Federated identity architecture of the european eID system

Federated identity management is a method that facilitates management of identity processes and policies among the collaborating entities without a centralized control. Nowadays, there are many federated identity solutions, however, most of them covers different aspects of the identification problem, solving in some cases specific problems. Thus, none of these initiatives has consolidated as a unique solution and surely it will remain like that in a near future. To assist users choosing a possible solution, we analyze different federated identify approaches, showing main features, and making a comparative study among them. The former problem is even worst when multiple organizations or countries already have legacy eID systems, as it is the case of Europe. In this paper, we also present the European eID solution, a purely federated identity system that aims to serve almost 500 million people and that could be extended in midterm also to eID companies. The system is now being deployed at the EU level and we present the basic architecture and evaluate its performance and scalability, showing that the solution is feasible from the point of view of performance while keeping security constrains in mind. The results show a good performance of the solution in local, organizational, and remote environments

Influence of zinc molybdenum phosphate pigment on coatings performance studied by electrochemical methods

The effect of the addition of the zinc molybdenum phosphate pigment, on the corrosion resistance properties of powder coating on steel, has been investigated by means of different electrochemical methods: electrochemical impedance spectroscopy (EIS) and the accelerated cyclic electrochemical technique (ACET). Anticorrosive properties obtained from both techniques showed similar results. Powder coatings incorporating this pigment have shown better performance which is attributed to both barrier properties enhancement and inhibition action of the pigment. This behavior can be correlated to the results obtained in the pigment extract study (polarization test and EIS). Finally, salt fog spray test was performed to confirm the electrochemical tests results.The authors would like to acknowledge Nubiola S.A. for supplying the raw materials, as well as Raquel Oliver and José Ortega for their help in the development of this project

Las competencias del profesional de los servicios de fitness para la inclusión de personas con discapacidad

La Organización Mundial de la Salud declara que 15% de la población mundial tiene algún tipo de condición de salud por discapacidad1, conociendo que actualmente, siguen encontrando barreras para la participación en actividades relacionadas con la actividad física, el deporte y el ocio saludable2. La determinación de las competencias del profesional del fitness del sector en relación a la inclusión en sus servicios de estas personas contribuirá a definir un óptimo desempeño profesional3, proporcionarán al profesional herramientas reales en su formación continua y maximizará sus posibilidades profesionales en los contextos reales4

Application of AC-SECM in corrosion science: Local visualization of heterogeneous chemical activity in AA2024 surfaces

Aluminium alloy AA2024-T3 surfaces have been characterised by using a new microelectrochemical technique, frequency-dependent alternating current scanning electrochemical microscopy (AC-SECM), which does not require the addition of any redox active species to the electrolyte solution. Information regarding the topography and/or redox activity of the solid/liquid interface is obtained in situ, allowing their evolution with time to be monitored with high spatial resolution. By scanning the microelectrode over the surface, an image is generated, as well as information concerning reactions that take place in the solution space between the tip and the sample or on the surface of the scanned sample. A heterogeneous response due to the presence of intermetallic inclusions precipitated in the material is found on AA2024-T3 surfaces. The highly localized anodic activity was thus detected, which has been interpreted as a result of the galvanic coupling between the matrix and the intermetallic particle

In depth characterisation of hydrocyclones: Ascertaining the effect of geometry and operating conditions on their performance

Hydrocyclones are used for densification of waste streams prior to drying or for classification of solid and liquids in two-phase streams. They are becoming popular in industrial units due to their simplicity, low energy consumption and high versatility. However, the effect of geometry and operating conditions on the cut diameter and solid recovery efficiency have been independently studied, and therefore there are no studies approaching the influence of all the parameters simultaneously. Thus, a detailed experimental study was conducted to ascertain the effect of the hydrocyclone body (diameter and angle) and the vortex finder and spigot size and shape, as well as operating conditions (inlet pressure and solid concentration) on the separation efficiency curve, cut diameter, solid and volume recovery and the main features of the outlet streams. It has been proven that separation efficiency and outlet stream composition are sensitive to both the geometry of the hydrocyclone and the operating parameters. Therefore, knowledge of their influence is essential for the design of industrial units where liquid reutilisation is a major concernThis work has been carried out with the financial support from the University of the Basque Country UPV/EHU (Projects US12=11 and US16=26) and the collaboration of Novattia Desarrollos Ltd. Javier Izquierdo thanks the University of the Basque Country UPV/EHU for his Ph.D. grant. Xabier Sukunza thanks the Ministry of Economy and Competitiveness for his Ph.D. grant (FPU18=04935)

Scanning electrochemical microscopy studies for the characterization of localized corrosion reactions at cut edges of coil-coated stee

The local distribution of anodic and cathodic sites in a corroding cut edge using the scanning electrochemical microscope is presented. Platinum and antimony microdisks were used as tips for combined amperometric/potentiometric operation. Local changes in electrochemical activity, oxygen concentration and pH distribution associated to the onset of localized anodes and cathodes were imaged in situ, as well as their evolution with time. Local alkalization and oxygen consumption related to cathodic activity were detected above the zinc layer covered with the thinner polymeric coating, providing a direct evidence of a differential aeration process effectively operating in an asymmetrical cut edge, in addition to the galvanic coupling of aluzinc and steel. Anodic activity leading to local acidification occurred at the other aluzinc layer at all exposures

SECM imaging of the cut edge corrosion of galvanized steel as a function of pH

Scanning electrochemical microscopy (SECM) and the Scanning vibrating electrode technique (SVET) were employed to identify the local reactivity and the cathodes and anodes on a cut edge of galvanized steel. The SECM was used in the amperometric feedback mode (for the oxidation of ferrocenemethanol as mediator) for sensing the conductivity of the surface and in the redox competition mode for locating the depletion of the cathodic reactant. Good agreement was observed in acidic solution between the location of the conductive regions of the surface and the depletion of oxygen estimated from amperometric lines across the cut edge. In neutral medium, non-uniform activity of the steel surface was observed and correlated well with the ionic current flows in solution and with the accumulation of zinc corrosion products on steel. In alkaline medium, the entire metallic surface operated as electron source for the regeneration cycle of the redox mediator. Irrespective of the pH of the solution, a maximum of the feedback observed over the cut edge is consentaneous with the thermodynamic stability of iron in the reduced form. SECM provided useful information regarding the steel conductivity, whereas the zinc anodes could only be resolved by the SVE

Simultaneous pit generation and visualization of pit topography using combined atomic force-scanning electrochemical microscopy

Combined atomic force microscopy – scanning electrochemical microscopy (AFM-SECM) is for the first time used to generate single corrosion pits on passivating iron surfaces in the micrometer range. The AFM-SECM probe locally generates nitric acid during the oxidation of nitrite ions with the release of protons at selected sites on the surface of the otherwise passive metal. High confinement of passive film breakdown is achieved from the combination of a small probe size and the inhibiting properties of non-reacted nitrite ions on the surrounding passivated surface. Simultaneous visualization of pit nucleation and propagation can be obtained in the same solution without changing the probe by AFM

Possibilities and limitations of scanning electrochemical microscopy of Mg and Mg alloys

Magnesium (Mg) and its alloys undergo corrosion at high rates in aqueous electrolytes of essentially any concentration, releasing copious amounts of hydrogen into the electrolyte, thereby making conventional SECM measurements difficult upon Mg. A few examples of the issues associated with Mg SECM, and strategies to counter these issues are discussed in this review. SECM has been employed in Sample Generation-Tip Collection (SG-TC) mode to image cathodic sites on the Mg surface, wherein, the Pt tip oxidises hydrogen emanating from the specimen surface. This mode of SECM does not clearly reveal a close correspondence between the Mg microstructure and its associated electrochemical reactivity; the hydrogen currents measured by the Pt tip found to vary by over an order of magnitude with time. Convective fluxes due to hydrogen bubbles, local acidification arising from protons released during hydrogen oxidation on the Pt tip, and the negative different effect of Mg may contribute to these high tip currents. SECM has also been performed on Mg using Mg2+ ion selective electrodes (ISEs), where an Mg2+ ionophore cocktail serves as a Mg2+ ion permeable membrane. The Mg2+ ions diffuse/migrate through the membrane which eventually settles at the equilibrium membrane (Donnan) potential. This potential varies with the logarithm of Mg2+ ion concentration in the electrolyte, and thus could be used to ascertain the local Mg2+ ion concentrations (or anodic sites) on the surface. This technique needs to be complimented with other modes of SECM to obtain holistic electrochemical micrographs of a corroding Mg surfac

In situ investigation of copper corrosion in acidic chloride solution using atomic force - scanning electrochemical microscopy

The anodic dissolution of pure copper surfaces in acidic chloride solution has been monitored in-situ using combined atomic force – scanning electrochemical microscopy (AFM-SECM). Here, the initial studies performed on model copper-modified substrates have been extended to the investigation of bulk copper samples used in industrial settings. The local release of Cu2+ ions was monitored through electrochemical reduction and deposition of the metal ions on the conductive frame of the AFM-SECM probe. Simultaneous monitoring of the topographical changes due to the corrosion process allowed the distinction and correlation of local passivation and pitting phenomena. The extent of the attack was estimated by anodic stripping of the copper metal deposited at the probe