We discuss the efficiency of a heat engine operating in a nonequilibrium steady state maintained by two heat reservoirs. Within the general framework of linear irreversible thermodynamics we derive a universal upper bound on the efficiency of the engine operating at arbitrary fixed power. Furthermore, we show that a slight decrease of the power below its maximal value can lead to a significant ...

We consider aspects of nonequilibrium statistical mechanics that have traditionally not been considered in irreversible thermodynamics. More specifically we refer to the frenetic contribution in fluctuation and response theory, which complements the entropic component. Frenesy then refers to an amount of volatility or of dynamical activity defined on trajectories in some reduced description. It...

A thermodynamical minimum principle valid for photon radiation is shown to hold for arbitrary geometries. It is successfully extended to neutrinos, in the zero mass and chemical potential case, following a parallel development of photon and neutrino statistics. This minimum principle stems more from that of Planck than that of classical Onsager-Prigogine irreversible thermodynamics. Its extensi...

Starting from a macroscopic nonequilibrium entropy, we obtain an expression for the nonequilibrium fluctuations of the electric current in a metallic resistor. Our method goes further than previous theories of irreversible thermodynamics and, as well as microscopic entropies, it leads to results of the same order of magnitude but not completely coincident with the full nonequilibrium correction...

To begin with, relaxation equations will be generally examined within the framework of the thermodynamics of irreversible processes. The relaxation in the glass transition region specifically proves to be a non-linear process which resembles an accelerated or retarded autocatalytic reaction. Therefore it is physically not very useful to split the relaxation in the glass transition region into a...

The irreversible thermodynamics of a continuous medium with magnetic dipoles predicts that a temperature gradient in the presence of magnetization waves induces a magnetic induction field, which is the magnetic analog of the Seebeck effect. This thermal gradient modulates the precession and relaxation. The magnetic Seebeck effect implies that magnetization waves propagating in the direction of ...

The mechanism of irreversible dynamics in the mixing systems is constructed in the frames of the classical mechanics laws. The offered mechanism can be found only within the framework of the generalized Hamilton's formalism. The generalized formalism is created by expansion of the canonical Hamilton's formalism to the open systems. A formula, which expresses the entropy through the work of subs...

We validate experimentally a fluctuation relation known as generalized Jarzynski equality governing the work distribution in a feedback-controlled system. The feedback control is performed on a single electron box analogously to the original Szilard engine. In the generalized Jarzynski equality, mutual information is treated on an equal footing with the thermodynamic work. Our measurements prov...

We analyze the structure of two dimensional disordered cellular systems generated by extensive computer simulations. These cellular structures are studied as topological trees rooted on a central cell or as closed shells arranged concentrically around a germ cell. We single out the most significant parameters that characterize statistically the organization of these patterns. Universality and s...

The behavior near the singularity of an isotropic, homogeneous cosmological model with a viscous fluid source is investigated. This turns out to be a relaxation dominated regime. Full extended irreversible thermodynamics is used, and comparison with results of the truncated theory is made. New singular behaviors are found and it is shown that a relaxation dominated inflationary epoch may exist ...