Abstract: An acousto-microwave system to determine a mass M of gas disposed in a vessel includes: a microwave transmitter disposed on the vessel to transmit microwave radiation inside the vessel, a portion of the microwave radiation occurring at a microwave resonance of the vessel; a microwave receiver disposed on the vessel to receive microwave radiation communicated through an interior of the vessel from the microwave transmitter; an acoustic transmitter disposed on the vessel to transmit acoustic radiation inside the vessel, a portion of the acoustic radiation occurring at an acoustic resonance of the gas in the vessel; and an acoustic receiver disposed on the vessel to receive acoustic radiation communicated through the gas from the acoustic transmitter. The mass M of the gas is determined by analyzing the microwave radiation received by the microwave receiver and the acoustic radiation received by the acoustic receiver.

Abstract: An acousto-microwave system to determine a mass M of gas disposed in a vessel includes: a microwave transmitter disposed on the vessel to transmit microwave radiation inside the vessel, a portion of the microwave radiation occurring at a microwave resonance of the vessel; a microwave receiver disposed on the vessel to receive microwave radiation communicated through an interior of the vessel from the microwave transmitter; an acoustic transmitter disposed on the vessel to transmit acoustic radiation inside the vessel, a portion of the acoustic radiation occurring at an acoustic resonance of the gas in the vessel; and an acoustic receiver disposed on the vessel to receive acoustic radiation communicated through the gas from the acoustic transmitter. The mass M of the gas is determined by analyzing the microwave radiation received by the microwave receiver and the acoustic radiation received by the acoustic receiver.

Abstract: The investigation, development and application of a laser-based ultrasonic inspection system to the problems of evaluating polymer/graphite composite materials has been realized. The use of lasers to generate and detect ultrasonic waveforms in materials provides a means to detect material properties remotely. The study consisted of three main aspects: 1) A confocal Fabry-Perot (CFP) based system has been devolved which uses light reflected from the CFP interferometer to derive the ultrasonic signal. This allows higher frequency components of the detected waveforms to be discerned when compared to a CFP-based system using light transmitted through the CFP interferometer. 2) Thermoelastic and ablative laser generation of acoustic pulses in polymer/graphite composite materials has been investigated. Thermoelastic generation of ultrasound occurs when thermal energy deposited by a pulsed laser creates a localized expansion in the material.