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Article
Projecting low and extensive dimensional chaos from spatio-temporal dynamics
We review the spatio-temporal dynamical features of the Ananthakrishna model for the Portevin-Le Chatelier effect, a kind of plastic instability observed under constant strain rate deformation conditions. We t...
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Article
Lifting the singular nature of a model for peeling of an adhesive tape
We investigate the dynamics of peeling of an adhesive tape subjected to a constant pull speed. Due to the constraint between the pull force, peel angle and the peel force, the equations of motion derived earl...
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Article
Negative strain rate sensitivity and the critical nature of type A bands in the Portevin-Le Chatelier effect
Describing spatio-temporal features of the Portevin-Le Chatelier (PLC) effect is a particularly difficult task as it arises from the interaction of the collective modes that have widely separated time scales. ...
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Chapter
Dynamics of Stick-Slip: Some Universal and Not So Universal Features
Stick-slip is usually observed in driven dissipative threshold systems. In these set of lectures, we discuss, some generic and system specific features of stickslip systems by considering a few examples wherei...
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Article
On the dynamical mechanism of cross-over from chaotic to turbulent states
The Portevin-Le Chatelier effect is one of the few examples of organization of defects. Here the spatio-temporal dynamics emerges from the cooperative behavior of the constituent defects, namely dislocations a...
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Article
Homoclinic bifurcation in Chua’s circuit
We report our experimental observations of the Shil’nikov-type homoclinic chaos in asymmetry-induced Chua’s oscillator. The asymmetry plays a crucial role in the related homoclinic bifurcations. The asymmetry ...
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Article
Influence of temperature inhomogeneity on product profile of reactions occurring within zeolites
In zeolites, diffusion is often accompanied by a reaction or sorption which in turn can induce temperature inhomogeneities. Monte Carlo simulations of Lennard-Jones atoms in zeolite NaCaA are reported for the ...
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Article
Monte Carlo simulation of nucleation and growth of thin films
We study thin film growth using a lattice-gas, solid-on-solid model employing the Monte Carlo technique. The model is applied to chemical vapour deposition (CVD) by including the rate of arrival of the precurs...
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Article
Chaos in jerky flow — Experimental verification of a theoretical prediction
Sometime ago Ananthakrishna and coworkers had predicted the existence of chaos in jerky flow based on a nonlinear dynamical model consisting of the time evolution equations for three types of dislocations and ...
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Article
Optimal barrier subdivision for Kramers’ escape rate
We examine the effect of subdividing the potential barrier along the reaction coordinate on Kramers’ escape rate for a model potential. Using the known supersymmetric potential approach, we show the existence ...
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Article
Formation and propagation of bands in jerky flow: a coupled lattice map description
There has been revival of interest in Jerky flow from the point of view of dynamical systems. The earliest attempt in this direction was from our group. One of the predictions of the theory is that Jerky flow ...
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Chapter and Conference Paper
Ginzburg-Landau form description for steps on creep curves
We consider the model proposed earlier by us for explaining the phenomenon of jumps on creep curves[1]. The model consists of three types of dislocations namely the mobile, the immobile and those with clouds o...
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Chapter and Conference Paper
Jerky flow, stick-slip in geological materials and earthquake models
There have been numerous studies on friction in geological materials in order to understand earthquakes [1]. The results are, in many respects similar to those on the Portevin-Le Chatelier effect (PLC). The st...
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Article
The effect of low intra-sublattice repulsion on phase diagram of YBa2Cu3O6+x : A Monte Carlo simulation study
We report the results of Monte Carlo simulation of the phase diagram and oxygen ordering in YBa2Cu3O6+x for low intra-sublattice repulsion. At low temperatures, apart from tetragonal (T), orthorh...
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Article
A multifractal study of wave functions in 1-D quasicrystals
Using multifractal analysis we study extended, self-similar and non-self-similar type of wave functions in the Fibonacci model. Extended states arising due to commutation of transfer matrices for certain block...
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Article
Random walk on a fibonacci chain
Random walk on a Fibonacci chain is studied both numerically and analytically. We demonstrate that the long-time behaviour is diffusive.
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Article
Repeated yield drop phenomena as a cooperative effect
We present a theoretical model of repeated yielding (ry) which reproduces many experimentally observed features, apart from showing how the temporal behaviour of the phenomenon emerges as a consequence of the coo...
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Article
Diffusion in a bistable potential: A comparative study of different methods of solution
The problem of diffusion in a bistable potential is studied by considering the associated nonlinear Langevin equation and its equivalent Fokker-Planck equation. Two numerically exact methods of solution, namel...
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Article
On the linearization of nonlinear langevin-type stochastic differential equations
We show that a logical extension of the piecewise optimal linearization procedure leads to the Gaussian decoupling scheme, where no iteration is required. The scheme is equivalent to solving a few coupled equa...
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Chapter and Conference Paper
On the approximate solutions of the nonlinear langevin equations
