Equation Icon  ∂u u (r,z) Err(r,z) = ---r(r,z) , Eϕϕ(r,z) =--r---- , ∂r [ r ] ∂uz- 1- ∂ur- ∂uz- Ezz(r,z) = ∂z (r,z) , Erz = 2 ∂z (r,z) + ∂r (r,z ) . (3.88 )