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Volume 44, Issue 2
Displaying 1-9 of 9 articles from this issue
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Mitsuru Egashira, Takeshi Konno, Mikihiko Kobayashi2007 Volume 44 Issue 2 Pages 94-100
Published: February 10, 2007
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSGold particles of 60-80μm in diameter are welded onto a gold substrate by applying high voltage of 4kV to a tungsten needle-like probe which is in contact with the particle at a very low contact pressure (contact welding). The joint is strengthened by an electric discharge from the probe positioned 20μm above the particle (non-contact welding). The welding area is estimated from SEM observation as well as by a laser microscope after the joint fracture. The fracture load is plotted against the welding area, and the effects of several factors on the strengthening are discussed. The fracture load increased 6 times or more by flowing N2 gas during non-contact welding. The effect of preheating to about 100°C during the non-contact welding is not clear. The fracture stress significantly scattered, because of the estimation error in welding area and distribution of stress concentration factor.View full abstractDownload PDF (4720K) -
Hidekazu Tanaka, Yoshiki Tanaka, Hiroshi Kira, Ryozi Hino2007 Volume 44 Issue 2 Pages 101-106
Published: February 10, 2007
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSNa-A zeolite was synthesized from diatomaceous earth (DE) of Si source. Pretreatment of DE with NaOH solution at 85°C for 24h was conducted to dissolve Si4+ from the amorphous phase of DE to form zeolite P. After the pretreatment, the molar ratio SiO2/Al2O3 of the solution was adjusted from 0.7 to 4.0 by adding NaAlO2 solution and aged at 85°C for 24h. The Na-A zeolite was formed at SiO2/Al2O3=0.7-1.3, although the materials were brown in color being a mixture with residual DE. In order to obtain a single phase Na-A zeolite, DE and NaOH solution added into the tube made by semipermeable membrane were pretreated in the same NaOH solution at 85°C for 24h. After the pretreatment, the tube was removed and the molar ratio SiO2/Al2O3 of solution was adjusted from 0.7 to 4.0. The precipitates formed from the solution were aged at 85°C for 24h. After the aging, white precipitates were obtained over the whole SiO2/Al2O3 ratio. At SiO2/Al2O3=1.3, the materials formed were identified as a single phase Na-A zeolite.View full abstractDownload PDF (3806K) -
Ryoichi Kurose, Takenobu Michioka, Hisao Makino, Satoru Komori2007 Volume 44 Issue 2 Pages 107-112
Published: February 10, 2007
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSEffect of flow behavior in a honeycomb rectangular channel of a de-NOX catalyst on the adhesion of particles onto the wall is studied using a direct numerical simulation (DNS). The results show that the adhesion of particles is markedly affected by the turbulent-laminar-transition flow and is enhanced by the turbulence in the upstream region near the inlet. This agrees well with the previous experimental observation, in which the degradation of catalyst appeared in the region near the inlet. The adhesion of particles is found to be enhanced by the turbulence especially for larger particles. In the downstream region, the adhesion on the wall near the corners of rectangular channels is suppressed since the turbulent-laminar transition proceeds from these regions.View full abstractDownload PDF (2363K) -
Hideto Yoshida2007 Volume 44 Issue 2 Pages 113-121
Published: February 10, 2007
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe effects of top plate rotation of hydro-cyclones on particle classification performance were studied experimentally as well as via the simulation study.
It was found that the cut size of a hydro-cyclone decreases as the rotation speed of top plate increases. The sharpness of classification with top plate rotation increases under the wide range of operational conditions.
The increase of classification sharpness is due to the generation of outward flow near the top plate and this result was confirmed with the results simulated by a CFD.
In order to classify fine particles in slurry flow, a horizontal type water elutriator with electro potential applied to the flow was newly developed. The cut size was reduced and the classification acuuracy was increased as the electro-potential is raised. The classification performance of three layers inlet type was higher than that of the two layers inlet type.View full abstractDownload PDF (5309K) -
Toshiyuki Nomura2007 Volume 44 Issue 2 Pages 122-126
Published: February 10, 2007
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe microbial adhesion is positively utilized for the immobilization of microorganisms in bioreactors although it causes troubles in medical implants and devices, food, metallic corrosion, pipeline, dental caries. Microbial adhesion is inevitable when solid surfaces are exposed to an aqueous phase. However, the mechanism of microbial adhesion to solid surface has not been well understood. In this paper, the interactions between microorganisms and solid surfaces are briefly reviewed. From the viewpoint of the colloid science, the measurements of the microbial surface characteristics, analysis of the microbial adhesion and its application are introduced.View full abstractDownload PDF (4121K) -
Satoshi Ishikawa2007 Volume 44 Issue 2 Pages 136
Published: February 10, 2007
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (2246K) -
Tomoaki Hino2007 Volume 44 Issue 2 Pages 137-139
Published: February 10, 2007
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (1911K) -
Makio Naito2007 Volume 44 Issue 2 Pages 140-141
Published: February 10, 2007
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (1673K) -
2007 Volume 44 Issue 2 Pages 142-148
Published: February 10, 2007
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (9836K)
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