Effect of copper(II) ions on the chaotic regime of the Belousov-Zhabotinskii reaction

We have studied the effect of low concentrations of copper(II) ions and also copper(II) ions in the presence of manganese (II) ions on the quantitative characteristics of the chaotic regime of the Belousov-Zhabotinskii reaction.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 29, No. 5, pp. 418–423, September–October, 1993.     

Periodic, Mixed-Mode, and Chaotic Regimes in the Belousov–Zhabotinskii Reaction Catalyzed by Ferroin

The periodic, mixed-mode, and chaotic regimes in the ferroin-catalyzed Belousov–Zhabotinskii (BZ) reaction observed in a continuous stirred tank reactor (CSTR) reactor at various flow rates were experimentally studied. It was found that an increase in the flow rate resulted in the appearance of various complex oscillations. The possibility of the numerical simulation of experimentally observed asymptotic mixed-mode oscillations and chaotic regimes with the use of a kinetic scheme that includes experimental rate constants of each step of the ferroin-catalyzed BZ reaction was first demonstrated. The reaction scheme adequately describes the bifurcation sequence of experimentally observed oscillating regimes.     

Determination of gases (NO, CO, Cl(2)) using mixed-mode regimes in the Belousov-Zhabotinskii oscillating chemical reaction

We show a principle possibility of the determination of gases concentrations (NO, CO, Cl(2)) by their affect on mixed-mode oscillations in the Belousov-Zhabotinskii (BZ) oscillating chemical reaction. These oscillations are characterized by single large amplitude oscillation followed by a number of small amplitude oscillations. The method of the determination is based on a construction of a calibration plot given by the dependence of the number of small amplitude oscillations on gas concentration.     

Kinetics of outer-sphere electron transfer reactions involving synthetic models of copper “blue"” proteins

A model is constructed for a two-dimensional cellular automaton describing an autooscillatory chemical reaction in a spatially distributed medium on the basis of experimental data on the reentry map of the Belousovo-Zhabotinskii (BZ) reaction. It is shown that the behavior of such a cellular automaton is qualitatively similar to the temporal evolution of spatial structures in the BZ reaction.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 29, No. 1, pp. 31–36, January, 1993.     

Effect of ZrO<Subscript>2</Subscript> morphology in copper–cerium–zirconium oxide systems on their catalytic properties in the reaction of co oxidation in hydrogen-rich mixtures

We studied the catalytic properties of copper–cerium oxide systems, deposited on supports obtained by calcination of yttrium-stabilized zirconium dioxide at 300-1000 °C, in the reaction of selective oxidation of CO in a stream of hydrogen. We have shown that the catalytic activity of the samples obtained correlates with the activity of the original supports in the reaction of CO oxidation: the highest CO conversion is observed on catalysts with the highest and the lowest specific surface area. Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 45, No. 2, pp. 115-120, March-April, 2009.     

Morphology of carbon nanotubes,obtained by decomposition of ethylene on nickel nanoparticles at various rates of flow and concentration of C<Subscript>2</Subscript>H<Subscript>4</Subscript>

The influence of flow rate and concentration of source of hydrocarbon on the properties of the carbon nanotubes formed in the process of thermal decomposition of ethylene on nickel nanoparticles have been investigated. Changes in the rate of gaseous flow has practically no effect on the specific yield and the mean diameter of the nanotubes. However, an increase in the mean diameter and a decrease in the value of the specific yield occurs with increase in the concentration of ethylene. __________ Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 44, No. 4, pp. 228–232, July–August, 2008.     

Features of the Reaction of the CO Molecule with a Platinum Atom and Its Diatomic Cluster

The potential energy profile of the Pt⋯CO and Pt₂⋯CO systems was calculated within the formalism of density functional theory. It was shown that bonding in these systems is only achieved after a triplet-singlet transition, which is unusual for the interaction of a CO molecule with the surface of a platinum crystal. __________ Translated from Teoreticheskaya i Eksperimental'naya Khimiya, Vol. 41, No. 5, pp. 278–282, September–October, 2005.     

Effect of Manganese(II) Ions on Regular Self-Oscillations in the Belousov–Zhabotinskii Reaction in a Tank Reactor with Constant Stirring

The effect of manganese(II) ions on the asymptotically regular self-oscillation regime of the Belousov–Zhabotinskii reaction, catalysed by ferroin, in a tank reactor with constant stirring has been studied. An increase in the manganese(II) ion concentration in the system leads to an increase in the period of the self-oscillations. The sensitivity of the self-oscillation of the chemical reaction on the addition of Mn²⁺ ions is decreased with an increase in acidity. To explain the results obtained we have used a reversible Oregonator model, which is supplemented with reactions between manganese(II) and manganese(III) ions and bromoxyl radicals, malonic acid, and ferroin.     

Scalings of mixed-mode regimes in a simple polynomial three-variable model of nonlinear dynamical systems

We describe scaling laws for a control parameter for various sequences of bifurcations of the LSn mixed-mode regimes consisting of single large amplitude maximum followed by n small amplitude peaks. These regimes are obtained in a normalized version of a simple three-variable polynomial model that contains only one nonlinear cubic term. The period adding bifurcations for LSn patterns scales as 1/n at low n and as 1/n2 at sufficiently large values of n. Similar scaling laws 1/k at low k and 1/k2 at sufficiently high values of k describe the period adding bifurcations for complex k(LSn)(LS(n + 1)) patterns. A finite number of basic LSn patterns and infinite sequences of complex k(LSn)(LS(n + 1)) patterns exist in the model. Each periodic pattern loses its stability by the period doubling bifurcations scaled by the Feigenbaum law. Also an infinite number of the broken Farey trees exists between complex periodic orbits. A family of 1D return maps constructed from appropriate Poincaré sections is a very fruitful tool in studies of the dynamical system. Analysis of this family of maps supports the scaling laws found using the numerical integration of the model.