Volume 106, Issue 3, September 1999
Index of content:
- NONLINEAR ACOUSTICS 
Comparison of theoretical and experimental ultrasonic velocity in three-component mixtures of methyl ethyl ketone and toluene with n-alkanols and estimation of acoustic nonlinearity parameter (B/A)106(1999); http://dx.doi.org/10.1121/1.427162View Description Hide Description
A theoretical estimation of ultrasonic velocity using Flory–Patterson theory (FPT), Jacobson’s free length theory, Schaaffs’ collision factor theory, Nomoto’s relation, and Van Dael’s ideal mixture relation (IMR) has been done in the three-component (ternary) mixtures of methyl ethyl ketone and toluene with n-alkanols. The theoretically predicted ultrasonic velocities are compared with the experimentally determined velocities in the ternary mixtures at 30 °C. It is found that the velocities evaluated using all the theories except FPT and IMR are in fairly good agreement with the experimental velocity values. Acoustic nonlinearity parameter (B/A) and a few thermodynamic parameters have been evaluated theoretically for the ternary mixtures using the Tong and Dong equation combined with Flory’s statistical theory and its extended version to ternary mixtures.
106(1999); http://dx.doi.org/10.1121/1.427163View Description Hide Description
Results of experiments concerning nonlinear effects for elastic waves in metal rods with the crack-type defects are presented. The dependence of the nonlinear effect on the contact type is discussed. The crack has been modeled by cutting a rod and tightly filling the crack with metal plates. Two types of contact have been studied: a dry contact and a contact with lubricant. The modulation of high-frequency torsional waves (20 and 22.8 kHz) in the rod under the effect of low-frequency flexural vibrations has been investigated. Flexural vibrations have been excited by a shock and by a vibrator. The modulation of high-frequency torsional waves under the effect of low-frequency vibrations has been observed only in the rod with a crack. The level of modulation drastically decreases in the presence of liquid lubricant.