[en] The Italian program for developing and testing steam separators for nuclear plants is presented. This program is carried out in the frame of a research agreement between ENEA and ANSALDO DBGV S.p.A. The experimental activity includes: (1) small scale experiments intended to obtain first screening of steam separators geometry: these experiments are carried out in air-water facility (L.AR.A). Results are merely qualitative; (2) full scale experiments carried out in air water facility (ARAMIS). These experiments are intended to obtain quantitative results concerning carryover, carryunder, efficiency, pressure drops; and (3) full scale tests intended to qualify both new designed and licensee models of steam separators. Tests will be carried out in Gest-Sep facility operating at the actual reactor conditions. This paper contains: LARA loop presentation, ARAMIS loop presentation, GEST-SEP loop presentation, some scaling criteria utilized to choice the air-water operatng parameters, and examples of results obtained in air water small scale experiments

[en] We investigate the relation between the structure and the viscoelastic properties of a model polymer nanocomposite system based on a mixture of inorganic particles and poly(ethyleneoxide). Hydrophilic fumed silica nanoparticles were used as fillers and PEO-based nanocomposites were prepared by melt compounding and freeze-dryng. In both cases, dynamic oscillatory measurements in the melt state highlighted an increase of the frequency-dependent linear viscoelastic moduli with the filler content and a solid-like behaviour above a critical volume fraction. The freeze-dried samples exibhited a significant enhancement of the elasticity at lower filler contents as a result of the effect of particle dispersion on polymer chain dynamics.