  Neutrino oscillations, especially to light sterile states, can affect the
nucleosynthesis yields because of their possible feedback effect on the
electron fraction (Ye). For the first time, we perform nucleosynthesis
calculations for neutrino-driven wind trajectories from the neutrino-cooling
phase of an 8.8 Msun electron-capture supernova, whose hydrodynamic evolution
was computed in spherical symmetry with sophisticated neutrino transport and
whose Ye evolution was post-processed by including neutrino oscillations both
between active and active-sterile flavors. We also take into account the
alpha-effect as well as weak magnetism and recoil corrections in the neutrino
absorption and emission processes. We observe effects on the Ye evolution which
depend in a subtle way on the relative radial positions of the sterile MSW
resonances, of collective flavor transformations, and on the formation of alpha
particles. For the adopted supernova progenitor, we find that neutrino
oscillations, also to a sterile state with eV-mass, do not significantly affect
the element formation and in particular cannot make the post-explosion wind
outflow neutron rich enough to activate a strong r-process. Our conclusions
become even more robust when, in order to mimic equation-of-state dependent
corrections due to nucleon potential effects in the dense-medium neutrino
opacities, six cases with reduced Ye in the wind are considered. In these
cases, despite the conversion of active neutrinos to sterile neutrinos, Ye
increases or is not significantly lowered compared to the values obtained
without oscillations and active flavor transformations. This is a consequence
of a complicated interplay between sterile-neutrino production,
neutrino-neutrino interactions, and alpha-effect.
