VOL 82, No. 5 (2009)

The EPR and optical absorption spectra of V ⁴⁺ ions and their relationship with the structural features of glasses of the La ² O ³ - Al ^{2 < / sup> O 3 - SiO 2. Three characteristic ranges of EPR parameters of V 4+ ions have been established: I - A _II & # 8776; 167 x 10 -4 cm -1, g _II = 1.937 - 1.938; II - A _II & # 8776; (163... 164) x; 10 -4 cm -1, g _II = 1.939 - 1.940; III - A _II & # 8776; (156... 159) ?; 10 -4 cm -1, g _II = 1.945. It was shown that in the region with a low La ₂ O ₃ content, lanthanum plays predominantly the role of a modifier ion, while in glasses with a high La ₂ O ₃ lanthanum gradually takes a place in the glass network, linking silicon-oxygen and alumino-oxygen tetrahedrons, i.e., it becomes a glass former despite the large ionic radius. Glasses in region III with a high La ₂ O ₃ content have a high softening point and an abnormally high thermal conductivity (& # 8776; 12.6 W / (m * K)) .Table. 2, ill. 6, bibliography: 10 titles.}

The effect of small additions of phosphorus oxide on the optical transmission of silicate glasses in the visible and near-IR regions has been studied. It is shown that an increase in the phosphorus concentration is accompanied by an increase in absorption in the IR region, which is due to an increase in the relative content of ferrous iron and its possible transition to octahedral coordination. The increase in absorption in the visible region is insignificant and cannot become an obstacle for doping industrial silicate glasses with phosphorus. Tab. 1, ill. 2, bibliography: 6 titles.

One of the techniques allowing to limit the excess of the regulated concentrations of oxygen and moisture is the organization of gas exchange in the float bath, which ensures their continuous removal until the permissible concentrations are reached. Such a gas exchange can be organized by continuously feeding a certain amount of a nitrogen-hydrogen protective mixture into the bath, i.e., a certain exchange rate must be observed. A method for determining the frequency of exchange in a float bath is considered, taking into account its sealing, the quantity and quality of the protective mixture supplied to it. Techniques are proposed to ensure the required exchange rate. Tab. 1, ill. 1, bibliography: 9 titles.

The temperature regimes of obtaining glass granulate, which is the initial raw material for glass-ceramic foam materials, are considered, depending on the composition of the charge and the nature of the main glass-forming component. It was found that when heating the charge based on silica and alumina-containing natural materials, they have different behavior. When processing the charge in an industrial conveyor-type furnace, for each charge, it is necessary to select an individual temperature regime in order to obtain a high-quality glass granulate. Tab. 3, ill. 3, bibliography: 2 titles.

On the basis of the principle of superposition of wave addition, a mathematical model of the power distribution on the surface of a glass plate when it is heated with the help of tubular heaters is proposed. Such a model makes it possible to predict the propagation of the temperature field on the surface of the glass plate, depending on the location and power of the heating elements. Il. 4, bibliography: 3 titles.

Several types of structural glue are considered, their performance properties in the case of application for the production and assembly of high-precision optical products when joining glass-metal. Tab. 3, bibliography: 2 titles.

With the use of a natural impurity - albite - a qualitative picture of the enrichment of the fine fraction of quartz sand in the grinding process has been experimentally established. It is shown that in terms of optical and structural characteristics, glass melted from a fine fraction of sand is inferior to glass obtained from a coarse fraction. Il. 3, bibliography: 5 titles.

The results of the work obtained during the implementation of the joint project of Glaverbel Czech JSC and the Department of Machines and Robots for Glass Production at the University of Liberec (Czech Republic) are presented. For a more accurate assessment of the quality of float glass on the production line, the corrugation test was objectified. The processes for the production of large laminated glasses, as well as the causes and sources of cracking and breaking of glass in the process of autoclaving, are analyzed. Computer simulation of the deformation characteristics of the racks in the production of large laminated glass made it possible to carry out calculations to optimize the rack design and ensure its maximum strength. Tab. 1, ill. 6, bibliography: 7 titles.

Mathematical models have been developed that describe the effect of the tempering process on the characteristics of automotive glass, in particular, on the nature of destruction during testing. Linear regression models adequately describe the maximum number and length of fragments obtained during testing. The effect of the hardening regime on the nature of glass destruction is shown. Bibliography: 3 titles.

Using the equations of equilibrium of internal and external forces, formulas were obtained and a program "Solid glass" was developed for the practical calculation of the strength of sheet glass in transverse bending under the influence of a uniform load. The calculated values ??of strength and deflection of sheet glass are in good agreement with experimental data. Il. 3, bibliography: 1 title.

Optimization of compositions and areas of application of unfired refractory concretes determine the need to study the processes of their structure formation, which take place in the material when the temperature rises to operating temperature. Methods of using IR spectroscopy to study the processes of structure formation in refractory aluminosilicate concretes are considered. Il. 2, bibliography: 6 titles.

An algorithm for optimal control of charge loading into a glass-making furnace is considered, taking into account the possible use of partial doses of rejected charge. According to the results of the calculation, the permissible changes in the category of the mixture of the conditioned charge with a partial dose of the rejected charge are determined, and when the category is changed, the charge is redistributed along the width of the loading pocket. Il. 1, bibliography: 4 titles.