The electrochemical behaviour of Ti-13Nb-13Zr alloy in various solutions

The electrochemical behaviour of a near-beta Ti-13Nb-13Zr alloy for the application as implants was investigated in various solutions. The electrolytes used were 0.9 wt% NaCl solution, Hanks` solution and a culture medium known as minimum essential medium (MEM) composed of salts, vitamins and amino acids, all at 37 degrees C. The electrochemical behaviour was investigated by the following electrochemical techniques: open circuit potential measurements as a function of time, electrochemical impedance spectroscopy (EIS) and determination of polarisation curves. The obtained results showed that the Ti alloy was passive in all electrolytes. The EIS results were analysed using an equivalent electrical circuit representing a duplex structure oxide layer, composed of an inner barrier layer, mainly responsible for the alloy corrosion resistance, and an outer and porous layer that has been associated to osteointegration ability. The properties of both layers were dependent on the electrolyte used. The results suggested that the thickest porous layer is formed in the MEM solution whereas the impedance of the barrier layer formed in this solution was the lowest among the electrolytes used. The polarisation curves showed a current increase at potentials around 1300 mV versus saturated calomel electrode (SCE), and this increase was also dependent on the electrolyte used. The highest increase in current density was also associated to the MEM solution suggesting that this is the most aggressive electrolyte to the Ti alloy among the three tested solutions.

Effect of Ti and C additions on structural and magnetic properties of (Pr,Nd)-Fe-B nanocrystalline magnetic materials

Effects of titanium carbide (TiC) addition on structural and magnetic properties of isotropic (Pr,Nd)-Fe-B nanocrystalline magnetic materials have been investigated. In this work, we investigate the effect of TiC addition on a (Pr,Nd)-poor and B-rich composition, as well as on a B-poor and (Nd, Pr)-rich composition. Rapidly solidified (Pr, Nd)-Fe-B alloys were prepared by melt-spinning. The compositions studied were (Pr(1-x)Nd(x))(4)Fe(78)B(18) (x = 0, 0.5, and 1) with addition of 3 at% TiC. Unlike the (Pr(x)Nd(1-x))(9.5)Fe(84.5)B(6) materials that present excellent values for coercive. field and energy product, the (Pr,Nd)-poor and B-rich composition alloys with TiC addition present lower values. Rietveld analysis of X-ray data and Mossbauer spectroscopy revealed that samples are predominantly composed of Fe(3)B and alpha-Fe. For the RE-rich compositions (Pr(x)Nd(1-x))(9.5)Fe(84.5)B(6) (x = 0.1, 0.25, 0.5, 0.75, and 1) with the addition of 3 at% TiC, the highest coercive field and energy product (8.4 kOe and 14.4 MGOe, respectively) were obtained for the composition Pr(9.5)Fe(84.5)B(6). (c) 2008 Elsevier B.V. All rights reserved.

Oxidation of toluene in waste gas streams using mesoporous Ti-hexagonal mesoporous silica

Various mesoporous catalysts with titanium loadings between 0.5 and 4 Ti wt. % and surface areas between 600 and 1,600 m(2)/g were synthesized using the molecular designed dispersion technique. These catalysts were tested using toluene oxidation in a fixed bed reactor at temperatures between 300 and 550degreesC. The reaction products were found to be CO2 and CO with selectivity towards CO2 above 80% for all catalysts. The catalytic activity of the catalysts increases with titanium loading. The total conversion at 550degreesC was not affected by the textural porosity, but increased textural porosity did significantly reduce the ignition temperature by up to 50degreesC. The Thiele modulus was calculated to be much less than one for all these materials indicating that the reaction rate is not diffusion, limited.

Application of Ti/RuO(2)-Ta(2)O(5) electrodes in the electrooxidation of ethanol and derivants: Reactivity versus electrocatalytic efficiency

The influence of the preparation method on the performance of RuO(2)-Ta(2)O(5) electrodes was evaluated toward the ethanol oxidation reaction (EOR). Freshly prepared RuO(2)-Ta(2)O(5) thin films containing between 30 and 80 at.% Ru were prepared by two different methods: the modified Pechini-Adams method (DPP) and standard thermal decomposition (STD). Electrochemical investigation of the electrode containing RuO(2)-Ta(2)O(5) thin films was conducted as a function of electrode composition in a 0.5-mol dm(-3) H(2)SO(4) solution, in the presence and absence of ethanol and its derivants (acetaldehyde and acetic acid). At a low ethanol concentration (5 mmol dm(-3)), ethanol oxidation leads to high yields of acetic acid and CO(2). On the other hand, an increase in ethanol concentration (15-1000 mmol dm(-3)) favors acetaldehyde formation, so acetic acid and CO(2) production is hindered, in this case. Electrodes prepared by DPP provide higher current efficiency than STD electrodes for all the investigated ethanol concentrations. This may be explained by the increase in electrode area obtained with the DPP preparation method compared with STD. (c) 2008 Elsevier Ltd. All rights reserved.

Effect of argon purity on mechanical properties, microstructure and fracture mode of commercially pure (cp) Ti and Ti-6Al-4V alloys for ceramometal dental prostheses

Provision of an inert gas atmosphere with high-purity argon gas is recommended for preventing titanium castings from contamination although the effects of the level of argon purity on the mechanical properties and the clinical performance of Ti castings have not yet been investigated. The purpose of this study was to evaluate the effect of argon purity on the mechanical properties and microstructure of commercially pure (cp) Ti and Ti-6Al-4V alloys. The castings were made using either high-purity and/or industrial argon gas. The ultimate tensile strength (UTS), proportional limit (PL), elongation (EL) and microhardness (VHN) at different depths were evaluated. The microstructure of the alloys was also revealed and the fracture mode was analyzed by scanning electron microscopy. The data from the mechanical tests and hardness were subjected to a two-and three-way ANOVA and Tukey`s test (alpha = 0.05). The mean values of mechanical properties were not affected by the argon gas purity. Higher UTS, PL and VHN, and lower EL were observed for Ti-6Al-4V. The microhardness was not influenced by the argon gas purity. The industrial argon gas can be used to cast cp Ti and Ti-6Al-4V.

Modelo de gest??o do ambiente de TI aplicado ao IBGE

A arquitetura de inform??tica do IBGE busca refletir a evolu????o das Tecnologias da Informa????o e de Comunica????o (TIC) e vem sendo modificada ao longo dos anos, de maneira a manter - se um equil??brio entre os anseios e diretrizes institucionais e governamentais. A partir do aprendizado e do sucesso obtidos no Censo Demogr??fico 2010, o IBGE inova agora na forma de administrar sua ??rea de TIC, baseado em software especialista adquirido.O IBGE se beneficia da administra????o dos bens de inform??tica, da responsabilidade sobre contratos, da gest??o do patrim??nio, do uso otimizado dos softwares comerciais, da agilidade de obten????o de informa????es sobre o parque computacional instalado, do monitoramento on-line dos servi??os oferecidos pela TI, da economia de gastos com viagens para suporte t??cnico dentro dos estados e entre os mesmos, da reeduca????o de funcion??rios quanto ao uso de tecnologias, da forma organizada e planejada de trabalho e, portanto, da gest??o p??blica das TIC

M??dulo 1- plano diretor de TI: curso elabora????o do Plano Diretor de Tecnologia da Informa????o (PDTI)

Esse documento trata de: Plano Diretor de TI; Fase de prepara????o do PDTI; Aprovar o Plano de Trabalho do PDTI

M??dulo 2 - fase de diagn??stico: avaliando o uso e a gest??o da TI: curso elabora????o do Plano Diretor de Tecnologia da Informa????o (PDTI)

Esse documento trata de: fase de diagn??stico; os resultados do Planejamento de TI anterior; o Relat??rio de Resultados do Planejamento de TI anterior; o Referencial Estrat??gico da ??rea de TI; a Organiza????o da TI; an??lise SWOT da TI

M??dulo 1 - planejamento das contrata????es de TI na APF e documento de oficializa????o da demanda: curso planejamento da contrata????o de TI (PCTI)

Esse documento trata de: Raz??es para contratar servi??os de TI; Fundamentos legais da contrata????o de Solu????es de TI; Contrata????o de servi??os de TI na APF: O estado da arte; No????es de Planejamento; Planejamento de TI; Rela????o entre planejamento e contrata????o; Modelo de Contrata????o de TI na vis??o da SLTI/MP; IN 04/2008 x IN 04/2010; Instru????o Normativa n?? 04/2010 - Vis??o Geral; Guia Pr??tico para Contrata????o de solu????es de TI; Quadro Referencial Normativo; Planejamento da Contrata????o de Tecnologia da Informa????o; O Documento de Oficializa????o da Demanda ??? DOD; Equipe de Planejamento da Contrata????o

M??dulo 2 - an??lise de viabilidade da contrata????o e plano de sustenta????o: curso planejamento da contrata????o de TI (PCTI)

Esse documento trata de: An??lise de Viabilidade da Contrata????o; Requisitos do Demandante; Requisitos Tecnol??gicos; Requisitos adicionais; Avalia????o das necessidades de adequa????o do ambiente do ??rg??o; Plano de Sustenta????o; Prazo das contrata????es p??blicas; Recursos materiais e humanos necess??rios ?? continuidade do neg??cio; Continuidade do fornecimento da Solu????o em caso de interrup????o contratual; Transi????o contratual e encerramento do contrato; Estrat??gia de independ??ncia em rela????o ?? contratada

M??dulo 3 - estrat??gia da contrata????o e an??lise de riscos: curso planejamento da contrata????o de TI (PCTI)

Esse documento trata de: estrat??gia da contrata????o e an??lise de riscos; estrat??gia da contrata????o; indica????o dos termos contratuais; or??amento detalhado; termos de compromisso e de ci??ncia; crit??rios de julgamento das propostas; evolu????o do direito de prefer??ncia nas contrata????es de TI; licita????es do tipo t??cnica e pre??o; an??lise de riscos; conceito de risco; riscos no processo de sele????o do fornecedor e na gest??o contratual; riscos de que a solu????o de TI n??o atenda ??s necessidades; probabilidades e danos

M??dulo 4 - termo de refer??ncia: curso Planejamento da Contrata????o de TI (PCTI)

Esse documento trata de: termo de refer??ncia; fundamentos legais do termo de refer??ncia; quem ?? respons??vel pela elabora????o do Termo de Refer??ncia; conte??do do Termo de Refer??ncia; parcelamento da contrata????o; termo de Refer??ncia para dispensa, inexigibilidade e ades??o a ata de registro de pre??os; consulta e audi??ncia p??blica; encerramento da fase de planejamento da contrata????o

Planejamento da contrata????o de TI (PCTI)

Esse documento trata de: oficializa????o da demanda; an??lise de viabilidade da contrata????o;plano de sustenta????o;estrat??gia da contrata????o;an??lise de riscos;elabora????o do Termo de Refer??ncia

M??dulo 1 - contextualiza????o e planejamento das contrata????es de TI: curso sele????o de fornecedores de TI (SFTI)

Esse documento trata de: solu????es de Tecnologia da Informa????o nos ??rg??os p??blicos; fundamentos legais da sele????o de fornecedores de TI na APF; rela????o entre as ??reas de neg??cio, administrativa e de tecnologia da informa????o; conex??es com o PDTI e PCTI; vis??o geral do processo; gest??o or??ament??ria; c??rculo or??ament??rio; etapas da despesa or??ament??ria;despesas com TI

M??dulo 2 - conceitos, princ??pios e boas pr??ticas da licita????o p??blica aplicadas ?? SFTI: curso sele????o de fornecedores de TI (SFTI)

Esse documento trata de: conceito de licita????o p??blica e princ??pios; finalidades; princ??pios b??sicos; modalidades de licita????o; tipos de Licita????o; preg??o; bens e servi??os comuns; sistema de registro de pre??os; ades??o ao registro de pre??o (O Carona); inten????o ao registro de pre??o - Decreto N?? 7892/13; contrata????o direta; fases da licita????o; or??amento estimado; pre??o m??ximo; consulta ou audi??ncia p??blica; comiss??o de licita????o e pregoeiro; questionamentos, impugna????es e controle social; proibi????o de Participar; boas pr??ticas de licita????o; projeto b??sico e Termo de Refer??ncia; edital e Termo de Refer??ncia; prazos do ato convocat??rio; impugna????es ao edital; boas pr??ticas de licita????o