Abstract: A process is described which uses a "cold" gas shock to accelerate microprojectiles wherein particles are presented to the gas shock on a planar surface perpendicular to the plane of expansion of the gas shock wave. Several different apparatus capable of accomplishing this method are described.

Abstract: A non-invasive ultrasonic flowmeter which utilizes the phase modulation of an ultrasonic beam transmitted through a fluid carrying conduit to determine the fluid volumetric flow rate. Transmitting and receiving transducer pairs are diametrically disposed on the outside of the conduit. The received signal is filtered, amplified and phase demodulated. In one embodiment dual loop-circuits having different carrier frequencies have their output signals combined in a differential amplifier. Instrumentation such as frequency meters or RMS voltmeters are utilized to measure either the zero-crossing frequency or amplitude, respectively, of the resulting voltage signal. Both of these quantities are nearly linearly related to the fluid flow rate.