Ultrasonics
Mostrando 13-24 de 26 artigos, teses e dissertações.
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13. Método de otimização topológica aplicado ao projeto de sonotrodos para transdutores piezelétricos. / Topology optimization method applied to the design of transducers sonotrodos piezoelectric.
This work aims at the development of a method based on Topology Optimization to design a mechanical structure, called sonotrode, which is a device usually connected to a high power piezoelectric transducer (mechanical device capable of converting electric energy into mechanical displacement or vice-versa). A sonotrode transmits mechanical vibrations of a pie
Publicado em: 2008
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14. Influência do ultra-som na resistência à abrasão e na rugosidade de superfície dos cimentos de ionômero de vidro submetidos à escovação / Influence of the ultrasound in the abrasion resistance and in superficial roughness of the glass ionomer cements submitted to toothbrush
The purpose of this work was to evaluate abrasion resistance, by means of weight loss, and surface roughness (SR) of GIC, using ultrasonic excitation as a command set. The materials tested were Fuji II LC and Fuji IX (GC Corporation), Ketac Molar (3M ESPE), Resiglass and Bioglass (Biodinâmica), Vitro Fil LC, Vitro Molar and Vitro Fil (DFL). Twenty specimens
Publicado em: 2007
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15. "Estudo da influência de instrumentos e técnicas alternativas de preparo cavitário na resistência de união de sistema adesivos à dentina" / Study of the influence of alternative tools and techniques of cavity preparation on teh bond strength of adhesive system to dentin
The current trend toward minimal invasive dentistry has introduced alternative cavity preparation techniques. However, these technologies should not only fulfill the requirements of a conservative philosophy, but also prepare the cavity walls for the subsequent bonding restoration. The purpose of this study was to assess the null hypotheses that: (1) both co
Publicado em: 2007
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16. Avaliação da influência do ultra-som em cimentos de ionômero de vidro na adesão à dentina e nas características dentinárias / Evaluation of ultrasound influence on glass ionomer cement (GIC) regarding its adhesion to dentin and the clinical dentin characteristics
Avaliou-se diferentes formas de aplicação do ultra-som (US) sobre a microtração de CIVs (Ketac Molar Aplicap, Ketac Molar Easymix e Fui IX GP) à dentina; e o potencial clínico de restaurações de CIV (Ketac Molar) com US remineralizarem a dentina e seu efeito sobre a flora bacteriana por meio PCR em tempo real, após período de três meses. Na parte
Publicado em: 2007
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17. Avaliação de parâmetros ultra-sônicos utilizados na caracterização de tecidos ósseos / Assessment of Ultrasonics Parameters Utility in Customization of Bone Tissues.
A transmissão do ultra-som no organismo humano tem sido objeto de estudos a várias décadas, com a finalidade de promover diagnóstico. Recentemente tem sido usada para avaliar a densidade óssea e poder diagnosticar precocemente o aparecimento da osteoporose e prever o risco de fratura. Nesse trabalho foi desenvolvido um sistema capaz de gerar, receber e
Publicado em: 2006
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18. Estudo e avaliação mecânica das juntas soldadas por ultra-som de policarbonato e poli (metacrilato de metila). / Study and avaliation mechanics of join welding by ultrasound of polycarbonate and poli(metacrilate of metila, PMMA).
Nesta pesquisa estudou-se a soldagem de materiais poliméricos por ultra-som, sendo estes, policarbonato (PC) e poli(metacrilato de metila, PMMA. As soldagens foram obtidas através do equipamento especifico para soldagem Soldadoras Integradas, série 900IW, empresa BRANSON Ultrasonics Corporation. Onde detalhamos alguns aspectos do equipamento: mecanismo de
Publicado em: 2005
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19. Influencia da vibração na permeabilidade absoluta de meios porosos saturados com agua / Influence of the vibration on the absolute permeability of porous media satured with water
This work verifies experimentally the effects of the mechanical vibration on the absolute permeability of saturated porous media upon which a uniform flow is simultaneously imposed. After finding a driving range within which indirect effects of the vibration are excluded, such as those resulting from ultrasonic heating and mechanical disintegration of the ro
Publicado em: 2004
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20. Avaliação da superfície radicular após instrumentação manual, ultra-sônica e ultra-sônica seguida de instrumentação manual utilizando dentes mineralizados e desmineralizados / Evalution of root surface after manual and ultra-sonic instrumentation, following by a manual instumentation, utilizing mineralized and desmineralized teeth
The present work aimed at evaluating the effect of root treatment by instrumentation of not only mineralized teeth with curettes, ultra-sonics (US) and US followed by curettes, but also of teeth intermediately demineralized in combined instrumentations, by using citric acid and tetracycline. The dental surfaces were analysed on SEM by a unique examiner, bein
Publicado em: 2003
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21. Caracterização de vidros e vitro-cerâmicas com composição 2Na2O1CaO3SiO2 / Characterization of glasses and glass-ceramics with composition 2Na2O1CaO3SiO2
Glass with composition 2Na2O1CaO3SiO2, undergoes homogeneous crystal nucleation between 450 and 56OoC. The nuclei are essentially spherical and presumable have the same composition as the glass matrix. Measuriments of density, X-ray diffraction, thermal analysis by differential scanning calorimetry (DSC), ultrasonics by pulse-echo method, optical absorption,
Publicado em: 1990
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22. ULTRASONICS IN CLINICAL DIAGNOSIS
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23. Diagnostic Ultrasonics: Principles and Uses of Instruments
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24. Left atrial myxomas in childhood: Presentation with emboli—diagnosis by ultrasonics
Three children with left atrial myxomas are described. All suffered major arterial occlusion with consequent permanent morbidity before the diagnosis was made and the tumour removed. Each child had had previous small embolic phenomena. In two, the diagnosis was made by ultrasound. In any child who has had an arterial embolus without obvious cause, a left atr