23 research outputs found

    Revisiting the Local Scaling Hypothesis in Stably Stratified Atmospheric Boundary Layer Turbulence: an Integration of Field and Laboratory Measurements with Large-eddy Simulations

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    The `local scaling' hypothesis, first introduced by Nieuwstadt two decades ago, describes the turbulence structure of stable boundary layers in a very succinct way and is an integral part of numerous local closure-based numerical weather prediction models. However, the validity of this hypothesis under very stable conditions is a subject of on-going debate. In this work, we attempt to address this controversial issue by performing extensive analyses of turbulence data from several field campaigns, wind-tunnel experiments and large-eddy simulations. Wide range of stabilities, diverse field conditions and a comprehensive set of turbulence statistics make this study distinct

    Assessing the dependence of surface layer atmospheric stability on measurement height at offshore locations

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    This was published in the Journal of Wind Engineering and Industrial Aerodynamics [© Elsevier] and the definitive version is available at: http://dx.doi.org/10.1016/j.jweia.2014.06.002Incorporating atmospheric stability into wind resource assessment modelling is becoming more common. This study investigates some of the challenges associated with calculating stability in the offshore environment. Data are analysed from meteorological masts FINO1 and FINO3 in the German North Sea using measurements at three different heights and results show significant differences in stability assessment depending on which combination of heights are used. All methods show the North Sea to be very unstable for the majority of the time, although by ignoring wind and thermal data from below 50m, the atmosphere appears more stable, indicating the presence of a marine internal boundary layer. Even 80km out to sea, it is suggested FINO3 still feels the effects of land, and it is clear the height of the atmospheric surface layer effects wind speed measurements under certain conditions

    Standardizing ordinal subadult age indicators : testing for observer agreement and consistency across modalities

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    Skeletal and dental data for subadult analyses obtained from dry bones or various types of medical images, such as computed tomography (CT) scans or conventional radiographs/x-rays, should be consistent and repeatable to ensure method applicability across modalities and support combining study samples. The present study evaluates observer agreement of epiphyseal fusion and dental development stages obtained on CT scans of a U.S. sample and the consistency of epiphyseal fusion stages between CT scans and projected scan radiographs/scout images (U.S. CT sample), and between dry bones and conventional x-rays (Colombian osteological sample). Results show that both intra- and interobserver agreements of scores on CT scans were high (intra: mean Cohen’s kappa = 0.757–0.939, inter: mean Cohen’s kappa = 0.773–0.836). Agreements were lower for dental data (intra: mean Cohen’s kappa = 0.757, inter: mean Cohen’s kappa = 0.773–0.0.820) compared to epiphyseal fusion data (intra: mean Cohen’s kappa = 0.939, inter: mean Cohen’s kappa = 0.807–0.836). Consistency of epiphyseal fusion stages was higher between dry bones and conventional x-rays than between CT scans and scout images (mean Cohen’s kappa = 0.708–0.824 and 0.726–0.738, respectively). Differences rarely surpassed a one-stage value between observers or modalities. The complexity of some ossification patterns and superimposition had a greater negative impact on agreement and consistency rates than observer experience. Results suggest ordinal subadult skeletal data can be collected and combined across modalities.The National Institute of Justice and the National Science Foundation.http://www.elsevier.com/locate/forsciint2022-01-10hj2021Anatom

    Effect of the synthetic immunomodulator, Linomide, on experimental models of thyroiditis

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    The drug Linomide is an immunomodulator showing marked down-regulation of several experimental autoimmune diseases. In this study, its effect on three different experimental models of thyroid disease and on spontaneous infiltration of salivary glands (sialoadenitis), was investigated. Although very effective at preventing thyroid infiltrates in mice immunized with mouse thyroglobulin and complete Freund’s adjuvant and in spontaneous models of thyroiditis and sialoadenitis, it completely failed to modify experimental autoimmune thyroiditis (EAT) induced in mice immunized with mouse thyroglobulin and lipopolysaccharide. There was no significant shift in the observed isotypes of anti-mouse thyroglobulin antibodies and only anti-mouse thyroglobulin antibodies in the spontaneous model were completely down-modulated by the drug. One surprising fact to emerge was that Linomide-treated donor mice, although protected from thyroid lesions themselves, were still able to transfer EAT showing that they must have been effectively primed while being treated with Linomide. It is possible that the drug down modulated EAT by interfering with the trafficking of primed effector cells
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