A novel bifunctional oxygen GDE for alkaline secondary batteries

AbstractThis paper describes a novel procedure for the fabrication of a gas diffusion electrode (GDE) suitable for use as a bifunctional oxygen electrode in alkaline secondary batteries. The electrode is fabricated by pre-forming a PTFE-bonded nickel powder layer on a nickel foam substrate followed by deposition of NiCo2O4 spinel electrocatalyst by dip coating in a nitrate solution and thermal decomposition. The carbon-free composition avoids concerns over carbon corrosion at the potentials for oxygen evolution. The electrode shows acceptable overpotentials for both oxygen evolution and oxygen reduction at current densities up to 100mAcm−2. Stable performance during >100 successive, 1h oxygen reduction/evolution cycles at a current density of 20mAcm−2 in 8M NaOH at 333K was achieved

A novel bifunctional oxygen GDE for alkaline secondary batteries

This paper describes a novel procedure for the fabrication of a gas diffusion electrode (GDE) suitable for use as a bifunctional oxygen electrode in alkaline secondary batteries. The electrode is fabricated by pre-forming a PTFE-bonded nickel powder layer on a nickel foam substrate followed by deposition of NiCo2O4 spinel electrocatalyst by dip coating in a nitrate solution and thermal decomposition. The carbon-free composition avoids concerns over carbon corrosion at the potentials for oxygen evolution. The electrode shows acceptable overpotentials for both oxygen evolution and oxygen reduction at current densities up to 100 mA cm−2. Stable performance during >100 successive, 1 h oxygen reduction/evolution cycles at a current density of 20 mA cm−2 in 8 M NaOH at 333 K was achieved.European Commissio

Multibeam Maser Survey of methanol and excited OH in the Magellanic clouds: new detections and maser abundance estimates

‘The definitive version is available at www.blackwell-synergy.com.’ Copyright Blackwell Publishing DOI: 10.1111/j.1365-2966.2008.12888.xPeer reviewe

Weak convergence of finite element approximations of linear stochastic evolution equations with additive noise II. Fully discrete schemes

We present an abstract framework for analyzing the weak error of fully discrete approximation schemes for linear evolution equations driven by additive Gaussian noise. First, an abstract representation formula is derived for sufficiently smooth test functions. The formula is then applied to the wave equation, where the spatial approximation is done via the standard continuous finite element method and the time discretization via an I-stable rational approximation to the exponential function. It is found that the rate of weak convergence is twice that of strong convergence. Furthermore, in contrast to the parabolic case, higher order schemes in time, such as the Crank-Nicolson scheme, are worthwhile to use if the solution is not very regular. Finally we apply the theory to parabolic equations and detail a weak error estimate for the linearized Cahn-Hilliard-Cook equation as well as comment on the stochastic heat equation

Parton content of the real photon: astrophysical implications

We possess convincing experimental evidence for the fact that the real photon has non-trivial parton structure. On the other hand, interactions of the cosmic microwave background photons with high energy particles propagating through the Universe play an important role in astrophysics. In this context, to invoke the parton content could be convenient for calculations of the probabilities of different processes involving these photons. As an example, the cross section of inclusive resonant $W^+$ boson production in the reaction $\nu \gamma\to W^+X$ is calculated by using the parton language. Neutrino--photon deep inelastic scattering is considered.Comment: 4 pages, 2 figures. The spin states of the initial particles in the reaction $\nu\gamma\to W^+X$ are correctly treated. As a result, the corresponding cross section becomes two times greater than the one from the previous version. Some changes in the tex

Probing bactericidal mechanisms induced by cold atmospheric plasmas with Escherichia coli mutants

Mechanisms of plasma induced microbial inactivation have commonly been studied with physico-chemical techniques. In this letter, Escherichia coli K-12 and its ∆recA, ∆rpoS and ∆soxS mutants are employed to discriminate effects of UV photons, OH radicals, and reactive oxygen species produced in atmospheric discharges. This microbiological approach exploits the fact that these E. coli mutants are defective in their resistance against various external stresses. By interplaying bacterial inactivation kinetics with optical emission spectroscopy, oxygen atoms are identified as a major contributor in plasma inactivation with minor contribution from UV photons, OH radicals, singlet oxygen metastables, and nitric oxide