“…In cylindrical coordinates, we can express this requirement through the three equations* rr cos(n,r) + r rz cos(n,z) + Tr cos(n,p) = T r 0 0 T cos(n,r) + Tr cos(n,z) + Tr cos(n,cp) = T = 0 , (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19) rz zz zcp z r cos(n,r) + r cos(n,z) + T" cos(n,qp) = T = 0 rcp zcp cq C where T, Tz, and T are the three components of the traction, and (n,r), (n,z), and (n,cp) represent the angles between the outward-directed normal to the surface and the r-, z-, and 9-directions, respectively.…”