36,912 research outputs found

    MASSCLEAN - MASSive CLuster Evolution and ANalysis Package - Description, Tests, and Results

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    MASSCLEAN is a new, sophisticated and robust stellar cluster image and photometry simulation package. This package is able to create color-magnitude diagrams and standard FITS images in any of the traditional optical and near-infrared bands based on cluster characteristics input by the user, including but not limited to distance, age, mass, radius and extinction. At the limit of very distant, unresolved clusters, we have checked the integrated colors created in MASSCLEAN against those from other simple stellar population (SSP) models with consistent results. Because the algorithm populates the cluster with a discrete number of tenable stars, it can be used as part of a Monte Carlo Method to derive the probabilistic range of characteristics (integrated colors, for example) consistent with a given cluster mass and age. We present the first ever mass dependent integrated colors as a function of age, derived from over 100,000 Monte Carlo runs, which can be used to improve the current age determination methods for stellar clusters.Comment: 4 pages, 5 figures, Proceedings International Astronomical Union Symposium No. 266, Star Clusters - Basic Galactic Building Blocks throughout Time and Space, Editors: Richard de Grijs & Jacques R. D. Lepin

    The Closed Booth

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    Turbo-machine blade vibration damper Patent

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    Blade vibration damping pins for turbomachiner

    Feasibility of Kevlar 49/PMR-15 Polyimide for High Temperature Applications

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    Kevlar 49 aramid organic fiber reinforced PMR-15 polyimide laminates were characterized to determine the applicability of the material to high temperature aerospace structures. Kevlar 49/3501-6 epoxy laminates were fabricated and characterized for comparison with the Kevlar 49/PMR-15 polyimide material. Flexural strengths and moduli and interlaminar shear strengths were determined from 75 F to 600 F for the PMR-15 and from 75 F to 450 F for the Kevlar/3501-6 epoxy material. The effects of hydrothermal and long-term elevated temperature exposures on the flexural strengths and moduli and the interlaminar shear strengths were also studied

    Static and dynamic fatigue behavior of glass filament-wound pressure vessels at ambient and cryogenic temperatures

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    Static and dynamic fatigue behavior of glass filament-wound plastic pressure vessels at ambient and cryogenic temperature

    Surface protection of graphite fabric/PMR-15 composites subjected to thermal oxidation

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    Graphite fabric/PMR-15 laminates develop matrix cracks during long-term exposure in air at temperatures in the range of 500 to 600 F. This study was performed to demonstrate the effectiveness of incorporating graphite mat surface plies as a means of reducing the developing of matrix cracks. Celion 3000 graphite fabric/PMR-15 laminates were fabricated with graphite or graphite mat/325-mesh boron powder surface plies. Laminates without mat surface plies were also fabricated for control purposes. Composite flexural strength, flexural modulus, and interlaminar shear strength were determined at 288 C before and after long-term exposure (up to 1500 hr) in air at 316 C. The results of this study showed that the incorporation of graphite mat surface plies reduces matrix cracking and improves the elevated temperature mechanical property retention characteristics of the composites

    The impact of information and communication technology on family carers of older people and professionals in Sweden

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    Government policy in Sweden, as in other developed countries, pays increasing attention as to how best to support the family carers of older people. New and innovative means of support, such as information and communication technology, are emerging. This paper explores the perceived benefits of, and barriers to, information technology as a means of supporting family carers of older people. Following a brief overview of the care-giving literature, with particular reference to the Swedish context, interview and questionnaire data collected from 34 families who took part in the Swedish ACTION project are used to explore the role of user-friendly information and communication technology to inform and enable family carers of older people to exercise choice, to care more effectively and to work in partnership with professionals. Interview data from two groups of professionals that utilised ACTION are also examined to throw light on its potential benefits for both carers and professionals. Consideration is given to the barriers to using information technology, and to identifying those carers most likely to benefit. Areas for further development are the need for practitioners' education and a wider range of programmes to address carers' diverse needs. Clearly, lessons learned from the Swedish project have wider relevance, given that new forms of support are being developed in most technically advanced countries

    Stoner-Wohlfart model applied to bicrystal magnetoresistance hysteresis

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    We calculate numerically the magnetization direction as function of magnetic field in the Stoner-Wohlfart theory and are able to reproduce the shape of the low-field magnetoresistance hysteresis observed in manganite grain boundary junctions. Moreover, we show that it is necessary to include biaxial magnetocrystalline anisotropy to fully describe the grain boundary magnetoresistance in La0.7_{0.7}Sr0.3_{0.3}MnO3_3/SrTiO3_3 bicrystal tunnel junctions.Comment: 5 pages, 4 figure
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