The coupling beam damper is a fundamental energy dissipation component in coupling shear wall structures that directly influences the performance of the shear wall. Here, we proposed a two-fold design method that can give better energy dissipation performance and hysteretic behavior to coupling beam dampers. First, we devised four in-plane yielding coupling beam dampers that have different open...

The stability of a coasting beam against selfbunching (negative mass instability) may be expressed in terms of a beam coupling impedance. The impedance has contributions from self-fields, wall impedance, and curvature effects. This paper describes procedures for measuring the wall and curvature contributions to the coupling impedance by means of an analog in which the beam is replaced by a cond...

To achieve high luminosity, the target vertical beam size at the TESLA interaction point is 5 nm. The long solenoid encompassing the detector introduces coupling effects that increase the vertical beam size. In the case that the last quadrupole of the final focus lies inside the solenoid field, the increase in vertical beam size is by as much as two orders of magnitude. In this note, we describ...

In the present study an evaluation of the potential for bend-twist coupling effects in wind turbine blades is addressed. A method for evaluation of the coupling magnitude based on the results of finite element modeling and full-field displacement measurements obtained by experiments is developed and tested on small-scale coupled composite beams. In the proposed method the coupling coefficient f...

A fast stripline beam kicker is used to dynamically switch a high current electron beam between two beamlines. The transverse dipole impedance of a stripline beam kicker has been previously determined from a simple transmission line model of the structure [1]. This model did not include effects due to the long axial slots along the structure as well as the cavities and coaxial feed transition s...

We present our experimental and theoretical studies of multi-dark-state resonances (MDSRs) generated in a unique cold rubidium atomic system with only one coupling laser beam. Such MDSRs are caused by different transition strengths of the strong coupling beam connecting different Zeeman sublevels. Controlling the transparency windows in such an electromagnetically induced transparency system ca...

Wave equations describing the quasi-degenerated two-beam coupling in the photorefractive crystals for high frequency gratings have been solved. In the case of the quasidegenerate two-beam coupling, equations depend upon the coupling coefficient, the response time of the medium, the input beams frequencies, the absorption coefficient and the input intensity ratio. The response time of the medium...

We report a theoretical and experimental study of laser coupling in hollow-core, fiber-optic waveguides with small-bore diameters of d=200 μm. For the experiments we utilized three mid-infrared quantum cascade lasers with different emission wavelength, which were coupled into the waveguides using lenses with focal lengths in the range 25-76 mm. Measurements of the output beam profiles and propa...

The brightness of light produced at a point (s) in a light source is inversely proportional to ψ(s)f(β), where ψ(s) is the local coupling angle, f(β) is a function of the transverse beta-functions and n depends on photon diffraction effects and ranges from 1 to 2. As well, brightness is proportional to the circulating current, which, for a given lifetime, is proportional to the average vertical...