The urban morphology of Braga between Late Antiquity and the fourteenth-fifteenth centuries

This paper aims to approach the urban transformation processes occurring in the city of Braga between Late Antiquity and the fourteenth-fifteenth centuries. Our approach is based upon the cross-referencing of documental, iconographic and cartographic data with data emerging from archaeological works conducted across the city throughout the last two decades. Despite the scarcity in sources documenting the historical period under study, a similar circumstance registered in other western European cities, new and emerging archaeological data associated with a regressive analysis of available information for the forthcoming centuries —documents, maps, plans and illustrations, have been contributing towards an advance in the overall knowledge regarding the continuity and changing processes impacting upon the urban area of Braga. Thereby, our goal is to develop a synthesis work describing the major evolutionary stages happening in Braga from the fifth to the fifteenth centuries and based upon anintegrated analysis of the architectonic markers, the morphology present in the urban setting, the existing Christian topography, the defensive system and the main road network.

Phase morphology and crystallinity of poly(vinylidene fluoride)/poly(ethylene oxide) piezoelectric blend membranes

Polymer blends based on poly(vinylidene fluoride), PVDF and poly(ethylene oxide), PEO, with varying compositions have been prepared by solvent casting, the polymer blend films being obtained from solutions in dimethyl formamide at 70ºC. Under these conditions PVDF crystallizes from solution while PEO remains in the molten state. Then, PEO crystallizes from the melt confined by PVDF crystalls during cooling to room temperature. PVDF crystallized from DMF solutions adopt predominantly the electroactive β-phase (85%). Nevertheless when PEO is introduced in the polymer blend the β-phase content decreases slightly to 70%. The piezoelectric coefficient (d33) in pristine PVDF is -5 pC/N and decreases with increasing PEO content in the PVDF/PEO blends. Blend morphology, observed by electron and atomic force microscopy, shows the confinement of PEO between the already formed PVDF crystals. On the other hand the sample contraction when PEO is extracted from the blend with water (which is not a solvent for PVDF) allows proving the co-continuity of both phases in the blend. PEO crystallization kinetics have been characterized by DSC both in isothermal and cooling scans experiments showing important differences in crystalline fraction and crystallization rate with sample composition.

Fuzzy maintenance costs of a wind turbine pitch control device

This paper deals with the problem of estimation maintenance costs for the case of the pitch controls system of wind farms turbines. Previous investigations have estimated these costs as (traditional) “crisp” values, simply ignoring the uncertainty nature of data and information available. This paper purposes an extended version of the estimation model by making use of the Fuzzy Set Theory. The results alert decision-makers to consequent uncertainty of the estimations along with their overall level, thus improving the information given to the mainte-nance support system.

Biomaterials for cartilage tissue engineering under mechanical stimulus

Tese de Doutoramento em Ciências (Especialidade de Física)

Como o videojogo se afastou do jogo, através da narrativa e criatividade

(Excerto) Continuamos a confundir o jogo com o videojogo, assumindo na maior parte das vezes, o segundo como um mero sucedâneo digital do primeiro. Contudo esta não passa de uma ideia simplista da arte dos videojogos que se transformou por completo desde que surgiu em meados do século vinte. O jogo enquanto estrutura sistémica criada pelo ser-humano responde por um lado às necessidades sociais e culturais de aprendizagem (Huizinga, 1939; Caillois, 1958; Gee, 2003), e por outro às necessidades cognitivas de recompensa na forma de resolução de problemas (Kenrick e Griskevicius, 2013). Ou seja, enquanto artefacto cultural o jogo permite-nos apreender o desconhecido, interagir com o outro e optimizar as nossas respostas sociais. Enquanto estímulo cognitivo o jogo atua de forma a recompensar o nosso esforço, engajando-nos através da insistência e da repetição com descargas de prazer. E é por isso que o jogo tem sido visto pela cultura humana como um dos mais importantes exercícios no processo de construção civilizacional.