Network-controlled mobility within radio access networks based onWLAN technologies

This article presents a network-controlled approach of user terminal mobility within anIP based WirelessLAN Access Network. In a first part, this article makes a review of the mobility support, on the subject of emergingWLAN technologies asHIPERLAN/2 andIEEE 802.11, on the one hand, and, regardingIP networks as currently studied withinIETF, on the other hand. Both types ofIP mobility protocols are presented, either global mobility protocols such as MobileIP, or local mobility management protocols (micro mobility). In the next part, the overall principles of our mobility management approach are explained; this approach is based on the implementation of a new network entity dedicated to the control of user terminal mobility. The last part details a practical implementation of this approach. The implementation is carried out on the basis of Hierarchical MobileIPv6 (HMIPv6). The experimental results confirm the importance to carefully plan and control the user terminal mobility within largeIP based Access Networks, as this brings benefit to the user as well as to the operator.     

Potential influence of microorganisms on the corrosion of carbon steel in the French high- and intermediate-level long-lived radioactive waste disposal context

In the context of the high-level radioactive waste disposal CIGEO, the corrosion rate due to microbially influenced corrosion (MIC) has to be evaluated. In France, it is envisaged to dispose of high- and intermediate-level long-lived radioactive waste at a depth of 500 m in a deep geological disposal, drilled in the Callovo-Oxfordian claystone (Cox) formation. To do so, a carbon steel casing will be inserted inside disposal cells, which are horizontal tunnels drilled in the Cox. A specific cement grout will be injected between the carbon steel casing and the claystone. A study was conducted to evaluate the possibility of MIC on carbon steel in the foreseeable high radioactive waste disposal. The corrosiveness of various environments was investigated at 50°C and 80°C with or without microorganisms enriched from samples of Andra's underground research laboratory. The monitoring of corrosion during the experiments was ensured using gravimetric method and real-time corrosion monitoring using sensors based on the measurements of the electrical resistance. The corrosion data were completed with microbiological analyses including cultural and molecular characterizations.     

Synthesis by Spark Plasma Sintering: A new way to obtain electrode materials for lithium ion batteries

In the search of high-performance materials for lithium ion batteries, Li₂CoPO₄F offers many advantages like high theoretical capacity and high operating potential. The synthesis of Li₂CoPO₄F has been reinvestigated considering a conventional solid state reaction and an unconventional way. Due to the long heat-treatments required by the conventional approach, a beginning of grains coalescence is observed. Limiting particles growth has been allowed by a shorter reaction done by SPS (Spark Plasma Sintering). By this method, the synthesis of Li₂CoPO₄F was greatly shortened (from 10 h to 9 min), which favours the getting of submicrometric particles. The comparison of the electrochemical properties of the Li₂CoPO₄F obtained by the different ways confirms the advantages of SPS synthesis in performance enhancement.     

Experimental investigation of a pulsating heat pipe for hybrid vehicle applications

This paper deals with the experimental results of an unlooped pulsating heat pipe (PHP) developed and tested in an electronic thermal management field with hybrid vehicle applications in mind. The 2.5 mm inner tube diameter device was cooled by an air heat exchanger to replicate the environment of a vehicle.In order to characterize this pulsating heat pipe, four working fluids have been tested. They are acetone, methanol, water, and n-pentane, with applied thermal power ranging from 25 W to 550 W, air temperature ranging from 10 °C to 60 °C and air velocity ranging from 0.25 m s^?1 to 2 m s^?1. Three inclinations have also been tested according to their horizontal positions: +45° (condenser above the evaporator), 0° and ?45° (condenser below the evaporator).Among the different results, some of the most revelatory were obtained with regard to unfavourable inclination (?45°), for which the performances were very interesting considering a terrestrial application. On the other hand, one also observed low temperature limitations for water as a working fluid and degradation of performances for n-pentane tested at 60 °C air temperature. On an overall basis, however, it should be noted that the PHP functioned with high reliability and reproducibility and without any failure during the start-up or working stage.     

Influence of pH on complexing of model beta-d-glucans with zearalenone

Previous studies have shown that isolated beta-(1,3 and 1,6)-D-glucans and related alkali-extracted fractions from the cell wall of Saccharomyces cerevisiae are able to complex with zearalenone in vitro (affinity up to 50%) and thus may reduce the bioavailability of toxins in the digestive tract. The complexation mechanisms involve cooperative interaction between the two chemical entities that can be computed by Hill's model. Various linear or branched soluble or insoluble beta-D-glucans were evaluated to elucidate their roles in the adsorption mechanisms under three pH conditions (3.0, 6.0, and 8.0) found in the digestive tract. A constant quantity of each beta-D-glucans (1 mg/ml) was mixed at 39 degrees C with increasing amounts of zearalenone (2 to 100 microg/ml), and the amount of bound toxin was measured. Acidic and neutral conditions gave the highest affinity rates (64 to 77%) by beta-(1,3)-D-glucans, whereas alkaline conditions decreased adsorption except when beta-(1,6)-D-glucan side chains were branched on beta-(1,3)-D-glucans. Alkaline conditions appear to impede the active three dimensional conformation of beta-D-glucans and favor single helix and/or random coil structures. Study of the equilibrium between beta-D-glucan-bound and free toxins revealed that two types of chemical interactions occur during toxin complexation with beta-D-glucans, identified as weak chemical linkages such as hydrogen and van der Waals bonds.     

Thermal behavior of an electrical motor through a reduced model

The aim of this study is to obtain quickly thermal information on some sensitive components of an electrical motor in a short lapse of time. The thermal behavior of this complex system is modeled and validated. The corresponding detailed model leads to the resolution of a linear system of differential equations of high order, but is not easy to handle for control purposes, due to long CPU time. In order to compute faster, two model reduction techniques are used: the Eitelberg method and the reduction by modal identification. The reduced models effectively give good temperature accuracy on the critical points of the motor with very fast computation time     

Heck–Matsuda Arylation of Olefins Through a Bicatalytic Approach: Improved Procedures and Rationalization

The scope of the palladium‐catalyzed Heck–Matsuda reaction, proceeding through the catalytic activation of anilines into the corresponding diazonium salts, has been considerably extended and is now working with deactivated electrophiles. Two different procedures, using catalytic amounts of both palladium and acid, have been optimized allowing the concept of bicatalysis to cover the complete electronic range of anilines. These environmentally friendly procedures proceed under very mild conditions, at room temperature in methanol, and only generate tert‐butyl alcohol, water and nitrogen as by‐products. Rationalization of reaction outcomes encountered in this work has been discussed with the support of computational studies.

     

Design Impact on Airflow Patterns in Fluidization Units

The airflow behavior in a fluidization unit was integrally studied by means of experimental work and computational fluid dynamics simulation. The computational domain included the gas inlet pipe, plenum, perforated plate, fluidization chamber, and air outlet pipe. Different scenarios were simulated to allow distinguishing the best way to represent perforated‐plate distributors and elucidate the impact of the grid design on the fluidization performance. The simulated pressure drop across the distributor and the plenum flow pattern were in concordance with the experimental data. It was found that the distance between the peripheral holes and walls has a great impact on the airflow downstream the distributor.