Consult: Billings, C. E. and Gussman, R. A. Dynamic behavior of aerosols. In: Handbook on Aerosols, R. Dennis, Ed. National Technical Information Service Publication TID-26608, 1976 as well as Hatch, T. F. and Gross, P. Pulmonary deposition and retention of inhaled particles. Academic Press, NY, 1964, 192 pp. The problem is that these publications are now difficult to find. Consult ref 3 given above which is easier to obtain.