Standard procedure for dispersing natural soils for particle size fractionation can be too aggressive for soil containing coal and other organic particles from coal industries. We have investigated ultrasonic dispersion for the latter in four soils differing in pedogenesis (Phaeozem, Podzol, reclaimed mine soils), carbon content (27.5±138.6 g kg), clay content (80±153 g kg) and sources of parti...

The feasibility for speed of sound dispersion (SOSD) imaging was investigated here. A through transmission new method for measuring the SOSD was utilized. With this method a long pulse comprising of two frequencies one being the double of the other is transmitted through the object and detected on its other side. SOSD projection images were obtained by scanning objects immersed in water using a...

A new conceptual non-thermal anti-icing system for helicopter rotor blades is introduced. Theoretical calculations predict that certain ultrasonic modes generated by horizontal shear waves produce sufficient interface stresses between a host structure and ice to remove the accreted ice layer. Experimentally obtained ultrasonic shear dispersion curves are compared to theoretical predictions for ...

Most ultrasonic systems employing guided waves for flaw detection require information such as dispersion curves, transducer locations, and expected propagation loss. Degraded system performance may result if assumed parameter values do not accurately reflect the actual environment. By characterizing the propagating environment in situ at the time of test, potentially erroneous a priori estimate...

In many industrial applications through transmission ultrasonic measurements are widely used because they enable to perform characterization and long term monitoring of material properties. The waveform of the signal transmitted through the plastic object usually is distorted due to different factors, such as frequency dependent attenuation, phase velocity dispersion, diffraction, geometry of b...

Using a broadband through-transmission technique, the attenuation coefficient and phase velocity spectra have been measured for a set of multi-wall carbon nanotube (MWCNT)-nylon composites (from pure nylon to 20% MWCNT by weight) in the ultrasonic frequency band from 4 to 14 MHz. The samples were found to be effectively homogeneous on spatial scales from the low end of ultrasonic wavelengths in...