Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Microscopic chaos and macroscopic entropy in fluids   In nonequilibrium thermodynamics macroscopic entropy creation plays an
important role. Here we study, from various viewpoints, its relation with the
phase space contraction, which has been recently proposed as an apparently
alternative quantity. quantity.

18
The categories of this paper are: econ
35
The categories of this paper are: mtrl-th
6
The categories of this paper are: astro-ph
34
The categories of this paper are: chem-ph
29
The categories of this paper are: funct-an
32
The categories of this paper are: atom-ph
20
The categories of this paper are: acc-phys
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
21
The categories of this paper are: adap-org
22
The categories of this paper are: chao-dyn
14
The categories of this paper are: math-ph
5
The categories of this paper are: gr-qc
27
The categories of this paper are: comp-gas
15
The categories of this paper are: nucl-ex
0
The categories of this paper are: hep-ph