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We analyze the results of an experiment using an explosive sound source in the tropical part of the Indian Ocean. We consider the time structure of sound signals in geometric shadow zones to a distance of 270 km and the scheme of how the sound field in the shadow zone is formed by rays reflected from horizontally extended fine-structured sound velocity layers. From the results of calculation using a wave program that realizes the method of psuedodifferential parabolic equations, we analyze the influence of signal scattering by fine-structure sound velocity inhomogeneities on the sound field distribution in a waveguide. We show that the field formed by spots of light in each of the shadow zones is generated by a regular field and propagates in parallel to it, taking energy from the regular zone in the near field and in each subsequent convergence zone. This mechanism causes an additional decrease in the field in illuminated zones, which can be interpreted as additional attenuation of the regular sound field.

A wave-field computer code based on the wide-angle parabolic equation is used to analyze the data of the in-sea experiment on sound scattering by fractal inhomogeneities of the sound speed in the central part of the tropical zone of the Indian Ocean. Good agreement is obtained with the previous interpretation of the same data in terms of the model describing the penetration of sound into a shadow zone, which combines ray acoustics with the wave-field description of the scattering events in caustic zones. The previously drawn conclusion about the possibility of diagnosing and monitoring fractal-type fine-structural inhomogeneities by acoustic methods is confirmed.

The wave-field computer code based on the wide-angle parabolic equation is modified and adapted to the problems of sound scattering in a medium with anisotropic inhomogeneities of fractal type. To verify the computer code, a model numerical experiment on determining the angular dependence of the scattered sound field is performed for different anisotropy coefficients of the sound speed inhomogeneities. The comparison of the computed data with the theoretical dependences shows their rather good agreement and indicates that the computer code can be applied to calculations of sound propagation in the ocean with fine-structure inhomogeneities possessing fractal properties.

The experimental data on the sound field structure, which were obtained by emitting a continuous pseudonoise signal (a midfrequency of 3.2 kHz) in a two-channel oceanic waveguide, are compared with the calculations performed by the wave program with allowance for the fine structure of the sound speed inhomogeneities. A considerable increase in the intensity of the sound field with a definite angular spectrum is observed in the upper channel in the first shadow zone, and, in the experiment, the increase begins nearer to the sound source than predicted by the wave and ray calculations for a smooth sound speed profile. These features of the field structure are explained by the illumination of the shadow zone by the regular scattering of signals from highly anisotropic fine-structure inhomogeneities of the sound speed profile, which are clearly pronounced in the region of the given oceanic experiment.

In analyzing experimental results obtained with explosive sources in the tropical zone of the Indian Ocean, a good agreement was obtained for spectral-energy characteristics of signals observed in the first geometrical shadow zone with computer calculations of the sound field scattered by fine structure inhomogeneities of the fractal type. From the comparison of the results of calculating the frequency characteristics of sound fields in the shadow zone by the wave code and by the method combining ray acoustics with the wave theory of sound scattering, it was found that both methods are appropriate for describing the real processes of scattering and propagation of sound in the ocean with fine-structured stratification and that these methods can be used for solving inverse problems.

The results of a computer modeling of sound propagation in the ocean with fine-structured inhomogeneities are presented. The modeling was performed using a wave code based on the wide-angle approximation, which allows one to estimate the effects of sound field perturbations. These effects include the insonification of the geometric shadow zones and the abnormal attenuation of low-frequency sound in the course of its propagation in an oceanic waveguide. Calculations clearly demonstrate that the fine-structured inhomogeneities of the sound velocity considerably affect the sound propagation in the ocean.

The amount and degree of detail of the initial information are analyzed as applied to the new method of ocean bottom mapping on the basis of the fine structure of the bottom-reflected sound field at normal incidence. For the mapping data obtained with a planar multielement receiving array, the distortions caused by insufficiently detailed information derived from discrete measurements of the bottom-reflected amplitude are considered. The relations between the number of receivers, the receiver spacing, the array aperture, and the horizontal correlation length of the sound field are determined. The problem is solved by computer simulation with the use of generalized quantitative data obtained in deep-water ocean experiments.

The regional variability of the phenomenon of the shadow zone insonification in the ocean is manifested in the variability of the main parameters of the sound signals that penetrate into these zones because of the scattering by the fine-structure inhomogeneities of the refractive index. The intensity of the phenomenon is governed by a combination of the vertical distribution of intensity of the fine-structure inhomogeneities and the caustics that exist in the insonified domains, along with the caustic intensity and position, both of which depend on the mean sound speed profile and on the geometry of the experiment. For the chosen typical regions of the ocean, the characteristics of the fine structure are systematized, and the phenomenon under study is analyzed. The results obtained offer a justified approach to solving inverse problems and a way to perform practical-purpose studies aimed at improving the ultimate performance of underwater observation and monitoring systems.

A specific addition of protein nitrogen was obtained in the agglutinate of dermatol particles, covered by antigen. Protein combined with azo-dye with bis-diazotized dianisidine gives stable sorption on the surface of the paper, cotton material or cotton wool. Such paper azo-antigen gives a pronounced specific addition of protein nitrogen which comes from the proteins of the antiserum. Analogous data were obtained with native paper antigens, secured by simple drying of the protein solution in which chromatographic paper is soaked. Reaction of specific fixation of the protein nitrogen on the surface of the paper antigen represents an easily performed new serological reaction in immunology. This reaction gives a numerical value of quantitative characteristics of the immunological antigen-antibody relation.

As a result of the comparative study of the serological properties of the various fractions of the anticancer serum of the horse by different methods, it has thus been shown that the serological activity is concentrated mainly in the γ-globulin fraction and, to some extent, is present also in the α1, α1 and β-globulin fractions, and this must be taken into consideration during the production of purified, concentrated preparations. The method of determination of the serological activity of an anticancer preparation which we have developed expresses this as units of activity towards malignant and normal human tissues.

Bases on the analysis of 10 clinical observations, it was found that closed injuries of the diaphragm occur mainly in the use of great mechanic force (compression, a fall from great height, an impact of quick-acting object). In the acute period these are frequently not accompanied by diaphragmatic hernia and remain unrecognized. It is the author's opinion that in early diagnosis of acute diaphramatic hernia clinical symptoms play no leading role, but chest roentgenography is of primary importance. The terms of surgical treatment and the choice of the operative access are determined by general patient's state and the character of associated lesions.