4,614 research outputs found

    Ward Identities and chiral anomalies for coupled fermionic chains

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    Coupled fermionic chains are usually described by an effective model written in terms of bonding and anti-bonding spinless fields with linear dispersion in the vicinities of the respective Fermi points. We derive for the first time exact Ward Identities (WI) for this model, proving the existence of chiral anomalies which verify the Adler-Bardeen non-renormalization property. Such WI are expected to play a crucial role in the understanding of the thermodynamic properties of the system. Our results are non-perturbative and are obtained analyzing Grassmann functional integrals by means of Constructive Quantum Field Theory methods.Comment: TeX file, 26 pages, 7 figures. Published version, new section added to answer referee remarks and derive the Ward Identites, no modifications in the main resul

    Cesta para colher figos.

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    Applications of Bioceramics in the Management of Orbital Floor Fractures and Anophthalmic Cavity: A Review

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    Biocompatible ceramics, commonly known as “bioceramics”, are an extremely versatile class of materials with a wide range of applications in modern medicine. Given the inorganic nature and physico-mechanical properties of most bioceramics, which are relatively close to the mineral phase of bone, orthopedics and dentistry are the preferred areas of usage for such biomaterials. Another clinical field where bioceramics play an important role is oculo-orbital surgery, a highly cross-and interdisciplinary medical specialty addressing to the management of injured eye orbit, with particular focus on the repair of orbital bone fractures and/or the placement of orbital implants following removal of a diseased eye. In the latter case, orbital implants are not intended for bone repair but, being placed inside the ocular cavity, have to be biointegrated in soft ocular tissues. This article reviews the state of the art of currently-used bioceramics in orbital surgery, highlighting the current limitations and the promises for the future in this field

    Uso da tomografia de ressonância magnética para diagnosticar os efeitos das injúrias mecânicas em figos "roxo de valinhos".

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    A produção de frutas de qualidade visando atender o crescente consumo de produtos frescos para mercados cada vez exigentes, tem sido o grande desafio para a fruticultura brasileira. Os impactos mecânicos a que as frutas estão submetidas durante as operações de manejo na colheita e pós-colheita são responsáveis por perdas fignificativas na produção, distribuição e comercialização. E importante ressaltar que a aparência externa também é um atributo de qualidade do fruto, sendo considerado como o principal fator de rejeição por parte do consumidor. Frutos murchos, amassados, e sem a cor característica, aparentando fruto de baixa qualidade sobram nas prateleiras dos supermercados. A busca de qualidade requer técnicas rápidas e não-destrutivas para a medida de algumas propriedades físicas dos frutos.bitstream/CNPDIA/8721/1/CT52_2003.pd

    Spatial variability of soil fertility attributes and productivity in a coffee crop farm

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    ArticleCoffee cultivation is of great importance to Brazilian agribusiness, as coffee occupies extensive production areas and is one of the most exported Brazilian products. To maintain coffee production numbers, productive techniques must be adopted that optimize productive system use. The objective of this work was to apply geostatistical techniques in the evaluation of soil fertility attributes to construct maps of variability in soil fertility parameters and the productivity of a coffee crop in the municipality of Monte Carmelo, Minas Gerais (MG), Brazil. The work was developed with coffee of the cultivar Mundo Novo 379/19, and 19 sample points were georeferenced in Universal Transverse Mercator coordinates. Spatial dependence of the fertility and productivity parameters was analysed via classic semivariogram fitting and interpolation by ordinary kriging using the statistical computer system, R. All parameters evaluated showed high degrees of spatial dependence. The attribute values varied along the sampling points, except for the sodium (Na) contents, which had similar values in all samplings. The studied parameters ranged from 80 to 200 metres. It is conclusion, the use of productivity maps linked to soil chemical attributes can be useful for determining the occurrence of variable productivity rates throughout the area, allowing the adoption of corrective practices for subsequent crops and thus making the maps very useful tools for producers

    Espacialização da soja nos biomas Amazônia, Cerrado, Mata Atlântica e Pampa entre os anos de 2007 e 2012.

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    Uma das culturas agrícolas que está em maior ascensão no Brasil nas últimas três décadas é a soja, que ocupa 49% da área plantada de grãos no país. A soja é cultivada principalmente nas regiões Sul e Centro-Oeste. A pesquisa feita objetivou demonstrar a distribuição espacial da produção de soja no Brasil em quatro biomas, Amazônia, Cerrado, Mata Atlântica e Pampa, nos anos de 2007 a 2012. A análise de cluster revelou as similaridades entre os biomas Amazônia e Cerrado quanto à produtividade média anual (kg/ha/ano). Os biomas Amazônia e Pampa apresentaram similaridades quanto à área plantada (ha). Mato Grosso, inserido nos biomas Amazônia e Cerrado, foi o estado que apresentou os maiores valores de produção média total e área média plantada
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