6,311 research outputs found

    General-aviation's view of progress in the aviation weather system

    Get PDF
    For all its activity statistics, general-aviation is the most vulnerable to hazardous weather. Of concern to the general aviation industry are: (1) the slow pace of getting units of the Automated Weather Observation System (AWOS) to the field; (2) the efforts of the National Weather Service to withdraw from both the observation and dissemination roles of the aviation weather system; (3) the need for more observation points to improve the accuracy of terminal and area forecasts; (4) the need for improvements in all area forecasts, terminal forecasts, and winds aloft forecasts; (5) slow progress in cockpit weather displays; (6) the erosion of transcribed weather broadcasts (TWEB) and other deficiencies in weather information dissemination; (7) the need to push to make the Direct User Access Terminal (DUAT) a reality; and (7) the need to improve severe weather (thunderstorm) warning systems

    Charged Black Hole in a Canonical Ensemble

    Get PDF
    We consider the thermodynamics of a charged black hole enclosed in a cavity. The charge in the cavity and the temperature at the walls are fixed so that we have a canonical ensemble. We derive the phase structure and stability of black hole equilibrium states. We compare our results to that of other work which uses asymptotically anti-de Sitter boundary conditions to define the thermodynamics. The thermodynamic properties have extensive similarities which suggest that the idea of AdS holography is more dependent on the existence of the boundary than on the exact details of asymptotically AdS metrics.Comment: 9 pages; 4 multipart figure

    Topics on urban planning annotated bibliography

    Get PDF
    Urban planning and development - bibliography and abstract

    The Distribution and Prevalence of the Alfalfa Blotch Leafminer (Diptera: Agromyzidae) in Illinois

    Get PDF
    Surveys were made in 2001 and 2002 to determine the distribution and prevalence of the alfalfa blotch leafminer, Agromyza frontella (Diptera: Agromyzidae), and its primary parasitoids, Dacnusa dryas and Chrysocharis liriomyzae (Hymenoptera: Braconidae and Eulophidae, respectively), in Illinois. We collected 239 samples from alfalfa fields in the alfalfa-producing regions of Illinois. Samples from each site consisted of 20 cut stems and 10 sets of 10 sweeps in 2001, and 40 stems and 10 sets of 20 sweeps in 2002. Each trifoliate was examined for mining and pinholing injury, and the number of adult A. frontella, D. dryas, and C. liriomyzae per 10 sweeps was calculated for each site. We found that 16.3% of the sites were infested with A. frontella, and all infested fields were north of 39.95 N latitude. Although up to 95% of stems were injured at some sites, mean injury per stem never exceeded 12% of trifoliates. Maximum adult abundance was 8.1 adults per 10 sweeps. We did not detect D. dryas or C. liriomyzae in any of the sweep samples. Because of consistently low populations and the relatively slow rate of A. frontella’s spread in Illinois, we conclude that A. frontella is not a serious threat to alfalfa production in this state at this time
    corecore