Bounds on the electromagnetic interactions of excited spin-3/2 leptons

We discuss possible deviations from QED produced by a virtual excited spin-3/2 lepton in the reaction $e^+e^- \longrightarrow 2\gamma$. Data recorded by the OPAL Collaboration at a c.m. energy $\sqrt{s} = 183 GeV$ are used to establish bounds on the nonstandard-lepton mass and coupling strengths.Comment: Latex, 5 pages, 7 ps figures. To be published in Phys. Rev.

Water activity in lamellar stacks of lipid bilayers: "Hydration forces" revisited

Water activity and its relationship with interactions stabilising lamellar stacks of mixed lipid bilayers in their fluid state are investigated by means of osmotic pressure measurements coupled with small-angle x-ray scattering. The (electrically-neutral) bilayers are composed of a mixture in various proportions of lecithin, a zwitterionic phospholipid, and Simulsol, a non-ionic cosurfactant with an ethoxylated polar head. For highly dehydrated samples the osmotic pressure profile always exhibits the "classical" exponential decay as hydration increases but, depending on Simulsol to lecithin ratio, it becomes either of the "bound" or "unbound" types for more water-swollen systems. A simple thermodynamic model is used for interpreting the results without resorting to the celebrated but elusive "hydration forces"Comment: 24 pages, 12 figures. Accepted for publication in The European Physical Journal

A new picture of the Lifshitz critical behavior

New field theoretic renormalization group methods are developed to describe in a unified fashion the critical exponents of an m-fold Lifshitz point at the two-loop order in the anisotropic (m not equal to d) and isotropic (m=d close to 8) situations. The general theory is illustrated for the N-vector phi^4 model describing a d-dimensional system. A new regularization and renormalization procedure is presented for both types of Lifshitz behavior. The anisotropic cases are formulated with two independent renormalization group transformations. The description of the isotropic behavior requires only one type of renormalization group transformation. We point out the conceptual advantages implicit in this picture and show how this framework is related to other previous renormalization group treatments for the Lifshitz problem. The Feynman diagrams of arbitrary loop-order can be performed analytically provided these integrals are considered to be homogeneous functions of the external momenta scales. The anisotropic universality class (N,d,m) reduces easily to the Ising-like (N,d) when m=0. We show that the isotropic universality class (N,m) when m is close to 8 cannot be obtained from the anisotropic one in the limit d --> m near 8. The exponents for the uniaxial case d=3, N=m=1 are in good agreement with recent Monte Carlo simulations for the ANNNI model.Comment: 48 pages, no figures, two typos fixe

Efeito da adição de sacarose e tempo de pasteurização sobre a tonalidade cromática e características microbiológicas de conservas de soja tipo hortaliça.

A soja tipo hortaliça é colhida no estádio de desenvolvimento R6, quando os grãos apresentam-se de coloração verde e totalmente desenvolvidos, mas ainda imaturos. Quando comparada com a soja convencional apresenta sabor suave e adocicado, textura macia e qualidade nutricional superior. Uma alternativa de consumo da soja tipo hortaliça, além do in natura, é o seu processamento em conservas que pode contribuir para sua disponibilidade em todas as épocas do ano. Durante o preparo das conservas, os grãos são tratados termicamente ocasionando perdas de cor e textura. A adição de sacarose em pequenas quantidades na salmoura das conservas contribui para manter a coloração, a firmeza e sabor ácido mais brando. O objetivo do trabalho foi avaliar o efeito da adição de sacarose e tempo de pasteurização sobre a tonalidade cromática e características microbiológicas de conservas em pH 3,9 de grãos de soja da cultivar tipo hortaliça BRS 267. Para isso foi utilizado o delineamento experimental composto central rotacional (DCCR) 22 com 4 pontos axiais e 4 ensaios no ponto central, totalizando 12 ensaios. O teor de sacarose na salmoura (variável X1 ) foi de 0,45 a 2,5 g ml-1 e o tempo de pasteurização em minutos (variável X2) de 10 a 40. Após 30 dias de armazenamento, foram determinadas as funções repostas Y1 (graus de tonalidade cromática) e Y2 (esterilidade comercial). A validação do modelo proposto foi realizada após estabelecer concentração de sacarose igual a 2,89 g por mL e 10 min de pasteurização. A adição de sacarose e tempo de pasteurização influenciaram a tonalidade cromática das conservas. As conservas atingiram esterilidade comercial. A melhor formulação de conserva de grãos de soja tipo hortaliça em pH 3,9 foi com adição de 2,89 g de sacarose, 6 g de NaCl e 0,29 g de CaCl2 em 100 mL de salmoura

Dinâmica da pecuária leiteira no Brasil: evolução e características das propriedades.

bitstream/item/139898/1/Cnpgl-2015-PanLeite-Dinamica.pd

Logarithmic periodicities in the bifurcations of type-I intermittent chaos

The critical relations for statistical properties on saddle-node bifurcations are shown to display undulating fine structure, in addition to their known smooth dependence on the control parameter. A piecewise linear map with the type-I intermittency is studied and a log-periodic dependence is numerically obtained for the average time between laminar events, the Lyapunov exponent and attractor moments. The origin of the oscillations is built in the natural probabilistic measure of the map and can be traced back to the existence of logarithmically distributed discrete values of the control parameter giving Markov partition. Reinjection and noise effect dependences are discussed and indications are given on how the oscillations are potentially applicable to complement predictions made with the usual critical exponents, taken from data in critical phenomena.Comment: 4 pages, 6 figures, accepted for publication in PRL (2004

Identificação de QTLs ligados a resistência ao crestamento bacteriano em Phaseolus vulgaris.

O objetivo deste trabalho foi identificar QTLs associados à resistência do feijoeiro ao crestamento bacteriano comum, a fim de auxiliar a seleção com marcadores

Anatomia foliar de maracujazeiros infectados por vírus do endurecimento dos frutos e tratados com fertilizante foliar.

Um dos principais problemas enfrentados pelos produtores de maracujazeiro amarelo, Passiflora edulis Sims. f. flavicarpa Deg., são as doenças virais, destacando-se a do endurecimento dos frutos, provocada, principalmente, pelo vírus Cowpea aphid-borne mosaic virus (CABMV). Fertilizantes foliares têm sido utilizados na tentativa de reduzir os danos causados pelo vírus, mas nenhum estudo foi desenvolvido buscando elucidar os efeitos destes produtos sobre as alterações estruturais em plantas infectadas. Este trabalho teve como objetivo uma análise anatômica das folhas de indivíduos de maracujazeiro amarelo infectados pelo vírus CABMV e tratados com fertilizante foliar

Effect of zinc addition and pasteurization time on the zinc content and color stability of acid canned vegetable-type soybean.

For the processing of canned vegetable-type soybean, it is important to realize the heat treatment. However, during the treatment may occur loss of green color that is an indicator of its quality. In the brine canned, the presence of metal ions such as zinc, allows to maintain green color of canned vegetables. The objective of this study was to investigate the effect of zinc addition (X1 = ppm of zinc in the brine) and pasteurization time (X2 = min) on zinc content and color stability of acid canned vegetable-type soybean by using Central Composite Rotatable Design (CCRD). The response functions Y1 (ppm of zinc) and Y2 (degrees of hue of the canned vegetable-type soybean) were analyzed. The model validation was performed after establishing X1 = 10.91 ppm and X2 = 10 min and ?1 = 73.49 ppm of zinc. The experimental answer (Y1) was 72.74 ppm of zinc. At the response surface can be observed a region where Y2 is maximal and equal to 93°. The model validation was performed, at the point where, x1 = -1.5, x2 = -1.41 and ? 2 = 92.81° of hue of canned. The response obtained experimentally (Y1) was 92.86° hue of canned vegetable-type soybean. Therefore, for adequate formulation of vegetable-type soybean grains should be zinc acetate (10.91 ppm), NaCl (100 mL 6 g-1), CaCl2 (0.29 g 100 mL -1) and citric acid (to pH 3.9) with thermal processing of 10 min