1,437 research outputs found

    NiO-nanoflowers decorating a plastic electrode for the non-enzymatic amperometric detection of H2O2 in milk: old issue, new challenge

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    In food supply chain, there are regulatory limitations on the use of chemicals for cleaning processing lines since the healthiness of the commodities must be guaranteed if accidentally traces of these detergents and sanitizers pass to them. Hydrogen peroxide, is a commonly used sanitizer in the cleaning of the food processing lines having both bactericidal and bacteriostatic properties, however, it produces inflammatory effects on the human body. The availability of rapid systems to detect its accidental presence is therefore useful to speed up the control and apply corrective actions. In the present work, a drop casting and easily prepared plastic graphite / PVC electrode decorated with NiO nanostructures has been investigated as electrochemical sensor for the non-enzymatic amperometric determination of H2O2. 24 The catalytic activity, dispersion, and stability of NiO nanostructures mixed with plastic nanocomposite electrode have been studied in detail. The preparation method, particularly the precipitating agents used in the synthesis of NiO nanostructures strongly influenced their morphology and porosity. Further, the electrochemical response of NiO-PE electrodes towards H2O2 resulted to be morphology-dependent. The non-enzymatic electrochemical sensor was optimized for the rapid and sensitive detection of H2O2 present in milk with no sample pre- treatments. NiO nanoflowers showed the best catalytic activity towards H2O2, a linear range that extends up to 4 mM and a LOD of 5 μM (3sd of the blank signal) were obtained

    Use of camera trapping in determining Iberian lynx population parameters: The use area and its limitations

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    Below are the results of the survey of the Iberian lynx obtained with camera-trapping between 2000 and 2007 in Sierra Morena. Two very important aspects of camera-trapping concerning its efficiency are also analyzed. The first is the evolution along years according to the camera-trapping type used of two efficiency indicators. The results obtained demonstrate that the most efficient lure is rabbit, though it is the less proven (92 trap-nights), followed by camera-trapping in the most frequent marking places (latrines). And, we propose as a novel the concept of use area as a spatial reference unit for the camera-trapping monitoring of non radio-marked animals is proposed, and its validity discussed

    Cerium‐Copper Oxides Synthesized in a Multi‐Inlet Vortex Reactor as Effective Nanocatalysts for CO and Ethene Oxidation Reactions

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    In this study, a set of CuCeOx catalysts was prepared via the coprecipitation method using a Multi‐Inlet Vortex Reactor: the Cu wt.% content is 5, 10, 20, 30 and 60. Moreover, pure CeO2 and CuO were synthesized for comparison purposes. The physico‐chemical properties of this set of samples were investigated by complementary techniques, e.g., XRD, N2 physisorption at −196 °C, Scanning Electron Microscopy, XPS, FT‐IR, Raman spectroscopy and H2‐TPR. Then, the CuCeOx catalysts were tested for the CO and ethene oxidation reactions. As a whole, all the prepared samples presented good catalytic performances towards the CO oxidation reaction (1000 ppm CO, 10 vol.% O2/N2): the most promising catalyst was the 20%CuCeOx (complete CO conversion at 125 °C), which exhibited a long‐term thermal stability. Similarly, the oxidative activity of the catalysts were evaluated using a gaseous mixture containing 500 ppm C2H4, 10 vol.% O2/N2. Accordingly, for the ethene oxidation reaction, the 20%CuCeOx catalyst evidenced the best catalytic properties. The elevated catalytic activity towards CO and ethene oxidation was mainly ascribed to synergistic interactions between CeO2 and CuO phases, as well as to the high amount of surface‐chemisorbed oxygen species and structural defects

    Modelo para estimativa de produtividade da cultura do milho no Estado do Piauí.

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    Modelo para Estimativa de Produtividade da Cultura do Milho no Estado do Piauí; Desenvolvimento do modelo; Conversão de CO2 em CH2 O; Correção para respiração de manutencão e crescimento; CRMCI; Correcão para interceptação de radiação solar (CRs); índice de colheita (IC); Produtividade potencial de grãos (PPgr); Balanco hídrico; Evapotranspiracão de referência; índice térmico e coeficiente empírico composto; Evapotranspiração da cultura; Capacidade de água disponível; Saldo (SI e negativo acumulado (L); Variaçao do armazenamento; Evapotranspiracao real; Deficiência hidrica; Fator de depleção de produtividade (Fd); Produtividade deplecionada de grãos (Pgrãos).bitstream/item/35900/1/Doc157.pd

    Segurança.

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