856 research outputs found

    Measurement of Atmospheric Neutrino Oscillations with a High-Density Detector

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    We propose an experiment to test the hypothesis that the reported anomaly on atmospheric neutrino fluxes is due to nu_mu nu_x oscillations. It will rely both on a disappearance technique, exploiting the method of the dependence of the event rate on L/E, which was recently shown to be effective for detection of neutrino oscillation and measurement of the oscillation parameters, and on an appearance technique, looking for an excess of muon-less events at high energy produced by upward-going tau neutrinos. The detector will consist of iron planes interleaved by limited streamer tubes. The total mass will be about 30 kt. The possibility of recuperating most of the instrumentation from existing detectors allows to avoid R&D phases and to reduce construction time. In four years of data taking, this experiment will be sensitive to oscillations nu_mu nu_x with Delta m^2 > 10^-4 eV^2 and a mixing near to maximal, and answer the question whether nu_x is a sterile or a tau neutrino

    Photosensitive Strip RETHGEM

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    An innovative photosensitive gaseous detector, consisting of a GEM like amplification structure with double layered electrodes (instead of commonly used metallic ones) coated with a CsI reflective photocathode, is described. In one of our latest designs, the inner electrode consists of a metallic grid and the outer one is made of resistive strips; the latter are manufactured by a screen printing technology on the top of the metallic strips grid The inner metallic grid is used for 2D position measurements whereas the resistive layer provides an efficient spark protected operation at high gains - close to the breakdown limit. Detectors with active areas of 10cm x10cm and 10cm x20cm were tested under various conditions including the operation in photosensitive gas mixtures containing ethylferrocene or TMAE vapors. The new technique could have many applications requiring robust and reliable large area detectors for UV visualization, as for example, in Cherenkov imaging devices.Comment: Presentes at the International Conference NDIP 2008, July 2008, Franc

    A methodological approach to assess the effect of organic, biodynamic, and conventional production processes on the intrinsic and perceived quality of a typical wine: The case study of chianti docg

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    The aim of this study was to propose a methodological approach to evaluate the impact of the organic, biodynamic, and conventional production processes on the intrinsic and perceived quality of a typical wine. For this purpose, fourteen commercial Chianti DOCG wines from the 2016 harvest were selected based on the type of production management. A survey was set up to get winemaking information from the estate’s producer of the wines to estimate the carbon dioxide production under the three types of management. The eligibility, identity, and style properties (the intrinsic quality) of the wines were defined. A group of 45 experts evaluated the differences between wines by the Napping test and rated their typicality (perceived quality). The organic and biodynamic management showed a lower level of estimated values of carbon dioxide production. The overall statistical elaboration of the chemical and sensory data highlighted that the registered differences of the intrinsic, perceived quality, and typicality level of the respective wines, did not depend on the type of management. The comparison of the three kinds of wine by SIMCA modeling, put in evidence that the conventional ones showed a greater homogeneity regarding chemical composition, sensory characteristics, and typicality

    The use of mercury against pediculosis in the Renaissance: tha case of Ferdinand of Aragon, King of Naples (1467-1496)

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    Pediculosis seems to have afflicted humans since the most ancient times and lice have been found in several ancient human remains. Examination of the head hair and pubic hair of the artificial mummy of Ferdinand II of Aragon (1467-1496), King of Naples, revealed a double infestation with two different species of lice, Pediculus capitis, the head louse, and Pthirus pubis, the pubic louse. The hair samples were also positive for the presence of mercury, probably applied as an anti-pediculosis therapy. This is the first time that these parasites have been found in the hair of a king, demonstrating that even members of the wealthy classes in the Renaissance were subject to louse infestation

    Comparação dos métodos Turbidimétrico e ICP OES para determinação de enxofre em amostras de tecido vegetal.

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    O enxofre (S) é um nutriente com funções similares ao nitrogênio no metabolismo das plantas, sendo este componente das proteínas, o qual é assimilado por meio de reações bioquímicas envolvendo reações de oxidação e redução. O S é encontrado em dois aminoácidos e é constituinte de várias coenzimas, além de vitaminas essenciais ao metabolismo das plantas. Muitos dos sintomas de deficiência são similares aos sintomas de deficiência do Nitrogênio, como a clorose, a redução do crescimento e o acumulo de antocianinas. Dessa forma, a diagnose foliar facilita a obtenção de informações precisas sobre o estado nutricional das plantas para que se possa garantir a produtividade e a qualidade das diversas culturas. O objetivo do trabalho foi comparar os resultados de análises de enxofre, em amostra de tecido vegetal, por meio dos métodos de quantificação por turbidimetria com sulfato de bário e espectrometria de emissão ótica com plasma induzido (ICP OES)

    Programa colaborativo interlaboratorial ano 6 - 2003.

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    A new concept for streamer quenching in resistive plate chambers

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    In this paper we propose a new concept for streamer quenching in Resistive Plate Chambers (RPCs). In our approach, the multiplication process is quenched by the appropriate design of a mechanical structure inserted between the two resistive electrodes. We show that stable performance is achieved with binary gas mixtures based on argon and a small fraction of isobutane. Fluorocarbons, deemed responsible for the degradation of the electrode inner surface of RPC detectors, are thus fully eliminated from the gas mixture. This design {also resulted} in a simplified assembly procedure. Preliminary results obtained with a few prototypes of ``Mechanically Quenched RPCs'' and some prospects for future developments are discussed
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