Fabrication technology for high light-extraction ultraviolet thin-film flip-chip (UV TFFC) LEDs grown on SiC

The light output of deep ultraviolet (UV-C) AlGaN light-emitting diodes (LEDs) is limited due to their poor light extraction efficiency (LEE). To improve the LEE of AlGaN LEDs, we developed a fabrication technology to process AlGaN LEDs grown on SiC into thin-film flip-chip LEDs (TFFC LEDs) with high LEE. This process transfers the AlGaN LED epi onto a new substrate by wafer-to-wafer bonding, and by removing the absorbing SiC substrate with a highly selective SF6 plasma etch that stops at the AlN buffer layer. We optimized the inductively coupled plasma (ICP) SF6 etch parameters to develop a substrate-removal process with high reliability and precise epitaxial control, without creating micromasking defects or degrading the health of the plasma etching system. The SiC etch rate by SF6 plasma was ~46 \mu m/hr at a high RF bias (400 W), and ~7 \mu m/hr at a low RF bias (49 W) with very high etch selectivity between SiC and AlN. The high SF6 etch selectivity between SiC and AlN was essential for removing the SiC substrate and exposing a pristine, smooth AlN surface. We demonstrated the epi-transfer process by fabricating high light extraction TFFC LEDs from AlGaN LEDs grown on SiC. To further enhance the light extraction, the exposed N-face AlN was anisotropically etched in dilute KOH. The LEE of the AlGaN LED improved by ~3X after KOH roughening at room temperature. This AlGaN TFFC LED process establishes a viable path to high external quantum efficiency (EQE) and power conversion efficiency (PCE) UV-C LEDs.Comment: 22 pages, 6 figures. (accepted in Semiconductor Science and Technology, SST-105156.R1 2018

The development of a project typology and selection tool to improve decision-making in sustainable projects

Decision-making in sustainable projects is a complex and challenging process, especially during the initiating and planning phases of project development, due to influence from several external factors, as well as the uncertain environments surrounding their creation. It is essential to improve the decision-making process in sustainable projects during these two phases by relying on strong decision-making tools. The first contribution in this work identifies gaps in the literature of how institutionalization can impact sustainable projects through the effects of institutional isomorphisms from institutional theory. This helps decision makers better understand the relationship between institutionalization and sustainable projects. The second contribution is a sustainable project typology based on the affects that the coercive, normative, and mimetic institutional pressures have on common key sustainable project characteristics. The typology can improve decision-making by providing realistic predictions about the project early in the planning phase. The third contribution further develops this typology into a project selection tool that can be used in the initiating phase. It applies the Fuzzy Analytic Hierarchy Process (FAHP) to rank the key project characteristics based on importance as selection criteria by utilizing the literature as the voice of expert opinion. Because using the literature as a source of expert opinion can present its own set of challenges, the fourth contribution considers how the choice of selection tool inputs can impact project selection. Accordingly, Subject Matter Experts (SMEs) are utilized as an alternative source of expert opinion in an effort to validate the previously generated results and compare how these selection criteria are prioritized in literature and practice --Abstract, page iv

Homological and homotopical constructions for functors on ordered groupoids

The main topic of this thesis is the generalization to ordered groupoids of some results and constructions that have arisen in groupoid theory and its applications in homological and homotopical algebra. We study fibrations of ordered groupoids, and show that the covering homotopy property and star-surjectivity are not equivalent properties. We establish some formal properties of functors having these properties, and define a new quotient construction for ordered groupoids that leads to a factorization of any functor of ordered groupoids as a star-surjective followed by a star-injective functor. We give a direct proof of Ehresmann’s Maximum Enlargement Theorem. Coupled with our quotient construction, The Maximum Enlargement Theorem gives a universal factorization of any functor of ordered groupoids as a fibration followed by an enlargement followed by a covering. We construct the mapping cocylinder M of an ordered functor : G ! H, and show directly that the morphism M ! H has the covering homotopy property. We construct the derived module D of an ordered functor and use it to study two adjoint functors between the category of ordered crossed complexes and the category of ordered chain complexes. Finally, we consider the groupoid of derivations of crossed modules of groups and of ordered groupoids, and in the latter case we use semiregular crossed modules to derive results on homotopies and endomorphisms. (Mathematical symbols not available - please refer to the PDF)

Determination of Novel Metabolites of Therapeutic Agents used in the Treatment of Castration-Resistant Prostate Cancer

Despite an array of improved treatment options over the past decade, prostate cancer remains the second leading cause of cancer mortality for men in the United States. Abiraterone and galeterone are oral steroidal compounds that are used to treat metastatic castration-resistant prostate cancer (CRPC). Abiraterone blocks 17a-hydroxylase/17,20-lyase (CYP17A1), an enzyme required for androgen synthesis. Galeteron inhibits CYP17A1, blocks the androgen receptor (AR), and decreases AR protein levels. Both drugs share the same structure with endogenous androgens such as dehydroepiandrosterone, which are substrates for the enzyme, 3ß-hydroxysteroid dehydrogenase (3ßHSD). Metabolites of 3ßHSD undergo further metabolism to produce the AR ligand, testosterone and dihydrotestosterone. Overall this project aimed to investigate the steroidogenic metabolism of abiraterone and galeterone and evaluate the metabolites’ role in prostate cancer. The background on prostate cancer, steroid biosynthesis, and treatment options is described in Chapter I. Chapter II describes the development and validation of a liquid chromatography mass spectrometry method LC-MS/MS to determine abiraterone metabolites. My method distinguished between all the diastereoisomers with conventional chromatographic conditions. In chapter III and IV my validated LC-MS/MS method was utilized to study the metabolism of abiraterone in vitro using prostate cancer cell lines and in vivo using mice. It also helped in determining abiraterone metabolites in a pharmacokinetic trial in healthy human subjects and in prostate cancer patients enrolled in several clinical trials. The trials aimed to evaluate the standard dose of abiraterone acetate, combining abiraterone acetate with androgen deprivation therapy (ADT), adding dutasteride (an SRD5A inhibitor), or increasing the frequency of the standard dose of abiraterone acetate. In chapter V, galeterone metabolism was studied in vitro and in vivo and the metabolites’ activities were evaluated for their roles in prostate cancer. Chapter VI discusses the overall conclusions and future directions. This project identified a new subset of abiraterone and galeterone metabolites that are generated by steroidogenic enzyme conversion. These metabolites had opposing effects on prostate cancer. These findings suggest a common pathway for steroidal drugs with a Δ5, 3ß-hydroxyl structure. This project also provides new strategies in prostate cancer treatment that will make the current treatment options more beneficial

CatchIt: Capturing Cues of Bookmarked Moment to Feed Digital Parrot

CatchIt is a mobile application which aims to capture information about moments in a user’s life in a semi-automatic way. The captured moments are then ready to be fed into an augmented memory system for later retrieval. In CatchIt, the time and location contexts of the captured moment will be saved automatically from the system and GPS respectively once the user bookmarks the moment with the ability of modifying them later; whereas the desired other context, people, will be saved manually. The user of CatchIt also can capture further details (contents) of the moments by different ways: taking notes (textual information), taking photo, recording video, and recording audio. Additionally, the user can revise an earlier moment if the user wishes to. Later on, the user can transfer the selective bookmarked moments into the augmented memory system called the Digital Parrot. The implementation of CatchIt is the central focus of this study. To do so, the requirements of CatchIt are specified based on results of a previous study and from a scenario. The conceptual architecture and the user interface of CatchIt are designed according to the CatchIt requirements. The user interface is implemented in addition to the database where is the captured information from the user interface will be stored in and retrieved from. Evaluating the usability of CatchIt will come next. In the evaluation, the study will involve three sessions: (1) initial questionnaire to know more about the preferred capturing ways of different scenarios, (2) testing the applications where an existing mobile application, Hansel, will be tested for the same length of testing CatchIt (one week for each) and (3) a guided interview which will extract the usability of CatchIt comparing with Hansel on one hand and adding a new contact to the phone using the application Contacts. An additional goal of the last session of the study will be to extract the feeling and the interests of using CatchIt. The results of this study indicated the user interface of CatchIt needs to be even easier to use. The findings of the study form the foundation for further work to improve the user interface of CatchIt and to understand more of the user needs of such mobile capturing application

Old World cutaneous leishmaniasis treatment response varies depending on parasite species, geographical location and development of secondary infection

Background: In the Kingdom of Saudi Arabia (KSA), Leishmania major and L. tropica are the main causative agents of Old World cutaneous leishmaniasis (CL). The national CL treatment regimen consists of topical 1% clotrimazole/2% fusidic acid cream followed by 1–2 courses of intralesional sodium stibogluconate (SSG); however, treatment efficacy is highly variable and the reasons for this are not well understood. In this study, we present a complete epidemiological map of CL and determined the efficacy of the standard CL treatment regime in several endemic regions of KSA.Results: Overall, three quarters of patients in all CL-endemic areas studied responded satisfactorily to the current treatment regime, with the remaining requiring only an extra course of SSG. The majority of unresponsive cases were infected with L. tropica. Furthermore, the development of secondary infections (SI) around or within the CL lesion significantly favoured the treatment response of L. major patients but had no effect on L. tropica cases.Conclusions: The response of CL patients to a national treatment protocol appears to depend on several factors, including Leishmania parasite species, geographical location and occurrences of SI. Our findings suggest there is a need to implement alternative CL treatment protocols based on these parameters

Aerobic and facultative anaerobic bacteria from gut of red palm weevil (Rhynchophorus ferrugineus)

Red palm weevil (RPW), Rhynchophorus ferrugineus Oliver is one of the insects that attack date palm trees directly and cause its death. This infection poses serious economical consequences in SaudiArabia and other gulf countries. RPW assimilates the components of palm tree tissues. Significant amount of microbiota in the gut of RPW may contribute to success of its pathogenesis. This studyexplored the nature of microbiota in RPW by culture-dependent and molecular-based techniques using PCR and sequencing analysis. Larvae of RPW were fed on an artificial diet and were fixed beforeopening its gut for microbial cultivation on enrichment media. Pure cultures were obtained after incubating the plates at different atmospheric conditions (aerobic, and strictly anaerobic). The majorityof isolated microbiota observed were aerobes and facultative anaerobes (Bacillus sp., Salmonella sp., Enterococcus sp., and Xanthomonas sp.). These qualitative differences of bacteria, suggest the presence of a complex ecosystem in the gut of RPW. Subsequently, bacterial DNAs were extracted from pure cultures for definitive molecular identifications. Hot start-touchdown PCR was performed toamplify regions within 16S rDNA. Amplicons were cloned into the TOPO-TA vector for sequencing. The data reveal to some extent that aerobic and facultative anaerobic bacteria are more distributed in the gut of RPW