Consider the steady-state diffusion of hydrogen through the walls of a cylindrical nickel tube as described in Problem 6.D2. One design calls for a diffusion flux of 5 × 10^-8 mol/m²-s, a tube radius of 0.125 m, and inside and outside pressures of 2.026MPa (20atm) and 0.0203MPa (0.2atm), respectively; the maximum allowable temperature is 450°C. Specify a suitable temperature and wall thickness to give this diffusion flux and yet ensure that the tube walls will not experience any permanent deformation.