1,480 research outputs found
BQC: A free web service to quality control solar irradiance measurements across Europe
Classical quality control (QC) methods of solar irradiance apply easy-to-implement physical or statistical limits that are incapable of detecting low-magnitude measuring errors due to the large width of the intervals. We previously presented the bias-based quality control (BQC), a novel method that flags samples in which the bias of several independent gridded datasets is larger for consecutive days than the historical value. The BQC was previously validated at 313 European and 732 Spanish stations finding multiple low-magnitude errors (e.g., shadows, soiling) not detected by classical QC methods. However, the need for gridded datasets, and ground measurements to characterize the bias, was hindering the BQC implementation.
To solve this issue, we present a free web service, www.bqcmethod.com, that implements the BQC algorithm incorporating both the gridded datasets and the reference stations required to use the BQC across Europe from 1983 to 2018. Users only have to upload a CSV file with the global horizontal irradiance measurements to be analyzed. Compared to previous BQC versions, gridded products have been upgraded to SARAH-2, CLARA-A2, ERA5, and the spatial coverage has been extended to all of Europe. The web service provides a flexible environment that allows users to tune the BQC parameters and upload ancillary rain data that help in finding the causes of the errors. Besides, the outputs cover not only the visual and numerical QC flags but also daily and hourly estimations from the gridded datasets, facilitating the access to raster data.We thank the Instituto de Estudios Riojanos for funding part of the web service within the program Estudios CientÃficos de Temática Riojana, Spain. This research used resources from the Supercomputing Castilla y Leon Center (SCAYLE, www.scayle.es), funded by the European Regional Development Fund (ERDF). We would also like to thank the EU meteorological networks that freely distribute their datasets and particularly those researchers who helped us in retrieving these data: Aku Riiëla and Anders Lindfors (FMI), Virginie Gorjoux (Météo France), Sandra Andersson (SHMI), and Jakub Walawender (IMGW-PIB). Finally, we thank the CMSAF and ECMWF for freely distributing their products, and particularly Jörg Trentmann, for providing a beta version of CLARA-A2.1.
RU is a postdoc from the University of La Rioja working as a visiting scientist at the European Commission’s Joint Research Center (JRC). RU is funded by the Plan Propio de la Universidad de La Rioja, Spain and V Plan Riojano de I+D, Spain . The views expressed here are purely those of the authors and may not, under any circumstances, be regarded as an official position of the European Commission
Molecular structure of one-electron diatomic molecules subject to plasma screening and its e ect on the dynamics
ABSTRACT: The effect of plasma screening on the electronic and vibrational structure of one-electron diatomic molecules is analyzed by including screened Coulomb interactions among all their particles in the solution of the Schrodinger equation. The breakdown of the well-known separability of the Schrodinger equation in confocal
elliptical coordinates, the lost of long-range Coulomb interaction and the non-degeneracy in both the united atom and separated atom limits bring new elements into the analysis of the modified binding energies (electronic and vibrational), adiabatic correlation rules, molecular Stark mixings due to polarization effects, unexpected presence of molecular shape resonances and changes in non-adiabatic and radiative couplings upon the variation of the screening strength
Effect of potential screening on the H2 autoionizing states
ABSTRACT: We study the behavior of autoionizing states of the hydrogen molecule subject to screened Coulomb interactions using an ab initio Feshbach configuration interaction method. Special attention is given to the algorithms developed for the evaluation of (i) screened molecular orbitals expressed in terms of one-center expansions using B-spline polynomial basis functions and (ii) screened two-electron integrals between configurations expressed in terms of such molecular orbitals, by solving the screened Poisson equation. As an illustration of the method we focus on the lowest Feshbach resonance of the Q1 1+g series of doubly excited states of H2, which lies between the first H2 + (1sσg) and the second H2 + (2pσu) ionization thresholds. We show that Coulomb screening in the electron-proton interaction and between electrons may significantly alter the resonance position and autoionizing decay as a function of internuclear distance. In general, screening increases the resonance lifetime. However, when electron-proton screening dominates over electron-electron screening, we find that the Q1 resonance acquires a pronounced shape-resonance character at internuclear distances where the resonance approaches the lower ionization threshold, thus leading to a pronounced decrease of its lifetime
Manual de prevención de riesgos laborales en un taller mecánico de un centro docente universitario
Este TFG engloba entre las páginas de la memoria un resumen de la normativa que se ha considerado más importante en materia de seguridad y salud, asà como tres epÃgrafes (Riesgos, Señalización y Equipos de Protección Individual) que incluyen los pilares básicos en los que se asientan los anexos. Estos anexos son fichas en las que se describe la máquina objeto de estudio, los principales riesgos a los que se está expuesto, las causas más comunes, las medidas preventivas para tratar de evitar y/o minimizarlos y una serie de equipos de protección individual para el uso de dicha máquina
Método para la comparación y caracterización del ruido de paso en trenes de alta velocidad
El ferrocarril está llamado a ser uno de los modos de transporte del futuro tanto para mercancÃas como para viajeros. Esto conduce a la necesidad de reducir los efectos negativos que la explotación ferroviaria produce, y entre ellos los más relevantes son el ruido y las vibraciones, que causan molestias a usuarios y habitantes cercanos y perturbaciones en infraestructuras propias de la red o cercanas a la misma.
En el trabajo de investigación que aquà se resume, se ha realizado un estudio teórico exhaustivo de los fenómenos de emisión de ruido ferroviario analizando sus causas y parámetros de influencia. A partir de este estudio, se ha elaborado una metodologÃa completa y sencilla para la caracterización del ruido de paso que cubre todas las fases necesarias, desde la adquisición de datos de ruido, hasta la obtención de resultados numéricos y de forma gráfica a través de una herramienta software desarrollada a tal efecto.
De las distintas metodologÃas de caracterización se escogió, por ser la más representativa para el estudio, la caracterización del ruido de paso de vehÃculos (a velocidad constante).
La herramienta informática, la metodologÃa en sà y sus resultados han sido comprobados y ratificados con ensayos reales en las instalaciones de Alta Velocidad de la red española, registrándose el paso de diferentes composiciones. Además se puede afirmar que cumplen con las especificaciones y restricciones establecidas por la normativa vigente en España y Europa.
Este trabajo ha sido desarrollado en el Centro de Investigación en TecnologÃas Ferroviarias (CITEF), centro ligado a la Escuela Técnica Superior de Ingenieros Industriales de la Universidad Politécnica de Madrid
Adverse aerodynamics effects of a high speed train under the influence of cross winds, analysis and optimization of wind fence
The research work that here is summarized, it is classed on the area of dynamics and measures of railway safety, specifically in the study of the influence of the cross wind on the high-speed trains as well as the study of new mitigation measures like wind breaking structures or wind fences, with optimized shapes. The work has been developed in the Research Center in Rail Technology (CITEF), and supported by the Universidad Politécnica de Madrid, Spain
Evaluation and improvement of empirical models of global solar irradiation: Case study northern Spain
This paper presents a new methodology to build parametric models to estimate global solar
irradiation adjusted to specific on-site characteristics based on the evaluation of variable im-
portance. Thus, those variables higly correlated to solar irradiation on a site are implemented
in the model and therefore, different models might be proposed under different climates. This
methodology is applied in a study case in La Rioja region (northern Spain). A new model is
proposed and evaluated on stability and accuracy against a review of twenty-two already exist-
ing parametric models based on temperatures and rainfall in seventeen meteorological stations
in La Rioja. The methodology of model evaluation is based on bootstrapping, which leads to
achieve a high level of confidence in model calibration and validation from short time series (in
this case five years, from 2007 to 2011).
The model proposed improves the estimates of the other twenty-two models with average
mean absolute error (MAE) of 2.195 MJ/m2 day and average confidence interval width (95%
C.I., n=100) of 0.261 MJ/m2 day. 41.65% of the daily residuals in the case of SIAR and 20.12% in
that of SOS Rioja fall within the uncertainty tolerance of the pyranometers of the two networks
(10% and 5%, respectively). Relative differences between measured and estimated irradiation
on an annual cumulative basis are below 4.82%. Thus, the proposed model might be useful
to estimate annual sums of global solar irradiation, reaching insignificant differences between
measurements from pyranometers
Supported bifunctional thioureas as recoverable and reusable catalysts for enantioselective nitro-Michael reactions
Producción CientÃficaThe catalytic activity of different supported bifunctional thioureas on sulfonylpolystyrene resins has been studied in the nitro-
Michael addition of different nucleophiles to trans-β-nitrostyrene derivatives. The activity of the catalysts depends on the length of
the tether linking the chiral thiourea to the polymer. The best results were obtained with the thiourea derived from (L)-valine and
1,6-hexanediamine. The catalysts can be used in only 2 mol % loading, and reused for at least four cycles in neat conditions. The
ball milling promoted additions also worked very well.Ministerio de EconomÃa, Industria y Competitividad (CTQ2014-59870-P)Junta de Castilla y León (programa de apoyo a proyectos de investigación – Ref. VA064U13
Análisis de la internacionalización de la Revista Española de Documentación CientÃfica: 2010-2015
Articles and Reviews (n=197) published in Revista Española de Documentación CientÃfica (REDC) over the six-year period 2010-2015 were analyzed. 25.9% of them are related to metric studies of information, a subject that has characterized the journal since its creation in 1977. The Library and Information Science (LIS) category of the Journal Citation Reports has been analyzed through direct citation analysis techniques and a structure of three major clusters has been found. Within this classification, the REDC fits into the bibliometric-Scientometric cluster The REDC maintains some inbred character, both in the references provided by the journal itself (5% of the total references) and in the self-citations received (39% of all citations), most of them referring to bibliometric studies, which is explained by its high specialization in this field. The standardized impact (INR, Standardized Impact to the Journal) for the different thematic areas published is not related to the productivity of each area, but it is the less represented areas that present the greatest impact. On the other hand, the articles published by foreign institutions with or without Spanish collaboration are 16% of the total, and come mainly from Latin America, specially Cuba and Colombia.Se analizan los 197 artÃculos publicados en la Revista Española de Documentación CientÃfica (REDC) durante el sexenio 2010-2015. El 25,9% de los mismos se relaciona con estudios métricos de la información e indicadores cientÃficos, temática que ha caracterizado a la revista desde su creación en el año 1977, y por la que forma parte del clúster de CienciometrÃa y BibliometrÃa, según la red de citación de revistas de la categorÃa Library and Information Science (LIS), del Journal Citation Reports, donde ocupa una posición media en el ranking de revistas de su especialidad, oscilando entre el segundo y tercer cuartil. La REDC mantiene un cierto carácter endogámico, tanto en las referencias aportadas por la propia revista (5% del total de referencias), como en las autocitas recibidas (39% de todas las citas), la mayorÃa de ellas referidas a estudios bibliométricos, lo que se explica por su alta especialización en dicha materia. El impacto normalizado (INR, Impacto Normalizado a la Revista) para las distintas áreas temáticas publicadas no está relacionado con la productividad de cada área, sino que son las áreas menos representadas las que mayor impacto presentan. Por otra parte, los artÃculos publicados por instituciones extranjeras, tanto en colaboración con España o sin colaboración española, suponen el 16% del total (32 artÃculos), y proceden principalmente de América Latina, destacando Cuba y Colombia como los más productivos
The 'africanity' of the Canary Islands: From international debate to the Spanish reaction (1956-1981)
El presente artÃculo estudia el debate que se produjo sobre la españolidad de las Islas Canarias en la segunda mitad del siglo XX (1956–1981) con un doble objetivo: analizar la controversia internacional sobre si el archipiélago era un territorio a descolonizar y examinar las reacciones del Gobierno de España ante este asunto. Las fuentes utilizadas se basan en una pormenorizada revisión bibliográfica, junto a la documentación de organismos internacionales, la prensa escrita y los testimonios de algunos protagonistas. La implicación de diversos actores –tanto nacionales como regionales e internacionales– nos da una idea de la dimensión que tuvo este polémico debate. Los hallazgos de esta investigación revelan que la controversia no fue algo anecdótico, sino que se prolongó durante más de dos décadas, durante las cuales existió la posibilidad de que las Islas Canarias pudieran pasar por un proceso de descolonización.This article examines the debate on the Spanishness of the Canary Islands in the second half of the twentieth century (1956-1981) with a twofold objective: to analyse the international controversy on whether the archipelago was a territory to be decolonized, and to examine the Spanish Government’s reaction to this issue. The work draws on detailed bibliographical study, together with international organisations documentation, the published press, and some protagonists’ testimonies. The involvement of various actors –both national, regional and international– provides an idea of the dimension of this controversial debate. The findings of this research reveal that the controversy was not anecdotic, but lasted for more than two decades. In fact, there was a real possibility that the Canary Islands could go through a decolonization process
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