2,550 research outputs found

    Test status and experience with the 7.5 megawatt Mod-2 wind turbine cluster

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    The Mod-2 wind turbine cluster is described. The site preparation and construction activities are discussed, and preliminary test results, status, and plans are presented

    A Study of a Mini-drift GEM Tracking Detector

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    A GEM tracking detector with an extended drift region has been studied as part of an effort to develop new tracking detectors for future experiments at RHIC and for the Electron Ion Collider that is being planned for BNL or JLAB. The detector consists of a triple GEM stack with a small drift region that was operated in a mini TPC type configuration. Both the position and arrival time of the charge deposited in the drift region were measured on the readout plane which allowed the reconstruction of a short vector for the track traversing the chamber. The resulting position and angle information from the vector could then be used to improve the position resolution of the detector for larger angle tracks, which deteriorates rapidly with increasing angle for conventional GEM tracking detectors using only charge centroid information. Two types of readout planes were studied. One was a COMPASS style readout plane with 400 micron pitch XY strips and the other consisted of 2x10mm2 chevron pads. The detector was studied in test beams at Fermilab and CERN, along with additional measurements in the lab, in order to determine its position and angular resolution for incident track angles up to 45 degrees. Several algorithms were studied for reconstructing the vector using the position and timing information in order to optimize the position and angular resolution of the detector for the different readout planes. Applications for large angle tracking detectors at RHIC and EIC are also discussed.Comment: Submitted to the IEEE Transactions on Nuclear Scienc

    The spotlight effect and the illusion of transparency in social anxiety

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    [Clark, D. M., & Wells, A. (1995). A cognitive model of social phobia. In: R. G. Heimberg, M. R. Liebowitz, D. A. Hope, & F. R. Schneier (Eds.), Social phobia: diagnosis, assessment, and treatment (pp. 69–93). New York: Guildford Press] cognitive model of social phobia suggests that both public and private sources of information contribute to the construction of the self as a social object, which is thought to maintain the disorder. This study used two concepts developed in social psychology that might help to explain the processes that contribute to the development of this constructed self. These two concepts are the spotlight effect [Gilovich, T., Medvec, V. H., & Savitsky, K. (2000). The spotlight effect in social judgment: an egocentric bias in estimates of the salience of one’s own actions and appearance. Journal of Personality and Social Psychology, 78(2), 211–222] and the illusion of transparency [Gilovich, T., Medvec, V. H., & Savitsky, K. (1998). The Illusion of transparency: biased assessments of others’ ability to read one’s own emotional states. Journal of personality and social psychology, 75(2), 332–346]. Participants performed a memory task under either a low or a high social-evaluative condition. In the high social-evaluative condition, participants reported higher levels of the spotlight effect and more negative evaluation of task performance, compared to participants in the low social-evaluative condition. There were no differences between the two conditions in levels of the illusion of transparency. Surprisingly, however, in the low socialevaluative condition, participants reported higher levels of the illusion of transparency than the spotlight effect, whereas, in the high social-evaluative condition, they reported the opposite. Results suggest that the spotlight effect may be specific to social-evaluative concerns, whereas, the illusion of transparency may represent more general features of social anxiety concerns. Implications of the results for Clark and Wells’ cognitive model of social phobia model are discussed

    ANALISA JENIS MANGROVE MENGGUNAKAN CITRA UAV DENGAN KLASIFIKASI OBIA

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    The difficulty of the inventory carried out in the mangrove forest area is due to the vast expanse of ​​mangrove forests with a high-density level, so it must use High-Resolution Satellite Imagery (CSRT) which requires high costs. The approach to processing very high-resolution images is the object-based approach (OBIA). UAV technology development using cameras mounted on UAVs has been widely used in forest inventories that have benefits, low costs, and high flexibility. Therefore, this study aims to analyze the types of mangroves using UAV images with OBIA classification and calculate the tree canopy height model in mangrove forests. The results showed that the accuracy-test used a confusion matrix with Producer accuracy for BG 78%, CT 97%, RS 96.63%, RA 91.04%. In comparison, the user accuracy for BG is 88.89%, CT 97.73%, RS 97.73%, and RA 85%. Thus the overall efficiency is 92.98%

    Exposure damage mechanisms for KCl windows in high power laser systems

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    An experimental study of the 10.6 micrometer and 0.6328 micrometer optical properties of single crystal and europium doped polycrystal is described. Significant variations in the optical properties are observed over periods of exposure up to 100 hours. Models are proposed to predict the 10.6 micrometer absorptivity for long exposure periods. Mechanical creep has been detected in both materials at high temperature

    A λ = 1.3 Millimeter Aperture Synthesis Molecular Line Survey of Orion Kleinmann-Low

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    We present a 1".3 spatial resolution interferometric spectral line survey of the core of the Orion molecular cloud, obtained with the OVRO millimeter array. Covering 4 GHz bandwidth in total, the survey contains ~100 emission lines from 18 chemical species. The spatial distributions of a number of molecules point to source I near the IRc2 complex as the dominant energy source in the region but do not rule out the presence of additional lower luminosity objects. At arcsecond resolution, the offsets between dust emission and various molecular tracers suggest that the spectacular "hot core" emission in the Orion core arises via the heating and ablation of material from the surfaces of very high density clumps located ≳500 AU from source I and traced by the dust emission. We find no evidence for a strong internal heating source within the hot core condensation(s)

    Construction and Expected Performance of the Hadron Blind Detector for the PHENIX Experiment at RHIC

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    A new Hadron Blind Detector (HBD) for electron identification in high density hadron environment has been installed in the PHENIX detector at RHIC in the fall of 2006. The HBD will identify low momentum electron-positron pairs to reduce the combinatorial background in the e+ee^{+}e^{-} mass spectrum, mainly in the low-mass region below 1 GeV/c2^{2}. The HBD is a windowless proximity-focusing Cherenkov detector with a radiator length of 50 cm, a CsI photocathode and three layers of Gas Electron Multipliers (GEM). The HBD uses pure CF4_{4} as a radiator and a detector gas. Construction details and the expected performance of the detector are described.Comment: QM2006 proceedings, 4 pages 3 figure

    The Cornell Caltech Atacama Telescope status and technical progress

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    Five partners have currently joined a Consortium to develop the Cornell Caltech Atacama Telescope (CCAT.) Included are Cornell University, the California Institute of Technology (Caltech), the University of Colorado at Boulder, the United Kingdom as represented by the Astronomy Technology Centre (ATC), and Canada as represented by the Universities of British Columbia and Waterloo. This consortium has continued work toward the design of the telescope and instrumentation, pursued fund raising, and further developed the science case for CCAT. An Engineering Design Phase is being planned for 2009-2011 with construction planned to begin shortly thereafter. CCAT continues as a wide field (20 arc min) FOV telescope operating from a shortest wavelength of 200µ. Testing has continued near the summit of Cerro Chajnantor in the Atacama Region of Chile above 5600 meters altitude and data indicates significantly lower water vapor in the seeing column than measured at the ALMA site on the plateau below. Work over the past two years has included research on manufacturing methods for optical segments, extensive study of mirror alignment sensing and control techniques, additional concepts for major structures, and further development of instrumentation
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