This paper considers permeation through microporous or nanoporous inorganic membranes under the influence of an applied pressure gradient. In general membrane permeation may be considered as a diffusive process, driven by the gradient of chemical potential (which depends on both composition and pressure). The relative importance of these two factors varies greatly for different types of system....

• ERI-type molecular sieves enhance ethylene selectivity in MTO . Acidity significantly influences ethylene-to-propylene ratio materials. Changes acidity alter hydrocarbon-pool species concentration and composition. Low acid site densities hinder the formation of aromatics (thus, ethylene) ERI. (SSZ-98, UZM-12, zeolite, SAPO-17) are synthesized with varying Si/Al = 5–9 Si/T-atoms 0.034–0.12 usi...

The influence of the acid site density on diffusivities alkanes and alkenes through 8-ring windows SAPO-34 was probed using a complementary set ab initio MD simulations experimental techniques (PFG-NMR TAP pulse-response measurements). presence Brønsted sites found to have clear promotional effect alkene diffusion but it does not alkane diffusion.

The cell-surface protein APO-1 is a member of the nerve growth factor (NGF)/tumor necrosis factor (TNF) receptor superfamily. APO-1 mediates apoptosis in susceptible cells upon stimulation with the monoclonal antibody anti-APO-1 or upon binding of its natural ligand. Soluble receptors had previously been identified for most members of the NGF/TNF receptor superfamily. Recently, a soluble form o...

The influence of the nature of the cation on the interaction of the silicoaluminophosphate SAPO-34 with small hydrocarbons (ethane, ethylene, acetylene, propane, propylene) is investigated using periodic density-functional theory calculations including a semi-empirical dispersion correction (DFT-D). Initial calculations are used to evaluate which of the guest-accessible cation sites in the chab...

Operando UV/Vis spectroscopy with on-line mass spectrometry was used to study the effect of different types of impurities on the hydrocarbon pool species and the activity of H-SAPO-34 as a methanol-to-olefins (MTO) catalyst. Successive reaction cycles with different purity feedstocks were studied, with an intermittent regeneration step. The combined study of two distinct impurity types (i.e., f...