Stationary Oscillations in a Damped Wave Equation from Isospectral   Bessel Functions
  Using the isospectral partners of the Bessel functions derived by Reyes et al., we find, on one hand, that these functions show non-typical supersymmetric (SUSY) behavior and, on the other, that the isospectral partner of the classical wave equation is equivalent to that of a damped system whose oscillations do not vanish in time, but show a non-harmonic shape. 
N. Barbosa-Cendejas and M. A. Reyes