Gold Platinum
Mostrando 1-12 de 21 artigos, teses e dissertações.
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1. Technological innovation in Córrego do Sítio Mineração - A study of technical and economic aspects by using sensor-based sorting for refractory gold ore
Abstract The mining sector has a fundamental financial and economical role in the country where it practices these activities. In addition to employment creation and social-cultural development, the mining sector brings economic growth to the country. However, the sector is facing challenges due to COVID-19, incidents involving tailings dam facilities, risin
REM, Int. Eng. J.. Publicado em: 2021-01
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2. COMPOSTOS QUIMIOTERÁPICOS DE OURO: UMA VISÃO GERAL DOS COMPLEXOS ANTICÂNCER DE Au(I/III) EM RELAÇÃO À ESTRUTURA DO LIGANTE
Gold compounds engage an important place in the field of medicinal chemistry due to their therapeutic properties. Since the last four decades, Au(I) and Au(III) complexes have attracted the attention of researchers due to their anti-tumor proprieties and the different mechanisms of action they display in comparison to conventional anticancer platinum compoun
Quím. Nova. Publicado em: 2020-09
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3. Nanoporous Gold Surface: An Efficient Platform for Hydrogen Evolution Reaction at Very Low Overpotential
A nanostructured porous gold film (NPGF) was fabricated onto a gold electrode surface by an electrochemical approach involving anodization followed by electrochemical reduction in absence of binary alloys, templates and chemical reducing agents. The electrocatalytic activity of the as-fabricated electrocatalyst was examined towards hydrogen evolution reactio
J. Braz. Chem. Soc.. Publicado em: 2018-02
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4. Processamento de placas de circuito impresso de equipamentos eletroeletrônicos de pequeno porte
A hydrometallurgical process applicable to printed circuit boards of small electrical and electronic devices was developed. This involved three leaching steps (60 ºC, 2 h): 6 mol L-1 NaOH, 6 mol L-1 HCl and aqua regia. NaOH removed the resin and flame retardant that covered the circuit boards. HCl dissolved the most electropositive metals and a small amount
Quím. Nova. Publicado em: 2013
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5. Characterization of thiol-functionalised silica films deposited on electrode surfaces
Thiol-functionalised silica films were deposited on various electrode surfaces (gold, platinum, glassy carbon) by spin-coating sol-gel mixtures in the presence of a surfactant template. Film formation occurred by evaporation induced self-assembly (EISA) involving the hydrolysis and (co)condensation of silane and organosilane precursors on the electrode surfa
Materials Research. Publicado em: 2008-12
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6. Synthesis, characterization and evaluation of the biological activity of metalic complexes with dithiocarbimates / Síntese, caracterização e estudo da atividade biológica de complexos metálicos com ditiocarbimatos
The dithiocarbimates are structurally related to the dithiocarbamates, but are less studied. This work describes the syntheses of zinc(II), platinum(II) and gold(III) complexes with dithiocarbimates anions and their characterization by elemental analyses, conductance measurements, infrared, electronic, and NMR spectroscopies. Some substances were also charac
Publicado em: 2007
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7. Supramolecular chemistry of tetrapyridylporphyrins associated with platinum(II) complexes / Química supramolecular de tetrapiridilporfirinas associadas a complexos de platina(II)
The synthesis, characterization and investigation of the molecular and supramolecular behaviour of meso-tetrapyridylporphyrins containing four chloro(bipyridine) platinum(II) complexes attached at the meta and para positions of the peripheral pyridine ligands is focused on this thesis. The isomeric supermolecules were isolated in the solid state, and extensi
Publicado em: 2006
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8. In vitro and in vivo electrochemical studies of nickel-chromium-molybdenum-titanium alloy applied to oral implant suprastructures / Estudos eletroquímicos in vitro e in vivo da liga níquelcromomolibdênio titânio aplicada em supraestruturas de implantes orais
The electrochemical behavior of the nickel-chromium-molybdenum-titanium (Ni-Cr-Mo-Ti) alloy was studied and compared to a gold-platinum-palladium (Au-Pt-Pd) alloy in 0.15 mol.L -1 NaCl medium at 36.5ºC. In vitro studies also involved the electrochemical titanium characterization since these alloys are employed in osseointegrated implant suprastructures. In
Publicado em: 2005
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9. "Fabricação e avaliação de microdispositivos para eletroforese com detecção eletroquímica" / "Fabrication and Evaluation of Electrophoresis Microdevices coupled with Electrochemical Detection"
This work describes the development of electrophoresis microchip fabricated by direct-printing and photolithographic processes. The channel structures of the devices fabricated by direct-printing process are defined by polyester films (base and cover) and by a toner layer (walls). The characterization of toner surface and composition were necessary for a bet
Publicado em: 2004
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10. A comparative study of electrochemical and optical properties of rhenium deposited on gold and platinum
Filmes de rênio e de óxido de rênio foram depositados sobre eletrodos de ouro e platina aplicando polarizações potenciostáticas e potenciodinâmicas numa região compreendida entre -- 0,20 V e 0,70 V (vs rhe) em meio aquoso ácido contendo íons perrenato. As espessuras e as variáveis óticas dos filmes foram obtidas empregando perturbações triangul
Journal of the Brazilian Chemical Society. Publicado em: 2002-08
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11. AVALIAÇÃO METROLÓGICA DA ESTABILIDADE TERMOELÉTRICA DE TERMOPAR AUPT / METROLOGICAL ESTIMATION OF THERMOELECTRIC STABILITY IN AUPT THERMOCOUPLE
In 1990, with the adoption of the International Temperature Scale of 1990, the platinum/platinum-rhodium thermocouple was removed as the interpolation instrument between 630°C and 1064°C, due its low stability, in favor of the high temperature standard platinum resistance thermometer (HTSPRT) and the radiation thermometer. In this work, it is performed a p
Publicado em: 2002
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12. Estudo voltamÃtrico de haletos insaturados e suas participaÃÃes em reaÃÃes do tipo barbier-grignard em meio aquoso
In this work it has been done a qualitative electrochemical study on the following halides: allyl bromide and chloride, benzyl bromide and chloride, propargyl bromide and chloride. The electrochemical technique used was cyclic voltammetry. As solvent it was used a mixture of H2O/MeOH in different proportions and NH4Cl 0,1M or KBr 0,1M as the supporting elect
Publicado em: 2002