Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Advanced holographic nondestructive testing system for residual stress
  analysis   The design and operating of a portable holographic interferometer for
residual stress analysis by creating a small scratch along with a new
mathematical algorithm of calculations are discussed. Preliminary data of the
stress investigations on aluminum and steel alloys have been obtained by the
automatic processing of the interference pattern using a notebook computer. A
phase-shift compensation technique in real-time reflection interferometry is
used to measure the out-of-plane stress release surface displacement
surrounding a small scratch (25 um depth and 0.5 mm width) in a plate with
residual stress of around 50 MPa. Comparison between theoretical models for a
rectangular and triangular shaped scratch with the experimental data are
presented.

30
The categories of this paper are: q-alg
0
The categories of this paper are: hep-ph
31
The categories of this paper are: ao-sci
19
The categories of this paper are: eess
10
The categories of this paper are: q-bio
4
The categories of this paper are: cond-mat
21
The categories of this paper are: adap-org
11
The categories of this paper are: hep-lat
8
The categories of this paper are: hep-ex
16
The categories of this paper are: stat
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th
13
The categories of this paper are: quant-ph
33
The categories of this paper are: plasm-ph
36
The categories of this paper are: cmp-lg
5
The categories of this paper are: gr-qc