ρ	Solution density (kg/m3)
η B	Dynamic viscosity (kg/(m⋅s))
ξ	Dimensionless independent variables, x/W
τ	Residence time (s)
τ D	Diffusion time (s)
υξ	X-directional velocity (m/s)
Φ	Flow rate (µL/min)
ψ	Dimensionless independent variables, y/W