A measuring device was constructed in an attempt to measure the concentration of sus-pension by a change in the dielectric constant. The dielectric constant of suspension depends on the temperature of the suspension, the flocculation of dispersed particles in the liquid and their sedimentation. Therefore, in this device, temperature control was employed for the test liquid. Also, a shearing velocity was applied to keep constant the measuring conditions of the suspension, throughout the measurement of its dielectric constant. In addition, a micro-computer was used, for the data processing of measurement. The result of the measurement of the concentration for carbon black and etc. using this device proved the applicability of the device.
CdS and ZnS crystals were grown using the sublimation method by controlling the vapour pressure of the constituent elements. The crystallographic polarity of the grown crys-tals was determined by chemical etching. In the growth of US or ZnS crystals on almina substrates under 2Pcd_??_Ps2, or 2Pzn Ps2, it was found that US crystals grew in the +c direction at the initial stage, while ZnS crystals grew in the -c direction. In the case of a prolonged growth time, growth along the -c direction became predominant for both CdS and ZnS crystals. US and ZnS ctystals on carbon substrates grew in both the c directions at the initial stage and grew preferentially in the -c direction after a prolonged growth time. Effects of excess constituent elements on the polarity of the grown crystals are discussed.
The measuring principle of the present viscometer is based on the correct theory of the previously reported capillary viscometer for gases. The viscometer, here reported, has a very simple construction and enables us to measure easily the viscosities of gases in a short time (a few minutes), without the necessity of measuring the flow rate. Results of experiments show that the viscosities measured by the present viscometer are in good accordance with those obtained by Sutherland's equation for the viscosity of gases.
In doubly insulated thin film electrolumi-nescent device having ZnS: ErF3, YbF3 as the emission layer, the emitting color changed from green to red with increase of electric field excitation frequency. Infrared-to-visible conversion properties of ZnS: ErF3, YbF3 phosphors are measured in order to investigate the mechanism of energy transfer from Yb3+ to Er3+ ion. On exciting the phosphor with 950nm light, both the green and red emission bands of Er3+ ion showed the quadratic ex-citation power dependence while the red-to-green emission intensity ratio increased with excitation pulse width.