One Estimate for Divided Differences and its Applications

Ukrainian Mathematical Journal - We give an estimate for the general divided differences [x0, . . . ,xm; f], where some points xi are allowed to coalesce (in this case, f is assumed to be...     

Physico-mathematical simulation of methane and argon removal absorption process by liquid ammonia from synthesis gas of ammonia production

Abstract

The elaboration of the theoretical experimental model of the absorption process under a pressure of 30 MPa and moderate temperatures included the experimental research of methan and argon absorption from the five-component mixture H₂-N₂-CH₄-Ar-NH₃ by liquid ammonia on a pilot plant and carrying out the computerized research of process statics.     

Oleksandr Ivanovych Stepanets' (On His 60th Birthday)

Ukrainian Mathematical Journal -     

A study of the influence of physico-chemical processes in a metal base/nonmetallic coating system on the operational properties of coatings in a chemically active medium

We propose a method for the analytic computation and prediction of the lifetime of electrically nonconducting coatings in chemically active media. We study the role that the quantity of passivating additives in the coating and other parameters of the medium-coating-base system play in the destruction of the coating. We investigate the influence of passivating components on the process of corrosive destruction of the metal under the coating.Translated fromMatematicheskie Metody i Fiziko-Mekhanicheskie Polya, Issue 31, 1990, pp. 30–36.     

Remark on the Lebesgue constant in the Rogosinski Kernel

For every n, we compute the Lebesgue constant of Rogosinski kernel with any preassigned accuracy.     

Highly enantioselective iridium-catalysed allylic aminations with anionic N-nucleophiles

Iridium-catalysed allylic substitutions with anionic N-nucleophiles were achieved with regioselectivity of up to 49:1 and enantiomeric excess of up to 98%.     

Calculation of the preexponential factors of free-radical and molecular reactions based on the principle of bond entropy additivity

Assuming the additivity of bond entropies in an activated complex, a method for calculation is proposed, and the entropies of a number of activated bonds are presented. The possibility for calculating the entropy of activation of radical and molecular reactions is shown and permits calculating the preexponential factors of the most diverse reactions (approximately 20 types). The calculated values of the preexponential factors encompass an interval of almost six orders of magnitude. Agreement between the calculated values and experimental data is satisfactory.The authors wish to thank F. B. Moin for his valuable advice.