mass-transfer problem

Water saturated with air at 20C passes through a hydrophobic-hollow fiber(membrane) at a speed of 50 cm/s. The hollow fiber is 1 m long and has an inner diameter of 500 m, and a vacuum was created outside the hollow fiber to remove oxygen as soon as it diffused to the walls of the hollow fiber. Calculate the material transfer coefficient for oxygen. (Use Sh=1.62 Gz^1/3, Gz=m/(Dv*L*rho)=/4* Re*Sc*D/L, Dv at 26 C = 2.41*10^-5 cm²/sec)