  The evolution of a star of initial mass 9 M_s, and Z = 0.02 in a Close Binary
System is followed in the presence of different mass companions in order to
study their influence on the final evolutionary stages and, in particular, on
the structure and composition of the remnant components. We study two extreme
cases. In the first one the mass of the secondary is 8 M_s, whereas in the
second one the mass was assumed to be 1 M_s. For the first of those cases we
have also explored the possible outcomes of both conservative and
non-conservative mass-loss episodes. During the first mass transfer episode,
several differences arise between the models. The system with the more extreme
mass ratio is not able to survive the 1st. Roche lobe overflow, and spiral-in
of the secondary onto the envelope of the primary is most likely. The system
formed by two stars of comparable mass undergoes two mass transfer episodes in
which the primary is the donor. We have performed two sets of calculations
corresponding to this case in order to account for conservative and
non-conservative mass transfer during the first mass loss episode. One of our
main results is that for the non-conservative case the secondary becomes a
Super-AGB. Such a star undergoes a final dredge-up episode, similar to that of
a single star of comparable mass. The primary components do not undergo a
Super-AGB phase, but instead a carbon-oxygen white dwarf is formed in both
cases, before reversal mass transfer occurs. However, given the extreme mass
ratios at this stage between the components of the binary system, the
possibility of merger episodes remains likely. We also discuss the presumable
final outcomes of the system and possible observational counterparts.
