Influence of sensitisation on the corrosion behaviour of Alloy 926 (UNS N08926) in concentrated aqueous lithium bromide solutions at different temperatures

[EN] The aim of this work is to study the influence of sensitisation to intergranular corrosion on a highly alloyed austenitic stainless steel, Alloy 926 (UNS N08926). Some specimens of this steel have been heated in an argon atmosphere at 825 degrees C during 1 hour. The degree of sensitisation has been characterised by means of SEM, etching (with oxalic acid), and electrochemical reactivation methods (single and double loop tests). The corrosion behaviour of sensitised and unsensitised Alloy 926 has been analysed in a concentrated aqueous lithium bromide (LiBr) solution of 992 g/L by means of cyclic potentiodynamic curves at different temperatures. The results indicate that chromium carbide precipitates reduce the pitting potential value of Alloy 926. Besides, the pitting potential decreases with temperature. On the other hand, the corrosion potential and open circuit potential values increase with temperature and sensitisation.We wish to express our gratitude to MICINN (CTQ2009-07518), to FEDER, to Dr. Helena Alves from Krupp VDM for supplying the materials, and to Dr. Asunción Jaime for her translation assistance.Leiva García, R.; Muñoz-Portero, M.; Garcia-Anton, J. (2011). Influence of sensitisation on the corrosion behaviour of Alloy 926 (UNS N08926) in concentrated aqueous lithium bromide solutions at different temperatures. International Journal of Electrochemical Science. 6(2):442-460. http://hdl.handle.net/10251/61141S4424606

In-Situ Study of Single and Double Loop Reactivation Methods During the Characterisation of the Degree of Sensitisation of a Duplex Stainless Steel (UNS 1.4462) Using a Minicell and a Confocal Microscope

[EN] The aim of this work is to study the evolution of the electrode surface during the single and double reactivation methods at microscopic scale. The tested material has been a duplex stainless steel (UNS 1.4462) in its as-received state and heated at 825 degrees C for 1 hour in an inert atmosphere. Tests have been carried out in an electrochemical minicell that can be put in the stage of a confocal microscope. These devices allow the in-situ observation of the electrode surface at microscopic scale during the tests. Differences in the evolution of the electrode surface have been observed between the single and the double loop methods. Furthermore, the sensitised sample shows different evolution during the electrochemical tests than the as-received sample. These differences are due to the formation of new phases during the heat treatment. Therefore, the minicell permits obtaining additional information during the electrochemical characterisation of the degree of sensitisation in duplex stainless steels.We wish to express our gratitude to MICINN (CTQ2009-07518), to FEDER, to the Generalitat Valenciana for its help in the CLSM acquisition (MY08/ISIRM/S/100), and to Dr. Asunción Jaime for her translation assistance.Leiva García, R.; Muñoz-Portero, M.; Garcia-Anton, J. (2011). In-Situ Study of Single and Double Loop Reactivation Methods During the Characterisation of the Degree of Sensitisation of a Duplex Stainless Steel (UNS 1.4462) Using a Minicell and a Confocal Microscope. International Journal of Electrochemical Science. 6(3):830-846. http://hdl.handle.net/10251/61142S8308466

Effects of Hydrodynamic Conditions and LiBr Concentration on the Corrosion of Copper in LiBr Absorption Machines

Refrigeration absorption machines are again considered as suitable refrigeration systems and they are replacing compression machines due to the ban of chlorofluorocarbons (CFCs) and the strict regulations of hydrochlorofluorocarbons. Lithium Bromide (LiBr) is one of the most widely used absorbents in refrigeration technology. However, the operating conditions of absorption machines (high concentration and high temperature) can cause serious corrosion problems in the structural materials. Corrosion problems can be enhanced by the hydrodynamic conditions of the system. The present work studies of the influence of hydrodynamic conditions on copper corrosion under different LiBr conditions. Polarisation potentiodynamic curves obtained following ASTM G-5 were used to study the influence of the LiBr concentration and hydrodynamic conditions. Parameters such as corrosion current density and corrosion potential were obtained from the potentiodynamic curves. A rotating disk electrode (RDE) was used to determine the hydrodynamic conditions. Three LiBr solutions of different concentration (400 g/l, 700 g/l, and 850 g/l) at 25 degrees C and different rotation rates (0 r.p.m. - 3000 r.p.m.) were used during the tests. Results show that an increase of the bromide concentration and rotation rate favours copper corrosion and enhances anodic dissolution. The effects of the hydrodynamic conditions are smaller at higher LiBr concentrations.Leiva García, R.; Muñoz-Portero, M.; Garcia-Anton, J.; Sánchez Tovar, R. (2012). Effects of Hydrodynamic Conditions and LiBr Concentration on the Corrosion of Copper in LiBr Absorption Machines. International Journal of Electrochemical Science. 7(2):1332-1347. http://hdl.handle.net/10251/61162S133213477

Improvement of the electrochemical behaviour of Zn-electroplated steel using regenerated Cr(III) passivation baths

Conversion coatings based on trivalent chromium are more sensitive to the presence of zinc and iron impurities than the chromate formulations. This fact contributes to a decrease in the quality of passivation and to the generation of a significant amount of hazardous liquid waste. Recently, a new eco-innovative process based on Emulsion Pertraction Technology (EPT) is being implemented at industrial scale for selectively removing Zn and Fe from spent passivation baths in order to enhance the lifetime of the Cr (III) baths. In this study, the effect of Zn and Fe removal on the electrochemical behaviour of Zn-electroplated steel samples was evaluated by means of polarisation curves and electrochemical impedance spectroscopy measurements at open circuit potential conditions in 3.5 g/L NaCl solutions. The main objective was to assess the benefits brought by EPT using electrochemical methods. Cr (III) passivation baths regenerated using the EPT process have been compared to the bath used in a local industry as well as to fresh and spent baths. According to the results, the samples passivated in the EPT regenerated bath showed a significant improvement in their electrochemical behaviour compared to the samples passivated in the spent baths. This study concluded the suitability of EPT for regenerating Cr (III) passivation baths

Effect of Welding on The Corrosion Behaviour of a Highly Alloyed Austenitic Stainless Steel UNS N06027 in Polluted Phosphoric Acid Media

[EN] The objective of this work is to study the effect of welding on the corrosion resistance of the austenitic stainless steel Alloy 59 (UNS N06027) as well as the galvanic corrosion generated by the base/weld pair estimated from the polarisation curves according to the mixed potential theory. The materials have been exposed to polluted phosphoric acid at several temperatures. The microstructure of the samples was studied by SEM and EDX analysis. The results show that the welding process shifts the corrosion potential values to more anodic potentials. The corrosion current densities and the passive current densities also increased by the effect of welding. This effect is aggravated with the increase in temperature. Open circuit potential values were located in the passive zone of the potentiodynamic curves, which means that the materials passivated spontaneously.The galvanic corrosion of the pair is not severe in the studied conditions. The ratio between the galvanic current density of the pair and the corrosion current density of the uncoupled anode is less than 5, which implies compatibility of the members in the couple.The authors acknowledge the Spanish Ministerio de Asuntos Exteriores y Cooperacion "MAEC" (PCI Mediterraneo C78196/07, D/023608/09, D/030177/10 and D/030177/10) for its financial support to the Krupp VDM Group (Germany) for the supplied alloys and to Dr. Asuncion Jaime for her translation assistance.Bakour, S.; Guenbour, A.; Bellaouchou, A.; Escrivá Cerdán, C.; Sánchez Tovar, R.; Leiva García, R.; Garcia-Anton, J. (2012). Effect of Welding on The Corrosion Behaviour of a Highly Alloyed Austenitic Stainless Steel UNS N06027 in Polluted Phosphoric Acid Media. International Journal of Electrochemical Science. 7(11):10530-10543. http://hdl.handle.net/10251/61163S105301054371

Empoderamiento del alumnado adulto y de las personas mayores para una ciudadanía activa

Esta obra reúne iniciativas y experiencias de sensibilización y formación del profesorado y del alumnado adulto y mayor hacia una educación en competencias que contribuya a desarrollar la práctica de una ciudadanía activa compartiendo el tiempo libre, los conocimientos y las experiencias en proyectos sociales que consoliden y mejoren el entramado social de la ciudad, de las personas que la habitan y de la atención a sus necesidades. Su origen fue el proyecto CiudAct cofinanciado por el Programa Erasmus+ de la Unión Europea y en su desarrollo ha intervenido un equipo interinstitucional liderado por el Aula de Mayores+55 de la Universidad de Málaga y participado por el Centro de Profesorado «José Rodríguez Galán» de Antequera, la Asociación Cívica para la Prevención (ACP), la Asociación de Igualdad de Género Universitario (AIGU), y el Ayuntamiento de Faraján (Málaga). Con ellos, y con otras tantas instituciones y sus respectivos consorcios locales en toda Europa, se participa en la red supranacional Ciudades en Crecimiento.Programa Erasmus+ de la Unión Europea (referencia de proyecto 2015-1-ES01-KA104-014944

Refined physical parameters for Chariklo's body and rings from stellar occultations observed between 2013 and 2020

Context. The Centaur (10199) Chariklo has the first ring system discovered around a small object. It was first observed using stellar occultation in 2013. Stellar occultations allow sizes and shapes to be determined with kilometre accuracy, and provide the characteristics of the occulting object and its vicinity. Aims. Using stellar occultations observed between 2017 and 2020, our aim is to constrain the physical parameters of Chariklo and its rings. We also determine the structure of the rings, and obtain precise astrometrical positions of Chariklo. Methods. We predicted and organised several observational campaigns of stellar occultations by Chariklo. Occultation light curves were measured from the datasets, from which ingress and egress times, and the ring widths and opacity values were obtained. These measurements, combined with results from previous works, allow us to obtain significant constraints on Chariklo's shape and ring structure. Results. We characterise Chariklo's ring system (C1R and C2R), and obtain radii and pole orientations that are consistent with, but more accurate than, results from previous occultations. We confirm the detection of W-shaped structures within C1R and an evident variation in radial width. The observed width ranges between 4.8 and 9.1 km with a mean value of 6.5 km. One dual observation (visible and red) does not reveal any differences in the C1R opacity profiles, indicating a ring particle size larger than a few microns. The C1R ring eccentricity is found to be smaller than 0.022 (3σ), and its width variations may indicate an eccentricity higher than ~0.005. We fit a tri-axial shape to Chariklo's detections over 11 occultations, and determine that Chariklo is consistent with an ellipsoid with semi-axes of 143.8-1.5+1.4, 135.2-2.8+1.4, and 99.1-2.7+5.4 km. Ultimately, we provided seven astrometric positions at a milliarcsecond accuracy level, based on Gaia EDR3, and use it to improve Chariklo's ephemeris.Fil: Morgado, B.E.. Centre National de la Recherche Scientifique. Observatoire de Paris; Francia. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; BrasilFil: Sicardy, Bruno. Centre National de la Recherche Scientifique. Observatoire de Paris; FranciaFil: Braga Ribas, Felipe. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil. Centre National de la Recherche Scientifique. Observatoire de Paris; Francia. Universidade Tecnologia Federal do Parana; BrasilFil: Desmars, Josselin. Centre National de la Recherche Scientifique. Observatoire de Paris; FranciaFil: Gomes Júnior, Altair Ramos. Universidade de Sao Paulo; BrasilFil: Bérard, D.. Centre National de la Recherche Scientifique. Observatoire de Paris; FranciaFil: Leiva, Rodrigo. Universidad de Chile; Chile. Centre National de la Recherche Scientifique. Observatoire de Paris; FranciaFil: Vieira Martins, Roberto. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil. Universidade Federal do Rio de Janeiro; BrasilFil: Benedetti Rossi, G.. Centre National de la Recherche Scientifique. Observatoire de Paris; Francia. Universidade Federal de Sao Paulo; BrasilFil: Santos Sanz, Pablo. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; BrasilFil: Camargo, Julio Ignacio Bueno. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; BrasilFil: Duffard, R.. Universidade Federal do Rio de Janeiro; BrasilFil: Rommel, F.L.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; BrasilFil: Assafin, M.. Centre National de la Recherche Scientifique. Observatoire de Paris; FranciaFil: Boufleur, R.C.. Universidad Nacional de Córdoba; ArgentinaFil: Colas, F.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; BrasilFil: Kretlow, Mike. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; BrasilFil: Beisker, W.. University of North Carolina; Estados UnidosFil: Sfair, Rafael. Centre National de la Recherche Scientifique. Observatoire de Paris; FranciaFil: Snodgrass, Colin. University of Edinburgh; Reino UnidoFil: Morales, N.. Pontificia Universidad Católica de Chile; Chile. Universidad Católica de Chile; ChileFil: Fernández Valenzuela, E.. Pontificia Universidad Católica de Chile; Chile. Universidad Católica de Chile; ChileFil: Amaral, L.S.. Massachusetts Institute of Technology; Estados UnidosFil: Amarante, A.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; BrasilFil: Artola, R.A.. Centre National de la Recherche Scientifique. Observatoire de Paris; FranciaFil: Backes, M.. Universidad Nacional de Córdoba; ArgentinaFil: Bath, K. L.. University of North Carolina; Estados UnidosFil: Bouley, S.. University of St. Andrews; Reino UnidoFil: Garcia Lambas, Diego Rodolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Schneiter, Ernesto Matías. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Ingeniería Económica y Legal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; Argentin

Autonomic Management of Large Clusters and Their Integration into the Grid

We present a framework for the co-ordinated, autonomic management of multiple clusters in a compute center and their integration into a Grid environment. Site autonomy and the automation of administrative tasks are prime aspects in this framework. The system behavior is continuously monitored in a steering cycle and appropriate actions are taken to resolve any problems. All presented components have been implemented in the course of the EU project DataGrid: The Lemon monitoring components, the FT fault-tolerance mechanism, the quattor system for software installation and configuration, the RMS job and resource management system, and the Gridification scheme that integrates clusters into the Grid

CARB-ES-19 Multicenter Study of Carbapenemase-Producing Klebsiella pneumoniae and Escherichia coli From All Spanish Provinces Reveals Interregional Spread of High-Risk Clones Such as ST307/OXA-48 and ST512/KPC-3

ObjectivesCARB-ES-19 is a comprehensive, multicenter, nationwide study integrating whole-genome sequencing (WGS) in the surveillance of carbapenemase-producing K. pneumoniae (CP-Kpn) and E. coli (CP-Eco) to determine their incidence, geographical distribution, phylogeny, and resistance mechanisms in Spain.MethodsIn total, 71 hospitals, representing all 50 Spanish provinces, collected the first 10 isolates per hospital (February to May 2019); CPE isolates were first identified according to EUCAST (meropenem MIC > 0.12 mg/L with immunochromatography, colorimetric tests, carbapenem inactivation, or carbapenem hydrolysis with MALDI-TOF). Prevalence and incidence were calculated according to population denominators. Antibiotic susceptibility testing was performed using the microdilution method (EUCAST). All 403 isolates collected were sequenced for high-resolution single-nucleotide polymorphism (SNP) typing, core genome multilocus sequence typing (cgMLST), and resistome analysis.ResultsIn total, 377 (93.5%) CP-Kpn and 26 (6.5%) CP-Eco isolates were collected from 62 (87.3%) hospitals in 46 (92%) provinces. CP-Kpn was more prevalent in the blood (5.8%, 50/853) than in the urine (1.4%, 201/14,464). The cumulative incidence for both CP-Kpn and CP-Eco was 0.05 per 100 admitted patients. The main carbapenemase genes identified in CP-Kpn were blaOXA–48 (263/377), blaKPC–3 (62/377), blaVIM–1 (28/377), and blaNDM–1 (12/377). All isolates were susceptible to at least two antibiotics. Interregional dissemination of eight high-risk CP-Kpn clones was detected, mainly ST307/OXA-48 (16.4%), ST11/OXA-48 (16.4%), and ST512-ST258/KPC (13.8%). ST512/KPC and ST15/OXA-48 were the most frequent bacteremia-causative clones. The average number of acquired resistance genes was higher in CP-Kpn (7.9) than in CP-Eco (5.5).ConclusionThis study serves as a first step toward WGS integration in the surveillance of carbapenemase-producing Enterobacterales in Spain. We detected important epidemiological changes, including increased CP-Kpn and CP-Eco prevalence and incidence compared to previous studies, wide interregional dissemination, and increased dissemination of high-risk clones, such as ST307/OXA-48 and ST512/KPC-3