393 research outputs found

    Reduction of Skylab 2 ground winds

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    A dampometer was designed and fabricated for measuring the amount of damping in the wind tunnel test model. The ground winds data reduction system (GWDRS) was taken to Langley Research Center in support of wind tunnel tests on the Skylab 2 program. Final data reduction of the test results was accomplished by the GWDRS

    Considerations on the frequency resource of professional wireless microphone systems

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    This Paper presents the results of spectral observations in the UHF TV Bands IV and V from 470 MHz up to 862 MHz with focus on the TV-Channels 61 to 63 and 67 to 69. Concerning the discussions on citet{WRC} this frequency range is in great demand of several applications and is usually treated as a "white space" in the TV-Bands. According to typical scenarios, two different spectral loads will be presented considering the requirements of professional wireless microphone receivers with respect to in-band intermodulation

    Die Betriebswirtschaftliche Beratung in Deutschland

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    Auszug aus einem Vortrag, gehalten am 9. 11.1956 in der Finnischen Landwirtschaftswissenschaftlichen Gesellschaft in Helsink

    Optimization-based calibration of hydrodynamic drag coefficients for a semisubmersible platform using experimental data of an irregular sea state

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    For the simulation of the coupled dynamic response of floating offshore wind turbines, it is crucial to calibrate the hydrodynamic damping with experimental data. The aim of this work is to find a set of hydrodynamic drag coefficients for the semisubmersible platform of the Offshore Code Comparison Collaboration, Continuation, with Correlation and unCertainity (OC6) project which provides suitable results for an irregular sea state. Due to the complex interaction of several degrees of freedom (DOF), it is common to calibrate drag coefficients with the time series of decay tests. However, applying these drag coefficients for the simulation of an irregular sea state results in misprediction of the motions. By using numerical optimization, it is possible to calibrate multiple drag coefficients simultaneously and effectively, while also considering several DOF. This work considers time series of structural displacements from wave tank tests of the OC6 project and from simulations of the same load cases in OpenFAST. Results are transferred into the frequency domain and the deviation between power spectral densities of surge, pitch and heave from experiment and numerical simulation is used as an objective function to obtain the best fitting drag coefficients. This novel numerical optimization approach enables finding one set of drag coefficients for different load cases, which is a major improvement compared to decay-test-tuned drag coefficients. © Published under licence by IOP Publishing Ltd

    Cryptococcus neoformans ex vivo capsule size is associated with intracranial pressure and host immune response in HIV-associated cryptococcal meningitis

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    <p>Background. The Cryptococcus neoformans polysaccharide capsule is a well-characterised virulence factor with immunomodulatory properties. The organism and/or shed capsule is postulated to raise intracranial pressure(ICP) in cryptococcal meningitis(CM) by mechanical obstruction of cerebrospinal fluid(CSF) outflow. Little is known regarding capsule phenotype in human cryptococcosis. We investigated the relationship of ex vivo CSF capsular phenotype with ICP and CSF immune response, as well as in vitro phenotype.</p> <p>Methods. 134 HIV-infected Ugandan adults with CM had serial lumbar punctures with measurement of CSF opening pressures, quantitative cultures, ex vivo capsule size and shedding, viscosity, and CSF cytokines. 108 had complete data. Induced capsular size and shedding were measured in vitro for 48 C. neoformans isolates.</p> <p>Results. Cryptococcal strains producing larger ex vivo capsules in the baseline(pre-treatment) CSF correlated with higher ICP(P=.02), slower rate of fungal clearance(P=.02), and paucity of CSF inflammation, including decreased CSF white blood cell(WBC) count(P<.001), interleukin(IL)-4(P=.02), IL-6(P=.01), IL-7(P=.04), IL-8(P=.03), and interferon-gamma(P=.03). CSF capsule shedding did not correlate with ICP. On multivariable analysis, capsule size remained independently associated with ICP. Ex vivo capsular size and shedding did not correlate with that of the same isolates grown in vitro.</p> <P>Conclusions. Cryptococcal capsule size ex vivo is an important contributor to virulence in human cryptococcal meningitis.</P&gt

    Material Modelling of Short Fiber Reinforced Thermoplastic for the FEA of a Clinching Test

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    In modern car body construction, multi-material and hybrid design is used, whereby short fibre reinforced plastics combined with light metals represent an interesting class of work-piece materials. In order to realize modern hybrid construction, suitable joining techniques are therefore required. Clinching represents a cost-effective and easy to implement joining method. In this paper the material modelling of the short fibre reinforced thermoplastic sheets considering the fibre orientation tensor for the FEA of the clinching process is presented

    Importance of decision support implementation in emergency department vancomycin dosing

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    INTRODUCTION: The emergency department (ED) plays a critical role in the management of life-threatening infection. Prior data suggest that ED vancomycin dosing is frequently inappropriate. The objective is to assess the impact of an electronic medical record (EMR) intervention designed to improve vancomycin dosing accuracy, on vancomycin dosing and clinical outcomes in critically ill ED patients. METHODS: Retrospective before-after cohort study of all patients (n=278) treated with vancomycin in a 60,000-visit Midwestern academic ED (March 2008 and April 2011) and admitted to an intensive care unit. The primary outcome was the proportion of vancomycin doses defined as “appropriate” based on recorded actual body weight. We also evaluated secondary outcomes of mortality and length of stay. RESULTS: The EMR dose calculation tool was associated with an increase in mean vancomycin dose ([14.1±5.0] vs. [16.5±5.7] mg/kg, p<0.001) and a 10.3% absolute improvement in first-dose appropriateness (34.3% vs. 24.0%, p=0.07). After controlling for age, gender, methicillin-resistant staphylococcus aureus infection, and Acute Physiology and Chronic Health Evaluation II score, 28-day in-hospital mortality (odds ratio OR 1.72; 95% CI [0.76–3.88], p=0.12) was not affected. CONCLUSION: A computerized decision-support tool is associated with an increase in mean vancomycin dose in critically ill ED patients, but not with a statistically significant increase in therapeutic vancomycin doses. The impact of decision-support tools should be further explored to optimize compliance with accepted antibiotic guidelines and to potentially affect clinical outcome

    Manipulating ionization path in a Stark map: Stringent schemes for the selective field ionization in highly excited Rb Rydberg atoms

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    We have developed a quite stringent method in selectivity to ionize the low angular- momentum (\ell) states which lie below and above the adjacent manifold in highly excited Rb Rydberg atoms. The method fully exploits the pulsed field-ionization characteristics of the manifold states in high slew-rate regime: Specifically the low \ell state below (above) the adjacent manifold is firstly transferred to the lowest (highest) state in the manifold via the adiabatic transition at the first avoided crossing in low slew-rate regime, and then the atoms are driven to a high electric field for ionization in high slew-rate regime. These extreme states of the manifold are ionized at quite different fields due to the tunneling process, resulting in thus the stringent selectivity. Two manipulation schemes to realize this method actually are demonstrated here experimentally.Comment: 10 pages, 4 figure

    Saccadic suppression in schizophrenia

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    About 40% of schizophrenia patients report discrete visual disturbances which could occur if saccadic suppression, the decrease of visual sensitivity around saccade onset, is impaired. Two mechanisms contribute to saccadic suppression: eeference copy processing and backwards masking. Both are reportedly altered in schizophrenia. However, saccadic suppression has not been investigated in schizophrenia. 17 schizophrenia patients and 18 healthy controls performed a saccadic suppression task using a Gabor stimulus with individually adjusted contrast, which was presented within an interval 300 ms around saccade onset. Visual disturbance scores were higher in patients than controls, but saccadic suppression strength and time course were similar in both groups with lower saccadic suppression rates being similarly related to smaller saccade amplitudes. Saccade amplitudes in the saccadic suppression task were reduced in patients, in contrast to unaltered amplitudes during a saccade control task. Notably, smaller saccade amplitudes were related to higher visual disturbances scores in patients. Saccadic suppression performance was unrelated to symptom expression and antipsychotic medication. Unaltered saccadic suppression in patients suggests sufficiently intact eeference copy processing and backward masking as required for this task. Instead, visual disturbances in patients may be related to restricted saccadic amplitudes arising from cognitive load while completing a task
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