Influence of the Design of Metal Receivers of Slab Continuous-Casting Machines on the Motion of Flow in the Tundish in the Case of Deviations of the Metal Stream from the Required Position. Part II. Procedure of Simulation1

Refractories and Industrial Ceramics - We study the problem of evaluation of the influence of design of the metal receiver of a large-capacity tundish of slab continuous-casting machine on the...     

Model of heating of the lining of a steel-teeming ladle

The thermal fields of the refractory linings of metallurgical equipment are investigated. Using as an example the lining of a steel-teeming ladle, mathematical modeling of the thermal fields in preliminary heating of the ladle and during smelting is performed. An approach to the construction of thermal fields, assuming the presence of defects in the lining and in the case of intersecting thermal fields, is proposed.     

Effect of <Emphasis Type="Italic">d</Emphasis>-metal hydroxides on water dissociation in bipolar membranes

Methods of electrochemical impedance, voltammetry, and ion transport numbers are used to study bipolar membranes that contain hydroxides of transition metals on the bipolar boundary. It is shown that the introduction of hydroxides significantly increases the rate of water dissociation in bipolar membranes, and the catalytic activity of transition metal compounds depends on the nature of the metal. It was found that the pseudounimolecular rate constants of the rate-limiting steps of dissociation calculated from the thermodynamic and kinetic data are two orders of magnitude higher than the effective constants derived from experiment. This suggests that only a small fraction of the surface of metal hydroxide particles is in the space-charge region (bipolar region), in which the dissociation of water molecules occurs in high-intensity electric fields.     

Reaction between carbon fibers and nickel through a zirconium nitride or titanium carbide diffusion barrier

Conclusions Carbon fibers in contact with nickel suffer a pronounced loss of strength at temperatures above 600°C as a result of surface attack by the nickel (at temperatures of 800–900°C and treatment times of 10–20 h) or recrystallization (during heating for more than l h at 1000°C). There is no unique correlation between fiber structure and strength. A zirconium nitride coating fails to prevent carbon fibers from reacting with nickel. A titanium carbide coating reduces, even at high temperatures, the strength loss experienced by carbon fibers by decreasing the rate of dissolution of the material of the fibers in nickel and by slowing down the fiber recrystallization process.Translated from Poroshkovaya Metallurgiya, No. 7(175), pp. 32–35, July, 1977.     

Dipole-Dipole Interaction in a Helical Molecular Aggregate

The formation and dynamics of excitations in an atomic or molecular nano chain of a helical shape are studied. The dipole-dipole interaction between the circular polarizations of the optical transitions of neighboring molecules is taken into account. The derived Bloch equations are solved in a continuum approximation using the Frenet–Serret coordinate system. Solutions are obtained that describe the formation of stable localized structures (solitons) due to the curvature of the chain, which can have a critical influence on the luminescent properties of the chiral medium.     

Influence of Response Nonlocality of a Medium on Soliton Polarization

Optoelectronics, Instrumentation and Data Processing - Influence of nonlocality on the polarization dynamics of an electric field pulse in a medium with cubic nonlinearity is under study. Nonlinear...