Sismicidade e correlação com feições geológicas: o caso do lineamento Pernambuco e seu entorno

This thesis presents and discusses the results of the various seismic areas in the State of Pernambuco, with the aim of having a vision of regional seismicity and its causes. To the papers published in journals were added two new original works submitted to international journals, dealing with seismic areas located in the counties of São Caetano, Cupira, and Agrestina. All seismic areas mentioned in this thesis are located on the Pernambuco Lineament and its surroundings (both in branches or single faults within 40 km of it). The Pernambuco Lineament is a Neoproterozoic shear zone of continental-scale that deformed the Borborema Province, and presents as branches, shear zones with NE-SW direction. The new submitted papers are from the analysis of data collected by three local networks of stations that operated in the following areas: network SO07 (seismicity in the district of Santa Luzia - São Caetano, 2007), network BM10 (data from seismic areas of Serra Verde ( Cupira) and Barra do Chata (Agrestina), in 2010), network SO10 (seismicity near the urban center of São Caetano in 2010). These data were used for determining the hypocenters and focal mechanisms in order to discuss the relationship between the seismicity and geological features of the area. The new mechanisms obtained, as well as the previously published allowed the determination of the direction of the average stress in the region. The direction of stress in the region involving the various seismic areas, now or previously studied, is quite stable and approximate EW direction (SHmax). The correlation between seismicity and geological features is observed on the lineament and north of it. In the south (Cupira and Agrestina), in seismic areas nearby shear zones NE-SW, there is no correlation and seismogenic EW normal faults are active and its motion is compatible with regional stresses. It is probable that these active faults are more recent than the Neoproterozoic, probably of the Cretaceous period, when the last great movement of the Pernambuco Lineament occurred

Espectros fractais em sistemas nanoestruturados e cristais fotônicos

The study of the elementary excitations such as photons, phonons, plasmons, polaritons, polarons, excitons and magnons, in crystalline solids and nanostructures systems are nowdays important active field for research works in solid state physics as well as in statistical physics. With this aim in mind, this work has two distinct parts. In the first one, we investigate the propagation of excitons polaritons in nanostructured periodic and quasiperiodic multilayers, from the description of the behavior for bulk and surface modes in their individual constituents. Through analytical, as well as computational numerical calculation, we obtain the spectra for both surface and bulk exciton-polaritons modes in the superstructures. Besides, we investigate also how the quasiperiodicity modifies the band structure related to the periodic case, stressing their amazing self-similar behavior leaving to their fractal/multifractal aspects. Afterwards, we present our results related to the so-called photonic crystals, the eletromagnetic analogue of the electronic crystalline structure. We consider periodic and quasiperiodic structures, in which one of their component presents a negative refractive index. This unusual optic characteristic is obtained when the electric permissivity and the magnetic permeability µ are both negatives for the same range of angular frequency ω of the incident wave. The given curves show how the transmission of the photon waves is modified, with a striking self-similar profile. Moreover, we analyze the modification of the usual Planck´s thermal spectrum when we use a quasiperiodic fotonic superlattice as a filter.

Iinterpretação conjunta de dados de GPR e medidas de permeabilidade sobre um análogo de reservatório siliciclástico falhado na bacia de Tucano, no NE do Brasil

It is presented an integrated geophysical investigation of the spatial distribution of faults and deformation bands (DB´s) in a faulted siliciclastic reservoir analogue, located in Tucano Basin, Bahia State, northeastern Brazil. Ground Penetrating Radar (GPR) and permeability measurements allowed the analysis of the influence of DB´s in the rock permeability and porosity. GPR data were processed using a suitable flow parametrization in order to highlight discontinuities in sedimentary layers. The obtained images allowed the subsurface detection of DB´s presenting displacements greater that 10 cm. A good correlation was verified between DB´s detected by GPR and those observed in surface, the latter identified using conventional structural methods. After some adaptations in the minipermeameter in order to increase measurement precision, two approaches to measure permeabilities were tested: in situ and in collected cores. The former approach provided better results than the latter and consisted of scratching the outcrop surface, followed by direct measurements on outcrop rocks. The measured permeability profiles allowed to characterize the spatial transition from DB´s to undeformed rock; variation of up to three orders of magnitude were detected. The permeability profiles also presented quasi-periodic patterns, associated with textural and granulometric changes, possibly associated to depositional cycles. Integrated interpretation of the geological, geophysical and core data, provided the subsurface identification of an increase in the DB´s number associated with a sedimentary layer presenting granulometric decrease at depths greater than 8 m. An associated sharp decrease in permeability was also measured in cores from boreholes. The obtained results reveal that radagrams, besides providing high resolution images, allowing the detection of small structures (> 10 cm), also presented a correlation with the permeability data. In this way, GPR data may be used to build upscaling laws, bridging the gap between outcrop and seismic data sets, which may result in better models for faulted reservoirs

Feira livre de Macaíba/RN : um estudo das modificações na dinâmica socioespacial (1960/2006)

The objective of the current piece of research is to reflect upon the diverse changes that have occurred in the social and spatial dynamics of the Macaíba fair in the period between 1960 and 2006. During the second half of the 19th century, Macaíba had in the commerce one of this principle economic base a contribution for which the city became one of the main commercial warehouses of the East coast of the Rio Grande do Norte region. This helped lead to the growth of Macaíba s fair, which proved to be one of the most important existing in the state until the 1970 s. In the last two decades of the 20th century, certain elements represented challenges to the fair at Macaíba. These challenges stimulated substantial changes in the fair s dynamics which include the growth and expansion of the commercial and service sector, primarily though supermarkets; consolidation among the commercial and distribution networks, represented by the Central Office of Supply of the Rio Grande do Norte S/A (Ceasa/RN), by the wholesale and refrigeration companies; and the modernization of transportation methods, which permitted an expanded reach for these networks. Even with all these changes, the fair continues to be one of the strongest aspects of the city being the center of resistance against the surge of new forms of commerce and consumption in the city (notable the supermarkets) and the diffusion of other aspects of globalization. The fair has economic importance, as it offers a popular marketplace for the commercialization of very different products and a means for supplying goods to the residents of the city and the rural communities of Macaíba and the surrounding municipalities; and socio-cultural importance in that the fair is a place where popular tradition is expressed, a place where a great number of parallel activities occur, a place for meeting again and again, of conversations, of manifestations of culture and art, and of socialization in all of its dimensions

A relação urbano-rural no contexto da metrópole: um enfoque nos assentamentos rurais da RMN

The work however presented try to make an analysis of the relation urban-agricultural in the context of the process of metropolization of Natal. On the basis of this approach searched to argue the estruturation of the Brazilian urban space and the relation with the agricultural one, evidencing an academic debate little contemplated, in view of that the space transformations guided by Brazilian industrialization had earned as endorsement a mere urban direction, fact that neglected factors more complex than they for the urban-agricultural relation in the context of the urbanization and, more recently, of the metropolization. Another important factor in the construction of the work was the contextualization of the urbanization of the Rio Grande do Norte, as well as of the metropolization of Natal, where if the significant presence of an agricultural reality made an analysis of the configuration metropolitan in the present time displaying that also remains and reproduces the metropolis, fact that conditions and justifies the treatment of the reality metropolitan for the bias of the urban-agricultural relation. The approach of this relation was directed for the agricultural nestings of the Region Metropolitan of Natal (RMN), understood as fragments agricultural in the context of the metropolis, in view of that a tenuous correspondence of these nestings with the metropolis in the direction of its integration was observed. As methodology one used bibliographical survey in periodic and books and collected secondary data-collecting next to the IBGE and to the INCRA and still were directed a field research where interviews next to the seated ones had been carried through. In this direction, one evidenced that the metropolization also absorbs and even though it reproduces the ruralidade that if verifies in the RMN finishing for mining the idea of an urban one that it excludes the agricultural one. In the case of the RMN, we have agricultural and the urban one exactly if conforming in one space that is metropolitan