Volume 15, Nº 2 (2025)

Some amplification properties of the copper vapor laser active element GL-202 were studied. The radiation amplification coefficient in the experiments conducted with optimal heating of the active element reached a value of 204 ± 14 units.

The structure of carbon nanotubes in polymer matrix of nanocomposites at their ultrasmall content (< 0,01) by volume was studied. It has been shown that in this case nanotubes form is approached to linear one. This leads to exceeding overstepping nanotubes effective characteristics by their nominal values. In its turn, this effect improves substantially nanocomposites properties.

A hypothetical model of the initial stage of contact eutectic melting is proposed, explaining the phase transition through the synchronization of oscillations of atoms at the phase boundary, with a change in the contact temperature. Synchronization leads to a resonant increase in the amplitudes of atomic (molecule) oscillations, a decrease in their bond energy, and a transition to the liquid phase. The model is consistent with the classical phase diagram, where the eutectic point corresponds to the energetically favorable state of resonant melting. To analyze the eutectic behavior, heterogeneous systems were studied: non-metallic H₂O– NaCl and metallic Ga–In and Al–Cu, in which intermetallic phases are formed. In all cases, a characteristic drop in temperature and transition to a liquid state upon reaching the eutectic are observed. The results confirm that local oscillatory processes play a key role in the formation of a liquid layer of eutectic composition, complementing traditional thermodynamic concepts.

The article provides information on the curing of epoxy oligomers containing hexachloroethane with various hardeners, and epoxy polymers with good technological properties have been obtained.
The influence of various factors on the duration of the curing process and the yield of products has been studied. The resulting new filling compounds had good thermal stability.

The results of the study of the biochemical composition of the apple mass of the Golden Delicious and Idared varieties grown in the Kabardino-Balkarian Republic, before and after long-term storage (six months or more), at a temperature of +2–5 C are discussed. The processes of gelation and the possibility of obtaining gelatinous products with functional properties, taking into account the shelf life of the products and poststorage effects are studied. The content of vitamin C and pectin substances before and after long-term storage (six months or more) are determined.

The copolymerization of (meth)acrylyl chloride with methacrylate and chloroprene has been studied. The use of acrylic acid halides as the second comonomer is of great interest, since such copolymerization and subsequent substitution of mobile chlorine atoms with various functional groups makes it possible to synthesize copolymers with a complex of required properties.

Potentiometric titration and PMR spectroscopy in non-aqueous media determined quantitative physicochemical parameters reflecting the reactivity of diphenols and their conjugated diphenoxide anions. A large series of correlation relationships was obtained between the above parameters and data of kinetic studies of reactions of nonequilibrium high-temperature polyesterification in the synthesis of polyarylates and aromatic polyethers. The results of experimental and theoretical studies were the establishment of the mechanisms of these reactions.

Effect of a number of cationic polyelectolytes on the biofouling and physical and mechanical properties of polymer material based on styrene-acrylic water dispersion has been studied. The antifouling properties of the material were tested against gram-positive and gram-negative bacteria as well as micromycetes. The effective concentrations of the additives have been determined for inhibiting the formation of biofilm on the polymer surface.