12,239 research outputs found

    Experimental aerodynamic heating to simulated shuttle tiles

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    The heat transfer to simulated shuttle thermal protection system tiles was investigated experimentally using a highly instrumented metallic thin wall tile arranged with other metal tiles in a staggered tile array. Cold-wall heating rate data for laminar and turbulent flow were obtained in the Langley 8-foot high temperature tunnel at a nominal Mach number of 7, a nominal total temperature of 3300 R, free-stream unit Reynolds number from 3.4 x 10 to the 5th power to 2.2 x 10 to the 6th power per foot, and free-stream dynamic pressure of 1.8 psia to 9.1 psia. Experimental data are presented to illustrate the effects of flow angularity and gap width on both local peak heating and overall heating loads

    Weight outcomes audit for 34,271 adults referred to a primary care/commercial weight management partnership scheme

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    Copyright © 2011 S. Karger AG, Basel.Peer reviewedPublisher PD

    Closed-circuit television welding- electrode guidance system

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    Closed-circuit TV camera is mounted parallel to electrode and moves along with it. Camera is scanned along seam so seam is viewed parallel with scan lines on TV monitor. Two fiber optics illuminators are attached to guidance system; they illuminate seam for TV camera

    Aerosol chemical composition in Asian continental outflow during the TRACE-P campaign: Comparison with PEM-West B

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    Aerosol associated soluble ions and the radionuclide tracers 7Be and 210Pb were quantified in 414 filter samples collected in spring 2001 from the DC-8 during the Transport and Chemical Evolution over the Pacific (TRACE-P) campaign. Binning the data into near Asia (flights from Hong Kong and Japan) and remote Pacific (all other flights) revealed large enhancements of NO3−, SO4=, C2O4=, NH4+, K+, Mg2+, and Ca2+ near Asia. The boundary layer and lower troposphere were most strongly influenced by continental outflow, and the largest enhancements were seen in Ca2+ (a dust tracer) and NO3− (reflecting uptake of HNO3 onto the dust). Comparing the TRACE P near Asia bin with earlier results from the same region during PEM-West B (in 1994) shows at least twofold enhancements during TRACE P in most of the ions listed above. Calcium and NO3− were most enhanced in this comparison as well (more than sevenfold higher in the boundary layer and threefold higher in the lower troposphere). Independent estimation of Asian emissions of gaseous precursors of the aerosol-associated ions suggest only small changes between the two missions, and precipitation fields do not suggest any significant difference in the efficiency of the primary sink, precipitation scavenging. It thus appears that with the possible exception of dust, the enhancements of aerosol-associated species during TRACE P cannot be explained by stronger sources or weaker sinks. We argue that the enhancements largely reflect the fact that TRACE P focused on characterizing Asian outflow, and thus the DC-8 was more frequently flown into regions that were influenced by well-organized flow off the continent

    Virtual Data in CMS Analysis

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    The use of virtual data for enhancing the collaboration between large groups of scientists is explored in several ways: - by defining ``virtual'' parameter spaces which can be searched and shared in an organized way by a collaboration of scientists in the course of their analysis; - by providing a mechanism to log the provenance of results and the ability to trace them back to the various stages in the analysis of real or simulated data; - by creating ``check points'' in the course of an analysis to permit collaborators to explore their own analysis branches by refining selections, improving the signal to background ratio, varying the estimation of parameters, etc.; - by facilitating the audit of an analysis and the reproduction of its results by a different group, or in a peer review context. We describe a prototype for the analysis of data from the CMS experiment based on the virtual data system Chimera and the object-oriented data analysis framework ROOT. The Chimera system is used to chain together several steps in the analysis process including the Monte Carlo generation of data, the simulation of detector response, the reconstruction of physics objects and their subsequent analysis, histogramming and visualization using the ROOT framework.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics (CHEP03), La Jolla, Ca, USA, March 2003, 9 pages, LaTeX, 7 eps figures. PSN TUAT010. V2 - references adde

    Ds+ϕρ+D_s^+ \to \phi \rho^+ Decay

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    Motivated by the experimental measurement of the decay rate, Γ\Gamma, and the longitudinal polarization, PLP_L, in the Cabibbo favored decay Ds+ϕρ+D_s^+\to \phi {\rho}^{+}, we have studied theoretical prediction within the context of factorization approximation invoking several form factors models. We were able to obtain agreement with experiment for both Γ\Gamma and PLP_L by using experimentally measured values of the form factors A1Dsϕ(0)A_1^{D_s\phi}(0), A2Dsϕ(0)A_2^{D_s\phi}(0) and VDsϕ(0)V^{D_s\phi}(0) in the semi-leptonic decay Ds+ϕl+νlD_s^+\to \phi l^{+}\nu_{l}. We have also included in our calculation the effect of the final state interaction (fsifsi) by working with the partial waves amplitudes SS, PP and DD. Numerical calculation shows that the decay amplitude is dominated by SS wave, and that the polarization is sensitive to the interference between SS and DD waves. The range of the phase difference δSD=δSδD\delta_{SD} = \delta_S - \delta_D accommodated by experimental error in PLP_L is large.Comment: 7 pages, LaTe

    Impact of multiscale dynamical processes and mixing on the chemical composition of the upper troposphere and lower stratosphere during the Intercontinental Chemical Transport Experiment–North America

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    We use high-frequency in situ observations made from the DC8 to examine fine-scale tracer structure and correlations observed in the upper troposphere and lower stratosphere during INTEX-NA. Two flights of the NASA DC-8 are compared and contrasted. Chemical data from the DC-8 flight on 18 July show evidence for interleaving and mixing of polluted and stratospheric air masses in the vicinity of the subtropical jet in the upper troposphere, while on 2 August the DC-8 flew through a polluted upper troposphere and a lowermost stratosphere that showed evidence of an intrusion of polluted air. We compare data from both flights with RAQMS 3-D global meteorological and chemical model fields to establish dynamical context and to diagnose processes regulating the degree of mixing on each day. We also use trajectory mapping of the model fields to show that filamentary structure due to upstream strain deformation contributes to tracer variability observed in the upper troposphere. An Eulerian measure of strain versus rotation in the large-scale flow is found useful in predicting filamentary structure in the vicinity of the jet. Higher-frequency (6–24 km) tracer variability is attributed to buoyancy wave oscillations in the vicinity of the jet, whose turbulent dissipation leads to efficient mixing across tracer gradients
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