Influences of the dust size and the dust charge variations to the low-frequency wave modes in a dusty plasma

2006 ◽  
Vol 13 (8) ◽  
pp. 082107 ◽  
Author(s):  
Gui-xin Wan ◽  
Wen-shan Duan ◽  
Quan-hai Chen ◽  
Xiao-yun Wang
Keyword(s):  
Dusty Plasma ◽  
Low Frequency ◽  
Frequency Wave ◽  
Dust Charge ◽  
Wave Modes

Low-frequency wave modulations in an electronegative dusty plasma in the presence of charge variations

2011 ◽  
Vol 84 (6) ◽  
Author(s):  
Samiran Ghosh ◽  
Subrata Sarkar ◽  
Manoranjan Khan ◽  
M. R. Gupta
Keyword(s):  
Dusty Plasma ◽  
Low Frequency ◽  
Frequency Wave

scholarly journals Brain Waves: Emergence of Localized, Persistent, Weakly Evanescent Cortical Loops

2020 ◽  
Vol 32 (11) ◽  
pp. 2178-2202
Author(s):  
Vitaly L. Galinsky ◽  
Lawrence R. Frank
Keyword(s):  
Low Frequency ◽  
Signal Propagation ◽  
Fiber Direction ◽  
Spatial Gradient ◽  
Excitation Threshold ◽  
Nonlinear Coupling ◽  
Brain Wave ◽  
Frequency Wave ◽  
The Brain ◽  
Wave Modes

An inhomogeneous anisotropic physical model of the brain cortex is presented that predicts the emergence of nonevanescent (weakly damped) wave-like modes propagating in the thin cortex layers transverse to both the mean neural fiber direction and the cortex spatial gradient. Although the amplitude of these modes stays below the typically observed axon spiking potential, the lifetime of these modes may significantly exceed the spiking potential inverse decay constant. Full-brain numerical simulations based on parameters extracted from diffusion and structural MRI confirm the existence and extended duration of these wave modes. Contrary to the commonly agreed paradigm that the neural fibers determine the pathways for signal propagation in the brain, the signal propagation because of the cortex wave modes in the highly folded areas will exhibit no apparent correlation with the fiber directions. Nonlinear coupling of those linear weakly evanescent wave modes then provides a universal mechanism for the emergence of synchronized brain wave field activity. The resonant and nonresonant terms of nonlinear coupling between multiple modes produce both synchronous spiking-like high-frequency wave activity as well as low-frequency wave rhythms. Numerical simulation of forced multiple-mode dynamics shows that, as forcing increases, there is a transition from damped to oscillatory regime that can then transition quickly to a nonoscillatory state when a critical excitation threshold is reached. The resonant nonlinear coupling results in the emergence of low-frequency rhythms with frequencies that are several orders of magnitude below the linear frequencies of modes taking part in the coupling. The localization and persistence of these weakly evanescent cortical wave modes have significant implications in particular for neuroimaging methods that detect electromagnetic physiological activity, such as EEG and magnetoencephalography, and for the understanding of brain activity in general, including mechanisms of memory.

scholarly journals On low-frequency dust-modes in a collisional and streaming dusty plasma with dust charge fluctuation

2003 ◽  
Vol 10 (3) ◽  
pp. 591-595 ◽  
Author(s):  
M. K. Islam ◽  
Y. Nakashima ◽  
K. Yatsu ◽  
M. Salimullah
Keyword(s):  
Dusty Plasma ◽  
Low Frequency ◽  
Charge Fluctuation ◽  
Dust Charge ◽  
Dust Charge Fluctuation

Nonlinear low frequency wave propagation in electronegative dusty plasma: Effects of adiabatic and nonadiabatic charge variations

2011 ◽  
Vol 18 (9) ◽  
pp. 093703 ◽  
Author(s):  
Subrata Sarkar ◽  
Samiran Ghosh ◽  
Manoranjan Khan ◽  
M. R. Gupta
Keyword(s):  
Wave Propagation ◽  
Dusty Plasma ◽  
Low Frequency ◽  
Frequency Wave ◽  
Plasma Effects

Low frequency wave propagation in a cold magnetized dusty plasma

1998 ◽  
Vol 47 (1-2) ◽  
pp. 273-280 ◽  
Author(s):  
Susmita Sarkar ◽  
Samiran Ghosh ◽  
Manoranjan Khan
Keyword(s):  
Wave Propagation ◽  
Dusty Plasma ◽  
Low Frequency ◽  
Frequency Wave ◽  
Magnetized Dusty Plasma
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