1. Inst. of Energy Sci., Facu. of Engrg., Univ. of Perugia, 06125 Perugia, Italy.
2. Dept. of Civ. and Envir. Engrg., Cornell Univ., Ithaca, NY 14853.
3. Aerodyn. im Bauwesen, Ruhr-Universitaet Bochum, Germany.
4. Build. and Fire Res. Lab., National Inst. of Standards and Technology, Gaithersburg, MD 20899-8611.