Dielectric and Piezoelectric Properties of Pb(Co1/3Nb2/3)O3-PbTiO3-PbZrO3 Solid Solution Ceramics

Ceramic and piezoelectric properties of the Pb(Co_1/3Nb_2/3)O₃-PbTiO₃-PbZrO₃ system were investigated. The system contains rhombohedral, tetragonal, and pseudocubic phases at room temperature. The triple point is at 0.07Pb(Co_1/3Nb_2/3)O₃-0.43PbTiO₃-0.50PbZrO₃. High dielectric constants (750 to 1500) and radial coupling coefficients (40 to 45%) and low average temperature coefficients of resonant frequency (of the order of 10^-6°C) were obtained for compositions near the morphotropic phase boundary.     

EFFECTS OF VARIOUS INGREDIENTS ON THE TEXTURE OF MILK JELLY

Effects of various ingredients on the texture of milk jellies prepared from gellan gum, milk powder, sweetener were examined using a sensory test and physical measuring apparatus. The data were analyzed by use of the modification ofScheffé's mixture experiment method in rectangular experimental area in the Scheffé's triangle. "Hardness" and "smoothness" of milk jellies estimated by a subjective method were influenced by the content of gellan gum. The evaluations of "milk flavor" and "sweetness" estimated by a subjective method were varied with the content of sweetener and evaluated as higher for softer milk jellies. The correlation coefficients between "hardness" estimated by a subjective method and "smoothness", "milk flavor", and "sweetness" estimated by a subjective method were negative.     

Formation process of β-FeSi2 from amorphous Fe-Si synthesized by ion implantation: Fe concentration dependence

Formation processes of β-FeSi₂ from amorphous Fe-Si layers have been investigated using transmission electron microscopy (TEM). Si(111) substrates were irradiated with 120 keV Fe ions at −150°C to fluences of 1.0 × 10¹⁷ and 4.0 × 10¹⁷ cm^–2. An amorphous Fe-Si layer embedded in an amorphous Si was formed in the low-fluence sample, whereas an amorphous Fe-Si surface layer on an amorphous Si was obtained in the high-fluence one. The amorphous Fe-Si layers were crystallized to β-FeSi₂ after thermal annealing at 800°C for 2 h. Cross-sectional and plan-view TEM observations revealed that, prior to the formation of β-FeSi₂, the amorphous Fe-Si layers crystallized to α-FeSi₂ in the low-fluence sample and to ɛ-FeSi in the high-fluence one. The absence of metastable γ-FeSi₂ which is considered as a precursor of epitaxially grown β-FeSi₂ on Si was attributed to the instability of γ-phase in an amorphous matrix.     

Present Situation of Fukushima and Possibility of Decontamination Technology by Superconducting Magnetic Separation System

A large amount of radionuclides were spread by the accident of Fukushima Daiichi nuclear power plant in 2011. The situation of surrounding area of nuclear power plant is momentarily changing. In order to consider for decontamination or volume reduction of radioactive wastes, it is necessary taking into account not only the technical needs but also feelings of inhabitants, reduction of environmental load, reduction of the radiation exposure on workers, and efficiency and cost of decontamination work. In this paper, the application possibility of superconducting magnetic separation system for decontamination and volume reduction was discussed compared with other technologies from above multidirectional viewpoint.     

Single-crystal growth of a new sodium molybdenum bronze Na0.86Mo5O14

Abstracts are not published in this journal     

AGAR AND GELATIN GEL FLAVOR RELEASE

The taste suppression and rupture properties of 0.8-2.0% w/w agar gel and 3.0-6.5% w/w gelatin gel were studied by sensory evaluation and objective measurement. Flavor compound concentrations were determined to equalize the intensity of aspartame sweetness (0.02% w/w for both agar and gelatin gels), sodium chloride saltiness (0.9% w/w for agar gel and 0.2% w/w for gelatin gel), and caffeine bitterness (0.08% w/w for agar gel and 0.07% w/w for gelatin gel) in 1% w/w agar gel and 4.5% w/w gelatin gel. The coefficient of taste intensity = (concentration of flavor compound in the aqueous solution of equiintense taste in gel)/(concentration of flavor compound in gel) was used to compare the difference in gel taste suppression. The coefficient of saltiness intensity of 3.0% w/w gelatin gel exceeded 1.0, and those of other gels were below 1.0. The suppressed variation of the coefficient of saltiness intensity in agar gel was significantly (P<0.01) smaller than that of bitterness depending on agar concentration. No significant differences (P>0.05) in taste suppression between gelatin gels containing the 3 flavor compounds due to changes in gelatin concentration were observed. Rupture energy, which is related to mastication and is a common scale for agar and gelatin gels, was used to evaluate changes in suppression of the coefficient of taste intensities of the 2 gels. The coefficient of bitterness intensity of agar gels was more significantly (P<0.01) suppressed than sweetness and saltiness intensities of gelatin gels. The coefficient of sweetness intensity of gelatin gels was suppressed significantly less than bitterness (P < 0.05) of gelatin gels and sweetness (P < 0.05) and bitterness (P < 0.01) of agar gels.     

Preparation of Thorium Carbides

Some factors influencing the formation of thorium carbide from a mixture of thorium dioxide and graphite powder were studied. The effects of the molecular ratio of the reactants, reaction temperature, extrinsic properties (such as surface area, defects, and crystallinity of the materials), and the ambient pressure were examined. The molecular ratio of the reactants gave the most important effect on the composition of the final products. Thorium dicarbide was formed from a mixture having a molecular ratio (C/ThO₂) of more than three and the reaction rate then obeyed the parabolic rate equation. To form thorium monocarbide, it is necessary to use a mixture having a ratio less than four. A tentative explanation of the reaction mechanism of ThC formation is given.     

Solubility of KUO3 in BaUO3

The formation of a solid solution between cubic perovskne-type KUO₃ and pseudocubic BaUO₃ was investigated. The reaction begins at 550°C, and the solubility of KUO₃ reaches more than 30 mol% KUO₃ in BaUO₃ at 750°C. The region in which a single-phase solid solution exists was determined. The variation of the lattice parameter of the reacted samples was caused by solid solution formation and by oxygen absorption. The electrical conductivities of the samples varied with composition and showed a distinct maximum. The activation energy for electric conduction was very low compared to that for UO_z+x, or U₃O₈.