Chemical Removal of CeO2 Segregated on the Surface of CeO2–ZrO2 Binary Oxides for Improvement of OSC

A chemical treatment to remove residual CeO₂ phase on CeO₂–ZrO₂ (CZ) solid solution was carried out. A CZ was treated by H₂O₂ for the reduction of Ce⁴⁺ to Ce³⁺ and then HNO₃ for the dissolution of Ce³⁺ compounds (H–CZ). H₂-TPR, TEM-EDX and XPS analyses revealed the removal of CeO₂ phase and the homogeneous distribution of Ce species. About 20% improvement in oxygen storage capacity (OSC) of H–CZ was confirmed at 773 K by the weight measurements under H₂/N₂ and air atmospheres, indicating that the HNO₃/H₂O₂ treatment was effective to avoid the deterioration of the OSC by segregated CeO₂ on the CZ binary oxides.     

Low Frictional Coating of Copper Oxide with Preferred Crystal Orientation

Coating films of copper oxide were synthesized on stainless steel substrates with a r.f. magnetron sputter. The composition of the films could be controlled by changing a gas ratio of oxygen and argon in sputter plasma, which was analyzed with X-ray diffraction spectroscopy. Frictional property of the films in an atmospheric pressure and in an ultra high vacuum (UHV) was measured with a pin-on-disk vacuum tribometer. Frictional coefficients of the film as low as 0.03 and 0.05 were achieved in an atmospheric pressure and in UHV, respectively. It is therefore, expected that the films are applicable to smooth-drive movable materials for ultimate conditions such as UHV and high temperature.     

Determination of nequinate and buquinolate in livestock products using liquid chromatography-tandem mass spectrometry

We studied the simultaneous determination of nequinate and buquinolate, which are used as feed additives to prevent coccidiosis, by means of liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). The sample was extracted with acetonitrile, then loaded onto an HLB mini-column with 20% methanol. After clean-up with 20% methanol, the analytes were eluted with acetonitrile-methanol (1 : 1). The coccidiostats in the purified samples were determined using ESI-MRM mode LC-MS/MS with a sample matrix calibration curve. Mean recoveries of nequinate and buquinolate from 8 kinds of livestocks samples (chicken muscle, chicken liver, chicken heart, swine muscle, swine heart, cattle muscle, sheep muscle, egg) were in the range of 89.5% to 108.6%, and the relative standard deviation values were <20% (n=10) at the levels of 0.01 μg/g and 0.05 μg/g, respectively. The limits of quantification of these compounds were 0.001 μg/g in each sample.     

析出相对Cr-Mn-N奥氏体不锈钢应力腐蚀性能的影响

本文研究了合金碳化物M_(23)C_6和金属间化合物x相对Cr-Mn-N奥氏体不锈钢应力腐蚀性能的影响。结果指出,在4NNaCl溶液中,上述两种沉淀相对钢的自然腐蚀电位和不同电位下的断裂时间影响明显,而在45％MgCl_2溶液中,两种沉淀相的影响甚微。从断裂机制上对两种沉淀相的影响进行了讨论。     

Fabrication of a simultaneous red-green-blue reflector using single-pitched cholesteric liquid crystals

A cholesteric liquid crystal (CLC) is a self-assembled photonic crystal formed by rodlike molecules, including chiral molecules, that arrange themselves in a helical fashion. The CLC has a single photonic bandgap and an associated one-colour reflection band for circularly polarized light with the same handedness as the CLC helix (selective reflection). These optical characteristics, particularly the circular polarization of the reflected light, are attractive for applications in reflective colour displays without using a backlight, for use as polarizers or colour filters and for mirrorless lasing. Recently, we showed by numerical simulation that simultaneous multicolour reflection is possible by introducing fibonaccian phase defects. Here, we design and fabricate a CLC system consisting of thin isotropic films and of polymeric CLC films, and demonstrate experimentally simultaneous red, green and blue reflections (multiple photonic bandgaps) using the single-pitched polymeric CLC films. The experimental reflection spectra are well simulated by calculations. The presented system can extend applications of CLCs to a wide-band region and could give rise to new photonic devices, in which white or multicolour light is manipulated.     

A highly sensitive method for quantifying gallocatechin gallate and its epimer using a catechin-specific peptide

We have developed a method for quantifying gallocatechin gallate (GCg) and epigallocatechin gallate (EGCg) using a catechin-binding peptide (part of the 67-kDa laminin receptor). Using micro titer plates, we investigated various conditions, including the quantifiable range of EGCg concentrations, the optimal concentration of the catechin-binding peptide, and the optimal reaction conditions. In this microplate assay, after each well was coated with bovine serum albumin, sample containing GCg and EGCg was added at pH 8.0, and allowed to stand at 37 °C for 2 h. After washing, biotinylated-peptide solution was added at 1 μg mL^?1 and allowed to react for 1 h at 37 °C. Each well was added with streptavidin–horseradish peroxidase conjugate, followed by chromogenic reaction for 25 min at room temperature. After the reaction, absorbance was measured at 405 nm. Our method is capable of quantifying EGCg in the range of approximately 0.1–2.0 mg L^?1 with a high degree of sensitivity and a high correlation (R² = 0.98) between EGCg concentration and absorbance. The method was specific to GCg and EGCg and seems capable of estimating GCg and EGCg contents in the presence of other catechin compounds. The method is simple and highly sensitive for quantitative GCg and EGCg measurement that requires no special equipment or operation and can measure multiple samples simultaneously.     

Development of calculation methodology for estimation of radionuclide composition in wastes generated at Fukushima Daiichi nuclear power station

ABSTRACT

A calculation methodology for estimating the radionuclide composition in the wastes generated at the Fukushima Daiichi nuclear power station has been developed by constructing a skeleton overview of the distribution of radionuclides considering the material balance in the system and calculation flowcharts of the transportation of radionuclides into the wastes. The wastes have a distinctive feature that their level of contamination includes considerable uncertainties because the process behind the contamination with the radionuclides released from the damaged fuel during and after the accident is not yet fully understood. Here, the developed method can explicitly specify the intrinsic uncertainties as a band to be included in the estimated radionuclide composition in the wastes and can quantitatively describe the uncertainties by calibration using analytically measured data on actual waste samples collected at the site. Further studies to improve the quality of the calculation method, the introduction of a stochastic approach to describe uncertainties, and acquiring a quantitative understanding of the spatial distribution of radionuclides inside the reactor building are suggested as important steps toward reasonable and sustainable waste management as an integral part of the decommissioning of the Fukushima Daiichi nuclear power station.     

Synthesis and characterization of positive photosensitive polyimide precursors

This paper is concerned with the study of the positive photosensitive polyimide precursors, and deals with monomer synthesis, polymerization, and characterization. The polymers were prepared from diamines and diaeid chlorides whieh were derived from the reactant with biphenyltetracarboxilic dianhydride and o-nitrobenzyl alcohol. The molecular weights of the polymer were controlled by adjusting the monomer stoichiometry. The photoreaction of the polymers was confirmed from the change in IR spectra between the film exposed and unexposed to UV light from a Hg? Xe lamp. The exposed areas of the film dissolved in alkaline solution, forming the positive tones. There was a marked difference in sensitivity between the polymers having different molecular weights. Their sensitivities decrease as their molecular weights increase. Further, there was a difference in the thermal behavior. Imidization temperature was shifted to a high temperature side and thermal stabilities increased with an increase in molecular weight.     

Production of n-3 polyunsaturated fatty acid-enriched fish oil by lipase-catalyzed acidolysis without solvent

Fish oil rich in n-3 polyunsaturated fatty acid (n-3 PUFA) was prepared by nonsolvent enzymic acidolysis. n-3 PUFA-enriched fish oil contained 25% eicosapentaenoic acid (EPA) and 40% docosahexaenoic acid (DHA). In acidolysis of cod liver oil, EPA content of the original fish oil was reduced at 5 h, but DHA content of the fish oil increased. It was assumed that EPA in the fish oil was replaced by DHA to reach a new chemical equilibrium. Two-stage acidolysis, which was carried out under CO₂ replacement early (about 3 h) and also in vacuum at 5–24 h, was effective for reduction in the content of diacylglycerol, which was formed by reverse reaction, hydrolysis. This method has industrial significance because PUFA-enriched triacylglycerol is easily separated from the reaction mixture by molecular distillation. Bioreactors for fats and their derivatives, Part XIV.