In this report we made experiments on the abrasion resistance of phenol resin by the Amsler abrasion testing machine under the condition of water lubrication. Phenol resin applied to tests was the laminate of canvas base which is often used as machine parts, that is, bearing materials, piston rings, brake linings, silent gears, cams, rollers and etc. For comparisons sake expriments were made also on casted bronze under the condition of oil lubrication. In the abrasion tests the materials paired with the specimens were medium carbon steel and gray cast iron, which were rotated at the peripheral velocity of 0.5m/s, while the specimens were fixed. Experiments were made till the rubbing distance of about 302 kilometer, and amount of wear, frictional moment and temperature were measured. As the rerults, it was clearedt hat the abrasion resistance of phenol resin is very superior to that of casted bronze when the contact pressure is high.

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To specify the notch toughness of materials, so-called the “Transition Temperature” is used as a criterion with the general belief that the characteristics of notch toughness cannot be evaluated by ordinary mechanical tests such as tension test etc.
In the factory, however, it will be very inconvenient that we cannot judge the notch toughness of materials from the ordinary mechanical test and must obtain the transition temperature of each material. From this point of view authors have carefully experimented the ordinary tension test and torsional test in addition to slow bending test, Charpy impact and side notched tension test from which the transition temperature of materials are obtained, using four kinds of rimmed steels.
These test results at low temperatures are shown in Figs. 2-6, from which we can see that it is difficult to specify the notch toughness of materials from the customary values such as elongation, tensile strength etc.. Then φ, φ', Φ or Ψ is defined respectively at each test (see Fig. 7).
As to the value of φ, φ', Φ or Ψ the following characteristics are notable:
a) Each value is constant within the tamperature range of -80°C to +100°C; therefore, these values can be easily obtained only by room temperature test.
b) The relations between transition temperature and the values of φ, φ', Φ and Ψ within the temperature range of -80°C to +100°C are shown respectively in Figs. 12, 13, 14 and 15. From them, it is clear that the material of which φ, φ', Φ or Ψ value is the smaller shows the lower transition temperature.
Thus authors propose to adopt φ, φ', Φ or Ψ as an index of the notch toughuess of materials.

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In this article, the macroscopic observation of the dynamic behaviour of rubber vibration-absorber is made from the author's original viewpoint.
Further, the most generalized explanation is given to the stress relaxation, strain relaxation, the result of test at different constant rates of stress, the deformation under vibrating stress, etc., over which more or less individual views have been published elsewhere. In particular an interesting conclusion was reached as to the mechanism of dynamic stiffness and dynamic viscosity.
A new dynamic model with an element of Bingham plasticity was devised to explain the non-linear and hysteric behaviour of the rubber, and the explanation was found quite satisfactory in practice.

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A falling ball viscometer which can be used availably for viscous and particularly opaque solution as well has been tested.
Two several turns coils independent on each other are set up instead of visible marks round the viscometer tube filled with solution of unknown viscosity. The coils form respectively electric oscilator circuits of different radio frequencies. Falling down a small metal ball in the solution, the inetant when it passes through the coil is to be detected by means of measuring or watching the voltage of heterodyne beat produced by two electric oscilations, of which frequencies deviate alternately by passing of the metal ball, and out-put voltage in question dips consequently owing to the band pass filter. Some considerations for suitable choice of every part and its dimension, namely diameters of ball and coils, frequencies applied etc., which effects to sensitivity and stability, are also given.
Result obtained shows that the system is applicable effectively for measuring viscosity of various kinds of solution, for example, dull viscous solution (contains Titanium dioxide), pastes of pigment dyestuff, printing inks, paints, and so on.

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