Figure 8 shows XANES spectra for the deposits on the
insulating paper after heating tests in oil B (with DBPC).
It was found that the deposits were mainly Cu2S as well
as the case of oil A (DBPC free) in Figure 7. In addition,
it was found that Cu2S deposition on the insulating papers
was remarkably accelerated with the existence of DBPC
in the oil from the comparison between Figures 7 and 8.
Also, the existence of copper compounds other than Cu2S
on the insulating papers was described in section 3.4