Rotating parts of indicating instruments such as switchboard instruments are supported by pivots on jewel bearings because of very small torque. Distribution of internal stress induced in sharp-pointed tip of such pivots has not been dealt with in the past. It is of great importance to study how to produce the pivot and how to harden it by quenching. Distribution of induced internal stress among other various relating problems was treated analytically in Part I in which pivots now in ordinary use and pivots made by the method devised by the author were compared on their photographs taken with an electron microscope, and the undesirability of the hardest part of commonly used pivots being not in the surface but below it was expressly stated. In Part II, the advantage of electric discharge quenching, by which only the tip of pivot is quenched, over total quenching is stressed along with the description of practical layout of the quenching and results of observation. The analytical treatment given in Part I is supported by photoelastical evidence.
One of the most important conditions that a microswitch should furnish is that the speed (cm/sec) of separation of contact electrodes at the instant of circuit cut-off is great. If the speed is great, shortening of the duration of arcing will reduce the wear on electrodes and prolong the life-defined by the number of operations-of the switch. For increasing the speed of separation, snap action of a spring system is taken up and, on a particular type of microswitch, this snap action is dynamically analyzed by calculating deformation energy of involved springs, contributing to the design of the switch. Similar analysis can be applied to any type of microswitch that is being used.
Polarization optical pyrometer is a kind of optical pyrometer of filament vanishing type. Intensity of light from a hot body is modified instantaneously by the rotation of one of the polarizers. Brightness of image of the hot body and angle of rotation of the polarizer are always in unison with no time lag.
The effect of elevated temperature and of porosity on thermal conductivity of porous materials has been investigated. “Comparison Method” is used and the experiment is carried out with three types of models. A generalized formula on thermal conductivity is derived empirically. This formula can represent every other formula on thermal conductivity of porous materials.
In recent years, several papers on solid-state image intensifier by the use of eleltroluminescentphosphor and photo conductive materials have appeared as one of the important applications of solid state electronics. It is convenient and important to use the solid-state intensifier for light amplification. The purpose of this experimental work is to achieve more amplification by cascading the intensitier in multi-stages. This paper first deals with electrical and optical characteristics of a single element light intensifier, then points out briefly the advantage of employing parallel resistance with electroluminescent-panel to improve its characteristics. The effects of this resistance are studies theoretically and experimentally. Two type of photo conductive cell were used, one was a sintered CdS cell and the other a CdS photosensitive powder molded with plastic binder. According to the results obtained on a single element of light intensifier two-stage and threestage light intensifiers were made and their characteristics were experimented on for various parallel resistances. The use of resistances in the first stage of electroluminescent-panels was effective in improving the amplification characteristics. In a three-stage light intensifier, amplification of about 400 was obtained at 0.3 rlux in-put radiation, and these results suggest the possibility of obtaining more amplification at lower in-put radiation. The experimental results are believed to be applicable to solid-state image intensifier by devising a suitable construction.
In the previous work, the author studied the method of measuring response function of focusing screen. In this paper, studies on the relation between response function and performance of focusing screen are reported. Psychometric method of evaluating the quality of image on a focusing screen by recognition is investigated as an integral method of evaluation. To facilitate the study on the relation between response function and performance, several ways of representing response function by a single number are critically examined, the result of which made the author adopt S1=_??_ [DF(ω)] 2dω as representing the normalized response function DF (ω) of the screen. Recognition and normalized response function of various focusing screens are determined and the study is continued to explain the relation between recognition and S1.
Measuring of graininess is asserted to be more important than measuring of granularity for estimating focusing screens, on which account the method of measurement and measuring arrangement for graininess are studied. Graininess of various focusing screens is measured and relations among the graininess, recognition, and S1 which is equal to ∫100 0 [DF(ω)]2dω-DF(ω) is the normalized response function of the screen-are investigated with the following results: 1) Quality of the recognition of focusing screens depends on the graininess as well as the value of S1. 2) The larger the value of S1 and the smaller the value of graininess, the better the performance of the screen. 3) The graininess and S1 of focusing screens are scarcely correlated. 4) An experimental G. S. wax layer screen (I) with layer thickness of about 8μ was proved to be excellent in performance especially in regard to its recognition.
The double modulation method of determining two parameters of elliptically polarized light, which was newly devised by the author, enables an automatic determination of birefringence. Two ADP units and two quarter-wave plates are used to assemble a modulator which modulates two parameters of elliptically polarized light. Two kinds of signals corresponding to the two modulations are produced by inadequacy of azimuth setting of used test piece and that of compensation for retardation caused by the same test piece. These signals are separated and fed back so as to close two servo loops, and the azimuth setting of and the retardation caused by the test piece are automatically determined. This method is successfully applied to record isoclinic fringe pattern at low fringe order.
Rheoiogical behavior of bituminous materials is studied by torsional creep test on coal pitch, wood pitch and mixtures of asphalt with powdered solid and turpentine oil. Steady flow viscosity, retarded elastic compliance as a function of time, retardation time spectra and their temperature dependence are observed on all the materials. Equilibrium compliance and shape of retardation spectra of asphalt and powdered solid mixtures are as predicted by the theory derived from rigid sphere model, but viscosity and retardation times are very much influenced by the shape of powder grains. Turpentine oil, markedly increases the segmental mobility of molecular network in asphalt, but gives only a small change to the length of segment within the studied concentration range at least. Four kinds of coal pitch are investigated. Wood pitch shows no elastic compliance, probably because the molecules are too small to form a network structure.
Variation of flow stress of tin single crystal is examined by applying to it successive impacts by means of two similar pendulums weighing 180g each, -one with the specimen fixed at its end which is hit by the swinging weight of the other-instead of applying a single strong impact as is usually practised. Results of observation are as follows. Behavior of impure tin crystals grown from melt of 99% tin was found strongly dependent on impact velocity. At 28cm/sec velocity, general yielding occurred, while at 24 cm/sec, discontinuous slips were seen. At smaller velocities of 20, 16, 12 and 9cm/sec, there were almost elastic collisions, but when the velocity was further reduced to 6cm/sec, a small amount of slip in discontinuous steps was noticed. At large velocities, rapid age-hardening was observed but not at 6cm/sec. In as-grown specimens, the discontinuous slips were indistinct and general yielding occurred more readily than in annealed specimens. In purer specimens grown from melt of 99.99% tin, the slip proceeded smoothly irrespective of impact velocity. The above results seem to be explainable by a mechanism similar to that of Liiders band observed on mild steel.
It is known that the reckoning on only the 3rd and 5th order aberrations is not sufficient for photographic lens design. The 7th order aberration is investigated. It is shown that the 7th order aberrations in Gaussian image plane are caused by the combination of the 7th order terms and the 3rd order terms.