3,766 research outputs found

    Communication system features dual mode range acquisition plus time delay measurement

    Get PDF
    Communication system combines range acquisition system and time measurement system for tracking high velocity aircraft and spacecraft. The range acquisition system uses a pseudonoise code to determine range and the time measurement system reduces uncontrolled phase variations in the demodulated signal

    Increased Productivity of a Cover Crop Mixture Is Not Associated with Enhanced Agroecosystem Services

    Get PDF
    Cover crops provide a variety of important agroecological services within cropping systems. Typically these crops are grown as monocultures or simple graminoid-legume bicultures; however, ecological theory and empirical evidence suggest that agroecosystem services could be enhanced by growing cover crops in species-rich mixtures. We examined cover crop productivity, weed suppression, stability, and carryover effects to a subsequent cash crop in an experiment involving a five-species annual cover crop mixture and the component species grown as monocultures in SE New Hampshire, USA in 2011 and 2012. The mean land equivalent ratio (LER) for the mixture exceeded 1.0 in both years, indicating that the mixture over-yielded relative to the monocultures. Despite the apparent over-yielding in the mixture, we observed no enhancement in weed suppression, biomass stability, or productivity of a subsequent oat (Avena sativa L.) cash crop when compared to the best monoculture component crop. These data are some of the first to include application of the LER to an analysis of a cover crop mixture and contribute to the growing literature on the agroecological effects of cover crop diversity in cropping systems

    CP Nonconservation in e+e−→ttˉge^+e^-\to t\bar tg

    Full text link
    CP violation effects in e+e−→ttˉge^+ e^- \to t\bar tg are examined. CP-odd, TnT_n-odd and TnT_n-even observables can both be used to extract information on the real and imaginary parts of Feynman amplitudes. Two Higgs doublet model with CP violating phase from neutral Higgs exchange is used to estimate possible effects.Comment: 9 pages, 4 Figures, Late

    The Anomalous Magnetic Moment of the Muon and Higgs-Mediated Flavor Changing Neutral Currents

    Full text link
    In the two-Higgs doublet extension of the standard model, flavor-changing neutral couplings arise naturally. In the lepton sector, the largest such coupling is expected to be $\mu-\tau-\phi#. We consider the effects of this coupling on the anomalous magnetic moment of the muon. The resulting bound on the coupling, unlike previous bounds, is independent of the value of other unknown couplings. It will be significantly improved by the upcoming E821 experiment at Brookhaven National Lab.Comment: 7 pages Latex, 2 figure

    The Wallace W. Atwood Papers

    Get PDF
    The papers of Wallace W. Atwood (1872-1949), geographer, geologist, and President of Clark University spans the period 1901-1946, but by far the largest amount dates from after 1920. These papers consist largely of correspondence, being for the most part the official correspondence of the President\u27s Office. There is also correspondence with various officials of the U.S. Geological Survey which documents Atwood\u27s Rocky Mountain researches. Several files with various members of the Boston publishing house of Ginn and Company are concerned with the production of various Atwood textbooks. The papers include folders dealing with various geography organizations

    B-4-6-5 Yard, Mr Robert Sterling Jan-Sep 1929 (folder 1)

    Get PDF
    Correspondence between Wallace W. Atwood and Robert Sterling Yard, 1929

    Fermi Space Telescope highlights

    Get PDF
    The Fermi Space Mission has had a remarkable first two years of operation in low-Earth orbit, collecting over 380 million events, and revealing unprecedented details of the gamma-ray sky. The Large Area Telescope (LAT) has lived up to expectations. Being the first all-sky monitor in almost real time has revealed a wealth of transient phenomena. Some highlights of the discoveries made by the Fermi-LAT in the past two years are presented. Possible future directions for this highly successful mission will be discussed

    B4-2-15 US Geological Survey, Birdseye, C.H., 1923-1925

    Get PDF
    Correspondence between Wallace W. Atwood and C.H. Birdseye of the U.S. Geological Survey, 1923-1925

    B4-7-3 Merriam, Dr. John C., 1929-1930 (folder 1)

    Get PDF
    Correspondence between Wallace W. Atwood and John C. Merriam, President of the Carnegie Institution of Washington, 1929-1930

    B4-2-15 US Geological Survey, White, David, 1920-1930

    Get PDF
    Correspondence between Wallace W. Atwood and David White of the U.S. Geological Survey, 1920-1930
    • …
    corecore