Catalysis
Mostrando 25-36 de 1422 artigos, teses e dissertações.
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25. Estudio de las propiedades, estructurales, morfológicas y ópticas de nanopartículas de Cr2O3 sintetizadas por procesos de combustión de un solo paso y diferentes combustibles
ABSTRACT This research presents a novel one–step solution combustion synthesis to obtain nano-structured Cr2O3 from chrome nitrate solution and one fuel such as aspartic acid (Asp) or Lysine (Lys), or Autor Restrihydroxymethylaminomethane (Tris) or ethylenediaminetetraacetic acid (Edta). Once obtained, the ashes were calcined at 500°C. The powders were ch
Matéria (Rio J.). Publicado em: 16/09/2019
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26. Synthesis and Characterization of Modified Polystyrene with Oleic Acid and an Allyl Ester Derivative
Polystyrene (PS) is one of the most widely used polymers in the world, having a wide applicability. PS can be used in pure or modified forms, and the commercial materials most used for modifications are non-renewable and have high costs. For this reason, studies have been carried in order to evaluate renewable components application such as vegetable oils, f
Mat. Res.. Publicado em: 05/09/2019
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27. SYNTHESIS AND THEORETICAL STUDY OF HPW CATALYSTS SUPPORTED ON NIOBIA CALCINATED AT 500 AND 600 ºC
Keggin heteropolyacids (HPW) supported on niobia have been considered for both homogeneous and heterogeneous catalysis due to its special features, like the strong Brönsted acidity, low volatility, high activity and high selectivity for various reactions in comparison with mineral acids. Literature reports many different preparation methods for these cataly
Quím. Nova. Publicado em: 26/08/2019
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28. Protein identification from the parotoid macrogland secretion of Duttaphrynus melanostictus
ABSTRACT Background: Bufonid parotoid macrogland secretion contains several low molecular mass molecules, such as alkaloids and steroids. Nevertheless, its protein content is poorly understood. Herein, we applied a sample preparation methodology that allows the analysis of viscous matrices in order to examine its proteins. Methods: Duttaphrynus melanostic
J. Venom. Anim. Toxins incl. Trop. Dis. Publicado em: 19/08/2019
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29. ORGANOCATÁLISE ENANTIOSSELETIVA: EVOLUÇÃO E ASPECTOS RECENTES
In the last two decades, enantioselective organocatalysis has established itself as one of the three pillars of asymmetric catalysis. The rapid growth in the area is due to the rationalization of organocatalysis based on the generic modes of catalyst activation, being applied to several types of reactions, in a rather generic and predictable way and providin
Quím. Nova. Publicado em: 27/05/2019
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30. Estudo de obtenção da membrana cerâmica densa BaCeO3
RESUMO Nos últimos anos, pós cerâmicos à base de óxidos de estrutura do tipo perovskita ganharam atenção considerável devido às suas aplicações tecnológicas na área de membranas permeáveis de oxigênio. O óxido misto BaCeO3 apesenta-se como um material amplamente estudado em uma grande diversidade de aplicações, seja como materiais eletrolí
Matéria (Rio J.). Publicado em: 20/05/2019
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31. New Composites CP@AC Based on Lanthanide Succinates
Composites derived from coordination polymers have been gathering great attention due to their singular properties and applications, especially catalysis and adsorption. In this work, seven new composites based on activated carbon (AC) and lanthanide-succinates (LnSuc; Ln = Pr, Nd, Sm, Gd, Dy, Er and Tm, and Suc = succinate) 3D-coordination polymers were obt
J. Braz. Chem. Soc.. Publicado em: 2019-04
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32. Micronutrients: Speculation on Inborn Errors, Nutrigenomics, Evolution, the Microbiome, and Nutritional Immunity
Abstract Many micronutrients or cofactors derived from micronutrients are highly reactive, hence their role in catalysis of reactions by enzymes. The concentration of cofactors has to be kept low to avoid unwanted reactions while allowing them to bind to the (apo)enzymes that need them. A new disorder causing B6-responsive epilepsy (proline synthetase cotran
J. inborn errors metab. screen.. Publicado em: 28/02/2019
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33. Chemical modification of in natura collagen by acidic catalysis – structural characterization and mechanistic features of Cd(II) sorption by solution microcalorimetry
ABSTRACT Chemically-modified in natura collage was prepared under acidic catalysis for using in sorption of Cd(II) from aqueous solutions. Simultaneous determination of the quantity and energetic parameters of Cd(II) sorption on PGA-scale at pH 8.0 were determined using solution microcalorimetry (SM). The calorimetric enthalpies of Cd(II) sorption on PGA-sca
Matéria (Rio J.). Publicado em: 06/12/2018
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34. EXPERIMENTO COM ABACATE, BORRA DE CAFÉ, LICURI E LEITE DE COCO PARA EXTRAÇÃO DE ÓLEO, PRODUÇÃO DE BIODIESEL E ANÁLISE ESPECTRAL
An undergraduate organic chemistry experiment for oil extraction and biodiesel production using alternative biomass was developed, whereby oils of avocado, coconut and spent coffee grounds were obtained and submitted to transesterification reaction with CH3OH under NaOH catalysis. Avocado and coffee oils were obtained by typical extraction and coconut oil wa
Quím. Nova. Publicado em: 2018-06
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35. OS LANTANÍDEOS NAS REDES METALORGÂNICAS: UMA NOVA CLASSE DE MATERIAIS POROSOS
Lanthanoid organic frameworks (LOFs) stand out as an important class of functional materials. The possibility to employ a great range of metals and ligands lead to the formation of varied and highly porous structures, with diverse applications. The presence of lanthanoid ions favours the improvement of the optical, magnetic and redox properties of MOFs. This
Quím. Nova. Publicado em: 2018-06
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36. COMO OBTER NANOPARTÍCULAS DE OURO USANDO SUCO DE LIMÃO?
This article refers about a green method for the preparation of gold nanoparticles using juice from four types of lemon (Tahiti, Key lime, Sicilian and Rangpur). The approach is based on a classic synthesis of nanoparticles using sodium citrate as reducing agent, since all these lemon varieties have citric acid in their compositions. Several characterization
Quím. Nova. Publicado em: 2018-05