1,231,435 research outputs found

    Measurement of radon concentrations at Super-Kamiokande

    Full text link
    Radioactivity from radon is a major background for observing solar neutrinos at Super-Kamiokande. In this paper, we describe the measurement of radon concentrations at Super-Kamiokande, the method of radon reduction, and the radon monitoring system. The measurement shows that the current low-energy event rate between 5.0 MeV and 6.5 MeV implies a radon concentration in the Super-Kamiokande water of less than 1.4 mBq/m3^3.Comment: 11 pages, 4 figure

    Calibration of Super-Kamiokande Using an Electron Linac

    Get PDF
    In order to calibrate the Super-Kamiokande experiment for solar neutrino measurements, a linear accelerator (LINAC) for electrons was installed at the detector. LINAC data were taken at various positions in the detector volume, tracking the detector response in the variables relevant to solar neutrino analysis. In particular, the absolute energy scale is now known with less than 1 percent uncertainty.Comment: 24 pages, 16 figures, Submitted to NIM

    Evaluating the Eleventh District's Beige Book

    Get PDF
    In this study, Nathan Balke and Mine Yucel ask whether the Eleventh Federal Reserve District's Beige Book description contains timely information about economic activity within the District. They examine whether the Beige Book description tracks current Texas real gross state product (GSP) growth and current Texas employment growth. They also study whether the Beige Book has information about growth not present in other regional indicators that would have been available to analysts at the time of the Beige Book's release. They find that both the Beige Book summary and the average across sectors reflect Texas GSP and employment growth very well. These two measures of the Beige Book also have predictive content for one quarter ahead GSP growth. Balke and Yucel also find that the Eleventh District's Beige Book has information content for Texas economic activity over and above other state economic indicators such as Texas employment growth, personal income, or sectoral employment growth. Because the Beige Book is released at least one month earlier than employment data and at least two years before GSP data, its timeliness makes it a good tool for current regional economic analysis.Employment (Economic theory) ; Unemployment ; Economic indicators

    The larval mine of Stigmella lappovimella (Svensson, 1976) on Salix lapponum (L.) (Lepidoptera, Nepticulidae)

    Get PDF
    The larval mine of Stigmella lappovimella in leaves of Salix lapponum of different host leaf thickness is described and differences between the mine and the mines of Stigmella salicis on Salix caprea and Stigmella zelleriella on Salix repens are noted. The best diagnostic characters differentiating the mine of S. lappovimella from the two others was the almost unbroken frass line in the first half and the limited frass particle dispersion in the second half of the mine. Wing length was also measured and a small but statistically significant difference was observed between S. lappovimella and S. zelleriella

    Nematic elastomers with aligned carbon nanotubes: new electromechanical actuators

    Full text link
    We demonstrate, for the first time, the large electromechanical response in nematic liquid crystalline elastomers filled with a very low (~0.01%) concentration of carbon nanotubes, aligned along the nematic director at preparation. The nanotubes create a very large effective dielectric anisotropy of the composite. Their local field-induced torque is transmitted to the rubber-elastic network and is registered as the exerted uniaxial stress of order ~1kPa in response to a constant field of order ~1MV/m. We investigate the dependence of the effect on field strength, nanotube concentration and reproducibility under multiple field-on and -off cycles. The results indicate the potential of the nanotube-nematic elastomer composites as electrically driven actuators

    DDASaccident295

    Get PDF
    After replacing the pin, he turned the mine over and put pressure on the base of the mine to try to force it open. The mine detonated. He lost the hand that was holding the mine and had extensive damage to his leg(s) under the table

    Projectile impact effects on a 50 psi plug type coal mine seal

    Get PDF
    The current lack of projectile damage criteria for mine seals is assessed to determine if criteria should be developed. Impact experiments were performed on a full-scale 50 psi mine seal to determine failure modes, dynamic stress state, and assess risk to existing operational mine seals. Test projectiles were selected from common underground coal mine items propelled by means of a black powder projectile generator. Projectile velocities attained in testing ranged from approximately 100 to 650 ft/s (30 to 200 m/s). Dynamic strain was measured on the non-impact face to derive the state of stress and estimate failure criteria. Penetration models were used to estimate depth of penetration and compared to empirical data. Finite element analysis impact simulation was compared with empirical data and a critical impact velocity for rigid body projectiles of 20 to 30 lb (9 to 14 kg) was estimated to be in the range of 550 to 600 ft/s (168 to 183 m/s). Damage to the mine seal was observed and compared with numerical simulation to assess the need for defined projectile damage criteria to mine seals --Abstract, page iii

    Oil price shocks and U.S. economic activity: an international perspective

    Get PDF
    Oil price shocks are thought to have played a prominent role in U.S. economic activity. In this paper, we employ Bayesian methods with a dynamic stochastic general equilibrium model of world economic activity to identify the various sources of oil price shocks and economic fluctuation and to assess their effects on U.S. economic activity. We find that changes in oil prices are best understood as endogenous. Oil price shocks in the 1970s and early 1980s and the 2000s reflect differing mixes of shifts in oil supply and demand, and differing sources of oil price shocks have differing effects on economic activity. We also find that U.S. output fluctuations owe mostly to domestic shocks, with productivity shocks contributing to weakness in the 1970s and 1980s and strength in the 2000s.Petroleum products - Prices ; Petroleum industry and trade ; Economic conditions - United States ; Business cycles
    • …
    corecore