In this study, a flexible ultrasonic transducer (FUT) was applied in a laser ultrasonic technique (LUT) for non-destructive characterization of metallic pipes at high temperatures of up to 176 °C. Compared with normal ultrasound transducers, a FUT is a piezoelectric film made of a PZT/PZT sol-gel composite which has advantages due to its high sensitivity, curved surface adaptability and high te...

A study was conducted to characterize the aerosols produced by a medical ultrasonic nebulizer using solutions containing antimicrobials appropriate for therapy of equine lower respiratory bacterial infections (gentamicin sulfate and ceftiofur sodium). Test aerosols were generated using an ultrasonic nebulizer and were analyzed using a laser diffraction aerosol particle analyzer. The aerosol was...

Ultrasonic guided waves offer the promise of fast and reliable methods for interrogating large, plate-like structures. Distributed arrays of permanently attached, inexpensive piezoelectric transducers have thus been proposed as a cost-effective means to excite and measure ultrasonic guided waves for structural health monitoring (SHM) applications. Guided wave data recorded from a distributed ar...

We determine time correlation functions and dynamic structure factors of the number and charge density of liquid water from molecular dynamics simulations. Using these correlation functions we consider dielectric friction and electro-acoustic coupling effects via linear response theory. From charge-charge correlations, the drag force on a moving point charge is derived and found to be maximal a...

Previous work from our laboratory showed that the widely reported decrease in phase velocity with frequency (negative dispersion) for ultrasonic waves propagating through trabecular bone can arise from the interference of two compressional waves, each of which exhibits a positive dispersion. Previous simulations suggest that Bayesian probability theory can be employed to recover the material pr...

A low-frequency ultrasonic method presented in this paper is suitable for measuring any one of the four characteristic parameters, i.e., thickness, density, shear, and longitudinal wave velocities, of a thin elastic layer given the remaining three. Thickness of the thin layer is much smaller than the longitudinal wavelength of the ultrasonic wave used in the experiments. The method employs the ...

Non contact laser ultrasonic methods are appropriated for investigating SAW propagation on curved surfaces. They eliminate coupling issues in the generation and detection of the waves, and their high temporal resolution enables studying the dispersion effect on a large frequency range. We investigate the variations of the phase and group velocities for Rayleigh waves propagating on a sphere or ...