Research on some basic deformations in free forging with robot and servo-press

Due to the disadvantages in casting or hot forging of Ti alloy artificial bones, such as low strength and high energy cost, this paper prompted an alternative method to manufacture individuated artificial bones. Free forging with a 6-axis freedom robot and servo-press could be very economical in the forming of complex shape parts because of its high flexibility and simple die-setting. Based on this system, the authors studied deformations of some basic elements, which could be assembled to artificial bones with complex shape. Firstly, the compression limit and effect of compression parameters on the roundness during reducing diameter process were declared for Al alloy and pure Ti. Secondly, an approximate theoretical equation of bending angle or curvature radius was proposed, and it matches experimental results well. Finally, a dimension prediction equation was presented by considering effect of material anisotropy, and then the ladder part without width spread was manufactured accordingly.     

Characterisation of volatile sulphur-containing compounds generated in crushed leaves of Chinese chive (Allium tuberosum Rottler)

To characterise the composition of sulphur-containing constituents in Chinese chive (Allium tuberosum Rottler), GC–MS and HPLC analyses were carried out, using 12 varieties of Chinese origin, 4 varieties of Japanese origin and 6 commercially available cultivars. Five disulphides (dimethyl, allyl methyl, methyl 1-(E)-propenyl, diallyl, and allyl 1-(E)-propenyl), two trisulphides (dimethyl and allyl methyl), and two vinyldithiins (3-vinyl-[4H]-1,2- and 2-vinyl-[4H]-1,3-) were identified on the basis of their mass spectral and GC-retention data. Among the detected sulphur compounds, sulphides with a methyl group predominated over those with an allyl group. This was supported by the HPLC estimations, suggesting that all cultivars examined had much greater amounts of methiin than alliin. Also, two novel compounds were tentatively identified as [3H,4H]-1,2-dithiin and [2H,4H]-1,3-dithiin on the basis of their mass spectral features, GC-retention data, and some experimental results on their formation in reaction mixtures with different proportions of methiin and alliin. Their formation mechanism was proposed.     

Effect of transition elements on the properties of MC carbides in IN-100 nickel-based superalloy

The effect of nine transition elements on the morphology, distribution and composition of MC carbides (MCs) in a nickel-base superalloy, IN-100, was investigated by differential thermal analysis (DTA), microstructural observation and X-ray microanalysis. The doping with tantalum, tungsten and molybdenum caused a significant change in the morphology and distribution of MCs as well as the profile of DTA curve of IN-100. The compositions of the MC in IN-100 were TiC and (Ti_0.80Mo_0.17V_0.03) C, and the doping with niobium, tantalum and tungsten changed significantly the composition of MC. On the other hand, the doping with chromium, vanadium, hafnium and zirconium scarcely changed the composition. In addition to TiC and (Ti, Mo, V) C, zirconium- and hafnium-rich MCs were found in the zirconium- and hafnium-doped alloys, respectively. The effect of the dopants on the composition of MCs could be explained by a relationship between the metallic radius and the free energy of formation for the MC.     

Organic Analysis of Peridotite Rocks from the Ashadze and Logatchev Hydrothermal Sites

This article presents an experimental analysis of the organic content of two serpentinized peridotite rocks of the terrestrial upper mantle. The samples have been dredged on the floor of the Ashadze and Logatchev hydrothermal sites on the Mid-Atlantic Ridge. In this preliminary analysis, amino acids and long chain n-alkanes are identified. They are most probably of biological/microbial origin. Some peaks remain unidentified.     

Purification and characterization of an extracellular alpha-neoagarooligosaccharide hydrolase from Bacillus sp. MK03

An agarolytic bacterium was isolated from soil in Gifu prefecture, Japan, and identified as Bacillus sp. strain MK03. The strain secreted neoagarooligosaccharide hydroluse into the culture medium. The enzyme was purified 49.7-fold from the culture fluid by ammonium sulfate precipitation and anion-exchange and gel-filtration column chromatographic methods. The purified enzyme appeared as a single band on polyacrylamide gel electrophoresis (PAGE) and sodium dodecyl sulfate (SDS)-PAGE. Estimations of the molecular mass by gel filtration and SDS-PAGE gave values of 320 kDa and 42 kDa, respectively, indicating that the enzyme is octametric. The enzyme cleaved the alpha-1,3 linkage in neoagarobiose to produce 3,6-anhydro-L-galactose and D-galactose. It also selectively cleaved the alpha-1,3 linkage at the nonreducing end in neoagarotetraose or neoagarohexaose to give 3,6-anhydro-L-galactose and agarotriose or agaropentaose. The optimum temperature and pH for the enzyme were 30 degrees C and 6.1, respectively. The N-terminal amino acid sequence showed no homology to sequences of other known neoagarooligosaccharide hydrolases and agarases.     

A novel MOSFET with vertical signal‐transfer capability for 3D‐structured CMOS image sensors

We have developed a novel MOSFET that can transfer signals vertically without through‐silicon vias but by using a fully depleted silicon‐on‐insulator (FDSOI) structure with its source region connected to the back electrodes as well as the front ones. A prototype MOSFET fabricated using the backside anisotropic wet etching technique has confirmed that the electrical characteristics measured from the front and the back electrodes are identical. The subthreshold factor S of the prototype was found to be 64.5 mV/decade, suggesting a good switching performance. Since the double‐sided MOSFET has vertical signal‐transfer capability and excellent operating characteristics, it is expected to contribute to developing a More‐than‐Moore type device of three‐dimensional integration such as pixel‐parallel image sensors. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Inhibitory effects of flavonoid glycosides isolated from the peel of Japanese persimmon (Diospyros kaki Fuyu) on antigen-stimulated degranulation in rat basophilic leukaemia RBL-2H3 cells

We found that two distinct flavonoid glycosides isolated from the peel of Japanese persimmon (Diospyros kaki Fuyu), isoquercitrin (Isq) and hyperin (Hyp), are capable of inhibiting antigen-stimulated degranulation in rat basophilic leukaemia RBL-2H3 cells. In order to elucidate the underlying mechanisms, we examined effects of Isq and Hyp on cellular responses induced by antigen stimulation. Treatment with both Isq and Hyp markedly inhibited antigen-stimulated elevation of intracellular free Ca²⁺ concentration and reactive oxygen species (ROS). Isq and Hyp did not affect NADPH oxidase (NOX) activity, but they possessed DPPH radical-scavenging activity similar to that of epigallocatechin gallate, a potent anti-oxidant, Finally, Isq and Hyp showed little or no effects on Ag-stimulated Syk activation or phosphorylation of signalling molecules. These results indicate that inhibition of antigen-stimulated degranulation by Isq and Hyp is mainly due to suppression of intracellular Ca²⁺ elevation, which is caused by direct scavenging of ROS that are generated by NOX. Our findings suggest that Isq and Hyp, isolated from the peel of persimmon, would be beneficial for alleviating symptoms of type I allergy.     

Synthesis and electronic structure of proton-type partially substituted birnessite by period-four transition metal

Partially substituted proton-type birnessite were prepared by solid state reaction and their structures were refined. The formed birnessite with no substitution is identified to rhombohedral phase. In the case of substitution treatment by V and Cr for Mn, birnessite phase was not formed. On substituting Fe, hexagonal phase increased with increase of the amount of the Fe. For Co and Ni-substitution, monoclinic phase emerged at substitution ratio of around 0.37 and 0.02, respectively. For the substitution of Cu, only the monoclinic birnessite formed irrespective of the ratio. The electric conductivity of the partially substituted birnessites was examined at room temperature. The general trend is lower conductivity with increasing ratio of contained substituents. On several mol% of the substitution by Ni and Cu, the conductivity slightly increased. From DOS calculation of these compounds, the partially substitution for Mn by Fe, Co and Ni in the birnessite poses splitting of crystal field to emerge new bands at around −1 and +1 eV by Mn(IV) 3d orbital.     

Mechanical stress effect on oxygen ion mobility in 8 mol% yttria-stabilized zirconia electrolyte

In the present study, the effect of mechanical tensile stress on oxygen mobility in 8 mol% yttria-stabilized zirconia (8YSZ) was investigated. The experimental results show that the ionic conductivity increases with stress and saturates. The maximum improvement in the conductivity was about 18% observed at 973 K. The simulation results show that the diffusion coefficient increases with stress and decreases with excessive stress. The maximum improvement was about 40% observed at 973 K. The improvement was larger at lower temperatures in both the experiment and the simulation. The strain caused by the stress is considered to have caused the gradient in the potential energies of the neighbouring oxygen sites, especially around the yttrium ions, which probably facilitated the migration of the oxygen ions.