We consider the one-dimensional nonlinear Schrödinger equation with Dirichlet boundary conditions in the fully resonant case (absence of the mass term). We investigate conservation of small amplitude periodic solutions for a large measure set of frequencies. In particular we show that there are infinitely many periodic solutions which continue the linear ones involving an arbitrary number of re...

It has been suggested that poststenotic weakening of arterial walls is caused by arterial wall vibration and structural fatigue initiated by pressure disturbances in turbulent blood flow. We examined the frequency spectra of wall vibration downstream from experimental arterial stenoses and compared them with the natural resonant vibration characteristics of the artery walls. Spectra of arterial...

The wide application of switched reluctance motors (SRM) is limited by their higher vibration and acoustic noise. An accurate determination of resonant frequencies and mode shapes of the SRM stator is therefore essential for low acoustic noise design. Based on the structural finite element method and elasticity theory, 3D vibration modes and resonant frequencies of a 5 hp SRM with 8/6 poles are...

An innovative concept is utilized to develop the fractal antenna by coalesce the Koch prefractal and meander line. This fractal antenna is proposed for multistandard wireless applications. The shape and dimensions of the proposed antenna are chosen to obtain the multiband behaviour as well as miniaturized structure. Initially two different fractal concepts have been chosen through previous rese...

( 3 ) where c is the velocity of light in free space, s = 7cr2 (area of the original circle) and (s Ax) is the overlapping area of the two circles. The theoretical resonant frequencies for ports 1 and 2 are 2.609 and 3.129GHz, respectively. The experiment has been repeated with substrates of different thickness and dielectric constant. The agreement between theoretical and experimental resonanc...

This paper presents the design of a wheel shaped multiband fractal Antenna. This Fractal antenna has been designed on substrate εr = 4.3 and thickness h = 1.53 mm. This new antenna has been fed with CPW – Fed. The antenna exhibits the multiband resonances due to selfsimilarity in antenna structure. The experimental results indicate that resonant frequencies occur at 1.34 GHz, 2.575 GHz, 4.22 GH...

An electromagnetically coupled feed arrangement is proposed for simultaneously exciting multiple concentric ring antennas for multi-frequency operation. This has a multi-layer dielectric configuration in which a transmission line is embedded below the layer containing radiating rings. Energy coupled to these rings from the line beneath is optimised by suitably adjusting the location and dimensi...