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Документ ANN simulation of nanocomposites Fe(Co)-W corrosion resistance(Харківський національний університет міського господарства імені О. М. Бекетова, 2019) Ved, M. V.; Sakhnenko, N. D.; Nenastina, T. A.; Volobuyev, M. N.; Yar-Muhamedova, G. H.Документ Cobalt based coatings as catalysts for methanol oxidation(Науково-технологічний комплекс "Інститут монокристалів", 2020) Nenastina, T. A.; Ved, M. V.; Sakhnenko, N. D.; Yermolenko, I. Yu.; Volobuyev, M.; Proskurina, V. O.The cobalt based coatings with refractory metals (Mo, W, Zr) were deposited from pyrophosphate-citrate electrolytes in a pulsed mode. It has been shown that, with increasing current density, Co-Mo-W and Co-W-ZrO2 alloys are enriched in tungsten, grain sizes decrease, but a network of cracks appears on the surface of the Co-Mo-W coating. In the Co-Mo-ZrO2 coating, with increasing current density, the zirconium content increases due to molybdenum, and the surface is the most fractured and small-globular. The surface roughness parameters for Co-Mo-ZrO2 are one order of magnitude higher than those for Co-Mo-W. Cyclic voltammograms show that the Co-Mo-ZrO2 deposits are characterized by the highest stability under anodic polarization due to the inclusion of molybdenum and zirconium(IV) oxide in their composition. The kinetics of the methanol anodic oxidation on electrodes coated with cobalt alloys was studied, and the participation of intermediate metal oxides in oxygen transport was revealed. A significant increase in the anode current peak indicates a higher electro-catalytic activity of the zirconium-containing coatings among the studied alloys.Документ Functional coatings by ternary cobalt based alloys for the autumobile industry(Харківський національний автомобільно-дорожній університет, 2015) Nenastina, T. O.; Hapon, Yu. K.; Glushkova, M. A.; Sakhnenko, N. D.; Ved, M. V.The environmentally friendly and resource-saving technologies for producing multifunctional coatings based on cobalt and silver alloys with refractory metals are proposed. The catalytic activity testing results of binary and ternary alloys based on cobalt in the carbon monoxide oxidation reaction in carbon dioxide were analyzed. It was revealed that there is on improvement of functional properties of galvanic alloys when the content of tungsten and molybdenum is within the range of 10–30 wt. %.Документ Synthesis of catalytic cobalt-containing coatings on alloy AL25 surface by plasma electrolytic oxidation(Інститут хімії поверхні ім. О. О. Чуйка НАН України, 2017) Ved, M. V.; Karakurkchi, A. V.; Sakhnenko, N. D.; Gorohivskiy, A. S.The study aims at the investigation of the influence of electrolyte composition and plasma electrolytic oxidation modes on the composition and morphology of a mixed aluminum and cobalt oxides at the AL25 alloy. Composition, morphology and surface roughness of the oxide systems are examined by scanning electron microscopy, X-ray analysis and atomicforce microscopy. Mixed oxide coatings Al₂O₃·CoOₓ formed from the diphosphate electrolytes at various concentration ratio diphosphate/cobalt sulfate contain cobalt of 8-30 at. % (in terms of metal) in the matrix of alumina. Plasma electrolytic oxidation in a two-stage mode of the incident power provided formation of strongly adhered coatings characterized by non-stoichiometry ratio of cobalt and oxygen as well aslow content of silicon in deposits. Obtained mixed oxide systems have developed surface with alternating the spheroid and torus-shaped structures which is associated with a large number of catalytic sites. They exhibit catalyticbehavior in the model reactions of CO conversion to CO₂ and benzene oxidation not inferior to the contacts with noble metals. The coatings Al₂O₃·CoOₓ contribute to fuel economy and improve the environmental performance of the internal combustion engine thus can be recommended for use in the neutralization of gas emissions systems and as coatings for pistons of combustion chamber.Документ Increasing the efficiency of intra-cylinder catalysis in diesel engines(Украинский государственный химико-технологический университет, 2017) Parsadanov, I. V.; Sakhnenko, N. D.; Ved, M. V.; Rykova, I. V.; Khyzhniak, V. A.; Karakurkchi, A. V.; Gorokhivskiy, A. S.The data of research done to systemize and choose scientific fields and search for the rational ways of an increase in the efficiency of intra-cylinder catalysis in diesel engines have been given. The use of base metal oxides and composite oxides of transition metals as the coatings for the piston combustion chamber has been substantiated. This allows us to control chemical reaction rates and reduce the formation of toxic substances. When selecting the scientific fields and rational practical ways of an increase in the efficiency of intra-cylinder catalysis in diesel engines chemical, physical and technological factors were taken into consideration. The formation of catalytic coatings based on the oxides of transition metals (Mn, Co) was provided using the plasma-electrolytic oxidizing on the Al25 alloy. These included both individual manganese and cobalt oxides and the mixed oxides of both metals. The investigation of catalytic coatings of the combustion chamber in the diesel engine piston on the basis of manganese and cobalt oxides and mixed oxides enabled the establishment of a maximum catalytic effect when cobalt oxides were used. The prototype diesel test data showed that the fuel rate in this case is decreased by 4 to 6 %, NOx emissions were reduced by 14 to 15 % and carbon oxide emissions were reduced by 20 through 25 %.Документ Synthesis and functional properties of mixed titanium and cobalt oxides(Institute for Single Crystals, 2017) Ved, M. V.; Sakhnenko, N. D.; Karakurkchi, A. V.; Mayba, M. V.; Galak, A. V.Peculiarities of plasma-electrolytic oxidation of the aluminum alloys in diphosphate electrolytes are discussed. It is shown that PEO parameters depend on the composition and concentration of the components of the working solutions. The mechanism of cobalt oxides incorporation into the composition of surface layers is proposed. It has been established that the oxidation of titanium in citrate-diphosphate electrolytes promotes the formation of mixed oxide layers TiOx·CoOy. The obtained mixed oxide systems have a developed microporous globular-toroidal surface and are characterized by a complex of enhanced functional properties - corrosion and abrasion resistance, catalytic activity in the carbon (II) oxide conversion reaction.Документ Mixed alumina and cobalt containing plasma electrolytic oxide coatings(IOP Publishing Ltd, 2017) Yar-Mukhamedova, G. Sh.; Ved, M. V.; Karakurkchi, A. V.; Sakhnenko, N. D.Principles of plasma electrolytic oxidation of the AL25 aluminum alloy in diphosphate alkali solutions containing cobalt(2+) cations are discussed. It has been established that a variation in the concentration of the electrolyte components provides the formation of mixed-oxide coatings consisting of the basic matrix materials and the cobalt oxides of different content. An increase in the cobalt oxide content in the coating is achieved by the variation in electrolysis current density as well as the treatment time due to both the electrochemical and thermo-chemical reactions at substrate surface and in spark region. Current density intervals that provide micro-globular surface formation and uniform cobalt distribution in the coating are determined. The composition and morphology of the surface causes high catalytic properties of synthesized materials, which confirmed the results of testing in model reaction CO and benzene oxidation as well as fuel combustion for various modes of engine operation.Документ Functional mixed cobalt and aluminum oxide coatings for environmental safety(Institute for Single Crystals, 2017) Ved, M. V.; Sakhnenko, N. D.; Karakurkchi, A. V.; Myrna, T. Yu.Principles of plasma-electrolytic oxidation of the aluminum alloys in diphosphate electrolytes are discussed. It has been established that a variation in concentration of the electrolyte components and electrolysis parameters (current density and treatment time) provides the formation of oxide coatings consisting of the basic matrix materials and the cobalt oxides of different composition and morphology that are expected to affect their functional properties. Mixed oxide coatings formed in a plasma-electrolytic mode characterized by microglobular structure with reducing the conglomerate size have an increased abrasion and wear resistance and an intense catalytic activity. Thus, there is a prospect of using such coatings in the process of burning fuel in internal combustion engines and reduce the toxicity of emissions improving fuel efficiency and environmental performance of engines and in the industrial systems of catalytic purification of exhaust gases of industrial plants and power system facilities.Документ Formation of coatings of mixed aluminum and manganese oxides on the AL25 alloy(Allerton Press, 2016) Sakhnenko, N. D.; Ved, M. V.; Androshchuk, D. S.; Korniy, S. A.Features of plasma electrolytic oxidation of the AL25 cast complex-alloyed aluminum alloy are discussed. It has been shown that a variation in the nature and concentration ratio of the electrolyte components provides the formation of mixed-oxide coatings containing the materials of the basic matrix and the dopant. An increase in the coating thickness and the manganese oxide content in the coating is achieved by the homogenization of the treated surface owing to the simultaneous formation of oxides and the removal of alloying components of the alloy from the surface layers. Current density intervals that provide a uniform distribution of elements in the coating and a high efficiency of the Faraday and thermochemical reactions are determined. It is found that the stoichiometric oxygen index in MnOx oxides is x = 1.71–1.87. Testing of the synthesized oxide systems in the model oxidation of carbon (II) oxide to CO₂ shows that the ignition and complete conversion temperatures are at the level of values characteristic of platinum catalysts.