The microtubes are important structures in nano electromechanical system .in this study a nonlocal model is presented to investigate the static torsion behavior of microtubes made of bi-directional factionally graded material (BDFGM) subjected to a longitudinal magnetic field. Mechanical properties of BDFGM microtube varies in the radial and longitudinal direction according to an arbitrary func...

Introduction. Static converters are among the most widely used equipment in several applications, for example, electric power transmission, motor speed variation, photovoltaic panels, which constitute electronic components. The design of a electronics device is done without any real means predicting electromagnetic disturbances during product development phase. This case-by-case process repeate...

A method of speech enhancement is developed that reconstructs clean speech from a set of acoustic features using a sinusoidal model of speech. This is a significant departure from traditional filtering-based methods of speech enhancement. A major challenge with this approach is to estimate accurately the acoustic features (voicing, fundamental frequency, spectral envelope) from noisy speech. Th...

In a patient with no prior history of seizures we were able to record static (mean) intracranial pressure (ICP) and pulsatile ICP (mean ICP wave amplitude) continuously during a first-time generalized epileptic seizure. The patient experienced episodic headache five months after a subarachnoid haemorrhage. In order to rule out low-pressure hydrocephalus she was admitted for a 24-hour intracrani...

cylindrical steel tanks are important components of many industrial plants such as oil refineries and chemical plants. usually failure of cylindrical tanks leads to serious consequences. during the past earthquakes such as 1964 alaska and 1999 turkey seismic performance of cylindrical tanks revealed that tanks are seismically vulnerable. therefore, evaluation of seismic performance of these str...

The tube wave, or low-frequency manifestation of the Stoneley wave, has been modeled previously using the quasi-static approximation; I extend this method to include the effect of the formation matrix compressibility, which tends to marginally increase the tube-wave attenuation. Using the Biot theory of poroelasticity, I develop a fully dynamic description of the Stoneley wave. The dispersion r...

We consider a burst of quadrupole gravitational radiation in the presence of a large static mass M situated at its source. Some of the radiation is back-scattered off the static field of the large mass, forming a wave tail. After the burst, the tail is a pure incoming wave, carrying energy back towards the source. We calculate this energy, and, in a numerical example , compare it with the outgo...

This report describes a program of work in which both electrostatic and electromagnetic wave amplifying mechanisms are under investigation. For the former, studies in the absence of a static magnetic field are direcced towards verifying the theory for beam/surface wave amplification. Two distinctly different lines are being followed for interaction in the presence of a static magnetic iield: El...

Abstract A novel hybrid control strategy for reducing torque ripple in permanent magnet brushless direct current motors has been developed by combining the deterministic nature of and adaptive fuzzy logic control. Direct using space vector pulse width modulation developed. This technique ensures near-sinusoidal stator rotor current. The impact commutation corresponding to sinusoidal is reduced ...