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The article describes the developed asymmetric self-oscillating hydraulic drive and a stand for determining its dynamic characteristics. The design feature of the self-oscillating drive is that the switching of the working fluid in the cylinder cavity is made by two spools mounted inside the piston, while the working fluid is supplied to the spools by the hollow rod. The test stand is based on the principle of throttling the working fluid when it flows from one cavity of the loaded hydraulic cylinder to another. Stand tests of the developed drive have shown its reliability at different values of the piston stroke and at different operating pressures. The paper presents the characteristics of the drive when operating under load and at idle..

Currently, there are no sufficiently effective submersible vibrators for the implementation of a promising technology for vibro-seismic impact on oil and gas reservoirs. In this paper, we consider the possibility of using a downhole elastic wave generator based on a two-stage centrifugal nozzle for the vibro-seismic impact technology (VSIT). The equation of non-stationary fluid flow through the nozzle has the form of a nonlinear Van der Pol differential equation. In this paper, when using the method of studying this equation in the Matlab/Simulink application package, the principal possibility of tincture of a well generator to the dominant frequency of an oil reservoir is shown. The result of the study showed that when using an automatic control system, taking into account the hydraulic flow and pressure transmission line, the elastic wave generator can be controlled by the generation frequency with the accuracy necessary for vibro-seismic action on oil and gas formations.

The inverse problem of voice source pulse recovery from a segment of a speech signal is under consideration. A special mathematical model is used for the solution that relates these quantities. A variational method of solving inverse problem of voice source recovery for a new parametric class of sources, that is for piecewise-linear sources (PWL-sources), is proposed. Also, a technique for a posteriori numerical error estimation for obtained solutions is presented. A computer study of the adequacy of adopted speech production model with PWL-sources is performed in solving the inverse problems for various types of voice signals, as well as corresponding study of a posteriori error estimates. Numerical experiments for speech signals show satisfactory properties of proposed a posteriori error estimates, which represent the upper bounds of possible errors in solving the inverse problem. The estimate of the most probable error in determining the source-pulse shapes is about 7-8% for the investigated speech material. It is noted that a posteriori error estimates can be used as a criterion of the quality for obtained voice source pulses in application to speaker recognition.

We report on accurate measurements of the scalar αS and tensor αT polarizabilities of the 5D fine structure levels 5D3/2 and 5D5/2 in Rb.