  Oscillatory shear on two-dimensional monodisperse liquid foams was performed.
We show that the effect of the oscillatory shear is to cause the migration of
bubbles which size is greater than that of a typical bubble of the foam. These
so-called flaws move towards the periphery of the foam in a non random motion,
thus realizing size segregation in a system which is by construction gravity
insensitive. We also show that elongated cavities in the foam could be relaxed
towards a more isotropic form with oscillatory shear, and we discuss the
pertinent parameters of this relaxation.
