We study the existence and stability of space-periodic standing waves for the space-periodic cubic nonlinear Schrödinger equation with a point defect determined by a space-periodic Dirac distribution at the origin. This equation admits a smooth curve of positive space-periodic solutions with a profile given by the Jacobi elliptic function of dnoidal type. Via a perturbation method and continuat...

In their proof of the stability of standing-wave solutions of nonlinear Schrödinger equations, Cazenave and Lions used the principle of concentration compactness to characterize the standing waves as solutions of a certain variational problem. In this article we first review the techniques introduced by Cazenave and Lions, and then discuss their application to solitary-wave solutions of nonloca...

The rectangular Microstrip patch antenna is a popular choice for 5G applications due to its integrated design and wideband capabilities. Operating in the 1 GHz 3 range, this boasts gain of 4 dBi. In recent study, researchers utilized mm-wave bands at resonance frequency 39 create high-definition video various applications. proposed incorporates dielectric constant 4.4 was analyzed simulated usi...

A cascade thermoacoustic engine is described, consisting of one standing-wave stage plus two traveling-wave stages in series. Most of the acoustic power is produced in the efficient traveling-wave stages. The straight-line series configuration is easy to build and allows no Gedeon streaming. The engine delivers up to 2 kW of acoustic power, with an efficiency (the ratio of acoustic power to hea...

An investigation of the effect of resonator dimensions on nonlinear standing waves in shaped resonators is conducted. Simple forms of the shear viscosity term in the momentum equations are developed for an axisymmetric (2D) resonator and a low aspect ratio rectangular (3D) resonator. The cross sections of the resonators are exponentially expanded and the one-dimensional wave equations are solve...

Structured light, with its ability to tailor diverse degrees of freedom (DoFs) light has recently attracted increasing attention, especially as geometric beams that can open multiple DoFs by the ray-wave duality. Here, a generalized beam family is proposed unify azimuthally traveling-wave (TW) and standing-wave (SW) structured introducing ray-split/fusion state tunable spatial mode continuously...

Using two-dimensional hybrid-kinetic simulations, we explore the nonlinear "interruption" of standing and traveling shear-Alfvén waves in collisionless plasmas. Interruption involves a self-generated pressure anisotropy removing the restoring force of a linearly polarized Alfvénic perturbation, and occurs for wave amplitudes δB_{⊥}/B_{0}≳β^{-1/2} (where β is the ratio of thermal to magnetic pre...

The purpose of this study was to investigate a numerical method for calculating impedances and standing wave patterns of flute structures. To this end, the physical dimensions of flute joints and tone holes were used to compute impedance and standing waves as a function of frequency for several different fingerings. Numerically computed resonance frequencies for head joint, middle and foot join...

Existing schemes for the calibration of radio-astronomical observations are insufficient for the application in forthcoming space missions with heterodyne systems like HIFI. Many of the approximations used are not valid for systems with large IF frequencies and they are too rough for the desired calibration accuracy of a few percent. Moreover, they do not exploit the full capabilities of instru...