NATO Advanced Study Institute Series Research Articles

Near resonant bubble acoustic cross-section corrections, including examples from oceanography, volcanology, and biomedical ultrasound

The scattering cross-section sigma(s) of a gas bubble of equilibrium radius R(0) in liquid can be written in the form sigma(s)=4piR(0) (2)[(omega(1) (2)omega(2)-1)(2)+delta(2)], where omega is the excitation frequency, omega(1) is the resonance frequency, and delta is a frequency-dependent dimensionless damping coefficient. A persistent discrepancy in the frequency dependence of the contribution to delta from radiation damping, denoted delta(rad), is identified and resolved, as follows. Wildt's [Physics of Sound in the Sea (Washington, DC, 1946), Chap. 28] pioneering derivation predicts a linear dependence of delta(rad) on frequency, a result which Medwin [Ultrasonics 15, 7-13 (1977)] reproduces using a different method. Weston [Underwater Acoustics, NATO Advanced Study Institute Series Vol. II, 55-88 (1967)], using ostensibly the same method as Wildt, predicts the opposite relationship, i.e., that delta(rad) is inversely proportional to frequency. Weston's version of the derivation of the scattering cross-section is shown here to be the correct one, thus resolving the discrepancy. Further, a correction to Weston's model is derived that amounts to a shift in the resonance frequency. A new, corrected, expression for the extinction cross-section is also derived. The magnitudes of the corrections are illustrated using examples from oceanography, volcanology, planetary acoustics, neutron spallation, and biomedical ultrasound. The corrections become significant when the bulk modulus of the gas is not negligible relative to that of the surrounding liquid.

Ultrasonic determination of texture and residual stress in polycrystalline metals : Sayers, C.M. Ultrasonic Methods in Evaluation of Inhomogeneous Materials, Proceedings, Erice, (Italy), 15–25 Oct. 1985, pp. 367–380. Edited by A. Alippi and W.G. Mayer. NATO Advanced Study Institute Series E Applied Sciences, Vol. 126, Martinus Nijhoff, 1987

Ultrasonic determination of texture and residual stress in polycrystalline metals : Sayers, C.M. Ultrasonic Methods in Evaluation of Inhomogeneous Materials, Proceedings, Erice, (Italy), 15–25 Oct. 1985, pp. 367–380. Edited by A. Alippi and W.G. Mayer. NATO Advanced Study Institute Series E Applied Sciences, Vol. 126, Martinus Nijhoff, 1987

Characterization of porous media with elastic waves: 40582 Tittmann, B.R. Ultrasonic Methods in Evaluation of Inhomogeneous Materials, Proceedings, Erice, (Italy), 15–25 Oct. 1985, pp. 301–322. Edited by A. Alippi and W.G. Mayer, Nato Advanced Study Institute Series E Applied Sciences, Vol. 126, Martinus Nijhoff, 1987

Characterization of porous media with elastic waves: 40582 Tittmann, B.R. Ultrasonic Methods in Evaluation of Inhomogeneous Materials, Proceedings, Erice, (Italy), 15–25 Oct. 1985, pp. 301–322. Edited by A. Alippi and W.G. Mayer, Nato Advanced Study Institute Series E Applied Sciences, Vol. 126, Martinus Nijhoff, 1987

Stereo perception in callosal agenesis and partial callosotomy

Stereoperception in two acallosal patients and two partial callosotomy patients was compared with that of three normal subjects. All three patients with the splenium missing, whether due to agenesis or surgical intervention, showed midline deficits and broadly similar profiles; namely, they made few uncrossed midline responses. The patient with partial callosal section but with the splenium almost totally spared performed better at the midline than in the periphery. All degrees of disconnection produced some overall loss of performance, confirming the results of H AMILTON and V ERMEIRE (In Two Hemispheres—One Brain, F. L EPORE, M. P ITTO and H.H. J ASPER (Editors), pp. 315–333. Alan R. Liss Inc., New York, 1986) and H AMILTON et al. ( Suppl. Invest. Ophthal. Vis. Sci. 28, 294, 1987). The results are discussed in the context of earlier reports of human and animal studies of stereoperception. Bearing in mind reports of structural alterations in layer III of the striate cortex in acallosals (S HOUMJRA, K. et al. Brain Res. 93, 241–252, 1975. Also, A KERT, K. et al. Trans. Am. Neurol. Assoc. 79, 151–153, 1954), it is speculated that the specific difficulties encountered by them in handling uncrossed disparities may be due to a marked reduction or absence of far neurones in acallosal brains (P OGGIO, G.F. and P OGGIO, T. Ann. Rev. Neurosci. 7, 379–412, 1984). The likely importance of the anterior commissure in the efficient integration of crossed disparity ( near neurones) (C OWEY, A. In Brain Mechanisms and Spatial Vision, D. I NGLE (Editor), NATO Advanced Study Institute Series, Martinus Nijhoff, The Hague, 1985) is seen as a possible explanation of the acallosals relative success in making crossed disparity judgements. The variability of performance in normals documented by H AMILTON and V ERMEIRE (In Two Hemispheres—One Brain, F. L EPORE, M. P ITTO and H.H. J ASPER (Editors), pp. 315–333. Alan R. Liss Inc., New York, 1986) and H AMILTON et al. ( Suppl. Invest. Ophthal. Vis. Sci. 28, 294, 1987) is, not surprisingly, even more marked amongst acallosals.

Cryogenic acoustic microscopy : Cheeke, J.D.N. Ultrasonic Methods in Evaluation of Inhomogeneous Materials, Proceedings, Erice, (Italy), 15–25 Oct. 1985, pp. 123–162. Edited by A. Alippi and W.G. Mayer. Nato Advanced Study Institute Series E Applied Sciences, Vol. 126, Martinus Nijhoff, 1987

In order to improve the piezoelectric properties of ferroelectric materials, an optimization based method is developed to identify the topology of the piezoelectric material in the unit cell. A mathematical model is first established to identify the relationship between the piezoelectricity and some observable or measurable parameters in the unit cell. As for single crystal, the noncollinear polarization angles are chosen as the optimization variables. While for polycrystalline materials, the orientations of the grain are chosen as the optimization variables, which falling in a Gaussian distribution after poling. Since it is impossible to analyze all possible combinations of the distribution parameters or the angles, the differential evolution (DE) is applied to solve the proposed optimization model as a widely used global optimization method. Numerical experiments are carried out in Pb(Mg1/3Nb2/3)O3–PbTiO3(PMN–PT) for both single crystals and polycrystalline materials. A good agreement is achieved with the published data in single crystals, and the distribution parameters with enhanced piezoelectric properties are obtained for crystals. This study provides a fundamental perspective to enhance the piezoelectricity by designing of microscopic crystal morphology.

Characterisation through thermal waves: applications of optoacoustic and photothermal methods : Busse, G. Ultrasonic Methods in Evaluation of Inhomogeneous Materials, Proceedings, Erice, (Italy), 15–25 Oct. 1985, pp. 105–119. Edited by A. Alippi and W.G. Mayer. NATO Advanced Study Institute Series E Applied Sciences, Vol. 126, Martinus Nijhoff, 1987

Characterisation through thermal waves: applications of optoacoustic and photothermal methods : Busse, G. Ultrasonic Methods in Evaluation of Inhomogeneous Materials, Proceedings, Erice, (Italy), 15–25 Oct. 1985, pp. 105–119. Edited by A. Alippi and W.G. Mayer. NATO Advanced Study Institute Series E Applied Sciences, Vol. 126, Martinus Nijhoff, 1987

Ultrasonic determination of texture and residual stress in polycrystalline metals : Sayers, C.M. Ultrasonic Methods in Evaluation of Inhomogeneous Materials, Proceedings, Erice, (Italy), 15–25 Oct. 1985, pp. 367–380. Edited by A. Alippi and W.G. Mayer. NATO Advanced Study Institute Series E Applied Sciences, Vol. 126, Martinus Nijhoff, 1987

Ultrasonic determination of texture and residual stress in polycrystalline metals : Sayers, C.M. Ultrasonic Methods in Evaluation of Inhomogeneous Materials, Proceedings, Erice, (Italy), 15–25 Oct. 1985, pp. 367–380. Edited by A. Alippi and W.G. Mayer. NATO Advanced Study Institute Series E Applied Sciences, Vol. 126, Martinus Nijhoff, 1987

Study of the dislocation dynamics by ultrasonic cyclic bias stress experiments Gremaud, G. Ultrasonic methods in evaluation of inhomogeneous materials, proceedings, Erice, (Italy), 15–25 Oct. 1985, pp. 187–196. Edited by A. Alippi and W.G. Mayer, Nato Advanced Study Institute Series E Applied Sciences, vol. 126, Martinus Nijhoff, 1987

Study of the dislocation dynamics by ultrasonic cyclic bias stress experiments Gremaud, G. Ultrasonic methods in evaluation of inhomogeneous materials, proceedings, Erice, (Italy), 15–25 Oct. 1985, pp. 187–196. Edited by A. Alippi and W.G. Mayer, Nato Advanced Study Institute Series E Applied Sciences, vol. 126, Martinus Nijhoff, 1987

Study of the dislocation dynamics by ultrasonic cyclic bias stress experiments: Gremaud, G. Ultrasonic methods in evaluation of inhomogeneous materials, proceedings, Erice, (Italy), 15–25 Oct. 1985, pp. 187–196. Edited by A. Alippi and W.G. Mayer, Nato Advanced Study Institute Series E Applied Sciences, vol. 126, Martinus Nijhoff, 1987

Study of the dislocation dynamics by ultrasonic cyclic bias stress experiments: Gremaud, G. Ultrasonic methods in evaluation of inhomogeneous materials, proceedings, Erice, (Italy), 15–25 Oct. 1985, pp. 187–196. Edited by A. Alippi and W.G. Mayer, Nato Advanced Study Institute Series E Applied Sciences, vol. 126, Martinus Nijhoff, 1987

Ultrasonic determination of texture and residual stress in polycrystalline metals: Sayers, C.M. Ultrasonic methods in evaluation of inhomogeneous materials, proceedings, Erice, (Italy), 15–25 Oct. 1985, pp. 367–380. Edited by A. Alippi and W.G. Mayer. NATO Advanced Study Institute Series E Applied Sciences, vol. 126, Martinus Nijhoff, 1987

Ultrasonic determination of texture and residual stress in polycrystalline metals: Sayers, C.M. Ultrasonic methods in evaluation of inhomogeneous materials, proceedings, Erice, (Italy), 15–25 Oct. 1985, pp. 367–380. Edited by A. Alippi and W.G. Mayer. NATO Advanced Study Institute Series E Applied Sciences, vol. 126, Martinus Nijhoff, 1987

Recent advances in group theory and their application to spectroscopy. by John C. Donini, ed., nato advanced study institute series, vol. b43. plenum press, new york, 1979, pp xii + 692.

Recent advances in group theory and their application to spectroscopy. by John C. Donini, ed., nato advanced study institute series, vol. b43. plenum press, new york, 1979, pp xii + 692.

Twistor theory and the Einstein equations

R. Penrose (in Advances in twistor theory , pp. 168‒176, and in Cosmology and gravitation ; Nato advanced study institute series , pp. 287‒316 (1980). New York: Plenum Press) has argued that the goal of twistor theory with regard to the vacuum Einstein equations ought to consist of some kind of unification of twistor-theoretic descriptions of anti-self-dual (a. s. d. ) and self-dual (s. d. ) space-times. S. d. space‒times currently possess a description only in terms of dual twistor space, however, rather than twistor space. In this paper, suggestions due to Penrose for providing a purely twistor space description of s. d. space‒times are investigated. It is shown how the points of certain s. d. space‒times define mappings on twistor space and the geometry of these mappings is studied. The families of mappings for two particular s. d. space‒times are presented explicitly.

Biological Effects and Dosimetry of Nonionizing Radiation (NATO Advanced Study Institutes Series, Series A: Life Sciences) edited by M. Grandolfo, S. M. Michaelson, and A. Rindi

<i>Biological Effects and Dosimetry of Nonionizing Radiation (NATO Advanced Study Institutes Series, Series A: Life Sciences)</i> edited by M. Grandolfo, S. M. Michaelson, and A. Rindi

Water resources and land use planning: A systems approach. P. Laconte and Y. Y. Haines (Eds). Nato Advanced Study Institutes Series D No. 11, Martinus Nijhoff, 1982

Water resources and land use planning: A systems approach. P. Laconte and Y. Y. Haines (Eds). Nato Advanced Study Institutes Series D No. 11, Martinus Nijhoff, 1982

Water Resources and Land-use Planning: A Systems Approach, Edited by P. Laconte &amp; Y. Y. Haimes. (NATO Advanced Study Institutes Series, Series D: Behavioural and Social Sciences, No. 11.) Martinus Nijhoff Publishers, The Hague, Netherlands: vi + 470 pp., illustr., 23 × 16 × 3 cm, Dfl 135, US $57.50, 1982.

Water Resources and Land-use Planning: A Systems Approach, Edited by P. Laconte &amp; Y. Y. Haimes. (NATO Advanced Study Institutes Series, Series D: Behavioural and Social Sciences, No. 11.) Martinus Nijhoff Publishers, The Hague, Netherlands: vi + 470 pp., illustr., 23 × 16 × 3 cm, Dfl 135, US $57.50, 1982. - Volume 11 Issue 2

Book reviews : Berger, A. editor, 1981: Climatic variations and variability: facts and theories. NATO Advanced Study Institutes Series. Dordrecht: D. Reidel. 795 pp. US $87.50

Book reviews : Berger, A. editor, 1981: Climatic variations and variability: facts and theories. NATO Advanced Study Institutes Series. Dordrecht: D. Reidel. 795 pp. US $87.50

Reviews: City Trenches: Urban Politics and the Patterning of Class in the United States, New Perspectives in Urban Change and Conflict, Topics in Applied Geography Series: The Geography of Urban Crime, Regional Wage Inflation and Unemployment, Welfare Economics and Urban Problems, NATO Advanced Study Institutes Series D, Number 4: Cities in Transition—Problems and Policies, Number 5: Locational Developments and Urban

Reviews: City Trenches: Urban Politics and the Patterning of Class in the United States, New Perspectives in Urban Change and Conflict, Topics in Applied Geography Series: The Geography of Urban Crime, Regional Wage Inflation and Unemployment, Welfare Economics and Urban Problems, NATO Advanced Study Institutes Series D, Number 4: Cities in Transition—Problems and Policies, Number 5: Locational Developments and Urban

Nonlinear Phenomena at Phase Transitions and Instabilities: Nato Advanced Study Institutes Series

B T Riste (ed) 1982 New York: Plenum xii + 481 pp price £37.49 This volume contains the invited lectures and contributed papers presented at the Nato advanced study institute on phase transitions and instabilities, held at Geilo, Norway in April 1981. An understanding of the role of anharmonicity in the treatment of structural phase transitions formed a central theme for this school, with interest in nonlinear excitations and solitons.

NOTICES OF RECENT PUBLICATIONS

Journal Article NOTICES OF RECENT PUBLICATIONS Get access Neurotransmitter Interaction and Compartmentation. Edited by H. F. Bradford. NATO Advanced Study Institute Series. 1982. Pp. 839. New York and London: Plenum Press. Price $95.00. PETER J. ROBERTS PETER J. ROBERTS Search for other works by this author on: Oxford Academic PubMed Google Scholar Brain, Volume 106, Issue 3, September 1983, Pages 783–784, https://doi.org/10.1093/brain/106.3.783 Published: 01 September 1983

Quantum dynamics of molecules: The new experimental challenge to theorists. Edited by R. G. Woolley. NATO Advanced Study Institute Series B57, Plenum, New York and London, 1980

International Journal of Quantum ChemistryVolume 22, Issue 5 p. 1083-1084 Book Review Quantum dynamics of molecules: The new experimental challenge to theorists. Edited by R. G. Woolley. NATO Advanced Study Institute Series B57, Plenum, New York and London, 1980 Jean-Louis Calais, Jean-Louis CalaisSearch for more papers by this author Jean-Louis Calais, Jean-Louis CalaisSearch for more papers by this author First published: November 1982 https://doi.org/10.1002/qua.560220519AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume22, Issue5November 1982Pages 1083-1084 RelatedInformation