# Equation of motion At the continuum level

At the continuum level, considering the translational motion of the NP in the direction that BGB-324 is vertical to the solidification front, the critical solidification velocity of capturing the nanoparticle is determined from the equation of motion asequation(17)mdvdt=fm+fdwhere vv is the particle velocity, m is the particle mass, t is the time, fmfm is the intermolecular force (van der Waals force) between the solidification front and nanoparticle, and fdfd is the drag force due to the pressure gradient around the particle.

In steady-state models, left hand side (LHS) of Eq. (17) is taken as zero.