Magnetic fluids are stable colloidal suspensions of ferromagnetic nano-particles (of size 10-20 nm) in a nonmagnetic liquid carrier. An initially uniform particle distribution in the carrier becomes spatially inhomogeneous in nonuniform magnetic fields. Motion of particles in magnetic fluids under the action of magnetic fields is of particular interest for contemporary mathematical and numerica...

in this paper, the static var compensator (svc) has been used to improve dynamic behaviour of power system. to do this, a new objective function is formulated considering power loss reduction, voltage profile improvement and loadability margin decrease. other contribution of this research is proposing a novel structure for particle swarm optimization (pso) algorithm through modifying the initia...

quantum dots of cds with hexagonal phase were prepared at relatively low temperature (60 oc) and short time by micro-emulsion (o/w) under ultrasound. this study was focused on the particle size distribution and the growth kinetics. the particle size distribution obtained from the optical absorption edge. it was relatively symmetrical with sonication time. in addition, an agreement was observed ...

soil erosion causes sediments to be detached from their source materials and transported as suspended particles. the present study was conducted to evaluate the effects of sand exploitation on the distribution of suspended sediments in the educational and research forest watershed of tarbiat modares university, which comprises approximately 50,000 ha. fifty-one water samples were collected befo...

We extend the homogeneous model for the synchrotron emission from plerions to allow more realistic predictions of the surface brightness profiles of the Crab Nebula at radio, optical and X-ray frequencies. Abandoning the assumption of a uniform particle distribution, we assume that particles are injected into the synchrotron nebula only in the vicinity of the pulsar. Their distribution is then ...

We generalize a recent study of random space-filling bearings to a more realistic situation, where the spacing offset varies randomly during the space-filling procedure, and show that it reproduces well the size distributions observed in recent studies of real fault gouges. In particular, we show that the fractal dimensions of random polydisperse bearings sweep predominantly the low range of va...

This paper discusses an imperfect preventive maintenance model for a deteriorating repairable system with consideration of the reliability limitand random maintenance quality. The model is derived from the combination of failure rate adjustment and age over an infinite time horizon. The maintenance intervals are obtained assuming both the failure rate increase factor and age restoration factor ...

This paper describes the concept of energy holes in sensor networks, their effects on network lifetime and various techniques to avoid them. The lifespan of sensor networks finish in short duration due to the presence of energy holes. A comparative study of strength and shortcoming of various techniques for combating energy holes problem has been discussed which shows that none of energy balanc...

Thorium-230 ages of emergent marine deposits on Oahu, Hawaii, have a uniform distribution of ages from approximately 114,000 to approximately 131,000 years, indicating a duration for the last interglacial sea-level high stand of approximately 17,000 years, in contrast to a duration of approximately 8000 years inferred from the orbitally tuned marine oxygen isotope record. Sea level on Oahu rose...