  The universal aspects of atom-dimer elastic collisions are investigated
within the framework of Faddeev equations. The two-body interactions between
the neutral atoms are approximated by the separable potential approach. Our
analysis considers a pure van der Waals potential tail as well as soft-core van
der Waals interactions permitting us in this manner to address the universally
general features of atom-dimer resonant spectra. In particular, we show that
the atom-dimer resonances are solely associated with the {\it excited} Efimov
states. Furthermore, the positions of the corresponding resonances for a
soft-core potentials with more than 5 bound states are in good agreement with
the corresponding results from an infinitely deep pure van der Waals tail
potential.
