VOL 76, No. 4 (2003)

The issues necessary to find the optimal annealing mode for glassware in terms of energy savings are considered. The structure of an automated system for calculating the modes of annealing of glass products is proposed, which makes it possible to simulate and optimize the process of annealing of sheet, container and high-quality glass. Bibliography: 4 titles.

The technology and installation of laser etching and polishing of quartz pipes, which allow contactless removal of the surface layer of dirt and cracks and polish the pipe surface, are considered. The use of this technology improves the quality of pipes for diffuse ovens and UV illuminators. Il. 4, bibliography: 5 titles.

The chemical resistance of zinc-containing glass-crystalline glaze, developed to protect refractory products made of quartz glass-ceramics from the action of alkaline media, has been studied. The water and acid resistance of the glaze exceeds that of conventional glazed glasses. The alkali resistance of quartz glass-ceramics during its glazing with glass-crystalline glaze increases more than 4 times. Tab. 2, ill. 1, bibliography: 8 titles.

The effect of iron oxides with a molar content of 2.5 to 35.0% (over 100%) on the properties of aluminoborosilicate glasses has been investigated. The peculiarity of the phase separation of iron-containing glasses, products of their heat treatment, and the kinetics of segregation processes are shown. The valence-coordination state of iron ions and the effect of heat treatment modes on it have been determined. The dependence of the physicochemical properties of glasses on their chemical composition and structure has been studied. The possibility of forming colored glaze coatings with specified properties and texture has been substantiated. Il. 4, bibliography: 6 titles.

Investigated in the temperature range from 900 to 1600 ° C and oxygen partial pressures from 2 x; 104 to 1 x 10 -10 Pa electro-physical properties and nature of electrical conductivity of oxide interlanthanoids LaYO ₃, LaYbO ₃, LaErO ₃, NdLuO _{3, LaGdO 3, GdLuO 3, pure and doped with calcium and hafnium oxides close in ionic radii. It is shown that the electrical conductivity of the studied materials is determined by nonstoichiometric disordering. The results obtained can be used to synthesize new types of thermistors, oxygen sensors and other ceramic sensors, as well as various dielectric materials. Tab. 1, ill. 4, bibliography: 6 titles.}

The influence of the glass phase of the eutectoid composition on the sintering of corundum masses is considered. It has been established that an additive corresponding to the composition of the eutectic of the CaO - Al ₃ O ₃ system, melting at a temperature of 1395 ° C, improves the performance properties of corundum concrete as a result of activation of its sintering. Tab. 1, bibliography: 4 titles.

The relationship between the temperature dependence of X-ray luminescence and the change in the parameters of the unit cell of BeO has been established. Lattice deformation and pyroelectric fields lead to the formation of point defects (which are luminescence centers) on which excitons, as well as holes or conduction electrons, are likely to be localized. Il. 3, bibliography: 7 titles.

Methods for determining frost resistance of facing materials and products are considered. Experimental results are presented. A Lithuanian standard has been developed (LST 1413.12: 1998). The standard specifies the grades of composites and their frost resistance in accordance with three different categories of use. Tab. 2, ill. 1, bibliography: 3 titles.

Compositions based on feldspar raw materials and hydroxyapatite with fluorite additives, suitable for the manufacture of ceramic coating of dentures with good masking properties and dimensional stability, have been developed. The mechanism of formation of coatings and their physicochemical properties have been investigated. Tab. 5, ill. 2, bibliography: 4 titles.

Industrial testing of soda from nepheline raw materials of improved quality has shown the economic feasibility of using this product in the production of glass for various purposes. Tab. 2, bibliography: 1 title.