Kinetics of the polarization reversal process in a non-constant applied electric field and the generalized superposition principle

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Investigation into the impact of embedded generators on distribution system performance using theorem of superposition

Since the 1980s, huge efforts have been made to utilise renewable energy sources to generate electric power. One of the interesting issues about embedded generators is the question of optimal placement and sizing of the embedded generators. This paper reports an investigation of impact of the integration of embedded generators on the overall performances of the distribution networks in the steady state, using theorem of superposition. Set of distribution system indices is proposed to observe performances of the distribution networks with embedded generators. Results obtained from the case study using IEEE test network are presented and discussed.

Morphometric characteristics of Prochilodus lineatus (Valenciennes 1847), of the migratory and resident stocks of the river Mogí-Guaçu, São Paulo State, Brazil

A espécie Prochilodus lineatus é de grande importância comercial na região dos rios Grande, Pardo e Mogi-Guaçu e tem como característica a formação de grandes cardumes, apta a desenvolver amplos deslocamentos migratórios. O presente trabalho objetivou avaliar, por meio das características morfométricas e etária, se os curimbatás (P. lineatus) dos diferentes estoques migradores e residentes constituem uma única população, havendo interação entre as sub-populações no período de piracema (migração reprodutiva). Utilizou-se um delineamento inteiramente casualizado em esquema fatorial 4 x 2, com quatro tipos de estoques (um residente e três migradores) e dois sexos (macho e fêmea) com trinta repetições, considerando cada peixe como unidade experimental. Foi observada variação de 80,19% para o primeiro componente principal e 8,09% do segundo componente principal fornecida pelas dez variáveis morfométricas dos estoques residentes e migradores. O estoque residente correspondeu aos maiores valores para todas as variáveis morfométricas. Houve sobreposição dos escores individuais das mesmas características entre os estoques migradores. Observou-se predominância de machos entre os estoques residentes e migrador I e II. As semelhanças morfométricas verificadas entre os estoques migradores indicam tratar-se de uma única população, com pequenas variações interpopulacional.

Spray layer-by-layer films based on phospholipid vesicles aiming sensing application via e-tongue system

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Molecular approaches for structural characterization of Bothrops L-amino acid oxidases with antiprotozoal activity: cDNA cloning, comparative sequence analysis, and molecular modeling

Two L-amino acid oxidases (LAAOs) were identified by random sequencing of cDNA libraries from the venom glands of Bothrops moojeni (BmooLAAO) and Bothrops jararacussu (Bjussu LAAO). Phylogenetic analysis involving other SV-LAAOs showed sequence identities within the range 83-87% being closely related to those from Agkistrodon and Trimeresurus. Molecular modeling experiments indicated the FAD-binding, substrate-binding, and helical domains of Bmoo and Bjussu LAAOs. The RMS deviations obtained by the superposition of those domains and that from Calloselasma rhodostoma LAAO crystal structure confirm the high degree of structural similarity between these enzymes. Purified BjussuLAAO-I and BmooLAAO-I exhibited antiprotozoal activities which were demonstrated to be hydrogen-peroxide mediated. This is the first report on the isolation and identification of cDNAs encoding LAAOs from Bothrops venom. The findings here reported contribute to the overall structural elucidation of SV-LAAOs and will advance the understanding on their mode of action. (c) 2006 Elsevier B.V. All rights reserved.

Vesicle-to-micelle transition in dioctadecyldimethylammonium bromide and dioctadecyldimethylammonium chloride dispersions induced by octaethylene glycol n-dodecyl monoether. An isothermal titration calorimetry study

We have used isothermal titration calorimetry to investigate the vesicle-to-micelle transition in dioctadecyldimethylammonium bromide (DODAB) and chloride (DODAC) vesicle dispersions induced by the nonionic surfactant octaethylene glycol n-dodecyl monoether (C12E8) at room temperature. Small and giant unilamellar vesicles were prepared by sonication and without sonication, respectively, of the pure cationic surfactants at low concentrations in water. The titration of 1.0 mM DODAX (X = Cl- and Br-) by a concentrated micellar solution of C12E8 shows that the enthalpy of interaction (DeltaH(obs)) of C12E8 in micellar form with DODAX is always endothermic. The titration curves are understood on the basis of superposition of the enthalpies of partitioning of C12E8 into the bilayer, of micelle formation and of vesicle-to-micelle transformation. The enthalpy, DeltaH(obs), initially increases owing to the incorporation of C12E8 into the vesicle bilayer until the C12E8/DODAX saturation ratio (R-sat) is reached, then DeltaH(obs) decreases, in different ways for DODAB and DODAC, owing to degradation of vesicles and formation of mixed micelles and intermediary structures up to the C12E8/DODAX solubilization ratio, R-sol. Above R-sol only mixed micelles exist. The surfactant solubilization takes place in three stages. All the critical ratios are lower for DODAB than for DODAC, meaning that C12E8 solubilizes more strongly in DODAB for example, R-sat is 0.8 for DODAB and 1.2 for DODAC. Sonication has no significant effect on the transition.

Gap solitons in Bose-Einstein condensates in linear and nonlinear optical lattices

Properties of localized states on array of BEC confined to a potential, representing superposition of linear and nonlinear optical lattices are investigated. For a shallow lattice case the coupled mode system has been derived. We revealed new types of gap solitons and studied their stability. For the first time a moving soliton solution has been found. Analytical predictions are confirmed by numerical simulations of the Gross-Pitaevskii equation with jointly acting linear and nonlinear periodic potentials. (c) 2007 Elsevier B.V. All rights reserved.

Permutability of Backlund transformation for N=1 supersymmetric sinh-Gordon

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Integrability vs supersymmetry: Poisson structures of the pohlmeyer reduction

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Permutability of Backlund transformations for N=2 supersymmetric sine-Gordon

The permutability of two Backlund transformations is employed to construct a nonlinear superposition formula and to generate a class of solutions for the N=2 super sine-Gordon model. We present explicitly the one and two soliton solutions.

Localization of a Bose-Einstein-condensate vortex in a bichromatic optical lattice

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Photoluminescent behavior of SrZrO3/SrTiO3 multilayer thin films

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Alguns estudos de fluxo de fluido utilizando software gráfico

Analisamos alguns modelos de fluxo de fluido utilizando o software gráfico F(C): Funções Complexas. Descrevemos as equações que expressam o potencial complexo, bem como a velocidade complexa para cada modelo. Os modelos estudados são fluxo uniforme, com fonte, com sumidouro, composto, circular e com obstáculo. Apresentamos o conceito de Domínio de Cores e o mecanismo de leitura dos gráficos. Cada modelo é apresentado de forma exemplificada, incluindo representações geométricas das curvas de fluxo e equipotenciais, bem como os gráficos do potencial complexo e velocidade complexa.

Structural control over well productivity in the Jundiaí River Catchment, Southeastern Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Análise comparativa entre a fecundidade de Dilocarcinus pagei Stimpson e Sylviocarcinus australis Magalhães & Turkay (Crustacea, Decapoda, Trichodactylidae) no Pantanal do Rio Paraguai, Porto Murtinho, Mato Grosso do Sul

The aim of this study was to estimate the fecundity of Dilocarcinus pagei Stimpson, 1861 and Sylviocarcinus australis Magalhães & Turkay, 1996, collected in the Paraguay River, Porto Murtinho County, State of Mato Grosso do Sul, Brazil, between coordinates 21º42,000'S 57º33,649'W and 21º41,449'S 57º33,770'W, in the period of April 1999 to March 2000. After general collection procedures, the specimens were measured and processed in laboratory conditions. The river water crab species hatch like juveniles and, frequently, female specimens were observed carrying eggs in different stages of development, besides juveniles and eggs at the same time. It was apparent in the frequency distributions that D. pagei has a carapace width average greater than S. australis. The number of eggs and juveniles transported varied amongst species and amongst size class. A size superposition was observed between young and adult females for both species. According to the calculated fecundity index, D. pagei presented slightly more elevated values (7.41) than S. australis (6.65). Eggs are spherical and are not adhering to pleopods. Egg size did not varied during development, continuing with 2mm diameters.