521 research outputs found

    A FORMAÇÃO CONTINUADA DE PROFESSORES DO ENSINO COMUM NO CAMPO DA EDUCAÇÃO ESPECIAL

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    Sistematizam-se reflexões de dados decorrentes de uma pesquisa que teve como propósito analisar uma formação continuada desenvolvida em um curso de extensão, que envolveu oito professores atuando com estudantes público-alvo da Educação Especial no ensino comum. Trata-se de uma pesquisa qualitativa, delineada como pesquisa-formação. Os dados foram coletados por meio de questionário, registros em diário de campo, entrevista e documentos legais orientadores dos sistemas de ensino municipal, estadual e privado. Sustentam-se as análises nos pressupostos da perspectiva histórico-cultural e também na Sociologia Figuracional, elaborada por Norbert Elias. Nos resultados, observa-se que a prática cotidiana das escolas é marcada por questões objetivas que dificultam o trabalho docente. Observa-se, que a formação docente precisa constituir-se como convite à reflexão sobre a escola, sua política interna e o seu funcionamento. Também verifica-se que, embora os professores não devam restringir suas práticas aos conhecimentos específicos, nos espaços de formação docente para a sala comum, o acesso a orientações acerca do uso de tecnologias e de metodologias que qualifiquem e potencializem a escolarização dos estudantes público-alvo da Educação Especial é absolutamente pertinente

    Band structure and optical properties of germanium sheet polymers

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    The band structure of H-terminated Ge sheet polymers is calculated using density-functional theory in the local density approximation and compared to the optical properties of epitaxial polygermyne layers as determined from reflection, photoluminescence, and photoluminescence excitation measurements. A direct band gap of 1.7 eV is predicted and a near resonant excitation of the photoluminescence is observed experimentally close to this energy

    Mass and angular momentum loss via decretion disks

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    We examine the nature and role of mass loss via an equatorial decretion disk in massive stars with near-critical rotation induced by evolution of the stellar interior. In contrast to the usual stellar wind mass loss set by exterior driving from the stellar luminosity, such decretion-disk mass loss stems from the angular momentum loss needed to keep the star near and below critical rotation, given the interior evolution and decline in the star's moment of inertia. Because the specific angular momentum in a Keplerian disk increases with the square root of the radius, the decretion mass loss associated with a required level of angular momentum loss depends crucially on the outer radius for viscous coupling of the disk, and can be significantly less than the spherical mass loss the spherical, wind-like mass loss commonly assumed in evolutionary calculations. We discuss the physical processes that affect the outer disk radius, including thermal disk outflow, and ablation of the disk material via a line-driven wind induced by the star's radiation. We present parameterized scaling laws for taking account of decretion-disk mass loss in stellar evolution codes, including how these are affected by metallicity, or by presence within a close binary and/or a dense cluster. Effects similar to those discussed here should also be present in accretion disks during star formation, and may play an important role in shaping the distribution of rotation speeds on the ZAMS.Comment: 10 pages, accepted for publication in A&

    Relations between assemblages of carpological remains and modern vegetation in a shallow reservoir in southern Poland

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    This paper explores relations between assemblages of carpological remains and vegetation in and around a small, shallow reservoir in southern Poland. The study was conducted from 2006 to 2008. Quantity and distribution of species in the reservoir were recorded annually during the growing season. In October 2008, 40 samples of surface sediment (top 2 cm) were collected along transects at 10 m intervals. Samples of 100 cm3 were prepared for analysis of plant macroremains. Assemblages of carpological remains generally reflect local vegetation well. In some cases, however, even analysis of numerous samples failed to fully capture the species composition or reflect plant ratios in the parent phytocenosis. Reasons for this include factors that affect seed production, transport and fossilization, which differ among species. Among the best-represented macroremains were plants of the rush phytocenosis. In analysed samples, macroremains of 68.8 % of extant rushes were identified. Sixty percent of submerged and floating-leaf taxa were found in carpological samples, whereas 26.7 % of the trees and bushes were represented in sediment deposits. Species composition of phytocenoses in the reservoir and in surrounding areas was best reflected by macroremains from the nearby reed bed. Numbers of diaspores of Mentha aquatica, Hippuris vulgaris and Carex reflected well their relative abundance in phytocenoses. Chara sp., Juncus inflexus and Eupatorium cannabinum were overrepresented, whereas Typha latifolia and Sparganium minimum were poorly represented in relation to contemporary plant cover. There were no diaspores of Phragmites australis, which dominates the contemporary reed bed. Besides the shape of a reservoir, the key factor influencing diaspore numbers is distribution of plant cover. In many cases, single diaspores (Potentilla erecta, Myosotis scorpioides, Lythrum salicaria, Scutellaria galericulata), or higher concentrations (Hippuris vulgaris, Mentha aquatica, Eleocharis palustris, Schoenoplectus tabernaemontani, Chara sp.) reflected well the location of parent vegetation. The findings indicate that carpological remains in sediments can be an important source of information about plants in and around lakes. They generally reflect well local vegetation and in some cases may be used to identify taxa that dominated in the past
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