Equipment is available for ultrafiltration of a protein solution at constant volume to remove low molecular weight species by addition of water or buffer to feed in an operation called diafiltration. The flow channels for this system are tubes $0\mathrm{.}1$ cm in diameter and $100$ cm long. The protein has a diffusion coefficient of $9\backslash$times $10-7$ cm$2/$s$.$ the solution has a viscosity of $1\mathrm{.}2$ cp and a density of $1\mathrm{.}1$ g$/$cm$3$

The system is capable of operating at a bulk stream velocity of $300$ cm$/$s$.$ At this velocity, determine the polarization modulus for a transmembrane flux of $45$ liters m$-2$h$-1$