2,369 research outputs found

    Airborne forest fire research

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    The research relating to airborne fire fighting systems is reviewed to provide NASA/Langley Research Center with current information on the use of aircraft in forest fire operations, and to identify research requirements for future operations. A literature survey, interview of forest fire service personnel, analysis and synthesis of data from research reports and independent conclusions, and recommendations for future NASA-LRC programs are included

    Man-machine shuttle support program

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    Human factors support requirements for space shuttle progra

    Hybrid water immersion simulation of manual IVA performance in weightlessness

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    A description is given of the development, tests, and analysis of a manual simulator. The simulator was developed to test mass handling and translation under weightlessness conditions by a test subject. The system is composed of a hybrid simulator with a combination of water immersion and mechanical, Peter Pan, simulation. The concept operates on the equivalence principle, with the subject and the cargo remaining quasi-stationary. Movement is effected through a moving device controlled through force by the subject. Motion response is determined through computations of the inertial movement under such conditions

    Correlation Study of the Simulation of Gemini Extravehicular Activity with Flight Results

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    Correlation study of simulation of Gemini extravehicular activity with flight result

    Preliminary design polymeric materials experiment

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    A typical Advanced Technology Laboratory mission flight plan was developed and used as a guideline for the identification of a number of experiment considerations. The experiment logistics beginning with sample preparation and ending with sample analysis are then overlaid on the mission in order to have a complete picture of the design requirements. The results of this preliminary design study fall into two categories. First specific preliminary designs of experiment hardware which is adaptable to a variety of mission requirements. Second, identification of those mission considerations which affect hardware design and will require further definition prior to final design. Finally, a program plan is presented which will provide the necessary experiment hardware in a realistic time period to match the planned shuttle flights. A bibliography of all material reviewed and consulted but not specifically referenced is provided

    Orbital Cargo Transfer Simulation

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    Future space operations will require transfers of a large variety of cargo under both intravehicular and extravehicular conditions. In order to determine the techniques, human factor considerations, assistive devices, package limitations, training procedures, and so forth related to the cargo transfer problem, extensive ground-based simulation is required. To date, several zero- and reduced-gravity simulation techniques have been developed and utilized. All of these techniques have both limitations and definite areas of application. Two of these techniques, water-immersion and zero-g aircraft, are considered usable for cargo transfer simulation. However, the results being obtained using the techniques differ substantially. The reasons for disagreement are to be found in the limitations of the techniques and how they are considered. The purpose of this paper is to provide a comparison of zero-g aircraft .and water-immersion simulation, and to discuss various techniques which can be used to minimize the limitations associated with water immersion

    Limits to differences in active and passive charges

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    We explore consequences of a hypothetical difference between active charges, which generate electric fields, and passive charges, which respond to them. A confrontation to experiments using atoms, molecules, or macroscopic matter yields limits on their fractional difference at levels down to 10^-21, which at the same time corresponds to an experimental confirmation of Newtons third law.Comment: 6 pages Revtex. To appear in Phys. Rev.

    Past and future blurring at fundamental length scale

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    We obtain the κ\kappa-deformed versions of the retarded and advanced Green functions and show that their causality properties are blurred in a time interval of the order of a length parameter q=1/(2κ)q=1/(2\kappa). The functions also indicate a smearing of the light cone. These results favor the interpretation of qq as a fundamental length scale below which the concept of a point in spacetime should be substituted by the concept of a fuzzy region of radius qq, as proposed long ago by Heisenberg.Comment: Essentially, this is the version published in the Phys. Rev. Lett. 105, 211601 (2010). It has 4 pages and contains 2 figure

    Modified Dispersion Relations from the Renormalization Group of Gravity

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    We show that the running of gravitational couplings, together with a suitable identification of the renormalization group scale can give rise to modified dispersion relations for massive particles. This result seems to be compatible with both the frameworks of effective field theory with Lorentz invariance violation and deformed special relativity. The phenomenological consequences depend on which of the frameworks is assumed. We discuss the nature and strength of the available constraints for both cases and show that in the case of Lorentz invariance violation, the theory would be strongly constrained.Comment: revtex4, 9 pages, updated to match published versio
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