147,262 research outputs found

    Gimbaled, partially submerged rocket nozzle Patent

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    Gimbaled partially submerged nozzle for solid propellant rocket engines for providing directional contro

    Photon Bunching at TeV Energies

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    Harwit, Protheroe, and Biermann (1999) recently proposed that Bose-Einstein photon bunching might significantly affect the interpretation of Cerenkov counts of TeV gamma photons. Here, we show that a combination of two recent results of Aharonian et al. (2000) and Aharonian et al. (2001) permits us to set new, more stringent upper limits of 10\lesssim 10% on the fractional amount of photon bunching in the 7-10 TeV radiation from Markarian 501. Potential bunching at even higher energies should nevertheless continue to be investigated for this and other TeV sources, since a clear understanding of TeV energy spectra is required to unambiguously determine the spectral energy density of the mid-infrared extragalactic background

    Simple spectroscope used with solid state image amplifier over wide spectral range

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    Prism plus image amplifier panel provides visual image of many infrared spectral lines from carbon arc impregnated with metal compound. Different metal compounds generate various desired spectra. Panel also aligns and focuses simple spectroscopes for detecting spectral lines inside and outside visible region

    Improved radiographic image amplifier panel

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    Layered image amplifier for radiographic /X ray and gamma ray/ applications, combines very high radiation sensitivity with fast image buildup and erasure capabilities by adding a layer of material that is both photoconductive and light-emitting to basic image amplifier and cascading this assembly with a modified Thorne panel

    Aircraft communication via telefacsimile system

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    Based on reading rate of between 500-1000 words/minute, transmitting typewritten matter only, system uses lowest possible bandwidth to avoid overcrowding, while furnishing data as fast as it can be absorbed by pilot. Bandwidth requirements are less than 150 kHz, a considerable saving over conventional television

    Study to define and verify the personal oral hygiene requirements for extended manned space flight: Oral physiology and microbiology in Skylab manned space missions

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    Methods for metabolic fingerprinting of pathogenic oral bacteria were developed and the effects of Skylab missions on salivary electrolyte levels were studied. High resolution gas liquid chromatographic (GLC) and pyrolysis-GLC procedures were used to obtain metabolic profiles of closely related bacteria associated with dental caries and periodontal disease. It was found that the GLC procedures provide a practical and reproducible means of obtaining metabolic markers for identifying closely related strains of these organisms. Fractions of stimulated whole saliva samples from the prime and back-up crews of the three Skylab missions were used to measure salivary electrolyte concentrations. All the electrolytes previously reported as having increased in urine and feces during the missions were assessed. Sodium, potassium, calcium, magnesium, phosphorous and chloride were studied. A decrease in sodium and an increase in magnesium were observed, but the mineral imbalances attributable to the mission-related increases in urinary electrolytes were not detected

    Water quality conditions in San Francisco Bay delta

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    There are no author-identified significant results in this report

    Detection and location of metallic objects imbedded in nonmetallic structures

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    Small battery operated eddy current proximity measuring device detects and locates metal objects the size of a dime at distances up to one foot within nonmetallic structures. This device weighs approximately two pounds, occupies approximately 60 cubic inches, and is battery powered

    Error behavior of multistep methods applied to unstable differential systems

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    The problem of modeling a dynamic system described by a system of ordinary differential equations which has unstable components for limited periods of time is discussed. It is shown that the global error in a multistep numerical method is the solution to a difference equation initial value problem, and the approximate solution is given for several popular multistep integration formulas. Inspection of the solution leads to the formulation of four criteria for integrators appropriate to unstable problems. A sample problem is solved numerically using three popular formulas and two different stepsizes to illustrate the appropriateness of the criteria

    Water quality conditions in San Francisco Bay delta

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    There are no author-identified significant results in this report
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