To incorporate distributed energy exchange processes into the previous models from lectures 1 through 3 which are based on a "Landauer-like picture" where the Joule heating associated with current flow occurs entirely in the two contacts.
Although there is experimental evidence that this idealization is not too far from the truth in many nanodevices of today, dissipation generally occurs throughout the channel. Moreover there is great interest in energy conversion devices that convert heat into electricity or use electrical energy to pump heat. Our purpose here is (1) to describe the basic principles that must be obeyed by any model for energy conversion processes in order to comply with the laws of thermodynamics and (2) to convey the insights that nanodevices provide into the subtle issues of irreversibility that Boltzmann struggled with over a century ago when he constructed the first transport theory.
This lecture is part 1 of 2.