171 research outputs found

    Multilevel metallization method for fabricating a metal oxide semiconductor device

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    An improved method is described of constructing a metal oxide semiconductor device having multiple layers of metal deposited by dc magnetron sputtering at low dc voltages and low substrate temperatures. The method provides multilevel interconnections and cross over between individual circuit elements in integrated circuits without significantly reducing the reliability or seriously affecting the yield

    High and low threshold P-channel metal oxide semiconductor process and description of microelectronics facility

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    The fabrication techniques and detail procedures for creating P-channel Metal-Oxide-Semiconductor (P-MOS) integrated circuits at George C. Marshall Space Flight Center (MSFC) are described. Examples of P-MOS integrated circuits fabricated at MSFC together with functional descriptions of each are given. Typical electrical characteristics of high and low threshold P-MOS discrete devices under given conditions are provided. A general description of MSFC design, mask making, packaging, and testing procedures is included. The capabilities described in this report are being utilized in: (1) research and development of new technology, (2) education of individuals in the various disciplines and technologies of the field of microelectronics, and (3) fabrication of many types of specially designed integrated circuits which are not commercially feasible in small quantities for in-house research and development programs

    The MSFC complementary metal oxide semiconductor (including multilevel interconnect metallization) process handbook

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    The fabrication techniques for creation of complementary metal oxide semiconductor integrated circuits at George C. Marshall Space Flight Center are described. Examples of C-MOS integrated circuits manufactured at MSFC are presented with functional descriptions of each. Typical electrical characteristics of both p-channel metal oxide semiconductor and n-channel metal oxide semiconductor discrete devices under given conditions are provided. Procedures design, mask making, packaging, and testing are included

    Speech-Language Pathology Graduate Student Clinicians’ Self-Perceived Competency in Dysphagia Management

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    Speech-language pathologists (SLPs) are the preferred healthcare providers for managing the direct clinical care of patients with dysphagia. By assessing self-perceived competency during academic training, SLP graduate student clinicians may increase their understanding of their skills in dysphagia management. We modified the Dysphagia Competency Verification Tool (DCVT) to use a 5-point ordinal scale to explore how SLP graduate student clinicians’ self-perception of competency in dysphagia management changes over time and to determine the impact of clinical practicum experiences. Seventy-two SLP graduate student clinicians rated their self-perceived competency for four DCVT domains. We used Generalized Estimating Equations (GEE) models to analyze the statistical significance of self-perception of competency ratings for each of the DCVT domains across semesters while accounting for clinical practicum experiences. Overall, the SLP graduate student clinicians indicated an increase in DCVT scores from the beginning of their graduate training program to the time of graduation, but did not perceive themselves as Adequate on most items of the DCVT until their last semester. These results suggest that both SLP graduate student clinicians and SLP graduate training programs would benefit from using a standardized metric to assess self-perceived competence in dysphagia management. DCVT self-perceived competency ratings could inform SLP graduate student clinicians about areas of dysphagia management practice and skills that need further development, allowing them to target these specific areas and gain actual competence

    Pathogenesis of trimethyltin neuronal toxicity. Ultrastructural and cytochemical observations.

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    The ultrastructural cytopathologic and cytochemical effects of trimethyltin (TMT) neurotoxicity were delineated in hippocampal and pyriform neurons of acutely intoxicated adult rats. TMT produced neuronal necrosis that preferentially involved hippocampal formation pyriform cortex. The first subcellular alterations were multifocal collection of dense-cored vesicles and tubules and membrane-delimited vacuoles in the cytoplasm of the perikaryon and proximal dendrite. Ultrastructural cytochemical examination revealed that the vesicles and tubules had acid phosphatase activity analagous to Golgi-associated endoplasmic reticulum (GERL). Shortly after the appearance of the GERL-like vesicles and tubules, autophagic vacuoles and polymorphic dense bodies accumulated in the neuronal cytoplasm. Some dense bodies appeared to arise from the dense-cored tubules. Neuronal necrosis was characterized by increased electron density of the cytoplasm and large, electron-dense intranuclear masses. Alterations of mitochondria and other organelles were not observed in the early stages of cell injury. No light- or electron-microscopic alterations were found in liver or kidney. Comparable subcellular alterations were observed in adult and neonatal rats chronically intoxicated with TMT. A series of other trialkyl and tricyclic tins and dimethyltin did not produce similar pathologic findings. The GERL-like accumulations are unique in neuronal cytopathology. These findings suggests that GERL and autophagy play an important role in the pathogenesis of TMT-induced neuronal injury

    The Physics of the B Factories

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    This work is on the Physics of the B Factories. Part A of this book contains a brief description of the SLAC and KEK B Factories as well as their detectors, BaBar and Belle, and data taking related issues. Part B discusses tools and methods used by the experiments in order to obtain results. The results themselves can be found in Part C

    TRAPPIST Habitable Atmosphere Intercomparison (THAI) workshop report

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    This is the final version. Available on open access from IOP Publishing via the DOI in this recordThe era of atmospheric characterization of terrestrial exoplanets is just around the corner. Modeling prior to observations is crucial in order to predict the observational challenges and to prepare for the data interpretation. This paper presents the report of the TRAPPIST Habitable Atmosphere Intercomparison (THAI) workshop (14-16 September 2020). A review of the climate models and parameterizations of the atmospheric processes on terrestrial exoplanets, model advancements and limitations, as well as direction for future model development was discussed. We hope that this report will be used as a roadmap for future numerical simulations of exoplanet atmospheres and maintaining strong connections to the astronomical community
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