17 resultados para Moments of inertia
em Universidade do Minho
Resumo:
Poly(vinylidene fluoride), PVDF, has been blended with different ionic liquids (IL) in order to evaluate the effect of the different IL anions and cations on the electroative -phase, thermal, mechanical and electrical properties of the polymer blend. [C2MIM][Cl], [C6MIM][Cl], [C10MIM][Cl], [C2MIM][NTf2], [C6MIM][NTf2], [C10MIM][NTf2] have been selected and were introduced in the polymer at a weight percentage of 40 wt%. It was found that the incorporation of ILs into the PVDF matrix leads to an increase of the -phase content due to the strong electrostatic interactions between the dipolar moments of PVDF and the ILs. Further, the incorporation of ILs into PVDF strongly decreases the elastic modulus and increases the electrical conductivity of the blend with respect to the pure polymer matrix, all these effects being accompanied by a modification of the crystallization kinetics, as indicated by the modified spherulitic microstructure. Thus, novel PVDF/IL blends films with high transparency, excellent antistatic properties, and highly polar crystal form fraction were successfully achieved.
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The barrier effect and the performance of an organic–inorganic hybrid (OIH) sol–gel coating are highlydependent on the coating deposition method as well as processing conditions. In this work, studies onthe influence of experimental parameters using the dip coating method were performed. Factors suchas residence time (Rt), a curing step between each dip step and the number of layers of sol–gel OIHfilms deposited on HDGS to prevent corrosion in highly alkaline environments were studied. These OIHcoatings were obtained using a functionalized siloxane, 3-isociantepropyltriethoxysilane that reactedwith a diamino-functionalized oligopolymer (Jeffamine®D-230). The barrier efficiency of OIH coatings insimulated concrete pore solutions (SCPS) was assessed in the first moments of contact, by electrochemicalimpedance spectroscopy and potentiodynamic methods. The durability and stability of the OIH coatings inSCPS was monitored during eight days by macrocell current density. The morphological characterizationof the surface was performed by scanning electronic microscopy before and after exposure to SCPS.Glow discharge optical emission spectroscopy was used to obtain quantitative composition profiles toinvestigate the thickness of the OIH coatings as a function of the number of layers deposited and theinfluence of the Rt in the coating thickness.
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Mitochondrial DNA (mtDNA) haplogroup L2 originated in Western Africa but is nowadays spread across the entire continent. L2 movements were previously postulated to be related to the Bantu expansion, but L2 expansions eastwards probably occurred much earlier. By reconstructing the phylogeny of L2 (44 new complete sequences) we provide insights on the complex net of within-African migrations in the last 60 thousand years (ka). Results show that lineages in Southern Africa cluster with Western/Central African lineages at a recent time scale, whereas, eastern lineages seem to be substantially more ancient. Three moments of expansion from a Central African source are associated to L2: (1) one migration at 70-50 ka into Eastern or Southern Africa, (2) postglacial movements (15-10 ka) into Eastern Africa; and (3) the southward Bantu Expansion in the last 5 ka. The complementary population and L0a phylogeography analyses indicate no strong evidence of mtDNA gene flow between eastern and southern populations during the later movement, suggesting low admixture between Eastern African populations and the Bantu migrants. This implies that, at least in the early stages, the Bantu expansion was mainly a demic diffusion with little incorporation of local populations.
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The fundamental goal we set ourselves when developing this study is to try to characterize, both technically and formally, ceramics made in the city of Braga and its territory from the initial moments of the Late Antiquity to the Middle Ages. Thus, we will focus on analyzing some own productions that appear attached to the phases of late antique occupation —ceramics of red engobes and late gray—, as well as in the early medieval containers identified in different archaeological interventions practiced in the Braga environment. Concretely, we will analyze the material from various excavations conducted recently at the Theatre in the solar number 20/28 and 36/56 from the Afonso Henriques Street and the former District Hostel as well as the church of São Martinho de Dume.
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Relatório de estágio de mestrado em Educação Pré-Escolar e Ensino do 1.º do Ensino Básico
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Relatório de estágio de mestrado em Ensino de Música
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Relatório de estágio de mestrado em Educação Pré-Escolar e Ensino do 1ºCiclo do Ensino Básico
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Relatório de estágio de mestrado em Educação Pré-Escolar e Ensino do 1º Ciclo do Ensino Básico
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Em Portugal, os programas de televisão feitos com adeptos notáveis de três grandes clubes de futebol correspondem a um formato com menos de uma década e meia de existência: apareceram primeiro na RTP2 e, logo a seguir, na SIC. Os canais generalistas rapidamente os adoptaram como conteúdos privilegiados para atrair audiência. Hoje constituem âncoras das grelhas dos três canais temáticos de informação, rivalizando entre si nos comentadores permanentes que conseguem fixar em estúdio. Apresentados por jornalistas, estes programas criam momentos de grande polémica e, com isso, marcam, de certa forma, a agenda do campo do futebol. Neste artigo, explicamos a génese destes formatos, traçamos o seu percurso na TV portuguesa e, através de entrevistas aos seus responsáveis editoriais, analisamos a estratégia que seguem na construção do alinhamento, discutimos a distância que mantêm dos clubes que comentam e perspectivamos formas de evolução deste tipo de conteúdos televisivos. Uma linha sobressai neste trabalho: quem participa nestes programas é uma elite de comentadores que se apresentam como adeptos do Futebol Clube do Porto, do Sporting e do Benfica, mas que mais não são do que uma confraria do comentário do futebol que semanalmente contribui para a construção de um espaço público cada vez mais rarefeito em torno daquilo que se discute no futebol.
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Tese de Doutoramento em Ciências da Comunicação
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Dissertação de mestrado em Direito Administrativo
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Tese de doutoramento em Estudos da Criança (área de especialização em Formação de Professores).
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Dissertação de mestrado integrado em Arquitectura
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Dissertação de mestrado em História
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Trabalho de projeto de mestrado em Políticas Comunitárias e Cooperação Territorial