4,115 research outputs found

    Gamma rays of 0.3 to 30 MeV from PSR 0531+21

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    Pulsed gamma rays from the Crab Pulsar PSR 0531+21 are reported for energies of 0.3 to 30 MeV. The observations were carried out with the UCR gamma ray double Compton scatter telescope launched on a balloon from Palestine, Texas at 4.5 GV, at 2200 LT, September 29, 1978. Two 8 hr observations of the pulsar were made, the first starting at 0700 UT (0200 LT) September 30 just after reaching float altitude of 4.5 g/sq cm. Analysis of the total gamma ray flux from the Crab Nebula plus pulsar using telescope vertical cell pairs was published previously. The results presented supersede the preliminary ones. The double scatter mode of the UCR telescope measures the energy of each incident gamma ray from 1 to 30 MeV and its incident angle to a ring on the sky. The time of arrival is measured to 0.05 ms. The direction of the source is obtained from overlapping rings on the sky. The count rate of the first scatter above a threshold of 0.3 MeV is recorded every 5.12 ms. The Crab Pulsar parameters were determined from six topocentric arrival times of optical pulses

    The Commercial Preparation of Oxygen from Lime and Chlorine

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    The reaction of chlorine on a suspension of lime in the presence of suitable catalysts, such as nickel, cobalt and iron salts, has been studied. It was found that the optimum temperature is 94° C.; that the greatest unit efficiency of the catalyst, nickel nitrate, is obtained at a concentration of.02 g. per 100 c.c; that the rate of generation of oxygen is almost directly proportional to the rate of flow of the chlorine and that nickel and cobalt salts are distinctly superior to all other catalysts which were used. In addition it has been found that the catalyst is not easily poisoned, and may be used throughout a number of runs

    Personal Selling: A Humanist Perspective

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    Association of Marketing Theory and Practice Proceedings 2014

    A Risk Analysis of Carbon Sequestration in Claypan Soil with Conservation Tillage Systems and Nitrogen Fertilizers for Grain Sorghum and Soybean

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    Replaced with revised version of paper 02/15/06.carbon sequestration, carbon credits, nitrogen, risk, tillage, Crop Production/Industries, Risk and Uncertainty, Q12,

    Measured performance of the new University of California gamma ray telescope

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    The design of the new medium energy balloon-borne gamma ray telescope is discussed. This telescope is sensitive to 1-30 MeV gamma rays. The results of the initial calibration are described. The position and energy resolutions of 32 plastic and NaI(Tl) scintillator bars, each 100 cm long are discussed. The telescope's measured angular and energy resolutions as a function of incident angle are compared with detailed Monte Carlo calculations at 1.37, 2.75 and 6.13 MeV. The expected resolutions are 5 deg FHWM and 8% at 2.75 MeV. The expected area-efficiency is 250 cm

    Selective and Differential Feeding on Marine Prokaryotes by Mucous Mesh Feeders

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    Microbial mortality impacts the structure of food webs, carbon flow, and the interactions that create dynamic patterns of abundance across gradients in space and time in diverse ecosystems. In the oceans, estimates of microbial mortality by viruses, protists, and small zooplankton do not account fully for observations of loss, suggesting the existence of underappreciated mortality sources. We examined how ubiquitous mucous mesh feeders (i.e. gelatinous zooplankton) could contribute to microbial mortality in the open ocean. We coupled capture of live animals by blue-water diving to sequence-based approaches to measure the enrichment and selectivity of feeding by two coexisting mucous grazer taxa (pteropods and salps) on numerically dominant marine prokaryotes. We show that mucous mesh grazers consume a variety of marine prokaryotes and select between coexisting lineages and similar cell sizes. We show that Prochlorococcus may evade filtration more than other cells and that planktonic archaea are consumed by macrozooplanktonic grazers. Discovery of these feeding relationships identifies a new source of mortality for Earth\u27s dominant marine microbes and alters our understanding of how top-down processes shape microbial community and function

    The Production of Chloropicrin as Needed from Dry Mixtures of Picric Acid and Bleaching Powder

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    Chloropicrin or trichloromethane is a colorless liquid boiling at l 12°C and having a specific gravity of 1.69. It was first prepared by Stenhouse from picric acid and bleaching powder. Its first use was in chemical warfare by the Allied troops in 1918. It was prepared in large quantities at Edgewood Arsenal during the World War, by the method developed and patented by the senior author. Picric acid, hydrated lime, and water were mixed to form a calcium picrate suspension. This suspension together with a suspension of bleaching powder and water was run into a still. The chloropicrin was steam-distilled off
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