59,240 research outputs found

    Rate constant for deuterium atom recombination calculated by the orbiting resonance theory

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    Resonance theory for three body recombination kinetics for calculating recombination rate constant of deuterium ato

    Study of a contractors capabilities center and the technology transfer process Final report, 15 Mar. 1966 - 30 Jun. 1968

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    Feasibility of NASA Contractors Capabilities Center, and approaches to technology utilizatio

    Experimental clean combustor program, phase 1

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    A program of screening three low emission combustors for conventional takeoff and landing, by testing and analyzing thirty-two configurations is presented. Configurations were tested that met the emission goals at idle operating conditions for carbon monoxide and for unburned hydrocarbons (emission index values of 20 and 4, respectively). Configurations were also tested that met a smoke number goal of 15 at sea-level take-off conditions. None of the configurations met the goal for oxides of nitrogen emissions at sea-level take-off conditions. The best configurations demonstrated oxide of nitrogen emission levels that were approximately 61 percent lower than those produced by the JT9D-7 engine, but these levels were still approximately 24 percent above the goal of an emission index level of 10. Additional combustor performance characteristics, including lean blowout, exit temperature pattern factor and radial profile, pressure loss, altitude stability, and altitude relight characteristics were documented. The results indicate the need for significant improvement in the altitude stability and relight characteristics. In addition to the basic program for current aircraft engine combustors, seventeen combustor configurations were evaluated for advanced supersonic technology applications. The configurations were tested at cruise conditions, and a conceptual design was evolved

    A Remark on Quantum Group Actions and Nuclearity

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    Let H be a compact quantum group with faithful Haar measure and bounded counit. If H acts on a C*-algebra A, we show that A is nuclear if and only if its fixed-point subalgebra is nuclear. As a consequence H is a nuclear C*-algebra.Comment: 12 pages, LateX 2

    Extensive inventory of forest resources by multistage sampling

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    There are no author-identified significant results in this report

    Experimental clean combustor program, phase 2

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    The alternate fuels investigation objective was to experimentally determine the impacts, if any, on exhaust emissions, performance, and durability characteristics of the hybrid and vorbix low pollution combustor concepts when operated on test fuels which simulate composition and property changes which might result from future broadened aviation turbine fuel specifications or use of synthetically derived crude feedstocks. Results of the program indicate a significant increase in CO and small NOX increase in emissions at idle for both combustor concepts, and an increase in THC for the vorbix concept. Minimal impact was observed on gaseous emissions at high power. The vorbix concept exhibited significant increase in exhaust smoke with increasing fuel aromatic content. Altitude stability was not affected for the vorbix combustor, but was substantially reduced for the hybrid concept. Severe carbon deposition was observed in both combustors following limited endurance testing with No. 2 home heat fuel. Liner temperature levels were insensitive to variations in aromatic content over the range of conditions investigated

    Two Trapping Systems to Determine Incidence and Duration of Migration of Adult Alfalfa Weevils, \u3ci\u3eHypera Postica\u3c/i\u3e (Coleoptera: Curculionidae)

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    Emergence and flight traps were used to study the pre- and post-diapause movements of the alfalfa weevil, Hypera postica. The emergence traps proved to be an excellent tool in determining the time of diapause termination and in providing an accurate accounting of the number of weevils per unit area in aestivation sites. The flight traps showed when diapause flights to and from alfalfa fields took place. Both trapping systems can be utilized in a pest control program to locate more closely where the alfalfa weevil aestivates and when diapause related movements occur

    Fall Termination of Aestivation and Field Dispersal of the Alfalfa Weevil (Coleoptera: Curculionidae) in Illinois

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    Emergence traps, flight traps, sweeping, and egg sampling were employed to determine fall termination of aestivation of the alfalfa weevil, Hypera postica, and patterns and timing of field reentry, and subsequent fall oviposition. Adult alfalfa weevils were found to terminate aestivation in wood edge field borders in mid-late October. Field reentry began in late October as a gradual process, starting at wooded field borders, with the field population equally dispersed by mid-November
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