Christian Gruber
Thermodynamics of systems with internal adiabatic constraints:
time evolution of the adiabatic piston
(168K, Postscript)

ABSTRACT.  The equations for the time evolution of the controversial
adiabatic piston problem are obtained using a very primitive model
of the fluids. It thus shows that the 1st and 2nd laws of
thermodynamics lead to equations of motion which determine uniquely
the final equilibrium state, while this state cannot be predicted
using the laws of thermostatics only.