3,718 research outputs found

    A Novel Generic Framework for Track Fitting in Complex Detector Systems

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    This paper presents a novel framework for track fitting which is usable in a wide range of experiments, independent of the specific event topology, detector setup, or magnetic field arrangement. This goal is achieved through a completely modular design. Fitting algorithms are implemented as interchangeable modules. At present, the framework contains a validated Kalman filter. Track parameterizations and the routines required to extrapolate the track parameters and their covariance matrices through the experiment are also implemented as interchangeable modules. Different track parameterizations and extrapolation routines can be used simultaneously for fitting of the same physical track. Representations of detector hits are the third modular ingredient to the framework. The hit dimensionality and orientation of planar tracking detectors are not restricted. Tracking information from detectors which do not measure the passage of particles in a fixed physical detector plane, e.g. drift chambers or TPCs, is used without any simplifications. The concept is implemented in a light-weight C++ library called GENFIT, which is available as free software

    Enfermedad de Alzheimer y pérdida auditiva

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    Despite the different epidemiological, neurophysiological and morphological studies published in the literature, it is still not known for sure whether there is a relation between Alzheimer's disease (AD) and peripheral hearing loss. In this work we conduct an auditory study in patients with AD and in volunteer controls in order to investigate this possible relationship. SUBJECTS AND METHODS: The sample studied consisted of 14 patients with a clinical diagnosis of probable AD (age: 79 Y 6 years) and 14 volunteers (age: 76 Y 5 years) who visited the Clinica Universidad de Navarra. After applying a set of thorough criteria to preclude any previous hearing problems, all the participants underwent a subjective hearing assessment by means of pure-tone threshold audiometry and vocal audiometry and an objective auditory assessment using a tympanometry study, stapedial reflex, otoacoustic emissions and brainstem auditory evoked potentials. For the analysis, patients with AD and controls were paired homogenously by sex and age. RESULTS: The main obstacle hindering the study was to recruit the participants, due to the fact that they did not see any direct benefit from the study and it demanded an excessive amount of their time. Pure-tone threshold audiometry showed that patients with AD had a pattern of greater hearing loss for acute frequencies, with statistically significant differences. No significant differences were found in the analysis of the rest of the subjective and objective hearing tests. CONCLUSIONS: The findings of our study both agree and disagree with some earlier works from the literature, which suggests that patients with AD may have their own auditory patter

    Aqueous suspension processing of multicomponent submicronic Y-TZP/Al2O3/SiC particles for suspension plasma spraying

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    In order to obtain thermal barrier coatings by Suspension Plasma Spraying (SPS) process with potential new self-healing ability multicomponent submicronic Y-TZP/Al2O3/SiC suspensions were prepared. For this purpose, concentrated aqueous suspensions of individual components, as well as the multicomponent mixture were studied and characterised, in terms of colloidal stability and rheological behaviour to determine the best conditions for processing and preparation of the coatings. In the study, different dispersant contents and sonication times were tested. Subsequently, low concentrated suspensions were prepared to obtain preliminary thermal barrier coatings with the optimised feedstock. Thus, ceramic coatings were deposited by SPS and then characterised in order to assess the microstructure and phase distribution, in particular, the degree of preservation of the sealing agent, SiC, in the final coating as a previous indicator of its self-healing ability

    Modulating the phase transition temperature of giant magnetocaloric thin films by ion irradiation

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    Magnetic refrigeration based on the magnetocaloric effect at room temperature is one of the most attractive alternative to the current gas compression/expansion method routinely employed. Nevertheless, in giant magnetocaloric materials, optimal refrigeration is restricted to the narrow temperature window of the phase transition (Tc). In this work, we present the possibility of varying this transition temperature into a same giant magnetocaloric material by ion irradiation. We demonstrate that the transition temperature of iron rhodium thin films can be tuned by the bombardment of ions of Ne 5+ with varying fluences up to 10 14 ions cm --2 , leading to optimal refrigeration over a large 270--380 K temperature window. The Tc modification is found to be due to the ion-induced disorder and to the density of new point-like defects. The variation of the phase transition temperature with the number of incident ions opens new perspectives in the conception of devices using giant magnetocaloric materials

    Innovación docente mediante la creación de recursos visuales para el aprendizaje de las ciencias geológicas

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    En el contexto de los proyectos “Redes de investigación en docencia universitaria de la Universidad de Alicante”, se ha creado la red Banco de imágenes de minerales y rocas. El objetivo es elaborar un banco de imágenes empleando los materiales de las colecciones docentes de mineralogía y petrología, para usarlo como herramienta docente en todos los Grados que imparten alguna asignatura de Geología, así como en los cursos del Grado en Geología. En esta fase de la red, se establecen las pautas para la elaboración del material, utilizando los más altos criterios de calidad en las imágenes obtenidas. Se determina cuál es el instrumental más adecuado para la obtención de las imágenes, el cual depende de las condiciones de la muestra cuya imagen se pretende obtener. Además cada muestra presenta diferentes requisitos de iluminación, que son establecidos tras la realización de numerosos ensayos. Para la obtención de pequeños detalles, se hace uso de instrumental específico (microscopios compuestos y de polarización o lupas) que requiere de adaptadores especiales para poder obtener las imágenes. Una vez creado el banco de imágenes se elaborarán recursos didácticos específicos, como guiones de prácticas, manuales, páginas web y otros recursos que permitan el autoaprendizaje del alumno

    Optical fibers to measure temperature vertical profile at sea

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    The paper is focus in the use the optical fiber to measure the temperature in various heigh at the same time to get a temperature vertical variation. The temperature measurements are puntual while the Bragg gratings located in the fiber.Peer Reviewe

    Fabrication and Characterization of Multiband Solar Cells Based on Highly Mismatched Alloys

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    Multiband solar cells are one type of third generation photovoltaic devices in which an increase of the power conversion efficiency is achieved through the absorption of low energy photons while preserving a large band gap that determines the open circuit voltage. The ability to absorb photons from different parts of the solar spectrum originates from the presence of an intermediate energy band located within the band gap of the material. This intermediate band, acting as a stepping stone allows the absorption of low energy photons to transfer electrons from the valence band to the conduction band by a sequential two photons absorption process. It has been demonstrated that highly mismatched alloys offer a potential to be used as a model material system for practical realization of multiband solar cells. Dilute nitride GaAs1-xNx highly mismatched alloy with low mole fraction of N is a prototypical multiband semiconductor with a well-defined intermediate band. Currently, we are using chemical beam epitaxy to synthesize dilute nitride highly mismatched alloys. The materials are characterized by a variety of structural and optical methods to optimize their properties for multiband photovoltaic devices
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