Properties of Materials Using Acoustic Waves.
Abstract
Our research efforts can be classified into four broad categories; Applications of acoustic levitation; nonlinear acoustics and radiation pressure; acoustic cavitation; and the development of a facility for the characterization of small samples. Although these classifications are somewhat arbitrary, with major overlaps existing among different categories, they do allow us to discuss the major thrusts of our work. When the acoustic radiation stress on an object produces a force that balances the gravitational force on it, the object will be levitated. One can either use levitation to characterize the sample mechanically, in a manner analogous to Millikin's characterization of the electric charge on an oil drop, or one can merely use the levitation as a tool for manipulating the sample. Our results have shown a new anomaly for liquid water: a turning point in the sound velocity at approximately -33 C. These are the first of only a few bits of data that argue against the more popular speculation that water is approaching (but never reaching) a critical type of behavior at around -45 C.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1982
- Accession Number
- ADA114124
Entities
People
- Robert E. Apfel
Organizations
- Yale University