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Volume 2002 (2002)
- Issue 205 Pages 221-
- Issue 204 Pages 159-
- Issue 203 Pages 113-
- Issue 202 Pages 71-
- Issue 201 Pages 2-
Volume 2002, Issue 201
Displaying 1-8 of 8 articles from this issue
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Takashi Yamasaki, Tsutomu Mine, Etsuko Furukawa, Kuniaki Oogami2002 Volume 2002 Issue 201 Pages 2-6
Published: February 25, 2002
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSBecause microorganisms adhere to carbon fibers, it has been used in the purification of fresh water in rivers and lakes. However, presently there has been little known about the purification of seawater. The authors investigated the adhesion of marine organisms to carbon fibers and attempted to broaden the variety of uses for carbon fibers. Initially they extracted carbon fibers previously placed in the sea and took samples of the microorganisms and measured the number of viable bacteria. They found that the marine microbes adhered to the carbon fibers in a short time. Subsequently, carbon fibers suspended in dirty seawater had reduced the turbidity and COD. They then laid the carbon fibers near a fish farm at the sea, and investigated the adhesive strength at the surface and at the bottom, for not only microorganisms but also the quantity of shrimp and lugworms. They considered that carbon fibers could be used in purification of seawater and formation of artificial seaweed beds.View full abstractDownload PDF (3986K) -
Takashi Maeda, Young Jung Kim, Kenji Koshiba, Kiyohiro Ishii, Toshiyuk ...2002 Volume 2002 Issue 201 Pages 7-11
Published: February 25, 2002
Released on J-STAGE: July 05, 2011
JOURNAL FREE ACCESSAt present, activated carbon fiber (ACF) generally consists of materials such as cellulose, acrylic phenol and so on. Activated carbon fiber is usually made by gas activation by CO2, and steam. Mesophase pitch-based carbon fiber (MPCF) has been developed to achieve higher strength and elasticity. Due to the difficulty of activating the MPCF using conventional methods, it has not been used as a starting material for ACFs. In spite of having such difficulties, the development of new activation method can lead us to a new ACF having pore structure and adsorption property different from conventional materials.
In this paper, we present the study on the relation between the newly developed KOH activation method and the specific surface area of the activated MPCFs by changing the activating conditions. Using our method, we could suc-cessfully control the specific surface area of the MPCF-based ACFs. This activation method proved to be promising for the development of the ACFs with novel characteristics.View full abstractDownload PDF (2578K) -
Michio Inagaki, Tomohiro Imase, Hiroyuki Iwata, Keiko Fujita, Hidetaka ...2002 Volume 2002 Issue 201 Pages 12-15
Published: February 25, 2002
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe formation of graphite crystals was found at relatively low temperatures as 900-1100°C from the powder mixtures of poly (vinyl alcohol) and either iron or nickel oxide. From the mixtures with Fe2O3, graphite crystals were formed above 900°C, but those with NiO the heat treatment at 1000°C for more than 5h. Before graphite formation from the mixtures with NiO, well-developed turbostratic structure was found to be formed. Formation of graphite crystals at the temperatures as low as 900-1000°C was supposed to occur through the dissolution and precipitation from nickel melt, but through the decomposition of various iron carbides.View full abstractDownload PDF (2746K) -
Michio Inagaki, Masahiro Toyoda, Norio Iwashita, Yoko Nishi, Hidetaka ...2002 Volume 2002 Issue 201 Pages 16-25
Published: February 25, 2002
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSSorption capacity for heavy oils was determined on different carbon materials; exfoliated graphite showed very high capacity for A-grade heavy oil as 83g/g, fir fibers carbonized up to 900°C as 78g/g and carbon fiber felt as 20g/g. Sorption capacity depended strongly on bulk density of carbon sorbents. Heavy oils sorbed into exfoliated graphite were able to be recovered by filtration under suction, but the repetition of sorption and recovery (recycling) resulted in a rapid decrease in sorption capacity. Carbonized fir fibers and carbon fiber felts were found to have a better recycling performance, even by washing with a solvent as well as filtration. Viscous C-grade heavy oil could be washed out by using less viscous A-grade oil, resulting in the recovery as B-grade oil. Carbon fiber felts were found to show excellent recycling performance; almost 100% of sorbed oil was recovered by centrifugation without marked reduction in sorption capacity. Recovered oils were confirmed to have the same chemical and physical properties as the original. Exfoliated graphite was able to pump up heavy oil from contaminated sand. The relation between grain size of sand and bulk density of exfoliated graphite is discussed.View full abstractDownload PDF (7119K) -
Takaomi Suzuki2002 Volume 2002 Issue 201 Pages 26-30
Published: February 25, 2002
Released on J-STAGE: March 01, 2011
JOURNAL FREE ACCESSCreation of nano-sized spaces by agitation was carried out on graphite, and the created nano-spaces were characterized by scanning tunneling microscope (STM). Observation of nano-space on activated carbon fiber was carried out by transmission electron microscope (TEM), and analyzed using image processing technique. STM and TEM provide local information around the nano-space, but the boundary between nano-space and solid wall is not clear. Therefore, the determination of the boundary is controversial. On the other hand, X-ray diffraction (XRD) provides clear information about the regular order of graphitic structure, and the size of nano-space can be determined by the central positions of carbon atoms. However, it gives average information of the graphitic material which has nano-spaces. Grand canonical Monte Carlo (GCMC) simulation reproduces molecular adsorption isotherms on graphitic nano-spaces, and the shape of isotherm is sensitively depends on the model of nano-space. The combination of several kinds of analysis method gives detailed structural information of nano-spaces.View full abstractDownload PDF (5576K) -
Yoko Nishi, Norio Iwashita, Michio Inagaki2002 Volume 2002 Issue 201 Pages 31-34
Published: February 25, 2002
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSPore structure of exfoliated graphite. which is responsible for sorption of various liquids, was evaluated by a mercury porosimeter. By using of a U-shape dilatometer, large pores, which seemed to correspond to the spaces among particles, were measured. The pore volume measured by this U-dilatometer was a little less than the value calculated from the theoretical density of graphite. It is worthwhile to be pointed out. however, that the pore structure determined by this U-dilatometer is closer to the real one than that by normal type dilatometer.View full abstractDownload PDF (1865K) -
Dimensional Changes and Irradiation Creep PropertiesTatsuo Oku2002 Volume 2002 Issue 201 Pages 35-41
Published: February 25, 2002
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (1118K) -
[in Japanese]2002 Volume 2002 Issue 201 Pages 44
Published: February 25, 2002
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (195K)
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