143 research outputs found

    Effect of the ingestion in the WRF model of different Sentinel-derived and GNSS-derived products: analysis of the forecasts of a high impact weather event

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    This paper presents the first experimental results of a study on the ingestion in the Weather Research and Forecasting (WRF) model, of Sentinel satellites and Global Navigation Satellite Systems (GNSS) derived products. The experiments concern a flash-floodevent occurred in Tuscany (Central Italy) in September 2017. The rationale is that numerical weather prediction (NWP) models are presently able to produce forecasts with a km scale  spatial resolution, but the poor knowledge of the initial state of the atmosphere may imply an inaccurate simulation of the weather phenomena. Hence, to fully exploit the advances in numerical weather modelling, it is necessary to feed them with high spatiotemporal resolution information over the surface boundary and the atmospheric column. In this context, the Copernicus Sentinel satellites represent an important source of data, because they can provide a set of high-resolution observations of physical variables (e.g. soil moisture, land/sea surface temperature, wind speed) used in NWP models runs. The possible availability of a spatially dense network of GNSS stations is also exploited to assimilate water vapour content. Results show that the assimilation of Sentinel-1 derived wind field and GNSS-derivedwater vapour data produce the most positive effects on the performance of the forecast

    Essential oil composition from hop cultivated at Southern Brazil.

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    Edition of Abstracts of the 48th International Symposium on Essential Oils, Pécs, Hungary, 2017. Abstracts. Babedio, 2017. ISEO 2017, 10 a 13 set. 2017. P-05

    Sistema E.V.A. 1.0

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    Dentro del campo del crecimiento y desarrollo, el cálculo antropométrico, es una de las herramientas más utilizadas para encontrar indicadores válidos del estado general del crecimiento biológico de una población en su interacción con los diversos factores sociales. Frente al evidente proceso de pauperización por el que viene transcurriendo el país, la evaluación del estado nutricional de la población infantil, tanto en sus aspectos poblacionales como individuales, se hace necesaria y cotidiana. Presentamos aquí un software de escritorio que permite el cálculo y la graficación de las principales variables antropométricas. El E.V.A. 1.0 (Evaluación y Visualización Antropométrica) brinda también la posibilidad de almacenar los datos, de incorporar tablas de comparación (por default el sistema trae las tablas de la SAP y del NCHS), y de exportar la información al programa EPINFO y a la mayoría de las aplicaciones estándar de escritorio (planillas de cálculo, procesadores de texto, etc.). La aplicación posee también una modalidad de sugerencias de diagnóstico, con referencias bibliográficas, que puede ser de ayuda, tanto para el profesional de A.P.S. como para el investigador.Asociación de Antropología Biológica de la República Argentin

    Sistema E.V.A. 1.0

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    Dentro del campo del crecimiento y desarrollo, el cálculo antropométrico, es una de las herramientas más utilizadas para encontrar indicadores válidos del estado general del crecimiento biológico de una población en su interacción con los diversos factores sociales. Frente al evidente proceso de pauperización por el que viene transcurriendo el país, la evaluación del estado nutricional de la población infantil, tanto en sus aspectos poblacionales como individuales, se hace necesaria y cotidiana. Presentamos aquí un software de escritorio que permite el cálculo y la graficación de las principales variables antropométricas. El E.V.A. 1.0 (Evaluación y Visualización Antropométrica) brinda también la posibilidad de almacenar los datos, de incorporar tablas de comparación (por default el sistema trae las tablas de la SAP y del NCHS), y de exportar la información al programa EPINFO y a la mayoría de las aplicaciones estándar de escritorio (planillas de cálculo, procesadores de texto, etc.). La aplicación posee también una modalidad de sugerencias de diagnóstico, con referencias bibliográficas, que puede ser de ayuda, tanto para el profesional de A.P.S. como para el investigador.Asociación de Antropología Biológica de la República Argentin

    A Synergistic Use of a High-Resolution Numerical Weather Prediction Model and High-Resolution Earth Observation Products to Improve Precipitation Forecast

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    open20siThe Mediterranean region is frequently struck by severe rainfall events causing numerous casualties and several million euros of damages every year. Thus, improving the forecast accuracy is a fundamental goal to limit social and economic damages. Numerical Weather Prediction (NWP) models are currently able to produce forecasts at the km scale grid spacing but unreliable surface information and a poor knowledge of the initial state of the atmosphere may produce inaccurate simulations of weather phenomena. The STEAM (SaTellite Earth observation for Atmospheric Modelling) project aims to investigate whether Sentinel satellites constellation weather observation data, in combination with Global Navigation Satellite System (GNSS) observations, can be used to better understand and predict with a higher spatio-temporal resolution the atmospheric phenomena resulting in severe weather events. Two heavy rainfall events that occurred in Italy in the autumn of 2017 are studied—a localized and short-lived event and a long-lived one. By assimilating a wide range of Sentinel and GNSS observations in a state-of-the-art NWP model, it is found that the forecasts benefit the most when the model is provided with information on the wind field and/or the water vapor content.openLagasio, Martina; Parodi, Antonio; Pulvirenti, Luca; Meroni, Agostino N.; Boni, Giorgio; Pierdicca, Nazzareno; Marzano, Frank S.; Luini, Lorenzo; Venuti, Giovanna; Realini, Eugenio; Gatti, Andrea; Tagliaferro, Giulio; Barindelli, Stefano; Monti Guarnieri, Andrea; Goga, Klodiana; Terzo, Olivier; Rucci, Alessio; Passera, Emanuele; Kranzlmueller, Dieter; Rommen, BjornLagasio, Martina; Parodi, Antonio; Pulvirenti, Luca; Meroni, Agostino N.; Boni, Giorgio; Pierdicca, Nazzareno; Marzano, Frank S.; Luini, Lorenzo; Venuti, Giovanna; Realini, Eugenio; Gatti, Andrea; Tagliaferro, Giulio; Barindelli, Stefano; Monti Guarnieri, Andrea; Goga, Klodiana; Terzo, Olivier; Rucci, Alessio; Passera, Emanuele; Kranzlmueller, Dieter; Rommen, Bjor

    Noncommutative Differential Forms on the kappa-deformed Space

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    We construct a differential algebra of forms on the kappa-deformed space. For a given realization of the noncommutative coordinates as formal power series in the Weyl algebra we find an infinite family of one-forms and nilpotent exterior derivatives. We derive explicit expressions for the exterior derivative and one-forms in covariant and noncovariant realizations. We also introduce higher-order forms and show that the exterior derivative satisfies the graded Leibniz rule. The differential forms are generally not graded-commutative, but they satisfy the graded Jacobi identity. We also consider the star-product of classical differential forms. The star-product is well-defined if the commutator between the noncommutative coordinates and one-forms is closed in the space of one-forms alone. In addition, we show that in certain realizations the exterior derivative acting on the star-product satisfies the undeformed Leibniz rule.Comment: to appear in J. Phys. A: Math. Theo

    Evaluation of [C(sp3)/[C(sp2)] ratio in diamondlike films through the use of a complex dielectric constant

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    The evaluation of the amount of tetrahedral and trigonal cross-linking, that is, the sp3- and sp2-hybridized carbon, is of great importance in understanding the properties of amorphous carbon films. In this paper we report a method for deducing the [sp3]/[sp2] ratio from the experimental values of the complex dielectric constant as obtained by optical transmittance and reflectance measurements. We assume a Gaussian-like distribution of π and π* electronic densities of states in order to fit the contribution of π→π* to the imaginary part, ε2, of the dielectric constant in the low-energy region. Through the Kramers-Kronig relationships we deduce the corresponding values of the real part ε1 of the dielectric constant for such transitions. By subtracting these values from the measured ε1 we deduce the contribution of σ→σ* to ε1. The Wemple-Didomenico model has been used to obtain the dispersion energy and the average excitation energy. Knowing the plasmon energies, we apply the ‘‘f-sum rule'' to deduce the [sp3]/[sp2] ratio. The method applied to a-C:H films deposited by rf diode sputtering provides results in agreement with those obtained by other techniques

    Tetrahedrally bonded ternary amorphous semiconductor alloys

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    The properties of tetrahedrally bonded ternary amorphous semiconductors a-CSiSn:H and a-CSiGe:H are reviewed with particular emphasis on the temperature dependence of dark conductivity and the coordination in random networks. It is shown here that the dark conductivity as a function of the temperature strongly depends on the carbon content and, more precisely, on the proportion of sp3 and sp2 sites in the carbon. Ternary alloys with different carbon contents are compared to binary alloys using the average coordination number. The ternary alloys have an average coordination number close to the optimal value predicted for amorphous covalent networks
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