Estudo da oxidação superficial de ligas odontológicas de Ni-Cr em plasma pulsado para uso em restaurações metalocerâmicas

Metal ceramic restorations matches aesthetic and strength, and in your making occurs an interface oxide layer, wetting resulting and atomic and ionic interactions resulting between metal, oxide and porcelain. However, frequent clinical fails occurs in this restoration type, because lost homogeneous deposition oxide layer and lost interface bond. Thus, in this study, thought depositate homogeneous oxide films above Ni-Cr samples surfaces polite previously, at plasma oxide environment. Six samples was oxided at 300 and 400ºC at one hour, and two samples was oxided in a comum chamber at 900ºC, and then were characterized: optical microscopic, electronic microscopic, micro hardness, and X ray difratometry. Colors stripes were observed at six samples plasma oxided and a grey surface those comum oxided, thus like: hardness increase, and several oxides from basic metals (Ni-Cr)

Análise estrutural da deformação cenozóica na Bacia de Cumuruxatiba (BA)

The Cumuruxatiba basin is located at the southern coast State of Bahia in northeastern of Brazil. This basin was formed in distensional context, with rifting and subsequent thermal phase during Neocomian to late Cretaceous. At Cenozoic ages, the Abrolhos magmatism occurs in the basin with peaks during the Paleocene and Eocene. In this period, there was a kinematic inversion in the basin represented by folds related to reverse faults. Structural restoration of regional 2D seismic sections revealed that most of the deformation was concentrated at the beginning of the Cenozoic time with the peak at the Lower Eocene. The post-Eocene is marked by a decrease of strain rate to the present. The 3D structural modeling revealed a fold belt (trending EW to NE-SW) accommodating the deformation between the Royal Charlotte and Sulphur Minerva volcanic highs. The volcanic eruptions have caused a differential overburden on the borders of the basin. This acted as the trigger for halokinesis, as demonstrated by physical modeling in literature. Consequently, the deformation tends to be higher in the edges of the basin. The volcanic rocks occur mainly as concordant structures (sills) in the syn-tectonic sediment deposition showing a concomitant deformation. The isopach maps and diagrams of axis orientation of deformation revealed that most of the folds were activated and reactivated at different times during the Cenozoic. The folds exhibit diverse kinematic patterns over time as response to behavior of adjacent volcanic highs. These interpretations allied with information on the petroleum system of the basin are important in mapping the prospects for hydrocarbons

Ícones urbanos na cidade de Natal: arquitetura e desenvolvimento urbano na cidade do sol e mar

Natal has come through major changes in the last 150 years, since the actions of city beautification, in the 19th century, until the present day, when such transformations start to have the objective of including the city in the competition for the attraction of the capital flows and consumption, domestically and in a foreign sense. It is thought that the first initiatives aimed at increasing tourism in Natal occurred in the 1960s, however, it became apparent that only from the 1980s was there a significant increase in tourist activities in Natal and the Metropolitan Region, especially on the east coast of the state of Rio Grande do Norte, leading to an expansion of the labour market, the significant increase of foreign investment, territorial changes of great impact and the production of buildings primarily intended for the hotel industry and second residence for European tourists. Since then, the incentives for tourist activity in the state have been maintained and even increased, based on tourism aimed at natural beauties, local cuisine and events, which transformed the tourist activity in one of the main sources of foreign exchange for the city of Natal. In the early 21st century, the construction of high-rise condominiums, monuments (including the designer ones), such as the Parque da Cidade, designed by Oscar Niemeyer, were already established. Also, shopping centers and, in order to host the World Cup, the new football stadium, the Arena das Dunas, among others, which were aimed at local and foreign consumers, especially European, stood out in the city. It is understood that these new buildings, monuments and also renovations and restorations that were deployed in the city of Natal aimed at constructing a new identity for the city, within the process of capitalist development and urban spectacle. It is considered that the monuments and the iconic buildings are attributes of the cities aimed at selling locations as goods, establishing a new urban environment, a new role as cities, which aimed at seeking greater autonomy from the nation-state. In this research, it was sought to analyze the architectural object, that is, buildings and monuments built or restored in Natal and its relevance to the city marketing promoted by the city itself. It was found that, indeed, such buildings and monuments are inserted in contemporary architectural production as a basis for increasing the competitive nature of Natal. In addition, they reveal a capitalist mode of production, supported by public resources, operating in the production of urban space with a view to repeating the hegemonic model of a competitive city