Formulação de betão autocompactável com resíduos de pedreiras do Alentejo: Aproveitamento de resíduos no fabrico do betão

Os betões autocompactáveis (BAC) são betões que se definem pela capacidade de fluir no interior das cofragens, preenchendo-as e envolvendo as armaduras só por acção do seu próprio peso, sem bloqueio dos agregados e mantendo-se homogéneo em todo o seu volume. As adições activas do tipo II nomeadamente as cinzas volantes, utilizadas na fabricação do BAC irão escassear no futuro pelo facto de provirem da queima do carvão da qual resulta uma quantidade elevada de C02. Para minimizar estas emissões, o carvão começa a ser substituído por gás natural. Mas, como o BAC necessita duma grande quantidade de finos, há necessidade de encontrar outros subprodutos que a substituam. Tendo em conta o que atrás se afirma introduziram-se na fabricação do BAC resíduos de pedreira do Alentejo, identificaram-se as suas características no estado fresco e no estado endurecido. Este estudo teve também em conta o factor económico da sua produção. /ABSTRACT: Self-Compacting (SCC) is concrete which may be defined by the ability to flow inside the formwork, filling them and involving the reinforcements only by action of its own weight, without blocking and maintaining uniformity throughout its volume. Type II additions, as fly ash, are used in the manufacture of SCC. The supply of fly ash in the future will be difficult because they come from the burning of coal resulting in a high amount of C02. To minimize these emissions, coal is being replaced by natural gas. But, as the BAC requires a large amount of fine materials, the formulation of SCC requires other fine products. Having this in mind, the use of waste from Alentejo quarries in concrete was tested. The characteristics of SCC with waste material were identified in fresh and hardened state. This study also took into account the economic factor of production.

Evaluating potential olive orchard sugar food sources for the olive fly parasitoid Psyttalia concolor

Olive fruit fly Bactrocera oleae (Rossi) (Diptera: Tephritidae) is a major olive pest in the Mediterranean basin where increasing insecticide resistance has enhanced damage and necessitates more reliance on other control strategies, such as biological control. Provision of floral resources has been reported to improve the effectiveness of natural enemies. Here, we tested the effect of six plant nectars and two honeydew sources on the survival of Psyttalia concolor (Szépligeti) (Hymenoptera: Braconidae), a parasitoid wasp used in the biological control of olive fruit fly. Our results showed a positive effect on survival associated with nectars of Anchusa azurea Mill., Rosmarinus officinalis L., Lavatera cretica L. and Calamintha nepeta (L.) Savi, while honeydew proved to be a valuable alternative food source. When offering flowers directly to insects, Anchusa azurea, Lavatera cretica, and Foeniculum vulgare L. were found to be the most beneficial species, indicating also that P. concolor feeds predominantly on shallow corollas.