  Here we generalize the results of the work of ref. [10] in modified Chaplygin
gas model and tachyonic field model. Here we have studied the thermodynamical
behaviour and the equation of state in terms of volume and temperature for both
models. We have used the solution and the corresponding equation of state of
our previous work [12] for tachyonic field model. We have also studied the
thermodynamical stability using thermal equation of state for the tachyonic
field model and have shown that there is no critical points during
thermodynamical expansion. The determination of $T_{*}$ due to expansion for
the tachyonic field have been discussed by assuming some initial conditions.
Here, the thermal quantities have been investigated using some reduced
parameters.
