Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Realistic thermal heat engine model and its generalized efficiency   We identify a realistic model of thermal heat engines and obtain the
generalized efficiency, $\eta= 1- \left(\frac{T_c}{T_h}\right)^{1/\delta}$,
where $\delta=1+\frac{1}{\gamma}$ and $\gamma$ is the ratio of thermal heat
capacities of working substance at two thermal stages of the hot heat reservoir
temperature, $T_h$ and the cold heat reservoir temperature, $T_c$. We find that
the observed efficiency of practical heat engines satisfy the above generalized
efficiency with $1/\delta=0.35594$ $\pm$ $0.07$. The Curzon-Ahlborn efficiency,
$\eta_{CA}=1-\left(\frac{T_c}{T_h}\right)^{1/2}$ is obtained for the symmetric
case, $\gamma=1$. The generalized efficiency approaches the Carnot efficiency,
$\eta_C=1-\frac{T_c}{T_h}$, in the asymmetric limit, $\gamma \to \infty$.

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The categories of this paper are: cmp-lg
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The categories of this paper are: funct-an
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The categories of this paper are: alg-geom
9
The categories of this paper are: nlin
30
The categories of this paper are: q-alg
26
The categories of this paper are: bayes-an
5
The categories of this paper are: gr-qc
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The categories of this paper are: stat
10
The categories of this paper are: q-bio
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The categories of this paper are: mtrl-th
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The categories of this paper are: quant-ph
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The categories of this paper are: solv-int
0
The categories of this paper are: hep-ph
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The categories of this paper are: econ
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The categories of this paper are: hep-ex
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The categories of this paper are: chem-ph