Competition on European energy markets: between policy ambitions and practical restrictions

This Document describes the background and the rationale of the European Union for pursuing liberalised energy markets, explains why this policy goal is not achieved yet, and discusses recent developments and some of the future challenges faced by political decision makers. Read also the accompanying press release .Five years after launching the process of electricity liberalisation, dominance of large utilities, lack of international transmission capacity, and national energy policies hinder the creation of competitive energy markets in Europe. Consequently, the expected downward convergence of electricity prices for EU business and EU consumers has only partly been realised. Established utility companies still have a strong position on some national electricity markets. By means of (inter)national mergers, they increase their market shares at the European level. As a consequence, the price of electricity remains at a higher level than the costs of generating the electricity. In addition, producers lack strong incentives to decrease costs and to develop new techniques of generation owing to missing fierce competitive market forces. The document shows that liberalising electricity markets increases competition provided that adequate institutional arrangements have been made. This requires, in general terms, combating dominant positions of producers by splitting up large established utility companies and implementing adequate surveillance on mergers, increasing capacities of interconnectors among the several member states, establishing spot markets at an international level, and encouraging encouraging transparency of national policies regarding production, transmission and trade.

Test of the fluctuation theorem for stochastic entropy production in a nonequilibrium steady state

We derive a simple closed analytical expression for the total entropy production along a single stochastic trajectory of a Brownian particle diffusing on a periodic potential under an external constant force. By numerical simulations we compute the probability distribution functions of the entropy and satisfactorily test many of the predictions based on Seifert's integral fluctuation theorem. The results presented for this simple model clearly illustrate the practical features and implications derived from such a result of nonequilibrium statistical mechanics.Comment: Accepted in Phys. Rev.

Measurement of Stochastic Entropy Production

Using fluorescence spectroscopy we directly measure entropy production of a single two-level system realized experimentally as an optically driven defect center in diamond. We exploit a recent suggestion to define entropy on the level of a single stochastic trajectory (Seifert, Phys. Rev. Lett. {\bf 95}, 040602 (2005)). Entropy production can then be split into one of the system itself and one of the surrounding medium. We demonstrate that the total entropy production obeys various exact relations for finite time trajectories.Comment: Phys. Rev. Lett., in pres

Probability density functions of work and heat near the stochastic resonance of a colloidal particle

We study experimentally and theoretically the probability density functions of the injected and dissipated energy in a system of a colloidal particle trapped in a double well potential periodically modulated by an external perturbation. The work done by the external force and the dissipated energy are measured close to the stochastic resonance where the injected power is maximum. We show a good agreement between the probability density functions exactly computed from a Langevin dynamics and the measured ones. The probability density function of the work done on the particle satisfies the fluctuation theorem

On the hyperbolicity and causality of the relativistic Euler system under the kinetic equation of state

We show that a pair of conjectures raised in [11] concerning the construction of normal solutions to the relativistic Boltzmann equation are valid. This ensures that the results in [11] hold for any range of positive temperatures and that the relativistic Euler system under the kinetic equation of state is hyperbolic and the speed of sound cannot overcome $c/\sqrt{3}$.Comment: 6 pages. Abridged version; full version to appear in Commun. Pure Appl. Ana

Switch on the engine: how the eukaryotic replicative helicase MCM2–7 becomes activated

© 2014, Springer-Verlag Berlin Heidelberg.A crucial step during eukaryotic initiation of DNA replication is the correct loading and activation of the replicative DNA helicase, which ensures that each replication origin fires only once. Unregulated DNA helicase loading and activation, as it occurs in cancer, can cause severe DNA damage and genomic instability. The essential mini-chromosome maintenance proteins 2–7 (MCM2–7) represent the core of the eukaryotic replicative helicase that is loaded at DNA replication origins during G1-phase of the cell cycle. The MCM2–7 helicase activity, however, is only triggered during S-phase once the holo-helicase Cdc45-MCM2–7-GINS (CMG) has been formed. A large number of factors and several kinases interact and contribute to CMG formation and helicase activation, though the exact mechanisms remain unclear. Crucially, upon DNA damage, this reaction is temporarily halted to ensure genome integrity. Here, we review the current understanding of helicase activation; we focus on protein interactions during CMG formation, discuss structural changes during helicase activation, and outline similarities and differences of the prokaryotic and eukaryotic helicase activation process

The Einstein relation generalized to non-equilibrium

The Einstein relation connecting the diffusion constant and the mobility is violated beyond the linear response regime. For a colloidal particle driven along a periodic potential imposed by laser traps, we test the recent theoretical generalization of the Einstein relation to the non-equilibrium regime which involves an integral over measurable velocity correlation functions

First-principles study of epitaxial strain in perovskites

Using an extension of a first-principles method developed by King-Smith and Vanderbilt [Phys. Rev. B {\bf 49}, 5828 (1994)], we investigate the effects of in-plane epitaxial strain on the ground-state structure and polarization of eight perovskite oxides: BaTiO$_3$, SrTiO$_3$, CaTiO$_3$, KNbO$_3$, NaNbO$_3$, PbTiO$_3$, PbZrO$_3$, and BaZrO$_3$. In addition, we investigate the effects of a nonzero normal stress. The results are shown to be useful in predicting the structure and polarization of perovskite oxide thin films and superlattices.Comment: 10 page