The experimental light transmitting results obtained from a laminar diffusion acetylene-air flame and coupled with electron micrographs and cathode ray diffraction of the collected soot particles are summarized as follows:
(i) Soot particle size becomes larger in the heighest temperature zone, and in upper zone, it is nearly same.
(ii) Soot concentration is little in the pyrolysis zone. But it increases sharply in the heighest temperature zone, and decreases largely in the same zone. In the upper zone, it decreases slightly.
(iii) Single soot particle measured with electron micrograph is a sphere of 500Å-diameter and its size is almostly same in all zone of the flame.
(iv) In the cathode ray diffraction of carbon particles, three rings are strongly observed from the three planes, viz. (0001), (1010) and (1120) . Grain size of carbon particle is 10- 20Å-diameter.
These experimental results suggest that, in the laminar diffusion flame, many nuclei (grain size) of carbon particles are formed firstly in the pyrolysis zone or the heighest temperature zone, and they grow in any single soot particles. Some of them coagulate in soot particles, conversely, other of them are oxided oxigen in the heighest temperature zone. Soot particles which are not sufficiently oxided in the upper zone are finally discharged upper the flame as soot.

View full abstract

The Research Commitee on Machinery Vibration had sent out a questionnaire to 56 makers or users of machineries for naval use, to obtain information on the trouble due to vibration. On the information which were sent from 27 makers or users, the detail of them and the result of factor analysis were also described.

View full abstract