Estudo da adesão de pinos endodônticos modificados superficialmente por plasma de oxigênio

The work presents the effect of plasma treatment when applied in fibers or carbon/glass posts in the adhesion fiber/resin and posts/cement. This has for objective the modification of the surface of the fibers, as well as the wettability of the posts, seeking the improvement of the adhesion and of the connection fiber/resin in the processing of polymeric composites reinforced with the same ones. 120 posts (Reforpost) were used and 30 meters of fibers of carbon and of glass (Fibrex), of the company Angelus. The samples were divided in three groups of 40 specimens: GROUP I - 20 posts of glass fiber and 20 of carbon without treatment to it shapes, GROUP II -20 posts of glass fiber and 20 of carbon treated to it shapes in the surface and GROUP III - 20 posts of glass fiber and 20 of carbon make with fibers in natura after plasma treatment. The plasma treatment was accomplished with oxygen and with temperature in the camera fixed at 200°C, for one hour of exhibition. The posts and the fibers were characterized before and after the treatment. The wettability was measure by pendent drop method, and interface fiber/resin and posts/cement were observed by optical and electronic microscopy. It was observed that both wettability and texture were increased with plasma treatment

Estudo de revestimentos inorgânicos com inibidor de corrosão aplicado na superfície do concreto

The corrosive phenomenon on reinforced concrete structures is one of the most founded pathologies on the coastal area. With the objective to prevent the process development, or even, retard its beginning, it was studied the application of inorganic covering over concrete surfaces, after its cure, as well as, evaluate the efficiency of the covering applied on the concrete in reducing its porosity of concrete preventing the entrance of aggressive agents to preserve the integrity of the existing armor inside it, comparing the result obtained with the body-of-proof reference, that didn´t receive covering protection. On the concrete production it was used Portland Cement CP II 32, coarse aggregate, fine aggregate and water from the local distributive. Two types of covering were used, one resin based of silicon and solvent and other white cement based, selected sands and acrylic resin. The concrete mixture adopted was 1:1,5:2,5 (cement, fine aggregate, coarse aggregate) and 0.50 water/cement ratio. With the concrete on fresh state was made the experiment test to determinate the workability. On the hardened state was made the concrete resistance experiment, absorption of water and electrochemical experiments, through polarization curves. Also was held optical microscopy and Scanning Electron Microscopy experiments to analyze the layer of the covering applied to the concrete surface and the interface between the concrete and the layer. The obtained results shows that the covering applied to the concrete surface didn´t affect the resistance towards compression. On the absorption of water occurred a diminution of the percentage absorbed, improving the concrete development by making it more impermeable towards the entrance of aggressive agents. The electrochemical experiment results confirmed the water absorption results; the body-of-proof covered presented larger protection towards the development of corrosives process and retarded the evolution of the corrosive phenomenon

Efetividade do flúor e da escovação e eficácia dos materiais de colagem ionômero de vidro e resina composta na reversão das microporosidades criadas pelo condicionamento ácido no esmalte dentário

The objectives of this clinical study was to evaluate the use of the toothpaste with fluoride and without fluoride and the daily tooth brushing are effective in the reversion of the dental enamel conditioned by acid. Another objective of this clinical study was to evaluate if the positioning of orthodontic accessories with glass ionomer cement helps in the reversion of the dental enamel conditioned by acid, when compared to composed resin. One hundred and twenty teeth were selected with indication of extraction by orthodontic reasons. The 30 volunteers were divided, randomly, in two groups. A group used toothpaste without fluoride and the other with it. The teeth of the sample were shuffled, in each volunteer. The teeth were conditioned by the 37% orthophosphoric acid. One of the conditioned teeth stayed in the mouth and suffered action of the abrasion for the tooth brushing, in another teeth a stainless steel mesh protection was positioned with glass ionomer cement, in another tooth the screen was glued with composed resin, in a fourth tooth (the control) was only conditioned after the extractions, 60 days later. All the teeth were appraised through DIAGNOdent, MEVA and EDS. In the obtained data it was possible to observe that there were not statistic significant differences in any comparison, even in the group that did not have access to the fluoride in the toothpaste as in the other that had. According with the used methodology, it was possible to observe too that there was not statistic significant differences in any comparison, even in the group that had the stainless steel mesh positioned with glass ionomer cement as in the group that the stainless steel mesh was positioned with composed resin. However, it was observed that there was an improvement in the topography of the enamel in all the teeth. The accomplishment of this study was facilitated due to the participation of the researchers' of the health area (dentistry), materials engineer, physics and chemistry. The researchers were originating from the Federal University of Rio Grande do Norte and of the University of Queensland, in Australia. This interdisciplinary group was decisive in the accomplishment of the study. It can be concluded that the enamel tends to return to its initial aspect, even if the patient does not have access to fluoride. That is probably due the action of the abrasion for the tooth brushing and mastication. In spite of it not being significant, it is suggested that the conditioned enamel was more resistant to the abrasion in the group that had access to fluoride. It was also possible to conclude that the fluoride liberated by the glass ionomer was not enough to provide a significant difference in the enamel conditioned by the acid, when compared with the composed resin, even in the group that did not use fluoride in the toothpaste as in the group that used

Integrating strategic and sustainable design approach for innovation process: a cement case study

Global society and technology have changed the relationships of the market. Quality and cost are not the main aspects of any industrial product. On the other hand, design, innovation and sustainability became significant requirements to company’s competitiveness. In this context, the design approach has shown evolutions, integrating social and environmental aspects beside traditional aspects such as technical and economic. Still, design has been becoming a strategic opportunity for companies, improving their competitiveness and increasing their market share. Thus, this research has analyzed the integration of both the Sustainable Design and Strategic Design Coaching (SDC) method in the making decision activities of companies. A cement company (BQMIL) was assigned as case study, in which the previous results have pointed out the significant hole of those concepts to generate Eco-innovation and Eco-Brand to increase its market share, corroborating the expectative of the design team