Time filter

Source Type

Anisimov V.,Ukrainian State University of Chemical Technology
Chemistry and Chemical Technology | Year: 2012

The interrelation between structures and strength, deformation, rheological, and tribotechnical characteristics of thermoplastic polyurethanes based on oligoether blends has been studied. A notable change of properties over the whole concentration range was observed. The best compositions have been found. © Anisimov V., 2012. Source

Amadelli R.,CNR Institute for Organic Syntheses and Photoreactivity | Samiolo L.,CNR Institute for Organic Syntheses and Photoreactivity | Battisti A.D.,University of Ferrara | Velichenko A.B.,Ukrainian State University of Chemical Technology
Journal of the Electrochemical Society | Year: 2011

The oxidative degradation of phenolic compounds (4-chlorophenol and 4-nitrophenol) was studied using different electrochemical systems involving ozone formation at PbO2 anodes: (i) direct electrolysis at constant current; (ii) ex-situ use of O3 and (iii) combined use of anodically generated stream of O3/O2 fed into the cathode where H2O2 is electrogenerated by O2 reduction. We show that the latter advanced oxidation method gives the best results: it is a Fenton-type degradation of the target pollutants taking place in the cathodic compartment by reason of the highly oxidizing environment brought about by radicals that are formed mainly in the reactions of O3 with OH - and HO2 -. © 2011 The Electrochemical Society. Source

Vinogradov B.V.,Ukrainian State University of Chemical Technology
Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu | Year: 2016

Purpose: To estimate the effectiveness of the coupling with rubber-cord shells for evenly distributed load between the transmission lines in the twin-motor drives of tumbling mills. Methodology: We gave the dynamic and static elastic characteristics of clutches and drive containing the coupling with rubber-cord shells. The performance of couplings containing rubber-cord shell was analyzed based on the mathematical models describing the load transmission lines of each engine depending on the displacement angle of the motor and hydraulic couplings parameters. Findings: The schemes and characteristics of clutches containing rubber-cord shell are presented. It was proved that these couplings, in case of use of the rubber-cord shells available at the market allow transmitting the torque of up to 8,000 kN · m, which satisfies the twin-engine drives with a total capacity up to 10,000 kW. We considered the drives containing the coupling with rubber-cord shells filled with a liquid and connected with hydropneumatic accumulator for the cases when the hydraulic system of rubber-cord shells is independent and connected by the common pipeline. The technique of quantitative evaluation of the uneven distribution of load between the engines was developed. Originality: The regularities of distribution of static loads in synchronous twin-drum drive mills containing elastic couplings with rubber-cord shells Practical value: It was proved that the use of flexible couplings with rubber-cord shells without hydraulic connection between the couplings results in a more even load distribution due to the increased compliance of the mechanical system. Source

Protsenko V.S.,Ukrainian State University of Chemical Technology | Danilov F.I.,Ukrainian State University of Chemical Technology
Journal of Electroanalytical Chemistry | Year: 2011

Equations are derived and analyzed that interrelate the quantities of the ideal activation energy W (determined at a constant Galvani potential value), the real activation energy A (measured at a constant overpotential value) and the so-called formal activation energy Ω (measured at a constant electrode potential vs. an arbitrarily chosen reference electrode). The mathematical forms of dependence of apparent formal activation energy on electrode potential are established. It is shown that using formal activation energy (measured at a constant electrode potential) is applicable for kinetics analysis of various electrode processes. The expressions obtained in this study may be used when processing temperature dependences of highly irreversible electrochemical reactions. © 2010 Elsevier B.V. All rights reserved. Source

Shmychkova O.,Ukrainian State University of Chemical Technology | Luk'yanenko T.,Ukrainian State University of Chemical Technology | Velichenko A.,Ukrainian State University of Chemical Technology | Meda L.,Istituto Guido Donegani Energie Non Convenzionali | Amadelli R.,CNR Institute for Organic Syntheses and Photoreactivity
Electrochimica Acta | Year: 2013

The influence of bismuth ions on kinetics of lead dioxide electrodeposition from methanesulfonate elec-trolytes and physico-chemical properties of obtained coatings were studied. Experimental results areconsistent with a mechanism previously proposed in the literature for lead dioxide electrodeposition.The presence of bismuth ions in the electrodeposition solution causes a decrease of rate constants oflead dioxide formation due to co-adsorption phenomena. Deposits from solutions containing bismuthions appear shiny dark grey, and show good adhesion to metal support. SEM images reveal a compactstructure with spindle-shaped submicron and nanosized crystals and X-ray diffractograms demonstratedthat incorporation of bismuth diminishes the size of crystal particles. Oxygen evolution was investigatedto test electrocatalytic activity. It is shown, that oxygen overpotential on modified electrodes is signifi-cantly higher than on non-modified PbO2-electrode, which depends on bismuth content in deposit andsegregation of bismuth that induces surface heterogeneity due to sites with different electroactivity forwater oxidation. © 2013 Elsevier Ltd. Source

Discover hidden collaborations