Anisotropic properties of materials can be determined by measuring the propagation of elastic waves in different directions. A laser imaging approach is presented that utilizes the adaptive property of photorefractive materials to produce a real-time measurement of the antisymmetric Lamb or flexural traveling wave mode displacement and phase. Continuous excitation is employed and the data is re...

For untold millennia certain animals have used ultrasound to probe places where light is unavailable, echo-locating bats being among the most adept. With ultrasonics, bats can quickly and safely 'see' at night in pursuing insects or flying in dark caves. Unable to hear ultrasound, humans have nevertheless made use of it. They did this anciently by taming wolves, with their keen ultrasonic heari...

This is a study of elastic waves diffracted by corrugated metallic surfaces. The corrugations consist of triangular grooves with variable parameters. The results of the narrow band experiments show significant diffraction patterns depending on angle and frequency. In addition, a continuous schlieren system is used to visualize the diffracted orders. Measurements were also carried out using a br...

Vibrothermography is a promising technique that uses elastic ultrasonic wave excitation in solids for quality maintenance, e.g. in aerospace and automotive industry to monitor the integrity of surface or subsurface features. Vibrothermography allows for defect selective imaging using thermal waves that are generated by elastic sound or ultrasound waves. The mechanism involved is local friction ...

The recently developed laser-induced phonon spectroscopy (LIPS) technique is applied to the determination of dynamic mechanical properties of aligned dilauroylphosphatidylcholine (DLPC) multibilayer arrays containing 2 and 20% water by weight. Sample excitation by two crossed 100-ps laser pulses generates a longitudinal ultrasonic wave whose wavelength depends on the crossing angle. In these ex...

In this paper, ultrasonic irradiation was applied for the synthesis of K2Ti6O13 nanobelts and novel nanocomposite (PbS-CdS/Ti6O13) through ion exchanging and co-intercalation processes. Thirty minutes of ultrasonic irradiation caused the formation of pure, uniform potassium hexatitanate with smaller particle size. The incorporation of PbS and CdS nanoparticles into the layers and on the surface...

Currently, many medical devices are made of implantable metals such as 316LVM stainless steel. Electropolishing is a common process to obtain a smooth surface, free of contaminants and more passive, which allows for minimizing the foreign body response and cell adhesion. However, polishing of small implants with a highly complicated geometry and nonuniform metallurgy might result in unsatisfact...

Over the years British Energy, in collaboration with British Nuclear Group, has developed an extensive suite of computer codes for modelling the ultrasonic inspection of ferritic steel components. The models predict the echo amplitude, relative to a specified threshold level, as a probe scans over a component containing a hypothetical smooth or rough planar defect. The models are used to help i...

Nanocrystalline complex oxides have been synthesized by combination of sol–gel auto combustion and ultrasonic irradiation techniques using copper nitrate, zinc nitrate as metallic nitrates and glycine, urea and thiourea as fuels. Sol-gel combustion (combination of the chemical sol–gel process and the combustion process) as a proper synthesized technique is used to synthesize ZnO/CuO nanocomposi...

Nanoparticles of a new dinuclear silver(I) complex [Ag2(PPh3)2(μ-S-4nb-tsc)2(η1-S-4nb-tsc)2](NO3)2, where 4nb-tsc = 4-nitrobenzylidenethiosemicarbazone and PPh3 = triphenylphosphine, were prepared in an ultrasonic bath and characterized by FT-IR and SEM. The crystal structure of a suitable single crystal prepared by slow evaporation was determined by single crystal X-ray diffraction. The compou...