1,269 research outputs found

    Evaluation of DSS-14 pedestal-review of top surface repair procedures

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    Proposed repair procedures for the top surface of the pedestal supporting the hydrostatic bearing runner for the 64m Antenna are presented. These procedures included: (1) removal of existing grout and concrete to approximately 8 in. below original concrete surface using a presplitting technique with expansive cement followed by secondary breaking; (2) preparation of exposed concrete surface including an epoxy bonding agent; and (3) replacement of material removed with 8 in. of new concrete surface including an epoxy bonding agent; and (4) replacement of material removed with 8 in. of new concrete and 4 in. of new grout

    Case Study of Stratified Chilled Water Storage Utilization for Comfort and Process Cooling in a Hot, Humid Climate

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    The advantages of thermal storage are enhanced in hot and humid climates. Year-round cooling loads increase thermal storage operating cost savings. The absence of a long winter during which major maintenance tasks can be accomplished without compromising system reliability increases the importance of thermal storage as back-up capacity. In an industrial setting, operating cost savings due to thermal storage go directly to the bottom line of a manufacturing process and the avoidance of lost production due to process cooling outages can save millions of dollars per year. This paper presents a case study of chilled water storage use at the campus of a major US electronics manufacturer located in Dallas, TX. An overview of the system and its operation is followed by presentation of operating data taken during 1997

    UNIVERSAL RODENT CONTAMINATION PROTECTION COVER PLATE FOR NATURAL CONVECTION PRODUCTS

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    Techniques are presented herein that support a universal rodent contamination cover plate for natural convection products. Aspects of the presented techniques encompass a top cover with integrated magnets that may be attached to the top of a piece of equipment (e.g., on-demand, within a poorly managed environment) thus not adding an extra cost to a base design or to a default field installation. Importantly, a solution according to aspects of the presented techniques is scalable to support all product sizes. Further aspects of the presented techniques will work with all flat surface ferrous metallic chassis (thus staying within the top surface footprint and not interfering with other mounting brackets). Additionally, if an enclosure’s top surface is non-metallic or plastic, an add-on adhesive ferrous metallic plate kit may be applied to the equipment surface so that the magnetic cover may be attached. Under still further aspects of the presented techniques, one cover plate stock keeping unit (SKU) may support many products if a chassis width is approximately the same given a certain limit range of depth

    New Measurement of the Cosmic-Ray Positron Fraction from 5 to 15 GeV

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    We present a new measurement of the cosmic-ray positron fraction at energies between 5 and 15 GeV with the balloon-borne HEAT-pbar instrument in the spring of 2000. The data presented here are compatible with our previous measurements, obtained with a different instrument. The combined data from the three HEAT flights indicate a small positron flux of non-standard origin above 5 GeV. We compare the new measurement with earlier data obtained with the HEAT-e+- instrument, during the opposite epoch of the solar cycle, and conclude that our measurements do not support predictions of charge sign dependent solar modulation of the positron abundance at 5 GeV.Comment: accepted for publication in PR

    An experiment for the measurement of the bound-beta decay of the free neutron

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    The hyperfine-state population of hydrogen after the bound-beta decay of the neutron directly yields the neutrino left-handedness or a possible right-handed admixture and possible small scalar and tensor contributions to the weak force. Using the through-going beam tube of a high-flux reactor, a background free hydrogen rate of ca. 3 s−1^{-1} can be obtained. The detection of the neutral hydrogen atoms and the analysis of the hyperfine states is accomplished by Lamb shift source type quenching and subsequent ionization. The constraints on the neutrino helicity and the scalar and tensor coupling constants of weak interaction can be improved by a factor of ten.Comment: 9 pages, 5 figures. Submitted to EPJ

    The QUEST large area CCD camera

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    We have designed, constructed, and put into operation a very large area CCD camera that covers the field of view of the 1.2 m Samuel Oschin Schmidt Telescope at the Palomar Observatory. The camera consists of 112 CCDs arranged in a mosaic of four rows with 28 CCDs each. The CCDs are 600 x 2400 pixel Sarnoff thinned, back-illuminated devices with 13 ”m x 13 ”m pixels. The camera covers an area of 4.6° x 3.6° on the sky with an active area of 9.6 deg_2. This camera has been installed at the prime focus of the telescope and commissioned, and scientific-quality observations on the Palomar-QUEST Variability Sky Survey were started in 2003 September. The design considerations, construction features, and performance parameters of this camera are described in this paper
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