982 resultados para AUTO-COMBUSTION


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This paper investigated the influence of the amount of superplasticizer and mineral adding - silica fume and basaltic filer - in plastic shrinkage and cracking of self-compacting concrete (SCC) mortars. Initially analysis was performed of the rheological behavior of cement paste and mortars phases of the compositions of SCC. Then the deformations of mortars were measured by the effect of shrinkage and evaluation of cracking. On plastic shrinkage and cracking, the composition with silica fume showed superior results, independent of wind and superplasticizer content, relative to the composition with addition of basalt filler. However, the composition with silica fume showed superior results only in the tests with imposed ventilation at vertical plastic deformation. The rheological behavior affected directly the plastic shrinkage and cracking at early ages, fact confirmed by the analysis of capillary pressures of mortars tested.

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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)

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This work focuses on the study of BaMgAl10O17:Eu2+ (BAM:Eu) nanophosphors prepared by a microwave-assisted combustion procedure and more especially on the polymer/BAM:Eu nanocomposite film suitable for optical devices such as solid-state-lighting. Powder presented a specific nanomorphology, highly friable and thus easily ground into fine particles. They were then homogeneously dispersed into a polymer solution (poly(N-vinylpyrrolidone) or PVP) to elaborate a polymer phosphor nanocomposite. The structural, morphological and optical features of the nanocomposite film have been studied and compared to those of a pristine PVP film and BAM:Eu powder. All the characterizations (XRD, SEM, SAXS, etc.) proved that the blue phosphor nanoparticles are well incorporated into the polymer nanocomposite film which exhibited the characteristic blue emission of Eu2+ under UV light excitation. Furthermore, the photostability of the polymer/phosphor nanocomposite film has been studied after exposure to accelerated artificial photoageing at wavelengths above 300 nm.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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

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The increased fuel economy and driveability of modern internal combustion engine vehicles (ICEVs) are the result of the application of advanced digital electronics to control the operation of the internal combustion engine (ICE). Microprocessors (and micro controllers) play a key role in the engine control, by precisely controlling the amount of both air and fuel admitted into the cylinders. Air intake is controlled by utilizing a throttle valve equipped with a motor and gear mechanism as actuator, and a sensor enabling the measurement of the angular position of the blades. This paperwork presents a lab setup that allows students to control the throttle position using a microcontroller that runs a program developed by them. A commercial throttle body has been employed, whereas a power amplifier and a microcontroller board have been hand assembled to complete the experimental setup. This setup, while based in a high-tech, microprocessor-based solution for a real-world, engine operation optimization problem, has the potential to engage students around a hands-on multidisciplinary lab activity and ignite their interest in learning fundamental and advanced topics of microprocessors systems.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The German philosopher G.W.F. Hegel (1770-1831) had as one of his thesis in the doctorate the affirmation that philosophy can only be properly taken as a system. He intends with that to point out the identity between thinking and being. This is, for Hegel, the task of philosophy, i. e., to bring together all that was set apart. This position can be recognized in all his works and it is tried here to exemplify it in The Philosophy of Right and in special in the section dedicated to the abstract right. This one is the first moment of the text in question that begins with the statement of the dignity of the person confirmed in the property. The following moments make evident that the formal ones are also results. It becomes clear in this way that the all the moments create together an ongoing organization, disorganization and reorganization. This process reveals the relation as a constitutive element of thinking and being exemplified in the abstract right. Each moment overcomes the preceding one and comes out as a much more complex one. In the case of the abstract right what appears is the realization of a free subject in all that he does as the making of himself.

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Introduction: The neuropsicomotor development could be negatively affected by several factors occurred in the pre, peri and pos natal period. The early stimulation is implemented by a set of dynamic activities which aim the child development according to the child’s phase. Objective: The purpose of this study was to analyze the functional skills acquisition in the self care area in children with development delay. Participated of this study 9 caregiver of children aged of 0 to 3 years with delay neuropsicomotor. Method: For the data collect was used the self-care area of the Pediatric Evaluation of Disability Inventory (PEDI) in the version adapted for Brazil. The data collect was performed in two different stages, with an interval of 6 months between the collects. The raw score were transformed in continuous score by the Rasch statistics, then was applied the Shapiro-Wilk and t-student test. Results: The participants obtained a signifi cant higher score in the second stage than in the fi rst (p<0,01). Conclusion: The results of the present study suggests that the early stimulation could be an important intervention in the process of self-care skills acquisition in children with neuropsicomotor delay.

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

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Ethanol, the main automotive biofuel, has its production based on the fermentation of sugars found in biological materials and on the distillation of the alcoholic media formed during the fermentative process. Stillage is the main residue from ethanol production, containing a high organic loading in addition to acidic and corrosive characteristics. Considering the available technologies to treat stillage, we highlight anaerobic digestion, which allows the reduction of the impacts associated to pollutants loading of this effluent and the generation of energy from the methane gas produced in the process. Based on the high treatment efficiency usually associated to the anaerobic process, this work aimed to assess whether anaerobic systems applied to the treatment of stillage are energetically self-sufficient. First we evaluated the energy recovery capacity in an anaerobic reactor applied to the treatment of stillage resulting from corn-to-ethanol processing. The results indicated the great influence that a correct selection of electrical equipment and their respective operating periods have on the net energy balance of the anaerobic treatment. The high energy consumption of the heater would not allow the system to achieve a positive net energy balance – the maximum energy recovery would reach only 0.68% of the consumption. However, the replacement of the mixture equipment would result in energy gains ranging from 8.5 to 967.9% of the consumption. In this work we also assessed the efficiency of methane yields for a few studies and the correlation between some parameters of the anaerobic process. With respect to the methane yield, we noted that mesophilic systems tend to be more advantageous than the thermophilic ones (efficiency of 76.45 ± 22.51% vs. 69.40 ± 30.36%). Considering the study... (Complete abstract click electronic access below)