Sorption of thallous ion from acidic aqueous solutions onto ETS-10 titanosilicate

The sorption of the thallous ion from aqueous acidic solution (pH = 1.5) onto as-synthesized and modified ETS-10 titanosilicates was studied by using an isotope dilution method and a batch-mode technique. The present results show that the thallium(I) sorption was effective onto all three considered materials and is enhanced by the porosity and acidity modification of the ETS-10 titanosilicate. The best uptake performance was achieved by the meso-ETS-10. This behavior is explained based on the newly created additional mesoporous system and enriching the external surface with silanol groups. Also, the presence of phosphorus enhanced the inherent porosity allowing thus better internal diffusion properties of crystalline material. However, the chemically modified surface seems to have a negative contribution to the kinetic uptake of thallous ion as shown by the positive value of the activation energy E _a, in comparison with the processes more favorable energetically for ETS-10 and meso-ETS-10 materials.     

Second-order efficient nonlinear filter stabilization for high Reynolds number flows

In this article, we develop a second-order nonlinear filter based stabilization scheme for high Reynolds number flows. We prove the unconditional stability of the method, establish the second order consistency and discuss the dynamical tuning of the relaxation parameter. The scheme is then validated against experimental data for an isothermal turbulent flow in a Staggered Tube Bundle at Reynolds number of 18,000. Numerical results are found to be in an overall good qualitative and quantitative agreement with the benchmark results.