Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Exergy analysis of marine waste heat recovery CO2 closed-cycle gas
  turbine system
22
The categories of this paper are: chao-dyn
8
The categories of this paper are: hep-ex
12
The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
30
The categories of this paper are: q-alg
7
The categories of this paper are: hep-th
18
The categories of this paper are: econ
4
The categories of this paper are: cond-mat
17
The categories of this paper are: q-fin
21
The categories of this paper are: adap-org
20
The categories of this paper are: acc-phys
29
The categories of this paper are: funct-an
3
The categories of this paper are: physics
32
The categories of this paper are: atom-ph
25
The categories of this paper are: patt-sol
33
The categories of this paper are: plasm-ph