35,259 research outputs found

    Standard arc welders provide high amperage direct current source

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    Standard arc welders or power supplies are hooked up in parallel or series connections to obtain an adequate supply of current or voltage for various purposes. This method provides maximum flexibility in a wide range of voltages and currents

    Measurement of model aeroelastic deformations in the wind tunnel at transonic speeds using stereophotogrammetry

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    A stereophotographic method of determining the aeroelastic deformations of an airplane model under aerodynamic load in the wind tunnel was evaluated. Wind tunnel tests were conducted in the Langley 8 foot transonic pressure tunnel on the wing of a 0.0625 scale model of the TF-8A supercritical wing research airplane to obtain simultaneously the aerodynamic forces and moments, pressure distributions, and stereophotographs. Tests were conducted at Mach numbers of 0.80, 0.95, and 1.20, and at free stream dynamic pressures of 20,349 Pa and 40,698 Pa. Accuracy of the stereophotographic technique in determining wing deflections was within 0.013 cm under static conditions. This value translates to an error in wing twist of 0.10 deg inboard and increases to 0.20 deg outboard. When the model was under aerodynamic load in the wind tunnel, the accuracy of the stereophotographic technique of determining wind deflections increased to 0.052 cm when compared with static wing loadings because of the dynamic motion of the model in the tunnel

    The Future of Particle Physics

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    After a very brief review of twentieth century elementary particle physics, prospects for the next century are discussed. First and most important are technological limits of opportunities; next, the future experimental program, and finally the status of the theory, in particular its limitations as well as its opportunities.Comment: Invited talk given at the International Conference on Fundamental Sciences: Mathematics and Theoretical Physics, Singapore, 13-17 March 200

    Continuously operating induction plasma accelerator Patent

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    Continuous operation, single phased, induction plasma accelerator producing supersonic speed

    Directly comparing coronal and solar wind elemental fractionation

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    As the solar wind propagates through the heliosphere, dynamical processes irreversibly erase the signatures of the near-Sun heating and acceleration processes. The elemental fractionation of the solar wind should not change during transit however, making it an ideal tracer of these processes. We aimed to verify directly if the solar wind elemental fractionation is reflective of the coronal source region fractionation, both within and across different solar wind source regions. A backmapping scheme was used to predict where solar wind measured by the Advanced Composition Explorer (ACE) originated in the corona. The coronal composition measured by the Hinode Extreme ultraviolet Imaging Spectrometer (EIS) at the source regions was then compared with the in-situ solar wind composition. On hourly timescales there was no apparent correlation between coronal and solar wind composition. In contrast, the distribution of fractionation values within individual source regions was similar in both the corona and solar wind, but distributions between different sources have significant overlap. The matching distributions directly verifies that elemental composition is conserved as the plasma travels from the corona to the solar wind, further validating it as a tracer of heating and acceleration processes. The overlap of fractionation values between sources means it is not possible to identify solar wind source regions solely by comparing solar wind and coronal composition measurements, but a comparison can be used to verify consistency with predicted spacecraft-corona connections.Comment: Accepted version; 8 pages, 7 figure

    Applicability of Skylab remote sensing for detection and monitoring of surface mining activities

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    There are no author-identified significant results in this report

    Applicability of satellite remote sensing for monitoring surface mining activities

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    There are no author-identified significant results in this report

    Laboratory investigation of diffraction and reflection of sonic booms by buildings

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    Laboratory investigation of diffraction and reflection of sonic booms by building
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