We conduct experiments on two-dimensional packings of colloidal thermosensitive hydrogel particles whose packing fraction can be tuned above the jamming transition by varying the temperature. By measuring displacement correlations between particles, we extract the vibrational properties of a corresponding "shadow" system with the same configuration and interactions, but for which the dynamics o...

A rotating machine is a very complex device that involves electrical, mechanical and control systems. Therefore, the whole representation of a machine requires the specification of electrical and mechanical parameters, as well as control system data. The representation of the mechanical part and the control systems are only needed for low frequency transients [1]. An accurate representation of ...

Self-excited vibrations are developed when mechanical system includes internal or external source of energy, which gives energy equal or larger than energy loss [1-5]. The same source of energy, which keeps vibrations in order is permanent. The system makes sure that the energy inflow from permanent source through internal energy converter, which is a part of a feedback. Frequency of energy inf...

Torsional vibrations and resonance problems with synchronous machines are most frequently encountered in rotor systems with long shafts and large inertias constituting a weakly damped mechanical resonator which exhibits a low resonance frequency. It is impossible to obtain a effective mechanical damping for these torsional vibrations, but by using a power electronics device and an inductive or ...

The use of distinguishable complex vibrations that have multiple spectral components can improve the transfer of information by vibrotactile interfaces. We investigated the qualitative characteristics of dual-frequency vibrations as the simplest complex vibrations compared to single-frequency vibrations. Two psychophysical experiments were conducted to elucidate the perceptual characteristics o...

A procedure for calculating the amplitudes of the normal and tangential components of the displacement vector of three-dimensional vibrations of any point on the surface of mechanical wave system is proposed on the basis of experimental holographic interfrometry data and the theory of vibrations of mechanical systems The problem of determination the amplitude – frequency response characteristic...

We review the mechanical origin of auditory-nerve excitation, focusing on comparisons of the magnitudes and phases of basilar-membrane (BM) vibrations and auditory-nerve fiber responses to tones at a basal site of the chinchilla cochlea with characteristic frequency approximately 9 kHz located 3.5 mm from the oval window. At this location, characteristic frequency thresholds of fibers with high...

Magnetic resonance elastography (MRE) is a noninvasive method of measuring tissue compliance. Current MRE methods rely on custom-built hardware to elicit vibrations that are tracked by MR imaging. Knowledge of the wave propagation can be used to calculate the local shear stiffness of the tissue. We sought to determine whether the vibrations of the patient table that result from low-frequency sw...