  We investigate whether the anomalous elemental abundance patterns in some of
the C-enhanced metal-poor-s+r (CEMP-r/s) stars are consistent with predictions
of nucleosynthesis yields from the i-process, a neutron-capture regime at
neutron densities intermediate between those typical for the slow (s) and rapid
(r) processes. Conditions necessary for the i-process are expected to be met at
multiple stellar sites, such as the He-core and He-shell flashes in
low-metallicity low-mass stars, super-AGB and post-AGB stars, as well as
low-metallicity massive stars. We have found that single-exposure one-zone
simulations of the i-process reproduce the abundance patterns in some of the
CEMP-r/s stars much better than the model that assumes a superposition of
yields from s- and r-process sources. Our previous study of nuclear data
uncertainties relevant to the i-process revealed that they could have a
significant impact on the i-process yields obtained in our idealized one-zone
calculations, leading, for example, to ~0.7dex uncertainty in our predicted
[Ba/La] ratio. Recent 3D hydrodynamic simulations of convection driven by a
He-shell flash in post-AGB Sakurai's object have discovered a new mode of
non-radial instabilities: the Global Oscillation of Shell H-ingestion. This has
demonstrated that spherically symmetric stellar evolution simulations cannot be
used to accurately model physical conditions for the i-process.
