Transactions of the Materials Research Society of Japan
Online ISSN : 2188-1650
Print ISSN : 1382-3469
ISSN-L : 1382-3469
34 巻 , 3 号
選択された号の論文の52件中1~50を表示しています
  • T. Koga, H. Kita, K. Uemura, K. Tanaka, I. Kawafune, M. Funaoka
    2009 年 34 巻 3 号 p. 371-374
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    Carbon membranes were prepared by pyrolyzing lignocresol derived from wood using high frequency induction heating. The pore structure of the carbon membrane was studied by adsorption measurements and XPS. Gas adsorption measurements indicated that lignin carbon membrane has micropores in the range of 0.6-0.5 nm. C1s peak of XPS spectra of the lignin carbon membranes clearly showed that there are several hydrophilic functional groups, containing oxygen groups, on the surface of the membranes. Gas permeation rates through the membranes were also measured at 35℃. Carbon membranes from lignin-based materials have higher performance than conventional polymer membranes and provide a promising new class of separation membranes.
  • Nobutaka Endo, Mikinori Sugita, Mitsuru Higa, Young Moo Lee
    2009 年 34 巻 3 号 p. 375-378
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    Polymer electrolyte membranes (PEMs) composed of poly(vinyl alcohol) (PVA), modified PVA polyanion containing 2 mol% of 2-methyl-1-propanesulfonic acid (AMPS) groups as a copolymer and sulfosuccinic acid (SSA) were prepared by solution blending. The PEMs of various AMPS and SSA contents (CAMPS and CSSA, respectively) and crosslinking conditions were prepared to determine the effect of sulfonic acid group contents and crosslinking conditions on PEM properties. Proton conductivity and methanol barrier property through the PEMs increased with increasing SSA content and have maximum value at respective SSA contents. The proton permeselectivity of the PEM , which is defined as the ratio of the proton conductivity to the permeability coefficient of methanol, gave a maximum value of 190×103 S cm-3 s. The value is about 4 times higher than that of Nafion 117.
  • Panida Prawitwong, Katsuji Shimoda, Kentaro Ishikuri, Yukihiro Ishikur ...
    2009 年 34 巻 3 号 p. 379-382
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    The properties of the lubricant get worse with the usage time due to oxidation reaction and contamination. Incorporation of the fine particles is a main factor of the deterioration of the lubricant. If the particles are removed effectively, the used oil could be reused. Using high voltage, electric charges could flow through the cutting oil. Metal particles and contaminants migrated under high electric field and aggregated on the surface of electrodes. Using the high electric field, fine metal particles were separated from the used cutting oil and then the oil became clear. The core chemical structure of the used oil was hardly degraded by the treatment. The application of the high electric field is the useful method to remove the metal particles effectively.
  • Takayuki Kohiruimaki, Ayano Toda
    2009 年 34 巻 3 号 p. 383-386
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
      Zr-Ce composite oxides were synthesized by the combination methods of homogeneous precipitation and sintering. Granular Zr-Ce composite oxide particles with mean diameter of 3μm, having high photocatalytic ability under the visible ray, were synthesized when the sintering temperature was 400℃. The methylene blue decomposition ability higher than TiO2 was confirmed by comparing the reactions under the fluorescent lamp and in the dark place. It may be caused by both the photocatalysis and the adsorption of Zr-Ce composite oxides. The high effectiveness was found also for the decomposition of the following organic substances; methylene blue, cooking oil, surfactant, and whey protein.
  • Takashi SUZUKI
    2009 年 34 巻 3 号 p. 387-390
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    Trial to synthesize propene from ethene was carried out on silica supported cobalt (Co/SiO2) catalyst by using slurry bubble column reactor. Catalytic propene formation was recognized on that catalyst. When a gas mixture of ethene and synthesis gas (syngas), which is 1:2 mixture of carbon monoxide and hydrogen was fed onto Co/SiO2 catalyst, the produce rate of propene was increased 4-fold as much as that in the case flowing ethene alone. It was conjectured that the enhancement of propene formation in the presence of ethene and syngas was caused by increase methylidene (=CH2) species which was readily reacted with ethene to form propene.
  • Machiko Takigami, Akihiro Hiroki, Naotsugu Nagasawa, Takamitsu Kasahar ...
    2009 年 34 巻 3 号 p. 391-394
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    Carboxymethyl cellulose (CMC) with different molar mass was prepared by acid hydrolysis at 121℃. CMC thus prepared was mixed with citric acid aqueous solution to form CMC-acid gel. By replacing sodium existing as counter ion in carboxymethyl group with hydrogen, CMC molecules coagulate and hydrogen bonds are formed among CMC molecules. The CMC-acid gel prepared in that way was subjected to evaluation of gel fraction, water absorption and mechanical properties. Gel fraction was higher in CMC with higher molar mass than that in CMC with lower molar mass at short incubation time. However, there was no difference in gel fraction attributable to molar mass of CMC after long time incubation. CMC with higher molar mass crosslinked more easily than CMC with lower molar mass. The gel made of CMC with lower molar mass was softer and absorbed more amount of water than that with higher molar mass. All the results were elucidated by number of hydrogen bonds in CMC molecule. The gel made of higher molar mass CMC becomes stiff and brittle after long time incubation, however, the gel made of lower molar mass CMC keeps softness and strength longer.
  • T. Kasahara, M. Takigami, N. Nagasawa, S. Takigami
    2009 年 34 巻 3 号 p. 395-398
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    Carboxymethyl cellulose (CMC) forms a gel when mixed with acid as a result of replacement of sodium in carboxymethyl group with hydrogen; hydrogen bonds are formed among CMC molecules. CMC gel having new properties can be formed by mixing CMC with other materials. Konjac glucomannan (KM) is a water-soluble glucomannan with high molar mass and has high viscosity in low concentration aqueous solution. Previous study showed that CMC-KM-acid gel was stronger than CMC-acid gel, however, the strength depended on the molar mass of KM. When KM with high molar mass was mixed with CMC and acid, the gel was uniform, however, turbid at first glance, showing that compatibility of CMC and KM with high molar mass was not so good. However, when KM with low molar mass was mixed with CMC and acid, the gel was uniform and transparent, showing good compatibility of CMC and KM. Molar mass of KM showing good compatibility was less than 300 kDa. Scanning electron micrographs taken under moist condition clearly showed uneven and even surfaces for gels made using high molar mass and low molar mass KM, respectively. The compatibility of CMC and KM affected the mechanical properties of the CMC-KM-acid gels.
  • Ryota Hatakeyama, Yuki Tomita, Shoji Takigami
    2009 年 34 巻 3 号 p. 399-402
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    Water soluble wool keratin was prepared by derivatization of disulfide (SS) bonds of cystine residues to carboxymethylalanyl disulfide (CMAD) groups. The solubilization reaction was carried out in 0.2 M thioglycolic acid aqueous solution under alkaline conditions (pH 11 - pH 13.5). CMAD wool keratin was successfully obtained even in the absence of urea and dithiodiglycolic acid. The solubilization reaction was performed by two stages, derivatization reaction including reduction step, oxidation step and oxidation reactions. The derivatization reaction was accelerated by increment of alkali concentration, however, hydrolysis of wool keratin occurred simultaneously at high alkaline concentration more than pH 13. Molecular degradation hardly occurred when reaction time was short, even pH 13 system. To investigate the prevention of hair damage, CMAD wool keratin was prepared at pH 13 for 12 h. It was added in permanent waving agent and the bleaching and permanent waving (B&P) treatments were carried out. Human hair was damaged remarkably by repetition of B&P treatments. However, cuticle layers of treated hair using CMAD wool keratin were hardly damaged even if the treatment was repeated for 3 times. CMAD wool keratin is useful for prevention of hair damage.
  • T. Saito, A. Takasaki
    2009 年 34 巻 3 号 p. 403-406
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    Three kinds of elemental powders consisted of Ti and Ni, with different chemical compositions, Ti50Ni50, Ti45Ni55 and Ti55Ni45, were mechanically alloyed for 30h by a planetary ball mill, compacted, sintered at 973K and annealed at several temperatures, 673K, 773K and 873K, and the martensitic transformation behaviors for those bulk samples were investigated. All three samples turned into amorphous state after mechanical alloying for 30h. After compacting, sintering and annealing, however, TiNi (B2) phase with a small amount of Ti2Ni phase formed in the Ti50Ni50 sample, while TiNi (B2), Ti2Ni and TiNi3 phases formed in Ti45Ni55, and TiNi (monoclinic), Ti2Ni and Ti3Ni4 phases in Ti55Ni45. The fraction of Ti in all the samples was reduced by approximately 1at% after a series of fabrication processes, suggesting that mechanical alloying (MA) process contributed to the phenomenon. Martensitic transformation behavior was observed in all the samples after a series of fabrication processes. Several precipitated phases influenced the martensitic transformation behavior, temperature and enthalpy for the transformation, suggesting that the precipitated phases have possibility to control martensitic transformation temperature. The martensitic transformation behavior was also dependent on annealing temperature.
  • Terumitsu Tanaka, Junsuke Matsuzaki, Hiroki Kurisu, Setsuo Yamamoto
    2009 年 34 巻 3 号 p. 407-409
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    Relationship between coercivity and micromagnetic structure was estimated using a micromagnetic simulator assuming permalloy film as a magnetic film. Wire-like shaped magnetic film showed relatively high coercivity and the magnetization reversed thorough coherent rotation. Coercivity was found to relate to the micromagnetic structure, and large sized film tends to configure vortex micromagnetic structure and coercivity becomes small.
  • H. J. Cha, T. Sato, T. Kanewaki, T. Tanaka, H. Kurisu, S. Yamamoto
    2009 年 34 巻 3 号 p. 411-414
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
      The feasibility of multi-frequency-band operation was studied using a finite element method simulator with respect to the authors proposed bottom mounting type isolator whose size is only 1/5 of the world smallest commercialized isolator in volume. The bottom mounting type isolator was found to exhibit practically usable non-reciprocal transmission characteristics in a wide frequency range from several hundred MHz to 5 GHz without change in the size of the isolator by changing bias magnetic field. Bias magnetic field control system composed of electromagnet, magnetic core and soft magnetic disk was proposed. It was found that the bottom mounting type isolator equipped with the bias magnetic field control system operates frequency range including 460 and 750 MHz bands planned for 4th generation mobile communication systems.
  • Junsuke Matsuzaki, Terumitsu Tanaka, Hiroki Kurisu, Setsuo Yamamoto
    2009 年 34 巻 3 号 p. 415-418
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    A hard/soft magnetic composite pillar array medium(CPA media) is proposed for Tera-bits/inch2 recording. The recording frequency of 1.5 GHz is considered to be necessary to obtain high data rate with 1 Tbits/inch2 recording rensity. A magnetization switching time for the single hard/soft magnetic composite pillar was evaluated using a micromagnetic simulator based on the Landau-Lifshitz-Gilbert equation. The switching time less than 0.33 nano second was found to be attained by appropriately setting the damping constant, the incident angle of applied field, and the exchange constant between the hard and soft magnetic units. The influence of the neighboring pillars in the array was also evaluated. The CPA media was found to be available for the high frequency recording corresponding to 1.5 GHz.
  • S. Miyamoto, H. Kurisu, J. Seiki, T. Tanaka, S. Yamamoto
    2009 年 34 巻 3 号 p. 419-422
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    This paper demonstrates the effect of N2O gas on HfO2 thin film and (λ/4) HfO2 / (λ/4) SiO2 distributed Bragg reflector (DBR) during reactive sputter deposition. HfO2 thin film fabricated with N2O as reactive gas during sputter deposition improved its surface roughness and crystal structure. A remarkable improvement of optical transmittance in HfO2 thin film deposited with N2O gas was also found. An optimum supply of oxygen atoms is considered to give efficient oxidation for hafnium metal during reactive sputter deposition due to the relatively small dissociation energy from N2O molecules to N2 molecules and O atom. The transmittance of (λ/4) HfO2 / (λ/4) SiO2 DBR value was obtained to be 98 %. This value is close to the optical transmittance of the dielectric multilayer for highly efficient microcavity.
  • Y. Miyaji, H. Kurisu, T. Tanaka, S. Yamamoto, M. Furuya
    2009 年 34 巻 3 号 p. 423-426
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    The paper addresses the vacuum performance of a carbon-doped titanium oxide film on a titanium material and applicability of the surface modification of vacuum flange to ultrahigh vacuum systems. The total amount of desorption gases of this material is almost the same as that of chemically-polished stainless steel with very low outgassing under non-vacuum baking conditions. Its total amount is half of that of stainless steel after the vacuum baking process. These results indicate that the carbon-doped titanium oxide film has very low outgassing properties. The surface modification was also applied to knife edge of a titanium vacuum-flange. The carbon-doped titanium oxide film exhibits sufficient durability so that after being tightened 40 times the knife edge was not worn out. It was found that Conflat flange made of this material can be utilized for practical vacuum systems.
  • Yuichiro Kawahara, Takanori Sasaki, Yoshimine Tanabu, Kiyoshi Kawamoto ...
    2009 年 34 巻 3 号 p. 427-430
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    The conversion efficiency decrease due to temperature rise and the loss of incident light due to surface reflection are problems in solar cells. Multi-functional optical films which have functions of wavelength selective transmission to cut off infrared rays and antireflection are an effective solution. However, optical characteristics of these films is changed by incident angle of ray, and in practical use, the incident angle of solar light is changes depending on time. Therefore, in this research, we investigated the incident angle dependency of transmittance of the cover glass and conversion efficiency for solar cells with multi-functional optical films. The results show that incident angle dependency appears for angles in excess of 10 degrees. The center of the wavelength cut off range shifted by 140 nm for an incident angle of 30 degrees and conversion efficiency decreased 0.7%. From this result, it is thought that a decrease of conversion efficiency results from a collapse of the balance between decreasing the transmitted light used for power generation and preventing a temperature rise.
  • Yoshimine Tanabu, Takanori Sasaki, Kohei Kawaragi, Teruyoshi Takahashi ...
    2009 年 34 巻 3 号 p. 431-434
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    OLED (Organic Light Emitting Diode) devices, which are receiving attraction as next generation FPDs (Flat Panel Displays) and lighting devices, suffer from the problem of having a short lifetime. The relationship between lifetime and brightness represents a trade-off. A mechanism for improving durability and extending lifetime is necessary in order to create a bright and stable device. Therefore, it is important to ascertain the causes by which application of voltage leads to deterioration of OLEO devices. It is considered that one of the causes of deterioration of the device is a chemical change in the interface between the electrode and organic layer that occurs when a voltage is applied. In this research, the authors investigated the chemical change in the interface between the electrode and organic layer that occur when a voltage is applied. The structure of device used in this research consisted of CuPc (Copper Phthalocyanine) formed between ITO (Indium Tin Oxide) and aluminum. We analyzed the chemical composition of the device using XPS (X-ray Photoelectron Spectroscopy) after peeling off the aluminum cathode with carbon tape and compared chemical condition in the interface between CuPc layer and ITO anode before and after applying voltage. The results of this analysis show that indium, which was not detected before applying voltage, was detected in the CuPc layer on the substrate side after applying it. Therefore, there are possibilities that the ITO, located under the CuPc layer, appeared because the adhesion between the ITO and CuPc layer had become weak or the adhesion between the aluminum and CuPc layer had become strong. In addition, indium was also detected in the CuPc layer on the carbon tape side after applying voltage. Therefore, two possibilities are considered as the cause of these results. One is diffusion of the ITO into the CuPc layer and the other is some chemical change occurring between the ITO and the CuPc. We consider that these results cause decrease of the OLED lifetime in the early stage.
  • Yoshie Ishikawa, Naoto Koshizaki
    2009 年 34 巻 3 号 p. 435-437
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    B4C spherical particles were fabricated by laser irradiation at various wavelengths (355, 532, and 1064 nm) of B dispersed in organic solvents. Obtained B4C yields were 78, 90, and 84% in ethanol and 68, 82 and 65% in ethyl acetate by irradiation at 355, 532 and 1064 nm. The highest B4C yield was obtained at 532 nm in each solvent. Important factors for large B4C yield were considered to be laser irradiation at long wavelength and large absorbance.
  • N. Nakayama, A. Satoh, K. Fujiwara, A. Nakatsuka, Y. Ueda
    2009 年 34 巻 3 号 p. 439-442
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    Over-stoichiometric BaRCo4O7+δ phases have been investigated by powder XRD, TG-DTA, and high resolution TEM. Three ordered structures of excess oxygen atoms were confirmed. In the case of Lu compound with the oxygen composition of δ = 0.80, an orthorhombic superlattice with the triple periods, 3ao, based on the fundamental orthorhombic structure of stoichiometeric phase. In the case of Y compound with the oxygen composition of δ = 0.96 equilibrated in the 1 atm O2 at 364℃, we observed the 2ao superlattice, which agrees with the results of recent neutron diffraction study. For the Y compound slowly cooded down to room temperature, a superlattice with a = 5ao was observed although the superlattice period is heavily disordered.
  • Akihiko Nakatsuka, Ken Uyama, Keiko Fujiwara, Noriaki Nakayama, Tadato ...
    2009 年 34 巻 3 号 p. 443-446
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    Structure analysis of a natural chabazite was conducted at 123 K using single crystal X-ray diffraction. We have observed that in one of water sites, the electron density distribution, which seemingly has one peak at room temperature, is clearly separated into the two peaks at 123 K because of the reduction of atomic thermal vibrations. Thus, we have revealed that this water site is located at the different Wyckoff position from the previously assigned position. The refined occupancies show that the crystal was partially dehydrated by a continuous flow of dry cold N2 gas introduced in the intensity measurements at low temperature. This partial dehydration provides important knowledge of the site preference for dehydration and the cation migration with dehydration, from comparison with the occupancies at room temperature with full hydration.
  • K. Fujiwara, K. Akedo, Y. Tasaki, A. Nakatsuka, N. Nakayama
    2009 年 34 巻 3 号 p. 447-450
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    The birnessite-type K0.28MnO2 hydrates with the average crystalline size of about 10-20 nm have been prepared by a sol-gel method using KMnO4 and glucose aqueous solutions. Their crystal structure and thermal stability have been investigated by XRD, TG-DTA, and TEM-EDX. The dehydration reaction occurs at around 180℃. The samples heated in between 600 and 800℃ transform into a cryptomelane-type phase with 2×2 tunnel type structure. Not so much change in the crystalline size due to the above phase transformation was observed. The heating at above 900℃ causes the decomposition reaction into the tetragonal spinel-phase Mn3O4 and the layered K-rich birnessite, K0.31MnO2, accompanied with the release of oxygen and the 4 times increase in the crystalline size.
  • Kazuo Kasatani, Hinako Hanabusa, Hiroaki Okamoto, Yuki Morita
    2009 年 34 巻 3 号 p. 451-454
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    We have measured resonant third-order optical nonlinearities of organic nanoparticles. Five kinds of near-infrared dyes, silicon 2,3-naphthalocyanine bis(trihexysiloxide) (dye 1), methylsilicon (IV) phthalocyanine chloride (dye 2), 2,3-naphthalocyanine (dye 3), 2,4-di-3-guaiazulenyl-1,3-dihydroxycyclobutendiyliumdihydroxide, bis(inner salt) (dye 4), and 1,3-bis-[(3,3-dimethylindolin-2-ylidene)-methyl] croconium (dye 5) were used to prepare organic nanoparticles. The values of the electronic component of the molecular hyperpolarizability, γe, were determined to be ca. 1.9 × 10-29 esu, ca. 1.9 × 10-30 esu, ca. 3.4 × 10-31 esu, ca. 2.1 × 10-30 esu, and ca. 3.0 × 10-30 esu, for dyes 1, 2, 3, 4, and 5, respectively.
  • Yuki Morita, Ryota Ono, Hiroaki Okamoto, Kazuo Kasatani
    2009 年 34 巻 3 号 p. 455-458
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    This paper describes synthesis and physico-chemical properties of 2-oxo-2H-chromen-6-yl 6-alkoxybenzoates (compounds 1-n) and 6-thioalkylbenzoates (compounds 2-n). Compounds 1-n exhibit a monotropic nematic phase for earlier member or a monotropic smectic A phase for later ones, while compounds 2-n are non-mesogenic even in a rapid cooling process. The virtual transition temperature from isotropic phase to smectic A phase for compounds 2-10 was estimated to be 70℃ by means of a binary phase diagram. It was found that both compounds 1-n and 2-n form gel in organic solvents, such as propylene carbonate, acetonitrile. However, there are differences between the gelation ability of compounds 1-n and that of 2-n.
  • Shunsuke Ouchi, Tetsu Mitsumata
    2009 年 34 巻 3 号 p. 459-460
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    The relationship between the diameter or the number density of magnetic-particle columns and the magnetorheological effect has been investigated using carrageenan gels containing iron oxide particles. The diameter and the number density of the columns were changed by magnetic fields applied while gelation. The column diameter increased with the magnetic field, and the number density of columns decreased with the field. The Young's modulus of the gels synthesized at higher magnetic fields than 0.5 T was approximately 2 MPa, which was higher than the gel at 0.05 T. In addition, the change in Young’s modulus for the gel synthesized at 0.5 T was 0.19 MPa upon magnetization, which is 8 times larger than that at 0.05 T. The results revealed that the gels with thick columns demonstrate high Young's modulus and remarkable magnetorheological effect.
  • K. Hara, Y. Sueyoshi, M. Sugiyama, T. Tanigawa, S. Yoshioka
    2009 年 34 巻 3 号 p. 461-464
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    After brief reviews on the high sensitivity to water content and multivalent-ion adsorption of a peak in the homogeneous NIPA/SA gels' the small angle X-ray scattering (SAXS) profiles, the influence of the crosslinker concentration, which gives rise to the heterogeneity in the NIPA/SA gel, on the SAXS peak has been reported. It has been found that there is a considerable change in the location and intensity of the SAXS peak around a certain crosslinker concentration where the gels become opaque.
  • Daisuke Suzuki, Ryo Yoshida
    2009 年 34 巻 3 号 p. 465-467
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    Different from simple stimuli-sensitive microgels, herein, we report “self-oscillating” microgel. This microgel shows an autonomic and periodical swelling/deswelling oscillation that is synchronized with redox oscillation of the Belousov-Zhabotinsky (BZ) reaction. The cross-linked microgels were synthesized by the copolymerization of N-isopropylacrylamide (NIPAm) with ruthenium tris(2,2′-bipyridine) [Ru(bpy)3] as a catalyst for the BZ reaction by surfactant-free aqueous precipitation polymerization. The self-oscillation of the microgels was detected by changes in optical transmittance. The microgels showed not only the swelling/deswelling oscillation, which is synchronized with the redox oscillation of the Ru(bpy)3 complex immobilized in the microgels, but also flocculating/dispersing oscillation around the phase transition temperature of the microgels, with a remarkable change in optical transmittance.
  • T. Makabe, S. Komiya, P. Prawitwong, R. Takahashi, M. Takigami, N. Nag ...
    2009 年 34 巻 3 号 p. 469-472
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    Konjac glucomannan (KM) is a water soluble glucomannan with high molar mass. KM aqueous solution shows extremely high viscosity. KM can be depolymerized by γ-rays irradiation. The molar mass of original KM was 1020 kDa. The molar mass of irradiated KM decreased significantly with increase of absorbed dose up to 2 kGy and then decreased gradually. The molar mass of 10 kGy irradiated KM was 236 kDa. The radius of gyration (RG) of original KM was 98.0 nm. The RG value decreased significantly with increase of the dose up to 2 kGy and then reached to 46.4 nm at 10 kGy of absorbed dose. KM molecules were solvated in the form of random coils in water. The flexibility of molecular chain increased with increasing temperature. SPM image of original KM molecular chain showed rod-like pattern. The chain length and thickness of original KM was 1150 nm and 1.04 nm, respectively. The chain length decreased significantly with decrease of molar mass. However, the chain height scarcely changed regardless of molar mass. The chain lengths of low molar mass KM with 507 kDa and 236 kDa were 440 nm and 250 nm, respectively.
  • S. Takigami, P. Prawitwong, G. O. Phillips
    2009 年 34 巻 3 号 p. 473-476
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    Phase transition behavior of sorbed water in Konjac glucomannan (KM)-water systems with various molar mass was investigated using differential scanning calorimetry (DSC). The measurements were performed repeatedly for 3 cycles. In KM-water systems, non-freezing water (Wnf), four types of freezing bound water (Wfb) and free water (Wf) were identified. The Wfb appeared at increasing water content (Wc) in the order; Wfb1, Wfb2, Wfb2* and Wfb3. The proportion of each type of Wfb changed with increasing Wc. Wfb1, Wfb2, and Wfb2* transferred to Wf in high Wc region, but Wfb3 still kept interaction with KM chains. The same types of sorbed water existed in KM with lower molar mass. The amount of Wnf decreased with decreasing molar mass at high Wc, in particular for KM with molar mass less than 2.0×105 Da. The Wfb in KM matrix with high molar mass is strongly influenced by surrounding KM chains, that is to say the water binding ability decreases with decreasing molar mass.
  • R. Ojima, T. Makabe, P. Prawitwong, R. Takahashi, M. Takigami, S. Taki ...
    2009 年 34 巻 3 号 p. 477-480
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    Konjac glucomannan (KM) is a water soluble glucomannan with high molar mass. KM aqueous solution shows extremely high viscosity. KM can be depolymerized by chemical hydrolysis. The molar mass of hydrolyzed KM decreased with increase of acid concentration and hydrolysis time. The acid hydrolysis led chain scission of KM, but introduced no significant new chemical groups into the structure. KM molecular chain was hydrolyzed randomly by acid hydrolysis. The viscosity of KM aqueous solutions decreased with decreasing molar mass. KM solution changed to Newtonian fluid with decreasing molar mass at low concentration. KM with molar mass less than 320 kDa was Newtonian fluid in semi-dilute region. KM aqueous solution showed two kinds of critical overlap concentration of C* and C**. C* is onset of shrinkage of the polymer coils and C** is the critical concentration to attain their limiting size. The overlapping and entanglement of KM chains with high molar mass occurred at lower concentration as compared to those of KM with low molar mass.
  • E. Ogawa, K. Yamazaki, K. Sugimoto, R. Takahashi, K. Kubota, H. Yajima ...
    2009 年 34 巻 3 号 p. 481-484
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    Using three kinds of well-purified sodium type gellan gums (Na-gellan, Mw= 12.7x103, 9.7x103, 7.1x103), we studied the effects of molar mass on the sol to gel transition and the coil to double-helix transition in aqueous solutions with and without NaCl, KCl, and CaCl2 by rheological measurements. In aqueous solutions with and without salts, the temperature dependence of storage modulus (G′) and loss modulus (G") for the three sample solutions of various polymer concentrations (cp=0.5-5.0%) was measured from 60 to 5 ℃. In aqueous solutions without salts (cp=0.5-5.0%), the coil to double-helix transition temperature (Tch) for the three Na-gellans were the same, however, the sol to gel transition temperature (Tsg) depended markedly on molar mass; Tsg of Na-gellan samples decreased with decreasing molar mass. In aqueous solutions with salts (cp=1.0 %), Tsg and Tch overlapped, indicating that the sol to gel transition and the coil to double-helix transition for Na-gellans (GF1-GF3) occurred concurrently. It was found that, in salt solutions, Tch and Tsg were almost independent of molar mass.
  • Atsushi Nakamura, Ken-ichi Hirakawa, Kazuhiro Hara, Nobuyasu Hiramatsu
    2009 年 34 巻 3 号 p. 485-488
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    We have already reported that the transition behavior of NIPA (700mM) gel is complicated in low water contents (wc) ranging from 0.01 to 1.7. The thermogram shows a glass transition, an endothermic peak around 34℃ and peaks related to the melting and recrystallization of water. In the present study, the sol-gel transition behavior of egg-white in low water contents (wc= 0.1-1.8) was studied by differential scanning calorimetry. Moreover, the thermal behavior of the gels were intensively studied. In a sol-gel transition process, three endothermic peaks were observed. The peak temperatures are increased as the water content wc is reduced (wc< 1). The thermal behavior of egg-white gel showed complicated behavior similar to the NIPA gel. Amount of free water (which is frozen at 0 ℃) in the gel is estimated from the thermogram.
  • K. Hara, N. Kawamura, D. Yamada, S. Yoshioka, T. Nishida
    2009 年 34 巻 3 号 p. 489-492
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    The successive Ni(II) adsorption and adsorbed-Ni(II) desorption experiments have been performed in order to clarify the repetitive heavy-metal-cation recovering functionality of p-Styrenesulfonicacidsodiumsalt/Acrylamide (p-SSAS/AAm) and Sodium acrylate/Acrylamide (SA/AAm) gels, and also to examine the effect of the terminal group in the side chain. It has been revealed that the SA/AAm gels show high recovering functionality usable in the actual applications while that the p-SSAS/AAm gels can be used in limited conditions.
  • N. Kawamura, D. Yamada, T. Nishida, S. Yoshioka, K. Hara
    2009 年 34 巻 3 号 p. 493-496
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    pH-dependences of Ni(II)-adsorbing and -desorbing properties of p-styrenesulfonicacidsodiumsalt/acrylamide (p-SSAS/AAm) and sodium acrylate/acrylamide (SA/AAm) gels have been investigated. Though the p-SSAS/AAm gel can capture more amount of Ni(II) even at a low pH region, its desorption ratio is below ~92 wt% even in 3 M of HC concentration. On the other hand, though Ni(II)-capturing efficiencies of the SA/AAm gel is lower; its Ni(II)-desorption ratio is ~100 wt% in all the measured HC concentrations.
  • K. Hara, N. Kawamura, K. Nagamatsu, D. Hisajima, M. Yoshigai, S. Yoshi ...
    2009 年 34 巻 3 号 p. 497-500
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    The authors have investigated heavy-metal-anion (hexavalent chromium, Cr(VI)) adsorption and desorption properties of N,N-dimethylaminoethylacrylamide/acrylamide (DMAEAAm/ AAm) gels successively. Though the DMAEAAm/AAm gels show relatively low Cr(VI)-capturing efficiencies, the hydrogels have a possibility of actual use as a heavy-metal-anion recovering material because the DMAEAAm/AAm gels with some compositions show high desorption efficiency of the captured-Cr(VI), which is advantageous to a heavy-metal-anion recycling system with repetitive use of the hydrogel.
  • K. Hara, N. Kawamura, K. Nagamatsu, D. Hisajima, M. Yoshigai, S. Yoshi ...
    2009 年 34 巻 3 号 p. 501-504
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    In the present study, in order to examine the N,N-dimethylaminopropylacrylamide/acrylamide {DMAPAA/AAm} hydrogels' capabilities of repetitive heavy-metal-anion recovery from waste fluid, the authors performed successive Cr(VI) adsorption and the adsorbed-Cr(VI) desorption experiments. It has been proved that the DMAPAA/AAm gels show both of the high Cr(VI)-capturing functionality and Cr(VI)-desorption efficiencies. The results in the present study have demonstrated a possibility of a heavy-metal-anion recycling system in which the hydrogels are reused a number of times.
  • T. Nagata, Y. Kikuzawa, T. Nagasawa, Suleyman I. Allakhverdiev
    2009 年 34 巻 3 号 p. 505-508
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    Synthesis and photochemistry of new “ternary” quinone-pool molecules containing TEMPO (2,2,6,6-tetramethylpiperidinyloxy), porphyrin, and quinones are described, as a new model for plant photosynthesis. The quinones were successfully reduced by irradiation in the presence of 4-t-butylthiophenol.
  • J. Matsumoto, Y. Kajita, Y. Wasada-Tsutsui, Y. Funahashi, T. Ozawa, H. ...
    2009 年 34 巻 3 号 p. 509-512
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    Previously, the reactions of three μ-η22-disulfidodicopper(II) complexes with N-alkylated cis,cis-1,3,5-triaminocyclohexane derivatives, [Cu2(S2)(R3TACH)]X2 [(R, X) = (Et, CF3SO3) (1), (iBu, SbF6) (2), and (Bn, SbF6) (3)], with PPh3 and BnBr were reported. In order to clarify the relationship between the structures and reactivities, DFT calculations of the two complexes with bent and planar Cu2S2 structures have been performed, and the bond orders around the metals and atomic charges on Cu and S atoms have been estimated. The electron density is localized on Cu and S atoms when the dihedral angle (δ) is decreased; 1.137 and -0.470 for the bent type structure (δ = 156.67 °) and 1.107 and -0.450 for the planar one (δ = 175.56 °), respectively. The reactivity of disulfidodicopper(II) complexes against PPh3 has been explained to depend upon the electrophilicity of Cu atoms and the nucleophilicity of S atoms, which are raised up by bending of two CuS2 planes. These findings show that the disulfides of 1, 2, and 3 are electrophilic against exogenous substrates.
  • Daisuke Nakane, Yasuhiro Funahashi, Tomohiro Ozawa, Hideki Masuda
    2009 年 34 巻 3 号 p. 513-516
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    An N3S2-type Ni(II) complex (8) has been synthesized as a model compound of NiSOD active site, which is coordinated with an amide, an amine, and a pyridyl nitrogens and a thioether sulfur atom in the equatorial positions and with the remaining sulfur weakly bound at the axial position. The UV-vis spectroscopic and electrochemical characterizations of complex 8 showed that the square pyramidal structure was kept in the solution in both the Ni(II) and Ni(III) states. In Ni(III) state, EPR spectrum exhibited a rhombic signal pattern without any hyperfine splittings, indicating no structural change depending on oxidation states. If a protonation to the coordinated thiolate in Cys2 or Cys6 of NiSOD is caused during the oxidative disproportionation process, the thiolate may be kicked up to the axial position because the donor ability of the sulfur has been weakened.
  • Masafumi Inoue, Kazuki Tainaka, Akiyoshi Hirata, Takashi Konno, Takash ...
    2009 年 34 巻 3 号 p. 517-520
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    Post-translational phosphorylation of the microtubule-associated protein tau is believed to have close relevance to the pathogenesis of Alzheimer's disease. The growth of amyloid fibrils of the short peptide segment VQIVY310K (PHF6) corresponding to the core part of tau fibril formation is strongly affected by the phospholylation at Tyr310 via its electrostatic pairing with the neighboring charged lysine. Herein, we studied the propensity of resultant fibrils from PHF6 derivative peptides with charged aromatic amino acid residue at Tyr310. The results showed that the phosphorylation at Tyr310 contributed to significant enhancement of the amyloidogenicity and the stability of fibrillar aggregates. The physical origin of remarkable stabilization of fibrils by tyrosine phosphorylation is plausibly attributed to the charge pairing with the adjacent lysine residue in a similar fashion to the phosphorylation effect on the growth of amyloid fibril.
  • Z. Zhang, H. Kanamori, T. Ozawa, K. Jitsukawa, H. Masuda, L. Zhang
    2009 年 34 巻 3 号 p. 521-524
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    A new Ni(II) complex with 8-(2-pylidylmethyl)-1,4-dithia-8,11-diazacyclotetradecane ligand (P[14]aneN2S2), [NiP[14]aneN2S2(H2O)](ClO4)2 (1), was prepared as a structural model of [FeNi] hydrogenase active site. The X-ray crystal structure analysis of the complex, in which the coordinated water molecule was replaced by Br-, revealed an octahedral geometry coordinated with P[14]aneN2S2 and Br-. The cyclic voltammograms of complex 1 gave only a reversible wave of Ni2+/+ couple at E1/2 = -920 mV vs. SCE in MeOH and two reversible waves of Ni2+/+ and Ni3+/2+couples at E1/2 = -970 and 1350 mV vs. SCE in MeCN, respectively, indicating that complex 1 can take a wide range of oxidation states of nickel ion. The reduction of complex 1 with NaBH4 in MeOH at -20 ℃ gave the Ni(I) complex with a hydride ion at the axial position, which was demonstrated by ESR spectroscopy.
  • Masatora Fukuda, Hironori Hayashi, Tetsuya Hasegawa, Takashi Morii
    2009 年 34 巻 3 号 p. 525-527
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    Biologically active amines play major roles in the regulation of movement and are implicated in the pathophysiology of Parkinson’s and Huntington’s diseases, psychosis, and drug addiction. Fluorescent biosensors based on the biological macromolecule receptor are useful tool for investigating the function of biologically active amines. Our strategy of the stepwise molding using a ribonucleopeptide (RNP) framework provides fluorescent biosensors with a variety of binding and optical characteristics for small molecules. Here we report fluorescent RNP sensors for histamine with a variety of binding and signal-transducing characteristics. Combination of RNA subunits of histamine-binding RNP receptors obtained by in vitro selection and a Rev peptide modified with 7-methoxycoumarin-3-carboxylic acid afforded a fluorescent RNP sensor with distinct signaling characteristics in the changes of fluorescence emission intensity upon binding to histamine. The fluorescent histamine sensor showed distinct selectivity for histamine over structurally related histamine analogs, such as imidazole, ethylamine and L-histidine.
  • Zizheng Zhang, Takuma Yano, Tomonori Shibayama, Tatsuya Suwabe, Tomohi ...
    2009 年 34 巻 3 号 p. 529-532
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    Synthesis and preparation of a square pyramidal Fe(III) complex with an N2S2-type ligand which can provide a strong σ donor sets of 4-. The strong ligand field makes the Lewis acidity of the metal center decrease. The Fe(III) complex showed a intermediate spin state and reduced to Fe(II) species at -0.77 V vs. NHE. The complex also easily reacted with NO molecule under Ar atmosphere to form a nitrosyl complex, which is confirmed with an appearance of N-O stretching mode at 1809 cm-1. The reaction exhibited a clear spectral change: An absorption band at 525 nm shifted to 660 nm, which is responsible for a color change from reddish-orange to pale green. Furthermore, the same color change was also observed in a solid state.
  • Masahiko Nagaki, Kazuhiko Miyata, Jun Kawakami, Ryo Miyamoto, Yuji Mak ...
    2009 年 34 巻 3 号 p. 533-536
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    6,7-Epoxygeranyl diphosphate was examined for reactivity as an allylic substrate of wild and mutated farnesyl diphosphate (FPP) synthases of Bacillus stearothermophilus. 6,7-Epoxygeranyl diphosphate was accepted by wild and mutated (Y81R, Y81D, and Y81S) farnesyl diphosphate synthases as a substrate in reaction with isopentenyl diphosphate, yielding 10,11-epoxyfarnesyl and 14,15-epoxygeranylgeranyl diphosphates, respectively.
  • T. Kato, T. Shirai, H. Watanabe, M. Fuji, M. Takahashi
    2009 年 34 巻 3 号 p. 537-539
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
      Alumina and nano carbon network (NCN) composites material for electrical conductive use are fabricated by a combination of gelcasting method and sintering under argon atmosphere. This paper describes a characterization of the NCN composites. On the surface and boundary of alumina particles, the NCN was homogeneously observed by SEM. High graphitization and a few defects on the graphite structure could be confirmed on the carbon structure analysis by Raman spectroscopy. The electrical conductivity shows the semiconductor like behavior depending on the defects in the carbon. Effect of the graphite structure on electrical conductivity was shown.
  • K. Ohki, H. Matsuda, Y. Nakagawa, H. Yamasaki, I. Honma
    2009 年 34 巻 3 号 p. 541-543
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    Thin film solid oxide fuel cells are expected to lower operating temperature. Silicon substrate is well suited to fabricate a window structure, which is necessary for depositing electrodes on both side of an electrolyte film. However, cracks occur because of a thermal expansion coefficient mismatch between silicon and the electrolyte material. In order to suppress the cracks, lowering of growth temperature is desirable. In this paper, we focus on the crystallinity and ionic conductivity of 8-mole% yttria-stabilized zirconia (8YSZ) thin films deposited at low temperature.
  • 1. Agglomerate Problem of Titanate Nanotubes for Thin-Film Processing
    Yoshikazu Suzuki, Benoît P. Pichon, Mathieu Grandcolas, Nicolas Keller ...
    2009 年 34 巻 3 号 p. 545-549
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    Titanate nanotubes prepared by a hydrothermal process in an alkali solution are promising for environmental and energy applications. A serious (but not-widely-recognized) problem of titanate nanotubes for potential device applications is their strong agglomeration (or even aggregation), which disturb thin-film processing in nanometer order thickness. The objective of this study is to demonstrate how the agglomerates/aggregates behave in an actual wet thin-film process, i.e., spray Layer-by-Layer (spray LbL) coating process. Under acidic (pH=2) and stirred conditions, apparently-dispersed titanate nanotube suspension actually contained plenty of micrometer-sized agglomerates/aggregates. The formation of the large agglomerates/aggregates disturbs the spray LbL process, suggesting an alternative dispersion method is necessary for wet processes of titanate nanotubes.
  • Fumiaki Mitsugi, Yoshihiro Umeda, Tomoaki Ikegami
    2009 年 34 巻 3 号 p. 551-554
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    Recently, it has been required to develop large-area deposition techniques for transparent conductive doped ZnO thin films. In this paper, we report position dependencies of film thickness, carrier concentration, carrier mobility, resistivity and transmittance of a Ga doped ZnO thin film deposited on a 10 x 10 cm2 silica glass substrate which was set at a distance of 28 cm from the target by Pulsed Laser Deposition method. In addition, mass spectrometry of the ablated species was measured at the substrate position using a quadrupole mass spectrometry system.
  • Taro Shimonosono, Yoshio Sakka, Yoshihiro Hirata
    2009 年 34 巻 3 号 p. 555-559
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    Ce0.8Gd0.2O1.9 (Gd-doped ceria, GDC) powder synthesized by glycine-nitrate combustion process was densified to 96 % of theoretical density at 900 ℃ for 5 min using spark plasma sintering (SPS) process. The grain size of the GDC sintered using the SPS process was about 20 nm. The electrical conductivity of GDC sintered using SPS process was obtained from the AC impedance measured at a frequency range of 42 Hz to 5 MHz, and was compared with that of GDC sintered at 1200 ℃ for 4 h in air using normal sintering process with a grain size of 150 nm. The electrical conductivity of GDC sintered using SPS process was one order of magnitude lower than that of GDC sintered using normal sintering process. The contributions of the bulk and the grain boundary to the total electrical conductivity were distinguished by analyzing the AC impedance of the GDC sample. The conductivity of the bulk slightly decreased with decreasing the grain size, while the conductivity of grain boundary increased with decreasing the grain size.
  • R. Inada, Y. Mitsuno, S. Baba, Y. Nakamura, A. Oota, C.S. Li, P.X. Zha ...
    2009 年 34 巻 3 号 p. 561-564
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    We fabricated twisted Bi2223 tapes with interfilamentary oxide barriers and evaluated their AC loss properties in an AC perpendicular magnetic field. The conventional powder-in-tube method was used for tape fabrication. In order to avoid the side effect on Bi2223 phase formation, SrZrO3 was selected for barrier materials. In addition, 20wt% Bi2212 was mixed with SrZrO3 to improve its ductility for cold working. Monocore Ag-sheathed rods were dip-coated by the oxide barriers with slurry before stacking with multifilamentary structures. By applying both the tight twisting with twist pitch length below 10 mm and introducing SrZrO3 + Bi2212 barriers, the coupling frequency in a perpendicular field was increased above 100 Hz and perpendicular field losses were reduced from the analytical prediction for fully coupled filaments around power-grid frequency range.
  • Agus Sukarto Wismogroho, Nurul Taufiqu Rochman, Soichiro Sameshima, Ko ...
    2009 年 34 巻 3 号 p. 565-569
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
      A new type of iron aluminide coating on a steel substrate by mechanical alloying (MA) with Al-Fe powders was examined. Precoating was carried out by a high-energy planetary MA with Al-Fe powder at room temperature, followed by low-energy MA at an elevated temperature. In MA at 500 ℃, the precoating layer becomes soft and the interdiffusion between Al and Fe is enhanced, resulting in the formation of a homogenous iron aluminide coating layer on a steel substrate. By MA at 500 ℃ for 4 h, a Fe2Al5 coating layer is formed for Al-25 at%Fe powder, and a FeAl coating layer with a small amount of Fe2Al5 is formed for Al-50 at%Fe powder. The Fe-Al solid solution is achieved near the steel substrate/coating layer interface in a substrate, resulting in good bonding between the substrate and the coating layer. The Al-50 at%Fe coating layer has a hardness of 7.8 GPa and high fracture toughness.
  • D B Gadkari, B M Arora
    2009 年 34 巻 3 号 p. 571-574
    発行日: 2009/09/01
    公開日: 2014/05/13
    ジャーナル フリー
      A vertical directional solidification (VDS) technique is used to grow GaSb bulk single crystals without seed and without contact to ampoule wall. We have designed and fabricated furnace with special axial and radial temperature gradients with optimized growth parameters. The goal is to develop gap for growing crystal, therefore a tiny melt is lowered down from hot zone for constricted solidification.
      As grown GaSb crystals have been characterized for the macro and micro growth features of ingots. Physical and electrophysical properties of GaSb studied to know the enhancement in crystallography and crystal quality. The detached growth is possible due to the appropriate gap developed in between the solidifying melt and the wall of the ampoule. For typical detached ingots, growth reveal high quality bulk single crystals with mobility p-GaSb = 1060 cm2/Vsec at 300K. In VDS, detached solidification is possible, it is reproducible and reliable.
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