Showing papers by "Tokyo University of Science published in 1989"

Synthesis of surface nitride on Pd(100) surface by a reaction of NO with H2

Abstract: A c(2{times}2) overlayer of surface nitride was for the first time synthesized on Pd(100) surface by a catalytic reaction of NO + H{sub 2} {yields} (N) + H{sub 2}O at several Torr of total pressure at 500-600 K. Pure c(2{times}2) surface nitride on Pd(100) surface is stable up to about 600K in vacuum but reacts readily with H{sub 2} at 10{sup {minus}6}-10{sup {minus}9} Torr to give NH{sub 3} at 440 K, that is, c(2{times}2)-N is an intermediate compound of the NH{sub 3} formation reaction.

Properties and structure of microemulsions of the system sodium octyl sulfate/n-hexyl alcohol/n-decane/brine

Abstract: Etude de la variation de la microstructure et du mecanisme de transition de phase de la microemulsion en fonction de la concentration en NaCl

Structural control of poly(2-hydroxyethyl methacrylate)-graft-polyamine copolymers for differential retention of rat lymphocyte subpopulations.

Abstract: Poly(2-hydroxyethyl methacrylate)-graft-polyamine copolymers (HA copolymers) of varying composition and chain length of the polyamine graft were prepared by radical copolymerization of 2-hydroxyethyl methacrylate with a given quantity of polyamine macromonomer having a controlled molecular weight, and their interaction with lymphocyte subpopulations (B and T cells) was estimated using a column method From these results, it was revealed that the most suitable molecular structure of HA copolymers for separating lymphocyte subpopulations is that of an HA copolymer with 13 wt% of polyamine graft with a chain length 3000-6600 in molecular weight It is concluded that the retention process of lymphocytes on the HA graft copolymers is driven primarily by ionic interactions between the protonated amino groups and the cells However, the mode of the polyamine microdomain structure, that is the distribution of protonated amino groups, and the conformation of the polyamine chains, which varies with the chain length of the HA copolymer, are also important factors in determining differential lymphocyte retention

Production of polychlorinated phenoxyphenols (predioxins) by aqueous chlorination of organic compounds

Abstract: The reactions of phenolic substances with hypochlorite in water were investigated by means of gas chromatography-mass spectrometry. Chlorinated and methylated phenols were shown to produce polychlorinated phenoxyphenols (predioxins), having one to nine chlorine atoms, as the by-products in chlorine-treated water. The production of some of these compounds is dependent on the number of equivalents of chlorine per mol of compound and on the reaction pH.

Superconducting Oxides Coating on Ceramics

Abstract: Electroless Ag plating was investigated as a method of coating of Al2O3 ceramics with YBCO superconducting oxides. The adhesion strength of the Ag plating increased greatly when the ceramics were pretreated by both mechanical and chemical etchings. From a study on the electrophoretic deposition of superconducting oxides particles from acetone baths, it was found that the amount of deposit increases with the I2 and H2O content of the bath, but excessive addition of I2 or H2O caused an increase in bath conductivity and electrolytic current, resulting in significant hydrogen evolution and a decrease in deposition.After electrophoretic deposition of the superconducting oxides on the ceramics, the ceramics were heat-treated at 940°C for 6h and at 450°C for 4h. The oxide coating was found to be smooth, uniform, and adhesive, and the superconducting properties of the coating were fully verified by X-ray diffraction, diamagentic measurement, and measurement of resistivity.Moreover, coil of Ag wire (φ0.7mm) was completely coated with superconducting oxides just like as above. These facts confirmed that electrophoretic deposition is an effective method for the preparation of superconducting oxides on various substrates of various shapes.