Global electromagnetic turbulence is simulated in stellarator geometry using the gyrokinetic particle-in-cell code EUTERPE. The evolution of turbulent field and plasma profiles considered at different values beta for magnetic configurations. It found that linearly driven relatively high toroidal mode numbers. In nonlinear regime, lower numbers, including zonal flows, are excited resulting a que...

Propagation of monochromatic elastic waves across cracks is investigated in 1D, both theoretically and numerically. Cracks are modeled by nonlinear jump conditions. The mean dilatation of a single crack and the generation of harmonics are estimated by a perturbation analysis, and computed by the harmonic balance method. With a periodic and finite network of cracks, direct numerical simulations ...

In this paper, the analytical methods for approximate solutions of periodic motions to chaos in nonlinear dynamical systems are reviewed. Briefly discussed are the traditional analytical methods including the Lagrange stand form, perturbation methods, and method of averaging. A brief literature survey of approximate methods in application is completed, and the weakness of current existing appro...

We study directed ratchet transport of a harmonically driven overdamped Brownian particle subjected to shaken periodic potential. The existence frequency-dependent optimal value the relative amplitude two harmonic excitations involved is theoretically predicted from criticality scenario giving rise universality and numerically confirmed by extensive numerical experiments. robustness also demons...

This article analyzes a strongly nonlinear oscillator with cubic and harmonic restoring force and proposes an efficient analytical technique based on the modified energy balance method (MEBM). The proposed method incorporates higher-order approximations. After applying the proposed MEBM, a set of complicated higher-order nonlinear algebraic equations are obtained. Higher-order nonlinear algebra...

The purpose of this thesis is to gain an understanding of how the zonal heating asymmetries associated with the distribution of continents and oceans produce a wave response in the atmosphere. In particular, we wish to study the manner in which the advection processes of both the planetary and cyclonic scales influence the atmospheric climate as described by geographical variations in both the ...

In absence of explicit solutions of the perturbation equation of a static symmetrical homogeneous space-time, the best we can do is to construct a quasi-transformation. In this framework, we solve the perturbation equation with initial data and a number of results are derived. Far from the horizon of a black hole of even space dimension N , a mass-less field decays as r(−r + t) 1−N 2 −l in spac...