The use of biopolyesters, as polymeric matrices, and natural fillers derived from wastes or by-products of food production to achieve biocomposites is nowadays a reality. The present paper aims to valorize mussel shells, 95% made of calcium carbonate (CaCO₃), converting them into high-value added products. The objective of this work was to verify if CaCO₃, obtained from Mediterranean Sea mussel shells, can be used as filler for a compostable matrix made of Polylactic acid (PLA) and Poly(butylene adipate-co-terephthalate) (PBAT). Thermal, mechanical, morphological and physical properties of these biocomposites were evaluated, and the micromechanical mechanism controlling stiffness and strength was investigated by analytical predictive models. The performances of these biocomposites were comparable with those of biocomposites produced with standard calcium carbonate. Thus, the present study has proved that the utilization of a waste, such as mussel shell, can become a resource for biocomposites production, and can be an effective option for further industrial scale-up.

The study and the evolution of a simple air-assisted injection system for two-cycle, S.I. engines is described. In the first stage of the research the validity of the system was investigated. During this time the system underwent several improvements and modifications. Later, the research was carried on with the following aims: a) to distinguish the spray characteristics by means of a high speed photographic technique; b) to investigate the dependence of such characteristics on some parameters of the injection system, and their influence on engine performance, with special regard to fuel economy and exhaust emissions. Finally, the case of fuel vaporisation at the outlet of the electroinjector was investigated. In fact, vaporisation and ideal atomisation are similar under some aspects and the knowledge of b.s.f.c. and HC emission in the limit case of perfect atomisation would give a precise idea of the improvements obtainable through betterments in spray characteristics.