3,639 research outputs found

    The Space Station Photovoltaic Panels Plasma Interaction Test Program: Test plan and results

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    The Plasma Interaction Test performed on two space station solar array panels is addressed. This includes a discussion of the test requirements, test plan, experimental set-up, and test results. It was found that parasitic current collection was insignificant (0.3 percent of the solar array delivered power). The measured arcing threshold ranged from -210 to -457 V with respect to the plasma potential. Furthermore, the dynamic response of the panels showed the panel time constant to range between 1 and 5 microsec, and the panel capacitance to be between .01 and .02 microF

    Novel Superconducting Tunneling Structures

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    Contains a description of one research project.Joint Services Electronics Program Contract DAAL03-89-C-000

    The Mechanical Properties of Rat Tail Tendon

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    Brief of Corporate Law Professors as Amici Curie in Support of Respondents

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    The Supreme Court has looked to the rights of corporate shareholders in determining the rights of union members and non-members to control political spending, and vice versa. The Court sometimes assumes that if shareholders disapprove of corporate political expression, they can easily sell their shares or exercise control over corporate spending. This assumption is mistaken. Because of how capital is saved and invested, most individual shareholders cannot obtain full information about corporate political activities, even after the fact, nor can they prevent their savings from being used to speak in ways with which they disagree. Individual shareholders have no ā€œopt outā€ rights or practical ability to avoid subsidizing corporate political expression with which they disagree. Nor do individuals have the practical option to refrain from putting their savings into equity investments, as doing so would impose damaging economic penalties and ignore conventional financial guidance for individual investors

    A semi-empirical model for two-level system noise in superconducting microresonators

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    We present measurements of the low--temperature excess frequency noise of four niobium superconducting coplanar waveguide microresonators, with center strip widths srs_r ranging from 3 Ī¼\mum to 20 Ī¼\mum. For a fixed internal power, we find that the frequency noise decreases rapidly with increasing center strip width, scaling as 1/sr1.61/s_r^{1.6}. We show that this geometrical scaling is readily explained by a simple semi-empirical model which assumes a surface distribution of independent two-level system fluctuators. These results allow the resonator geometry to be optimized for minimum noise.Comment: 3 fig

    ISS-Experiments of Columnar-to-Equiaxed Transition in Solidification Processing

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    The main topic of the research project CETSOL in the framework of the Microgravity Application Promotion (MAP) programme of the European Space Agency (ESA) is the investigation of the transition from columnar to equiaxed grain growth during solidification. Microgravity environment allows for suppression of buoyancy-driven melt flow and for growth of equiaxed grains free of sedimentation and buoyancy effects. This contribution will present first experimental results obtained in microgravity using hypo-eutectic AlSi alloys in the Materials Science Laboratory (MSL) on-board the International Space Station (ISS). The analysis of the experiments confirms the existence of a columnar to equiaxed transition, especially in the refined alloy. Temperature evolution and grain structure analysis provide critical values for the position, the temperature gradient and the solidification velocity at the columnar to equiaxed transition. These data will be used to improve modeling of solidification microstructures and grain structure on different lengths scales

    Scholarship Series: KSU Faculty Showcase

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    Kennesaw State University School of Music presents Faculty Showcase, a KSU School of Music Scholarship Series concert.https://digitalcommons.kennesaw.edu/musicprograms/1534/thumbnail.jp
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