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Development of an oil spill hazard scenarios database for risk assessment
The occurrence of oil spills in coastal regions may have catastrophic consequences on the environment and severesocio-economic impacts. This work presents a new methodology to evaluate the risk associated with oil spills in coastalzones and estuaries, and illustrates its application in a coastal lagoon (Ria de Aveiro, Portugal). A ranked list of thehydrodynamic scenarios under which oil spills are most likely generated through the analysis of 33 years of wave andwind data, retrieved from the ERA-INTERIM project database, and from the analysis of oil spills that occurred in theAtlantic Iberian shelf. Considering six spill locations and a single oil type spill inside the Aveiro harbor, the databaseresulted in approximately 3500 simulations. Hydrodynamic simulations were made with the MORSYS2D modelingsystem, a soft coupling of the hydrodynamic model ELCIRC and the wave model SWAN. The high-accuracy,unstructured grid, oil fate model VOILS was used in 2D mode to simulate the transport and the oil weathering processesat the surface and in the intertidal areas. The hazard assessment analysis included the determination of the trajectory ofthe plumes, the shoreline retention areas affected by the oil and their oil exposure time. Time evolution of the oilproperties, such as the oil evaporation rate and emulsification processes of the mixture, are provided to support clean-upoperations, as well as robustness controls such as oil mass balance.
Year: 2014
Number Pages:
p6.
Author(s): Boer, S.; Azevedo, A.; Vaz, L.; Costa, R.; Fortunato, A. B.; Oliveira, A.; Tomas, L.; Dias, J. M.; Rodrigues, M.
: Journal of Coastal Research
Keywords: Risk assessment; Oil spill modeling; Climatology
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Diálogos entre património imaterial e material. O que dizem os artesãos sobre os revestimentos históricos com base em cal
A relação entre património material no caso arquitetónico e imaterial enquanto saber técnico tradicional é um pressuposto que orientou um dos estudos efetuados no âmbito do Projeto Conservação e durabilidade de revestimentos históricos: compatibilidade, técnicas e materiais (LIMECONTECH), desenvolvido no LNEC (Laboratório Nacional de Engenharia Civil) e cofinanciado pela FCT (Fundação para a Ciência e Tecnologia). De espectro mais alargado, este Projeto atendeu também ao estudo das técnicas e materiais tradicionais relacionados com os revestimentos históricos exteriores com base em cal. O principal objetivo deste artigo é apresentar a informação recolhida no âmbito do estudo referido, designadamente no que se refere ao levantamento do conhecimento técnico-tradicional junto de artífices da cal. Visa-se, assim, assinalar o potencial que o levantamento, registo e sistematização deste conhecimento detém para a conservação e restauro do património arquitetónico.
Year: 2014
Number Pages:
246-251pp..
Author(s): Menezes, M.; Veiga, M. R.; Lopes dos Santos, A. R.
: Anuário do Património
Editor: Canto Redondo
Volume:
n.º 2.
Keywords: Conservação; Património; Revestimentos históricos; Saber técnico-tradicional; Testemunho oral
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Diversas opções para os espaços da habitação ou Zonas domésticas: propostas organizativas
Desenvolvimento de matérias associadas a um leque de propostas organizativas para as zonas domésticas, sob o ponto de vista de diversos autores especialistas nestas matérias, apontando-se, desde já, a importância deste tipo de reflexões, designadamente, quando aplicadas a soluções habitacionais espacialmente muito condicionadas, como é o caso das soluções de habitação de interesse social.
Year: 2014
Number Pages:
5 p.
Author(s): Baptista Coelho, A.
: Revista Infohabitar
Editor: Revista www
Volume:
Infohabitar, Ano X, n.º 493.
Keywords: Organização da casa; Espaços domésticos
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Diversidade na organização habitacional
Mais do que tudo o que, em seguida, se aponte sobre as matérias associáveis à organização doméstica e à sua influência numa expressiva satisfação dos habitantes, na fruição doméstica há aspectos que importa sublinhar por se considerarem determinantes num tal resultado.
Year: 2014
Number Pages:
7 p.
Author(s): Baptista Coelho, A.
: Revista Infohabitar
Editor: Revista www
Volume:
Infohabitar, Ano X, n.º 471.
Keywords: Soluções domésticas; Organização habitacional; Habitação e imaginação; Funcionalidade habitacional; Espaço uno ou diferenciado; Adaptabilidade habitacional; Acessibilidade habitacional
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Duas décadas de cooperação europeia no âmbito da ID&I em engenharia sísmica no LNEC
O Laboratório Nacional de Engenharia Civil tem uma longa experiência na área da Engenharia Sísmica, sendo uma das instituições de referência, a nível europeu, em todos os campos desta área das Ciências da Engenharia. A investigação europeia em Engenharia Sísmica teve início no final da década de 50, tendo sido o LNEC, na pessoa do Engenheiro Júlio Ferry Borges, o seu principal impulsionador. Desde então, assistiu-se ao estudo dos diferentes aspetos da fenomenologia ligada à caraterização da ação sísmica e ao comportamento das estruturas sujeitas à ação dos sismos, como ilustrado pelas cerca de 50 teses de mestrado e doutoramento nos diferentes domínios da Engenharia Sísmica, desenvolvidas no Núcleo de Engenharia Sísmica e Dinâmica de Estruturas (NESDE), nas duas ultimas décadas, e por mais de uma centena de investigadores visitantes, nacionais e estrangeiros. No âmbito da avaliação do risco sísmico, o LNEC tem tido um papel fundamental a nível nacional, assumindo a liderança da investigação científica nas matérias relacionadas com a perigosidade sísmica, a caraterização da ação sísmica, a avaliação do risco, e o desenvolvimento de estratégias para redução da vulnerabilidade sísmica...
Year: 2014
Number Pages:
22-25pp.
Author(s): Campos Costa, A.; Coelho, E.; Carvalho, A. M.; Candeias, P.; Correia, A.A.
: Construção Magazine
Editor: Engenho e Média
Volume:
Nº 62.
Keywords: Engenharia sísmica
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Durability of ancient lime mortars in humid environment
Historical buildings are important fingerprints of the history and culture of a region and its communities. Climatic and environmental conditions are often very severe for construction materials, namely in presence of high humidity or in direct contact with water and salts. However, some historical buildings have in our days a very good condition, probably due to careful construction and/or accurate materials selection and to a specific technology. The knowledge of old mortars composition has a fundamental role on the preservation of cultural heritage, allowing information about the used materials, their performance in their specific environment, conducting to adequate and compatible materials to conservation purposes. This article presents two case studies of historical buildings with important defense functions in Lisbon coast, in which ancient lime mortars where used under severe seaside environmental actions. Mortar samples from these two case studies are characterized and the relationship of their composition with the good performance and high durability observed is discussed.
Year: 2014
Number Pages:
606-620pp.
Author(s): Borges, C.; Santos Silva, A.; Veiga, M. R.
: Construction and Building Materials
Editor: Elsevier
Volume:
66.
Keywords: Seaside; Humidity; Durability; Degradation/conservation; Air lime; Historical mortars
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Effect of internal curing by using superabsorbent polymers (SAP) on autogenous shrinkage and other properties of a high-performance fine-grained concrete: results of a RILEM round-robin test
The article presents the results of a round robin test performed by 13 international research groups (representing fifteen institutions) in the framework of the activities of the RILEM Technical Committee 225-SAP Applications of Superabsorbent Polymers in Concrete Construction. Two commercially available SAP materials were used for internal curing of a high-performance, fine-grained concrete in combination with the addition of extra water. The concrete had the same mix composition in all laboratories involved but was composed of local materials. All found a considerable decrease in autogenous shrinkage attributable to internal curing. Also, with regard to the shrinkage-mitigating effect of both particular SAP materials, the results were consistent. This demonstrates that internal curing using SAP is a robust approach, working independently of some variations in the concretes raw materials, production process, or measuring technique. Furthermore, the effects of internal curing on other properties of concrete in its fresh and hardened states were investigated. These are consistent as well and expand considerably the existing data basis on properties of concrete materials containing SAP.
Year: 2014
Number Pages:
541562.
Author(s): Mechtcherine, V.; Gorges, M.; Schroefl, C.; Assmann, A.; Brameshuber, W.; Ribeiro, A. C.; Cusson, D.; Custódio, J.
: Materials and Structures
Volume:
47.
Keywords: Superabsorbent polymer; Internal curing; Autogenous shrinkage
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Effect of the metallic cleaning and oxidizing pre-treatments on the corrosion behaviour of sol-gel hybrid coated EN AW-6063 alloy
The effect of alloy surface pre-treatments on the corrosion behaviour of sol gel hybrid coated EN AW 6063 alloy was studied. Five pre-treatments were used: solvent degreasing; alkaline degreasing followed by acid etching; alkaline degreasing followed by alkaline plus acid etching, alkaline degreasing followed by acid etching and oxide growth in boiling water and alkaline degreasing followed by acid etching and anodization. Surface morphology depends on the pre-treatment: SEM/EDS analysis revealed that alkaline plus acid cleaned samples exhibited a very smooth deoxidized surface, while all the others showed a rougher surface covered with an oxide layer. This oxide layer is denser and more homogeneous in the samples subjected to the oxide growth steps. A hybrid sol-gel coating, synthesized from glycidoxypropyltrimethoxysilane (GPTMS) and zirconium n-propoxide (TPOZ) precursors, was applied to the different pre-treated metallic substrate by dip-coating. The corrosion behaviour of the coated samples was evaluated by Electrochemical Impedance Spectroscopy (EIS) and by an accelerated corrosion test. Complementarily to the corrosion study, the adhesion of the hybrid sol-gel coating was evaluated by cross-cut and bend tests. The corrosion tests revealed that the pre-treatments including the oxide growth steps lead to the best protection performance, followed by the alkaline degreasing and alkaline plus acid etching one. However, the latter exhibits the worst adhesive behaviour, attributed to the smoother and deoxidized surface of the substrate.
Year: 2014
Number Pages:
38-43pp.
Author(s): Fontinha, I. R.; Salta, M. M.; Zheludkevich, M.; Ferreira, M. G. S.
: Corros. Prot. Mater.
Editor: LNEG
Volume:
33, Nº 3 (2014).
Keywords: Corrosion; Anodization; Pre-treatment; Aluminium; Hybrid solgel coatings
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Effects of thermal cycles on the mechanical response of pultruded GFRP profiles used in civil engineering applications
This paper presents a literature review and results of an experimental study about the effects of thermal cycles on the physical and mechanical properties of pultruded glass fibre reinforced polymer (GFRP) profiles used in civil engineering structural applications. The GFRP profiles used in this study present similar fibre architecture, differing only in their matrix nature: unsaturated polyester and vinylester. Small-scale coupons obtained from both types of GFRP profiles were exposed to a Mediterranean range of thermal variations (-5 °C to 40 °C) for up to 190 cycles in a dry condition. The effects of such exposure on the physical and mechanical response of the GFRP materials were assessed and compared using the following experimental techniques: (a) dynamic mechanical analyses (DMA) to assess the viscoelastic behaviour; (b) tensile, flexural and interlaminar shear tests, to evaluate the mechanical properties; and (c) scanning electron microscopy (SEM), to monitor the potential changes in the microstructure due to the degradation (if any) caused by the thermal cycles, as well as the possible changes into the main mechanisms of fracture. After exposure to thermal cycles, the viscoelastic behaviour of the GFRP profiles presented only slight changes, indicating no significant degradation, neither in the matrix structure nor at the fibre-matrix interphase. In terms of mechanical properties, both types of GFRP materials suffered slight changes regarding tensile and interlaminar shear properties. Flexural properties were more affected, particularly the flexural modulus, especially in the first cycles, as degradation tended to stabilize for increasing cycles. The GFRP profile made of vinylester resin presented better overall performance than the one made of polyester, especially regarding the tensile properties. SEM observations of the surfaces of fracture of mechanically tested pultruded specimens showed two main mechanisms of crack propagation: cohesive rupture (matrix cracking), where the crack propagates inside the matrix, and adhesive rupture (fibre-matrix debonding), where the crack propagates at the interface fibre-matrix. Degradation of the polyester matrix caused by the thermal cycles is evidenced by extensive matrix microcracking and increased fibre-matrix debonding. The vinylester matrix resists better to such degradation as fibre-matrix debonding occurs in less extent, and matrix microcracking is scarcely present.
Year: 2014
Number Pages:
12.
Author(s): Sousa, J.; Correia, J. R.; Cabral-Fonseca, S.; Diogo, A.
: Composite Structures
Editor: Elsevier
Volume:
116.
Keywords: Experimental tests; Polyester; Vinylester; Thermal cycles; Durability; Gfrp
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Eficiência energética e comportamento passivo dos edifícios
Apesar da extensa utilização no léxico técnico, o conceitode eficiência energética nos edifícios sendo fácil deapreender é difícil de quantificar e de utilizar na comparaçãoe classificação de edifícios. A eficiência energéticado edifício é o quociente entre o serviço prestado (confortotérmico, qualidade do ar, água quente sanitária) e oconsumo de energia associado. Resulta, que a eficiênciaenergética depende das características do edifício, dosseus equipamentos de climatização (e todos os outros),mas também dos ocupantes, das suas preferências deconforto e da forma como estes utilizam (ou não) os dispositivose controlos à sua disposição. Este aspeto dosocupantes é decisivo na avaliação da eficiência energéticados edifícios e nas soluções ótimas.Desde o RCCTE de 1990 que a avaliação do desempenhotérmico e energético dos edifícios é realizada comparandoo indicador necessidades térmicas nominais do edifícioface a um valor de referência, admitindo que existe
Year: 2014
Number Pages:
31-36pp.
Author(s): Pinto, A.
: Energuia
Editor: Engenho e Media, Lda.
Volume:
8.ª Edição - maio 2014.
Keywords: Conforto; Comportamento térmico; Reabilitação; Eficiência energética
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