Phase space representation of sound field excited by a noise source in underwater acoustic waveguide.

The analysis of the field excited in a waveguide by a point noise source is performed using the phase space representation of this field given by the distribution of its amplitude in the depth-angle-time space. The transition from the traditional description of the field amplitude as a function of depth and time to phase space representation is performed using the coherent state expansion developed in quantum mechanics. In this paper, the correlation function of noise signals arriving at different points of the phase plane depth-angle is investigated.

Ray-based description of shadow zone arrivals.

Field experiments and numerical simulation show that due to scattering from internal-wave-induced sound speed perturbations, the sound energy at megameter ranges penetrates well below the unperturbed timefront, i.e., into the geometric shadow.

Ray-based description of normal modes in a deep ocean acoustic waveguide.

Modal structure of the wave field in a deep ocean environment with sound speed fluctuations induced by random internal waves is considered. An approximate analytical description of the modal structure at megameter ranges is derived by combining two known results: (i) relations expressing mode amplitudes through parameters of ray paths and (ii) stochastic ray theory. For a monochromatic wave field, a simple analytical estimate has been obtained for a coarse-grained distribution of acoustic energy between normal modes.

Statistical description of chaotic rays in a deep water acoustic waveguide.

This paper analyzes the chaotic ray dynamics at multimegater ranges in a deep water environment with internal-wave-induced fluctuations of the sound speed. The behavior of acoustic ray paths is investigated using the Hamiltonian formalism expressed in terms of action-angle variables. It is shown that the range dependence of the action variable of chaotic ray can be approximated by a random Wiener process.

[Administration of the immunomodulator gepon after tonsillectomy].

The study included 37 patients with chronic tonsillitis. Before and after tonsillectomy all the patients' humoral and cellular immunities were studied. Local thermometry and physiological test "pharynx" were made.