
39Principles of Non-Equilibrium Thermodynamics and Friction
smoke particle concentration will be reduced in the vicinity of the rod (the
scale of the effect is less than 1 mm, but it can be seen with the naked eye).
This is because hotter air molecules hit smoke particles from the side of the
wire, pushing the particles in the opposite direction away from the wire.
When a substance ows from a low to a high concentration region, it must
be coupled with a compensating process. The principles of thermodynamics
allow the progress of a process without or against its primary driving force
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only if it is coupled with another process.
It is expec