Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Bubble kinetics in a steady-state column of aqueous foam   We measure the liquid content, the bubble speeds, and the distribution of
bubble sizes, in a vertical column of aqueous foam maintained in steady-state
by continuous bubbling of gas into a surfactant solution. Nearly round bubbles
accumulate at the solution/foam interface, and subsequently rise with constant
speed. Upon moving up the column, they become larger due to gas diffusion and
more polyhedral due to drainage. The size distribution is monodisperse near the
bottom and polydisperse near the top, but there is an unexpected range of
intermediate heights where it is bidisperse with small bubbles decorating the
junctions between larger bubbles. We explain the evolution in both bidisperse
and polydisperse regimes, using Laplace pressure differences and taking the
liquid fraction profile as a given.

28
The categories of this paper are: alg-geom
17
The categories of this paper are: q-fin
19
The categories of this paper are: eess
34
The categories of this paper are: chem-ph
36
The categories of this paper are: cmp-lg
31
The categories of this paper are: ao-sci
1
The categories of this paper are: cs
27
The categories of this paper are: comp-gas
2
The categories of this paper are: math
33
The categories of this paper are: plasm-ph
6
The categories of this paper are: astro-ph
30
The categories of this paper are: q-alg
15
The categories of this paper are: nucl-ex
7
The categories of this paper are: hep-th
18
The categories of this paper are: econ
14
The categories of this paper are: math-ph