6,464 research outputs found

    Low-speed wind tunnel investigation of the lateral-directional characterisitcs of a large-scale variable wing-sweep fighter model in the high-lift configuration

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    The low-speed characteristics of a large-scale model of the F-14A aircraft were studied in tests conducted in the Ames Research Center 40- by 80-Foot Wind Tunnel. The primary purpose of the present tests was the determination of lateral-directional stability levels and control effectiveness of the aircraft in its high-lift configuration. Tests were conducted at wing angles of attack between minus 2 deg and 30 deg and with sideslip angles between minus 12 deg and 12 deg. Data were taken at a Reynolds number of 8.0 million based on a wing mean aerodynamic chord of 2.24 m (7.36 ft). The model configuration was changed as required to show the effects of direct lift control (spoilers) at yaw, yaw angle with speed brake deflected, and various amounts and combinations of roll control

    COMMUNITY ECONOMIC EFFECTS OF POPULATION CHANGE IN THE MID-CONTINENT REGION

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    Population estimates for counties in the Mid-Continent Region were compiled by multi-county economic area for 1950, 1960, 1970, 1974, and 1976. Net migration estimates were compiled, also, by economic area. Finally, community economic effects for a metropolitan area and a nonmetropolitan area in Minnesota were estimated in terms of local government and personal income and expenditures and their relation to population change.Community/Rural/Urban Development,

    MINNESOTA ECONOMIC INDICATORS: PART II METHODOLOGY AND FINDINGS

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    Community/Rural/Urban Development,

    ECONOMIC IMPORTANCE OF EXPORT-PRODUCING INDUSTRY IN MINNEAPOLIS-ST. PAUL METROPOLITAN REGION

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    Community/Rural/Urban Development, International Relations/Trade,

    ECONOMIC IMPORTANCE OF EXPORT-PRODUCING INDUSTRY IN MINNESOTA

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    In this report, the role and importance of export-producing industries in Minnesota are discussed. Major emphasis is on agricultural-related industries and their economic importance to the State in value of gross output and contribution to gross state product.Community/Rural/Urban Development, International Relations/Trade,

    ECONOMIC IMPORTANCE OF AGRICULTURE-RELATED INDUSTRY IN MINNESOTA

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    This report is the third in a series on interindustry and interregional relationships and their implications for the economy of Minnesota and its substate development regions. In this report, the role and importance of agriculture-related industries in Minnesota are discussed. A total of 19 agriculture and 35 food products manufacturing industries are identified as the principal agriculture-related industries in the state and the nation. Their interindustry and interregional (Minnesota and rest-of-nation) linkages are derived for the 1977 calendar year.Community/Rural/Urban Development,

    Collective modes and sound propagation in a p-wave superconductor: Sr2_2RuO4_4

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    There are five distinct collective modes in the recently discovered p-wave superconductor Sr2_2RuO4_4; phase and amplitude modes of the order parameter, clapping mode (real and imaginary), and spin wave. The first two modes also exist in the ordinary s-wave superconductors, while the clapping mode with the energy 2Ξ”(T)\sqrt{2} \Delta(T) is unique to Sr2_2RuO4_4 and couples to the sound wave. Here we report a theoretical study of the sound propagation in a two dimensional p-wave superconductor. We identified the clapping mode and study its effects on the longitudinal and transverse sound velocities in the superconducting state. In contrast to the case of 3^3He, there is no resonance absorption associated with the collective mode, since in metals Ο‰/(vF∣q∣)β‰ͺ1\omega/(v_F |{\bf q}|) \ll 1, where vFv_F is the Fermi velocity, {\bf q} is the wave vector, and Ο‰\omega is the frequency of the sound wave. However, the velocity change in the collisionless limit gets modified by the contribution from the coupling to the clapping mode. We compute this contribution and comment on the visibility of the effect. In the diffusive limit, the contribution from the collective mode turns out to be negligible. The behaviors of the sound velocity change and the attenuation coefficient near TcT_c in the diffusive limit are calculated and compared with the existing experimental data wherever it is possible. We also present the results for the attenuation coefficients in both of the collisionless and diffusive limits at finite temperatures.Comment: RevTex, 12 pages, 2 figures, Replaced by the published versio
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