Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Laser studies of metallic artworks   Museum curators and archaeologists use analytical science to provide
important information on artworks and objects. For example, scientific
techniques provide information on artwork elemental composition, origin and
authenticity, and corrosion products, while also finding use in the day-to-day
conservation of many historical objects in museums and archaeological sites
around the world. In this work two special cases are being discussed. In the
first part of our work, physicochemical studies of an icon on a metal substrate
were carried out using non-destructive, qualitative analysis of pigments and
organic-based binding media, employing various microscopic and analytical
techniques, such as Optical Fluorescence Microscopy, XRF, and Gas
Chromatography. In the second part of our work, laser cleaning of late Roman
coins has been performed using a Q-switched Nd:YAG laser (1064 nm, 6 ns) and a
GaAlAs diode laser (780 nm, 90 ps). The corrosion products have been removed,
while we observe increased concentrations in Ag, which is the main material of
the silvering plating found in late Roman coins.

30
The categories of this paper are: q-alg
28
The categories of this paper are: alg-geom
17
The categories of this paper are: q-fin
25
The categories of this paper are: patt-sol
19
The categories of this paper are: eess
2
The categories of this paper are: math
6
The categories of this paper are: astro-ph
18
The categories of this paper are: econ
8
The categories of this paper are: hep-ex
23
The categories of this paper are: solv-int
3
The categories of this paper are: physics
24
The categories of this paper are: dg-ga
29
The categories of this paper are: funct-an
5
The categories of this paper are: gr-qc
12
The categories of this paper are: nucl-th
37
The categories of this paper are: supr-con