84,367 research outputs found

    HTS quasiparticle injection devices with large current gain at 77 K

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    Recent progress on the development of planar QP-injection devices using YBCO and STO as an epitaxial injection barrier will be discussed. The main problem for HTS injection devices is to grow reliably a well defined, ultra-thin tunneling barrier suitable for QP tunneling. For this purpose, we used inverted cylindrical magnetron sputtering to first optimize the smoothness of our YBCO films by controlling tightly an relevant sputtering conditions. We are able to prepare smooth (001) YBCO films on (001) STO substrates on a routine basis with an average roughness varying between 1 and 2 nm. With these flat YBCO films both planar as well as grain boundary junctions were fabricated using epitaxial STO barriers between 2 and 8 nm thick and a 50 nm of Au counter electrode. Planar junctions with 6 nm STO barriers were in most cases fully insulating, in some cases, a current gain of up to 7.4 at 77 K was obtained. For 3 nm STO barriers, the highest current gain was 15 at 81 K. The injection results also show a scaling behavior with junction size. Based on the present materials development and device understanding, we consider a current gain of up to 20 at 77 K possibl

    When is 0.999... equal to 1?

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    A doubly infinite sum, numerically evaluated at between 0.999 and 1.001, turns out to have a nice value

    The NOAA/NESS program for operational snowcover mapping: Preparing for the 1980's

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    There are no author-identified significant results in this report

    NOAA satellite programs and technology requirements

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    Information concerning NOAA satellite programs is presented in vugraph form. The following topics are discussed: NOAA's space philosophy, the NESDIS FY-93 budget summary, LANDSAT program status, a history of geostationary satellites, the GOES program, current GOES instruments, improved GOES capabilities, polar orbiters, a history of TIROS R&D satellites, a history of ESSA operational satellites, a history of ITOS/NOAA satellites, and a history of TIROS-N/NOAA satellites

    The operational program of satellite snowcover observations at NOAA/NESS

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    The operational river basin snow mapping program at NESS is described with emphasis on quality control techniques and results for the 1974-1975 snow season

    Electronic detection of weak spectrum links

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    Recording spectroscopic data by digital and analog electronic systems - Detection of weak spectrum line

    Photoelectric Detection of Weak Spectrum Lines

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    Photoelectric detection of weak spectral lines by application of digital and gated filter electronic devices to optical spectrometr

    Threaded pilot insures cutting tool alignment

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    Threaded pilot allows machining of a port component, or boss, after the reciprocating hole has been threaded. It is used to align cutting surfaces with the boss threads, thus insuring precision alignment
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