The modied Zakharov–Kuznetsov (mZK) equation, ut + uux + uxxx + uxyy = 0, (1) represents an anisotropic two-dimensional generalization of the Korteweg–de Vries equation and can be derived in a magnetized plasma for small amplitude Alfvén waves at a critical angle to the undisturbed magnetic field, and has been studied by many authors because of its importance [1–5]. However, Eq. (1) possesses m...

A modified F-expansion method to find the exact traveling wave solutions of  two-component nonlinear partial differential equations (NLPDEs) is discussed. We use this method to construct many new solutions to the nonlinear Whitham-Broer-Kaup system (1+1)-dimensional. The solutions obtained include Jacobi elliptic periodic wave solutions which exactly degenerate to the soliton solutions, triangu...

In this article we are concerned with the existence and orbital stability of traveling wave solutions of a general class of nonlocal wave equations: utt − Luxx = B(±|u|u)xx, p > 1. The main characteristic of this class of equations is the existence of two sources of dispersion, characterized by two coercive pseudo-differential operatorsL and B. Members of the class arise as mathematical models ...

We present some variants of Burgers-type equations for incompressible and isothermal planar flow of viscous non-Newtonian fluids based on the Cross, the Carreau and the power-law rheology models, and on a symmetry assumption on the flow. We numerically solve the associated traveling wave equations by using industrial data and in order to validate the models we prove existence and uniqueness of ...

A midsystolic plateau differentiates the pattern of fetal pulmonary trunk blood flow from aortic flow. To determine whether this plateau arises from interactions between the left (LV) and right ventricle (RV) via the ductus arteriosus or from interactions between the RV and the lung vasculature, we measured blood flows and pressures in the pulmonary trunk and aorta of eight anesthetized (ketami...

By spectrally and temporally reshaping the gain-window of a traveling-wave semiconductor optical amplifier (TWSOA) with a backward injected multi- or single-wavelength inverse-optical-comb, we theoretically and experimentally investigate the dynamic frequency chirp of the all-optical 10GBit/s Return-to-Zero (RZ) data-stream format-converted from the TWSOA under strong cross-gain depletion schem...

Performance characteristics of a fundamental cyclotron harmonic, distributed-loss, TE01-mode gyrotron traveling-wave amplifier are studied theoretically. Absolute instabilities on both lower and higher order modes at the fundamental and second cyclotron harmonic frequencies present a severe limitation to the stable operating current and hence the device capability. General methods for stabilizi...

For effective use of frequency band, carrier superposing (common band) technique has been introduced to satellite communication systems. Meanwhile the satellite’s Traveling Wave Tube Amplifier (TWTA) is preferred to be operated near saturation level for power efficiency. However nonlinearity characteristics of TWTA around that level become the cause of interference for carrier superposing syste...

Motivated by recent advances in wideband-gap (WBG) gallium nitride (GaN) semiconductor technology, there is considerable interest in developing efficient solidstate power amplifiers (SSPAs) as an alternative to the traveling-wave tube amplifier (TWTA) for space applications. This article documents the general architecture considerations pertinent to developing SSPA architectures that can enable...

We describe a multioctave power-combiner structure using finline arrays in an oversized coaxial waveguide. The spectral-domain method (SDM) is used to compute the propagation constant in this structure, and is verified with HFSS simulations. The SDM method is then employed to synthesize broad-band tapered impedance transformers in finline for coupling energy to and from a set of monolithic micr...