Variation of carbon steel corrosion rate with flow conditions in the presence of an inhibitive formulation

This work is an extension of studies into the mechanism of inhibition of a carbon steel by a non-toxic multicomponent inhibitor (fatty amines associated with phosphonocarboxylic acid salts) used for the treatment of water in cooling circuits. In a previous work [N. Ochoa, F. Moran, N. Pébère, B. Tribollet, Corros. Sci. 47 (2005) 593], it was shown that the properties of the protective layers formed on the metal surface were dependent on the electrode rotation rate. Moreover, two distinct surface areas were visualised on the metal surface and the ratio between the two zones was dependent on the flow conditions. The present study focuses on the measurement of the corrosion rate from impedance diagrams obtained at the corrosion potential for different electrode rotation rates. The measured polarisation resistances correspond to the anodic process. A non-monotonic variation of the corrosion current densities was observed and explained by the variation of the ratio between the two layers, which each have different intrinsic protective properties. From the polarisation curves plotted in the same conditions, the non-monotonic variation was not shown. Independently of the electrode rotation rate, the corrosion current densities remained low. This study brought an original approach to the influence of flow on the corrosion rate in the presence of inhibitors.     

Design of extractive distillation for the separation of close-boiling mixtures: Solvent selection and column optimization

A practical methodology for the design and optimization of extractive distillation is proposed in this work. The extractive distillation is generally applied to the separation of close-boiling mixtures, which by conventional distillation is difficult to separate. The design and optimization of extractive distillation is more complex than that of the conventional distillation when considering the selection of suitable solvent to enhance the separation. Currently, the solvent selection can be effectively handled by the assistance of the computer-aided molecular design (CAMD) approach. The selection result may however be inconclusive due to the lack of accurate or missing parameters in the property model. In this work, the experimental verification and the property parameter determination were proved to be necessary as an additional step to achieve a successful and reliable design. The overall design methodology was illustrated through an industrial separation of C8-Aromatics mixture.     

Corrosion Fatigue Study of 6061 Aluminum Alloy: The Effect of Coatings on the Fatigue Characteristics

Metallurgical and Materials Transactions A - This study proposes a method for protecting 6061 aluminum alloy from corrosion fatigue. Corrosion fatigue can reduce fatigue strength at the endurance...     

Alteration of Extracellular Matrix Components in the Anterior Pituitary Gland of Neonatal Rats Induced by a Maternal Bisphenol A Diet during Pregnancy

The extracellular matrix (ECM) plays crucial roles in the anterior pituitary gland via the mechanism of cell–ECM interaction. Since bisphenol A (BPA), a well-known endocrine disruptor, can cross through the placenta from mother to fetus and bind with estrogen receptors, cell populations in the neonatal anterior pituitary gland could be the target cells affected by this chemical. The present study treated maternal rats with 5000 µg/kg body weight of BPA daily throughout the pregnancy period and then investigated the changes in ECM-producing cells, i.e., pericytes and folliculostellate (FS) cells, including their ECM production in the neonatal anterior pituitary at Day 1. We found that pericytes and their collagen synthesis reduced, consistent with the increase in the number of FS cells that expressed several ECM regulators—matrix metalloproteinase (MMP) 9 and the tissue inhibitors of metalloproteinase (TIMP) family. The relative MMP9/TIMP1 ratio was extremely high, indicating that the control of ECM homeostasis was unbalanced. Moreover, transmission electron microscopy showed the unorganized cell cluster in the BPA-treated group. This study revealed that although the mother received BPA at the “no observed adverse effect” level, alterations in ECM-producing cells as well as collagen and the related ECM balancing genes occurred in the neonatal anterior pituitary gland.