Cracks creation in solids can be accompanied by electromagnetic emission (EME). On the faces of new created crack electric charges constitute electric dipole system and due to crack walls vibration an EME signal is detected with frequency from 1 to 10 MHz corresponding to crack length 0.1 to 1 mm. The second source of EME signal is later activated due to whole sample mechanical vibrations with ...

In wind pollination, the release of pollen from anthers into airflows determines the quantity and timing of pollen available for pollination. Despite the ecological and evolutionary importance of pollen release, wind-stamen interactions are poorly understood, as are the specific forces that deliver pollen grains into airflows. We present empirical evidence that atmospheric turbulence acts direc...

The current manuscripts deals with the design of passive mechanical filters for vibration attenuation a low frequencies. Traditionally, this has been addressed employing dissipation as the attenuation mechanism. While such strategy provides broadfrequency effectiveness, attenuation at any given frequency is modest. Mass and stiffness-modulated periodic systems, on the other hand, exploit disper...

Background: Previous studies demonstrated a health improving effect in patients underwent an automatic vibratory massage taking 10 minutes. One of reasons that may explain a healing effect of the automatic massage is a stimulated increase in both blood circulation through vascular system and effective size of blood vessels. Objective: This paper aims to quantify a contribution of the auto...

The combination of high-frequency vibrations and metallic transport in graphene makes it a unique material for nanoelectromechanical devices. In this Letter, we show that graphene-based nanoelectromechanical devices are extremely well suited for charge pumping due to the sensitivity of its transport coefficients to perturbations in electrostatic potential and mechanical deformations, with the p...

Devices that harvest electrical energy from mechanical vibrations have the problem that the frequency of the source vibration is often not matched to the resonant frequency of the energy harvesting device. Manufacturing tolerances make it difficult to match the Energy Harvesting Device (EHD) resonant frequency to the source vibration frequency, and the source vibration frequency may vary with t...

Large mechanical equipment is subject to periodic vibrations in harsh operating environments for a long time. Bearing failure produces violent changes the behaviors of large rotating machinery as safety and reliability scene. Therefore, it especially significant effectively identify early bearing. Since signal bearing fault belongs low-frequency weak fault, hard classify characteristic frequenc...

Ginkgo biloba L. has significant health benefits and considerable economic value, but harvesting the fruit is highly labor-intensive. Mechanical vibration been shown effective in various types. In study of harvesting, research on characteristics trees focuses natural frequency (resonance frequency), model, damping coefficient, which are main factors affecting trees. But field experiments have t...

A low-temperature specific heat study has been performed on the insulating giant dielectric constant material CaCu3Ti4O12 and two related compounds, Bi2/3Cu3Ti4O12 and La0.5Na0.5Cu3Ti4O12, from 0.6 to 10 K. From analyzing the specific heat data in a very low-temperature range, 0.6–1.5 K, and moderately low-temperature range, 1.5–5 K, in addition to the expected Debye terms, we observed signific...

We investigate the in-line and cross-flow vortex-induced vibrations of a long cylindrical tensioned beam, with length to diameter ratio L/D=200, placed within a linearly sheared oncoming flow, using three-dimensional direct numerical simulation. The study is conducted at three Reynolds numbers, from 110 to 1100 based on maximum velocity, so as to include the transition to turbulence in the wake...