94 research outputs found

    Steady incompressible potential flow around lifting bodies immersed in a fluid

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    The refinement was investigated of a method for evaluating the pressure distribution on a body surface of arbitrary shape in incompressible flow. The solution was obtained in terms of the velocity potential, through numerical approximations which require the use of a high speed digital computer. The box method and the modal method are described in detail, and were applied to a very thin, rectangular wing in incompressible, steady flow. The box method is found to be more practical as it is applicable to more general geometries (the modal method requires a new set of functions for each geometry), and requires less computer time (fifty percent of that required by the modal method for the same problem)

    Identification and Characterization of Microcin S, a New Antibacterial Peptide Produced by Probiotic Escherichia coli G3/10

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    Escherichia coli G3/10 is a component of the probiotic drug Symbioflor 2. In an in vitro assay with human intestinal epithelial cells, E. coli G3/10 is capable of suppressing adherence of enteropathogenic E. coli E2348/69. In this study, we demonstrate that a completely novel class II microcin, produced by probiotic E. coli G3/10, is responsible for this behavior. We named this antibacterial peptide microcin S (MccS). Microcin S is coded on a 50.6 kb megaplasmid of E. coli G3/10, which we have completely sequenced and annotated. The microcin S operon is about 4.7 kb in size and is comprised of four genes. Subcloning of the genes and gene fragments followed by gene expression experiments enabled us to functionally characterize all members of this operon, and to clearly identify the nucleotide sequences encoding the microcin itself (mcsS), its transport apparatus and the gene mcsI conferring self immunity against microcin S. Overexpression of cloned mcsI antagonizes MccS activity, thus protecting indicator strain E. coli E2348/69 in the in vitro adherence assay. Moreover, growth of E. coli transformed with a plasmid containing mcsS under control of an araC PBAD activator-promoter is inhibited upon mcsS induction. Our data provide further mechanistic insight into the probiotic behavior of E. coli G3/10

    First Cold Powering Test of REBCO Roebel Wound Coil for the EuCARD2 Future Magnet Development Project

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    EuCARD-2 is a project partly supported by FP7-European Commission aiming at exploring accelerator magnet technology for 20 T dipole operating field. The EuCARD-2 collaboration is liaising with similar programs for high field magnets in the USA and Japan. EuCARD-2 focuses, through the work-package 10 'Future magnets,' on the development of a 10 kA-class superconducting, high current density cable suitable for accelerator magnets, for a 5 T stand-alone dipole of 40 mm bore and about 1 m length. After standalone testing, the magnet will possibly be inserted in a large bore background dipole, to be tested at a peak field up to 18 T. This paper starts by reporting on a few of the highlight simulations that demonstrate the progress made in predicting: dynamic current distribution and influence on field quality, complex quench propagation between tapes, and minimum quench energy in the multitape cable. The multiphysics output importantly helps predicting quench signals and guides the development of the novel early detection systems. Knowing current position within individual tapes of each cable we present stress distribution throughout the coils. We report on the development of the mechanical component and assembly processes selected for Feather-M2 the 5 T EuCARD2 magnet. We describe the CERN variable temperature flowing helium cold gas test system. We describe the parallel integration of the FPGA early quench detection system, using pickup coils and temperature sensors, alongside the standard CERN magnet quench detection system using voltage taps. Finally we report on the first cold tests of the REBCO 10 kA class Roebel subscale coil named Feather-M0

    Design of a Protective Single-Dose Intranasal Nanoparticle-Based Vaccine Platform for Respiratory Infectious Diseases

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    Despite the successes provided by vaccination, many challenges still exist with respect to controlling new and re-emerging infectious diseases. Innovative vaccine platforms composed of adaptable adjuvants able to appropriately modulate immune responses, induce long-lived immunity in a single dose, and deliver immunogens in a safe and stable manner via multiple routes of administration are needed. This work describes the development of a novel biodegradable polyanhydride nanoparticle-based vaccine platform administered as a single intranasal dose that induced long-lived protective immunity against respiratory disease caused by Yesinia pestis, the causative agent of pneumonic plague. Relative to the responses induced by the recombinant protein F1-V alone and MPLA-adjuvanted F1-V, the nanoparticle-based vaccination regimen induced an immune response that was characterized by high titer and high avidity IgG1 anti-F1-V antibody that persisted for at least 23 weeks post-vaccination. After challenge, no Y. pestis were recovered from the lungs, livers, or spleens of mice vaccinated with the nanoparticle-based formulation and histopathological appearance of lung, liver, and splenic tissues from these mice post-vaccination was remarkably similar to uninfected control mice

    Cryogenic temperature monitoring in superconducting power transmission line at CERN with hybrid multi-point and distributed fiber optic sensors

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    Distributed and multi-point fiber-optic based measurements of cryogenic temperature down to 30 K are presented. Measurements have been performed along the cryostat of a superconducting power transmission line, which is currently being tested at CERN over a length of about 20 m. Multi-point measurements were based on two kinds of FBG with different coatings (epoxy and PMMA). In addition, distributed measurements exploited optical frequency-domain reflectometry to analyze the Rayleigh scattering along two concatenated fibers with different coatings (acrylate and polyimmide). Results confirm the viability of these approaches to monitor cryogenic temperatures along a superconducting transmission line.© (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only

    Embedded fiber Bragg grating sensors for true temperature monitoring in Nb3_3Sn superconducting magnets for high energy physics

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    The luminosity upgrade of the Large Hadron Collider (HL-LHC) planned at the European Organization for Nuclear Research (CERN) requires the development of a new generation of superconducting magnets based on Nb3_{3}Sn technology. The instrumentation required for the racetrack coils needs the development of reliable sensing systems able to monitor the magnet thermo-mechanical behavior during its service life, from the coil fabrication to the magnet operation. With this purpose, Fiber Bragg Grating (FBG) sensors have been embedded in the coils of the Short Model Coil (SMC) magnet fabricated at CERN. The FBG sensitivity to both temperature and strain required the development of a solution able to separate mechanical and temperature effects. This work presents for the first time a feasibility study devoted to the implementation of an embedded FBG sensor for the measurement of the "true" temperature in the impregnated Nb3_{3}Sn coil during the fabrication process. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only
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