Influence of flow on the corrosion inhibition of carbon steel by fatty amines in association with phosphonocarboxylic acid salts

This work was carried out to study the inhibition mechanism of a carbon steel in a 200 mg l−1 NaCl solution by a non-toxic multi-component inhibitor used for water treatment in cooling circuits. The inhibitive formulation was composed of 50 mg l−1 fatty amines associated with 200 mg l−1 phosphonocarboxylic acid salts. Steady-state current–voltage curves, obtained with a rotating disc electrode, revealed that the properties of the protective layer were dependent on the electrode rotation rate and on the immersion time. The cathodic process of oxygen reduction was not modified in the presence of the inhibitive mixture. As expected, the current densities increased when the rotation rate was increased. In the anodic range, original behaviour was observed: the current densities decreased when the electrode rotation rate increased. The morphology and the chemical composition of the inhibitive layers allowed the electrochemical results to be explained. Two distinct surface areas were visualised on the metal surface and the ratio between the two zones was dependent on the flow conditions. This behaviour was attributed to a mechanical effect linked to centrifugal force. XPS analysis revealed that the formation of a chelate between the phosphonocarboxylic acid salt molecules and the iron oxide/hydroxide was enhanced by the increase of the electrode rotation rate

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

Ensayo de mantenimiento de alevines de Oncorhynchus mykiss (Walbaum, 1792) (Pisces: Salmonidae) en acuarios y jaulas flotantes

Con el fin de evaluar el crecimiento de alevines de trucha arcoíris (O. mykiss), en una primera fase se consideraron los periodos 12.Ago-01.Sep.11 y 27.Sep-08.Oct.11 y jaulas flotantes (50 alevines/jaula) ubicadas en un reservorio rural en Cajicá-Cundinamarca. Se suministraron dos dietas: Truchina 45% + alimento vivo (T+AV) y alimento vivo (AV). La segunda fase (19. Ene- 19. May.12) consistió en la evaluación, en laboratorio, de dos densidades diferentes en tres acuarios, uno con densidad óptima (120 peces) y dos con densidad alta (266 peces en cada uno). En ambas fases se registraron algunas variables abióticas.Pregrad

CO2 corrosion resistance of carbon steel in relation with microstructure changes

The microstructural effects on the corrosion resistance of an API 5L X42 carbon steel in 0.5 M NaCl solution saturated with CO2 was investigated. Four microstructures were considered: banded (B), normalized (N), quenched and tempered (Q&T), and annealed (A). Electrochemical measurements (polarization curves and electrochemical impedance spectroscopy) were coupled with surface analyses (scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS)) to characterize the formation of the corrosion product layers. Electrochemical results revealed that corrosion resistance increased in the following order: B < N < Q&T < A. From the polarization curves it was shown that specifically, cathodic current densities were affected by microstructural changes. SEM images indicated that ferrite dissolved earlier than cementite and a thin layer of corrosion products was deposited on the steel surface. XPS analyses revealed that this layer was composed of a mixture of iron carbonate and non-dissolved cementite. It was also found that the quantity of FeCO3 content on the steel surface was greater for Q&T and A microstructures. These results, in agreement with the electrochemical data, indicate that the deposition mechanism of iron carbonate is closely related to the morphology of the non-dissolved cementite, determining the protective properties of the corrosion product layers

Preexisting autoantibodies to type I IFNs underlie critical COVID-19 pneumonia in patients with APS-1

Patients with biallelic loss-of-function variants of AIRE suffer from autoimmune polyendocrine syndrome type-1 (APS-1) and produce a broad range of autoantibodies (auto-Abs), including circulating auto-Abs neutralizing most type I interferons (IFNs). These auto-Abs were recently reported to account for at least 10% of cases of life-threatening COVID-19 pneumonia in the general population. We report 22 APS-1 patients from 21 kindreds in seven countries, aged between 8 and 48 yr and infected with SARS-CoV-2 since February 2020. The 21 patients tested had auto-Abs neutralizing IFN-α subtypes and/or IFN-ω; one had anti–IFN-β and another anti–IFN-ε, but none had anti–IFN-κ. Strikingly, 19 patients (86%) were hospitalized for COVID-19 pneumonia, including 15 (68%) admitted to an intensive care unit, 11 (50%) who required mechanical ventilation, and four (18%) who died. Ambulatory disease in three patients (14%) was possibly accounted for by prior or early specific interventions. Preexisting auto-Abs neutralizing type I IFNs in APS-1 patients confer a very high risk of life-threatening COVID-19 pneumonia at any age.publishedVersio

EuReCa ONE—27 Nations, ONE Europe, ONE Registry A prospective one month analysis of out-of-hospital cardiac arrest outcomes in 27 countries in Europe

AbstractIntroductionThe aim of the EuReCa ONE study was to determine the incidence, process, and outcome for out of hospital cardiac arrest (OHCA) throughout Europe.MethodsThis was an international, prospective, multi-centre one-month study. Patients who suffered an OHCA during October 2014 who were attended and/or treated by an Emergency Medical Service (EMS) were eligible for inclusion in the study. Data were extracted from national, regional or local registries.ResultsData on 10,682 confirmed OHCAs from 248 regions in 27 countries, covering an estimated population of 174 million. In 7146 (66%) cases, CPR was started by a bystander or by the EMS. The incidence of CPR attempts ranged from 19.0 to 104.0 per 100,000 population per year. 1735 had ROSC on arrival at hospital (25.2%), Overall, 662/6414 (10.3%) in all cases with CPR attempted survived for at least 30 days or to hospital discharge.ConclusionThe results of EuReCa ONE highlight that OHCA is still a major public health problem accounting for a substantial number of deaths in Europe.EuReCa ONE very clearly demonstrates marked differences in the processes for data collection and reported outcomes following OHCA all over Europe. Using these data and analyses, different countries, regions, systems, and concepts can benchmark themselves and may learn from each other to further improve survival following one of our major health care events