4,641 research outputs found

    O programa nacional de fortalecimento da agricultura familiar no Brasil: uma análise sobre a distribuição regional e setorial dos recursos.

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    No Brasil, as políticas públicas para o espaço rural sempre tenderam a priorizar a agricultura patronal, em detrimento dos agricultores familiares. Todavia, os estudos realizados pelos órgãos FAO - INCRA deram subsídio para a criação do Programa Nacional de Fortalecimento da Agricultura Familiar (PRONAF), resultando em um novo direcionamento dos investimentos públicos, os quais passaram a contemplar o segmento dos agricultores familiares. Entende-se o PRONAF como uma política não-compensatória, que, apesar de seus problemas, tem contribuído de fato para mudanças e melhorias no espaço agrário brasileiro. Desde sua criação no final da década de 1990, o PRONAF passou por várias mudanças em sua estrutura administrativa e operacional, a fim de alcançar seus objetivos e adequar-se face a complexa realidade social agrária brasileira. Sendo assim, o presente estudo visa discutir as ações do Estado por meio desse Programa, a partir de suas linhas de atuação, bem como analisar a distribuição de suas concessões de crédito regional e setorialmente. Assim, os procedimentos metodológicos utilizados para a realização deste trabalho compreendem pesquisa bibliográfica e documental, além de pesquisa em fontes secundárias, no intuito de obter dados e informações relevantes para a análise das relações sociais estabelecidas em meio a esse processo de concretização e espacialização desse Programa. Dentre as implicações do PRONAF pode-se notar em âmbito nacional, uma diminuição da disparidade regional brasileira, bem como a preocupação que o Programa tem demonstrado com os aspectos socioculturais locais e regionais, como forma de garantir que seus investimentos perpassem a dimensão econômica, mas valorize outras dimensões, a exemplo dos elementos culturais

    The Resistive-Plate WELL with Argon mixtures - a robust gaseous radiation detector

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    A thin single-element THGEM-based, Resistive-Plate WELL (RPWELL) detector was operated with 150 GeV/c muon and pion beams in Ne/(5%CH4_4), Ar/(5%CH4_4) and Ar/(7%CO2_2); signals were recorded with 1 cm2^2 square pads and SRS/APV25 electronics. Detection efficiency values greater than 98% were reached in all the gas mixtures, at average pad multiplicity of 1.2. The use of the 109^9{\Omega}cm resistive plate resulted in a completely discharge-free operation also in intense pion beams. The efficiency remained essentially constant at 98-99% up to fluxes of \sim104^4Hz/cm2^2, dropping by a few % when approaching 105^5 Hz/cm2^2. These results pave the way towards cost-effective, robust, efficient, large-scale detectors for a variety of applications in future particle, astro-particle and applied fields. A potential target application is digital hadron calorimetry.Comment: presented at the 2016 VIenna Conf. On instrumentation. Submitted to the Conference proceeding

    Pressure effect in the X-ray intrinsic position resolution in noble gases and mixtures

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    A study of the gas pressure effect in the position resolution of an interacting X- or gamma-ray photon in a gas medium is performed. The intrinsic position resolution for pure noble gases (Argon and Xenon) and their mixtures with CO2 and CH4 were calculated for several gas pressures (1-10bar) and for photon energies between 5.4 and 60.0 keV, being possible to establish a linear match between the intrinsic position resolution and the inverse of the gas pressure in that energy range. In order to evaluate the quality of the method here described, a comparison between the available experimental data and the calculated one in this work, is done and discussed. In the majority of the cases, a strong agreement is observed

    Helicobacter pylori : role of water on survival and transmission

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    Detection of Salmonella enterica serovar Enteritidis using real time PCR, immunocapture assay, PNA FISH and standard culture methods in different types of food samples

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    Several methods for the rapid and specific detection of Salmonella in food samples have been described. Here, we compare 4 of those methods in terms of assay time, procedure complexity, detection limit, sensitivity, specificity and accuracy. Milk, eggs and mayonnaise samples were artificially contaminated with Salmonella enterica serovar Enteritidis cell concentrations ranging from 1 × 10- 2 to 1 × 102 CFU per 25 g or ml of food. Samples were then pre-enriched and analyzed by either: i) real-time PCR, using the iQ-Check Salmonella kit; ii) immunocapture, using the RapidChek SELECT Salmonella; iii) a peptide nucleic acid fluorescence in situ hybridization (PNA FISH) method and iv) the traditional bacteriological method ISO 6579:2002. All methods were able to detect Salmonella in the different types of food matrixes and presented a similar detection level of 1 CFU per 25 g or ml of food sample. The immunocapture and the PNA FISH methods proved to be very reliable, as their results were 100% in agreement with the ISO method. However, real-time PCR presented a significant number of false positives, which resulted in a specificity of 55.6% (CI 95%, 31.3 – 77.6) and an accuracy of 82.2%(CI 95%, 63.2 – 91.4) for this method. Sensitivity was 100% since no false negative results were observed. In conclusion, the implementation of these molecular techniques, mainly the immunocapture and PNA-FISH methods, provides a reliable and less time-consuming alternative for the detection of Salmonella spp. in food samples.This work was supported by the Portuguese Institute Fundacao para a Ciencia e Tecnologia (Project "DNA mimics" PIC/IC/82815/2007; Post-Doc Fellowship SFRH/BPD/74480/2010 and PhD Fellowship SFRH/BD/38124/2007)

    A STEADY PSEUDO-COMPRESSIBILITY APPROACH BASED ON UNSTRUCTURED HYBRID FINITE VOLUME TECHNIQUES APPLIED TO TURBULENT PREMIXED FLAME PROPAGATION

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    A pseudo-compressibility method for zero Mach number turbulent reactive flows with heat release is combined with an unstructured finite volume hybrid grid scheme. The spatial discretization is based on an overlapped cell vertex approach. An infinite freely planar flame propagating into a turbulent medium of premixed reactants is considered as a test case. The recourse to a flamelet combustion modeling for which the reaction rate is quenched in a continuous way ensures the uniqueness of the turbulent flame propagation velocity. To integrate the final form of discretized governing equations, a three-stage hybrid time-stepping scheme is used and artificial dissipation terms are added to stabilize the convergence path towards the final steady solution. The results obtained with such a numerical procedure prove to be in good agreement with those reported in the literature on the very same flow geometry. Indeed, the flame structure as well as its propagation velocity are accurately predicted thus confirming the validity of the approach followed and demonstrating that such a numerical procedure will be a valuable tool to deal with complex reactive flow geometries

    The determinants of risk reporting during the period of adoption of Basel II Accord: Evidence from the Portuguese commercial banks

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    The purpose of this paper to analyze the risk reporting practices and its determinants of commercial banks during the period of the adoption of the Basel II Accord in Portugal. The paper conducts a content analysis of the risk and risk management sections included in the management reports and the notes of the annual reports of Portuguese commercial banks, for the years 2007, 2010 and 2013. Findings show that theoretical frameworks underpinned in agency and legitimacy theories continue to provide valid explanations for risk reporting by Portuguese banks. More specifically, findings indicate that agency costs, public visibility and reputation are crucial drivers of risk reporting. Findings also indicate that younger banks with lower risk management skills use risk reporting either as an informational process or as a channel to manage organizational legitimacy. The content analysis does not allow readily for in-depth qualitative inquiry. The coding instrument is subject to coder bias. Information about risk can be provided in sources other than annual reports. Additionally, not all banks disclose information on corporate governance-related variables that could also influence risk reporting. The current research setting has never been studied hitherto. In this sense, this study seems to be of great relevance given the scarcity of literature on the subject in Portugal.info:eu-repo/semantics/publishedVersio

    Argamassas fotocatalíticas: influência da composição na resistência mecânica e na capacidade de auto-limpeza

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    O presente artigo apresentam-se resultados relativos ao estudo conjunto de diversos parâmetros na resistência mecânica e na capacidade de auto-limpeza de argamassas fotocatalíticas. Os resultados obtidos mostram que a fim de manter a mesma consistência em todas as argamassas se torna necessário aumentar a razão w/b com a percentagem de TiO2 o que se traduz numa redução acentuada da resistência mecânica das argamassas. Os resultados mostram ainda que que as composições com 2% de TiO2 são as que apresentam uma maior capacidade de auto-limpeza
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