Efficient control of the molecular weight of modified epoxy resins in the course of their synthesis

Epoxy resin modified with sebacic acid was synthesized. It exhibits improved elastic properties and impact resistance.     

Influence of small polymer additives on the behavior of a linear viscoelastic fluid

A system of equations is obtained, describing a dilute polymer solution in an incompressible linear viscoelastic fluid as a nonlinear viscoelastic medium. As an example, motion with a specified velocity gradient is analyzed in the linear approximation. An expression is given for the dynamic modulus of the system in terms of the dynamic modulus of the most viscoelastic fluid containing the macro-molecules and in terms of the polymer concentration.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 6, pp. 3–12, November–December, 1976.     

A corollary of the Poincaré-Bendixson theorem and periodic canards

The role of topological methods in the analysis of canard-type periodic trajectories is discussed. A special corollary of the Poincaré-Bendixson theorem is used to prove the existence of periodic planar canards.     

Optical characteristics of thin rutile films on fused quartz substrates

Polycrystalline rutile films are synthesized on fused quartz substrates by the method of thermal oxidation of a titanium metal layer in air at 800°C. The optical parameters of the TiO ₂ films are determined for a wavelength of λ = 0.6328 μm by the method of laser zero ellipsometry. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, pp. 15–20, May, 2006.