Rectangular parallelepiped resonance--a technique of resonance ultrasound and its applications to the determination of elasticity at high temperatures.

The experimental work on resonance ultrasound, especially using the technique called rectangular parallelepiped resonance (RPR) is reviewed and summarized. The work on high-temperature (at temperatures beyond the Debye temperature) measurements of elastic constants is emphasized. Several applications of this high temperature work are described, including thermal equations of state, the determination of thermodynamic functions, and the determination of the bulk modulus at temperatures beyond experimental capability.