Volume 118, Issue 3, September 2005
Index of content:
- ULTRASONICS, QUANTUM ACOUSTICS, AND PHYSICAL EFFECTS OF SOUND 
118(2005); http://dx.doi.org/10.1121/1.2000771View Description Hide Description
This paper describes a method for measuring the velocity and attenuation of high-frequency sound waves traveling through liquid materials. This method is based on the measurement of the forward scattering parameter of the acoustic system composed of two transducers and the liquid between them. The acoustic parameters are obtained from the analysis of in the time domain. Various experiments using distilled water as the liquid sample have been carried out. They show the influence on the measurement sensitivity of receiver detection bandwidth, liquid thickness, and difference of temperature between the room and the test cell. The method was used for the measurement of the attenuation and velocity of mixtures of alcohol and water.
Polydisperse particle size characterization by ultrasonic attenuation spectroscopy for systems of diverse acoustic contrast in the large particle limit118(2005); http://dx.doi.org/10.1121/1.2000773View Description Hide Description
Ultrasonic attenuation spectroscopy offers advantages over other spectrometric methods for the determination of suspension and emulsion size distributions. One advantage is the possibility of conducting measurements in highly concentrated or optically opaque dispersions. Models useable for the inversion of measured attenuation spectra to calculate particle size distributions are available and widely used, but their applied forms only allow for the characterization of particles smaller than . In this paper, a methodology using the Faran model for elasticscatterers is examined in the region of micrometer-sized particles with respect to its suitability for the prediction of measured attenuation spectra and size distributions of various material combinations. All selected particle fractions and fluid materials were characterized independently from ultrasonic attenuation spectroscopy with respect to their material properties, size distributions, and shape. A comparison of measured and calculated attenuation spectra shows an acceptable agreement. The chosen methodology for particle sizing applications is further confirmed if a fit of the model to the measurement data is performed. In this approach, the solids volume fraction is treated as the only fit parameter. The findings indicate that the methodology is suitable for polydisperse particle size characterization for a wide range of acoustic contrast.