11,697 research outputs found

    Shutters and slats for the integral sunshade of an optical reception antenna

    Get PDF
    Optical reception antennas used at a small Sun-Earth-probe angle (small solar elongation E) require sunshading to prevent intolerable scattering of light from the surface of the primary mirror. An integral sunshade consisting of hexagonal tubes aligned with the segmentation of a large mirror was proposed for use down to E = 12 degrees. For smaller angles, asterisk-shaped vanes inserted into the length of the hexagonal tubes would allow operation down to about 6 degrees with a fixed obscuration of 3.6 percent. Two alternative methods are investigated to extend the usefulness of the integral sunshade to smaller angles by adding either variable-area shutters to block the tube corners that admit off-axis sunlight or by inserting slats (partial vanes) down the full length of some tubes. Slats are effective for most operations down to 6 degrees, and obscure only 1.2 percent. For E between 10.75 and 12 degrees, shutters cause even less obscuration

    Development of biaxial test fixture includes cryogenic application

    Get PDF
    Test fixture has the capability of producing biaxial stress fields in test specimens to the point of failure. It determines biaxial stress by dividing the applied load by the net cross section. With modification it can evaluate materials, design concepts, and production hardware at cryogenic temperatures

    Program Trading-A Critical Analysis

    Full text link

    What Kind of ’Big Government’ is the Big Society? A Reply to Bulley and Sokhi-Bulley

    Get PDF
    This article is a reply to Bulley and Sokhi-Bulley's recent article on the Big Society. We put forward two main criticisms of Bulley and Sokhi-Bulley's governmentality-focused approach in our alternative reading of the Big Society. Firstly, we argue that, given the ethopolitical strategies Bulley and Sokhi-Bulley focus their attention on are unlikely to produce the kind of transformation in the ethical outlook of citizens they suppose, the real historical significance of the Big Society must lie elsewhere. Secondly, we argue that Bulley and Sokhi-Bulley overlook the lines of continuity and discontinuity linking the Big Society to the forms of neo-liberal governmentality that have preceded it in British politics. In the final section of the article, we argue that the Cameron project amounts to both a partial continuation of the type of neo-liberal governmental rationality characteristic of the New Labour project and a partial reversion to a more rudimentary Thatcherite form of neo-liberal governmentality

    Planar electroluminescent panel techniques

    Get PDF
    Investigations of planar electroluminescent multipurpose displays with latch-in memory are described. An 18 x 24 in. flat, thin address panel with elements spacing of 0.100 in. was constructed which demonstrated essentially uniform luminosity of 3-5 foot lamberts for each of its 43200 EL cells. A working model of a 4-bit EL-PC (electroluminescent photoconductive) electrooptical decoder was made which demonstrated the feasibility of this concept. A single-diagram electroluminescent display device with photoconductive-electroluminescent latch-in memory was constructed which demonstrated the conceptual soundness of this principle. Attempts to combine these principles in a single PEL multipurpose display with latch-in memory were unsuccessful and were judged to exceed the state-of-the-art for close-packed (0.10 in. centers) photoconductor-electroluminescent cell assembly

    An experimental evaluation of a loop versus a reference design for two-channel microarrays

    Get PDF
    Motivation: Despite theoretical arguments that socalled "loop designs" of two-channel DNA microarray experiments are more efficient, biologists keep on using "reference designs". We describe two sets of microarray experiments with RNA from two different biological systems (TPA-stimulated mammalian cells and Streptomyces coelicor). In each case, both a loop and a reference design were performed using the same RNA preparations with the aim to study their relative efficiency. Results: The results of these experiments show that (1) the loop design attains a much higher precision than the reference design, (2) multiplicative spot effects are a large source of variability, and if they are not accounted for in the mathematical model, for example by taking log-ratios or including spot-effects, then the model will perform poorly. The first result is reinforced by a simulation study. Practical recommendations are given on how simple loop designs can be extended to more realistic experimental designs and how standard statistical methods allow the experimentalist to use and interpret the results from loop designs in practice
    • …
    corecore