Dead Zone
Mostrando 1-12 de 26 artigos, teses e dissertações.
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1. Simulação computacional de dispositivos de mistura em câmara de combustão para gases de carbonização
Resumo O carvão vegetal proveniente de florestas plantadas é uma fonte de energia renovável utilizada na siderurgia do Brasil, todavia, em sua produção há liberação do gás de pirólise, que pode ser considerado um gás com baixo poder calorífico inferior. A sustentabilidade da produção de carvão vegetal tem demandado a queima destes gases, poden
Ciênc. Florest.. Publicado em: 30/09/2019
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2. Allometric models to estimate tree height in northern Amazonian ecotone forests
RESUMO Modelos alométricos que definem o relacionamento entre diâmetro do tronco e a altura total da árvore na bacia amazônica são importantes porque refinam as estimativas de fluxo e estoques de carbono arbóreo na região. Este estudo testou diferentes modelos alométricos para estimar a altura total de árvores a partir do diâmetro do tronco em uma
Acta Amaz.. Publicado em: 06/05/2019
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3. Efficient numerical method for solution of boundary value problems with additional conditions
Abstract An efficient numerical method for solution of boundary value problems with additional condition is presented. The approach is based on the shooting method but the procedure of seeking “the proper shot” allows one to satisfy “additional” boundary conditions. General considerations are illustrated by a real example. The computational example c
Braz. J. Chem. Eng.. Publicado em: 2017-07
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4. Crack Propagation Analysis of Magnesium Rod Processed by Extrusion-shear: Numerical Modeling and Experimental Verification
During extrusion-shear (ES) process, the surface cracks would be formed in the processed rod for AZ31 magnesium caused by nonhomogeneous metal flow and stress. To reduce the cracks defects, three-dimensional (3D) finite element method (FEM) of ES on a wrought AZ31 magnesium alloy have been performed. ES process experiments have been also conducted to verify
Mat. Res.. Publicado em: 2015-08
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5. Two-parameter Rigid Block Approach to Upper Bound Analysis of Equal Channel Angular Extrusion Through a Segal 2θ-die
This article deals with a phenomenological description of experimentally determined complex geometric shape of material dead zone during Equal Channel Angular Extrusion (ECAE) through a Segal 2θ-die with a channel intersection angle of 2θ>0°and 2θ<180°. Taking into account the complex dead zone geometry in a 2θ-die, a two-parameter Rigid Block Method (
Mat. Res.. Publicado em: 2015-06
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6. 2D upper bound analysis of ECAE through 2θ-dies for a range of channel angles
Equal Channel Angular Extrusion (ECAE), sometimes referred to as Equal Channel Angular Pressing (ECAP), is a Severe Plastic Deformation technique. However the energy-power parameters of ECAE have not been fully addressed in previous known publications. The present article is focused on the punching pressure, accumulated plastic strain, and dead metal zone ge
Mat. Res.. Publicado em: 26/10/2014
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7. Analysis of equal channel angular extrusion by upper bound method and rigid blocks model
In present paper the Equal Channel Angular Extrusion (ECAE) through a rectangular die was firstly physically simulated using plasticine and then theoretically analyzed by upper bound method. Physical simulation was used to identify the deformation zone and as a background for the following theoretical ECAE analysis by rigid block model. The plane strain defo
Mat. Res.. Publicado em: 15/11/2013
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8. Microhardness and EBSD microstructure mapping in partially-pressed al and cu through 90º ECAP die
Equal-channel angular pressing (ECAP) is widely recognized as an effective method for processing ultrafine-grained and even nanostructured materials. Important details on processes occurring in the die intersections can be obtained by mapping the microhardness and EBSD microstructures in partially-pressed aluminum and copper through the 90º die of ECAP. Pre
Mat. Res.. Publicado em: 08/03/2013
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9. Desenvolvimento de células solares com metalização por serigrafia : influência do emissor N+
The main goal of the solar cell industry is to obtain high efficiency and low production cost. One line of action is to increase the efficiency of industrial solar cell . The goal of this dissertation is to develop n+pn+ solar cells in p-type Si-Cz wafer, solar grade, with metallization by screen printing and to evaluate the influence of the n+ emitter and P
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 06/12/2012
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10. Design of a computer aided quick-stop device for study of dead metal zone formation
The use of quick-stop device allows observing a sequence of frozen images focused on the chip formation area when machining in orthogonal turning tests. This work records the development of a quick-stop device employing a servo motor. The present invention relates generally to a quick stop device, for combination with a cutting machine that is able to abrupt
J. Braz. Soc. Mech. Sci. & Eng.. Publicado em: 2012-12
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11. Slip-line metal cutting model with negative rake angle
A small dead region is seen in front of the rake face of the tool during cutting with negative rake. The lack of knowledge about the stagnant region in the cutting with negative rake requires researching new models. In this work, cutting mechanism of the metal cutting with negative rake angle tools and the stagnation zone formation were studied. A model was
J. Braz. Soc. Mech. Sci. & Eng.. Publicado em: 2012-09
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12. Stability analysis and stabilization of systems presenting nested saturations
This note addresses the problems of stability analysis and stabilization of systems presenting nested saturations. Depending on the open-loop stability assumption, the global stability analysis and stabilization problems are considered. In the (local) analysis problem, the objective is the determination of estimates of the basin of attraction of the system.
Publicado em: 2011