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Search Results: 1 - 10 of 324885 matches for " Sérgio; "
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Model of Three-Phase Transmission Line with the Theory of Modal Decomposition Implied  [PDF]
Rodrigo Cleber da Silva, Sérgio Kurokawa
Energy and Power Engineering (EPE) , 2013, DOI: 10.4236/epe.2013.54B217

This paper shows the development of transmission line model, based on lumped element circuit that provides answers directly in the time and phase domain. This model is valid to represent the ideally transposed line, the phases of each of the small line segments are separated in their modes of propagation and the voltage and current are calculated at the modal domain. However, the conversion phase-mode-phase is inserted in the state equations which describe the currents and voltages along the line of which there is no need to know the user of the model representation of the theory in the line modal domain.

Influence of Phosphoric Acid Etching on the Bond Strength of a Universal Adhesive System to Caries-Affected Dentin  [PDF]
Renata Pavanello, Sérgio Luiz Pinheiro
Advances in Biological Chemistry (ABC) , 2018, DOI: 10.4236/abc.2018.83004
Abstract: The purpose of this study was to evaluate the influence of acid etching on the bond strength of a universal adhesive system (Single Bond Universal, 3M) to caries-affected dentin. Forty permanent third molars were selected and carious lesions were induced by the microbiological method with?S. mutans?ATCC25175. Teeth were allocated randomly across four experimental designs (n=10): PA-I: phosphoric acid etching and application of the adhesive system, followed by immediate microtensile bond strength testing; PA-CC: phosphoric acid etching and application of the adhesive system, followed by microtensile bond strength testing after a 14-day cariogenic challenge; NPA-I: application of the adhesive system without acid etching, followed by immediate bond strength testing and NPA-CC: application of the adhesive system without acid etching followed by bond strength testing after 14-day cariogenic challenge. For microtensile bond strength testing,a restoration with Charisma composite resin was made and each specimen was sectioned with a cross-sectional area of 1 mm2. Only adhesive and mixed fractures were considered for bond strength calculation. Results were evaluated by the Kruskal-Wallis and Friedman tests. The highest bond strengths were observed in the phosphoric acid etching groups (p<0.05). Cariogenic challenge did not affect bond strength (p>0.05). The predominant fracture type was adhesive. We conclude that phosphoric acid increased the bond strength of the Single Bond Universal system to caries-affected dentin, and
Sombras como indicadores da percep??o de profundidade
Fukusima, Sérgio S.;
Psicologia: Reflex?o e Crítica , 1997, DOI: 10.1590/S0102-79721997000200008
Abstract: the cast shadow of a flat square was depicted on a computer screen by orthografic projection, and investigated as a perceived depth cue. the shadow was projected to five positions relative to the incidence of the light in each quadrant of the screen. five adults participated in the experiment. results indicated that the magnitude of the depth estimates increased as a function of the exposed shadow area when the same was partially ocluded. in the conditions in which the shadow was not ocluded, perceptual and cognitive factor can bias the depth estimates.
Sombras como indicadores da percep o de profundidade
Fukusima Sérgio S.
Psicologia: Reflex?o e Crítica , 1997,
Abstract: A sombra de um quadrado projetada ortograficamente sobre uma superfície plana foi investigada como indicadora de profundidade percebida. A sombra foi simulada por computador em cinco posi es, relativas ao angulo de incidência da luz, em cada quadrante da tela do monitor. Os resultados indicaram que as magnitudes das estimativas de profundidade aumentam em fun o da área exposta da sombra nos casos em que a mesma é parcialmente ocluída. No caso em que a sombra n o é ocluída, fatores perceptivos e cognitivos podem afetar as estimativas de profundidade.
Feedback boundary stabilization to trajectories for 3D Navier-Stokes equations
Sérgio S. Rodrigues
Mathematics , 2015,
Abstract: Given a nonstationary trajectory of the Navier-Stokes system, a finite-dimensional feedback boundary controller stabilizing locally the system to the given trajectory is derived. Moreover the controller is supported in a given open subset of the boundary of the domain containing the fluid. In a first step a controller is derived that stabilizes the linear Oseen-Stokes system "around the given trajectory" to zero; for that a corollary of a suitable truncated boundary observability inequality, the regularizing property for the system, and some standard techniques of the optimal control theory are used. Then it is shown that the same controller also stabilizes, locally, the Navier-Stokes system to the given trajectory.
Exclus?o socioecon?mica e violência urbana
Adorno, Sérgio;
Sociologias , 2002, DOI: 10.1590/S1517-45222002000200005
Abstract: this text approaches the relationship between socioeconomic exclusion and violence based on one specific case: brazil. it draws a picture of violence's the most recent characteristics and trends. it also examines three causes that emerge in public debate: the changes in violence and crime patterns; the crisis in the criminal justice system; and social inequality and urban segregation. specifically regarding the latter aspect, it seeks to make a general comment on the central "theses" that sustain or challenge the so-called structural violence.
As iniciativas e experiências em agroecologia como estratégia de desenvolvimento local em um assentamento de reforma agrária
Botton Barcellos,Sérgio;
Mundo agrario , 2011,
Abstract: this paper searches to understand which disputes and conflicts are around the consolidation of agroecology as one of the alternatives and initiatives of local development in a land reform settlement. thus, this paper, which consists of one of the results presented in the author's dissertation, aims to identify the disputes and conflicts that occur among local initiatives related to agroecology. santa rosa settlement is located in one of the densest areas in relation to rural settlements in rio grande do sul (rs) state. the research sources used to collect data and references to this paper were obtained in: researched bibliography in the writing of the author's dissertation; academic articles; and perceptions from the author's experiences in some land reform settlements. in this research it was considered that initiatives and actions in agroecology in the studied settlement can be strategic to make the social relations potential to the occurrence of experiences in local development different from those that occur alongside agribusiness
Estatais e ajuste fiscal: uma análise da contribui??o das empresas federais para o equilíbrio macroecon?mico
Gobetti, Sérgio Wulff;
Economia e Sociedade , 2010, DOI: 10.1590/S0104-06182010000100002
Abstract: this article expose a historical and empirical analysis of the transformations in the administration of the brazilian state owned enterprises during the last 20 years. the main insight of the study is to show how the federal companies, considered villains of the fiscal crisis in the 80's - because its manipulation by military dictatorship to his foreign indebtedness policy -, assumed a decisive role in fiscal and macroeconomic equilibrium in the recent period. we estimate that the effective contribution of federal companies to primary surplus has been above 50%, accounting the indirect contributions, like dividends and royalties. moreover, we calculate that the share of this enterprises in tax revenues of federal, state and municipal governments have grown from 7,7% in 1999 to 14% in 2005-06, representing around 40% of the increase in tax rate. we also found evidences, here, that the investments executed by those companies has contributed to compensate the fiscal and monetary contraction between 2002 e 2004.
Amores fáceis: romantismo e consumo na modernidade tardia
Costa, Sérgio;
Novos Estudos - CEBRAP , 2005, DOI: 10.1590/S0101-33002005000300008
Abstract: the article discusses relations between economy and love in contemporary complex societies. the author sees romantic love as a particular form of communication that detaches lovers out of their environment. thus, what defines loving interaction is not the consumption of romantic rituals, as stated by critical theory and cultural studies, but the singular sense that lovers attribute to their relation and activities.
Dialogismo, polifonia e carnavaliza??o em Dostoiévski
Schaefer, Sérgio;
Bakhtiniana: Revista de Estudos do Discurso , 2011, DOI: 10.1590/S2176-45732011000200013
Abstract: dostoevsky is the creator, in literature, of three new artistic forms: dialogism, polyphony and carnivalization. dostoevsky is the artist. bakhtin sees clearly how this writer was able to retain his creation in historical trends of ancient menippus satire and at the same time, keep them fresh. bakhtin is the critic. this article attempts to show dostoevsky's creation through the critique of bakhtin.
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