Hybridization of acoustic waves in piezoelectric plates

The conditions for hybridization of the zero-order and high-order acoustic waves propagating in a piezoelectric crystal plate have been studied. The dependence of the phase velocity of the hybrid waves on the parameter hf (h is the plate thickness and f is the wave frequency) is established for the potassium niobate and lithium niobate plates possessing various crystallographic orientations and conductivities. It is found that hybridization takes place when the conductivity of a thin surface layer exceeds a certain critical value, which can vary within broad limits depending on the plate material and orientation. The degree of dispersive repulsion of the coupled modes grows with increasing electromechanical coupling coefficient.     

Multipurpose electroslag remelting furnace for modern energy and heavy engineering industry

In 2011, a unique complex based on a multipurpose unit-type electroslag remelting (ESR) furnace is created to meet the demand for large high-quality solid and hollow billets for the products of power, atomic, petrochemical, and heavy machine engineering. This complex has modern low-frequency power supplies with a new control level that ensure a high homogeneity and quality of the billets and an increase in the engineering-and-economical performance of the production. A unique pilot ESR furnace is erected to adjust technological conditions and the main control system elements.     

Modeling the System of Determination of the Motion of a Technological Platform Using GLONASS Positioning and Newtonometry Data

Technical Physics Letters - Theoretical models of reconstruction of the linear and angular parameters of motion using onboard integrated GLONASS systems with a two-position data receiver and...     

Technological possibilities of manufacturing high-grade ferrotitanium from crude ore

The content of metal and oxide phases that form during aluminothermic melting of a mixture of ilmenite and rutile concentrates is studied by X-ray diffraction, electron probe, and metallographic analyses. The main components of the high-grade ferrotitanium melted from the crude ore are represented by the solid solutions of oxygen and iron in titanium and the Ti₄Fe₂O phase, which is not reduced to TiO₂. It has been shown experimentally that rich ferrotitanium (60–70% Ti) containing <5 wt % oxygen cannot be produced by the aluminothermic melting of the crude ore.     

Spatial and spectral calibration of an acousto-optical spectrometer

The problem of determining the optical spectra at separate points of images that are recorded with an endoscopic acousto-optical spectrometer is considered. The factors that cause distortions in images and spectra are investigated. Algorithms for calibration of this type of instruments and digital data correction for the sequential elimination of distortions of various types are developed. In a model experiment, it is shown that the proposed algorithm provides a quite high quality of determining spectra at arbitrary points of the field of vision.     

Calculation of the temperature field of heated transport cylinders with a liquid filler

The concentrated element method allows efficiently solving problems of calculating the temperature field of multiphase objects. Numerical modeling of thermal processes in an induction-heated drum with a liquid filler allowed selecting the rational drum design that ensured a high degree of uniformity of the temperature field around its working zone. The method can be used in designing not only cylinders but also other heated equipment. St. Petersburg State University of Technology and Design. Translated fromKhimicheskie Volokna, No. 1, pp. 52–54, January–February, 1999.