{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,30]],"date-time":"2025-10-30T22:35:13Z","timestamp":1761863713823,"version":"build-2065373602"},"reference-count":31,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2017,6,8]],"date-time":"2017-06-08T00:00:00Z","timestamp":1496880000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Entropy"],"abstract":"<jats:p>The paper addresses the problem of the existence and quantification of the exergy of non-equilibrium systems. Assuming that both energy and exergy are a priori concepts, the Gibbs \u201cavailable energy\u201d A is calculated for arbitrary temperature or concentration distributions across the body, with an accuracy that depends only on the information one has of the initial distribution. It is shown that A exponentially relaxes to its equilibrium value, and it is then demonstrated that its value is different from that of the non-equilibrium exergy, the difference depending on the imposed boundary conditions on the system and thus the two quantities are shown to be incommensurable. It is finally argued that all iso-energetic non-equilibrium states can be ranked in terms of their non-equilibrium exergy content, and that each point of the Gibbs plane corresponds therefore to a set of possible initial distributions, each one with its own exergy-decay history. The non-equilibrium exergy is always larger than its equilibrium counterpart and constitutes the \u201creal\u201d total exergy content of the system, i.e., the real maximum work extractable from the initial system. A systematic application of this paradigm may be beneficial for meaningful future applications in the fields of engineering and natural science.<\/jats:p>","DOI":"10.3390\/e19060263","type":"journal-article","created":{"date-parts":[[2017,6,8]],"date-time":"2017-06-08T10:26:09Z","timestamp":1496917569000},"page":"263","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["Exergy Dynamics of Systems in Thermal or Concentration Non-Equilibrium"],"prefix":"10.3390","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2220-1762","authenticated-orcid":false,"given":"Enrico","family":"Sciubba","sequence":"first","affiliation":[{"name":"Department of Mechanical and Aerospace Engineering, Sapienza University of Rome, 00184 Roma, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6000-7376","authenticated-orcid":false,"given":"Federico","family":"Zullo","sequence":"additional","affiliation":[{"name":"Department of Mathematics and Physics, Universit\u00e0 Degli Studi Roma Tre, 00146 Roma, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2017,6,8]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"953","DOI":"10.1016\/j.jnnfm.2010.02.006","article-title":"Nonequilibrium thermodynamics modeling of coupled biochemical cycles in living cells","volume":"165","author":"Demirel","year":"2010","journal-title":"J. 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