O impacto do preparo, da cerâmica e do contato oclusal na distribuição de tensões em facetas

Pós-graduação em Odontologia Restauradora - ICT

Resistência de união entre um cimento resinoso e uma cerâmica aluminizada submetida a diferentes tratamentos de superfície

Pós-graduação em Odontologia Restauradora - ICT

Reabilitação protética implantossuportada em região anterior maxilar com utilização de gengiva artificial cerâmica: relato de caso

The osseointegrated implants created a progress in oral rehabilitation. But this rehabilitation may be complicated by anatomical conditions, mainly in maxillary anterior region, where a higher aesthetic is required. The aim of study was to report one case which the use of angled abutments were necessary to allow the correct positioning of the prosthesis and also the prosthetic reconstruction with gingival-colored ceramic to provide best aesthetic result for patient. The aesthetic and functional results provided greater patient satisfaction with her smile. The correct planning is essential to provide to patient the best aesthetic and functional results, being necessary the use of abutments and gingival-colored ceramic to reach better results. Uniterms: dental implantacion, esthetics, mouth rehabilitation.

Avaliação dos preparos da superfície cerâmica para a colagem de acessórios ortodônticos

The purpose of this study was to evaluate the effects of two conditioning methods used to enhance the shear strength of orthodontic brackets bonded to porcelain surfaces. A total of 18 feldspathic specimens were used. The specimens were divided randomly into two groups (n = 9): group free silane, the porcelain specimens were etched with hidrofuoric acid 10% (Acid Gel-Maquira) for 4 minutes followed by adhesive-primer (Transbond XT) and the metallic brackets (Morelli Roth Light .022" x .030") were bonded with a light-cured microfilled resin (Transbond XT Light Cure Orthodontic Adhesive); group silane, the porcelain specimens were etched with hidrofuoric acid 10% (Acid Gel-Maquira) for 4 minutes followed by silane (Silano Ângelus) for 1 minute, adhesive-primer (Transbond XT) and the metallic brackets (Morelli Roth Light .022" x .030") were bonded with a light-cured microfilled resin (Transbond XT Light Cure Orthodontic Adhesive). All specimens were stored in solution of artificial saliva at ambient temperature for 24 hours. The debonding was done with shear strength through a universal testing machine (DL 500-Emic) calibrated with a fixed speed of 1mm/minute. Statical analysis was performed using the Student t test. The results indicated that in the free silane group the mean bond strength was 9,97 MPA, significantly lower than the silane group, that was 12,38 MPa (p < 0,05). The both groups were effective for bonding, although the silane group had the highest bond strength values.

Caracterização e utilização do resíduo de cerâmica vermelha como material pozolânico em matrizes cimentantes

Pós-graduação em Engenharia Civil - FEIS

Lubrificante diluído em água na retificação cilíndrica externa de mergulho em cerâmica avançada

Este trabalho pretende analisar o comportamento da fetificação de cerâmica avançada juntamente com a técnica de MQL. Foram avaliadas variáveis de saída do processo de retificação, tais como comportamento de potência de corte, rugosidade e desgaste do rebolo. Dos resultados de rugosidade obtidos, o MQL feito com lubrificante diluído em água, na proporção de 1 : 1 foi considerado um potencial substituto ao MQL tradicional.

Padronagem visual e cultural japonesa: cerâmica e kimono

Pós-graduação em Artes - IA

Síntese e caracterização da cerâmica de [BaZr0,1Ce0,7Y0,1Yb0,1O3-δ] para uso como eletrólito de Células a Combustível de Cerâmicas Protônicas (PCFCs)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Usinagem do alumínio da classe 6005 com uso de ferramenta cerâmica

The machining process is so much important in the economic world. Many machining parameters have been studied to maximize results, in terms of cost and lifetime. (decrease of cutting tool wear, improved surface finish, among others). The objective of this study is to evaluate the wear of a ceramic tool in the machining of the aluminum alloy 6005 A. The analysis of the wear of the cutting tools is very important due to its big impact on the final finishing of the piece as a whole. The evaluation took place in two stages, first it was done a detailed study of the literature of the whole machining process, where the study of the formation and swarf classification were among the most important steps in this phase. The second step consisted in the machining of the piece of aluminum 6005 A with a ceramic cutting tool constituded of aluminum oxide and magnesium oxide with silicon carbide impregnation. The swarf generated in this process was then photographed with a Zeiss optical microscope and analyzed for its size and shape. Through this comparison it was concluded that the swarf are generated shear swarfs, shaped like a tangled, fragmented and arcs connected, thus classifying the material as medium difficulty machining. Through the image analysis tool it was concluded that the parameter of lower wear was the: Vc = 500m / min, f = 0.10mm / rev and ap = 0.5mm

Torneamento da liga de alumínio da classe 6005 utilizando ferramenta cerâmica

Machining processes are one of the most important manufacturing processes in the modern world. In these processes, there are many elements which will influence in the final result of the machined part. Among them, the tools are the principal factor of the rising cost, because its global influence on the process. In aeronautical industries, this can be more evidenced due the need to machining several alloys, between them, aluminum alloys. These alloys have to demonstrate a specific surface finishing to be used in aircraft's fuselage. This kind of industry is one of the segments which is still rising in Brazil, and they are looking viable alternatives in the manufacturing processes of materials, due the need to produce more and more parts and equipment, with costs increasingly reduced. The purpose of this project is the development of a ceramic with differentiated properties. The ceramics were developed using a pre-sintering at 1200 °C, with posterior sintering at 1600°C, and subjected to dry turning process on aluminum alloy 6005. The characterizations showed that ceramics presented with toughness on the center of 1700 MPa and on the surface of 1950 MPa, density 98,5 ±0,14. g/cm³. Ceramics were grinded and faceted, according to ISO standard 1832, and subjected to turning tests in a ROMI lathe brand, model GL240M, using cutting speeds of 500, 800 and 1000 m/min with different feed rates. The machining results showed low occurrence of flank wear to all cutting speeds, and better surface finishing average values of Ra = 0,4935 μm and Rt = 8,112 μm. In general, it could be seen that the tool presents important potential to machining 6005 alloy, and that the use of correct parameters can decrease and/or eliminate subsequent processes, providing important reductions in costs related to the machining processes

Usinagem do alumínio da classe 6005 com uso de ferramenta cerâmica

The machining process is so much important in the economic world. Many machining parameters have been studied to maximize results, in terms of cost and lifetime. (decrease of cutting tool wear, improved surface finish, among others). The objective of this study is to evaluate the wear of a ceramic tool in the machining of the aluminum alloy 6005 A. The analysis of the wear of the cutting tools is very important due to its big impact on the final finishing of the piece as a whole. The evaluation took place in two stages, first it was done a detailed study of the literature of the whole machining process, where the study of the formation and swarf classification were among the most important steps in this phase. The second step consisted in the machining of the piece of aluminum 6005 A with a ceramic cutting tool constituded of aluminum oxide and magnesium oxide with silicon carbide impregnation. The swarf generated in this process was then photographed with a Zeiss optical microscope and analyzed for its size and shape. Through this comparison it was concluded that the swarf are generated shear swarfs, shaped like a tangled, fragmented and arcs connected, thus classifying the material as medium difficulty machining. Through the image analysis tool it was concluded that the parameter of lower wear was the: Vc = 500m / min, f = 0.10mm / rev and ap = 0.5mm

Torneamento da liga de alumínio da classe 6005 utilizando ferramenta cerâmica

Machining processes are one of the most important manufacturing processes in the modern world. In these processes, there are many elements which will influence in the final result of the machined part. Among them, the tools are the principal factor of the rising cost, because its global influence on the process. In aeronautical industries, this can be more evidenced due the need to machining several alloys, between them, aluminum alloys. These alloys have to demonstrate a specific surface finishing to be used in aircraft's fuselage. This kind of industry is one of the segments which is still rising in Brazil, and they are looking viable alternatives in the manufacturing processes of materials, due the need to produce more and more parts and equipment, with costs increasingly reduced. The purpose of this project is the development of a ceramic with differentiated properties. The ceramics were developed using a pre-sintering at 1200 °C, with posterior sintering at 1600°C, and subjected to dry turning process on aluminum alloy 6005. The characterizations showed that ceramics presented with toughness on the center of 1700 MPa and on the surface of 1950 MPa, density 98,5 ±0,14. g/cm³. Ceramics were grinded and faceted, according to ISO standard 1832, and subjected to turning tests in a ROMI lathe brand, model GL240M, using cutting speeds of 500, 800 and 1000 m/min with different feed rates. The machining results showed low occurrence of flank wear to all cutting speeds, and better surface finishing average values of Ra = 0,4935 μm and Rt = 8,112 μm. In general, it could be seen that the tool presents important potential to machining 6005 alloy, and that the use of correct parameters can decrease and/or eliminate subsequent processes, providing important reductions in costs related to the machining processes

Necrose avascular da cabeça femoral em pacientes HIV positivos: resultados iniciais do tratamento cirúrgico por substituição articular cerâmica-cerâmica

OBJETIVOS: Avaliar os resultados funcionais iniciais e o índice de complicações precoces das artroplastias totais do quadril cerâmica-cerâmica em pacientes que convivem com o HIV e apresentam osteonecrose da cabeça femoral. MÉTODO: Doze pacientes HIV+ com diagnóstico de osteonecrose da cabeça do fêmur incongruente foram avaliados através de critérios clínicos, laboratoriais, pela escala funcional WOMAC antes e após o tratamento com substituição articular. RESULTADOS: Observamos que 83,3% dos indivíduos faziam uso de inibidores de protease, 75% apresentavam dislipidemia e 66,6% síndrome lipodistrófica, a melhora na evolução no escore WOMAC foi estatisticamente significativa para seis e 12 meses de pós-operatório em comparação com o escore pré-operatório e não observamos complicações secundárias a esse procedimento. CONCLUSÃO: A artroplastia total do quadril com implante de cerâmica-cerâmica para o tratamento da necrose avascular do quadril nessa parcela da população é opção cirúrgica adequada, apresenta melhora funcional inicial significativa e baixo índice de complicação precoce.

Pozolanicidade dos resíduos industriais, lã de vidro e lã cerâmica

As fibras cerâmicas se caracterizam por ser um material leve, com alto grau de pureza, baixo armazenamento de calor, baixa condutividade térmica, resistência a choque térmico e alta resistência à corrosão em altas temperaturas. Essas características levam a uma grande procura das indústrias mínero-metalúrgicas e de outros setores para revestimentos de distribuidores, muflas, fornos de aquecimentos, entre outros. Após utilização no processo, por perderem sua capacidade de isolamento, os resíduos gerados precisam de destinação. Esse trabalho enfoca, especificamente, resíduos de lã cerâmica e lã de vidro. Pelo fato de a composição das fibras cerâmicas ser rica em sílica e alumina, efetuou-se uma investigação acerca da atividade pozolânica das mesmas com a cal e o cimento, especificamente CPV ARI, CPII E32 e CPIII 32RS, para avaliação da perspectiva de reciclagem em possível incorporação no concreto.