Increased Donnan Exclusion at High Salt Concentrations

The swelling of univalent and multivalent charged polymeric networks in electrolytic solutions is studied using a classical thermodynamic model. Such systems were first modeled by Donnan, who derived an expression...

Economic Cycles of Carnot Type

Originally, the Carnot cycle was a theoretical thermodynamic cycle that provided an upper limit on the efficiency that any classical thermodynamic engine can achieve during the conversion of heat into work, or conversely, the efficiency of a refrigeration system in creating a temperature difference by the application of work to the system. The first aim of this paper is to introduce and study the economic Carnot cycles concerning Roegenian economics, using our thermodynamic–economic dictionary. These cycles are described in both a Q−P diagram and a E−I diagram. An economic Carnot cycle has a maximum efficiency for a reversible economic “engine”. Three problems together with their solutions clarify the meaning of the economic Carnot cycle, in our context. Then we transform the ideal gas theory into the ideal income theory. The second aim is to analyze the economic Van der Waals equation, showing that the diffeomorphic-invariant information about the Van der Waals surface can be obtained by examining a cuspidal potential.

Digitalization in Thermodynamics

Digitalization is about data and how they are used. This has always been a key topic in applied thermodynamics. In the present work, the influence of the current wave of digitalization on thermodynamics is analyzed. Thermodynamic modeling and simulation is changing as large amounts of data of different nature and quality become easily available. The power and complexity of thermodynamic models and simulation techniques is rapidly increasing, and new routes become viable to link them to the data. Machine learning opens new perspectives, when it is suitably combined with classical thermodynamic theory. Illustrated by examples, different aspects of digitalization in thermodynamics are discussed: strengths and weaknesses as well as opportunities and threats.

Advances in dynamically controlled catalytic reaction engineering

Dynamically forced input oscillations exhibit ability to surpass classical thermodynamic barriers through reactor operation and surface resonance.

Beyond the classical thermodynamic contributions to hydrogen atom abstraction reactivity

Hydrogen atom abstraction (HAA) reactions are cornerstones of chemistry. Various (metallo)enzymes performing the HAA catalysis evolved in nature and inspired the rational development of multiple synthetic catalysts. Still, the factors determining their catalytic efficiency are not fully understood. Herein, we define the simple thermodynamic factor η by employing two thermodynamic cycles: one for an oxidant (catalyst), along with its reduced, protonated, and hydrogenated form; and one for the substrate, along with its oxidized, deprotonated, and dehydrogenated form. It is demonstrated that η reflects the propensity of the substrate and catalyst for (a)synchronicity in concerted H+/e− transfers. As such, it significantly contributes to the activation energies of the HAA reactions, in addition to a classical thermodynamic (Bell–Evans–Polanyi) effect. In an attempt to understand the physicochemical interpretation of η, we discovered an elegant link between η and reorganization energy λ from Marcus theory. We discovered computationally that for a homologous set of HAA reactions, λ reaches its maximum for the lowest |η|, which then corresponds to the most synchronous HAA mechanism. This immediately implies that among HAA processes with the same reaction free energy, ΔG0, the highest barrier (≡ΔG≠) is expected for the most synchronous proton-coupled electron (i.e., hydrogen) transfer. As proof of concept, redox and acidobasic properties of nonheme FeIVO complexes are correlated with activation free energies for HAA from C−H and O−H bonds. We believe that the reported findings may represent a powerful concept in designing new HAA catalysts.

Intensity in Context: Thermodynamics and Transcendental Philosophy

Deleuze's use of thermodynamics in the fifth chapter of his masterwork Difference and Repetition ushers in perhaps the most crucial notion for understanding this work: intensity. Given that the process of actualisation relies on the intensive necessarily means that any discussion of the relationship between the virtual and the actual must include a thorough explanation of the role of intensity, and where exactly this notion sits within the virtual–actual doublet. As such, we must return to the fifth chapter of Difference and Repetition in order to assess the way in which Deleuze conceives of this complex and indispensable cog in his ontological and metaphysical philosophy. In this paper we turn, then, to Deleuze's engagement with the theories of the intensive as found in classical thermodynamic theory. Quite simply, Deleuze will highlight the way in which the productive force of differences in intensity remains under-appreciated in contrast to the extensive states they create in this classical framework. We can understand this engagement, then, as an example of the way in which the extensive is continually privileged over the intensive. In this paper we will outline the details of the engagement between Deleuze and thermodynamics, as this paves the way for his own philosophy of intensity. Furthermore, we will provide a theory of the relationship between intensity, the virtual and the actual as these notions appear in Difference and Repetition.