The aim of this study is to assess the main factors that affect the behaviour of carbon steel and galvanised steel in tropical and non‐tropical marine environments, identifying those factors that directly affect the behaviour. The results from the INNOVA (Chile) and MICAT/PATINA (Venezuela) projects will be used. These projects evaluated metals exposed to different marine environments using procedures outlined in ISO 9223/9226. The results show that temperature has no significant effect on the behaviour of the materials at the study sites in question (Venezuela being 10 °C warmer than Chile), independent of the tropical nature of the exposure environment, while it is precipitation (>600 mm) and chloride and SO2 content in the environment that mainly influence the behaviour of the carbon steel and the galvanised steel. In addition, an artificial neural network was generated to evaluate the corrosion rate of the studied metals, using meteoro‐chemical variables. The neural network for the carbon and galvanised steel was more precise for the exposure sites located in Chile.

onThis article presents the results obtained for the atmospheric corrosion of copper after 3 years of exposure at different sites within the region of Valparaiso, Chile. Frames were installed with samples at seven sites located close to the coast and inland. They were accompanied by devices to measure atmospheric chloride and sulphur dioxide content and weather stations to obtain data on temperature, humidity, amount of rainfall and wind speed. The results show a correlation between corrosion rate and the environmental and meteorological conditions in the area, and with the morphology and electrochemical properties of the corrosion product formed on the copper surface. The sites gave corrosivity categories of C5, C4, C3 and C2. The behaviour of corrosion rate was modelled using power function models and neural networks. The main corrosion products were cuprite, posnjankite, covelite and atacamite. O (M) Covelite, CuS (t) Cuprite, Cu 2 O (M) Covelite, CuS (t) Valparaíso Cuprite, Cu 2 O (M) Covelite, CuS (M) Atacamite, Cu 2 Cl(OH) 3 (M) Brochantite, Cu 4 (SO 4 )(OH) 6 (t) Atacamite, Cu 2 Cl(OH) 3 (M) Covelite, CuS (M) Cuprite, Cu 2 O (t) Thenardite, Na 2 SO 4 (t) M, major; m, minor; t, traces.

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Pentachlorophenol (PCP) is a widely used and highly toxic fungicide. Its toxicity is mainly expressed at the cell membrane level. It is, therefore, of interest to test its ability to alter the lipid bilayer organization. The present study was performed by X-ray diffraction techniques on dimyristoylphosphatidylethanolamine (DMPE) and dimyristoylphosphatidylcholine (DMPC) bilayers and by fluorescence on DMPC liposomes. These two phospholipids are respectively found at the inner and outer monolayers of human erythrocyte membranes. Each type of phospholipid was made to interact with different concentrations of the sodium form of PCP in absence and in presence of water. It was found that PCP significatively affected the structure of both phospholipids, being the damage much higher in DM PC bilayers.

Several hypotheses link the molecular mechanism of action of the antiarrhythmic drugs (AAD) that belong to class I to non-specific interactions with phospholipids sited in the neighborhood of sodium channels in the membrane of the myocardium. Procainamide (PROC ), one of the least lipophilic drugs of this group, was induced to interact with bilayers of dimyristoylphosphatidylcholine (DMPC) and dimirystoylphosphatidylethanolamine (DMPE), liposomes of DMPC and human erythrocytes. The perturbing effects of PROC upon these systems were respectively determined by X-ray diffraction, fluorescence spectroscopy and scanning electron microscopy. It was found that PROC exerted very little effect upon DMPC and DMPE even at such a high concentration as 10 mᴍ . However, at therapeutical plasma concentrations, PROC induced shape changes in vitro to red cells.