1000 resultados para Mello-Leitão
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A historiografia política que se debruça sobre o fim do regime monárquico refere, abundantemente, as ligações dos políticos e dos partidos aos jornais, no entanto, o jornalismo é assunto lateral e excêntrico da história política. Quando nos aproximamos dos estudos jornalísticos portugueses e procuramos compreender o comportamento dos jornais face ao político na viragem do século XIX temos de imediato uma grelha interpretativa acessível e dicotómica: em Portugal existiria uma imprensa de opinião, partidária, apaixonada, e uma outra informativa e apartidária. A esta última caberia a fórmula do sucesso. Esta abordagem do jornalismo, se têm a vantagem de nos chamar a atenção para a existência de várias práticas jornalísticas remete, porém, para um âmbito cronológico longo e vago ( “ século XIX”, “ último quartel do século XIX”) dizendo-nos pouco, sobre o objeto que enfatiza: o jornalismo informativo. Tende ainda a reproduzir as histórias institucionais dos jornais e as memórias dos profissionais do jornalismo, secundarizando a análise dos jornais. Nos escassos estudos jornalísticos sobre o período é forte a tendência para procurar encontrar e identificar no passado indícios dos vícios ou idealizações do jornalismo contemporâneo. Tanto mais que cronologicamente coincide o nosso estudo com o período (para alguns a “etapa” decisiva, ao ponto de lhe chamarem a ”idade de ouro da imprensa”) particularmente acarinhado por uma história “natural”do jornalismo, que aqui encontra a modernidade (leia-se autonomia face ao poder político, profissionalização do jornalista) “pela mão” da publicidade ( libertadora) fruto da industrialização oitocentista. A maior dificuldade para quem estuda os jornais da época contemporânea é o carácter gigantesco do acervo documental. O carácter serial dos periódicos, o seu ritmo diário, ao remeterem para rotinas, sugeriram-nos o presente trabalho: procurar surpreender o tratamento e organização da “ notícia” em nove jornais diários ( “ informativos” e de “opinião”) no dia 1 de Abril de 1906: no Século, Diário de Notícias, Mundo, Vanguarda, Luta, Popular, Opinião, Novidades e Diário Ilustrado. Nesse dia, os jornais informativos registavam com minúcia atos administrativos e rotinas burocráticas. Boa parte delas antecipavam a letra do Diário de Governo, outras, seguiam os trâmites legais dos processos coletivos e individuais que, por uma razão ou por outra, viajavam para nova instância administrativa à espera de decisão superior. E corria eficiente a máquina do Estado nas páginas do Século e no Diário de Notícias. Ministérios, secretarias, direções gerais, comissões, conselhos, etc., despachavam serviço. Parte do trabalho dos jornais informativos passava então por recolher e transcrever estas informações. Uma parcela significativa trabalho jornalístico era o puro registo, com pouco ou nenhum lugar para tratamento de edição, seja na seleção ou hierarquização dos factos noticiados, seja na contextualização dos atos administrativos editados. A reprodução integral das informações recolhidas junto da máquina do Estado dotava a “notícia” de uma linguagem técnico-burocrática que remetia para um rigor e racionalidade ausente, na concepção do próprio jornal, e verdadeiramente contrastante com o “ reflexo” caótico da sociedade que este dava a ler .
Jornalismo político e censura na I Guerra – uma visão comparativa entre os jornais O Mundo e A Lucta
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“Se os governantes soubessem a curiosidade que desperta a censura, se pudessem ler as perguntas feitas aos jornais censurados, se avaliassem bem os efeitos da criação deste novo fruto proibido, mandariam para as profundezas do inferno a lei da censura preventiva”, escrevia João Barbosa, a 1 de Maio de 1917, no diário A Lucta. A materialização da censura nas páginas dos jornais diários, por via de intrusivos espaços em branco, de configuração variável, não deixou de constituir uma nova forma de enunciar o “problema” político. Na nossa análise sobre a censura aos jornais A Lucta e o O Mundo, durante a I Guerra Mundial, procuraremos ultrapassar a visão excessivamente redutora dos jornais como sendo meros transmissores de mensagens de um emissor para um recetor, aceitando a proposta de M. Schudson:“ que o poder dos média está não apenas (e nem sequer primariamente) no seu poder de declarar as coisas como sendo verdadeiras mas no poder de fornecer as formas nas quais as declarações aparecem”. A prática de censura constitui elemento determinante na reconfiguração do campo político republicano.
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In this work, tin selenide thin films (SnSex) were grown on soda lime glass substrates by selenization of dc magnetron sputtered Sn metallic precursors. Selenization was performed at maximum temperatures in the range 300 °C to 570 °C. The thickness and the composition of the films were analysed using step profilometry and energy dispersive spectroscopy, respectively. The films were structurally and optically investigated by X-ray diffraction, Raman spectroscopy and optical transmittance and reflectance measurements. X-Ray diffraction patterns suggest that for temperatures between 300 °C and 470 °C, the films are composed of the hexagonal-SnSe2 phase. By increasing the temperature, the films selenized at maximum temperatures of 530 °C and 570 °C show orthorhombic-SnSe as the dominant phase with a preferential crystal orientation along the (400) crystallographic plane. Raman scattering analysis allowed the assignment of peaks at 119 cm−1 and 185 cm−1 to the hexagonal-SnSe2 phase and those at 108 cm−1, 130 cm−1 and 150 cm−1 to the orthorhombic-SnSe phase. All samples presented traces of condensed amorphous Se with a characteristic Raman peak located at 255 cm−1. From optical measurements, the estimated band gap energies for hexagonal-SnSe2 were close to 0.9 eV and 1.7 eV for indirect forbidden and direct transitions, respectively. The samples with the dominant orthorhombic-SnSe phase presented estimated band gap energies of 0.95 eV and 1.15 eV for indirect allowed and direct allowed transitions, respectively.
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In this work we employed a hybrid method, combining RF-magnetron sputtering with evaporation, for the deposition of tailor made metallic precursors, with varying number of Zn/Sn/Cu (ZTC) periods and compared two approaches to sulphurization. Two series of samples with 1×, 2× and 4× ZTC periods have been prepared. One series of precursors was sulphurized in a tubular furnace directly exposed to a sulphur vapour and N2+5% H2 flux at a pressure of 5.0×10+4 Pa. A second series of identical precursors was sulphurized in the same furnace but inside a graphite box where sulphur pellets have been evaporated again in the presence of N2+5% H2 and at the same pressure as for the sulphur flux experiments. The morphological and chemical analyses revealed a small grain structure but good average composition for all three films sulphurized in the graphite box. As for the three films sulphurized in sulphur flux grain growth was seen with the increase of the number of ZTC periods whilst, in terms of composition, they were slightly Zn poor. The films' crystal structure showed that Cu2ZnSnS4 is the dominant phase. However, in the case of the sulphur flux films SnS2 was also detected. Photoluminescence spectroscopy studies showed an asymmetric broad band emission whichoccurs in the range of 1–1.5 eV. Clearly the radiative recombination efficiency is higher in the series of samples sulphurized in sulphur flux. We have found that sulphurization in sulphur flux leads to better film morphology than when the process is carried out in a graphite box in similar thermodynamic conditions. Solar cells have been prepared and characterized showing a correlation between improved film morphology and cell performance. The best cells achieved an efficiency of 2.4%.
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The temperature dependence of electrical conductivity and the photoconductivity of polycrystalline Cu2ZnSnS4 were investigated. It was found that at high temperatures the electrical conductivity was dominated by band conduction and nearest-neighbour hopping. However, at lower temperatures, both Mott variable-range hopping (VRH) and Efros–Shklovskii VRH were observed. The analysis of electrical transport showed high doping levels and a large compensation ratio, demonstrating large degree of disorder in Cu2ZnSnS4. Photoconductivity studies showed the presence of a persistent photoconductivity effect with decay time increasing with temperature, due to the presence of random local potential fluctuations in the Cu2ZnSnS4 thin film. These random local potential fluctuations cannot be attributed to grain boundaries but to the large disorder in Cu2ZnSnS4.
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OBJETIVO: Analisar o efeito da Estratégia Saúde da Família na vigilância de óbitos infantis. MÉTODOS: Estudo ecológico de múltiplos grupos, tendo municípios do Estado da Bahia no ano de 2008 como unidade de análise. Os 3.947 óbitos analisados foram obtidos do Sistema de Informação sobre Mortalidade e a meta mínima de investigação considerada foi de 25% dos óbitos. Foram utilizados modelos de regressão logística bivariado e múltipla, ajustados por variáveis sociodemográficas e de organização de serviços. RESULTADOS: Em 48,9% dos municípios houve investigação de pelo menos um óbito infantil e em 35,5% foi alcançada a meta mínima de investigação. Nos modelos bivariados para avaliação da investigação de pelo menos um óbito, foram observadas associações estatisticamente significantes com maior porte populacional, maiores valores de Índice de Desenvolvimento Humano, existência de Comitê de Investigação e de leito obstétrico no município; não foram observadas associações com a cobertura da Estratégia Saúde da Família e existência de responsável técnico no município. Na análise ajustada, a investigação de pelo menos um óbito infantil esteve associada a porte populacional (OR = 4,02) e existência de leito obstétrico (OR = 2,68). O alcance da meta municipal mínima esteve associado apenas com a existência de leito obstétrico no município (OR = 1,76). CONCLUSÕES: O percentual de óbitos de menores de um ano investigados foi inferior ao pactuado na Bahia em 2008. Não houve associação entre a cobertura da Estratégia Saúde da Família e essa ação, o que sugere que a Vigilância de Óbitos Infantis é incipiente no Estado, principalmente quanto à sua descentralização para a atenção primária.
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In this work, we investigated structural, morphological, electrical, and optical properties from a set of Cu2ZnSnS4 thin films grown by sulfurization of metallic precursors deposited on soda lime glass substrates coated with or without molybdenum. X-ray diffraction and Raman spectroscopy measurements revealed the formation of single-phase Cu2ZnSnS4 thin films. A good crystallinity and grain compactness of the film was found by scanning electron microscopy. The grown films are poor in copper and rich in zinc, which is a composition close to that of the Cu2ZnSnS4 solar cells with best reported efficiency. Electrical conductivity and Hall effect measurements showed a high doping level and a strong compensation. The temperature dependence of the free hole concentration showed that the films are nondegenerate. Photoluminescence spectroscopy showed an asymmetric broadband emission. The experimental behavior with increasing excitation power or temperature cannot be explained by donor-acceptor pair transitions. A model of radiative recombination of an electron with a hole bound to an acceptor level, broadened by potential fluctuations of the valence-band edge, was proposed. An ionization energy for the acceptor level in the range 29–40 meV was estimated, and a value of 172 ±2 meV was obtained for the potential fluctuation in the valence-band edge.
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In this work, we show a set of growth conditions, for the two step process, with which the growth of CZTSe is successful and reproducible. The properties of the best CTZSe thin films grown by this method were examined by SEM/EDS, XRD, Raman scattering, AFM/EFM, transmittance and reflectance measurements, photoluminescence (PL) measurements and hot point probe. A broad emission band was observed in the photoluminescence spectrum of the CZTSe thin film. The band gap energy was estimated to be around 1.05 eV at room temperature, using the transmittance and reflectance data, and CZTSe samples show p-type conductivity with the hot point probe. The different characterization techniques show that we could grow single phase CZTSe thin films with our optimized process conditions.
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Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Química e Biológica
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Cu2ZnSnS4 is a promising semiconductor to be used as absorber in thin film solar cells. In this work, we investigated optical and structural properties of Cu2ZnSnS4 thin films grown by sulphurization of metallic precursors deposited on soda lime glass substrates. The crystalline phases were studied by X-ray diffraction measurements showing the presence of only the Cu2ZnSnS4 phase. The studied films were copper poor and zinc rich as shown by inductively coupled plasma mass spectroscopy. Scanning electron microscopy revealed a good crystallinity and compactness. An absorption coefficient varying between 3 and 4×104cm−1 was measured in the energy range between 1.75 and 3.5 eV. The band gap energy was estimated in 1.51 eV. Photoluminescence spectroscopy showed an asymmetric broad band emission. The dependence of this emission on the excitation power and temperature was investigated and compared to the predictions of the donor-acceptor-type transitions and radiative recombinations in the model of potential fluctuations. Experimental evidence was found to ascribe the observed emission to radiative transitions involving tail states created by potential fluctuations.
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Trabalho de Projeto para obtenção do grau de Mestre em Engenharia de Eletrónica e Telecomunicações
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Cu2ZnSnS4 (CZTS) and Cu2ZnSnSe4 (CZTSe) with their band gap energies around 1.45 eV and 1.0 eV, respectively, can be used as the absorber layer in thin film solar cells. By using a mixture of both compounds, Cu2ZnSn(S,Se)4 (CZTSSe), a band gap tuning may be possible. The latter material has already shown promising results such as solar cell efficiencies up to 10.1%. In this work, CZTSSe thin films were grown in order to study its structure and to establish the best growth precursors. SEM micrographs reveal an open columnar structure for most samples and EDS composition profiling of the cross sections show different selenium gradients. X-ray diffractograms show different shifts of the kesterite/stannite (1 1 2) peak, which indicate the presence of CZTSSe. From Raman scattering analysis, it was concluded that all samples had traces of CZTS and CZTSSe. The composition of the CZTSSe layer was estimated using X-ray diffraction and Raman scattering and both results were compared. It was concluded that Se diffused more easily in precursors with ternary Cu–Sn–S phases and metallic Zn than in precursors with ZnS and/or CZTS already formed. It was also showed that a combination of X-ray diffraction and Raman scattering can be used to estimate the ratio of S per Se in CZTSSe samples.
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Mestrado em Fisioterapia
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OBJECTIVE: To review the use of accelerometry as an objective measure of physical activity in adults and elderly people. METHODS: A systematic review of studies on the use of accelerometty as an objective measure to assess physical activity in adults were examined in PubMed Central, Web of Knowledge, EBSCO and Medline databases from March 29 to April 15, 2010. The following keywords were used: "accelerometry," "accelerometer," "physical activity," "PA," "patterns," "levels," "adults," "older adults," and "elderly," either alone or in combination using "AND" or "OR." The reference lists of the articles retrieved were examined to capture any other potentially relevant article. Of 899 studies initially identified, only 18 were fully reviewed, and their outcome measures abstracted and analyzed. RESULTS: Eleven studies were conducted in North America (United States), five in Europe, one in Africa (Cameroon) and one in Australia. Very few enrolled older people, and only one study reported the season or time of year when data was collected. The articles selected had different methods, analyses, and results, which prevented comparison between studies. CONCLUSIONS: There is a need to standardize study methods for data reporting to allow comparisons of results across studies and monitor changes in populations. These data can help design more adequate strategies for monitoring and promotion of physical activity.
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Revisão histórica sobre ideias e conceitos da organização sanitária que se seguiram à introdução do modelo do Centro de Saúde distrital pela reforma do Serviço Sanitário em 1925. Discute-se o pensamento dos sanitaristas Geraldo de Paula Souza, Rodolfo Mascarenhas e Reinaldo Ramos, representantes ilustres do "pensamento clássico" da saúde pública de São Paulo.