background: diabetes is one of the most common chronic diseases worldwide. the number of diabetic patients in iran is estimated 1.5 million. this survey has been conducted to evaluate diabetes and impaired fasting glucose status among 25-64 aged inhabitants of 17th zone of tehran, selected as population lab region. methods: this study is a part of the cardiovascular risk factors survey in the p...

In this study, the damping mechanism at the interface of the mating spur gear teeth is investigated. The dynamic behaviour of a spur gear pair is represented by a two Degree-of-Freedom (DOF) nonlinear model with the damping provided by the instantaneous tribological behaviour of the tooth contacts. The shear stress distributions along the tooth surfaces are incorporated with the dynamic model t...

In this paper,we established a seismic resistance and damping model to study the effects of tunnel under seismic waves.We took the entrance of Galongla Tunnel as prototype, drafted the similarity relationships of the model.Damping layers and the measuring points of shaking table model have been arranged. We carried out loading test of the shaking table. Compared with the results of finite eleme...

We study the dynamics of N charges interacting with the Maxwell field. If their initial velocities are small compared to the velocity of light, c, then in lowest order their motion is governed by the static Coulomb Lagrangian. We investigate higher order corrections with an explicit control on the error terms. The Darwin correction, order |v/c|2, has been proved previously. In this contribution...

In this study, a single-degree-of-freedom (SDOF) model with cable inerter viscous damper (CIVD) is established, and the vibration control equations frequency response functions are established. Then, influence of parameters, including inertia mass ratio, additional damping stiffness studied. Finally, dynamic time history analysis SDOF CIVD under earthquake fluctuating wind load carried out to v...

Abstract A novel dynamic vibration absorber(DVA) model with negative stiffness and inerter-mass is presented analytically studied in this paper. The research shows there are still two fixed points independent of the absorber damping amplitude frequency curve primary system when contains inerter-mass. optimum ratio obtained based on fixed-point theory. In order to ensure stability system, it fou...

Steel large-megawatts wind turbines have the light-damping and long-period properties, resulting in adverse vibrations under loads. In this paper, a novel tuned mass damper refitted via inner platform (IP-TMD) is proposed to control excessive vibration of steel turbine tower (WTT). Firstly, dynamic equation WTT controlled by IP-TMD system established according principle virtual work, its coeffi...

this study contains the identification of modal dynamic properties of a 3-story large-scale steel test frame structure through shaking table measurements. shaking table test is carried out to estimate the modal properties of the test frame such as natural frequencies, damping ratios and mode shapes. among many different model structures, arx (auto recursive exogenous) model structure is used fo...