Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Optical properties (uv-vis and ftir) of gamma irradiated polymethyl
  methacrylate (pmma)   The effect of gamma irradiation on the UV-Vis and FTIR spectroscopy of
polymethyl methacrylate (PMMA) foils has been studied. A new absorption band is
observed in the visible spectral range due to color centers induced in the
gamma irradiated PMMA. This band shows maximum absorption (low transmission)
for 10 kGy irradiation, which decreases and saturates after 50 kGy followed by
a further increase at 500 kGy. The FTIR peaks show an increased absorption up
to ~100 kGy irradiation, which reverses for higher doses. Broad band absorption
is observed in FTIR spectra around 1600 and 3600 cm-1 due to absorption of
moisture in the irradiated samples. The reduction in the absorption intensity
at 1718 cm-1 in the irradiated PMMA (> 100 kGy) is found associated with the
demerization of the carbonyl groups. An initial increase in the absorption of
FTIR peaks with increase in the doses of irradiation is due to increased cross
linking in the PMMA structure that is induced by the absorption of moisture.
The demerization of carbonyl groups becomes dominant at higher doses of
irradiation (~500 kGy).

14
The categories of this paper are: math-ph
8
The categories of this paper are: hep-ex
25
The categories of this paper are: patt-sol
34
The categories of this paper are: chem-ph
5
The categories of this paper are: gr-qc
21
The categories of this paper are: adap-org
15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an
11
The categories of this paper are: hep-lat
32
The categories of this paper are: atom-ph
18
The categories of this paper are: econ
24
The categories of this paper are: dg-ga
30
The categories of this paper are: q-alg
22
The categories of this paper are: chao-dyn
33
The categories of this paper are: plasm-ph
2
The categories of this paper are: math