Creation of Laser-Induced Long Ionized Channels in Air Suspension

Russian Physics Journal - The paper deals with the propagation of the powerful laser beam in gas-dispersion systems and atmospheric aerosol background, which is accompanied by a wide spectrum of...     

Electrical Conductivity in a Laser Beam Channel

Russian Physics Journal - Electrical conductivity in a laser beam channel has been investigated. Oscillations of the conductivity caused by the oscillation motion of electrons in laser-induced...     

Optimal output feedback stabilization

We show that optimal stabilization of a linear dynamic plant can be implemented on the basis of the solution of linear matrix inequalities even if the plant state cannot be measured. By way of example, we obtain optimal control laws for a double inverted pendulum assuming that only the lower link deflection angle is measured.     

Measurement of the Intensity Distribution of a Hard X-Ray Radiation Source

Physics of Atomic Nuclei - The procedure of measurement of the brightness distribution of the hard X-ray source of the MIB-7.5 betatron with a penumbral aperture is detailed (i.e., a measurement...     

Investigation of Dynamic Properties of Water-Saturated Sand by the Results of the Inverse Experiment Technique

We present new experimental results on the investigation of the dynamic properties of sand soil on the basis of the inverse experiment technique using a measuring rod with a flat front-end face. A limited applicability has been shown of the method using the procedure for correcting the shape of the deformation pulse due to dispersion during its propagation in the measuring rod. Estimates of the pulse maximum have been obtained and the results of comparison of numerical calculations with experimental data are given. The sufficient accuracy in determining the drag force during the quasi-stationary stage of penetration has been established. The parameters of dynamic compressibility and resistance to shear of water-saturated sand have been determined in the course of the experimental-theoretical analysis of the maximum values of the drag force and its values at the quasi-stationary stage of penetration. It has been shown that with almost complete water saturation of sand its shear properties are reduced but remain significant in the practically important range of penetration rates.     

Ionization Processes in a Carbon Aerosol Upon Exposure to Long Laser Pulses. I

Russian Physics Journal - The interaction mechanisms of low-energy long-duration (~1 ms) laser pulses with dispersed particles in air are considered. The basic equations describing the mechanisms...     

Experimental‐theoretical analysis of nonstationary interaction of deformable impactors with soil

An experimental method for determining the force of resistance to penetration of a deformable impactor into soft soil was developed in the inverted formulation: the impactor and the target exchange roles and the necessary parameters of contact interaction are recorded in an immovable measuring rod (impactor). To verify the basic principles of this experimental technique, wave processes were analyzed numerically using a modified Godunov's scheme. The applicability of various models of soil deformation was studied, and the calculation results obtained were compared with experimental data.