The mathematical description of the electrosynthesis of composites of oxy-hydroxycompounds cobalt with polypyrrole overooxidazed

The electrosynthesis of the composite with of the overoxidized polypyrrole with cobalt oxy-hydroxide in strongly acidic media has been described mathematically, using linear stability theory and bifurcation analysis. The steadystates stability conditions and oscillatory and monotonic instability requirements have been described too. The system´s behavior was compared with behavior of other systems with overoxidation, electropolymerization of heterocyclic compounds and electrosynthesis of the cobalt oxy-hydroxides

Evapotranspiração da videira festival sob diferentes intermitências de irrigação.

Dados de experimentos conduzidos no Campo Experimental de Bebedouro, pertencente à Empresa Brasileira de Pesquisa Agropecuária foram usados na determinação da evapotranspiração da cultura da videira, variedade Festival sem semente, sob diferentes intermitências de irrigação por gotejamento, pelo método do balanço hídrico no solo, para ciclos de produção nas estações: seca e chuvosa. O ciclo de produção foi dividido em oito estádios fenológicos distintos, como segue: período de brotação (PB); desenvolvimento vegetativo (DV); pré e plena floração (PFF); primeira fase de crescimento do fruto (1 a FCF); parada de crescimento do fruto (PCF); segunda fase de crescimento do fruto (2 a FCF); maturação final do fruto (MFF); e repouso fisiológico (RF). Os resultados indicaram que a evapotranspiração (ETc) para o ciclo de produção da videira Festival sem sementes varia de 432 a 510 mm a medida que a intermitência de irrigação de I-I a I-4 durante a estação seca e de 243 a 382 mm durante a estação chuvosa. Evidenciaram também que o aumento do número de intermitências de irrigação conduz a uma redução significativa das perdas de água por percolação profunda, ou seja, reduções médias em relação à testemunha da ordem de 20,46, 46,26 e de 79,80%, para as intermitências II, III e IV, respectivamente

Balanço de energia em parreirais cultivados na região do Submédio do Rio São Francisco.

O objetivo principal deste estudo compreendeu a determinação do balanço de energia num parreiral consorciado com culturas destinadas à adubação orgânica

Retinal Vessel Segmentation Using the 2-D Morlet Wavelet and Supervised Classification

We present a method for automated segmentation of the vasculature in retinal images. The method produces segmentations by classifying each image pixel as vessel or non-vessel, based on the pixel's feature vector. Feature vectors are composed of the pixel's intensity and continuous two-dimensional Morlet wavelet transform responses taken at multiple scales. The Morlet wavelet is capable of tuning to specific frequencies, thus allowing noise filtering and vessel enhancement in a single step. We use a Bayesian classifier with class-conditional probability density functions (likelihoods) described as Gaussian mixtures, yielding a fast classification, while being able to model complex decision surfaces and compare its performance with the linear minimum squared error classifier. The probability distributions are estimated based on a training set of labeled pixels obtained from manual segmentations. The method's performance is evaluated on publicly available DRIVE and STARE databases of manually labeled non-mydriatic images. On the DRIVE database, it achieves an area under the receiver operating characteristic (ROC) curve of 0.9598, being slightly superior than that presented by the method of Staal et al.Comment: 9 pages, 7 figures and 1 table. Accepted for publication in IEEE Trans Med Imag; added copyright notic

Comment on ``BCS to Bose-Einstein crossover phase diagram at zero temperature for a d_{x^2-y^2} order parameter superconductor: Dependence on the tight-binding structure''

The work by Soares et al. [Phys. Rev. B 65, 174506 (2002)] investigates the BCS-BE crossover for d-wave pairing in the 2-dimensional attractive Hubbard model. Contrary to their claims, we found that a non-pairing region does not exist in the density vs coupling phase diagram. The gap parameter at T=0, as obtained by solving analytically as well as numerically the BCS equations, is in fact finite for any non-zero density and coupling, even in the weak-coupling regime.Comment: 7 pages, 1 figur