Study of NH3-Standard SCR reactions over a commercial catalyst on powder and mini-SCRF forms

SSCI-VIDE+CARE+SML:AGFInternational audienceNon

Study of NH3-Standard SCR reactions over a commercial catalyst on powder and mini-SCRF forms

SSCI-VIDE+CARE+SML:AGFInternational audienceNon

Sulfur Deactivation of NOx Storage Catalysts: A Multiscale Modeling Approach

Lean NOx Trap (LNT) catalysts, a promising solution for reducing the noxious nitrogen oxide emissions from the lean burn and Diesel engines, are technologically limited by the presence of sulfur in the exhaust gas stream. Sulfur stemming from both fuels and lubricating oils is oxidized during the combustion event and mainly exists as SOx (SO2 and SO3) in the exhaust. Sulfur oxides interact strongly with the NOx trapping material of a LNT to form thermodynamically favored sulfate species, consequently leading to the blockage of NOx sorption sites and altering the catalyst operation. Molecular and kinetic modeling represent a valuable tool for predicting system behavior and evaluating catalytic performances. The present paper demonstrates how fundamental ab initio calculations can be used as a valuable source for designing kinetic models developed in the IFP Exhaust library, intended for vehicle simulations. The concrete example we chose to illustrate our approach was SO3 adsorption on the model NOx storage material, BaO. SO3 adsorption was described for various sites (terraces, surface steps and kinks and bulk) for a closer description of a real storage material. Additional rate and sensitivity analyses provided a deeper understanding of the poisoning phenomena

Cross-layer Optimization in the Next-generation Broadband Satellite Systems

Next-generation broadband satellite systems will have the capability to provide cost-effective universal broadband access for the users. In order to meet users’ requirements on high quality multimedia services, many enhancements have to be made on the existing satellite technologies. One of the promising methods is the introduction of cross-layer design. There are several advantages of a layered approach since modularity, robustness and ease of designs are achieved without difficulty. However the properties of the different layers have substantial interdependencies and a modularised design may therefore be suboptimal with regards to performance and availability in a hybrid satellite and mobile wireless environment. In this paper, we will carry out a review of the cross-layer design in satellite systems. Based on this, a cross-layer architecture for the next-generation broadband satellite system is proposed. The proposed cross-layer architecture has two main components: QoS and resource management and mobility management. In each component, the cross-layer techniques that have been used are described in details

Cross-layer optimization in the next-generation broadband satellite systems

Next-generation broadband satellite systems will have the capability to provide costeffective universal broadband access for the users. In order to meet users' requirements on high quality multimedia services, many enhancements have to be made on the existing satellite technologies. One of the promising methods is the introduction of cross-layer design. There are several advantages of a layered approach since modularity, robustness and ease of designs are achieved without difficulty. However the properties of the different layers have substantial interdependencies and a modularised design may therefore be suboptimal with regards to performance and availability in a hybrid satellite and mobile wireless environment. In this paper, we will carry out a review of the cross-layer design in satellite systems. Based on this, a cross-layer architecture for the next-generation broadband satellite system is proposed. The proposed cross-layer architecture has two main components: QoS and resource management and mobility management. In each component, the cross-layer techniques that have been used are described in details