We experimentally investigate the nonlinear reshaping of a continuous wave that leads to chirp-free and flat-top intense pulses or flaticons exhibiting strong temporal oscillations at their edges and a stable self-similar expansion upon propagation of their central region. This study was performed in the normal dispersion regime of a nonzero dispersion-shifted fiber and involved a sinusoidal ph...

[1] We present calibrated measurements of ELF waves generated by modulated HF heating of the auroral electrojet by the High frequency Active Auroral Research Program (HAARP) HF transmitter in Gakona, Alaska, and detected after propagating more than 4400 km in the Earth-ionosphere waveguide to Midway Atoll. The magnitude of the 2125 Hz wave received at Midway Atoll is consistent with the radiati...

Internal waves in the atmosphere and ocean are generated frequently from the interaction of mean flow with bottom obstacles such as mountains and submarine ridges. Analysis of these environmental phenomena involves theoretical models of non-homogeneous fluid affected by the gravity. In this paper, a semi-analytical model of stratified flow over the mountain range is considered under the assumpt...

The apparently intractable shape of a fold in a compressed elastic film lying on a fluid substrate is found to have an exact solution. Such systems buckle at a nonzero wave vector set by the bending stiffness of the film and the weight of the substrate fluid. Our solution describes the entire progression from a weakly displaced sinusoidal buckling to a single large fold that contacts itself. Th...

This paper proposes a new three-phase diode rectifier system with a sinusoidal input current at unity power factor and a regulated and isolated output voltage at low level. The inherent natural wave-shaping capability of the reduced kVA polyphase transformer together with an active current wave-shaping technique results in a significant reduction of input and output filter requirements associat...

This paper presents a static analysis of laminated composite doubly-curved shells using refined kinematic models with polynomial and non-polynomial functions recently introduced in the literature. To be specific, Maclaurin, trigonometric, exponential and zig-zag functions are employed. The employed refined models are based on the equivalent single layer theories. A simply supported shell is sub...

We report experiments and model simulations of patterns of parametrically excited capillary ripples in a large aspect-ratio cell with thin horizontal layer of viscous fluid subjected to sinusoidal vertical oscillations. We found stable rotating spirals with different topological charges in the parameter range where steady straight rolls were observed previously. Formation of multiarmed spirals ...

The methods of finite-time thermodynamics are used to find the optimal time path of an Otto cycle with friction and heat leakage. Optimality is defined by maximization of the work per cycle; the system is constrained to operate at a fixed frequency, so the maximum power is obtained. The result is an improvement of about 10% in the effectiveness (second-law efficiency) of a conventional near-sin...

We present data from recent high-energy-density laboratory experiments designed to explore the Rayleigh– Taylor instability under conditions relevant to supernovae. The Omega laser is used to create a blast wave structure that is similar to that of the explosion phase of a core-collapse supernova. An unstable interface is shocked and then decelerated by the planar blast wave, producing Rayleigh...

We analyse the temporal properties of optical pulse wave that is obtained by applying a discrete set spectral π/2 phase shifts to continuous-wave light phase-modulated sinusoidal wave. develop an analytical model describe this new waveform we name ‘besselon’. also discuss reduction sidelobes in intensity profiles means additional π shift, and show resulting pulses can be efficiently time-interl...