Faraday-effect optical current sensor with a garnet film/ring core in a transverse configuration

A new scheme of the Faraday effectcurrent sensor of a magnetic ring-core type is reported. With this scheme a uniaxial magnetic garnet film is obliquely inserted into a very narrow gap in the ring core and a probe light beam is passed through the garnet film in the transverse direction to the core. It is experimentally demonstrated that this current sensor shows good sensitivity as well as good isolation from surrounding currents, particularly because of the very narrow core gap allowed. This transverse scheme is much simpler and less expensive than the known longitudinal scheme and can offer a practical optical current sensor of a ring-core type.     

System for high-level radioactive waste using microchannel chip — extraction behavior of metal ions from aqueous phase to organic phase in microchannel

In order to clarify the extraction behavior of U(VI) from aqueous phase to organic one in microchannel, we have carried out extraction experiments of U(VI) from HNO₃ aqueous solution of 3 M (M = mol/dm³) to 30% or 100% TBP phase in microchannel. From the results of extraction experiments, it was found that the extraction of U(VI) in microchannel could be performed in a short time for approximately 1 s with a good extractability in both organic phases of 30% and 100% TBP, and suggested that the other nuclides could be extracted with high extraction efficiency in microchannel. Furthermore, it is expected that the innovative and sophisticated nuclide separation systems can be developed by using microchannel extraction with selective extractants for specific nuclide.     

A simulation on growth of multiple small cracks under stress corrosion

In order to keep high reliability of components in a nuclear power plant, it is important to understand the damaging process due to multiple small cracks. The growth shows random behavior because of the microstructural inhomogeneity and the interaction between cracks. The former includes the effects of crack kinking and anisotropic deformation in each crystal of polycrystalline. In this study, a Monte Carlo simulation method is developed in order to analyze the random behavior, taking into account the their influences on the stress intensity factor. The damaging process of mill-annealed alloy 600 in the primary water stress corrosion cracking (PWSCC) is numerically simulated by the proposed method. The crack size distribution obtained agrees well with the experimental observation, and the maximum crack size is statistically estimated on the basis of the Gumbel statistics.     

Sodium carboxylate effect of non-cross-linked hydrogel on plasma-induced radical formation as studied by electron spin resonance

The possibility of refining the functionality of vinyl alcohol-sodium acrylate copolymer, P(VA-AANa), regarding its curative effect on chemo-embolic agents by plasma treatment, was examined, We have carried out argon plasma-irradiation onto the P(VA-AANa) microsphere and the surface radicals formed were studied by ESR and compared with those of vinyl alcohol-acrylic acid copolymer, P(VA-AA), as well as its respective component homopolymer, PVA, PAA and its sodium salt (PAANa). It was found that the ESR spectra have shown a vast difference in pattern between P(VA-AANa) and P(VA-AA), demonstrating the strong sodium carboxylate effect on the nature of plasma-induced surface radical formation resulting from the difference in the surface morphology between P(VA-AANa) and P(VA-AA).     

Fabrication of hexagonal GaN on the surface of β-Ga2O3 single crystal by nitridation with NH3

The fabrication of GaN on the surface of a bulk β-Ga₂O₃ single crystal by nitridation with NH₃ was investigated for the purpose of using it as a substrate for GaN epitaxial growth. A β-Ga₂O₃ single crystal was prepared using a floating zone furnace with double ellipsoidal mirrors, and its polished (100) plane was nitridated in NH₃ atmosphere at 850 °C for 5 h. It was found that hexagonal GaN with preferred in-plane orientation was produced on the surface of β-Ga₂O₃, and the thickness of nitride layers was approximately 50 nm. High resolution transmission electron microscopic observation indicated that the synthesized GaN was composed of the aggregation with single crystalline GaN particles, whose size ranged from ∼ 5 nm to ∼ 50 nm, and dislocation or defect was not observed in a GaN particle. This method could be expected as a new route to fabricate a substrate for epitaxial growth of III-nitride materials instead of using a bulk GaN single crystal.     

X-Ray Powder Diffraction Data for Two Hexagonal Aluminum Monoxycarbide Phases

Aluminum monoxycarbide formed when Al₂O₃ is reduced by carbon in the presence of Si₃N₄ gives two X-ray diffraction profiles. The high-temperature phase exhibits the normal 2H wurtzite-type pattern, whereas the low-temperature phase produces three major lines in addition to the 2H profile. Interplanar spacings and lattice dimensions are reported, both phases can be regarded as solid solutions with AIN and / or SiC. It is suggested that the p-Al₄SiC₄ reported by Barczak may have been a mixture of these monoxycarbides.     

A study on the thawing process of frozen fish blocks in water

Experiments are reported on the thawing time of fish blocks for three different types of fish; sand fish, sohachi flat fish and sardines. The optimum form of water circulation is investigated together with the effects of water velocity and temperature. An alternative method termed ‘thawing by water spray impact’ was tested and was found to be more effective than the best of the water circulation methods. Thawing is quicker and the quality of the product is improved.     

A new route to 4-, 5-, and 6-indolecarboxylic acids

There are many indole derivatives bearing carboxyl or methoxycarbonyl groups on the benzene ring and these often have patent physiological activities. Synthesis of these compounds usually starts from indoles having a halogen group at the desired position on an indole ring. We now report a facile synthesis of 4-, 5-, and 6-indolecarboxylic acids from 2-bromoaniline derivatives ( 1 ). The synthetic route is shown in Figure 1.