Institutional Repository

The University of Houston Institutional Repository (UHIR) collects, preserves and distributes scholarly output and creative works produced by the University of Houston community. UHIR provides free and open online access to the university’s research and scholarship, including electronic theses and dissertations.


Recent Submissions

Recent Advances in Geochemical and Mineralogical Studies on CO2–Brine–Rock Interaction for CO2 Sequestration: Laboratory and Simulation Studies
(2024-07-08) Khan, Muhammad Noman; Siddiqui, Shameem; Thakur, Ganesh C.
The urgent need to find mitigating pathways for limiting world CO2 emissions to net zero by 2050 has led to intense research on CO2 sequestration in deep saline reservoirs. This paper reviews key advancements in lab- and simulation-scale research on petrophysical, geochemical, and mineralogical changes during CO2–brine–rock interactions performed in the last 25 years. It delves into CO2 MPD (mineralization, precipitation, and dissolution) and explores alterations in petrophysical properties during core flooding and in static batch reactors. These properties include changes in wettability, CO2 and brine interfacial tension, diffusion, dispersion, CO2 storage capacity, and CO2 leakage in caprock and sedimentary rocks under reservoir conditions. The injection of supercritical CO2 into deep saline aquifers can lead to unforeseen geochemical and mineralogical changes, possibly jeopardizing the CCS (carbon capture and storage) process. There is a general lack of understanding of the reservoir’s interaction with the CO2 phase at the pore/grain scale. This research addresses the gap in predicting the long-term changes of the CO2–brine–rock interaction using various geochemical reactive transport simulators. Péclet and Damköhler numbers can contribute to a better understanding of geochemical interactions and reactive transport processes. Additionally, the dielectric constant requires further investigation, particularly for pre- and post-CO2–brine–rock interactions. For comprehensive modeling of CO2 storage over various timescales, the geochemical modeling software called the Geochemist’s Workbench was found to outperform others. Wettability alteration is another crucial aspect affecting CO2–brine–rock interactions under varying temperature, pressure, and salinity conditions, which is essential for ensuring long-term CO2 storage security and monitoring. Moreover, dual-energy CT scanning can provide deeper insights into geochemical interactions and their complexities.
Urban–Rural Disparities in Food Insecurity and Weight Status among Children in the United States
(2024-07-04) Dave, Jayna M.; Chen, Tzuan A.; Castro, Alexandra N.; White, Mamie A.; Onugha, Elizabeth A.; Zimmerman, Sloane; Thompson, Debbe
Place of residence (urban versus rural) is a contextual determinant of health that has received less attention in the food insecurity literature. The purpose of this study was to assess the urban–rural disparity in the prevalence of food insecurity and weight status among US children. Using data from the National Health and Nutrition Examination Survey (NHANES) 2013–2016 with three age groups of children (2–5, 6–11, and 12–17 years old), the associations of weight status and child and household food security status by urban–rural residence were examined using Rao–Scott Chi-square tests. Statistical significance was set at p < 0.05. Children living in urban areas were significantly more likely to experience household food insecurity (29.15%) compared to their rural counterparts (19.10%), among those aged 6–11 years. The associations between children’s weight status and child and household food security status were significant for children living in urban areas overall and different age groups but not for children living in rural areas. These trends were more pronounced in older age groups. Given the link between food insecurity and higher obesity rates, particularly among urban children, this study highlights the importance of incorporating food security interventions into future obesity prevention programs.
TGF-β-Based Therapies for Treating Ocular Surface Disorders
(2024-06-26) Ogata, Fernando T.; Verma, Sudhir; Coulson-Thomas, Vivien J.; Gesteira, Tarsis F.
The cornea is continuously exposed to injuries, ranging from minor scratches to deep traumas. An effective healing mechanism is crucial for the cornea to restore its structure and function following major and minor insults. Transforming Growth Factor-Beta (TGF-β), a versatile signaling molecule that coordinates various cell responses, has a central role in corneal wound healing. Upon corneal injury, TGF-β is rapidly released into the extracellular environment, triggering cell migration and proliferation, the differentiation of keratocytes into myofibroblasts, and the initiation of the repair process. TGF-β-mediated processes are essential for wound closure; however, excessive levels of TGF-β can lead to fibrosis and scarring, causing impaired vision. Three primary isoforms of TGF-β exist—TGF-β1, TGF-β2, and TGF-β3. Although TGF-β isoforms share many structural and functional similarities, they present distinct roles in corneal regeneration, which adds an additional layer of complexity to understand the role of TGF-β in corneal wound healing. Further, aberrant TGF-β activity has been linked to various corneal pathologies, such as scarring and Peter’s Anomaly. Thus, understanding the molecular and cellular mechanisms by which TGF-β1-3 regulate corneal wound healing will enable the development of potential therapeutic interventions targeting the key molecule in this process. Herein, we summarize the multifaceted roles of TGF-β in corneal wound healing, dissecting its mechanisms of action and interactions with other molecules, and outline its role in corneal pathogenesis.
Subsurface Imaging by a Post-Stimulation Walkaway Vertical Seismic Profile Using Distributed Acoustic Sensing at the Utah FORGE Enhanced Geothermal System Site
(2024-06-25) Wang, Yin-Kai; Stewart, Robert R.
A 2D walkway vertical seismic profile (VSP) survey was conducted using a distributed acoustic sensing (DAS) system in southwest Utah, which is part of an enhanced geothermal system (EGS) project. The VSP was undertaken to obtain detailed structural information for a better understanding of the area’s subsurface geology and associated fracture development. By combining a 3D composite velocity model from previous studies and considering the complex geological structure beneath this region, we processed the data to create P-P depth image. We also modified the interval Q calculation using a moving window over the gauge-length corrected DAS record to generate the velocity profile and the comparable interval attenuation curve. The correlated P-P images from two DAS records successfully indicate not only the main contact between shallow unconsolidated sediments and the metamorphic basement rocks at 2650 ft (807.72 m) but also several distinct reflections related to the geological contacts. The refined velocity profiles and the depth images can provide baseline results for further seismic modeling and time-lapse imaging.
Supporting Information for Reskilling and Upskilling for Decarbonization: Analyzing Micro-credential Programs for Energy Workforce Development
(2024-07-02) Datta, Aparajita; Coates, Stephanie; Rossiter, Alan; Krishnamoorti, Ramanan
Supporting Information for Reskilling and Upskilling for Decarbonization: Analyzing Micro-credential Programs for Energy Workforce Development in the Journal of Continuing Higher Education. 2024. ABSTRACT Decarbonization and the energy transition require many workers in the incumbent energy industry to transform their knowledge base and skills. Upskilling and reskilling programs that address the skills gap and offer opportunities for continued education are critical for workforce development and social equity. We evaluate if six online energy transition-related micro-credentialing programs met students’ expectations for augmenting foundational knowledge and skills. Additionally, we assess the role of energy companies in supporting reskilling and upskilling opportunities for their workforce and the potential of micro-credentialing programs for addressing interdisciplinary and continued education. The students, predominantly mid to senior-level energy professionals, were surveyed through a pre-study upon enrollment, a post-study upon completion, and a panel study that measured learning outcomes over six months. Our results evidence that the programs were successful in supporting continued education by offering new areas of knowledge and meeting students’ expectations of increased foundational knowledge and skills. Most students were also able to apply the acquired knowledge and skills to their jobs while still enrolled in the programs. Moreover, the workforce is self-motivated to augment their foundational knowledge and develop their skills through continued education without inducement from their employers.