the efficiency of induction motors decreases at light loads. efficiency optimizer control systemsadjust the motor flux value to achieve the best efficiency in a wide range of load variations. reduced fluxoperation has some other benefits such as power factor improvement and torque ripple reduction. the latter isan important issue in a direct torque controlled induction motor drive. in this pape...

The dynamics of one-dimensional, piston-driven hydrogen–air detonations are predicted in the presence of physical mass, momentum and energy diffusion. The calculations are automatically verified by the use of an adaptive wavelet-based computational method which correlates a user-specified error tolerance to the error in the calculations. The predicted frequency of 0.97 MHz for an overdriven pul...

In this paper we investigate the properties and linear stability of travelling premixed combustion waves and the formation of pulsating combustion waves in a model with two-step chain-branching reaction mechanism. These calculations are undertaken in the adiabatic limit, in one spatial dimension and for the case of arbitrary Lewis numbers for fuel and radicals. It is shown that the Lewis number...

[Purpose] The aim of the study was to establish whether pulsating electrostatic field application, shown to increase blood flow and metabolic activity and to function as an ion pump, is able to reduce muscle pain after exercise-induced muscle damage. [Subjects and Methods] Seven participants (4 males, 3 females) performed two sessions of downhill running separated by at least 4 weeks. After the...

Pulsating jet is visualized using hydrogen bubble method to clarify the vortex nature in the near field of the jet. This study focused on the development in space and time of vortex structures evolution in low aspect-ratio rectangular jet with pulsation. Pulsation means large-amplitude, low-frequency excitation which is expected to increase the mixing and spreading of the jet and to accelerate ...

Three giant flares have been detected so far from soft gamma-ray repeaters, each characterized by an initial short hard spike and a pulsating tail. The observed pulsating tails are characterized by a duration of ∼100 s, an isotropic energy of∼10 erg, and a pulse period of a few seconds. The pulsating tail emission likely originates from the residual energy after the intense energy release durin...

ASTRONOMY AND ASTROPHYSICS Study of an unbiased sample of B stars observed with Hipparcos: the discovery of a large amount of new Slowly Pulsating B Stars Abstract. We present a classiication of 267 new variable B-type stars discovered by Hipparcos. We have used two diierent classiication schemes and they both result in only a few new Cephei stars, a huge number of new Slowly Pulsating B stars,...

stars: magnetic fields It is essential for the understanding of stellar structure models of high mass stars to explain why constant stars, non-pulsating chemically peculiar hot Bp stars and pulsating stars co-exist in the slowly pulsating B stars and β Cephei instability strips. We have conducted a search for magnetic fields in the four Bp stars HD 55522, HD 105382, HD 131120, and HD 138769 whi...

Motivated by recent analytical and numerical work on two-and three-dimensional convection with imposed spatial periodicity, we analyse three examples of bifurcations from a continuous group orbit of spatio-temporally symmetric periodic solutions of partial differential equations. Our approach is based on centre manifold reduction for maps, and is in the spirit of earlier work by Iooss (1986) on...

This paper is concerned with the existence and qualitative properties of transition fronts for spatially periodic reaction-diffusion equations with bistable nonlinearities. The notion of transition fronts connecting two stable steady states generalizes the standard notion of pulsating fronts. In this paper, we prove that the time-global solutions in the class of transition fronts share some com...