Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Piezonuclear Reactions   In this paper, we deal with the subject of piezonuclear reactions, namely
nuclear reactions (of new type) triggered by pressure waves. We discuss the
experimental evidences obtained in the last two decades, which can be
summarized essentially as follows: experiments in cavitation of liquids, where
transmutation of elements, creation of elements and emission of neutrons have
been observed; emission of neutrons in brittle failure of solids subjected to
mechanical pressure; alteration of the lifetime of un unstable element
(thorium) subjected to cavitation. A theoretical model to explain these facts
is proposed. Future perspectives of these experimental and theoretical
investigations are also underlined.

34
The categories of this paper are: chem-ph
23
The categories of this paper are: solv-int
22
The categories of this paper are: chao-dyn
31
The categories of this paper are: ao-sci
14
The categories of this paper are: math-ph
9
The categories of this paper are: nlin
17
The categories of this paper are: q-fin
8
The categories of this paper are: hep-ex
24
The categories of this paper are: dg-ga
5
The categories of this paper are: gr-qc
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The categories of this paper are: mtrl-th
11
The categories of this paper are: hep-lat
30
The categories of this paper are: q-alg
16
The categories of this paper are: stat
2
The categories of this paper are: math
18
The categories of this paper are: econ