Journal of the Research Association of Powder Technology, Japan 

About: Journal of the Research Association of Powder Technology, Japan is an academic journal. The journal publishes majorly in the area(s): Mixing (physics) & Granular material. It has an ISSN identifier of 1883-8766. Over the lifetime, 174 publications have been published receiving 499 citations.

On the ζ-Potential

Abstract: The eigenchannel method, generalizing the familiar phaseshift method, is formulated for scattering from a Hermitian short range potential. Scattering eigenchannels are defined as eigenstates of some generalized (weighted) operator spectral problem. Eigenvalues of that problem define eigenphaseshifts, the former being the negative of cotangents of the latter. Eigenchannel representations of generalized scattering states, transition operators, and Green operators are constructed. A variational approach to the method is also presented. The general theory is illustrated by applications to scattering of Schr€ odinger and Dirac particles. 2003 Elsevier Inc. All rights reserved.

Characteristic Constants in Kawakita's Powder Compression Equation

Abstract: Kawakita's experimental equation has been introduced from the relationship observed between pressure and volume in the case of piston compression.Although the cheracteristic constants a and b in Kawakita's eq. can be obtained by a graphical method, any clear relationship between these constants and physical properties has not been found out.The authors have carried out an experimental work on the hydrostatic compaction using several kinds of powders, i.e. electrolytic copper, electrolytic iron, reduced iron, atomized iron, molybdenum and tungsten.From the data obtained, it is found out that the constant a in Kawakita's eq. is nearly equal to the value of volume reducticn at infinitely large pressure, that is the initial porosity.On all the powders tested, two stages are recognized of the curve of Pb (V-V∞)/(Vao-V∞) versus (Vao-V)/(Vao-V∞), where P is the compacting pressure, b the constant, V-V∞ the volume of residual porosity, Vao-V∞ the volume of initial porosity and Vao-V the volume of reduced porosity.In the first stage that is the linear part of the curve, the constant b has a constant value. In this region, the constant b appears to be related with the yield strength σ0 of the powder particles and apparent initial porosity Nao.In the secondary stage that is the curved portion of the figure (Fig. 3), the constant b has not a constant value. In this region, the constant b appears to be related with σ0*, Nao and (Vao-V)/(Vao-V∞).The relationship between σt/P and 1/b has a clear linearity, and then this fact means that the constant b is related indirectly to the strength of powder particles.

A Direct Shear Test for Powders and Granular Materials

Abstract: A new method for direct shear tests was devised to measure easily the flow properties of a powder and a granular material. This method is based on the stress resulted from expansion in volume of the specimen during a shear test.Expansion is caused by the movements of each particle in shearing zone. Such a stress increses with increased shear strain while expansion occurs. A yield locus is therefore obtained from a single shear test recording simultaneously the normal and the shear components of the stress by a X-Y recorder.The yield locus of the granular material is a straight line through the origin. The slope of this line, that is, the apparent coefficient of internal friction is depend on the height of the specimen. Therefore the true coefficient of internal friction is determined by extrapolating the height of the specimen toward zero. Furthermore, the cohesion and the unconfined yield strength of the powder are determined very easily from a single shear test in the region of low stress. The reproducibility of the results in the present method is satisfactory.