Forming Of Metals
Mostrando 13-24 de 39 artigos, teses e dissertações.
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13. ESTUDOS SOBRE A RELAÇÃO ENTRE O CARBONO ORGÂNICO DISSOLVIDO E ELEMENTOS METÁLICOS MAIORES E TRAÇOS EM ÁGUAS DO LESTE DO QUADRILÁTERO FERRÍFERO,MG
In this work relations between the metallic elements and organic carbon dissolved (COD) in aquatic environments in the east of the Iron Quadrangle, Minas Gerais state, have been studied. This region was chosen for the study, because it is very rich in metals and one of the biggest mining areas in Brazil. It possesses many old mines and others which continue
Publicado em: 2010
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14. SÍNTESE E ARRANJOS SUPRAMOLECULARES DE COMPLEXOS BIS(TRIAZENIDO) MACROCÍCLICOS E TRIAZENIDO 1-ÓXIDO COM OS CÁTIONS Cu2+, Ni2+, Cu+, K+. / SYNTHESIS AND SUPRAMOLECULAR ARRANGEMENTS OF BIS(TRIAZENIDE) MACROCYCLIC AND TRIAZENIDE 1-OXIDE COMPLEXES WITH Cu2+, Ni2+, Cu+, K+ CATIONS.
This work elaborates on the determination of crystal and molecular structures of four pro-ligands, emphasizing bis(triazenes), triazene 1-oxide and a new class of bis(triazenes) macrocyclic, and eight complexes involving Cu+, Cu2 +, Ni2 + and K+. Pro-ligands triazenes 1-oxide are relatively small and simple molecules. When they are deprotonated they presen a
Publicado em: 2010
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15. Estudo comparativo da estampabilidade da liga de aluminio AA1050 partindo de placas obtidas por vazamento direto e bobinas obtidas por vazamento contínuo. / Comparative study of the deep drawing alloy AA1050 from plates obtained by direct casting and coils obtained by continuos casting.
Stampability of aluminum alloys is a subject of interest to several industrial sectors because they are largely used in the fabrication of several parts and components. The choice is based upon the stampability and the relative manufacturing capability in relation to other aluminum alloys that contain larger amounts of alloying elements and, consequently, hi
Publicado em: 2010
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16. INFLUENCE OF SiO2 ON MECHANICAL PROPERTIES OF DGEBA / INFLUÊNCIA DO SIO2 NAS PROPRIEDADES MECÂNICAS DA DGEBA
In this study we used a different route, simple and economical: the dissolution of the SiO2 powder DGEBA with a hardener to base polymercaptan ( aradur 90 ). Analysis was performed micro hardness in different percentages of the concentration of SiO2. The hardness of multicomponent solid is approximately equal to the average hardness of the material compositi
Publicado em: 2009
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17. Study of behavior of copper in systhetic rainwater of São Paulo and Rio de Janeiro and its protection against corrosion by coating and patino exposed to climate action. / Estudo do comportamento de cobre em águas de chuva sintéticas de São Paulo e Rio de Janeiro e sua proteção contra corrosão por revestimentos e pátinas expostos à ação climática.
Copper is one of the metals most widely used to produce metallic artifacts of the artistic and cultural heritage. This is partially due to its great ability to combine with other compounds, forming patinas of different colors. Many of such artifacts are permanently exposed to open air, being thus subjected to the action of atmospheric agents such as rain and
Publicado em: 2009
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18. Use of modified silica gel for concentrating Pb (II) and Cd (II) occurring in form of complex anions
The performance of silica gel, modified by the impregnation with a high molecular weight quaternary amine (triethyl octadecyl ammonium iodide), used for the concentration of heavy metals occurring in water is studied. The material under study captures Cd, Pb, which are capable of forming stable complexes with I- ions.The results obtained about the metal capt
Eclética Química. Publicado em: 2007
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19. Analise numerica e experimental do cravamento de componentes mecanicos tubulares em haste com ponta esferica / Numerical and experimental analysis of tubular metallic parts indented with spherical punchs
Crimping is a cold metal forming process that presents low costs for use in holding tubular components. The type of crimping analyzed is used in projects of components that transmit rotating motion, such as joining systems of brake pedals. If the joining clearance, in this case, is less than 0,02mm the brake movement will be restrained and may not close the
Publicado em: 2007
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20. Influence of the lubricant use in the process of deep drawing with thick steel sheeet metals / Influencia do uso de lubrificantes no processo de estampagem profunda com chapas espessas de aço
The objective of this work was to evaluate the influence of the lubrication on the process and product during the deep drawing of metallic cups, as Brazilian standard ABNT NBR 5906:1984, degree EPA to thickness 3,5mm and to understand the causes of the cracking during deep drawing, on specific conditions of this process. Occurrences of defects as crack, unde
Publicado em: 2007
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21. Alilação e crotilação catalítica e enantiosseletiva de aldeídos
The field of chiral catalysis has experienced explosive growth over the last two decades. By now, many of the classical reactions in organic synthesis can be carried out efficiently in asymmetric manner. As one of the fundamental and powerful C-C bond-forming reactions, enantioselective catalytic allylation (ECA) and crotylation (ECC) of aldehydes has attrac
Química Nova. Publicado em: 2006-10
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22. The effect of cyclic torsion on the dislocation structure of drawn mild steel
Cold forming is usually associated with the "work hardening" of the material being formed. The work hardening behavior of metals subject to complex processing paths is different from that in monotonic deformation. The results show that, after some initial hardening, there is a possibility that further deformation will cause softening in the material ("work s
Materials Research. Publicado em: 2006-09
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23. FUNÇÃO DO METAL BIVALENTE NA RNA TRIFOSFATASE DE TRYPANOSOMA CRUZI. / The role of the divalente metal in the RNA triphosphatase from Trypanosoma cruzi.
Cap triphosphatases act in the first step of the mRNA capping process, removing the -phosphoryl group from the 5 end of nascent RNA. Enzymes from trypanosomatids and other lower eukaryotes depend on metals for this catalysis. This contrasts with the cysteine-dependent activity of the corresponding enzymes of mammals. This difference points to these enzymes a
Publicado em: 2006
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24. Crystallographic orientation-spray formed hypereutectic aluminium-silicon alloys
Aluminium-silicon alloys have been wide accepted in the automotive, electric and aerospace industries. Preferred orientation is a very common condition for metals and alloys. Particularly, aluminium induces texture during the forming process. The preparation of an aggregate with completely random crystal orientation is a difficult task. The present work was
Materials Research. Publicado em: 2005-06