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Volume 16, Issue 12
Displaying 1-16 of 16 articles from this issue
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Saburo Yashima1979 Volume 16 Issue 12 Pages 680
Published: December 10, 1979
Released on J-STAGE: April 30, 2010
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Hideo TAKENAKA, Yoshiaki KAWASHIMA, Masahiro NAKASHIMA, Yoshisuke KURA ...1979 Volume 16 Issue 12 Pages 681-686
Published: December 10, 1979
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe wet spherical agglomeration technique with a small amount of bridging liquid which preferentially wets solid particles, is one of the accepted method to agglomerate the particles dispersed in liquid. In the present study, the effects of addition of ethanol and surface active agent to the suspension on the agglomeration behavior of sulfisomidine dispersed in chloroform were investigated. Addition of a suitable amount of ethanol, say 100ml, slightly increased the agglomerate size compared with the case without addition. When the ethanol was added more than this amount, the agglomerate size decreased significantly. While, the agglomeration did not occur absolutely when ionic surfactant was added.
The contact angles of bridging liquid on solid particles in the same system as the agglomeration process were measured as a function of surfactant concentration and the methodology, i. e. sessile drop, hanging drop and Wilhelmy method. The contact angles obtained by the sessile drop method were reasonably correlated with the agglomerate size, which decreased with increasing the contact angle. The correlation of agglomerate size with both parameters of the interfacial tension between the bridging liquid and the dispersing medium and the contact angle were described linearly by equation (11) as seen in Fig. 6.View full abstractDownload PDF (799K) -
Kenji FUJII, Tohei YOKOYAMA1979 Volume 16 Issue 12 Pages 686-691
Published: December 10, 1979
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe measurement of the tensile strength of powder bed has been carried out by means of the swing method measuring instrument, which has been developed by the authors.
It was evident that a displacement in a breakable section of powder bed appears as the tensile stress increases, then the stress displacement curves are obtaind respectively for each powder. These curves provide the energy required to the tensile breakage which may be correlated with practical particulate phenomena.
The most interesting problem is the application of the measurement of tensile strength for the design of powder equipment and material handling.
The floodability of fine material, which will indicate the tendency to liquidlike flow due to natural fluidization of a mass of particles by air, has been discussed empirically but theoretical bases are not sufficient on the evaluation of the potential floodability of fine material.
The dimensionless number deduced from our theoretical consideration is given by the following equation
Fc/mp·g=3·σ/(1-ε)dp·ρp·g
The ratio of the cohesive force affecting a single particle to a particle weight indicates a good correlation with empirical floodability evaluated by R. L. Carr's method.View full abstractDownload PDF (646K) -
Chikao Kanaoka, Shigehisa Endo, Hitoshi Emi, Seichi Kawai, Hiroaki Doi1979 Volume 16 Issue 12 Pages 691-696
Published: December 10, 1979
Released on J-STAGE: April 30, 2010
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Hajime MATSUOKA, Kazuo TAKEDA1979 Volume 16 Issue 12 Pages 696-703
Published: December 10, 1979
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe shear mechanism of granular materials has been studied from a microscopic point of view in order to derive their macroscopic stress-strain relationship. For this purpose, direct shear box tests and simple shear tests were carried out using a pile of aluminium rods (or photoelastic rods) to simulate granular materials in a two-dimensional state. In the analysis, granular materials are considered to be an assembly of a unit element composed of two particles, which is named “two particles model”. According to this model, the sliding displacements between two particles across the potential sliding plane were formulated by considering the mechanism of disappearance and generation of angles of interparticle contacts. A new stress-strain equation was derived from the relationship of these sliding displacements, and compared with results of a cyclic simple shear test on aluminium rod mass. Furthermore, the proposed stress-strain relationship in a two-dimensional state was extended to that in a three-dimensional state by introducing the concept of “Spatial Mobilized Plane” (SMP), and compared with results of true triaxial tests on Toyoura sand.View full abstractDownload PDF (2298K) -
Ken-ichi KANATANI1979 Volume 16 Issue 12 Pages 703-708
Published: December 10, 1979
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe author's theory in the previous paper is extended and compared with experimental observations. The material is assumed to consist of cohesionless rigid spheres of uniform size and weight, and interparticle friction and collisions are assumed to take place. The velocity fluctuations of the particles are determined by equations of state under the assumption of local equilibrium. A simple microscopic model and an equivalence principle of particle interactions are utilized. The analysis of the flow on an inclined plane reveals that various experimental facts such as the powerr law and the dilatation and acceleration of the upper layer are well accounted for by the present theory.View full abstractDownload PDF (698K) -
Keishi GOTOH1979 Volume 16 Issue 12 Pages 709-713
Published: December 10, 1979
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSSpatial distribution of the first-layer neighbors in a random assemblage of equal spheres is discussed from the radial distribution function in the Percus-Yevick approximation The first-layer neighbors are defined as the particles which lie within the first peak of the radial distribution function. The average distance of the first layer from a central sphere is obtained along with a simple, approximate expression. In the range higher than the particle volume fraction 0.4, the particle distribution can be modeled such that the average number of the first-layer neighbors is twelve, one half of them being distributed inside of the position expressed by Eq. (3) and the other half lying outside.View full abstractDownload PDF (634K) -
1979 Volume 16 Issue 12 Pages 713
Published: December 10, 1979
Released on J-STAGE: April 30, 2010
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Saburo YASHIMA, Fumio SAITO1979 Volume 16 Issue 12 Pages 714-720
Published: December 10, 1979
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSAn experimental study of the size effects of particle compressive strength of brittle solids under slow rate of compression was carried out by using spheres made of two kinds of glassy materials and five kinds of natural minerals. The particle diameters of specimens ranged from about 10cm to 0.0030cm.
Followings are conclusions of the present experiment. Particle compressive strength of the glassy materials was linearly increased with the decrease of their volumes when the data were plotted on a logarithmic coordinate. Each relationship was simply expressed by the Weibull's equation. On the other hand, particle compressive strength of the minerals was increased along with a warped line with the decrease of their volumes on a logarithmic coordinate. The relationship was expressed by respective refractive lines having different gradients. This warpage may be due to the status of pre-existent cracks in the specimen. Throughout all the processes of experiment, the strength of size of 0.0050cm is about 17 to 50 times larger than that of 2.0cm.View full abstractDownload PDF (922K) -
[in Japanese]1979 Volume 16 Issue 12 Pages 720
Published: December 10, 1979
Released on J-STAGE: April 30, 2010
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Toshio INOUE, Kazuhiro ITOH, Katsunori OKAYA, Hajime OHTA, Tsunemasa I ...1979 Volume 16 Issue 12 Pages 721-727
Published: December 10, 1979
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSComminution process can be regarded as an assembly of single fractures, and as a natural result the behaviour of the materials in single fracture an essential role in the performance of the comminution system. In this paper glass spheres and irregular shaped limestone particles with different grain sizes have been comminuted under various impact velocities and the behaviour of these materials in high velocity comminution has been investigated and the results have been analysed for the size distribution of the products. Using these results the authors have tried to estimate a performance of a high velocity impact comminution system by simulation study. A summary of the results is as follows:
(1) Size distribution of the product is with a unique function of the impact velocity, and can be normalized in terms of the feed size.
(2) The results of simultion indicates that the multistage comminution system of relatively low impact velocity can make the best use of comminution energy.
(3) Impact comminution experiments on limestone particles showed that the peak of the size distribution of the products is consistent with the crystalline grain size of the materials.View full abstractDownload PDF (2269K) -
Keishi Gotoh1979 Volume 16 Issue 12 Pages 727
Published: December 10, 1979
Released on J-STAGE: April 30, 2010
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Kazumi Danjo, Akinobu Otsuka1979 Volume 16 Issue 12 Pages 728
Published: December 10, 1979
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (119K) -
[in Japanese]1979 Volume 16 Issue 12 Pages 729
Published: December 10, 1979
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (119K) -
[in Japanese]1979 Volume 16 Issue 12 Pages 729a
Published: December 10, 1979
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (118K) -
[in Japanese]1979 Volume 16 Issue 12 Pages 730-736
Published: December 10, 1979
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (4616K)
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