The first law of thermodynamics has been first proposed by MAYER^{2.8} in
1841 [74]: ``Heat is a kind of energy and can therefore neither be
created nor destroyed.'' Hence, heat has been defined as the transfered thermal
energy between two systems if they are brought into thermal
contact [75]. The infinitesimal change of the internal energy
of a system
can be expressed as

where is the infinitesimal heat added to the system and represents the infinitesimal work performed by the system . This equation follows directly from the total differential of the entropy

(2.29) |

With the equations (2.22)-(2.24), the total differential of the entropy becomes

where the pressure can be found as

and the chemical potential as

By comparison of the coefficients from (2.28) and (2.30)-(2.32), the net heat flow and the work done by the system can be found as

(2.33) | |||

(2.34) |

Stefan Holzer 2007-11-19