The effect of clouds on the dynamical and chemical evolution of gas-rich
  dwarf galaxies
  We study the effects of clouds on the dynamical and chemical evolution of
gas-rich dwarf galaxies, in particular focusing on two model galaxies similar
to IZw18 and NGC1569. We consider both scenarios, clouds put at the beginning
of the simulation and continuously created infalling ones. Due to dynamical
processes and thermal evaporation, the clouds survive only a few tens of Myr,
but during this time they act as an additional cooling agent and the internal
energy of cloudy models is typically reduced by 20 - 40% in comparison with
models without clouds. The clouds delay the development of large-scale
outflows, therefore helping to retain a larger amount of gas inside the galaxy.
However, especially in models with continuous creation of infalling clouds,
their bullet effect can pierce the expanding supershell and create holes
through which the superbubble can vent freshly produced metals. Moreover,
assuming a pristine chemical composition for the clouds, their interaction with
the superbubble dilutes the gas, reducing the metallicity (by up to ~ 0.4 dex)
with respect to the one attained by diffuse models.
