Physical Acoustics: Principles and Methods, Volume IX includes four chapters that are device-oriented and devoted to understanding electron drag stresses on dislocations and difference in flow stress between the normal and superconducting states of Type I and Type II superconductors. Chapter 1 explains that when a dislocation moves through a crystal, it gives up energy to the medium either through a nonlinear motion over a dynamic Peierls barrier or through conversion of energy by scattering of electrons or phonons, which takes place with an energy loss proportional to the velocity. The next chapter discusses the propagation of ultrasonic surface waves in thin layers. The thin layer confines a surface wave laterally, providing a desired dispersion characteristic, acting as part of a transducer for generating surface waves, or providing an interaction region for other phenomena. Chapter 3 deals with a generation of solid state control elements that utilize the inverse piezoelectric effect. The last chapter provides approximate equations for coupled resonators and methods for accurately controlling the band frequency and bandwidth. This book is a useful reference for students and physicists working on physical acoustics.