I read 195 watts input, up to 20 watts excess. Is that correct? That's a little weak and seems subject to measurement error.
On Thu, Jul 25, 2013 at 7:57 PM, Jed Rothwell <jedrothw...@gmail.com> wrote: > Kitamura et al. have been working on gas loaded Pd and Ni for some time, > originally in a replication of Arata's Zr+Pd alloy. > > Kitamura's experiment looks much better to me than it did last year. They > finally made a precision flowmeter. It holds a much larger sample of powder. > It is about time they scaled up the sample size. It can be run at high > temperature with reasonable accuracy. I think they are now getting more heat > from the Ni alloys than Pd. They get 20 to 30 W from Ni. It only works at > high temperatures, as I recall around 300 deg C. One lesson from the last > few years is that if you want to make Ni work, you need a high temperature. > > I have a few concerns about the calorimetry, but that is probably because I > am unfamiliar with some aspects of it, to wit: > > They are using oil instead of water as the working fluid. It is a good > choice for such high temperatures, but I have not used it myself so I can't > judge. I am a little concerned about a curve they showed from the > manufacturer of heat capacity and viscosity at different temperatures. It > varies a great deal. You have to trust the manufacturer on this. > > The flow rate is only 20 ml/min. That would be too slow with water. I don't > know about oil. > > They measure the temperature on the outside of a small copper pipe. I guess > that should work but I don't see why they did not use a T. Again . . . maybe > that is not a good idea with oil? I have heard the stuff leaks out of seals, > pumps and Ts. > > On the plus side: > > They used several other temperature sensors on the cell wall. They were well > calibrated and they all agree on the power levels. > > The recovery rate is 88% as I recall. That's high. The whole thing is > insulated in a vacuum jacket (like a giant Dewar). > > The calibration seems rock steady, and the calibration curve is linear. > > These people have been dealing with this for a while so they have probably > answered all concerns. McKubre asked Kitamura to estimate the error as a > percent of input but Kitamura could not. Perhaps he misunderstood the > question. McKubre said it was a "good job" despite this. > > U. Missouri intends to upload the slides from this conference, with > permission from the authors. I expect Kitamura will grant permission. This > is one you should look at. > > - Jed >
