Epitaxial growth of ferromagnetic CrO2 films in air

Epitaxial growth of CrO₂ films under atmospheric pressure has been investigated. Single crystal films of CrO₂ were obtained by the thermal decomposition of gaseous CrO₃ onto the substrates of rutile single crystals in air. The optimum temperature of the substrate for the pure CrO₂ epitaxial films was found to be 390°C. At the substrate temperature of 380°C, the obtained film included Cr₂O₅ as impurities, and Cr₂O₃ appeared at 400°C. Magnetic domain patterns of these films were observed by longitudinal Kerr effect. The growth patterns of domain were obtained with applied field.     

A photosensitive polyimide using an alkaline aqueous solution as a developer

Compared with the nonphotosensitive polyimide, the photosensitive polyimide has become very important in the simplification of the patterning process. Its importance has prompted the development of a new type of photosensitive polyimide, using an alkaline aqueous solution as a developer. This photosensitive polyimide allows the formation of 40-μm-square via-holes in a film with a thickness of 15 μm and exhibits excellent physical properties after curing.     

Auto-oxidation products of astaxanthin

The auto-oxidation products of astaxanthin were investigated. Astaxanthin was allowed to react with atmospheric oxygen at 55°C in the dark for 35 days. A series of oxidative cleavage products, 7-apoastaxanthinal (1), 9-apoastaxanthinone (2), 11-apoastaxanthinal (3), 13-apoastaxanthinone (4), 15-apoastaxanthinal (5), 14'-apoastaxanthinal (6), 12'-apoastaxanthinal (7), 10'-apoastaxanthinal (8), and 8'-apoastaxanthinal (9), were identified. Among them, 3 and 6 were isolated and characterized for the first time. Cleavage of the double bond in astaxanthin was discussed on the basis of the calculation of the stable molecular energy.     

Dieless incremental micro-forming of miniature shell objects of aluminum foils

Single-point incremental forming of thin aluminum foils, which did not require any die and any backing plate, was developed for fabricating customized parts of thin shell miniature objects. Thin aluminum foils were deformed incrementally using a round-tip single point tool on a desktop type of milling machine controlled with a personal computer. It was found that an aluminum foil 12 μm thick was much smaller in forming limit than an aluminum foil 50 μm thick when a single point tool with a tip radius of 0.5 mm was not rotated, but its forming limit was improved greatly by rotating the tool up to 20,000 rpm. Measured forming forces revealed that the tool rotation decreases the in-plane forces by approximately 50%. Hydrodynamic lubrication at the interface between a rotating tool and aluminum foil must have had a direct and favorable influence on the forming process, while increasing the forming limit of the thinner foil. It was also found that the optimum stepwise axial feed was found to be around the value of foil thickness. Then, incremental forming of arrays of dots 0.1 mm in diameter, miniature pyramids, a miniature car and miniature letters was performed successfully under the optimized conditions at arbitrary positions of 12-μm-thick foils.     

Phenomena in GTA and GHTA welding in Mars-like atmosphere

NASA is advancing the project of manned Mars exploration. In the future, Martian outposts and structures will be constructed. To realize this, welding technology is expected to be applied. The main atmospheric component of Mars is carbon dioxide, and the atmospheric pressure is approximately 700 Pa. In this study, welding experiments were carried out in a simulated Mars atmosphere of 99.5% carbon dioxide and a pressure of 700 Pa. Conventional gas tungsten arc (GTA) welding and gas hollow tungsten arc (GHTA) welding, in which arc operating gas is allowed only to flow out from the electrode tip of a hollow tungsten electrode, were investigated. The arc discharge behaviour and the melting characteristics in the simulated Mars atmosphere were studied. As a result, it was shown that GTA welding and GHTA welding might be applicable even in the Mars atmosphere.     

A functionally separated nanoimprinting material tailored for homeotropic liquid crystal alignment

In order to homeotropically align liquid crystals (LCs) at the nanosized surface grooves processed by nanoimprint lithography technology (NIL), we propose to design a hybrid-type homeotropic polymer material consisting of two distinct moieties with largely different thermo-mechanical properties and surface activity. Surface contact angle measurements and sum-frequency vibrational spectroscopy allow us to conclude that the polymer film is a functionally separated composite suitable for the homeotropic LC alignment processed by NIL. As one of the potential applications using the hybrid-type homeotropic polymer, we demonstrate that the nanoimprinted grooves at the polymer surface can achieve a zenithal nematic LC bistability.     

Magneto-Peltier cooling of single-crystal Bi<Subscript>1-<Emphasis Type="Italic">X</Emphasis></Subscript>Sb<Subscript><Emphasis Type="Italic">X</Emphasis></Subscript> (<Emphasis Type="Italic">X </Emphasis>= 0.12 and 0.15) alloys

The cooling temperatures of rectangular parallelepiped Bi_1-X Sb _X (X = 0.12 and 0.15) single-crystals with the same thickness of t = 2 mm but different width W were measured at 113 K and 290 K as a function of electric current in the magnetic field B up to 2.17 T. The magnetic field was aligned along the thickness t of a sample and the current flows along its length L through the copper leads soldered to both end surfaces of cross section (W × t), where W, t and L are parallel to the binary, bisector and trigonal axes of the single-crystal, respectively. The thermoelement was not in contact with a heat sink. The cooling temperature of Bi_0.85Sb_0.15 at 290 K was increased with an increase of B and was almost symmetric for the reverse of the field direction, while at 113 K it exhibited a maximum at B = ±0.25 T and a strong asymmetry for the field direction. The largest maximum cooling temperature ΔT _max of Bi_0.85Sb_0.15 was achieved when a thermoelement has optimum dimensions so that heat energy is hardly generated at the cold side. When the single-crystal Bi_0.85Sb_0.15 alloy has optimum dimensions of L = 15 mm, W = 4 mm and t = 2 mm, the ΔT _max at 290 K increased from 4.2 K in B = 0 T to 9.6 K in B = +2.17 T, so that it exceeded ΔT _max values of 5.7 K obtained for a typical Bi₂Te₃ and 8.5 K measured previously for Bi single-crystal in B = +2.17 T.     

Baker's yeast reduction of α-(alkoxycarbonylamino)acetophenones and Lipase-catalysed resolution of 2-(alkoxycarbonylamino)-1-arylethanols

Enzymatic reduction of α-(alkoxycarbonylamino)acetophenones with baker's yeast afforded optically active (R)-2-(alkoxycarbonylamino)-1-arylethanols. However, the reduction of α-(benzyloxycarbonylamino)-4-methoxyacetophenone ( 3c ) with immobilized baker's yeast gave (S)-2-(benzyloxycarbonylamino)-1-(4-methoxyphenyl) ethanol. The lipase PS-catalysed transesterification of 2-(allyloxycarbonylamino)-1-arylethanols ( 5 ) using vinyl acetate as an acyl donor resulted in the formation of (S)-2-(allyloxycarbonyl-amino)-1-arylethyl acetates [( S )- 9 ] and (R)-2-(allyloxycarbonylamino)-1-aryle-thanols [( R )- 5 ].     

The superstructure toward open bioinformatics grid

The grid design strongly depends on not only a network infrastructure but also a superstructure, that is, a social structure of virtual organizations where people trust each other, share resources and work together. Open Bioinformatics Grid (OBIGrid) is a grid aimed at building a cooperative bioinformatics environment for computer sicentists and biologists. In October 2003, OBIGrid consisted of 293 nodes with 492 CPUs provided by 27 sites at universities, laboratories and other enterprises, connected by a virtual private network over the Internet. So many organizations have participated because OBIGrid has been conscious of constructing a superstructure on a grid as well as a grid infrastructure. For the benefit of OBIGrid participants, we have developed a series of life science application services: an open bioinformatics environment (OBIEnv), a scalable genome database (OBISgd), a genome annotation system (OBITco), a biochemical network simulator (OBIYagns), and to name a few. Akihiko Konagaya, Dr.Eng.: He is Project Director of Bioinformatics Group, RIKEN Genomic Sciences Center. He received his B.S. and M.S. from Tokyo Institute of Technology in 1978 and 1980 in Informatics Science, and joined NEC Corporation in 1980, Japan Advanced Institute of Science and Technology in 1997, RIKEN GSC in 2003. His research covers wide area from computer architectures to bioinformatics. He has been much involved into the Open Bioinformatics Grid project since 2002. Fumikazu Konishi, Dr.Eng.: He is researcher at Bioinformatics Group, RIKEN Genomic Sciences Center since 2000. He received his M.S. (1996) and Ph.D. (2001) from Tokyo Metropolitan Institute of Technology. He served as an assistant in Department of Production and Information Systems Engineering, Tokyo Metropolitan Institute of Technology since 2000. He also works in Structurome Research Group, RIKEN Harima Institute from 2001. His research interests include concurrent engineering, bioinformatics and the Grid. He has deeply affected to the design of OBIGrid. Mariko Hatakeyama, Ph.D.: She recieved her Ph.D. degree from Tokyo University of Agriculture and Technology. She is Research Scientist at Bioinformactis Group, RIKEN Genomic Sciences Center. Her research topics are: microbiology, enzymology and signal transduction of mammalian cells. She is now working on computational simulation of signal transduction systems and on thermophilic bacteria project. Kenji Satou, Ph.D.: He is Associate Professor of School of Knowledge Science at Japan Advanced Institute of Science and Technology. He received B.S., M.E. and Ph.D. degrees from Kyushu University, in 1987, 1989 and 1995 respectively. For each degree, he majored in computer engineering. His research interests have progressed from deductive database application through data mining to Grid computing and natural language processing. His current field of research is bioinformatics. He prefers set-oriented manner of thinking, and usually wonders how he can construct an intelligent-looking system based on large amount of heterogeneous data and computer resources.