Influência do número de refundições da liga Ni-Cr-Mo-Ti sobre as propriedades de próteses metalocerâmicas

A frequently encountered difficulty in oral prosthetics is associated with the loss of metallic alloys during the melting stage of the production of metal-ceramic replacement systems. Remelting such materials could impar their use in oral rehabilitation due to loss in esthetics, as well as in the chemical, physical, electrochemical and mechanical properties. Nowadays, the Ni-Cr-Mo-Ti alloy is widely used in metal-ceramic systems. Manufacturers state that this material can be remelted without significant alterations in its behavior, however little has been established as to the changes in the performance of this alloy after successive remelting, which is common practice in oral prosthetics. Therefore, the objective of this study was to evaluate possible changes in the esthetics and associated properties of metalceramic samples consisting of Ni-Cr-Mo-Ti and dental porcelain. Three to five remelting steps were carried out. The results revealed that Ni-Cr-Mo-Ti can be safely used even after three remelting steps. Further remelting significantly affect the characteristics of the alloys and should not be recommended for the manufacture of metal-ceramic systems

Catálogo de Serviços de TI

As Tecnologias de Informação são responsáveis pelas transformações que vivemos, pois permitiram a construção de um mundo global, quebraram fronteiras, gerando conhecimento de uma forma cada vez mais rápida o que levanta enormes desafios às organizações. Estas transformações originam a necessidade de as organizações procurarem soluções e inovarem o seu modelo de estratégia organizacional, para conseguirem sobreviver e agregarem valor ao negócio. As Tecnologias de Informação são parte integrante nos processos das empresas, levando à necessidade de estarem alinhados com a estratégia de Governance, procurando aumentar a confiabilidade das suas operações e o presente trabalho aborda a adoção das melhores práticas das frameworks orientadas para esta área nomeadamente o COBIT 5, a ITIL V3, introduzindo os conceitos de Governance de TI e Gestão de TI. A Design Science Research foi a metodologia de investigação adotada, pois permite a construção e operacionalização de artefactos para os SI e encontrar uma solução para a construção de um Catálogo de Serviços como fator diferenciador para o negócio. Para a construção de um Catálogo de Serviços, é proposto um método baseado nas melhores práticas para a área dos Sistemas de informação, em que este passa a ser o principal ponto de contacto, permitindo o registo dos pedidos, mas também a definição de tempos de resposta, custos, faturação de serviços e ainda a construção de um repositório de conhecimento. São definidos os processos que se consideram mais relevantes, são propostos artefactos para a construção do catálogo, é efetuada a modelação em BPMN dos processos inerentes ao registo de pedidos, pois desta forma facilita o entendimento, bem como a sua implementação.

Influência das espécies ativas na absorção de intersticiais durante a carbonitretação a plasma do TI

Physical-chemical properties of Ti are sensible to the presence of interstitial elements. In the case of thermochemical treatments plasma assisted, the influence of different active species is not still understood. In order to contribute for such knowledge, this work purposes a study of the role played by the active species atmosphere into the Ar N2 CH4 carbonitriding plasma. It was carried out a plasma diagnostic by OES (Optical Emission Spectroscopy) in the z Ar y N2 x CH4 plasma mixture, in which z, y and x indexes represent gas flow variable from 0 to 4 sccm (cm3/min). The diagnostic presents abrupt variations of emission intensities associated to the species in determined conditions. Therefore, they were selected in order to carry out the chemical treatment and then to investigate their influences. Commercial pure Ti disks were submitted to plasma carbonitriding process using pre-established conditions from the OES measurements while some parameters such as pressure and temperature were maintained constant. The concentration profiles of interstitial elements (C and N atoms) were determined by Resonant Nuclear Reaction Analysis (NRA) resulting in a depth profile plots. The reactions used were 15N(ρ,αγ)12C and 12C(α,α)12C. GIXRD (Grazing Incidence X-Ray Diffraction) analysis was used in order to identify the presence of phases on the surface. Micro-Raman spectroscopy was used in order to qualitatively study the carbon into the TiCxN1 structure. It has been verified which the density species effectively influences more the diffusion of particles into the Ti lattice and characteristics of the layer formed than the gas concentration. High intensity of N2 + (391,4 nm) and CH (387,1 nm) species promotes more diffusion of C and N. It was observed that Hα (656,3 nm) species acts like a catalyzer allowing a deeper diffusion of nitrogen and carbon into the titanium lattice.

Adição de nanopartículas de Ti em matriz de Fe através da deposição por magnetron sputtering

Microalloyed steels constitute a specific class of steel with low amount of carbon and microalloying elements such as Vanadium (V), Niobium (Nb) and Titanium (Ti). The development and application of microalloyed steels and steels in general are limited to the handling of powders with particles of submicron or nanometer dimensions. Therefore, this work presents an alternative in order to construction of microalloyed steels utilizing the deposition by magnetron sputtering technique as a microalloying element addiction in which Ti nanoparticles are dispersed in an iron matrix. The advantage of that technique in relation to the conventional metallurgical processes is the possibility of uniformly disperse the microalloying elements in the iron matrix. It was carried out deposition of Ti onto Fe powder in high CH4, H2, Ar plasma atmosphere, with two deposition times. After the deposition, the iron powder with nanoparticles of Ti dispersed distributed, were compacted and sintered at 1120 ° C in resistive furnace. Characterization techniques utilized in the samples of powder before and after deposition of Ti were Granulometry, Scanning Electron Microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction (DRX). In the case of sintered samples, it was carried out characterization by SEM and Vickers Microhardness assays. The results show which the deposition technique by magnetron sputtering is practicable in the dispersion of particles in iron matrix. The EDX microanalysis detected higher percentages of Ti when the deposition were carried out with the inert gas and when the deposition process was carried out with reactive gas. The presence of titanium in iron matrix was also evidenced by the results of X-ray diffraction peaks that showed shifts in the network matrix. Given these results it can be said that the technique of magnetron sputtering deposition is feasible in the dispersion of nanoparticles of iron matrix in Ti.

Caracterização Microestrutural e Tribocorrosiva de Sistemas Metalocerâmicos Odontológicos do Tipo Ni-Cr/Porcelana E Ni-Cr/Ti/Porcelana

The partial fixed prosthodontics restoration is used to rehabilitate form and function of partial or total compromised teeth, having to remain permanently joined to remainder tooth. The most useful material on prosthodontics is the feldspar porcelain, commercialized as aluminosilicate powders. Dental porcelains are presented with limited mechanical properties to rehabilitate extensive spaces. The association with Ni-Cr metallic systems (metal-ceramic system) allows that the metallic substructure compensates the fragile porcelain nature, preserving the thermal insulation and aesthetics desirable, as well as reducing the possibility of cracking during matication efforts. Cohesive flaws by low mechanical strength connect the metallic substructure to the oral environment, characterized by a electrolytic solution (saliva), by aggressive temperature, pH cyclic changes and mechanical requests. This process results on ionic liberation that could promote allergic or inflammatory responses, and/or clinical degradation of ceramometal system. The aim of this study was to evaluate the presence of an intermediate titanium layer on the microscopic fracture behavior of porcelains on ceramometal systems. Plasma deposition of titanium films result in regular passivating oxide layers which act as barriers to protect the metallic substrate against the hazardous effects of corrosive saliva. Tribocorrosion tests were performed to simulate the oral environment and mechanical stress, making it possible the early detection of crack formation and growth on metal-ceramic systems, which estimate the adherence between the compounds of this system. Plain samples consisting of dental feldspar porcelain deposited either onto metallic substrates or titanium films were fired and characterized by scanning electron microscopy. The result showed that the titanium film improved the adherence of the system compared to conventional metal-ceramic interfaces, thus holding crack propagation

Contributos para um guião de referência para planeamento estratégico de SI/TI na administração pública portuguesa

Dissertação de mest. em Ciências Económicas e Empresariais, Unidade de Ciências Económicas e Empresariais, Univ. do Algarve, Instituto Superior de Economia e Gestão, Univ. Técnica de Lisboa, 1997

Muito além da tecnologia : o impacto dos mecanismos não operacionais na efetividade da governança de TI na administração pública

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Economia, Administração e Contabilidade, Programa de Pós-Graduação em Administração, 2016.

Propuesta de un marco de referencia simplificado para la implementación de un Gobierno de TI en Pymes de Servicios en Colombia

El siguiente trabajo de grado propone un modelo simplificado de gobierno y gestión de las tecnologías de información en las pequeñas y medianas empresas de servicios en Colombia, a partir de la selección e integración de procesos enunciados por algunos de los marcos de trabajo y buenas prácticas de TI que gozan de un reconocimiento generalizado -- En concreto, se han tomado elementos de COBIT 5, ISO/IEC 20000, ITIL V3, CMMI 1.3, PMBOK 5 e ISO/IEC 27000 -- Para el diseño del modelo propuesto se han identificado cada uno de los procesos dispuestos por los diferentes marcos de referencia -- Acto seguido se ha procedido a identificar todos los procesos comunes entre los diferentes modelos de gestión, seleccionando aquellos que se consideran imprescindibles en la generación de valor y evitando aquellos que complejizaran la gestión para el foco de nuestro alcance -- Los procesos identificados y seleccionados fueron agrupados bajo áreas de proceso, las cuales, a su vez, describen subprocesos que tienen un propósito declarado y unas estrategias de gestión y actividades propuestas, que seguidas, satisfacen el objetivo establecido para cada uno de los subprocesos, y en conjunto, suponen un modelo de gobierno de TI adecuado para las pequeñas y medianas empresas prestadoras de servicios en Colombia

Diseño de un proceso de mejoramiento y control de la estructura contable y administrativa de la Fundación Caminando con Jesús y María "Góticas de Amor por Ti"

Bogotá (Colombia): Universidad de La Salle. Facultad de Ciencias Administrativas y Contables. Programa de Administración de Empresas

Autoavaliação da governança de TI em uma autarquia federal com base na gestão de riscos

Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Exatas, Departamento de Ciência da Computação, 2016.