Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Diffuse planar phase boundaries in a two-phase fluid with one
  incompressible phase   This note studies a family of Navier-Stokes-Allen-Cahn systems parameterized
by temperature. Derived from an internal energy that corresponds to one
incompressible and one compressible phase, this family is considered as a
simple model for water. Decreasing temperature across a critical value, a
transition takes places from a situation without towards one with planar
diffuse phase boundaries.

22
The categories of this paper are: chao-dyn
34
The categories of this paper are: chem-ph
32
The categories of this paper are: atom-ph
26
The categories of this paper are: bayes-an
27
The categories of this paper are: comp-gas
16
The categories of this paper are: stat
12
The categories of this paper are: nucl-th
13
The categories of this paper are: quant-ph
35
The categories of this paper are: mtrl-th
5
The categories of this paper are: gr-qc
17
The categories of this paper are: q-fin
3
The categories of this paper are: physics
31
The categories of this paper are: ao-sci
30
The categories of this paper are: q-alg
15
The categories of this paper are: nucl-ex
23
The categories of this paper are: solv-int