IEC 61508: Effect of Test Policy on the Probability of Failure on Demand of Safety Instrumented Systems Sergio Contini, Sabrina Copelli*, Massimo Raboni , Vincenzo Torretta , Carlo Sala Cattaneo , Renato Rota b a Università degli Studi dell’Insubria Dip. di Scienza e Alta Tecnologia, Via G.B. Vico 46 21100 Varese Italy b Politecnico di Milano Dip. di Chimica, Materiali e Ingegneria Chimica “G. ...

Understanding the kinetics of olefin polymerization with Ziegler-Natta and related catalysts means identifying the main kinetic parameters such as k(p) and concentration of active sites. The high-pressure quenched-flow technique could be an absolute method for counting active sites and for activation studies of molecular catalysts. A kinetic study of metallocene catalysts and a phenoxy-imine ti...

a fourth-generation ziegler-natta catalyst was prepared to synthesize polypropylene (pp), which was stabilized by in situ polymerization employing lignin as antioxidant. the antioxidant properties of lignin were compared with those of the commercial antioxidant irganox 1010. the presence of lignin in the reaction medium slightly decreased the catalytic activity of the reaction. the isotacticity...

In propylene (C3) polymerization with Ziegler-Natta catalyst, not only internal donor but also external is very important to make isotactic polypropylene (PP) higher yield. Most propylene-based polymers have been commercially produced catalysts combined dialkyl-dialkoxy silane compounds (R2Si(OR)2) such as C-donor, P-donor, and D-donor donors. this paper, we will introduce the performance amino...

Magnesium alkyls such as butyl octyl magnesium and ethyl are used precursors for highly active water-free chloride support materials Ziegler–Natta catalysts. These show a high viscosity in hydrocarbon solvents which negatively affect their industrial application. Density functional theory (DFT) calculations supported the hypothesis that can form oligomeric chain structures responsible viscosity...