12 resultados para Al addition
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O presente relatório tem como objectivo descrever o trabalho desenvolvido na Biblioteca Nacional de Portugal, concretamente no Arquivo de Cultura Portuguesa Contemporânea (ACPC), no sentido da conclusão do Mestrado de Edição de Texto ministrado pela Faculdade de Ciências Sociais e Humanas da Universidade Nova de Lisboa. O estágio foi acompanhado pela Drª. Fátima Lopes, responsável pelo ACPC, e realizou-se na Sala de Leitura de Reservados. No encontro anterior ao início do estágio, foi proposto pela mesma realizar o Inventário de um autor português contemporâneo e facultada a lista de «Elenco dos Acervos Existentes em setembro de 2014», para seleccionar o autor. Era importante ter em conta que só podia escolher os autores que tinham como menção na coluna de observação a informação «guia preliminar» e não os que tinham «inventário». O contacto com o espólio d’ O Medo do escritor Al Berto foi imprescindível para a realização do trabalho de inventariação. Surgiu a proposta de complementação ao inventário, a qual tinha como objectivo escolher um texto para observar as várias versões a que o mesmo foi sujeito até à sua publicação, tendo sido seleccionado Luminoso Afogado. O relatório apresenta quatro capítulos. Após a introdução do mesmo, inicia o primeiro capítulo, o qual centra-se na história da instituição onde decorreu o estágio, para além da abordagem da importância da arquivística textual. O segundo capítulo introduz o autor e as obras trabalhadas. No terceiro capítulo é exposto todo o trabalho de descrição, identificação e inventariação e a análise das versões de Luminoso Afogado. Por fim, o quarto capítulo destina-se aos resultados do trabalho efectuado. Procede em seguida com uma Conclusão, a Bibliografia e os anexos com os inventários e exemplos ilustrativos do trabalho desenvolvido.
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Abstract Background: Nanotechnology has the potential to provide agriculture with new tools that may be used in the rapid detection and molecular treatment of diseases and enhancement of plant ability to absorb nutrients, among others. Data on nanoparticle toxicity in plants is largely heterogeneous with a diversity of physicochemical parameters reported, which difficult generalizations. Here a cell biology approach was used to evaluate the impact of Quantum Dots (QDs) nanocrystals on plant cells, including their effect on cell growth, cell viability, oxidative stress and ROS accumulation, besides their cytomobility. Results: A plant cell suspension culture of Medicago sativa was settled for the assessment of the impact of the addition of mercaptopropanoic acid coated CdSe/ZnS QDs. Cell growth was significantly reduced when 100 mM of mercaptopropanoic acid -QDs was added during the exponential growth phase, with less than 50% of the cells viable 72 hours after mercaptopropanoic acid -QDs addition. They were up taken by Medicago sativa cells and accumulated in the cytoplasm and nucleus as revealed by optical thin confocal imaging. As part of the cellular response to internalization, Medicago sativa cells were found to increase the production of Reactive Oxygen Species (ROS) in a dose and time dependent manner. Using the fluorescent dye H2DCFDA it was observable that mercaptopropanoic acid-QDs concentrations between 5-180 nM led to a progressive and linear increase of ROS accumulation. Conclusions: Our results showed that the extent of mercaptopropanoic acid coated CdSe/ZnS QDs cytotoxicity in plant cells is dependent upon a number of factors including QDs properties, dose and the environmental conditions of administration and that, for Medicago sativa cells, a safe range of 1-5 nM should not be exceeded for biological applications.
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Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Engenharia do Ambiente, perfil de Engenharia Ecológica
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pp. 73-85
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Dissertação apresentada para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Arqueologia.
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Dissertação apresentada para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Ciência Política e RelaçõesInternacionais.
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We present the fi rst review of Hymenoptera alien to Europe. Our study revealed that nearly 300 species of Hymenoptera belonging to 30 families have been introduced to Europe. In terms of alien species diversity within invertebrate orders, this result ranks Hymenoptera third following Coleoptera and Hemiptera. Two third of alien Hymenoptera are parasitoids or hyperparasitoids that were mostly introduced for biological control purposes. Only 35 phytophagous species, 47 predator species and 3 species of pollinators have been introduced. Six families of wasps (Aphelinidae, Encyrtidae, Eulophidae, Braconidae, Torymidae, Pteromalidae) represent together with ants (Formicidae) about 80% of the alien Hymenoptera introduced to Europe. Th e three most diverse families are Aphelinidae (60 species representing 32% of the Aphelinid European fauna), Encyrtidae (55) and Formicidae (42) while the Chalcidoidea together represents 2/3 of the total Hymenoptera species introduced to Europe. Th e fi rst two families are associated with mealybugs, a group that also included numerous aliens to Europe. In addition, they are numerous cases of Hymenoptera introduced from one part of Europe to another, especially from continental Europe to British Islands. Th ese introductions mostly concerned phytophagous or gall- maker species (76 %), less frequently parasitoids. Th e number of new records of alien Hymenoptera per year has shown an exponential increase during the last 200 years. Th e number of alien species introduced by year reached a maximum of 5 species per year between 1975 and 2000. North America provided the greatest part of the hymenopteran species alien to Europe (96 species, 35.3%), followed by Asia (84 species, 30.9%) and Africa (49 species, 18%). Th ree Mediterranean countries (only continental parts) hosted the largest number of alien Hymenoptera: Italy (144 spp.), France (111 spp.) and Spain (90 spp.) but no correlation was found with the area of countries. Intentional introduction, mostly for biological control, has been the main pathway of introduction for Hymenoptera. Consequently, the most invaded habitats are agricultural and horticultural as well as greenhouses. To the contrary, Hymenoptera alien in Europe are mostly associated with woodland and forest habitats. Ecological and economic impacts of alien Hymenoptera have been poorly studied. Ants have probably displaced native species and this is also true for introduced parasitoids that are suspected to displace native parasitoids by competition, but reliable examples are still scarce. Th e cost of these impacts has never been estimated.
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Dissertação para obtenção do Grau de Mestre em Engenharia Química e Bioquímica
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Clayish earth-based mortars are been recognized, all over the world, as eco-efficient products for plastering. Apart from being a product with low embodied energy when compared to other types of plasters, their application on the interior surface of walls may give a strong contribution for the health and comfort of inhabitants. As part of an ongoing research regarding earth-based plasters this work assesses the influence of the addition of two types of natural fibres – oat straw and typha fiber-wool – on the characteristics of plastering mortars made with a clayish earth. Mechanical and physical characteristics were tested, showing that addition of these fibers contribute to decrease linear drying shrinkage and thermal conductivity, as well as promoting the adhesion strength of plaster to the substrate. The improvement of mechanical resistance reveal to be dependent on the type of fiber added while the hygroscopic capacity of the plaster is maintained regardless of the fiber additions.
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Transparent conducting oxides (TCOs) have been largely used in the optoelectronic industry due to their singular combination of low electrical resistivity and high optical transmittance. They are usually deposited by magnetron sputtering systems being applied in several devices, specifically thin film solar cells (TFSCs). Sputtering targets are crucial components of the sputtering process, with many of the sputtered films properties dependent on the targets characteristics. The present thesis focuses on the development of high quality conductive Al-doped ZnO (AZO) ceramic sputtering targets based on nanostructured powders produced by emulsion detonation synthesis method (EDSM), and their application as a TCO. In this sense, the influence of several processing parameters was investigated from the targets raw-materials synthesis to the application of sputtered films in optoelectronic devices. The optimized manufactured AZO targets present a final density above 99 % with controlled grain size, an homogeneous microstructure with a well dispersed ZnAl2O4 spinel phase, and electrical resistivities of ~4 × 10-4 Ωcm independently on the Al-doping level among 0.5 and 2.0 wt. % Al2O3. Sintering conditions proved to have a great influence on the properties of the targets and their performance as a sputtering target. It was demonstrated that both deposition process and final properties of the films are related with the targets characteristics, which in turn depends on the initial powder properties. In parallel, the influence of several deposition parameters in the film´s properties sputtered from these targets was investigated. The sputtered AZO TCOs showed electrical properties at room temperature that are superior to simple oxides and comparable to a reference TCO – indium tin oxide (ITO), namely low electrical resistivity of 5.45 × 10-4 Ωcm, high carrier mobility (29.4 cm2V-1s-1), and high charge carrier concentration (3.97 × 1020 cm-3), and also average transmittance in the visible region > 80 %. These superior properties allowed their successful application in different optoelectronic devices.
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Siguiendo algunos desarrollos de Walter Benjamin y la lectura de su pensamiento que realiza Giorgio Agamben, este artículo explora ciertas aristas de la relación entre historia, tiempo y catástrofe como la crisis que permite comprender el vínculo del hombre con la experiencia en la modernidad. Esto implica tematizar una nueva noción de experiencia a fin de pensar modos de concebir la relación entre las prácticas artísticas y la historia, fundados en la discontinuidad, la interrupción y el shock. Dar por tierra el tiempo continuo y vacío significa asumir un tiempo “pleno, separado, indivisible y perfecto de la experiencia humana concreta”, tal como propone Agamben. A esta nueva concepción de la historia y al arte les compete posibilitar el advenimiento del tiempo pleno que supone la liberación del goce ahistórico, para acceder a una temporalidad placentera, cualitativamente transformadora del tiempo, a la vez crítica y destructiva.
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Alcácer do Sal é uma cidade que esteve desde sempre ligada ao rio Sado, permitindo essa mesma ligação, que nela se fossem fixando ao longo do tempo, distintos povos, provindos das mais diversas partes do mundo. Esta ocupação por parte das populações, só foi possível, porque o território era abundante em recursos naturais e, entre eles, possuía solos bastante férteis para a agricultura. Uma das comunidades que mais marcas deixou da sua presença naquele núcleo urbano, foi, sem dúvida, a muçulmana, tal como se pode verificar no topónimo que dá o nome à cidade, assim como pela presença dos vários vestígios materiais, como a imponente fortificação militar, que se ergue na colina mais alta da povoação, assim como pelas estruturas e espólios encontrados nas diversas intervenções arqueológicas realizadas naquela cidade. Tendo em conta estes aspetos, esta dissertação pretende fazer uma aproximação ao estudo do urbanismo da medina islâmica de al-Qasr, abarcando cronologicamente o século IX, altura em que os Banu Danis se fixam na cidade, até aos inícios do século XIII, correspondente à última fase de ocupação muçulmana da cidade.