A two-step method of writing high di raction efciency holographic gratings in photopolymer using just one writing beam during the second step is discussed. The technique is based on the use of weak gratings (<1%) recorded during a rst step which during the second step are illuminated with a single beam to form strong highly e cient holographic gratings. The weak grating provides a second interf...

A new three-dimensional model of the FEL is presented. A system of scaled, coupled Maxwell–Lorentz equations are derived in the paraxial limit. A minimal number of limiting assumptions are made and the equations are not averaged in the longitudinal direction of common radiation/electron beam propagation, allowing the effects of coherent spontaneous emission and non-localised electron propagatio...

Recently, a large amount of studies have been related to nonlinear systems with multi-degrees of freedom as well as continuous systems. The purpose of this paper is to optimize passive vibration absorbers in linear and nonlinear states for an Euler-Bernoulli beam with a nonlinear vibratory behavior under concentrated moving load. The goal parameter in the optimization is maximum deflection of t...

This paper examines the solution of a damped beam equation whose damping characteristics are well-defined by the fractional derivative (FD). Homotopy Analysis Method (HAM) is applied for calculating the dynamic response (DR). Unit step and unit impulse functions are deliberated for this analysis. Acquired results are illustrated to show the movement of the beam under various sets of parameters ...

Abstract. This study presents an original inelastic beam-like model for the simulation of nonlinear dynamic behaviour three-dimensional buildings subjected to earthquake loadings. The proposed is defined as a step-wise shear only cantilever beam, whose segments have same mechanical properties corresponding inter-storeys building. inter-storey constitutive laws are calibrated by means results st...

We apply the dressing method to a string solution given by a static string wrapped around the equator of a three-sphere and find that the result is the single spike solution recently discussed in the literature. Further application of the method allows the construction of solutions with multiple spikes. In particular we construct the solution describing the scattering of two single spikes and c...