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Volume 47, Issue 1
Displaying 1-4 of 4 articles from this issue
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Original Paper
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Tadao Haraguchi, Tomohiro Adachi, Hiroshi Kawasaki2010 Volume 47 Issue 1 Pages 4-10
Published: January 10, 2010
Released on J-STAGE: February 13, 2010
JOURNAL FREE ACCESSHowever, practical use is not advanced as thought by problems of the cost and durability, etc. Whether highly effective and lowering cost can be done is one of the keys to practical use. Up to now, direct dimethyl ether fuel cell (DDFC) that used DME as a fuel in polymer electrolyte fuel cell (PEFC) has been being researched. The research on the catalyst in them was to have done the optimization by changing the catalyst quantity of the anode or the cathode.
Then, the purpose of this research is to improve the performance of DDFC without changing the catalyst quantity. The structure of the catalyst is changed by adding the glycerin when the catalyst seat is made, and the fuel often comes in contact with the catalyst and the performance is improved. The made glycerin addition catalyst is used for either of the anode or the cathode.View full abstractDownload PDF (1033K) -
Hideyuki Hisashi, Masanori Nakano, Masahide Kawaraya, Hidehiro Kamiya2010 Volume 47 Issue 1 Pages 11-16
Published: January 10, 2010
Released on J-STAGE: February 13, 2010
JOURNAL FREE ACCESSSome kinds of surface oxidized carbon black (CB) particles were prepared by ozone treatment system with different reaction time. The morphological damages on CB, for examples, porous or oxidized amorphous phase structure, were generally formed by other oxidation method, such as acid treatment. Such damages on CB surface after ozone oxidation were not generated by STEM observation. The amount of generated functional group by surface oxidation on CB was determined by the vacuum pyrolysis and TG/MS (thermo-gravimetric and mass spectrometry). The amount of CO from -OH groups and CO2 from -COOH groups during vacuum pyrolysis from surface treated CB increased in proportional to ozone oxidation time. Furthermore, NO and SO2 functional groups on ozone oxidized CB surface were discovered by using TG/MS method. The amount of each functional group increased with increase of ozone oxidizing time, it seems that such functional groups were produced by the reaction with during ozone treatment. TG/MS is useful method for detecting the various functional groups of CB.View full abstractDownload PDF (1039K) -
Mikio Sakai, Kazuya Shibata, Vanessa M. Kawasaki, Seiichi Koshizuka2010 Volume 47 Issue 1 Pages 17-25
Published: January 10, 2010
Released on J-STAGE: February 13, 2010
JOURNAL FREE ACCESSDiscrete Element Method (DEM) is widely used in many powder systems. The DEM makes possible to figure out the complicated phenomena related to particle flowability. On the other side, the DEM has a fatal problem, that is, the number of calculated particles is restricted due to the excessive calculation cost. Thereat, we have developed a large scale model of the DEM which is called coarse grain model. The coarse grain represents a group of the original particles so that a large-scale DEM simulation can be performed by using extremely small number of the calculated particles. In our previous studies, the coarse grain model was used in not only gas-solid flow simulations like a pneumatic conveying system but also a fundamental study of solid liquid flows. The coarse grain model is expected to be used in various powder systems. Therefore, in the current study, the coarse grain model was applied to a two-dimensional bubbling fluidized bed. The results by the coarse grain model were in good agreement with that of the original system. The coarse grain model was shown to be available in the bubbling fluidized bed. Moreover, it is exhibited that the calculation speed with the coarse grain model is much faster than that of the original one.View full abstractDownload PDF (952K)
Review
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Masataro Okumiya, Hiroya Abe, Makio Naito2010 Volume 47 Issue 1 Pages 26-34
Published: January 10, 2010
Released on J-STAGE: July 29, 2017
JOURNAL RESTRICTED ACCESSThis paper reviews the importance of the control of non-uniform structure of sintered ceramics for its reliability improvements. The effect of coarse particles in raw powder materials on the mechanical strength of ceramics will be explained based on the experimental results, and the procedures for the reliability improvements will be discussed. It is pointed out that the binders added in the slurry also affect the mechanical strength of the final ceramics. Further analysis of the evolution mechanism of fracture origins made through the manufacturing process is crucial for better control of the reliability of mechanical strength of the sintered ceramics.
View full abstractDownload PDF (1922K)
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