2,729 research outputs found

    Selective parametric specificity of Cluj-Napoca meteorological station according to Annex 1B of WMO No. 8 Guide

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    Meteorological metadata are required to be used for all types of measurements. Metadata is information about when, where, how and by whom the meteorological data was measured. Detailed metadata are important to understand the characteristics and limits of measurements, especially for climatology. But detailed metadata, due to their complexity, can greatly reduce their operational use. In the usual practice, the measurement characteristics and limits of a sensor are taken into account at the expense of the environmental conditions in which the measurement of a meteorological parameter takes place. W. M. O., based on the Meteo-France`s proposals (M. Leroy, 1998), has defined a classification for some base surface variables to document the environment near a site. Site classification requires assigning a class number for each measured parameter, which varies from 1 to 5. By convention, a class 1 location complies with WMO regulations. In this paper, the classification criteria set out in Annex 1B of wmo Guide No. 8, are adapted and applied for Cluj-Napoca meteorological station. As a result of applying the classification for Cluj-Napoca Automatic Weather Station, a class number is assigned for the air temperature-humidity, precipitation and wind sensor. The application proposals for the site classification based on results can then be applied to the rest of the meteorological network taking into account the characteristics of the location of a meteorological platform

    RDFauthor: Employing RDFa for Collaborative Knowledge Engineering

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    Analysing the homogeneity of air temperature, relative air humidity, precipitation and wind data series using ‘Climatol’ and meteorological metadata

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    Errors are inherent in all measurement activity, and meteorology is no exception. Homogenization of climatological series to eliminate disturbances often contained in them, due to changes in the conditions of observations, is a mandatory process to increase the reliability of studies of climate variability derived from their analysis. The “Climatol” R package is devoted to the problem of homogenizing climatological data series in order to remove the perturbations produced e.g. by changes in the conditions of observation or in the nearby environment, to allow the series to reflect the climatic variations. As it is known, changes in the location of meteorological observatories, changes in instrumentation (from classic equipment to automated sensors) or in shelters intended to protect sensors from solar radiation, or even changes in the environment (land uses, new constructions, etc.) are alterations that can not be attributed to changes in the climate. Such information regarding this changes are known as “metadata”. In this paper the “Climatol” method was used for air temperature, relative air humidity, precipitation and wind daily data homogenization for the period since 1961 till 2015 at Cluj-Napoca, Oradea, Satu Mare and Vlădeasa 1800 meteorological stations. With the help of metadata, the results were validated and changes in statistical parameters of meteorological data string were identified, for the analysed meteorological parameters, due to the relocation of the meteorological platforms, changes of the meteorological equipment and changes of the measuring methodology

    X-ray transition yields of low-Z kaonic atoms produced in Kapton

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    The X-ray transition yields of kaonic atoms produced in Kapton polyimide (C22H10N2O5) were measured for the first time in the SIDDHARTA experiment. X-ray yields of the kaonic atoms with low atomic numbers (Z = 6, 7, and 8) and transitions with high principal quantum numbers (n = 5-8) were determined. The relative yield ratios of the successive transitions and those of carbon-to-nitrogen (C:N) and carbon-to-oxygen (C:O) were also determined. These X-ray yields provide important information for understanding the capture ratios and cascade mechanisms of kaonic atoms produced in a compound material, such as Kapton.Comment: Accepted in Nucl. Phys. A (2013

    Preliminary study of kaonic deuterium X-rays by the SIDDHARTA experiment at DAFNE

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    The study of the KbarN system at very low energies plays a key role for the understanding of the strong interaction between hadrons in the strangeness sector. At the DAFNE electron-positron collider of Laboratori Nazionali di Frascati we studied kaonic atoms with Z=1 and Z=2, taking advantage of the low-energy charged kaons from Phi-mesons decaying nearly at rest. The SIDDHARTA experiment used X-ray spectroscopy of the kaonic atoms to determine the transition yields and the strong interaction induced shift and width of the lowest experimentally accessible level (1s for H and D and 2p for He). Shift and width are connected to the real and imaginary part of the scattering length. To disentangle the isospin dependent scattering lengths of the antikaon-nucleon interaction, measurements of Kp and of Kd are needed. We report here on an exploratory deuterium measurement, from which a limit for the yield of the K-series transitions was derived: Y(K_tot)<0.0143 and Y(K_alpha)<0.0039 (CL 90%). Also, the upcoming SIDDHARTA-2 kaonic deuterium experiment is introduced.Comment: Accepted by Nuclear Physics

    First measurement of kaonic helium-3 X-rays

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    The first observation of the kaonic 3He 3d - 2p transition was made using slow K- mesons stopped in a gaseous 3He target. The kaonic atom X-rays were detected with large-area silicon drift detectors using the timing information of the K+K- pairs of phi-meson decays produced by the DAFNE e+e- collider. The strong interaction shift of the kaonic 3He 2p state was determined to be -2+-2 (stat)+-4 (syst) eV.Comment: Accepted for publication in Phys. Lett.

    A New Measurement of Kaonic Hydrogen X rays

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    The KˉN\bar{K}N system at threshold is a sensitive testing ground for low energy QCD, especially for the explicit chiral symmetry breaking. Therefore, we have measured the KK-series x rays of kaonic hydrogen atoms at the DAΦ\PhiNE electron-positron collider of Laboratori Nazionali di Frascati, and have determined the most precise values of the strong-interaction energy-level shift and width of the 1s1s atomic state. As x-ray detectors, we used large-area silicon drift detectors having excellent energy and timing resolution, which were developed especially for the SIDDHARTA experiment. The shift and width were determined to be ϵ1s=283±36±6(syst)\epsilon_{1s} = -283 \pm 36 \pm 6 {(syst)} eV and Γ1s=541±89(stat)±22(syst)\Gamma_{1s} = 541 \pm 89 {(stat)} \pm 22 {(syst)} eV, respectively. The new values will provide vital constraints on the theoretical description of the low-energy KˉN\bar{K}N interaction.Comment: 5 figures, submitted to Physics Letters

    A European study on decellularized homografts for pulmonary valve replacement: initial results from the prospective ESPOIR Trial and ESPOIR Registry data\u2020

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    OBJECTIVES: Decellularized pulmonary homografts (DPH) have shown excellent results for pulmonary valve replacement. However, controlled multicentre studies are lacking to date.METHODS: Prospective European multicentre trial evaluating DPH for pulmonary valve replacement. Matched comparison of DPH to bovine jugular vein (BJV) conduits and cryopreserved homografts (CH) considering patient age, type of heart defect and previous procedures.RESULTS: In total, 121 patients (59 female) were prospectively enrolled (August 2014-December 2016), age 21.3 +/- 14.4 years, DPH diameter 24.4 +/- 2.8 mm. No adverse events occurred with respect to surgical handling; there were 2 early deaths (30 + 59 years) due to myocardial failure after multi-valve procedures and no late mortality (1.7% mortality). After a mean follow-up of 2.2 +/- 0.6 years, the primary efficacy end points mean peak gradient (16.1 +/- 12.1 mmHg) and regurgitation (mean 0.25 +/- 0.48, grade 0-3) were excellent. One reoperation was required for recurrent subvalvular stenosis caused by a pericardial patch and 1 balloon dilatation was performed on a previously stented LPA. 100% follow-up for DPH patients operated before or outside the trial (n = 114) included in the ESPOIR Registry, age 16.6 +/- 10.4 years, diameter 24.1 +/- 4.2 mm, follow-up 5.1 +/- 3.0 years. The combined DPH cohort, n = 235, comprising both Trial and Registry data showed significantly better freedom from explantation (DPH 96.7 +/- 2.1%, CH 84.4 +/- 3.2%, P = 0.029 and BJV 82.7 +/- 3.2%, P = 0.012) and less structural valve degeneration at 10 years when matched to CH, n = 235 and BJV, n = 235 (DPH 61.4 +/- 6.6%, CH 39.9 +/- 4.4%, n.s., BJV 47.5 +/- 4.5%, P = 0.029).CONCLUSIONS: Initial results of the prospective multicentre ESPOIR Trial showed DPH to be safe and efficient. Current DPH results including Registry data were superior to BJV and CH.Thoracic Surger

    Kaonic hydrogen X-ray measurement in SIDDHARTA

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    Kaonic hydrogen atoms provide a unique laboratory to probe the kaon-nucleon strong interaction at the energy threshold, allowing an investigation of the interplay between spontaneous and explicit chiral symmetry breaking in low-energy QCD. The SIDDHARTA Collaboration has measured the KK-series X rays of kaonic hydrogen atoms at the DAΦ\PhiNE electron-positron collider of Laboratori Nazionali di Frascati, and has determined the most precise values of the strong-interaction induced shift and width of the 1s1s atomic energy level. This result provides vital constraints on the theoretical description of the low-energy KˉN\bar{K}N interaction.Comment: 11 pages, 7 figures, Nuclear Physics A (in press) Special Issue on Strangeness Nuclear Physic
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