9 resultados para Data Flows
em Repositório Institucional UNESP - Universidade Estadual Paulista "Julio de Mesquita Filho"
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Pós-graduação em Engenharia Elétrica - FEIS
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This paper is concerned with the numerical solutions of time dependent two-dimensional incompressible flows. By using the primitive variables of velocity and pressure, the Navier-Stokes and mass conservation equations are solved by a semi-implicit finite difference projection method. A new bounded higher order upwind convection scheme is employed to deal with the non-linear (advective) terms. The procedure is an adaptation of the GENSMAC (J. Comput. Phys. 1994; 110: 171-186) methodology for calculating confined and free surface fluid flows at both low and high Reynolds numbers. The calculations were performed by using the 2D version of the Freeflow simulation system (J. Comp. Visual. Science 2000; 2:199-210). In order to demonstrate the capabilities of the numerical method, various test cases are presented. These are the fully developed flow in a channel, the flow over a backward facing step, the die-swell problem, the broken dam flow, and an impinging jet onto a flat plate. The numerical results compare favourably with the experimental data and the analytical solutions. Copyright (c) 2006 John Wiley & Sons, Ltd.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The C 2 * radical is used as a system probe tool to the reactive flow diagnostic, and it was chosen due to its large occurrence in plasma and combustion in aeronautics and aerospace applications. The rotational temperatures of C 2 * species were determined by the comparison between experimental and theoretical data. The simulation code was developed by the authors, using C++ language and the object oriented paradigm, and it includes a set of new tools that increase the efficacy of the C 2 * probe to determine the rotational temperature of the system. A brute force approach for the determination of spectral parameters was adopted in this version of the computer code. The statistical parameter c 2 was used as an objective criterion to determine the better match of experimental and synthesized spectra. The results showed that the program works even with low-quality experimental data, typically collected from in situ airborne compact apparatus. The technique was applied to flames of a Bunsen burner, and the rotational temperature of ca. 2100 K was calculated.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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A second-order closure is developed for predicting turbulent flows of viscoelastic fluids described by a modified generalised Newtonian fluid model incorporating a nonlinear viscosity that depends on a strain-hardening Trouton ratio as a means to handle some of the effects of viscoelasticity upon turbulent flows. Its performance is assessed by comparing its predictions for fully developed turbulent pipe flow with experimental data for four different dilute polymeric solutions and also with two sets of direct numerical simulation data for fluids theoretically described by the finitely extensible nonlinear elastic - Peterlin model. The model is based on a Newtonian Reynolds stress closure to predict Newtonian fluid flows, which incorporates low Reynolds number damping functions to properly deal with wall effects and to provide the capability to handle fluid viscoelasticity more effectively. This new turbulence model was able to capture well the drag reduction of various viscoelastic fluids over a wide range of Reynolds numbers and performed better than previously developed models for the same type of constitutive equation, even if the streamwise and wall-normal turbulence intensities were underpredicted.
Erosion Protection by Calcium Lactate/Sodium Fluoride Rinses under Different Salivary Flows in vitro
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This study investigated the effect of a calcium lactate pre-rinse on sodium fluoride protection in an in vitro erosion-remineralization model simulating two different salivary flow rates. Enamel and dentin specimens were randomly assigned to 6 groups (n = 8), according to the combination between rinse treatments - deionized water (DIW), 12 mm NaF (NaF) or 150 mm calcium lactate followed by NaF (CaL + NaF) and unstimulated salivary flow rates - 0.5 or 0.05 ml/min simulating normal and low salivary flow rates, respectively. The specimens were placed into custom-made devices, creating a sealed chamber on the specimen surface connected to a peristaltic pump. Citric acid was injected into the chamber for 2 min, followed by artificial saliva (0.5 or 0.05 ml/min) for 60 min. This cycle was repeated 4x/day for 3 days. Rinse treatments were performed daily 30 min after the 1st and 4th erosive challenges, for 1 min each time. Surface loss was determined by optical profilometry. KOH-soluble fluoride and structurally bound fluoride were determined in specimens at the end of the experiment. Data were analyzed by 2-way ANOVA and Tukey tests (alpha = 0.05). NaF and CaL + NaF exhibited significantly lower enamel and dentin loss than DIW, with no difference between them for normal flow conditions. The low salivary flow rate increased enamel and dentin loss, except for CaL + NaF, which presented overall higher KOH-soluble and structurally bound fluoride levels. The results suggest that the NaF rinse was able to reduce erosion progression. Although the CaL prerinse considerably increased F availability, it enhanced NaF protection against dentin erosion only under hyposalivatory conditions. (C) 2014 S. Karger AG, Basel
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Organizational environments are related to hierarchic levels existing in a determined organization, and they influence in the formal and informal flows origin and in their monitoring and/or extinction. Informational environments are a result of organizational environments, of which focus is information and knowledge. Information flows are a fundamental element to informational environments, in a way that there´s no informational environments if there´s no information flows. Informational flows are natural reflections from their environments, in terms of content and in the way they occur. This qualitative and quantitative research was developed in three stages, in a way to allow the comprehension of the phenomena related to information and knowledge environments and information flows that occur in the meat sector from the Province of Salamanca, Spain. We used Laurence Bardin´s ‘Analysis of Content’, more specifically the ‘Categorical Analysis’ technique to data analysis. As data collection procedure we accomplished a field research, applying a questionnaire as an intentional sample of the meat industries segment from the Province of Salamanca, Spain. From data tabulation and analysis, we infer that information environments and flows are relevant to these companies business development, as well as we emphasized the need of information and knowledge management deployment, in a way to insure organizational processes quality, industrial chain production and companies competition to conquer potential markets.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)