2,003 research outputs found
Spin-1 Particles with Light-Front Approach
For the vector sector, i.e, mesons with spin-1, the electromagnetic form
factors and anothers observables are calculated with the light-front approach.
However, the light-front quantum field theory have some problems, for example,
the rotational symmetry breaking. We solve that problem added the zero modes
contribuition to the matrix elements of the electromagnetic current, besides
the valence contribuition. We found that among the four independent matrix
elements of the plus component in the light-front helicity basis only the one carries zero mode contributions.Comment: 5 pages. 3 Figures, use latex and EPJ styl
Ephedranthus dimerus (Annonaceae), a new species from the Atlantic Forest of Brazil, with a key to the species of Ephedranthus
A new species of Ephedranthus from the Brazilian Atlantic Forest is described and illustrated, and a preliminary key to the species of Ephedranthus is presented. Ephedranthus dimerus is the only species of the genus from the Atlantic Forest region and the first species of the genus with dimerous flowers. It is similar to E. guianensis in having narrowly obovate to elliptic leaves with similar dimensions and a cuneate to acute base. Nevertheless, the two species can be distinguished from each other by the number of monocarps per fruit and by the length of the stipe
CARTOGRAFIA DA ACESSIBILIDADE E DA INTERAÇÃO NO ESTADO DA BAHIA
The objective of this paper is to contribute to a better conceptual and methodological systematization and development of fundamental aspects of the spatial organization in Brazil and, particularly, in the State of Bahia, taking as reference the accessibility and the interacion. It is recognized the importance of these concepts in the comprehension of the spatial organization dynamics where they appear as corollaries of the locational aspects. The spatial organization model of Janelle (1969) is introduced and discussed, pointing out the position of the accessibility and the interaction as central concepts in the questions related to the own nature of the geographical problems. Having in view the development of spatial analysis, several theoretical-conceptual observations are discussed aiming to unite the cartographic methodology to a solid conceptual framework.
The use of the accessibility and interaction concepts to the State of Bahia is carried out on the basis of two sets of maps. The first one underlines the evolution of the accesssibility to Salvador, the regional metropolis, by means of isocrones maps for the years of 1956, 1972 and 1981. These maps show the importance of the changes in the transportation sector, affecting the accessibility degrees, even in a relatively short period. The various levels os accessibility to Salvador have a clear influence upon the intensity of the flows, these constituting the second set of maps. Five maps were produced on these flows, two of them representing the intensity of the total traffic of vehicles per day and two for the importance of truckage for the years of 1973 and 1979. A distinction was made for the vehicles flows in 1979 in the Eastern region of the State - the most developed one. The first maps show the evolution and a great superiority of the traffic intensity in the Recôncavo and in the axis of national circulation over other regions of the State. The sections with superiority of trucks circulation are mainly of national chacacter, being reduced in the vicinity of larger cities.
In conclusion, considerations are made concerning the relation between the concepts of accessibility, interaction, spatial organization and the cartographic methodology, pointing out the spatial-temporal effect of distances.
evolution and a great superiority of the traffic 
Electromagnetic Structure of the Pion
In this work, we analyze the electromagnetic structure of the pion. We
calculate its electromagnetic radius and electromagnetic form factor in low and
intermediate momentum range. Such observables are determined by means of a
theoretical model that takes into account the constituent quark and antiquark
of the pion within the formalism of light-front field theory. In particular, we
consider a nonsymmetrical vertex in this model, with which we calculate the
electromagnetic form factor of the pion in an optimized way, so that we obtain
a value closer to the experimental charge radius of the pion. The theoretical
calculations are also compared with the most recent experimental data involving
the pion electromagnetic form factor and the results show very good agreement.Comment: Paper with 4 pages, 1 figure, presented in XII HADRON PHYSICS
Conference - to appear in AIP Conference Proceeding
Estudo comparativo de métodos de produção de amostras para identificação de espécies de Trichoderma pela técnica MALDI-TOF MS.
Autochthonous yeast populations from different brazilian geographic indications.
Yeasts are versatile microorganisms which show heterogeneity in their abilities of aromatic molecules formation. The metabolic conversions may improve the production of a particular compound already formed by the microorganism or promote the production of a completely new biochemicals. These conversions depend on the environment. The microbiome of terroir is unique. If the term terroir is a set of physical properties of a vineyard that contribute to the specific characteristics of its wine, the microorganisms will undoubtedly form an integral part of this concept. There are yeasts, filamentous fungi and bacteria that can affect the quality of the wine. The aim of the present study was to identify the autochthonous yeast populations of grape berries collected from regions with Geographic Indications or under construction. The identification was carried out by an approach, combining Maldi-Tof-MS, PCR-RFLP of the internal transcribed spacer with 5.8S ribosomal DNA (rDNA) (ITS1-5.8S-ITS2) and sequences of the D1/D2 domain of the 26S rRNA gene. Some species are common to different GIs and in some of them other species are completely absent, besides some places are contiguous areas. In some areas, Hanseniaspora opuntiae, Saccharomyces cerevisiae, Pichia myanmarensis and Hanseniaspora uvarum were the predominant species.Também publicado em: CONGRESSO MUNDIAL DA VINHA E DO VINHO, 39., 2016, Bento Gonçalves. Programa...Bento Gonçalves, RS: International Organisation of Vine and Wine (OIV): Ministério da Agricultura, Pecuária e Abastecimento, de 19 a 21 outubro, 2016. Artigo nº 7, 02030. 2016
Resíduos sólidos de uva e compostos com capacidade oxi-redox favorável.
O objetivo deste estudo foi determinar a diferença existente entre os resíduos dos cultivares Isabel, Niágara, Chardonnay, Pinot Noir e uma mistura de cultivares em relação à concentração dos agentes oxi-redoxf para exploração industrial e comercial.Resumo
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