ATLAS Data Challenge 1

In 2002 the ATLAS experiment started a series of Data Challenges (DC) of which the goals are the validation of the Computing Model, of the complete software suite, of the data model, and to ensure the correctness of the technical choices to be made. A major feature of the first Data Challenge (DC1) was the preparation and the deployment of the software required for the production of large event samples for the High Level Trigger (HLT) and physics communities, and the production of those samples as a world-wide distributed activity. The first phase of DC1 was run during summer 2002, and involved 39 institutes in 18 countries. More than 10 million physics events and 30 million single particle events were fully simulated. Over a period of about 40 calendar days 71000 CPU-days were used producing 30 Tbytes of data in about 35000 partitions. In the second phase the next processing step was performed with the participation of 56 institutes in 21 countries (~ 4000 processors used in parallel). The basic elements of the ATLAS Monte Carlo production system are described. We also present how the software suite was validated and the participating sites were certified. These productions were already partly performed by using different flavours of Grid middleware at ~ 20 sites.Comment: 10 pages; 3 figures; CHEP03 Conference, San Diego; Reference MOCT00

Generation of silicone poly-HIPES with controlled pore sizes via reactive emulsion stabilization

Macrocellular silicone polymers are obtained after solidification of the continuous phase of a PDMS (polydimethylsiloxane) emulsion, which contains PEG (polyethylene glycol) drops of sub-millimetric dimensions. Coalescence of the liquid template emulsion is prohibited by a reactive blending approach. We investigate in detail the relationship between the interfacial properties and the emulsion stability, and we use micro- and millifluidic techniques to generation macro-cellular polymers with controlled structural properties over a wider range of cell-sizes (0.2-2mm) and volume fractions of the continuous phase (0.1-40%). This approach could easily be transferred to a wide range of polymeric systems

Protocol to perform pressurized blister tests on thin elastic films

This work aims to identify common challenges in the preparation of the blister test devices designed for measurement of energy release rate for brittle thin films and to propose easy-to-implement solutions accordingly. To this end, we provide a step-by-step guide for fabricating a blister test device comprised of thin polystyrene films adhered to glass substrates. Thin films are first transferred from donor substrates to an air-water interface, which is then used as a platform to locate them on a receiver substrate. We embed a microchannel at the back of the device to evacuate the air trapped in the opening, through which the pressure is applied. We quantify the height and the radius of the blister to estimate the adhesion energy using the available expressions correlating the normal force and the moment with the shape of the blister. The present blister test provided adhesion energy per unit area of $G = 18 \pm 2$ \mbox{mJ}/{\mbox m}^2 for polystyrene on glass, which is in good agreement with the measurement of $G = 14 \pm 2$ \mbox{mJ}/{\mbox m}^2 found in our independent cleavage test

Rescaling the dynamics of evaporating drops

The dynamics of evaporation of wetting droplets has been investigated experimentally in an extended range of drop sizes, in order to provide trends relevant for a theoretical analysis. A model is proposed, which generalises Tanner's law, allowing us to smooth out the singularities both in dissipation and in evaporative flux at the moving contact line. A qualitative agreement is obtained, which represents a first step towards the solution of a very old, complex problem

The effect of the thermal conductivity of the substrate on droplet evaporation

The evaporation of liquid droplets is of fundamental importance to industry, with a vast number of applications including ink-jet printing, spray cooling and DNA mapping, and has been the subject of considerable theoretical and experimental research in recent years. Significant recent papers include those by Deegan [1], Deegan et al. [2], Hu and Larson [3], Poulard et al. [4], Sultan et al. [5], and Shahidzadeh-Bonn et al. [6]

Quelques retours d'expérience d'instabilités de terrain liées aux exploitations pentées

8 p.National audienceSuite au recensement de plus de 1000 exploitations en gisements pentés ou filoniens français, des désordres caractéristiques liés à ce type d'exploitation sont passés en revue : effondrements localisés liés à une rupture de la couronne, à un débourrage, à une rupture du toit, affaissements dissymétriques... L'objectif est de caractériser ces désordres qui sont influencés par les méthodes d'exploitation et les caractéristiques géologiques propres à ce type de dépôt. Ce travail devra servir à une méthodologie d'évaluation des aléas en vue de l'élaboration des Plans de Prévention des Risques Miniers (PPRM)

Screening of french mining exploitations : a methodology and a national hierarchisation to evaluate the geotechnical risk

International audienceThe French Ministry, in charge of mining and post-mining issues, plans to perform as effectively as possible its future investigations (Mining Risk Prevention Plans, MRPP, in particular). In this way, an ambitious program, called Screening, has been engaged in order to classify and to evaluate all French mining sites according to their mining risk level and then, to perform a quick risk evaluation for the most critical sites. This process included an important stage of hierarchisation. After many months of works, a multi-criteria analysis (based on ELECTRE's method) was finally adopted. It required an appropriated selection of experts, an effective criteria definition, use of adapted tools and a precise validation before application to given mining sites. The different steps of this work are presented in this paperLe Ministère en charge, en France, de la gestion des problèmes miniers tente de planifier le plus efficacement possible ses futures études (Plans de Prévention des Risques Miniers, PPRM, notamment). Pour ce faire, un programme ambitieux, baptisé Scanning, a été engagé afin de classer et d'évaluer les risques, liés aux exploitations minières, de potentiels mouvements de terrains. Ce processus comprend une phase importante de hiérarchisation. Après de mois de réflexions, c'est une analyse de type multicritères (de la famille des méthodes ELECTRE) qui a finalement été retenue. Cette hiérarchisation nécessite de faire appel à un groupe d'experts, de définir des critères de hiérarchisation efficaces, d'utiliser des outils adaptés et de valider précisément chacune des étapes avant d'envisager de hiérarchiser des sites miniers. L'article suivant présente la démarche complète de cette mise en oeuvr

Water-based peeling of thin hydrophobic films

Inks of permanent markers and water-proof cosmetics create elastic thin films upon application on a surface. Such adhesive materials are deliberately designed to exhibit water-repellent behavior. Therefore, patterns made up of these inks become resistant to moisture and cannot be cleaned by water after drying. However, we show that sufficiently slow dipping of such elastic films, which are adhered to a substrate, into a bath of pure water allows complete removal of the hydrophobic coatings. Upon dipping, the air-water interface in the bath forms a contact line on the substrate, which exerts a capillary-induced peeling force at the edge of the hydrophobic thin film. We highlight that this capillary peeling process is more effective at lower velocities of the air-liquid interface and lower viscosities. Capillary peeling not only removes such thin films from the substrate but also transfers them flawlessly onto the air-water interface