It was presumed by Dr. M. T
AUT ?? and was proved afterwards by Mr. M. U
NO that the following equation, obtained for the white cords, holds good for the dyed netting cords, too; -
log
T/
T0-
T=-(
Klog
e)
t+const.,
where
T0 and
T are the breaking strengths of wetted cord at the beginning and after
t days' submersion, respectively, and
K is a constant. According to the mentioned workers, the value of
K is nearly constant, independent of the kind of preservative dye in common use, not containing tar, and it has the same value whether the cord is dyed or not.
If
t0 and
t1, respectively, represent the days of submersion when
T/
T0, assumus two different constant ratios, we obtain from the above equation; -
K'(
t1-
t0)=const.,
K'=
Klog
e.
The present author examined this relation with available data of two or three observations, with the following results: -(1) The relation of 1/
K to
t1-
t0, where for
t1,
T/
T0=1/2 and for
t0, the cord begins to decompose, shows that 1/
t1-
t0 can be employed instead of 1/
K, and that any of the available observations is not sufficient to decide the difference in quality of the dyes used. (Fig. 1, 2 top).
(2) In the case, where no remarkable difference in strength is caused by dying, the efficacy of dying is mainly results in the value of
K and
t0 (Fig.1, 2 bottom).
(3)
K is the less, when
t0 is the greater; specially so with those results, in which the relation of 1/
K to
t1-
t0 shows little scattering, such as for silk and cotton cords supplied by N
IPPON T
EITI G
YOGYÖ K
ENKYÛ-K
WAI (The Japanese Society for the Study of the Fixed Net Fishery), and those of Mr. M
URATA. This is in accordance with the findings of Dr. M. T
AUTI and of the present author for undyed cords.
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