Portable BΔ-12HΦM and BΔ-12HΦΠ eddy-current flaw detectors

The scope of application, specific features of design and operation, and the main technical characteristics of portable BΔ-12HΦM and BΔ-12HΦΠ eddy-current flaw detectors are considered.     

Transportable quantum clocks based on a hydrogen generator with a small resonator

Translated from Izmeritel'naya Tekhnika, No. 4, pp. 17–18, April, 1989.     

Identification of commutative covariance structures by successive testing of statistical hypotheses

For the multidimensional stochastic systems obeying the regression models with unknown covariances of disturbances, consideration was given to the choice of a covariance model and estimation of its parameters. The invariant behavior of the regression model with the covariance matrix of a special structure was studied. In the problem of identifying the structure of a set of feasible covariance matrices, a procedure of successive testing of hypotheses was proposed. The unbiased and invariant uniformly optimal estimates of the parameters of the observation-based model were determined. The problem of identifying the model of covariances in experiment design with random factors was considered as an example.Translated from Avtomatika i Telemekhanika, No. 3, 2005, pp. 48–64.Original Russian Text Copyright © 2005 by Sysoev, Shaikin.This paper was recommended for publication by V.A. Lototskii, a member of the Editorial Board     

Coordinate methods for evaluating deviation of surface shapes of large ellipsoidal components

We present a method and algorithms that are rather efficient for application to identification of large ellipsoidal surfaces for floors or lids of nuclear reactors, chemical reservoirs, etc. The method is based on the use of an unconventional metric. Translated from Izmeritel'naya Tekhnika, No. 12, pp. 13–16, December, 1997.     

Thermophysical analysis of thermal polymerization of silica-organic cladding for silica fibers

The paper shows the advantages of graded furnaces for the thermal polymerization of a silica-organic polymer cladding for silica fibers. Owing to the optimal longitudinal distribution of the heaters a fivefold increase of the fiber drawing speed can be achieved using heaters of the same lengths and power.     

Exact Solutions of Navier–Stokes,Boundary-Layer,and Heat-Conduction Equations

Multiparametric families of exact solutions are obtained for the steady-state two-dimensional Navier–Stokes equations in Cartesian, polar, and cylindrical coordinates. General exact solutions depending on arbitrary functions are derived for the equations of a nonstationary axisymmetric boundary layer. New noninvariant solutions of the heat conduction equation are presented. Various modifications of the method of generalized (and functional) separation of variables are used in seeking exact solutions.