Consider the steady state diffusion of a solute through a membranous sphere as shown

below. Such a situation occurs when drugs are released from liposomes. The membrane

is defined by the region between $R_0$ and $R_i.$ The solute concentration is highest at the

core region. The spheres are placed in a large reservoir and the solute concentration in

the bath is zero. Assume that the partition coefficient is one and there is no reaction in

the membrane.

$($a$)$ Given the simplified form of the governing equation for diffusion in this system.

$($b$)$ State the boundary conditions.

$($c$)$ Solve to obtain the concentration distribution in the membrane.

$($d$)$ Determine the flux at $r=R_0.$ THIS IS A FLUID MECHANICS BIOTRANSPORTS QUESTION PLZ BE CLEAR WITH EQUATIONS AND HOW U SIMPLIFIED