Fig. 6. Effects of (a) bulk dry density (for (A_es = 100 m² g^-1, _bw = 15 S m^-1, _fw = 0.6 S m^-1, and = 0.5) and (b) specific surface on dielectric permittivity based on four component volumetric mixing model (_d = 1.56 g cm^-3, _bw = 15 S m^-1, _fw = 0.6 S m^-1, and = 0.5).