  We reinvestigate the Bose-Einstein condensation (BEC) thermodynamics of a
weakly interacting dilute Bose gas under the action of a trap using a
semiclassical two-fluid mean-field model in order to find the domain of
applicability of the model. Such a model is expected to break down once the
condition of diluteness and weak interaction is violated. We find that this
breakdown happens for values of coupling and density near the present
experimental scenario of BEC. With the increase of the interaction coupling and
density the model may lead to unphysical results for thermodynamic observables.
