I asked Takahashi some questions about the
Kitamura experiment. I will summarize some of his
responses and quote others, with a little editing
for the English and for Japanese fonts that did not survive the e-mail.
I have been calling Kitamura's first experiment a
replication of Arata's DS-Cathode. That is not
quite accurate. Kitamura is using steel cells
with palladium black in them. He does not use an
outer palladium shell (DS cathode).
I have some concerns about the calorimetry at
such a low flow rate: 6 ml/min. The outlet water
may not be mixed at such a low flow rate. On the
other hand, there is so little water perhaps all
that comes in contact with the thermocouple. Peak
power range from 180 mW to 250 mW, which is
fairly high and can probably be detected with
confidence. The Pd-H null runs seem to be close to the zero.
I thought perhaps the palladium black powder was
being sintered but Takahashi thinks the clumping
together of the powder has other causes. He
explained: "Sticking of Pd-black powders was
caused by D-(H)-absorption and rearrangement of
nano-structures of surfaces. See the SEM images
on p. 27, 28. It was not caused by sintering,
because we baked Pd-black sample before the run
#1 up to 300°C, but Pd black showed high activity
as seen on p. 24 and 25, compared with p. 26.
After #1 run, we baked again up to the same
temperature (300°C) and started the #2 run (p. 26) to find a big change."
Talbott Chubb commented on these slides as
follows: "I think Slide 55 comparing Arata-Zhang
(A-Z) results with the Kobe group's result is in
error with regard the weight of catalysts used by
A-Z. I think the A-Z weight was about 7 g, and
not 24.4 g. So the net Pd weight ascribed to A-Z
is correspondingly high. A-Z used something like
25 g in their ZrO2,NiO,Pd catalyst run, but not in their ZrO2,Pd runs."
Here some of Takahashi's responses I did not
cover above. "Q" is what I asked, "A" indicates Akito's Answer:
Q) On p. 9 and 11 it shows the flow rate is 6
ml/min. Is that correct? That is an unusually low flow rate.
A) The flow rate for the water mass-flow
calorimtery was chosen so to detect temperature
differences between inlet and outlet points with
good accuracy. 14mW power level was the lowest
limit of detection and that was the standard
deviation of stability run with zero-power
input (see p. 21). If we choose much larger flow
rate, delta-T becomes too small to detect with reliable accuracy.
Q) There are various estimates of the energy
normalized against the mass of Pd (J/g), but I do
not see any listing of the power levels. For the
DS-Cathode experiment, p. 26 appears to show peak
excess power at around 50 mW. Right?
A) Power levels, especially in the first phase
(zero pressure interval), are strongly
dependent on the D(or H) gas-flow rates and total
number of absorbed D(or H) atoms. Integrated
values of power (namely heat in Joule unit) per
one Pd-atom and/or one absorbed D(H) atom are
more meaningful like physical specific values.
. . .
On p. 26, we showed the case of D-loading to
used Pd-black powders. Power level in the
second phase was observed low (50 mW or less),
due to the sticking [clumping together] of the Pd
powder (decrease of effective active surface of
powder). However, if you see heat per D-atom
(Table on p. 47), specific values are similar to the virgin Pd-black.
This fact shows that smaller active sites on
surface of used sample were active, compared with
much larger active sites for the #1 (virgin) run.
And similar reaction is taking place in each
active surface sites (namely fractal
nano-trapping points on surface of nano-structure or particle: see p. 51)
If we use higher gas-flow rate, power level in
the first phase went up large as seen in P.46
(the case of H-gas charging). However, specific
values (normalized heat (energy) per g-Pd or per
D/H-atom) are appropriate for comparisons with
data with different gas-flow rates.
Q) For the Zr-Pd experiments, p. 36 seems to show
peak power at about ~180 mW. Is that correct?
A) That's correct. It is about 180 mW averaged
in fluctuation for for the second phase power
level evolution, while much higher power levels in the first phase.
Q) p. 54 shows the absolute total energy for the
Zr-Pd: 6.8 kJ. What was the peak power?
A) Peak power was about 250mW for the second
phase, where integrated heat was 6.8kJ. For the
first phase peak power was about 900 mW for
D-flow of 2.8 sccm. We have also excess heat
(over the heat by H-gas) in the first phase of
3.4 kJ (7.0-3.6), which might be due to nuclear
origin. Altogether, 10.2 kJ is the total heat
(energy) as defined as excess heat for the
Santoku 1 #1 run, and may correspond to nuclear origin.
Q) p. 56 seems to show peak power for the second
Zr-Pd run is ~100 mW. Is that correct?
A) Peak power appeared after Evacuation was
about 180 mW. Before the evacuation, yes about 150 mW at peak.
- Jed
