18,504 research outputs found

    Report on the City of Chattahoochee Hill Country. Potential Revenues and Expenditures - Brief

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    Using Fulton County revenue and expenditure data and benchmarks developed from other Georgia city data, this report evaluates the fiscal consequences of incorporating a new city of Chattahoochee Hill Country. FRC Brief 16

    Report on the City of Chattahoochee Hill Country. Potential Revenues and Expenditures

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    Using Fulton County revenue and expenditure data and benchmarks developed from other Georgia city data, this report evaluates the fiscal consequences of incorporating a new city of Chattahoochee Hill Country. FRC Report 16

    An Initial Evaluation of a Proposed Statewide Education Sales Tax

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    This report provides a preliminary analysis of a proposal to replace education property taxes with a statewide sales tax

    Flight data display studies for real time computer flight evaluation Final report

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    Real time displays for in-flight monitoring of Saturn launch vehicle

    Dusty plasma cavities: probe-induced and natural

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    A comprehensive exploration of regional dust evacuation in complex plasma crystals is presented. Voids created in 3D crystals on the International Space Station have provided a rich foundation for experiments, but cavities in dust crystals formed in ground-based experiments have not received as much attention. Inside a modified GEC RF cell, a powered vertical probe was used to clear the central area of a dust crystal, producing a cavity with high cylindrical symmetry. Cavities generated by three mechanisms are examined. First, repulsion of micrometer-sized particles by a negatively charged probe is investigated. A model of this effect developed for a DC plasma is modified and applied to explain new experimental data in RF plasma. Second, the formation of natural cavities is surveyed; a radial ion drag proposed to occur due to a curved sheath is considered in conjunction with thermophoresis and a flattened confinement potential above the center of the electrode. Finally, cavity formation unexpectedly occurs upon increasing the probe potential above the plasma floating potential. The cavities produced by these methods appear similar, but each are shown to be facilitated by fundamentally different processes.Comment: 10 pages, 12 figure

    Pulsation models for the roAp star HD 134214

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    Precise time-series photometry with the MOST satellite has led to identification of 10 pulsation frequencies in the rapidly oscillating Ap (roAp) star HD 134214. We have fitted the observed frequencies with theoretical frequencies of axisymmetric modes in a grid of stellar models with dipole magnetic fields. We find that, among models with a standard composition of (X,Z)=(0.70,0.02)(X,Z) = (0.70,0.02) and with suppressed convection, eigenfrequencies of a 1.65M1.65\,{\rm M}_\odot model with logTeff=3.858\log T_{\rm eff} = 3.858 and a polar magnetic field strength of 4.1kG agree best with the observed frequencies. We identify the observed pulsation frequency with the largest amplitude as a deformed dipole (=1\ell = 1) mode, and the four next-largest-amplitude frequencies as deformed =2\ell = 2 modes. These modes have a radial quasi-node in the outermost atmospheric layers (τ103\tau \sim 10^{-3}). Although the model frequencies agree roughly with observed ones, they are all above the acoustic cut-off frequency for the model atmosphere and hence are predicted to be damped. The excitation mechanism for the pulsations of HD 134214 is not clear, but further investigation of these modes may be a probe of the atmospheric structure in this magnetic chemically peculiar star.Comment: 9 pages, 6 figures; accepted for publication in MNRA

    Space shuttle: Heat transfer rate measurements on Convair booster (B-15B-2) at nominal Mach number of 8

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    Plotted and tabulated data on heat transfer from a thin-skin thermocouple are presented. The data is representative of the reentry event of the booster alone configuration. The data were generated during wind tunnel tests of the B-15B-2 delta wing booster at Mach 8. Thermocouple measurements are reduced to heat transfer coefficient ratio and the data are presented as plotted variations versus longitudinal, lateral, and vertical local model positions

    STOP - A computer program for supersonic transport trajectory optimization

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    IBM 7094 digital program using steepest ascent technique for optimizing flight path of supersonic transport aircraf
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