selectivity

The influence of the reaction conditions on the selectivity of the interaction of oct-1-ene with tert-butyl hydroperoxide in the presence of MoB was investigated. It is shown that the selectivity of 1,2-epoxyoctane formation can vary depending on the reaction conditions.With the participation of the activated form of the catalyst, the selectivity increases significantly, but does not reach 100%. The optimal reaction conditions under which the selectivity of 1,2-epoxyoctane formation exceeds 90% have been established.

Nickel-containing mordenite samples were synthesized by impregnation from aqua's solution of nickel nitrate. Porous and catalytic characteristics of the catalysts were studied by means of low temperature nitrogen adsorption/desorption and micropulse n-hexane isomerisation. The maximum isomer yields are 10-12 wt % for 1-5 wt % Ni content at 523–573 K.

A theoretical study of the detection limit concept of copper traces in aqueous solution by using two thiosemicarbazides derivatives as ligands: 4-ethyl-3-thiosemicarbazide and thiosemicarbazide has been thoroughly investigated. The study was carried out experimentally by adsorptive stripping voltammetry.

The investigation of the influence of on-load tap-changing device on the algorithm of identification of winding short circuits in multi-winding power transformers was conducted.

Regularities of the reaction of oleic acid with a mixture of ethanolamines have been investigated under non-stationary conditions in the presence of H-form of cation-exchange resin KU-2-8 as a catalyst. The effect of a ratio between reagents and the catalyst on the acid conversion, selectivity and products yield has been determined. N-acylation of mono- and diethanolamines by an oleic acid was found to be more intensive compared with esterification of hydroxy groups of ethanolamine.

In this work the electrical properties of vapor detectors, formed from composites of conductive carbon-black and insulating organic multifunctional polymers having metal ions complexing ability, were investigated. The new composites are tailored to produce increased sensitivity toward specific classes of analyte vapors. Resonant frequency shift of a Quartz Crystal Microbalance (QCM) and dc resistance measurements have been also performed simultaneously on polymer-carbon black composite materials.

The selectivity of the spectrophotometric methods for determination of microgram quantities of osmium (IV) with acidic monoazo dyes Tropaeolin O (TpO) and Tropaeolin OOO-I (TpOOOI) in the presence of concomitant metals, particularly platinum group, heavy and rare earths (RE) has been studied. The tolerance ratios of interfering elements have been established. The selectivity of the interaction of TpOOOI with osmium (IV) relatively to platinum group elements (PGEs) is much better than TpO.

The effect of temperature, catalyst type, alcohol and dicarboxylic structures, as well as reagents ratio on the selectivity of formation and yield of mono- and diesters has been determined under stationary conditions for adipic (AA) and succinic acids (SA) esterification by C2–C5 aliphatic alcohols. It has been proved by the theory and experiments that maximum selectivity of dicarboxylic acids (DCA) monoesters formation during their esterification by alcohols is achieved at the ratio between flow rate constants of monoester and DCA less than 0.1.