Mathematical Model of Speeds Change Device on the Basis of Switched Differential Mechanisms

International Applied Mechanics - The geometry and kinematics of a dynamic system with several degrees of freedom and controllable friction clutches are considered. The necessary kinematic...     

Kinetics of catalytic oxidation of carbon black in the presence of [Cu(L<Superscript>1</Superscript>/L<Superscript>2</Superscript>)][MCl<Subscript>4</Subscript>] complexes deposited on its surface

We have studied the kinetics of oxidation of carbon black by atmospheric oxygen in the presence of heterogenized heterobimetallic complexes [Cu(L¹/L²)][MCl₄] (M = Zn, Mn; L¹ = 4,6,6-trimethyl-1,9-diamino-3,7-diazanona-3-ene; L² = 1,15-dihydroxy-7,9,9-trimethyl-3,6,10,13-tetraazapentadeca-6-ene). We have established that deposition of the complexes considerably increases the oxidation rate for carbon black compared with deposition of the salts. Complexes containing the metal pair Cu–Mn and more hydrophobic ligands have the highest catalytic activity. We have obtained the kinetic parameters of the carbon black oxidation process in the presence of the complexes. Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 45, No. 3, pp. 190-195, May-June, 2009.     

Kinetics of Pyrene Fluorescence Quenching in the Presence of N,N-Dimethylaniline on the Surface of Titania Silica Colloids

A study was carried out on pyrene (Py) fluorescence quenching in the presence of N,N-dimethylaniline (DMA) on the surface of titania–silica colloids. Py fluorescence quenching is a function of the TiO₂ content in the binary colloids. The coadsorption of DMA molecules is accompanied by an increase in the Py fluorescence intensity due to the competitive adsorption of amine on the surface. Calculation of the formal kinetics of Py fluorescence quenching indicates the existence of two groups of sites differing in adsorption activity within each group.     

Vibrations of a rigid body with a controlled frictional electromagnetic seismic damper: nonlinear model

A nonlinear mathematical model of a gravitational vibratory system with a controlled electromagnetic seismic damper is developed. The dependence of the force of attraction of ferromagnetic bodies by the solenoid of the frictional device on the solenoid current is established for a specific solenoid design. The analytic expression for this force is derived by the least-squares method using a system of continuous piecewise-linear functions. It is used to describe the pressure of the solenoid on the friction surface. For multifrequency inertial excitation, the acceleration amplification factor is evaluated depending on the time constant and gain for two cases of control. The possibility of damping vibrations by controlling the absolute velocity and acceleration is established     

Low-temperature carbon oxidation in a gradient-free reactor

Measurements have been made on carbon oxidation kinetics at 693–923 K. There are two parallel reactions here: 2C + O₂=2 CO and C + O₂=CO₂, with carbon dioxide formation predominating above 823 K.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 24, No. 6, pp. 757–759, November–December, 1988.     

Nonlinear dynamics of a system of rigid bodies with controlled electromagnetic dampers

A nonlinear mathematical model of a system of n rigid bodies undergoing translational vibrations under inertial loading is constructed. The system includes ball supports as a seismic-isolation mechanism and electromagnetic dampers controlled via an inertial feedback channel. A system of differential dynamic equations in normal form describing accelerative damping is derived. The frequencies of small undamped vibrations are calculated. A method for analyzing the dynamic coefficients of rigid bodies subject to accelerative damping is developed. The double phase–frequency resonance of a two-mass system is studied