Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Two-phase interfacial structure of bubbly-to-slug transition flows in a
  12.7 mm ID vertical tube
10
The categories of this paper are: q-bio
20
The categories of this paper are: acc-phys
27
The categories of this paper are: comp-gas
22
The categories of this paper are: chao-dyn
32
The categories of this paper are: atom-ph
30
The categories of this paper are: q-alg
23
The categories of this paper are: solv-int
34
The categories of this paper are: chem-ph
13
The categories of this paper are: quant-ph
15
The categories of this paper are: nucl-ex
11
The categories of this paper are: hep-lat
14
The categories of this paper are: math-ph
26
The categories of this paper are: bayes-an
31
The categories of this paper are: ao-sci
2
The categories of this paper are: math
21
The categories of this paper are: adap-org