Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Thomson's formulation of the second law: an exact theorem and limits of
  its validity   Thomson's formulation of the second law - no work can be extracted from a
system coupled to a bath through a cyclic process - is believed to be a
fundamental principle of nature. For the equilibrium situation a simple proof
is presented, valid for macroscopic sources of work. Thomson's formulation gets
limited when the source of work is mesoscopic, i.e. when its number of degrees
of freedom is large but finite. Here work-extraction from a single equilibrium
thermal bath is possible when its temperature is large enough. This result is
illustrated by means of exactly solvable models. Finally we consider the
Clausius principle: heat goes from high to low temperature. A theorem and some
simple consequences for this statement are pointed out.

24
The categories of this paper are: dg-ga
15
The categories of this paper are: nucl-ex
16
The categories of this paper are: stat
35
The categories of this paper are: mtrl-th
23
The categories of this paper are: solv-int
6
The categories of this paper are: astro-ph
31
The categories of this paper are: ao-sci
11
The categories of this paper are: hep-lat
19
The categories of this paper are: eess
34
The categories of this paper are: chem-ph
0
The categories of this paper are: hep-ph
29
The categories of this paper are: funct-an
22
The categories of this paper are: chao-dyn
37
The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th
3
The categories of this paper are: physics