3,247 research outputs found

    OGO-E space vehicle response to transient loading at Atlas booster engine cutoff

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    Computer program for OGO-E vehicle response analysis to transient loading during Atlas booster burnou

    Liquid metal magnetohydrodynamics (LMMHD) technology transfer feasibility study. Volume 1: Summary

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    The potential application of liquid metal magnetohydrodynamics (LMMHD) to central station utility power generation through the period to 1990 is examined. Included are: (1) a description of LMMHD and a review of its development status, (2) LMMHD preliminary design for application to central station utility power generation, (3) evaluation of LMMHD in comparison with conventional and other advanced power generation systems and (4) a technology development plan. One of the major conclusions found is that the most economic and technically feasible application of LMMHD is a topping cycle to a steam plant, taking advantage of high temperatures available but not usable by the steam cycle

    Molecular dynamics simulations of liquid nitromethane

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    A potential energy function with harmonic intramolecular and Lennard-Jones plus Coulombic intermolecular terms was tested in molecular dynamics simulations of liquid nitromethane. Parameter values were adjusted iteratively until satisfactory agreement with density functional pair calculations and experimental data was achieved. The properties computed using the NVT and NPT ensembles were the heat of vaporization, dielectric constant, self-diffusion coefficient, density, heat capacity at constant pressure, pair correlation functions, single molecule and collective dipole moment reorientation times, the vibrational spectrum, and the effect of increasing pressure upon the C−N stretching frequency. Overall, the results were in reasonable accord with experimental results, the greatest discrepancy being for the dielectric constant. It was concluded, on the basis of the reorientation times and the calculated molecular

    Effect of kinetic resonances on the stability of Resistive Wall Mode in Reversed Field Pinch

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    The kinetic effects, due to the mode resonance with thermal particle drift motions in the reversed field pinch (RFP) plasmas, are numerically investigated for the stability of the resistive wall mode, using a non-perturbative MHD-kinetic hybrid formulation. The kinetic effects are generally found too weak to substantially change the mode growth rate, or the stability margin, re-enforcing the fact that the ideal MHD model is rather adequate for describing the RWM physics in RFP experiments.Comment: Submitted to: Plasma Phys. Control. Fusio

    The Young and Bright Type Ia Supernova ASASSN-14lp: Discovery, Early-Time Observations, First-Light Time, Distance to NGC 4666, and Progenitor Constraints

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    On 2014 Dec. 9.61, the All-Sky Automated Survey for SuperNovae (ASAS-SN or "Assassin") discovered ASASSN-14lp just 2\sim2 days after first light using a global array of 14-cm diameter telescopes. ASASSN-14lp went on to become a bright supernova (V=11.94V = 11.94 mag), second only to SN 2014J for the year. We present prediscovery photometry (with a detection less than a day after first light) and ultraviolet through near-infrared photometric and spectroscopic data covering the rise and fall of ASASSN-14lp for more than 100 days. We find that ASASSN-14lp had a broad light curve (Δm15(B)=0.80±0.05\Delta m_{15}(B) = 0.80 \pm 0.05), a BB-band maximum at 2457015.82±0.032457015.82 \pm 0.03, a rise time of 16.940.10+0.1116.94^{+ 0.11 }_{- 0.10 } days, and moderate host--galaxy extinction (E(BV)host=0.33±0.06E(B-V)_{\textrm{host}} = 0.33 \pm 0.06). Using ASASSN-14lp we derive a distance modulus for NGC 4666 of μ=30.8±0.2\mu = 30.8 \pm 0.2 corresponding to a distance of 14.7±1.514.7 \pm 1.5 Mpc. However, adding ASASSN-14lp to the calibrating sample of Type Ia supernovae still requires an independent distance to the host galaxy. Finally, using our early-time photometric and spectroscopic observations, we rule out red giant secondaries and, assuming a favorable viewing angle and explosion time, any non-degenerate companion larger than 0.34Rsun0.34 R_{\textrm{sun}}.Comment: 12 pages, 9 figures, 4 tables. Accepted to ApJ. Photometric data presented in this submission are included as an ancillary file. For a brief video explaining this paper, see https://www.youtube.com/watch?v=1bOV-Cqs-a

    Integration of Evidence Based Medicine into a Medical Curriculum

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    The College of Medicine at King Saud bin Abdulaziz University for Health Sciences (KSAU-HS) was established in January 2004. The four-year curriculum was based on the Problem Based Learning (PBL) format and involved the web-based graduate medical program adopted from the University of Sydney, Australia. At KSAU-HS, one additional semester was added to the beginning of this curriculum to prepare the students in English language skills, PBL, Information Technology and Evidence Based Medicine (EBM). EBM is part of the Personal and Professional Development (PPD) theme of the medical curriculum and is integrated into each stage of the medical curriculum. These modifications of the University of Sydney curriculum are presented here as a model of EBM integration into a college of medicine curriculum

    Higher-Order QCD Corrections to Inclusive Particle Production in p anti-p Collisions

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    Inclusive single-particle production cross sections have been calculated including higher-order QCD corrections. Transverse-momentum and rapidity distributions are presented and the scale dependence is studied. The results are compared with experimental data from the CERN S(p anti-p)S Collider and the Fermilab Tevatron.Comment: 28 pages, [12 uuencoded PS figures, 3 available under request]. Preprint DESY 92-13

    Thermal phenomenology of hadrons from 200 AGeV S+S collisions

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    We develop a complete and consistent description for the hadron spectra from heavy ion collisions in terms of a few collective variables, in particular temperature, longitudinal and transverse flow. To achieve a meaningful comparison with presently available data, we also include the resonance decays into our picture. To disentangle the influences of transverse flow and resonance decays in the mTm_T-spectra, we analyse in detail the shape of the mTm_T-spectra.Comment: 31 pages, 13 figs in seperate uuencoded file, for LaTeX, epsf.sty and dvips, TPR-93-16 and BNL-(no number yet
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