English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Given a system with a finite heat capacity and a heat reservoir, and twovalues of initial temperatures, $T_+$ and $T_- (< T_+)$, we enquire, in whichcase the optimal work extraction is larger: when the reservoir is an infinitesource at $T_+$ and the system is a sink at $T_-$, or, when the reservoir is aninfinite sink at $T_-$ and the system acts as a source at $T_+$? It is foundthat in order to compare the total extracted work, and the correspondingefficiency in the two cases, we need to consider three regimes as suggested byan inequality, the so-called arithmetic mean-geometric mean inequality,involving the arithmetic and the geometric means of the two temperature values$T_+$ and $T_-$. In each of these regimes, the efficiency at total work obeyscertain universal bounds, given only in terms of the ratio of initialtemperatures. The general theoretical results are exemplified for thermodynamicsystems for which internal energy and temperature are power laws of theentropy. The conclusions may serve as benchmarks in the design of heat engines,where we can choose the nature of the finite system, so as to tune the totalextractable work and/or the corresponding efficiency.

Optimal performance of heat engines with a finite source or sink and inequalities between means