Dissertation Defense Announcements

In recent years, Wide Bandgap (WBG) semiconductor based power devices has matured rapidly and are playing a significant role in high switching frequency power electronic applications. WBG materials such as silicon carbide (SiC) and gallium nitride (GaN) possess a higher critical breakdown strength, an increased thermal conductivity, and a wider energy bandgap than silicon which make WBG semiconductors as a material of choice in low on-resistance, high blocking voltage, high switching frequency and high operating temperature power applications. In addition, using these devices result in the overall size reduction of the devices as higher doping levels can be achieved at similar voltage levels.
A gate driver acts as an interface between power devices and logic-level control signals and plays a significant role in the switching behaviour of WBG devices. To increase the overall efficiency and reduce the footprint of the system high switching frequency operation of the devices is desirable. However, power consumption in the gate driving circuit increases with frequency. A viable strategy to reduce the gate driving power consumption is to use resonant gate driving technique where part of the energy stored in the gate capacitance is recycled.
In this dissertation, a novel resonant gate driver (RGD) for WBG devices is proposed which drives the semiconductor device using quasi-square wave by utilizing higher order harmonics. Firstly, the operating principles of the proposed gate driver circuit is presented. Secondly, a detailed characteristic analysis and power loss analysis of the circuit are provided. Additionally, a comprehensive simulation study of the proposed circuit is introduced. Moreover, a prototype of the proposed RGD was built and tested. Experimental results demonstrate that the proposed gate driving technique can significantly reduce power consumption in the gate driver circuit in comparison to conventional gate driving techniques.

There is a long history of limited nutrition education in advanced healthcare curricula. This leaves healthcare providers unprepared to use nutrition to treat diagnoses that have been shown to respond to dietary intervention. This project attempted to determine if the knowledge, attitudes and confidence about nutrition could be improved with a short course.

The sample consisted of seven students in master’s programs in the social work and nursing fields. Students completed an eight module virtual training on the Mediterranean diet and phytochemical specific prescribing strategies. Participants completed a pre- and post-assessment evaluation gauging knowledge, Likert scale questions evaluating confidence, and open-ended questions assessing attitudes toward implementing gained knowledge into practice.

Results showed the mean score for the pre-assessment was 60.39 (S.D.=14.12) and for the post-assessment was 65.58 (S.D.=9.32). The Wilcoxon Ranks Test shows significant improvement (p<0.05) for fifteen of the eighteen questions related to confidence in nutrition information. Open-ended attitude questions revealed that participants were interested in sharing the newly-learned nutrition information with community members and clients. Social work and nursing students may benefit from incorporating added nutrition education into their curricula. Further programming implementations in the area, including possible trial integration into curricula, are needed to further evaluate effectiveness.

The resident advisor (RA) position is one of the most complex and important roles on college campuses in the United States. There are few other student staff positions that require the same level of training and have the same level of responsibilities. While these staff members serve many functions, a primary responsibility of RAs is to make their residents feel welcomed and valued in their community. Black students who take on the RA role at historically White institutions (HWIs) are charged with creating welcoming environments for students and making them feel valued in the community while often not feeling welcomed or valued themselves in these same environments due to the stereotypes and racism they encounter on their campuses. Navigating the RA role as a Black student may mean helping their residents develop their sense of belonging while simultaneously trying to find spaces where they feel they belong. This study is a qualitative phenomenological one that explored the lived experiences of Black students serving in the RA role at HWIs and where they found belonging and support in their residence life department. The study shares the stories of 10 students using interviews and photovoice. The findings of this study are broken down into five themes: (1) Motivation, (2) Isolation, (3) Stereotyping, (4) Labor, and (5) Underrepresentation. The words and images captured by the participants of the study are used to better understand these themes and the needs of Black RAs.

As student demographics continue to evolve in higher education, the intersection of college-going generation status and U.S. immigrant-generation status needs to be considered; particularly, how these bi/polycultural experiences may play a role in the experience of belonging in college. This qualitative, phenomenological research study aimed to explore the lived experiences of four-year university students identifying as first-generation in college (FGC) and second-generation immigrants (SGI) in the U.S., with a focus on sense of belonging experiences at this identity intersection. Ten in-depth, semi-structured interviews with FGC-SGI students at an institution in the Southeastern U.S. were conducted to highlight identity and belonging narratives. Findings revealed that FGC-SGI students more readily engaged in identity disclosure with peers who shared at least one identity, and experienced implicit pressures to succeed due to their identities. Findings also revealed that FGC-SGI students sought out peers with similar identity characteristics to feel belonging, and that belonging played a critical role in how they viewed both their identities and their abilities to succeed in college. Thus, understanding FGC-SGI students' lived experiences may assist equity-minded higher education professionals with framing and creating settings that purposefully engage with this population to promote a positive, inclusive college experience, aiding in persistence and success.