In the preceding paper, design of three different types of generators for plasma jet was given; they were stabilized by running water, argon and nitrogen gas, respectively. Their electrical characteristics were measured under various conditions of plasma pinch. In the present work, some information on the temperatures of the plasma jet and the plasma column squeezed by the so-called thermal pinch effect between both electrodes are obtained by spectroscopic means. The temperature of the plasma jet stabilized by water is measured by means of the Stark broadening of Hβ line and the intensity distribution of rotational lines in OH (0, 0) band spectrum. The temperature of the argon plasma column is calculated with the aid of the relative intensity distribution of A I and All spectral lines. In this method it is necessary to know the densities of ions; theoretically, they are obtained from the Saha equation or from the formula for corona. In our experiment, the latter seemed appropriate rather than the former. In addition, the velocity distribution of electrons deviated considerably from the Maxwell distribution, especially in high energy region, which is considered attributable to the temperature gradient existing in the plasma column.
In recent years several papers on parametric amplifiers have appeared in reference to micro-wave amplification. Circuit analogues of these amplifiers were proposed and the analogue circuits have been analyzed in various ways. Those methods of analysis, however, are based upon some assumptions concerning the form of currents in the circuit. It is the purpose of this paper to prove the validity of the above mentioned conventional methods from the standpoint of the theory of oscillation. Two types of analogue circuits, linear and nonlinear, are considered and correspondingly a system of linear differential equations with time-varying coefficients and a system of nonlinear differential equations with constant coefficients, which govern the behaviours of the circuits are derived. Following the so called ‘asymptotic method’ of N. Bogoliuboff et al., it is shown that these systems of differential equations have almost periodic solutions which are asymptotically stable, with the consequent result that the steady state oscillations of the circuits are almost periodic. Average power is calculated and expressions for amplification factor is obtained. These results are in perfect agreement with that of the conventional methods.
Crystals of glycine sulfate are grown in ferroelectric and paraelectric temperature ranges by circulating method, by slowly cooling method and as b-plate. Changes of domain structure by poling and annealing are investigated. The crystals prepared in ferroelectric phase tend to assume multidomain structure in time, while those prepared in paraelectric phase do not. Addition of metallic ions to mother solution such as Fe, Cr, Cd, Mg and Cu, changes the crystal habit, and the grown crystals show some anomalies in dielectric hysteresis loop. The coersive field increases and there appears a biasing field. The effects of irradiation of β rays on the domain structure and the hysteresis loop are observed. The polarization is apt to resume the direction in which the crystal was polarized when irradiated and, therefore, a biased or double hysteresis loop appears. The shape of the double loop and the mechanism of its appearance are discussed.
In the previous paper (Part 1), a study on the measurement of power spectrum of photographic material was reported. This work was undertaken to determine the autocorrelation function of grain pattern of printed image by using an optical autocorrelator, to obtain the power spectrum of grain pattern with the use of Fourier transformation, and to evaluate each spectrum. When the picture quality of release cinema positive film and of medical X-ray film are concerned, it is very important to consider the graininess of printed image, Because the image of cinema positive film and of X-ray film are formed by printing with negative film and fluorescent intensifying screens respectively, the grain patterns of these printed images are seriously affected by the grain pattern of negative film and of fluorescent screens. Autocorrelation function of granularity pattern of printed image consists of two components. One of these components, which has shorter correlation distance, corresponds to the grain pattern of positive film or that of X-ray film, and the other corresponds to the grain pattern of negative film or fluorescent screens. Fourier transform of the autocorrelation function was obtained and then the contribution of each component to magnitude of graininess was determined. When the Fuji cinema positive film is printed with Fuji Neopan SSS film, the contribution of grain pattern of Neopan SSS film was about one hundred times as large in the magnitude of graininess as that of grain pattern of positive film. When the Fuji medical X-ray film is printed with fluorescent screens, the contribution of grain pattern of fine grain fluorescent screens was about three times as large as that of X-ray film and the contribution of grain pattern of coarse grain screens was about ten times as large as that' of X-ray film. The quantitative comparison of two types of screens on graininess was made with the use of this method. Response function of the printing optical system, which includes spatial frequency characteristic of positive materials and that of printer, was obtained by using the following quantities, the power spectrum of grain pattern of negative film and that of printed grain pattern.
The image converter tube, being an electronic device which provides a visible image of irradiation pattern incident on its photocathode, is applied for multiple-frame-photography of very high speed phenomena such as plasma of thermonuclear reaction. The construction and operating characteristics of this experimental tube are described. The tube incorporates with a photo-sensitive cathode, a shuttering electrode, a focusing electrode, an anode, a circular-time-axis deflection system, and three-step post-deflection accelerator. The grid of shuttering electrode is normally operated at cut-off potential (-17 volts to photocathode), and when the shuttering electrode becomes positive the electron beam passes through the focusing electrode then on to the screen where the optical image is reproduced. During conduction the electrons normally pass through the central portion of the tube and produce an image at the center of the screen. By applying multi-phase sinusoidal wave voltages to each deflection plate the electron beam may be deflected in circle. Framing action can be achieved by repeating pulses on the shuttering electrode; adozen framed images can be recorded on stationary film with a conventional oscilloscope recording camera.
With a cylindrical flow counter which served as a proportional counter or a Geiger counter by the use of PR gas or Q gas, the end effect on the counting rate is rate is examined by applying collimated Cs137 γ-rays lengthwise along the counter tube. The anode wire had a guard tube at each end. The following results are obtained. (1) Sharp increases in counting rate are observed at both ends of the counter and at the ends of the guard tubes where the anode wire becomes bare. This is attributed to emerging photo and Compton electrons. (2) In the central portion of the counter, the counting rate with PR gas is higher by about 10 percent than with Q gas. (3) With the γ-ray applied at the central portion of the counter, good plateau curves are obtained, but near the ends, the rate is seen increasing rapidly as the anode voltage is raised.
A new type of apparatus for high-speed microscopic photography, the cine-micrograph, has been developed. Being based on the modified Cranz-Schardin's method, it has no mechanically moving parts. It is equipped with a six-faced pyramidal reflector just behind the objective lens for the purpose of image splitting, and high pressure Xe flash lamps are used as the short duration light source. Six successive pictures are possible to be taken, but in this paper the result of the experiment for three is described. The exposure time for each frame is 6×10-7 sec, and the time interval between them can be electronically controlled within the range of about 8×10-5-2.5×10-7 sec. With this cine-micrograph, the propagation velocity of cracks produced in a thin glass plate submerged in water by the impact of destructive electric spark was measured. Observed values are greater than the generally accepted one, and on this account some discussions are given.
Surface struture of buff polished metals is studied by polarimeric analysis. The appratus used is a photoelectric polarization goniophotometer newly devised by the author. Empirical calibration method is employed throughout this study. The principal results obtained are: 1. Polarimetric properties of metal surface are predetermined byt he polishing mechanism and affected little by surface roughness. 2. Apparent refractive index ‘n’ of metal decreases and absorption constant ‘k’ increases by buff polish. 3. On the mechanically effected layer formed in the course of pre-finish, at least two more layers are formed by buff polish; one is a thin surface layer of the order of 70sÅ, another is an intermediate of the order of μ.
The present authors have reported in another paper about the glass transition phenomena and rheological properties of asphalt in a very wide range of asphaltene content. According to them, asphalt exhibits glass transition temperature Tg, which varies with asphaltene content from -40 to 10°C. Creep test has revealed that, above Tg, asphalt shows retarded elasticity as well as viscosity. Furthermore, the temperature dependence of the steady flow viscosity and retardation times obey Williams-Landel-Ferry's equation, the standard temperature TS involved in this equation being 56°C higher than Tg for each epecimen. In this paper, physical interpretation of the penetration test and softening point test of asphalt is presented on the basis of these rheological results. The penetration, when measured at 25°C in 5 or 60 seconds (JIS K 2530), is not necessarily a measure of viscosity alone, but influenced by elasticity also. In the case of asphalt of high asphltene content, the penetration consists mostly of elastic deformation and is scarcely influenced by viscosity A simple theory on the “Ring & Ball” softening point test is developed. The theory predicts that the softening temperature Tb should correspond to the temperature at which the viscosity of test material reaches a definite value, and log η(TS) (viscosity at TS) should be linearly dependent on (Tb-TS). The viscosity at Tb is predicted to be 2.5×104 poises from the dimensions of the routine test instrument (JIS K 2531). These predictions are very satisfactorily proved by experi-mental results.