The theory of internal tidal waves is briefly reviewed in order to demonstrate the importance of simultaneous observations at different positions. After a description of the expectancy test it is shown that a reasonably high probability exists that the internal tidal oscillations found at Meteor Station 385 in the temperature observations are real and not purely formal results of the harmonic a...

Spectral evolution equations are used to perform analytical and numerical studies of nonlinear surface acoustic waves in the (001) plane of a variety of nonpiezoelectric cubic crystals. The basic theory underlying the model equations is outlined, and quasilinear solutions of the equations are presented. Expressions are also developed for a characteristic length scale for nonlinear distortion an...

The fundamental solution of the Dirac equation for an electron in an electromagnetic field with harmonic dependence on space-time coordinates is obtained. The field is composed of three standing plane harmonic waves with mutually orthogonal phase planes and the same frequency. Each standing wave consists of two eigenwaves with different complex amplitudes and opposite directions of propagation....

We develope a No Response Test for the reconstruction of some polyhedral obstacle from one or few time-harmonic electromagnetic incident waves in electromagnetics. The basic idea of the test is to probe some region in space with waves which are small on some test domain and, thus, do not generate a response when the scatterer is inside of this test domain. This is the first formulation of the N...

In this paper an attempt is made to explain the period-doubling of wind-generated gravity-capillary waves as observed in the experimentofChoi (1977). It is conjectured that period-doubling is closely related to the phenomenon of second-harmonic resonance. In order to obtain a simple dynamical model, results of McGoldrick (1970) and Simmons (1969) are extended to include the effect of wind input...

Second harmonic generation (SHG) is applied for the first time to study the surfaces of clay particles. An SHG signal was detected from an aqueous suspension of disk-shaped montmorillonite clay particles of 0.5 μm diameter and 0.01 μm thickness. The origin of the SHG signal is the polarization of water molecules by surface charges located in the edge region of the clay particles. On addition of...

Abstract Spurious harmonics generation can occur in wave basins when strongly nonlinear waves are generated with linear maker theory. For regular long crested waves, the phenomena is known to cause a beating pattern for amplitude of higher harmonics, while irregular effect often thought average out. We here report on recent experimental results spurious harmonic highly waves. Long at two depths...

Abstract The reflection of time-harmonic waves in a waveguide with nonlinear boundary stiffness is considered applications to rods and beams. Incident at frequencies that are multiples fundamental frequency give rise reflected propagating nearfield the same frequencies. An infinite set equations developed for coefficients, which depend on amplitudes phases incident waves. Nonlinear conditions a...

It is shown that flare-produced fast electrons with a power-law energy distribution trapped in magnetic loops are capable to produce plasma waves at the upper hybrid frequency due to a loss-cone instability. Conditions for instability are obtained in dependence of the parameters of the power-law distribution and the magnetic-loop parameters. The growth rate of the plasma waves has been calculat...

Magnetic resonance elastography (MRE) is an increasingly used noninvasive modality for diagnosing diseases using the response of soft tissue to harmonic shear waves. We present a study on the algebraic Helmholtz inversion (AHI) applied to planar MRE, demonstrating that the deduced phase speed of shear waves depends strongly on the relative orientations of actuator polarization, motion encoding ...