Reflection of sound waves, due to acoustic impedance mismatch at the interface of two media, is the principal physical property which allows visualization with ultrasound. In this paper, we investigate reconstruction of the acoustic impedance from ultrasound images for the first time. Similar to ...
The acoustic radiation force (ARF), which is generated by the exchange of momentum and energy between an acoustic wave and particles, enables ultrasound to manipulate objects whose densities or compressibilities differ from those of their surrounding media. Acoustic manipulation of cells has already ...
Unveiling the potential of ultrasound in brain imaging: Innovations, challenges, and prospects 2025, Ultrasonics Citation Excerpt : In the adult brain, skull or dura mater resection is required to form emission and reception sound windows. The high density and acoustic impedance mismatch of the skull...
Obviously, the propagation of acoustic waves through multi-layered structures depends on the acoustics impedance mismatch at each of the boundaries the ultrasound has to pass, furthermore it depends on the attenuation of the ultrasound in the different materials and finally in some cases on the ...
Findings – At defective bumps, the formation of a crack causes a larger acoustic impedance mismatch which provides a stronger ultrasound reflection. The intensity of solder joints in the acoustic image increase according to the level of damage during the ATC tests. By analysing the variation of ...
This is not surprising in the cases W or dλ, as exemplified in the case of organ pipes36, owing to the increase in acoustic impedance mismatch under these conditions. Moreover, simulations (see Supplementary Information) show that surface waves can be confined at the end of a ...
although the level of reflection at such a bond layer will be an extremely strong function of the level of acoustic impedance mismatch between the bond layer and the barrier and carrier materials. Alternatively, if acoustic resonance within the carrier plates can be tolerated, the transducers need...
If the part is a metal, direct electromagnetic generation of ultrasound in the part itself can be accomplished through the induction of eddy currents in the metal and their redirection by a strong magnetic field, leading to a net mechanical displacement of the lattice ions, that is, a sound ...
(FFT). To remove the ultrasound transducer spectral response and other influences, the amplitude spectrum (high-impedance reference, highZin Fig.3c) of an echo signal from a polished, thick aluminum block—an approximation of a perfect reflector—was subtracted on the dB/log scale. An example ...
Fig. 1. Schematic of ultrasound wave propagation and measurement in two broad method classes: (a) a representative long-range method, where the whole extent of the container is considered, and (b) an example of proposed short-range method, where a subsection of the container in contact with...