The lead inventor of that 1990 Japanese patent, S. Yamazaki, CEO of the semiconductor Co SEL is the most prolific inventor with more than 6K patents to his name. Quite remarkable and in one example even hints at very dense D formation, perhaps a forerunner of UDD? Maybe, but he certainly makes the case for plasma rather than electrolytic systems.,,,,,
Lest you think he only works on circuit board designs, one of his recent patents is an "Electrochemical Method for Creating Nuclear Fusion". In his description of this invention, Yamazaki starts by summarizing what is wrong with the way Jones+(89) carries out electrolytic cold fusion. The use of atmospheric pressure reduces the probability of cold fusion; the reaction tends to occur at a localized section of the electrode from the rise in temperature at that point; poisoning of the cathode leads to side reactions and product decomposition, and the deuterium ends up in the atmosphere, so the amount used for fusion is small; says Yamazaki.
Another is a "Plasma Method for Creating Nuclear Fusion". In this patent he sets out to solve several problems with "conventional" cold fusion apparati and thereby gives us reliable cold fusion.
And still another is an "Electrode for Use in Nuclear Fusion". In this patent, as the previous patent one, he tries to provide a reliable method for creating cold fusion. Here, instead of using microwave resonance with magnetism, a high frequency electric field ("500 KHz to 500 MHz, for example 13.56 MHz") produces the plasma, which is beamed at the target.
No wonder the Japanese are way ahead on LENR, you can all forget AR.