Chlorine evolution reaction on platinum and several alloys

The chlorine evolution reaction on platinum and several alloys was studied by galvanostatic polarization measurements. Linear relationships are found between logarithmic current density, the electrode potential and the coverage of oxide, through the d-band vacancy in the electrode. Logarithmic exchange current density can be related to the dissociation energy of chloride, while any other significant relationships could not be found in its plots against % d-character or the work function. This result suggests that the dissociation energy of chloride plays an important part of chlorine evolution reaction.     

The anodic characteristics of massive manganese oxide electrode

The massive Mn oxides were synthesized and their anodic characteristics were investigated in aqueous solutions. The thermal treatment of the massive β-MnO₂ at 480°C or above leads to the formation of α-Mn₂O₃, and the relatively high activity was observed for the anodic evolution of oxygen on the mixed oxide of ν-MnO₂ and α-Mn₂O₃, compared with the pure oxide of β-MnO₂. The active sites for the oxygen evolution reaction were regarded as the Mn(III) sites on the oxide surfaces. From the kinetic considerations for the oxygen and chlorine evolutions, it was suggested that the oxidation process of the electrode surface is a common rate-determining step in both reactions on the massive Mn oxide electrodes.     

Fabrication of CrN/Cr2N Bulk Composites and Their Mechanical Properties

Bulk CrN/Cr₂N billet with almost full density was successfully fabricated using spark-plasma sintering. Elastic moduli, hardness, and fracture toughness were evaluated to investigate the effect of sintering conditions on the mechanical properties. Ball-on-disk testing was performed to understand the wear and friction behavior of this bulk CrN/Cr₂N composite solid. The wear map was constructed as a function of the sliding velocity and the applied pressure, to categorize the wear mechanism of this nitride composite.     

Analysis of sterol fractions from twenty vegetable oils

The unsaponifiables separated from 20 vegetable oils were divided into sterol and three other (less polar compound, triterpene alcohol, and 4-methylsterol) fractions by preparative thin layer chromatography. The amounts of the sterol fractions were more than ca. 30% in the unsaponifiables from all of the oils, except tohaku, pumpkin seed, and fagara seed oils. Composition of the sterol fractions were determined by gas liquid chromatography. Individual components of the sterol fractions were identified by gas liquid chromatography and combined gas liquid chromatography-mass spectrometry. β-Sitosterol was found as the most predominant component in the sterol fractions from all oils, except two, i.e. the sterol fraction from pumpkin seed oil contained no detectable amount of β-sitosterol and the sterol fraction from akamegashiwa oil contained Δ⁵-avenasterol as the most abundant component. Campesterol, stigmasterol, Δ⁵-avenasterol, Δ⁷-stigmastenol, and Δ⁷-avenasterol and also trace amounts (at the very least) of cholesterol and brassicasterol were found in most of the oils analyzed. It may be noted that a large amount (ca. 9%) of cholesterol was detected in the sterol fraction from capsicum seed oil. The presence of 24-methylenecholesterol and Δ⁵-avenasterol in the sterol fraction of akamegashiwa oil was demonstrated by isolation of these sterols.     

Surface Andreev Bound States and Odd-Frequency Pairing in Topological Superconductor Junctions

In this review, we summarize the achievement of the physics of surface Andreev bound states (SABS) up to now. The route of this activity has started from the physics of SABS of unconventional superconductors where the pair potential has a sign change on the Fermi surface. It has been established that SABS can be regarded as a topological edge state with topological invariant defined in the bulk Hamiltonian. On the other hand, SABS accompanies odd-frequency pairing like spin-triplet s-wave or spin-singlet p-wave. In a spin-triplet superconductor junction, induced odd-frequency pairing can penetrate into a diffusive normal metal (DN) attached to the superconductor. It causes so called anomalous proximity effect where the local density of states of quasiparticle in DN has a zero energy peak. When bulk pairing symmetry is spin-triplet \(p_{x}\)-wave, the anomalous proximity effect becomes prominent and the zero bias voltage conductance is always quantized independent of the resistance in DN and interface. Finally, we show that the present anomalous proximity effect is realized in an artificial topological superconducting system, where a nanowire with spin-orbit coupling and Zeeman field is put on the conventional spin-singlet s-wave superconductor.     

Highly Efficient Water Oxidation Photoanode Made of Surface Modified LaTiO2N Particles

An improved variation of highly active/durable O₂‐evolving LaTiO₂N powder‐based photoelectrode has been fabricated by pre‐cleaning the powder with mild polysulfonic acid and by homogeneous deposition of CoO_x co‐catalyst aided by microwave annealing. The treatment in aqueous solution of poly(4‐styrene sulfonic acid) results in removal of surface LaTiO₂N layers, forming fine pores in the crystallites. The CoO_x co‐catalyst by microwave deposition in Co(NH₃)₆Cl₃/ethylene glycol homogeneously covers the particle surface. The LaTiO₂N powder is fabricated into particle‐transferred electrodes on Ti thin film supported on solid substrate. The modified LaTiO₂N grains on the electrode serve as a highly active O₂‐evolving photoanode achieving 8.9 mA cm^?2 of the photocurrent density at 1.23 V versus reversible hydrogen electrode (RHE) in 0.1 m NaOH (pH 13) under solar‐simulator irradiation Airmass 1.5 Global (AM 1.5G). The activity has been much improved, compared with conventional LaTiO₂N treated in mineral acid or with CoO_x deposited by impregnation. The new electrode also exhibits better durability in fixed‐potential chronoamperometric tests under AM 1.5G irradiation.     

Estimation of heat of dilution of polymer solution: a trial on a correction of the heat of stirring ascribed to the viscosity difference before and after dilution

The heat of dilution for the polystyrene and methyl ethyl ketone system was measured using an isothermal calorimeter, and the heat correction due to the change of stirring before and after dilution was estimated from the observed change in heat of dilution. The net heat of dilution of the polystyrene and methyl ethyl ketone system obtained was very small and the system was considered to be almost athermal. The heat correction due to the change of stirring was unexpectedly large, and often exceeded the net heat of dilution. The interaction parameters obtained for the polystyrene and methyl ethyl ketone system were +0·035, +0·012, ?0·022, and ?0·062 for molecular weights of 2100, 22 000, 57 500, and 212 000, respectively, at 298·15K.     

Electron spin resonance studies of γ-irradiated cellulose. I. Free radicals in decrystallized cellulose

The types of free radicals formed in decrystallized cellulose prepared from cellulose I and II after γ-irradiation in nitrogen atmosphere at room temperature were studied by ESR spectroscopy. X-Ray diffraction revealed that decrystallized cellulose I and II have the same microstructure. The ESR spectra obtained with the γ-irradiated decrystallized samples are simple. By contacting the irradiated sample with moisture in nitrogen atmosphere, the ESR spectrum changed to a narrow singlet, which gradually decreased in intensity until the spectrum completely disappeared. It was found that the types of free radicals generated in the decrystallized cellulose by γ-irradiation consist of the overlap of singlet and doublet. The singlet spectrum is mainly attributed to alkoxyl radical formed by the rupture of glycosidic linkage at the C 1 or C 4 position, and the doublet spectrum is ascribed to radical formed by hydrogen abstraction from the C 1 position in cellulose molecule.