  We study the influence of the repulsive Coulomb interactions on thermodynamic
properties of the boson fermion model with an anisotropic (d-wave, and extended
s-wave) order parameter. Superconductivity is induced in this model from the
anisotropic charge exchange interaction between the conduction band fermions
(electrons or holes) and the immobile hard-core bosons (the localized electron
pairs). The on-site Coulomb repulsion competes with this pairing interaction
and hence is expected to have a detrimental influence on superconductivity. We
analyze this effect in some detail considering the two opposite limits of: the
weak and strong repulsion. A possible crossover between both these regimes is
also discussed.
