1. Dr., Institute of Science and Technology for Ceramics, via Granarolo 64, 48018 Faenza, Italy.
2. Professor, Dept. of Energetic, Univ. of Ancona, via Brecce Bianche, 100 Ancona, Italy.
3. Dr., Consorzio Aveolater, Viale A. Moro 16, 40127 Bologna, Italy.