Effect of electrohydropulsed treatment on the characteristics of the fine structure of 30KhN2MFA steel

Translated from Fiziko-Khimicheskaya Meckhanika Materialov, No. 6, pp. 77–80, November–December, 1989.     

Estimation of the matrices of parameters and covariations of the perturbation vectors in multidimensional discrete-time dynamic systems under special structure of the unknown covariance matrices

For the multidimensional linear dynamic system obeying a difference equation with an unknown covariance matrix of the vector of random perturbations having dependent components, consideration was given to estimation of the matrix of system parameters and the covariance matrix represented by a linear combination of the given symmetrical matrices. The family of joint probability densities of the observation vector was factorized, and the sufficient statistics was determined. For the estimates of the maximum likelihood of the system parameter matrices and the estimates of the coefficients of expansion of the covariance matrix, equations were presented. Developed was a recurrent procedure for joint estimation of the system parameter matrices and the covariance matrix with arrival of observations.     

Exact Solutions of Nonlinear Unsteady-State Equations of Mass and Heat Transfer with Bulk Reaction

New exact solutions of some nonlinear unsteady-state mass- and heat-transfer equations are obtained by functional separation of variables. Nonlinearities related to the complex kinetics of chemical reactions and the dependence of the transfer coefficients on concentration or temperature are considered. Particular attention is given to the solutions of equations containing arbitrary functions.     

Control of membrane drives

A method is proposed for increasing the efficiency of membrane drives by adjusting the effective area of the membrane. A device with adjustable effective area of the membrane is developed, with variation in the rod force by changing the working pressure in the chamber.     

Reconstruction of the coupling architecture in an ensemble of coupled time-delay systems

A method for reconstructing the coupling architecture and values in an ensemble of time-delay interacting systems with an arbitrary number of couplings between ensemble elements is proposed. This method is based on reconstruction of the model equations of ensemble elements and diagnostics of the coupling significance by successive trial exclusion or adding coupling coefficients to the model.     

Experience in Using PR-50 and PR-51 Polymetallic Reforming Catalysts

In 1977-1979, Ryazan' Oil Refinery was the first in the industry to convert all reforming units to KR-102, KR-104, and KR-106 polymetallic catalysts. The individual stages of the process were perfected, which allowed improving the technical and economic indexes of operation of the units in comparison to the indexes for the monometallic AP-64 catalyst [1–3]. KR-108 and KR-110 catalysts, primarily distinguished by high selectivity, were used in three reforming units in 1982-1983 [4]. These catalysts were the most widely used in the industry and were successfully used to the beginning of the 1990s [5].     

Effect of Pb ions on the optical absorption in Gd<Subscript>3</Subscript>Ga<Subscript>5</Subscript>O<Subscript>12</Subscript> epitaxial films

We have studied the effect of Pb²⁺ impurities and Pb²⁺-Pb⁴⁺ pairs on the optical absorption between 200 and 860 nm in single-crystal gadolinium gallium garnet films grown by liquid-phase epitaxy from supercooled PbO-B₂O₃ fluxed melts containing 0.1–0.5 mol% gadolinia.     

Use of hollow glass microspheres in organosilicon syntact foam plastics

The use of hollow glass microspheres in syntact foam plastics with organosilicon binders is described. The physicomechanical and thermophysical properties of the heat-insulating materials obtained are investigated. Translated from Steklo i Keramika, No. 2, pp. 11–12, February, 2000.