6,697 research outputs found

    Multiplate focusing collimator

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    An appartus is described for scanning relatively small near sources of penetrating radiation to obtain the energy distribution thereof, wherein a collimator assembly is interposed between a radiation source and a radiation detector. The collimator assembly has a plurality of plates aligned in parallel planes with respect to a common axis normal to their centers. All the plates have similar random distribution of apertures. All apertures on each plate are the same size. The size of respective plates, the size of the apertures of said respective plates, and the spacing between said respective plates vary precisely according to a predetermined ratio to produce radiation channels which converge to a focal point. The radiation incident to the radiation detector is maximized when the focal point and the radiation source are co-incident

    STARPROBE: Scientific rationale

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    The scientific rationale and instrumentation problems in the areas of solar internal dynamics and relativity, solar plasma and particle dynamics, and solar atmosphere structure were studied. Current STARPROBE mission and system design concepts are summarized

    Subsonic stability and control characteristics of a 0.015-scale (remotely controlled elevon) model 44-0 of the space shuttle orbiter tested in the NASA/ARC 12-foot pressure tunnel (LA66)

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    The investigation was conducted in the NASA/Ames Research Center 12-foot Pressure Tunnel. The model was a Langley-built 0.015-scale SSV orbiter model with remote independently operated left and right elevon surfaces. The objective of the test was to generate a detailed aerodynamic data base for the current shuttle orbiter configuration. Special attention was directed to definition of nonlinear aerodynamic characteristics by taking data at small increments in angle of attack, angle of sideslip, and elevon position. Six-component aerodynamic force and moment and elevon position data were recorded over an angle of attack range from -4 deg to 24 deg at angles of sideslip of 0 deg and + or - 4 deg. Additional tests were made over an angle of sideslip range from -6 deg to 6 deg at selected angles of attack. The test Mach numbers were 0.22 and 0.29 and the Reynolds number was varied from 2.0 to 8.5 million per foot

    The minimum flux corona; theory or concept

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    The reply to the criticisms of the minimum flux theory is discussed. These criticisms are correct in substance, as well as in detail. Counter arguments that the minimum flux corona theory is untenable, because of errors in its formulation, are presented

    Experimental and analytical strains in an edge-cracked sheet

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    Elastoplastic strain distribution in edge-cracked metal sheets determined by optical interference and moire technique

    Crimesong: Some Murder Ballads and Poems Revisited

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    This short Article, by a law professor and a law librarian, was written because of our personal interest in the old ballads, and because of the professor\u27s desire to spice up the “meals-ready-to-eat” diet of problems and cases fed to students in law school courses. But more than anything else, this Article was written for the fun of it. To the extent that we appear to be advancing the occasional high-sounding hypothesis, we want the reader to understand that our speculations are offered only as an invitation to the sociologists, musicologists, and historians. Our backgrounds are limited, and we do not expect to be taken all that seriously

    Sharks of the order Carcharhiniformes from the British Coniacian, Santonian and Campanian (Upper Cretaceous).

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    Bulk sampling of phosphate-rich horizons within the British Coniacian to Campanian (Upper Cretaceous) yielded very large samples of shark and ray teeth. All of these samples yielded teeth of diverse members of the Carcharhiniformes, which commonly dominate the fauna. The following species are recorded and described: Pseudoscyliorhinus reussi (Herman, 1977) comb. nov., Crassescyliorhinus germanicus (Herman, 1982) gen. nov., Scyliorhinus elongatus (Davis, 1887), Scyliorhinus brumarivulensis sp. nov., ? Palaeoscyllium sp., Prohaploblepharus riegrafi (Müller, 1989) gen. nov., ? Cretascyliorhinus sp., Scyliorhinidae inc. sedis 1, Scyliorhinidae inc. sedis 2, Pteroscyllium hermani sp. nov., Protoscyliorhinus sp., Leptocharias cretaceus sp. nov., Palaeogaleus havreensis Herman, 1977, Paratriakis subserratus sp. nov., Paratriakis tenuis sp. nov., Paratriakis sp. indet. and ? Loxodon sp. Taxa belonging to the families ?Proscylliidae, Leptochariidae, and Carcharhinidae are described from the Cretaceous for the first time. The evolutionary and palaeoecological implications of these newly recognised faunas are discussed

    The Treatment of Chronic Athletic Injuries of the Low Back and Lower Extremity Utilizing Manipulation

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    The purpose of this study was to determine whether spinal manipulation and/or lower extremity manipulation could be effective in a specific clinical situation -the treatment of chronically injured athletes. It was deemed important to set up a small pilot study that reflected exactly how a practitioner would deal with an injured athlete. Past trials of manipulation have been criticized because they did not resemble what actually occurs in a clinical situation. Participants were restricted to a few standard manipulations. They were not allowed to treat the participating patient as they normally would have(l)

    Film calibration for the Skylab/ATM S-056 X-ray telescope

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    The sensitometry and film calibration effort for the Skylab/ATM S-056 X-ray telescope is summarized. The apparatus and procedures used are described together with the two types of flight film used, Kodak SO-212 and SO-242. The sensitometry and processing of the flight film are discussed, and the results are presented in the form of the characteristic curves and related data. The use of copy films is also discussed

    The development and application of aerodynamic uncertainties: And flight test verification for the space shuttle orbiter

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    The approach used in establishing the predicted aerodynamic uncertainties and the process used in applying these uncertainties during the design of the Orbiter flight control system and the entry trajectories are presented. The flight test program that was designed to verify the stability and control derivatives with a minimum of test flights is presented and a comparison of preflight predictions with preliminary flight test results is made. It is concluded that the approach used for the Orbiter is applicable to future programs where testing is limited due to time constraints or funding
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