“…which is a good approximation for the gas-phase synthesis of nanoparticles (Medalia, 1982;Köylü & Faeth, 1992;Kiss, Sönderlund, Niklasson, & Granqvist, 1999) may be assumed, and the count median diameter d med and geometric standard deviation g as characteristic parameters of this distribution are then to be determined. These parameters may be obtained by a direct multi-dimensional non-linear regression (Lehre et al, 2003), i.e., finding an optimum with a variation of test distributions, which of course requires additional computing time and thus complicates in situ application to transient processes.…”