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Physics in industry
BOOKREVIEWS
60’;
account of special subjects in the field of acoustics. The subjects covered here are just as diverse as in Vol. I (which was reviewed in Vol. 40, p. 578, of thisJournal), but here preference has been given by the editors to fewer and more extensive articles about subjects more in the “mainstream” of acoustics. After Traffic Noise, Acoustic Emission, Chemical Aspects of Ultrasonics, Vibration and Noise Transmission in Building Structures and Underwater Ambient Noise, which were covered in Vol. I, we find in Vol. II essays on Holography and Acoustics, Acoustics as a Diagnostic Aid in Diseases of the Ear, Nose and Throat, and Non-linear Acoustics. The first article, “Holography and Acoustics”, by P. Greguss is easily the best in the book. The reader is introduced to light holography in acoustics, acoustical holography, problems of reconstruction in both techniques and bio-holography. Not too much stress is laid upon theoretical explanations but the prospective experimentalist gets much relevant advice on the use of holographic equipment and a very good survey of its applications in engineering, and, at the same time, an excellent explanation of the physical processes involved. The highlight, for me, of this article is the short but fascinating chapter on bio-holography, which for instance suggests that the echo-locating animals like bats and owls in fact use a very complicated holographic method. This chapter opens the door for thoughts on further developments and possibilities in the field of holography and is a joy to read. Unfortunately, this cannot be said of the next article, “Acoustics as a Diagnostic Aid in Diseases of the Ear, Nose and Throat”, by J. J. Knight, which actually, apart from two pages on “nose and throat”, deals only with the ear. After an introduction to the anatomy of the ear, which is quite informative, the author reviews types of hearing disorders and the principle,s and methods of subjective and objective audiometry. This, however, is done in a very qualitative, slightly unorganized way with large numbers of graphs, partly obvious to the acoustician, partly unintelligible without further explanation. The article may be of interest to physicians interested in learning new and quickly applicable methods of medical examination, but is quite unsatisfactory for the acoustician interested in general principles. The third and last article, which takes up half of the book is “Non-linear Acoustics” by L. Bjorno, a very readable, comprehensive resume of this increasingly important area. The article starts off with an interesting historical sketch of the developments leading to non-linear acoustics, followed by a chapter on the fundamental equations. The main part is taken up by the description of theoretical and experimental investigations of finite-amplitude waves in fluids. A short section on finite-amplitude waves in solids concludes this chapter. The physica. yet application-orientated approach of the introduction to the fundamental equations and the thoughtful and comprehensive discussion of finite-amplitude waves makes this article the finest introduction to non-linear acoustics the reviewer has seen. This volume has established the Acoustics and Vibration Progress series as an important source of information for acousticians and workers in related fields, and the reviewer is looking forward to the next volume. K. BROI) PHYSICSIN INDUSTRY1976 E. O’Mongain and C. P. O’Toole, editors. Oxford : Pergamon 612 pp. ; price E17.00. ISBN 0 08 020922X.
Press.
This book is a collection of papers which form the proceedings of an international conference held in Dublin during March 1976. As would perhaps be expected from the title, a wide range of topics is covered by the 85 papers included. The subject groups show that the papers cover fields ranging from technological aspects of experimental physics to data processing and biological applications. A section on acoustics is included but it is rather short as it contains only six papers which cover 40 pages out of a total of almost 600. The volume as a whole can
608
BOOK REVIEWS
therefore only be of restricted interest to those working in the field of acoustics. However, the acoustical papers, which essentially with one exception are reviews, would be of interest to anyone entering the field or wishing to read of the basic approaches to noise measurement, industrial noise sources and control. A good discussion is given of aerodynamic noise in theory and in practice and the use of ultrasonics in N.D.T. is also reviewed. The last acoustical paper reports on the development of ultrasonic lenses with variable focal length. The final comment, however, can only be that the proceedings will be of limited interest to the acoustician. R. G. WHITE
60’;
account of special subjects in the field of acoustics. The subjects covered here are just as diverse as in Vol. I (which was reviewed in Vol. 40, p. 578, of thisJournal), but here preference has been given by the editors to fewer and more extensive articles about subjects more in the “mainstream” of acoustics. After Traffic Noise, Acoustic Emission, Chemical Aspects of Ultrasonics, Vibration and Noise Transmission in Building Structures and Underwater Ambient Noise, which were covered in Vol. I, we find in Vol. II essays on Holography and Acoustics, Acoustics as a Diagnostic Aid in Diseases of the Ear, Nose and Throat, and Non-linear Acoustics. The first article, “Holography and Acoustics”, by P. Greguss is easily the best in the book. The reader is introduced to light holography in acoustics, acoustical holography, problems of reconstruction in both techniques and bio-holography. Not too much stress is laid upon theoretical explanations but the prospective experimentalist gets much relevant advice on the use of holographic equipment and a very good survey of its applications in engineering, and, at the same time, an excellent explanation of the physical processes involved. The highlight, for me, of this article is the short but fascinating chapter on bio-holography, which for instance suggests that the echo-locating animals like bats and owls in fact use a very complicated holographic method. This chapter opens the door for thoughts on further developments and possibilities in the field of holography and is a joy to read. Unfortunately, this cannot be said of the next article, “Acoustics as a Diagnostic Aid in Diseases of the Ear, Nose and Throat”, by J. J. Knight, which actually, apart from two pages on “nose and throat”, deals only with the ear. After an introduction to the anatomy of the ear, which is quite informative, the author reviews types of hearing disorders and the principle,s and methods of subjective and objective audiometry. This, however, is done in a very qualitative, slightly unorganized way with large numbers of graphs, partly obvious to the acoustician, partly unintelligible without further explanation. The article may be of interest to physicians interested in learning new and quickly applicable methods of medical examination, but is quite unsatisfactory for the acoustician interested in general principles. The third and last article, which takes up half of the book is “Non-linear Acoustics” by L. Bjorno, a very readable, comprehensive resume of this increasingly important area. The article starts off with an interesting historical sketch of the developments leading to non-linear acoustics, followed by a chapter on the fundamental equations. The main part is taken up by the description of theoretical and experimental investigations of finite-amplitude waves in fluids. A short section on finite-amplitude waves in solids concludes this chapter. The physica. yet application-orientated approach of the introduction to the fundamental equations and the thoughtful and comprehensive discussion of finite-amplitude waves makes this article the finest introduction to non-linear acoustics the reviewer has seen. This volume has established the Acoustics and Vibration Progress series as an important source of information for acousticians and workers in related fields, and the reviewer is looking forward to the next volume. K. BROI) PHYSICSIN INDUSTRY1976 E. O’Mongain and C. P. O’Toole, editors. Oxford : Pergamon 612 pp. ; price E17.00. ISBN 0 08 020922X.
Press.
This book is a collection of papers which form the proceedings of an international conference held in Dublin during March 1976. As would perhaps be expected from the title, a wide range of topics is covered by the 85 papers included. The subject groups show that the papers cover fields ranging from technological aspects of experimental physics to data processing and biological applications. A section on acoustics is included but it is rather short as it contains only six papers which cover 40 pages out of a total of almost 600. The volume as a whole can
608
BOOK REVIEWS
therefore only be of restricted interest to those working in the field of acoustics. However, the acoustical papers, which essentially with one exception are reviews, would be of interest to anyone entering the field or wishing to read of the basic approaches to noise measurement, industrial noise sources and control. A good discussion is given of aerodynamic noise in theory and in practice and the use of ultrasonics in N.D.T. is also reviewed. The last acoustical paper reports on the development of ultrasonic lenses with variable focal length. The final comment, however, can only be that the proceedings will be of limited interest to the acoustician. R. G. WHITE