267 research outputs found

    El Neógeno del Empordà y Baix Ebre (CAtalunya): estudio comparativo

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    The Neogene infill of the Empordà and Baix Ebre basins was undifferentiated up to now. In Empordhthere are five sedimentary systems and in Baix Ebre six lithostratigraphic units are distinguished. In the Empordà, Esponellà conglomerates are continental diposits of Upper Miocene (Turolian) and coastal sediments are Tortonian (GEOT-1 borehole). Pliocene sedimentation shows a similarity in both basins. In the Empordà basin deltaic (Avinyonet, Vilamalla, etc.) and bay environments (Siurana marls) are dominant, while littoral (Lower Marine Detrital Unit) and bay (Campredó marls) environrnents appear in the Baix Ebre. The Pliocene series culminate withlacustrine-aliuvial facies (Sant Onofre limestone and Roca Corba conglomerate units) in the Baix Ebre basin and with alluvial facies (Sant Climent-Perelada and Cistelia systems) in the Empordà basin. We propose a similarity between Siurana and Campredó marls, and we consider it as a guide leve1 in the catalonian marine pliocene

    Quemadura solar y fotodermatosis

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    Los autores describen las características de la luz solar y las radiaciones que afectan a la piel, las quemaduras producidas por el sol y las denominadas fotodermatosis idiopáticas, como son la erupción polimorfa lumínica, urticaria solar, hidroa vacciniforme, prurigo actínico y dermatosis actínica crónica. Se expone el concepto de reacción fototóxica y fotoalérgica y se describen las medidas protectoras frente a la luz solar, basadas en evitar la exposición directa al sol y la aplicación de agentes químicos, físicos y biológicos en las zonas expuestas de la piel

    Urgencias Psiquiátricas en un Hospital General.

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    Se presentan los resultados de la evaluación, en el período de un año, de todas las urgencias psiquiátricas atendidas en el Hospital Central de Asturias, y se realiza una discusión de los mismos a partir de los principales estudios nacionales e internacionales publicados al respecto en los últimos años

    Magnetoelectric Coupling in epsilon-Fe2O3

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    Nanoparticles of the ferrimagnetic epsilon-Fe2O3 oxide have been synthesized by sol-gel method. Here, we report on the measurements of the dielectric permittivity as a function of temperature, frequency and magnetic field. It is found that, coinciding with the transition from collinear ferrimagnetic ordering to an incommensurate magnetic state occurring at about 100 K, there is an abrupt change (about 30 %) of permittivity suggesting the existence of a magnetoelectric coupling in this material. Indeed, magnetic field dependent measurements at 100 K have revealed an increase of the permittivity by about 0.3 % in 6 T. Prospective advantages of epsilon-Fe2O3 as multiferroic material are discussed.Comment: 17 pages, 4 figures, submitted to Nanotechnolog

    Urgencias Psiquiátricas en un Hospital General.

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    Se presentan los resultados de la evaluación, en el período de un año, de todas las urgencias psiquiátricas atendidas en el Hospital Central de Asturias, y se realiza una discusión de los mismos a partir de los principales estudios nacionales e internacionales publicados al respecto en los últimos años

    Prototyping of petalets for the Phase-II Upgrade of the silicon strip tracking detector of the ATLAS Experiment

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    In the high luminosity era of the Large Hadron Collider, the HL-LHC, the instantaneous luminosity is expected to reach unprecedented values, resulting in about 200 proton-proton interactions in a typical bunch crossing. To cope with the resultant increase in occupancy, bandwidth and radiation damage, the ATLAS Inner Detector will be replaced by an all-silicon system, the Inner Tracker (ITk). The ITk consists of a silicon pixel and a strip detector and exploits the concept of modularity. Prototyping and testing of various strip detector components has been carried out. This paper presents the developments and results obtained with reduced-size structures equivalent to those foreseen to be used in the forward region of the silicon strip detector. Referred to as petalets, these structures are built around a composite sandwich with embedded cooling pipes and electrical tapes for routing the signals and power. Detector modules built using electronic flex boards and silicon strip sensors are glued on both the front and back side surfaces of the carbon structure. Details are given on the assembly, testing and evaluation of several petalets. Measurement results of both mechanical and electrical quantities are shown. Moreover, an outlook is given for improved prototyping plans for large structures.Comment: 22 pages for submission for Journal of Instrumentatio

    Precision scans of the pixel cell response of double sided 3D pixel detectors to pion and x-ray beams

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    hree-dimensional (3D) silicon sensors offer potential advantages over standard planar sensors for radiation hardness in future high energy physics experiments and reduced charge-sharing for X-ray applications, but may introduce inefficiencies due to the columnar electrodes. These inefficiencies are probed by studying variations in response across a unit pixel cell in a 55μm pitch double-sided 3D pixel sensor bump bonded to TimePix and Medipix2 readout ASICs. Two complementary characterisation techniques are discussed: the first uses a custom built telescope and a 120GeV pion beam from the Super Proton Synchrotron (SPS) at CERN; the second employs a novel technique to illuminate the sensor with a micro-focused synchrotron X-ray beam at the Diamond Light Source, UK. For a pion beam incident perpendicular to the sensor plane an overall pixel efficiency of 93.0±0.5% is measured. After a 10o rotation of the device the effect of the columnar region becomes negligible and the overall efficiency rises to 99.8±0.5%. The double-sided 3D sensor shows significantly reduced charge sharing to neighbouring pixels compared to the planar device. The charge sharing results obtained from the X-ray beam study of the 3D sensor are shown to agree with a simple simulation in which charge diffusion is neglected. The devices tested are found to be compatible with having a region in which no charge is collected centred on the electrode columns and of radius 7.6±0.6μm. Charge collection above and below the columnar electrodes in the double-sided 3D sensor is observed
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