Europhys. Lett.
Volume 70, Number 4, May 2005
Page(s) 446 - 451
Section General
Published online 13 April 2005
Europhys. Lett., 70 (4), pp. 446-451 (2005)
DOI: 10.1209/epl/i2004-10508-7

Positive and negative entropy production in an ideal-gas expansion

J. I. Belandria

Escuela de Ingeniería Química, Facultad de Ingeniería, Universidad de los Andes Mérida, Venezuela

received 22 September 2004; accepted in final form 23 March 2005
published online 13 April 2005

A theoretical thermodynamic analysis shows that an irreversible isothermal expansion of an ideal gas in a cylinder equipped with a piston may occur through trajectories involving a simultaneous positive and negative entropy production. Under these trajectories the operation is more efficient than a reversible expansion between the same initial and final states. This unexpected behavior may be explained as a consequence of an entropy coupling between the simultaneous positive and negative entropy production processes.

05.70.Ce - Thermodynamic functions and equations of state.
05.70.Ln - Nonequilibrium and irreversible thermodynamics.
65.40.Gr - Entropy and other thermodynamical quantities.

© EDP Sciences 2005