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Osamu Yamamoto, Jun Sawai, Kyoko Nakakoshi, Hiroyuki Nakagawa, Kouichi ...
2000 Volume 2000 Issue 191 Pages
2-7
Published: February 25, 2000
Released on J-STAGE: July 05, 2011
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Ion-exchange resins with particle size of 0.5mm were treated for 24h by an aqueous solution containing [Zn (NH
3)
4]
2+ and then they were carbonized for 10 min in N
2 at 500, 700 and 900°C. The antibacterial activity of sphericalcarbon samples containing ZnO obtained was studied by measuring the change in the electrical conductivity withbacterial growth. From the results, it was clarified that the antibacterial activity increased with increasing amount ofthe carbon samples in an incubation cell. The antibacterial activity against
Staphylococcus aureus on carbon sampleswas found to be stronger than that against
Escherichia coli. However, no activity for spherical carbon samples without ZnO was observed. In the results of bacteriostatic and bactericidal tests, the bactericidal effect was confirmed in the samplescarbonized at lower temperature: the effect increased with decreasing the carbonizing temperature. The appearance ofantibacterial activity was presumed to be due to the generation of H
2O
2 from zinc oxide in carbon samples.
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Shinji Misono, Yasushi Takeuchi
2000 Volume 2000 Issue 191 Pages
8-14
Published: February 25, 2000
Released on J-STAGE: June 28, 2010
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The intra-aggregate void size distribution (VSD) and void volume, and fractal dimension D of rubber gradecarbon black dispersed in undecane were measured by thermoporometry. The value of Rmax corresponding to themaximum value of the VSD curve was confirmed to be proportional to the DBP (dibutyl phthalate) volume and thesize Rn of the primary particles constituting the aggregates. The VSD curves obtained with undecane shifted towardsmaller void sizes than those obtained with water. This fact indicates a larger interpenetration of the carbon blackaggregates resulting from the stronger interaction of the oleophilic carbon black surface with undecane than withwater. The intra-aggregate void volume measured by thermoporometry was compared with the occluded volumecalculated by Medalia. It appears that experimental values agree well with calculated but the occluded volume calculatedis overestimated.
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Yutaka Kaburagi, Tomokazu Onodera, Yoshihiro Hishiyama
2000 Volume 2000 Issue 191 Pages
15-19
Published: February 25, 2000
Released on J-STAGE: July 05, 2011
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Graphite films prepared from aromatic polyimides and a3000°C-treated grafoil were mixed with iron and heat-treated up to 2700°C and/or above. Effects of iron on the transverse magnetoresistance Δρ/ρ
0, Hall coefficient
RH and residual resistivity ratio
RRR of these iron-doped graphite materials have been investigated.
RH data imply that only a small amount of iron can substitute into the graphite lattice irrespective of the crystal perfection, and act as acceptors and impure. The heat treatment of graphite materials mixed with iron induces a decrease of Δρ/ρ
0 and
RRR for the original specimens with
RRR>4, but an increase for those with
RRR<4. These results indicate that the improvement of crystallinity of graphite materials through a catalytic action of iron becomes predominant for the specimens with
RRR<4.
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Hiroshi Shioyama
2000 Volume 2000 Issue 191 Pages
20-23
Published: February 25, 2000
Released on J-STAGE: June 28, 2010
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KC
24 was allowed to react with the unsaturated hydrocarbon-organic solvent mixtures. Isoprene molecules were introduced into the interlayer of KC
24 and polymerized, whereupon organic solvents such as cyclohexane,
n-hexane or 2, 5-dimethyltetrahydrofuran was incorporated into the polyisoprene. On the other hand, the polymerization of styrene in the interlayer spacing of graphite was carried out without the incorporation of
n-hexane or 2, 5-dimethyltetrahydrofuran. This is explained on the basis of the low affinity of aromatic styrene for aliphatic solvents. The polymerization of styrene was not observed in the presence of cyclohexane, which is attributed to a low reactivity of styrene to polymerize in the interlayer spacing of graphite.
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Hideo Yamada, Osamu Tsuji
2000 Volume 2000 Issue 191 Pages
24-31
Published: February 25, 2000
Released on J-STAGE: June 28, 2010
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Amorphous carbon thin films containing nitrogen were deposited by the radio frequency (13.56MHz) selfbias method, using acetonitrile as a starting material. The effects of the deposition conditions and the behavior of nitrogen atoms during the film depositions were investigated in detail with controlling the deposition temperature by the plasma pulsed deposition technique. The results show that the nitrogen doped high quality films are prepared under only the deposition conditions for higher r.f. powers and higher deposition temperatures, compared to undoped hard amorphous carbon thin films. Furthermore, the incorporation of nitrogen reduces the internal film stress without significant modification of the film hardness. X-ray photoelectron spectroscopy indicates that nitrogen concentrations in the carbon films decrease with increasing deposition temperatures and r.f. powers. Infrared absorption and Raman spectroscopy suggest that nitrogen atoms are incorporated into the nitrile groups and into the graphite-like carbon clusters and/or into the random network structures as the C =N bonds.
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Kazuro Kawamura, Mitsuyoshi Amari, Atsushi Aruga, Shinichiro Ozawa
2000 Volume 2000 Issue 191 Pages
32-36
Published: February 25, 2000
Released on J-STAGE: June 28, 2010
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The relationship, σ=aρ
n was recognized between bending strength (σ) and bulk density (ρ) of the heat-treated charcoals at various heat treatment temperatures (HTT) below 2500°C, and the exponent (n) was almost constant (n=1.3). Usually, the bending strength of carbon materials decreases by the proceeding of graphitization with temperature heat treatment. On the other hand, the bending strength of the bincho-tan manufactured by carbonization of oak (ubamegashi) ncreased with increasing HTT. The specific surface area of the powdered samples decreased with increasing HTT and converged to a value near 80m
2/g at HTT 2500°C regardress of the different texture of charcoals. The small angle X-ray scattering (SAXS) data of the heat-treated charcoals showed that the micropores of R=10-50 nm (R Guinier radius) almost disappeared with high temperature treatment.
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Miwako Ito, Kensuke Sassa, Hiroyasu Ogawa, Masao Doyama, Shigehiko Yam ...
2000 Volume 2000 Issue 191 Pages
37-41
Published: February 25, 2000
Released on J-STAGE: June 28, 2010
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A high static magnetic field was imposed on PAN-based carbon fibers in the graphitization process. Oxidized fibers were graphitized in the magnetic field of 12 T and at the temperature of 2, 273 K. Samples were made under the magnetic fields perpendicular to fiber axis and parallel to it. The latter treatment has improved the tensile strength more than the former does. In the both samples the increase of the tensile strength more than 30% has been achieved by imposing the magnetic field. The reason of improvement of the tensile strength is discussed from the view points of magnetic energies difference due to the magnetic anisotropy of a six carbocyclic ring and of flaws on a fiber.
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Osamu Yamamoto, Kyoko Nakakoshi, Jun Sawai, Tadashi Sasamoto
2000 Volume 2000 Issue 191 Pages
42-44
Published: February 25, 2000
Released on J-STAGE: June 28, 2010
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Spherical carbon powders were prepared by carbonizing ion-exchange resin at the temperature ranging from 500 to 900°C. The adsorption of bacteria by the samples obtained was studied. The specific surface area of samples was a range from 25 to 50 m
2g
-1 and increased slightly with increasing the carbonizing temperature. By the measurements of the adsorbed amount of bacteria, it was found that the adsorbed amount on the surface of samples increased withthe increase of carbonizing temperature. The adsorbed amount of
Staphylococcus aureus was smaller han that of
Escherichia coli.
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Yasuhiro Tanabe, Daiji Tahara, Takashi Akatsu, Mototsugu Sakai, Eiichi ...
2000 Volume 2000 Issue 191 Pages
45-48
Published: February 25, 2000
Released on J-STAGE: June 28, 2010
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Vickers indentation is applied to oxidized graphite materials for evaluating theiroxidizing behavior. An elastic-plastic analysis applicable to metals and ceramics cannot be applied to graphite materials. We propose a parameter, normalized dissipation energy, i.e., dissipation strength, which is defined as follows: the area encompassed by loading and unloading curves in the indentation process is divided by the maximum indented volume. The local oxidation behavior of graphite materials was successfully analyzed by this parameter.
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it's Biological Significance
Shozo Koyama
2000 Volume 2000 Issue 191 Pages
49-61
Published: February 25, 2000
Released on J-STAGE: June 28, 2010
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This review indicates a possible biological concept for an application of carbon-based materials based on a recent established physiological knowledge. A key point of this review is to open a new avenue to povide a new material into our life by integtating a poject-oriented task work together with several different kinds of scientific fields. In order to disclose the above concept, severalexperimental evidences have been demonstrated. Firstly, immunological reactions of activated carbon fibers (ACFs) have been detected by measuring CD4 and CD8 cells in mice that have been implanted ACFs subcutaneously for 6 months. Histological examinations have been done. An important parameter of surface area and/or pore-size has been demonstrated. Second, ability of IgE-induced histamine release from rat mast cells was also investigated
in vitro to confirm whether ACFs has a potency of inducers of acute allergic reactions. Thirdly, fundtions of cells growing and/proliferation were influenced under coexisting enviroment with ACFs
in vitro. It was found by using newly planned and sythesized materials (our ID: HDI) that an optimal survival parameter of a cell survival was dependent on the pore-size of materials. In addiction, bioimplantable materials have been reviewed and application fields of carbon-based materials have been discussed. As an overall, this review has shown that scientific field of this carbonalloy (carbon-based materials) has a great potency to lead into a new scientific frontier toward many biomedical applications.
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Jacques Conard, Pierre Lauginie
2000 Volume 2000 Issue 191 Pages
62-70
Published: February 25, 2000
Released on J-STAGE: June 28, 2010
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We present in this paper the main results of
7Li NMR on lithium intercalated in graphite, disordered pregraphitic cokes and other allotropic forms of hexagonal C-lattices like C
60 and nanotubes. First we present the main parameters accessible by this technique when this new C-Li bonding is obtained, giving to the solid, the character of an alloy. The main observed shift has nothing to do with chemical shift but is a paramagnetic one produced by the presence of free e-wave on the lithium atom. A comparison is made of graphite intercalated by various methods either chemical or electrochemical or under high pressure. The dynamics of Li atoms inside the alloy is described. A chapter is devoted to the theoretical description of this new Li-C bonding from literature and various calculation derived from experiments. Then the new results obtained in porous carbons, favourable to anode production, helps us to describe the new used storage sites. Then preliminary results on fullerenes and nanotubes are given.
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Keiko Nishikawa
2000 Volume 2000 Issue 191 Pages
71-76
Published: February 25, 2000
Released on J-STAGE: June 28, 2010
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Katsuki Kusakabe
2000 Volume 2000 Issue 191 Pages
77-79
Published: February 25, 2000
Released on J-STAGE: June 28, 2010
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Shojun Hino
2000 Volume 2000 Issue 191 Pages
80-82
Published: February 25, 2000
Released on J-STAGE: July 05, 2011
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[in Japanese]
2000 Volume 2000 Issue 191 Pages
83
Published: February 25, 2000
Released on J-STAGE: June 28, 2010
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[in Japanese]
2000 Volume 2000 Issue 191 Pages
84-85
Published: February 25, 2000
Released on J-STAGE: June 28, 2010
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[in Japanese]
2000 Volume 2000 Issue 191 Pages
87
Published: February 25, 2000
Released on J-STAGE: June 28, 2010
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