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

Searching the Health Literature 101
(2023-09-07) Helbing, Rachel
This session will provide an introduction to searching the health literature with tips, tricks, and best practices to make your searches more successful. Rachel Helbing, Head of Health Sciences Libraries, will cover searching basics like choosing appropriate databases, using PICO to generate a list of keywords, constructing a strategy with Boolean operators, and more. Skills learned in this session will be applicable for searching a variety of biomedical and social sciences databases.
(2022-12-13) Cheng, Kuan; Ardebili, Haleh; Karim, Alamgir; Ghasemi, Hadi; Bao, Jiming; Ryou, Jae-Hyun
Conventional techniques to harvest and store energy are challenged by the ever-increasing demand for versatile forms of electrical energy caused by the rapid expansion of the Internet of Things (IoTs). As emergent solutions, flexible triboelectric nanogenerators (TENGs) and lithium-ion batteries (LIBs) have been invented and extensively studied in recent years. Different TENGs are fabricated to scavenge mechanical energy from most natural sources and human motions, making them portable solutions to energy generation on-demand. On the other hand, rechargeable LIBs play critical roles in the evolution of energy over 50 years, owing to its abilities to store massive amount of energy, lay the foundation for portable smart devices, and make possible a fossil fuel-free world. At the beginning of this dissertation, latest efforts that incorporating low-dimension carbon materials with TENG systems will be systematically reviewed. Carbon materials, including graphene and carbon nanotube, can bring many synergistic properties to TENGs, such as output enhancement and multifunctionality. They are poised to further the reach of TENG applications and make a positive impact on common issues related to TENG technology. The second section is to present a robust route to fabricate flexible TENGs with multifunctionality by nano-patterning thermoplastic polyurethane (TPU) thin films. Topographically optimized TENGs could promote higher power generation while preventing biofilm formation without using any chemical additives. Analysis of pattern amplitude and wavelength correlation to output power is uniquely provided for a deeper understanding of how patterned TENGs enable peak performance. The last part of this work presents the fabrication and characterization of lithium-ion batteries based on solid-state polymer electrolytes. Efforts made to substitute conventional liquid electrolyte and plastic separators make a great accomplishment on mechanical properties and safety aspects of LIBs. Fluoroethylene carbonate (FEC) has been proved as an effective electrolyte additive, which helps building LIB systems with ultra-high capacity and low self-discharge. Comprehensive electrochemical properties along with thermal properties of LIBs will be closely scrutinized in this work.
A Three-Part Study Investigating Parent Perceptions of Control Regarding Their Child’s Autism Spectrum Disorder
(2023-08-17) McNeel, Morgan Margaret; Mire, Sarah; Keller-Margulis, Milena A.; Kim, Hanjoe; Storch, Eric
Background: While children with autism spectrum disorder (ASD) experience symptoms that affect them as individuals, the impact of ASD extends beyond the diagnosed child. Despite strengths, parents of children with ASD face unique challenges and experience higher levels of stress and depression. It is critical to understand and address parent-specific factors that may negatively affect families and, ultimately, children. Parent cognitions, such as perceptions and beliefs, influence coping and have implications for important health-related behaviors, such as those related to intervention needs, decision-making, and processes. More specifically, better understanding parent perceptions regarding control, a construct related to parenting self-efficacy, may aid researchers and healthcare providers in improving support for families of autistic children. Purpose: This three-part study investigated: (1) parent, child, and family variables as predictors of parents’ perceived control; (2) how parents’ perceived control may change over time, and possible relationships between those changes and changes in other child, parent, and/or family factors; and (3) relationship between parents’ perceived control over ASD symptoms and their treatment decision making, when also considering other parent, child, and family characteristics. Methods/Results: Study 1 used data from 362 parents of children with ASD. Multiple linear regression revealed that parents’ perceptions of more/higher control over their children’s symptoms was predicted by lower Parental Distress, child age, and overall ASD symptom severity, as well as higher Positive Coping Skills. Study 2 examined parent perceptions of control related to their child’s ASD for a subset of 16 parents across two time points alongside other individual, parent, and family characteristics. Change in parents’ perceptions of control over symptoms was examined at the item-and scale-level, and findings included that perceptions of control among parents in this small sample were generally high and relatively stable over time, though the sample size limits interpretation and generalizability of these findings; the clinical significance of the change was also considered. Study 3 used a subset of data from 327 parents from study 1. A series of binary logistic regression analyses identified several predictors of ever using specific autism-focused interventions among families in this sample. Parent perceptions of effects of the child’s diagnosis, perceived controllability of symptoms, and perceived severity of core ASD symptoms were the most common significant predictors of families endorsing ever having used certain popular interventions. Conclusion: Outcomes of these interrelated studies have both research and practice implications for better understanding and supporting parents and families of children with ASD. The studies highlight the importance of further exploring parent perceptions regarding control and self-efficacy when working with this population.
The Impact of Teachers’ Words: A Phenomenological Study of Teachers’ Perceptions of Their Talk Used with Students
(2023-08-16) Thornell, Sydney Taylor; Hutchison, Laveria; Cooper, Jane; Reis, Nancy; Thomas, Dustine
Background: School districts and other educational systems have extensive options of programs to choose to implement for various types of professional and student learning. These well-intentioned and often research-supported programs and learning systems aim to improve education for students. A problem is that once a program is adopted, emphasis is often placed on its potential and routine classroom usage, rather than on how it is being implemented and if it is effective for students. Instruction on how teachers speak and present content is missing, leaving educators, especially novice teachers, unable to attain the full potential of the adopted program. Successful implementation of programs and curricula is directly impacted by teachers’ talk. Purpose: The purpose of this study was to explore teachers’ talk in their classroom settings, with students, and their perceptions of it after participating in professional development on the topic of teachers’ use of classroom talk. Teacher talk in this study is defined as the words educators say to students and the tone of voice in which they say them. Professional development is focused on warm, respectful, and student-centered talk moves. The following research question guided this study: What are the perceptions of both novice and experienced teachers toward their use of talk used with students before and after professional development? Methods: This study employed a qualitative phenomenology approach to collect and analyze data from eight participants. Four of the participants in the study were teachers at the study site with less than one year of teaching experience in the profession. The other four participants in the study were experienced teachers at the study site but with less than one year of teaching experience in the school district. Data sources included semi structured one-on-one interviews with participants designed by the researcher and reviewed by an educational expert, participants’ reflections on classroom talk and interactions with students, a contemporaneous researcher field journal used to document the researchers’ experience and observations throughout the study, and audio recorded semi-structured group conversations with participants. Both thematic and discourse analysis were used to make sense of the data collected. Member-checking was also utilized to ensure accuracy in representing participants’ perceptions of teacher talk. Results: The findings from this study revealed four themes: Professional development on teacher talk improved both novice and experienced teachers’ awareness of their teacher talk used with students; Both novice and experienced teachers recognized areas of growth in their own teacher talk after professional development on the topic; New-to-district and novice teachers benefited from the campus-designed induction program where professional development was presented, and lastly; New-to-district and novice teachers shared the feeling that professional expectations, including teacher talk, were different for them when compared to their more established colleagues. Conclusion: The perceptions of both novice and experienced teachers in this study have shown that the phenomenon of professional development on the topic of teacher talk has increased self-awareness and sparked a change in the way that teachers talk with students.
An Analysis of Colony Movement and The Effects of Movement on Fitness in the Western Harvester Ant, Pogonomyrmex Occidentalis
(2023-08-07) Ramsaroop, Maxximus
Colony movement in ants (Hymenoptera: Formicidae), is well documented and several studies have explored the fitness costs and causes of colony movement in different species. Attempts to describe the purpose or patterns of colony movement have been made on many species within Pogonomyrmex spp. However, research into these aspects of colony movement has yet to be described in P. occidentalis, The Western Harvester ant. This thesis examines the fitness costs, potential causes, and behavioral syndrome associated with colony movement in P. occidentalis. I analyzed Dr. Cole & Dr. Wiernasz's data from 1993-2023 on colony movement, age, size, distances traveled, and survivorship for 6,066 colonies. Moved colonies were found to have a smaller colony size, shorter colony lifespan, and lower rates of survivorship when compared to unmoved colonies using t-tests and a Kaplan-Meier survivorship analysis. Moreover, moved colonies were compared against 1-year-old colonies, and were found to have a larger colony size. Colonies were also found to have a greater tendency to move later in age, and 16.6% of colonies had moved at least once. These results suggest that colonies that move incur fitness costs, as colony size and lifespan are proxies for fitness, and that colony movement is more costly for younger or smaller colonies. Furthermore, because P. occidentalis is notably long-lived, shows high nest fidelity, and their movements are associated with a loss in fitness, they likely exhibit an adventitious nest relocation syndrome. Through this thesis, we can better contextualize P. occidentalis in the greater scheme of animal architects and the decisions they make.