3,959 research outputs found

    Aspects of CPT-even Lorentz-symmetry violating physics in a supersymmetric scenario

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    Background fermion condensates in a landscape dominated by global SUSY are reassessed in connection with a scenario where Lorentz symmetry is violated in the bosonic sector (actually, the photon sector) by a CPTCPT-even kFk_F-term. An effective photonic action is discussed that originates from the supersymmetric background fermion condensates. Also, the photino mass emerges in terms of a particular condensate contrary to what happens in the kAFk_{AF}-violation. Finally, the interparticle potential induced by the effective photonic action is investigated and a confining profile is identified.Comment: 14 pages. arXiv admin note: text overlap with arXiv:1102.3777 by other author

    Spatialization of soil carbon stock in a rural landscape - a study case in the Southest of Brazil.

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    Agriculture is one of the main responsible for the increase of CO2 atmospheric in Brazil. However, the adoption of conservation farming practices is an alternative to mitigate climate change. Geoprocessing tools can assist in land use mapping process and associate different landscape parameters in an integrated spatial analysis. To carry out this study, the C stock was calculated and spatialized using the software Arcis® 10.2. A gradual C stock values categorization is presented according to land use cover map. It was observed that Annual e Perennial crops land use classes presented the lowest values of C stock. That showed the fragility of agrosystems concerning C stocks, but in the other hand, the great opportunity and importance of to improve agricultural management practices seeking decrease the impact of food production into the global C cycle

    Blog sobre legislação ambiental brasileira na Embrapa: a informação ao alcance de todos.

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    A legislação ambiental brasileira visa fiscalizar e punir aquele que causa dano ao meio ambiente, bem como garantir qualidade de vida e sustentabilidade ambiental para todos. Através de meios eletrônicos é possível obter informações da legislação brasileira. A disponibilidade em meios eletrônicos, especialmente internet, facilita o acesso da população às leis, levando a todos a conscientização das legislações existentes no Brasil. O objetivo desta pesquisa é reunir, classificar e disponibilizar a legislação ambiental, de forma fácil e clara, ao alcance e acesso a toda população. O acesso pode ser feito através de um link que será disponibilizado no site da Embrapa Gado de Corte. Ao acessar a página, o visitante visualiza a legislação ambiental que foi dividida por assuntos. Disponibiliza-se também a sinopse da lei, o número da legislação e o texto da legislação na íntegra através de hiperlink. Este é interligado e direcionado a um site do governo federal, que atualiza regularmente todas as legislações. No site da Embrapa será disponibilizado o acesso de diversas normas jurídicas e administrativas, de âmbito ambiental para pesquisas e download. Hoje temos, relacionado com a legislação ambiental, registros de 37 Leis, 18 Decretos, dois Decreto-Lei, 10 Portarias Normativas do IBAMA, 33 Resoluções do Conama, uma Portaria IPHAN, uma Instrução Normativa MMA, duas Portarias do Ibama, uma Portaria do Ministério da Saúde, uma Resolução RDC e a Constituição da República Federativa do Brasil de 1988. As normas jurídicas ambientais têm como objetivo disciplinar atividades humanas, para torná-las compatível com a proteção do meio ambiente. A pesquisa procura conscientizar a existência das leis ambientais, facilitando e disponibilizando seu acesso pela internet na página da Embrapa. A educação e informações direcionadas e especializadas, como a proposta desta pesquisa, pode auxiliar na transformação do ambiente em que vivemos, além de contribuir na pesquisa educacional dos interessados

    An Investigation of the KFK_{F}-type Lorentz-Symmetry Breaking Gauge Models in N=1N=1-Supersymmetric Scenario

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    In this work, we present two possible venues to accomodate the KFK_{F}-type Lorentz-symmetry violating Electrodynamics in an N=1N=1-supersymmetric framework. A chiral and a vector superfield are chosen to describe the background that signals Lorentz-symmetry breaking. In each case, the  Kμνκλ\ K_{\mu \nu \kappa \lambda }-tensor is expressed in terms of the components of the background superfield that we choose to describe the breaking. We also present in detail the actions with all fermionic partners of the background that determine  Kμνκλ\ K_{\mu \nu \kappa \lambda }.Comment: 10 page

    Soft lubrication: the elastohydrodynamics of non-conforming and conforming contacts

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    We study the lubrication of fluid-immersed soft interfaces and show that elastic deformation couples tangential and normal forces and thus generates lift. We consider materials that deform easily, due to either geometry (e.g. a shell) or constitutive properties (e.g. a gel or a rubber), so that the effects of pressure and temperature on the fluid properties may be neglected. Four different system geometries are considered: a rigid cylinder moving parallel to a soft layer coating a rigid substrate; a soft cylinder moving parallel to a rigid substrate; a cylindrical shell moving parallel to a rigid substrate; and finally a cylindrical conforming journal bearing coated with a thin soft layer. In addition, for the particular case of a soft layer coating a rigid substrate we consider both elastic and poroelastic material responses. For all these cases we find the same generic behavior: there is an optimal combination of geometric and material parameters that maximizes the dimensionless normal force as a function of the softness parameter = hydrodynamic pressure/elastic stiffness = surface deflection/gap thickness which characterizes the fluid-induced deformation of the interface. The corresponding cases for a spherical slider are treated using scaling concepts.Comment: 61 pages, 20 figures, 2 tables, submitted to Physics of Fluid

    Estoque de carbono no solo e avaliação de serviços ecossistêmicos em paisagens rurais.

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    O objetivo desse estudo foi analisar, de forma integrada, valores de estoque de carbono no solo com mapas de uso e cobertura, utilizando ferramentas de geoprocessamento, tendo em vista a identificação de áreas prestadoras de serviços ecossistêmicos

    Qualidade da água do Rio Poty para irrigação em Teresina, PI.

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    Polyphosphates and poly-β-hydroxybutyrate granules identification through quantitative image analysis in enhanced biological phosphorus removal systems

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    Enhanced biological phosphorus removal (EBPR) is a widely implemented technique for having the potential to cheaply and reliably remove phosphate from wastewater treatment processes, than traditional chemical methods. EBPR is performed by operating the system sequentially with anaerobic and aerobic conditions. Several studies were already performed ranging from different strategies for the competition between polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs) to modeling both types of bacterial activities. Until now, slight attention has been given to the development of newer, faster, simpler, and better suited monitoring techniques for this type of system. This work is focused on the development of image analysis techniques for polyphosphates and poly-β-hydroxybutyrate granules in EBPR systems since off-line analyses are labor intensive and not able to be performed in full-scale plants. A lab-scale sequencing batch reactor fed with synthetic wastewater containing volatile fatty acids (VFAs) and orthophosphate was used. The reactor had a working volume of 4 L and was operated with a cycle time of 6 h consisting of 2 h anaerobic, 3 h aerobic, 50 min settling and decanting, and 5 min anaerobic idle periods. In each cycle, 2 L of synthetic wastewater was fed to the reactor in the first 5 min of the anaerobic period, resulting in a hydraulic retention time (HRT) of 12 h. The pH was controlled during both the anaerobic and aerobic periods around 7, and the temperature was controlled at 30 ºC in order to provide selective advantages to GAOs over PAOs. The ratio between chemical oxygen demand (COD) and P in the feed was kept at 10 (gCOD/g P). Biomass samples were collected at the end of the anaerobic and aerobic phases and fixed with phosphate buffer saline solution (PBS) and ethanol. Two fluorescence staining methods were used: (1) DAPI for poly-P identification; and (2) nile blue for poly-β-hydroxybutyrate granules. So far, promising results were achieved regarding the type of images achieved by these fluorescence staining methods and the image analysis procedures still under development
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