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Search Results: 1 - 10 of 406140 matches for " Renato M.;Coury "
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Filtragem adaptativa para a estima??o da freqüência em sistemas elétricos de potência
Barbosa, Daniel;Monaro, Renato M.;Coury, Denis V.;Oleskovicz, Mário;
Sba: Controle & Automa??o Sociedade Brasileira de Automatica , 2008, DOI: 10.1590/S0103-17592008000200010
Abstract: this research presents a method for frequency estimation in power system using adaptive filter based on the least mean square algorithm (lms). in power system analysis, the three-phase voltages are converted to a complex signal with the application of α β-transform whose complex form was submitted to the algorithm of adaptive filtering. the computational simulations were accomplished using the software atp. this utilization had as objective to generate data for the most severe and different situations for the verification and analysis of the proposed methodology. the results were to those of a commercial relay for validation, showing the advantages of the new method.
Performance of a Venturi scrubber in the removal of fine powder from a confined gas stream
Costa, Maria Angélica Martins;Ribeiro, Ana Paula Rodrigues Alves;Tognetti, érica Rodrigues;Aguiar, M?nica Lopes;Gon?alves, José Ant?nio Silveira;Coury, José Renato;
Materials Research , 2005, DOI: 10.1590/S1516-14392005000200016
Abstract: experimental results on the performance of a laboratory scale rectangular venturi scrubber in the removal of fine mineral particles from a confined air stream are presented, and a new correlation is proposed and evaluated. the scrubber was operated with air velocities in the throat varying from 58 m/s to 75 m/s and liquid flow rates varying from 280 ml/min to 900 ml/min. liquid was injected as a jet emerging from a 1.0 mm orifice at the throat. results for dust collection grade efficiency varied from 87% to 98% for particles from 0.1 μm to 2.0 μm.
Some Remarks on Energy Storage and Energetic Complementarity  [PDF]
Renato M. Brito
Energy and Power Engineering (EPE) , 2017, DOI: 10.4236/epe.2017.99031
Abstract: This letter to the editor presents some notes related to the technological and economic limitations of the means actually available for energy storage and highlights the role that can be played by the notion of energetic complementarity in order to make feasible alternatives for a better use of the energy resources at our disposal. The notion of complementarity may represent a major advance in the design of energy generation projects, but its application depends on a broader conception of the projects and the contexts in which they are included.
Film fraction in a vertical circular Venturi scrubber
Guerra, Andressa Pinheiro;Guerra, Vádila Giovana;Coury, José Renato;Gon?alves, José Ant?nio S.;
Journal of the Brazilian Society of Mechanical Sciences and Engineering , 2011, DOI: 10.1590/S1678-58782011000500004
Abstract: the liquid film affects significantly the venturi scrubber efficiency. film fraction was measured in a vertically mounted laboratory scale venturi scrubber with a 0.020 m throat diameter. the liquid was injected at the throat by one to six 0.001 m holes. the throat gas velocity varied from 50 to 90 m/s and the relative jet penetration varied between 0.05 and 0.85. a special test section with a slot was used to extract the film. the test section could be placed at different axial positions, allowing measurements at 0.0075, 0.0275 and 0.0675 m after the injection point. results showed that film fraction varies as a function of the relative jet penetration and with distance from the injection point. there exists an optimal relative jet penetration (between 0.25 and 0.40) which minimizes film fraction. film fraction increased with axial distance in the range studied, up to 3.375 throat diameters after the injection point.
Drop Size Measurements in a Laboratory Scale Venturi Scrubber
Alonso, Diego Fernández;Azzopardi, Barry J.;Gon?alves, José Ant?nio Silveira;Coury, José Renato;
Journal of the Brazilian Society of Mechanical Sciences , 2001, DOI: 10.1590/S0100-73862001000400008
Abstract: venturi scrubbers are high efficiency gas cleaners in which suspended particles are removed from gas streams by droplets formed by liquid atomisation, usually in the venturi throat. the size of the droplets formed is of fundamental importance to the performance of the equipment, both in terms of pressure drop and collection efficiency. in this study, drop sizes in a cylindrical laboratory scale venturi scrubber were measured using a laser diffraction technique. gas velocity and liquid to gas ratios varied from 50 to 90 m/s and 0.5 to 2.0 l/m3, respectively. water was inserted as perpendicular jets at the beginning of the throat. measurements were performed at three positions: two located along the throat, and the last one at the end of the diffuser. the data presented here are a typical example of pneumatic atomisation and can be relevant to other industrial applications such as combustion and engine technology. finally, results are compared to available correlations and the validity of these equations is discussed.
Drop Size Measurements in a Laboratory Scale Venturi Scrubber
Alonso Diego Fernández,Azzopardi Barry J.,Gon?alves José Ant?nio Silveira,Coury José Renato
Journal of the Brazilian Society of Mechanical Sciences , 2001,
Abstract: Venturi scrubbers are high efficiency gas cleaners in which suspended particles are removed from gas streams by droplets formed by liquid atomisation, usually in the venturi throat. The size of the droplets formed is of fundamental importance to the performance of the equipment, both in terms of pressure drop and collection efficiency. In this study, drop sizes in a cylindrical laboratory scale venturi scrubber were measured using a laser diffraction technique. Gas velocity and liquid to gas ratios varied from 50 to 90 m/s and 0.5 to 2.0 l/m3, respectively. Water was inserted as perpendicular jets at the beginning of the throat. Measurements were performed at three positions: two located along the throat, and the last one at the end of the diffuser. The data presented here are a typical example of pneumatic atomisation and can be relevant to other industrial applications such as combustion and engine technology. Finally, results are compared to available correlations and the validity of these equations is discussed.
High Temperature PI/2-SQUID
M. H. S. Amin,M. Coury,G. Rose
Physics , 2001,
Abstract: A new DC-SQUID is proposed that exploits the properties of the grain boundary junctions in high T_c superconductors. The orientations of the grain boundaries are chosen in such a way to establish a pi/2 (rather than 0 or pi) phase difference between the equilibrium phases of the two Josephson junctions in the SQUID loop. This property is exploited to increase the sensitivity and direction dependence of the SQUID for measuring magnetic flux without additional flux generating coils.
Filtra??o de aerossóis em altas temperaturas utilizando filtros ceramicos de dupla camada: influência do diametro de partícula na eficiência de coleta
Freitas, N. L de;Maniero, M. G.;Coury, J. R.;
Ceramica , 2004, DOI: 10.1590/S0366-69132004000400011
Abstract: in this work, ceramic filters were used for aerosol filtration. the filters were constituted by two layers, where the first layer was formed by of a highly porous ceramic support with controlled pore size and the second layer constituted by a fine membrane. the ceramic support was obtained from polymeric foams utilizing a technique of alumina impregnation. the supports had 45 and 75 pores per inch (ppi). the membrane (a mixture of alumina and clay) was the same for the two supports, with much smaller pore sizes. the filtration experiments were accomplished at temperatures varying from 25 to 700 oc, where the ability of the filters for cleaning an aerosol constituted by fine particles (median diameter of 4.6 μm) was measured. the collection efficiency was calculated for particle diameters between 0.4 and 8.5 μm. the results showed that the collection efficiency decreased with the increase of the temperature and increased with particle diameter.
O emprego de redes neurais artificiais na detec??o, classifica??o e localiza??o de faltas em linhas de transmiss?o
Oleskovicz, M.;Coury, D. V.;Aggarwal, R. K.;
Sba: Controle & Automa??o Sociedade Brasileira de Automatica , 2003, DOI: 10.1590/S0103-17592003000200006
Abstract: this study has as objective the application of artificial neural networks (anns) theory as pattern classifiers. the implemented neural networks acquire knowledge for the detection, classification and localization of the fault facing different network conditions. the neural networks were implemented using neuralworks software. in this approach the three-phase voltage and current pre and post-fault values were utilized as inputs, for training and test purposes. the alternative transients program (atp) software was used to generate data for the transmission line (440 kv) in a faulted condition, both for the purposes of training and tests. the results obtained showed that the global performance of the ann architectures is highly satisfactory for fault detection, classification and localization purposes. considering all the studied cases, the ann outputs converged to the correct levels very rapidly after fault occurrence.
Genetic algorithms applied to a faster distance protection of transmission lines
Coury, Denis V.;Oleskovicz, Mário;Souza, Silvio A.;
Sba: Controle & Automa??o Sociedade Brasileira de Automatica , 2011, DOI: 10.1590/S0103-17592011000400002
Abstract: the main purpose of this paper is to implement a new methodology based on genetic algorithms (gas) to extract the fundamental voltage and current phasors from noisy waves in power systems to be applied to a faster distance protection. gas solve optimization problems based on natural selection principles. this application was then formulated as an optimization problem, and the aim was to minimize the estimation error. a 440 kv, 150 km transmission line was simulated using the atp (alternative transients program) software in order to show the efficiency of the new method. the results from this application show that the global performance of gas was highly satisfactory concerning speed and accuracy of response, if compared to the traditional discrete fourier transform (dft).
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