Estudo da distribuição de tensões em inlays cerâmicos: influência da profundidade do preparo cavitário, da utilização de bases cavitárias e da espessura do material cerâmico

Tese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde. Programa de Pós-Graduação em Odontologia.O presente estudo avalia a distribuição de tensões de Von Mises em modelos tridimensionais de pré-molares pelo método dos elementos finitos. Os modelos geométricos foram confeccionados com o programa SolidWorks (Dassault, França) e se diferenciavam pela profundidade da parede pulpar, espessura do material cerâmico e presença de bases cavitárias de resina composta com diferentes módulos de elasticidade. Após a construção, os modelos foram discretizados no programa Ansys Workbench (Swanson Analysis Inc. Houston, PA, EUA), por meio de elementos tetraédricos parabólicos. Todos os constituintes dos modelos foram considerados elásticos, contínuos e isotrópicos. As constantes elásticas aplicadas, selecionadas a partir de estudos publicados, foram o módulo de elasticidade e o coeficiente de Poisson. Os modelos foram engastados nas faces proximais e na base do osso maxilar, e uma carga de 100 N foi aplicada nas vertentes internas das cúspides vestibular e lingual, com uma inclinação de 45 graus. Após a execução das simulações, os diagramas de tensões de Von Mises foram analisados. Foi possível verificar que a profundidade do preparo cavitário, a espessura do material cerâmico e a utilização de bases cavitárias influenciaram na distribuição de tensões nos diferentes modelos estudados. As restaurações com maior espessura de material cerâmico tendem a apresentar uma distribuição de tensões mais favorável, principalmente quando cimentadas diretamente sobre o preparo cavitário, sem a existência de materiais intermediários.The present study applied the finite element method to analyze the Von Mises stress in three-dimensional premolar models. The geometric models were developed using the SolidWorks (Dassault, France) program and presented different pulpal floor depth, thickness of the ceramic material and composite resin bases with different elastic modulus. After construction the models were submitted to discretization through the Ansys Workbench program (Swanson Analysis Incorporation. Houston, PA, USA). Parabolic tetraedrical elements were selected to compose the mesh. All the structures were considered elastic, continuous and isotropic. The elastic modulus and Poisson#s coefficient were selected from published studies. The models were fixed on the proximal surfaces and upper part of the maxillary bone. A load of 100N was applied in the buccal and lingual cusps with an inclination of 45 degrees. After the simulations were performed, the Von Mises diagrams were analyzed, and it was possible to verify that the depth of the cavity floor, the thickness of the ceramic material and the use of composite bases influenced the stress distribution in the different models. Restorations with larger thickness of ceramic material tend to present a more favorable stress distribution, especially when cemented directly over the dental tissues without the existence of intermediate materials

Vibration control in buildings under seismic excitation using optimized tuned mass dampers

Earthquakes can cause vibration problems in many types of structures, generating large displacements. The interstory drift is a design criterion very used in seismic analysis and the structural control is an alternative to reduce these displacements and improve the performance of these structures adapting them to the imposed criteria. TMD is a device widely used due to the simple principle of operation and many successful applications in real life practice. This paper investigates the use of optimized TMD for reduction of maximum horizontal displacement at the top floor and interstory drift of a steel building under seismic excitation considering three scenarios: single TMD at the top floor; MTMD horizontally arranged at the top floor; and MTMD vertically arranged on the structure. By a metaheuristic optimization algorithm, the parameters and positions of the devices are obtained. Three real and one artificial earthquakes are employed in the simulations. The results showed that all proposed scenarios are efficient in reducing top floor response and interstory drift to values below of the interstory drift limits allowed by the standard code consulted. However, Scenario 2 presented the best reduction for the top displacement and interstory drift to the critical floor for the worst earthquake considered

Vibration control in buildings under seismic excitation using optimized tuned mass dampers

Earthquakes can cause vibration problems in many types of structures, generating large displacements. The interstory drift is a design criterion very used in seismic analysis and the structural control is an alternative to reduce these displacements and improve the performance of these structures adapting them to the imposed criteria. TMD is a device widely used due to the simple principle of operation and many successful applications in real life practice. This paper investigates the use of optimized TMD for reduction of maximum horizontal displacement at the top floor and interstory drift of a steel building under seismic excitation considering three scenarios: single TMD at the top floor; MTMD horizontally arranged at the top floor; and MTMD vertically arranged on the structure. By a metaheuristic optimization algorithm, the parameters and positions of the devices are obtained. Three real and one artificial earthquakes are employed in the simulations. The results showed that all proposed scenarios are efficient in reducing top floor response and interstory drift to values below of the interstory drift limits allowed by the standard code consulted. However, Scenario 2 presented the best reduction for the top displacement and interstory drift to the critical floor for the worst earthquake considered

Ao apagar das luzes: a relegada história de Dalva de Oliveira e Dolores Duran

A pesquisa procura em seu levantamento questões que levem a uma reflexão da relação dessas duas mulheres/artistas, representadas por Dolores Duran e Dalva de Oliveira, junto ao público e a sociedade na perspectiva da literatura teórica sobre gênero. Esta pesquisa procurou compreender de que forma ações e produções musicais das cantoras de rádio romperam com os padrões normativos do período, visto que os comportamentos contrários aos modelos impostos eram mal interpretados e marginalizados socialmente dentro do contexto determinante, ocasionando a essas agentes a exclusão do meio social. Ao analisar a história pessoal dessas mulheres inspiradoras, ratificamos o pioneirismo assistido e validado na história do rádio nacional, na música e cultura. Diante disso, as trajetórias de sucesso e narrativas cristalizadas por preconceitos, silenciamento, engendrados na sociedade, família ou relacionamentos amorosos permitem certa inferência, baseada em indícios, sinais e detalhes, nos quais oportunizam reconstruir personalidades, individualidades e realidades. Nota-se que as cantoras aqui abordadas trazem características transgressoras e permanências em relação a representações de gêneros. A luta pelo livre arbítrio e aspirações profissionais teve por condutor a paixão pela música, esse ser invisível, expressão poderosa da máxima revolução dos costumes, relação social, de gênero e poder

Locust bean gum hydrogels are bioadhesive and improve indole-3-carbinol cutaneous permeation: influence of the polysaccharide concentration

The locust bean gum (LBG) is a polysaccharide with thickening, stabilizing and gelling properties and it has been used in the preparation of pharmaceutical formulations. Hydrogels (HGs) are obtained from natural or synthetic materials that present interesting properties for skin application. This study aimed to develop HGs from LBG using indole-3-carbinol (I3C) as an asset model for cutaneous application. HGs were prepared by dispersing LBG (2%, 3% and 4% w/v) directly in cold water. The formulations showed content close to 0.5 mg/g (HPLC) and pH ranging from 7.25 to 7.41 (potentiometry). The spreadability factor (parallel plate method) was inversely proportional to LBG concentration. The rheological evaluation (rotational viscometer) demonstrated a non-Newtonian pseudoplastic flow behavior (Ostwald De Weale model), which is interesting for cutaneous application. The HET-CAM evaluation showed the non-irritating characteristic of the formulations. The bioadhesive potential demonstrated bioadhesion in a concentration-dependent manner. Permeation in human skin using Franz cells showed that the highest LBG concentration improved the skin distribution profile with greater I3C amounts in the viable skin layers. The present study demonstrated the feasibility of preparing HGs with LBG and the formulation with the highest polymer concentration was the most promising to transport active ingredients through the skin

IMPLANTAÇÃO DE SISTEMA DE INFORMAÇÕES SOBRE FAUNA NAS UNIDADES DE CONSERVAÇÃO DO ESTADO DE SÃO PAULO (NOTA PRÉVIA)

Para registrar as informações existentes sobre a fauna nas Unidades de Conservação do estado de São Paulo foi elaborado um sistema informatizado com parâmetros de: taxonomia, localidade, status, distribuição geográfica e referências bibliográficas de cada espécie, de forma a permitir fácil acesso e uso das informações catalogadas

Amphibia, Anura, Hylidae, Hypsiboas buriti (Caramaschi and Cruz, 1999): distribution update and map

We present a new locality record for Hypsiboas buriti, and review the previous records. The species is found associated to permanent ponds at open physiognomies on the top of high plateaus (over 900 m a.s.l.) in Central Brazil

Methodology to minimize the dynamic response of tall buildings under wind load controlled through semi-active magneto-rheological dampers

This paper proposes a methodology to evaluate and optimize the dynamic response of tall buildings under wind loading, controlled through semi-active Magneto-Rheological dampers (MR dampers). For this, a tall building, modeled as a 2D frame, is taken as case study and three structural control configurations are proposed. The original structural configuration of the building is the first configuration analyzed, called Uncontrolled Original (C1). In the second configuration, called Uncontrolled Optimized (C2), the fundamental frequency of the building is optimized via PSO algorithm as a function of its mass. Then, in the third configuration, Controlled Optimized (C3), a set of MR dampers with behavior formulated via the modified Bouc-Wen rheological model and controlled through the Linear Quadratic Regulator associated with the Clipped Optimal control strategy (LQR-CO) is applied to the structure. Finally, the dynamic response of the three scenarios under wind action is analyzed and compared to performance criteria established in the literature. The results demonstrate that the C3 configuration is the only one able of satisfying all the established performance criteria, proving that the proposed methodology y that combines structural optimization with MR dampers is a powerful tool for vibration control

Native foods from Brazilian biodiversity as a source of bioactive compounds

AbstractThe interest in South American native plant species has been growing in recent years due to their health benefits. Brazil is one of the world's mega-diverse locations with over 40,000 different plant species representing 20% of the world's flora. The country was visited in the 19th century by European travelers and naturalists, who described the use of native plant species as food. In this study, data on 67 species was recovered from historical documents and bibliographies. Several of the recorded species show potential as functional food in laboratory studies. Other species are unknown or not yet submitted to any study, in order to verify their health benefits