A series of compression tests have been carried out with silica sands put in a square box (300mm×300mm×270mm) compressed with a shorter punch (180mm×300mm). The distributions of the pressure and the friction stress on the inner surface of the box, the internal stress, the deformation and the strain in the box, and the relationship between the load and the displacement of punch have been measured by using the pressure cells, the friction cells and the internal stress cells developed by the authors. The following conclusions have been obtained:
(1) The pressure distribution shows the maximum values at the centers and the minimum at the ends below the lower surface of punch and on the bottom of the box. The maximum values are 1.67 and 1.19 times as great as the mean pressure below the lower surface of punch, respectively. Rounded corners of the punch scarcely affect the pressure distribution. The hysterisis effect of decreasing pressure in unloading is small.
(2) The maximum friction stresses occur at about 1/3 and 1/4 on the way from the centers to the ends below the lower surface of punch and on the bottom of box, respectively. Those are 0.42 and 0.29 times as great as the mean pressure below the lower surface of punch.
(3) The flows of principal stresses coincide well with those of principal strains.
(4) Slip-lines occur one by one at the intervals of increase of the mean pressure of punch by 10kgf/cm² along the characteristics of stresses at the lowest place where the grains are pushed up because of the shearing stress exceeding the limit of the friction stress.
(5) The displacement of punch increases in proportion to the load.

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A fundamental equation is presented for predicting the compaction behavior of flocculated suspensions.
It is assumed that the porosity of flocculated material is uniquly determined by the effective (interparticle) pressure and that the permiability of slurry is a function of both porosity and the mean diameter of particles of which flocs are made up. In deriving the fundamental equation, the material and the momentum balance of solid phase and of liquid phase are respectively considerd together with above two assumptions. An analogy between floc-compression and soil consolidation is presented in this study.
Sedimentation of flocculated suspensions of initially uiform concentration is also studied experimentally. The numerical solutions of this fundamental equation are in good agreement with the experimental results.

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The amounts of water vapor adsorbed on KCl and KBr particles have been determined, applying water vapor adsorption-desorption cycles, and the adsorption characteristic of water vapor in respect of these salts was interpreted. The configuration of surface ions of the salts is slightly transformed by water molecules adsorbed into a structure on which its adsorption is made conveniently. This configuration change in the surface ions is transmitted inside, and the influenced part may have a depth of several atom layers. Therefore, a prolonged time of adsorption is required to reach the equilibrium state. In the case of KCl, the mechanism of the surface change is found to alter at the end of a stepwise rise observed in an adsorption isotherm. The change which occurs in a low vapor pressure region shows a flucturation of ionic configuration at the surface, and the adsorbability of water molecules on KCl increases. On the other hand, in a high pressure region the change means a surface area decrease due to forming hydrated ions. Moreover, two-dimentional contacts among the adsorbed water molecules are necessary to form the hydrated ions which can easily migrate at the surface of KCl particles.

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