  The themes covered in the present thesis are: a detailed study of double
phonon giant resonances in normal nuclei, the enhancement of the excitation of
Giant Pairing Vibrations using weakly-bound nuclei, an extension of the
Steinwedel-Jensen model for Giant Dipole Resonances to treat surface effects
and presence of neutron skin and, finally, a model on breakup reactions in
weakly-bound dicluster nuclei.
