128 research outputs found

    Formation of a galaxy with a central black hole in the Lemaitre-Tolman model

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    We construct two models of the formation a galaxy with a central black hole, starting from a small initial fluctuation at recombination. This is an application of previously developed methods to find a Lemaitre-Tolman model that evolves from a given initial density or velocity profile to a given final density profile. We show that the black hole itself could be either a collapsed object, or a non-vacuum generalisation of a full Schwarzschild-Kruskal-Szekeres wormhole. Particular attention is paid to the black hole's apparent and event horizons.Comment: REVTeX, 22 pages including 11 figures (25 figure files). Replacement has minor changes in response to the referee, and editorial corrections. To appear in PR

    Applied science facilitates the large-scale expansion of protected areas in an Amazonian hot spot

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    Meeting international commitments to protect 17% of terrestrial ecosystems worldwide will require \u3e3 million square kilometers of new protected areas and strategies to create those areas in a way that respects local communities and land use. In 2000–2016, biological and social scientists worked to increase the protected proportion of Peru’s largest department via 14 interdisciplinary inventories covering \u3e9 million hectares of this megadiverse corner of the Amazon basin. In each landscape, the strategy was the same: convene diverse partners, identify biological and sociocultural assets, document residents’ use of natural resources, and tailor the findings to the needs of decision-makers. Nine of the 14 landscapes have since been protected (5.7 million hectares of new protected areas), contributing to a quadrupling of conservation coverage in Loreto (from 6 to 23%). We outline the methods and enabling conditions most crucial for successfully applying similar campaigns elsewhere on Earth

    Os interiores domésticos após a expansão da economia exportadora paulista

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    The present article aims at describing São Paulo city dwellings and at studying its trade and crafts production in the first half of the 19th Century. Our work is chiefly based on information collected from post-mortem inventories registered in São Paulo capital city. Memorialists have described São Paulo city and its market as insignificant until coffee cultivation took over as the main economic activity. However, our research has found out that, on the contrary, the domestic trade had been very active since the beginning of the 19th century.Este artigo se propõe a descrever os interiores domésticos dos paulistanos e a refletir sobre o comércio e a produção artesanal da cidade de São Paulo na primeira metade do Oitocentos. Baseamo-nos principalmente nas informações dos inventários post-mortem da capital. Os memorialistas descreveram a cidade e seu mercado acanhados até o advento do café. Nossa pesquisa, ao contrário, identificou-os muito ativo desde o início do século XIX

    Água de beber: a filtração doméstica e a difusão do filtro de água em São Paulo

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    This work studies the advent and diffusion of water filter usage in São Paulo State, during the 20th Century. The water filter, a set of two terracotta vessels equipped with a filtering device, was a product of the ceramics industry, one of the first to be developed in São Paulo. This research shows that in São Paulo at the end of 19th and beginning of 20th Centuries, with the growth of cities and rapid urbanisation, a concern about the quality of water increased due to serious public health hazards, mainly epidemics caused by the consumption of unhealthy drinking water. Despite the existence of an incipient market of domestic equipment for water filtration, these were imported and of limited usage. From the 1910's, ceramics companies, owned by Portuguese and Italian immigrants, started installing filtering devices in terracotta vessels, launching the water filter set. It caught on and became the main domestic filtering equipment after the 1930's, when several companies specialized in this kind of product and started catering for the national market, such as Filtros Salus (from São Paulo city), Pozzani (Jundiaí) and Stéfani (Jaboticabal). Studying the advent and diffusion of the water filter entails knowledge about one of the first consumer goods of the Brazilian industry and, at the same time, knowledge about the history of the ways in which the Brazilian population obtained water to drink.Este artigo trata do processo de surgimento e difusão do uso do filtro de água no Estado de São Paulo, ao longo do século XX. O filtro de água, conjunto de dois recipientes de argila equipado com vela filtrante, é um produto da indústria cerâmica, uma das primeiras a se desenvolver em São Paulo. A pesquisa mostra que, em São Paulo, no final do século XIX e início do XX, com o aumento da urbanização e o crescimento das cidades, a preocupação com a qualidade da água que se consumia ganhou importância em virtude de graves problemas de saúde pública principalmente epidemias causadas por águas impróprias para beber. Embora já existisse um incipiente mercado de equipamentos domésticos de filtração da água, eles eram ainda importados e de uso restrito. A partir da década de 1910, empresas cerâmicas, de imigrantes portugueses e italianos, passaram a acoplar velas filtrantes a recipientes de argila, dando origem ao filtro de água. Depois dos anos de 1930, o filtro difundiu-se e tornou-se o principal equipamento de filtração doméstica, quando diversas empresas, como Filtros Salus (São Paulo-SP), Pozzani (Jundiaí-SP) e Stéfani (Jaboticabal-SP), especializaram-se nesse produto e passaram a atender ao mercado nacional. Estudar o surgimento e a difusão do filtro de água significa conhecer um dos primeiros bens de consumo da indústria brasileira e, ao mesmo tempo, a história de como a população obtém água para beber

    Uma promenade nos trópicos: os barões do café sob as palmeiras-imperiais, entre o Rio de Janeiro e São Paulo

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    This paper proposes to discuss the transformation of urban landscapes in the Paraíba River Valley as members of the coffee elite emerged in this area and a specific landscape configuration was projected there based on the use of imperial palms (Roystonea oleracea). Chronologically speaking, the paper covers a period from 1808 to 1911; with regard to space, it focuses on the stretch between Rio de Janeiro and São Paulo, with a closer look at the case of the city of Lorena (SP), so as to encompass all the changes that took place in this region from the introduction to the decline of coffee growing as an economic activity. The urban changes during this period were accompanied by the advent and consolidation of landscapes typical of the society of coffee growers: streets lined with palm trees, a token of their close connections with the royal court, a display of their adherence to "Frenchified customs". Such configurations were used to characterize public areas and raise them to the same status as the new buildings that gradually replaced those built in colonial style. The paper is structured around three key moments, namely: the introduction of imperial palms in Rio de Janeiro and their association with the idea of nobility and rank, and consequently with neoclassical architecture, which was brought to the colony by the 1816 French Mission; the dissemination of the use of imperial palms as a landscaping resource typical of public spaces from the royal court to the capital of São Paulo, particularly by the coffee barons during the second period of monarchic rule; and, finally, the hypothesis that the use of imperial palms to embellish public areas in São Paulo may have been introduced by a Lorena citizen associated with the coffee elite, albeit later, when Brazil was already a republic.O presente trabalho propõe-se a discutir a transformação da paisagem urbana das cidades vale-paraibanas, a partir do estabelecimento de uma elite ligada à cultura do café nessa região e do surgimento de uma configuração paisagística específica, apoiada na utilização da palmeira-imperial (Roystonea oleracea). Seu recorte cronológico abrange o período entre 1808 e 1911, enquanto espacialmente seu foco direciona-se para o eixo Rio de Janeiro-São Paulo, com estudo mais aproximado do caso da cidade de Lorena, São Paulo, de modo a cobrir as transformações aí ocorridas desde a chegada do café até o esgotamento dessa cultura. Acompanhando as transformações urbanas do período, surgiram e consolidaram-se exemplos paisagísticos próprios da sociedade do café: ruas arborizadas com renques de palmeiras, a demonstrar a proximidade com a Corte, a sinalizar os novos "modos afrancesados". Utilizaram-se tais configurações com o propósito de qualificar os logradouros públicos, a fim de equipará-los aos novos edifícios que substituíam aqueles da tradição colonial. O texto desenvolve-se em três momentos principais: a introdução da palmeira-imperial no Rio de Janeiro, sua vinculação à idéia de nobreza e classe, e conseqüente aproximação com a arquitetura neoclássica trazida pela Missão Francesa de 1816; a difusão de sua utilização como recurso paisagístico qualificador dos espaços públicos desde a Corte até a capital paulista, principalmente pelo baronato do Segundo Império; e, finalmente, a possibilidade de sua introdução nos espaços públicos paulistanos ter sido viabilizada por um lorenense, vinculado à elite cafeeira, embora já sob a República
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