The most common cause of power transformer failures is mechanical defect brought about by excessive vibration, which is formed by the combination of multiples of a frequency of 120 Hz. In this paper, the types of mechanical exciting forces applied to the power transformer were classified, and the mechanical damage mechanism of the power transformer was identified using the vibration transfer ro...

The traditional ultrasonic apparatus cannot be operated at high temperature, explaining why the effect of ultrasonic-vibration on high temperature metal forming has seldom been addressed in literature. This study establishes an ultrasonic-vibration hot upsetting system. A cooling mechanism is used to solve the problem of high temperature. The effects of temperature and strain rate during ultras...

Dissociation rates o f H F in electrical discharges have been calculated by solving a system of vibrational master equations, including e-V (electron-vibration), V-V (vibration-vibration) and V-T (vibration-translation) energy exchanges. The results show that large dissociation rates can be obtained by this mechanism only when the e-V pumping rates overcome the V-T deactivating rates. This occu...

Previous investigations have shown that one mechanism of irregular vocal fold vibration may be a desynchronization of two or more vibratory modes of the vocal fold tissues. In the current investigation, mechanisms of irregular vibration were further examined using a self-oscillating, physical model of vocal fold vibration, a hemi-model methodology, and high-speed, stereoscopic, digital imaging....

A vibration isolation module with zero-power magnetic suspension is developed to retrofit a passive vibration isolation system to improve the performance against direct disturbance. In the module, the zero-power magnetic suspension mechanism is connected in series with a normal spring through a middle mass. This structure can generate zero compliance to direct disturbance while the transmitted ...

Rat experiments were performed to study variations in serotonin (5-HT) and its metabolite (5-hydroxy indole acetic acid) in different CNS compartments. Control animals were exposed to an acute vibration stress (10 Hz, 1 mm, 2 m/sec2, 15 min) and experimental animals to a prolonged (52-54 days) vibration test. Acute vibration led to 5-HT activation which was most significant in the hippocampus, ...

To control underwater acoustic radiation of ships and protect against detection, coatings are attached to the vibrating wet surface of the hulls. Coatings with different pores or scatterers enclosed will attenuate vibration and suppress sound radiation with different mechanisms. However, there are very few experimental studies concerning vibration measurement of a coated structure in water, mai...