--- George Hathaway wrote: > "Although I could believe that a tiny amount of magneotcaloric effect is taking place in the Newman/Bedini/etc etc devices, I claim it would be undetectable certainly by any such method as Jean-Louis is using."
Well - his results speak for themself, and they do to make a respectable putative case for a small drop. The effect of his experiment, if it were to be analogous to a legal precedent, would be to shift the burden of proof; and if proper funding were available, this would be a good experiment to pursue for several reasons beyond Newman. The spark gap and the work of Leon Dragone figure in there also. That was a full 2 degree drop. The only real way to counter what JLN has done is to repeat it dozens of times with variations, and pinpoint some relic in his meter that gives the false reading. These meters are extremely reliable however. >From everything I have been told from others doing similar work, a small dT drop appears to be commonplace in magnetic cycling of many types of highly efficient devices, even if they cannot (yet) self-power. A regular poster to Vo, who will remain unnamed, may want to chime-in with an appropriate anecdote here, about a magnetic motor being developed which shows a much greater dT than what JLN has shown... or not. Anyway - to my thinking, and lacking any counter-experiment that shows otherwise, this appears to be accurate and not measurement error; possibly even understated, but of unknown potential for exploiting to a higher level. However, of great interest is the exact mechanism being employed, since pure copper magnet wire itself is not included in any list of materials which show the effect. "Shape memory" alloys (SMA) - almost all show strong magnetocaloric effects, and may of these are copper based. Most often they are tertiary such as CuZnAl- copper zinc aluminum. The peculiar property called shape memory involves the repeated recovery of macroscopic shape at different temperatures following mechanical distortion. The origin of this phenomenon lies in the fact that the material changes its internal crystalline structure with changing temperature. My suspicion is that copper oxides which have formed under the enamel of the magnet wire are the magnetocaloric 'culprit'. The 'ordering' transitions, in alloys, from 'martensitic' to 'austenitic' allow SMA materials to regain deformed shape on cooling. Martensitic transformation reversibility in copper-based shape memory alloys is strongly influenced by repeated *cycling* and *ageing effects*, due to the metastable character. This is exactly why it is seen in motors which have undergone a lot of experimentation, especially when magnet wire has been reused from older experiments. A surface layer of CuO is to be expected. Perhaps the MC effect is not seen in newly constructed motors using new wire, at least for some threshold time. As with anything this newly evolving, controversial and unpublished in a major journal, you can forget reliance on self-appointed 'experts' who are going "by the book." Here is an interesting article, which demonstrates the average age, the less than stellar credentials, and maybe even the normal dress attire, of the real experts in cutting-edge SMA magnetocalorics. http://www.siu.edu/~perspect/07_sp/cold_front.html Jones
