TIC et prise en charge des personnes handicapées mentales

International audienceL’utilisation de l’informatique et de l’Internet par les personnes handicapées mentales accueillies en établissements spécialisés s’inscrit aujourd’hui dans les pratiques professionnelles du champ médico-social. Si cette communication médiatisée devient un relais de la prise en charge, elle équipe et valorise une professionnalité, mais participe aussi d’une évolution des représentations des professionnels sur les usagers de ces établissements

Sustainable concrete production with recycled concrete wash water beneficiated with CO2

A significant amount of wastewater is generated through the cleaning of equipment utilized within the ready mixed concrete production cycle. The reuse of concrete wash water as mix water is limited by the negative material performance impacts associated with the suspended solids; the effects are exacerbated with increasing solids contents and water aging. A novel carbon dioxide treatment to allow the use of high solids wash water (specific gravity 1.10) as mix water was examined. Seven batches of concrete were produced and compared: a reference mix, two batches with untreated wash water and four batches with CO2 treated wash water. The carbon dioxide treatment mineralized CO2 at 28% by mass of the treated solids. Acceptable concrete was produced through adjusting admixtures for workability. The compressive strength at 1, 7, 28 and 56 days was improved relative to both the reference and the concrete produced with untreated wash water. The suspended solids containing mineralized CO2 served as a viable cement replacement. The avoided cement and bound carbon dioxide served to lower the carbon impact of the concrete by about 14%. The approach allows three waste streams (CO2, wash water and wash water solids) to be reused to produce more sustainable concrete

Lattice model study of the thermodynamic interplay of polymer crystallization and liquid-liquid demixing

We report Monte Carlo simulations of a lattice-polymer model that can account for both polymer crystallization and liquid-liquid demixing in solutions of semiflexible homopolymers. In our model, neighboring polymer segments can have isotropic interactions that affect demixing, and anisotropic interactions that are responsible for freezing. However, our simulations show that the isotropic interactions also have a noticeable effect on the freezing curve, as do the anisotropic interactions on demixing. As the relative strength of the isotropic interactions is reduced, the liquid-liquid demixing transition disappears below the freezing curve. A simple, extended Flory-Huggins theory accounts quite well for the phase behavior observed in the simulations.Comment: Revtex, 7 pages, the content accepted by J. Chem. Phy

Performance characteristics of a new structured packing

A new structured packing using carbon fibres, called Sepcarb® 4D, is presented. This packing has several attractive properties, such as high voidage (ε=94%) and high effective area (a=420 m2 m−3). These properties are advantageous for packing used as a gas–liquid contactor for separation units. To determine the internal characteristics of this packing, we performed several experiments using a 150-mm-internal-diameter column. Firstly, hydrodynamics experiments were conducted using an air–water counter current flow to determine the pressure drop (for both dry and wet packing) and flooding point. Secondly, the mass transfer efficiency was determined in terms of HETP (height equivalent to theoretical plate) by total reflux experiments with an n-heptane/cyclohexane mixture at atmospheric pressure. Hydrodynamic performance and mass transfer efficiency were compared with those of packings generally used in distillation and absorption

Optimization-based scheduling of data center workload in function of outside weather conditions

International audienceData centers are the fifth largest energy consumerin the world and demand for data center services, driven bycloud computing, is rising rapidly. There is also a lot of interestin using data centers for offering grid services. Here, focus isput on scheduling, or in other words, shifting workload in time.This work explores the possible gains that could be achieved ifworkload would be easily scheduled. An energetic model of thedata-center is used, taking into account the dependency of thecooling's coefficient of performance (COP) on the outside weatherconditions as well as the influence of the heat load on the powerconsumption of the fans and pumps. This model is used to showthe possible energy savings that could be obtained by schedulingthe workload in function of outside wet bulb temperatures and fanpowers.</p