Ultrasonic point‐source/point‐receiver measurements in thin specimensa)

Ultrasonic measurements in pigs

We quantitatively analyzed blood flow through the major arteries supplying the pig’s femoral head during various hip positions and following ligation of various vessels in order to identify the vascular abnormalities which may be responsible for the development of avascular necrosis during the treatment of developmental dysplasia of the hip. Our findings reveal that a decrease in total blood fl...

Ultrasonic measurements in superconducting UPt3

Ultrasonic classification of thin layers

Methods for non-destructive inspection of layered materials are becoming more and more popular as a way of assuring product integrity and quality. In this paper, we present a model-based technique using ultrasonic measurements for classification of thin bonding layers within three-layered materials. This could be, for example, an adhesive bond between two thin plates, where the integrity of the...

Ultrasonic measurements of breast viscoelasticity.

In vivo measurements of the viscoelastic properties of breast tissue are described. Ultrasonic echo frames were recorded from volunteers at 5 fps while applying a uniaxial compressive force (1-20 N) within a 1 s ramp time and holding the force constant for up to 200 s. A time series of strain images was formed from the echo data, spatially averaged viscous creep curves were computed, and viscoe...

Absolute Ultrasonic Measurements with Piezoelectric Transducers

The absolute calibration of a piezoelectric transducer refers to the determination of the relationship between the electrical and acoustical quantities for a transducer coupled to a solid. It is shown how a well-characterized ultrasonic system, consisting of source,structure and receiver can be used to make such measurements for transducers operating as sources or receivers. Results are given, ...