3,199 research outputs found
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 .Comment: 6 pages. Abridged version; full version to appear in Commun. Pure
Appl. Ana
A Comparative Study of Social Comparison, Materialism, and Subjective Well-Being in the U. S., China, Croatia, and India
As the globalization of markets spreads Western media and consumerism across the world, it raises the question as to whether the arguments proposed by theories of social comparison and cultivation hold true in non-Western societies. In this study, we test the relationships between social comparison associated with television programming, materialism, and subjective well-being among college students from the United States, China, Croatia, and India. Structural equation modeling results reveal that the positive relationship between social comparison and materialism is universal. However, the mediating role of materialism between social comparison and subjective well-being is different between individualistic and collectivistic societies
Cognitive Foundation of Diversity Management: Bridging the Gap between Aspiration and Reality
Lewin’s change model states that the most effective way to implement a change is to reduce restraining forces. In this article, we suggest that cognitive biases are a major restraining force that has been ignored in diversity management research. Drawing upon the theory of rationality/intuition two-system thinking, we explain that the driving forces for workforce diversity are primarily propelled by rational reasoning. Yet, their effects are impeded by the cognitive roadblocks rooted in intuitive thinking. We propose a behavioral design approach to reduce the restraining forces by mitigating perceptual biases and judgment errors in the work context
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
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