996 resultados para Superfícies seletivas em frequências


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The aim of this study was to evaluate the effect of the working angle variation of the magnetoestritive ultrasonic (MU) and air polishing devices (APD) on the roughness and wear of dental root. Fifty bovine incisive teeth were used in this study. The proximal surfaces of the teeth were divided in three regions: coronal, median, and an apical. The coronal region was treated with a manual scaler, the apical region was treated with APD or with a MU and the medium region was maintained untreated to serve as a control. The teeth were divided in 11 groups according to the treatment applied: MU-0º; MU-30º; MU-45º; MU-60º; MU-90º; AP-0º; AP-30º; AP-45º; AP-60º; AP-90º; MS: manual scaler. To the statistical analysis, data submitted to the Anova and Tukey's test (p < 0.05). The manual curette promotes less roughness and higher tooth wear in comparison with the both ultrasonic and air polishing devices (p < 0.05). The angles of 45º, 60º and 90º caused higher rate of tooth wear and roughness when the MU was used (p < 0.05), while the angle of 90° caused a higher tooth wear than the angle of 30° when the APD was used (p < 0.05). The working angle variation influenced the tooth wear and roughness promoted by MU, whereas when using APD, the working angle variation influenced only the tooth wear.

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Osseointegration involves a cascade of biological events, which can be accelerated by modifying the micro and/or nanometric topography of dental implant surfaces. Considering that different treatment types modify the titanium surface giving it a more pronounced rough topography, and physicochemical changes that appear to positively influence the osseointegration process, a literature review was made on the main types of surface treatments and their influence on the biological and cellular aspects of osseointegration, with publications dating from 1969 until the present moment. Although the precise role of the implant surface on the osseointegration of dental implants is not completely clear, the specific effects of implant surface on bone regeneration, initial kinetics, and evolution of mechanical properties have shown to be quite promising. Thus, based on dental implant surface modifications, osseointegration can be defined as a process by which rigid asymptomatic fixation of an alloplastic material can be achieved and kept in close contact with bone tissue, being resistant to early and late functional loads. This process can be modulated by an appropriate treatment of the alloplastic material surface.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Introduction: As a new alternative in the complementary treatment lasers teem different systems were employed in the decontamination of dental surfaces implants however, some systems have caused significant changes in its surface. Purpose: Analyze by Scanning Electron Microscopy (SEM) the effects of laser irradiation of Er,Cr: YSGG on different surfaces of titanium. Material and method: Study of 20 titanium discs, and 10 Machined Surface (MS) and 10 surfaces treated with acid (AC). The 10 discs with the same treatment were divided into two groups with five units each, the irradiation was performed in powers of 1 W and 2 W. Result: Showed that the irradiation with 1 W of power resulted in no significant morphological changes in the MS-irradiated compared to non-irradiated surfaces. In MS surfaces, minor changes were observed in the increase of 1000× when compared to non-irradiated surface. With 2 W of power, there were no significant morphological changes in the MS, compared to non-irradiated areas. In AC some changes were observed in the increase of X 1000, showing areas of wear suggestive of treatment and some areas with melting point. Conclusion: Considering the results and the parameters used in this study it was concluded that the Er, Cr: YSGG irradiation can be used for the machined surfaces of implants, but in acid-treated surfaces irradiation parameters should be more controlled.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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This study aims to recognize the Surface Design as specialty hybrid and clarify the relationship between surface and design through projetual creative act and technical. The study shows that there projetual hybridity in the design of the Surface Design and the same occurs in two distinct stages: the creative phase , where the inherent design specialties together for their training , and executive process in which the diversity of technical information and construction procedures to assist the integration of design with other productive areas . Identify the products presented its projected surface condition , based on concepts checked the state of the art Surface Design was an action that enabled the verification of functional, aesthetic and symbolic object concepts . To evaluate this condition are presented six case studies to verify the levels of cooperation and implementation of the specialties of Design in objects that are highlighted by presenting different surfaces. Among the products are: DKR chair, bench Pai João, bench R540, Híbridos table, Facetas table and bench Xique-xique.

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Evaluated statistical equations estimates (based on radiometric fractions) of the hourly diffuse radiation incident on inclined surfaces for the North to 12.85, 22.85 and 32.85°, the climate and geographical conditions of Botucatu, SP. The database was generated from April/1998 to December/2007, with measures in the three tilted surfaces in different periods, but concomitant to the horizontal plane. In the validation of the equations were used indicative statistics MBE (mean absolute error), RMSE (square root mean square error) and index adjustment (d) for three inclinations and conditions of sky coverage. The increased angle of inclination of the surface led to increased scattering of hourly values for the coefficient of atmospheric transmissivity of diffuse radiation for inclined and horizontal surfaces. Estimates of diffuse radiation on the basis of hourly tilted horizontal global radiation occur for quadratic polynomial models, which adjust K'Dβ maximum values of between 0.14 and 0.30 for winter and summer when KTH varies between 0.40 and 0.66, indicating that energy, the highest values of diffuse radiation occur in partly cloudy sky conditions and / or partially open. The increase in atmospheric transmissivity decreases the performance of annual and monthly equations at all inclinations.

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Pós-graduação em Física - IFT

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In this work, the author looks forward to develop a new method capable of incorporate the concepts of the Reliability Theory and Ruin Probability in Deep Foundations, in order to do a better quantification of the uncertainties, which is intrinsic in all geotechnical projects, meanly because we don't know all the properties of the materials that we work with. Using the methodologies of Decourt Quaresma and David Cabral, resistance surfaces have been developed utilizing the data achieved from the Standard Penetration Tests performed in the field of study, in conjecture with the loads defined in the executive project of the piles. The construction of resistance surfaces shows to be a very useful tool for decision making, no matter in which phase it is current on, projecting or execution. The surfaces were developed by Kriging (using the software Surfer® 12), making it easier to visualize the geotechnical profile of the field of study. Comparing the results, the conclusion was that a high safety factor doesn't mean higher security. It is fundamental to consider the loads and resistance of the piles in the whole field, carefully choosing the project methodology responsible to define the diameter and length of the piles

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In this work, the author looks forward to develop a new method capable of incorporate the concepts of the Reliability Theory and Ruin Probability in Deep Foundations, in order to do a better quantification of the uncertainties, which is intrinsic in all geotechnical projects, meanly because we don't know all the properties of the materials that we work with. Using the methodologies of Decourt Quaresma and David Cabral, resistance surfaces have been developed utilizing the data achieved from the Standard Penetration Tests performed in the field of study, in conjecture with the loads defined in the executive project of the piles. The construction of resistance surfaces shows to be a very useful tool for decision making, no matter in which phase it is current on, projecting or execution. The surfaces were developed by Kriging (using the software Surfer® 12), making it easier to visualize the geotechnical profile of the field of study. Comparing the results, the conclusion was that a high safety factor doesn't mean higher security. It is fundamental to consider the loads and resistance of the piles in the whole field, carefully choosing the project methodology responsible to define the diameter and length of the piles

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O artigo apresenta uma reflexão sobre a gestão do processo de projeto paramétrico, com superfícies complexas, baseado em duas experiências realizadas no Instituto de Arquitetura e Urbanismo, da USP de São Carlos, pelo grupo de pesquisa Nomads.usp. SLICE é o resultado parcial de um pavilhão temporário, com superfícies complexas, desenvolvido por meio de projeto paramétrico e técnicas de fabricação digital. Utilizou-se o procedimento de uma pesquisa-ação2 com alunos de graduação e recém-formados em arquitetura, arquitetos do Nomads.usp e a indústria. Os experimentos apontaram para reflexões sobre algumas mudanças na gestão destes processos, para facilitar a viabilidade técnico-construtiva e gerar conhecimento nas áreas de projeto paramétrico, fabricação digital e gestão. O artigo tem caráter exploratório e o desafio é entender e avaliar a gestão do projeto paramétrico em relação a restrição de material, custo de execução e tempo de produção.

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Existem diversas técnicas para caracterização do módulo de elasticidade de madeiras e, dentre as atualmente empregadas, destacam-se aquelas que utilizam as frequências naturais de vibração, por serem técnicas não destrutivas e, portanto, apresentarem resultados que podem ser repetidos e comparados ao longo do tempo. Este trabalho teve como objetivo avaliar a eficácia, dos métodos de ensaios baseados nas frequências naturais de vibração comparando-os aos resultados obtidos na flexão estática na obtenção das propriedades elásticas em peças estruturais de madeira de reflorestamento que são usualmente empregadas na construção civil. Foram avaliadas 24 vigas de Eucalyptus sp. com dimensões nominais (40 x 60 x 2.000 mm) e 14 vigas de Pinus oocarpa com dimensões nominais (45 x 90 x 2.300 mm), ambas sem tratamento; 30 pranchas com dimensões nominais (40 x 240 x 2.010 mm) e 30 pranchas com dimensões nominais (40 x 240 x 3.050 mm), ambas de Pinnus oocarpa e com tratamento preservativo à base de Arseniato de Cobre Cromatado - CCA. Os resultados obtidos apresentaram boa correlação quando comparados aos resultados obtidos pelo método mecânico de flexão estática, especialmente quando empregada a frequência natural de vibração longitudinal. O emprego da frequência longitudinal mostrou-se confiável e prático, portanto recomendada para a determinação do módulo de elasticidade de peças estruturais de madeira. Verificou-se ainda que, empregando a frequência longitudinal, não há necessidade de um suporte específico para os corpos de prova ou calibrações prévias, reduzindo assim o tempo de execução e favorecendo o ensaio de grande quantidade de amostras.