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Conformality, Quantum Instability, Thermality and Spacetime Entanglement in Causal Diamonds
No full textIn this dissertation, we explore the spectral properties of symmetry generators in conformal quantum mechanics (CQM) and their relationship to thermal effects and entanglement dynamics within a causal diamond in flat (Minkowski) space. Using a path-integral framework, we analyzed generalized CQM operators, including elliptic, parabolic, and hyperbolic classes, identifying their propagators, Green functions, and eigenstates. Our work yielded new results for the noncompact hyperbolic generator , which has a continuous spectrum and governs time evolution for observers constrained to a causal diamond. In quantum field theory in curved spacetime, key properties like a system's ground state and particle number are observer dependent. For instance, in the Hawking effect, static observers near a black hole detect thermal radiation. Similar effects appear even in flat spacetime, where accelerated observers detect thermal particles in the Minkowski vacuum. Likewise, a finite-lifetime observer with lifetime perceives the Minkowski vacuum as a thermal state at temperature , due to its restricted access within a double-cone-shaped region. We use path-integral representations of CQM generators in canonical and microcanonical forms to explore the emergence of thermality in causal diamonds and interpret how finite-lifetime observers perceive temperature . The hyperbolic operator plays a central role in this process, not only governing time evolution but also due to its dynamical behavior exhibiting a quantum instability with a positive Lyapunov exponent , which is half the upper saturation bound of the information scrambling rate. This work also explores a connection to quantum information, where we examine how causal horizons impact entanglement. Finite-lifetime “diamond” observers experience a lower entanglement between scalar field modes compared to inertial observers. Similar to the Unruh effect, where entanglement degradation arises from acceleration, here the degradation is enforced by the causal boundary of the diamond. Starting from a maximally entangled state, we show how this causal structure governs entanglement dynamics for observers in this restricted spacetime regions. This work contributes to a deeper theoretical understanding of the interplay between thermal effects, causal structures, quantum instabilities, and entanglement dynamics, with potential implications for broader applications in quantum field theory and quantum information science
A Place for Us: (Re) Imagining a Sense of Belonging for Primary-Grade Latine Students Attending Independent Private Schools
No full textBackground: The need for belonging is fundamental, especially for primary-grade Latine students navigating the unique and often exclusive environments of independent private schools. Despite the increasing emphasis on Diversity, Equity, Inclusion, and Belonging (DEIB) initiatives over the past decade, significant gaps persist in how these efforts address the needs of culturally and socioeconomically diverse student populations. Purpose: This qualitative study investigated the strategic initiatives employed by independent private schools to foster a sense of belonging for Latine primary-grade students and examined how these initiatives impact students' academic and social experiences. This qualitative study explored the following research question: What are the strategic initiatives used to support Latine primary grade students enrolled in independent private schools to feel a sense of belonging? This study was grounded in Critical Race Theory (CRT) and the concept of liminality. Methods: Utilizing purposeful sampling, three DEIB leaders from independent private schools each participated in a 45-minute, semi-structured interview conducted by the principal investigator via Zoom. Each interview consisted of 11 open-ended questions. The audio recordings of the interviews were transcribed using Adobe Premier Pro, edited for clarity by the principal investigator, and sent to participants for member-checking to ensure reliability of the data. Thematic analysis was conducted, incorporating insights from participants’ experiences, with data triangulation used to validate findings. Findings: The research identified several notable themes. First, the evolution and adaptability of DEIB roles were highlighted, as participants described how their responsibilities have expanded from policy implementation to direct student and family engagement. Second, institutional leadership emerged as a pivotal factor, with schools led by diverse leaders demonstrating deeper, more integrated commitments to equity. Third, proactive measures such as culturally responsive programming and bilingual resources were found to be effective, especially when students were given agency to lead DEIB initiatives. However, persistent socioeconomic and cultural barriers were noted, underscoring the need for a multifaceted and intersectional approach. Lastly, engaging Latine families through culturally sensitive practices and bilingual communication was seen as crucial yet complex, requiring continuous and adaptive strategies. Implications: This study extends CRT by emphasizing the intersection of race, socioeconomic status, and regional context, and suggests the need for more culturally competent and sustainable DEIB practices. Practical recommendations include investing in comprehensive DEIB training, hiring diverse leadership, and empowering student voices to shape school culture. The research underscores the importance of viewing DEIB work as an ongoing, community-wide effort, requiring commitment from administrators, educators, students, and families alike. Conclusion: While independent schools have made strides in DEIB integration, lasting impact depends on continuous investment, adaptive leadership, and genuine engagement with diverse communities. The findings illuminate the complexities of fostering belonging and call for a holistic, intersectional approach that celebrates cultural identities and addresses systemic inequities. Future research should explore longitudinal impacts and incorporate the voices of students and families to further enhance the inclusivity of independent education
National Hydrogen Transportation Fuel Supply
No full textHydrogen (H2) fuel cell electric vehicles (FCEVs) refuel in less than 5 minutes with water vapor as their only exhaust emission and are more energy efficient than internal combustion engine vehicles (ICEVs). Consequently, they represent potentially attractive alternatives to battery electric vehicles (BEVs) and ICEVs. However, rare access to hydrogen refueling limits this choice in the United States (US). This research assessed the viability of switching from liquid fuels to hydrogen at all locations in the contiguous US. Preliminary work has provided compelling evidence that the projected hydrogen cost is competitive with that of gasoline and diesel in the Greater Houston Area (GHA). Hydrogen generated from the electrical grid using commercially available electrolyzers costs more in the Houston area than hydrogen generated with steam methane reforming (SMR) with Carbon Capture (SMRCC), but less than diesel fuel. The electric grid can supply hydrogen at any location with sufficient water. However, where methane supply is available, hydrogen generated from methane requires less water and is more cost effective. We integrate existing tools and data for US counties and municipalities to assess hydrogen generation costs using the model created for the preliminary work to develop a prototype application to model and evaluate the cost of hydrogen generation at any location in the contiguous US via either the existing natural gas infrastructure or the electric grid. This research provides a methodology for determining the competitive price of hydrogen for the US. Mechanisms that make hydrogen attractive for transportation may also make it attractive for other industrial and commercial applications
A Comparison of the Braking and Propulsion Phase Characteristics of Traditional and Accentuated Eccentric Loaded Back Squats in Resistance-Trained Women
No full textThe aim of this study was to compare the braking and propulsion force–time and barbell velocity characteristics between back squat sets performed using traditional (TRAD) or accentuated eccentric loading (AEL) in resistance-trained women. In total, 14 participants completed four separate testing sessions that included a one repetition maximum (1RM) back squat and three squat testing sessions that used either TRAD or AEL. During the squat testing sessions, participants performed sets of three back squat repetitions using TRAD loads with 50, 60, 70, and 80% 1RM or performed the same loads with the addition of weight releasers that equated the total load to 100% (AEL-MAX) or 110% (AEL-SUPRA) 1RM during the eccentric phase of the first repetition of each set. Braking and propulsion mean force, duration, and impulse as well as mean and peak barbell velocity were examined across each back squat set. Significantly greater braking impulses were produced during the AEL conditions across all loads (p < 0.02), while greater braking mean force during AEL-SUPRA was produced compared to TRAD during with 50 and 60% 1RM (p < 0.02). There were no other significant differences in braking, propulsion, or barbell velocity that existed between different conditions (p > 0.05). AEL-MAX and AEL-SUPRA provide a greater braking stimulus compared to TRAD squats, while the propulsion phase may not be significantly impacted. Rapid and maximal force production may be favored by larger and smaller load spreads, respectively
Regulation of High Blood Pressure by Somatic Neuromodulation
No full textHypertension is a main cause of death in the US with more than 103 million adults affected. While pharmacological treatments are effective, approximately 20-30% of hypertensive subjects do not respond to these pharmacological treatments also known as drug-resistant hypertension (DRH). Drug resistant hypertension is known to be a risk factor for cardiovascular events, including stroke, myocardial infarction, heart failure, and cardiovascular mortality, as well as adverse renal events, including chronic kidney disease and end-stage kidney disease. This thesis aims to look at an alternative treatment for drug resistant hypertension through neuromodulation of the common peroneal nerve to elicit a depressor response in Spontaneously Hypertensive rats (SHR). Firstly, an acute study was performed on both SHR rats and normotensive rats (WKY) to optimize the stimulation parameters for neuromodulation treatment. The optimized parameters, 1 mA amplitude, 1 ms cathodic monophasic pulse, at 2 Hz were deemed to produce the best depressor response without causing damage to the peroneal nerve. After finding the optimal parameters for stimulation we performed a sub-chronic experiment in which animals implanted with a novel wireless miniature electrode(w-µCE) and blood pressure (BP) telemetry systems underwent daily peroneal nerve stimulation at threshold for 8 minutes for five weeks. This reduced systolic blood pressure (SBP) in WKY animals by -7 mmHg, and in SHR animals by 20 mmHg during treatment (p<0.01). Ambulatory SBP measured daily recorded approximately twenty-four hours after the cPNS treatment, showed a significant reduction from the first (176.6 ± 24.1 mm Hg; n=5) to the last week of treatment (165.7± 42.7 mm Hg; n=4), a -9 mm Hg reduction (p<0.01). Evaluation of heart rate during the treatment showed no significant difference caused by the daily 8-minute cPNS. Electrical stimulation of the common peroneal nerve induced a reduction in SBP that is comparable to that reportedly achieved pharmacologically by ACE inhibitor Ramipril, or by renal denervation procedures. Lastly histological analysis of the heart and aorta in which we analyzed heart wall thickness, aorta thickness, and fibrosis in the heart showed no significant differences in the treatment group versus normotensive rats, highlighting that a longer treatment period might be needed to see significant changes in these anatomical structures. These results support the notion that neuromodulation of the common peroneal nerve can serve as an alternative treatment for drug resistant hypertension
Racial and Ethnic Disparity in Access to Care, Health Behavior and Health Outcomes Among Adults With Cardiovascular Disease
No full textBackground: Racial and ethnic disparities significantly impact healthcare access, resource utilization, expenditures, and perceived health status among individuals with cardiovascular disease (CVD). Methods: Using data from the Medical Expenditure Panel Survey (2014–2021), we conducted retrospective cross-sectional analyses to evaluate disparities among Black, Hispanic, and White CVD populations. Results: Unadjusted findings indicated that Black and Hispanic individuals consistently experienced lower access to timely care, fewer healthcare visits, and reduced total expenditures compared to White cohorts. For example, Hispanic and Black individuals had 23% and 11% lower healthcare expenditures (both p<0.001), and reduced odds of CVD visits (Hispanic: OR=0.61; Black: OR=0.58). Adjusted models revealed that disparities were influenced by physical and cognitive limitations, insurance status, income, and education. Moreover, perceived health status was significantly poorer among Black (OR=1.89) and Hispanic (OR=2.05) individuals relative to Whites, with variations in how age, socioeconomic factors, and health limitations shaped outcomes across racial groups. Conclusion: These findings underscore the urgent need for targeted, culturally tailored interventions to address the systemic inequities contributing to healthcare and health outcome disparities in minority populations with CVD. Enhanced collaboration between healthcare providers, policymakers, and community leaders is essential to achieve equity and improve the quality of life for these vulnerable groups
A Qualitative Exploration of the New Texas Performance-Based Funding Model’s Influence on Midsized Community College Transfer Efforts
No full textBackground: State-funded, Texas community colleges have a new model for receiving state allocations, which has only three student performance outcomes with vertical transfer being one. The average transfer rate for Texas community colleges has remained low, even though most students who enroll at a community college intend to transfer. Purpose: The following research question guided this study: What are the perceptions of transfer professionals at midsized Texas community colleges about the influence of the new performance-based funding model on transfer efforts? This study explored the extent to which transfer practices and priorities were altered to align with the new performance-based funding model through the perceptions of community college transfer professionals. Method: This research was a qualitative design using an exploratory, multiple case study approach. The resource dependency theory framework guided the study. Data collection included one-on-one interviews with five transfer professionals, researcher journaling, and document analysis. Data analysis was accomplished by open coding followed by constant comparative analysis. Findings: Data analysis led to three themes: (a) Perceptions of the PBF Model, (b) Perceptions of the PBF Model Implementation, and (c) Perceptions of Potential for Improved Transfer Efforts. The overall findings of this study suggest the PBF model lacked an influence on transfer efforts. Discussion: Findings of this study highlighted the lack of detailed and regular communication about the funding model with transfer professionals. Findings from this study also showed transfer professionals were omitted from conversations on how to improve efforts to increase transfer rates to receive increased state funding. Additionally, findings from this study led to several recommendations and implications for higher education policy and practice
Capturing the Variability of Atmospheric Trace Gases Using Satellite Observations
No full textSatellite instruments have the most potential to capture trace gas variability on various spatial and temporal scales as they continually observe the atmosphere and its composition. However, this potential may be limited by traditional data processing methods that are not agile in extracting spatiotemporal variability from satellite products as their resolutions increase. In this dissertation, we test the skill of Tropospheric Monitoring Instrument’s (TROPOMI, 3.5x5.5 km² at nadir) in capturing the varying behavior of atmospheric trace gases and offer novel ways to view variability. First, the analysis of TROPOMI products established that this instrument can capture the heterogeneity of available ozone precursor species, nitrogen oxides (NOx=NO+NO2), and volatile organic compounds (VOCs) in different chemical and meteorological conditions across Texas. We illustrated that it could capture single emission events. The 2021 hurricane, Ida, caused irregular NO₂ emissions in the impacted region of southwestern Louisiana, where a significant increase in the TROPOMI NO₂ level was captured and then quantified during the post-hurricane period. After the confirmation that manual methods of identifying trace gas variability are inefficient, the dissertation presents an agile clustering algorithm, CLustering of Atmospheric Satellite Products (CLASP), to identify the spatiotemporal variability of trace gases captured in satellite observations. CLASP detects features from satellite observations on their spatial, magnitude, and temporal axis to capture irregularity, aiding to the improved understanding of the spatiotemporal variability of atmospheric trace gases. CLASP is then applied to show the variations of TROPOMI NO2 in high-temperature extremes in an urban domain (Houston) and how its variability contributes to ozone formation. We show for the first time how CLASP and TROPOMI captured the time-varying NO2 emissions from peak power plants and other major emission points. CLASP identified that urban dwelling populations can experience greater magnitude and frequency of atmospheric pollutants in high-temperature extremes which is compounded with the stress of high heat and worsening air quality. This dissertation demonstrates how using CLASP and satellite observations, like TROPOMI, can increase our understanding of what processes control the spatiotemporal structure of key atmospheric constituents and how variable emissions change the Earth system and affect our populations
Learning-Based Controller for Aerial Robotics
No full textDeep Reinforcement Learning (RL) has demonstrated remarkable potential in solving complex robotic locomotion tasks by leveraging neural networks as function approximators. Building on this foundation, we developed a low-level controller for trajectory tracking of the Crazyflie 2.0 quadcopter using model-free RL. Specifically, we implemented a single-agent reinforcement learning (SARL) approach and trained our agent using the Soft Actor-Critic (SAC) algorithm, renowned for its strong exploratory capabilities and stability in learning. For training and simulation, we utilized the Gym-PyBullet-Drone environment due to its versatility and ease of integration, enabling efficient development and testing of our RL-based controller
An Examination of Course Scheduling and Middle School Band Enrollment and Retention
No full textBackground: Recruiting, retention, and advocacy are the lifelines of band programs across the United States. Keeping a high number of students enrolled in band classes during the school day is necessary for the success of the band programs. High band enrollment can also positively impact the overall school culture (Lautzenheiser, 2005). Analyzing the fine arts enrollment data in the State of Texas reveals how the number of students enrolled in band programs drastically drops from one grade level to the next (Texas Education Agency, 2018). Based on conversations with other music educators and personal experience, I posit that the school schedule is a possible factor in this decline in enrollment from one grade level to the next. Research on school scheduling and music education supports this notion. Purpose: This study aims to analyze the potential impact the school master schedule has on the recruiting and retention outcomes of junior high band programs. The research examines how stakeholders, including the principals, counselors, parents, students, and band directors, describe the relationship between the master schedule and band enrollment and retention. It also examines different factors these participants identify as influencing band enrollment and retention. The study's goal is to create a resource that administrators and band directors can use when making or altering the master schedule for the school and highlight common factors in encouraging students to sign up for and stay in band class. Methods: This study will use qualitative methods to interview school stakeholders who may influence band programs' enrollment and retention practices. These stakeholders include the band director, principal, parents, and band students. I interviewed three or four participants from each group of stakeholders. I analyzed the interview results to find significant patterns, disconnects, or similarities across the campus schedules that influence band enrollment and retention. The research questions for this study are: 1) What elements regarding the development of the master schedule influence the band schedule? 2) How do middle school stakeholders (principals, counselors or master schedule builders, parents, and band directors) describe the different factors influencing band enrollment and retention? 3) How do middle school stakeholders (principals, counselors or master schedule builders, and band directors) describe the relationship between the master schedule and band enrollment and retention? Results: Different themes emerged from analyzing and coding the transcripts of the interviews. I derived six main themes from the interview responses. The six main themes include the benefits of offering band, band experience, joining band, scheduling of classes, schedule conflicts and difficulties, and other reasons for dropping. Nineteen subsections are also identified within these sections. In this chapter, I also included a breakdown of the schedules from several participating schools and provided demographic profiles of the participating schools and districts. Conclusion: Using the findings, I constructed an updated gatekeeping theory model. This model reflects the primary sections and forces found in the interview data. I found students to be the most influential gatekeepers. It appears most other gatekeepers rely on students to be the primary voice for whether they wish to join or continue in the band program. Scheduling was a factor in whether students would join or remain in the band program, but it is one of many other factors. The main conflicts between band participation and scheduling included the number of electives the school offers, honor/high school credit classes, remedial classes, and other singleton courses. The most influential forces on students' continued participation were their relationship with the band director, the amount of work and dedication the band requires, and whether they retained an interest in the band