Fibrillation is an erratic electrical state of the heart, of rapid twitching rather than organized contractions. Ventricular fibrillation is fatal if not treated promptly. The standard treatment, defibrillation, is a strong electrical shock to reinitialize the electrical dynamics and allow a normal heart beat. Both the normal and the fibrillatory electrical dynamics of the heart are organized i...

A new template simulation tool is developed for scroll compressors/expanders. This scroll template generates a high quality multi-block structured mesh from the outlines of stationary and orbiting rotors, which are inputs from a user. The mesh movement is also automatically calculated to account for every position of the orbiting rotor, maintaining good grid quality and smooth movement througho...

Rotating spiral and scroll waves (vortices) are investigated in the FitzHugh-Nagumo model of excitable media. The focus is on a parameter region in which there exists bistability between alternative stable vortices with distinct periods. Response functions are used to predict the filament tension of the alternative scrolls and it is shown that the slow-period scroll has negative filament tensio...

Using total energy and structure optimization calculations, we investigate the relative stability and the conversion mechanism between multiwall carbon nanotubes and graphitic scrolls. We suggest that axial segments of a nanotube and a scroll may coexist within the same tubular nanostructure, separated by a dislocation region. A scroll may convert to the more stable nanotube by concerted bond-r...

In this paper, we consider rational functions [Formula: see text] with some minor restrictions over the finite field where for prime and positive integer text]. We establish a sufficient condition existence of pair primitive normal elements in Moreover, quadratic numerators denominators, explicitly find that there are at most fields which such may not exist.

When two-dimensional browsing is needed in paint or draw programs, geographic information systems, medical image systems, or advanced window managers, designers have merely used two one-dimensional scroll bars or they have made ad hoc designs for a two-dimensional scroll bar. However, the complexity of two-dimensional and higher dimensional browsing suggests that more careful analysis, design, ...

In this paper the attention is focused on the generation of new hyperchaotic attractors from coupled Chua circuits. By exploiting sine functions as nonlinearities, the proposed technique enables nxm-scroll attractors to be obtained. In particular, it is shown that nxm-scroll dynamics can be easily designed by modifying four parameters, which characterize the circuit nonlinearities. Finally, som...

Controlled transitions between a hierarchy of n-scroll attractors are investigated in a nonlinear optoelectronic oscillator. Using the system's feedback strength as a control parameter, it is shown experimentally the transition from Van der Pol-like attractors to 6-scroll, but in general, this scheme can produce an arbitrary number of scrolls. The complexity of every state is characterized by L...