An overview is given of the attempts to understand the behavior of scroll waves in threedimensional excitable media using analytical methods, and these results are compared with recent numerical and experimental results. The behavior of untwisted planar scroll rings, twisted rings and helices, and knotted scroll wave filaments is discussed.

Nonlinear waves of the reaction-diffusion (RD) type occur in many biophysical systems, including the heart, where they initiate cardiac contraction. Such waves can form vortices called scroll waves, which result in the onset of life-threatening cardiac arrhythmias. The dynamics of scroll waves is affected by the presence of inhomogeneities, which, in a very general way, can be of (i) ionic type...

A first-order delayed chaotic model with n-double scroll attractors is investigated. The associated piecewise-linear activation function requires only a few operational amplifiers, which can easily be realized by an electronic circuit. The typical waveforms and phase portraits are plotted to illustrate n-double scroll chaotic oscillations. Keywords—delay; chaotic attractor; n-double scroll; cir...

We consider the dynamics of scroll waves in the presence of rotating anisotropy, a model of the left ventricle of the heart in which the orientation of fibers in successive layers of tissue rotates. By choosing a coordinate system aligned with the fiber rotation and studying the phase dynamics of a straight but twisted scroll wave, we derive a Burgers' equation with forcing associated with the ...

In this paper, new results are derived for the anti-synchronization of identical Liu-Chen four-scroll chaotic systems (Liu and Chen, 2004) and identical Lü-Chen-Cheng four-scroll chaotic systems (Lü, Chen and Cheng, 2004) by sliding mode control. The stability results derived in this paper for the antisynchronization of identical four-scroll chaotic systems are established using sliding mode co...

AIM Our study was conducted to evaluate whether higher temperature leads to increased - or wider - scroll widths of the Descemet's membrane endothelial keratoplasty (DMEK) donor graft. PURPOSE To investigate the effects of temperature and fluid media on the DMEK donor graft scroll widths. MATERIALS AND METHODS This research work was a laboratory investigation. Baseline cell count was taken ...

In this paper a new family of scroll grid attractors is presented. These families are classified into three called 1D-, 2Dand 3D-grid scroll attractors depending on the location of the equilibrium points in state space. The scrolls generated from 1D-, 2Dand 3D-grid scroll attractors are located around the equilibrium points on a line, on a plane or in 3D, respectively. Due to the generalization...

This study investigated the static and dynamic phenomena on R410A scroll compressor components by using finite element analysis (FEA) with ITRI self-developed scroll type compressor software (ITRI_STC software). The simulation results of the coefficient of performance, cooling capacity by tuning the design parameters integrated scroll geometric parameters with compressed discharge procedure and...

This paper focuses on the geometric theory of scroll compressor, which includes the determination of the discharge angle, the calculation of the volume in different compression stages, the axial gas force under the condition that the number of scroll turns equals an arbitrary real number. NOMENCLATURE . (J :expanding angle of the involute (rad) a :initial angle of the involute (rad) 6 : orbitin...

On the basis of the elastic mechanics theories, heat transfer theories, and CAE, the non-uniform temperature distribution was studied, Mises stress and deformation distribution of 3D twin-spirals scroll plates was presented. The Mises stress and deformation of scroll plates induced by non-uniform temperature field and gas pressure was investigated. Orbiting and fixed scrolls were engaged with e...