3,700 research outputs found

    NNLOPS accurate associated HW production

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    We present a next-to-next-to-leading order accurate description of associated HW production consistently matched to a parton shower. The method is based on reweighting events obtained with the HW plus one jet NLO accurate calculation implemented in POWHEG, extended with the MiNLO procedure, to reproduce NNLO accurate Born distributions. Since the Born kinematics is more complex than the cases treated before, we use a parametrization of the Collins-Soper angles to reduce the number of variables required for the reweighting. We present phenomenological results at 13 TeV, with cuts suggested by the Higgs Cross Section Working Group.Comment: Minor changes, plots updated, matches the version published in JHE

    Natural laminar flow nacelle for transport aircraft

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    The potential of laminar flow nacelles for reducing installed engine/nacelle drag was studied. The purpose was twofold: to experimentally verify a method for designing laminar flow nacelles and to determine the effect of installation on the extent of laminar flow on the nacelle and on the nacelle pressure distributions. The results of the isolated nacelle tests illustrated that laminar flow could be maintained over the desired length. Installing the nacelles on wing/pylon did not alter the extent of laminar flow occurring on the nacelles. The results illustrated that a significant drag reduction was achieved with this laminar flow design. Further drag reduction could be obtained with proper nacelle location and pylon contouring

    A Wind Tunnel Investigation of Three NACA 1-Series Inlets at Mach Numbers up to 0.92

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    Pressure distributions on three NACA 1-series inlets have been obtained in the Langley 16-Foot Transonic Tunnel. The cowl diameter ratio (ratio of cowl highlight diameter to cowl maximum diameter) was 0.85 for all three inlets. The cowl length ratio (ratio of cowl length to cowl maximum diameter) was 1.0 for two of the inlets (NACA 1-85-100) and 0.439 for the other (NACA 1-85-43.9) inlet. One of the inlets with a cowl length ratio of 1.0 had an internal contraction ratio (ratio of highlight area to throat area) of 1.009 and the other had a contraction ratio of 1.250. The inlet with a cowl length ratio of 0.439 also had an internal contraction ratio of 1.250. All three inlets had longitudinal rows of static pressure orifices on the top and bottom external cowl surfaces. The inlet with a contraction ratio of 1.009 also had a row of static pressure orifices on the side of the cowl (external surface). The two inlets with a contraction ratio of 1.250 had a longitudinal row of static pressure orifices on the diffuser surface

    Wind tunnel investigation of three axisymmetric cowls of different lengths at Mach numbers from 0.60 to 0.92

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    Pressure distributions on three inlets having different cowl lengths were obtained in the Langley 16-Foot Transonic Tunnel. The cowl diameter ratio (highlight diameter to maximum diameter) was 0.85 and the cowl length ratios (cowl length to maximum diameter) were 0.337, 0.439, and 0.547. The cowls had identical nondimensionalized (with respect to cowl length) external geometry and identical internal geometry. The internal contraction ratio (highlight area to throat area) was 1.250. The inlets had longitudinal rows of static pressure orifices on the top and bottom (external) surfaces and on the contraction (internal) and diffuser surfaces. The afterbody was cylindrical in shape, and its diameter was equal to the maximum diameter of the cowl. Depending on the cowl configuration and free-stream Mach number, the mass-flow ratio varied between 0.27 and 0.87 during the tests. Angle of attack varied from 0 to 4.1 deg at selected Mach numbers and mass-flow ratios, and the Reynolds number varied with the Mach number from 3.2x10(exp 6) to 4.2x10(exp 6) per foot

    Transonic Aerodynamic Loading Characteristics of a Wing-Body-Tail Combination Having a 52.5 deg. Sweptback Wing of Aspect Ratio 3 With Conical Wing Camber and Body Indentation for a Design Mach Number of Square Root of 2

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    An investigation has been made of the effects of conical wing camber and body indentation according to the supersonic area rule on the aerodynamic wing loading characteristics of a wing-body-tail configuration at transonic speeds. The wing aspect ratio was 3, taper ratio was 0.1, and quarter-chord-line sweepback was 52.5 deg. with 3-percent-thick airfoil sections. The tests were conducted in the Langley 16-foot transonic tunnel at Mach numbers from 0.80 to 1.05 and at angles of attack from 0 deg. to 14 deg., with Reynolds numbers based on mean aerodynamic chord varying from 7 x 10(exp 6) to 8 x 10(exp 6). Conical camber delayed wing-tip stall and reduced the severity of the accompanying longitudinal instability but did not appreciably affect the spanwise load distribution at angles of attack below tip stall. Body indentation reduced the transonic chordwise center-of-pressure travel from about 8 percent to 5 percent of the mean aerodynamic chord

    Simulation of 3D periodic piezoelectric transducers radiating in layered media using Finite Element/Boundary element Analysis

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    Abstract. This paper is devoted to the description of a mixed finite element/boundary element analysis for the simulation of any periodic transducer radiating in any combination of solid and fluids assuming flat interfaces and linear operation regime. The theoretical developments required in that purpose are described and different examples of transducers are considered to demonstrate the interest of the proposed approach. 1

    A hepatitis C avidity test for determining recent and past infections in both plasma and dried blood spots

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    DBS testing has been used successfully to detect HCV antibody positive individuals. Determining how long someone has been infected is important for surveillance initiatives. Antibody avidity is a method that can be used to calculate recency of infection. A HCV avidity assay was evaluated for both plasma and DBS. Study design: To measure antibody avidity a commercial HCV ELISA was modified using 7 M urea. The plasma samples were split into: group 1 (recently infected N = 19), group 2 (chronic carrier N = 300) and group 3 (resolved infection N = 82). Mock DBS made from group 1 (N = 12), group 2 (N = 50), group 3 (N = 25) and two seroconverter panels were evaluated. 133 DBS taken from patients known to have a resolved infection or be a chronic carrier were also tested. The avidity assay cut-off was set at AI ≤ 30 for a recent infection. Using sequential samples the assay could detect a recent infection in the first 4–5 months from the point of infection. Most of the false positive results (AI < 30 among cases known not to have had recent infection) were detected among known resolved infections, in both the plasma and DBS; as a result, a testing algorithm has been designed incorporating both PCR and two dilution factors. The sensitivity and specificity of the assay on plasma was 100% and 99.3%, respectively, while DBS had 100% sensitivity and 98.3% specificity. The HCV avidity assay can be used to distinguish between chronic and recent infection using either plasma or DBS as the sample type

    The cyclic GMP modulators YC-1 and zaprinast reduce vessel remodeling through anti-proliferative and pro-apoptotic effects

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    Guanosine-specific cyclic nucleotide signaling is suggested to serve protective actions in the vasculature; however, the influence of selective pharmacologic modulation of cyclic guanosine monophosphate (GMP)-synthesizing soluble guanylate cyclase (sGC) or cyclic GMP-degrading phosphodiesterase (PDE) on vessel remodeling has not been thoroughly examined. In this study, rat carotid artery balloon injury was performed and the growth-modulating effects of the sGC stimulator YC-1 or the cGMP-dependent PDE-V inhibitor zaprinast were examined. YC-1 or zaprinast elevated vessel cyclic GMP content, reduced medial wall and neointimal cell proliferation, stimulated medial and neointimal cellular apoptosis, and markedly attenuated neointimal remodeling in comparable fashion. Interestingly, sGC inhibition by ODQ failed to noticeably alter neointimal growth, and concomitant zaprinast with YC-1 did not modify any parameter compared to individual treatments. These results provide novel in vivo evidence that YC-1 and zaprinast inhibit injury-induced vascular remodeling through anti-mitogenic and pro-apoptotic actions and may offer promising therapeutic approaches against vasoproliferative disorders. Originally published J Cardiovasc Pharmacol Ther, Vol. 14, No. 2, June 200
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