Oxygen reduction at the silver/hydroxide-exchange membrane interface

A solid-state cell is used to study the electrocatalysis of oxygen reduction at the silver/hydroxide-exchange membrane interface. The catalyst/membrane interface exhibits improved performance in comparison to a catalyst/aqueous sodium hydroxide interface. Surprisingly, the half-wave potential for oxygen reduction is shown to shift 185 mV higher at the silver/hydroxide-exchange membrane interface than for the silver/aqueous hydroxide solution interface, and the exchange current density is significantly higher at 1.02 × 10−6 A m−2. On a cost per performance basis, silver electrocatalysts in a hydroxide-exchange membrane fuel cell may provide better performance than platinum in a proton-exchange membrane fuel cell. Keywords: Oxygen reduction reaction, Electrocatalyst, Alkaline membrane, Solid-state cell, Silve

Synthesis, structure and conductivity of sulfate and phosphate doped SrCoO3

In this paper we report the successful incorporation of sulfate and phosphate into SrCoO3 leading to a change from a 2H– to a 3C–perovskite polymorph. Structural characterization by neutron diffraction showed extra weak peaks related to oxygen vacancy ordering, and these could be indexed on an expanded tetragonal cell, containing two inequivalent Co sites, similar to previously reported for Sb doped SrCoO3. Conductivity measurements on the doped systems showed a large enhancement compared to the undoped hexagonal system, consistent with corner–sharing of CoO6 octahedra for the former. Further work on the doped samples shows, however, that they are metastable, transforming back to the hexagonal cell on annealing at intermediate temperatures. The incorporation of Fe was shown, however, to improve the stability at intermediate temperatures, and these co–doped phases also showed high conductivities

Internal-quantum-state engineering using magnetic fields

We present a general, semi-classical theory describing the interaction of an atom with an internal state consisting of a number of degenerate energy levels with static and oscillating magnetic fields. This general theory is applied to the 3P2 metastable energy level of neon to determine the dynamics of the populations and coherences that are formed due to the interaction. Through these calculations we demonstrate how the interaction may be used for the internal state preparation of an atom

Subtle Sensing:Detecting Differences in the Flexibility of Virtually Simulated Molecular Objects

During VR demos we have performed over last few years, many participants (in the absence of any haptic feedback) have commented on their perceived ability to 'feel' differences between simulated molecular objects. The mechanisms for such 'feeling' are not entirely clear: observing from outside VR, one can see that there is nothing physical for participants to 'feel'. Here we outline exploratory user studies designed to evaluate the extent to which participants can distinguish quantitative differences in the flexibility of VR-simulated molecular objects. The results suggest that an individual's capacity to detect differences in molecular flexibility is enhanced when they can interact with and manipulate the molecules, as opposed to merely observing the same interaction. Building on these results, we intend to carry out further studies investigating humans' ability to sense quantitative properties of VR simulations without haptic technology

Clinical utility of magnetocardiography in cardiology for the detection of myocardial ischemia

It is a review article. The abstract is not availabl