Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Non-linear plane perturbation in a non-ohmic/ohmic fluid interface in a
  vertical electric field   The stability of a non-ohmic/ohmic fluid interface in the presence of a
constant gravitational field and stressed by a vertical stationary electric
field with unipolar injection is studied, focusing on the destabilizing action
of the electric pressure when charge relaxation effects can be ignored. We use
a hydraulic model, whose static equilibrium condition is written and analysed
as a function of the ohmic fluid conductivity when subjected to a non-linear
perturbation. The combined action of the polarization and free interfacial
charges on the pressure instability mechanism is also analysed. The results
show some important peculiarities of the fluid interface behaviour in the
presence of a stationary space charge distribution generated by unipolar
injection in the non-ohmic fluid.

22
The categories of this paper are: chao-dyn
37
The categories of this paper are: supr-con
0
The categories of this paper are: hep-ph
12
The categories of this paper are: nucl-th
29
The categories of this paper are: funct-an
32
The categories of this paper are: atom-ph
7
The categories of this paper are: hep-th
21
The categories of this paper are: adap-org
35
The categories of this paper are: mtrl-th
28
The categories of this paper are: alg-geom
5
The categories of this paper are: gr-qc
8
The categories of this paper are: hep-ex
11
The categories of this paper are: hep-lat
19
The categories of this paper are: eess
26
The categories of this paper are: bayes-an
20
The categories of this paper are: acc-phys