87,167 research outputs found

    Thermal stress-relief treatments for 2219 aluminum alloy are evaluated

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    Evaluation of three thermal stress relief treatments for 2219 aluminum alloy in terms of their effect on residual stress, mechanical properties, and stress corrosion resistance. The treatments are post aging and stress relieving fullscale and subscale parts formed in the aged T81 condition, and aging subscale parts formed in the unaged T31 condition

    Fabricating subscale components for application to full-scale parts

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    Equipment requirements and fabrication methods required for manufacture of large cylindrical boron/epoxy shroud are based on subscale component production methods. Plywrap technique is well suited to fabrication of cylindrical shapes using composite materials. This method offers savings in time, labor, raw materials, and equipment costs

    The stability of the ways of coping (revised) questionnaire over time in parents of children with Downs-Syndrome:a research note

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    The stability of the Ways of Coping (Revised) Questionnaire over time was assessed by comparing the scores of 68 mothers and 53 fathers of school-aged children with Down's syndrome over a 3-year time interval on the five coping strategy subscales described by Knussen et al. (1992). For this analysis, mothers' and fathers' scores were analysed separately. It was shown by t tests that mothers' and fathers' scores on the coping strategy subscales had not significantly changed over the three-year period. Time 1 and Time 2 scores on all of the coping subscales were strongly positively associated, with the exception of fathers' scores on the Stoicism subscale. Test-retest reliability was adequate for all subscales except mothers' scores on the Passive Acceptance subscale and fathers' scores on the Stoicism subscale. These results, by demonstrating the stability of the Ways of Coping (Revised) Questionnaire over a 3-year time period, further illustrate the utility of this instrument for investigating coping in families with special problems

    Master’s and Doctoral Occupational Therapy Students’ Perceptions of Research Integration in Their Programs

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    This is a pilot study with the intent of identifying occupational therapy doctorate (OTD) and master’s (MOT) students’ perceptions of research in their coursework. A cross-sectional study was conducted through a survey of OTD and MOT students. The Student Perception of Research Integration Questionnaire (SPRIQ) was emailed to graduate occupational therapy programs in the United States. An unpaired single tailed t-test was used to compare the mean scores between the MOT and OTD student responses for each scale and subscale. Two hundred and twenty-six students filled out the questionnaire. Both the OTD and MOT students had a favorable perception of the integration of research into the curriculum with a mean score of 3.63 (MOT) and 3.85 (OTD) out of five. An independent t-test found there was a statistically significant difference between the mean scores for two of the subscales for research integration (current research subscale p = .000 and motivation subscale p = .02) and for the beliefs scale (p = .002). Students enrolled in both MOT and OTD programs have a favorable perception of research being integrated into their curriculums. The OTD students have a more favorable perception of the integration of research in their curriculums, with a 0.30 mean difference between all items on the scale

    Subsonic Dynamic Testing of a Subscale ADEPT Entry Vehicle

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    The Adaptive Deployable Entry and Placement Technology (ADEPT) is a mechanically-deployed entry system. A sounding rocket test flight of an ADEPT vehicle, known as ADEPT SR-1, was conducted in September 2018. Prior to this sounding rocket test, an investigation was performed using the NASA Langley Research Center 20-ft Vertical Spin Tunnel (VST) to assess the free-flight dynamic characteristics of ADEPT SR-1 at subsonic speeds. The model of ADEPT SR-1 for this VST test was fabricated at 50-percent geometric scale, with dynamically scaled mass properties (Froude scaled) to represent full-scale flight at an altitude of 1.2 km above sea level. The subsonic dynamic characteristics of ADEPT SR-1 were of interest prior to the sounding rocket test because of payload recovery considerations. At low roll rates the model was found to have acceptable dynamic characteristics. It was statically stable in pitch and yaw, exhibiting limit cycle pitch/yaw oscillations of no greater than 20 degrees (the angle between the models longitudinal axis and nadir). The model was able to recover from large upsets in pitch and yaw, although if sufficiently provoked it tumbled. Damping in roll was low. At high roll rates the pitch and yaw oscillations grew in magnitude and rate. This behavior was also observed during the sounding rocket flight test

    Subscale Mars Colonization Mission

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    The team will compete in the SAE (Society of Automotive Engineers) Aero Design West Advanced Class competition, held 5-7th April 2019 in Van Nuys, California. The team will work to develop, through research, design, optimizational trade studies, and manufacturing, a system for the deployment of parasitic aircraft, as well as payload. The system will consist of a primary fixed-wing aircraft, parasitic autonomous gliders, a real-time altitude data acquisition system, as well as both static and releasable payload. The deployable gliders must navigate autonomously to a targeting area on the ground without any on-board propulsion. The releasable payload, which will consist of habitat modules and water bottles, must also be dropped in such a manner that they land within the same targeting area. The primary aircraft must be powered through only electric power, with an installed power limiter of 750 watts. In general, the wing and powertrain must be optimized to provide sufficient lift given a limit on available power. The project will require robust systems-level engineering as well as rigorous research, design, testing, and iteration
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