Análise wavelet em curvas de luz estelares de sistemas binários da missão espacial CoRoT

Binary systems are key environments to study the fundamental properties of stars. In this work, we analyze 99 binary systems identified by the CoRoT space mission. From the study of the phase diagrams of these systems, our sample is divided into three groups: those whose systems are characterized by the variability relative to the binary eclipses; those presenting strong modulations probably due to the presence of stellar spots on the surface of star; and those whose systems have variability associated with the expansion and contraction of the surface layers. For eclipsing binary stars, phase diagrams are used to estimate the classification in regard to their morphology, based on the study of equipotential surfaces. In this context, to determine the rotation period, and to identify the presence of active regions, and to investigate if the star exhibits or not differential rotation and study stellar pulsation, we apply the wavelet procedure. The wavelet transform has been used as a powerful tool in the treatment of a large number of problems in astrophysics. Through the wavelet transform, one can perform an analysis in time-frequency light curves rich in details that contribute significantly to the study of phenomena associated with the rotation, the magnetic activity and stellar pulsations. In this work, we apply Morlet wavelet (6th order), which offers high time and frequency resolution and obtain local (energy distribution of the signal) and global (time integration of local map) wavelet power spectra. Using the wavelet analysis, we identify thirteen systems with periodicities related to the rotational modulation, besides the beating pattern signature in the local wavelet map of five pulsating stars over the entire time span.

Análise wavelet em curvas de luz estelares de sistemas binários da missão espacial CoRoT

Binary systems are key environments to study the fundamental properties of stars. In this work, we analyze 99 binary systems identified by the CoRoT space mission. From the study of the phase diagrams of these systems, our sample is divided into three groups: those whose systems are characterized by the variability relative to the binary eclipses; those presenting strong modulations probably due to the presence of stellar spots on the surface of star; and those whose systems have variability associated with the expansion and contraction of the surface layers. For eclipsing binary stars, phase diagrams are used to estimate the classification in regard to their morphology, based on the study of equipotential surfaces. In this context, to determine the rotation period, and to identify the presence of active regions, and to investigate if the star exhibits or not differential rotation and study stellar pulsation, we apply the wavelet procedure. The wavelet transform has been used as a powerful tool in the treatment of a large number of problems in astrophysics. Through the wavelet transform, one can perform an analysis in time-frequency light curves rich in details that contribute significantly to the study of phenomena associated with the rotation, the magnetic activity and stellar pulsations. In this work, we apply Morlet wavelet (6th order), which offers high time and frequency resolution and obtain local (energy distribution of the signal) and global (time integration of local map) wavelet power spectra. Using the wavelet analysis, we identify thirteen systems with periodicities related to the rotational modulation, besides the beating pattern signature in the local wavelet map of five pulsating stars over the entire time span.

A paisagem da Mata Atlântica do estado do Rio Grande do Norte: remanescentes, configuração espacial e disponibilidade de habitat

The Atlantic Forest in Rio Grande do Norte (RN) is included in Pernambuco biogeographic sub-region and it is composed by Semi-deciduous Forest, deciduous Forest, Mangrove and Restinga. We assessed the conservation status of Atlantic Forest in the RN through remnants mapping using high resolution satellite images and landscape ecology approaches. We evaluated if there is difference between the north and south coastal regions considering their natural a historical land use differences. We also assessed the influence of the small remnants on landscape cover and configuration. The proportion of the original biome area with remnants larger than 3 hectares is 15.60% for the official governmental limit and is 16.60% for the alternative limit (SNE, 2002). This remnants proportion varies between 0.56 and 46.52% in the hydrographic basins. 89.70% of the remnants are smaller than 50 hectares. Only 6.00% of the remnants are greater than 100 hectares, and these remnants are responsible by 65% of remaining area. The patches with smaller area influence all calculated metrics. The south coastal hydrographic basins have higher percentage of coverage of remnants, larger patch densities and fragments with larger areas than north coastal hydrographic basins. The diffuse drainage basins of the southern coastal have the highest percentage of coverage with remnants. 18.28% and 10% of the biome area are protected by reserves, according to the official governmental and alternative limits respectively. The reserves are mainly of sustainable use (IUCN V-VI). Therefore, the Atlantic Forest in Rio Grande do Norte is in critical situation, with low proportion of remaining area and high fragmentation level. It’s indispensable to biome conservation keep all the remaining area, especially the large remnants, and restore areas to increase remnants proportion and to increase landscape connectivity

Arquitetura da (in)segurança: estudando relações entre configuração espacial, artifícios de segurança e violência urbana no bairro Manaíra, João Pessoa, Paraíba

João Pessoa, the capital city of the state of Paraíba (Northeast Brazil), is reputed throughout the country as a quiet place, although it has been acquiring, over the past years, an urban character with social implications similar to those of major metropolitan Brazilian areas. The new situation is evident by the social inequalities, with the creation of confined spaces, which segregate and cause enclosure of the inhabitants, leading to death the public space. This study correlates accessibility in spatial structure with two types of crime data, burglary and robbery, recorded in 2008 and 2009, by the Secretaria de Segurança da Paraíba (The government agency public in charge of safety), in the district of Manaíra, an upper middle class neighborhood, which has, in recent times, been considered one of the most violent areas in João Pessoa. Sought to understand connections between these events and morpho-social aspects of the built environment, where examined the spatial properties, such as accessibility of the urban net, the presence of control measures, the safety of buildings and their uses. Spatial properties were also validated by the observation of pedestrian flows at strategic points of the study area. It was concluded that the presence of intense flows helps to attract potential thieves, physical security and control offers little protection

Aparências da forma e forma do espaço: análise da configuração espacial de residências unifamiliares dos anos 1970 em João Pessoa PB

Assuming that the form of a building shell and its content the spatial form are distinct dimensions of architecture - however indivisible and interdependent -, this study focus, in the light of the Social Logic of Space (HILLIER; HANSON, 1984), on the intrinsic properties through which domestic space was structured in a sample of single-family dwellings built in João Pessoa (PB) during the 1970s - when the vocabulary of modern architecture still prevailed in Brazil though sharing the urban scene with other architectural trends -, in order to investigate regularities or divergences underlying their conception. These dwellings were originally classified (ARAÚJO, 2010a) in five categories defined according to the form of their building shells and to their prevailing construction techniques: (1) Brazilian modern legacy (considered as truly Brazilian modern style); (2) Paulista architecture (that refers to the modern production of São Paulo, Brazil, from the 1950s through the 1970s); (3) experiences of rationalization and prefabrication ; (4) experiences of adaptation to the climate (referring to a design strongly influenced by the hot and humid climate of North-eastern Brazil); and (5) hybrid (to account for a kind of stylistic hybridism that includes formal attributes, which evoke our colonial past). This study aims to determine, through the analyses of nineteen cases that represent each category, whether this taxonomy corresponds to distinct modes of spatial configuration. This research therefore proposes an approach to the classification of domestic architecture based on topological properties. The dwellings spatial organization was represented, quantified and analyzed, their spatial properties explored in consonance with one another and with the literature. Results pointed out that there is no evidence of a reciprocal relationship between the formal look of the built shells and their respective spatial structures

Geografia da dominação: um estudo sobre a organização espacial da terra do sal (Macau-RN)

This work aims to understand the spatial organization in the Town of Macau, State of Rio Grande do Norte, Brazil. This approach focus on bringing back the history of the town, the main personages responsible for the construction of this place, denominated "social agents", as well as its social processes and the spatial forms derived from them. As the personages and their practices were identified, it was found out the existence of a driving force for structuring, interlocking, and maintaining the actions carried out by the social agents during the time. Such actions were materialized in the urban space: "the social segregation". The social segregation takes place as a specific geography of domination. The outcome of those owning the best areas" and ways of accessibility in the urban space, varies from the enrichment by property valorization, because of the concentration of public investments of infrastructure, to the comfort of easily reaching all the daily needs related to the displacements in the urban space. In the latter case, such facility has contributed to improve life quality. While one takes advantage of the location in the urban space, others are negatively affected by the same process. This research identified the salina worker as the weakest element of this social structure, occupying the urban periphery of the town of Macau. Such area is characterized by the lack of services and urban equipment in opposition to the center of the town, the locus of elite. This way, it is established the most known segregation pattern: center x periphery, in which the space acts as a mechanism of segregation