13,511 research outputs found

    Massive relic neutrinos in the galactic halo and the knee in the cosmic ray spectrum

    Get PDF
    Despite many efforts to find a reasonable explanation, the origin of the "knee" in the cosmic ray spectrum at energy around 10**15.5 eV remains mysterious. In this letter we suggest that the "knee" may be due to a GZK-like effect of cosmic rays interacting with massive neutrinos in the galactic halo. Simple kinematics connects the location of the "knee" with the mass of the neutrinos, and, while the required interaction cross section is larger than that predicted by the Standard Model, it can be accommodated by a small neutrino magnetic dipole moment. The values for the neutrino parameters obtained from the analysis of existing experimental data are compatible with present laboratory bounds.Comment: 8 pages, 1 figure, uses RevTe

    Layered classification techniques for remote sensing applications

    Get PDF
    The layered classifier method is outlined and several applications to pattern classification for which the approach is suited are discussed

    Numerical Construction of Likelihood Distributions and the Propagation of Errors

    Get PDF
    The standard method for the propagation of errors, based on a Taylor series expansion, is approximate and frequently inadequate for realistic problems. A simple and generic technique is described in which the likelihood is constructed numerically, thereby greatly facilitating the propagation of errors

    First unitarity-independent determination of the CKM matrix elements VtdV_{td}, VtsV_{ts}, and VtbV_{tb} and the implications for unitarity

    Get PDF
    The magnitudes of the CKM matrix elements VtdV_{td}, VtsV_{ts}, and VtbV_{tb} are determined for the first time without any assumptions of unitarity. The implications for the unitarity of the CKM matrix as a whole are discussed

    Data analysis: a physicist's perspective

    Get PDF

    Visualization of hydrogen injection in a scramjet engine by simultaneous PLIF imaging and laser holographic imaging

    Get PDF
    Flowfield characterization has been accomplished for several fuel injector configurations using simultaneous planar laser induced fluorescence (PLIF) and laser holographic imaging (LHI). The experiments were carried out in the GASL-NASA HYPULSE real gas expansion tube facility, a pulsed facility with steady test times of about 350 microsec. The tests were done at simulated Mach numbers 13.5 and 17. The focus of this paper is on the measurement technologies used and their application in a research facility. The HYPULSE facility, the models used for the experiments, and the setup for the LHI and PLIF measurements are described. Measurement challenges and solutions are discussed. Results are presented for experiments with several fuel injector configurations and several equivalence ratios

    Sponges of Navassa

    Get PDF
    This photographic guide was compiled from data collected during the 2004 NOAA survey of the coral reefs of Navassa and does not represent a comprehensive list of all Porifera in Navassa. Specifically missing are taxa that inhabit caves, overhangs, vertical walls; species that live in the interstices of the reef framework; and species found at depths greater than 50 meters. Specimens were identified by Janie Wulff and Timothy Swain of Florida State University using a combination of digital photography, field observations, and microscopic examination of siliceous spicules. Genera are organized into higher taxa according to Systema Porifera, Hooper & van Soest (ed.) 2002. We have purposefully erred on the side of splitting similar taxa for which a species designation could not be definitively assigned, in order to demonstrate the range of forms observed in this survey. Some species are shown with symbiotic zoanthids on the surface of the sponge, but zoanthids are not always present and should not be relied on for identification of the sponge taxa

    Energy Balance During Backpacking

    Get PDF
    Energy expenditure and energy intake were determined in three Subjects during a 160-kilometer backpacking trip. Prior to the trip, heart rate and oxygen consumption during treadmill walking while carrying a backpack were measured. Subjects recorded heart rate during hiking. Heart rate Was used to estimate energy expenditure based on the heart rate: oxygen consumption relationship (Heart Rate Method). Expenditure was also estimated from distance walked and elevation gained (Terrain Method). Subjects recorded food consumption, and were weighed upon finishing the hike. Mean heart rate during biking was 105 +/- 12 beats per Minute. According to the Heart Rate Method, net expenditure averaged 3410 +/- 955 kilocalories on days 1-4, and 2586 +/- 974 kilocalories on day 5. Net expenditure from the Terrain Method was approximately 28% lower. Gross expenditure, using the Heart Rate Method, averaged 4928 +/- 1050 kilocalories on days 1-4, and 3550 +/- 1052 kilocalories on day 5. Energy intake averaged 2134 +/- 625 kilocalories on days 1-4,and 1117 +/- 320 kilocalories on day 5. Expected weight loss due to the caloric deficit was 1.8 +/- 0.4 kilograms, and actual weight loss was 1.7 +/- 0.6 kilograms. Subjects expended nearly 5000 kilocalories per clay and did not consume sufficient food to maintain body mass

    ECHO user's guide

    Get PDF
    There are no author-identified significant results in this report

    Final Report: National Science Foundation Remote Sensing Workshop. Held at Purdue University February 28, 29, March 1, 1984

    Get PDF
    It was the purpose of this workshop to examine the potential for further advancement of the science of remote sensing, and to define directions which the Engineering aspects of remote sensing research could not take in order to maximize the scientific and technological return
    • …
    corecore