Analysis of Impact Chattering

In this paper, mechanical models with Newton's Law of impacts are studied. One of the most interesting properties in some of these models is chattering. This phenomenon is understood as the appearance of an infinite number of impacts occurring in a finite time. Conclusion on the presence of chattering is made exclusively by examination of the right hand side of impact models for the first time. Criteria for the sets of initial data which always lead to chattering are established. The Moon-Holmes model is subject to regular impact perturbations for the chattering generation. Using the chattering solutions, continuous chattering is generated. To depress the chattering, Pyragas control is applied. Illustrative examples are provided to demonstrate the impact chattering.Comment: 16 pages, 8 figure

Extension of Lorenz Unpredictability

It is found that Lorenz systems can be unidirectionally coupled such that the chaos expands from the drive system. This is true if the response system is not chaotic, but admits a global attractor, an equilibrium or a cycle. The extension of sensitivity and period-doubling cascade are theoretically proved, and the appearance of cyclic chaos as well as intermittency in interconnected Lorenz systems are demonstrated. A possible connection of our results with the global weather unpredictability is provided.Comment: 32 pages, 13 figure

Asymptotic equivalence of differential equations and asymptotically almost periodic solutions

In this paper we use Rab's lemma [M. Rab, Uber lineare perturbationen eines systems von linearen differentialgleichungen, Czechoslovak Math. J. 83 (1958) 222-229; M. Rab, Note sur les formules asymptotiques pour les solutions d'un systeme d'equations differentielles lineaires, Czechoslovak Math. J. 91 (1966) 127-129] to obtain new sufficient conditions for the asymptotic equivalence of linear and quasilinear systems of ordinary differential equations. Yakubovich's result [V.V. Nemytskii, VX Stepanov, Qualitative Theory of Differential Equations, Princeton University Press, Princeton, New Jersey, 1966; V.A. Yakubovich, On the asymptotic behavior of systems of differential equations, Mat. Sb. 28 (1951) 217-240] on the asymptotic equivalence of a linear and a quasilinear system is developed. On the basis of the equivalence, the existence of asymptotically almost periodic solutions of the systems is investigated. The definitions of biasymptotic equivalence for the equations and biasymptotically almost periodic solutions are introduced. Theorems on the sufficient conditions for the systems to be biasymptotically equivalent and for the existence of biasymptotically almost periodic solutions are obtained. Appropriate examples are constructed

Nonautonomous transcritical and pitchfork bifurcations in impulsive systems

For the first time analogues of nonautonomous transcritical and pitchfork bifurcations are investigated for impulsive systems

Safety assessment of shoe insoles treated with various biocidal compositions

The article deals with the study of the antimicrobial activity of shoe insoles treated with biocidal compositions . Antimicrobial treatment was carried out in distilled water using the following chemical agents: polyvinyl alcohol (PVA), salicylic acid (SA), copper sulfate, urea, polyvinylpyrrolidone (PVP), benzoic acid. The antimicrobial activity of the modified materials was determined against test cultures - E. coli and molds p.Penicillium. It was found that the studied samples of shoe insoles have a stable antibacterial effect - the growth inhibition zone is from 2 mm to 4 mm, but there is no fungal resistance

Poincaré chaos for a hyperbolic quasilinear system

The existence of unpredictable motions in systems of quasilinear differential equations with hyperbolic linear part is rigorously proved. We make use of the topology of uniform convergence on compact sets and the contraction mapping principle to prove the existence of unpredictable motions. Appropriate examples with simulations that support the theoretical results are provided