8 resultados para Reflection and design
em Repositório Científico do Instituto Politécnico de Lisboa - Portugal
Resumo:
The effects of the Miocene through Present compression in the Tagus Abyssal Plain are mapped using the most up to date available to scientific community multi-channel seismic reflection and refraction data. Correlation of the rift basin fault pattern with the deep crustal structure is presented along seismic line IAM-5. Four structural domains were recognized. In the oceanic realm mild deformation concentrates in Domain I adjacent to the Tore-Madeira Rise. Domain 2 is characterized by the absence of shortening structures, except near the ocean-continent transition (OCT), implying that Miocene deformation did not propagate into the Abyssal Plain, In Domain 3 we distinguish three sub-domains: Sub-domain 3A which coincides with the OCT, Sub-domain 3B which is a highly deformed adjacent continental segment, and Sub-domain 3C. The Miocene tectonic inversion is mainly accommodated in Domain 3 by oceanwards directed thrusting at the ocean-continent transition and continentwards on the continental slope. Domain 4 corresponds to the non-rifted continental margin where only minor extensional and shortening deformation structures are observed. Finite element numerical models address the response of the various domains to the Miocene compression, emphasizing the long-wavelength differential vertical movements and the role of possible rheologic contrasts. The concentration of the Miocene deformation in the transitional zone (TC), which is the addition of Sub-domain 3A and part of 3B, is a result of two main factors: (1) focusing of compression in an already stressed region due to plate curvature and sediment loading; and (2) theological weakening. We estimate that the frictional strength in the TC is reduced in 30% relative to the surrounding regions. A model of compressive deformation propagation by means of horizontal impingement of the middle continental crust rift wedge and horizontal shearing on serpentinized mantle in the oceanic realm is presented. This model is consistent with both the geological interpretation of seismic data and the results of numerical modelling.
Resumo:
A Blumlein line is a particular Pulse Forming Line, PFL, configuration that allows the generation of high-voltage sub-microsecond square pulses, with the same voltage amplitude as the dc charging voltage, into a matching load. By stacking n Blumlein lines one can multiply in theory by n the input dc voltage charging amplitude. In order to understand the operating behavior of this electromagnetic system and to further optimize its operation it is fundamental to theoretically model it, that is to calculate the voltage amplitudes at each circuit point and the time instant that happens. In order to do this, one needs to define the reflection and transmission coefficients where impedance discontinuity occurs. The experimental results of a fast solid-state switch, which discharges a three stage Blumlein stack, will be compared with theoretical ones.
Resumo:
Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Civil Especialização em Hidráulica
Resumo:
O presente Relatório de Estágio tem como objecto de pesquisa a concepção e monitorização de duas Oficinas de Teatro dirigidas a dois grupos de mulheres constituídos, respectivamente, por estudantes universitárias e desempregadas. O estágio realizou-se entre Novembro/2013 e Junho/2014 na Quarta Parede - Associação de Artes Performativas da Covilhã e inseriu-se nos Empowerment Labs, laboratórios formativos que cruzam artes performativas e ciências sociais na reflexão e intervenção sobre a igualdade de género com foco no desemprego feminino. Este relatório expõe os três momentos do processo do estágio: pesquisa de referenciais teórico-práticos, concepção e monitorização das Oficinas de Teatro e reflexão a partir da prática laboratorial. Na pesquisa de referenciais, essencial para delinear a metodologia operacional e o programa de conteúdos, explorei dimensões como o feminismo e a igualdade de género, e procurei compreender de que forma o empowerment, a pedagogia de Paulo Freire e as metodologias do teatro aplicado serviam os objectivos do meu trabalho. A realização das oficinas foi o momento de experimentar as metodologias e o programa delineado. Tendo a igualdade de género como temática unificadora, o empowerment através da arte como objectivo maior e o teatro aplicado como base metodológica, as oficinas inserem-se nos processos de educação não-formal aplicados ao incremento de recursos intelectuais, emocionais, sociais, expressivos e criativos e, neste caso específico, à ampliação da consciência de género. Neste sentido, as oficinas desenvolveram uma abordagem metodológica processual, participativa e multidisciplinar, orientada para a pesquisa performativa, primeiro de uma dramaturgia individual, depois de uma dramaturgia do colectivo e, por fim, de uma dramaturgia orientada para a igualdade de género. O conceito de “dramaturgia” surge aqui no sentido metodológico do pachwork (trabalho com retalhos) e do sampling (recolha e transformação de materiais), relevante sobretudo na última fase, dedicada à construção colectiva de um exercício performativo apresentado publicamente.
Resumo:
Laminate composite multi-cell structures have to support both axial and shear stresses when sustaining variable twist. Thus the properties and design of the laminate may not be the most adequate at all cross-sections to support the torsion imposed on the cells. In this work, the effect of some material and geometric parameters on the optimal mechanical behaviour of a multi-cell composite laminate structure is studied when torsion is present. A particle swarm optimization technique is used to maximize the multi-cell structure torsion constant that can be used to obtain the angle of twist of the composite laminate profile.
Resumo:
This paper models an n-stage stacked Blumlein generator for bipolar pulses for various load conditions. Calculation of the voltage amplitudes in time domain at the load and between stages is described for an n-stage generator. For this, the reflection and transmission coefficients are mathematically modeled where impedance discontinuity occurs (i.e., at the junctions between two transmission lines). The mathematical model developed is assessed by comparing simulation results to experimental data from a two-stage Blumlein solid-state prototype.
Physical, chemical and mineralogical properties of fine recycled aggregates made from concrete waste
Resumo:
This paper assesses the physical, chemical and mineralogical characteristics of fine recycled aggregates obtained from crushed concrete waste, comparing them with two types of natural fine aggregates from different origins. A commercial concrete was jaw crushed, and the effect of different aperture sizes on the particle size distribution of the resulting aggregates was evaluated. The density and water absorption of the recycled aggregates was determined and a model for predicting water absorption over time is proposed. Both natural and recycled aggregates were characterized regarding bulk density and fines content. Recycled aggregates were additionally characterized by XRD, SEM/EDS and DTA/TG of individual size fractions. The results show that natural and recycled fine aggregates have very different characteristics. This should be considered in potential applications, both in terms of the limits for replacing amounts and of the rules and design criteria of the manufactured products. (C) 2015 Elsevier Ltd. All rights reserved.
Resumo:
Relatório Final de Estágio apresentado à Escola Superior de Dança, com vista à obtenção do grau de Mestre em Ensino de Dança.