  The historical development of the Carnot cycle necessitated the construction
of isothermal and adiabatic pathways within the cycle that were also
mechanically "reversible" which lead eventually to the Kelvin-Clausius
development of the entropy function where the heat absorption is for the
diathermal (isothermal) paths of the cycle only. It is deduced from traditional
arguments that Fourier heat conduction involves mechanically "reversible" heat
transfer with irreversible entropy increase. Here we model heat conduction as a
thermodynamically reversible but mechanically irreversible process. The MD
simulations conducted shows excellent agreement with the theory. Such views and
results as these, if developed to a successful conclusion could imply that the
Carnot cycle be viewed as describing a local process of energy-work conversion
and that irreversible local processes might be brought within the scope of this
cycle, implying a unified treatment of thermodynamically (i) irreversible, (ii)
reversible, (iii) isothermal and (iv) adiabatic processes.
