79 research outputs found

    Analytical study of electrical disconnect system for use on manned and unmanned missions

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    The objective of this contract is to establish an optimum electrical disconnect system design(s) for use on manned and unmanned missions. The purpose of the disconnect system is to electrically mate and demate the spacecraft to subsystem module interfaces to accomplish orbital operations. The results of Task 1 and Task 2 of the effort are presented. Task 1 involves the definition of the functional, operational, and environmental requirements for the connector system to support the leading prototype candidate concepts. Task 2 involves the documentation review and survey of available existing connector designs

    Space station definition and preliminary design, WP-01. Volume 1: Executive summary

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    System activities are summarized and an overview of the system level engineering tasks performed are provided. Areas discussed include requirements, system test and verification, the advanced development plan, customer accommodations, software, growth, productivity, operations, product assurance and metrication. The hardware element study results are summarized. Overviews of recommended configurations are provided for the core module, the USL, the logistics elements, the propulsion subsystems, reboost, vehicle accommodations, and the smart front end. A brief overview is provided for costing activities

    Space station definition and preliminary design, WP-01. Volume 2: Results

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    The basis for the studies and analyses which led to the results and conclusions documented and summarized, was the Engineering Master Schedule (EMS) generated by NASA and used as the controlling set of milestones and associated activities required to produce in a timely manner those products needed by all program participants in the establishment of an approved program baseline. The EMS consisted of twenty themes grouped into categories covering requirements, configurations, and strategies. A number of studies and analyses that were coordinated with the MSFC program and technical personnel as being needed to provide the requisite back-up material to satify the EMS were identified. These studies and analyses provided the data sufficient to support the conclusions and recommendations given to the MSFC in response to their EMS activity and to support the system level and conceptual design level approaches developed and reflected in the detailed sections of this document

    Manned maneuvering unit: User's guide

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    The space shuttle will provide an opportunity to extend and enhance the crew's inherent capabilities in orbit by allowing them to operate effectively outside of their spacecraft by means of extravehicular activity. For this role, the shuttle crew will have a new, easier to don and operate space suit with integral life support system, and a self-contained propulsive backpack. The backpack, called the manned maneuvering unit, will allow the crew to operate beyond the confines of the Shuttle cargo bay and fly to any part of their own spacecraft or to nearby free-flying payloads or structure. This independent mobility will be used to support a wide variety of activities including free-space transfer of cargo and personnel, inspection and monitoring of orbital operations, and construction and assembly of large structures in orbit

    Modification of an astronaut's mock up tool kit Final report

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    Design and tests of astronauts tool kit and tools for in-flight space maintenanc

    MODELISATION DE L'INFLUENCE DU TRAITEMENT THERMIQUE SUR LES PROPRIETES MECANIQUES DES ALLIAGES ALUMINIUM-CUIVRE (Al-Cu)

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    In order to master and improve the quality and properties of the final products, the major industrial challenge lies in the possibility of controlling the morphology, size of microstructures that reside within the molded pieces, as well as their defects; this is the fundamental reason according to which we are more and more interested in mastering the growth and germination of such alloys, as well as the developing structures, at the time of solidification process. The modeling reveals as a valuable aid in the mastery of the formation of such heterogeneousness: segregation cells that are incompatible with industrial requirements. The whole work focuses upon the modeling of the segregation phenomenon of the four hypoeutectic alloys, Al1%Cu, Al2%Cu, Al3%Cu et Al4%Cu, as well as the copper effect upon certain mechanical properties of aluminum. Usually, the microstructure and mechanical behavior of such alloys as Al-Cu are directly influenced by some parameters such as composition, cooling velocity and homogenization process

    STUDI KERAGAMAN JENIS DAN POLA AKTIVITAS HARIAN LALAT DI PETERNAKAN SAPI SEMI EKSTENSIF DI KELURAHAN TUATUKA KECAMATAN KUPANG TIMUR KABUPATEN KUPANG

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    Tujuan Penelitian ini dilakukan untuk mengetahui keragaman jenis, pola aktivitas  lalat dan hubungannya dikaitkan dengan suhu, musim, serta jenis kelamin. Penelitian di peternakan sapi semi ektensif kelurahan tuatuka Kecamatan Kupang Timur, Kabupaten Kupang, Nusa Tenggara Timur. Sampel  lalat dikoleksi menggunakan New Zealand 1 trap di peternakan sapi. Perangkap dipasang secara random langsung di lokasi padang penggembalaan, sedangkan di kandang, perangkap ditempatkan pada jarak 3-5 meter dari pagar pembatas kandang. Perangkap dipasang pada jarak kurang lebih 10-15 cm di atas permukaan tanah. Pengumpulan  sampel lalat dilakukan dalam interval waktu satu jam sejak pemasangan, yaitu pukul 09;00, 10;00, 11;00, 12;00, 14;00 dan pukul 15;00. Lalat dikumpulkan dan dieuthanasia dengan alkohol 70%, kemudian di identifikasi  menurut spesies dengan kunci identifikasi menurut  Scott et al (1967) dan  Dodge (1967), selanjutnya data  dianalisa secara deskriptif

    Pseudomonas aeruginosa biofilm is a potent inducer of phagocyte hyperinflammation

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    OBJECTIVE: Pseudomonas aeruginosa effectively facilitate resistance to phagocyte killing by biofilm formation. However, the cross talk between biofilm components and phagocytes is still unclear. We hypothesize that a biofilm provides a concentrated extracellular source of LPS, DNA and exopolysaccharides (EPS), which polarize neighbouring phagocytes into an adverse hyperinflammatory state of activation. METHODS: We measured the release of a panel of mediators produced in vitro by murine neutrophils and macrophages exposed to various biofilm components of P. aeruginosa cultures. RESULTS: We found that conditioned media from a high biofilm-producing strain of P. aeruginosa, PAR5, accumulated high concentrations of extracellular bacterial LPS, DNA and EPS by 72 h. These conditioned media induced phagocytes to release a hyperinflammatory pattern of mediators, with enhanced levels of TNF-α, IL-6, IL12p40, PGE2 and NO. Moreover, the phagocytes also upregulated COX-2 and iNOS with no influence on the expression of arginase-1. CONCLUSIONS: Phagocytes exposed to biofilm microenvironment, called by us biofilm-associated neutrophils/macrophages (BANs/BAMs), display secretory properties similar to that of N1/M1-type phagocytes. These results suggest that in vivo high concentrations of LPS and DNA, trapped in biofilm by EPS, might convert infiltrating phagocytes into cells responsible for tissue injury without direct contact with bacteria and phagocytosis

    Intestinal Microbiota Composition of Interleukin-10 Deficient C57BL/6J Mice and Susceptibility to Helicobacter hepaticus-Induced Colitis

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    The mouse pathobiont Helicobacter hepaticus can induce typhlocolitis in interleukin-10-deficient mice, and H. hepaticus infection of immunodeficient mice is widely used as a model to study the role of pathogens and commensal bacteria in the pathogenesis of inflammatory bowel disease. C57BL/6J Il10[superscript −/−] mice kept under specific pathogen-free conditions in two different facilities (MHH and MIT), displayed strong differences with respect to their susceptibilities to H. hepaticus-induced intestinal pathology. Mice at MIT developed robust typhlocolitis after infection with H. hepaticus, while mice at MHH developed no significant pathology after infection with the same H. hepaticus strain. We hypothesized that the intestinal microbiota might be responsible for these differences and therefore performed high resolution analysis of the intestinal microbiota composition in uninfected mice from the two facilities by deep sequencing of partial 16S rRNA amplicons. The microbiota composition differed markedly between mice from both facilities. Significant differences were also detected between two groups of MHH mice born in different years. Of the 119 operational taxonomic units (OTUs) that occurred in at least half the cecum or colon samples of at least one mouse group, 24 were only found in MIT mice, and another 13 OTUs could only be found in MHH samples. While most of the MHH-specific OTUs could only be identified to class or family level, the MIT-specific set contained OTUs identified to genus or species level, including the opportunistic pathogen, Bilophila wadsworthia. The susceptibility to H. hepaticus-induced colitis differed considerably between Il10[superscript −/−] mice originating from the two institutions. This was associated with significant differences in microbiota composition, highlighting the importance of characterizing the intestinal microbiome when studying murine models of IBD.National Institutes of Health (U.S.) (Grant NIH P01-CA26731)National Institutes of Health (U.S.) (Grant NIH P30ES0026731)National Institutes of Health (U.S.) (Grant NIH R01-OD011141
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