Magneto Special Anodes (Netherlands)

Seawater electrolysis offers significant logistical advantagesover freshwater electrolysis but suffers from a fundamental selectivityproblem at the anode. To prevent the evolution of toxic chlorine alongsidethe evolution of oxygen, a promising approach is the use of electrochemicallyinert overlayers. Such thin films can exert a perm-selective effect,allowing the transport of water and oxygen between the bulk electrolyteand the electrocatalytic buried interface while suppressing the transportof chloride ions. In this work, we investigate thin (5–20 nm)overlayer films composed of amorphous silicon oxide (SiOx) and their application to suppressing the chlorineevolution reaction (CER) in favor of the oxygen evolution reaction(OER) during acidic saltwater electrolysis on three different typesof electrodes. While SiOx overlayers areseen to be an effective barrier against the CER on well-defined, smoothPt thin films, decreasing the CER activity roughly 20-fold, this abilityhas not been previously explored on Ir-based catalysts with a highersurface area relevant to industrial applications. On amorphous iridiumoxide electrodes, the selectivity toward the CER versus the OER wasmarginally reduced from ∼98 to ∼94%, which was attributedto the higher abundance of defects in overlayers deposited on therougher electrode. On the other hand, Ir-based anodes consisting ofthick mixed metal oxide films supported on Ti showed a significantdecrease in CER selectivity, from ∼100 to ∼50%, althoughthis came at the cost of reduced activity toward the OER. These resultsshow that the morphology and composition of the underlying electrodeplay important roles in the effectiveness of the selective overlayersand provide guidance for further development of high-surface-areaOER-selective anodes.

Correlations were established between the hyperfine field distribution around the Fe atoms, the multiferroic properties, and the high magnetoelectric coefficient in BaTiO3-BiFeO3 multilayer stacks with variable BiFeO3 single layer thickness, down to 5 nm. Of key importance in this study was the deposition of 57Fe - enriched BiFeO3, which enhances the sensitivity of conversion electron Mössbauer spectroscopy by orders of magnitude. The magnetoelectric coefficient αME reaches a maximum of 60.2 V cm-1 Oe-1 at 300 K and at a DC bias field of 2 Tesla for a sample of 15 × (10 nm BaTiO3-5 nm BiFeO3) and is one of the highest values reported so far. Interestingly, the highest αME is connected to a high asymmetry of the hyperfine field distribution of the multilayer composite samples. The possible mechanisms responsible for the strong magnetoelectric coupling are discussed.

When a web service or application evolves, its database schema --- tables, constraints, and indices --- often need to evolve along with it. Depending on the database, some of these changes require a full table lock, preventing the service from accessing the tables under change. To deal with this, web services are typically taken offline momentarily to modify the database schema. However with the introduction of concepts like Continuous Deployment, web services are deployed into their production environments every time the source code is modified. Having to take the service offline --- potentially several times a day --- to perform schema changes is undesirable. In this paper we introduce QuantumDB--- a tool-supported approach that abstracts this evolution process away from the web service without locking tables. This allows us to redeploy a web service without needing to take it offline even when a database schema change is necessary. In addition QuantumDB puts no restrictions on the method of deployment, supports schema changes to multiple tables using changesets, and does not subvert foreign key constraints during the evolution process. We evaluate QuantumDB by applying 19 synthetic and 95 industrial evolution scenarios to our open source implementation of QuantumDB. These experiments demonstrate that QuantumDB realizes zerodowntime migrations at the cost of acceptable overhead, and is applicable in industrial continuous deployment contexts.

New remote navigation systems have been developed to improve current limitations of conventional manually guided catheter ablation in complex cardiac substrates such as left atrial flutter. This protocol describes all the clinical and invasive interventional steps performed during a human electrophysiological study and ablation to assess the accuracy, safety and real-time navigation of the Catheter Guidance, Control and Imaging (CGCI) system. Patients who underwent ablation of a right or left atrium flutter substrate were included. Specifically, data from three left atrial flutter and two counterclockwise right atrial flutter procedures are shown in this report. One representative left atrial flutter procedure is shown in the movie. This system is based on eight coil-core electromagnets, which generate a dynamic magnetic field focused on the heart. Remote navigation by rapid changes (msec) in the magnetic field magnitude and a very flexible magnetized catheter allow real-time closed-loop integration and accurate, stable positioning and ablation of the arrhythmogenic substrate.

Phased out: A combination of electrochemical and optical techniques is used to study the interaction of hydrogen with palladium nanoclusters. Hydrogen pressure-composition isotherms reveal the reduced presence of the beta phase in palladium nanoclusters. Hydrogen extraction transients relate the reduced miscibility gap to a core-shell phase transformation in the palladium nanoclusters (see picture).