Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Large variation in the boundary-condition slippage for a rarefied gas
  flowing between two surfaces   We study the slippage of a gas along mobile rigid walls in the sphere-plane
confined geometry and find that it varies considerably with pressure. The
classical no-slip boundary condition valid at ambient pressure changes
continuously to an almost perfect slip condition in a primary vacuum. Our study
emphasizes the key role played by the mean free-path of the gas molecules on
the interaction between a confined fluid and solid surfaces and further
demonstrates that the macroscopic hydrodynamics approach can be used with
confidence even in a primary vacuum environment where it is intuitively
expected to fail.

24
The categories of this paper are: dg-ga
1
The categories of this paper are: cs
7
The categories of this paper are: hep-th
2
The categories of this paper are: math
26
The categories of this paper are: bayes-an
19
The categories of this paper are: eess
27
The categories of this paper are: comp-gas
8
The categories of this paper are: hep-ex
14
The categories of this paper are: math-ph
35
The categories of this paper are: mtrl-th
25
The categories of this paper are: patt-sol
31
The categories of this paper are: ao-sci
0
The categories of this paper are: hep-ph
5
The categories of this paper are: gr-qc
28
The categories of this paper are: alg-geom
33
The categories of this paper are: plasm-ph