Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: First-principles study of UO$_2$ lattice thermal-conductivity: A simple
  description   Modeling the high-$T$ paramagnetic state of bulk UO$_2$ by a
non-spin-polarized calculation and neglecting the Hubbard-U correction for the
$f$ electrons in U atoms, the lattice thermal conductivity of bulk UO$_2$ is
investigated by the exact solution of the Boltzmann transport equation for the
steady-state phonon distribution function. The results show that TA branches
corresponding to U-atoms vibrations have the largest lifetimes and therefore
have dominant role in thermal conductivity, while the optical branches
corresponding mainly to O-atoms vibrations have the shortest lifetimes. Using
this simple model, our results for the thermal conductivity show a very good
agreement with the experiments. The calculations are repeated for bulk UO$_2$
with different U-235 concentrations of 3\%, 5\%, 7\%, and 20\%, and the results
show a small decrease of thermal conductivity which arise from scattering of
phonons by impurities.

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The categories of this paper are: astro-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: hep-lat
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The categories of this paper are: bayes-an
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The categories of this paper are: math
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The categories of this paper are: solv-int
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The categories of this paper are: chem-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: patt-sol
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The categories of this paper are: eess
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The categories of this paper are: nucl-th
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The categories of this paper are: hep-th
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The categories of this paper are: quant-ph
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The categories of this paper are: adap-org
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The categories of this paper are: comp-gas
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The categories of this paper are: dg-ga