962 resultados para Affinor of Composition


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The component-based development of systems revolutionized the software development process, facilitating the maintenance, providing more confiability and reuse. Nevertheless, even with all the advantages of the development of components, their composition is an important concern. The verification through informal tests is not enough to achieve a safe composition, because they are not based on formal semantic models with which we are able to describe precisally a system s behaviour. In this context, formal methods provide ways to accurately specify systems through mathematical notations providing, among other benefits, more safety. The formal method CSP enables the specification of concurrent systems and verification of properties intrinsic to them, as well as the refinement among different models. Some approaches apply constraints using CSP, to check the behavior of composition between components, assisting in the verification of those components in advance. Hence, aiming to assist this process, considering that the software market increasingly requires more automation, reducing work and providing agility in business, this work presents a tool that automatizes the verification of composition among components, in which all complexity of formal language is kept hidden from users. Thus, through a simple interface, the tool BST (BRIC-Tool-Suport) helps to create and compose components, predicting, in advance, undesirable behaviors in the system, such as deadlocks

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The honey of Melipona fasciculata is few known in terms of composition, and therefore generally associated with the characteristics of the honey of Apis mellifera. This study contributes to the knowledge of the physico-chemical characteristics of honey of M. fasciculata of the municipalities of Barra do Corda, Jenipapo dos Vieiras, Fernando Falcão, Carolina and Riachão, in cerrado region from Maranhão. The parameters studied were: moisture, pH, acidity, reducing sugars, apparent sucrose, hydroxymethylfurfural, diastase activity, insoluble solids, ash and color. Some of the observed patterns may conform to the established for A. mellifera, but others must be accompanied by a specific legislation.

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

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

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

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The temperature dependence of the electrical conductivity and the F-19 nuclear magnetic resonance (NMR) of PbGeO3-PbF2CdF, glasses and glass ceramics are investigated. The measured conductivity values of the glasses are above 10(-5) Skin at 500 K, and increase with increasing lead fluoride content. Activation energies extracted from the conductivity data are in the range 0.59-0.73 eV. Results are consistent with the hypothesis that in these oxyfluoride glasses lead fluoride rich clusters are dispersed in a metagermanate based matrix providing increasing mobility pathways for conducting ions. The conductivity of a sample of the glass ceramic of composition (mol%) 60PbGeO(3-)20PbF(2)-20CdF(2) was found to be smaller than that in the corresponding glass, suggesting that there are poor ionic conducting regions in the interface between the nanometer sized crystals. The temperature dependence of the F-19 relaxation times, measured in the range 100-800 K, exhibit the qualitative features associated with high fluorine mobility in both, glass and glass ceramics materials. We suggest that de-convolution of the spin-lattice relaxation rates observed in the glass ceramics shows that the observed high temperature rate maximum is associated with the diffusional motions of the fluorine ions in beta-PbF2 crystals. (c) 2005 Elsevier B.V. All rights reserved.

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Organic-inorganic hybrids containing methacrylic acid (McOH, CH(2)= C(CH(3))COOH)) modified zirconium tetrapropoxide, Zr(OPr(n))(4), classed as di-ureasil-zirconium oxo-cluster hybrids, have been prepared and structurally characterized by X-ray diffraction (XRD), small-angle X-ray scattering (SAXS), Fourier transform infrared (FT-IR) and Raman (FT-Raman) spectroscopies, Si and C nuclear magnetic resonance (NMR), and atomic force microscopy (AFM). XRD and SAXS results have pointed out the presence of Si- and Zr-based nanobuilding blocks (NBBs) dispersed into the organic phase. Inter-NBBs correlation distances have been estimated for the pure di-ureasil and a model compound obtained. by hydrolysis/condensation of Zr(OPr(n))(4):McOH (molar ratio 1: 1): d(Si) approximate to 26 +/- 1 angstrom and d(Zr) approximate to 16 +/- 1 angstrom, respectively. In the case of the di-ureasil-zirconium oxo-cluster hybrids, these distances depend on the Zr relative molar percentage (rel. mol. Zr %) (d(Si) ranges from 18 to 25 angstrom and d(Zr) from 14 to 23 angstrom, as the rel. mol. Zr % increases from 5 to 75), suggesting that the Si- and Zr-based clusters are interconstrained. Complementary data from FT-IR, FT-Raman, (29)Si and (13)C NMR, and AFM support to a structural model where McOH-modified Zr-based NBBs (Zr-OMc) are present over the whole range of composition. At low Zr-OMc contents (rel. mol. Zr % <30) the clusters are well-dispersed within the di-ureasil host, whereas segregation occurs at the 0.1 mu m scale at high Zr-OMc concentration (rel. mol. Zr % = 50). No Zr-O-Si heterocondensation has been discerned. Monomode waveguides, diffractions gratings, and Fabry-Perot cavities have been written through the exposure of the hybrid monoliths to UV light. FT-Raman has shown that the chemical process that takes place under illumination is the polymerization of the methacrylate groups of the Zr-OMc NBBs. The guidance region in patterned channels is a Gaussian section located below the exposed surface with typical dimensions of 320 mu m wide and 88 mu m deep. The effective refractive index is 1.5162 (maximum index contrast on the order of 1 x 10(-4)) and the reflection coeficient of the Fabry-Perot cavity (formed by a grating patterned into a 0.278 cm channel) is 0.042 with a free spectral range value of 35.6 GHz.

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An evaluation of the composition of soil cement bricks with construction and demolition waste. Sustainable development requires the existence of a production network that includes the reuse of construction waste for new materials. Current analysis investigates an optimal soil-cement composition made up of construction and demolition waste for the manufacture of pressed bricks. Soil-cement bricks were manufactured from construction and demolition wastes (CDW), A-4 classified fine sandy soil and cement CP II Z 32. Laboratory tests, comprising test compaction, optimum water content and maximum dry specific weight, consistency limits, grain size distribution and linear shrinkage, were made to characterize the materials researched. Compressive strength and absorption tests were also undertaken in different combinations of composition. Results showed that the application of CDW improved soil-cement qualities and reduced shrinkage of the material used.

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Glasses of composition 40InF3-20SrF2-16BaF2-20ZnF 2-2GdF3-2NaF (mol%) have been prepared under controlled atmosphere. The time response of the stresses under the application of a constant strain was determined by microellipsometer technique, performed in ambient atmosphere at T < Tg = 294°C. The glasses show a Newtonian behavior at small stress level. During the relaxation process, very small grooves perpendicular to the applied strain appeared on the glass surface and affected its behavior after a time. The formation of these grooves is associated with the ambient atmosphere. Measurements in dry atmosphere showed that humidity was an important parameter in the relaxation process.

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Aqueous dispersions of monoolein (MO) with a commercial hydrophobically modified ethyl hydroxyethyl cellulose ether (HMEHEC) have been investigated with respect to the morphologies of the liquid crystalline nanoparticles. Only very low proportions of HMEHEC are accepted in the cubic and lamellar phases of the monoolein-water system. Due to the broad variation of composition and size of the commercial polymer, no other single-phase regions were found in the quasi-ternary system. Interactions of MO with different fractions of the HMEHEC sample induced the formation of lamellar and reversed hexagonal phases, identified from SAXD, polarization microscopy, and cryogenic TEM examinations. In excess water (more than 90 wt %) coarse dispersions are formed more or less spontaneously, containing particles of cubic phase from a size visible by the naked eye to small particles observed by cryoTEM. At high polymer/MO ratios, vesicles were frequently observed, often oligo-lamellar with inter-lamellar connections. After homogenization of the coarse dispersions in a microfluidizer, the large particles disappeared, apparently replaced by smaller cubic particles, often with vesicular attachments on the surfaces, and by vesicles or vesicular particles with a disordered interior. At the largest polymer contents no proper cubic particles were found directly after homogenization but mainly single-walled defected vesicles with a peculiar edgy appearance. During storage for 2 weeks, the dispersed particles changed toward more well-shaped cubic particles, even in dispersions with the highest polymer contents. In some of the samples with low polymer/MO ratio, dispersed particles of the reversed hexagonal type were found. A few of the homogenized samples were freeze-dried and rehydrated. Particles of essentially the same types, but with a less well-developed cubic character, were found after this treatment. © 2007 American Chemical Society.

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PtFe/C nanocatalysts of different compositions and nearly constant particle size were prepared by a microemulsion method. Crystallite sizes and degree of alloying were determined by X-ray diffraction. Particle size and distribution were characterized by transmission electron microscopy and average composition was determined by energy dispersive X-ray analysis. Measurements of electrocatalytic activity for oxygen reduction were done using the rotating disk electrode technique in O2 saturated 0.5 mol L-1 sulfuric acid solutions, at room temperature. For all catalysts oxygen reduction begins at ̃ 0.90V. Tafel plots show slopes of c.a. 60 and 120 mV dec in the regions of low and high overpotentials, respectively. The best results for the ORR were obtained for the PtFe/C catalyst of composition Pt:Fe 70:30. This catalyst was also found to exhibit the largest methanol tolerance. © The Electrochemical Society.

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Pós-graduação em Artes - IA

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

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)