[en] A method is proposed to characterize single-fiber composite interphases from the frequency-domain characteristics of scattered ultrasonic waves, and its feasibility is investigated theoretically. It has been shown that the locations and magnitudes of the peaks and valleys in the frequency domain are affected significantly by the interphase properties, which may indicate the effectiveness of the proposed method. Although the frequency-domain behavior is basically associated with the resonance of the fiber-interphase system, it is not dominantly affected by the scatterer's resonance unlike that in the case of acoustic wave scattering. Therefore, the conventional acoustic resonant scattering theory is not directly applicable to the characterization of composite interphases. In order to solve the inverse problem of predicting the interphase properties from the frequency-domain characteristics of the ultrasonic scattered waves, an artificial neural network has been constructed. This approach has demonstrated reasonable accuracy in most cases considered in this study

[en] A review of the recent works on electric field gradient in metals is given. The main emphasis is put on the temperature dependence of the electric field gradient in nonmagnetic metals. Some methods of investigation of this effect using nuclear probes are described. One of them is nuclear accoustic resonance method. (S.B.)

[en] The major aims in tissue characterization are the differentiation between normal, benign and malignant (primary/metastasic) tissues. Usually the information of standard spin echo images as well as the MR parameters T1, T2 and spin density are used for clinical diagnosis. Pattern recognition methods are applied to improve the specifity of MRI. The variety of all these parameters requires the selection of the parameters containing the relevant diagnostic information. Therefore images with optimum contrast to a given diagnostic task are generated

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[en] We have performed detailed numerical calculations for nuclear-acoustic-resonance line shapes appropriate for Ta where the spin relaxation is dominated by mobile hydrogen impurities. These calculations include intraspin cross relaxation due to defect-generated static electric field gradients. The calculated line shapes show a large amount of structure and are in almost complete quantitative agreement with recent experimental results

[en] After a brief summary of the theoretical bases of nuclear acoustic resonance (NAR) and of the experimental techniques used to detect NAR, a detailed review is given of results obtained in the application of NAR to the study of metals, metal hydrides, and alloys. (Auth.)

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