18,249 research outputs found

    Applications of aerospace technology in the public sector

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    Current activities of the program to accelerate specific applications of space related technology in major public sector problem areas are summarized for the period 1 June 1971 through 30 November 1971. An overview of NASA technology, technology applications, and supporting activities are presented. Specific technology applications in biomedicine are reported including cancer detection, treatment and research; cardiovascular diseases, diagnosis, and treatment; medical instrumentation; kidney function disorders, treatment, and research; and rehabilitation medicine

    The Transformation of Energy by Lucifer chacei (Crustacea, Decapoda)

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    A laboratory study of energy transformations by the pelagic decapod crustacean Lucifer chacei was made. Three combined stages were cultured and studied: the protozoea-zoea stages, the combined early and late schizopod stages, and the combined adult stages. Growth rates, dry weight, ash content, and calorific values were determined for each. Number of calories per hour ingested, assimilated, and respired were also determined for each of the combined stages. An energy flow diagram was constructed from the data. Growth from egg to adult took slightly more than 3 weeks. Protozoea-zoea and schizopod stages assimilated 10.1 percent and 10.4 percent of ingested Dunaliella tertiolecta. Adults assimilated 7.7 percent of ingested Dunaliella tertiolecta and approximately 22 percent of ingested Artemia salina nauplii. The data indicate that a change from herbivorous larvae to omnivorous adults may have to occur in the natural environment because the older stages cannot obtain enough energy for growth from phytoplankton alone. When data for all stages were combined, gross growth efficiency and net growth efficiency for Lucifer were approximately 10 percent and 81 percent, respectively

    Technology applications

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    A summary of NASA Technology Utilization programs for the period of 1 December 1971 through 31 May 1972 is presented. An abbreviated description of the overall Technology Utilization Applications Program is provided as a background for the specific applications examples. Subjects discussed are in the broad headings of: (1) cancer, (2) cardiovascular disease, (2) medical instrumentation, (4) urinary system disorders, (5) rehabilitation medicine, (6) air and water pollution, (7) housing and urban construction, (8) fire safety, (9) law enforcement and criminalistics, (10) transportation, and (11) mine safety

    An analysis of I/O efficient order-statistic-based techniques for noise power estimation in the HRMS sky survey's operational system

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    Noise power estimation in the High-Resolution Microwave Survey (HRMS) sky survey element is considered as an example of a constant false alarm rate (CFAR) signal detection problem. Order-statistic-based noise power estimators for CFAR detection are considered in terms of required estimator accuracy and estimator dynamic range. By limiting the dynamic range of the value to be estimated, the performance of an order-statistic estimator can be achieved by simpler techniques requiring only a single pass of the data. Simple threshold-and-count techniques are examined, and it is shown how several parallel threshold-and-count estimation devices can be used to expand the dynamic range to meet HRMS system requirements with minimal hardware complexity. An input/output (I/O) efficient limited-precision order-statistic estimator with wide but limited dynamic range is also examined

    Metallurgy and properties of plasma spray formed materials

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    Understanding the fundamental metallurgy of vacuum plasma spray formed materials is the key to enhancing and developing full material properties. Investigations have shown that the microstructure of plasma sprayed materials must evolve from a powder splat morphology to a recrystallized grain structure to assure high strength and ductility. A fully, or near fully, dense material that exhibits a powder splat morphology will perform as a brittle material compared to a recrystallized grain structure for the same amount of porosity. Metallurgy and material properties of nickel, iron, and copper base alloys will be presented and correlated to microstructure

    Shaped Pupil Lyot Coronagraphs: High-Contrast Solutions for Restricted Focal Planes

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    Coronagraphs of the apodized pupil and shaped pupil varieties use the Fraunhofer diffraction properties of amplitude masks to create regions of high contrast in the vicinity of a target star. Here we present a hybrid coronagraph architecture in which a binary, hard-edged shaped pupil mask replaces the gray, smooth apodizer of the apodized pupil Lyot coronagraph (APLC). For any contrast and bandwidth goal in this configuration, as long as the prescribed region of contrast is restricted to a finite area in the image, a shaped pupil is the apodizer with the highest transmission. We relate the starlight cancellation mechanism to that of the conventional APLC. We introduce a new class of solutions in which the amplitude profile of the Lyot stop, instead of being fixed as a padded replica of the telescope aperture, is jointly optimized with the apodizer. Finally, we describe shaped pupil Lyot coronagraph (SPLC) designs for the baseline architecture of the Wide-Field Infrared Survey Telescope-Astrophysics Focused Telescope Assets (WFIRST-AFTA) coronagraph. These SPLCs help to enable two scientific objectives of the WFIRST-AFTA mission: (1) broadband spectroscopy to characterize exoplanet atmospheres in reflected starlight and (2) debris disk imaging.Comment: 41 pages, 15 figures; published in the JATIS special section on WFIRST-AFTA coronagraph

    Effective Field Theory of pure Gravity and the Renormalization Group

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    The general structure of the renormalization group equations for the low energy effective field theory formulation of pure gravity is presented. The solution of these equations takes a particular simple form if the mass scale of the effective theory is much smaller than the Planck mass (a possibility compatible with the renormalization of the effective theory). A theory with just one free renormalized parameter is obtained when contributions suppressed by inverse powers of the Planck mass are neglected.Comment: latex, 9 pages, minor correction, version publishe

    A search for 183-GHz emission from water in late-type stars

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    A search was made for 183 GHz line emission from water vapor in the direction of twelve Mira and two semiregular variables. Upper limits to the emission are in the range of 2000 to 5000 Jy. It is estimated that thermal emission from the inner regions of late type stellar envelopes will be on the order of ten Jy. Maser emission, according to one model, would be an order of magnitude stronger. From the limited set sampled, the possibility of very strong maser emission at 183 GHz cannot yet be ruled out

    Overlapping-gate buried-channel charge-coupled devices

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    In this letter the advantages of the overlapping-gate buried-channel charged-coupled devices over the 3-phase metal-gate and resistive-gate buried-channel c.c.d. are discussed and pertinent design considerations for the overlapping-gate c.c.d.s are presented
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