University of the Littoral Opal Coast

About: University of the Littoral Opal Coast is a education organization based out in Dunkirk, France. It is known for research contribution in the topics: Catalysis & Dielectric. The organization has 1242 authors who have published 2383 publications receiving 46230 citations. The organization is also known as: ULCO.

Formation of cereous sulphate phase upon interaction of So2 with ceria at room temperature

Abstract: The adsorption of SO2 gas on ceria solid at room temperature has been investigated by thermal analysis, Raman spectroscopy and electron paramagnetic resonance (EPR). The results confirm that SO2 transformation into sulphate species occurs at 25°C with a concomitant reduction of Ce4+ to Ce3+ ions. The formation of Ce(III)-sulphate phase has been evidenced on ceria surface. The thermal analysis revealed a complete decomposition of cereous sulphate phase to CeO2 at 785°C. The change of oxidation state of Ce(IV) to Ce(III) during the formation of sulphate phase has been confirmed also by EPR technique.

CO2 reforming of methane over Ni and/or Ru catalysts supported on mesoporous KIT-6: Effect of promotion with Ce

Abstract: CO2 reforming of methane was studied over Ni and/or Ru supported on KIT-6 and KIT-6 promoted with Ce catalysts synthesized using the wet impregnation technique. The percent of nickel and ruthenium in all catalysts was fixed at 15 wt% and/or 1 wt% respectively. All catalysts were calcined at 550 °C and characterized by XRD, N2 adsorption/desorption, H2-TPR and CO2-TPD. All catalysts exhibited type IVa isotherms attributed to their mesoporous nature. Ce promotion resulted in a significant destruction of the porous structure which was demonstrated by the change in the shape of the isotherm as well as decreased surface areas and pore volumes. H2-TPR profiles showed reduction peaks corresponding to the reduction of agglomerated RuO2 species as well as different NiO species that are either free or in interaction with the support. It was noticed that the incorporation of Ce impaired the interactions between the active phase and the support. CO2-TPD profiles demonstrated that promoting the catalysts with Ce increased their basicity. Among the non-promoted catalysts, Ni-Ru/KIT-6 presented enhanced active phase dispersion, reducibility, and the highest basicity which resulted in an ameliorated catalytic performance. However, the promoted Ni-Ru/Ce-KIT-6 catalyst exhibited much higher activity and stability after 12 h on stream despite the formation of graphitic carbon resulting from the decomposition of methane.

A change propagation model and platform for multi-database applications

Abstract: In this paper, we propose a formal model and a platform for software change management. The model is based on graphs rewriting, and deals with both multi-language source codes and heterogeneous database schemas. These are represented by software components linked by meaningful relationships. The change impact analysis is done, using a knowledge-based system, that includes impact propagation rules preserving the software consistency. This is implemented by an integrated platform including a multilanguage parsing tool, and a soft-ware change management module.

A new calorimetric technique for phase change materials and its application to alkane-based PCMs

Abstract: The correct determination of the phase transition behaviour of phase change materials (PCMs) is paramount for assessing their application potential. In this work, the merits of a novel calorimetric technique, Peltier-element-based adiabatic scanning calorimetry (pASC), for PCM characterisation are investigated, especially in comparison with the commonly-used differential scanning calorimeter (DSC). A comparative study of two alkane-based PCMs, the commercial mixture RT42 and the pure alkane tricosane (C23) with these two techniques shows that pASC provides data at much higher resolution than DSC, due to its operation in thermodynamic equilibrium. Specifically the rate-dependence and deformation that is inherent to DSC experiments is absent in pASC. In addition, the enthalpy of the PCM is directly obtained. pASC results easily conform to the accuracy limits that are proposed in literature for the transition temperature and storage capacity of PCMs.