Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Wicking in a powder   We investigate the wicking in granular media by considering layers of grains
at the surface of a liquid, and discuss the critical contact angle below which
spontaneous impregnation takes place. This angle is found to be on the order of
55{\deg} for monodisperse layers, significantly smaller than 90{\deg}, the
threshold value for penetrating assemblies of tubes: owing to geometry,
impregnating grains is more demanding than impregnating tubes. We also consider
the additional effects of polydispersity and pressure on this wetting
transition and discuss the corresponding shift observed on the critical contact
angle.

9
The categories of this paper are: nlin
18
The categories of this paper are: econ
27
The categories of this paper are: comp-gas
25
The categories of this paper are: patt-sol
10
The categories of this paper are: q-bio
15
The categories of this paper are: nucl-ex
37
The categories of this paper are: supr-con
20
The categories of this paper are: acc-phys
24
The categories of this paper are: dg-ga
29
The categories of this paper are: funct-an
11
The categories of this paper are: hep-lat
0
The categories of this paper are: hep-ph
21
The categories of this paper are: adap-org
19
The categories of this paper are: eess
33
The categories of this paper are: plasm-ph
26
The categories of this paper are: bayes-an