Valve philosophy

[Mark]

This morning I was thinking about the nature of valved and valveless engines and how nature often makes something inbetween, that lives in two realms instead of a neat catagory like a moth or butterfly, frog or toad, turtle or tortoise, snake or semi-legless lizard, etc.
So what might be considered inbetween niches in the valve and aerodynamic valve spectrum? How might you construct something that would qualify? The vanes or blades of a jet kind of seem like something in that direction. And since pulsejets breathe from tail end, even this distinction is blurred with equal sized Elbonia exhaust/intake designs, there must be some kind of quasi-valve that is a little bit valveless and a little bit valved. Some sort of spinning something perhaps.
Mark

[Mark]

Just something else that occurred to me, another kind of inbetween land.
Mark
http://www.public.asu.edu/~jpbirk/CHM-1 ... img039.jpg
http://en.wikipedia.org/wiki/Metalloid

[lucky rookie]

metalloid sounds like a case of piles for robots

[Mark]

One of the metalloids has been in the news lately.
"Weight-for-weight, polonium's toxicity is around 109 times greater than hydrogen cyanide. The main hazard is its intense radioactivity (as an alpha emitter), which makes it very difficult to handle safely - one gram of Po will self-heat to a temperature of around 500°C."
"Famous polonium poisoning cases
This article documents a current event.
Information may change rapidly as the event progresses.
Notably, the murder of Alexander Litvinenko in 2006 has been announced as due to 210Po poisoning."
Note the figure is 10 to the 9 power, but the copy/paste pushes the 9 down.
http://en.wikipedia.org/wiki/Polonium