  We present yields from stars of mass in the range Mo<M<8Mo of metallicities
Z=0.0003 and Z=0.008, thus encompassing the chemistry of low- and high-Z
Globular Clusters. The yields are based on full evolutionary computations,
following the evolution of the stars from the pre-Main Sequence through the
Asymptotic Giant Branch phase, until the external envelope is lost.
Independently of metallicity, stars with M<3Mo are dominated by Third
Dredge-Up, thus ejecting into their surroundings gas enriched in carbon and
nitrogen. Conversely, Hot Bottom Burning is the main responsible for the
modification of the surface chemistry of more massive stars, whose mass exceeds
3Mo: their gas shows traces of proton-capture nucleosynthesis. The extent of
Hot Bottom Burning turns out to be strongly dependent on metallicity. In this
paper we analyze the consequences of this fact. These results can be used to
understand the role played by intermediate mass stars in the self-enrichment
scenario of globular clusters: the results from spectroscopic investigations of
stars belonging to the second generation of clusters with different metallicity
will be used as an indirect test of the reliability of the present yields. The
treatment of mass loss and convection are confirmed as the main uncertainties
affecting the results obtained in the context of the modeling of the thermal
pulses phase. An indirect proof of this comes from the comparison with other
investigations in the literature, based on a different prescription for the
efficiency of convection in transporting energy and using a different recipe to
determine the mass loss rate.
