Note that no channels can be observed during the aeration
process since the sound wave energy effectively disrupts the
channels. As a result of the surface modification of the nanoparticles,
the agglomerates have a relatively small average
size leading to a significant reduction in the minimum fluidization
velocity, 0.0452 m/s. At f = 40 Hz, the fluidized bed
tends to fluidize at u = 0.0241 m/s.