Browsing by Issue Date, starting with "2019-05-10"
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- Caracterização microbiológica de amostras no âmbito da monitorização de águas balnearesPublication . Leonardo, Alcina da Graça; Santos, Maria Teresa Loureiro dos; Cunha, Maria AnaA monitorização da qualidade das águas balneares reveste-se de extrema importância, pois permite identificar e qualificar as praias com qualidade para banhos, fornecer informações ao público sobre a qualidade da água, em cada zona, protegendo assim a saúde pública. Este trabalho tem como objectivo caracterizar e avaliar a qualidade das águas balneares, costeiras e interiores, através da análise de parâmetros microbiológicos, nomeadamente bactérias Escherichia coli e Enterococos intestinais, pelo método de microplacas, realizando-se, ainda a comparação de três métodos de análise: Filtração por Membrana, Microplacas e Colilert/Enterolert. As quarenta amostras de águas balneares utilizadas neste trabalho foram colhidas nos concelhos de Almada, Cascais, Oeiras, Mafra, Sesimbra e Sintra procedendo-se à detecção e quantificação das bactérias Escherichia coli e Enterococos intestinais. A monitorização da qualidade da água foi realizada durante a época balnear com uma frequência definida nos planos de monitorização elaborados anualmente, permitindo uma gestão eficiente do ambiente que nos rodeia e dos seus recursos, bem como a salvaguarda da saúde pública. Através da análise dos resultados obtidos, foi possível concluir que os parâmetros Escherichia coli e Enterococos intestinais na maioria das amostras de águas balneares analisadas está abaixo dos valores da norma de qualidade para a classificação de qualidade Excelente, Boa ou Aceitável (Anexo I do Decreto-Lei n.º 113/2012).
- Performance and durability properties of self-compacting mortars with electric arc furnace dust as fillerPublication . Lozano-Lunar, Angélica; Raposeiro Da Silva, Pedro; De Brito, Jorge; Álvarez, J. I.; Fernandez Rodriguez, Jose Maria; Jimenez, Jose RamonThis study analyses the feasibility of incorporating electric arc furnace dust (EAFD) in the production of self-compacting mortars from the point of view of durability. Two types of EAFD, previously characterized and classified as hazardous waste, were used. Siliceous filler (powder) was replaced at different ratios (25%, 50%, and 100%, by volume). The following self-compacting mortar properties were measured at different curing times: total heat of hydration, compressive strength, ultrasonic pulse velocity, pore size distribution through mercury intrusion porosimetry, shrinkage and mass loss, water absorption by capillary, water absorption capacity, bulk density, skeletal density, open porosity for water, wettability by contact angle measurement, electrical resistivity, and carbonation depth. Although some of properties linked to the durability of the mortars, such as water absorption by capillarity, wettability or carbonation, were negatively affected by the incorporation of the EAFD, the results show the feasibility of replacing siliceous filler at up to 25% and the valorisation of EAFD as a secondary raw material (SRM). This research demonstrated that EAFD can be used as SRM as an alternative to landfills, thereby contributing to the promotion of the new circular economic model pursued by the European Union.
- Performance and durability properties of self-compacting mortars with electric arc furnace dust as fillerPublication . Lozano-Lunar, A.; Raposeiro Da Silva, Pedro; De Brito, Jorge; Alvarez, Jose Ignacio; Fernandez Rodriguez, Jose Maria; Jimenez, Jose RamonThis study analyses the feasibility of incorporating electric arc furnace dust (EAFD) in the production of self-compacting mortars from the point of view of durability. Two types of EAFD, previously characterized and classified as hazardous waste, were used. Siliceous filler (powder) was replaced at different ratios (25%, 50%, and 100%, by volume). The following self-compacting mortar properties were measured at different curing times: total heat of hydration, compressive strength, ultrasonic pulse velocity, pore size distribution through mercury intrusion porosimetry, shrinkage and mass loss, water absorption by capillary, water absorption capacity, bulk density, skeletal density, open porosity for water, wettability by contact angle measurement, electrical resistivity, and carbonation depth. Although some of properties linked to the durability of the mortars, such as water absorption by capillarity, wettability or carbonation, were negatively affected by the incorporation of the EAFD, the results show the feasibility of replacing siliceous filler at up to 25% and the valorisation of EAFD as a secondary raw material (SRM). This research demonstrated that EAFD can be used as SRM as an alternative to landfills, thereby contributing to the promotion of the new circular economic model pursued by the European Union.