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Hydrogen, as chain transfer agent, effects on kinetic of propylene polymerization; consequently variation of hydrogen concentration leads to change final product properties and also activates site of used catalyst. This phenomenon is one of the most important process variables is to adjust the final product properties and optimize the operating conditions. This work has attempted to present a mathematical model that cable to calculate the most important indices of end used product, such as melt flow index, number and weight average molecular weight and poly dispersity index. The model can predict profile polymerization rates determining important kinetic parameters such as the activation energy, lumped deactivation reaction initial reaction rate and deactivation constant. The mathematical model was implemented in Matlab/Simulink environment for slurry polymerization in laboratory scale. The modeling approach is based on polymer moment balance method in the slurry semi-batch reactor. In addition, in this work have provided a model that calculating fraction activated sites catalyst via hydrogen concentration. The model was validated by experimental data from lab scale, reactor. The experimental and model outputs were compared; consequently, the errors were within acceptable range.

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Purpose This paper aims to study the inhibition effect of 2-pyridinealdazine on the corrosion of mild steel in an acidic medium. The inhibition effect was studied using weight loss, electrochemical impedance spectroscopy, and Tafel polarization measurements. Design/methodology/approach Weight loss measurements, potentiodynamic tests, electrochemical impedance spectroscopy, X-ray diffraction and spectral and conformational isomers analysis of A (E-PAA) and B (Z-PAA) were performed were investigated. Findings 2-pyridinealdazine (PAA) acts as a good inhibitor for the corrosion of steel in 2.0 M H3PO4. The inhibition efficiency increases with an increase in inhibitor concentration but decreases with an increase in temperature. Originality/value This paper is intended to be added to the family of azines which are highly efficient inhibitors and can be used in the area of corrosion prevention and control.

International audienceThere is a growing trend in utilizing plant extracts and pharmaceutical compounds as corrosion inhibitors. Accurate identification of the essential oil of aerial parts of Pelargonium was obtained using hydrodistillation, gas chromatography and gas chromatography–mass spectrometry. The oil was predominated by citronellol (22.8 %). The inhibitory effect of essential oil and extract of Pelargonium was estimated on the corrosion of mild steel in 1 M hydrochloric acid (HCl) using weight loss, electrochemical impedance spectroscopy (EIS) and Tafel polarization curves. Inhibition was found to increase with increasing concentration of the essential oil and extractof Pelargonium. The effect of temperature on the corrosion behavior of mild steel in 1 M HCl with addition of essential oil and extract was also studied, and the thermodynamic parameters were determined and discussed. Values of inhibition efficiency were calculated from weight loss, Tafel polarization curves, and EIS. All results are in good agreement. Polarization curves showed that essential oil and extract of Pelargonium behave as mixed type inhibitors in HCl (1 M). The results obtained showed that the essential oil and extract of Pelargonium could serve as an effective inhibitor of the corrosion of mild steel in HCl solution. To avoid any unexpected toxicity, the majority of compounds have been studied by using POM analyses