Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Thermal flux in unsteady Rayleigh-B\'{e}nard magnetoconvection   We present results of numerical investigation on thermal flux in
Rayleigh-B\'{e}nard magnetoconvection in the presence of a uniform vertical
magnetic field. We have studied thermal flux in different viscous fluids with a
range of Prandtl number ($0.1 \le \mathrm{Pr} < 6.5$) and a range of
Chandrasekhar number ($50 \le \mathrm{Q} \le 2.5 \times 10^4$). The power
spectral density of the Nusselt number varies with frequency $f$ approximately
as $f^{-2}$. The probability distribution function of the fluctuating part of
the Nusselt number is nearly normal distribution with slight asymmetric tails.
For a fixed value the Rayleigh number $\mathrm{Ra}$, the time averaged Nusselt
number $\langle \mathrm{Nu} (\mathrm{Q})\rangle$ decreases logarithmically with
Chandrasekhar number for $\mathrm{Q} > \mathrm{Q}_c$, which depends on
$\mathrm{Ra}$ and $\mathrm{Pr}$. The reduced Nusselt number $\mathrm{Nu_r}$ $=$
$\langle \mathrm{Nu}(\mathrm{Q})\rangle/{\langle \mathrm{Nu}(0)\rangle}$ rises
sharply, reaches a maximum slightly above unity and then start decreasing very
slowly to unity as the value of a dimensionless parameter
$\sqrt{\mathrm{Ra/(Q~Pr)}}$ is raised. The probability distribution function of
the local thermal flux in the vertical direction is found to be asymmetric and
non-Gaussian with a cusp at its maximum.

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The categories of this paper are: math
11
The categories of this paper are: hep-lat
4
The categories of this paper are: cond-mat
15
The categories of this paper are: nucl-ex
14
The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
26
The categories of this paper are: bayes-an
8
The categories of this paper are: hep-ex
31
The categories of this paper are: ao-sci
5
The categories of this paper are: gr-qc
35
The categories of this paper are: mtrl-th
17
The categories of this paper are: q-fin
10
The categories of this paper are: q-bio
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The categories of this paper are: hep-th
16
The categories of this paper are: stat