Air-coupled ultrasound (ACU) is used in through transmission to detect delamination, rot, and cracks in wood without altering the structure permanently. Novel ferroelectret transducers with a high signal-to-noise ratio enable high-precision structure recognition. Transducers made of cellular ...
The falling cost of embedded sensor systems has opened up the possibility of in-transit air-coupled ultrasound interior imaging of shipping container cargo. This new technology could allow for real-time cargo integrity verification and improved shipping and transportation security. This paper takes the...
We experimentally demonstrate and theoretically analyze high Q-factor (~107) capillary-based optical ring resonators for non-contact detection of air-coupled ultrasound. Noise equivalent pressures in air as low as 215 mPa/√Hz and 41 mPa/√Hz at 50
In the case of non-linear air-coupled ultrasound, the sample is excited at frequencies that have the centre frequency of the air-coupled narrow band receiver as an overtone. When the receiver scans across the sample, it responds selectively to the higher harmonics.In this study, high ...
or otherwise be destroyed. Additionally, air-coupled ultrasound offers the benefit of low, highly penetrating frequency ultrasound combined with the short wavelength in air. This allows the nondestructive inspection of previously untestable composits like thick, multilayer honeycombs, foam cores or green...
Air-coupled ultrasound stimulated optical vibrometry is proposed to generate and detect the resonances of a rubber tube in air. Amplitude-modulated (AM) focused ultrasound radiation force from a broadband air-coupled ultrasound transducer with center frequency of 500kHz is used to generate a low freq...
NIR has been used as a complimentary technique to test food materials where propagation of air‐coupled ultrasound was found to be difficult. This could be due to the presence of air pockets within the food material, as in the case of bread dough. 展开 ...
aIt is therefore apparent that minimization of loss at every stage is key to achieving an acceptable signal to noise ratio for the inspection if air-coupled ultrasound is the chosen method of inspection 因此它是明显的损失的低估在每个阶段是关键的到达到一个可接受的针对噪音的信号比率为检查,如果空气...
Passive focusing devices for Air-Coupled Ultrasound (ACU) transducers provide simple methods to concentrate the sound beam into a focus. This helps to improve lateral resolution and increase sensitivity. This work analyzed both theoretical and experimentally the behavior of three passive focusing devices...
Medical ultrasound digital beamforming on a massively parallel processing array platform Digital beamforming has been widely used in modern medical ultrasound instruments. Flexibility is the key advantage of a digital beamformer over the tradit... P Chen,M Butts,B Budlong - 《Proceedings of Spie ...