Expressions for frictional and conservative force combinations within   the dissipative Lagrange-Hamilton formalism
  Dissipative Lagrangians and Hamiltonians having Coulomb, viscous and quadratic damping,together with gravitational and elastic terms are presented for a formalism that preserves the Hamiltonian as a constant of the motion. Their derivations are also shown. The resulting L's and H's may prove useful in exploring new types of damped quantum systems. 
Charles E. Smith