Percolation approach to glassy dynamics with continuously broken ergodicity

We show that the relaxation dynamics near a glass transition with continuous ergodicity breaking can be endowed with a geometric interpretation based on percolation theory. At mean-field level this approach is consistent with the mode-coupling theory (MCT) of type-A liquid-glass transitions and allows to disentangle the universal and nonuniversal contributions to MCT relaxation exponents. Scaling predictions for the time correlation function are successfully tested in the F12 schematic model and facilitated spin systems on a Bethe lattice. Our approach immediately suggests the extension of MCT scaling laws to finite spatial dimensions and yields new predictions for dynamic relaxation exponents below an upper critical dimension of 6

Estudio y análisis de las relaciones proveedor-cliente: el caso de la Denominación de Origen (D.O.) Somontano

El establecimiento, desarrollo y mantenimiento de relaciones duraderas entre proveedores y clientes es una tendencia que cuenta cada día con mayor número de defensores. Gran número de autores soportan esta idea y que apuestan por la gestión de relaciones en detrimento de las clásicas transacciones de intercambio. Y todavía más en el contexto de los mercados industriales, donde tanto proveedor como cliente pueden conseguir beneficios mutuos fruto de este contacto permanente. Nuestro trabajo analiza este tipo de relaciones comerciales en el contexto de la industria agroalimentaria. Más concretamente, estudiamos el caso de la Denominación de Origen (D.O.) del Somontano.The establishment, development and maintenance of lasting relationships between suppliers and customers is a trend that has an ever greater number of defenders. Large number of authors support this idea of relationship management to the detriment of classic exchange transactions. And even more in the context of industrial markets, where both ,supplier and customer, can get mutual benefits of this permanent contact. Our work takes this kind of trade relations in the context of the food industry. More specifically, we study the case of the Designation of Origin (DO) Somontano

Glass transition in granular media

In the framework of schematic hard spheres lattice models for granular media we investigate the phenomenon of the ``jamming transition''. In particular, using Edwards' approach, by analytical calculations at a mean field level, we derive the system phase diagram and show that ``jamming'' corresponds to a phase transition from a ``fluid'' to a ``glassy'' phase, observed when crystallization is avoided. Interestingly, the nature of such a ``glassy'' phase turns out to be the same found in mean field models for glass formers.Comment: 7 pages, 4 figure

Data sources for rescuing the rich heritage of Mediterranean historical surface climate data

10.1002/gdj3.4Availability of long-term and high-quality instrumental climate records is still insufficient and the rich heritage of meteorological surface observations is largely underexploited in many parts of the world. This is particularly striking over the Greater Mediterranean region (GMR), where meteorological observations have been taken since the 18th century at some locations. The lack of high quality and long series here is despite this region being regarded as a climate change hot spot. This article mainly assesses relevant sources containing Mediterranean historical climate data and metadata either from online repositories worldwide or physical archives, with the emphasis here on the rich holdings kept at French archives. A particular case study is the data rescue (DARE) program undertaken by the Algerian National Meteorological Service, as well as some of the past and ongoing projects and initiatives aimed at enhancing climate data availability and accessibility over the GMR. Our findings point to the high potential for undertaking DARE activities over the GMR and the need for bringing longer and higher quality climate time series to support a diverse number of scientific and technical assessments and policies

Measurements and understanding of radon adsorption in nanoporous materials

International audienceFor many experiments working at low energy and very low counting rate in particle and astroparticle physics, the background from the Radon decay chain is one of the strongest constraints. Most of the time, activated charcoal filters are used to dynamically capture the radon from the air or from the gas of the detectors. In general case activated charcoal is a good adsorptive material. It has large effective surface and broad porosity, going from macro to nanopores. However, the big constraints from futures experiments need ad hoc radon capture filters. The optimal adsorption depends on various parameters such as the correct pore size and shape, the temperature, the microscopic structure of the adsorbent or the competition between radon and carrier gas. In this context, we have developed at Centre de Physique des Particules de Marseille (CPPM), a test bench to study the radon capture in various porous materials1. Several very interesting results have been already obtained with non-standard, commercially and research adsorbents like some Carbon Molecular Sieves (CMS), organic molecular cage (CC3)2, or carbon aerogels.In this talk we present a global quantitative and qualitative study of radon adsorption in porous materials. This work is the results of the analysis of more than 30 porous materials in the framework of the collaboration between particle physicist and chemist from several universities

First Detection of the Crab Pulsar above 100 GeV

We present the detection of pulsed gamma-ray emission from the Crab pulsar above 100 GeV with the VERITAS array of atmospheric Cherenkov telescopes. Gamma-ray emission at theses energies was not expected in pulsar models. The detection of pulsed emission above 100 GeV and the absence of an exponential cutoff makes it unlikely that curvature radiation is the primary production mechanism of gamma rays at these energies.Comment: 5 pages, proceedings of the TAUP 2011 conference in Munich, German