Physical Acoustics: Principles and Methods, Volume XIII is a six-chapter text that covers a variety of topics in physical acoustics, including the principles of ultrasonic waves, plate modes, diffraction, mode vibrators, ray theory, and acoustic emission. Chapter 1 deals with the theory and application of anelasticity in studying various types of relaxations, such as point defect, grain-boundary, thermoelastic, phonon and electron relaxations, and magnetic relaxations. Chapter 2 presents the different methods used in studying the very important Type II superconductor materials. Chapter 3 surveys the plate modes in surface acoustic wave devices and the theory needed to understand plate modes in piezoelectric media, as well as to eliminate or reduce their effect on the response. Chapter 4 tackles the ways of predicting diffraction loss and phase distortion, and discusses the alleviation of diffraction effects by acoustic beam shaping, material selection and orientation, and alterations in the transducer structure. Chapter 5 examines plate vibrators whose thickness direction has an arbitrary crystallographic orientation and the tools for the analysis of the properties of doubly rotated cuts, with special emphasis on such cuts in quartz, berlinite, lithium tantalate, and lithium niobate. Chapter 6 discusses generalized ray theory and transient responses of layered elastic solids. This book will be of great value to researchers in the fields of electronics technology and applied and engineering mechanics.

There is no respect for mere age in Science or Technology. Yet the cen tenary of the discovery, by the third Lord Rayleigh, that elastic waves can be guided by a surface, is memorable for the contradictions which it encompasses: Rayleigh's assessment of his classic 1885 paper as a rather minor mathematical development with a potential value only in seismology on the one hand; on the other the rediscovery of the subject in a totally that of electronic signal processing - which has led to its different fiel- explosive growth over the last twenty years. The new surface acoustic wave (SAW) devices have proved to be per electronic components. Today almost all television receivers con vasive tain one or more SAW filters, sophisticated radars depend on SAW signal processing, and SAW devices have been incorporated in ultra-high perfor mance opto-electronic systems. With the objective of surveying these developments and attempting to predict those that can be foreseen, as well as marking the centenary of Lord Rayleigh's discovery, The Rank Prize Funds' Committee for Opto Electronics organised a symposium in London, in July 1985. It was held in the Royal Institution, London, where Rayleigh himself once worked and often lectured. The present volume is the tangible outcome of the symposium, In which international experts survey.ed their various fields, and presented the most exciting recent developments.

Phonons are always present in the solid state even at an absolute temperature of 0 K where zero point vibrations still abound. Moreover, phonons interact with all other excitations of the solid state and, thereby, influence most of its properties. Historically experimental information on phonon transport came from measurements of thermal conductivity. Over the past two decades much more, and much more detailed, information on phonon transport and on many of the inherent phonon interaction processes have come to light from experiments which use nonequilibrium phonons to study their dynamics. The resultant research field has most recently blossomed with the development of ever more sophisticated experimental and theoretical methods which can be applied to it. In fact, the field is moving so rapidly that new members of the research community have difficulties in keeping up to date. This NATO Advanced Study Institute (ASI) was organized with the objective of overcoming the information barrier between those expert in the field and those who are new to it. Thus it was decided to (i) organize a set of tutorially based lectures covering most of the important facets in the field, and (ii) to produce an Institute proceedings which would serve both as the first general textbook, as well as a valuable reference book, for this field of knowledge.

In recent years substantial progress has been made in the detection of surface phonons owing to considerable improvements in inelastic rare gas scattering tech niques and electron energy loss spectroscopy. With these methods it has become possible to measure surface vibrations in a wide energy range for all wave vectors in the two-dimensional Brillouin zone and thus to deduce the complete surface phonon dispersion curves. Inelastic atomic beam scattering and electron energy loss spectroscopy have started to play a role in the study of surface phonons similar to the one played by inelastic neutron scattering in the investigation of bulk phonons in the last thirty years. Detailed comparison between experimen tal results and theoretical studies of inelastic surface scattering and of surface phonons has now become feasible. It is therefore possible to test and to improve the details of interaction models which have been worked out theoretically in the last few decades. At this point we felt that a concise, coherent and self-contained guide to the rapidly growing field of surface phonons was needed.

Ultrasonics. A subject with applications across all the basic sciences, engineering, medicine, and oceanography, yet even the broader topic of acoustics is now rarely offered at undergraduate levels. Ultrasonics is addressed primarily at the doctoral level, and texts appropriate for beginning graduate students or newcomers to the field are virtuall