Interaction of an elastic wave with a plate

Within the framework of the dynamic theory of elasticity a numerical solution is set up for an axisymmetric problem which arises in connection with the problem of measuring stresses on the boundary between a solid medium and a rigid wall. In the cylindrical r, z coordinates the medium fills the cylinder z > 0, r < R, the case R being possible when the medium occupies the half-space z > 0. The elastic medium borders on a rigid wall which in the plane z = 0 has a deformable part in the form of a circular elastic plate clamped along the edges. A plane longitudinal wave in the form of a semiinfinite step falls from infinity. The interaction of this wave with the plate is investigated, with the main attention given to the study of the effect of the problem parameters on the deflection of the plate subjected to the wave.Deceased.Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 2, pp. 74–85, March–April, 1972.Concluding, the author thanks the participants of the Seminar on Dynamics of Solids, at the Institute of Problems of Mechanics, for the discussion of the paper.     

Kinetics of removal of dissolved iron from natural water

The relationships of iron(II) oxidation in water using a new type of aerator based on a disk disperser were studied. The oxidation rate constants and the iron(II) to iron(III) half-conversion time were determined. The iron(II) oxidation in water follows a first-order rate equation. Changes in the water quality parameters depending on the conditions of the iron(II) oxidation were analyzed.     

Iron Removal from the Groundwater by Aeration

Russian Journal of General Chemistry - The data on oxidation of iron(II) in aqueous medium using a novel device based on disc disperser are presented. The rate constants and half-time of the...     

Diffraction of an elastic wave in a disc

A numerical solution is constructed for the axisymmetric problem of the diffraction of a plane longitudinal wave in a rigid disc (cylinder) of finite thickness. The disc is enclosed in an unbounded elastic medium; at the contact surface, the tangential stresses are limited by some constant. The incident wave moves along the axis of the cylinder and has the form of a semiinfinite washed-out step. At the same time, a solution is obtained to the corresponding static problem. A study was made of the dependence of the rate of motion of the cylinder and the stress field on the parameters of the problem. In particular, it is shown that the contact conditions have a considerable effect on the stress field only near the lateral surface. The results obtained can be useful for evaluating the errors in measurement of the stresses and velocities in an elastic medium, and possibly also in certain other cases.Deceased.Translated from Zhurnal Prikladnoi Mekhaniki i Teknicheskoi Fiziki, No. 3, pp. 139–150, May–June, 1972.     

Interaction between an acoustic wave and a disc

A numerical solution is obtained to the problem concerning a pressure measurement at the boundary between an ideal compressible fluid and a solid wall. It is assumedthat the fluid occupies a semiinfinite cylinder with a rigid bottom into which an elastic disc is inserted and heldfirmly around its edges. Motion is produced by a pressure wave originating at infinity. A finite-difference grid for this application is described and the results of actual calculations are shown.Deceased.Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 1, pp. 84–91, January–February, 1972.The authors thank L. M. Flitman for reviewing the work.