?", "Texans One and All", and "New Texans Today"
Artificial Intelligence as Enabler for Adoption of Sustainable Nuclear-Powered Maritime Ships: Challenges and Opportunities
No full textDecarbonization stands as one of humanity&rsquo;s most pressing challenges, demanding collective efforts from multiple sectors to meet established goals. The transportation industry plays a pivotal role in this endeavor, with the maritime sector offering significant potential to reduce emissions. As a cornerstone of global goods and commodity transport, the maritime industry is uniquely positioned to contribute meaningfully to the global drive for lower carbon emissions. Artificial intelligence (AI), with its profound influence across diverse domains, is anticipated to play a vital role in supporting the nuclear shipping industry on its path to a decarbonized future. Specifically, AI provides tools to make nuclear power on ships a more economically viable solution while enhancing the safety and security of nuclear systems. This paper explores AI tools as an enabler for adopting nuclear-powered ships, delving into the challenges and opportunities associated with their implementation. Ultimately, it highlights AI&rsquo;s role in fostering sustainable nuclear-powered maritime solutions, which align with and contribute to achieving global decarbonization goals.Electrical and Computer Engineerin
Essays in Green Debt and Customer Social Unrest
No full textThis dissertation explores how environmental and social factors influence firm-level financing decisions and outcomes. The first essay examines the factors that make firms more likely to issue green and sustainability-linked bonds (SLBs) and how these bonds are priced relative to regular bonds. I use a multinomial probit model to analyze a firm’s issuance decision and find that firms are more likely to issue green and SLB securities when credit spreads are high, suggesting that the selection of these bonds is endogenous with pricing. I then use OLS, matching, and heteroskedasticity-based instrumental variable regressions to examine green and SLB pricing and document significantly lower spreads for SLBs and, to some degree, green bonds.
The second essay investigates the selection, contractual design, and pricing dynamics of green and sustainability-linked debt, this time in the syndicated loan market. Using a trivariate choice model, I find that firms are more likely to issue green loans and SLLs when credit spreads are high and following the introduction of mandatory disclosure laws. Further, I examine the contractual stringency of green and SLL securities using a matched sample analysis and find that, relative to regular loans, green loans include fewer restrictive covenants, whereas sustainable-linked loans include a greater number of restrictive covenants. I consider OLS, Bartik instruments, and heteroskedasticity-based instruments to assess green and SLL pricing and find that both green and SLL securities are issued at lower initial spreads relative to regular loans.
The third essay explores how international social unrest propagates through customer networks and affects the stock returns of U.S. exporters. I consider a set of pooled regressions and an event study analysis using a sample of firms with varying degrees of exposure to social unrest and find that firms exposed to political instability experience negative stock price reactions, specifically in the immediate aftermath of instability events. Further, I show that the degree to which a firm is exposed to a social unrest event is positively related to the magnitude of the stock price decline. The findings underscore the vulnerabilities that firms encounter as their revenue streams are linked to unstable regions.Financ
Amplifying Voices: Honoring How Black Women Middle School Assistant Principals, Navigate, Strategize, and Advocate for Educational Equity
No full textBlack women educational leaders are crucial in creating equitable and inclusive school environments, particularly in urban middle schools. This study examined the leadership practices of Black women assistant principals (APs), focusing on how they navigated systemic barriers related to race and gender while fostering positive, culturally responsive learning environments. Grounded in Black Feminist Thought, the research utilized a qualitative case study approach, featuring semi-structured interviews and a sista circle session with three Black women assistant principals (APs).
Lyric described the burden of hypervisibility and the emotional toll of servant leadership. Doc reflected on how faith and family pride shaped her leadership while also acknowledging obstacles such as limited advancement opportunities and harmful stereotypes. Mz. Thanng shared her experiences with colorism and her commitment to "othermothering,” a nurturing leadership style centered on holistic student care.
Thematic analysis revealed that these leaders drew on resilience, advocacy, and cultural responsiveness to address the diverse needs of their school communities. As mentors and community builders, they championed both academic achievement and emotional well-being, especially for students of color. Despite facing racial and gender biases, they transformed their lived experiences into powerful leadership strategies that fostered affirming and inclusive school cultures. This study underscored the transformative impact of Black women in leadership and the urgent need to amplify their voices. It called for systemic change through intentional recruitment, support, and retention efforts to ensure educational spaces where all students—and leaders—could thrive.
Educational Leadership and Policy Studie
The Metaphysical Problem of Evil
No full textThis thesis seeks to reconcile the logical problem of evil by considering and identifying the possible metaphysical status of the premises in John L Mackie’s original problem of evil. The purpose of the project is to refute Mackie’s conclusion that belief in God is irrational. The conclusion is not merely objectionable for theological reasons, but for metaphysical reasons. If one were to be erroneously persuaded of a particular type of metaphysical existence, then they would preclude themselves from metaphysical possibilities without sufficient justification. I have spent the last few years focusing on the study of metaphysics and how metaphysics impacts all other areas of philosophy. This constant study and synthesis of ideas has been the primary method of research and development.Philosoph
EVALUATING VEGETATION COMPOSITION AND SOIL ORGANIC CARBON SEQUESTRATION OF ROADSIDE STORMWATER DETENTION BASINS AND VEGETATED SWALES WITHIN THE EDWARDS AQUIFER RECHARGE ZONE
No full textThe full text of this item is not available at this time because the author has placed this item under an embargo until May 15, 2026.The replacement of natural landscapes with impervious surfaces reduces carbon sequestration and generates greater volumes of stormwater runoff that transport pollutants such as sediment, vehicle fluids, and heavy metals directly to the aquifer. Green stormwater infrastructures are emerging strategies in urban stormwater management because of the ecosystem services they provide, including removing contaminants from runoff and sequestering atmospheric carbon within their vegetation and soil. This study evaluated three roadside stormwater detention basins and vegetated swales within the Edwards Aquifer recharge zone for differences in vegetation composition and soil organic carbon (SOC). Significantly greater vegetation biomass and cover in summer 2021 compared to 2020 was likely due to increased rainfall and cooler temperatures in 2021. Vegetated swales were observed to have significantly greater vegetation and SOC when compared to detention basins. No seasonal differences in vegetation or SOC were found between winter and summer collections for both detention basins and vegetated swales. SOC concentrations were observed to decrease with increased distance from the location of stormwater inflow at vegetated swales and detention basins. SOC was highest in the top 0.0-7.0 cm of soil and decreased with depth. Non-native plant species were greater in cover and biomass, but native species exhibited greater richness, evenness, and diversity. The native species with the greatest average biomass within vegetated swales was sideoats grama (Bouteloua curtipendula), and the non-native with the greatest average biomass was King Ranch bluestem (Bothriochloa ischaemum). The native species with the greatest average biomass within detention basins was tropical flat sedge (Cyperus surinamensis), and the non-native species with the greatest average biomass within detention basins was bermudagrass (Cynodon dactylon). Best management practices that promote native vegetation growth, reduce non-native species, and protect soil from tillage and removal could maximize the ecosystem services potential of these systems.Integrative Biolog