52,405 research outputs found

    Relativistic astrophysics

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    The design, experimental testing, and calibration (error analysis) of a high resolution Cerenkov-scintillation detector is presented. The detector is capable of detecting iron isotopes and heavy ions of cosmic rays, and of performing direct measurements of individual neighboring isotopes at charge resolution 26. It utilizes Lexan (trademark) sheets, and has been used in flight packages of balloons and on the Skylab. The detector will be able to provide more information on violet astrophysical processes, such as thermonuclear reactions on neutron stars. Ground support and display equipment which are to be used in conjunction with the detector are also discussed

    Feedback laws for fuel minimization for transport aircraft

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    The Theoretical Mechanics Branch has as one of its long-range goals to work toward solving real-time trajectory optimization problems on board an aircraft. This is a generic problem that has application to all aspects of aviation from general aviation through commercial to military. Overall interest is in the generic problem, but specific problems to achieve concrete results are examined. The problem is to develop control laws that generate approximately optimal trajectories with respect to some criteria such as minimum time, minimum fuel, or some combination of the two. These laws must be simple enough to be implemented on a computer that is flown on board an aircraft, which implies a major simplification from the two point boundary value problem generated by a standard trajectory optimization problem. In addition, the control laws allow for changes in end conditions during the flight, and changes in weather along a planned flight path. Therefore, a feedback control law that generates commands based on the current state rather than a precomputed open-loop control law is desired. This requirement, along with the need for order reduction, argues for the application of singular perturbation techniques

    An annotated checklist of Wisconsin sap and short-winged flower beetles (Coleoptera: Nitidulidae, Kateretidae)

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    A survey of Wisconsin Nitidulidae and Kateretidae yielded 78 species through analysis of literature records, museum and private collections, and three years of field research (2000-2002). Twenty-seven species (35% of the Wisconsin fauna) represent new state records, having never been previously recorded from the state. Wisconsin distribution, along with relevant collecting techniques and natural history information, are summarized. The Wisconsin nitidulid and kateretid faunae are compared to reconstructed and updated faunal lists for Illinois, Indiana, Michigan, Minnesota, Ohio, and south-central Canada. Literature and distributional records suggest at least 11 additional nitidulid species may occur in Wisconsin

    An Annotated Checklist of Wisconsin Handsome Fungus Beetles (Coleoptera: Endomychidae)

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    The first comprehensive survey of Wisconsin Endomychidae was initiated in 1998. Throughout Wisconsin sampling sites were selected based on habitat type and sampling history. Wisconsin endomychids were hand collected from fungi and under tree bark; successful trapping methods included cantharidinbaited pitfall traps, flight intercept traps, and Lindgren funnel traps. Examination of literature records, museum and private collections, and field research yielded 10 species, three of which are new state records. Two dubious records, Epipocus unicolor Horn and Stenotarsus hispidus (Herbst), could not be confirmed. Wisconsin distribution, along with relevant collecting techniques and natural history information, are summarized

    Comparison of Optical, Radio, and Acoustical Detectors for Ultrahigh-Energy Neutrinos

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    For electromagnetic cascades induced by electron-neutrinos in South Pole ice, the effective volume per detector element (phototube, radio antenna, or acoustic transducer) as a function of cascade energy is estimated, taking absorption and scattering into account. A comparison of the three techniques shows that the optical technique is most effective for energies below ~0.5 PeV, that the radio technique shows promise of being the most effective for higher energies, and that the acoustic method is not competitive. Due to the great transparency of ice, the event rate of AGN ne-induced cascades is an order of magnitude greater than in water. For hard source spectra, the rate of Glashow resonance events may be much greater than the rate for non-resonant energies. The radio technique will be particularly useful in the study of Glashow events and in studies of sources with very hard energy spectra.Comment: 22 pages Postscript, including 4 figure

    Surface roughness detector Patent

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    Roughness detector for recording surface pattern of irregularitie

    Grid service orchestration using the Business Process Execution Language (BPEL)

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    Modern scientific applications often need to be distributed across grids. Increasingly applications rely on services, such as job submission, data transfer or data portal services. We refer to such services as grid services. While the invocation of grid services could be hard coded in theory, scientific users want to orchestrate service invocations more flexibly. In enterprise applications, the orchestration of web services is achieved using emerging orchestration standards, most notably the Business Process Execution Language (BPEL). We describe our experience in orchestrating scientific workflows using BPEL. We have gained this experience during an extensive case study that orchestrates grid services for the automation of a polymorph prediction application
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