Planetary nebulae in the inner Milky Way: new abundances
  The study of planetary nebulae in the inner-disk and bulge gives important
information on the chemical abundances of elements such as He, N, O, Ar, Ne,
and on the evolution of these abundances, which is associated with the
evolution of intermediate-mass stars and the chemical evolution of the Galaxy.
  We present accurate abundances of the elements He, N, S, O, Ar, and Ne for a
sample of 54 planetary nebulae located towards the bulge of the Galaxy, for
which 33 have the abundances derived for the first time. The abundances are
derived based on observations in the optical domain made at the National
Laboratory for Astrophysics (LNA, Brazil). The data show a good agreement with
other results in the literature, in the sense that the distribution of the
abundances is similar to those works.
