Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A biaxial apparatus for the study of heterogeneous and intermittent
  strains in granular materials   We present an experimental apparatus specifically designed to investigate the
precursors of failure in granular materials. A sample of granular material is
placed between a latex membrane and a glass plate. A confining effective
pressure is applied by applying vacuum to the sample. Displacement-controlled
compression is applied in the vertical direction, while the specimen deforms in
plane strain. A Diffusing Wave Spectroscopy visualization setup gives access to
the measurement of deformations near the glass plate. After describing the
different parts of this experimental setup, we present a demonstration
experiment where extremely small (of order $10^{-5}$) heterogeneous strains are
measured during the loading process.

32
The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an
37
The categories of this paper are: supr-con
19
The categories of this paper are: eess
7
The categories of this paper are: hep-th
5
The categories of this paper are: gr-qc
23
The categories of this paper are: solv-int
22
The categories of this paper are: chao-dyn
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
10
The categories of this paper are: q-bio
18
The categories of this paper are: econ
17
The categories of this paper are: q-fin
1
The categories of this paper are: cs
28
The categories of this paper are: alg-geom
11
The categories of this paper are: hep-lat