Applicability of fractals to the analysis of the projection of small flocs

The validity of the concept of fractal structure for the analysis of the pr ojection of small flocs was examined using the data obtained from a table-t ennis-ball simulation and a coagulation experiment with polystyrene latex p articles. Two methods defining a fractal dimension, the box-counting techni que and the enumeration of primary particles in an enclosing circle as a fu nction of the radius, were tested for the result of numerical simulations. Comparison of the two results revealed their qualitative tendencies and the limits of their applicability. The projection of flocs was also examined u sing the relation between the maximum distance in the projected hoc, D-m, a nd the number of primary particles composing the hoc, i. The decrease of fr actal dimension, D, in the lower limit of i was demonstrated both numerical ly and experimentally. (C) 1998 Academic Press.