Matching Items (162)
Description
GaN-based devices are currently limited by reliability issues such as gate leakage and current collapse, where the mechanisms responsible for degradation are closely related to the electronic surface state configuration. Therefore, understanding the electronic surface state configuration of GaN-based materials will help improve device performance. Since GaN has an inherent polarization, these materials are also subject to a bound polarization charge, which influences the electronic state configuration. In this study, the surface band bending of N-face GaN, Ga-face GaN, and Ga-face AlGaN was measured with x-ray photoemission spectroscopy after various cleaning steps to investigate the effects of the polarization. Despite the different surface bound charge on these materials, similar band bending was observed regardless of the magnitude or direction of the charge. Specifically, the band bending varied from −0.1 eV to 0.9 eV on these samples, which supported the models of a Fermi level pinning state at ∼0.4 eV to 0.8 eV below the conduction band. Based on available literature, we suggest this pinning state is indirectly evident of a nitrogen vacancy or gallium-dangling bond.
ContributorsEller, Brianna S. (Author) / Yang, Jialing (Author) / Nemanich, Robert (Author) / College of Liberal Arts and Sciences (Contributor) / Department of Physics (Contributor)
Created2014-12-01
Description
Time restricted eating (TRE) is an increasingly popular diet strategy that has shown promise for weight loss and improving metabolic health. The impact of TRE on bone health has not been extensively studied, and the goal of this experiment is to provide more insight into this subject. 32 10-week old female mice were randomly assigned to 4 groups (n = 8). These included low fat diet fed ad-libitum, low fat time restricted feeding (TRF), high fat diet fed ad-libitum, and high fat TRF. The mice adhered to these diets for 9 weeks, with the TRF groups having access to food for 8 hours per day until the sacrifice. At nine weeks, the TRF mice had significantly lowered body weight, improved body composition, and a lower fasting blood glucose. The TRF groups also experienced significant improvements in the trabecular bone density of the tibia, femur, and L3 vertebral body. This was found alongside reductions in osteoclast count and activity in the TRF mice. When compared to a baseline group of 10-week old mice, it was found that the TRF group had significantly less bone loss relative to the ad-libitum fed mice. Improvements in metabolic health, gut barrier function, and inflammation may have all contributed to the observed improvements in bone health. These results reveal a promising and previously unrecognized dietary tool to improve bone health and counteract age-related bone loss.
ContributorsJakiche, Michael (Author) / Collis, Graham (Co-author) / Roberts, Joseph (Thesis director) / Johnston, Carol (Committee member) / Barrett, The Honors College (Contributor) / Department of Physics (Contributor)
Created2024-05