We study a modified Bullard dynamo and show that this system is equivalent to a nonlinear oscillator subject to a multiplicative noise. The stability analysis of this oscillator is performed. Two bifurcations are identified, first towards an “intermittent”state where the absorbing (non-dynamo) state is no more stable but the most probable value of the amplitude of the oscillator is still zero a...

The classical three-body problem { where is abstract mathematics, physical intuition, computational physics most powerful? We propose a simple oscillator model for the reduced three-body problem to understand the stability of orbits with small eccentricity of the light planet. It models the main short-time features for small mass ratios of the other bodies. These results are confronted with the...

A CMOS standard three-stage ring oscillator is examined in UMC 0.13 m technologies. As the ring oscillator is a part of IR-UWB (Impulse Radio Ultra Wide Band) pulse generator, its oscillating frequency determines the central frequency of the pulse spectrum and has significant effect on spectrum fitting within UWB FCC mask. The influence of inverter feedback resistors on the ring oscillator freq...

OF THE THESIS OSCILLATOR STRENGTHS FROM TIME-DEPENDENT DENSITY FUNCTIONAL THEORY by Heiko Appel Thesis Director: Kieron Burke We consider different forms of single-pole approximations (SPA) for oscillator-strengths in the response formalism of time-dependent density functional theory. Numerical calculations of oscillator strengths are presented for a simple model system, Hooke’s atom, and vario...

In its most basic form an oscillator consists of a resonator driven on resonance, through feedback, to create a periodic signal sustained by a static energy source. The generation of a stable frequency, the basic function of oscillators, is typically achieved by increasing the amplitude of motion of the resonator while remaining within its linear, harmonic regime. Contrary to this conventional ...

This paper describes a computational study of fluidic oscillator-crossflow interactions. Fluidic oscillators are high potential active flow control devices, which offer promise for cooling and separation. Previous experimental studies have investigated the internal/external fields oscillators. improved understanding three-dimensional fields; however, this has been limited to single aspect ratio...

A new conceptual model for ENSO has been constructed based upon the positive feedback of tropical ocean– atmosphere interaction proposed by Bjerknes as the growth mechanism and the recharge–discharge of the equatorial heat content as the phase-transition mechanism suggested by Cane and Zebiak and by Wyrtki. This model combines SST dynamics and ocean adjustment dynamics into a coupled basinwide ...

objective: the incidence of heart valve disease is increasing worldwide and the number of heart valve replacements is expected to increase in the future. by mimicking the main tissue structures and properties of heart valve, tissue engineering offers new options for the replacements. applying an appropriate scaffold in fabricating tissue-engineered heart valves (tehvs) is of importance since it...