My unique aim in this thread is to congratulate those who usually posts at PF engineering forums. I have noticed here the people gives more importance to physics experts (maybe due to the name of this forums), and I want to claim the extraordinary technical skill of people like: -Astronuc, -FredGarvin, -Brewnog, -CliffJ, -Minger, -Morbius, -PerenialIII -Hitssquad, and some others which just now I don't remember. All of them gathers experience with technical knowledge, a very valuable sum. The fact is it is going to be impossible to renew my Pf-Eng. gurú medal with these guys walking around here. They are too good.