5,190 research outputs found

    Performance of a C4F8O Gas Radiator Ring Imaging Cherenkov Detector Using Multi-anode Photomultiplier Tubes

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    We report on test results of a novel ring imaging Cherenkov (RICH) detection system consisting of a 3 meter long gaseous C4F8O radiator, a focusing mirror, and a photon detector array based on Hamamatsu multi-anode photomultiplier tubes. This system was developed to identify charged particles in the momentum range from 3-70 GeV/c for the BTeV experiment.Comment: 28 pages, 23 figures, submitted to Nuclear Instruments and Method

    Hydrographic features off northeast coast and Andaman - Nicobar Islands in relation to demersal finfish resources

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    Temperature varied from 17.6 to 28.5°C, salinity values from 32.12 to 35.21 x 10"" and dissolved oxygen from 0.8 to 4.41 ml/1. No identifiable relationship could be established between these three parameters and the total fish abundance, probably because the catch was made up of many species having different requirements. Higher abundance of trawl catches was from January to May when bottom water temperature was relatively low. The highest level of abundance of 2764 kg/hr in February 1989 was recorded when the parameters were 26°C, 33.6 x 10" and 2.71 ml/1; and the lowest level of 43.2 kg/hr in July 1988 was when the parameters were 25.3°C, 34.48 x 10'^ and 1.6 ml/1

    Salinity changes in the estuary and the coastal sea adjacent to the portmouth at Cochin

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    The article deals with the details of salinity changes in the Cochin estuary and its influence and interrelations with the Vembanad lake

    A Novel Algorithm for Cooperative Spectrum Sensing in Cognitive Radio Networks

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    The rapid growth in wireless communication technology has led to a scarcity of spectrum. But, studies are saying that licensed spectrum is underutilized. Cognitive Radio Networks (CRNs) seem to be a promising solution to this problem by allowing unlicensed users to access the unused spectrum opportunistically. In this paper we proposed a novel spectrum sensing algorithm to improve the probabilities of detection and false alarm in a CRN, using the traditional techniques of energy and first order correlation detection. Results show a significant improvement in performance in cooperative spectrum sensing

    Fish biomass estimation by calibrating the echointegrator deflection against catch data

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    Acoustic survey for fish resources was conducted using echosounder (EK-400) with echointegrator (QD). The echointegrator coupled with echosounder sums-up the echo signal received. The sum of the echo signal received per nautical mile covered is an index of the quantum of fish recorded and therefore a measure of the relative density of fish in surveyed area. It is converted into absolute biomass using the calibrarion constant obtained by correlating the trawl catch data against the echointegrator reading corresponding to the opening of the net. The calibration constant thus arrived at was 1327 kg/n.mile corresponding to 1 mm integrator deflection per nautical mile covered
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