As the nefractory materials of gas turbine parts, nickel-chromium base, nickel base and cobalt base super alloys are briefly abstracted. Ceramic coating increases life of engine exhaust but the value of ceramios or cerametalics are unknown to date. Nitrides and carbides of II, III and IV groups of atoms in periodic tables are studied with this object by powder metargy, and it seems that the mixture of 80% TiC and 15_??_20% of nickel or cobalt known as Kentaniam is one of champions in to-morrow.
Recent development of Schwalzschild type reflecting microscopes are reviewed. Especially Grey's, Norris' and the anther's own designer are compared.Third orderaberrations and central obstructions are analysed. In addition a short note on the application of reflecting microscopes is given.
Surface potentials of hydrogen (or oxygen) films adsorbed on the clean surfaces of various metals prepared by evaporation processes were measured at the room temperature with a vibrating reed electrometer. It was found that: (1) Both hydrogen and oxygen films formed on the surfaces of Ni, Ag, or Pd, show wellsaturated negative surface potentials below 1 Volt. Those potentials appear in a substantially irreversible manner, suggesting occurrences of chemisorption. (2) For Zn and Cd, the potential varies in a specific manner on admitting the gas. The reason for it is as yet unknown. (3) By subsequent admission of hydrogen, the potential of an oxygen-covered Ni (or Ag) surface remains almost constant, while for Pd the potential changes toward the value for a hydrogen covered state.
Balanced filter method of X-ray diffraction measurements developed by P. A. Rosshas been applied to photographing Debye-Scherrer diffraction patterns. Balanced filters of Ni and. CO are used for Cu Ka radiation. In this camera one side of the photographic film is exposed to filtered radiation by Ni foil and the other side to filtered radiation by Co foil. The construction of the camera and the photographs and microphotometer curves of several diffraction patterns obtained with it are reproduced. It is also shown that the camera may be employed successfully for the identification of crystals, because two patterns of the samples to be compared may be photographed side, by side on a film, samples being replaceable accurately to the same position by a device of the specimen holder.
Investigated the nature of the steady flow of sand (uniform size of mean diameter 0.68mm) in the wooden inclined channel (width, 3cm). The obtained results are as follows: (1) Three types of flow are observed. (2) At laminar flow there is following relation between inclination θ and flowing velocity V. sin θ=KV0.689 where K does not depend on apparent density but on depth of flow. (3) At every inclination flowing mass per unit time W and apparent density ρ are in following relation. W=a+bρ a, b are constants and b is positive. (4) There is upper limiting value in flowing mass at every inclination.
D. C. potential distributions in the cylindrical soda-lime glass specimen were studied by means of the probe-method with aid of an electrometer tube. Fine threeplatimurn probes of 0.05mm in dia. were sealed into, the glass, one of which wasat the center and other two of which were near at the anode and cathode respectively. Electrode materials contacted with the both ends of the annealed specimen were molten sodium salts, silver nitrate, and copper, platinum and pure mercury.In the ease of copper, surrounding atmosphere was evacuated in order to prevent the oxidation. The measurement were mainly carried out at about 300°C. The potential curves was linear between both electrodes when Na or Ag salts were employed as the anode. For Pt, Cu or mercury anode the curves of different types, distinguisεd in following respects, were obtained. (1) The potential drop increased near at anode layer, (2) The potential curve was linear except near the anode, but its inclination and the current decreased gradually. From comparison of the conductivitieε, the normal conduction by Na ions was verified to take place in glass except the anode layer. In the anode layer, the composition of glass seemed different. Due to racking of Na ions, O2- ions, strongly bonded to, the network, contributed on the condition.