How does the hypersonic steamboat work... and was humidification the limitation of the ultra-sonic piezo?

1) "Ultrasonic signals are typically generated by stressing a piezoelectric material with sinusoidal electrical signal. When the electrical signal is terminated, the transducer continues to ring in damped oscillation over several cycles. The length of the electrical signal plus the ringing period determines the duration of the output ultrasonic signal, commonly referred to as a pulse, although in fact consists of many cycles of a sinusoidal wave.

The width of this pulse limits temporal resolution when used in nondestructive testing, complicates its use in depth-finding, and limits the minimum usable depth. Additionally, the major power limitation in depth-finding usage is cavitation at the transducer surface. It would be desirable to generate an output pulse of minimum width using a conventional piezoelectric ultrasonic transducer."

Source and further information: http://www.freepatentsonline.com/4507762.html Further information: http: ... more.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.