Revising the Theory of Cross Phenomena

Abstract: Recently, the present author proposed a Theory of Cross Phenomena (TCP), which asserts that the flux of a molar quantity is governed solely by the gradient of its conjugate potential, as derived from the combined law of thermodynamics. This contrasts with the classical Onsager theorem, i.e., flux equations and reciprocal relations, which posit that fluxes are linearly related to the gradients of all potentials through a symmetric kinetic coefficient matrix. In the present work, the original TCP is revised with the flux equation derived from the first law of thermodynamics and the definitions of the total entropy change and the total work change of an internal process. Although the revision is foundational, both original and revised TCP frameworks lead to similar conclusions with respect to the Onsager theorem.