328 resultados para Ângulo de Fase
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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As características estruturais de sonogéis obtidos a partir da hidrólise ácida do TEOS estimulada por ultrasom foram estudadas por espalhamento de raios-x a baixo ângulo (SAXS). O estudo inclui: i) o processo de agregação em diferentes temperaturas; ii) o envelhecimento dos géis úmidos na fase líquida de preparação e depois da troca da fase líquida por álcool e acetona; iii) a secagem dos géis; iv) a estrutural evolução de xerogéis e aerogéis com o tratamento térmico até 1100 oC; e v) um estudo comparativo usando SAXS e adsorção de nitrogênio na caracterização de aerogéis e xerogéis... (Resumo completo, clicar acesso eletrônico abaixo)
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The main objective of this study was to analyze the behavior of variables related to swim ability at and above maximal lactate steady state (MLSS), performed at continuous and intermittent conditions in individuals with different aerobic performance levels. Participated of this study male swimmers with ages between 20 to 25 years, specialists in events of 400 m, 800 m and 1500 m and open water swims, with at least 3 years of experience in the modality. The individuals performed a maximal 400-m swim test. After this test, they were divided into two groups, in accordance with the speed attained during 400-m swim test: G1 (higher performance) and G2 (lower performance). For the determination of continuous MLSS (MLSSc), 2 to 4 trials of 30-min were performed. For the determination of the intermittent MLSS (MLSSi) 2 to 4 trials of 30-min (12 repetitions of 2 min 30 s, with 30 s of rest) were performed, in constant speed, with the first trial performed at 102.5% MLSSc. Th technical indexes, stroke rate (FB) and stroke length (CB) were determined in all tests. The SR was calculated trough recordings using the time needed to perform five stroke cycles. The SL was calculated dividing the speed by the SR. There was no significant difference on the antropometric characteristics between groups. The speed at and above MLSSc were significantly higher at G1 (1,23±0,05 e 1,27±0,06, respectively) than G2 (1,10±0,06 e 1,13±0,06, respectively). There was significant change in SL and SR in G2. In the same way, there was significant change in SL and SR only in G2, above MLSSc. Similar to continuous condition, the speeds at and above MLSSi were significantly higher in G1 (1,27±0,05 e 1,30±0,05, respectively) do que no G2 (1,14±0,07 e 1,16±0,07, respectively). There was significant change in SL and SR only in G2. There was significant change in SR and SL in both groups above MLSSi. Thus,...(Complete abstract click electronic access below)
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Schilder(1980) defines body image as the figuration of the body in your mind,ie to the way the body is presented to all. This image is constructed from six months in the infant´s contact with his mother by touch,thought the reflection of his image in the mirror and then in the contexto f activies préschool- didatic educator pedagogical proposes by consolidating the six years age. This importance of stdying the construction of body image pré-school educator is to prevent a failure in the process causing the child to change that image generating blocks and physical or psychological dificulties in the socialization process of children by promoting distortion of body image . O study objective is to understand how such package is the process of building up this image in preschool and your contribution to the process of learning of child. A methodology was a research review on amaig body, enconpassing the overall development of child and adult disorders the failure of the process constructive in this picture and a brief educational propose of how early childhood educator can work with this theme in pré-school. This study concluded that this topic is important to be working in the Field of education encompasses a degree in Physical Education and Pedagogy words.
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The small angle X-ray scattering (SAXS) technique has been used with very much versatility and success in the structural characterization of nanostructured materials. The present work deals with a study of the principles of the SAXS technique and of some classical models employed in the structural characterization of nanostructured materials. Particularly, the study of the models and of the associated methodologies is applied to a set of samples of silica gels, of varied typical structures, prepared in the Laboratório de Novos Materiais of the Departamento de Física of the IGCE. The work discusses in an introductory chapter the principles of the SAXS technique and the foundation of classical models often used in the structural characterization of materials. The classical models and the associated methodologies were applied to a variety of silica gel structures. The studies include: i) the scattering from a system of particles - Guinier's law; ii) the asymptotic scattering from a two-phase system - Porod's law; iii) systematic deviation from Porod's law - Surface Fractal; iv) heterogeneities in solids with random size distribution - DAB Model; and v) the scattering from mass fractal structures. The analyses were carried out from experimental SAXS data obtained in several opportunities at the Laboratório Nacional de Luz Síncrotron (LNLS)
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The aim of this study is to present those who are interested in mechanical engineering, specifically automotive engineering some ideas for improvements to the current concept of internal combustion engines. It is not intenden to change totally the design of the engine known today, but to exame the feasibility of reducing a small waste generated with the current positioning of the cylinder-piston assembly. The proposal solution consists in modifying the tilt cylinder-piston assembly in the angle between the rod and the cylinder axis. This inclination causes all the force generated in the combustion process within the cylinder is delivered to the rod.Delivery force is the made in the rod longitudinal direction and not on the axis of the cylinder, preventing the occurrence of a breakdown of the force generated in the combustion process. After analyzing the idea of repositioning the piston-cylinder assemble, it is concluded that the change has a positive result in the process of harnessing the power generated in the com bustion, but its not feasible due implementation to low gain presented in this study
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Of the four lacustrine deltaic models, which were found in the Pendência formation, two are represented in the Serraria field. Respectively the deltaic models 1 and 3 shows the reservoir zones A and B. The Zone A is divided into six sub-areas. Each is representing a smaller cycle of development of sigmoidal lobes of deltaic front. Zone B produces in reservoirs of Model 3, or so called Full delta. The Zone B is formed by overlapping the deltaic plain system over the deltaic/prodeltaic front (model 1). This work uses the method of zooming with the aim to contextualize the geometric aspects of the sand bodies, highlighting the analysis of facies and diagenesis with help of pictures and testimonies of thin sections. The sigmoidal lobes of Zone A are fine to very fine sandstones, well sorted, with a arcosian composition.;practically with a weak compaction and cementation of a kind of film of clay (if very fine) and overgrowth feldspar (fine texture). This silicate phases are succeeded by cementation of poiquilotópica calcite, and after this a stage of dissolution, containing only regular permoporosity for this reservoir. Zone B has a combination of two types of deltaic plain reservoir. One is the rarest of distributary channel and the other the most common of lobes of crevasse. In the channel coarse to medium-grained and poor to moderate sorted sandstones are formed (tuning up), and with a lytic arcosiana nature. Rarely there are cements, including growth of feldspar and rhombohedral dolomite, which prevent a high permoporosity of the reservoir. In the crevasse lobes, the sandstones are laminated, fine and well sorted, arkosic, rarely with overgrowth feldspar and calcite poiquilotópica, and with a good intergranular permoporosity
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The Vazante Fault Zone (VFZ), located northwestward of Minas Gerais, host the largest zinc deposit known in the Brazilian territory. This structure is hosted in Vazante’s Group rocks, a metassedimentary sequence of marine environment. Near Vazante is situated the south end of the VFZ. To the west, occur the Serra do Garrote inflexion, characterized by a curvature in the contact of Formations Serra do Garrote and Serra do Poço Verde. This structure is through the analysis of aerial imagery of the region and represented in the published geological maps. The objective of this work is to understand what causes this inflexion and determine whether it affects the VZF, causing a shift in the same, and possibly, in the mineralization as well. To this end, it was done a mapping work in the region covering the Serra do Garrote inflexion and the south end of the VFZ, in 1:25.000 scale, supplemented by petrographic description of thin section and geologic sections, with cooperated to the understanding of the structural evolution of the region. Data analysis allowed the identification of six deformation phases. The D1 an D2 phases generated the main foliation. The D3 phase generate kink bands folds, with NS axis and vertical axial plane. The fourth phase is responsible for generating the Vazante Fault Zone. The fifth phase produces low angle folds and shear zones, subparallel to S1//S2. The last phase generates folds with NW axis and vertical axial plane, with causes the inflection of lithologic contactas. Field observations also make possible the conclusion that the Vazante Fault Zone presents a south continuation, which is affected by deformation associated to D6 phase attributing to the trace of the VFZ a curved geometry, similar to that exhibited by lithologic contacts between units of the map
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In the eld of synthetical materials, often called in the literature as organic/molecular conductors or charge-transfer salts, the most prominient examples are the quasi onedimensional systems (TMTTF)2X and (TMTSF)2X, where TMTTF, TMTSF and X refers to tetrametiltetratiafuvaline, tetrametiltetraselenafuvaline and a monovalent anion (X = PF6
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This work aims to study the structural characteristics of silica gels obtained from the acid hydrolysis of tetraethoxysilane (TEOS) in water solutions with different concentrations of sodium dodecyl sulfate (SDS). The structural characteristics were studied in stages ranging from the wet gel to the dry stages of the gels (aerogels and xerogels). Aerogels were obtained by ambient pressure drying (APD) after silylation process using trimethylchlorosilane (TMCS) as silylating agent. Xerogels were obtained by conventional evaporating the liquid phase from non silylated gels. The samples were characterized by nitrogen adsorption and small angle X-ray scattering (SAXS). The structure of the wet gels and of the aerogels prepared with the surfactant exhibited characteristics of mass-fractal structures with fractal dimension D in the range 2.1-2.2 for the wet gels and 2.3-2.4 for the aerogels. The characteristic size of the fractal domain reduces while the size a0 of the primary silica particle composing the fractal structure increases with the drying of the gels, in a process in which share of the porosity is eliminated. Aerogels exhibited typical values for the specific surface of 900 m2g-1 and of 3.5 cm3.g-1 for the total pore volume. These values are correspondingly comparable to those of the aerogels prepared by supercritical drying, since the silylation process replaces hydrophilic –OH groups by hydrophobic –Si-R3 ones, inhibiting the porosity elimination on drying. The silica particle size also increases lightly with the silylation because the attachment of the –Si-R3 groups on the silica surface. The pore size distribution curves of the aerogels are similar for all samples exhibiting a maximum in around 40 nm, independent the concentration of surfactant. This suggests that the characteristic size of 40 nm is due to the association of surfactant micelles... (Complete abstract click electronic access below)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)