Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Determination of thermal and optical parameters of melanins by
  photopyroelectric spectroscopy   Photopyroelectric spectroscopy (PPE) was used to study the thermal and
optical properties of electropolymerized melanins. The photopyroelectric
intensity signal and its phase were independently measured as a function of
wavelength, as well as a function of chopping frequency for a given wavelength
in the saturation part of the PPE spectrum. Equations for both the intensity
and the phase of the PPE signal were used to fit the experimental results. From
the fittings we obtained for the first time, with great accuracy, the thermal
diffusivity coefficient, the thermal conductivity and the specific heat of the
samples, as well as a value for the condensed phase optical gap, which we found
to be 1.70 eV.

15
The categories of this paper are: nucl-ex
8
The categories of this paper are: hep-ex
28
The categories of this paper are: alg-geom
2
The categories of this paper are: math
29
The categories of this paper are: funct-an
35
The categories of this paper are: mtrl-th
21
The categories of this paper are: adap-org
17
The categories of this paper are: q-fin
27
The categories of this paper are: comp-gas
0
The categories of this paper are: hep-ph
10
The categories of this paper are: q-bio
7
The categories of this paper are: hep-th
6
The categories of this paper are: astro-ph
1
The categories of this paper are: cs
3
The categories of this paper are: physics
36
The categories of this paper are: cmp-lg