“…Over the years, research involving the blending of different pseudo-spherical particle sizes to maximize the packing fraction has been addressed to optimize several physical properties including viscosity [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ], modulus [ 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ], and impact [ 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 ]. The importance of the packing fraction for a property such as viscosity can easily be evaluated by addressing one of the more general models to characterize viscosity, such as the following generalized viscosity model [ 7 , 8 , 9 , 10 ]: where …”