In this study, two experiments were conducted to determine the curves of equal intensity perception for sinusoidal vertical whole-body vibrations (WBV) of seated subjects over the frequency range from 10Hz to 250Hz. Vibrations were presented to subjects using a at hard seat. In total, 10 participants were asked to match the intensity of di erent vibrations, using a method of adjustment. The obt...

The physical mechanism by which cells sense high-frequency mechanical signals of small magnitude is unknown. During exposure to vibrations, cell populations within a bone are subjected not only to acceleratory motions but also to fluid shear as a result of fluid-cell interactions. We explored displacements of the cell nucleus during exposure to vibrations with a finite element (FE) model and te...

in this paper, a rectangular sandwich plate with a constrained layer and an electrorheological (er) fluid core is investigated. the rectangular plate is covered an er fluid core and a constraining layer to improve the stability of the system. the two outer layers of the sandwich structure are elastic. the viscoelastic materials express the middle layer behavior under electric field and small st...

This paper presents the application of a time-delay neural network to the detection and classification of time signatures produced by insect sounds in a stored grain silo. Conventional methodr of insect monitoring can only detecr some of rhe adulr insects and none of the larvae insects, which are the most destructive to the grain. The acoustic vibrations generated by the adult and larvae when m...

A Fermi resonance-algebraic model is proposed for molecular vibrations, where a U(2) algebra is used for describing the vibrations of each bond, and Fermi resonances between stretching and bending modes are taken into account. The model for a bent molecule XY2 and a molecule XY3 is successfully applied to fit the recently observed vibrational spectrum of the water molecule and arsine (AsH3), re...

The nonlinear two-degree-of-freedom system under consideration consists of the linear oscillator with a relatively big mass, which is an approximation of some continuous elastic system, and of the vibro-impact oscillator with a relatively small mass, which is an absorber of the linear system vibrations. Analysis of nonlinear normal vibration modes shows that a stable localized vibration mode, w...

The problem of stabilizing vibrations of flexible cable related to an overhead crane is considered. The cable vibrations are described by a hyperbolic partial differential equation HPDE with an update boundary condition. We provide in this paper a systematic way to derive a boundary feedback law which restores in a closed form the cable vibrations to the desired zero equilibrium. Such a control...

In this paper we address the problems of hysteresis and vibrations that limit the accuracy of piezoelectric positioners. It is widely known that the use of charge control significantly reduces hysteresis, thus enabling high-accuracy positioning during low speed operations. However, charge control is unable to reduce vibrations that limit the positioning bandwidth. Our main contribution is to ov...

Some hazards posed by the operation of hydraulic systems, connected with low-frequency vibrations and noise are presented. Special attention is focused on infrasounds. The sources of low-frequency vibrations and noise and ways of reducing them are indicated. An original solution ensuring the effective reduction of vibrations and noise in a wide frequency range, i.e., a wide-band damper of press...

The structure and properties of absorbed fluorine and chlorine atoms on GaAs surfaces are investigated. The energies of surface species' localized vibrations are determined. Our results show that localized As±Cl and Ga±Cl valence vibrations occur in the 40 and 50 meV regimes, respectively, while As±F and Ga±F vibrations are found in the 90 and 80 meV regimes, respectively. Comparisons are made ...