Habitabilidade em exoplanetas do tipo terrestre

A astrobiologia, ciência que estuda a origem, evolução, distribuição e futuro da vida, tem como escopo a procura por vida em outros ambientes, como por exemplo, exoplanetas, planetas estes localizados fora do sistema solar. Através de observações e modelos teóricos que estimam alguns parâmetros gerais (composição, tipos de compostos presentes) pode-se criar um ambiente possível para o exoplaneta. O ambiente em que o planeta está inserido é um fator que pode ser determinante em relação a sua habitabilidade. A Zona Habitável é um dos parâmetros passíveis de delimitar os planetas que poderiam ser habitáveis. Muitos planetas identificados até agora têm características similares à da Terra. Entretanto, a maioria dos planetas, com possibilidade de ser do tipo terrestre, identificados até hoje são considerados Super Terras Quentes (STQ), pois estão fora da zona habitável uma vez que estão muito próximos de suas estrelas (período orbital da ordem de dias ou menos). Alguns desses estariam presentes na Zona habitável de suas respectivas estrelas, como é o caso de Gl 581 g, um planeta do sistema multi-planetário da estrela Gl 581. A proximidade da estrela sugere que eles apresentam uma rotação afetada por forças de maré. Deste modo, a taxa rotacional do planeta é sincronizada, sendo que uma de suas faces não recebe a energia da estrela, tornando-se gelada e a outra face recebe constantemente a energia da estrela, tornando-se muito quente. Embora em geral descarta-se a habitabilidade em STQ, estudos de resistência de vida em ambientes extremos não são muito explorados. As características analisadas partirão da premissa que o tipo de vida procurada será semelhante ao tipo de vida que encontramos na Terra, isto é, utilizando a água como solvente e apresentando uma química baseada no elemento carbono (Kaltenegger, L. et al., 2008)... (Resumo completo, clicar acesso eletrônico abaixo)

Litofácies e relações estratigráficas da formação Aquidauana no nordeste da Bacia do Paraná - São Sebastião do Paraíso (MG)

The Aquidauana Formation is characterized by sandstones of variable granulation, mudstones and diamectites abundant in clay, typical colors like brick red (vermelho tijolo) of glacial, fluvial and lacustrine origin. It’s chronostratigraphic equivalent to the Itarará group from the Neo Carboniferous age, that under the exploratory view, such units represent important intervals in the basin, occurring together with them minerals as well as energy resources as petroleum, underground water and coal – what requires a great paleogeography and stratigraphy knowledge for its exploration. By gathering information from the columnar sections of the area, it was possible to characterize the sedimentary facies, the stacking pattern as well as the association. It was also made an attempt of stratigraphic correlation, which showed great difficulties since glacial environments present a great lateral discontinuity of the facies besides the complex relationship process of formation. As a result, it was obtained 8 sedimentary facies, the lateral and vertical relations and genesis process. It is proposed that the sedimentary environment in the study area is the fluvio glacial, characterized by alluvial systems formed by defrosted water which transport the sediments that are deposited in plains in front of the glacier (distal outwash). Petrographic thin section analysis showed that the transportation process was ineffective. The grains present punctual to lobular contacts, characterizing good porosity and permeability to the rock, varying these qualities according to more or less existence of matrix. The presence of Iron Oxide deposited between the recrystallization border and feldspathic mineral indicates that this rock has possibly presented a primary rubefaction, intensified by alkaline fluid percolation

Levantamento da mastofauna terrestre de médio e grande porte em remanescentes florestais na Microbacia Córrego da Cascata - Botucatu, SP

Interessada em atividades com foco conservacionista, a Ong SOS Cuesta Botucatu foi selecionada pelo programa Petrobrás Ambiental para desenvolver o Projeto Córrego da Cascata no município de Botucatu. Este projeto é uma proposta de mobilização e educação ambiental para envolver a sociedade, principalmente a população ribeirinha, na gestão e no planejamento estratégico de recuperação e conservação ambiental da Microbacia Hidrográfica do Córrego da Cascata. O foco do projeto é promover a reversão dos processos de degradação e planejar ações estratégicas integradas e participativas de manejo e de gestão para a preservação da qualidade ambiental desse córrego urbano, por meio de uma caracterização socioambiental da referida Microbacia. Em relação à caracterização ambiental, o presente estudo refere-se ao levantamento da mastofauna em fragmentos de Mata Atlântica situados na área da Microbacia. O levantamento dos mamíferos terrestres de médio e grande porte foi realizado no período de abril de 2011 a fevereiro de 2012, com a utilização de dois métodos: parcelas de areia e câmeras trap. Outros dois métodos complementares também foram utilizados na tentativa de conseguir resultados que, invariavelmente, não seriam obtidos com as metodologias acima, como entrevistas e registro de atropelamentos. O objetivo é avaliar a riqueza da mastofauna da região comparando com trabalhos anteriores feitos em fragmentos com características semelhantes aos inseridos na Microbacia do Córrego da Cascata, Botucatu, São Paulo. Foram registradas 14 espécies de mamíferos pertencentes a sete Ordens distintas, sendo duas espécies consideradas ameaçadas. Houve predominância de registros de animais generalistas/oportunistas em áreas com menor diversidade de mastofauna

A implantação da televisão digital terrestre na Espanha

This monograph has as objectives introduce digital terrestrial television, describing the process of installation of this in Spain, their technical qualities and possibilities of change and innovation that this creates. The exposure of the different chapters of this monograph has a objective presenting and discussing what are the characteristics of this new technology, your birth, what is its importance in communication and how this is inserted inside the Spanish reality. The introduction of digital terrestrial television in Spain is cited as an example of a pioneer in the development and installation of this new technology, but also appears as a nation that has come a way with some economic failures, reaching one of the largest cases of delayed installation of digital television in Western Europe. Making use of the European system for digital terrestrial television (DVB-T - Digital Video Broadcasting) it was possible some advances as the quality of communication and strengthening national public television system, but many vices of analog system were transferred this new system, as the concentration of channels to a foreign group and interactivity opportunities were wasted. Digital terrestrial television can provides better picture quality and sound, possibility of interactivity, mobility, hypermedia and multiprogramming, while the latter tool may lead to the democratization of media, opening it to other social agents. Going much further than just a technological advancement, digital television is strongly connected with the politics and the economy of the nation in which it operates

Geologia e pesquisa mineral na região oeste do maciço Caritianas, municípios de Alto Paraíso e Itapuã D'Oeste, Rondônia

The granites Rondonianos, located in Rondônia Tin Pronvíncia, the southwestern portion of the Amazonian Craton, have great economic importance due to its large potential metallogenic. These granites stands out Intrusive Suite or Suite Granites Latest Rondônia Rondônia, with approximately 997-998 Ma (Bettencourt et al., 1997, 1999), for their tin mineralization having the largest reserves of this ore from Brazil. These tin mineralization in veins greissen are genetically related to these granites, deposits with different structural styles both within granitic plutons (endogreissen) as the host rocks (exogreissen). The western region of the Massif Caritianas has few published works, and the geology and potential econômicoão that were never fully known, now with the recovery of tin in the world market need new campaigns and prospective discoveries of new deposits

Dinâmica de rotação de exoplanetas tipo terrestre com perturbação de terceiro corpo

In this work we study some topics of Celestial Mechanics, namely the problem of rigid body rotation and “spin-orbit” resonances. Emphasis is placed on the problem formulation and applications to some exoplanets with physical parameters (e.g. mass and radius) compatible with a terrestrial type constitution (e.g. rock) belonging to multiple planetary systems. The approach is both analytical and numerical. The analytical part consists of: i) the deduction of the equation of motion for the rotation problem of a spherical body with no symmetry, disturbed by a central body; ii) modeling the same problem by including a third-body in the planet-star system; iii) formulation of the concept of “spin-orbit” resonance in which the orbital period of the planet is an integer multiple of the rotation’s period. Topics of dynamical systems (e.g. equilibrium points, chaos, surface sections, etc.) will be included at this stage. In the numerical part simulations are performed with numerical models developed in the previous analytical section. As a first step we consider the orbit of the planet not perturbed by a third-body in the star-planet system. In this case the eccentricity and orbital semi-major axis of the planet are constants. Here the technique of surface sections, widely used in dynamical systems are applied. Next, we consider the action of a third body, developing a more realistic model for planetary rotation. The results in both cases are compared. Since the technique of disturbed surface sections is no longer applicable, we quantitatively evaluate the evolution of the characteristic angles of rotation (e.g. physical libration) by studying the evolution of individual orbits in the dynamically important regions of phase space, the latter obtained in the undisturbed case

Levantamento da mastofauna terrestre de médio e grande porte ao longo da Rodovia Alcides Soares, Botucatu-SP, como subsídio para ações de conservação

Atropelamentos associados à fragmentação dos habitats naturais, tanto para construção de estradas, quanto para agricultura, são uma das principais causas de mortalidade para várias espécies de animais silvestres pelo mundo todo. Durante o período de agosto de 2011 e junho de 2012, em um trecho da Estrada Vicinal Alcides Rodrigues Soares do município de Botucatu, interior do estado de SP, foi realizado o levantamento de mamíferos terrestres de médio e grande porte através do método de parcelas de areia e transecto, além da procura de carcaça de animais atropelados. Espécies como Onça-parda (Puma concolor) e Tamanduá-bandeira (Myrmecophaga tridactyla), ambas em situação vulnerável de extinção, foram registradas em proximidade da estrada. Através dos dados obtidos, tem se como objetivo demonstrar a importância da valorização da fauna local, com a construção de passagens de fauna, como uma das medidas para a sua conservação e consequente redução dos diversos distúrbios e impactos causados por estradas

Datação por U-Pb em rutilos de rochas de metamorfismo de alta pressão do grupo Araxá na região de São Sebastião do Paraíso - MG

Although several studies of Araxá Group in the region of Passos, just a few works deal with the age of metamorphism of this group. The current work aims to determine the cooling age of these rocks by in situ U-Pb dating in rutiles. Interestingly, the region of São Sebastião do Paraíso shows a condensed lithostratigraphic column from the Passos Nappe and exposes the higher metamorphic grade rocks described for this unit. The use of rutile as a geochronometer is based on its ability to incorporate U in its structure, facilitating the calculation of the age of the isotope ratio by U-Pb. Furthermore, the use of in situ dating technique with Laser Ablation has been a reliable and advantageous study because the analysis are punctual, and do not destroy the whole sample to be analyzed. The analyses of this work were made at the University of Gothenburg - Sweden and obtained 238U/206Pb ages between 608-566 ± 10 Ma and 235U/207Pb between 627-572 ± 10 Ma, showing that these ages are concordant with the literature in the area and are interpreted as the cooling age of metamorphism

Estudo do metamorfismo de rochas de alto grau do grupo Araxá na região de São Sebastião do Paraíso - MG

This study focuses on metasedimentary rocks from the Passos Nappe in São Sebastião do Paraíso, southern Minas Gerais, Brazil. These rocks belong to the Internal Domain (Araxa Group) of the Southern Brasilia Belt, a Neproterozoic orogenic belt associated to the formation of the Gondwana Supercontinent. Rocks from the studied area are characterized by an inverted metamorphic gradient. Previously calculated metamorphic conditions show an increasing from geenschist facies at the base (450°C, 6 kbar), to upper amphibolite facies (750°C, 11 Kbar) at the top of the sequence. However, most of these estimates are based on Fe-Mg exchange thermometers and peak temperatures may be underestimated due to Fe-Mg exchange from cooling after peak metamorphism. In this study, we present new PT results for these rocks, based on metamorphic mineral assemblage LA-ICP-MS analyses. In the studied area, rocks from the top of the sequence have a typical granulite facies mineral assemblage: Grt+Ky+Kfs+/-Pl+liq. These rocks lack muscovite and have only minor amounts of Ti-rich, dark brown biotite. In a simplified NaKFMASH system the stability field for this mineral assemblage is bounded by the reactions Sil = Ky on the low pressure side, Ms+Ab = Ky+Kfs+liq on the low temperature side and for high-Mg bulk compositions Bt + Grt = Opx + Ky + liq on the high-temperature side. Minimum temperatures (considering post-peak reequilibration) of ca. 750°C are obtained by Fe/(Fe+Mg) values of 0.7 in garnets from a Grt+Ky+Kfs bearing sample. LA-ICP-MS results obtained for three samples show that rutiles included in garnets have up to 1847 ppm of Zr, which would translate into temperatures up to 830°C for a pressure between 12 to 15 kbar. Also for retroeclogite sample, the results indicate the contents of Zr in the garnet 537 ppm at a temperature of 708 ° C. It is noteworthy that several occurrences of retroeclogites occur in the upper part of the sequence and pressures...

Levantamento da mastofauna terrestre de médio e grande porte em três fragmentos de mata na Fazenda Experimental Lageado - Botucatu, SP

The present study aimed to survey the medium and large land mammals in three fragments at the Fazenda Experimental Lageado - UNESP/Botucatu, through the method of sand plots. 48 plots were used in total, 16 on each track. The paw prints found were photographed and identified from specific guides. 12 different species of mammals were found, these, 7 were classified at the level of species belonging to 9 families and 6 orders. The most representative order was Carnivora. Most of the species found have a generalist or omnivore habit, which can be related with the degree of the forest fragmentation. The only fragment of natural forest (semideciduous), presented the fewer numbers of species, which can be explained due to its isolation. The other fragment, which has near highway and other large fragment (Fazenda Experimental Edgárdia) was the most representative fragment, demonstrating the importance of nearest fragments to the continuity and survival of medium and large mammals

Visões seiscentistas do paraíso e do inferno: passos na construção da recepção da litratura brasileira na Alemanha

The present text intents to explore how the observation and the annotation of cultural practices of a nation can have a decisive role in the image construction of its literature and how this image can be decisive for the perception of the texts written about the target nation. To exemplify this idea, some important topics for the construction of the image of Brazil and for the text written about this country in Germany are taken under consideration.

O paraíso atrasado: a construção do rural no Brasil através do imaginário geográfico

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A compreensão de alunos do ensino médio sobre as relações CTSA e a preservação de um ecossistema terrestre a partir de uma aprendizagem centrada em eventos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Televisão digital terrestre na agenda do MERCOSUL

El escenario de la digitalización de los medios de comunicación, especialmente la televisión terrestre, y una política para el desarrollo de contenidos audiovisuales entraron en la agenda del MERCOSUR. Cambiar de el estándar de TV fue solamente el argumento embrionario para un conjunto de acciones destinadas a dar densidad a las iniciativas conjuntas de Argentina, Brasil, Paraguay y Uruguay en la jóven integración polí- tica y económica del Cono Sur. Así, nos propone- mos la reflexión en torno a las políticas públicas que provocan la implementación de la televisión digital en los países miembros del MERCOSUR intentando delinear los intereses políticos, la reestructuración del mercado regional y el establecimiento de modelos, patrones y sistemas de cooperación entre los países miembros. El análisis nos permite inferir que los gobiernos con matices de de centroizquierda de MERCOSUR optaron por la integración de las políticas públi- cas para fortalecer de la hegemonía del bloque en la innovación tecnológica, el desarrollo de contenido compartido y el fortalecimiento del capitalismo inmaterial.

Utilização de imagem de satélite Landsat no mapeamento da ocupação da terra e seus conflitos de uso em APPs na bacia hidrográfica do ribeirão Paraíso - São Manuel (SP)

The objectives of this study were to evaluate land use and occupation of Permanent Preservation Areas (PPA) as well as its use conflicts by TM (Thematic Mapper) image of the 2010 Landsat-5 satellite, according to the Forest Code. For that purpose, Geographic Information Systems in the Ribeirão Paraíso watershed, São Manuel, SP were used. The combination of Remote Sensing and Geographic Information System technologies allowed representation of spatial distribution of the landscape and data integration in the diagnosis of geographic interest. The 2010 mapping showed 12 use categories, and the sugar cane crop had the largest land occupation, 48.25% of the area. The areas of permanent preservation amounted to 925.74 ha, which is an ideal value based on the Brazilian legislation. Mapping of land use conflicts showed intensive anthropic actions going 80.13% forward on PPAs, with only 19.87% remaining forests, which highlights their negative impact and illegal situations in these areas.