This paper compares performance of a piezoelectric vibration energy harvester, in terms of output power, under different types of vibration. The most common method used to characterize a vibration energy harvester is to excite the energy harvester under a sinusoidal vibration of its resonant frequency and measure the voltage across certain electrical loads. However, in practical applications, t...

An explicit solution for the vibration of a carbon chain inside carbon nanotubes (CNTs) was obtained using continuum modeling of the van der Waals (vdW) interactions between them. The effect of the initial tensile force and the amplitude of the carbon chain as well as the radii of the CNTs on the vibration frequency were analyzed in detail, respectively. Our analytical results show that the vib...

The characteristics of mobile phone usage when user is moving are different from those when user is sedentary or working in an office (Baek et al., 2006). This means that the default vibration frequency of current mobile phones may not be suitable for use in a mobile environment. Therefore, this study was designed to investigate the optimal vibration frequency for the perception of mobile phone...

The purpose of the study was to examine the effect of prolonged vibration on the force fluctuations during a force-matching task performed at low-force levels. Fourteen young healthy men performed a submaximal force-matching task of isometric plantar flexion before and after Achilles tendon vibration (n = 8, vibration subjects) or lying without vibration (n = 6, control subjects) for 30 min. Th...

Fore-and-aft vibration of a backrest can influence discomfort and the risk of injury associated with whole-body vibration. Relevant standards (BS 6841:1987 and ISO2631-1:1997) recommend the W(c) frequency weighting for evaluating fore-and-aft vibration of backrests, but do not specify the precise location for measuring vibration. This study determined equivalent comfort contours for fore-and-af...

In this study, the effect of posture, vibration magnitude and frequency on seat-to-head (STH) and back support-tohead (BTH) transfer functions has been studied under vertical sinusoidal vibration. Twelve healthy male subjects were participated in experimental work to measure vertical vibration transmitted to the occupants head in three representative postures (erect, vertical back on and forwar...

This article studied static deflection, natural frequency and nonlinear vibration of a clamped-clamped microbeam under discontinues electrostatic actuation. The electrostatic actuation was induced by applying AC-DC voltage between the microbeam and electrode plate. In contrast to previous works, it was assumed that length of the electrode plate was smaller than that of the microbeam. In additio...

UNLABELLED This study determined how backrest inclination and the frequency and magnitude of vertical seat vibration influence vibration discomfort. Subjects experienced vertical seat vibration at frequencies in the range 2.5-25 Hz at vibration magnitudes in the range 0.016-2.0 ms(-2) r.m.s. Equivalent comfort contours were determined with five backrest conditions: no backrest, and with a stati...

OBJECTIVES/HYPOTHESIS To observe blood perfusion and vascular permeability changes under varying vibration frequency exposures. STUDY DESIGN Animal model. METHODS Blood perfusion was measured using laser Doppler flowmetry in eight rabbit auricular vessels (four rabbits) under nonvibration, and 62.5-Hz/1-mm, 125-Hz/1-mm, and 250-Hz/0.5-mm vibration frequency/amplitude exposures. Another 12 r...

With the trend of lighter vehicle and more powerful engine (power plant) passengers are subjected to large vibration and harshness coming from the engine through the chassis. This paper discusses the application of active vibration control to reduce this vibration effect. Using a mass-spring-damper model which represents a passive engine mount, dynamic characteristic of the mount is obtained fo...