Rhodium
Mostrando 1-12 de 61 artigos, teses e dissertações.
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1. Do laypersons perceive aesthetic differences between coated and uncoated orthodontic archwires?
RESUMO Introdução: rotineiramente na terapia ortodôntica fixa, utilizam-se braquetes estéticos combinados com fios metálicos, principalmente devido a algumas desvantagens no uso clínico dos fios estéticos. A percepção estética dos leigos nessa situação precisa ser explorada na literatura. Objetivo: o objetivo deste estudo transversal foi aval
Dental Press J. Orthod.. Publicado em: 2019-02
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2. Rhodium(III)-Catalyzed Addition of Indoles with Boc-Imines via C-H Bond Activation
A rhodium-catalyzed alkylation reaction of indoles with N-Boc-imines has been developed via C-H activation to afford a series of substituted 2-indolyl-methanamine derivatives with good functional group tolerance and regioselectivity. A wide range of indole-based alkylation products could be obtained in up to 95% yield.
J. Braz. Chem. Soc.. Publicado em: 2018-06
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3. Comparison of deflection forces of esthetic archwires combined with ceramic brackets
Abstract Coated archwires and ceramic brackets have been developed to improve facial esthetics during orthodontic treatment. However, their mechanical behavior has been shown to be different from metallic archwires and brackets. Therefore, the aim of this study was to compare the deflection forces in coated nickel-titanium (NiTi) and esthetic archwires combi
J. Appl. Oral Sci.. Publicado em: 08/02/2018
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4. Experimental Investigation of a Monopropellant Thruster Using Nitrous Oxide
ABSTRACT: Nitrous oxide is a monopropellant with potential for use in propulsion systems for orbit correction, positioning and attitude control of satellites. This paper presents experimental results with a 2N thruster prototype employing nitrous oxide gas decomposed by a rhodium oxide catalyst supported on alumina. Initially, the thruster design, the test b
J. Aerosp. Technol. Manag.. Publicado em: 2014-12
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5. An Electrostatically-Anchored Rhodium(I) Catalyst for the Hydroformylation and Tandem Hydroformylation/Acetalization of Biorenewable Allyl Benzenes
Um catalisador de ródio ancorado em uma resina de troca iônica comercial (IRA900/TPPMS/Rh) foi preparado de maneira direta, através de um protocolo simples, a partir de precursores prontamente disponíveis. O material foi usado como um catalisador heterogêneo para a hidroformilação e a sequência tandem hidroformilação/acetalização do eugenol e do
J. Braz. Chem. Soc.. Publicado em: 2014-12
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6. Metal nanoparticles/ionic liquid/cellulose: polymeric membrane for hydrogenation reactions
Rhodium and platinum nanoparticles were supported in polymeric membranes with 10, 20 and 40 µm thickness. The polymeric membranes were prepared combining cellulose acetate and the ionic liquid (IL) 1-n-butyl-3-methylimidazolium bis(trifluoromethane sulfonyl)imide (BMI.(NTf)2. The presence of metal nanoparticles induced an increase in the polymeric membrane
Polímeros. Publicado em: 18/04/2014
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7. Ligandless cloud point extraction of trace amounts of palladium and rhodium in road dust samples using Span 80 prior to their determination by flame atomic absorption spectrometry
In this study, a procedure is developed for cloud point extraction of Pd(II) and Rh(III) ions in aqueous solution using Span 80 (non-ionic surfactant) prior to their determination by flame atomic absorption spectroscopy. This method is based on the extraction of Pd(II) and Rh(III) ions at a pH of 10 using Span 80 with no chelating agent. We investigated the
Quím. Nova. Publicado em: 2014
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8. Estudo da oxidação parcial do etanol em catalisadores de Rh por DRIFTS
The partial oxidation of ethanol on γ-Al2O3, CeO2, ZrO2 and Ce xZr1-xO2 supported rhodium catalysts was investigated by Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS). The catalysts were characterized by temperature-programmed reduction (TPR) and cyclohexane dehydrogenation. DRIFTS studies on the partial oxidation of ethanol showed tha
Quím. Nova. Publicado em: 2013
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9. Succinato de ródio (II): síntese, caracterização e adsorção em nanopartículas de maghemita / Rhodium (II) succinate: synthesis, caracterization and adsorption on maghemite nanoparticles
In this work it was described the synthesis and characterization of rhodium(II) succinate complex unpublished and adsorption study in maghemite nanoparticles. The rhodium(II) succinate was synthesized from a precursor rhodium(II) carboxylate, rhodium(II) trifluoracetate with a yield of 48.2%. The complex has become completely soluble in aqueous medium only w
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 13/08/2012
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10. Desenvolvimento de método para a determinação de irídio, paládio, platina e ródio por ICP OES em sílica mesoporosa para uso catalítico / Development of method for the determination of iridium, palladium, platinum and rhodium in mesoporosa silica for catalyst use by ICP OES
O objetivo deste estudo foi avaliar parâmetros tais como, moagem, tamanho de partículas, homogeneidade, segregação, dissolução de amostras e amostragem de suspensão, visando o desenvolvimento de método para a determinação de Ir, Pd, Pt e Rh por espectrometria de emissão óptica com plasma indutivamente acoplado (ICP OES) em sílica mesoporosa para
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 10/07/2012
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11. Hidroformilação do oleato de metila catalisada por complexos de ródio
In this work, we describe the hydroformylation of methyl oleate catalyzed by several rhodium complexes. Parameters including total pressure, phosphorous/rhodium and CO/H2 ratio, temperature and phosphorous ligands were scanned. Total conversion of the starting double bonds was achieved while maintaining excellent selectivity in aldehydes.
Quím. Nova. Publicado em: 2012
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12. Preparação do composto de associação entre citrato de ródio(II) e β-ciclodextrina
Inclusion compound of rhodium(II) citrate with β-cyclodextrin in a 1:1 molar ratio was prepared using freeze-drying method. X-ray diffactometry, thermal analysis (TG/DTG/DSC), infrared and ¹H-NMR with ¹H spin lattice relaxation (¹H T1) measurements and 13C techniques were used to characterize the system prepared. The results indicated the formation of in
Química Nova. Publicado em: 2012