Desenvolvimento de método analítico para a determinação de vanádio em material vegetal por espectrometria de absorção atômica em forno de grafite

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência do oxigênio nas propriedades anelásticas e biocompatibilidade de ligas Ti-5Zr e Ti-10Zr

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Interações de alguns ácidos orgânicos com minerais e um latossolo vermelho

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Comportamento dielétrico e ferroéletrico de cerâmicas BA('TI IND1-X''ZR IND.X)'O IND.3' modificadas com íons vanádio e tungstênio obtidos a partir de mistura de óxidos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo das modificações na superfície do Ti cp titânio comercialmente puro e da liga Ti-6AI-4V usados como biomateriais utilizando-se deposição por plasma spray

Pós-graduação em Química - IQ

Síntese e caracterização de novos complexos de vanádio: estudo da utilização dos complexos no tratamento do Diabetes Mellitus

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Ensaio de citotoxicidade osteoblástica em amostras porosas das ligas Ti-6Al-4V, Ti-13Nb-13Zr, Ti-35Nb, Ti-35Nb-7Zr-5Ta e TiCP

Pós-graduação em Biopatologia Bucal - ICT

Corrosão e tribocorrosão de novas ligas Ti35Nb5Zr e Ti35Nb10Zr em saliva artificial

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Magnetocrystalline interactions and oxidation state determination of Mn(2-x)V(1+x)O4 (x=0, 1/3 and 1) magnetorresistive spinel family

Oxidation states of transition metal cations in spinels-type oxides are sometimes extremely difficult to determine by conventional spectroscopic methods. One of the most complex cases occurs when there are different cations, each one with several possible oxidation states, as in the case of the magnetoresistant Mn(2-x)V(1+x)O4 (x=0, 1/3 and 1) spinel-type family. In this contribution we describe the determination of the oxidation state of manganese and vanadium in Mn(2-x)V(1+x)O4 (x=0, 1/3,1) spinel-type compounds by analyzing XANES and high-resolution K beta X-ray fluorescence spectra. The ionic models found are Mn22+V4+O4, Mn5/32+V4/33.5+O4 and Mn2+V23+O4. Combination of the present results with previous data provided a reliable cation distribution model. For these spinels, single magnetic electron paramagnetic resonance (EPR) lines are observed at 480 K showing the interaction among the different magnetic ions. The analysis of the EPR parameters show that g-values and relative intensities are highly influenced by the concentration and the high-spin state of Mn2+. EPR broadening linewidth is explained in terms of the bottleneck effect, which is due to the presence of the fast relaxing V3+ ion instead of the weak Mn2+ (S state) coupled to the lattice. The EPR results, at high temperature, are well explained assuming the oxidation states of the magnetic ions obtained by the other spectroscopic techniques. (c) 2013 Elsevier Inc. All rights reserved.

Second Phase Precipitation in Ultrafine-grained Ferrite Steel

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influência dos elementos de liga nos parâmetros de processo de fundição de ferros fundidos especiais

Pós-graduação em Engenharia Mecânica - FEG

Efeito de tratamentos térmicos nas propriedades mecânicas, eletroquímicas e citotoxidade de ligas do sistema Ti-15Mo-XNb

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of Decomposition Procedure to Determine Ba, Co, Cr, Cu, Ni, Mn, V, and Zn Total Content in Soil Samples

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Chemical analysis and Vickers hardness of orthodontic mini-implants

Orthodontic mini-implants are used in clinical practice to provide efficient and aesthetically-pleasing anchorage. AIM: To evaluate the hardness Vickers hardness and chemical composition of mini-implant titanium alloys from five commercial brands. METHODS: Thirty self-drilling mini-implants, six each from the following commercial brands, were used: Neodent NEO, Morelli MOR, Sin SIN, Conexão CON, and Rocky Mountain RMO. The hardness and chemical composition of the titanium alloys were performed by the Vickers hardness test and energy dispersive X-ray spectroscopy, respectively. RESULTS: Vickers hardness was significantly higher in SIN implants than in NEO, MOR, and CON implants. Similarly, VH was significantly higher in RMO implants than in MOR and NEO ones. In addition, VH was higher in CON implants than in NEO ones. There were no significant differences in the proportions of titanium and aluminum in the mini-implant alloy of the five commercial brands. Conversely, the proportion of vanadium differed significantly between CON and MOR/NEO implants. CONCLUSIONS: Mini-implants of different brands presented distinct properties of hardness and composition of the alloy.

One-step glycerol oxidehydration to acrylic acid on multifunctional zeolite catalysts

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)