978 research outputs found

    Technical Note: Quantification of interferences of wet chemical HONO measurements under simulated polar conditions

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    International audienceIn the present pilot study, an optimized LOPAP instrument for the detection of nitrous acid (HONO) in the atmosphere (DL 0.2 pptV) was tested at the high alpine research station "Jungfraujoch" at 3580 m altitude in the Swiss Alps under conditions comparable to polar regions. HONO concentrations in the range <0.5?50 pptV with an average of 7.5 pptV were observed at the "Jungfraujoch". The diurnal profiles obtained exhibited clear maxima at noon and minima with very low concentration during the night supporting the proposed photochemical production of HONO. In good agreement with recent measurements at the South Pole, it was demonstrated, that interferences of chemical HONO instruments can significantly influence the measurements and lead to considerable overestimations, especially for low pollution level. Accordingly, the correction of interferences is of paramount importance for those instruments, which sample HONO on aqueous or humid surfaces

    Technical Note: Quantification of interferences of wet chemical HONO LOPAP measurements under simulated polar conditions

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    In the present pilot study, an optimized LOPAP instrument (LOng Path Absorption Photometer) for the detection of nitrous acid (HONO) in the atmosphere (DL 0.2 pptV) was tested at the high alpine research station Jungfraujoch at 3580 m altitude in the Swiss Alps under conditions comparable to polar regions. HONO concentrations in the range &amp;lt;0.5–50 pptV with an average of 7.5 pptV were observed at the Jungfraujoch. The diurnal profiles obtained exhibited clear maxima at noon and minima with very low concentration during the night supporting the proposed photochemical production of HONO. In good agreement with recent measurements at the South Pole, it was demonstrated, that interferences of chemical HONO instruments can significantly influence the measurements and lead to considerable overestimations, especially for low pollution level. Accordingly, the active correction of interferences is of paramount importance for the determination of reliable HONO data

    A general approach for estimating scale score reliability for panel survey data.

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    Scale score measures are ubiquitous in the psychological literature and can be used as both dependent and independent variables in data analysis. Poor reliability of scale score measures leads to inflated standard errors and/or biased estimates, particularly in multivariate analysis. To assess data quality, reliability estimation is usually an integral step in the analysis of scale score data. Cronbach’s α is a widely used indicator of reliability but, due to its rather strong assumptions, can be a poor estimator (Cronbach, 1951). For longitudinal data, an alternative approach is the simplex method; however, it too requires assumptions that may not hold in practice. One effective approach is an alternative estimator of reliability that relaxes the assumptions of both Cronbach’s α and the simplex estimator and, thus, generalizes both estimators. Using data from a large-scale panel survey, the benefits of the statistical properties of this estimator are investigated and its use is illustrated and compared with the more traditional estimators of reliability

    What you should know about Zika virus testing : for pregnant women who may have been exposed to Zika 2-12 weeks ago

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    If you or your sex partner live in or recently traveled to an area with Zika, you may have been exposed to Zika. You may havequestions about Zika and how to find out if you\ue2\u20ac\u2122ve been infected. Learn more about Zika virus testing for pregnant womenand what you might expect if you have Zika virus during pregnancy.CS272943Date printed on piece: December 20, 2016.Date from document properties: modified 1/4/2017igm.pd

    Comparison of H-mode plasmas in JET-ILW and JET-C with and without nitrogen seeding

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    In high confinement mode, highly shaped plasmas with edge localized modes in JET, and for heating power of 15-17 MW, the edge fluid code EDGE2D-EIRENE predicts transition to detachment assisted by nitrogen at the low field side (LFS) target when more than 50% of the power crossing the separatrix between ELMs is radiated in the divertor chamber, i.e. ∼4 MW. This is observed both in the ITER-like wall (JET-ILW) and in the carbon wall (JET-C) configurations and is consistent with experimental observations within their uncertainty. In these conditions, peak heat fluxes below 1 MW m-2 are measured at the LFS target and predicted for both wall configurations. When the JET-C configuration is replaced with the JET-ILW, a factor of two reduction in the divertor radiated power and 25-50% increase in the peak and total power deposited to the LFS divertor plate is predicted by EDGE2D-EIRENE for unseeded plasmas similar to experimental observations. At the detachment threshold, EDGE2D-EIRENE shows that nitrogen radiates more than 80% of the total divertor radiation in JET-ILW with beryllium contributing less than a few %. With JET-C, nitrogen radiates more than 70% with carbon providing less than 20% of the total radiation. Therefore, the lower intrinsic divertor radiation with JET-ILW is compensated by stronger nitrogen radiation contribution in simulations leading to detachment at similar total divertor radiation fractions. 20-100% higher deuterium molecular fraction in the divertor recycling fluxes is predicted with light JET-C materials when compared to heavy tungsten. EDGE2D-EIRENE simulations indicate that the stronger molecular contribution can reduce the divertor peak power deposition in high recycling conditions by 10-20% due to enhanced power dissipation by molecular interaction

    Chylous mesenteric cyst: A diagnostic dilemma

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    A mesenteric cyst is defined as a cyst that is located in the mesentery of the gastrointestinal tract and may extend from the base of the mesentery into the retroperito- neum. A case report of a patient with mesenteric cyst is presented. In addition, a systematic review was performed of English language literature on chylous mesenteric cysts in adult hu- mans. Of the 18 articles included in the review, there were 19 cases of chylous mesenteric cysts reported. Male to female ratio was 1.4:1 with a median age of 46 years. A preoperative diagnosis of mesenteric cyst was made in four patients based on computed to- mography. All patients underwent surgery and there were no reports of recurrence on follow up. Chylous mesenteric cyst is a rare entity that needs to be recognized whenever a prelimi- nary diagnosis of intra-abdominal cystic mass is made

    EUROfusion-theory and advanced simulation coordination (E-TASC) : programme and the role of high performance computing

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    This paper is a written summary of an overview oral presentation given at the 1st Spanish Fusion High Performance Computer (HPC) Workshop that took place on the 27 November 2020 as an online event. Given that over the next few years ITER24 will move to its operation phase and the European-DEMO design will be significantly advanced, the EUROfusion consortium has initiated a coordination effort in theory and advanced simulation to address some of the challenges of the fusion research in Horizon EUROPE (2021-2027), i.e. the next EU Framework Programme for Research and Technological Development. This initiative has been called E-TASC, which stands for EUROfusion-Theory and Advanced Simulation Coordination. The general and guiding principles of E-TASC are summarized in this paper. In addition, an overview of the scientific results obtained in the pilot phase (2019-2020) of E-TASC are provided while highlighting the importance of the required progress in computational methods and HPC techniques. In the initial phase, five pilot theory and simulation tasks were initiated: towards a validated predictive capability of the low to high transition and pedestal physics; runaway electrons in tokamak disruptions in the presence of massive material injection; fast code for the calculation of neoclassical toroidal viscosity in stellarators and tokamaks; development of a neutral gas kinetics modular code; European edge and boundary code for reactor-relevant devices. In this paper, we report on recent progress made by each of these projects.Peer reviewe
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