A cylindrical vessel is pressurized to 1.7 MPa. The structure on which the vessel rests becomes damaged, resulting in uneven support that causes a twisting moment T0 of 8 106 N-m on the vessel. The vessel has an outer diameter of 2.5 m and a wall thickness of 50 mm. The steel wall has a uniaxial yield strength of 600 MPa. Determine the factor of safety with respect to yielding (a) assuming a maximum shear stress yield criterion and (b) assuming a von Mises yield criterion.