Suchergebnisse

In the early nineteenth century, Portugal suffered one of the largest military offensives ever held in its territory. The Portuguese people, with his British Allies, prepared to resist the invasion. Between 1809 and 1811, a complex defensive system was built around Lisbon, called "The Defensive Lines of Torres", which objective was to protect the Portuguese capital during the Third French Invasion. The architecture and the military strategy of this defensive system have turned into a reference of the European history, because it determines the beginning of the defeat of the Napoleonic troops. This defensive system is composed by 152 fortifications and 85 km of length, organized by two Defensive Lines, at the North of Lisbon, connecting Tagus River to Atlantic Ocean. A vast area of military structures was implemented, including fortifications of massive dimensions, as well as small strongholds, redoubts and batteries. These military structures had to be built very quickly, using natural resources. The material withdrawn from the ditches excavated around them – earth and stones – was often employed in the forts' construction. However, rigorous plans and selected techniques were used, in order to achieve the strong, durable structures that could be preserved for two hundred years, until nowadays. Normally, inside the military square there was a powder magazine to store ammunitions, transverses made out of earth from the ditches to protect soldiers from the enemy fire and gun platforms where they manoeuvred the artillery pieces. The Forts' walls were lifted using military rammed earth, together with stone and possibly agglomerated with lime. The powder magazines and, in some cases, the gun platforms were built in masonry, of stone and lime-earth mortars. In the scope of a Project to restore the Forts and to enhance the Historical sets, the study of the construction techniques and materials is to be carried out. Mortars' samples were extracted from four forts of the two Defensive Lines of Torres, three from powder magazines and one from a gun platform. Samples of rammed earth were also collected from several forts. In the present paper the study of the mortars is presented. The stratigraphy of the applied mortars, their composition and physical characteristics are described and discussed. Conclusions are withdrawn concerning the military construction techniques in those difficult war conditions. ; DED/NRI ; 2011 ; 11-15 de Setembro

The potential of heat inactivated Saccharomyces cerevisiae in the bioremoval and reduction of Cr (VI) ions from wastewaters was evaluated in terms of metal uptake in time and at equilibrium, and biosorption efficiency, by varying pH, biosorbent doses, contact time and temperature, in batch mode. During the sorption process, the heat inactivated biomass of the yeast Saccharomyces cerevisiae is capable of reducing Cr(VI) to Cr(III). Different kinetic models based on adsorption and reduction are used to represent the kinetic data of Cr(VI) bioremoval by S. cerevisiae, in explaining the biosorption mechanism of heavy metals and potential rate-controlling steps, in the perspective of full-scale process design. The results indicated some potential differences in the Cr(VI) removal mechanism at different experimental conditions. FTIR and SEM analysis were performed as well as to elucidate the mechanism of metal bioremoval by S. cerevisiae. FTIR spectra indicate that heavy metal bioremoval process doesn't imply in this case the formation of stable covalent bonds, but it is predominantly based on chemical interactions, ion-exchange type. The SEM micrographs of Cr-loaded yeast, indicates that the surface morphology doesn't change much after chromium ions were uptaken. This leads to the conclusion that Cr(VI) reduction occurs at the interface of the adsorbent. ; This paper was elaborated with the support of BRAIN project Doctoral scholarships as an investment in intelligence - ID 6681, financed by the European Social Found and Romanian Government and with the support of a grant of the Romanian National Authority for Scientific Research, CNCS - UEFISCDI, project number PN-II-ID-PCE-2011-3-0559", Contract ...

7‐11 November 2010, Tenth International Congress on Drug Therapy in HIV Infection, Glasgow, UK