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Volume 45, Issue 4
Displaying 1-8 of 8 articles from this issue
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Katsunori Okaya, Jun Sadaki, Toyohisa Fujita2008 Volume 45 Issue 4 Pages 206-212
Published: April 10, 2008
Released on J-STAGE: May 27, 2010
JOURNAL FREE ACCESSGenerally speaking, the packing fraction is one of the most important parameters, when handling powder. Various methods for handling powder and measuring their properties are standardized and included in the Japanese Industrial Standard (JIS). However, there is no standard on how to treat or handle particles of irregular shapes or rough surfaces. Within this frame there is a need for calculating the packing fraction of particles of irregular shapes.
In this study, three different methods are employed and the obtained results are compared. Three different methods are (1) controlled volume method, (2) balance method, and (3) apparent volume method, in the context of the discrete element method (DEM), and the results are compared for pointing out the advantages and disadvantages of each method. As a result, (1) the controlled volume method enables the accurate calculation of the packing fraction although different values for the bed volume can be obtained due to the random packing; (2) balance method is simple and easy but sacrifices the accuracy in the calculated packing fraction; (3) apparent volume method, on the other hand, is the most suitable method for calculating the packing fraction. It is simple and accurate, since it excludes from the calculation the area or the gap between particles.View full abstractDownload PDF (1466K) -
Katsunori Okaya, Yuichiro Tamai, Jun Sadaki, Toyohisa Fujita2008 Volume 45 Issue 4 Pages 213-219
Published: April 10, 2008
Released on J-STAGE: May 27, 2010
JOURNAL FREE ACCESSThe aim of this work was to calculate the packing fraction of two-dimensional particles as a function of shape of particles by using a conventional simulation technique known as discrete element method (DEM).
The simulation results are presented as a set of photographs, which depicted the arrangement or packing of particles of different shapes. For the purpose of this study two different particle models were used: 1) lens-shaped particle model; and 2) circle-shaped particle model.
The main result of this study was such that the packing fraction of lens-shaped particles is higher than that of circle-shaped particles, indicating that the stress between lens-shaped particles is more uniformly distributed than the stress between circle-shaped particles. It was also found that the packing fraction of particles of similar size is lower than that of particles of various shapes. In other words, the packing fraction strongly depends on the size distribution of particles.View full abstractDownload PDF (3328K) -
Takamasa Ishigaki2008 Volume 45 Issue 4 Pages 220-228
Published: April 10, 2008
Released on J-STAGE: May 27, 2010
JOURNAL FREE ACCESSA method of synthesizing functional nanostructured powders through thermal plasma processing has been developed. Nano-submicron-size metal and carbide particles were synthesized through evaporation and subsequent condensation of powders in thermal plasma. The synthesis of nano-size titanium oxide powders was performed by the oxidation of solid and liquid precursors. The plasma-synthesized TiO2 nanoparticles showed phase preferences different from those synthesized by the conventional wetchemical processes. Nanosized particles of high crystallinity and nonequilibrium chemical composition were formed in one step via the reactive thermal plasma processing.View full abstractDownload PDF (12812K) -
Microdots and Micropatterns Consisting of Colloidal CrystalJun-ichi Hamagami2008 Volume 45 Issue 4 Pages 229-235
Published: April 10, 2008
Released on J-STAGE: May 27, 2010
JOURNAL FREE ACCESSMicrofabrication processes for particle arrangement is very important in developing micrometerscaled materials or devices with a high performance. It is especially well known that a three-dimensional ordering of monodisperse microspheres gives optical characteristics for future photonic application such as optical waveguide, laser oscillation, and sensor. Microdots and micropatterns consisting of three-dimensionally ordered monodisperse microspheres of polymer or ceramics were fabricated by using electrophoretic deposition process with a microelectrode or a patterned electrode.View full abstractDownload PDF (7564K) -
Kazutaka Nakayama2008 Volume 45 Issue 4 Pages 243
Published: April 10, 2008
Released on J-STAGE: May 27, 2010
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Tomoya Ohno2008 Volume 45 Issue 4 Pages 244-245
Published: April 10, 2008
Released on J-STAGE: May 27, 2010
JOURNAL FREE ACCESSDownload PDF (4136K) -
Soshu Kirihara2008 Volume 45 Issue 4 Pages 246
Published: April 10, 2008
Released on J-STAGE: May 27, 2010
JOURNAL FREE ACCESSDownload PDF (2079K) -
Hisao Makino2008 Volume 45 Issue 4 Pages 247
Published: April 10, 2008
Released on J-STAGE: May 27, 2010
JOURNAL FREE ACCESSDownload PDF (155K)
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