394 research outputs found

    Las toreras : sainet-lírico-taurómaco-flamenco-bailable en un acto, en prosa y verso

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    Estrenado... en el Teatro de Maravillas de Madrid la noche del 24 de agosto de 1888...Copia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 201

    Application of low-cost sensors for the development of a methodology to design front-end loaders for tractors

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    Tractor front-end loaders are an essential part of the equipment used on farms. At present, there are an important number of small- and medium-sized companies involved in the manufacturing of this equipment. These companies rely heavily on experience for innovative designs, as in the vast majority of cases they lack access to adequate methodology for the optimal design of new front-end loaders. The study conducted has developed a methodology to design tractor front-end loaders with a view of obtaining their accurate design during the bucket loading process. The methodology comprises two phases: the first phase involves a numerical analysis of the structural behaviour of the front-end loader components by means of the Finite Element Method; the second phase, the experimental phase, makes use of low-cost sensors, in particular, strain gauges, to analyse existing strains at selected points in the front-end loader structure. The experimental results obtained by means of low-cost sensors fitted onto the front-end loader allow analysing the existing strains at the points measured, as well as validate the numerical model developed. This methodology is validated by applying it to a commercial front-end loader, more specifically to model 430E2 of the company Maquinaria Agrícola El León S.A (Spain)

    Geomorphological setting and main technological features of new Middle and Upper Pleistocene sites in the Lower Manzanares River Valley (Madrid, Spain)

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    Las intervenciones arqueológicas llevadas a cabo durante los años 1996 en Tafesa, 2005 en el yacimiento Hospital 12 de Octubre y 2006 en la desembocadura del arroyo Butarque (Villaverde-Barrio de Butarque) situados al sur de la ciudad de Madrid (España), han aportado nuevos conjuntos líticos contextualizados estratigráficamente en los depósitos fluviales pleistocenos correspondientes al tramo inferior del valle del río Manzanares. Los yacimientos arqueológicos analizados se sitúan geomorfológicamente en la denominada “Terraza Compleja del Manzanares” (TCMZ), la cual constituye un nivel fluvial engrosado (20-15 m de potencia) situado entre +22-16 m sobre el cauce actual del río, a lo largo de su margen derecha. Este nivel fluvial ha sido tradicionalmente considerado de edad Pleistoceno medio en base a la industria achelense y complejos faunísticos encontrados en sus niveles inferiores. Ciertamente, Tafesa es un yacimiento situado en la parte inferior-media de la terraza de +22 m con industria achelense y fauna de Pleistoceno medio. Por el contrario, los niveles superiores de esta misma terraza en los sectores del 12 de Octubre y Villaverde-Butarque se encuentran asociados a industrias del Paleolítico inferior y medio ya pertenecientes al Pleistoceno superior, como sugieren el conjunto de dataciones OSL y TL existentes para la zona. Los datos analizados en este trabajo indican que el desarrollo de este nivel de terraza engrosado comienza durante la parte final de Pleistoceno medio y abarca todo el Estadio Isotópico OIS 5, ya dentro del Pleistoceno superiorThe archaeological works developed during the years 1996 in the site of Tafesa, 2005 in the 12 de Octubre Metro Station site and 2006 in the confluence of the Butarque Stream (Villaverde-Barrio de Butarque site) located south of the Madrid City (Spain), have provided new lithic assemblages. These assemblages have been stratigraphically contextualized in the Pleistocene deposits of the Lower Manzanares river valley within the so-called “Manzanares Complex Terrace” (TCMZ). This fluvial terrace constitutes an anomalous thickened (20-15m) deposit at +22-16m above the present river thalweg mainly developed along the right (southern) valley margin. This fluvial level has been traditionally considered of middle Pleistocene age on the basis of the acheulian lithics and faunal assemblages typically located within its lower stratigraphic layers. Certainly, the Tafesa is a fluvial terrace site at +22 m with acheulian industry and middle Pleistocene faunal remains at its lower sedimentary sequence. However, the upper sedimentary levels of this same terrace in the 12 de Octubre y Villaverde-Butarque sites throw lithic assemblages of the lower and upper Paleolithic belonging to upper Pleistocene, as suggested by the available set of TL and OSL dates for the zone. The analyses developed in this study indicate that the development of this thickened fluvial terrace started during the end of the middle Pleistocene, but also comprise the whole Oxygen Isotopic Stage OIS 5 during the upper Pleistocene

    X-ray absorption and emission spectroscopy study of Mn and Co valence and spin states in TbM n1-x C ox O3

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    The valence and spin state evolution of Mn and Co on TbMn1-xCoxO3 series is precisely determined by means of soft and hard x-ray absorption spectroscopy (XAS) and Kß x-ray emission spectroscopy (XES). Our results show the change from Mn3+ to Mn4+ both high-spin (HS) together with the evolution from Co2+ HS to Co3+ low-spin (LS) with increasing x. In addition, high energy resolution XAS spectra on the K pre-edge region are interpreted in terms of the strong charge transfer and hybridization effects along the series. These results correlate well with the spin values of Mn and Co atoms obtained from the Kß XES data. In this paper, we determine that Co enters into the transition metal sublattice of TbMnO3 as a divalent ion in HS state, destabilizing the Mn long-range magnetic order since very low doping compositions (x=0.1). Samples in the intermediate composition range (0.4=x=0.6) adopt the crystal structure of a double perovskite with long-range ferromagnetic ordering which is due to Mn4+-O-Co2+ superexchange interactions with both cations in HS configuration. Ferromagnetism vanishes for x=0.7 due to the structural disorder that collapses the double perovskite structure. The spectroscopic techniques reveal the occurrence of Mn4+ HS and a fluctuating valence state Co2+ HS/Co3+ LS in this composition range. Disorder and competitive interactions lead to a magnetic glassy behavior in these samples

    Long-term impact of sustainable land management practices on soil bacterial community in an almond orchard in south Spain

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    [SPA] Una estructura de comunidad bacteriana saludable es uno de los principales indicadores de calidad del suelo. Las prácticas agrícolas modernas en las que se aplican labranza intensa y fertilizantes químicos continúan poniendo en juego el equilibrio ambiental y la sostenibilidad de la producción día a día. En este estudio, nuestro objetivo fue evaluar el efecto a largo plazo de prácticas sostenibles de bajos insumos, como la labranza reducida y el abono verde sobre la comunidad bacteriana edáfica en un cultivo de almendros del sur de España. La labranza reducida y la adición de abono verde han demostrado la estructura de la comunidad bacteriana más estable y la abundancia de especies con respecto a los métodos convencionales. El carbono orgánico del suelo y la comunidad bacteriana se mejoran con un enfoque sostenible de bajos insumos. [ENG] A healthy bacterial community structure is one of the main aspects of soil quality indicators. Modern agricultural practices, where intense tillage and chemical fertilizers are applied, continue to put environmental balance and sustainability of production at stake day by day. In this study, we aimed to assess the long-term effect of low-input sustainable practices such as reduced tillage and green manure on soil bacterial communities in an almond orchard from south Spain. Reduced tillage and addition of green manure has shown the most stable bacterial community structure and species abundance with respect to conventional practice. Soil organic carbon and bacterial community are improved by low-input sustainable approach.This work was conducted as a part of the European Commission Horizon 2020 project Diverfarming [grant agreement 728003]

    Experimental study on AR fiberglass connectors for bridges made of composite materials

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    6 páginas, 11 figuras, 1 tabla.[ES] Un aspecto relevante dentro del proyecto de un puenterealizado en materiales compuestos es el estudio de losconectores. El caso mas frecuente de puente en materialescompuestos es aquel que presenta un tablero de materialescompuestos soportado por vigas metalicas o de hormigonarmado. En este trabajo se analizaran los tipos deconectores mas utilizados en este tipo de puentes Se analizaran tambien los conectores utilizados en elKing Stormwater Channel Bridge, donde ademas deltablero en fibra de vidrio, se fabricaron las vigas en fibrasde carbono rellenas de hormigon. En este articulo se propondran varios tipos de conectoresy se presentaran los resultados experimentales correspondientesal ensayo de “push-out” de varios prototipos condiferentes geometrias. Tras evaluar los resultados, se determinara el mas idoneopara su implantacion en el Paso Superior de la Autovia delCantabrico, de 46 metros de luz y que presenta las vigasen fibra de carbono y los conectores de vidrio AR.[EN] One highly relevant aspect in composite material bridge desing is the study of the shear connectors to be used. Composite material bridges most commonly comprise a composite deck resting on steel or reinforced concrete girders. This article analyzes the connectors most frequently used in such bridges. It also reviews the connectors used in the King Stormwater Channel Bridge, whose fibreglass deck is supported by girders made of concrete-filled carbon fibre girders. The paper advances proposals for several types of connectors and discusses the results of push-out test run on a number of prototypes with different geometries. The results are analyzed to identify the optimum model for the “Autovía del Cantábrico” Overpass, with its 46-m span, carbon fibre girders and AR glass shear connectors.Peer reviewe
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