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Volume 27, Issue 12
Displaying 1-8 of 8 articles from this issue
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Noriyuki YAMADA, Eiichi ABE, Hideharu HIROSUE1990 Volume 27 Issue 12 Pages 792-796
Published: December 10, 1990
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSFor the compression process with deformation of a particle, a new compression equation has been derived by combining Rumpf's equation and Hiramatsu's equation. The Rempf's equation can estimate the relationship between compressive stress and the force acting on a contact point between particles. Hiramatsu's equation gives the relationship between the compressive force and the tensile strength of a particle. The newly derived compression equation contains a tensile strength term for each particle that the bed consists of. When this equation is applied to the compression process, the tensile strength of a particle can be estimated, but the strain of a single particle during compressing should previously be estimated or measured.
It was shown that the Kawakita's equation was derived from the new compression equation with some assumptions. A constant, 1/b, in the Kawakita's equation has been considered to be correlated with the tensile strength of a particle.
It was shown in this investigation that the tensile strength of a particle was proportional to the constant, 1/b, under the condition that the strain was constant during the compression process.View full abstractDownload PDF (511K) -
Hirosuke OKAMOTO1990 Volume 27 Issue 12 Pages 797-803
Published: December 10, 1990
Released on J-STAGE: July 01, 2010
JOURNAL FREE ACCESSThe solitonic self-organization phenomena in a granular medium appear when an external force exceeds some threshold value so that the onset of the ordered solitonic states is regarded as energy transition similar to that observed in complex nonlinear cooperative systems. Experimental investigations were made on solitary wave propagation, on the energy transfer through nonlinearity, on the evolution of the ordering parameter and on the effect of external noise on the solitonic mechanism.
The phase plane of the ordered dynamic states is found to contain an attracting set on which the motion of the system is aperiodic, and which describes a complex dynamics. Information processing in the granular medium is characterized by parallel processing of the non-Von Neumann's type in selforganized systems (by cooperative actions).View full abstractDownload PDF (2291K) -
Procedure for Obtaining Different-length Samples for Biological ExperimentsToshihiko MYOJO, Norihiko KOHYAMA1990 Volume 27 Issue 12 Pages 804-810
Published: December 10, 1990
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSA size-selective procedure has been developed in order to obtain samples of asbestos fibers of different lengths for use in biological experiments. Short Chrysotile fibers less than 5μm in length are widely suspected to be less carcinogenic than longer fibers. The bulk sample of U. I. C. C. standard asbestos (Chrysotile B) was aerosolized using -component fluidized bed. It was then separated in the dry state by wire ens (200 mesh and 635 mesh) and a virtual impactor with a cut-off point of 2μm.
0.1g (sufficient weght for in-vitro tests) of a short-fiber fraction that passed through the wire screens and then onto the fine side of the virtual impactor, and 1.5g of a medium fraction that passed through the 200 mesh screen but did not pass through the 635 mesh screen, were obtained from about 20g of raw material. The length distribution of the short fiber fraction was 81% of fibers less than 5μm long and 96 percent of fibers less than 10μm long. X-ray diffraction analysis revealed that the crystallinity of the separated chrysotile was not markedly changed. The present dry and mild separation process that was developed thus successfully avoids any artificial change in the physicochemical properties of asbestos fibers.View full abstractDownload PDF (2451K) -
In-situ Surface Modifications of Fine Powdered PolypropyleneEiji YAMANAKA, Takamasa TANAKA, Kenji HAMADA, Mamoru SENNA1990 Volume 27 Issue 12 Pages 811-816
Published: December 10, 1990
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe variation in particle size, specific surface area, Sp, and dispersibility in a polar liquid were measured by the continuous grinding of polypropylene (PP) with a non-ionic surfactant (NP7.5) or a titanate coupling agent (KR9S). With an amount of additive of 1mmol per kg PP, Sp increased by 20-30%, and the energy efficiency of comminution increased by a factor of three to four. The surface of PP beeame hydrophilic by adding 60mmol NP 7.5 per kg PP during the comminution, as revealed from the comparison of apparent partice size in water, ethanol and cyclohexane. Although the crystallographical degradation was enhanced by the additives, no change in the molecular weight distribution was observed even after intensive grinding with additives. Tribochemical sorption on the surface of PP was, therefore, not detected.View full abstractDownload PDF (1921K) -
Makoto SAITO1990 Volume 27 Issue 12 Pages 817-820
Published: December 10, 1990
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (1668K) -
Toei MATSUDA, Toshihiro HAYASHI1990 Volume 27 Issue 12 Pages 821-826
Published: December 10, 1990
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (2734K) -
1990 Volume 27 Issue 12 Pages 838-841
Published: December 10, 1990
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (1370K) -
Kazuo SUZUKI1990 Volume 27 Issue 12 Pages 842-844
Published: December 10, 1990
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (357K)
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