Measurements of binary diffusion coefficients, retention factors and partial molar volumes for myristoleic acid and its methyl ester in supercritical carbon dioxide.

The binary diffusion coefficients, D(12), and retention factors for myristoleic acid and its methyl ester at infinite dilution were measured by the chromatographic impulse response technique in supercritical carbon dioxide at temperatures of 313.2, 333.2 and 343.2 K and pressures from 9.2 to 30 MPa for the acid, and from 8.0 to 14 MPa for the ester. Although the D(12) values were represented by the two correlations, the D(12)/T vs. CO(2) viscosity and the Schmidt-number correlations, which are valid for more than 40 compounds that we have measured so far, significant temperature dependences were observed for the ester. Moreover, the D(12) values for the ester at 313.2 K downward deviated from the background values around 400 kg m(-3), where the partial molar volumes, obtained from the correlation between the retention factors measured and CO(2) densities, showed large negative values.     

The Structure of Zirconium Oxide in Silica Matrix and its Epoxidation Activity

Zirconia-silica composite oxides were prepared by a sol-gel method, and the state of Zr in the silica matrix was analyzed in relation to its activity in the epoxidation of oct-1-ene with t-butyl hydroperoxide. XAFS analysis suggested that Zr in the composite oxides with low Zr content was in the coordinatively less saturated state compared with those in the oxides with higher Zr contents. Epoxidation of oct-1-ene proceeded effectively on the oxides with low Zr contents. The first step of the epoxidation was assumed to be the interaction of t-butyl hydroperoxide with the coordinatively unsaturated site of Zr.     

Ultraviolet-Cured Polymer Micro-Optical Elements

A new fabrication method for polymer micro-optical elements is described which uses the contracting effect of photopolymers during the process of polymerization. Convex and concave microlens arrays and phase gratings were formed by irradiating a ultraviolet (UV)-curable monomer with incoherent UV light through an appropriate metallic mask. The morphological and optical characterization of the fabricated elements reveals that the surface profile of the elements depends on the pattern and aperture size of the mask employed.     

Visualization of behaviors of a propagating flame quenching for hydrogen–air gas mixture

Abstract  

In this research, a flame arrester consisting of a slit structure was experimentally investigated. Experimental data show adequate maximum experimental safe gap (MESG) value for the flame arrester. The flow rate characteristics of the flame arrester were measured and compared with theoretical results. It was made clear that the flow impedance of convergent flow is 20% less than that of divergent flow. The experimental data and theoretical data show good agreement. The performance test by an EN12874 as ‘in-line stable detonation’ flame arrester was examined for a hydrogen–air gas mixture. The experimental data show that the gap was 0.2 times the MESG value in bi-directions for the flame arrester. The quenching and extinguishing processes were visualized by high-speed cameras.     

Spin-triplet superconductivity induced by off-site Coulomb interaction in a triangular lattice

In order to study how superconductivity emerges when the charge fluctuation coexists with the spin fluctuation in a triangular lattice, we obtain a phase diagram against the nearest-neighbor Coulomb repulsion V and band filling n on the extended Hubbard model using the fluctuation exchange (FLEX) approximation. We find that a charge density wave (CDW) phase exists in the region where the value of V is large, and the f-wave spin-triplet pairing mediated by a strong charge fluctuation is dominant near the CDW phase.