Kinetic approach to modeling the radical polymerization of butyl acrylate in the presence dibenzyl trithiocarbonate

A mathematical model of the kinetics of the radical polymerization of butyl acrylate in the presence of dibenzyl trithiocarbonate by the reversible addition-fragmentation chain transfer mechanism with cross-termination of radicals and intermediates and quadratic termination of intermediates. The viability of the polymerization mechanism underlying the model and the related mathematical formalism are tested by comparing the calculated and measured values of the average molecular-weight characteristics of resulting poly(butyl acrylate).     

Quasi-integrals and stochastic integration along sample paths

We construct deterministic analogues of the Stratonovich and Itô stochastic integrals, which coincide with the classical stochastic integrals in the case of the Wiener process.     

Steric structure of N-(halomethyl) imides

Conclusions N-(Chloromethyl)- and N-(bromomethyl)imides of phthalic and succinic acids exist in a conformation with arrangement of the C-Hal bond in the plane of the imide ring.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2487–2490, November, 1980.     

On continuous local times for functions and stochastic processes

For some classes of functions and stochastic processes X(s), s∈[0,1], with local times continuous with respect to the time parameter, the perturbation problem is considered: under what conditions does the function, X(s)+γ(s) also possess local time. The Hausdorff dimensionality of the level sets X⁻¹(u)={s: X(s)=u} is determined. Supported by the Russian Foundation for Fundamental Research, project 93-011-1447, and by the Bulgarian Academy of Sciences. Proceedings of the XVII Seminar on Stability Problems for Stochastic Models. Kazan, Russian, 1995. Part III.     

A new class of photo-induced phenomena in siloxane films

The light induced atomic desorption effect, known as LIAD, is observed whenever Pyrex cells, coated with siloxane films and containing alkali atoms, are illuminated. LIAD is a non-thermal phenomenon and it can be observed even with very weak light intensities. We show that the simultaneous contribution to the photo-emission of atoms adsorbed both at the film surface and within the film must be taken into account in order to fit the experimental data. We demonstrate that both the desorption efficiency and the diffusion coefficient of the alkali atoms embedded in the dielectric film depend on the desorbing light intensity. These features characterize a new class of photo-induced phenomena whose analysis gives new insights in the comprehension of the atom-surface interaction and of the atom-bulk diffusion and opens interesting perspectives for applications. Received 27 April 2000 and Received in final form 15 September 2000     

Synthesis of Dicycloheptano- and Dicyclooctanothiacrown Ethers Their Properties as Extractants

12- and 15-Membered thia- and oxathiacrown ethers and podands containing cycloheptane and cyclooctane fragments have been synthesized. The properties of the synthesized compounds as extractants for Ra²⁺ and Pd²⁺ ions have been studied.     

Improvement of the neodymium catalyst preparation step in isoprene rubber production

The results of pilot tests of a tubular reactor of the diffuser-confuser type in modification of neodymium chloride isopropanol complex in turbulent flows were presented. The new procedure leads to reduced catalyst consumption, as well as to increased average molecular weights and narrowed molecular weight distribution of cis-1,4-polyisoprene.