2,007 research outputs found

    A Comparison of the Effect of Atropine and Placebo on the Galvanic Skin Resistance

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    Front underride protection devices: design methodology for heavy vehicle crashworthiness

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    North American Heavy Vehicles contribute to a third of all road fatalities in Canada. Head on collisions are one of the most severe, as the mismatch of vehicle weight and sizing intensifies when a passenger vehicle is impacted. To improve crash safety, Front Underride Protection Devices (FUPDs) are a proposed solution to establishing a compatible collision between a passenger vehicle and a heavy vehicle. The European Union is among numerous administrations to regulate FUPDs, yet FUPDs are nonexistent in North America. Current regulations conform to European Cab-over Engine Tractors designs. Implementation of current regulations in North American conflicts with the widely driven Conventional Style Tractor due to the different design space for a FUPDs. This study builds on developing regulations for North America, and establishes a design methodology to developing and optimizing FUPDs for the Conventional Style Tractor enlightening the crashworthy importance of front underride protection devices to improving road safety. Advanced two stage optimization methodology was outlined to ensure industry targets are embedded with in the design to develop lightweight and cost effective devices. Recommendations for the modifications of the ECE R93 for Conventional Style Tractor are outlined; P1 load magnitudes requirements for FUPD stiffness should be increased from the regulated 80 kN to 160 kN to improve small overlap collisions. Regulated geometric parameters were recommended to have a minimal frontal contact height of 240mm, with ground clearance set between 350mm to 400mm. Geometric configurations were outlined and restricted to conform to the aerodynamic curvatures of the tractors bumper. After validation of the National Crash Analysis Center (NCAC) Toyota Yaris finite element analysis (FEA) model for side impact, the addition of a FUPD enhanced the survivability of passenger vehicle. The work achieved in enhancing the design methodology for industrial implementation and outlining regulations for North America

    Direct Sun measurements of NO_2 column abundances from Table Mountain, California: Intercomparison of low- and high-resolution spectrometers

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    The NO_2 total column abundance, C_(NO_2) was measured with a direct Sun viewing technique using three different instruments at NASA Jet Propulsion Laboratory's (JPL) Table Mountain Facility in California during an instrument intercomparison campaign in July 2007. The instruments are a high‐resolution (∌0.001 nm) Fourier transform ultraviolet spectrometer (FTUVS) from JPL and two moderate‐resolution grating spectrometers, multifunction differential optical absorption spectroscopy (MF‐DOAS) (∌0.8 nm) from Washington State University and Pandora (∌0.4 nm) from NASA Goddard Space Flight Center. FTUVS uses high spectral resolution to determine the absolute NO_2 column abundance independently from the exoatmospheric solar irradiance using rovibrational NO_2 absorption lines. The NO_2 total column is retrieved after removing the solar background using Doppler‐shifted spectra from the east and west limbs of the Sun. The FTUVS measurements were used to validate the independently calibrated measurements of multifunction differential optical absorption spectroscopy (MF‐DOAS) and Pandora. The latter two instruments start with measured high‐Sun spectra as solar references to retrieve relative NO_2 columns and then apply modified Langley or “bootstrap” methods to determine the amounts of NO_2 in the references to obtain the absolute NO_2 columns. The calibration offset derived from the FTUVS measurements is consistent with the values derived from Langley and bootstrap calibration plots of the NO_2 slant column measured by the grating spectrometers. The calibrated total vertical column abundances of NO_2, C_(NO_2) from all three instruments are compared showing that MF‐DOAS and Pandora data agree well with each other, and both data sets agree with FTUVS data to within (1.5 ± 4.1)% and (6.0 ± 6.0)%, respectively

    Probing the nuclide 180W for neutrinoless double-electron capture exploration

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    The mass difference of the nuclides 180W and 180Hf has been measured with the Penning-trap mass spectrometer SHIPTRAP to investigate 180W as a possible candidate for the search for neutrinoless doubleelectron capture. The Q-value was measured to 143.20(27)keV. This value in combination with the calculations of the atomic electron wave functions and other parameters results in a half-life of the 0+ \rightarrow 0+ ground-state to ground-state double-electron capture transition of approximately 5\cdot10E27 years/^2

    Measurement of the B0-anti-B0-Oscillation Frequency with Inclusive Dilepton Events

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    The B0B^0-Bˉ0\bar B^0 oscillation frequency has been measured with a sample of 23 million \B\bar B pairs collected with the BABAR detector at the PEP-II asymmetric B Factory at SLAC. In this sample, we select events in which both B mesons decay semileptonically and use the charge of the leptons to identify the flavor of each B meson. A simultaneous fit to the decay time difference distributions for opposite- and same-sign dilepton events gives Δmd=0.493±0.012(stat)±0.009(syst)\Delta m_d = 0.493 \pm 0.012{(stat)}\pm 0.009{(syst)} ps−1^{-1}.Comment: 7 pages, 1 figure, submitted to Physical Review Letter

    Measurement of D-s(+) and D-s(*+) production in B meson decays and from continuum e(+)e(-) annihilation at √s=10.6 GeV

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    This is the pre-print version of the Article. The official published version can be accessed from the links below. Copyright @ 2002 APSNew measurements of Ds+ and Ds*+ meson production rates from B decays and from qq̅ continuum events near the ΄(4S) resonance are presented. Using 20.8 fb-1 of data on the ΄(4S) resonance and 2.6 fb-1 off-resonance, we find the inclusive branching fractions B(B⃗Ds+X)=(10.93±0.19±0.58±2.73)% and B(B⃗Ds*+X)=(7.9±0.8±0.7±2.0)%, where the first error is statistical, the second is systematic, and the third is due to the Ds+→φπ+ branching fraction uncertainty. The production cross sections σ(e+e-→Ds+X)×B(Ds+→φπ+)=7.55±0.20±0.34pb and σ(e+e-→Ds*±X)×B(Ds+→φπ+)=5.8±0.7±0.5pb are measured at center-of-mass energies about 40 MeV below the ΄(4S) mass. The branching fractions ÎŁB(B⃗Ds(*)+D(*))=(5.07±0.14±0.30±1.27)% and ÎŁB(B⃗Ds*+D(*))=(4.1±0.2±0.4±1.0)% are determined from the Ds(*)+ momentum spectra. The mass difference m(Ds+)-m(D+)=98.4±0.1±0.3MeV/c2 is also measured.This work was supported by DOE and NSF (USA), NSERC (Canada), IHEP (China), CEA and CNRS-IN2P3 (France), BMBF (Germany), INFN (Italy), NFR (Norway), MIST (Russia), and PPARC (United Kingdom). Individuals have received support from the Swiss NSF, A. P. Sloan Foundation, Research Corporation, and Alexander von Humboldt Foundation
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