Energy release from hadron-quark phase transition in neutron stars and
  the axial $w$-mode of gravitational waves
  Describing the hyperonic and quark phases of neutron stars with an isospin-
and momentum-dependent effective interaction for the baryon octet and the MIT
bag model, respectively, and using the Gibbs conditions to construct the mixed
phase, we study the energy release due to the hadron-quark phase transition.
Moreover, the frequency and damping time of the first axial $w$-mode of
gravitational waves are studied for both hyperonic and hybrid stars. We find
that the energy release is much more sensitive to the bag constant than the
density dependence of the nuclear symmetry energy. Also, the frequency of the
$w$-mode is found to be significantly different with or without the
hadron-quark phase transition and depends strongly on the value of the bag
constant. Effects of the density dependence of the nuclear symmetry energy
become, however, important for large values of the bag constant that lead to
higher hadron-quark transition densities.
