D C Agrawal

Comment on `The Stefan-Boltzmann constant in n-dimensional space'

The expression for the Stefan-Boltzmann constant in n-dimensions as obtained by Landsberg and De Vos is modified by the appropriate spin-degeneracy factor of the photon.

The Carnot cycle with the van der Waals equation of state

The authors derive an expression for the efficiency of a Carnot engine using a van der Waals gas as the working substance.

Infinitesimal Carnot cycle and Maxwell's first relation

We demonstrate that by employing usual calculus along with the first law, the efficiency of a Carnot cycle can be evaluated when the working substance has an arbitrary equation of state. This leads to a neat derivation of Maxwells first relation without using either the properties of perfect differentials as done by Tjiang and Sutanto or the abstract symbolism of topology as done by Hannay.

First law of thermodynamics from Hamiltonian viewpoint

For a closed universe containing several interacting composite bodies we interpret the first law of thermodynamics in terms of the differentials of Hamiltons canonical coordinates.