[en] The authors draw on their experience of steels for nuclear purposes to discuss the production in recent years of a new type of austenitic stainless steel, SIAS 316LB (corresponding to AFNOR Z2CND 18-12, AUTAAS 722 with low C content and additions of B and N). This steel grade is employed in nuclear energy, particularly on fast reactors where thermal, mechanical and chemical stresses are considerably more severe than those which effect conventional thermal reactors. The simultaneous addition of interstitial alloying elements such as B and N substantially improves the hot mechanical resistance for protracted use; in particular boron affects creep properties and changes the sensitive area to higher temperatures and to longer time periods. The authors' purpose is to point out the metallurgical properties obtained in conditions of industrial-scale production of the material developed at the Cogne factory in Aosta. These properties are compared to those of the conventional AISI 316 grade of steel. The influence of the hot working processes on the material properties (heating condition, reduction ratios, etc.) is underlined taking into consideration forgings of large dimensions. The relationship between microstructure (precipitation of second phases containing B and N at the grain boundaries) and properties is also pointed out by TEM analysis. (author)

[en] Computer simulations have become a widely used and powerful tool to study the behaviour of many-particle and many-interaction systems and processes such as nucleic acid dynamics, drug-DNA interactions, enzymatic processes, membrane, antibiotics. The increased reliability of computational techniques has made possible to plane a bottom-up approach in drug design, i.e. designing molecules with improved properties starting from the knowledge of the molecular mechanisms. However, the in silico techniques have to face the fact that the number of degrees of freedom involved in biological systems is very large while the time scale of several biological processes is not accessible to standard simulations. Algorithms and methods have been developed and are still under construction to bridge these gaps. Here we review the activities of our group focussed on the time-scale bottleneck and, in particular, on the use of the meta dynamics scheme that allows the investigation of rare events in reasonable computer time without reducing the accuracy of the calculation. In particular, we have devoted particular attention to the characterization at microscopic level of translocation of antibiotics through membrane pores, aiming at the identification of structural and dynamical features helpful for a rational drug design.

[en] The amorphous/crystalline silicon (a-Si/c-Si) heterostructure has recently attracted new interest due to higher open circuit voltage V_oc and low temperature fabrication processes. By reducing the wafer thickness all these characteristics become a necessity, together with the requirement of a back reflecting mirror, to obtain an effective optical confinement. To this aim dielectric mirrors can be adopted in the rear side of the solar cells, together with a local process of laser fired back Al contact. Taking advantage of a-Si/SiN_x passivation properties of c-Si surface a Bragg reflector configuration can be formed on the rear side of the c-Si wafer by Plasma Enhanced Chemical Vapor Deposition (PECVD) alternating several couples of a-Si/SiN_x and choosing their thicknesses to maximize the reflectance inward the c-Si wafer in the NIR spectrum. In this work we have adopted this mirror on the rear side of an n-a-Si/i-a-Si/p-c-Si heterostructure solar cell to obtain a full low temperature process. The cell back contact has been ensured by an Al diffusion into the c-Si wafer promoted by Nd-YAG pulsed laser. The front cell contact has been enhanced by chromium silicide CrSi formation on top of the n-a-Si layer and ITO deposition followed by an Ag grid. A V_oc of 681 mV and 94% of IQE at 1000 nm have been reached.