Some Regularities of Heat and Mass Transfer in the Case of Fire Within a Building

Results of a numerical investigation of heat and mass transfer at the initial stage of fire within a building in combustion of kerosene, carried out with the use of a three-dimensional mathematical field model, are presented. A comparison of the distribution of the averaged temperatures and velocities along the vertical axis of the convective column and of the mass rates of gas flows through an open opening with the experimental data has been made. Substantial three-dimensional inhomogeneities of the velocities and the temperatures in the near-ceiling layer have been revealed. It has been established that near the opening there is a critical separation zone which influences significantly the parameters of natural gas transfer.     

Special features of the periodic-pulse-train laser radiation confinement in doped gallium arsenide and zinc selenide

Experimental data on the pulsed laser radiation confinement in compensated GaAs and ZnSe with deep impurity levels are reported for the laser wavelength λ=1.55 μm and a pulse repetition frequency of up to 100 kHz. It is demonstrated that an increase in the pulse repetition rate is accompanied by a decrease in the energy confinement threshold and by an increase in the radiation attenuation coefficient. These effects are explained by the accumulation of nonequilibrium charge carriers related to a dependence of the recombination time constant on the concentration of free impurity centers.     

Adaptive Optimal Nonlinear Filtration and Certain Related Topics. II

The properties of the solutions of optimal parametric filtration equations and an adaptive variant of the problem with regard for time-drift of the unknown parameters of the system are studied. Along with the Kalman interpretation of the optimal adaptive nonlinear filter, the Bayes approach to applying the respective a posteriori densities is also studied.     

Mechanisms of Active Fuzzy Expertise

Consideration was given to the decision making procedures based on the fuzzy messages of experts whose preferences on the set of collective decisions can also be fuzzy.     

High-voltage bridge for measuring spontaneous polarization,dielectric constants,and conductivity of ferroelectric crystals

Translated from Izmeritel'naya Tekhnika, No. 9, pp. 34–35, September, 1989.