Ultrasonic attenuation monitoring of fatigue damage in low carbon steels with electromagnetic acoustic resonance (EMAR)

We studied microstructure evolution during tension-compression fatigue in low carbon steels, containing C: 0.15 mass%. In situ monitoring of axial-shear-wave attenuation and velocity was achieved with electromagnetic acoustic resonance (EMAR), which is a combination of the resonant spectroscopy technique and a noncontacting electromagnetic acoustic transducer (EMAT). Transduction occurs with the magnetostriction effect and is the key to establish a continuous monitoring of microstructural changes in the surface region of the metals with high sensitivity. We found for the first time that the attenuation is highly sensitive to the accumulated fatigue damage, showing a minimum around 20% of the whole life. This phenomenon is interpreted in terms of drastic change of dislocation mobility and rearrangement, which is supported by TEM observation for dislocation structure. This technique has the potential to assess the damage advance and to predict the fatigue life of metals.     

Anomalous Hall effect governed by electron doping in a room-temperature transparent ferromagnetic semiconductor

Ferromagnetic semiconductors are believed to be suitable for future spintronics, because both charge and spin degrees of freedom can be manipulated by external stimuli. One of the most important characteristics of ferromagnetic semiconductors is the anomalous Hall effect. This is because the ferromagnetically spin-polarized carrier can be probed and controlled electrically, leading to direct application for electronics. Control of the Curie temperature and magnetization direction by electronic field, and photo-induced ferromagnetism have been performed successfully using the anomalous Hall effect for group III-V ferromagnetic semiconductors. In these cases, the operation temperature was much below room temperature because of the limited Curie temperature of less than 160 K (ref. 6). Here, we report on the anomalous Hall effect governed by electron doping in a room-temperature transparent ferromagnetic semiconductor, rutile Ti(1-x)Co(x)O(2-delta) (of oxygen deficiency delta). This result manifests the intrinsic nature of ferromagnetism in this compound, and represents the possible realization of transparent semiconductor spintronics devices operable at room temperature.     

Indentation creep in nanocrystalline Fe-TiN and Ni-TiN alloys prepared by mechanical alloying

Mechanical properties of nanocrystalline Fe-TiN and Ni-TiN alloys with various TiN contents between 17 and 64 vol pct, which are prepared by dynamically consolidating mechanically alloyed powders, have been investigated by means of hardness measurements and indentation creep tests at intermediate temperatures. The hardness increases with decreasing grain size to about 10 nm. The indentation creep curves conform well to an equation derived from a transient creep rate equation. The analysis of creep curves indicates that the deformation occurs by a dislocation mechanism controlled by grain boundary diffusion.     

Definition of the mitogenic factor (MF) as a novel streptococcal superantigen that is different from streptococcal pyrogenic exotoxins A, B, and C

Human T cell activation by recombinant mitogenic factor (rMF) was investigated in comparison with that by recombinant streptococcal pyrogenic exotoxins (rSPE) A, B, and C. Recombinant MF, rSPEA, and rSPEC were mitogenic for peripheral blood mononuclear cells (PBMC), whereas rSPEB was not. Recombinant MF required only HLA-DR for the stimulation of PBMC, as determined using monoclonal antibodies (mAb) to HLA class II molecules and the mouse L cells transfected with HLA class II molecules. Recombinant SPEA and rSPEC required HLA-DR or HLA-DQ molecule. Recombinant MF selectively stimulated V beta 2, V beta 7, V beta 8, V beta 18 and V beta 21-bearing T cells, whereas rSPEA and rSPEC activated V beta 2 and V beta 6-bearing T cells as evaluated by the quantitative T cell receptor (TCR) analytical method. No clonality was observed in the nucleotide sequences of complementarity determining region 3 of TCR V beta in T cells responding to rMF. The profiles of cytokine production by PBMC in response to rMF, rSPEA, and rSPEC were quite similar. In summary, these results demonstrate that both HLA class II molecules and the TCR V beta required for rMF-mediated T cell activation are distinct from those required for rSPEA or rSPEC-mediated activation. Therefore, the MF is a novel streptococcal super-antigen which is different from SPEA, SPEB, and SPEC.     

Biochemical characterization of l-arabitol 2-dehydrogenase from Pantoea ananatis

Two oxidoreductases, XDH and LAD, were found in the same operon that was involved in sugar metabolism in Pantoea ananatis. LAD, whose endogenous substrate was unknown, was recombinantly prepared and biochemically analyzed. Consequently, LAD was identified as l-arabitol 2-dehydrogenase and its substrate specificity was complementary to that of XDH.     

Effects of bleaching variables on residual sulfite content of salted jelly-fish

Summary The effects of bleaching variables on the residual sulfite content of jelly-fish were evaluated. The primary factor that affects the residual sulfite content appears to be the concentration of sodium bisulfite used as bleaching agent. The use of sodium bisulfite of less than 300 mg/kg as SO₂ the legally regulated level (below 30 mg/kg as SO₂). The ratio of combined to total sulfite was not less than 90% regardless of the total sulfite content.

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Einflüsse von Bleichbedingungen auf den Sulfitgehalt der gesalzenen Qualle

Zusammenfassung Es wurden die Einflüsse von Bleichbedingungen auf den Sulfitgehalt der Qualle untersucht. Der primäre Faktor, der den bleibenden Sulfitgehalt der Qualle bewirkt, war die Konzentration von Natriumbisulfit. Der verbleibende Sulfitgehalt in der Qualle, die mit Natriumbisulfit von 100–300 mg/kg (als SO₂) gebleicht wurde, betrug weniger als 30 mg/kg. Das Verhältnis von gebundenem Sulfit zu Gesamtsulfit betrug 9:1.

     

Magnetic-Pole Flip by Millimeter Wave

In the era of Big Data and the Internet of Things, data archiving is a key technology. From this viewpoint, magnetic recordings are drawing attention because they guarantee long-term data storage. To archive an enormous amount of data, further increase of the recording density is necessary. Herein a new magnetic recording methodology, “focused-millimeter-wave-assisted magnetic recording (F-MIMR),” is proposed. To test this methodology, magnetic films based on epsilon iron oxide nanoparticles are prepared and a focused-millimeter-wave generator is constructed using terahertz (THz) light. Irradiating the focused millimeter wave to epsilon iron oxide instantly switches its magnetic pole direction. The spin dynamics of F-MIMR are also calculated using the stochastic Landau–Lifshitz–Gilbert model considering all of the spins in an epsilon iron oxide nanoparticle. In F-MIMR, the heat-up effect of the recording media is expected to be suppressed. Thus, F-MIMR can be applied to high-density magnetic recordings.     

Effects of hydroperoxide in lipid peroxidation on dough fermentation

The effects on dough fermentation of hydroperoxides produced by lipid peroxidation through lipoxygenase induction were studied. The mechanism by which hydroperoxides accelerated dough fermentation was also investigated. Dough with lipoxygenase had a significantly increased amount of hydroperoxides after 90 min of fermentation, while dough without lipoxygenase had less generation of hydroperoxides until 30 min, after that time hydroperoxide generation decreased gradually. A hydroperoxide concentration of 30–40 mM had the greatest effect on accelerating dough fermentation. In the dough with hydroperoxides, the maximum expansion rate occurred with a 1% yeast concentration and a gluten concentration of 60%. The mechanism of dough fermentation using lipid peroxidation by lipoxygenase induction is discussed in detail. Gluten is formed from gliadin and glutenin. Gluten was denatured by hydroperoxides, which makes the gluten molecule grow larger (molecular weight of approximately 53 kDa). Fermentation is promoted by this phenomenon. This information provides new information for the bread-making industry.     

An approach to discovering risks in development process of large and complex systems

When building a large and complex system, such as satellites, all sorts of risks have to be managed if it were to be successful. For risks in the design of an artifact, various reliability analysis techniques such as FTA or FMEA have been employed in the engineering domain. However, risks exist as well in the development process, and they could result in a failure of the system. In this paper, we present an approach to discovering risks in development process by collecting and organizing information produced during development process at low cost. We describe a prototype system called IDIMS, and show how it can be used to discover risks from e-mail communications between developers. The motivation of our work is to overcome thecapture bottleneck problem, and utilize now wasted information to improve development process. Yoshikiyo Kato: He received his B. Eng. (1998) and M.Eng. (2000) degrees in aeronautics and astronautics from The University of Tokyo. From September 1998 to July 1999, he was an exchange student at Department of Computer Science and Engineering of University of California, San Diego, and worked on software engineering tools. From May 2001 to July 2002, he was a research assistant at National Institute of Informatics (Japan). He is currently a Ph.D. student at Department of Advanced Interdisciplinary Studies of the University of Tokyo. His research interests include knowledge management, CSCW, HCI and software engineering He is a member of AAAI and JSAI. Takahiro Shirakawa: He received his B.Eng. (2000) and M.Eng. (2002) degrees in aeronautics and astronautics from the University of Tokyo. He is currently an assistant examiner at Japan Patent Office. Kohei Taketa: He received his B.Eng. (2000) and M.Eng. (2002) degrees in aeronautics and astronautics from the University of Tokyo. He is currently a software engineer at NTT Data Corp. Koichi Hori, Dr.Eng.: He received B.Eng, M.Eng, and Dr.Eng. degrees in electronic engineering from the University of Tokyo, Japan, in 1979, 1981, and 1984, respectively. In 1984, he joined National Institute of Japanese Literature where he developed AI systems for literature studies. Since 1988, he has been with the U University of Tokyo. He is currently a professor with Department of Advanced Interdisciplinary Studies, The University of Tokyo. From September 1989 to January 1990, he also held a visiting position at University of Compiegne, France. His current research interests include AI technology for supporting human creative activities, cognitive engineering, and Intelligent CAD systems. He is a member of IEEE, ACM, IEICE, IPSJ, JSAI, JSSST and JCSS.