Shats, M; Punzmann, H; Xia, H
2010-03-12
We report the first observation of extreme wave events (rogue waves) in parametrically driven capillary waves. Rogue waves are observed above a certain threshold in forcing. Above this threshold, frequency spectra broaden and develop exponential tails. For the first time we present evidence of strong four-wave coupling in nonlinear waves (high tricoherence), which points to modulation instability as the main mechanism in rogue waves. The generation of rogue waves is identified as the onset of a distinct tail in the probability density function of the wave heights. Their probability is higher than expected from the measured wave background.
Kedziora, David J; Ankiewicz, Adrian; Akhmediev, Nail
2011-11-01
Using the Darboux transformation technique and numerical simulations, we study the hierarchy of rational solutions of the nonlinear Schrödinger equation that can be considered as higher order rogue waves in this model. This analysis reveals the existence of rogue wave clusters with a high level of symmetry in the (x,t) plane. These structures arise naturally when the shifts in the Darboux scheme are taken to be eigenvalue dependent. We have found single-shell structures where a central higher order rogue wave is surrounded by a ring of first order peaks on the (x,t) plane.
NASA Astrophysics Data System (ADS)
Yan, Zhenya
2011-11-01
The coupled nonlinear volatility and option pricing model presented recently by Ivancevic is investigated, which generates a leverage effect, i.e., stock volatility is (negatively) correlated to stock returns, and can be regarded as a coupled nonlinear wave alternative of the Black-Scholes option pricing model. In this Letter, we analytically propose vector financial rogue waves of the coupled nonlinear volatility and option pricing model without an embedded w-learning. Moreover, we exhibit their dynamical behaviors for chosen different parameters. The vector financial rogue wave (rogon) solutions may be used to describe the possible physical mechanisms for the rogue wave phenomena and to further excite the possibility of relative researches and potential applications of vector rogue waves in the financial markets and other related fields.
Solli, D R; Ropers, C; Koonath, P; Jalali, B
2007-12-13
Recent observations show that the probability of encountering an extremely large rogue wave in the open ocean is much larger than expected from ordinary wave-amplitude statistics. Although considerable effort has been directed towards understanding the physics behind these mysterious and potentially destructive events, the complete picture remains uncertain. Furthermore, rogue waves have not yet been observed in other physical systems. Here, we introduce the concept of optical rogue waves, a counterpart of the infamous rare water waves. Using a new real-time detection technique, we study a system that exposes extremely steep, large waves as rare outcomes from an almost identically prepared initial population of waves. Specifically, we report the observation of rogue waves in an optical system, based on a microstructured optical fibre, near the threshold of soliton-fission supercontinuum generation--a noise-sensitive nonlinear process in which extremely broadband radiation is generated from a narrowband input. We model the generation of these rogue waves using the generalized nonlinear Schrödinger equation and demonstrate that they arise infrequently from initially smooth pulses owing to power transfer seeded by a small noise perturbation.
Triangular rogue wave cascades.
Kedziora, David J; Ankiewicz, Adrian; Akhmediev, Nail
2012-11-01
By numerically applying the recursive Darboux transformation technique, we study high-order rational solutions of the nonlinear Schrödinger equation that appear spatiotemporally as triangular arrays of Peregrine solitons. These can be considered as rogue wave cascades and complement previously discovered circular cluster forms. In this analysis, we reveal a general parametric restriction for their existence and investigate the interplay between cascade and cluster forms. As a result, we demonstrate how to generate many more hybrid rogue wave solutions, including semicircular clusters that resemble claws.
NASA Astrophysics Data System (ADS)
Frisquet, Benoit; Kibler, Bertrand; Morin, Philippe; Baronio, Fabio; Conforti, Matteo; Millot, Guy; Wabnitz, Stefan
2016-02-01
Photonics enables to develop simple lab experiments that mimic water rogue wave generation phenomena, as well as relativistic gravitational effects such as event horizons, gravitational lensing and Hawking radiation. The basis for analog gravity experiments is light propagation through an effective moving medium obtained via the nonlinear response of the material. So far, analogue gravity kinematics was reproduced in scalar optical wave propagation test models. Multimode and spatiotemporal nonlinear interactions exhibit a rich spectrum of excitations, which may substantially expand the range of rogue wave phenomena, and lead to novel space-time analogies, for example with multi-particle interactions. By injecting two colliding and modulated pumps with orthogonal states of polarization in a randomly birefringent telecommunication optical fiber, we provide the first experimental demonstration of an optical dark rogue wave. We also introduce the concept of multi-component analog gravity, whereby localized spatiotemporal horizons are associated with the dark rogue wave solution of the two-component nonlinear Schrödinger system.
Frisquet, Benoit; Kibler, Bertrand; Morin, Philippe; Baronio, Fabio; Conforti, Matteo; Millot, Guy; Wabnitz, Stefan
2016-02-11
Photonics enables to develop simple lab experiments that mimic water rogue wave generation phenomena, as well as relativistic gravitational effects such as event horizons, gravitational lensing and Hawking radiation. The basis for analog gravity experiments is light propagation through an effective moving medium obtained via the nonlinear response of the material. So far, analogue gravity kinematics was reproduced in scalar optical wave propagation test models. Multimode and spatiotemporal nonlinear interactions exhibit a rich spectrum of excitations, which may substantially expand the range of rogue wave phenomena, and lead to novel space-time analogies, for example with multi-particle interactions. By injecting two colliding and modulated pumps with orthogonal states of polarization in a randomly birefringent telecommunication optical fiber, we provide the first experimental demonstration of an optical dark rogue wave. We also introduce the concept of multi-component analog gravity, whereby localized spatiotemporal horizons are associated with the dark rogue wave solution of the two-component nonlinear Schrödinger system.
Frisquet, Benoit; Kibler, Bertrand; Morin, Philippe; Baronio, Fabio; Conforti, Matteo; Millot, Guy; Wabnitz, Stefan
2016-01-01
Photonics enables to develop simple lab experiments that mimic water rogue wave generation phenomena, as well as relativistic gravitational effects such as event horizons, gravitational lensing and Hawking radiation. The basis for analog gravity experiments is light propagation through an effective moving medium obtained via the nonlinear response of the material. So far, analogue gravity kinematics was reproduced in scalar optical wave propagation test models. Multimode and spatiotemporal nonlinear interactions exhibit a rich spectrum of excitations, which may substantially expand the range of rogue wave phenomena, and lead to novel space-time analogies, for example with multi-particle interactions. By injecting two colliding and modulated pumps with orthogonal states of polarization in a randomly birefringent telecommunication optical fiber, we provide the first experimental demonstration of an optical dark rogue wave. We also introduce the concept of multi-component analog gravity, whereby localized spatiotemporal horizons are associated with the dark rogue wave solution of the two-component nonlinear Schrödinger system. PMID:26864099
NASA Astrophysics Data System (ADS)
Ding, Yingchun; Zhang, Bin; Feng, Qi; Tang, Xin; Liu, Zhongxuan; Chen, Zhaoyang; Lin, Chengyou
2017-01-01
The formation of extreme localization structures in nonlinear dispersive media (water or optical fibres) can be explained and described by the focusing nonlinear Schrödinger equation (NLSE). The NLSE is especially important in understanding how solitons on a condensate background (SCB) appear from a small perturbation through modulation instability. We have studied theoretically SCB solutions solved with the dressing method. A class of bipolar-rogue-wave structures that are constructed by collisions between elementary SCB or bipolar solitonic solutions was found. Besides, we have also found a new class of regular bright solitonic rogue waves that are originated from the collision between two bipolar-rogue-wave structures. The bipolar-rogue-wave structures can be considered to provide a new prototype for rogue-waves dynamics modeling. Our results extend previous studies in the area of rogue waves and may be important in the study of oceanography and optics.
Controllable parabolic-cylinder optical rogue wave.
Zhong, Wei-Ping; Chen, Lang; Belić, Milivoj; Petrović, Nikola
2014-10-01
We demonstrate controllable parabolic-cylinder optical rogue waves in certain inhomogeneous media. An analytical rogue wave solution of the generalized nonlinear Schrödinger equation with spatially modulated coefficients and an external potential in the form of modulated quadratic potential is obtained by the similarity transformation. Numerical simulations are performed for comparison with the analytical solutions and to confirm the stability of the rogue wave solution obtained. These optical rogue waves are built by the products of parabolic-cylinder functions and the basic rogue wave solution of the standard nonlinear Schrödinger equation. Such rogue waves may appear in different forms, as the hump and paw profiles.
Dark- and bright-rogue-wave solutions for media with long-wave-short-wave resonance.
Chen, Shihua; Grelu, Philippe; Soto-Crespo, J M
2014-01-01
Exact explicit rogue-wave solutions of intricate structures are presented for the long-wave-short-wave resonance equation. These vector parametric solutions feature coupled dark- and bright-field counterparts of the Peregrine soliton. Numerical simulations show the robustness of dark and bright rogue waves in spite of the onset of modulational instability. Dark fields originate from the complex interplay between anomalous dispersion and the nonlinearity driven by the coupled long wave. This unusual mechanism, not available in scalar nonlinear wave equation models, can provide a route to the experimental realization of dark rogue waves in, for instance, negative index media or with capillary-gravity waves.
Akhmediev, N.; Ankiewicz, A.; Soto-Crespo, J. M.
2009-10-15
We propose initial conditions that could facilitate the excitation of rogue waves. Understanding the initial conditions that foster rogue waves could be useful both in attempts to avoid them by seafarers and in generating highly energetic pulses in optical fibers.
Are Rogue Waves Really Unexpected?
NASA Astrophysics Data System (ADS)
Fedele, Francesco
2016-05-01
An unexpected wave is defined by Gemmrich & Garrett (2008) as a wave that is much taller than a set of neighboring waves. Their definition of "unexpected" refers to a wave that is not anticipated by a casual observer. Clearly, unexpected waves defined in this way are predictable in a statistical sense. They can occur relatively often with a small or moderate crest height, but large unexpected waves that are rogue are rare. Here, this concept is elaborated and statistically described based on a third-order nonlinear model. In particular, the conditional return period of an unexpected wave whose crest exceeds a given threshold is developed. This definition leads to greater return periods or on average less frequent occurrences of unexpected waves than those implied by the conventional return periods not conditioned on a reference threshold. Ultimately, it appears that a rogue wave that is also unexpected would have a lower occurrence frequency than that of a usual rogue wave. As specific applications, the Andrea and WACSIS rogue wave events are examined in detail. Both waves appeared without warning and their crests were nearly $2$-times larger than the surrounding $O(10)$ wave crests, and thus unexpected. The two crest heights are nearly the same as the threshold~$h_{0.3\\cdot10^{6}}\\sim1.6H_{s}$ exceeded on average once every~$0.3\\cdot 10^{6}$ waves, where $H_s$ is the significant wave height. In contrast, the Andrea and WACSIS events, as both rogue and unexpected, would occur slightly less often and on average once every~$3\\cdot10^{6}$ and~$0.6\\cdot10^6$ waves respectively.
Rogue Waves and Modulational Instability
NASA Astrophysics Data System (ADS)
Zakharov, V. E.; Dyachenko, A.
2015-12-01
The most plausible cause of rogue wave formation in a deep ocean is development of modulational instability of quasimonochromatic wave trains. An adequate model for study of this phenomenon is the Euler equation for potential flow of incompressible fluid with free surface in 2-D geometry. Numerical integration of these equations confirms completely the conjecture of rogue wave formation from modulational instability but the procedure is time consuming for determination of rogue wave appearance probability for a given shape of wave energy spectrum. This program can be realized in framework of simpler model using replacement of the exact interaction Hamiltonian by more compact Hamiltonian. There is a family of such models. The popular one is the Nonlinear Schrodinger equation (NLSE). This model is completely integrable and suitable for numerical simulation but we consider that it is oversimplified. It misses such important phenomenon as wave breaking. Recently, we elaborated much more reliable model that describes wave breaking but is as suitable as NLSE from the point of numerical modeling. This model allows to perform massive numerical experiments and study statistics of rogue wave formation in details.
Evolution of rogue waves in dusty plasmas
Tolba, R. E. El-Bedwehy, N. A.; Moslem, W. M.; El-Labany, S. K.
2015-04-15
The evolution of rogue waves associated with the dynamics of positively charged dust grains that interact with streaming electrons and ions is investigated. Using a perturbation method, the basic set of fluid equations is reduced to a nonlinear Schrödinger equation (NLSE). The rational solution of the NLSE is presented, which proposed as an effective tool for studying the rogue waves in Jupiter. It is found that the existence region of rogue waves depends on the dust-acoustic speed and the streaming densities of the ions and electrons. Furthermore, the supersonic rogue waves are much taller than the subsonic rogue waves by ∼25 times.
Slow deterministic vector rogue waves
NASA Astrophysics Data System (ADS)
Sergeyev, S. V.; Kolpakov, S. A.; Mou, Ch.; Jacobsen, G.; Popov, S.; Kalashnikov, V.
2016-03-01
For an erbium-doped fiber laser mode-locked by carbon nanotubes, we demonstrate experimentally and theoretically a new type of the vector rogue waves emerging as a result of the chaotic evolution of the trajectories between two orthogonal states of polarization on the Poincare sphere. In terms of fluctuation induced phenomena, by tuning polarization controller for the pump wave and in-cavity polarization controller, we are able to control the Kramers time, i.e. the residence time of the trajectory in vicinity of each orthogonal state of polarization, and so can cause the rare events satisfying rogue wave criteria and having the form of transitions from the state with the long residence time to the state with a short residence time.
Acoustic Remote Sensing of Rogue Waves
NASA Astrophysics Data System (ADS)
Parsons, Wade; Kadri, Usama
2016-04-01
We propose an early warning system for approaching rogue waves using the remote sensing of acoustic-gravity waves (AGWs) - progressive sound waves that propagate at the speed of sound in the ocean. It is believed that AGWs are generated during the formation of rogue waves, carrying information on the rogue waves at near the speed of sound, i.e. much faster than the rogue wave. The capability of identifying those special sound waves would enable detecting rogue waves most efficiently. A lot of promising work has been reported on AGWs in the last few years, part of which in the context of remote sensing as an early detection of tsunami. However, to our knowledge none of the work addresses the problem of rogue waves directly. Although there remains some uncertainty as to the proper definition of a rogue wave, there is little doubt that they exist and no one can dispute the potential destructive power of rogue waves. An early warning system for such extreme waves would become a demanding safety technology. A closed form expression was developed for the pressure induced by an impulsive source at the free surface (the Green's function) from which the solution for more general sources can be developed. In particular, we used the model of the Draupner Wave of January 1st, 1995 as a source and calculated the induced AGW signature. In particular we studied the AGW signature associated with a special feature of this wave, and characteristic of rogue waves, of the absence of any local set-down beneath the main crest and the presence of a large local set-up.
The destructive impact of the rogue waves
NASA Astrophysics Data System (ADS)
Shamin, Roman
2013-04-01
In our talk rogue waves at the ocean will be considered. By means of numerical modeling dangerous impact of rogue waves on the ships and oil rigs is calculated. Cases when these waves can bring in accident are considered. Using statistics of emergence of waves (see [1]-[2]), it is possible to estimate risks in each case. These results can be used for safety of the ships and oil rigs from rogue waves. References [1] V.E. Zakharov, A.I. Dyachenko, R.V. Shamin. How probability for freak wave formation can be found // THE EUROPEAN PHYSICAL JOURNAL - SPECIAL TOPICS Volume 185, Number 1, 113-124, DOI: 10.1140/epjst/e2010-01242-y [2] V.E. Zakharov, R.V. Shamin. Statistics of rogue waves in computer experiments // JETP Letters, 2012, V. 96, Issue 1, pp 66-69.
Nonlinear Talbot effect of rogue waves.
Zhang, Yiqi; Belić, Milivoj R; Zheng, Huaibin; Chen, Haixia; Li, Changbiao; Song, Jianping; Zhang, Yanpeng
2014-03-01
Akhmediev and Kuznetsov-Ma breathers are rogue wave solutions of the nonlinear Schrödinger equation (NLSE). Talbot effect (TE) is an image recurrence phenomenon in the diffraction of light waves. We report the nonlinear TE of rogue waves in a cubic medium. It is different from the linear TE, in that the wave propagates in a NL medium and is an eigenmode of NLSE. Periodic rogue waves impinging on a NL medium exhibit recurrent behavior, but only at the TE length and at the half-TE length with a π-phase shift; the fractional TE is absent. The NL TE is the result of the NL interference of the lobes of rogue wave breathers. This interaction is related to the transverse period and intensity of breathers, in that the bigger the period and the higher the intensity, the shorter the TE length.
Rogue waves in a multistable system.
Pisarchik, Alexander N; Jaimes-Reátegui, Rider; Sevilla-Escoboza, Ricardo; Huerta-Cuellar, G; Taki, Majid
2011-12-30
Clear evidence of rogue waves in a multistable system is revealed by experiments with an erbium-doped fiber laser driven by harmonic pump modulation. The mechanism for the rogue wave formation lies in the interplay of stochastic processes with multistable deterministic dynamics. Low-frequency noise applied to a diode pump current induces rare jumps to coexisting subharmonic states with high-amplitude pulses perceived as rogue waves. The probability of these events depends on the noise filtered frequency and grows up when the noise amplitude increases. The probability distribution of spike amplitudes confirms the rogue wave character of the observed phenomenon. The results of numerical simulations are in good agreement with experiments.
Book review: Rogue waves in the ocean
Geist, Eric L.
2011-01-01
Review info: Rogue Waves in the Ocean. Advances in Geophysical and Environmental Mechanics and Mathematics. By Christian Kharif, Efim Pelinovsky and Alexey Slunyaev, 2009. ISBN: 978-3540884187, xiii, 216 pp.
NASA Astrophysics Data System (ADS)
Waseda, Takuji
2010-03-01
Giant episodic ocean waves that suddenly soar like a wall of water out of an otherwise calm sea are not just a legend. Such waves—which in the past have been called “abnormal,” “exceptional,” “extreme,” and even “vicious killer” waves—are now commonly known as “rogue waves” or “freak waves.” These waves have sunk or severely damaged 22 supercarriers in the world and caused the loss of more than 500 lives in the past 40 years. The largest wave registered by reliable instruments reached 30 meters in height, and the largest wave recorded by visual observation reached about 34 meters, equivalent to the height of an eight-story building. Tales of seafarers from Christopher Columbus to the passengers of luxury cruise ships had long been undervalued by scientists, but in the past 10 or so years, those historical notes and modern testimonies have been scientifically dissected to reveal the nature of these monster waves.
Triggering rogue waves in opposing currents.
Onorato, Miguel; Proment, Davide; Toffoli, Alessandro
2011-10-28
We show that rogue waves can be triggered naturally when a stable wave train enters a region of an opposing current flow. We demonstrate that the maximum amplitude of the rogue wave depends on the ratio between the current velocity U(0) and the wave group velocity c(g). We also reveal that an opposing current can force the development of rogue waves in random wave fields, resulting in a substantial change of the statistical properties of the surface elevation. The present results can be directly adopted in any field of physics in which the focusing nonlinear Schrödinger equation with nonconstant coefficient is applicable. In particular, nonlinear optics laboratory experiments are natural candidates for verifying experimentally our results.
Optical rogue waves and stimulated supercontinuum generation
NASA Astrophysics Data System (ADS)
Solli, Daniel R.; Ropers, Claus; Jalali, Bahram
2010-06-01
Nonlinear action is known for its ability to create unusual phenomena and unexpected events. Optical rogue waves-freak pulses of broadband light arising in nonlinear fiber-testify to the fact that optical nonlinearities are no less capable of generating anomalous events than those in other physical contexts. In this paper, we will review our work on optical rogue waves, an ultrafast phenomenon counterpart to the freak ocean waves known to roam the open oceans. We will discuss the experimental observation of these rare events in real time and the measurement of their heavytailed statistical properties-a probabilistic form known to appear in a wide variety of other complex systems from financial markets to genetics. The nonlinear Schrödinger equation predicts the existence of optical rogue waves, offering a means to study their origins with simulations. We will also discuss the type of initial conditions behind optical rogue waves. Because a subtle but specific fluctuation leads to extreme waves, the rogue wave instability can be harnessed to produce these events on demand. By exploiting this property, it is possible to produce a new type of optical switch as well as a supercontinuum source that operates in the long pulse regime but still achieves a stable, coherent output.
Discrete rogue waves in an array of waveguides
NASA Astrophysics Data System (ADS)
Efe, S.; Yuce, C.
2015-06-01
We study discrete rogue waves in an array of nonlinear waveguides. We show that very small degree of disorder due to experimental imperfection has a deep effect on the formation of discrete rogue waves. We predict long-living discrete rogue wave solution of the discrete nonlinear Schrödinger equation.
Instabilities, breathers and rogue waves in optics
NASA Astrophysics Data System (ADS)
Dudley, John M.; Dias, Frédéric; Erkintalo, Miro; Genty, Goëry
2014-10-01
Optical rogue waves are rare, extreme fluctuations in the value of an optical field. The term 'optical rogue wave' was first used in the context of an analogy between pulse propagation in an optical fibre and wave group propagation on deep water, but has since been generalized to describe many other processes in optics. This Review provides an overview of the field, concentrating primarily on propagation in optical fibre systems that exhibit nonlinear breather and soliton dynamics, but also discussing other optical systems in which extreme events have been reported. Although statistical features such as long-tailed probability distributions are often considered to be the defining feature of rogue waves, we emphasize the underlying physical processes that drive the appearance of extreme optical structures.
Nonparaxial rogue waves in optical Kerr media.
Temgoua, D D Estelle; Kofane, T C
2015-06-01
We consider the inhomogeneous nonparaxial nonlinear Schrödinger (NLS) equation with varying dispersion, nonlinearity, and nonparaxiality coefficients, which governs the nonlinear wave propagation in an inhomogeneous optical fiber system. We present the similarity and Darboux transformations and for the chosen specific set of parameters and free functions, the first- and second-order rational solutions of the nonparaxial NLS equation are generated. In particular, the features of rogue waves throughout polynomial and Jacobian elliptic functions are analyzed, showing the nonparaxial effects. It is shown that the nonparaxiality increases the intensity of rogue waves by increasing the length and reducing the width simultaneously, by the way it increases their speed and penalizes interactions between them. These properties and the characteristic controllability of the nonparaxial rogue waves may give another opportunity to perform experimental realizations and potential applications in optical fibers.
NASA Astrophysics Data System (ADS)
Shukla, P. K.; Moslem, W. M.
2012-02-01
It is shown that the nonlinear interaction between the magnetic field-aligned circularly polarized (CP) dispersive Alfvén waves and low-frequency electrostatic perturbations give rise to Alfvénic rogue waves in magnetized plasmas. Our results reveal the left-hand CP Alfvénic wave supports both supersonic and subsonic Alfvénic rogue waves. The latter can propagate for backward wave only. The right-hand CP Alfvénic rouge waves appear on account of the amplitude modulation of the waves by quasi-stationary density modulations. The amplitude of the right-hand CP Alfvénic rogue waves decreases with the increase of the plasma number density, but it increases with the increase of the magnetic field strength. However, the amplitude of the subsonic left-hand CP Alfvénic rogue wave becomes stronger with the excess of the plasma number density, but it shrinks with stronger magnetic field strength. Finally, we briefly discuss the relevance of our investigation to the role of the nonlinear Alfvén waves that power the solar wind.
Rogue waves in Lugiato-Lefever equation with variable coefficients
NASA Astrophysics Data System (ADS)
Kol, Guy; Kingni, Sifeu; Woafo, Paul
2014-11-01
In this paper, we theoretically investigate the generation of optical rogue waves from a Lugiato-Lefever equation with variable coefficients by using the nonlinear Schrödinger equation-based constructive method. Exact explicit rogue-wave solutions of the Lugiato-Lefever equation with constant dispersion, detuning and dissipation are derived and presented. The bright rogue wave, intermediate rogue wave and the dark rogue wave are obtained by changing the value of one parameter in the exact explicit solutions corresponding to the external pump power of a continuous-wave laser.
Dynamics of nonautonomous rogue waves in Bose-Einstein condensate
Zhao, Li-Chen
2013-02-15
We study rogue waves of Bose-Einstein condensate (BEC) analytically in a time-dependent harmonic trap with a complex potential. Properties of the nonautonomous rogue waves are investigated analytically. It is reported that there are possibilities to 'catch' rogue waves through manipulating nonlinear interaction properly. The results provide many possibilities to manipulate rogue waves experimentally in a BEC system. - Highlights: Black-Right-Pointing-Pointer One more generalized rogue wave solutions are presented. Black-Right-Pointing-Pointer Present one possible way to catch a rouge wave. Black-Right-Pointing-Pointer Properties of rogue waves are investigated analytically for the first time. Black-Right-Pointing-Pointer Provide many possibilities to manipulate rogue waves in BEC.
Optical rogue waves associated with the negative coherent coupling in an isotropic medium
NASA Astrophysics Data System (ADS)
Sun, Wen-Rong; Tian, Bo; Jiang, Yan; Zhen, Hui-Ling
2015-02-01
Optical rogue waves of the coupled nonlinear Schrödinger equations with negative coherent coupling, which describe the propagation of orthogonally polarized optical waves in an isotropic medium, are reported. We construct and discuss a family of the vector rogue-wave solutions, including the bright rogue waves, four-petaled rogue waves, and dark rogue waves. A bright rogue wave without a valley can split up, giving birth to two bright rogue waves, and an eye-shaped rogue wave can split up, giving birth to two dark rogue waves.
Optical rogue waves associated with the negative coherent coupling in an isotropic medium.
Sun, Wen-Rong; Tian, Bo; Jiang, Yan; Zhen, Hui-Ling
2015-02-01
Optical rogue waves of the coupled nonlinear Schrödinger equations with negative coherent coupling, which describe the propagation of orthogonally polarized optical waves in an isotropic medium, are reported. We construct and discuss a family of the vector rogue-wave solutions, including the bright rogue waves, four-petaled rogue waves, and dark rogue waves. A bright rogue wave without a valley can split up, giving birth to two bright rogue waves, and an eye-shaped rogue wave can split up, giving birth to two dark rogue waves.
Breathing rogue wave observed in numerical experiment.
Ruban, V P
2006-09-01
Numerical simulations of the recently derived fully nonlinear equations of motion for long-crested water waves [V. P. Ruban, Phys. Rev. E 71, 055303(R) (2005)] with quasirandom initial conditions are reported, which show the spontaneous formation of a single extreme wave on deep water. This rogue wave behaves in an oscillating manner and exists for a relatively long time (many wave periods) without significant change of its maximal amplitude.
Complementary optical rogue waves in parametric three-wave mixing.
Chen, Shihua; Cai, Xian-Ming; Grelu, Philippe; Soto-Crespo, J M; Wabnitz, Stefan; Baronio, Fabio
2016-03-21
We investigate the resonant interaction of two optical pulses of the same group velocity with a pump pulse of different velocity in a weakly dispersive quadratic medium and report on the complementary rogue wave dynamics which are unique to such a parametric three-wave mixing. Analytic rogue wave solutions up to the second order are explicitly presented and their robustness is confirmed by numerical simulations, in spite of the onset of modulation instability activated by quantum noise.
Rogue-wave pattern transition induced by relative frequency
NASA Astrophysics Data System (ADS)
Zhao, Li-Chen; Xin, Guo-Guo; Yang, Zhan-Ying
2014-08-01
We revisit a rogue wave in a two-mode nonlinear fiber whose dynamics is described by two-component coupled nonlinear Schrödinger equations. The relative frequency between two modes can induce different rogue wave patterns transition. In particular, we find a four-petaled flower structure rogue wave can exist in the two-mode coupled system, which possesses an asymmetric spectrum distribution. Furthermore, spectrum analysis is performed on these different type rogue waves, and the spectrum relations between them are discussed. We demonstrate qualitatively that different modulation instability gain distribution can induce different rogue wave excitation patterns. These results would deepen our understanding of rogue wave dynamics in complex systems.
Rogue waves of a (3 + 1) -dimensional nonlinear evolution equation
NASA Astrophysics Data System (ADS)
Shi, Yu-bin; Zhang, Yi
2017-03-01
General high-order rogue waves of a (3 + 1) -dimensional Nonlinear Evolution Equation ((3+1)-d NEE) are obtained by the Hirota bilinear method, which are given in terms of determinants, whose matrix elements possess plain algebraic expressions. It is shown that the simplest (fundamental) rogue waves are line rogue waves which arise from the constant background with a line profile and then disappear into the constant background again. Two subclass of nonfundamental rogue waves are analyzed in details. By proper means of the regulations of free parameters, the dynamics of multi-rogue waves and high-order rogue waves have been illustrated in (x,t) plane and (y,z) plane by three dimensional figures.
Rogue-wave pattern transition induced by relative frequency.
Zhao, Li-Chen; Xin, Guo-Guo; Yang, Zhan-Ying
2014-08-01
We revisit a rogue wave in a two-mode nonlinear fiber whose dynamics is described by two-component coupled nonlinear Schrödinger equations. The relative frequency between two modes can induce different rogue wave patterns transition. In particular, we find a four-petaled flower structure rogue wave can exist in the two-mode coupled system, which possesses an asymmetric spectrum distribution. Furthermore, spectrum analysis is performed on these different type rogue waves, and the spectrum relations between them are discussed. We demonstrate qualitatively that different modulation instability gain distribution can induce different rogue wave excitation patterns. These results would deepen our understanding of rogue wave dynamics in complex systems.
Controlling rogue waves in inhomogeneous Bose-Einstein condensates.
Loomba, Shally; Kaur, Harleen; Gupta, Rama; Kumar, C N; Raju, Thokala Soloman
2014-05-01
We present the exact rogue wave solutions of the quasi-one-dimensional inhomogeneous Gross-Pitaevskii equation by using similarity transformation. Then, by employing the exact analytical solutions we have studied the controllable behavior of rogue waves in the Bose-Einstein condensates context for the experimentally relevant systems. Additionally, we have also investigated the nonlinear tunneling of rogue waves through a conventional hyperbolic barrier and periodic barrier. We have found that, for the conventional nonlinearity barrier case, rogue waves are localized in space and time and get amplified near the barrier, while for the dispersion barrier case rogue waves are localized in space and propagating in time and their amplitude is reduced at the barrier location. In the case of the periodic barrier, the interesting dynamical features of rogue waves are obtained and analyzed analytically.
Controllable optical rogue waves in the femtosecond regime.
Dai, Chao-Qing; Zhou, Guo-Quan; Zhang, Jie-Fang
2012-01-01
We derive analytical rogue wave solutions of variable-coefficient higher-order nonlinear Schrödinger equations describing the femtosecond pulse propagation via a transformation connected with the constant-coefficient Hirota equation. Then we discuss the propagation behaviors of controllable rogue waves, including recurrence, annihilation, and sustainment in a periodic distributed fiber system and an exponential dispersion decreasing fiber. Finally, we investigate nonlinear tunneling effects for rogue waves.
Spatial Rogue Waves in Photorefractive Ferroelectrics.
Pierangeli, D; Di Mei, F; Conti, C; Agranat, A J; DelRe, E
2015-08-28
Rogue waves are observed as light propagates in the extreme nonlinear regime that occurs when a photorefractive ferroelectric crystal is undergoing a structural phase transition. The transmitted spatial light distribution contains bright localized spots of anomalously large intensity that follow a signature long-tail statistics that disappears as the nonlinearity is weakened. The isolated wave events form as out-of-equilibrium response and disorder enhance the Kerr-saturated nonlinearity at the critical point. Self-similarity associable to the individual observed filaments and numerical simulations of the generalized nonlinear Schrödinger equation suggests that dynamics of soliton fusions and scale invariance can microscopically play an important role in the observed rogue intensities and statistics.
A coupled "AB" system: Rogue waves and modulation instabilities.
Wu, C F; Grimshaw, R H J; Chow, K W; Chan, H N
2015-10-01
Rogue waves are unexpectedly large and localized displacements from an equilibrium position or an otherwise calm background. For the nonlinear Schrödinger (NLS) model widely used in fluid mechanics and optics, these waves can occur only when dispersion and nonlinearity are of the same sign, a regime of modulation instability. For coupled NLS equations, rogue waves will arise even if dispersion and nonlinearity are of opposite signs in each component as new regimes of modulation instability will appear in the coupled system. The same phenomenon will be demonstrated here for a coupled "AB" system, a wave-current interaction model describing baroclinic instability processes in geophysical flows. Indeed, the onset of modulation instability correlates precisely with the existence criterion for rogue waves for this system. Transitions from "elevation" rogue waves to "depression" rogue waves are elucidated analytically. The dispersion relation as a polynomial of the fourth order may possess double pairs of complex roots, leading to multiple configurations of rogue waves for a given set of input parameters. For special parameter regimes, the dispersion relation reduces to a cubic polynomial, allowing the existence criterion for rogue waves to be computed explicitly. Numerical tests correlating modulation instability and evolution of rogue waves were conducted.
Generation of rogue waves in a wave tank
NASA Astrophysics Data System (ADS)
Lechuga, A.
2012-04-01
Rogue waves have been reported as causing damages and ship accidents all over the oceans of the world. For this reason in the past decades theoretical studies have been carried out with the double aim of improving the knowledge of their main characteristics and of attempting to predict its sudden appearance. As an effort on this line we are trying to generate them in a water tank. The description of the procedure to do that is the objective of this presentation. After Akhmediev et al. (2011) we use a symmetric spectrum as input on the wave maker to produce waves with a rate(Maximun wave height/ significant wave height) of 2.33 and a kurtosis of 4.77, clearly between the limits of rogue waves. As it was pointed out by Janssen (2003), Onorato et al. (2006) and Kharif, Pelinovsky and Slunyaev (2009) modulation instability is enhanced when waves depart from Gaussian statistics (i.e. big kurtosis) and therefore both numbers enforce the criterion that we are generating genuine rogue waves. The same is confirmed by Shemer (2010) and Dudley et al.(2009) from a different perspective. If besides being symmetrical the spectrum is triangular, following Akhmediev(2011),the generated waves are even more conspicuously rogue waves.
NASA Astrophysics Data System (ADS)
Polukhina, Oxana; Kurkin, Andrey; Pelinovsky, Efim
2010-05-01
The investigation of anomalously large amplitude surface gravity waves on the sea surface (rogue or freak waves), which can appear suddenly and disappear in the same abrupt way, is very extensive in the recent years (see e.g., book [Kharif, Pelinovsky, Slunyaev 2009] and references there). However, any sudden displacements of water level or changes in flow velocities can also appear in the ocean wave motions of other types, including geophysical large-scale fields. The number of observations of such waves is still very small, they are even almost absent, but the investigations of such possible processes seem to be important for the applications. In the present paper the problem of rogue waves is discussed for edge waves in the coastal zone. Such waves belong to the class of topographically trapped waves, which are supposed to play dominant role in the dynamics of oceanic coastal zone. The amplitude of the waves reaches a maximum at the edge, and they are attenuated offshore. Direct visual observations of such waves are difficult, but such waves have been detected instrumentally in the nearshore wave field many times (see e.g. [Huntley and Bowen 1973; Bryan, Hows and Bowen 1998]). Edge waves are often considered as the major factor of the long-term evolution of coastal line, forming the rhythmic crescentic bars [Dolan and Ferm 1968; Bowen and Inman 1971; Guza and Inman 1975; Guza and Bowen 1981; Holman and Bowen 1982; Komar 1998]. In the present paper we summarize the results of the study of the nonlinear mechanisms of possible freak edge wave appearance: nonlinear dispersion enhancement and modulation instability.
Rogue waves in the Davey-Stewartson I equation.
Ohta, Yasuhiro; Yang, Jianke
2012-09-01
General rogue waves in the Davey-Stewartson-I equation are derived by the bilinear method. It is shown that the simplest (fundamental) rogue waves are line rogue waves which arise from the constant background with a line profile and then disappear into the constant background again. It is also shown that multirogue waves describe the interaction of several fundamental rogue waves. These multirogue waves also arise from the constant background and then decay back to it, but in the intermediate times, interesting curvy wave patterns appear. However, higher-order rogue waves exhibit different dynamics. Specifically, only part of the wave structure in the higher-order rogue waves rises from the constant background and then retreats back to it, and this transient wave possesses patterns such as parabolas. But the other part of the wave structure comes from the far distance as a localized lump, which decelerates to the near field and interacts with the transient rogue wave, and is then reflected back and accelerates to the large distance again.
The Making of the Andrea Wave and other Rogues.
Donelan, Mark A; Magnusson, Anne-Karin
2017-03-08
Unexpectedly large ocean waves or 'rogues' are sometimes claimed to be the cause of damage to ships at sea and to offshore structures. While wind-driven wave models are capable of predicting the average characteristics of waves, the maximum height of rogues that may occur is yet unknown. Rogues form in the open ocean through the addition of elemental wave trains or groups and, infrequently, with many elements coming together in phase, producing rogues. Here we perform directional analyses on one of the steepest rogues ever recorded: the Andrea wave. We find that the Andrea wave was close to the breaking-limited height. Analysis of the 72 twenty minute records on the day of the Andrea wave yields encounter return periods of about 21 days for maximally steep waves, while less steep rogues occur about twice daily. An explicit formula is given for the encounter probability, based on the target area. This work answers the critical questions regarding rogues in the design and operation of ships and offshore structures: how high can rogues be and how frequently they occur.
Optical rogue waves in telecommunication data streams
Vergeles, Sergey; Turitsyn, Sergei K.
2011-06-15
Large broadening of short optical pulses due to fiber dispersion leads to a strong overlap in information data streams resulting in statistical deviations of the local power from its average. We present a theoretical analysis of rare events of high-intensity fluctuations--optical freak waves--that occur in fiber communication links using bit-overlapping transmission. Although the nature of the large fluctuations examined here is completely linear, as compared to commonly studied freak waves generated by nonlinear effects, the considered deviations inherit from rogue waves the key features of practical interest--random appearance of localized high-intensity pulses. We use the term ''rogue wave'' in an unusual context mostly to attract attention to both the possibility of purely linear statistical generation of huge amplitude waves and to the fact that in optics the occurrence of such pulses might be observable even with the standard Gaussian or even rarer-than-Gaussian statistics, without imposing the condition of an increased probability of extreme value events.
Rogue wave spectra of the Kundu-Eckhaus equation.
Bayındır, Cihan
2016-06-01
In this paper we analyze the rogue wave spectra of the Kundu-Eckhaus equation (KEE). We compare our findings with their nonlinear Schrödinger equation (NLSE) analogs and show that the spectra of the individual rogue waves significantly differ from their NLSE analogs. A remarkable difference is the one-sided development of the triangular spectrum before the rogue wave becomes evident in time. Also we show that increasing the skewness of the rogue wave results in increased asymmetry in the triangular Fourier spectra. Additionally, the triangular spectra of the rogue waves of the KEE begin to develop at earlier stages of their development compared to their NLSE analogs, especially for larger skew angles. This feature may be used to enhance the early warning times of the rogue waves. However, we show that in a chaotic wave field with many spectral components the triangular spectra remain as the main attribute as a universal feature of the typical wave fields produced through modulation instability and characteristic features of the KEE's analytical rogue wave spectra may be suppressed in a realistic chaotic wave field.
Rogue wave spectra of the Kundu-Eckhaus equation
NASA Astrophysics Data System (ADS)
Bayındır, Cihan
2016-06-01
In this paper we analyze the rogue wave spectra of the Kundu-Eckhaus equation (KEE). We compare our findings with their nonlinear Schrödinger equation (NLSE) analogs and show that the spectra of the individual rogue waves significantly differ from their NLSE analogs. A remarkable difference is the one-sided development of the triangular spectrum before the rogue wave becomes evident in time. Also we show that increasing the skewness of the rogue wave results in increased asymmetry in the triangular Fourier spectra. Additionally, the triangular spectra of the rogue waves of the KEE begin to develop at earlier stages of their development compared to their NLSE analogs, especially for larger skew angles. This feature may be used to enhance the early warning times of the rogue waves. However, we show that in a chaotic wave field with many spectral components the triangular spectra remain as the main attribute as a universal feature of the typical wave fields produced through modulation instability and characteristic features of the KEE's analytical rogue wave spectra may be suppressed in a realistic chaotic wave field.
Optical rogue wave statistics in laser filamentation.
Kasparian, Jérôme; Béjot, Pierre; Wolf, Jean-Pierre; Dudley, John M
2009-07-06
We experimentally observed optical rogue wave statistics during high power femtosecond pulse filamentation in air. We characterized wavelength-dependent intensity fluctuations across 300 nm broadband filament spectra generated by pulses with several times the critical power for filamentation. We show how the statistics vary from a near-Gaussian distribution in the vicinity of the pump to a long tailed "L-shaped" distribution at the short wavelength and long wavelength edges. The results are interpreted in terms of pump noise transfer via self-phase modulation.
Time-reversal generation of rogue waves.
Chabchoub, Amin; Fink, Mathias
2014-03-28
The formation of extreme localizations in nonlinear dispersive media can be explained and described within the framework of nonlinear evolution equations, such as the nonlinear Schrödinger equation (NLS). Within the class of exact NLS breather solutions on a finite background, which describe the modulational instability of monochromatic wave trains, the hierarchy of rational solutions localized in both time and space is considered to provide appropriate prototypes to model rogue wave dynamics. Here, we use the time-reversal invariance of the NLS to propose and experimentally demonstrate a new approach to constructing strongly nonlinear localized waves focused in both time and space. The potential applications of this time-reversal approach include remote sensing and motivated analogous experimental analysis in other nonlinear dispersive media, such as optics, Bose-Einstein condensates, and plasma, where the wave motion dynamics is governed by the NLS.
The Making of the Andrea Wave and other Rogues
Donelan, Mark A.; Magnusson, Anne-Karin
2017-01-01
Unexpectedly large ocean waves or ‘rogues’ are sometimes claimed to be the cause of damage to ships at sea and to offshore structures. While wind-driven wave models are capable of predicting the average characteristics of waves, the maximum height of rogues that may occur is yet unknown. Rogues form in the open ocean through the addition of elemental wave trains or groups and, infrequently, with many elements coming together in phase, producing rogues. Here we perform directional analyses on one of the steepest rogues ever recorded: the Andrea wave. We find that the Andrea wave was close to the breaking-limited height. Analysis of the 72 twenty minute records on the day of the Andrea wave yields encounter return periods of about 21 days for maximally steep waves, while less steep rogues occur about twice daily. An explicit formula is given for the encounter probability, based on the target area. This work answers the critical questions regarding rogues in the design and operation of ships and offshore structures: how high can rogues be and how frequently they occur. PMID:28272520
The Making of the Andrea Wave and other Rogues
NASA Astrophysics Data System (ADS)
Donelan, Mark A.; Magnusson, Anne-Karin
2017-03-01
Unexpectedly large ocean waves or ‘rogues’ are sometimes claimed to be the cause of damage to ships at sea and to offshore structures. While wind-driven wave models are capable of predicting the average characteristics of waves, the maximum height of rogues that may occur is yet unknown. Rogues form in the open ocean through the addition of elemental wave trains or groups and, infrequently, with many elements coming together in phase, producing rogues. Here we perform directional analyses on one of the steepest rogues ever recorded: the Andrea wave. We find that the Andrea wave was close to the breaking-limited height. Analysis of the 72 twenty minute records on the day of the Andrea wave yields encounter return periods of about 21 days for maximally steep waves, while less steep rogues occur about twice daily. An explicit formula is given for the encounter probability, based on the target area. This work answers the critical questions regarding rogues in the design and operation of ships and offshore structures: how high can rogues be and how frequently they occur.
Rogue waves emerging from the resonant interaction of three waves.
Baronio, Fabio; Conforti, Matteo; Degasperis, Antonio; Lombardo, Sara
2013-09-13
We introduce a novel family of analytic solutions of the three-wave resonant interaction equations for the purpose of modeling unique events, i.e., "amplitude peaks" which are isolated in space and time. The description of these solutions is likely to be a crucial step in the understanding and forecasting of rogue waves in a variety of multicomponent wave dynamics, from oceanography to optics and from plasma physics to acoustics.
Rogue waves in the ocean - review and progress
NASA Astrophysics Data System (ADS)
Pelinovsky, Efim; Kharif, Christian; Slunyaev, Alexey
2010-05-01
Rogue waves in the ocean and physical mechanisms of their appearance are discussed. Theyse waves are among waves naturally observed by people on the sea surface that represent inseparable feature of the Ocean. Rogue waves appear from nowhere, cause danger and disappear at once. They may occur at the surface of a relatively calm sea, reach not very high amplitudes, but be fatal for ships and crew due to their unexpectedness and abnormal features. The billows appear suddenly exceeding the surrounding waves twice and more, and obtained many names: abnormal, exceptional, extreme, giant, huge, sudden, episodic, freak, monster, rogue, vicious, killer, mad- or rabid-dog waves; cape rollers, holes in the sea, walls of water, three sisters… Freak monsters, though living for seconds, were able to arouse superstitious fear of the crew, cause damage, death of heedless sailors or the whole ship. All these epithets are full of human fear and feebleness. The serious studies of the phenomenon started about 20-30 years ago and have been intensified during the recent decade. The research is being conducted in different fields: in physics (search of physical mechanisms and adequate models of wave enhancement and statistics), in geoscience (determining the regions and weather conditions when rogue waves are most probable), and in ocean and coastal engineering (estimations of the wave loads on fixed and drifting floating structures). Thus, scientists and engineers specializing in different subject areas are involved in the solution of the problem. The state-of-art of the rogue wave study is summarized in our book [Kharif, Ch., Pelinovsky, E., and Slunyaev, A. Rogue Waves in the Ocean. Springer, 2009] and presented in given review. Firstly, we start with a brief introduction to the problem of freak waves aiming at formulating what is understood as rogue or freak waves, what consequences their existence imply in our life, why people are so worried about them. Then we discuss existing
Potential changes of wave steepness and occurrence of rogue waves
NASA Astrophysics Data System (ADS)
Bitner-Gregersen, Elzbieta M.; Toffoli, Alessandro
2015-04-01
Wave steepness is an important characteristic of a sea state. It is also well established that wave steepness is one of the parameter responsible for generation of abnormal waves called also freak or rogue waves. The study investigates changes of wave steepness in the past and future wave climate in the North Atlantic. The fifth assessment report IPCC (2013) uses four scenarios for future greenhouse gas concentrations in the atmosphere called Representative Concentration Pathways (RCP). Two of these scenarios RCP 4.5 and RCP 8.5 have been selected to project future wave conditions in the North Atlantic. RCP 4.5 is believed to achieve the political target of a maximum global mean temperature increase of 2° C while RPC 8.5 is close to 'business as usual' and expected to give a temperature increase of 4° C or more. The analysis includes total sea, wind sea and swell. Potential changes of wave steepness for these wave systems are shown and compared with wave steepness derived from historical data. Three historical data sets with different wave model resolutions are used. The investigations show also changes in the mean wind direction as well as in the relative direction between wind sea and swell. Consequences of wave steepness changes for statistics of surface elevation and generation of rogue waves are demonstrated. Uncertainties associated with wave steepness projections are discussed.
Caustics and Rogue Waves in an Optical Sea.
Mathis, Amaury; Froehly, Luc; Toenger, Shanti; Dias, Frédéric; Genty, Goëry; Dudley, John M
2015-08-06
There are many examples in physics of systems showing rogue wave behaviour, the generation of high amplitude events at low probability. Although initially studied in oceanography, rogue waves have now been seen in many other domains, with particular recent interest in optics. Although most studies in optics have focussed on how nonlinearity can drive rogue wave emergence, purely linear effects have also been shown to induce extreme wave amplitudes. In this paper, we report a detailed experimental study of linear rogue waves in an optical system, using a spatial light modulator to impose random phase structure on a coherent optical field. After free space propagation, different random intensity patterns are generated, including partially-developed speckle, a broadband caustic network, and an intermediate pattern with characteristics of both speckle and caustic structures. Intensity peaks satisfying statistical criteria for rogue waves are seen especially in the case of the caustic network, and are associated with broader spatial spectra. In addition, the electric field statistics of the intermediate pattern shows properties of an "optical sea" with near-Gaussian statistics in elevation amplitude, and trough-to-crest statistics that are near-Rayleigh distributed but with an extended tail where a number of rogue wave events are observed.
Caustics and Rogue Waves in an Optical Sea
Mathis, Amaury; Froehly, Luc; Toenger, Shanti; Dias, Frédéric; Genty, Goëry; Dudley, John M.
2015-01-01
There are many examples in physics of systems showing rogue wave behaviour, the generation of high amplitude events at low probability. Although initially studied in oceanography, rogue waves have now been seen in many other domains, with particular recent interest in optics. Although most studies in optics have focussed on how nonlinearity can drive rogue wave emergence, purely linear effects have also been shown to induce extreme wave amplitudes. In this paper, we report a detailed experimental study of linear rogue waves in an optical system, using a spatial light modulator to impose random phase structure on a coherent optical field. After free space propagation, different random intensity patterns are generated, including partially-developed speckle, a broadband caustic network, and an intermediate pattern with characteristics of both speckle and caustic structures. Intensity peaks satisfying statistical criteria for rogue waves are seen especially in the case of the caustic network, and are associated with broader spatial spectra. In addition, the electric field statistics of the intermediate pattern shows properties of an “optical sea” with near-Gaussian statistics in elevation amplitude, and trough-to-crest statistics that are near-Rayleigh distributed but with an extended tail where a number of rogue wave events are observed. PMID:26245864
Taming rogue waves in vector Bose-Einstein condensates.
Vinayagam, P S; Radha, R; Porsezian, K
2013-10-01
Using gauge transformation method, we generate rogue waves for the two-component Bose-Einstein condensates (BECs) governed by the symmetric coupled Gross-Pitaevskii (GP) equations and study their dynamics. We also suggest a mechanism to tame the rogue waves either by manipulating the scattering length through Feshbach resonance or the trapping frequency, a phenomenon not witnessed in the domain of BECs, and we believe that these results may have wider ramifications in the management of rogons.
NASA Astrophysics Data System (ADS)
Yu, Fajun
2016-05-01
We study multi-rogue wave solutions of a Schro¨dinger equation with higher-order terms employing the generalized Darboux transformation. Some properties of the nonautonomous rogue waves are investigated analytically for the combined Hirota-Lakshmanan-Porsezian-Daniel (LPD) equation. We consider the controllable behaviors of this nonautonomous rogue wave solution with the nonlinearity management function and gain/loss coefficient. It is reported that there are possibilities to 'catch' rogue waves through manipulating nonlinear function and gain/loss coefficient. Our approach can provide many possibilities to manipulate rogue waves and present the potential applications for the rogue wave phenomena.
Peregrine rogue waves induced by the interaction between a continuous wave and a soliton.
Yang, Guangye; Li, Lu; Jia, Suotang
2012-04-01
Based on the soliton solution on a continuous wave background for an integrable Hirota equation, the reduction mechanism and the characteristics of the Peregrine rogue wave in the propagation of femtosecond pulses of optical fiber are discussed. The results show that there exist two processes of the formation of the Peregrine rogue wave: one is the localized process of the continuous wave background, and the other is the reduction process of the periodization of the bright soliton. The characteristics of the Peregrine rogue wave are exhibited by strong temporal and spatial localization. Also, various initial excitations of the Peregrine rogue wave are performed and the results show that the Peregrine rogue wave can be excited by a small localized (single peak) perturbation pulse of the continuous wave background, even for the nonintegrable case. The numerical simulations show that the Peregrine rogue wave is unstable. Finally, through a realistic example, the influence of the self-frequency shift to the dynamics of the Peregrine rogue wave is discussed. The results show that in the absence of the self-frequency shift, the Peregrine rogue wave can split into several subpulses; however, when the self-frequency shift is considered, the Peregrine rogue wave no longer splits and exhibits mainly a peak changing and an increasing evolution property of the field amplitude.
Modulational Instability and Rogue Waves in Shallow Water Models
NASA Astrophysics Data System (ADS)
Grimshaw, R.; Chow, K. W.; Chan, H. N.
It is now well known that the focussing nonlinear Schrödinger equation allows plane waves to be modulationally unstable, and at the same time supports breather solutions which are often invoked as models for rogue waves. This suggests a direct connection between modulation instability and the existence of rogue waves. In this chapter we review this connection for a suite of long wave models, such as the Korteweg-de Vries equation, the extended Korteweg-de Vries (Gardner) equation, often used to describe surface and internal waves in shallow water, a Boussinesq equation and, also a coupled set of Korteweg-de Vries equations.
Dynamics of rogue waves on multisoliton background in the Benjamin Ono equation
NASA Astrophysics Data System (ADS)
LIU, YUN-KAI; LI, BIAO
2017-04-01
For the Benjamin Ono equation, the Hirota bilinear method and long wave limit method are applied to obtain the breathers and the rogue wave solutions. Bright and dark rogue waves exist in the Benjamin Ono equation, and their typical dynamics are analysed and illustrated. The semirational solutions possessing rogue waves and solitons are also obtained, and demonstrated by the three-dimensional figures. Furthermore, the hybrid of rogue wave and breather solutions are also found in the Benjamin Ono equation.
Rogue waves and breathers in Heisenberg spin chain
NASA Astrophysics Data System (ADS)
Mukhopadhyay, Aritra K.; Vyas, Vivek M.; Panigrahi, Prasanta K.
2015-07-01
Following the connection of the non-linear Schrödinger equation with the continuum Heisenberg spin chain, we find the rogue soliton equivalent in the spin system. The breathers are also mapped to the corresponding space or time localized oscillatory modes, through the moving curve analogy. The spatio-temporal evolution of the curvature and torsion of the curve, underlying these dynamical systems, are explicated to illustrate the localization property of the rogue waves.
Rogue wave observation in a water wave tank.
Chabchoub, A; Hoffmann, N P; Akhmediev, N
2011-05-20
The conventional definition of rogue waves in the ocean is that their heights, from crest to trough, are more than about twice the significant wave height, which is the average wave height of the largest one-third of nearby waves. When modeling deep water waves using the nonlinear Schrödinger equation, the most likely candidate satisfying this criterion is the so-called Peregrine solution. It is localized in both space and time, thus describing a unique wave event. Until now, experiments specifically designed for observation of breather states in the evolution of deep water waves have never been made in this double limit. In the present work, we present the first experimental results with observations of the Peregrine soliton in a water wave tank.
Electrostatic rogue-waves in relativistically degenerate plasmas
Akbari-Moghanjoughi, M.
2014-10-15
In this paper, we investigate the modulational instability and the possibility of electrostatic rogue-wave propagations in a completely degenerate plasma with arbitrary degree of degeneracy, i.e., relativistically degenerate plasma, ranging from solid density to the astrophysical compact stars. The hydrodynamic approach along with the perturbation method is used to reduce the governing equations to the nonlinear Schrödinger equation from which the modulational instability, the growth rate of envelope excitations and the occurrence of rogue as well as super-rogue waves in the plasma, is evaluated. It is observed that the modulational instability in a fully degenerate plasma can be quite sensitive to the plasma number-density and the wavenumber of envelop excitations. It is further revealed that the relativistically degeneracy plasmas (R{sub 0} > 1) are almost always modulationally unstable. It is found, however, that the highly energetic sharply localized electrostatic rogue as well as super-rogue waves can exist in the astrophysical compact objects like white dwarfs and neutron star crusts. The later may provide a link to understand many physical processes in such stars and it may lead us to the origin of the random-localized intense short gamma-ray bursts, which “appear from nowhere and disappear without a trace” quite similar to oceanic rogue structures.
Real world ocean rogue waves explained without the modulational instability
Fedele, Francesco; Brennan, Joseph; Ponce de León, Sonia; Dudley, John; Dias, Frédéric
2016-01-01
Since the 1990s, the modulational instability has commonly been used to explain the occurrence of rogue waves that appear from nowhere in the open ocean. However, the importance of this instability in the context of ocean waves is not well established. This mechanism has been successfully studied in laboratory experiments and in mathematical studies, but there is no consensus on what actually takes place in the ocean. In this work, we question the oceanic relevance of this paradigm. In particular, we analyze several sets of field data in various European locations with various tools, and find that the main generation mechanism for rogue waves is the constructive interference of elementary waves enhanced by second-order bound nonlinearities and not the modulational instability. This implies that rogue waves are likely to be rare occurrences of weakly nonlinear random seas. PMID:27323897
Langmuir rogue waves in electron-positron plasmas
Moslem, W. M.
2011-03-15
Progress in understanding the nonlinear Langmuir rogue waves which accompany collisionless electron-positron (e-p) plasmas is presented. The nonlinearity of the system results from the nonlinear coupling between small, but finite, amplitude Langmuir waves and quasistationary density perturbations in an e-p plasma. The nonlinear Schroedinger equation is derived for the Langmuir waves' electric field envelope, accounting for small, but finite, amplitude quasistationary plasma slow motion describing the Langmuir waves' ponderomotive force. Numerical calculations reveal that the rogue structures strongly depend on the electron/positron density and temperature, as well as the group velocity of the envelope wave. The present study might be helpful to understand the excitation of nonlinear rogue pulses in astrophysical environments, such as in active galactic nuclei, in pulsar magnetospheres, in neutron stars, etc.
Real world ocean rogue waves explained without the modulational instability
NASA Astrophysics Data System (ADS)
Fedele, Francesco; Brennan, Joseph; Ponce de León, Sonia; Dudley, John; Dias, Frédéric
2016-06-01
Since the 1990s, the modulational instability has commonly been used to explain the occurrence of rogue waves that appear from nowhere in the open ocean. However, the importance of this instability in the context of ocean waves is not well established. This mechanism has been successfully studied in laboratory experiments and in mathematical studies, but there is no consensus on what actually takes place in the ocean. In this work, we question the oceanic relevance of this paradigm. In particular, we analyze several sets of field data in various European locations with various tools, and find that the main generation mechanism for rogue waves is the constructive interference of elementary waves enhanced by second-order bound nonlinearities and not the modulational instability. This implies that rogue waves are likely to be rare occurrences of weakly nonlinear random seas.
Twisted rogue-wave pairs in the Sasa-Satsuma equation.
Chen, Shihua
2013-08-01
Exact explicit rogue wave solutions of the Sasa-Satsuma equation are obtained by use of a Darboux transformation. In addition to the double-peak structure and an analog of the Peregrine soliton, the rogue wave can exhibit an intriguing twisted rogue-wave pair that involves four well-defined zero-amplitude points. This exotic structure may enrich our understanding on the nature of rogue waves.
Simple determinant representation for rogue waves of the nonlinear Schrödinger equation.
Ling, Liming; Zhao, Li-Chen
2013-10-01
We present a simple representation for arbitrary-order rogue wave solution and a study on the trajectories of them explicitly. We find that the trajectories of two valleys on whole temporal-spatial distribution all look "X" -shaped for rogue waves. Additionally, we present different types of high-order rogue wave structures, which could be helpful towards realizing the complex dynamics of rogue waves.
Optical rogue waves for the inhomogeneous generalized nonlinear Schrödinger equation.
Loomba, Shally; Kaur, Harleen
2013-12-01
We present optical rogue wave solutions for a generalized nonlinear Schrodinger equation by using similarity transformation. We have predicted the propagation of rogue waves through a nonlinear optical fiber for three cases: (i) dispersion increasing (decreasing) fiber, (ii) periodic dispersion parameter, and (iii) hyperbolic dispersion parameter. We found that the rogue waves and their interactions can be tuned by properly choosing the parameters. We expect that our results can be used to realize improved signal transmission through optical rogue waves.
Capturing rogue waves by multi-point statistics
NASA Astrophysics Data System (ADS)
Hadjihosseini, A.; Wächter, Matthias; Hoffmann, N. P.; Peinke, J.
2016-01-01
As an example of a complex system with extreme events, we investigate ocean wave states exhibiting rogue waves. We present a statistical method of data analysis based on multi-point statistics which for the first time allows the grasping of extreme rogue wave events in a highly satisfactory statistical manner. The key to the success of the approach is mapping the complexity of multi-point data onto the statistics of hierarchically ordered height increments for different time scales, for which we can show that a stochastic cascade process with Markov properties is governed by a Fokker-Planck equation. Conditional probabilities as well as the Fokker-Planck equation itself can be estimated directly from the available observational data. With this stochastic description surrogate data sets can in turn be generated, which makes it possible to work out arbitrary statistical features of the complex sea state in general, and extreme rogue wave events in particular. The results also open up new perspectives for forecasting the occurrence probability of extreme rogue wave events, and even for forecasting the occurrence of individual rogue waves based on precursory dynamics.
High-order rogue waves for the Hirota equation
Li, Linjing; Wu, Zhiwei; Wang, Lihong; He, Jingsong
2013-07-15
The Hirota equation is better than the nonlinear Schrödinger equation when approximating deep ocean waves. In this paper, high-order rational solutions for the Hirota equation are constructed based on the parameterized Darboux transformation. Several types of this kind of solutions are classified by their structures. -- Highlights: •The determinant representation of the N-fold Darboux transformation of the Hirota equation. •Properties of the fundamental pattern of the higher order rogue wave. •Ring structure and triangular structure of the higher order rogue waves.
Rogue waves in a normal-dispersion fiber laser.
Liu, Zhanwei; Zhang, Shumin; Wise, F W
2015-04-01
Experimental evidence of rogue-wave formation in a normal-dispersion ytterbium fiber laser is reported. Spectral filtering is a primary component of pulse-shaping in normal-dispersion lasers, and we find that the choice of filter dramatically influences the distribution of noise-pulse energies produced by these lasers. With an interference filter in the cavity, non-Gaussian distributions with pulses as large as 6 times the significant wave height are observed. These correspond to pulse energies as high as ∼50 nJ. To our knowledge, the results presented are not accounted for by existing theoretical models of rogue-wave formation.
Vector rogue waves and baseband modulation instability in the defocusing regime.
Baronio, Fabio; Conforti, Matteo; Degasperis, Antonio; Lombardo, Sara; Onorato, Miguel; Wabnitz, Stefan
2014-07-18
We report and discuss analytical solutions of the vector nonlinear Schrödinger equation that describe rogue waves in the defocusing regime. This family of solutions includes bright-dark and dark-dark rogue waves. The link between modulational instability (MI) and rogue waves is displayed by showing that only a peculiar kind of MI, namely baseband MI, can sustain rogue-wave formation. The existence of vector rogue waves in the defocusing regime is expected to be a crucial progress in explaining extreme waves in a variety of physical scenarios described by multicomponent systems, from oceanography to optics and plasma physics.
On shallow water rogue wave formation in strongly inhomogeneous channels
NASA Astrophysics Data System (ADS)
Didenkulova, Ira; Pelinovsky, Efim
2016-05-01
Rogue wave formation in shallow water is often governed by dispersive focusing and wave-bottom interaction. In this study we try to combine these mechanisms by considering dispersive nonreflecting wave propagation in shallow strongly inhomogeneous channels. Nonreflecting wave propagation provides extreme wave amplification and the transfer of wave energy over large distances, while dispersive effects allow formation of a short-lived wave of extreme height (rogue wave). We found several types of water channels, where this mechanism can be realized, including (i) channels with a monotonically decreasing cross-section (normal dispersion), (ii) an inland basin described by a half of elliptic paraboloid (abnormal dispersion) and (iii) an underwater hill described by a half of hyperbolic paraboloid (normal dispersion). Conditions for variations of local frequency in the wave train providing optimal focusing of the wave train are also found.
Rogue Waves Associated with Circularly Polarized Waves in Magnetized Plasmas
NASA Astrophysics Data System (ADS)
Kourakis, I.; Borhanian, J.; Saxena, V.; Veldes, G.; Frantzeskakis, D. J.
2012-10-01
Extreme events occur in abundance in the ocean: an ultra-high ``ghost wave" often appears unexpectedly, against an otherwise moderate-on-average sea surface elevation, propagating for a short while and then disappearing without leaving a trace. Rogue waves are now recognized as proper nonlinear structures on their own. Unlike solitary waves, these events are localized in space and in time. Various approaches exist to model their dynamics, including nonlinear Schrodinger models, Ginzburg-Landau models, kinetic-theoretical models, and probabilistic models. We have undertaken an investigation, from first principles, of rogue waves in plasmas in the form of localized events associated with electromagnetic pulses. A multiple scale technique is employed to solve the fluid-Maxwell equations for nonlinear circularly polarized electromagnetic pulses. A nonlinear Schrodinger (NLS) type equation is shown to govern the amplitude of the vector potential. A set of non-stationary envelope solutions of the NLS equation is presented, and the variation of their structural properties with the magnetic field are investigated.
New Types of Rogue Wave in an Erbium-Doped Fibre System
NASA Astrophysics Data System (ADS)
He, Jingsong; Xu, Shuwei; Porsezian, Kuppuswamy
2012-03-01
We report a novel and new types of rogue optical wave propagation in an erbium-doped fibre system governed by the nonlinear Schrödinger and the Maxwell--Bloch equation. The breather solutions of the three fields, namely field envelop, polarization and population inversion, are used to generate the rogue waves. For the first time, we report bright and, in particular, dark rogue waves in a coupled nonlinear optical systems. The distinction between bright and dark rogue waves are discussed in detail through figures. The rogue wave formation in our model can also be connected to the generation of supercontinuum generation in resonant optical fibre.
Observation of three dimensional optical rogue waves through obstacles
NASA Astrophysics Data System (ADS)
Leonetti, Marco; Conti, Claudio
2015-06-01
We observe three-dimensional rogue waves in the speckle distribution of a spatially modulated optical beam. Light is transmitted beyond a partially reflecting obstacle generating optical rogue waves at a controlled position in the shadow of the barrier. When the barrier transmits only 0.07% of the input laser power, we observe the mostly localized event. These results demonstrate that an optimum amount of spatial non-homogeneity maximizes the probability of a gigantic event while the technique we exploit enables to control light behind a fully reflective wall.
Observation of three dimensional optical rogue waves through obstacles
Leonetti, Marco; Conti, Claudio
2015-06-22
We observe three-dimensional rogue waves in the speckle distribution of a spatially modulated optical beam. Light is transmitted beyond a partially reflecting obstacle generating optical rogue waves at a controlled position in the shadow of the barrier. When the barrier transmits only 0.07% of the input laser power, we observe the mostly localized event. These results demonstrate that an optimum amount of spatial non-homogeneity maximizes the probability of a gigantic event while the technique we exploit enables to control light behind a fully reflective wall.
Coexisting rogue waves within the (2+1)-component long-wave-short-wave resonance.
Chen, Shihua; Soto-Crespo, Jose M; Grelu, Philippe
2014-09-01
The coexistence of two different types of fundamental rogue waves is unveiled, based on the coupled equations describing the (2+1)-component long-wave-short-wave resonance. For a wide range of asymptotic background fields, each family of three rogue wave components can be triggered by using a slight deterministic alteration to the otherwise identical background field. The ability to trigger markedly different rogue wave profiles from similar initial conditions is confirmed by numerical simulations. This remarkable feature, which is absent in the scalar nonlinear Schrödinger equation, is attributed to the specific three-wave interaction process and may be universal for a variety of multicomponent wave dynamics spanning from oceanography to nonlinear optics.
Solar wind implication on dust ion acoustic rogue waves
NASA Astrophysics Data System (ADS)
Abdelghany, A. M.; Abd El-Razek, H. N.; Moslem, W. M.; El-Labany, S. K.
2016-06-01
The relevance of the solar wind with the magnetosphere of Jupiter that contains positively charged dust grains is investigated. The perturbation/excitation caused by streaming ions and electron beams from the solar wind could form different nonlinear structures such as rogue waves, depending on the dominant role of the plasma parameters. Using the reductive perturbation method, the basic set of fluid equations is reduced to modified Korteweg-de Vries (KdV) and further modified (KdV) equation. Assuming that the frequency of the carrier wave is much smaller than the ion plasma frequency, these equations are transformed into nonlinear Schrödinger equations with appropriate coefficients. Rational solution of the nonlinear Schrödinger equation shows that rogue wave envelopes are supported by the present plasma model. It is found that the existence region of rogue waves depends on the dust-acoustic speed and the streaming temperatures for both the ions and electrons. The dependence of the maximum rogue wave envelope amplitude on the system parameters has been investigated.
Three-dimensional rogue waves in nonstationary parabolic potentials.
Yan, Zhenya; Konotop, V V; Akhmediev, N
2010-09-01
Using symmetry analysis we systematically present a higher-dimensional similarity transformation reducing the (3+1) -dimensional inhomogeneous nonlinear Schrödinger (NLS) equation with variable coefficients and parabolic potential to the (1+1) -dimensional NLS equation with constant coefficients. This transformation allows us to relate certain class of localized exact solutions of the (3+1) -dimensional case to the variety of solutions of integrable NLS equation of the (1+1) -dimensional case. As an example, we illustrated our technique using two lowest-order rational solutions of the NLS equation as seeding functions to obtain rogue wavelike solutions localized in three dimensions that have complicated evolution in time including interactions between two time-dependent rogue wave solutions. The obtained three-dimensional rogue wavelike solutions may raise the possibility of relative experiments and potential applications in nonlinear optics and Bose-Einstein condensates.
Three-dimensional rogue waves in nonstationary parabolic potentials
Yan Zhenya; Konotop, V. V.; Akhmediev, N.
2010-09-15
Using symmetry analysis we systematically present a higher-dimensional similarity transformation reducing the (3+1)-dimensional inhomogeneous nonlinear Schroedinger (NLS) equation with variable coefficients and parabolic potential to the (1+1)-dimensional NLS equation with constant coefficients. This transformation allows us to relate certain class of localized exact solutions of the (3+1)-dimensional case to the variety of solutions of integrable NLS equation of the (1+1)-dimensional case. As an example, we illustrated our technique using two lowest-order rational solutions of the NLS equation as seeding functions to obtain rogue wavelike solutions localized in three dimensions that have complicated evolution in time including interactions between two time-dependent rogue wave solutions. The obtained three-dimensional rogue wavelike solutions may raise the possibility of relative experiments and potential applications in nonlinear optics and Bose-Einstein condensates.
Electromagnetic rogue waves in beam-plasma interactions
NASA Astrophysics Data System (ADS)
Veldes, G. P.; Borhanian, J.; McKerr, M.; Saxena, V.; Frantzeskakis, D. J.; Kourakis, I.
2013-06-01
The occurrence of rogue waves (freak waves) associated with electromagnetic pulse propagation interacting with a plasma is investigated, from first principles. A multiscale technique is employed to solve the fluid Maxwell equations describing weakly nonlinear circularly polarized electromagnetic pulses in magnetized plasmas. A nonlinear Schrödinger (NLS) type equation is shown to govern the amplitude of the vector potential. A set of non-stationary envelope solutions of the NLS equation are considered as potential candidates for the modeling of rogue waves (freak waves) in beam-plasma interactions, namely in the form of the Peregrine soliton, the Akhmediev breather and the Kuznetsov-Ma breather. The variation of the structural properties of the latter structures with relevant plasma parameters is investigated, in particular focusing on the ratio between the (magnetic field dependent) cyclotron (gyro-)frequency and the plasma frequency.
Optical rogue waves generated on Gaussian background beam.
Liu, Chong; Yang, Zhan-Ying; Zhao, Li-Chen; Xin, Guo-Guo; Yang, Wen-Li
2014-02-15
We study optical rogue waves (RWs) in a nonlinear graded-index waveguide with variable coefficients. An exact RW solution on Gaussian background beam is presented, in contrast to the previous studies about RWs, on plane wave background. It is shown that the characteristics of RWs are maintained on Gaussian background beam and that the beam's width is even a bit smaller than the RWs scale. These results may raise the possibility of related experiments and potential applications in nonlinear optics.
Integrable Turbulence and Rogue Waves: Breathers or Solitons?
Soto-Crespo, J M; Devine, N; Akhmediev, N
2016-03-11
Turbulence in dynamical systems is one of the most intriguing phenomena of modern science. Integrable systems offer the possibility to understand, to some extent, turbulence. Recent numerical and experimental data suggest that the probability of the appearance of rogue waves in a chaotic wave state in such systems increases when the initial state is a random function of sufficiently high amplitude. We provide explanations for this effect.
Watch-hand-like optical rogue waves in three-wave interactions.
Chen, Shihua; Soto-Crespo, Jose M; Grelu, Philippe
2015-01-12
We investigate the resonant interaction of three optical pulses of different group velocity in quadratic media and report on the novel watch-hand-like super rogue wave patterns. In addition to having a giant wall-like hump, each rogue-wave hand involves a peak amplitude more than five times its background height. We attribute such peculiar structures to the nonlinear superposition of six Peregrine-type solitons. The robustness has been confirmed by numerical simulations. This stability along with the non-overlapping distribution property may facilitate the experimental diagnostics and observation of these super rogue waves.
Circularly polarized few-cycle optical rogue waves: Rotating reduced Maxwell-Bloch equations
NASA Astrophysics Data System (ADS)
Xu, Shuwei; Porsezian, K.; He, Jingsong; Cheng, Yi
2013-12-01
The rotating reduced Maxwell-Bloch (RMB) equations, which describe the propagation of few-cycle optical pulses in a transparent media with two isotropic polarized electronic field components, are derived from a system of complete Maxwell-Bloch equations without using the slowly varying envelope approximations. Two hierarchies of the obtained rational solutions, including rogue waves, which are also called few-cycle optical rogue waves, of the rotating RMB equations are constructed explicitly through degenerate Darboux transformation. In addition to the above, the dynamical evolution of the first-, second-, and third-order few-cycle optical rogue waves are constructed with different patterns. For an electric field E in the three lower-order rogue waves, we find that rogue waves correspond to localized large amplitude oscillations of the polarized electric fields. Further a complementary relationship of two electric field components of rogue waves is discussed in terms of analytical formulas as well as numerical figures.
Dust-acoustic rogue waves in a nonextensive plasma
Moslem, W. M.; Shukla, P. K.; Sabry, R.; El-Labany, S. K.
2011-12-15
We present an investigation for the generation of a dust-acoustic rogue wave in a dusty plasma composed of negatively charged dust grains, as well as nonextensive electrons and ions. For this purpose, the reductive perturbation technique is used to obtain a nonlinear Schroedinger equation. The critical wave-number threshold k{sub c}, which indicates where the modulational instability sets in, has been determined precisely for various regimes. Two different behaviors of k{sub c} against the nonextensive parameter q are found. For small k{sub c}, it is found that increasing q would lead to an increase of k{sub c} until q approaches a certain value q{sub c}, then further increase of q beyond q{sub c} decreases the value of k{sub c}. For large k{sub c}, the critical wave-number threshold k{sub c} is always increasing with q. Within the modulational instability region, a random perturbation of the amplitude grows and thus creates dust-acoustic rogue waves. In order to show that the characteristics of the rogue waves are influenced by the plasma parameters, the relevant numerical analysis of the appropriate nonlinear solution is presented. The nonlinear structure, as reported here, could be useful for controlling and maximizing highly energetic pulses in dusty plasmas.
Dust-acoustic rogue waves in a nonextensive plasma.
Moslem, W M; Sabry, R; El-Labany, S K; Shukla, P K
2011-12-01
We present an investigation for the generation of a dust-acoustic rogue wave in a dusty plasma composed of negatively charged dust grains, as well as nonextensive electrons and ions. For this purpose, the reductive perturbation technique is used to obtain a nonlinear Schrödinger equation. The critical wave-number threshold k(c), which indicates where the modulational instability sets in, has been determined precisely for various regimes. Two different behaviors of k(c) against the nonextensive parameter q are found. For small k(c), it is found that increasing q would lead to an increase of k(c) until q approaches a certain value q(c), then further increase of q beyond q(c) decreases the value of k(c). For large k(c), the critical wave-number threshold k(c) is always increasing with q. Within the modulational instability region, a random perturbation of the amplitude grows and thus creates dust-acoustic rogue waves. In order to show that the characteristics of the rogue waves are influenced by the plasma parameters, the relevant numerical analysis of the appropriate nonlinear solution is presented. The nonlinear structure, as reported here, could be useful for controlling and maximizing highly energetic pulses in dusty plasmas.
Emergent rogue wave structures and statistics in spontaneous modulation instability.
Toenger, Shanti; Godin, Thomas; Billet, Cyril; Dias, Frédéric; Erkintalo, Miro; Genty, Goëry; Dudley, John M
2015-05-20
The nonlinear Schrödinger equation (NLSE) is a seminal equation of nonlinear physics describing wave packet evolution in weakly-nonlinear dispersive media. The NLSE is especially important in understanding how high amplitude "rogue waves" emerge from noise through the process of modulation instability (MI) whereby a perturbation on an initial plane wave can evolve into strongly-localised "breather" or "soliton on finite background (SFB)" structures. Although there has been much study of such structures excited under controlled conditions, there remains the open question of how closely the analytic solutions of the NLSE actually model localised structures emerging in noise-seeded MI. We address this question here using numerical simulations to compare the properties of a large ensemble of emergent peaks in noise-seeded MI with the known analytic solutions of the NLSE. Our results show that both elementary breather and higher-order SFB structures are observed in chaotic MI, with the characteristics of the noise-induced peaks clustering closely around analytic NLSE predictions. A significant conclusion of our work is to suggest that the widely-held view that the Peregrine soliton forms a rogue wave prototype must be revisited. Rather, we confirm earlier suggestions that NLSE rogue waves are most appropriately identified as collisions between elementary SFB solutions.
Emergent rogue wave structures and statistics in spontaneous modulation instability
Toenger, Shanti; Godin, Thomas; Billet, Cyril; Dias, Frédéric; Erkintalo, Miro; Genty, Goëry; Dudley, John M.
2015-01-01
The nonlinear Schrödinger equation (NLSE) is a seminal equation of nonlinear physics describing wave packet evolution in weakly-nonlinear dispersive media. The NLSE is especially important in understanding how high amplitude “rogue waves” emerge from noise through the process of modulation instability (MI) whereby a perturbation on an initial plane wave can evolve into strongly-localised “breather” or “soliton on finite background (SFB)” structures. Although there has been much study of such structures excited under controlled conditions, there remains the open question of how closely the analytic solutions of the NLSE actually model localised structures emerging in noise-seeded MI. We address this question here using numerical simulations to compare the properties of a large ensemble of emergent peaks in noise-seeded MI with the known analytic solutions of the NLSE. Our results show that both elementary breather and higher-order SFB structures are observed in chaotic MI, with the characteristics of the noise-induced peaks clustering closely around analytic NLSE predictions. A significant conclusion of our work is to suggest that the widely-held view that the Peregrine soliton forms a rogue wave prototype must be revisited. Rather, we confirm earlier suggestions that NLSE rogue waves are most appropriately identified as collisions between elementary SFB solutions. PMID:25993126
Optical rogue waves in whispering-gallery-mode resonators
NASA Astrophysics Data System (ADS)
Coillet, Aurélien; Dudley, John; Genty, Goëry; Larger, Laurent; Chembo, Yanne K.
2014-01-01
We report a theoretical study showing that rogue waves can emerge in whispering-gallery-mode resonators as the result of the chaotic interplay between Kerr nonlinearity and anomalous group-velocity dispersion. The nonlinear dynamics of the propagation of light in a whispering-gallery-mode resonator is investigated using the Lugiato-Lefever equation, and we give evidence of a range of parameters where rare and extreme events associated with non-Gaussian statistics of the field maxima are observed.
Optical amplification and reshaping based on the Peregrine rogue wave.
Wang, Yan; Song, Lijun; Li, Lu
2016-09-10
Based on the characteristics of the Peregrine rogue wave, the amplification and the reshaping of solitons are investigated. The numerical results show that the amplification and the reshaping of solitons can be realized by injecting a continuous wave (CW) and filtering the CW at suitable positions. The combination of a continuous-wave pump and a spectral filter placed suitably in fiber plays the role of the amplifier, which can be used to long-haul the transmission of solitons. As an example, a long-haul transmission with four amplification periods is demonstrated.
Roadmap on optical rogue waves and extreme events
NASA Astrophysics Data System (ADS)
Akhmediev, Nail; Kibler, Bertrand; Baronio, Fabio; Belić, Milivoj; Zhong, Wei-Ping; Zhang, Yiqi; Chang, Wonkeun; Soto-Crespo, Jose M.; Vouzas, Peter; Grelu, Philippe; Lecaplain, Caroline; Hammani, K.; Rica, S.; Picozzi, A.; Tlidi, Mustapha; Panajotov, Krassimir; Mussot, Arnaud; Bendahmane, Abdelkrim; Szriftgiser, Pascal; Genty, Goery; Dudley, John; Kudlinski, Alexandre; Demircan, Ayhan; Morgner, Uwe; Amiraranashvili, Shalva; Bree, Carsten; Steinmeyer, Günter; Masoller, C.; Broderick, Neil G. R.; Runge, Antoine F. J.; Erkintalo, Miro; Residori, S.; Bortolozzo, U.; Arecchi, F. T.; Wabnitz, Stefan; Tiofack, C. G.; Coulibaly, S.; Taki, M.
2016-06-01
The pioneering paper ‘Optical rogue waves’ by Solli et al (2007 Nature 450 1054) started the new subfield in optics. This work launched a great deal of activity on this novel subject. As a result, the initial concept has expanded and has been enriched by new ideas. Various approaches have been suggested since then. A fresh look at the older results and new discoveries has been undertaken, stimulated by the concept of ‘optical rogue waves’. Presently, there may not by a unique view on how this new scientific term should be used and developed. There is nothing surprising when the opinion of the experts diverge in any new field of research. After all, rogue waves may appear for a multiplicity of reasons and not necessarily only in optical fibers and not only in the process of supercontinuum generation. We know by now that rogue waves may be generated by lasers, appear in wide aperture cavities, in plasmas and in a variety of other optical systems. Theorists, in turn, have suggested many other situations when rogue waves may be observed. The strict definition of a rogue wave is still an open question. For example, it has been suggested that it is defined as ‘an optical pulse whose amplitude or intensity is much higher than that of the surrounding pulses’. This definition (as suggested by a peer reviewer) is clear at the intuitive level and can be easily extended to the case of spatial beams although additional clarifications are still needed. An extended definition has been presented earlier by N Akhmediev and E Pelinovsky (2010 Eur. Phys. J. Spec. Top. 185 1-4). Discussions along these lines are always useful and all new approaches stimulate research and encourage discoveries of new phenomena. Despite the potentially existing disagreements, the scientific terms ‘optical rogue waves’ and ‘extreme events’ do exist. Therefore coordination of our efforts in either unifying the concept or in introducing alternative definitions must be continued. From
Dust-acoustic waves modulational instability and rogue waves in a polarized dusty plasma
NASA Astrophysics Data System (ADS)
Bouzit, Omar; Tribeche, Mouloud
2015-10-01
The polarization force-induced changes in the dust-acoustic waves (DAWs) modulational instability (MI) are examined. Using the reductive perturbation method, the nonlinear Schrödinger equation that governs the MI of the DAWs is obtained. It is found that the effect of the polarization term R is to narrow the wave number domain for the onset of instability. The amplitude of the wave envelope decreases as R increases, meaning that the polarization force effects render weaker the associated DA rogue waves. The latter may therefore completely damp in the vicinity of R ˜ 1, i.e., as the polarization force becomes close to the electrostatic one (the net force acting on the dust particles becomes vanishingly small). The DA rogue wave profile is very sensitive to any change in the restoring force acting on the dust particles. It turns out that the polarization effects may completely smear out the DA rogue waves.
Dust-acoustic waves modulational instability and rogue waves in a polarized dusty plasma
Bouzit, Omar; Tribeche, Mouloud
2015-10-15
The polarization force-induced changes in the dust-acoustic waves (DAWs) modulational instability (MI) are examined. Using the reductive perturbation method, the nonlinear Schrödinger equation that governs the MI of the DAWs is obtained. It is found that the effect of the polarization term R is to narrow the wave number domain for the onset of instability. The amplitude of the wave envelope decreases as R increases, meaning that the polarization force effects render weaker the associated DA rogue waves. The latter may therefore completely damp in the vicinity of R ∼ 1, i.e., as the polarization force becomes close to the electrostatic one (the net force acting on the dust particles becomes vanishingly small). The DA rogue wave profile is very sensitive to any change in the restoring force acting on the dust particles. It turns out that the polarization effects may completely smear out the DA rogue waves.
Rogue waves of the Kundu-Eckhaus equation in a chaotic wave field.
Bayindir, Cihan
2016-03-01
In this paper we study the properties of the chaotic wave fields generated in the frame of the Kundu-Eckhaus equation (KEE). Modulation instability results in a chaotic wave field which exhibits small-scale filaments with a free propagation constant, k. The average velocity of the filaments is approximately given by the average group velocity calculated from the dispersion relation for the plane-wave solution; however, direction of propagation is controlled by the β parameter, the constant in front of the Raman-effect term. We have also calculated the probabilities of the rogue wave occurrence for various values of propagation constant k and showed that the probability of rogue wave occurrence depends on k. Additionally, we have showed that the probability of rogue wave occurrence significantly depends on the quintic and the Raman-effect nonlinear terms of the KEE. Statistical comparisons between the KEE and the cubic nonlinear Schrödinger equation have also been presented.
On the rogue wave propagation in ion pair superthermal plasma
Abdelwahed, H. G. E-mail: hgomaa-eg@mans.edu.eg; Zahran, M. A.; El-Shewy, E. K. Elwakil, S. A.
2016-02-15
Effects of superthermal electron on the features of nonlinear acoustic waves in unmagnetized collisionless ion pair plasma with superthermal electrons have been examined. The system equations are reduced in the form of the nonlinear Schrodinger equation. The rogue wave characteristics dependences on the ionic density ratio (ν = n{sub –0}/n{sub +0}), ionic mass ratio (Q = m{sub +}/m{sub −}), and superthermality index (κ) are investigated. It is worth mentioning that the results present in this work could be applicable in the Earth's ionosphere plasmas.
Rogue-wave-like characteristics in femtosecond supercontinuum generation.
Erkintalo, M; Genty, G; Dudley, J M
2009-08-15
We experimentally study the characteristics of optical rogue waves in supercontinuum generation in the femtosecond regime. Specifically, the intensity histograms obtained from spectrally filtering the supercontinuum exhibit the L-shaped characteristics typical of extreme-value phenomena on both the long-wavelength and short-wavelength edges of the spectrum owing to cross-phase modulation and soliton-dispersive wave coupling. Furthermore, the form of the histogram on the long-wavelength edge varies from L-shaped to quasi-Gaussian as wavelengths closer to the pump are included in the filtered measurements. Our observations are in agreement with numerical simulations.
Self-similar rogue waves and nonlinear tunneling effects in inhomogeneous nonlinear fiber optics
NASA Astrophysics Data System (ADS)
Wang, Lei; Zhu, Yu-Jie; Jiang, Dong-Yang
2016-04-01
Analytical first- and second-order rogue wave solutions of the inhomogeneous modified nonlinear Schrödinger equation are presented by using similarity transformation. Then, by the proper choices of the inhomogeneous coefficients and free parameters, the controllable behaviors of the optical rogue waves are graphically discussed in the nonlinear fiber optics context. It is found that the width of the rogue wave can be tuned by adjusting the parameter ? and the locations of the rogue waves are linearly controlled by the parameter ?. The intensities of the rogue waves are influenced by the inhomogeneous linear gain/loss coefficient ? and parameter ?. The dispersion management function ? has effects on the periods and trajectories of the rogue waves and can induce maintenance (or annihilation) along ? direction. Interestingly, the composite rogue waves are revealed, the location of which is manipulated through changing the dispersion management function ?. Additionally, the nonlinear tunneling of those rogue waves is investigated as they propagate through a dispersion barrier (or well) and nonlinear barrier (or well).
Rogue waves in multiphase solutions of the focusing nonlinear Schrödinger equation
NASA Astrophysics Data System (ADS)
Bertola, Marco; El, Gennady A.; Tovbis, Alexander
2016-10-01
Rogue waves appearing on deep water or in optical fibres are often modelled by certain breather solutions of the focusing nonlinear Schrödinger (fNLS) equation which are referred to as solitons on finite background (SFBs). A more general modelling of rogue waves can be achieved via the consideration of multiphase, or finite-band, fNLS solutions of whom the standard SFBs and the structures forming due to their collisions represent particular, degenerate, cases. A generalized rogue wave notion then naturally enters as a large-amplitude localized coherent structure occurring within a finite-band fNLS solution. In this paper, we use the winding of real tori to show the mechanism of the appearance of such generalized rogue waves and derive an analytical criterion distinguishing finite-band potentials of the fNLS equation that exhibit generalized rogue waves.
Two-dimensional dissipative rogue waves due to time-delayed feedback in cavity nonlinear optics
NASA Astrophysics Data System (ADS)
Tlidi, Mustapha; Panajotov, Krassimir
2017-01-01
We demonstrate a way to generate two-dimensional rogue waves in two types of broad area nonlinear optical systems subject to time-delayed feedback: in the generic Lugiato-Lefever model and in the model of a broad-area surface-emitting laser with saturable absorber. The delayed feedback is found to induce a spontaneous formation of rogue waves. In the absence of delayed feedback, spatial pulses are stationary. The rogue waves are exited and controlled by the delay feedback. We characterize their formation by computing the probability distribution of the pulse height. The long-tailed statistical contribution, which is often considered as a signature of the presence of rogue waves, appears for sufficiently strong feedback. The generality of our analysis suggests that the feedback induced instability leading to the spontaneous formation of two-dimensional rogue waves is a universal phenomenon.
Controlling formation and suppression of fiber-optical rogue waves.
Brée, Carsten; Steinmeyer, Günter; Babushkin, Ihar; Morgner, Uwe; Demircan, Ayhan
2016-08-01
Fiber-optical rogue waves appear as rare but extreme events during optical supercontinuum generation in photonic crystal fibers. This process is typically initiated by the decay of a high-order fundamental soliton into fundamental solitons. Collisions between these solitons as well as with dispersive radiation affect the soliton trajectory in frequency and time upon further propagation. Launching an additional dispersive wave at carefully chosen delay and wavelength enables statistical manipulation of the soliton trajectory in such a way that the probability of rogue wave formation is either enhanced or reduced. To enable efficient control, parameters of the dispersive wave have to be chosen to allow trapping of dispersive radiation in the nonlinear index depression created by the soliton. Under certain conditions, direct manipulation of soliton properties is possible by the dispersive wave. In other more complex scenarios, control is possible via increasing or decreasing the number of intersoliton collisions. The control mechanism reaches a remarkable efficiency, enabling control of relatively large soliton energies. This scenario appears promising for highly dynamic all-optical control of supercontinua.
NASA Astrophysics Data System (ADS)
Yang, Jin-Wei; Gao, Yi-Tian; Sun, Yu-Hao; Shen, Yu-Jia; Su, Chuan-Qi
2016-11-01
In this paper, a two-component (2 + 1) -dimensional long-wave-short-wave (LWSW) system with nonlinearity coefficients, which describes the nonlinear resonance interaction between two short waves and a long wave, is studied. Via the Hirota's bilinear method and Pfaffian, N -order rogue waves for the LWSW system are constructed. Furthermore, correction of the N -order rogue waves is proved directly via the Pfaffian, which is cumbersome or inaccessible in other methods. Results of the first- and second-order rogue waves are presented: 1) For the first-order rogue waves, the two short-wave components are bright, while the long-wave component is dark. The position of maximum amplitude of the rogue wave is analyzed. Evolution process for the first-order rogue wave is also presented and discussed. 2) Choosing different forms of the elements defined in the Pfaffian, we obtain some kinds of the second-order rogue waves with new spatial distributions: when the elements defined in Pfaffian are the same as the first-order rogue waves, we find that the second-order rogue waves for the two short-wave components are split into two first-order rogue waves and the two bumps coexist and interact with each other; when we change the combination of the elements in Pfaffian, we find that the second-order rogue waves for the two short-wave components are split into three and four first-order rogue waves. 3) N -order rogue waves for a general M -component LWSW system are constructed.
NASA Astrophysics Data System (ADS)
El-Tantawy, S. A.
2017-02-01
Progress is reported on the modulational instability (MI) of ion-acoustic waves (IAWs) and dissipative rogue waves (RWs) in ultracold neutral plasmas (UNPs). The UNPs consist of inertial ions fluid and Maxwellian inertialess hot electrons, and the presence of an ion kinematic viscosity is allowed. For this purpose, a modified nonlinear Schrödinger equation (NLSE) is derived and then solved analytically to show the occurrence of MI. It is found that the (in)stability regions of the wavepacks are dependent on time due to of the existence of the dissipative term. The existing regions of the MI of the IAWs are inventoried precisely. After that, we use a suitable transformation to convert the modified NLSE into the normal NLSE whose analytical solutions for rogue waves are known. The rogue wave propagation condition and its behavior are discussed. The impact of the relevant physical parameters on the profile of the RWs is examined.
Non-Rational Rogue Waves Induced by Inhomogeneity
NASA Astrophysics Data System (ADS)
He, Jing-Song; Wang, You-Ying; Li, Lin-Jing
2012-06-01
The variable Sine—Gordon (VSG) equation is often used to model several kinds of systems with inhomogeneity and it can be realized by the management of dispersion and nonlinearity in optics and Feschbach resonance in Bose-Einstein condensates. We derive four new kinds of non-rational rogue wave (RW) of the VSG by using an explicit transformation and the designable integrability. These RWs have novel profiles and interesting internal structures. It is shown that the RW is induced by the inhomogeneity of the system modeled by the VSG. The theoretical prediction of the corresponding relations between the RWs and some extreme events in DNA is discussed.
Generation and Limiters of Rogue Waves
2014-06-01
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Rational solitary wave and rogue wave solutions in coupled defocusing Hirota equation
NASA Astrophysics Data System (ADS)
Huang, Xin
2016-06-01
We derive and study a general rational solution of a coupled defocusing Hirota equation which can be used to describe evolution of light in a two-mode fiber with defocusing Kerr effect and some certain high-order effects. We find some new excitation patterns in the model, such as M-shaped soliton, W-shaped soliton, anti-eye-shaped rogue wave and four-petaled flower rogue wave. The results are compared with the solutions obtained in other coupled systems like vector nonlinear Schrödinger equation, coupled focusing Hirota and Sasa-Satsuma equations. We explain the new characters by modulational instability properties. This further indicates that rational solution does not necessarily correspond to rogue wave excitation dynamics and the quantitative relation between nonlinear excitations and modulational instability should exist.
Controlled generation of high-intensity optical rogue waves by induced modulation instability
Zhao, Saili; Yang, Hua; Chen, Nengsong; Zhao, Chujun
2017-01-01
Optical rogue waves are featured as the generation of high amplitude events at low probability in optical systems. Moreover, the formation of optical rogue waves is unpredictable and transient in photonic crystal fibers. In this paper, we put forward a method to generate high-intensity optical rogue waves in a more controlled way based on induced modulation instability, which can suppress the noise effect and hence play a leading role in the process of pulse evolution. Our numerical simulations indicate that the generation of rogue wave can be controlled when seeding at the optimal modulation frequency and the intensity of rogue wave can be enhanced with appropriate modulation depth. Further, high-intensity rogue wave can also be ejected in the fiber with a shorter propagation length by regulating the modulation depth. These results all provide a better understanding of optical rogue wave, which can contribute to the generation of tunable long-wavelength spectral components and selective excitation of mid-infrared supercontinuum. PMID:28051149
Few-cycle optical rogue waves: complex modified Korteweg-de Vries equation.
He, Jingsong; Wang, Lihong; Li, Linjing; Porsezian, K; Erdélyi, R
2014-06-01
In this paper, we consider the complex modified Korteweg-de Vries (mKdV) equation as a model of few-cycle optical pulses. Using the Lax pair, we construct a generalized Darboux transformation and systematically generate the first-, second-, and third-order rogue wave solutions and analyze the nature of evolution of higher-order rogue waves in detail. Based on detailed numerical and analytical investigations, we classify the higher-order rogue waves with respect to their intrinsic structure, namely, fundamental pattern, triangular pattern, and ring pattern. We also present several new patterns of the rogue wave according to the standard and nonstandard decomposition. The results of this paper explain the generalization of higher-order rogue waves in terms of rational solutions. We apply the contour line method to obtain the analytical formulas of the length and width of the first-order rogue wave of the complex mKdV and the nonlinear Schrödinger equations. In nonlinear optics, the higher-order rogue wave solutions found here will be very useful to generate high-power few-cycle optical pulses which will be applicable in the area of ultrashort pulse technology.
Controlled generation of high-intensity optical rogue waves by induced modulation instability.
Zhao, Saili; Yang, Hua; Chen, Nengsong; Zhao, Chujun
2017-01-04
Optical rogue waves are featured as the generation of high amplitude events at low probability in optical systems. Moreover, the formation of optical rogue waves is unpredictable and transient in photonic crystal fibers. In this paper, we put forward a method to generate high-intensity optical rogue waves in a more controlled way based on induced modulation instability, which can suppress the noise effect and hence play a leading role in the process of pulse evolution. Our numerical simulations indicate that the generation of rogue wave can be controlled when seeding at the optimal modulation frequency and the intensity of rogue wave can be enhanced with appropriate modulation depth. Further, high-intensity rogue wave can also be ejected in the fiber with a shorter propagation length by regulating the modulation depth. These results all provide a better understanding of optical rogue wave, which can contribute to the generation of tunable long-wavelength spectral components and selective excitation of mid-infrared supercontinuum.
Controlled generation of high-intensity optical rogue waves by induced modulation instability
NASA Astrophysics Data System (ADS)
Zhao, Saili; Yang, Hua; Chen, Nengsong; Zhao, Chujun
2017-01-01
Optical rogue waves are featured as the generation of high amplitude events at low probability in optical systems. Moreover, the formation of optical rogue waves is unpredictable and transient in photonic crystal fibers. In this paper, we put forward a method to generate high-intensity optical rogue waves in a more controlled way based on induced modulation instability, which can suppress the noise effect and hence play a leading role in the process of pulse evolution. Our numerical simulations indicate that the generation of rogue wave can be controlled when seeding at the optimal modulation frequency and the intensity of rogue wave can be enhanced with appropriate modulation depth. Further, high-intensity rogue wave can also be ejected in the fiber with a shorter propagation length by regulating the modulation depth. These results all provide a better understanding of optical rogue wave, which can contribute to the generation of tunable long-wavelength spectral components and selective excitation of mid-infrared supercontinuum.
Yomba, Emmanuel; Zakeri, Gholam-Ali
2016-08-01
The coupled inhomogeneous Schrödinger equations with a wide range of applications describing a field of pluses with the right and the left polarizations that take into account cross-phase modulations, stimulated Ramani scattering, and absorption effects are investigated. A combination of several different approaches is used in a novel way to obtain the explicit expressions for the rogue-pair and dark-bright-rogue waves. We study the dynamics of these structurally stable rogues and analyze the effects of a parameter that controls the region of stability that intrinsically connects the cross-phase modulation and other Kerr nonlinearity factors. The effects of the right and left polarizations on the shape of the rogue-pair and other solitary rogue waves are graphically analyzed. These rogue-pair waves are studied on periodic and non-periodic settings. We observe that rogue-pair wave from the right and left polarizations has a similar structure while the dark-bright-rogue waves have quite different intensity profiles.
NASA Astrophysics Data System (ADS)
Yomba, Emmanuel; Zakeri, Gholam-Ali
2016-08-01
The coupled inhomogeneous Schrödinger equations with a wide range of applications describing a field of pluses with the right and the left polarizations that take into account cross-phase modulations, stimulated Ramani scattering, and absorption effects are investigated. A combination of several different approaches is used in a novel way to obtain the explicit expressions for the rogue-pair and dark-bright-rogue waves. We study the dynamics of these structurally stable rogues and analyze the effects of a parameter that controls the region of stability that intrinsically connects the cross-phase modulation and other Kerr nonlinearity factors. The effects of the right and left polarizations on the shape of the rogue-pair and other solitary rogue waves are graphically analyzed. These rogue-pair waves are studied on periodic and non-periodic settings. We observe that rogue-pair wave from the right and left polarizations has a similar structure while the dark-bright-rogue waves have quite different intensity profiles.
The management of matter rogue waves in F = 1 spinor Bose-Einstein condensates
NASA Astrophysics Data System (ADS)
Loomba, Shally
2015-06-01
We have reported the matter rogue wave solutions for the nonautonomous three coupled Gross-Pitaevskii (GP) equation which governs the pulse propagation in spin-1 Bose-Einstein condensates (BECs) with time modulated nonlinearities. The system under consideration has attractive mean-field interactions and ferromagnetic spin-exchange interactions. The exact solutions have been worked out by using similarity and scaling transformations. We have depicted the controllable center characteristics of rogue waves for the kink-type spin-exchange interactions. Additionally, we have also discussed the management of rogue waves for the hyperbolic form of spin-exchange interactions by invoking isospectral Hamiltonian deformation technique.
Localized modes of the Hirota equation: Nth order rogue wave and a separation of variable technique
NASA Astrophysics Data System (ADS)
Mu, Gui; Qin, Zhenyun; Chow, Kwok Wing; Ee, Bernard K.
2016-10-01
The Hirota equation is a special extension of the intensively studied nonlinear Schrödinger equation, by incorporating third order dispersion and one form of the self-steepening effect. Higher order rogue waves of the Hirota equation can be calculated theoretically through a Darboux-dressing transformation by a separation of variable approach. A Taylor expansion is used and no derivative calculation is invoked. Furthermore, stability of these rogue waves is studied computationally. By tracing the evolution of an exact solution perturbed by random noise, it is found that second order rogue waves are generally less stable than first order ones.
Tao, Yongsheng; He, Jingsong
2012-02-01
The determinant representation of the n-fold Darboux transformation of the Hirota equation is given. Based on our analysis, the 1-soliton, 2-soliton, and breathers solutions are given explicitly. Further, the first order rogue wave solutions are given by a Taylor expansion of the breather solutions. In particular, the explicit formula of the rogue wave has several parameters, which is more general than earlier reported results and thus provides a systematic way to tune experimentally the rogue waves by choosing different values for them.
Weerasekara, Gihan; Tokunaga, Akihiro; Terauchi, Hiroki; Eberhard, Marc; Maruta, Akihiro
2015-01-12
One of the extraordinary aspects of nonlinear wave evolution which has been observed as the spontaneous occurrence of astonishing and statistically extraordinary amplitude wave is called rogue wave. We show that the eigenvalues of the associated equation of nonlinear Schrödinger equation are almost constant in the vicinity of rogue wave and we validate that optical rogue waves are formed by the collision between quasi-solitons in anomalous dispersion fiber exhibiting weak third order dispersion.
Nonlinear dynamics of trapped waves on jet currents and rogue waves.
Shrira, V I; Slunyaev, A V
2014-04-01
Nonlinear dynamics of surface gravity waves trapped by an opposing jet current is studied analytically and numerically. For wave fields narrow band in frequency but not necessarily with narrow angular distributions the developed asymptotic weakly nonlinear theory based on the modal approach of Shrira and Slunyaev [J. Fluid. Mech. 738, 65 (2014)] leads to the one-dimensional modified nonlinear Schrödinger equation of self-focusing type for a single mode. Its solutions such as envelope solitons and breathers are considered to be prototypes of rogue waves; these solutions, in contrast to waves in the absence of currents, are robust with respect to transverse perturbations, which suggests a potentially higher probability of rogue waves. Robustness of the long-lived analytical solutions describing modulated trapped waves and solitary wave groups is verified by direct numerical simulations of potential Euler equations.
Xie, Xi-Yang; Tian, Bo Wang, Yu-Feng; Sun, Ya; Jiang, Yan
2015-11-15
In this paper, we investigate a generalized nonautonomous nonlinear equation which describes the ultrashort optical pulse propagating in a nonlinear inhomogeneous fiber. By virtue of the generalized Darboux transformation, the first- and second-order rogue-wave solutions for the generalized nonautonomous nonlinear equation are obtained, under some variable–coefficient constraints. Properties of the first- and second-order rogue waves are graphically presented and analyzed: When the coefficients are all chosen as the constants, we can observe the some functions, the shapes of wave crests and troughs for the first- and second-order rogue waves change. Oscillating behaviors of the first- and second-order rogue waves are observed when the coefficients are the trigonometric functions.
Matter rogue waves in an F=1 spinor Bose-Einstein condensate.
Qin, Zhenyun; Mu, Gui
2012-09-01
We report new types of matter rogue waves of a spinor (three-component) model of the Bose-Einstein condensate governed by a system of three nonlinearly coupled Gross-Pitaevskii equations. The exact first-order rational solutions containing one free parameter are obtained by means of a Darboux transformation for the integrable system where the mean-field interaction is attractive and the spin-exchange interaction is ferromagnetic. For different choices of the parameter, there exists a variety of different shaped solutions including two peaks in bright rogue waves and four dips in dark rogue waves. Furthermore, by utilizing the relation between the three-component and the one-component versions of the nonlinear Schrödinger equation, we can devise higher-order rational solutions, in which three components have different shapes. In addition, it is noteworthy that dark rogue wave features disappear in the third-order rational solution.
Manipulating matter rogue waves and breathers in Bose-Einstein condensates.
Manikandan, K; Muruganandam, P; Senthilvelan, M; Lakshmanan, M
2014-12-01
We construct higher-order rogue wave solutions and breather profiles for the quasi-one-dimensional Gross-Pitaevskii equation with a time-dependent interatomic interaction and external trap through the similarity transformation technique. We consider three different forms of traps: (i) the time-independent expulsive trap, (ii) time-dependent monotonous trap, and (iii) time-dependent periodic trap. Our results show that when we change a parameter appearing in the time-independent or time-dependent trap the second- and third-order rogue waves transform into the first-order-like rogue waves. We also analyze the density profiles of breather solutions. Here we also show that the shapes of the breathers change when we tune the strength of the trap parameter. Our results may help to manage rogue waves experimentally in a BEC system.
Solutions of the vector nonlinear Schrödinger equations: evidence for deterministic rogue waves.
Baronio, Fabio; Degasperis, Antonio; Conforti, Matteo; Wabnitz, Stefan
2012-07-27
We construct and discuss a semirational, multiparametric vector solution of coupled nonlinear Schrödinger equations (Manakov system). This family of solutions includes known vector Peregrine solutions, bright- and dark-rogue solutions, and novel vector unusual freak waves. The vector rogue waves could be of great interest in a variety of complex systems, from optics and fluid dynamics to Bose-Einstein condensates and finance.
NASA Astrophysics Data System (ADS)
Tchinang Tchameu, J. D.; Togueu Motcheyo, A. B.; Tchawoua, C.
2016-09-01
The discrete multi-rogue waves (DMRW) as solution of the discrete nonlinear Schrödinger (DNLS) equation with saturable nonlinearities is studied numerically. These biological rogue waves represent the complex probability amplitude of finding an amide-I vibrational quantum at a site. We observe that the growth in the higher order saturable nonlinearity implies the formation of DMRW including an increase in the short-living DMRW and a decrease in amplitude of the long-living DMRW.
Nonlinear Schrödinger equation: generalized Darboux transformation and rogue wave solutions.
Guo, Boling; Ling, Liming; Liu, Q P
2012-02-01
In this paper, we construct a generalized Darboux transformation for the nonlinear Schrödinger equation. The associated N-fold Darboux transformation is given in terms of both a summation formula and determinants. As applications, we obtain compact representations for the Nth-order rogue wave solutions of the focusing nonlinear Schrödinger equation and Hirota equation. In particular, the dynamics of the general third-order rogue wave is discussed and shown to exhibit interesting structures.
NASA Astrophysics Data System (ADS)
Bains, A. S.; Tribeche, Mouloud; Saini, N. S.; Gill, T. S.
2017-01-01
A theoretical investigation is made to study envelope excitations and rogue wave structures of the newly predicted positron-acoustic waves (PAWs) in a plasma with nonextensive electrons and nonextensive hot positrons. The reductive perturbation technique (RPT) is used to derive a nonlinear Schrödinger equation-like (NLSE) which governs the modulational instability (MI) of the PAWs. The NLSE admits localized envelope solitary wave solutions of bright and dark type. These envelope solutions depend upon the intrinsic plasma parameters. It is found that the MI of the PAWs is significantly affected by nonextensivity and other plasma parameters. Further, the analysis is extended for the rogue wave structures of the PAWs. The findings of the present investigation should be useful in understanding the acceleration mechanism of stable electrostatic wave packets in four components nonextensive plasmas.
Rogue waves of the Sasa-Satsuma equation in a chaotic wave field.
Soto-Crespo, J M; Devine, N; Hoffmann, N P; Akhmediev, N
2014-09-01
We study the properties of the chaotic wave fields generated in the frame of the Sasa-Satsuma equation (SSE). Modulation instability results in a chaotic pattern of small-scale filaments with a free parameter-the propagation constant k. The average velocity of the filaments is approximately given by the group velocity calculated from the dispersion relation for the plane-wave solution. Remarkably, our results reveal the reason for the skewed profile of the exact SSE rogue-wave solutions, which was one of their distinctive unexplained features. We have also calculated the probability density functions for various values of the propagation constant k, showing that probability of appearance of rogue waves depends on k.
Wave Turbulence in Superfluid {sup 4}He: Energy Cascades and Rogue Waves in the Laboratory
Efimov, V. B.; Ganshin, A. N.; McClintock, P. V. E.; Kolmakov, G. V.; Mezhov-Deglin, L. P.
2008-11-13
Recent work on second sound acoustic turbulence in superfluid {sup 4}He is reviewed. Observations of forward and inverse energy cascades are described. The onset of the inverse cascade occurs above a critical driving energy and it is accompanied by giant waves that constitute an acoustic analogue of the rogue waves that occasionally appear on the surface of the ocean. The theory of the phenomenon is outlined and shown to be in good agreement with the experiments.
NASA Astrophysics Data System (ADS)
Zhang, Hai-Qiang; Yuan, Sha-Sha; Wang, Yue
2016-05-01
In this paper, the generalized Darboux transformation for the coherently-coupled nonlinear Schrödinger (CCNLS) system is constructed in terms of determinant representations. Based on the Nth-iterated formula, the vector bright soliton solution and vector rogue wave solution are systematically derived under the nonvanishing background. The general first-order vector rogue wave solution can admit many different fundamental patterns including eye-shaped and four-petaled rogue waves. It is believed that there are many more abundant patterns for high order vector rogue waves in CCNLS system.
Ocean rogue waves and their phase space dynamics in the limit of a linear interference model
NASA Astrophysics Data System (ADS)
Birkholz, Simon; Brée, Carsten; Veselić, Ivan; Demircan, Ayhan; Steinmeyer, Günter
2016-10-01
We reanalyse the probability for formation of extreme waves using the simple model of linear interference of a finite number of elementary waves with fixed amplitude and random phase fluctuations. Under these model assumptions no rogue waves appear when less than 10 elementary waves interfere with each other. Above this threshold rogue wave formation becomes increasingly likely, with appearance frequencies that may even exceed long-term observations by an order of magnitude. For estimation of the effective number of interfering waves, we suggest the Grassberger-Procaccia dimensional analysis of individual time series. For the ocean system, it is further shown that the resulting phase space dimension may vary, such that the threshold for rogue wave formation is not always reached. Time series analysis as well as the appearance of particular focusing wind conditions may enable an effective forecast of such rogue-wave prone situations. In particular, extracting the dimension from ocean time series allows much more specific estimation of the rogue wave probability.
Ocean rogue waves and their phase space dynamics in the limit of a linear interference model
Birkholz, Simon; Brée, Carsten; Veselić, Ivan; Demircan, Ayhan; Steinmeyer, Günter
2016-01-01
We reanalyse the probability for formation of extreme waves using the simple model of linear interference of a finite number of elementary waves with fixed amplitude and random phase fluctuations. Under these model assumptions no rogue waves appear when less than 10 elementary waves interfere with each other. Above this threshold rogue wave formation becomes increasingly likely, with appearance frequencies that may even exceed long-term observations by an order of magnitude. For estimation of the effective number of interfering waves, we suggest the Grassberger-Procaccia dimensional analysis of individual time series. For the ocean system, it is further shown that the resulting phase space dimension may vary, such that the threshold for rogue wave formation is not always reached. Time series analysis as well as the appearance of particular focusing wind conditions may enable an effective forecast of such rogue-wave prone situations. In particular, extracting the dimension from ocean time series allows much more specific estimation of the rogue wave probability. PMID:27731411
Ocean rogue waves and their phase space dynamics in the limit of a linear interference model.
Birkholz, Simon; Brée, Carsten; Veselić, Ivan; Demircan, Ayhan; Steinmeyer, Günter
2016-10-12
We reanalyse the probability for formation of extreme waves using the simple model of linear interference of a finite number of elementary waves with fixed amplitude and random phase fluctuations. Under these model assumptions no rogue waves appear when less than 10 elementary waves interfere with each other. Above this threshold rogue wave formation becomes increasingly likely, with appearance frequencies that may even exceed long-term observations by an order of magnitude. For estimation of the effective number of interfering waves, we suggest the Grassberger-Procaccia dimensional analysis of individual time series. For the ocean system, it is further shown that the resulting phase space dimension may vary, such that the threshold for rogue wave formation is not always reached. Time series analysis as well as the appearance of particular focusing wind conditions may enable an effective forecast of such rogue-wave prone situations. In particular, extracting the dimension from ocean time series allows much more specific estimation of the rogue wave probability.
Ion-acoustic super rogue waves in ultracold neutral plasmas with nonthermal electrons
El-Tantawy, S. A.; El-Bedwehy, N. A.; El-Labany, S. K.
2013-07-15
The ion-acoustic rogue waves in ultracold neutral plasmas consisting of ion fluid and nonthermal electrons are reported. A reductive perturbation method is used to obtain a nonlinear Schrödinger equation for describing the system and the modulation instability of the ion-acoustic wave is analyzed. The critical wave number k{sub c}, which indicates where the modulational instability sets in, has been determined. Moreover, the possible region for the ion-acoustic rogue waves to exist is defined precisely. The effects of the nonthermal parameter β and the ions effective temperature ratio σ{sub *} on the critical wave number k{sub c} are studied. It is found that there are two critical wave numbers in our plasma system. For low wave number, increasing β would lead to cringe k{sub c} until β approaches to its critical value β{sub c}, then further increase of β beyond β{sub c} would enhance the values of k{sub c}. For large wave numbers, the increase of β would lead to a decrease of k{sub c}. However, increasing σ{sub *} would lead to the reduction of k{sub c} for all values of the wave number. The dependence of the rogue waves profile on the plasma parameters is numerically examined. It is found that the rogue wave amplitudes have complex behavior with increasing β. Furthermore, the enhancement of σ{sub *} and the carrier wave number k reduces the rogue wave amplitude. It is noticed that near to the critical wave number, the rogue wave amplitude becomes high, but it shrinks whenever we stepped away from k{sub c}. The implications of our results in laboratory ultracold neutral plasma experiments are briefly discussed.
NASA Astrophysics Data System (ADS)
Sun, Wen-Rong; Tian, Bo; Xie, Xi-Yang; Chai, Jun; Jiang, Yan
2016-10-01
High-order rogue waves of the coupled nonlinear Schrödinger equations with negative coherent coupling, which describe the propagation of orthogonally polarized optical waves in an isotropic medium, are reported in this paper. Key point lies in the introduction of a limit process in the Darboux transformation, with which we obtain a family of the first- and second-order rational solutions for the purpose of modelling the rogue waves. We observe that the double-hump rogue wave in the course of evolution turns into the one-hump rogue wave, and that the dark rogue wave with four valleys in the course of evolution turns into the bright rogue wave. It is found that the second-order rogue wave can split up, giving birth to the multiple rogue waves.
Dust ion-acoustic rogue waves in a three-species ultracold quantum dusty plasmas
Sun, Wen-Rong; Tian, Bo Liu, Rong-Xiang; Liu, De-Yin
2014-10-15
Dust ion-acoustic (DIA) rogue waves are reported for a three-component ultracold quantum dusty plasma comprised of inertialess electrons, inertial ions, and negatively charged immobile dust particles. The nonlinear Schrödinger (NLS) equation appears for the low frequency limit. Modulation instability (MI) of the DIA waves is analyzed. Influence of the modulation wave number, ion-to-electron Fermi temperature ratio ρ and dust-to-ion background density ratio N{sub d} on the MI growth rate is discussed. The first- and second-order DIA rogue-wave solutions of the NLS equation are examined numerically. It is found that the enhancement of N{sub d} and carrier wave number can increase the envelope rogue-wave amplitudes. However, the increase of ρ reduces the envelope rogue-wave amplitudes. - Highlights: • The nonlinear Schrödinger equation is derived for the low frequency limit. • Modulational instability growth rate is discussed. • The first- and second-order dust ion-acoustic rogue waves are examined numerically.
Decay of capillary wave turbulence.
Deike, Luc; Berhanu, Michael; Falcon, Eric
2012-06-01
We report on the observation of freely decaying capillary wave turbulence on the surface of a fluid. The capillary wave turbulence spectrum decay is found to be self-similar in time with the same power law exponent as the one found in the stationary regime, in agreement with weak turbulence predictions. The amplitude of all Fourier modes are found to decrease exponentially with time at the same damping rate. The longest wavelengths involved in the system are shown to be damped by a viscous surface boundary layer. These long waves play the role of an energy source during the decay that sustains nonlinear interactions to keep capillary waves in a wave turbulent state.
On a plasma having nonextensive electrons and positrons: Rogue and solitary wave propagation
El-Awady, E. I.; Moslem, W. M.
2011-08-15
Generation of nonlinear ion-acoustic waves in a plasma having nonextensive electrons and positrons has been studied. Two wave modes existing in such plasma are considered, namely solitary and rogue waves. The reductive perturbation method is used to obtain a Korteweg-de Vries equation describing the system. The latter admits solitary wave pulses, while the dynamics of the modulationally unstable wave packets described by the Korteweg-de Vries equation gives rise to the formation of rogue excitation that is described by a nonlinear Schroedinger equation. The dependence of both solitary and rogue waves profiles on the nonextensive parameter, positron-to-ion concentration ratio, electron-to-positron temperature ratio, and ion-to-electron temperature ratio are investigated numerically. The results from this work are expected to contribute to the in-depth understanding of the nonlinear excitations that may appear in nonextensive astrophysical plasma environments, such as galactic clusters, interstellar medium, etc.
Rogue-wave bullets in a composite (2+1)D nonlinear medium.
Chen, Shihua; Soto-Crespo, Jose M; Baronio, Fabio; Grelu, Philippe; Mihalache, Dumitru
2016-07-11
We show that nonlinear wave packets localized in two dimensions with characteristic rogue wave profiles can propagate in a third dimension with significant stability. This unique behavior makes these waves analogous to light bullets, with the additional feature that they propagate on a finite background. Bulletlike rogue-wave singlet and triplet are derived analytically from a composite (2+1)D nonlinear wave equation. The latter can be interpreted as the combination of two integrable (1+1)D models expressed in different dimensions, namely, the Hirota equation and the complex modified Korteweg-de Vries equation. Numerical simulations confirm that the generation of rogue-wave bullets can be observed in the presence of spontaneous modulation instability activated by quantum noise.
Rogue wave triplets in an ion-beam dusty plasma with superthermal electrons and negative ions
NASA Astrophysics Data System (ADS)
Guo, Shimin; Mei, Liquan; Shi, Weijuan
2013-11-01
A new dust ion-acoustic wave structure called ‘Rogue wave triplets’ is investigated in an unmagnetized plasma consisting of stationary negatively charged dust grains, charged positive and negative ions, and electrons obeying kappa distribution, which is penetrated by an ion beam. The reductive perturbation theory is used to derive the nonlinear Schrödinger equation governing the dynamics as well as the modulation of wave packets. The rogue wave triplets which are composed of three separate Peregrine breathers can be generated in the modulation instability region. It has been suggested that a laboratory experiment be performed to test the theory presented here.
Ion-acoustic rogue waves in magnetized solar wind plasma with nonextensive electrons
NASA Astrophysics Data System (ADS)
Bacha, Mustapha; Gougam, Leila Ait; Tribeche, Mouloud
2017-01-01
Ion-acoustic rogue waves are investigated in a two-component magnetized solar wind plasma, composed of positively charged fluid ions, as well as nonextensive electrons. Typical solar wind plasmas parameters are used. It is shown that the wave number domain for the onset of ion-acoustic modulational instability enlarges as the electrons evolve towards their thermal equilibrium. Interestingly, we show that as the solar wind plasma expands far out from the sun, the wave amplitude increases and the IA rogue wave concentrates therefore a significant amount of energy. Our investigation may be of wide relevance to astronomers and space scientists working on the solar wind and interstellar plasmas.
Ion acoustic kinetic Alfvén rogue waves in two temperature electrons superthermal plasmas
NASA Astrophysics Data System (ADS)
Kaur, Nimardeep; Saini, N. S.
2016-10-01
The propagation properties of ion acoustic kinetic Alfvén (IAKA) solitary and rogue waves have been investigated in two temperature electrons magnetized superthermal plasma in the presence of dust impurity. A nonlinear analysis is carried out to derive the Korteweg-de Vries (KdV) equation using the reductive perturbation method (RPM) describing the evolution of solitary waves. The effect of various plasma parameters on the characteristics of the IAKA solitary waves is studied. The dynamics of ion acoustic kinetic Alfvén rogue waves (IAKARWs) are also studied by transforming the KdV equation into nonlinear Schrödinger (NLS) equation. The characteristics of rogue wave profile under the influence of various plasma parameters (κc, μc, σ , θ) are examined numerically by using the data of Saturn's magnetosphere (Schippers et al. 2008; Sakai et al. 2013).
Rogue wave variational modelling through the interaction of two solitary waves
NASA Astrophysics Data System (ADS)
Gidel, Floriane; Bokhove, Onno
2016-04-01
The extreme and unexpected characteristics of Rogue waves have made them legendary for centuries. It is only on the 1st of January 1995 that these mariners' tales started to raise scientist's curiosity, when such a wave was recorded in the North Sea; a sudden wall of water hit the Draupner offshore platform, more than twice higher than the other waves, providing evidence of the existence of rogue or freak waves. Since then, studies have shown that these surface gravity waves of high amplitude (at least twice the height of the other sea waves [Dyste et al., 2008]) appear in non-linear dispersive water motion [Drazin and Johnson, 1989], at any depth, and have caused a lot of damage in recent years [Nikolkina and Didenkulova, 2011 ]. So far, most of the studies have tried to determine their probability of occurrence, but no conclusion has been achieved yet, which means that we are currently unenable to predict or avoid these monster waves. An accurate mathematical and numerical water-wave model would enable simulation and observation of this external forcing on boats and offshore structures and hence reduce their threat. In this work, we aim to model rogue waves through a soliton splash generated by the interaction of two solitons coming from different channels at a specific angle. Kodama indeed showed that one way to produce extreme waves is through the intersection of two solitary waves, or one solitary wave and its oblique reflection on a vertical wall [Yeh, Li and Kodama, 2010 ]. While he modelled Mach reflection from Kadomtsev-Petviashvili (KP) theory, we aim to model rogue waves from the three-dimensional potential flow equations and/or their asymptotic equivalent described by Benney and Luke [Benney and Luke, 1964]. These theories have the advantage to allow wave propagation in several directions, which is not the case with KP equations. The initial solitary waves are generated by removing a sluice gate in each channel. The equations are derived through a
Dudley, J M; Sarano, V; Dias, F
2013-06-20
The Hokusai woodcut entitled The great wave off Kanagawa has been interpreted as an unusually large storm wave, likely to be classed as a rogue wave, and possibly generated from nonlinear wave dynamics (J. H. E. Cartwright and H. Nakamura, Notes Rec. R. Soc.63, 119-135 (2009)). In this paper, we present a complementary discussion of this hypothesis, discussing in particular how linear and nonlinear mechanisms can both contribute to the emergence of rogue wave events. By making reference to the Great wave's simultaneous transverse and longitudinal localization, we show that the purely linear mechanism of directional focusing also predicts characteristics consistent with those of the Great wave. In addition, we discuss the properties of a particular rogue wave photographed on the open ocean in sub-Antarctic waters, which shows two-dimensional localization and breaking dynamics remarkably similar to Hokusai's depiction in the woodcut.
Magnetic rogue wave in a perpendicular anisotropic ferromagnetic nanowire with spin-transfer torque
NASA Astrophysics Data System (ADS)
Zhao, Fei; Li, Zai-Dong; Li, Qiu-Yan; Wen, Lin; Fu, Guangsheng; Liu, W. M.
2012-09-01
We present the current controlled motion of a dynamic soliton embedded in spin wave background in ferromagnetic nanowire. With the stronger breather character we get the novel magnetic rogue wave and clarify its formation mechanism. The generation of magnetic rogue wave mainly arises from the accumulation of energy and magnons toward to its central part. We also observe that the spin-polarized current can control the exchange rate of magnons between the envelope soliton and the background, and the critical current condition is obtained analytically. Even more interesting is that the spin-transfer torque plays the completely opposite role for the cases below and above the critical value.
NASA Astrophysics Data System (ADS)
Tsai, Ya-Yi; Tsai, Jun-Yi; I, Lin
2016-06-01
Rogue waves--rare uncertainly emerging localized events with large amplitudes--have been experimentally observed in many nonlinear wave phenomena, such as water waves, optical waves, second sound in superfluid He II (ref. ) and ion acoustic waves in plasmas. Past studies have mainly focused on one-dimensional (1D) wave behaviour through modulation instabilities, and to a lesser extent on higher-dimensional behaviour. The question whether rogue waves also exist in nonlinear 3D acoustic-type plasma waves, the kinetic origin of their formation and their correlation with surrounding 3D waveforms are unexplored fundamental issues. Here we report the direct experimental observation of dust acoustic rogue waves in dusty plasmas and construct a picture of 3D particle focusing by the surrounding tilted and ruptured wave crests, associated with the higher probability of low-amplitude holes for rogue-wave generation.
On the rogue waves propagation in non-Maxwellian complex space plasmas
El-Tantawy, S. A. El-Awady, E. I.; Tribeche, M. E-mail: mtribeche@usthb.dz
2015-11-15
The implications of the non-Maxwellian electron distributions (nonthermal/or suprathermal/or nonextensive distributions) are examined on the dust-ion acoustic (DIA) rogue/freak waves in a dusty warm plasma. Using a reductive perturbation technique, the basic set of fluid equations is reduced to a nonlinear Schrödinger equation. The latter is used to study the nonlinear evolution of modulationally unstable DIA wavepackets and to describe the rogue waves (RWs) propagation. Rogue waves are large-amplitude short-lived wave groups, routinely observed in space plasmas. The possible region for the rogue waves to exist is defined precisely for typical parameters of space plasmas. It is shown that the RWs strengthen for decreasing plasma nonthermality and increasing superthermality. For nonextensive electrons, the RWs amplitude exhibits a bit more complex behavior, depending on the entropic index q. Moreover, our numerical results reveal that the RWs exist with all values of the ion-to-electron temperature ratio σ for nonthermal and superthermal distributions and there is no limitation for the freak waves to propagate in both two distributions in the present plasma system. But, for nonextensive electron distribution, the bright- and dark-type waves can propagate in this case, which means that there is a limitation for the existence of freak waves. Our systematic investigation should be useful in understanding the properties of DIA solitary waves that may occur in non-Maxwellian space plasmas.
On the rogue waves propagation in non-Maxwellian complex space plasmas
NASA Astrophysics Data System (ADS)
El-Tantawy, S. A.; El-Awady, E. I.; Tribeche, M.
2015-11-01
The implications of the non-Maxwellian electron distributions (nonthermal/or suprathermal/or nonextensive distributions) are examined on the dust-ion acoustic (DIA) rogue/freak waves in a dusty warm plasma. Using a reductive perturbation technique, the basic set of fluid equations is reduced to a nonlinear Schrödinger equation. The latter is used to study the nonlinear evolution of modulationally unstable DIA wavepackets and to describe the rogue waves (RWs) propagation. Rogue waves are large-amplitude short-lived wave groups, routinely observed in space plasmas. The possible region for the rogue waves to exist is defined precisely for typical parameters of space plasmas. It is shown that the RWs strengthen for decreasing plasma nonthermality and increasing superthermality. For nonextensive electrons, the RWs amplitude exhibits a bit more complex behavior, depending on the entropic index q. Moreover, our numerical results reveal that the RWs exist with all values of the ion-to-electron temperature ratio σ for nonthermal and superthermal distributions and there is no limitation for the freak waves to propagate in both two distributions in the present plasma system. But, for nonextensive electron distribution, the bright- and dark-type waves can propagate in this case, which means that there is a limitation for the existence of freak waves. Our systematic investigation should be useful in understanding the properties of DIA solitary waves that may occur in non-Maxwellian space plasmas.
NASA Astrophysics Data System (ADS)
Wang, Yue-Yue; Dai, Chao-Qing
2012-08-01
With the help of the similarity transformation connected the variable-coefficient (3+1)-dimensional nonlinear Schrödinger equation with the standard nonlinear Schrödinger equation, we firstly obtain first-order and second-order rogue wave solutions. Then, we investigate the controllable behaviors of these rogue waves in the hyperbolic dispersion decreasing profile. Our results indicate that the integral relation between the accumulated time T and the real time t is the basis to realize the control and manipulation of propagation behaviors of rogue waves, such as sustainment and restraint. We can modulate the value To to achieve the sustained and restrained spatiotemporal rogue waves. Moreover, the controllability for position of sustainment and restraint for spatiotemporal rogue waves can also be realized by setting different values of X0.
NASA Astrophysics Data System (ADS)
Ling, Liming; Feng, Bao-Feng; Zhu, Zuonong
2016-07-01
In the present paper, we are concerned with the general analytic solutions to the complex short pulse (CSP) equation including soliton, breather and rogue wave solutions. With the aid of a generalized Darboux transformation, we construct the N-bright soliton solution in a compact determinant form, the N-breather solution including the Akhmediev breather and a general higher order rogue wave solution. The first and second order rogue wave solutions are given explicitly and analyzed. The asymptotic analysis is performed rigorously for both the N-soliton and the N-breather solutions. All three forms of the analytical solutions admit either smoothed-, cusped- or looped-type ones for the CSP equation depending on the parameters. It is noted that, due to the reciprocal (hodograph) transformation, the rogue wave solution to the CSP equation can be a smoothed, cusponed or a looped one, which is different from the rogue wave solution found so far.
Amplification of matter rogue waves and breathers in quasi-two-dimensional Bose-Einstein condensates
NASA Astrophysics Data System (ADS)
Manikandan, K.; Senthilvelan, M.; Kraenkel, R. A.
2016-02-01
We construct rogue wave and breather solutions of a quasi-two-dimensional Gross-Pitaevskii equation with a time-dependent interatomic interaction and external trap. We show that the trapping potential and an arbitrary functional parameter that present in the similarity transformation should satisfy a constraint for the considered equation to be integrable and yield the desired solutions. We consider two different forms of functional parameters and investigate how the density of the rogue wave and breather profiles vary with respect to these functional parameters. We also construct vector localized solutions of a two coupled quasi-two-dimensional Bose-Einstein condensate system. We then investigate how the vector localized density profiles modify in the constant density background with respect to the functional parameters. Our results may help to manipulate matter rogue waves experimentally in the two-dimensional Bose-Einstein condensate systems.
Classifying the hierarchy of nonlinear-Schrödinger-equation rogue-wave solutions.
Kedziora, David J; Ankiewicz, Adrian; Akhmediev, Nail
2013-07-01
We present a systematic classification for higher-order rogue-wave solutions of the nonlinear Schrödinger equation, constructed as the nonlinear superposition of first-order breathers via the recursive Darboux transformation scheme. This hierarchy is subdivided into structures that exhibit varying degrees of radial symmetry, all arising from independent degrees of freedom associated with physical translations of component breathers. We reveal the general rules required to produce these fundamental patterns. Consequently, we are able to extrapolate the general shape for rogue-wave solutions beyond order 6, at which point accuracy limitations due to current standards of numerical generation become non-negligible. Furthermore, we indicate how a large set of irregular rogue-wave solutions can be produced by hybridizing these fundamental structures.
Rogue wave modes for a derivative nonlinear Schrödinger model.
Chan, Hiu Ning; Chow, Kwok Wing; Kedziora, David Jacob; Grimshaw, Roger Hamilton James; Ding, Edwin
2014-03-01
Rogue waves in fluid dynamics and optical waveguides are unexpectedly large displacements from a background state, and occur in the nonlinear Schrödinger equation with positive linear dispersion in the regime of positive cubic nonlinearity. Rogue waves of a derivative nonlinear Schrödinger equation are calculated in this work as a long-wave limit of a breather (a pulsating mode), and can occur in the regime of negative cubic nonlinearity if a sufficiently strong self-steepening nonlinearity is also present. This critical magnitude is shown to be precisely the threshold for the onset of modulation instabilities of the background plane wave, providing a strong piece of evidence regarding the connection between a rogue wave and modulation instability. The maximum amplitude of the rogue wave is three times that of the background plane wave, a result identical to that of the Peregrine breather in the classical nonlinear Schrödinger equation model. This amplification ratio and the resulting spectral broadening arising from modulation instability correlate with recent experimental results of water waves. Numerical simulations in the regime of marginal stability are described.
Rogue waves for a system of coupled derivative nonlinear Schrödinger equations
NASA Astrophysics Data System (ADS)
Chan, Hiu Ning; Malomed, Boris; Chow, Kwok Wing
2015-11-01
Previous works in the literature on water waves have demonstrated that the fourth-order evolution of gravity waves in deep water will be governed by a higher order nonlinear Schrödinger equation. In the presence of two wave trains, the system is described by a higher order coupled nonlinear Schrödinger system. Through a gauge transformation, these evolution equations are reduced to a coupled derivative nonlinear Schrödinger system. The goal here is to study rogue waves, unexpectedly large displacements from an equilibrium position, through the Hirota bilinear transformation theoretically. The connections between the onset of rogue waves and modulation instability are investigated. The range of cubic nonlinearity allowing rogue wave formation is elucidated. Under a finite group velocity mismatch between the two components, the existence regime for rogue waves is extended as compared to the case with a single wave train. The amplification ratio of the amplitude can be higher than that of the single component nonlinear Schrödinger equation. Partial financial support has been provided by the Research Grants Council through contracts HKU711713E and HKU17200815.
Amplitude modulation of hydromagnetic waves and associated rogue waves in magnetoplasmas.
Sabry, R; Moslem, W M; Shukla, P K
2012-09-01
It is shown that the dynamics of amplitude-modulated compressional dispersive Alfvénic (CDA) waves in a collisional megnetoplasma is governed by a complex Ginzburg-Landau (CGL) equation. The nonlinear dispersion relation for the modulational instability of the CDA waves is derived and investigated numerically. It is found that the growth rate of the modulational instability decreases (increases) with the increase of the normalized electron-ion collision frequency α (the plasma β). The modulational instability criterion for the CGL equation is defined precisely and investigated numerically. The region of the modulational instability becomes narrower with the increase of α and β, indicating that the system dissipates the wave energy by collisions, and a stable CDA wave envelope packet in the form of a hole will be a dominant localized pulse. For a collisionless plasma, i.e., α=0, the CGL equation reduces to the standard nonlinear Schrödinger (NLS) equation. The latter is used to investigate the modulational (in)stability region for the CDA waves in a collisionless magnetoplasma. It is shown that, within unstable regions, a random set of nonlinearly interacting CDA perturbations leads to the formation of CDA rogue waves. In order to demonstrate that the characteristics of the CDA rogue waves are influenced by the plasma β, the relevant numerical analysis of the appropriate nonlinear solution of the NLS equation is presented. The application of our investigation to space and laboratory magnetoplasmas is discussed.
Modelling rogue waves through exact dynamical lump soliton controlled by ocean currents
Kundu, Anjan; Mukherjee, Abhik; Naskar, Tapan
2014-01-01
Rogue waves are extraordinarily high and steep isolated waves, which appear suddenly in a calm sea and disappear equally fast. However, though the rogue waves are localized surface waves, their theoretical models and experimental observations are available mostly in one dimension, with the majority of them admitting only limited and fixed amplitude and modular inclination of the wave. We propose two dimensions, exactly solvable nonlinear Schrödinger (NLS) equation derivable from the basic hydrodynamic equations and endowed with integrable structures. The proposed two-dimensional equation exhibits modulation instability and frequency correction induced by the nonlinear effect, with a directional preference, all of which can be determined through precise analytic result. The two-dimensional NLS equation allows also an exact lump soliton which can model a full-grown surface rogue wave with adjustable height and modular inclination. The lump soliton under the influence of an ocean current appears and disappears preceded by a hole state, with its dynamics controlled by the current term. These desirable properties make our exact model promising for describing ocean rogue waves. PMID:24711719
Electron-acoustic rogue waves in a plasma with Tribeche-Tsallis-Cairns distributed electrons
NASA Astrophysics Data System (ADS)
Merriche, Abderrzak; Tribeche, Mouloud
2017-01-01
The problem of electron-acoustic (EA) rogue waves in a plasma consisting of fluid cold electrons, nonthermal nonextensive electrons and stationary ions, is addressed. A standard multiple scale method has been carried out to derive a nonlinear Schrödinger-like equation. The coefficients of dispersion and nonlinearity depend on the nonextensive and nonthermal parameters. The EA wave stability is analyzed. Interestingly, it is found that the wave number threshold, above which the EA wave modulational instability (MI) sets in, increases as the nonextensive parameter increases. As the nonthermal character of the electrons increases, the MI occurs at large wavelength. Moreover, it is shown that as the nonextensive parameter increases, the EA rogue wave pulse grows while its width is narrowed. The amplitude of the EA rogue wave decreases with an increase of the number of energetic electrons. In the absence of nonthermal electrons, the nonextensive effects are more perceptible and more noticeable. In view of the crucial importance of rogue waves, our results can contribute to the understanding of localized electrostatic envelope excitations and underlying physical processes, that may occur in space as well as in laboratory plasmas.
Modelling rogue waves through exact dynamical lump soliton controlled by ocean currents.
Kundu, Anjan; Mukherjee, Abhik; Naskar, Tapan
2014-04-08
Rogue waves are extraordinarily high and steep isolated waves, which appear suddenly in a calm sea and disappear equally fast. However, though the rogue waves are localized surface waves, their theoretical models and experimental observations are available mostly in one dimension, with the majority of them admitting only limited and fixed amplitude and modular inclination of the wave. We propose two dimensions, exactly solvable nonlinear Schrödinger (NLS) equation derivable from the basic hydrodynamic equations and endowed with integrable structures. The proposed two-dimensional equation exhibits modulation instability and frequency correction induced by the nonlinear effect, with a directional preference, all of which can be determined through precise analytic result. The two-dimensional NLS equation allows also an exact lump soliton which can model a full-grown surface rogue wave with adjustable height and modular inclination. The lump soliton under the influence of an ocean current appears and disappears preceded by a hole state, with its dynamics controlled by the current term. These desirable properties make our exact model promising for describing ocean rogue waves.
Raman rogue waves in a partially mode-locked fiber laser.
Runge, Antoine F J; Aguergaray, Claude; Broderick, Neil G R; Erkintalo, Miro
2014-01-15
We report on an experimental study of spectral fluctuations induced by intracavity Raman conversion in a passively partially mode-locked, all-normal dispersion fiber laser. Specifically, we use dispersive Fourier transformation to measure single-shot spectra of Raman-induced noise-like pulses, demonstrating that for low cavity gain values Raman emission is sporadic and follows rogue-wave-like probability distributions, while a saturated regime with Gaussian statistics is obtained for high pump powers. Our experiments further reveal intracavity rogue waves originating from cascaded Raman dynamics.
Rogue wave solutions to the generalized nonlinear Schrödinger equation with variable coefficients.
Zhong, Wei-Ping; Belić, Milivoj R; Huang, Tingwen
2013-06-01
A similarity transformation is utilized to reduce the generalized nonlinear Schrödinger (NLS) equation with variable coefficients to the standard NLS equation with constant coefficients, whose rogue wave solutions are then transformed back into the solutions of the original equation. In this way, Ma breathers, the first- and second-order rogue wave solutions of the generalized equation, are constructed. Properties of a few specific solutions and controllability of their characteristics are discussed. The results obtained may raise the possibility of performing relevant experiments and achieving potential applications.
Breather and rogue wave solutions of a generalized nonlinear Schrödinger equation.
Wang, L H; Porsezian, K; He, J S
2013-05-01
In this paper, using the Darboux transformation, we demonstrate the generation of first-order breather and higher-order rogue waves from a generalized nonlinear Schrödinger equation with several higher-order nonlinear effects representing femtosecond pulse propagation through nonlinear silica fiber. The same nonlinear evolution equation can also describe the soliton-type nonlinear excitations in classical Heisenberg spin chain. Such solutions have a parameter γ(1), denoting the strength of the higher-order effects. From the numerical plots of the rational solutions, the compression effects of the breather and rogue waves produced by γ(1) are discussed in detail.
Rogue-wave-like statistics in ultrafast white-light continuum generation in sapphire.
Majus, D; Jukna, V; Pileckis, E; Valiulis, G; Dubietis, A
2011-08-15
We experimentally study the statistics of the white-light continuum generated by focusing of 130 fs, 800 nm pulses in a sapphire plate and show that the statistical distributions of the spectral intensity of the blue-shifted continuum components obey the extreme-value statistics. This rogue-wave-like behavior is detected only within a narrow input-pulse energy interval. By the use of numerical simulations, we show that the observed rogue-wave-like behavior is associated with pulse splitting and build-up of intense trailing pulse. The extreme events are thereafter suppressed by the intensity clamping.
Rogue wave triggered at a critical frequency of a nonlinear resonant medium
NASA Astrophysics Data System (ADS)
He, Jingsong; Xu, Shuwei; Porsezian, K.; Cheng, Yi; Dinda, P. Tchofo
2016-06-01
We consider a two-level atomic system interacting with an electromagnetic field controlled in amplitude and frequency by a high intensity laser. We show that the amplitude of the induced electric field admits an envelope profile corresponding to a breather soliton. We demonstrate that this soliton can propagate with any frequency shift with respect to that of the control laser, except a critical frequency, at which the system undergoes a structural discontinuity that transforms the breather in a rogue wave. A mechanism of generation of rogue waves by means of an intense laser field is thus revealed.
Rogue wave triggered at a critical frequency of a nonlinear resonant medium.
He, Jingsong; Xu, Shuwei; Porsezian, K; Cheng, Yi; Dinda, P Tchofo
2016-06-01
We consider a two-level atomic system interacting with an electromagnetic field controlled in amplitude and frequency by a high intensity laser. We show that the amplitude of the induced electric field admits an envelope profile corresponding to a breather soliton. We demonstrate that this soliton can propagate with any frequency shift with respect to that of the control laser, except a critical frequency, at which the system undergoes a structural discontinuity that transforms the breather in a rogue wave. A mechanism of generation of rogue waves by means of an intense laser field is thus revealed.
Rogue-wave solutions of a three-component coupled nonlinear Schrödinger equation.
Zhao, Li-Chen; Liu, Jie
2013-01-01
We investigate rogue-wave solutions in a three-component coupled nonlinear Schrödinger equation. With certain requirements on the backgrounds of components, we construct a multi-rogue-wave solution that exhibits a structure like a four-petaled flower in temporal-spatial distribution, in contrast to the eye-shaped structure in one-component or two-component systems. The results could be of interest in such diverse fields as Bose-Einstein condensates, nonlinear fibers, and superfluids.
Dark three-sister rogue waves in normally dispersive optical fibers with random birefringence.
Chen, Shihua; Soto-Crespo, Jose M; Grelu, Philippe
2014-11-03
We investigate dark rogue wave dynamics in normally dispersive birefringent optical fibers, based on the exact rational solutions of the coupled nonlinear Schrödinger equations. Analytical solutions are derived up to the second order via a nonrecursive Darboux transformation method. Vector dark "three-sister" rogue waves as well as their existence conditions are demonstrated. The robustness against small perturbations is numerically confirmed in spite of the onset of modulational instability, offering the possibility to observe such extreme events in normal optical fibers with random birefringence, or in other Manakov-type vector nonlinear media.
NASA Astrophysics Data System (ADS)
Su, Chuan-Qi; Gao, Yi-Tian; Xue, Long; Yu, Xin
2015-10-01
Under investigation in this article is a higher-order nonlinear Schrödinger-Maxwell-Bloch (HNLS-MB) system for the optical pulse propagation in an erbium-doped fiber. Lax pair, Darboux transformation (DT), and generalised DT for the HNLS-MB system are constructed. Soliton solutions and rogue wave solutions are derived based on the DT and generalised DT, respectively. Properties of the solitons and rogue waves are graphically presented. The third-order dispersion parameter, fourth-order dispersion parameter, and frequency detuning all influence the characteristic lines and velocities of the solitons. The frequency detuning also affects the amplitudes of solitons. The separating function has no effect on the properties of the first-order rogue waves, except for the locations where the first-order rogue waves appear. The third-order dispersion parameter affects the propagation directions and shapes of the rogue waves. The frequency detuning influences the rogue-wave types of the module for the measure of polarization of resonant medium and the extant population inversion. The fourth-order dispersion parameter impacts the rogue-wave interaction range and also has an effect on the rogue-wave type of the extant population inversion. The value of separating function affects the spatial-temporal separation of constituting elementary rogue waves for the second-order and third-order rogue waves. The second-order and third-order rogue waves can exhibit the triangular and pentagon patterns under different choices of separating functions.
Vector rogue waves and dark-bright boomeronic solitons in autonomous and nonautonomous settings.
Mareeswaran, R Babu; Charalampidis, E G; Kanna, T; Kevrekidis, P G; Frantzeskakis, D J
2014-10-01
In this work we consider the dynamics of vector rogue waves and dark-bright solitons in two-component nonlinear Schrödinger equations with various physically motivated time-dependent nonlinearity coefficients, as well as spatiotemporally dependent potentials. A similarity transformation is utilized to convert the system into the integrable Manakov system and subsequently the vector rogue and dark-bright boomeronlike soliton solutions of the latter are converted back into ones of the original nonautonomous model. Using direct numerical simulations we find that, in most cases, the rogue wave formation is rapidly followed by a modulational instability that leads to the emergence of an expanding soliton train. Scenarios different than this generic phenomenology are also reported.
Magnetic rogue wave in a perpendicular anisotropic ferromagnetic nanowire with spin-transfer torque
Zhao, Fei; Li, Zai-Dong; Li, Qiu-Yan; Wen, Lin; Fu, Guangsheng; Liu, W.M.
2012-09-15
We present the current controlled motion of a dynamic soliton embedded in spin wave background in ferromagnetic nanowire. With the stronger breather character we get the novel magnetic rogue wave and clarify its formation mechanism. The generation of magnetic rogue wave mainly arises from the accumulation of energy and magnons toward to its central part. We also observe that the spin-polarized current can control the exchange rate of magnons between the envelope soliton and the background, and the critical current condition is obtained analytically. Even more interesting is that the spin-transfer torque plays the completely opposite role for the cases below and above the critical value. - Highlights: Black-Right-Pointing-Pointer We get the current controlled motion of a dynamic soliton embedded in spin wave background. Black-Right-Pointing-Pointer We get the novel magnetic rogue wave and clarify its formation mechanism. Black-Right-Pointing-Pointer The generation of magnetic rogue wave arises from the accumulation of energy and magnons. Black-Right-Pointing-Pointer The spin-polarized current controls exchange rate of magnons between the envelope soliton and the background. Black-Right-Pointing-Pointer The spin-transfer torque plays the completely opposite role below and above the critical value.
Nonlinear random optical waves: Integrable turbulence, rogue waves and intermittency
NASA Astrophysics Data System (ADS)
Randoux, Stéphane; Walczak, Pierre; Onorato, Miguel; Suret, Pierre
2016-10-01
We examine the general question of statistical changes experienced by ensembles of nonlinear random waves propagating in systems ruled by integrable equations. In our study that enters within the framework of integrable turbulence, we specifically focus on optical fiber systems accurately described by the integrable one-dimensional nonlinear Schrödinger equation. We consider random complex fields having a Gaussian statistics and an infinite extension at initial stage. We use numerical simulations with periodic boundary conditions and optical fiber experiments to investigate spectral and statistical changes experienced by nonlinear waves in focusing and in defocusing propagation regimes. As a result of nonlinear propagation, the power spectrum of the random wave broadens and takes exponential wings both in focusing and in defocusing regimes. Heavy-tailed deviations from Gaussian statistics are observed in focusing regime while low-tailed deviations from Gaussian statistics are observed in defocusing regime. After some transient evolution, the wave system is found to exhibit a statistically stationary state in which neither the probability density function of the wave field nor the spectrum changes with the evolution variable. Separating fluctuations of small scale from fluctuations of large scale both in focusing and defocusing regimes, we reveal the phenomenon of intermittency; i.e., small scales are characterized by large heavy-tailed deviations from Gaussian statistics, while the large ones are almost Gaussian.
Observation of a hierarchy of up to fifth-order rogue waves in a water tank.
Chabchoub, A; Hoffmann, N; Onorato, M; Slunyaev, A; Sergeeva, A; Pelinovsky, E; Akhmediev, N
2012-11-01
We present experimental observations of the hierarchy of rational breather solutions of the nonlinear Schrödinger equation (NLS) generated in a water wave tank. First, five breathers of the infinite hierarchy have been successfully generated, thus confirming the theoretical predictions of their existence. Breathers of orders higher than five appeared to be unstable relative to the wave-breaking effect of water waves. Due to the strong influence of the wave breaking and relatively small carrier steepness values of the experiment these results for the higher-order solutions do not directly explain the formation of giant oceanic rogue waves. However, our results are important in understanding the dynamics of rogue water waves and may initiate similar experiments in other nonlinear dispersive media such as fiber optics and plasma physics, where the wave propagation is governed by the NLS.
Influence of optical activity on rogue waves propagating in chiral optical fibers
NASA Astrophysics Data System (ADS)
Temgoua, D. D. Estelle; Kofane, T. C.
2016-06-01
We derive the nonlinear Schrödinger (NLS) equation in chiral optical fiber with right- and left-hand nonlinear polarization. We use the similarity transformation to reduce the generalized chiral NLS equation to the higher-order integrable Hirota equation. We present the first- and second-order rational solutions of the chiral NLS equation with variable and constant coefficients, based on the modified Darboux transformation method. For some specific set of parameters, the features of chiral optical rogue waves are analyzed from analytical results, showing the influence of optical activity on waves. We also generate the exact solutions of the two-component coupled nonlinear Schrödinger equations, which describe optical activity effects on the propagation of rogue waves, and their properties in linear and nonlinear coupling cases are investigated. The condition of modulation instability of the background reveals the existence of vector rogue waves and the number of stable and unstable branches. Controllability of chiral optical rogue waves is examined by numerical simulations and may bring potential applications in optical fibers and in many other physical systems.
Influence of optical activity on rogue waves propagating in chiral optical fibers.
Temgoua, D D Estelle; Kofane, T C
2016-06-01
We derive the nonlinear Schrödinger (NLS) equation in chiral optical fiber with right- and left-hand nonlinear polarization. We use the similarity transformation to reduce the generalized chiral NLS equation to the higher-order integrable Hirota equation. We present the first- and second-order rational solutions of the chiral NLS equation with variable and constant coefficients, based on the modified Darboux transformation method. For some specific set of parameters, the features of chiral optical rogue waves are analyzed from analytical results, showing the influence of optical activity on waves. We also generate the exact solutions of the two-component coupled nonlinear Schrödinger equations, which describe optical activity effects on the propagation of rogue waves, and their properties in linear and nonlinear coupling cases are investigated. The condition of modulation instability of the background reveals the existence of vector rogue waves and the number of stable and unstable branches. Controllability of chiral optical rogue waves is examined by numerical simulations and may bring potential applications in optical fibers and in many other physical systems.
Rogue wave formation under the action of quasi-stationary pressure
NASA Astrophysics Data System (ADS)
Abrashkin, A. A.; Oshmarina, O. E.
2016-05-01
The process of rogue wave formation on deep water is considered. A wave of extreme amplitude is born against the background of uniform waves (Gerstner waves) under the action of external pressure on free surface. The pressure distribution has a form of a quasi-stationary "pit". The fluid motion is supposed to be a vortex one and is described by an exact solution of equations of 2D hydrodynamics for an ideal fluid in Lagrangian coordinates. Liquid particles are moving around circumferences of different radii in the absence of drift flow. Values of amplitude and wave steepness optimal for rogue wave formation are found numerically. The influence of vorticity distribution and pressure drop on parameters of the fluid is investigated.
Two-dimensional linear and nonlinear Talbot effect from rogue waves.
Zhang, Yiqi; Belić, Milivoj R; Petrović, Milan S; Zheng, Huaibin; Chen, Haixia; Li, Changbiao; Lu, Keqing; Zhang, Yanpeng
2015-03-01
We introduce two-dimensional (2D) linear and nonlinear Talbot effects. They are produced by propagating periodic 2D diffraction patterns and can be visualized as 3D stacks of Talbot carpets. The nonlinear Talbot effect originates from 2D rogue waves and forms in a bulk 3D nonlinear medium. The recurrences of an input rogue wave are observed at the Talbot length and at the half-Talbot length, with a π phase shift; no other recurrences are observed. Differing from the nonlinear Talbot effect, the linear effect displays the usual fractional Talbot images as well. We also find that the smaller the period of incident rogue waves, the shorter the Talbot length. Increasing the beam intensity increases the Talbot length, but above a threshold this leads to a catastrophic self-focusing phenomenon which destroys the effect. We also find that the Talbot recurrence can be viewed as a self-Fourier transform of the initial periodic beam that is automatically performed during propagation. In particular, linear Talbot effect can be viewed as a fractional self-Fourier transform, whereas the nonlinear Talbot effect can be viewed as the regular self-Fourier transform. Numerical simulations demonstrate that the rogue-wave initial condition is sufficient but not necessary for the observation of the effect. It may also be observed from other periodic inputs, provided they are set on a finite background. The 2D effect may find utility in the production of 3D photonic crystals.
Kinetic Alfvén solitary and rogue waves in superthermal plasmas
Bains, A. S.; Li, Bo Xia, Li-Dong
2014-03-15
We investigate the small but finite amplitude solitary Kinetic Alfvén waves (KAWs) in low β plasmas with superthermal electrons modeled by a kappa-type distribution. A nonlinear Korteweg-de Vries (KdV) equation describing the evolution of KAWs is derived by using the standard reductive perturbation method. Examining the dependence of the nonlinear and dispersion coefficients of the KdV equation on the superthermal parameter κ, plasma β, and obliqueness of propagation, we show that these parameters may change substantially the shape and size of solitary KAW pulses. Only sub-Alfvénic, compressive solitons are supported. We then extend the study to examine kinetic Alfvén rogue waves by deriving a nonlinear Schrödinger equation from the KdV equation. Rational solutions that form rogue wave envelopes are obtained. We examine how the behavior of rogue waves depends on the plasma parameters in question, finding that the rogue envelopes are lowered with increasing electron superthermality whereas the opposite is true when the plasma β increases. The findings of this study may find applications to low β plasmas in astrophysical environments where particles are superthermally distributed.
Ankiewicz, Adrian; Wang, Yan; Wabnitz, Stefan; Akhmediev, Nail
2014-01-01
We consider an extended nonlinear Schrödinger equation with higher-order odd (third order) and even (fourth order) terms with variable coefficients. The resulting equation has soliton solutions and approximate rogue wave solutions. We present these solutions up to second order. Moreover, specific constraints on the parameters of higher-order terms provide integrability of the resulting equation, providing a corresponding Lax pair. Particular cases of this equation are the Hirota and the Lakshmanan-Porsezian-Daniel equations. The resulting integrable equation admits exact rogue wave solutions. In particular cases, mentioned above, these solutions are reduced to the rogue wave solutions of the corresponding equations.
Capillary wave spectroscopy on ferrofluids
NASA Astrophysics Data System (ADS)
Patzke, J.; Rathke, B.; Will, S.
2007-12-01
We investigate the magnetoviscous effect in ferrofluids by Capillary Wave Spectroscopy (CWS, Surface Light Scattering). This technique probes a specific mode of thermally excited surface waves giving information on surface tension and viscosity. In ferrofluids we detect a transition from propagating surface modes to overdamped ones depending on the particle concentration and strength and the orientation of an externally applied magnetic field. We interprete this effect as caused by an increase of the liquid viscosity with an increasing particle concentration and field-strength. Changing the relative orientation of the scattering vector and magnetic field shows that the viscous properties of ferrofluids in a magnetic field are anisotropic. Figs 8, Refs 12.
Mechanical energy fluctuations in granular chains: the possibility of rogue fluctuations or waves.
Han, Ding; Westley, Matthew; Sen, Surajit
2014-09-01
The existence of rogue or freak waves in the ocean has been known for some time. They have been reported in the context of optical lattices and the financial market. We ask whether such waves are generic to late time behavior in nonlinear systems. In that vein, we examine the dynamics of an alignment of spherical elastic beads held within fixed, rigid walls at zero precompression when they are subjected to sufficiently rich initial conditions. Here we define such waves generically as unusually large energy fluctuations that sustain for short periods of time. Our simulations suggest that such unusually large fluctuations ("hot spots") and occasional series of such fluctuations through space and time ("rogue fluctuations") are likely to exist in the late time dynamics of the granular chain system at zero dissipation. We show that while hot spots are common in late time evolution, rogue fluctuations are seen in purely nonlinear systems (i.e., no precompression) at late enough times. We next show that the number of such fluctuations grows exponentially with increasing nonlinearity whereas rogue fluctuations decrease superexponentially with increasing precompression. Dissipation-free granular alignment systems may be possible to realize as integrated circuits and hence our observations may potentially be testable in the laboratory.
Mechanical energy fluctuations in granular chains: The possibility of rogue fluctuations or waves
NASA Astrophysics Data System (ADS)
Han, Ding; Westley, Matthew; Sen, Surajit
2014-09-01
The existence of rogue or freak waves in the ocean has been known for some time. They have been reported in the context of optical lattices and the financial market. We ask whether such waves are generic to late time behavior in nonlinear systems. In that vein, we examine the dynamics of an alignment of spherical elastic beads held within fixed, rigid walls at zero precompression when they are subjected to sufficiently rich initial conditions. Here we define such waves generically as unusually large energy fluctuations that sustain for short periods of time. Our simulations suggest that such unusually large fluctuations ("hot spots") and occasional series of such fluctuations through space and time ("rogue fluctuations") are likely to exist in the late time dynamics of the granular chain system at zero dissipation. We show that while hot spots are common in late time evolution, rogue fluctuations are seen in purely nonlinear systems (i.e., no precompression) at late enough times. We next show that the number of such fluctuations grows exponentially with increasing nonlinearity whereas rogue fluctuations decrease superexponentially with increasing precompression. Dissipation-free granular alignment systems may be possible to realize as integrated circuits and hence our observations may potentially be testable in the laboratory.
Semirational and symbiotic self-similar rogue waves in a (2+1)-dimensional graded-index waveguide
NASA Astrophysics Data System (ADS)
De, Kanchan Kumar; Soloman Raju, Thokala; Kumar, C. N.; Panigrahi, Prasanta K.
2016-07-01
We have investigated the (?)-dimensional variable coefficient-coupled nonlinear Schrödinger equation (vc-CNLSE) in a graded-index waveguide. Similarity transformations are used to convert the vc-CNLSE into constant coefficient CNLSE. Under certain functional constraints we could extract semirational, multi-parametric solution of the associated Manakov system. This family of solutions include known Peregrine soliton, mixture of either bright soliton and rogue wave or dark soliton and rogue wave or breather and rogue wave. Under a distinct set of self-phase modulation and cross-phase modulation coefficients we could establish symbiotic existence of different soliton pairs as solutions. These soliton pairs may constitute of one bright and a dark soliton, two bright solitons or two dark solitons. Finally, when two wave components are directly proportional, we find bright and dark similaritons, self-similar breathers, and rogue waves as different solutions.
Rogue waves for a coupled nonlinear Schrödinger system in a multi-mode fibre
NASA Astrophysics Data System (ADS)
Li, Hui-Min; Tian, Bo; Wang, Deng-Shan; Sun, Wen-Rong; Xie, Xi-Yang; Liu, Lei
2016-10-01
In this paper, we investigate the rogue waves for an integrable coupled nonlinear Schrödinger (CNLS) system with the self-phase modulation, cross-phase modulation and four-wave mixing term, which can describe the propagation of optical waves in a multi-mode fibre. We construct a generalized Darboux transformation (GDT) for the CNLS system and find a gauge transformation which converts the Lax pair into the constant-coefficient differential equations. Solving those equations, we can obtain the vector solutions of the Lax pair. Using the GDT, we derive an iterative formula for the nth-order rogue-wave solutions for the CNLS system. We derive the first- and second-order rogue-wave solutions for the CNLS system and analyse the profiles for the rogue waves with respect to the self-phase modulation term a, cross-phase modulation term c and four-wave mixing term b, respectively. The rogue waves become thinner with the increase in the value for the real part of b and that the effect of a or c on the rogue waves is the same as the one of the real part of b.
NASA Astrophysics Data System (ADS)
Li, Jin Hua; Chan, Hiu Ning; Chiang, Kin Seng; Chow, Kwok Wing
2015-11-01
Breathers and rogue waves of special coupled nonlinear Schrödinger systems (the Manakov equations) are studied analytically. These systems model the orthogonal polarization modes in an optical fiber with randomly varying birefringence. Studies earlier in the literature had shown that rogue waves can occur in these Manakov systems with dispersion and nonlinearity of opposite signs, and that the criterion for the existence of rogue waves correlates closely with the onset of modulation instability. In the present work the Hirota bilinear transform is employed to calculate the breathers (pulsating modes), and rogue waves are obtained as a long wave limit of such breathers. In terms of wave profiles, a 'black' rogue wave (intensity dropping to zero) and the transition to a four-petal configuration are elucidated analytically. Sufficiently strong modulation instabilities of the background may overwhelm or mask the development of the rogue waves, and such thresholds are correlated to actual physical properties of optical fibers. Numerical simulations on the evolution of breathers are performed to verify the prediction of the analytical formulations.
Two-dimensional cylindrical ion-acoustic solitary and rogue waves in ultrarelativistic plasmas
Ata-ur-Rahman; Ali, S.; Moslem, W. M.; Mushtaq, A.
2013-07-15
The propagation of ion-acoustic (IA) solitary and rogue waves is investigated in a two-dimensional ultrarelativistic degenerate warm dense plasma. By using the reductive perturbation technique, the cylindrical Kadomtsev–Petviashvili (KP) equation is derived, which can be further transformed into a Korteweg–de Vries (KdV) equation. The latter admits a solitary wave solution. However, when the frequency of the carrier wave is much smaller than the ion plasma frequency, the KdV equation can be transferred to a nonlinear Schrödinger equation to study the nonlinear evolution of modulationally unstable modified IA wavepackets. The propagation characteristics of the IA solitary and rogue waves are strongly influenced by the variation of different plasma parameters in an ultrarelativistic degenerate dense plasma. The present results might be helpful to understand the nonlinear electrostatic excitations in astrophysical degenerate dense plasmas.
NASA Astrophysics Data System (ADS)
Gupta, Samit Kumar; Sarma, Amarendra K.
2016-07-01
In this work, we have studied the peregrine rogue wave dynamics, with a solitons on finite background (SFB) ansatz, in the recently proposed (Ablowitz and Musslimani, (2013) [31]) continuous nonlinear Schrödinger system with parity-time symmetric Kerr nonlinearity. We have found that the continuous nonlinear Schrödinger system with PT-symmetric nonlinearity also admits Peregrine soliton solution. Motivated by the fact that Peregrine solitons are regarded as prototypical solutions of rogue waves, we have studied Peregrine rogue wave dynamics in the c-PTNLSE model. Upon numerical computation, we observe the appearance of low-intense Kuznetsov-Ma (KM) soliton trains in the absence of transverse shift (unbroken PT-symmetry) and well-localized high-intense Peregrine rogue waves in the presence of transverse shift (broken PT-symmetry) in a definite parametric regime.
Analytical solutions and rogue waves in (3+1)-dimensional nonlinear Schrödinger equation
NASA Astrophysics Data System (ADS)
Ma, Zheng-Yi; Ma, Song-Hua
2012-03-01
Analytical solutions in terms of rational-like functions are presented for a (3+1)-dimensional nonlinear Schrödinger equation with time-varying coefficients and a harmonica potential using the similarity transformation and a direct ansatz. Several free functions of time t are involved to generate abundant wave structures. Three types of elementary functions are chosen to exhibit the corresponding nonlinear rogue wave propagations.
Solitons and rogue waves for a nonlinear system in the geophysical fluid
NASA Astrophysics Data System (ADS)
Xie, Xi-Yang; Tian, Bo; Liu, Lei; Wu, Xiao-Yu; Jiang, Yan
2016-12-01
In this paper, we investigate a nonlinear system, which describes the marginally unstable baroclinic wave packets in the geophysical fluid. Based on the symbolic computation and Hirota method, bright one- and two-soliton solutions for such a system are derived. Propagation and collisions of the solitons are graphically shown and discussed with β, which reflects the collision between the wave packet and mean flow, α, which measures the state of the basic flow, and group velocity γ. γ is observed to affect the amplitudes of the solitons, and α can influence the solitons’ traveling directions. By virtue of the generalized Darboux transformation, the first- and second-order rogue-wave solutions are derived. Properties of the first- and second-order rogue waves are graphically presented and analyzed: The first-order rogue waves are shown in the figures. α has no effects on A, which is the amplitude of the wave packet, but with the increase of α, amplitude of B, which is a quantity measuring the correction of the basic flow, decreases. When β is chosen differently, A and B do not keep their shapes invariant. With the value of γ increasing, amplitudes of A and B become larger. The second-order rogue wave is presented, from which we observe that with α increasing, amplitude of B decreases, but α has no effects on A. Collision features of A and B alter with the value of β changing. When we make the value of γ larger, amplitudes of A and B increase.
Rogue waves: from nonlinear Schrödinger breather solutions to sea-keeping test.
Onorato, Miguel; Proment, Davide; Clauss, Günther; Klein, Marco
2013-01-01
Under suitable assumptions, the nonlinear dynamics of surface gravity waves can be modeled by the one-dimensional nonlinear Schrödinger equation. Besides traveling wave solutions like solitons, this model admits also breather solutions that are now considered as prototypes of rogue waves in ocean. We propose a novel technique to study the interaction between waves and ships/structures during extreme ocean conditions using such breather solutions. In particular, we discuss a state of the art sea-keeping test in a 90-meter long wave tank by creating a Peregrine breather solution hitting a scaled chemical tanker and we discuss its potential devastating effects on the ship.
N-order bright and dark rogue waves in a resonant erbium-doped fiber system.
He, Jingsong; Xu, Shuwei; Porsezian, K; Porseizan, K
2012-12-01
The rogue waves in a resonant erbium-doped fiber system governed by a coupled system of the nonlinear Schrödinger equation and the Maxwell-Bloch equation (NLS-MB equations) are given explicitly by a Taylor series expansion about the breather solutions of the normalized slowly varying amplitude of the complex field envelope E, polarization p, and population inversion η. The n-order breather solutions of the three fields are constructed using a Darboux transformation (DT) by assuming periodic seed solutions. Moreover, the n-order rogue waves are given by determinant forms with n+3 free parameters. Furthermore, the possible connection between our rouge waves and the generation of supercontinuum generation is discussed.
N-order bright and dark rogue waves in a resonant erbium-doped fiber system
NASA Astrophysics Data System (ADS)
He, Jingsong; Xu, Shuwei; Porseizan, K.
2012-12-01
The rogue waves in a resonant erbium-doped fiber system governed by a coupled system of the nonlinear Schrödinger equation and the Maxwell-Bloch equation (NLS-MB equations) are given explicitly by a Taylor series expansion about the breather solutions of the normalized slowly varying amplitude of the complex field envelope E, polarization p, and population inversion η. The n-order breather solutions of the three fields are constructed using a Darboux transformation (DT) by assuming periodic seed solutions. Moreover, the n-order rogue waves are given by determinant forms with n+3 free parameters. Furthermore, the possible connection between our rouge waves and the generation of supercontinuum generation is discussed.
Dissipative rogue waves induced by soliton explosions in an ultrafast fiber laser.
Liu, Meng; Luo, Ai-Ping; Xu, Wen-Cheng; Luo, Zhi-Chao
2016-09-01
We reported on the observation of dissipative rogue waves (DRWs) induced by soliton explosions in an ultrafast fiber laser. It was found that the soliton explosions could be obtained in the fiber laser at a critical pump power level. During the process of the soliton explosion, the high-amplitude waves that fulfill the rogue wave criteria could be detected. The appearance of the DRWs was identified by characterizing the intensity statistics of the time-stretched soliton profile based on the dispersive Fourier-transform method. Our findings provide the first experimental demonstration that the DRWs could be observed in the soliton explosion regime and further enhance the understanding of the physical mechanism of optical RW generation.
Classification of homoclinic rogue wave solutions of the nonlinear Schrödinger equation
NASA Astrophysics Data System (ADS)
Osborne, A. R.
2014-01-01
Certain homoclinic solutions of the nonlinear Schrödinger (NLS) equation, with spatially periodic boundary conditions, are the most common unstable wave packets associated with the phenomenon of oceanic rogue waves. Indeed the homoclinic solutions due to Akhmediev, Peregrine and Kuznetsov-Ma are almost exclusively used in scientific and engineering applications. Herein I investigate an infinite number of other homoclinic solutions of NLS and show that they reduce to the above three classical homoclinic solutions for particular spectral values in the periodic inverse scattering transform. Furthermore, I discuss another infinity of solutions to the NLS equation that are not classifiable as homoclinic solutions. These latter are the genus-2N theta function solutions of the NLS equation: they are the most general unstable spectral solutions for periodic boundary conditions. I further describe how the homoclinic solutions of the NLS equation, for N = 1, can be derived directly from the theta functions in a particular limit. The solutions I address herein are actual spectral components in the nonlinear Fourier transform theory for the NLS equation: The periodic inverse scattering transform. The main purpose of this paper is to discuss a broader class of rogue wave packets1 for ship design, as defined in the Extreme Seas program. The spirit of this research came from D. Faulkner (2000) who many years ago suggested that ship design procedures, in order to take rogue waves into account, should progress beyond the use of simple sine waves. 1An overview of other work in the field of rogue waves is given elsewhere: Osborne 2010, 2012 and 2013. See the books by Olagnon and colleagues 2000, 2004 and 2008 for the Brest meetings. The books by Kharif et al. (2008) and Pelinovsky et al. (2010) are excellent references.
The low probability but increased hazard of a "rogue wave" from an unexpected direction
NASA Astrophysics Data System (ADS)
Gemmrich, Johannes; Baschek, Burkard; Garrett, Chris
2013-04-01
According to reports by the Captain and crew, the crab fishing vessel Early Dawn, while fishing near St. Paul, Alaska, on 14 January 2010, was hit by a wave "at least twice as high as the rest of the waves, if not 2.5 times as high" and propagating at an angle of 45o relative to the predominant waves. The significant wave height at the time of the incident was estimated as Hs = 4.5 - 5.5m. The Captain first saw the wave at a distance of approximately 100 metres and issued a warning. Three crew members were able to get to safety, while one crew member working at the stern of the vessel was injured. Simple models of "rogue waves" that do not specify directionality predict that a wave of the observed height or more could have been expected roughly once every 30 hours. However, the directionality of this wave clearly made it more unusual as well as increasing the potential for injuries and damage to the ship. Here we combine models of rogue wave directionality with the analysis of wave buoy observations and marine weather forecasts to argue that the chance of a wave of at least the observed height and at least the observed deviation from the main direction of the waves had a probability of only 1 in 500 of occurring in a 6 hour period.
Breathers and rogue waves excited by all-magnonic spin-transfer torque
NASA Astrophysics Data System (ADS)
Li, Zai-Dong; Li, Qiu-Yan; Xu, Tian-Fu; He, Peng-Bin
2016-10-01
In terms of Darboux transformation we investigate the dynamic process of spin wave passing through a magnetic soliton. It causes nonlinear excitations, such as Akhmediev breathers solution and Kuznetsov-Ma soliton. The former case demonstrates a spatial periodic process of a magnetic soliton forming the petal with four pieces. The spatial separation of adjacent magnetic petals increases rapidly, while one valley splits into two and the amplitude of valley increases gradually with the increasing amplitude of spin wave. The other case shows a localized process of the spin-wave background. In the limit case, we get rogue waves and clarify its formation mechanism.
Breathers and rogue waves excited by all-magnonic spin-transfer torque.
Li, Zai-Dong; Li, Qiu-Yan; Xu, Tian-Fu; He, Peng-Bin
2016-10-01
In terms of Darboux transformation we investigate the dynamic process of spin wave passing through a magnetic soliton. It causes nonlinear excitations, such as Akhmediev breathers solution and Kuznetsov-Ma soliton. The former case demonstrates a spatial periodic process of a magnetic soliton forming the petal with four pieces. The spatial separation of adjacent magnetic petals increases rapidly, while one valley splits into two and the amplitude of valley increases gradually with the increasing amplitude of spin wave. The other case shows a localized process of the spin-wave background. In the limit case, we get rogue waves and clarify its formation mechanism.
Multi-rogue waves solutions: from the NLS to the KP-I equation
NASA Astrophysics Data System (ADS)
Dubard, P.; Matveev, V. B.
2013-12-01
Our discovery of multi-rogue wave (MRW) solutions in 2010 completely changed the viewpoint on the links between the theory of rogue waves and integrable systems, and helped explain many phenomena which were never understood before. It is enough to mention the famous Three Sister waves observed in oceans, the creation of a regular approach to studying higher Peregrine breathers, and the new understanding of 2 + 1 dimensional rogue waves via the NLS-KP correspondence. This article continues the study of the MRW solutions of the NLS equation and their links with the KP-I equation started in a previous series of articles (Dubard et al 2010 Eur. Phys. J. 185 247-58, Dubard and Matveev 2011 Natural Hazards Earth Syst. Sci. 11 667-72, Matveev and Dubard 2010 Proc. Int. Conf. FNP-2010 (Novgorod, St Petersburg) pp 100-101, Dubard 2010 PhD Thesis). In particular, it contains a discussion of the large parametric asymptotics of these solutions, which has never been studied before.
NASA Astrophysics Data System (ADS)
Rodin, Artem; Rodina, Natalia
2016-04-01
Every year marine natural disasters claim thousands of lives. Only rogue waves during the last 10 years caused the death of 125 and injury of 169 people. In addition to studying the physical mechanisms of generation of rogue waves is important to study the mechanisms of human behavior in such extreme situations. The impact as large-scale natural disasters, as well as less severe (in its consequences) disaster strikes must be assessed on the basis of the entire set of conditions, in whose framework the community of people appears to be, taking into account both the power of the elements, and the available resources at their disposal to restore an acceptable level of life, including social and psychological context. Here particular relevance acquire interdisciplinary researches. This interaction is extremely important not only for sociologists and psychologists, but also for the representatives of the natural sciences (physics, chemistry, mathematics) since the ultimate goal of all efforts is to minimize the harm produced by any element or negative influence of technological progress.This also work contains statistical analysis of the appearance of rogue waves on the wind wave background in the shallow bay, obtained during the experiment in the Baltic Sea.
NASA Astrophysics Data System (ADS)
Weerasekara, Gihan; Maruta, Akihiro
2017-01-01
The dynamics of the optical rogue wave phenomenon in the framework of integrable higher-order nonlinear Schrödinger equation (HNLSE) including the third order dispersion term is presented in this paper. When rogue waves generate through soliton collision, the colliding solitons' eigenvalues of the associated equation of HNLSE should be constant in the vicinity of rogue wave generation. Our results reveal that soliton collision is one of the generation mechanisms of optical rogue waves in anomalous dispersion fiber by taking the third order dispersion into consideration in the HNLSE based model.
Lee, Min Won; Baladi, Fadwa; Burie, Jean-René; Bettiati, Mauro A; Boudrioua, Azzedine; Fischer, Alexis P A
2016-10-01
Rogue waves are observed for the first time, to the best of our knowledge, in a 980 nm laser diode subject to filtered optical feedback via a fiber Bragg grating. By counting the number of rogue waves in a fixed time window, a rogue wave map is established experimentally as a function of both the optical feedback ratio and the laser current. The comparison with low frequency fluctuations (LFFs) reveals that the rogue waves observed in our system are, in fact, LFF jump-ups.
Rogue waves as spatial energy concentrators in arrays of nonlinear waveguides.
Bludov, Yuliy V; Konotop, Vladimir V; Akhmediev, Nail
2009-10-01
In an array of nonlinear waveguides, a giant compression of the input beam can be achieved by exciting a rogue wave. Input field almost homogeneously distributed over hundreds of waveguides concentrates practically all the energy into a single waveguide at the output plane of the structure. We determine the required input profile of the electric field to achieve this. We illustrate the phenomenon by modeling the array by direct numerical simulations of the discrete nonlinear Schrödinger equation.
Reply to ''Comment on 'Optical rogue waves in telecommunication data streams'''
Vergeles, Sergey; Turitsyn, Sergei K.
2011-12-15
We feel that the main claim made in the abstract of the preceding Comment [Phys. Rev. A 84, 067801 (2011)] is wrong. Using results obtained in our paper [Phys. Rev. A 83, 061801 (2011)], we prove that rogue waves with amplitudes much larger than the average level can be observed during a short period of time in purely linear propagation regimes in optical fiber systems.
Rogue waves of the Hirota and the Maxwell-Bloch equations.
Li, Chuanzhong; He, Jingsong; Porsezian, K; Porseizan, K
2013-01-01
In this paper, we derive a Darboux transformation of the Hirota and the Maxwell-Bloch (H-MB) system which is governed by femtosecond pulse propagation through an erbium doped fiber and further generalize it to the matrix form of the n-fold Darboux transformation of this system. This n-fold Darboux transformation implies the determinant representation of nth solutions of (E([n]),p([n]),η([n])) generated from the known solution of (E,p,η). The determinant representation of (E([n]),p([n]),η([n])) provides soliton solutions, positon solutions, and breather solutions (both bright and dark breathers) of the H-MB system. From the breather solutions, we also construct a bright and dark rogue wave solution for the H-MB system, which is currently one of the hottest topics in mathematics and physics. Surprisingly, the rogue wave solution for p and η has two peaks because of the order of the numerator and denominator of them. Meanwhile, after fixing the time and spatial parameters and changing two other unknown parameters α and β, we generate a rogue wave shape.
NASA Astrophysics Data System (ADS)
Guo, Shimin; Mei, Liquan; He, Yaling; Li, Ying
2016-02-01
The nonlinear propagation of ion-acoustic waves is theoretically reported in a collisional plasma containing strongly coupled ions and nonthermal electrons featuring Tsallis distribution. For this purpose, the nonlinear integro-differential form of the generalized hydrodynamic model is used to investigate the strong-coupling effect. The modified complex Ginzburg-Landau equation with a linear dissipative term is derived for the potential wave amplitude in the hydrodynamic regime, and the modulation instability of ion-acoustic waves is examined. When the dissipative effect is neglected, the modified complex Ginzburg-Landau equation reduces to the nonlinear Schrödinger equation. Within the unstable region, two different types of second-order ion-acoustic rogue waves including single peak type and rogue wave triplets are discussed. The effect of the plasma parameters on the rogue waves is also presented.
NASA Astrophysics Data System (ADS)
Akhmediev, N.; Soto-Crespo, J. M.; Devine, N.
2016-08-01
Turbulence in integrable systems exhibits a noticeable scientific advantage: it can be expressed in terms of the nonlinear modes of these systems. Whether the majority of the excitations in the system are breathers or solitons defines the properties of the turbulent state. In the two extreme cases we can call such states "breather turbulence" or "soliton turbulence." The number of rogue waves, the probability density functions of the chaotic wave fields, and their physical spectra are all specific for each of these two situations. Understanding these extreme cases also helps in studies of mixed turbulent states when the wave field contains both solitons and breathers, thus revealing intermediate characteristics.
Akhmediev, N; Soto-Crespo, J M; Devine, N
2016-08-01
Turbulence in integrable systems exhibits a noticeable scientific advantage: it can be expressed in terms of the nonlinear modes of these systems. Whether the majority of the excitations in the system are breathers or solitons defines the properties of the turbulent state. In the two extreme cases we can call such states "breather turbulence" or "soliton turbulence." The number of rogue waves, the probability density functions of the chaotic wave fields, and their physical spectra are all specific for each of these two situations. Understanding these extreme cases also helps in studies of mixed turbulent states when the wave field contains both solitons and breathers, thus revealing intermediate characteristics.
NASA Astrophysics Data System (ADS)
Wang, Xiu-Bin; Tian, Shou-Fu; Qin, Chun-Yan; Zhang, Tian-Tian
2016-07-01
Under investigation in this work is a generalized (2+1)-dimensional Boussinesq equation, which can be used to describe the propagation of small-amplitude, long wave in shallow water. By virtue of Bell's polynomials, an effective way is presented to succinctly construct its bilinear form. Furthermore, based on the bilinear formalism and the extended homoclinic test method, the breather wave solution, rogue-wave solution and solitary-wave solution of the equation are well constructed. Our results can be used to enrich the dynamical behavior of the generalized (2+1)-dimensional nonlinear wave fields.
Brillouin scattering-induced rogue waves in self-pulsing fiber lasers
Hanzard, Pierre-Henry; Talbi, Mohamed; Mallek, Djouher; Kellou, Abdelhamid; Leblond, Hervé; Sanchez, François; Godin, Thomas; Hideur, Ammar
2017-01-01
We report the experimental observation of extreme instabilities in a self-pulsing fiber laser under the influence of stimulated Brillouin scattering (SBS). Specifically, we observe temporally localized structures with high intensities that can be referred to as rogue events through their statistical behaviour with highly-skewed intensity distributions. The emergence of these SBS-induced rogue waves is attributed to the interplay between laser operation and resonant Stokes orders. As this behaviour is not accounted for by existing models, we also present numerical simulations showing that such instabilities can be observed in chaotic laser operation. This study opens up new possibilities towards harnessing extreme events in highly-dissipative systems through adapted laser cavity configurations. PMID:28374840
Capillary wave measurements on helically-supported capillary channels
NASA Astrophysics Data System (ADS)
Chandurwala, Fahim; Thiessen, David
2010-10-01
NASA is considering power generation by the Rankine cycle to save weight on long-duration manned missions to the moon or Mars. Phase separation technology is critical to this process in microgravity. Arrays of capillary channels might be useful for filtering liquid drops from a flowing vapor. The efficiency of droplet capture by a helically-supported capillary channel is being studied. A droplet impinging on the channel launches capillary waves that propagate down the channel helping to dissipate some of the drop's kinetic energy. High-speed video of the channel combined with image processing allows for measurement of the amplitude and speed of the wave packets. Increasing the pitch of the support structure decreases the wave speed. An understanding of the dynamic response of the channel to drop impact is a first step in predicting drop-capture efficiency.
NASA Astrophysics Data System (ADS)
Su, Chuan-Qi; Gao, Yi-Tian; Xue, Long; Wang, Qi-Min
2016-07-01
Under investigation in this paper is the Gross-Pitaevskii equation which describes the dynamics of the Bose-Einstein condensate. Lax pair, conservation laws and Darboux transformation (DT) are constructed. Nonautonomous solitons and breathers are derived based on the DT obtained. A kind of modulation instability process is generated. Nonautonomous rogue waves are obtained via the generalized DT. Influence of the nonlinearity, linear external potential, harmonic external potential, and spectral parameter on the propagation and interaction of the nonautonomous solitons, breathers and rogue waves is also discussed. Amplitude of the first-order nonautonomous soliton is proportional to the imaginary part of the spectral parameter and inversely proportional to the nonlinearity parameter. Linear external potential parameter affects the location of the first-order nonautonomous soliton. Head-on interaction, overtaking interaction and bound-state-like nonautonomous solitons can be formed based on the signs of the real parts of the spectral parameters. Quasi-periodic behaviors are exhibited for the nonautonomous breathers. If the harmonic external potential parameter is negative, quasi-period decreases along the positive time axis, with an increase in the amplitude and a compression in the width. Quasi-period decreases with the increase of the nonlinearity parameter. The second-order nonautonomous rogue wave can split into three first-order ones. Nonlinearity parameter has an effect on the amplitude of the rogue wave. Linear external potential parameter influences the location of the rogue wave, while harmonic external potential parameter affects the curved direction of the background.
NASA Astrophysics Data System (ADS)
Wen, Xiao-Yong; Yan, Zhenya
2017-02-01
The novel generalized perturbation (n, M)-fold Darboux transformations (DTs) are reported for the (2 + 1)-dimensional Kadomtsev-Petviashvili (KP) equation and its extension by using the Taylor expansion of the Darboux matrix. The generalized perturbation (1 , N - 1) -fold DTs are used to find their higher-order rational solitons and rogue wave solutions in terms of determinants. The dynamics behaviors of these rogue waves are discussed in detail for different parameters and time, which display the interesting RW and soliton structures including the triangle, pentagon, heptagon profiles, etc. Moreover, we find that a new phenomenon that the parameter (a) can control the wave structures of the KP equation from the higher-order rogue waves (a ≠ 0) into higher-order rational solitons (a = 0) in (x, t)-space with y = const . These results may predict the corresponding dynamical phenomena in the models of fluid mechanics and other physically relevant systems.
Ion-acoustic solitons, double layers and rogue waves in plasma having superthermal electrons
NASA Astrophysics Data System (ADS)
Singh Saini, Nareshpal
2016-07-01
Most of the space and astrophysical plasmas contain different type of charged particles with non-Maxwellian velocity distributions (e.g., nonthermal, superthermal, Tsallis ). These distributions are commonly found in the auroral region of the Earth's magnetosphere, planetary magnetosphere, solar and stellar coronas, solar wind, etc. The observations from various satellite missions have confirmed the presence of superthermal particles in space and astrophysical environments. Over the last many years, there have been a much interest in studying the different kind of properties of the electrostatic nonlinear excitations (solitons, double layers, rogue waves etc.) in a multi-component plasmas in the presence of superthermal particles. It has been analyzed that superthermal distributions are more appropriate than Maxwellian distribution for the modeling of space data. It is interesting to study the dynamics of various kinds of solitary waves, Double layers, Shocks etc. in varieties of plasma systems containing different kind of species obeying Lorentzian (kappa-type)/Tsallis distribution. In this talk, I have focused on the study of large amplitude IA solitary structures (bipolar solitary structures, double layers etc.), modulational instability and rogue waves in multicomponent plasmas. The Sagdeev potential method has been employed to setup an energy balance equation, from which we have studied the characteristics of large amplitude solitary waves under the influence of superthermality of charged particles and other plasma parameters. The critical Mach number has been determined, above which solitary structures are observed and its variation with superthermality of electrons and other parameters has also been discussed. Double layers have also been discussed. Multiple scale reductive perturbation method has been employed to derive NLS equation. From the different kind of solutions of this equation, amplitude modulation of envelope solitons and rogue waves have been
NASA Astrophysics Data System (ADS)
Abdel-Gawad, H. I.; Tantawy, M.; Abo Elkhair, R. E.
2016-07-01
Rogue waves are more precisely defined as waves whose height is more than twice the significant wave height. This remarkable height was measured (by Draupner in 1995). Thus, the need for constructing a mechanism for the rogue waves is of great utility. This motivated us to suggest a mechanism, in this work, that rogue waves may be constructed via nonlinear interactions of solitons and periodic waves. This suggestion is consolidated here, in an example, by studying the behavior of solutions of the complex (KdV). This is done here by the extending the solutions of its real version.
NASA Astrophysics Data System (ADS)
Manikandan, Kannan; Senthilvelan, Murugaian; Kraenkel, Roberto André
2016-10-01
We construct vector rogue wave solutions of the two-dimensional two coupled nonlinear Schrödinger equations with distributed coefficients, namely diffraction, nonlinearity and gain parameters through similarity transformation technique. We transform the two-dimensional two coupled variable coefficients nonlinear Schrödinger equations into Manakov equation with a constraint that connects diffraction and gain parameters with nonlinearity parameter. We investigate the characteristics of the constructed vector rogue wave solutions with four different forms of diffraction parameters. We report some interesting patterns that occur in the rogue wave structures. Further, we construct vector dark rogue wave solutions of the two-dimensional two coupled nonlinear Schrödinger equations with distributed coefficients and report some novel characteristics that we observe in the vector dark rogue wave solutions.
Breathers and rogue waves for an eighth-order nonlinear Schrödinger equation in an optical fiber
NASA Astrophysics Data System (ADS)
Hu, Wen-Qiang; Gao, Yi-Tian; Zhao, Chen; Lan, Zhong-Zhou
2017-02-01
In this paper, an eighth-order nonlinear Schrödinger equation is investigated in an optical fiber, which can be used to describe the propagation of ultrashort nonlinear pulses. Lax pair and infinitely-many conservation laws are derived to verify the integrability of this equation. Via the Darboux transformation and generalized Darboux transformation, the analytic breather and rogue wave solutions are obtained. Influence of the coefficients of operators in this equation, which represent different order nonlinearity, and the spectral parameter on the propagation and interaction of the breathers and rogue waves is also discussed. We find that (i) the periodic of the breathers decreases as the augment of the spectral parameter; (ii) the coefficients of operators change the compressibility and periodic of the breathers, and can affect the interaction range and temporal-spatial distribution of the rogue waves.
NASA Astrophysics Data System (ADS)
Goyal, Amit; Raju, Thokala Soloman; Kumar, C. N.; Panigrahi, Prasanta K.
2016-04-01
We analytically explore optical rogue waves in a nonlinear graded-index waveguide, with spatially modulated dispersion, nonlinearity, and linear refractive-index. We study the evolution of first-order rogue wave and rogue wave triplet on Airy-Bessel, sech2, and tanh background beams, and reveal that the characteristics of RWs are well maintained while the amplitude of the first-order RW gets enhanced three times the maximum value of the Airy-Bessel and sech2 background beams and five times in the case of RW triplet. These results could be of great interest in realizing the RWs in experimentally realizable situations on small-amplitude background beams in nonlinear optics.
Transversally periodic solitary gravity–capillary waves
Milewski, Paul A.; Wang, Zhan
2014-01-01
When both gravity and surface tension effects are present, surface solitary water waves are known to exist in both two- and three-dimensional infinitely deep fluids. We describe here solutions bridging these two cases: travelling waves which are localized in the propagation direction and periodic in the transverse direction. These transversally periodic gravity–capillary solitary waves are found to be of either elevation or depression type, tend to plane waves below a critical transverse period and tend to solitary lumps as the transverse period tends to infinity. The waves are found numerically in a Hamiltonian system for water waves simplified by a cubic truncation of the Dirichlet-to-Neumann operator. This approximation has been proved to be very accurate for both two- and three-dimensional computations of fully localized gravity–capillary solitary waves. The stability properties of these waves are then investigated via the time evolution of perturbed wave profiles. PMID:24399922
Crossing sea state and rogue wave probability during the Prestige accident
NASA Astrophysics Data System (ADS)
Trulsen, Karsten; Nieto Borge, José Carlos; Gramstad, Odin; Aouf, Lotfi; Lefèvre, Jean-Michel
2015-10-01
We discuss the crossing sea state and the probability of rogue waves during the accident of the tanker Prestige on 13 November 2002. We present newly computed hindcast spectra for every hour during that day at nearby locations, showing the development of a bimodal sea state with two wave systems crossing at nearly right angle. We employ four different nonlinear models capable of computing the phase-resolved sea surface from the hindcast spectra, allowing us to estimate statistics for the occurrence of rogue waves. At the location and moment of the accident, the models give expected values for the kurtosis κ = 3.0119 ± 0.0078. The models coincide that the maximum crest elevation was about 5-6% larger than the expected maximum crest elevation in a Gaussian sea at the moment of the accident. We also conclude that the possible nonlinear interaction between the two crossing wave systems practically did not modify neither the kurtosis nor the largest crest elevation.
Compressional Alfvénic rogue and solitary waves in magnetohydrodynamic plasmas
Panwar, Anuraj; Rizvi, H.; Ryu, C. M.
2013-08-15
Generation of compressional Alfvénic rogue and solitary waves in magnetohydrodynamic plasmas is investigated. Dispersive effect caused by non-ideal electron inertia currents perpendicular to the ambient magnetic field can balance the nonlinear steepening of waves leading to the formation of a soliton. The reductive perturbation method is used to obtain a Korteweg–de Vries (KdV) equation describing the evolution of the solitary wave. The height of a soliton is proportional to the soliton speed “U” and inversely proportional to plasma “β” (ratio of plasma thermal pressure to pressure of the confining magnetic field) and the width of soliton is proportional to the electron inertial length. KdV equation is used to study the nonlinear evolution of modulationally unstable compressional Alfvénic wavepackets via the nonlinear Schrödinger equation. The characteristics of rogue wave influenced by plasma “β” and the electron inertial length are described.
Discrete rogue waves of the Ablowitz-Ladik and Hirota equations.
Ankiewicz, Adrian; Akhmediev, Nail; Soto-Crespo, J M
2010-08-01
We show that the Ablowitz-Ladik equation, which is an integrable form of the discretized nonlinear Schrödinger equation, has rogue wave solutions in the form of the rational solutions. We show that there is a hierarchy of rational solutions and we derive the two lowest-order ones using the Hirota technique. More generally, we present rational solutions for the discrete Hirota equation which includes, as particular cases, both the discrete Ablowitz-Ladik equation and the discrete modified Korteweg-de Vries (mKdV) equation.
Optical rogue-wave-like extreme value fluctuations in fiber Raman amplifiers.
Hammani, Kamal; Finot, Christophe; Dudley, John M; Millot, Guy
2008-10-13
We report experimental observation and characterization of rogue wave-like extreme value statistics arising from pump-signal noise transfer in a fiber Raman amplifier. Specifically, by exploiting Raman amplification with an incoherent pump, the amplified signal is shown to develop a series of temporal intensity spikes whose peak power follows a power-law probability distribution. The results are interpreted using a numerical model of the Raman gain process using coupled nonlinear Schrödinger equations, and the numerical model predicts results in good agreement with experiment.
Rogue waves lead to the instability in GaN semiconductors
Yahia, M. E.; Tolba, R. E.; El-Bedwehy, N. A.; El-Labany, S. K.; Moslem, W. M.
2015-01-01
A new approach to understand the electron/hole interfaced plasma in GaN high electron mobility transistors (HEMTs). A quantum hydrodynamic model is constructed to include electrons/holes degenerate pressure, Bohm potential, and the exchange/correlation effect and then reduced to the nonlinear Schrödinger equation (NLSE). Numerical analysis of the latter predicts the rough (in)stability domains, which allow for the rogue waves to occur. Our results might give physical solution rather than the engineering one to the intrinsic problems in these high frequency/power transistors. PMID:26206731
Rogue waves lead to the instability in GaN semiconductors.
Yahia, M E; Tolba, R E; El-Bedwehy, N A; El-Labany, S K; Moslem, W M
2015-07-24
A new approach to understand the electron/hole interfaced plasma in GaN high electron mobility transistors (HEMTs). A quantum hydrodynamic model is constructed to include electrons/holes degenerate pressure, Bohm potential, and the exchange/correlation effect and then reduced to the nonlinear Schrödinger equation (NLSE). Numerical analysis of the latter predicts the rough (in)stability domains, which allow for the rogue waves to occur. Our results might give physical solution rather than the engineering one to the intrinsic problems in these high frequency/power transistors.
Controllable Discrete Rogue Wave Solutions of the Ablowitz—Ladik Equation in Optics
NASA Astrophysics Data System (ADS)
Wen, Xiao-Yong
2016-07-01
With the aid of symbolic computation Maple, the discrete Ablowitz—Ladik equation is studied via an algebra method, some new rational solutions with four arbitrary parameters are constructed. By analyzing related parameters, the discrete rogue wave solutions with alterable positions and amplitude for the focusing Ablowitz—Ladik equations are derived. Some properties are discussed by graphical analysis, which might be helpful for understanding physical phenomena in optics. Supported by the Beijing Natural Science Foundation under Grant No. 1153004, and China Postdoctoral Science Foundation under Grant No. 2015M570161 and the Natural Science Foundation of China under Grant No. 61471406
Slunyaev, A; Pelinovsky, E; Sergeeva, A; Chabchoub, A; Hoffmann, N; Onorato, M; Akhmediev, N
2013-07-01
The rogue wave solutions (rational multibreathers) of the nonlinear Schrödinger equation (NLS) are tested in numerical simulations of weakly nonlinear and fully nonlinear hydrodynamic equations. Only the lowest order solutions from 1 to 5 are considered. A higher accuracy of wave propagation in space is reached using the modified NLS equation, also known as the Dysthe equation. This numerical modeling allowed us to directly compare simulations with recent results of laboratory measurements in Chabchoub et al. [Phys. Rev. E 86, 056601 (2012)]. In order to achieve even higher physical accuracy, we employed fully nonlinear simulations of potential Euler equations. These simulations provided us with basic characteristics of long time evolution of rational solutions of the NLS equation in the case of near-breaking conditions. The analytic NLS solutions are found to describe the actual wave dynamics of steep waves reasonably well.
Rogue waves in crossing seas: The Louis Majesty accident
NASA Astrophysics Data System (ADS)
Cavaleri, L.; Bertotti, L.; Torrisi, L.; Bitner-Gregersen, E.; Serio, M.; Onorato, M.
2012-11-01
We analyze the sea state conditions during which the accident of the cruise ship Louis Majesty took place. The ship was hit by a large wave that destroyed some windows at deck number five and caused two fatalities. Using the wave model (WAM), driven by the Consortium for Small-Scale Modelling (COSMO-ME) winds, we perform a detailed hindcast of the local wave conditions. The results reveal the presence of two comparable wave systems characterized almost by the same frequency. We discuss such sea state conditions in the framework of a system of two coupled Nonlinear Schrödinger (CNLS) equations, each of which describe the dynamics of a single spectral peak. For some specific parameters, we discuss the breather solutions of the CNLS equations and estimate the maximum wave amplitude. Even though, due to the lack of measurements, it is impossible to establish the nature of the wave that caused the accident, we show that the angle between the two wave systems during the accident was close to the condition for which the maximum amplitude of the breather solution is observed.
Dust kinetic Alfvén solitary and rogue waves in a superthermal dusty plasma
Saini, N. S. Singh, Manpreet; Bains, A. S.
2015-11-15
Dust kinetic Alfvén solitary waves (DKASWs) have been examined in a low-β dusty plasma comprising of negatively charged dust grains, superthermal electrons, and ions. A nonlinear Korteweg-de Vries (KdV) equation has been derived using the reductive perturbation method. The combined effects of superthermality of charged particles (via κ), plasma β, obliqueness of propagation (θ), and dust concentration (via f) on the shape and size of the DKASWs have been examined. Only negative potential (rarefactive) structures are observed. Further, characteristics of dust kinetic Alfvén rogue waves (DKARWs), by deriving the non-linear Schrödinger equation (NLSE) from the KdV equation, are studied. Rational solutions of NLSE show that rogue wave envelopes are supported by this plasma model. It is observed that the influence of various plasma parameters (superthermality, plasma β, obliqueness, and dust concentration) on the characteristics of the DKARWs is very significant. This fundamental study may be helpful in understanding the formation of coherent nonlinear structures in space and astrophysical plasma environments where superthermal particles are present.
Dust kinetic Alfvén solitary and rogue waves in a superthermal dusty plasma
NASA Astrophysics Data System (ADS)
Saini, N. S.; Singh, Manpreet; Bains, A. S.
2015-11-01
Dust kinetic Alfvén solitary waves (DKASWs) have been examined in a low-β dusty plasma comprising of negatively charged dust grains, superthermal electrons, and ions. A nonlinear Korteweg-de Vries (KdV) equation has been derived using the reductive perturbation method. The combined effects of superthermality of charged particles (via κ), plasma β, obliqueness of propagation (θ), and dust concentration (via f) on the shape and size of the DKASWs have been examined. Only negative potential (rarefactive) structures are observed. Further, characteristics of dust kinetic Alfvén rogue waves (DKARWs), by deriving the non-linear Schrödinger equation (NLSE) from the KdV equation, are studied. Rational solutions of NLSE show that rogue wave envelopes are supported by this plasma model. It is observed that the influence of various plasma parameters (superthermality, plasma β, obliqueness, and dust concentration) on the characteristics of the DKARWs is very significant. This fundamental study may be helpful in understanding the formation of coherent nonlinear structures in space and astrophysical plasma environments where superthermal particles are present.
Wang, Lei Li, Min; Qi, Feng-Hua; Xu, Tao
2015-03-15
Under investigation in this paper is a variable-coefficient derivative nonlinear Schrödinger (vc-DNLS) equation modeling the nonlinear Alfvén waves in the inhomogeneous plasmas. The modulation instability is examined for this inhomogeneous nonlinear model. The nonautonomous breather and rogue wave solutions of the vc-DNLS equation are obtained via the modified Darboux transformation. It is found that the velocity and amplitude of the breather can be controlled by the inhomogeneous magnetic field and nonuniform density. Such novel phenomena as breather amplification and nonlinear Talbot effect-like property are demonstrated with the proper choices of the inhomogeneous parameters. Furthermore, dynamics of the fundamental rogue wave, periodical rogue wave, and composite rogue wave are graphically discussed. The trajectories and amplitudes of the rogue waves can be manipulated by the inhomogeneous magnetic field and nonuniform density. In addition, the nonlinear tunneling of the rogue waves and breathers is studied. As an application, a sample model is treated with our results, and the graphical illustrations exhibit the compressing, expanding, and fluctuating phenomena of the Alfvén rogue waves.
Oscillon dynamics and rogue wave generation in Faraday surface ripples.
Xia, H; Maimbourg, T; Punzmann, H; Shats, M
2012-09-14
We report new experimental results which suggest that the generation of extreme wave events in the Faraday surface ripples is related to the increase in the horizontal mobility of oscillating solitons (oscillons). The analysis of the oscillon trajectories in a horizontal plane shows that at higher vertical acceleration, oscillons move chaotically, merge and form enclosed areas on the water surface. The probability of the formation of such craters, which precede large wave events, increases with the increase in horizontal mobility.
Rogue waves in crossing seas: the Louis Majesty accident
NASA Astrophysics Data System (ADS)
Cavaleri, L.; Bertotti, L.; Torrisi, L.; Bitner-Gregersen, E. M.; Serio, M.; Onorato, M.
2012-04-01
We analyze the sea state conditions during which the accident of the cruise ship Louis Majesty took place. The ship was hit by a large wave that destroyed some windows at deck number five and caused two fatalities. Using the WAM model, driven by the COSMO-ME winds, we perform a detailed hindcast of the local wave conditions. The results reveal the presence of two comparable wave systems characterized almost by the same frequency. We discuss such sea state condition in the framework of a system of two coupled Nonlinear Schr¨odinger, CNLS, equations, each of which describing the dynamics of a single spectral peak. For some specific parameters, we discuss the breather solutions of the CNLS equations and estimate the maximum wave amplitude. Even though,due to the lack of measurements, it is impossible to establish the nature of the wave that caused the accident, we show that the angle between the two wave systems during theaccident is close to the condition for which the maximum amplitude of the breather solution is observed.
Observation of gravity-capillary wave turbulence.
Falcon, Eric; Laroche, Claude; Fauve, Stéphan
2007-03-02
We report the observation of the crossover between gravity and capillary wave turbulence on the surface of mercury. The probability density functions of the turbulent wave height are found to be asymmetric and thus non-Gaussian. The surface wave height displays power-law spectra in both regimes. In the capillary region, the exponent is in fair agreement with weak turbulence theory. In the gravity region, it depends on the forcing parameters. This can be related to the finite size of the container. In addition, the scaling of those spectra with the mean energy flux is found in disagreement with weak turbulence theory for both regimes.
Sun, Wen-Rong; Tian, Bo Jiang, Yan; Zhen, Hui-Ling
2014-04-15
Plasmas are the main constituent of the Universe and the cause of a vast variety of astrophysical, space and terrestrial phenomena. The inhomogeneous nonlinear Schrödinger equation is hereby investigated, which describes the propagation of an electron plasma wave packet with a large wavelength and small amplitude in a medium with a parabolic density and constant interactional damping. By virtue of the double Wronskian identities, the equation is proved to possess the double-Wronskian soliton solutions. Analytic one- and two-soliton solutions are discussed. Amplitude and velocity of the soliton are related to the damping coefficient. Asymptotic analysis is applied for us to investigate the interaction between the two solitons. Overtaking interaction, head-on interaction and bound state of the two solitons are given. From the non-zero potential Lax pair, the first- and second-order rogue-wave solutions are constructed via a generalized Darboux transformation, and influence of the linear and parabolic density profiles on the background density and amplitude of the rogue wave is discussed. -- Highlights: •Double-Wronskian soliton solutions are obtained and proof is finished by virtue of some double Wronskian identities. •Asymptotic analysis is applied for us to investigate the interaction between the two solitons. •First- and second-order rogue-wave solutions are constructed via a generalized Darboux transformation. •Influence of the linear and parabolic density profiles on the background density and amplitude of the rogue wave is discussed.
Wave amplification in the framework of forced nonlinear Schrödinger equation: The rogue wave context
NASA Astrophysics Data System (ADS)
Slunyaev, Alexey; Sergeeva, Anna; Pelinovsky, Efim
2015-05-01
Irregular waves which experience the time-limited external forcing within the framework of the nonlinear Schrödinger (NLS) equation are studied numerically. It is shown that the adiabatically slow pumping (the time scale of forcing is much longer than the nonlinear time scale) results in selective enhancement of the solitary part of the wave ensemble. The slow forcing provides eventually wider wavenumber spectra, larger values of kurtosis and higher probability of large waves. In the opposite case of rapid forcing the nonlinear waves readjust passing through the stage of fast surges of statistical characteristics. Single forced envelope solitons are considered with the purpose to better identify the role of coherent wave groups. An approximate description on the basis of solutions of the integrable NLS equation is provided. Applicability of the Benjamin-Feir Index to forecasting of conditions favourable for rogue waves is discussed.
Theoretical and experimental evidence of non-symmetric doubly localized rogue waves
He, Jingsong; Guo, Lijuan; Zhang, Yongshuai; Chabchoub, Amin
2014-01-01
We present determinant expressions for vector rogue wave (RW) solutions of the Manakov system, a two-component coupled nonlinear Schrödinger (NLS) equation. As a special case, we generate a family of exact and non-symmetric RW solutions of the NLS equation up to third order, localized in both space and time. The derived non-symmetric doubly localized second-order solution is generated experimentally in a water wave flume for deep-water conditions. Experimental results, confirming the characteristic non-symmetric pattern of the solution, are in very good agreement with theory as well as with numerical simulations, based on the modified NLS equation, known to model accurately the dynamics of weakly nonlinear wave packets in deep water. PMID:25383023
Theoretical and experimental evidence of non-symmetric doubly localized rogue waves.
He, Jingsong; Guo, Lijuan; Zhang, Yongshuai; Chabchoub, Amin
2014-11-08
We present determinant expressions for vector rogue wave (RW) solutions of the Manakov system, a two-component coupled nonlinear Schrödinger (NLS) equation. As a special case, we generate a family of exact and non-symmetric RW solutions of the NLS equation up to third order, localized in both space and time. The derived non-symmetric doubly localized second-order solution is generated experimentally in a water wave flume for deep-water conditions. Experimental results, confirming the characteristic non-symmetric pattern of the solution, are in very good agreement with theory as well as with numerical simulations, based on the modified NLS equation, known to model accurately the dynamics of weakly nonlinear wave packets in deep water.
Panwar, Anuraj; Ryu, Chang-Mo
2014-06-15
The modulational instability and associated rogue structures of a slow magnetosonic wave are investigated for a Hall magnetohydrodynamic plasma. Nonlinear Schrodinger equation is obtained by using the multiple scale method, which shows a modulationally unstable slow magnetosonic mode evolving into bright wavepackets. The dispersive effects induced by the Hall electron current increase with the increase in plasma β and become weaker as the angle of propagation increases. The growth rate of the modulational instability also increases with the increase in plasma β. The growth rate is greatest for the parallel propagation and drops to zero for perpendicular propagation. The envelope wavepacket of a slow magnetosonic is widened with less oscillations as plasma β increases. But the wavepacket becomes slightly narrower and more oscillatory as the angle of propagation increases. Further a non-stationary envelope solution of the Peregrine soliton is analyzed for rogue waves. The Peregrine soliton contracts temporally and expands spatially with increase in plasma β. However, the width of a slow magnetosonic Peregrine soliton decreases both temporally and spatially with increase of the propagation angle.
Lu, Luyao; Xia, Ling; Ye, Xuesong; Cheng, Heping
2010-05-26
Calcium homeostasis is considered to be one of the most important factors for the contraction and relaxation of the heart muscle. However, under some pathological conditions, such as heart failure (HF), calcium homeostasis is disordered, and spontaneous waves may occur. In this study, we developed a mathematical model of formation and propagation of a calcium wave based upon a governing system of diffusion-reaction equations presented by Izu et al (2001 Biophys. J. 80 103-20) and integrated non-clustered or 'rogue' ryanodine receptors (rogue RyRs) into a two-dimensional (2D) model of ventricular myocytes isolated from failing hearts in which sarcoplasmic reticulum (SR) Ca(2+) pools are partially unloaded. The model was then used to simulate the effect of rogue RyRs on initiation and propagation of the calcium wave in ventricular myocytes with HF. Our simulation results show that rogue RyRs can amplify the diastolic SR Ca(2+) leak in the form of Ca(2+) quarks, increase the probability of occurrence of spontaneous Ca(2+) waves even with smaller SR Ca(2+) stores, accelerate Ca(2+) wave propagation, and hence lead to delayed afterdepolarizations (DADs) and cardiac arrhythmia in the diseased heart. This investigation suggests that incorporating rogue RyRs in the Ca(2+) wave model under HF conditions provides a new view of Ca(2+) dynamics that could not be mimicked by adjusting traditional parameters involved in Ca(2+) release units and other ion channels, and contributes to understanding the underlying mechanism of HF.
NASA Astrophysics Data System (ADS)
Lu, Luyao; Xia, Ling; Ye, Xuesong; Cheng, Heping
2010-06-01
Calcium homeostasis is considered to be one of the most important factors for the contraction and relaxation of the heart muscle. However, under some pathological conditions, such as heart failure (HF), calcium homeostasis is disordered, and spontaneous waves may occur. In this study, we developed a mathematical model of formation and propagation of a calcium wave based upon a governing system of diffusion-reaction equations presented by Izu et al (2001 Biophys. J. 80 103-20) and integrated non-clustered or 'rogue' ryanodine receptors (rogue RyRs) into a two-dimensional (2D) model of ventricular myocytes isolated from failing hearts in which sarcoplasmic reticulum (SR) Ca2+ pools are partially unloaded. The model was then used to simulate the effect of rogue RyRs on initiation and propagation of the calcium wave in ventricular myocytes with HF. Our simulation results show that rogue RyRs can amplify the diastolic SR Ca2+ leak in the form of Ca2+ quarks, increase the probability of occurrence of spontaneous Ca2+ waves even with smaller SR Ca2+ stores, accelerate Ca2+ wave propagation, and hence lead to delayed afterdepolarizations (DADs) and cardiac arrhythmia in the diseased heart. This investigation suggests that incorporating rogue RyRs in the Ca2+ wave model under HF conditions provides a new view of Ca2+ dynamics that could not be mimicked by adjusting traditional parameters involved in Ca2+ release units and other ion channels, and contributes to understanding the underlying mechanism of HF.
Närhi, Mikko; Wetzel, Benjamin; Billet, Cyril; Toenger, Shanti; Sylvestre, Thibaut; Merolla, Jean-Marc; Morandotti, Roberto; Dias, Frederic; Genty, Goëry; Dudley, John M.
2016-01-01
Modulation instability is a fundamental process of nonlinear science, leading to the unstable breakup of a constant amplitude solution of a physical system. There has been particular interest in studying modulation instability in the cubic nonlinear Schrödinger equation, a generic model for a host of nonlinear systems including superfluids, fibre optics, plasmas and Bose–Einstein condensates. Modulation instability is also a significant area of study in the context of understanding the emergence of high amplitude events that satisfy rogue wave statistical criteria. Here, exploiting advances in ultrafast optical metrology, we perform real-time measurements in an optical fibre system of the unstable breakup of a continuous wave field, simultaneously characterizing emergent modulation instability breather pulses and their associated statistics. Our results allow quantitative comparison between experiment, modelling and theory, and are expected to open new perspectives on studies of instability dynamics in physics. PMID:27991513
NASA Astrophysics Data System (ADS)
Närhi, Mikko; Wetzel, Benjamin; Billet, Cyril; Toenger, Shanti; Sylvestre, Thibaut; Merolla, Jean-Marc; Morandotti, Roberto; Dias, Frederic; Genty, Goëry; Dudley, John M.
2016-12-01
Modulation instability is a fundamental process of nonlinear science, leading to the unstable breakup of a constant amplitude solution of a physical system. There has been particular interest in studying modulation instability in the cubic nonlinear Schrödinger equation, a generic model for a host of nonlinear systems including superfluids, fibre optics, plasmas and Bose-Einstein condensates. Modulation instability is also a significant area of study in the context of understanding the emergence of high amplitude events that satisfy rogue wave statistical criteria. Here, exploiting advances in ultrafast optical metrology, we perform real-time measurements in an optical fibre system of the unstable breakup of a continuous wave field, simultaneously characterizing emergent modulation instability breather pulses and their associated statistics. Our results allow quantitative comparison between experiment, modelling and theory, and are expected to open new perspectives on studies of instability dynamics in physics.
Närhi, Mikko; Wetzel, Benjamin; Billet, Cyril; Toenger, Shanti; Sylvestre, Thibaut; Merolla, Jean-Marc; Morandotti, Roberto; Dias, Frederic; Genty, Goëry; Dudley, John M
2016-12-19
Modulation instability is a fundamental process of nonlinear science, leading to the unstable breakup of a constant amplitude solution of a physical system. There has been particular interest in studying modulation instability in the cubic nonlinear Schrödinger equation, a generic model for a host of nonlinear systems including superfluids, fibre optics, plasmas and Bose-Einstein condensates. Modulation instability is also a significant area of study in the context of understanding the emergence of high amplitude events that satisfy rogue wave statistical criteria. Here, exploiting advances in ultrafast optical metrology, we perform real-time measurements in an optical fibre system of the unstable breakup of a continuous wave field, simultaneously characterizing emergent modulation instability breather pulses and their associated statistics. Our results allow quantitative comparison between experiment, modelling and theory, and are expected to open new perspectives on studies of instability dynamics in physics.
NASA Astrophysics Data System (ADS)
Slunyaev, A. V.; Pelinovsky, E. N.
2016-11-01
The role of multiple soliton and breather interactions in the formation of very high waves is disclosed within the framework of the integrable modified Korteweg-de Vries (MKdV) equation. Optimal conditions for the focusing of many solitons are formulated explicitly. Namely, trains of ordered solitons with alternate polarities evolve to huge strongly localized transient waves. The focused wave amplitude is exactly the sum of the focusing soliton heights; the maximum wave inherits the polarity of the fastest soliton in the train. The focusing of several solitary waves or/and breathers may naturally occur in a soliton gas and will lead to rogue-wave-type dynamics; hence, it represents a new nonlinear mechanism of rogue wave generation. The discovered scenario depends crucially on the soliton polarities (phases), and is not taken into account by existing kinetic theories. The performance of the soliton mechanism of rogue wave generation is shown for the example of the focusing MKdV equation, when solitons possess "frozen" phases (certain polarities), though the approach is efficient in some other integrable systems which admit soliton and breather solutions.
Slunyaev, A V; Pelinovsky, E N
2016-11-18
The role of multiple soliton and breather interactions in the formation of very high waves is disclosed within the framework of the integrable modified Korteweg-de Vries (MKdV) equation. Optimal conditions for the focusing of many solitons are formulated explicitly. Namely, trains of ordered solitons with alternate polarities evolve to huge strongly localized transient waves. The focused wave amplitude is exactly the sum of the focusing soliton heights; the maximum wave inherits the polarity of the fastest soliton in the train. The focusing of several solitary waves or/and breathers may naturally occur in a soliton gas and will lead to rogue-wave-type dynamics; hence, it represents a new nonlinear mechanism of rogue wave generation. The discovered scenario depends crucially on the soliton polarities (phases), and is not taken into account by existing kinetic theories. The performance of the soliton mechanism of rogue wave generation is shown for the example of the focusing MKdV equation, when solitons possess "frozen" phases (certain polarities), though the approach is efficient in some other integrable systems which admit soliton and breather solutions.
Two different kinds of rogue waves in weakly crossing sea states.
Ruban, V P
2009-06-01
Formation of giant waves in sea states with two spectral maxima centered at close wave vectors k_{0}+/-Deltak/2 in the Fourier plane is numerically simulated using the fully nonlinear model for long-crested water waves [V. P. Ruban, Phys. Rev. E 71, 055303(R) (2005)]. Depending on an angle theta between the vectors k_{0} and Deltak , which determines a typical orientation of interference stripes in the physical plane, rogue waves arise having different spatial structure. If theta less, < or = arctan(1/sqrt[2]) , then typical giant waves are relatively long fragments of essentially two-dimensional (2D) ridges, separated by wide valleys and consisting of alternating oblique crests and troughs. At nearly perpendicular k_{0} and Deltak , the interference minima develop to coherent structures similar to the dark solitons of the nonlinear Schrodinger equation, and a 2D freak wave looks much as a piece of a one-dimensional freak wave bounded in the transversal direction by two such dark solitons.
Guo, Shimin Mei, Liquan
2014-11-15
The amplitude modulation of ion-acoustic waves is investigated in an unmagnetized plasma containing positive ions, negative ions, and electrons obeying a kappa-type distribution that is penetrated by a positive ion beam. By considering dissipative mechanisms, including ionization, negative-positive ion recombination, and electron attachment, we introduce a comprehensive model for the plasma with the effects of sources and sinks. Via reductive perturbation theory, the modified nonlinear Schrödinger equation with a dissipative term is derived to govern the dynamics of the modulated waves. The effect of the plasma parameters on the modulation instability criterion for the modified nonlinear Schrödinger equation is numerically investigated in detail. Within the unstable region, first- and second-order dissipative ion-acoustic rogue waves are present. The effect of the plasma parameters on the characteristics of the dissipative rogue waves is also discussed.
NASA Astrophysics Data System (ADS)
Xie, Xi-Yang; Tian, Bo; Jiang, Yan; Sun, Wen-Rong; Sun, Ya; Gao, Yi-Tian
2016-07-01
Under investigation in this paper is an inhomogeneous nonlinear system, which describes the marginally-unstable baroclinic wave packets in a geophysical fluid or ultra-short pulses in nonlinear optics with certain inhomogeneous medium existing. By virtue of a kind of the Darboux transformation, under the Painlevé integrable condition, the first- and second-order bright and dark rogue-wave solutions are derived. Properties of the first- and second-order bright and dark rogue waves with α(t), which measures the state of the basic flow, and β(t), representing the interaction of the wave packet and mean flow, are graphically presented and analyzed: α(t) and β(t) have no influence on the wave packet, but affect the correction of the basic flow. When we choose α(t) as a constant and linear function, respectively, the shapes of the first- and second-order dark rogue waves change, and the peak heights and widths of them alter with the value of β(t) changing.
The role of PR in the formation of psychological readiness for a rogue wave events.
NASA Astrophysics Data System (ADS)
Chaykovskaya, N.; Rodin, A.
2012-04-01
In recent years the study of psychological foundations of human behavior when dealing with rogue waves has received increasing attention. However, this problem is only in the interest of a narrow circle of specialists, while the task is to explain the rules of behavior when dealing with the phenomenon to anyone who can get into this situation. This problem can only be solved by media and PR-specialists working in this field. PR- specialists are required to convey to people the need of correct action stereotype for assault element, because, as it is known, a fact only becomes a fact when it is written about in a newspaper or is made a story about in a summary of radio or TV news. This publication is devoted to the developing of forms and methods of PR-specialists activity in this area.
Rogue waves for a system of coupled derivative nonlinear Schrödinger equations.
Chan, H N; Malomed, B A; Chow, K W; Ding, E
2016-01-01
Rogue waves (RWs) are unexpectedly strong excitations emerging from an otherwise tranquil background. The nonlinear Schrödinger equation (NLSE), a ubiquitous model with wide applications to fluid mechanics, optics, plasmas, etc., exhibits RWs only in the regime of modulation instability (MI) of the background. For a system of multiple waveguides, the governing coupled NLSEs can produce regimes of MI and RWs, even if each component has dispersion and cubic nonlinearity of opposite signs. A similar effect is demonstrated here for a system of coupled derivative NLSEs (DNLSEs) where the special feature is the nonlinear self-steepening of narrow pulses. More precisely, these additional regimes of MI and RWs for coupled DNLSEs depend on the mismatch in group velocities between the components, and the parameters for cubic nonlinearity and self-steepening. RWs considered in this paper differ from those of the NLSEs in terms of the amplification ratio and criteria of existence. Applications to optics and plasma physics are discussed.
A hybrid model for simulating rogue waves in random seas on a large temporal and spatial scale
NASA Astrophysics Data System (ADS)
Wang, Jinghua; Ma, Q. W.; Yan, S.
2016-05-01
A hybrid model for simulating rogue waves in random seas on a large temporal and spatial scale is proposed in this paper. It is formed by combining the derived fifth order Enhanced Nonlinear Schrödinger Equation based on Fourier transform, the Enhanced Spectral Boundary Integral (ESBI) method and its simplified version. The numerical techniques and algorithm for coupling three models on time scale are suggested. Using the algorithm, the switch between the three models during the computation is triggered automatically according to wave nonlinearities. Numerical tests are carried out and the results indicate that this hybrid model could simulate rogue waves both accurately and efficiently. In some cases discussed, the hybrid model is more than 10 times faster than just using the ESBI method, and it is also much faster than other methods reported in the literature.
Laser absorption waves in metallic capillaries
NASA Astrophysics Data System (ADS)
Anisimov, V. N.; Arutiunian, R. V.; Bol'Shov, L. A.; Kanevskii, M. F.; Kondrashov, V. V.
1987-07-01
The propagation of laser absorption waves in metallic capillaries was studied experimentally and numerically during pulsed exposure to CO2 laser radiation. The dependence of the plasma front propagation rate on the initial air pressure in the capillary is determined. In a broad range of parameters, the formation time of the optically opaque plasma layer is governed by the total laser pulse energy from the beginning of the exposure to the instant screening appears, and is weakly dependent on the pulse shape and gas pressure.
Essama, Bedel Giscard Onana; Atangana, Jacques; Frederick, Biya Motto; Mokhtari, Bouchra; Eddeqaqi, Noureddine Cherkaoui; Kofane, Timoleon Crepin
2014-09-01
We investigate the behavior of the electromagnetic wave that propagates in a metamaterial for negative index regime. Second-order dispersion and cubic-quintic nonlinearities are taken into account. The behavior obtained for negative index regime is compared to that observed for absorption regime. The collective coordinates technique is used to characterize the light pulse intensity profile at some frequency ranges. Five frequency ranges have been pointed out. The perfect combination of second-order dispersion and cubic nonlinearity leads to a robust soliton at each frequency range for negative index regime. The soliton peak power progressively decreases for absorption regime. Further, this peak power also decreases with frequency. We show that absorption regime can induce rogue wave trains generation at a specific frequency range. However, this rogue wave trains generation is maintained when the quintic nonlinearity comes into play for negative index regime and amplified for absorption regime at a specific frequency range. It clearly appears that rogue wave behavior strongly depends on the frequency and the regime considered. Furthermore, the stability conditions of the electromagnetic wave have also been discussed at frequency ranges considered for both negative index and absorption regimes.
Inverse scattering transform analysis of rogue waves using local periodization procedure
Randoux, Stéphane; Suret, Pierre; El, Gennady
2016-01-01
The nonlinear Schrödinger equation (NLSE) stands out as the dispersive nonlinear partial differential equation that plays a prominent role in the modeling and understanding of the wave phenomena relevant to many fields of nonlinear physics. The question of random input problems in the one-dimensional and integrable NLSE enters within the framework of integrable turbulence, and the specific question of the formation of rogue waves (RWs) has been recently extensively studied in this context. The determination of exact analytic solutions of the focusing 1D-NLSE prototyping RW events of statistical relevance is now considered as the problem of central importance. Here we address this question from the perspective of the inverse scattering transform (IST) method that relies on the integrable nature of the wave equation. We develop a conceptually new approach to the RW classification in which appropriate, locally coherent structures are specifically isolated from a globally incoherent wave train to be subsequently analyzed by implementing a numerical IST procedure relying on a spatial periodization of the object under consideration. Using this approach we extend the existing classifications of the prototypes of RWs from standard breathers and their collisions to more general nonlinear modes characterized by their nonlinear spectra. PMID:27385164
Inverse scattering transform analysis of rogue waves using local periodization procedure.
Randoux, Stéphane; Suret, Pierre; El, Gennady
2016-07-07
The nonlinear Schrödinger equation (NLSE) stands out as the dispersive nonlinear partial differential equation that plays a prominent role in the modeling and understanding of the wave phenomena relevant to many fields of nonlinear physics. The question of random input problems in the one-dimensional and integrable NLSE enters within the framework of integrable turbulence, and the specific question of the formation of rogue waves (RWs) has been recently extensively studied in this context. The determination of exact analytic solutions of the focusing 1D-NLSE prototyping RW events of statistical relevance is now considered as the problem of central importance. Here we address this question from the perspective of the inverse scattering transform (IST) method that relies on the integrable nature of the wave equation. We develop a conceptually new approach to the RW classification in which appropriate, locally coherent structures are specifically isolated from a globally incoherent wave train to be subsequently analyzed by implementing a numerical IST procedure relying on a spatial periodization of the object under consideration. Using this approach we extend the existing classifications of the prototypes of RWs from standard breathers and their collisions to more general nonlinear modes characterized by their nonlinear spectra.
Inverse scattering transform analysis of rogue waves using local periodization procedure
NASA Astrophysics Data System (ADS)
Randoux, Stéphane; Suret, Pierre; El, Gennady
2016-07-01
The nonlinear Schrödinger equation (NLSE) stands out as the dispersive nonlinear partial differential equation that plays a prominent role in the modeling and understanding of the wave phenomena relevant to many fields of nonlinear physics. The question of random input problems in the one-dimensional and integrable NLSE enters within the framework of integrable turbulence, and the specific question of the formation of rogue waves (RWs) has been recently extensively studied in this context. The determination of exact analytic solutions of the focusing 1D-NLSE prototyping RW events of statistical relevance is now considered as the problem of central importance. Here we address this question from the perspective of the inverse scattering transform (IST) method that relies on the integrable nature of the wave equation. We develop a conceptually new approach to the RW classification in which appropriate, locally coherent structures are specifically isolated from a globally incoherent wave train to be subsequently analyzed by implementing a numerical IST procedure relying on a spatial periodization of the object under consideration. Using this approach we extend the existing classifications of the prototypes of RWs from standard breathers and their collisions to more general nonlinear modes characterized by their nonlinear spectra.
Wen, Xiao-Yong; Yang, Yunqing; Yan, Zhenya
2015-07-01
In this paper, a simple and constructive method is presented to find the generalized perturbation (n,M)-fold Darboux transformations (DTs) of the modified nonlinear Schrödinger (MNLS) equation in terms of fractional forms of determinants. In particular, we apply the generalized perturbation (1,N-1)-fold DTs to find its explicit multi-rogue-wave solutions. The wave structures of these rogue-wave solutions of the MNLS equation are discussed in detail for different parameters, which display abundant interesting wave structures, including the triangle and pentagon, etc., and may be useful to study the physical mechanism of multirogue waves in optics. The dynamical behaviors of these multi-rogue-wave solutions are illustrated using numerical simulations. The same Darboux matrix can also be used to investigate the Gerjikov-Ivanov equation such that its multi-rogue-wave solutions and their wave structures are also found. The method can also be extended to find multi-rogue-wave solutions of other nonlinear integrable equations.
NASA Astrophysics Data System (ADS)
El-Tantawy, S. A.
2016-05-01
We examine the likelihood of the ion-acoustic rogue waves propagation in a non-Maxwellian electronegative plasma in the framework of the family of the Korteweg-de Vries (KdV) equations (KdV/modified KdV/Extended KdV equation). For this purpose, we use the reductive perturbation technique to carry out this study. It is known that the family of the KdV equations have solutions of distinct structures such as solitons, shocks, kinks, cnoidal waves, etc. However, the dynamics of the nonlinear rogue waves is governed by the nonlinear Schrödinger equation (NLSE). Thus, the family of the KdV equations is transformed to their corresponding NLSE developing a weakly nonlinear wave packets. We show the possible region for the existence of the rogue waves and define it precisely for typical parameters of space plasmas. We investigate numerically the effects of relevant physical parameters, namely, the negative ion relative concentration, the nonthermal parameter, and the mass ratio on the propagation of the rogue waves profile. The present study should be helpful in understanding the salient features of the nonlinear structures such as, ion-acoustic solitary waves, shock waves, and rogue waves in space and in laboratory plasma where two distinct groups of ions, i.e. positive and negative ions, and non-Maxwellian (nonthermal) electrons are present.
NASA Astrophysics Data System (ADS)
Liu, Junyang; Hang, Chao; Huang, Guoxiang
2016-06-01
We propose a scheme to demonstrate the existence of optical Peregrine rogue waves and Akhmediev and Kuznetsov-Ma breathers and realize their active control via electromagnetically induced transparency (EIT). The system we suggest is a cold, Λ -type three-level atomic gas interacting with a probe and a control laser fields and working under EIT condition. We show that, based on EIT with an incoherent optical pumping, which can be used to cancel optical absorption, (1+1)-dimensional optical Peregrine rogue waves, Akhmediev breathers, and Kuznetsov-Ma breathers can be generated with very low light power. In addition, we demonstrate that the Akhmediev and Kuznetsov-Ma breathers in (2+1)-dimensions obtained can be actively manipulated by using an external magnetic field. As a result, these breathers can display trajectory deflections and bypass obstacles during propagation.
NASA Astrophysics Data System (ADS)
Yu, Fajun
2017-02-01
Starting from a discrete spectral problem, we derive a hierarchy of nonlinear discrete equations which include the Ablowitz-Ladik (AL) equation. We analytically study the discrete rogue-wave (DRW) solutions of AL equation with three free parameters. The trajectories of peaks and depressions of profiles for the first- and second-order DRWs are produced by means of analytical and numerical methods. In particular, we study the solutions with dispersion in parity-time ( P T ) symmetric potential for Ablowitz-Musslimani equation. And we consider the non-autonomous DRW solutions, parameters controlling and their interactions with variable coefficients, and predict the long-living rogue wave solutions. Our results might provide useful information for potential applications of synthetic P T symmetric systems in nonlinear optics and condensed matter physics.
NASA Astrophysics Data System (ADS)
Wang, Lei; Qi, Feng-Hua; Tang, Bing; Shi, Yu-Ying
2016-12-01
Under investigation in this paper is a variable-coefficient AB (vcAB) system, which describes marginally unstable baroclinic wave packets in geophysical fluids and ultra-short pulses in nonlinear optics. The modulation instability analysis of solutions with variable coefficients in the presence of a small perturbation is studied. The modified Darboux transformation (mDT) of the vcAB system is constructed via a gauge transformation. The first-order non-autonomous rogue wave solutions of the vcAB system are presented based on the mDT. It is found that the wave amplitude of B exhibits two types of structures, i.e. the double-peak structure appears if the plane-wave solution parameter ω is equal to zero, while selecting ω≠0 yields a single-peak one. Effects of the variable coefficients on the rogue waves are graphically discussed in detail. The periodic rogue wave and composite rogue wave are obtained with different inhomogeneous parameters. Additionally, the nonlinear tunneling of the rogue waves through a conventional hyperbolic nonlinear well and barrier are investigated.
Wen, Xiao-Yong; Yan, Zhenya
2015-12-01
We study higher-order rogue wave (RW) solutions of the coupled integrable dispersive AB system (also called Pedlosky system), which describes the evolution of wave-packets in a marginally stable or unstable baroclinic shear flow in geophysical fluids. We propose its continuous-wave (CW) solutions and existent conditions for their modulation instability to form the rogue waves. A new generalized N-fold Darboux transformation (DT) is proposed in terms of the Taylor series expansion for the spectral parameter in the Darboux matrix and its limit procedure and applied to the CW solutions to generate multi-rogue wave solutions of the coupled AB system, which satisfy the general compatibility condition. The dynamical behaviors of these higher-order rogue wave solutions demonstrate both strong and weak interactions by modulating parameters, in which some weak interactions can generate the abundant triangle, pentagon structures, etc. Particularly, the trajectories of motion of peaks and depressions of profiles of the first-order RWs are explicitly analyzed. The generalized DT method used in this paper can be extended to other nonlinear integrable systems. These results may be useful for understanding the corresponding rogue-wave phenomena in fluid mechanics and related fields.
Waves in hyperbolic and double negative metamaterials including rogues and solitons.
Boardman, Allan D; Alberucci, Alessandro; Assanto, Gaetano; Grimalsky, Vladimir; Kibler, Bertrand; McNiff, Jim; Nefedov, Igor; Rapoport, Yuriy; Valagiannopoulos, Costas
2017-03-17
The topics here deal with some current progress in electromagnetic wave propagation in a family of substances known as metamaterials. To begin with, it is discussed how a pulse can develop a leading edge that steepens and it is emphasised that such self-steepening is an important inclusion within a metamaterial environment together with Raman scattering and third-order dispersion whenever very short pulses are being investigated. It is emphasised that the self-steepening parameter is highly metamaterial-driven compared to Raman scattering, which is associated with a coefficient of the same form whether a normal positive phase, or a metamaterial waveguide is the vehicle for any soliton propagation. It is also shown that, for leading outcomes, including the fascinating rogue waves, the influence of magnetooptics provides a beautiful and important control mechanism for metamaterial pointing to devices and that, in the future, will have a significant impact upon the manner in which data control systems will behave for optical computing.
Rogue waves in injected semiconductor lasers with current modulation: role of the modulation phase.
Ahuja, Jatin; Nalawade, Dhananjay Bhiku; Zamora-Munt, Jordi; Vilaseca, Ramon; Masoller, Cristina
2014-11-17
Semiconductor lasers with continuous-wave optical injection display a rich variety of behaviors, including stable locking, periodic or chaotic oscillations, excitable pulses, etc. Within the chaotic regime it has been shown that the laser intensity can display extreme pulses, which have been identified as optical rogue waves (RWs), and it has also been shown that such extreme pulses can be completely suppressed via direct modulation of the laser current, with appropriated modulation amplitude and frequency. Here we perform a numerical analysis of the RW statistics and show that, when RWs are not suppressed by current modulation, their probability of occurrence strongly depends on the phase of the modulation. If the modulation is slow (the modulation frequency, fmod, is below the relaxation oscillation frequency, fro), the RWs occur within a well-defined interval of values of the modulation phase, i.e., there is a "safe" window of phases where no RWs occur. The most extreme RWs occur for modulation phases that are at the boundary of the safe window. When the modulation is fast (fmod > fro), there is no safe phase window; however, the RWs are likely to occur at particular values of the modulation phase. Our findings are of interest for the study of RWs in other systems, where a similar response to external forcing could be observed, and we hope that they will motivate experimental investigations to further elucidate the role of the modulation phase in the likelihood of the occurrence of RWs.
Wen, Xiao-Yong; Yan, Zhenya; Malomed, Boris A
2016-12-01
An integrable system of two-component nonlinear Ablowitz-Ladik equations is used to construct complex rogue-wave (RW) solutions in an explicit form. First, the modulational instability of continuous waves is studied in the system. Then, new higher-order discrete two-component RW solutions of the system are found by means of a newly derived discrete version of a generalized Darboux transformation. Finally, the perturbed evolution of these RW states is explored in terms of systematic simulations, which demonstrates that tightly and loosely bound RWs are, respectively, nearly stable and strongly unstable solutions.
NASA Astrophysics Data System (ADS)
Wen, Xiao-Yong; Yan, Zhenya; Malomed, Boris A.
2016-12-01
An integrable system of two-component nonlinear Ablowitz-Ladik equations is used to construct complex rogue-wave (RW) solutions in an explicit form. First, the modulational instability of continuous waves is studied in the system. Then, new higher-order discrete two-component RW solutions of the system are found by means of a newly derived discrete version of a generalized Darboux transformation. Finally, the perturbed evolution of these RW states is explored in terms of systematic simulations, which demonstrates that tightly and loosely bound RWs are, respectively, nearly stable and strongly unstable solutions.
NASA Astrophysics Data System (ADS)
Yu, Dang-Jun; Zhang, Jie-Fang
2016-10-01
Based on the modified Darboux transformation method, starting from zero solution and the plane wave solution, the hierarchies of rational solutions and breather solutions with "high frequency" and "low frequency" of the coupled nonlinear Schrödinger equation in parity-time symmetric nonlinear couplers with gain and loss are constructed, respectively. From these results, some basic characteristics of multi-rogue waves and multi-breathers are studied. Based on the property of rogue wave as the "quantum" of pattern structure in rogue wave hierarchy, we further study the novel structures of the superposed Akhmediev breathers, Kuznetsov-Ma solitons and their combined structures. It is expected that these results may give new insight into the context of the optical communications and Bose-Einstein condensations.
Zhong, Wei-Ping; Belić, Milivoj; Zhang, Yiqi
2015-02-09
Nonlinear Schrödinger equation with simple quadratic potential modulated by a spatially-varying diffraction coefficient is investigated theoretically. Second-order rogue wave breather solutions of the model are constructed by using the similarity transformation. A modal quantum number is introduced, useful for classifying and controlling the solutions. From the solutions obtained, the behavior of second order Kuznetsov-Ma breathers (KMBs), Akhmediev breathers (ABs), and Peregrine solitons is analyzed in particular, by selecting different modulation frequencies and quantum modal parameter. We show how to generate interesting second order breathers and related hybrid rogue waves. The emergence of true rogue waves - single giant waves that are generated in the interaction of KMBs, ABs, and Peregrine solitons - is explicitly displayed in our analytical solutions.
Guo, Shimin; Mei, Liquan; Sun, Anbang
2013-05-15
The nonlinear propagation of planar and nonplanar (cylindrical and spherical) ion-acoustic waves in an unmagnetized electron–positron–ion–dust plasma with two-electron temperature distributions is investigated in the context of the nonextensive statistics. Using the reductive perturbation method, a modified nonlinear Schrödinger equation is derived for the potential wave amplitude. The effects of plasma parameters on the modulational instability of ion-acoustic waves are discussed in detail for planar as well as for cylindrical and spherical geometries. In addition, for the planar case, we analyze how the plasma parameters influence the nonlinear structures of the first- and second-order ion-acoustic rogue waves within the modulational instability region. The present results may be helpful in providing a good fit between the theoretical analysis and real applications in future spatial observations and laboratory plasma experiments. -- Highlights: ► Modulational instability of ion-acoustic waves in a new plasma model is discussed. ► Tsallis’s statistics is considered in the model. ► The second-order ion-acoustic rogue wave is studied for the first time.
Predictability of rogue events.
Birkholz, Simon; Brée, Carsten; Demircan, Ayhan; Steinmeyer, Günter
2015-05-29
Using experimental data from three different rogue wave supporting systems, determinism, and predictability of the underlying dynamics are evaluated with methods of nonlinear time series analysis. We included original records from the Draupner platform in the North Sea as well as time series from two optical systems in our analysis. One of the latter was measured in the infrared tail of optical fiber supercontinua, the other in the fluence profiles of multifilaments. All three data sets exhibit extreme-value statistics and exceed the significant wave height in the respective system by a factor larger than 2. Nonlinear time series analysis indicates a different degree of determinism in the systems. The optical fiber scenario is found to be driven by quantum noise whereas rogue waves emerge as a consequence of turbulence in the others. With the large number of rogue events observed in the multifilament system, we can systematically explore the predictability of such events in a turbulent system. We observe that rogue events do not necessarily appear without a warning, but are often preceded by a short phase of relative order. This surprising finding sheds some new light on the fascinating phenomenon of rogue waves.
Guo, Shimin Mei, Liquan
2014-08-15
Dust-ion-acoustic (DIA) rogue waves are investigated in a three-dimensional magnetized plasma containing nonthermal electrons featuring Tsallis distribution, both positive and negative ions, and immobile dust grains having both positive and negative charges. Via the reductive perturbation method, a (3 + 1)-dimensional nonlinear Schrödinger (NLS) equation is derived to govern the dynamics of the DIA wave packets. The modulation instability of DIA waves described by the (3 + 1)-dimensional NLS equation is investigated. By means of the similarity transformation and symbolic computation, both the first- and second-order rogue wave solutions of the (3 + 1)-dimensional NLS equation are constructed in terms of rational functions. Moreover, the dynamics properties and the effects of plasma parameters on the nonlinear structures of rogue waves are discussed in detail. The results could be useful for understanding the physical mechanism of rogue waves in laboratory experiments where pair-ion plasmas with electrons and dust grains can be found.
Kedziora, David J; Ankiewicz, Adrian; Akhmediev, Nail
2012-06-01
We present an explicit analytic form for the two-breather solution of the nonlinear Schrödinger equation with imaginary eigenvalues. It describes various nonlinear combinations of Akhmediev breathers and Kuznetsov-Ma solitons. The degenerate case, when the two eigenvalues coincide, is quite involved. The standard inverse scattering technique does not generally provide an answer to this scenario. We show here that the solution can still be found as a special limit of the general second-order expression and appears as a mixture of polynomials with trigonometric and hyperbolic functions. A further restriction of this particular case, where the two eigenvalues are equal to i, produces the second-order rogue wave with two free parameters considered as differential shifts. The illustrations reveal a precarious dependence of wave profile on the degenerate eigenvalues and differential shifts. Thus we establish a hierarchy of second-order solutions, revealing the interrelated nature of the general case, the rogue wave, and the degenerate breathers.
Noninvasive measurement of viscosity from damping of capillary waves.
Behroozi, F; Lambert, B; Buhrow, B
2003-01-01
Capillary waves are surface waves on fluids with wavelengths in the millimeter range. The determination of viscosity from the damping of capillary waves is of great practical importance as it affords the possibility of measuring the viscosity of fluids noninvasively. In this paper a noncontact method for generation and detection of capillary waves on fluid is described. A miniature laser interferometer is employed to measure noninvasively the wave amplitude and its attenuation with a resolution of about 10 nm. As a test case, the attenuation data for capillary waves on pure water are used to obtain the kinematic viscosity of water as a function of temperature. The results compare favorably with the most reliable published data on the subject.
NASA Astrophysics Data System (ADS)
Jia, Shu-Liang; Gao, Yi-Tian; Zhao, Chen; Lan, Zhong-Zhou; Feng, Yu-Jie
2017-01-01
Under investigation in this paper is a sixth-order variable-coefficient nonlinear Schrödinger equation in an ocean or optical fiber. Through the Darboux transformation (DT) and generalized DT, we obtain the multi-soliton solutions, breathers and rogue waves. Choosing different values of α( x), β( x), γ( x) and δ( x), which are the coefficients of the third-, fourth-, fifth- and sixth-order dispersions, respectively, we investigate their effects on those solutions, where x is the scaled propagation variable. When α( x), β( x), γ( x) and δ( x) are chosen as the linear, parabolic and periodic functions, we obtain the parabolic, cubic and quasi-periodic solitons, respectively. Head-on and overtaking interactions between the two solitons are presented, and the interactions are elastic. Besides, with certain values of the spectral parameter λ, a shock region between the two solitons appears, and the interaction is inelastic. Interactions between two kinds of the breathers are also studied, and we find that the interaction regions are similar to those of the second-order rogue waves. Rogue waves are split into some first-order rogue waves when α( x), β( x), γ( x) and δ( x) are the periodic or odd-numbered functions.
Numerical simulation of the resonantly excited capillary-gravity waves
NASA Astrophysics Data System (ADS)
Hanazaki, Hideshi; Hirata, Motonori; Okino, Shinya
2015-11-01
Capillary gravity waves excited by an obstacle are investigated by a direct numerical simulation. In the flow without capillary effects, it is well known that large-amplitude upstream advancing solitary waves are generated periodically under the resonant condition, i.e., when the phase velocity of the long surface waves and the mean flow velocity agrees. With capillary effects, solutions of the Euler equations show the generation of very short waves further upstream of the solitary waves and also in the depression region downstream of the obstacle. The overall characteristics of these waves agree with the solutions of the forced fifth-order KdV equation, while the weakly nonlinear theory generally overestimates the wavelength of the short waves.
NASA Astrophysics Data System (ADS)
Chefranov, Sergey; Chefranov, Alexander
2016-04-01
Linear hydrodynamic stability theory for the Hagen-Poiseuille (HP) flow yields a conclusion of infinitely large threshold Reynolds number, Re, value. This contradiction to the observation data is bypassed using assumption of the HP flow instability having hard type and possible for sufficiently high-amplitude disturbances. HP flow disturbance evolution is considered by nonlinear hydrodynamic stability theory. Similar is the case of the plane Couette (PC) flow. For the plane Poiseuille (PP) flow, linear theory just quantitatively does not agree with experimental data defining the threshold Reynolds number Re= 5772 ( S. A. Orszag, 1971), more than five-fold exceeding however the value observed, Re=1080 (S. J. Davies, C. M. White, 1928). In the present work, we show that the linear stability theory conclusions for the HP and PC on stability for any Reynolds number and evidently too high threshold Reynolds number estimate for the PP flow are related with the traditional use of the disturbance representation assuming the possibility of separation of the longitudinal (along the flow direction) variable from the other spatial variables. We show that if to refuse from this traditional form, conclusions on the linear instability for the HP and PC flows may be obtained for finite Reynolds numbers (for the HP flow, for Re>704, and for the PC flow, for Re>139). Also, we fit the linear stability theory conclusion on the PP flow to the experimental data by getting an estimate of the minimal threshold Reynolds number as Re=1040. We also get agreement of the minimal threshold Reynolds number estimate for PC with the experimental data of S. Bottin, et.al., 1997, where the laminar PC flow stability threshold is Re = 150. Rogue waves excitation mechanism in oppositely directed currents due to the PC flow linear instability is discussed. Results of the new linear hydrodynamic stability theory for the HP, PP, and PC flows are published in the following papers: 1. S.G. Chefranov, A
Yang, Yunqing; Yan, Zhenya; Malomed, Boris A
2015-10-01
We analytically study rogue-wave (RW) solutions and rational solitons of an integrable fifth-order nonlinear Schrödinger (FONLS) equation with three free parameters. It includes, as particular cases, the usual NLS, Hirota, and Lakshmanan-Porsezian-Daniel equations. We present continuous-wave (CW) solutions and conditions for their modulation instability in the framework of this model. Applying the Darboux transformation to the CW input, novel first- and second-order RW solutions of the FONLS equation are analytically found. In particular, trajectories of motion of peaks and depressions of profiles of the first- and second-order RWs are produced by means of analytical and numerical methods. The solutions also include newly found rational and W-shaped one- and two-soliton modes. The results predict the corresponding dynamical phenomena in extended models of nonlinear fiber optics and other physically relevant integrable systems.
Dam break problem for the focusing nonlinear Schrödinger equation and the generation of rogue waves
NASA Astrophysics Data System (ADS)
El, G. A.; Khamis, E. G.; Tovbis, A.
2016-09-01
We propose a novel, analytically tractable, scenario of the rogue wave formation in the framework of the small-dispersion focusing nonlinear Schrödinger (NLS) equation with the initial condition in the form of a rectangular barrier (a ‘box’). We use the Whitham modulation theory combined with the nonlinear steepest descent for the semi-classical inverse scattering transform, to describe the evolution and interaction of two counter-propagating nonlinear wave trains—the dispersive dam break flows—generated in the NLS box problem. We show that the interaction dynamics results in the emergence of modulated large-amplitude quasi-periodic breather lattices whose amplitude profiles are closely approximated by the Akhmediev and Peregrine breathers within certain space-time domain. Our semi-classical analytical results are shown to be in excellent agreement with the results of direct numerical simulations of the small-dispersion focusing NLS equation.
Microscale capillary wave turbulence excited by high frequency vibration.
Blamey, Jeremy; Yeo, Leslie Y; Friend, James R
2013-03-19
Low frequency (O(10 Hz-10 kHz)) vibration excitation of capillary waves has been extensively studied for nearly two centuries. Such waves appear at the excitation frequency or at rational multiples of the excitation frequency through nonlinear coupling as a result of the finite displacement of the wave, most often at one-half the excitation frequency in so-called Faraday waves and twice this frequency in superharmonic waves. Less understood, however, are the dynamics of capillary waves driven by high-frequency vibration (>O(100 kHz)) and small interface length scales, an arrangement ideal for a broad variety of applications, from nebulizers for pulmonary drug delivery to complex nanoparticle synthesis. In the few studies conducted to date, a marked departure from the predictions of classical Faraday wave theory has been shown, with the appearance of broadband capillary wave generation from 100 Hz to the excitation frequency and beyond, without a clear explanation. We show that weak wave turbulence is the dominant mechanism in the behavior of the system, as evident from wave height frequency spectra that closely follow the Rayleigh-Jeans spectral response η ≈ ω(-17/12) as a consequence of a period-halving, weakly turbulent cascade that appears within a 1 mm water drop whether driven by thickness-mode or surface acoustic Rayleigh wave excitation. However, such a cascade is one-way, from low to high frequencies. The mechanism of exciting the cascade with high-frequency acoustic waves is an acoustic streaming-driven turbulent jet in the fluid bulk, driving the fundamental capillary wave resonance through the well-known coupling between bulk flow and surface waves. Unlike capillary waves, turbulent acoustic streaming can exhibit subharmonic cascades from high to low frequencies; here it appears from the excitation frequency all the way to the fundamental modes of the capillary wave at some four orders of magnitude in frequency less than the excitation frequency
A Simple Theory of Capillary-Gravity Wave Turbulence
NASA Technical Reports Server (NTRS)
Glazman, Roman E.
1995-01-01
Employing a recently proposed 'multi-wave interaction' theory, inertial spectra of capillary gravity waves are derived. This case is characterized by a rather high degree of nonlinearity and a complicated dispersion law. The absence of scale invariance makes this and some other problems of wave turbulence (e.g., nonlinear inertia gravity waves) intractable by small-perturbation techniques, even in the weak-turbulence limit. The analytical solution obtained in the present work for an arbitrary degree of nonlinearity is shown to be in reasonable agreement with experimental data. The theory explains the dependence of the wave spectrum on wind input and describes the accelerated roll-off of the spectral density function in the narrow sub-range separating scale-invariant regimes of purely gravity and capillary waves, while the appropriate (long- and short-wave) limits yield power laws corresponding to the Zakharov-Filonenko and Phillips spectra.
NASA Astrophysics Data System (ADS)
Zhang, Hai-Qiang; Chen, Jian
2016-04-01
In this paper, we study a higher-order variable coefficient nonlinear Schrödinger (NLS) equation, which plays an important role in the control of the ultrashort optical pulse propagation in nonlinear optical systems. Then, we construct a generalized Darboux transformation (GDT) for the higher-order variable coefficient NLS equation. The Nth order rogue wave solution is obtained by the iterative rule and it can be expressed by the determinant form. As application, we calculate rogue waves (RWs) from first- to fourth-order in accordance with different kinds of parameters. In particular, the dynamical properties and spatial-temporal structures of RWs are discussed and compared with Hirota equation through some figures.
Dynamics of the higher-order rogue waves for a generalized mixed nonlinear Schrödinger model
NASA Astrophysics Data System (ADS)
Wang, Lei; Jiang, Dong-Yang; Qi, Feng-Hua; Shi, Yu-Ying; Zhao, Yin-Chuan
2017-01-01
Under investigation in this paper is a generalized mixed nonlinear Schrödinger equation (GMNLSE) which arises in several physical areas including the quantum field theory, weakly nonlinear dispersive water waves, and nonlinear optics. The linear stability analysis is performed and the instability zones as well as the modulational instability gain are obtained and discussed. Higher-order rogue waves (RWs) in terms of the determinants for the GMNLSE model are constructed by the N-fold Darboux transformation. Several patterns of the RWs are illustrated, such as the fundamental pattern, triangular pattern, circular pattern, pentagon pattern, circular-triangular pattern, and circular-fundamental pattern. Effects of the nonlinear parameters on the RWs are discussed. It is found that the nonlinear terms affect the widths and velocities of the RWs, although the amplitudes of these waves remain unchanged. The semirational RW solution, which is a combination of rational and exponential functions, is derived to describe the interaction between the RW and multi-breather.
Priya, N Vishnu; Senthilvelan, M; Lakshmanan, M
2014-06-01
We construct dark-dark soliton, general breather (GB), Akhmediev breather (AB), Ma soliton (MS), and rogue wave (RW) solutions of a coupled generalized nonlinear Schrödinger (CGNLS) equation. While dark-dark solitons are captured in the defocusing regime of the CGNLS system, the other solutions, namely, GB, AB, MS, and RW, are identified in the focusing regime. We also analyze the structures of GB, AB, MS, and RW profiles with respect to the four-wave mixing parameter. We show that when we increase the value of the real part of the four-wave mixing parameter, the number of peaks in the breather profile increases and the width of each peak shrinks. Interestingly, the direction of this profile also changes due to this change. As far as the RW profile is concerned the width of the peak becomes very thin when we increase the value of this parameter. Further, we consider the RW solution as the starting point, derive AB, MS, and GB in the reverse direction, and show that the solutions obtained in both directions match each other. In the course of the reverse analysis we also demonstrate how to capture the RW solutions directly from AB and MS.
El-Tantawy, S. A.; Moslem, W. M.
2014-05-15
Solitons (small-amplitude long-lived waves) collision and rogue waves (large-amplitude short-lived waves) in non-Maxwellian electron-positron-ion plasma have been investigated. For the solitons collision, the extended Poincaré-Lighthill-Kuo perturbation method is used to derive the coupled Korteweg-de Vries (KdV) equations with the quadratic nonlinearities and their corresponding phase shifts. The calculations reveal that both positive and negative polarity solitons can propagate in the present model. At critical value of plasma parameters, the coefficients of the quadratic nonlinearities disappear. Therefore, the coupled modified KdV (mKdV) equations with cubic nonlinearities and their corresponding phase shifts have been derived. The effects of the electron-to-positron temperature ratio, the ion-to-electron temperature ratio, the positron-to-ion concentration, and the nonextensive parameter on the colliding solitons profiles and their corresponding phase shifts are examined. Moreover, generation of ion-acoustic rogue waves from small-amplitude initial perturbations in plasmas is studied in the framework of the mKdV equation. The properties of the ion-acoustic rogue waves are examined within a nonlinear Schrödinger equation (NLSE) that has been derived from the mKdV equation. The dependence of the rogue wave profile on the relevant physical parameters has been investigated. Furthermore, it is found that the NLSE that has been derived from the KdV equation cannot support the propagation of rogue waves.
Resonant Interactions of Capillary-Gravity Water Waves
NASA Astrophysics Data System (ADS)
Martin, Calin Iulian
2016-11-01
We show here that capillary-gravity wave trains can propagate at the free surface of a rotational water flow of constant non-zero vorticity over a flat bed only if the flow is two-dimensional. Moreover, we also show that the vorticity must have only one non zero component which points in the horizontal direction orthogonal to the direction of wave propagation. This result is of relevance in the study of nonlinear resonances of wave trains. We perform such a study for three- and four wave interactions.
On the evolution of a rogue wave along the orthogonal direction of the (t, x)-plane
NASA Astrophysics Data System (ADS)
Yuan, Feng; Qiu, Deqin; Liu, Wei; Porsezian, K.; He, Jingsong
2017-03-01
The localization characters of the first-order rogue wave (RW) solution u of the Kundu-Eckhaus equation is studied in this paper. We discover a full process of the evolution for the contour line with height c2 + d along the orthogonal direction of the (t, x)-plane for a first-order RW |u|2: A point at height 9c2 generates a convex curve for 3c2 ≤ d < 8c2, whereas it becomes a concave curve for 0 < d < 3c2, next it reduces to a hyperbola on asymptotic plane (i.e. equivalently d = 0), and the two branches of the hyperbola become two separate convex curves when -c2 < d < 0 , and finally they reduce to two separate points at d = -c2 . Using the contour line method, the length, width, and area of the RW at height c2 + d(0 < d < 8c2) , i.e. above the asymptotic plane, are defined. We study the evolutions of three above-mentioned localization characters on d through analytical and visual methods. The phase difference between the Kundu-Eckhaus and the nonlinear Schrodinger equation is also given by an explicit formula.
Stability of steep gravity capillary solitary waves in deep water
NASA Astrophysics Data System (ADS)
Calvo, David C.; Akylas, T. R.
2002-02-01
The stability of steep gravity capillary solitary waves in deep water is numerically investigated using the full nonlinear water-wave equations with surface tension. Out of the two solution branches that bifurcate at the minimum gravity capillary phase speed, solitary waves of depression are found to be stable both in the small-amplitude limit when they are in the form of wavepackets and at finite steepness when they consist of a single trough, consistent with observations. The elevation-wave solution branch, on the other hand, is unstable close to the bifurcation point but becomes stable at finite steepness as a limit point is passed and the wave profile features two well-separated troughs. Motivated by the experiments of Longuet-Higgins & Zhang (1997), we also consider the forced problem of a localized pressure distribution applied to the free surface of a stream with speed below the minimum gravity capillary phase speed. We find that the finite-amplitude forced solitary-wave solution branch computed by Vanden-Broeck & Dias (1992) is unstable but the branch corresponding to Rayleigh’s linearized solution is stable, in agreement also with a weakly nonlinear analysis based on a forced nonlinear Schrödinger equation. The significance of viscous effects is assessed using the approach proposed by Longuet-Higgins (1997): while for free elevation waves the instability predicted on the basis of potential-flow theory is relatively weak compared with viscous damping, the opposite turns out to be the case in the forced problem when the forcing is strong. In this régime, which is relevant to the experiments of Longuet-Higgins & Zhang (1997), the effects of instability can easily dominate viscous effects, and the results of the stability analysis are used to propose a theoretical explanation for the persistent unsteadiness of the forced wave profiles observed in the experiments.
Experimental investigation of three-wave interactions of capillary surface-waves
NASA Astrophysics Data System (ADS)
Berhanu, Michael; Cazaubiel, Annette; Deike, Luc; Jamin, Timothee; Falcon, Eric
2014-11-01
We report experiments studying the non-linear interaction between two crossing wave-trains of gravity-capillary surface waves generated in a closed laboratory tank. Using a capacitive wave gauge and Diffusive Light Photography method, we detect a third wave of smaller amplitude whose frequency and wavenumber are in agreement with the weakly non-linear triadic resonance interaction mechanism. By performing experiments in stationary and transient regimes and taking into account the viscous dissipation, we estimate directly the growth rate of the resonant mode in comparison with theory. These results confirm at least qualitatively and extend earlier experimental results obtained only for unidirectional wave train. Finally we discuss relevance of three-wave interaction mechanisms in recent experiment studying capillary wave turbulence.
NASA Astrophysics Data System (ADS)
Akhmediev, Nail; Ankiewicz, Adrian
2011-04-01
We study modulation instability (MI) of the discrete constant-background wave of the Ablowitz-Ladik (A-L) equation. We derive exact solutions of the A-L equation which are nonlinear continuations of MI at longer times. These periodic solutions comprise a family of two-parameter solutions with an arbitrary background field and a frequency of initial perturbation. The solutions are recurrent, since they return the field state to the original constant background solution after the process of nonlinear evolution has passed. These solutions can be considered as a complete resolution of the Fermi-Pasta-Ulam paradox for the A-L system. One remarkable consequence of the recurrent evolution is the nonlinear phase shift gained by the constant background wave after the process. A particular case of this family is the rational solution of the first-order or fundamental rogue wave.
Akhmediev, Nail; Ankiewicz, Adrian
2011-04-01
We study modulation instability (MI) of the discrete constant-background wave of the Ablowitz-Ladik (A-L) equation. We derive exact solutions of the A-L equation which are nonlinear continuations of MI at longer times. These periodic solutions comprise a family of two-parameter solutions with an arbitrary background field and a frequency of initial perturbation. The solutions are recurrent, since they return the field state to the original constant background solution after the process of nonlinear evolution has passed. These solutions can be considered as a complete resolution of the Fermi-Pasta-Ulam paradox for the A-L system. One remarkable consequence of the recurrent evolution is the nonlinear phase shift gained by the constant background wave after the process. A particular case of this family is the rational solution of the first-order or fundamental rogue wave.
Periodic optical rogue waves (PORWs) in parity-time (PT) symmetric Bragg-grating structure
NASA Astrophysics Data System (ADS)
Gupta, Samit Kumar; Sarma, Amarendra K.
2014-10-01
In this work, we present an analytical investigation of traveling wave solution in a nonlinear Bragg grating structure with the core of the optical fiber having PT-symmetric refractive index distribution. Under the approximation of weak-nonlinearity and above the PT-threshold region, the existence of highly intense, well-localized periodic train of pulses has been explored for the backward-propagating wave for some suitable choice of the parameter values of the system. The result of the present study might be useful in practical purpose in generating high-power, periodic optical pulses.
NASA Astrophysics Data System (ADS)
Okal, Emile; de Beer, Coenie; Visser, Johan; Kalligeris, Nikos
2013-04-01
In the early hours of Wednesday, 27 August 1969, the village of Dwarskersbos, Western Cape, South Africa, was inundated by a wave which flooded houses and damaged small boats. This small tsunami took place in the absence of any seismic source or extreme weather, and its origin has remained mysterious. In September 2010, we conducted a field survey based on the interview of nine elderly witnesses still living in the village, using techniques developed earlier for the study of the 1946 Aleutian and 1956 Greek tsunamis. We measured 13 locations, with run-up reaching 2.9 m for a maximum inundation of 260 m from the sea shore. The most remarkable aspect of our dataset is the extreme concentration of the flooding along a stretch of coastline of less than 2 km. In particular, the tsunami did not reach the communities located on the opposite side of St. Helena's Bay, nor did it affect Elands Bay and Lamberts Bay, respectively 43 and 68 km to the North. In order to investigate the possible origin of the Dwarskersbos tsunami, we first simulated an underwater landslide taking place in a canyon 20 km Northwest of Shelley Point, using the MOST code. This model predicts comparable amplitudes along most of the regional coastlines, and thus fails to explain the documented concentration at Dwarskersbos. By contrast, we explore a meteorological origin for the event by simulating the coupling between a possible squall (modeled as a steep pressure front) propagating over St. Helena's Bay and the oceanic column, using Proudman's [1953] original model, as applied by Platzman [1958] to the case of the 1954 Chicago rogue wave. We find that a front moving at 15 m/s in the azimuth N100E can resonate exclusively with the shallow bathymetry off Dwarskersbos, and thus explain most of the features revealed by our survey. This interpretation would be in contrast to the case of the tsunami of 21 August 2008, for which a comprehensive seriesof maregraphs along a 900-km stretch of coastline
Rogue events in the group velocity horizon
Demircan, Ayhan; Amiranashvili, Shalva; Brée, Carsten; Mahnke, Christoph; Mitschke, Fedor; Steinmeyer, Günter
2012-01-01
The concept of rogue waves arises from a mysterious and potentially calamitous phenomenon of oceanic surfaces. There is mounting evidence that they are actually commonplace in a variety of different physical settings. A set of defining criteria has been advanced; this set is of great generality and therefore applicable to a wide class of systems. The question arises naturally whether there are generic mechanisms responsible for extreme events in different systems. Here we argue that under suitable circumstances nonlinear interaction between weak and strong waves results in intermittent giant waves with all the signatures of rogue waves. To obtain these circumstances only a few basic conditions must be met. Then reflection of waves at the so-called group-velocity horizon occurs. The connection between rogue waves and event horizons, seemingly unrelated physical phenomena, is identified as a feature common in many different physical systems. PMID:23152941
Rogue events in the group velocity horizon.
Demircan, Ayhan; Amiranashvili, Shalva; Brée, Carsten; Mahnke, Christoph; Mitschke, Fedor; Steinmeyer, Günter
2012-01-01
The concept of rogue waves arises from a mysterious and potentially calamitous phenomenon of oceanic surfaces. There is mounting evidence that they are actually commonplace in a variety of different physical settings. A set of defining criteria has been advanced; this set is of great generality and therefore applicable to a wide class of systems. The question arises naturally whether there are generic mechanisms responsible for extreme events in different systems. Here we argue that under suitable circumstances nonlinear interaction between weak and strong waves results in intermittent giant waves with all the signatures of rogue waves. To obtain these circumstances only a few basic conditions must be met. Then reflection of waves at the so-called group-velocity horizon occurs. The connection between rogue waves and event horizons, seemingly unrelated physical phenomena, is identified as a feature common in many different physical systems.
Regularity for steady periodic capillary water waves with vorticity.
Henry, David
2012-04-13
In the following, we prove new regularity results for two-dimensional steady periodic capillary water waves with vorticity, in the absence of stagnation points. Firstly, we prove that if the vorticity function has a Hölder-continuous first derivative, then the free surface is a smooth curve and the streamlines beneath the surface will be real analytic. Furthermore, once we assume that the vorticity function is real analytic, it will follow that the wave surface profile is itself also analytic. A particular case of this result includes irrotational fluid flow where the vorticity is zero. The property of the streamlines being analytic allows us to gain physical insight into small-amplitude waves by justifying a power-series approach.
Single-shot observation of optical rogue waves in integrable turbulence using time microscopy
Suret, Pierre; Koussaifi, Rebecca El; Tikan, Alexey; Evain, Clément; Randoux, Stéphane; Szwaj, Christophe; Bielawski, Serge
2016-01-01
Optical fibres are favourable tabletop laboratories to investigate both coherent and incoherent nonlinear waves. In particular, exact solutions of the one-dimensional nonlinear Schrödinger equation such as fundamental solitons or solitons on finite background can be generated by launching periodic, specifically designed coherent waves in optical fibres. It is an open fundamental question to know whether these coherent structures can emerge from the nonlinear propagation of random waves. However the typical sub-picosecond timescale prevented—up to now—time-resolved observations of the awaited dynamics. Here, we report temporal ‘snapshots' of random light using a specially designed ‘time-microscope'. Ultrafast structures having peak powers much larger than the average optical power are generated from the propagation of partially coherent waves in optical fibre and are recorded with 250 femtoseconds resolution. Our experiment demonstrates the central role played by ‘breather-like' structures such as the Peregrine soliton in the emergence of heavy-tailed statistics in integrable turbulence. PMID:27713416
Single-shot observation of optical rogue waves in integrable turbulence using time microscopy
NASA Astrophysics Data System (ADS)
Suret, Pierre; Koussaifi, Rebecca El; Tikan, Alexey; Evain, Clément; Randoux, Stéphane; Szwaj, Christophe; Bielawski, Serge
2016-10-01
Optical fibres are favourable tabletop laboratories to investigate both coherent and incoherent nonlinear waves. In particular, exact solutions of the one-dimensional nonlinear Schrödinger equation such as fundamental solitons or solitons on finite background can be generated by launching periodic, specifically designed coherent waves in optical fibres. It is an open fundamental question to know whether these coherent structures can emerge from the nonlinear propagation of random waves. However the typical sub-picosecond timescale prevented--up to now--time-resolved observations of the awaited dynamics. Here, we report temporal `snapshots' of random light using a specially designed `time-microscope'. Ultrafast structures having peak powers much larger than the average optical power are generated from the propagation of partially coherent waves in optical fibre and are recorded with 250 femtoseconds resolution. Our experiment demonstrates the central role played by `breather-like' structures such as the Peregrine soliton in the emergence of heavy-tailed statistics in integrable turbulence.
Entanglement effects in capillary waves on liquid polymer films.
Jiang, Zhang; Mukhopadhyay, Mrinmay K; Song, Sanghoon; Narayanan, Suresh; Lurio, L B; Kim, Hyunjung; Sinha, Sunil K
2008-12-12
Overdamped surface capillary wave relaxations on molten polymer films were measured using x-ray photon correlation spectroscopy. We found a transition from a single through a stretched to another single exponential regime as the temperature is decreased from well above to near the bulk glass transition temperature. A universal scaling of the dynamics was discovered over a wide range of film thicknesses, temperatures, and molecular weights (except in the multiple relaxation regime). These observations are justified by hydrodynamic theory and the time-temperature superposition principle by considering an effective viscosity instead of the bulk zero shear viscosity.
Capillary-wave description of rapid directional solidification.
Korzhenevskii, Alexander L; Bausch, Richard; Schmitz, Rudi
2012-02-01
A recently introduced capillary-wave description of binary-alloy solidification is generalized to include the procedure of directional solidification. For a class of model systems a universal dispersion relation of the unstable eigenmodes of a planar steady-state solidification front is derived, which readjusts previously known stability considerations. We moreover establish a differential equation for oscillatory motions of a planar interface that offers a limit-cycle scenario for the formation of solute bands and, taking into account the Mullins-Sekerka instability, of banded structures.
Liu, Meng; Cai, Ze-Rong; Hu, Song; Luo, Ai-Ping; Zhao, Chu-Jun; Zhang, Han; Xu, Wen-Cheng; Luo, Zhi-Chao
2015-10-15
We reported on the generation of dissipative rogue waves (DRWs) induced by long-range chaotic multi-pulse interactions in a fiber laser based on a topological insulator (TI)-deposited microfiber photonic device. By virtue of the simultaneous saturable absorption effect and high nonlinearity provided by the TI-deposited microfiber, a localized, chaotic multi-pulse wave packet with strong long-range nonlinear interactions could be obtained, which gives rise to the formation of DRWs. The results might enhance the understanding of DRWs in optical systems, and further demonstrated that the TI-deposited microfiber could be considered as an excellent photonic device with both saturable absorption and highly nonlinear effects for the application field of nonlinear optics.
Experimental study of three-wave interactions among capillary-gravity surface waves
NASA Astrophysics Data System (ADS)
Haudin, Florence; Cazaubiel, Annette; Deike, Luc; Jamin, Timothée; Falcon, Eric; Berhanu, Michael
2016-04-01
In propagating wave systems, three- or four-wave resonant interactions constitute a classical nonlinear mechanism exchanging energy between the different scales. Here we investigate three-wave interactions for gravity-capillary surface waves in a closed laboratory tank. We generate two crossing wave trains and we study their interaction. Using two optical methods, a local one (laser doppler vibrometry) and a spatiotemporal one (diffusive light photography), a third wave of smaller amplitude is detected, verifying the three-wave resonance conditions in frequency and in wave number. Furthermore, by focusing on the stationary regime and by taking into account viscous dissipation, we directly estimate the growth rate of the resonant mode. The latter is then compared to the predictions of the weakly nonlinear triadic resonance interaction theory. The obtained results confirm qualitatively and extend previous experimental results obtained only for collinear wave trains. Finally, we discuss the relevance of three-wave interaction mechanisms in recent experiments studying gravity-capillary turbulence.
Wave drag due to generation of capillary-gravity surface waves
NASA Astrophysics Data System (ADS)
Burghelea, Teodor; Steinberg, Victor
2002-11-01
The onset of the wave resistance via the generation of capillary-gravity waves by a small object moving with a velocity V is investigated experimentally. Due to the existence of a minimum phase velocity Vc for surface waves, the problem is similar to the generation of rotons in superfluid helium near their minimum. In both cases, waves or rotons are produced at V>Vc due to Cherenkov radiation. We find that the transition to the wave drag state is continuous: in the vicinity of the bifurcation the wave resistance force is proportional to (V-Vc) for various fluids. This observation contradicts the theory of Raphaël and de Gennes. We also find that the reduced wave drag force for different fluids and different ball size may be scaled in such a way that all the data collapse on a single curve. The capillary-gravity wave pattern and the shape of the wave-generating region are investigated both experimentally and theoretically. Good agreement between the theory and the experimental data is found in this case.
Capillary Waves And Energy Coupling In Laser Materials Processing
NASA Astrophysics Data System (ADS)
Gasser, A.; Herziger, G.; Holtgen, B.; Kreutz, E. W.; Treusch, H. G.
1987-09-01
Static and dynamic measurements of the incident laser power, of the diffuse and specular reflected power have been performed in order to determine the absorption behavior of various metals and semiconductors during the interaction with powerful CO2-and Nd:YAG-laser-radiation. The absorptivity of the vapor and laser-induced plasma was probed by high-speed photography and measurements of conductivity transients as a function of intensity, composition, and pressure of the ambient atmosphere. For I
Diffusing light photography of solitons and capillary-wave turbulence
Wright, W.; Budak, R.; Putterman, S. )
1994-11-01
The attenuation of light propagating through a slab of water (containing a dilute concentration of polyballs) is approximately proportional to its thickness. Application of this insight to the local elevation of a fluid surface has enabled us to use photography to determine the instantaneous global topography of the surface of a fluid in motion. Use of diffusing light enables us to obtain images that are free of the caustics which plague shadowgraphs. Applications include breather solitons and wave turbulence which results from the nonlinear interaction of a broadband spectrum of high amplitude surface ripples. Measurements indicate that as the amplitude of excitation of the surface of water is increased the wave number of the capillary motion displays a transition to a broadband spectrum. The temporal response of a single pixel yields the power spectrum of the surface height as a function of frequency [ital f].'' The numerous harmonics which can be seen at low amplitude merge at high amplitude into a broadband spectrum which goes as 1/[ital f][sup 3]. This technique should permit the measurement of turbulent parameters which go beyond the purported range of current theories. [Work supported by US DOE Division of Engineering and Geophysics and NASA Microgravity.
Rogue run-up events at the North Sea coast
NASA Astrophysics Data System (ADS)
Didenkulova, Ira; Blossier, Brice; Daly, Christopher; Herbst, Gabriel; Senichev, Dmitry; Winter, Christian
2015-04-01
On the 1st of January, 1995, the Statoil-operated "Draupner" platform located in the North Sea recorded the so-called "New Year wave". Since then, rogue waves have been the topic of active scientific discussions and investigations. Waves of extreme height appearing randomly at the sea surface have been measured in both deep and shallow waters and have been involved in a number of ship accidents. Nowadays rogue waves are frequently recorded all over the world with several different instruments (range finders installed on offshore platforms, deployed buoys, radars including SAR, etc.). Rogue wave also occur at the coast, where they appear as either sudden flooding of coastal areas or high splashes over steep banks or sea walls. These waves are especially dangerous for beach users and lead regularly to human injuries and fatalities. Despite numerous reports of human accidents, coastal rogue waves have not yet been recorded experimentally. In this paper we discuss the recording of rogue wave events at German North Sea coasts by using high-resolution beach cameras. The recorded rogue waves are observed during different tide levels and different weather conditions. Possible mechanisms of their generation are discussed.
Energy flux measurement from the dissipated energy in capillary wave turbulence.
Deike, Luc; Berhanu, Michael; Falcon, Eric
2014-02-01
We study experimentally the influence of dissipation on stationary capillary wave turbulence on the surface of a liquid by changing its viscosity. We observe that the frequency power-law scaling of the capillary spectrum departs significantly from its theoretical value when the dissipation is increased. The energy dissipated by capillary waves is also measured and found to increase nonlinearly with the mean power injected within the liquid. Here we propose an experimental estimation of the energy flux at every scale of the capillary cascade. The latter is found to be nonconstant through the scales. For fluids of low enough viscosity, we found that both capillary spectrum scalings with the frequency and the newly defined mean energy flux are in good agreement with wave turbulence theory. The Kolmogorov-Zakharov constant is then experimentally estimated and compared to its theoretical value.
NASA Astrophysics Data System (ADS)
Ball, Philip
2015-07-01
Once thought to be the stuff of exaggeration by seafaring folk, we now know that giant “rogue” waves that soar to heights of up to 30 m really do occur at sea. But scientists can't yet agree on why they happen, as Philip Ball reports.
NASA Astrophysics Data System (ADS)
Anisimov, V. N.; Kozolupenko, A. P.; Sebrant, A. Yu
1988-12-01
An experimental investigation was made of the plasma transparency to heating radiation in capillaries when absorption waves propagated in these capillaries as a result of interaction with a CO2 laser pulse of 5-μs duration. When the length of the capillary was in excess of 20 mm, total absorption of the radiation by the plasma was observed at air pressures of 1-100 kPa. When the capillary length was 12 mm, a partial recovery of the transparency took place. A comparison was made with the dynamics and recovery of the plasma transparency when breakdown of air took place near the free surface.
On the physical mechanism of front-back asymmetry of nonlinear gravity-capillary waves
NASA Astrophysics Data System (ADS)
Dosaev, Alexander; Troitskaya, Yulia; Shrira, Victor
2016-04-01
In nature wind waves of all scales are asymmetric both with respect to the horizontal and vertical axes. The front-back (or fore-aft asymmetry), i.e. the asymmetry with respect to the vertical axis, manifests itself in steeper front slopes. Although it can be important for remote sensing of sea surface and wave field interaction with wind, especially for the waves of gravity-capillary range, at present the understanding of physical mechanisms causing the gravity-capillary waves asymmetry and its dependence on parameters is very poor; there has been no study dedicated to this problem. Here we address this gap. The decimetre-range water waves in many respects essentially differ from the waves of other ranges: wind forcing is stronger, steep waves develop a characteristic pattern of capillary ripples on their forward slopes. These 'parasitic capillaries', generated by a narrow pressure distribution associated with an underlying longer wave' crest, remain quasi-stationary with regard to the longer wave. The train of capillaries is localised on the front slope and decays towards the trough. We investigate the nature of the asymmetry of such waves by extensive numerical simulations of the Euler equations employing the method of conformal mapping for two-dimensional potential flow and taking into account wave generation by wind and dissipation due to molecular viscosity. We examine the role of various factors contributing to the wave profile asymmetry: wind pumping, viscous stresses, the Reynolds stresses caused by ripples and found the latter to be by far the most important. It is the lop-sided ripple distribution which leads to noticeable fore-aft asymmetry of the mean wave profile. We also found how the asymmetry depends on wavelength, steepness, wind and viscosity, which enables us to parametrize these dependencies for applications in microwave remote sensing and wave generation.
Numerical simulation of the capillary-gravity waves excited by an obstacle
NASA Astrophysics Data System (ADS)
Hanazaki, Hideshi; Inomata, Ryosuke
2016-11-01
Capillary gravity waves excited by an obstacle are investigated by the unsteady numerical solution of the Euler equations. It is well known that the large-amplitude upstream advancing solitary waves are generated periodically under the resonant condition of Fr =1 (Fr: Froude number), i.e., when the phase velocity of the long surface waves agrees with the mean flow speed. With capillary effects (Bo>0), short waves are newly generated by the upstream solitary waves of large amplitude. In this study it is investigated how the characteristics of the solitary waves and the short waves, especially their amplitudes, change due to the variation of the obstacle height and the Froude number. The results will be compared also with the solutions of the forced KdV-type equations.
Isotropic-nematic interface in suspensions of hard rods: mean-field properties and capillary waves.
Wolfsheimer, S; Tanase, C; Shundyak, K; van Roij, R; Schilling, T
2006-06-01
We present a study of the isotropic-nematic interface in a system of hard spherocylinders. First we compare results from Monte Carlo simulations and Onsager density functional theory for the interfacial profiles of the orientational order parameter and the density. Those interfacial properties that are not affected by capillary waves are in good agreement, despite the fact that Onsager theory overestimates the coexistence densities. Then we show results of a Monte Carlo study of the capillary waves of the interface. In agreement with recent theoretical investigations [Elgeti and Schmid, Eur. Phys. J. E 18, 407 (2005)] we find a strongly anisotropic capillary wave spectrum. For the wave numbers accessed in our simulations, the spectrum is quadratic, i.e., elasticity does not play a role. We conjecture that this effect is due to the strong bending rigidity of the director field in suspensions of spherocylinders.
Confining capillary waves to control aerosol droplet size from surface acoustic wave nebulisation
NASA Astrophysics Data System (ADS)
Nazarzadeh, Elijah; Reboud, Julien; Wilson, Rab; Cooper, Jonathan M.
Aerosols play a significant role in targeted delivery of medication through inhalation of drugs in a droplet form to the lungs. Delivery and targeting efficiencies are mainly linked to the droplet size, leading to a high demand for devices that can produce aerosols with controlled sizes in the range of 1 to 5 μm. Here we focus on enabling the control of the droplet size of a liquid sample nebulised using surface acoustic wave (SAW) generated by interdigitated transducers on a piezoelectric substrate (lithium niobate). The formation of droplets was monitored through a high-speed camera (600,000 fps) and the sizes measured using laser diffraction (Spraytec, Malvern Ltd). Results show a wide droplet size distribution (between 0.8 and 400 μm), while visual observation (at fast frame rates) revealed that the large droplets (>100 μm) are ejected due to large capillary waves (80 to 300 μm) formed at the free surface of liquid due to leakage of acoustic radiation of the SAWs, as discussed in previous literature (Qi et al. Phys Fluids, 2008). To negate this effect, we show that a modulated structure, specifically with feature sizes, typically 200 μm, prevents formation of large capillary waves by reducing the degrees of freedom of the system, enabling us to obtain a mean droplet size within the optimum range for drug delivery (<10 μm). This work was supported by an EPSRC grant (EP/K027611/1) and an ERC Advanced Investigator Award (340117-Biophononics).
Extreme events in Faraday waves
NASA Astrophysics Data System (ADS)
Punzmann, Horst; Shats, Michael; Xia, Hua
2014-05-01
Observations of extreme wave events in the ocean are rare due to their low statistical probability. In the laboratory however, the evolution of extreme wave events can be studied in great detail with high spatial and temporal resolution. The reported surface wave experiments in the short wavelength gravity-capillary range aim to contribute to the understanding of some of the underlying mechanisms for rogue wave generation. In this talk, we report on extreme wave events in parametrically excited Faraday waves. Faraday waves appear if a fluid is accelerated (normal to the fluid surface) above a critical threshold. A variety of novel tools have been deployed to characterize the 2D surface elevation. The results presented show spatio-temporal and statistical data on the surface wave conditions leading up to extreme wave events. The peak in wave amplitude during such an event is shown to exceed six times the standard deviation of the average wave field with significantly increased statistical probability compared to the background wave field [1]. The experiments also show that parametrically excited waves can be viewed as assembles of oscillons [2] (or oscillating solitons) where modulation instability seems to play a crucial role in their formation. More detailed studies on the oscillon dynamics reveal that the onset of an increased probability of extreme wave events correlates with the increase in the oscillons mobility and merger [3]. Reference: 1. Xia H., Maimbourg T., Punzmann H., and Shats M., Oscillon dynamics and rogue wave generation in Faraday surface ripples, Physical Review Letters 109, 114502 (2012) 2. Shats M., Xia H., and Punzmann H., Parametrically excited water surface ripples as ensembles of oscillons, Physical Review Letters 108, 034502 (2012) 3. Shats M., Punzmann H., Xia H., Capillary rogue waves, Physical Review Letters, 104, 104503 (2010)
Experimental observation of gravity-capillary solitary waves generated by a moving air-suction
NASA Astrophysics Data System (ADS)
Park, Beomchan; Cho, Yeunwoo
2016-11-01
Gravity-capillary solitary waves are generated by a moving "air-suction" forcing instead of a moving "air-blowing" forcing. The air-suction forcing moves horizontally over the surface of deep water with speeds close to the minimum linear phase speed cmin = 23 cm/s. Three different states are observed according to forcing speed below cmin. At relatively low speeds below cmin, small-amplitude linear circular depressions are observed, and they move steadily ahead of and along with the moving forcing. As the forcing speed increases close to cmin, however, nonlinear 3-D gravity-capillary solitary waves are observed, and they move steadily ahead of and along with the moving forcing. Finally, when the forcing speed is very close to cmin, oblique shedding phenomena of 3-D gravity-capillary solitary waves are observed ahead of the moving forcing. We found that all the linear and nonlinear wave patterns generated by the air-suction forcing correspond to those generated by the air-blowing forcing. The main difference is that 3-D gravity-capillary solitary waves are observed "ahead of" the air-suction forcing, whereas the same waves are observed "behind" the air-blowing forcing. This work was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (NRF-2014R1A1A1002441).
Capillary Gravity Waves over an Obstruction - Forced Generalized KdV equation
NASA Astrophysics Data System (ADS)
Choi, Jeongwhan; Whang, S. I.; Sun, Shu-Ming
2013-11-01
Capillary gravity surface waves of an ideal fluid flow over an obstruction is considered. When the Bond number is near the critical value 1/3, a forced generalized KdV equation of fifth order is derived. We study the equation analytically and numerically. Existence and stability of solutions are studied and new types of numerical solutions are found.
Stability of Steep Gravity--Capillary Solitary Waves in Deep Water
NASA Astrophysics Data System (ADS)
Akylas, T. R.; Calvo, D. C.
2000-11-01
The stability of steep gravity--capillary solitary waves in deep water is numerically investigated using the full nonlinear water-wave equations with surface tension. As was found in prior work based on model equations for small-amplitude solitary waves in shallow water, out of the two solution branches that bifurcate at the minimum gravity--capillary phase speed, solitary waves of depression again turn out to be stable while those of elevation are unstable to small disturbances. Motivated by the experiments of Longuet-Higgins & Zhang (Phys. Fluids 9:1963--1968, 1997), we also consider the forced problem of a localised pressure distribution applied to the free surface of a stream with speed below the minimum gravity--capillary phase speed. We find that the finite-amplitude forced solitary-wave solution branch computed by Vanden-Broeck & Dias (J. Fluid Mech. 240:549--557, 1992) is unstable but the branch corresponding to Rayleigh's linearised solution is stable. The significance of viscous effects is assessed; the effects of instability in steep waves generally are comparable to, and in some cases greater than, those of dissipation. These findings are discussed in connection with the experimental observations of Longuet-Higgins & Zhang.
Instability of water jet: Aerodynamically induced acoustic and capillary waves
NASA Astrophysics Data System (ADS)
Broman, Göran I.; Rudenko, Oleg V.
2012-09-01
High-speed water jet cutting has important industrial applications. To further improve the cutting performance it is critical to understand the theory behind the onset of instability of the jet. In this paper, instability of a water jet flowing out from a nozzle into ambient air is studied. Capillary forces and compressibility of the liquid caused by gas bubbles are taken into account, since these factors have shown to be important in previous experimental studies. A new dispersion equation, generalizing the analogous Rayleigh equation, is derived. It is shown how instability develops because of aerodynamic forces that appear at the streamlining of an initial irregularity of the equilibrium shape of the cross-section of the jet and how instability increases with increased concentration of gas bubbles. It is also shown how resonance phenomena are responsible for strong instability. On the basis of the theoretical explanations given, conditions for stable operation are indicated.
A numerical study on parasitic capillary waves using unsteady conformal mapping
NASA Astrophysics Data System (ADS)
Murashige, Sunao; Choi, Wooyoung
2017-01-01
This paper describes fully nonlinear computation of unsteady motion of parasitic capillary waves that appear on the front face of steep gravity waves progressing on water of infinite depth, within the framework of irrotational plane flow. As an alternative to the widely-used boundary integral method with mixed-Eulerian-Lagrangian (MEL) time updating, we focus on a numerical method based on unsteady conformal mapping, which will be hereafter referred to as the unsteady hodograph transformation (UHT) method. In this method, we solve the nonlinear evolution equations to find an unsteady conformal map in a complex plane with which the flow domain is mapped onto the unit disk while the free surface is fixed on the unit circle. The aim of this work is to compare the UHT method with the MEL method and find a more efficient method to compute parasitic capillary waves. From linear stability analysis, it is found that a critical difference between these two methods arises from the kernel of cotangent function in singular integrals, and the UHT method can avoid some numerical instability due to it. Numerical examples demonstrate that the UHT method is more suitable than the MEL method for not only parasitic capillary waves, but also capillary dominated waves. In particular, the UHT method requires no artificial techniques, such as filtering, to control numerical errors, in these examples. In addition, another major difference between the two methods is observed in terms of the clustering property of sample points on the free surface, depending on the restoring force of waves (gravity or surface tension).
NASA Astrophysics Data System (ADS)
Duncan, J. H.; Diorio, J. D.; Lisiewski, A.; Harris, R.
2009-11-01
The wave pattern generated by a small pressure source moving across a water surface at speeds less than the minimum phase speed for linear gravity-capillary waves (cmin = 23 cm/s) was investigated experimentally. The resulting wave pattern was measured using cinematic shadowgraph and laser-induced fluorescence (LIF) techniques. The results show the existence of several distinct behavioral states. At low speeds, no wave behavior is observed and the pattern resembles the symmetric stationary condition. However, at a critical speed, but still below cmin, the pattern undergoes a sudden transition to an asymmetric state with a stationary, 2D solitary wave that forms behind the pressure source. This solitary wave is elongated in the cross-stream relative to the stream-wise direction and resembles gravity-capillary ``lumps'' observed in previous numerical calculations. As the translation speed approaches cmin, another time-dependent behavior is observed characterized by periodic ``shedding'' from a V-shaped solitary wave pattern. This work will be discussed in conjunction with the recent numerical calculations of T. Akylas and his research group.
An air/sea flux model including the effects of capillary waves
NASA Technical Reports Server (NTRS)
Bourassa, Mark A.
1993-01-01
An improved model of the air/sea interface is developed. The improvements consist in including the effect of capillary (surface tension) waves on the tropical surface fluxes and the consideration of the sea state, both of which increase the magnitude of tropical surface fluxes. Changes in surface stress are most significant in the low wind-speed regions, which include the areas where westerly bursts occur. It is shown that the changes, from the regular wind conditions to those of a westerly burst or El-Nino, can double when the effects of capillary waves are considered. This implies a much stronger coupling between the ocean and the atmosphere than is predicted by other boundary layer models.
Gravity-capillary waves in finite depth on flows of constant vorticity
NASA Astrophysics Data System (ADS)
Hsu, Hung-Chu; Francius, Marc; Montalvo, Pablo; Kharif, Christian
2016-11-01
This paper considers two-dimensional periodic gravity-capillary waves propagating steadily in finite depth on a linear shear current (constant vorticity). A perturbation series solution for steady periodic waves, accurate up to the third order, is derived using a classical Stokes expansion procedure, which allows us to include surface tension effects in the analysis of wave-current interactions in the presence of constant vorticity. The analytical results are then compared with numerical computations with the full equations. The main results are (i) the phase velocity is strongly dependent on the value of the vorticity; (ii) the singularities (Wilton singularities) in the Stokes expansion in powers of wave amplitude that correspond to a Bond number of 1/2 and 1/3, which are the consequences of the non-uniformity in the ordering of the Fourier coefficients, are found to be influenced by vorticity; (iii) different surface profiles of capillary-gravity waves are computed and the effect of vorticity on those profiles is shown to be important, in particular that the solutions exhibit type-2-like wave features, characterized by a secondary maximum on the surface profile with a trough between the two maxima.
Gravity-capillary waves in finite depth on flows of constant vorticity.
Hsu, Hung-Chu; Francius, Marc; Montalvo, Pablo; Kharif, Christian
2016-11-01
This paper considers two-dimensional periodic gravity-capillary waves propagating steadily in finite depth on a linear shear current (constant vorticity). A perturbation series solution for steady periodic waves, accurate up to the third order, is derived using a classical Stokes expansion procedure, which allows us to include surface tension effects in the analysis of wave-current interactions in the presence of constant vorticity. The analytical results are then compared with numerical computations with the full equations. The main results are (i) the phase velocity is strongly dependent on the value of the vorticity; (ii) the singularities (Wilton singularities) in the Stokes expansion in powers of wave amplitude that correspond to a Bond number of 1/2 and 1/3, which are the consequences of the non-uniformity in the ordering of the Fourier coefficients, are found to be influenced by vorticity; (iii) different surface profiles of capillary-gravity waves are computed and the effect of vorticity on those profiles is shown to be important, in particular that the solutions exhibit type-2-like wave features, characterized by a secondary maximum on the surface profile with a trough between the two maxima.
Maxwell, Eric J; Tong, William G
2016-05-01
An ultrasensitive label-free antibody-free detection method for malachite green and crystal violet is presented using nonlinear laser wave-mixing spectroscopy and capillary zone electrophoresis. Wave-mixing spectroscopy provides a sensitive absorption-based detection method for trace analytes. This is accomplished by forming dynamic gratings within a sample cell, which diffracts light to create a coherent laser-like signal beam with high optical efficiency and high signal-to-noise ratio. A cubic dependence on laser power and square dependence on analyte concentration make wave mixing sensitive enough to detect molecules in their native form without the use of fluorescent labels for signal enhancement. A 532 nm laser and a 635 nm laser were used for malachite green and crystal violet sample excitation. The use of two lasers of different wavelengths allows the method to simultaneously detect both analytes. Selectivity is obtained through the capillary zone electrophoresis separation, which results in characteristic migration times. Measurement in capillary zone electrophoresis resulted in a limit of detection of 6.9 × 10(-10)M (2.5 × 10(-19) mol) for crystal violet and 8.3 × 10(-11)M (3.0 × 10(-20) mol) for malachite green at S/N of 2.
Water Surface Currents, Short Gravity-Capillary Waves and Radar Backscatter
NASA Technical Reports Server (NTRS)
Atakturk, Serhad S.; Katsaros, Kristina B.
1993-01-01
Despite their importance for air-sea interaction and microwave remote sensing of the ocean surface, intrinsic properties of short gravity-capillary waves are not well established. This is largely due to water surface currents and their effects on the direct measurements of wave parameters conducted at a fixed point. Frequencies of small scale waves propagating on a surface which itself is in motion, are subject to Doppler shifts. Hence, the high frequency tail of the wave spectra obtained from such temporal observations is smeared. Conversion of this smeared measured-frequency spectra to intrinsic-frequency (or wavenumber) spectra requires corrections for the Doppler shifts. Such attempts in the past have not been very successful in particular when field data were used. This becomes evident if the amplitude modulation of short waves by underlying long waves is considered. Microwave radar studies show that the amplitude of a short wave component attains its maximum value near the crests and its minimum in the troughs of the long waves. Doppler-shifted wave data yield similar results but much larger in modulation magnitude, as expected. In general, Doppler shift corrections reduce the modulation magnitude. Overcorrection may result in a negligible modulation or even in a strong modulation with the maximum amplitude in the wave troughs. The latter situation is clearly contradictory to our visual observations as well as the radar results and imply that the advection by currents is overestimated. In this study, a differential-advection approach is used in which small scale waves are advected by the currents evaluated not at the free surface, but at a depth proportional to their wavelengths. Applicability of this approach is verified by the excellent agreement in phase and magnitude of short-wave modulation between results based on radar and on wave-gauge measurements conducted on a lake.
Spatiotemporal rogue events in femtosecond filamentation
Majus, D.; Jukna, V.; Valiulis, G.; Dubietis, A.; Faccio, D.
2011-02-15
We present experimental and numerical investigations of optical extreme (rogue) event statistics recorded in the regime of femtosecond pulse filamentation in water. In the spectral domain, the extreme events manifest themselves as either large or small extremes of the spectral intensity, justified by right- or left-tailed statistical distributions, respectively. In the time domain, the observed extreme events are associated with pulse splitting and energy redistribution in space and therefore are exquisitely linked to three-dimensional, spatiotemporal dynamics and formation of the X waves.
Damping of short gravity-capillary waves due to oil derivatives film on the water surface
NASA Astrophysics Data System (ADS)
Sergievskaya, Irina; Ermakov, Stanislav; Lazareva, Tatyana
2016-10-01
In this paper new results of laboratory studies of damping of gravity-capillary waves on the water surface covered by kerosene are presented and compared with our previous analysis of characteristics of crude oil and diesel fuel films. Investigations of kerosene films were carried out in a wide range values of film thicknesses (from some hundreds millimetres to a few millimetres) and in a wide range of surface wave frequencies (from 10 to 27 Hz). The selected frequency range corresponds to the operating wavelengths of microwave, X- to Ka-band radars typically used for the ocean remote sensing. The studied range of film thickness covers typical thicknesses of routine spills in the ocean. It is obtained that characteristics of waves, measured in the presence of oil derivatives films differ from those for crude oil films, in particular, because the volume viscosity of oil derivatives and crude oil is strongly different. To retrieve parameters of kerosene films from the experimental data the surface wave damping was analyzed theoretically in the frame of a model of two-layer fluid. The films are assumed to be soluble, so the elasticity on the upper and lower boundaries is considered as a function of wave frequency. Physical parameters of oil derivative films were estimated when tuning the film parameters to fit theory and experiment. Comparison between wave damping due to crude oil, kerosene and diesel fuel films have shown some capabilities of distinguishing of oil films from remote sensing of short surface waves.
Interfacial free energy of the NaCl crystal-melt interface from capillary wave fluctuations.
Benet, Jorge; MacDowell, Luis G; Sanz, Eduardo
2015-04-07
In this work we study, by means of molecular dynamics simulations, the solid-liquid interface of NaCl under coexistence conditions. By analysing capillary waves, we obtain the stiffness for different orientations of the solid and calculate the interfacial free energy by expanding the dependency of the interfacial free energy with the solid orientation in terms of cubic harmonics. We obtain an average value for the solid-fluid interfacial free energy of 89 ± 6 mN m(-1) that is consistent with previous results based on the measure of nucleation free energy barriers [Valeriani et al., J. Chem. Phys. 122, 194501 (2005)]. We analyse the influence of the simulation setup on interfacial properties and find that facets prepared as an elongated rectangular stripe give the same results as those prepared as squares for all cases but the 111 face. For some crystal orientations, we observe at small wave-vectors a behaviour not consistent with capillary wave theory and show that this behavior does not depend on the simulation setup.
Breakup of Bubbles or Drops by Capillary Waves Induced by Coalescence or Other Excitations
NASA Astrophysics Data System (ADS)
Zhang, Feng Hua; Taborek, Peter; Burton, Justin; Cheong Khoo, Boo; Thoroddsen, Siggi
2012-02-01
Capillary breakup of a bubble or drop by various excitations is ubiquitous in both nature and technology. Examples include coalescence with another bubble or drop, wetting on a solid surface, impact on a solid surface, detachment from a nozzle, or vibrations driven by acoustic, electrical, or magnetic fields. When the excitation ceases, capillary forces on the surface naturally drive the deformed bubble or drop to recover its spherical shape. However, when the viscosity is small, this recovery can lead to nonlinear oscillations of the interface and a singularity in the flow. Here we use high-speed imaging to investigate the coalescence of bubbles and drops of various sizes. In many cases, coalescence leads to pinch-off events and the formation of the satellite and sub-satellite. Our experiments use pressured xenon gas in glycerol/water mixtures so that the density ratio and viscosity ratio can be varied over many orders of magnitude. We characterize the generation, propagation, and convergence of capillary waves, the formation time and sizes of satellites, and the dynamics of two-fluid pinch-off as a function of the density ratio and viscosity ratio. The work shall benefit the wide-spread applications and fulfill the scientific and public curiosities.
Capillary waves and the decay of density correlations at liquid surfaces.
Hernández-Muñoz, Jose; Chacón, Enrique; Tarazona, Pedro
2016-12-01
Wertheim predicted strong density-density correlations at free liquid surfaces, produced by capillary wave fluctuations of the interface [M. S. Wertheim, J. Chem. Phys. 65, 2377 (1976)JCPSA60021-960610.1063/1.433352]. That prediction has been used to search for a link between capillary wave (CW) theory and density functional (DF) formalism for classical fluids. In particular, Parry et al. have recently analyzed the decaying tails of these CW effects moving away from the interface as a clue for the extended CW theory [A. O. Parry et al., J. Phys.: Condens. Matter 28, 244013 (2016)JCOMEL0953-898410.1088/0953-8984/28/24/244013], beyond the strict long-wavelength limit studied by Wertheim. Some apparently fundamental inconsistencies between the CW and the DF theoretical views of the fluid interfaces arose from the asymptotic analysis of the CW signal. In this paper we revisit the problem of the CW asymptotic decay with a separation of local non-CW surface correlation effects from those that are a truly nonlocal propagation of the CW fluctuations from the surface towards the liquid bulk.
Capillary waves and the decay of density correlations at liquid surfaces
NASA Astrophysics Data System (ADS)
Hernández-Muñoz, Jose; Chacón, Enrique; Tarazona, Pedro
2016-12-01
Wertheim predicted strong density-density correlations at free liquid surfaces, produced by capillary wave fluctuations of the interface [M. S. Wertheim, J. Chem. Phys. 65, 2377 (1976), 10.1063/1.433352]. That prediction has been used to search for a link between capillary wave (CW) theory and density functional (DF) formalism for classical fluids. In particular, Parry et al. have recently analyzed the decaying tails of these CW effects moving away from the interface as a clue for the extended CW theory [A. O. Parry et al., J. Phys.: Condens. Matter 28, 244013 (2016), 10.1088/0953-8984/28/24/244013], beyond the strict long-wavelength limit studied by Wertheim. Some apparently fundamental inconsistencies between the CW and the DF theoretical views of the fluid interfaces arose from the asymptotic analysis of the CW signal. In this paper we revisit the problem of the CW asymptotic decay with a separation of local non-CW surface correlation effects from those that are a truly nonlocal propagation of the CW fluctuations from the surface towards the liquid bulk.
Asymmetric Directional Multicast for Capillary Machine-to-Machine Using mmWave Communications.
Kwon, Jung-Hyok; Kim, Eui-Jik
2016-04-11
The huge demand for high data rate machine-to-machine (M2M) services has led to the use of millimeter Wave (mmWave) band communications with support for a multi-Gbps data rate through the use of directional antennas. However, unnecessary sector switching in multicast transmissions with directional antennas results in a long delay, and consequently a low throughput. We propose asymmetric directional multicast (ADM) for capillary M2M to address this problem in mmWave communications. ADM provides asymmetric sectorization that is optimized for the irregular deployment pattern of mulicast group members. In ADM, an M2M gateway builds up asymmetric sectors with a beamwidth of a different size to cover all multicast group members with the minimum number of directional transmissions. The performance of ADM under various simulation environments is evaluated through a comparison with legacy mmWave multicast. The results of the simulation indicate that ADM achieves a better performance in terms of the transmission sectors, the transmission time, and the aggregate throughput when compared with the legacy multicast method.
Asymmetric Directional Multicast for Capillary Machine-to-Machine Using mmWave Communications
Kwon, Jung-Hyok; Kim, Eui-Jik
2016-01-01
The huge demand for high data rate machine-to-machine (M2M) services has led to the use of millimeter Wave (mmWave) band communications with support for a multi-Gbps data rate through the use of directional antennas. However, unnecessary sector switching in multicast transmissions with directional antennas results in a long delay, and consequently a low throughput. We propose asymmetric directional multicast (ADM) for capillary M2M to address this problem in mmWave communications. ADM provides asymmetric sectorization that is optimized for the irregular deployment pattern of mulicast group members. In ADM, an M2M gateway builds up asymmetric sectors with a beamwidth of a different size to cover all multicast group members with the minimum number of directional transmissions. The performance of ADM under various simulation environments is evaluated through a comparison with legacy mmWave multicast. The results of the simulation indicate that ADM achieves a better performance in terms of the transmission sectors, the transmission time, and the aggregate throughput when compared with the legacy multicast method. PMID:27077859
Spatiotemporal rogue events in optical multiple filamentation.
Birkholz, Simon; Nibbering, Erik T J; Brée, Carsten; Skupin, Stefan; Demircan, Ayhan; Genty, Goëry; Steinmeyer, Günter
2013-12-13
The transient appearance of bright spots in the beam profile of optical filaments formed in xenon is experimentally investigated. Fluence profiles are recorded with high-speed optical cameras at the kilohertz repetition rate of the laser source. A statistical analysis reveals a thresholdlike appearance of heavy-tailed fluence distributions together with the transition from single to multiple filamentation. The multifilament scenario exhibits near-exponential probability density functions, with extreme events exceeding the significant wave height by more than a factor of 10. The extreme events are isolated in space and in time. The macroscopic origin of these experimentally observed heavy-tail statistics is shown to be local refractive index variations inside the nonlinear medium, induced by multiphoton absorption and subsequent plasma thermalization. Microscopically, mergers between filament strings appear to play a decisive role in the observed rogue wave statistics.
NASA Astrophysics Data System (ADS)
Kobyakov, D.; Bychkov, V.; Lundh, E.; Bezett, A.; Marklund, M.
2012-08-01
We study the parametric resonance of capillary waves on the interface between two immiscible Bose-Einstein condensates pushed towards each other by an oscillating force. Guided by analytical models, we solve numerically the coupled Gross-Pitaevskii equations for a two-component Bose-Einstein condensate at zero temperature. We show that, at moderate amplitudes of the driving force, the instability is stabilized due to nonlinear modifications of the oscillation frequency. When the amplitude of the driving force is large enough, we observe a detachment of droplets from the Bose-Einstein condensates, resulting in the generation of quantum vortices (skyrmions). We analytically investigate the vortex dynamics, and conditions of quantized vortex generation.
Dramatic enhancement of capillary wave fluctuations of a decorated water surface
Datta, A.; Kundu, S.; Sanyal, M.K.; Daillant, J.; Luzet, D.; Blot, C.; Struth, B.
2005-04-01
We have demonstrated by x-ray diffuse scattering that a bimolecular layer of a preformed three-tailed amphiphile, ferric stearate, drastically enhances capillary wave fluctuations on water surface due to a reduction in surface tension to 1 mN/m. The bimolecular layer is composed of molecules in symmetric configuration, on top of molecules in asymmetric configuration with ferric ions in contact with water. Unlike the usual Langmuir monolayers, this layer of molecules does not rupture under compression, but becomes thicker. This behavior mimics folding of a membrane on a liquid surface and is closely related to the cohesive interaction brought by the ferric ions. The low effective tension of this artificial membrane depends on the available area and reduces as the microscopic excess area increases.
Energy spectra of 2D gravity and capillary waves with narrow frequency band excitation
NASA Astrophysics Data System (ADS)
Kartashova, E.
2012-02-01
In this letter we present a new method, called increment chain equation method (ICEM), for computing a cascade of distinct modes in a two-dimensional weakly nonlinear wave system generated by narrow frequency band excitation. The ICEM is a means for computing the quantized energy spectrum as an explicit function of frequency ω0 and stationary amplitude A0 of excitation. The physical mechanism behind the generation of the quantized cascade is modulation instability. The ICEM can be used in numerous 2D weakly nonlinear wave systems with narrow frequency band excitation appearing in hydrodynamics, nonlinear optics, electrodynamics, convection theory etc. In this letter the ICEM is demonstrated with examples of gravity and capillary waves with dispersion functions ω(k)~k1/2 and ω(k)~k3/2, respectively, and for two different levels of nonlinearity ɛ=A0k0: small (ɛ~0.1 to 0.25) and moderate (ɛ~0.25 to 0.4).
The local structure factor near an interface; beyond extended capillary-wave models
NASA Astrophysics Data System (ADS)
Parry, A. O.; Rascón, C.; Evans, R.
2016-06-01
We investigate the local structure factor S (zq) at a free liquid-gas interface in systems with short-ranged intermolecular forces and determine the corrections to the leading-order, capillary-wave-like, Goldstone mode divergence of S (zq) known to occur for parallel (i.e. measured along the interface) wavevectors q\\to 0 . We show from explicit solution of the inhomogeneous Ornstein-Zernike equation that for distances z far from the interface, where the profile decays exponentially, S (zq) splits unambiguously into bulk and interfacial contributions. On each side of the interface, the interfacial contributions can be characterised by distinct liquid and gas wavevector dependent surface tensions, {σ l}(q) and {σg}(q) , which are determined solely by the bulk two-body and three-body direct correlation functions. At high temperatures, the wavevector dependence simplifies and is determined almost entirely by the appropriate bulk structure factor, leading to positive rigidity coefficients. Our predictions are confirmed by explicit calculation of S (zq) within square-gradient theory and the Sullivan model. The results for the latter predict a striking temperature dependence for {σ l}(q) and {σg}(q) , and have implications for fluctuation effects. Our results account quantitatively for the findings of a recent very extensive simulation study by Höfling and Dietrich of the total structure factor in the interfacial region, in a system with a cut-off Lennard-Jones potential, in sharp contrast to extended capillary-wave models which failed completely to describe the simulation results.
NASA Astrophysics Data System (ADS)
MacKenzie Laxague, Nathan Jean
Short ocean waves play a crucial role in the physical coupling between the ocean and the atmosphere. This is particularly true for gravity-capillary waves, waves of a scale (O(0.01-0.1) m) such that they are similarly restored to equilibrium by gravitational and interfacial tension (capillary) effects. These waves are inextricably linked to the turbulent boundary layer processes which characterize near-interfacial flows, acting as mediators of the momentum, gas, and heat fluxes which bear greatly on surface material transport, tropical storms, and climatic processes. The observation of these waves and the fluid mechanical phenomena which govern their behavior has long posed challenges to the would-be observer. This is due in no small part to the delicacy of centimeter-scale waves and the sensitivity of their properties to disruption via tactile measurement. With the ever-growing interest in satellite remote sensing, direct observations of short wave characteristics are needed along coastal margins. These zones are characterized by a diversity of physical processes which can affect the short-scale sea surface topography that is directly sensed via radar backscatter. In a related vein, these observations are needed to more fully understand the specific hydrodynamic relationship between young, wind-generated gravity-capillary waves and longer gravity waves. Furthermore, understanding of the full oceanic current profile is hampered by a lack of observations in the near-surface domain (z = O(0.01-0.1) m), where flows can differ greatly from those at depth. Here I present the development of analytical techniques for describing gravity-capillary ocean surface waves in order to better understand their role in the mechanical coupling between the atmosphere and ocean. This is divided amongst a number of research topics, each connecting short ocean surface waves to a physical forcing process via the transfer of momentum. One involves the examination of the sensitivity of
NASA Astrophysics Data System (ADS)
Bleibel, J.; Dietrich, S.; Domínguez, A.; Oettel, M.
2011-09-01
Using Brownian dynamics simulations, density functional theory, and analytical perturbation theory we study the collapse of a patch of interfacially trapped, micrometer-sized colloidal particles, driven by long-ranged capillary attraction. This attraction is formally analogous to two-dimensional (2D) screened Newtonian gravity with the capillary length λ^ as the screening length. Whereas the limit λ^→∞ corresponds to the global collapse of a self-gravitating fluid, for finite λ^ we predict theoretically and observe in simulations a ringlike density peak at the outer rim of a disclike patch, moving as an inbound shock wave. Possible experimental realizations are discussed.
Capillary wave Hamiltonian for the Landau-Ginzburg-Wilson density functional
NASA Astrophysics Data System (ADS)
Chacón, Enrique; Tarazona, Pedro
2016-06-01
We study the link between the density functional (DF) formalism and the capillary wave theory (CWT) for liquid surfaces, focused on the Landau-Ginzburg-Wilson (LGW) model, or square gradient DF expansion, with a symmetric double parabola free energy, which has been extensively used in theoretical studies of this problem. We show the equivalence between the non-local DF results of Parry and coworkers and the direct evaluation of the mean square fluctuations of the intrinsic surface, as is done in the intrinsic sampling method for computer simulations. The definition of effective wave-vector dependent surface tensions is reviewed and we obtain new proposals for the LGW model. The surface weight proposed by Blokhuis and the surface mode analysis proposed by Stecki provide consistent and optimal effective definitions for the extended CWT Hamiltonian associated to the DF model. A non-local, or coarse-grained, definition of the intrinsic surface provides the missing element to get the mesoscopic surface Hamiltonian from the molecular DF description, as had been proposed a long time ago by Dietrich and coworkers.
NASA Astrophysics Data System (ADS)
Hsu, Hung-Chu; Kharif, Christian; Francius, Marc; Chen, Yang-Yih
2015-04-01
In this study a nonlinear Schrödinger equation governing the complex envelope of a capillary-gravity water wave train propagating on uniform vertical shear current is derived. When the vorticity and surface tension vanishes, the classical NLS equation is found. The influence of constant vorticity and surface tension on the well-known stability properties of weakly nonlinear wave packets is studied. It is demonstrated that vorticity and surface tension modifies significantly the modulational instability properties of weakly nonlinear plane waves, namely the growth rate and bandwidth. Comparison with a fully nonlinear approach is conducted, too.
Capillary-Physics Mechanism of Elastic-Wave Mobilization of Residual Oil
NASA Astrophysics Data System (ADS)
Beresnev, I. A.; Pennington, W. D.; Turpening, R. M.
2003-12-01
Much attention has been given to the possibility of vibratory mobilization of residual oil as a method of enhanced recovery. The common features of the relevant applications have nonetheless been inconsistency in the results of field tests and the lack of understanding of a physical mechanism that would explain variable experiences. Such a mechanism can be found in the physics of capillary trapping of oil ganglia, driven through the pore channels by an external pressure gradient. Entrapping of ganglia occurs due to the capillary pressure building on the downstream meniscus entering a narrow pore throat. The resulting internal-pressure imbalance acts against the external gradient, which needs to exceed a certain threshold to carry the ganglion through. The ganglion flow thus exhibits the properties of the Bingham (yield-stress) flow, not the Darcy flow. The application of vibrations is equivalent to the addition of an oscillatory forcing to the constant gradient. When this extra forcing acts along the gradient, an instant "unplugging" occurs, while, when the vibration reverses direction, the flow is plugged. This asymmetry results in an average non-zero flow over one period of vibration, which explains the mobilization effect. The minimum-amplitude and maximum-frequency thresholds apply for the mobilization to occur. When the vibration amplitude exceeds a certain "saturation" level, the flow returns to the Darcy regime. The criterion of the mobilization of a particular ganglion involves the parameters of both the medium (pore geometry, interfacial and wetting properties, fluid viscosity) and the oscillatory field (amplitude and frequency). The medium parameters vary widely under natural conditions. It follows that an elastic wave with a given amplitude and frequency will always produce a certain mobilization effect, mobilizing some ganglia and leaving others intact. The exact macroscopic effect is hard to predict, as it will represent a response of the populations
Rogue America: Benevolent Hegemon or Occupying Tyrant?
2008-05-01
Johnson, The Sorrows of Empire (New York: Metropolitan Books), 3. 5 Noam Chomsky , Rogue States (Cambridge: South End Press, 2000), 4. 6 For more on...convenience in making their argument. Focusing his attention on the United States, linguistics professor Noam Chomsky limits his rogue state definition to...14. 39 Noam Chomsky , “Rogue States Draw the Usual Line,” The Noam Chomsky Website, May 2001, http://www.chomsky.info/interviews/200105--.htm
NASA Astrophysics Data System (ADS)
de Poyferré, Thibault; Nguyen, Quang-Huy
2016-07-01
We consider the gravity-capillary waves in any dimension and in fluid domains with general bottoms. Using the paradifferential reduction established in [19], we prove Strichartz estimates for solutions to this problem, at a low regularity level such that initially, the velocity field can be non-Lipschitz up to the free surface. We then use those estimates to solve the Cauchy problem at this level of regularity.
Contours of slope as a measure of gravity-capillary wind waves
NASA Astrophysics Data System (ADS)
Cox, C. S.; Zhang, X.
2012-12-01
Contours of both x and y components of water surface slopes can be generated optically. Two horizontal arrays of thin, linear lamps placed a few meters below the water surface are photographed from above. One array, consisting of a group of colored y-parallel lamps produces contours of x-slope. The value of each contour is recognized by its color. The other array, of x -parallel lamps produces contours of y-slope. When the two arrays are pulsed alternately and photographed by a fast camera, the full structure and evolution of the water surface shape can be monitored. In order to register capillaries down to one or two millimeter wavelengths the light pulses must be as short as 200 micro seconds to avoid smearing Adequate light intensity in such short pulses is generated by a row of high intensity light emitting diodes in each linear lamp. LEDs are advantageous because several different colored types are available. permitting many different contours to be generated. When each emitter has a narrow wavelength range, problems from light dispersion and differential color absorption in the water are avoided. In analyzing the photographs, correct identification of the color in the image of each contour is essential. Color sensing cameras have only the three color coordinates, red, green and blue. It is useful to identify each colored contour image by a unit vector in the 3-space of RGB for comparison with the array of expected values. This enables recognition of the most probable color and an estimate of probable error of the choice. If the probable error is large, the contour can then be discarded because of uncertainty of its value.. The conversion from a small number of contours to a continuous representation of the water surface shape is in theory perfect for a band limited spectrum of waves, but in practice inaccuracies, even at the pixel level, in the location of contours produce errors. The spacing of contours of slope is determined by the physical spacing between
Damage Caused by the Rogue Trustee
ERIC Educational Resources Information Center
O'Banion, Terry
2009-01-01
Fifty-nine community college presidents and chancellors in 16 states report on the damage caused by rogue trustees. While the damage to presidents, other trustees, and faculty and staff is alarming, the damage these trustees cause the college suggests that the rogue trustee may be the single most destructive force ever to plague an educational…
NASA Astrophysics Data System (ADS)
Cho, Yeunwoo
2014-11-01
The shedding phenomena of 3-D viscous gravity-capillary solitary waves generated by a moving air-forcing on the surface of deep water are investigated. Near the resonance where the forcing speed is close to 23 cm/s, two kinds of shedding modes are possible; Anti-symmetric and symmetric modes. A relevant theoretical model equation is numerically solved for the identification of shedding of solitary waves, and is analytically studied in terms of their linear stability to transverse perturbations. Furthermore, by tracing trajectories of shed solitary waves, the decay rate of a 3-D solitary wave due to viscous dissipation is estimated. This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (NRF-2014R1A1A1002441).
NASA Astrophysics Data System (ADS)
Bhattacharjee, P. K.; McDonnell, A. G.; Prabhakar, R.; Yeo, L. Y.; Friend, J.
2011-02-01
Forming capillary bridges of low-viscosity (lsim10 mPa s) fluids is difficult, making the study of their capillary-thinning behavior and the measurement of the fluid's extensional viscosity difficult as well. Current techniques require some time to form a liquid bridge from the stretching of a droplet. Rapidly stretching a liquid bridge using these methods can cause its breakup if the viscosity is too low. Stretching more slowly allows the bridge to thin and break up before a suitable bridge geometry can be established to provide reliable and accurate rheological data. Using a pulsed surface acoustic wave to eject a jet from a sessile droplet, a capillary bridge may be formed in about 7.5 ms, about seven times quicker than current methods. With this approach, capillary bridges may be formed from Newtonian and non-Newtonian fluids having much lower viscosities—water, 0.04% by weight solution of high-molecular-weight (7 MDa) polystyrene in dioctyl phthalate and 0.25% fibrinogen solution in demineralized water, for example. Details of the relatively simple system used to achieve these results are provided, as are experimental results indicating deviations from a Newtonian response by the low-viscosity non-Newtonian fluids used in our study.
Understanding the influence of capillary waves on solvation at the liquid-vapor interface.
Rane, Kaustubh; van der Vegt, Nico F A
2016-03-21
This work investigates the question if surface capillary waves (CWs) affect interfacial solvation thermodynamic properties that determine the propensity of small molecules toward the liquid-vapor interface. We focus on (1) the evaluation of these properties from molecular simulations in a practical manner and (2) understanding them from the perspective of theories in solvation thermodynamics, especially solvent reorganization effects. Concerning the former objective, we propose a computational method that exploits the relationship between an external field acting on the liquid-vapor interface and the magnitude of CWs. The system considered contains the solvent, an externally applied field (f) and the solute molecule fixed at a particular location. The magnitude of f is selected to induce changes in CWs. The difference between the solvation free energies computed in the presence and in the absence of f is then shown to quantify the contribution of CWs to interfacial solvation. We describe the implementation of this method in the canonical ensemble by using a Lennard-Jones solvent and a non-ionic solute. Results are shown for three types of solutes that differ in the nature of short-ranged repulsive (hard-core) interactions. Overall, we observe that CWs have a negligible or very small effect on the interfacial solvation free energy of a solute molecule fixed near the liquid-vapor interface for the above systems. We also explain how the effects of pinning or dampening of CWs caused by a fixed solute are effectively compensated and do not contribute to the solvation free energy.
NASA Astrophysics Data System (ADS)
Diorio, J. D.; Watkins, N.; Zuech, J.; Duncan, J. H.
2008-11-01
There have been several recent numerical investigations that have shown the existence of three-dimensional nonlinear solitary surface wave patterns that propagate with speeds less than the minimum wave phase speed prescribed by linear theory (23 cm/s for clean water). In the present study, wave patterns were generated by translating a small-diameter region of high pressure across a water surface. The high-pressure region was created by forcing air through a small-diameter vertically oriented tube attached to a carriage that propelled it horizontally at speeds near 23 cm/s. The wave pattern was measured with a cinematic LIF technique. It was found that a steady solitary wave pattern can exist at speeds below the linear-theory minimum phase speed, while for speeds above the minimum, a pattern of gravity-capillary waves was produced. The solitary wave pattern, which only appeared when the pressure forcing was large, dissipated rapidly when the forcing was turned off. The streamwise dimension of the solitary wave was much smaller than the transverse dimension.
Simulation of Rogue Planet Encounters with the Solar System: Is Planet 9 a Captured Rogue?
NASA Astrophysics Data System (ADS)
Vesper, James; Mason, Paul A.
2017-01-01
Rogue, or free-floating, planets may be abundant in the Galaxy. Several have been observed in the solar neighborhood. They have been predicted to even outnumber stars by a large fraction, and may partially account for dark matter in the disk of the galaxy, as the result of circumbinary planet formation. We performed N-body simulations of rogue encounters with the solar system with a variety of impact parameters. We find that Jupiter mass and higher rogues leave a significant imprint on planetary system architecture. Rogue formation models are therefore constrained by observed planetary system structure. We speculate that if rogue planets are abundant as predicted, then, Planet 9 may be a captured rogue.
NASA Astrophysics Data System (ADS)
Sato, Masanori; Matsuura, Kazuo; Fujii, Toshitaka
2001-02-01
We show the experimental data of selective ethanol separation from ethanol-water solution, using ultrasonic atomization. Pure ethanol could be obtained directly from a solution with several mol% ethanol-water solution at 10 °C. This result can be explained in terms of parametric decay instability of capillary wave, in which high localization and accumulation of acoustic energy occur, leading to ultrasonic atomization. That is, parametric decay instability condenses the energy of longitudinal waves in a highly localized surface area of the capillary wave, and causes ultrasonic atomization.
NASA Astrophysics Data System (ADS)
Majumder, D. P.; Dhar, A. K.
2015-12-01
A nonlinear spectral transport equation for the narrow band Gaussian random surface wave trains is derived from a fourth order nonlinear evolution equation, which is a good starting point for the study of nonlinear water waves. The effect of randomness on the stability of deep water capillary gravity waves in the presence of air flowing over water is investigated. The stability is then considered for an initial homogenous wave spectrum having a simple normal form to small oblique long wave length perturbations for a range of spectral widths. An expression for the growth rate of instability is obtained; in which a higher order contribution comes from the fourth order term in the evolution equation, which is responsible for wave induced mean flow. This higher order contribution produces a decrease in the growth rate. The growth rate of instability is found to decrease with the increase of spectral width and the instability disappears if the spectral width increases beyond a certain critical value, which is not influenced by the fourth order term in the evolution equation.
NASA Astrophysics Data System (ADS)
Cheung, David L.
2011-08-01
While the interaction of colloidal particles (sizes in excess of 100 nm) with liquid interfaces may be understood in terms of continuum models, which are grounded in macroscopic properties such as surface and line tensions, the behaviour of nanoparticles at liquid interfaces may be more complex. Recent simulations [D. L. Cheung and S. A. F. Bon, Phys. Rev. Lett. 102, 066103 (2009)], 10.1103/PhysRevLett.102.066103 of nanoparticles at an idealised liquid-liquid interface showed that the nanoparticle-interface interaction range was larger than expected due, in part, to the action of thermal capillary waves. In this paper, molecular dynamics simulations of a Lennard-Jones nanoparticle in a binary Lennard-Jones mixture are used to confirm that these previous results hold for more realistic models. Furthermore by including attractive interactions between the nanoparticle and the solvent, it is found that the detachment energy decreases as the nanoparticle-solvent attraction increases. Comparison between the simulation results and recent theoretical predictions [H. Lehle and M. Oettel, J. Phys. Condens. Matter 20, 404224 (2008)], 10.1088/0953-8984/20/40/404224 shows that for small particles the incorporation of capillary waves into the predicted effective nanoparticle-interface interaction improves agreement between simulation and theory.
Anderson localisation and optical-event horizons in rogue-soliton generation
NASA Astrophysics Data System (ADS)
Saleh, Mohammed F.; Conti, Claudio; Biancalana, Fabio
2017-03-01
We unveil the relation between the linear Anderson localisation process and nonlinear modulation instability. Anderson localised modes are formed in certain temporal intervals due to the random background noise. Such localised modes seed the formation of solitary waves that will appear during the modulation instability process at those preferred intervals. Afterwards, optical-event horizon effects between dispersive waves and solitons produce an artificial collective acceleration that favours the collision of solitons, which could eventually lead to a rogue-soliton generation.
On asymmetric generalized solitary gravity-capillary waves in finite depth.
Gao, T; Wang, Z; Vanden-Broeck, J-M
2016-10-01
Generalized solitary waves propagating at the surface of a fluid of finite depth are considered. The fluid is assumed to be inviscid and incompressible and the flow to be irrotational. Both the effects of gravity and surface tension are included. It is shown that in addition to the classical symmetric waves, there are new asymmetric solutions. These new branches of solutions bifurcate from the branches of symmetric waves. The detailed bifurcation diagrams as well as typical wave profiles are presented.
1993-01-01
doVA22202-4302 adto fte Office of Manaoement and BOW, PaperworkcReduction PrOlec (07040188). Wasbfinton, DC 2=63.1. Agency Use Only (Leave Blank). 2...by R . Lerner and G Trigg, VCH Publishers, Inc., New York. References 1. Watson, K. M., 1990. The coupling of surface and internal gravity waves...Creamer, D., F. Henyey, R . Schult, and J. Wright, 1989. Improved linear representation of ocean surface waves. J. Fluid Mech. 205, 135-161. •2:•2•:i
Foam on troubled water: Capillary induced finite-time arrest of sloshing waves
NASA Astrophysics Data System (ADS)
Viola, Francesco; Brun, P.-T.; Dollet, Benjamin; Gallaire, François
2016-09-01
Interfacial forces exceed gravitational forces on a scale small relative to the capillary length—two millimeters in the case of an air-water interface—and therefore dominate the physics of sub-millimetric systems. They are of paramount importance for various biological taxa and engineering processes where the motion of a liquid meniscus induces a viscous frictional force that exhibits a sublinear dependence in the meniscus velocity, i.e., a power law with an exponent smaller than one. Interested in the fundamental implications of this dependence, we use a liquid-foam sloshing system as a prototype to exacerbate the effect of sublinear friction on the macroscopic mechanics of multi-phase flows. In contrast to classical theory, we uncover the existence of a finite-time singularity in our system yielding the arrest of the fluid's oscillations. We propose a minimal theoretical framework to capture this effect, thereby amending the paradigmatic damped harmonic oscillator model. Our results suggest that, although often not considered at the macroscale, sublinear capillary forces govern the friction at liquid-solid and liquid-liquid interfaces.
... Why do capillary hemangiomas on the eyelids cause vision problems? Capillary Hemangiomas of the eyelid can cause ... a capillary hemangioma in the eye socket cause vision problems? A capillary hemangioma in the eye socket ( ...
NASA Astrophysics Data System (ADS)
Zhang, Anliang; Zha, Yan; Zhang, Jiansheng
2014-12-01
A new method for converting a microdroplet on a piezoelectric substrate into continuous fluid flow in microchannels is presented. An interdigital transducer with 27.5 MHz center frequency is fabricated on a 1280 yx-LiNbO3 piezoelectric substrate for exciting surface acoustic wave. A PDMS (Polydimethylsiloxane) microchannel is mounted on the piezoelectric substrate. One end of the microchannel is connected with water absorbing paper, while the other end of the microchannel is in touch with a droplet to be converted. The surface acoustic wave is used for controlling the evaporation velocity of the fluid in the microchannel. Part of fluid in the droplet can be entered into the microchannel and transported there due to the evaporation and capillary effects. Red dye solution is used to demonstrate the conversion of the droplet and the transportation of the fluid in the microchannel. Results show that the droplet on the piezoelectric substrate can successfully be converted into continuous fluid. The flow velocity is increased with the power of the electric signal applied to the interdigital transducer. Average flow velocity is 0.0235μl/s when the power of the electric signal is 30.0dBm. The work is helpful for piezoelectric microfluidic devices for biochemical analysis.
78 FR 60375 - Rogue Valley Terminal Railroad Corporation-Corporate Family Transaction Exemption
Federal Register 2010, 2011, 2012, 2013, 2014
2013-10-01
... TRANSPORTATION Surface Transportation Board Rogue Valley Terminal Railroad Corporation--Corporate Family Transaction Exemption Rogue Valley Terminal Railroad Corporation (Rogue Valley),\\1\\ a Class III rail carrier... White City Terminal & Utility Co. (WCTU) and was indirectly controlled by Berkshire Hathaway...
Wind driven capillary-gravity waves on Titan's lakes: Hard to detect or non-existent?
NASA Astrophysics Data System (ADS)
Hayes, A. G.; Lorenz, R. D.; Donelan, M. A.; Manga, M.; Lunine, J. I.; Schneider, T.; Lamb, M. P.; Mitchell, J. M.; Fischer, W. W.; Graves, S. D.; Tolman, H. L.; Aharonson, O.; Encrenaz, P. J.; Ventura, B.; Casarano, D.; Notarnicola, C.
2013-07-01
Saturn's moon Titan has lakes and seas of liquid hydrocarbon and a dense atmosphere, an environment conducive to generating wind waves. Cassini observations thus far, however, show no indication of waves. We apply models for wind wave generation and detection to the Titan environment. Results suggest wind speed thresholds at a reference altitude of 10 m of 0.4-0.7 m/s for liquid compositions varying between pure methane and equilibrium mixtures with the atmosphere (ethane has a threshold of 0.6 m/s), varying primarily with liquid viscosity. This reduced threshold, as compared to Earth, results from Titan's increased atmosphere-to-liquid density ratio, reduced gravity and lower surface tension. General Circulation Models (GCMs) predict wind speeds below derived thresholds near equinox, when available observations of lake surfaces have been acquired. Predicted increases in winds as Titan approaches summer solstice, however, will exceed expected thresholds and may provide constraints on lake composition and/or GCM accuracy through the presence or absence of waves during the Cassini Solstice Mission. A two-scale microwave backscatter model suggests that returns from wave-modified liquid hydrocarbon surfaces may be below the pixel-scale noise floor of Cassini radar images, but can be detectable using real-aperture scatterometry, pixel binning and/or observations obtained in a specular geometry.
NASA Astrophysics Data System (ADS)
Masnadi, Naeem; Duncan, James H.
2017-01-01
The unsteady response of a water free surface to a localized pressure source moving at constant speed $U$ in the range $0.95c_\\mathrm{min} \\lesssim U \\leq 1.02 c_\\mathrm{min}$, where $c_\\mathrm{min}$ is the minimum phase speed of linear gravity-capillary waves in deep water, is investigated through experiments and numerical simulations. This unsteady response state, which consists of a V-shaped pattern behind the source and features periodic shedding of pairs of depressions from the tips of the V, was first observed qualitatively by Diorio et al. (Phys. Rev. Let., 103, 214502, 2009) and called state III. In the present investigation, cinematic shadowgraph and refraction-based techniques are utilized to measure the temporal evolution of the free surface deformation pattern downstream of the source as it moves along a towing tank, while numerical simulations of the model equation described by Cho et al. (J. Fluid Mech., 672, 288-306, 2011) are used to extend the experimental results over longer times than are possible in the experiments. From the experiments, it is found that the speed-amplitude characteristics and the shape of the depressions are nearly the same as those of the freely propagating gravity-capillary lumps of inviscid potential theory. The decay rate of the depressions is measured from their height-time characteristics, which are well fitted by an exponential decay law with an order 1 decay constant. It is found that the shedding period of the depression pairs decreases with increasing source strength and speed. As the source speed approaches $c_\\mathrm{min}$, this period tends to about 1~s for all source magnitudes. At the low-speed boundary of state III, a new response with unsteady asymmetric shedding of depressions is found. This response is also predicted by the model equation.
NASA Astrophysics Data System (ADS)
Masnadi, Naeem; Cho, Yeunwoo; Duncan, James H.; Akylas, Triantaphyllos
2015-11-01
The non-linear response of a water free surface to a pressure source moving at speeds near the minimum speed of linear gravity-capillary waves (Cmin ~ 23 cm/s) is investigated with experiments and theory. In the experiments, waves are generated by a vertically oriented air-jet that moves at a constant speed over the water surface in a long tank. The 3-D surface shape behind the air-jet is measured using a cinematic refraction-based technique combined with an LIF technique. At towing speeds just below Cmin, an unsteady pattern is formed where localized depressions periodically appear in pairs and move away from the source along the arms of a downstream V-shaped pattern. This behavior is analogous to the periodic shedding of solitary waves upstream of a source moving at the maximum wave speed in shallow water. The gravity-capillary depressions are rapidly damped by viscosity and their speed-amplitude characteristics closely match those from inviscid calculations of gravity-capillary lumps. The shedding frequency of the lumps in the present experiments increases with both increasing towing speed and air-flow rate. Predictions of this behavior using a model equation that incorporates damping and a quadratic nonlinearity are in good agreement with the experiments. The partial support of the National Science Foundation under grant OCE0751853 is gratefully acknowledged.
Wang, Lei; Zhu, Yu-Jie; Qi, Feng-Hua; Li, Min; Guo, Rui
2015-06-01
In this paper, the nonautonomous Lenells-Fokas (LF) model is investigated. The modulational instability analysis of the solutions with variable coefficients in the presence of a small perturbation is studied. Higher-order soliton, breather, earthwormon, and rogue wave solutions of the nonautonomous LF model are derived via the n-fold variable-coefficient Darboux transformation. The solitons and earthwormons display the elastic collisions. It is found that the nonautonomous LF model admits the higher-order periodic rogue waves, composite rogue waves (rogue wave pair), and oscillating rogue waves, whose dynamics can be controlled by the inhomogeneous nonlinear parameters. Based on the second-order rogue wave, a diamond structure consisting of four first-order rogue waves is observed. In addition, the semirational solutions (the mixed rational-exponential solutions) of the nonautonomous LF model are obtained, which can be used to describe the interactions between the rogue waves and breathers. Our results could be helpful for the design of experiments in the optical fiber communications.
... repeat the test with blood drawn from a vein. Alternative Names Blood sample - capillary; Fingerstick; Heelstick Images Phenylketonuria test Phenylketonuria test Capillary sample References Garza ...
Tandiono; Ohl, Siew-Wan; Ow, Dave Siak-Wei; Klaseboer, Evert; Wong, Victor V T; Camattari, Andrea; Ohl, Claus-Dieter
2010-07-21
We present a study on achieving intense acoustic cavitation generated by ultrasonic vibrations in polydimethylsiloxane (PDMS) based microfluidic devices. The substrate to which the PDMS is bonded was forced into oscillation with a simple piezoelectric transducer attached at 5 mm from the device to a microscopic glass slide. The transducer was operated at 100 kHz with driving voltages ranging between 20 V and 230 V. Close to the glass surface, pressure and vibration amplitudes of up to 20 bar and 400 nm were measured respectively. It is found that this strong forcing leads to the excitation of nonlinear surface waves when gas-liquid interfaces are present in the microfluidic channels. Also, it is observed that nuclei leading to intense inertial cavitation are generated by the entrapment of gas pockets at those interfaces. Subsequently, cavitation bubble clusters with void fractions of more than 50% are recorded with high-speed photography at up to 250,000 frames/s. The cavitation clusters can be sustained through the continuous injection of gas using a T-junction in the microfluidic device.
Federal Register 2010, 2011, 2012, 2013, 2014
2010-08-02
... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF AGRICULTURE Forest Service Rogue River-Siskiyou National Forest, Oregon; Motorized Vehicle Use on the Rogue River-Siskiyou National Forest; Intent to Prepare a Supplemental Environmental Impact Statement (SEIS) To...
Enhancing optical extreme events through input wave disorder
NASA Astrophysics Data System (ADS)
Pierangeli, D.; Musarra, G.; Di Mei, F.; Di Domenico, G.; Agranat, A. J.; Conti, C.; DelRe, E.
2016-12-01
We demonstrate how the emergence of extreme events strongly depends on the correlation length of the input field distribution. Observing the behavior of optical waves in turbulent photorefractive propagation with partially incoherent excitations, we find that rogue waves are strongly enhanced for a characteristic input correlation scale. Waveform analysis identifies this scale with a characteristic peak-intensity-independent wave size, suggesting a general role played by saturation in the nonlinear response in rogue phenomena.
Manipulating localized matter waves in multicomponent Bose-Einstein condensates.
Manikandan, K; Muruganandam, P; Senthilvelan, M; Lakshmanan, M
2016-03-01
We analyze vector localized solutions of two-component Bose-Einstein condensates (BECs) with variable nonlinearity parameters and external trap potentials through a similarity transformation technique which transforms the two coupled Gross-Pitaevskii equations into a pair of coupled nonlinear Schrödinger equations with constant coefficients under a specific integrability condition. In this analysis we consider three different types of external trap potentials: a time-independent trap, a time-dependent monotonic trap, and a time-dependent periodic trap. We point out the existence of different interesting localized structures; namely, rogue waves, dark- and bright-soliton rogue waves, and rogue-wave breatherlike structures for the above three cases of trap potentials. We show how the vector localized density profiles in a constant background get deformed when we tune the strength of the trap parameter. Furthermore, we investigate the nature of the trajectories of the nonautonomous rogue waves. We also construct the dark-dark rogue wave solution for the repulsive-repulsive interaction of two-component BECs and analyze the associated characteristics for the three different kinds of traps. We then deduce single-, two-, and three-composite rogue waves for three-component BECs and discuss the correlated characteristics when we tune the strength of the trap parameter for different trap potentials.
Manipulating localized matter waves in multicomponent Bose-Einstein condensates
NASA Astrophysics Data System (ADS)
Manikandan, K.; Muruganandam, P.; Senthilvelan, M.; Lakshmanan, M.
2016-03-01
We analyze vector localized solutions of two-component Bose-Einstein condensates (BECs) with variable nonlinearity parameters and external trap potentials through a similarity transformation technique which transforms the two coupled Gross-Pitaevskii equations into a pair of coupled nonlinear Schrödinger equations with constant coefficients under a specific integrability condition. In this analysis we consider three different types of external trap potentials: a time-independent trap, a time-dependent monotonic trap, and a time-dependent periodic trap. We point out the existence of different interesting localized structures; namely, rogue waves, dark- and bright-soliton rogue waves, and rogue-wave breatherlike structures for the above three cases of trap potentials. We show how the vector localized density profiles in a constant background get deformed when we tune the strength of the trap parameter. Furthermore, we investigate the nature of the trajectories of the nonautonomous rogue waves. We also construct the dark-dark rogue wave solution for the repulsive-repulsive interaction of two-component BECs and analyze the associated characteristics for the three different kinds of traps. We then deduce single-, two-, and three-composite rogue waves for three-component BECs and discuss the correlated characteristics when we tune the strength of the trap parameter for different trap potentials.
Simulation of Arrhythmogenic Effect of Rogue RyRs in Failing Heart by Using a Coupled Model
Lu, Luyao; Xia, Ling; Zhu, Xiuwei
2012-01-01
Cardiac cells with heart failure are usually characterized by impairment of Ca2+ handling with smaller SR Ca2+ store and high risk of triggered activities. In this study, we developed a coupled model by integrating the spatiotemporal Ca2+ reaction-diffusion system into the cellular electrophysiological model. With the coupled model, the subcellular Ca2+ dynamics and global cellular electrophysiology could be simultaneously traced. The proposed coupled model was then applied to study the effects of rogue RyRs on Ca2+ cycling and membrane potential in failing heart. The simulation results suggested that, in the presence of rogue RyRs, Ca2+ dynamics is unstable and Ca2+ waves are prone to be initiated spontaneously. These release events would elevate the membrane potential substantially which might induce delayed afterdepolarizations or triggered action potentials. Moreover, the variation of membrane potential depolarization is indicated to be dependent on the distribution density of rogue RyR channels. This study provides a new possible arrhythmogenic mechanism for heart failure from subcellular to cellular level. PMID:23056145
Sherer, Brett M.
2003-03-24
Vegetation Management for the Bandon-Rogue-Gold Beach transmission line corridor. This corridor includes the Bandon-Rogue #1 115 kilovolt transmission line from Bandon Substation to Rogue Substation and the Rogue-Gold Beach #1 and #2 115 kilovolt transmission lines, starting at Rogue Substation and ending at Gold Beach Substation.
Functional description of signal processing in the Rogue GPS receiver
NASA Technical Reports Server (NTRS)
Thomas, J. B.
1988-01-01
Over the past year, two Rogue GPS prototype receivers have been assembled and successfully subjected to a variety of laboratory and field tests. A functional description is presented of signal processing in the Rogue receiver, tracing the signal from RF input to the output values of group delay, phase, and data bits. The receiver can track up to eight satellites, without time multiplexing among satellites or channels, simultaneously measuring both group delay and phase for each of three channels (L1-C/A, L1-P, L2-P). The Rogue signal processing described requires generation of the code for all three channels. Receiver functional design, which emphasized accuracy, reliability, flexibility, and dynamic capability, is summarized. A detailed functional description of signal processing is presented, including C/A-channel and P-channel processing, carrier-aided averaging of group delays, checks for cycle slips, acquistion, and distinctive features.
Hamida, Tarek; Babadagli, Tayfun
2007-09-01
Numerous studies done in the last four decades have demonstrated that acoustic stimulation may enhance recovery in oil reservoirs. This technology is not only technically feasible, but also serves as an economical, environmentally friendly alternative to currently accepted enhanced oil recovery (EOR) method. It requires low capital expenditure, and yields almost immediate improvement without any additional EOR agents. Despite a vast body of empirical and theoretical support, this method lacks sufficient understanding to make meaningful and consistent engineering predictions. This is in part due to the complex nature of the physical processes involved, as well as due to a shortage of fundamental/experimental research. Much of what the authors believe is happening within acoustically stimulated porous media is speculative and theoretical. This paper focuses on the effects of ultrasound on the interfacial forces between immiscible fluids. Capillary (spontaneous) imbibition of an aqueous phase into oil (or air)-saturated Berea sandstone and Indiana limestone samples experiments were conducted. Solutions of water, brine (15,000 and 150,000 ppm NaCl), anionic surfactant (sodium dodecyl diphenyloxide disulfonate), nonionic surfactant (alcohol ethoxylate) and polymer (xanthan gum) were prepared as the aqueous phase. Both counter-current and co-current geometries were tested. Due to the intrinsically unforced, gentle nature of the process, and their strong dependence on wettability, interfacial tension, viscosity and density, such experiments provide valuable insight into some of the governing mechanisms behind ultrasonic stimulation.
Short duration microlensing events: Searching for rogue planets
NASA Astrophysics Data System (ADS)
St. Laurent, Kathryn E.; Di Stefano, Rosanne; Primini, Francis A.; Lew, Wei Peng; Gau, Lai Su; Benson, Sophie
2015-01-01
Einstein described gravitational microlensing in 1936, at the same time suggesting it to be an unobservable phenomenon. He did not foresee technological advancements that would lead to microlensing becoming a productive tool for astronomy. Of particular interest may be the role it has begun to play in the discovery of rogue planets - exoplanets that are not bound to a star or stars. Rogue planets may be formed independently, or they may be formed in the confines of a stellar system and then ejected by gravitational interactions. Currently fewer than a dozen rogue planets are known but estimates of their abundance conservatively start at double the number of stars in our galaxy.The Optical Gravitational Lensing Experiment (OGLE) and Microlensing Observations in Astrophysics (MOA) teams have collectively detected approximately 2500 events this year alone. A significant portion of these events are of short duration, with an Einstein crossing time of less than 10 days. Microlensing events generally occur on a timescale of weeks to months, so short duration events are an interesting class for study, particularly with regard to searches for rogue planets. We have undertaken a systematic study and categorization of the short duration microlensing events from recent OGLE and MOA alerts, with a special eye to identifying exoplanet candidates.
Ambler, Michael; Vorselaars, Bart; Allen, Michael P; Quigley, David
2017-02-21
We apply the capillary wave method, based on measurements of fluctuations in a ribbon-like interfacial geometry, to determine the solid-liquid interfacial free energy for both polytypes of ice I and the recently proposed ice 0 within a mono-atomic model of water. We discuss various choices for the molecular order parameter, which distinguishes solid from liquid, and demonstrate the influence of this choice on the interfacial stiffness. We quantify the influence of discretisation error when sampling the interfacial profile and the limits on accuracy imposed by the assumption of quasi one-dimensional geometry. The interfacial free energies of the two ice I polytypes are indistinguishable to within achievable statistical error and the small ambiguity which arises from the choice of order parameter. In the case of ice 0, we find that the large surface unit cell for low index interfaces constrains the width of the interfacial ribbon such that the accuracy of results is reduced. Nevertheless, we establish that the interfacial free energy of ice 0 at its melting temperature is similar to that of ice I under the same conditions. The rationality of a core-shell model for the nucleation of ice I within ice 0 is questioned within the context of our results.
NASA Astrophysics Data System (ADS)
Ambler, Michael; Vorselaars, Bart; Allen, Michael P.; Quigley, David
2017-02-01
We apply the capillary wave method, based on measurements of fluctuations in a ribbon-like interfacial geometry, to determine the solid-liquid interfacial free energy for both polytypes of ice I and the recently proposed ice 0 within a mono-atomic model of water. We discuss various choices for the molecular order parameter, which distinguishes solid from liquid, and demonstrate the influence of this choice on the interfacial stiffness. We quantify the influence of discretisation error when sampling the interfacial profile and the limits on accuracy imposed by the assumption of quasi one-dimensional geometry. The interfacial free energies of the two ice I polytypes are indistinguishable to within achievable statistical error and the small ambiguity which arises from the choice of order parameter. In the case of ice 0, we find that the large surface unit cell for low index interfaces constrains the width of the interfacial ribbon such that the accuracy of results is reduced. Nevertheless, we establish that the interfacial free energy of ice 0 at its melting temperature is similar to that of ice I under the same conditions. The rationality of a core-shell model for the nucleation of ice I within ice 0 is questioned within the context of our results.
Compton, S W; Brownlee, R G
1988-05-01
While capillary electrophoresis, or historically related techniques, have been used for over a century, and recognition of the value of this separation methodology has certainly grown rapidly in the past few years, the technique has generally been used by analytical chemists, particularly in Europe and Japan, and small groups of researchers in the United States. Many of the basic instrumentation problems have been solved only relatively recently, and researchers using capillary electrophoresis are now turning their attention to studying specific applications which demonstrate the potential versatility of this electrophoretic technique. The appearance of standardized commercial instrumentation is imminent. With the availability of such technology, capillary electrophoresis will no longer be an academic curiosity, but rather a tool with the potential for routine separations of diverse samples of interest to analyst, researcher, and clinician.
Rational solutions to the KPI equation and multi rogue waves
NASA Astrophysics Data System (ADS)
Gaillard, Pierre
2016-04-01
We construct here rational solutions to the Kadomtsev-Petviashvili equation (KPI) as a quotient of two polynomials in x, y and t depending on several real parameters. This method provides an infinite hierarchy of rational solutions written in terms of polynomials of degrees 2 N(N + 1) in x, y and t depending on 2 N - 2 real parameters for each positive integer N. We give explicit expressions of the solutions in the simplest cases N = 1 and N = 2 and we study the patterns of their modulus in the (x , y) plane for different values of time t and parameters.
Breatherlike solitons extracted from the Peregrine rogue wave.
Yang, Guangye; Wang, Yan; Qin, Zhenyun; Malomed, Boris A; Mihalache, Dumitru; Li, Lu
2014-12-01
Based on the Peregrine solution (PS) of the nonlinear Schrödinger (NLS) equation, the evolution of rational fraction pulses surrounded by zero background is investigated. These pulses display the behavior of a breatherlike solitons. We study the generation and evolution of such solitons extracted, by means of the spectral-filtering method, from the PS in the model of the optical fiber with realistic values of coefficients accounting for the anomalous dispersion, Kerr nonlinearity, and higher-order effects. The results demonstrate that the breathing solitons stably propagate in the fibers. Their robustness against small random perturbations applied to the initial background is demonstrated too.
Localized waves in three-component coupled nonlinear Schrödinger equation
NASA Astrophysics Data System (ADS)
Xu, Tao; Chen, Yong
2016-09-01
We study the generalized Darboux transformation to the three-component coupled nonlinear Schrödinger equation. First- and second-order localized waves are obtained by this technique. In first-order localized wave, we get the interactional solutions between first-order rogue wave and one-dark, one-bright soliton respectively. Meanwhile, the interactional solutions between one-breather and first-order rogue wave are also given. In second-order localized wave, one-dark-one-bright soliton together with second-order rogue wave is presented in the first component, and two-bright soliton together with second-order rogue wave are gained respectively in the other two components. Besides, we observe second-order rogue wave together with one-breather in three components. Moreover, by increasing the absolute values of two free parameters, the nonlinear waves merge with each other distinctly. These results further reveal the interesting dynamic structures of localized waves in the three-component coupled system. Project supported by the Global Change Research Program of China (Grant No. 2015CB953904), the National Natural Science Foundation of China (Grant Nos. 11275072 and 11435005), the Doctoral Program of Higher Education of China (Grant No. 20120076110024), the Network Information Physics Calculation of Basic Research Innovation Research Group of China (Grant No. 61321064), and Shanghai Collaborative Innovation Center of Trustworthy Software for Internet of Things, China (Grant No. ZF1213).
The rogue nature of hiatuses in a global warming climate
NASA Astrophysics Data System (ADS)
Sévellec, F.; Sinha, B.; Skliris, N.
2016-08-01
The nature of rogue events is their unlikelihood and the recent unpredicted decade-long slowdown in surface warming, the so-called hiatus, may be such an event. However, given decadal variability in climate, global surface temperatures were never expected to increase monotonically with increasing radiative forcing. Here surface air temperature from 20 climate models is analyzed to estimate the historical and future likelihood of hiatuses and "surges" (faster than expected warming), showing that the global hiatus of the early 21st century was extremely unlikely. A novel analysis of future climate scenarios suggests that hiatuses will almost vanish and surges will strongly intensify by 2100 under a "business as usual" scenario. For "CO2 stabilisation" scenarios, hiatus, and surge characteristics revert to typical 1940s values. These results suggest to study the hiatus of the early 21st century and future reoccurrences as rogue events, at the limit of the variability of current climate modelling capability.
NSLS-II BPM System Protection from Rogue Mode Coupling
Blednykh, A.; Bach, B.; Borrelli, A.; Ferreira, M.; Hseuh, H.-C.; Hetzel, C.; Kosciuk, B.; Krinsky, S.; Singh, O.; Vetter, K.
2011-03-28
Rogue mode RF shielding has been successfully designed and implemented into the production multipole vacuum chambers. In order to avoid systematic errors in the NSLS-II BPM system we introduced frequency shift of HOM's by using RF metal shielding located in the antechamber slot of each multipole vacuum chamber. To satisfy the pumping requirement the face of the shielding has been perforated with roughly 50 percent transparency. It stays clear of synchrotron radiation in each chamber.
Signal-processing theory for the TurboRogue receiver
NASA Technical Reports Server (NTRS)
Thomas, J. B.
1995-01-01
Signal-processing theory for the TurboRogue receiver is presented. The signal form is traced from its formation at the GPS satellite, to the receiver antenna, and then through the various stages of the receiver, including extraction of phase and delay. The analysis treats the effects of ionosphere, troposphere, signal quantization, receiver components, and system noise, covering processing in both the 'code mode' when the P code is not encrypted and in the 'P-codeless mode' when the P code is encrypted. As a possible future improvement to the current analog front end, an example of a highly digital front end is analyzed.
Deep-Water Waves: on the Nonlinear Schrödinger Equation and its Solutions
NASA Astrophysics Data System (ADS)
Vitanov, Nikolay K.; Chabchoub, Amin; Hoffmann, Norbert
2013-06-01
We present a brief discussion on the nonlinear Schrödinger equation for modelling the propagation of the deep-water wavetrains and a discussion on its doubly-localized breather solutions, that can be connected to the sudden formation of extreme waves, also known as rogue waves or freak waves.
NASA Astrophysics Data System (ADS)
Ali Shan, S.; El-Tantawy, S. A.
2016-07-01
In this work, we examine the nonlinear propagation of planar ion-acoustic freak waves in an unmagnetized plasma consisting of cold positive ions and superthermal electrons subjected to cold positrons beam. For this purpose, the reductive perturbation method is used to derive a nonlinear Schrödinger equation (NLSE) for the evolution of electrostatic potential wave. We determine the domain of the plasma parameters where the rogue waves exist. The effect of the positron beam on the modulational instability of the ion-acoustic rogue waves is discussed. It is found that the region of the modulational stability is enhanced with the increase of positron beam speed and positron population. Second as positrons beam increases the nonlinearities of the plasma system, large amplitude ion acoustic rogue waves are pointed out. The present results will be helpful in providing a good fit between the theoretical analysis and real applications in future laboratory plasma experiments.
The local properties of ocean surface waves by the phase-time method
NASA Technical Reports Server (NTRS)
Huang, Norden E.; Long, Steven R.; Tung, Chi-Chao; Donelan, Mark A.; Yuan, Yeli; Lai, Ronald J.
1992-01-01
A new approach using phase information to view and study the properties of frequency modulation, wave group structures, and wave breaking is presented. The method is applied to ocean wave time series data and a new type of wave group (containing the large 'rogue' waves) is identified. The method also has the capability of broad applications in the analysis of time series data in general.
Turbulent Transitions in Optical Wave Propagation
NASA Astrophysics Data System (ADS)
Pierangeli, D.; Di Mei, F.; Di Domenico, G.; Agranat, A. J.; Conti, C.; DelRe, E.
2016-10-01
We report the direct observation of the onset of turbulence in propagating one-dimensional optical waves. The transition occurs as the disordered hosting material passes from being linear to one with extreme nonlinearity. As the response grows, increased wave interaction causes a modulational unstable quasihomogeneous flow to be superseded by a chaotic and spatially incoherent one. Statistical analysis of high-resolution wave behavior in the turbulent regime unveils the emergence of concomitant rogue waves. The transition, observed in a photorefractive ferroelectric crystal, introduces a new and rich experimental setting for the study of optical wave turbulence and information transport in conditions dominated by large fluctuations and extreme nonlinearity.
Nonlinearity Role in Long-Term Interaction of the Ocean Gravity Waves
2012-09-30
the Nonlinear Schrodinger equation and its exact solutions. Numerical simulations of the fully nonlinear Euler equation have also been performed in... Schrodinger breathers, Proceedings of ECMWF Workshop on "Ocean Waves" - 25 to 27 June 2012 [published] • Onorato, M. and Proment, D.; Approximate rogue wave
Multiple capillary biochemical analyzer
Dovichi, Norman J.; Zhang, Jian Z.
1995-01-01
A multiple capillary analyzer allows detection of light from multiple capillaries with a reduced number of interfaces through which light must pass in detecting light emitted from a sample being analyzed, using a modified sheath flow cuvette. A linear or rectangular array of capillaries is introduced into a rectangular flow chamber. Sheath fluid draws individual sample streams through the cuvette. The capillaries are closely and evenly spaced and held by a transparent retainer in a fixed position in relation to an optical detection system. Collimated sample excitation radiation is applied simultaneously across the ends of the capillaries in the retainer. Light emitted from the excited sample is detected by the optical detection system. The retainer is provided by a transparent chamber having inward slanting end walls. The capillaries are wedged into the chamber. One sideways dimension of the chamber is equal to the diameter of the capillaries and one end to end dimension varies from, at the top of the chamber, slightly greater than the sum of the diameters of the capillaries to, at the bottom of the chamber, slightly smaller than the sum of the diameters of the capillaries. The optical system utilizes optic fibres to deliver light to individual photodetectors, one for each capillary tube. A filter or wavelength division demultiplexer may be used for isolating fluorescence at particular bands.
Multiple capillary biochemical analyzer
Dovichi, N.J.; Zhang, J.Z.
1995-08-08
A multiple capillary analyzer allows detection of light from multiple capillaries with a reduced number of interfaces through which light must pass in detecting light emitted from a sample being analyzed, using a modified sheath flow cuvette. A linear or rectangular array of capillaries is introduced into a rectangular flow chamber. Sheath fluid draws individual sample streams through the cuvette. The capillaries are closely and evenly spaced and held by a transparent retainer in a fixed position in relation to an optical detection system. Collimated sample excitation radiation is applied simultaneously across the ends of the capillaries in the retainer. Light emitted from the excited sample is detected by the optical detection system. The retainer is provided by a transparent chamber having inward slanting end walls. The capillaries are wedged into the chamber. One sideways dimension of the chamber is equal to the diameter of the capillaries and one end to end dimension varies from, at the top of the chamber, slightly greater than the sum of the diameters of the capillaries to, at the bottom of the chamber, slightly smaller than the sum of the diameters of the capillaries. The optical system utilizes optic fibers to deliver light to individual photodetectors, one for each capillary tube. A filter or wavelength division demultiplexer may be used for isolating fluorescence at particular bands. 21 figs.
Reconstruction of arbitrary surface wave fields by refraction global method in a wave tank
NASA Astrophysics Data System (ADS)
Garcia, Heynert; Ludu, Andrei
2015-11-01
We use a new photographic procedure and design to construct reliable system for measurement and analysis of various surface water waves in a wave tank, including rogue and tsunami-like waves. The image of a grid placed at the bottom of the tank (3 feet maximum depth) is deformed by the surface waves and recorded on one or two cameras placed above the water. The measurement of the height and slope of the surface waves is determined by inverse refraction calculations plus the calibration information at four grouped points from capacitive level gauges. This research was supported by ERAU INTERNAL STUDENT RESEARCH AWARD.
Forecasting extreme wave events in moderate and high sea states
NASA Astrophysics Data System (ADS)
Magnusson, Anne Karin; Reistad, Magnar; Bitner-Gregersen, Elzbieta Maria
2013-04-01
Empirical studies on measurements have not yet come to conclusive relations between occurrence of rogue waves and - parameters which could be forecasted . Theoretical and tank experiments have demonstrated that high spectral peakedness and low spectral width combined (high Benjamin-Feir instability index, Onorato et al., 2006) give higher probability of rogue wave occurrence. Directional spread seems to reduce the probability of occurrence of rogue waves in these studies. Many years of experience with forecasting and discussions with people working in ocean environment indicate that rogue waves may as well occur in crossing seas. This was also indicated in a study in the Maxwave project (Toffoli et al., 2003) and the EXTREME SEAS project (Toffoli et al., 2011). We have here experimented with some indexes describing both high BFI and crossing seas and run the WAM model for some North Sea storm cases. Wave distributions measured at Ekofisk are analysed in the different cases. References • Onorato, M., Osborne, A., Serio, M., Cavaleri, L., Brandini, C., and Stansberg, C.: Extreme waves, modulational instability and second order theory: wave flume experiments on irregular waves,Europ. J. Mech. B/Fluids, 25, 586-601, 2006. • Toffoli, A., Lefevre, J.M., Monbaliu, J., Savina, H., and Bitner-Gregersen, E., "Freak Waves:Clues for Prediction in Ship Accidents?", Proc. ISOPE'2003 Conf. Hawai, USA, 2003. • Toffoli A., Bitner-Gregersen E. M., Osborne A. R., Serio M. Monbaliu J., Onorato M. (2011) Extreme Waves in Random Crossing Seas: Laboratory Experiments and Numerical Simulations. Geophys. Res. Lett., Vol. 38, L06605, 5 pp. doi: 10.1029/2011.
Intranasal lobular capillary haemangioma
Nayak, Dipak Ranjan; Bhandarkar, Ajay M; Shivamurthy, Archana; Joy, Jasmi
2014-01-01
Lobular capillary haemangioma (LCH) is a benign proliferation of capillaries with a characteristic lobular architecture on microscopy; it has an affinity for mucous membrane and skin of the head and neck. It is extremely rare in the nasal cavity. We present the case of a 45-year-old man who presented with epistaxis without any predisposing factors, which was diagnosed as lobular capillary haemangioma. PMID:25304675
Critical Velocities in Open Capillary Flow
NASA Technical Reports Server (NTRS)
Dreyer, Michael; Langbein, Dieter; Rath, Hans J.
1996-01-01
This paper describes the proposed research program on open capillary flow and the preliminary work performed theoretically and in drop tower experiments. The work focuses on the fundamental physical understanding of the flow through capillary bound geometries, where the circumference of the cross section of the flow path contains free surfaces. Examples for such a flow configuration are capillary vanes in surface tension tanks, flow along edges and corners and flow through liquid bridges. The geometries may be classified by their cross section areas, wetted circumferences and the radii of curvature of the free surfaces. In the streaming float zone the flow path is bound by a free surface only. The ribbon vane is a model for vane types used in surface tension tanks, where a structure in proximity to the tank wall forms a capillary gap. A groove is used in heat pipes for the transportation of the condensed working fluid to the heat source and a wedge may occur in a spaceborne experiment where fluid has to be transported by the means of surface tension. The research objectives are the determination of the maximum volume flux, the observation of the free surfaces and the liquid flow inside the flow path as well as the evaluation of the limiting capillary wave speed. The restriction of the maximum volume flux is due to convective forces (flow velocity exceeding the capillary wave speed) and/or viscous forces, i.e. the viscous head loss along the flow path must be compensated by the capillary pressure due to the curved free surface. Exceeding the maximum volume flux leads to the choking of the flow path, thus the free surface collapses and.gas ingestion occurs at the outlet. The means are ground-based experimental work with plateau tanks and in a drop tower, a sounding rocket flight, and theoretical analysis with integral balances as well as full three dimensional CFD solutions for flow with free surfaces.
Identification of rogue datasets in serial crystallography1
Assmann, Greta; Brehm, Wolfgang; Diederichs, Kay
2016-01-01
Advances in beamline optics, detectors and X-ray sources allow new techniques of crystallographic data collection. In serial crystallography, a large number of partial datasets from crystals of small volume are measured. Merging of datasets from different crystals in order to enhance data completeness and accuracy is only valid if the crystals are isomorphous, i.e. sufficiently similar in cell parameters, unit-cell contents and molecular structure. Identification and exclusion of non-isomorphous datasets is therefore indispensable and must be done by means of suitable indicators. To identify rogue datasets, the influence of each dataset on CC1/2 [Karplus & Diederichs (2012 ▸). Science, 336, 1030–1033], the correlation coefficient between pairs of intensities averaged in two randomly assigned subsets of observations, is evaluated. The presented method employs a precise calculation of CC1/2 that avoids the random assignment, and instead of using an overall CC1/2, an average over resolution shells is employed to obtain sensible results. The selection procedure was verified by measuring the correlation of observed (merged) intensities and intensities calculated from a model. It is found that inclusion and merging of non-isomorphous datasets may bias the refined model towards those datasets, and measures to reduce this effect are suggested. PMID:27275144
Evaluation of streamflow records in Rogue River basin, Oregon
Richardson, Donald
1952-01-01
This report presents data which are, in general, supplementary to those the surface-water investigations made in the past by the U. S. Geological Survey. Those have been essentially investigations of the operation of the many gaging stations on the Rogue River and tributaries. The data presented were obtained from a detailed field investigation of the various #actors resulting from man-made structures that influence the quantity or regimen of the flow at the gaging stations. These factors include diversions from the stream, bypass channels carrying water around the gaging stations, return flow from irrigation or other projects, storage and release of flood waters, and other similar factors. Where feasible, the location, size, effect upon the streamflow periods of use, method of operation,, and similar information are. given. The information is divided into sections corresponding to areas determined by the location of gaging stations. An index of streamflow records is included. A section dealing with the adequacy of available water-resources data and containing location and period of record also is included. This information is given in general terms only, and is portrayed mainly by maps and graphs.
Blakely, Richard J.; Senior, Lisa
1983-01-01
The mapped geology of the Wild Rogue Wilderness (Gray and others, 1982) consists of a tectonic wedge of volcanic and intrusive rocks of Jurassic age surrounded on all sides by thick sequences of Jurassic, Creacetous, and Tertiary sedimentary rocks. Normally, volcanic and intrusive rocks are more magnetic than sedimentary rocks, a property which should be reflected by the areomagnetic data. We conclude, however, that most of the magnetic anomalies of the Wild Rogue Wilderness are caused by magnetic rocks that are not exposed but which occur at relatively shallow depth below the topographic surface.
Numerical bifurcation for the capillary Whitham equation
NASA Astrophysics Data System (ADS)
Remonato, Filippo; Kalisch, Henrik
2017-03-01
The so-called Whitham equation arises in the modeling of free surface water waves, and combines a generic nonlinear quadratic term with the exact linear dispersion relation for gravity waves on the free surface of a fluid with finite depth. In this work, the effect of incorporating capillarity into the Whitham equation is in focus. The capillary Whitham equation is a nonlocal equation similar to the usual Whitham equation, but containing an additional term with a coefficient depending on the Bond number which measures the relative strength of capillary and gravity effects on the wave motion. A spectral collocation scheme for computing approximations to periodic traveling waves for the capillary Whitham equation is put forward. Numerical approximations of periodic traveling waves are computed using a bifurcation approach, and a number of bifurcation curves are found. Our analysis uncovers a rich structure of bifurcation patterns, including subharmonic bifurcations, as well as connecting and crossing branches. Indeed, for some values of the Bond number, the bifurcation diagram features distinct branches of solutions which intersect at a secondary bifurcation point. The same branches may also cross without connecting, and some bifurcation curves feature self-crossings without self-connections.
Capillary solitons on a levitated medium.
Perrard, S; Deike, L; Duchêne, C; Pham, C-T
2015-07-01
A water cylinder deposited on a heated channel levitates on its own generated vapor film owing to the Leidenfrost effect. This experimental setup permits the study of the one-dimensional propagation of surface waves in a free-to-move liquid system. We report the observation of gravity-capillary waves under a dramatic reduction of gravity (up to a factor 30), leading to capillary waves at the centimeter scale. The generated nonlinear structures propagate without deformation and undergo mutual collisions and reflections at the boundaries of the domain. They are identified as Korteweg-de Vries solitons with negative amplitude and subsonic velocity. The typical width and amplitude-dependent velocities are in excellent agreement with theoretical predictions based on a generalized Korteweg-de Vries equation adapted to any substrate geometry. When multiple solitons are present, they interact and form a soliton turbulencelike spectrum.
Freak waves in negative-ion plasmas: an experiment revisited
NASA Astrophysics Data System (ADS)
Kourakis, Ioannis; Elkamash, Ibrahem; Reville, Brian
2016-10-01
Extreme events in the form of rogue waves (freak waves) occur widely in the open sea. These are space- and time-localised excitations, which appear unexpectedly and are characterised by a significant amplitude. Beyond ocean dynamics, the mechanisms underlying rogue wave formation are now being investigated in various physical contexts, including materials science, nonlinear optics and plasma physics, to mention but a few. We have undertaken an investigation, from first principles, of the occurrence of rogue waves associated with the propagation of electrostatic wavepackets in plasmas. Motivated by recent experimental considerations involving freak waves in negative-ion plasmas (NIP), we have addresed the occurrence of freak waves in NIP from first principles. An extended range of plasma parameter values was identified, where freak wave formation is possible, in terms of relevant plasma parameters. Our results extend -and partly contradict- the underlying assumptions in the interpretation of the aforementioned experiment, where a critical plasma configuration was considered and a Gardner equation approach was adopted. This work was supported from CPP/QUB funding. One of us (I. Elkamash) acknowledges financial support by an Egyptian Government fellowship.
Capillary rheometry for thermosets
NASA Technical Reports Server (NTRS)
Malguarnera, S. C.; Carroll, D. R.
1982-01-01
Capillary rheometry is effectively used with thermosets. Most important is providing a uniform temperature in the barrel. This was successfully accomplished by using a circulating hot oil system. Standard capillary rheometry methods provide the dependence of thermoset apparent viscosity on shear rate, temperature and time. Such information is very useful in evaluating resin processability and in setting preliminary fabrication conditions.
NMD Against Rogue States-- Are We On the Right Track?
NASA Astrophysics Data System (ADS)
Garwin, Richard L.
2001-04-01
The national missile defense (NMD) under development at present will deploy 100-200 interceptor missiles in Alaska and North Dakota and conduct hit-to-kill mid-course intercepts of strategic payloads-- biological warfare agents (BW) or nuclear warheads. Mid-course intercept is vulnerable to penetration aids-- hundreds of BW bomblets dispensed just after the ICBM reaches its full speed; and decoy balloons (aided by an enclosing balloon on the re-entry vehicle of a nuclear warhead). The NMD organization has not seriously considered countermeasures, which I believe are much easier to build than the ICBMs themselves. Only now is NMD beginning to structure a program to evaluate and determine the response to such countermeasures. Defense against North Korean ICBMs can be obtained by boost-phase intercept, while the ICBM rocket engines are still burning. I will discuss a proposal to conduct such intercepts from a joint U.S.- Russian base south of Vladivostok, and with some interceptors based on U.S. military cargo ships hundreds of km from North Korea. A similar system would counter ICBMs from Iraq, with a base in Southeast Turkey; but the much larger country, Iran, would need at least two bases-- perhaps one in the Caspian Sea and U.S. ships in the Gulf of Oman. Simple countermeasures and possible responses to them will be discussed, together with some problems and characteristics of boost-phase intercept systems. For a given level of kill-vehicle technology, space-based boost-phase interceptors are inferior to surface-based for the "rogue nation" potential ICBM threat, and weapons in space are likely to provoke a severe response that would endanger critical U.S. satellites.
Chromosome aberrations and rogue cells in lymphocytes of Chernobyl clean-up workers.
Lazutka, J R
1996-03-09
A cytogenetic analysis was performed on peripheral blood lymphocytes from 183 Chernobyl clean-up workers and 27 control individuals. Increased frequencies of chromosome aberrations were associated with exposure to radiation at Chernobyl, alcohol abuse and a history of recent influenza infection. However, only approximately 20% of Chernobyl clean-up workers had an increased frequency of dicentric and ring chromosomes. At the same time, an increased frequency of acentric fragments in lymphocytes of clean-up workers was characteristic. The use of multivitamins as dietary supplement significantly decreased the frequency of chromosome aberrations, especially of chromatid breaks. Rogue cells were found in lymphocytes of 28 clean-up workers and 3 control individuals. The appearance of rogue cells was associated with a recent history of acute respiratory disease (presumably caused by adenoviral infection) and, probably, alcohol abuse. Dicentric chromosomes in rogue cells were distributed according to a negative binomial distribution. Occurrence of rogue cells due to a perturbation of cell cycle control and abnormal apoptosis is suggested.
ERIC Educational Resources Information Center
Wild, Nancy
Each year, Rogue Community College (Oregon) conducts a student satisfaction survey measuring the college's achievements in the areas of services, classes, and facilities. This document reports findings from the winter 2000 administration of the survey, including, for the second time, students from the Workforce Training Center (WFTC). The study's…
ERIC Educational Resources Information Center
Wild, Nancy
The Annual Student Satisfaction Survey at Oregon's Rogue Community College (RCC) allows the school to measure achievement in services, classes, and facilities. Three hundred and eleven students responded to this winter 2000 survey. Findings include: (1) seventeen percent of all respondents at the Redwood and Riverside campuses were very satisfied…
Multiplexed capillary electrophoresis system
Yeung, E.S.; Li, Q.; Lu, X.
1998-04-21
The invention provides a side-entry optical excitation geometry for use in a multiplexed capillary electrophoresis system. A charge-injection device is optically coupled to capillaries in the array such that the interior of a capillary is imaged onto only one pixel. In Sanger-type 4-label DNA sequencing reactions, nucleotide identification (``base calling``) is improved by using two long-pass filters to split fluorescence emission into two emission channels. A binary poly(ethyleneoxide) matrix is used in the electrophoretic separations. 19 figs.
Multiplexed capillary electrophoresis system
Yeung, E.S.; Chang, H.T.; Fung, E.N.; Li, Q.; Lu, X.
1996-12-10
The invention provides a side-entry optical excitation geometry for use in a multiplexed capillary electrophoresis system. A charge-injection device is optically coupled to capillaries in the array such that the interior of a capillary is imaged onto only one pixel. In Sanger-type 4-label DNA sequencing reactions, nucleotide identification (``base calling``) is improved by using two long-pass filters to split fluorescence emission into two emission channels. A binary poly(ethyleneoxide) matrix is used in the electrophoretic separations. 19 figs.
Multiplexed capillary electrophoresis system
Yeung, Edward S.; Li, Qingbo; Lu, Xiandan
1998-04-21
The invention provides a side-entry optical excitation geometry for use in a multiplexed capillary electrophoresis system. A charge-injection device is optically coupled to capillaries in the array such that the interior of a capillary is imaged onto only one pixel. In Sanger-type 4-label DNA sequencing reactions, nucleotide identification ("base calling") is improved by using two long-pass filters to split fluorescence emission into two emission channels. A binary poly(ethyleneoxide) matrix is used in the electrophoretic separations.
Multiplexed capillary electrophoresis system
Yeung, Edward S.; Chang, Huan-Tsang; Fung, Eliza N.; Li, Qingbo; Lu, Xiandan
1996-12-10
The invention provides a side-entry optical excitation geometry for use in a multiplexed capillary electrophoresis system. A charge-injection device is optically coupled to capillaries in the array such that the interior of a capillary is imaged onto only one pixel. In Sanger-type 4-label DNA sequencing reactions, nucleotide identification ("base calling") is improved by using two long-pass filters to split fluorescence emission into two emission channels. A binary poly(ethyleneoxide) matrix is used in the electrophoretic separations.
Unsteady evolution of localized unidirectional deep-water wave groups
NASA Astrophysics Data System (ADS)
Cousins, Will; Sapsis, Themistoklis P.
2015-06-01
We study the evolution of localized wave groups in unidirectional water wave envelope equations [the nonlinear Schrödinger (NLSE) and the modified NLSE (MNLSE)]. These localizations of energy can lead to disastrous extreme responses (rogue waves). We analytically quantify the role of such spatial localization, introducing a technique to reduce the underlying partial differential equation dynamics to a simple ordinary differential equation for the wave packet amplitude. We use this reduced model to show how the scale-invariant symmetries of the NLSE break down when the additional terms in the MNLSE are included, inducing a critical scale for the occurrence of extreme waves.
Unsteady evolution of localized unidirectional deep-water wave groups.
Cousins, Will; Sapsis, Themistoklis P
2015-06-01
We study the evolution of localized wave groups in unidirectional water wave envelope equations [the nonlinear Schrödinger (NLSE) and the modified NLSE (MNLSE)]. These localizations of energy can lead to disastrous extreme responses (rogue waves). We analytically quantify the role of such spatial localization, introducing a technique to reduce the underlying partial differential equation dynamics to a simple ordinary differential equation for the wave packet amplitude. We use this reduced model to show how the scale-invariant symmetries of the NLSE break down when the additional terms in the MNLSE are included, inducing a critical scale for the occurrence of extreme waves.
Neel, J V
1998-01-01
Data from a previous study of the cytogenetic effects, in cultured lymphocytes, of exposure to the atomic bomb in Hiroshima have been reanalyzed to determine the relationship between the occurrence of "rogue" cells in an individual and the frequency of "simple" chromosomal damage in the nonrogue cells of the same individual. Rogue cells are cells with complex chromosomal damage, currently believed to be a manifestation of the activity of a human polyoma virus termed "JC." Among a total of 1,835 persons examined, there were 45 exhibiting rogue cells. A total of 179,599 cells were scored for simple chromosomal damage. In both the exposed and the control populations, there was an absolute increase of approximately 1.5% in the frequency of simple chromosomal damage in the nonrogue cells of those exhibiting rogue cells, when compared with the frequencies observed in those not exhibiting rogue cells, which is a statistically significant difference. It is argued that this phenomenon, occurring not only in lymphocytes but possibly also in other cells/tissues, may play a contributory role in the origin of malignancies characterized by clonal chromosome abnormalities. Unexpectedly, among those exhibiting rogue cells, there was a disproportionately greater representation of persons who had received relatively high radiation exposures from the bomb. The reason for this is unclear, but it is tempting to relate the finding to some lingering effect of the exposure (or the circumstances surrounding the exposure) on immunocompetence. PMID:9683586
... may indicate: Dehydration Shock Peripheral vascular disease (PVD) Hypothermia Alternative Names Nail blanch test; Capillary refill time ... Elsevier Saunders; 2016:chap 79. Read More Dehydration Hypothermia Peripheral artery disease - legs Shock Review Date 4/ ...
Kalejs, Juris P.; Chalmers, Bruce; Surek, Thomas
1984-01-01
An asymmetrical shaped capillary die made exclusively of graphite is used to grow silicon ribbon which is capable of being made into solar cells that are more efficient than cells produced from ribbon made using a symmetrically shaped die.
Kalejs, Juris P.; Chalmers, Bruce; Surek, Thomas
1982-01-01
An asymmetrical shaped capillary die made exclusively of graphite is used to grow silicon ribbon which is capable of being made into solar cells that are more efficient than cells produced from ribbon made using a symmetrically shaped die.
Capillary rise of superspreaders.
Radulovic, Jovana; Sefiane, Khellil; Shanahan, Martin E R
2011-09-15
Trisiloxane surfactants, known as 'superspreaders', are commonly employed in numerous applications where enhanced wetting is of the utmost importance. The underlying mechanisms of superspreader wetting have been a focus of scientific interest for ca. 2 decades, and a number of mechanisms have been proposed to explain the unique trisiloxane dynamics. We have studied trisiloxane behaviour in thin capillaries to get further insight into their interfacial activity. Additionally, our knowledge of the capillary rise of superspreaders is surprisingly limited, and the effect of this extraordinary group of surfactants on capillary phenomena has been largely overlooked. Diffusion was confirmed to be the limiting factor of trisiloxane behaviour. A tentative theoretical explanation for the phenomenon studied and an appropriate mathematical model are presented. It is concluded that the enhancement of wetting due to surfactant addition is also a function of geometry: the effect is clear for a sessile drop, but more complex and less beneficial in a capillary.
Bender, III, Howard Albert
2003-11-25
Debris generation from an EUV electric discharge plasma source device can be significantly reduced or essentially eliminated by encasing the electrodes with dielectric or electrically insulating material so that the electrodes are shielded from the plasma, and additionally by providing a path for the radiation to exit wherein the electrodes are not exposed to the area where the radiation is collected. The device includes: (a) a body, which is made of an electrically insulating material, that defines a capillary bore that has a proximal end and a distal end and that defines at least one radiation exit; (b) a first electrode that defines a first channel that has a first inlet end that is connected to a source of gas and a first outlet end that is in communication with the capillary bore, wherein the first electrode is positioned at the distal end of the capillary bore; (c) a second electrode that defines a second channel that has a second inlet end that is in communication with the capillary bore and an outlet end, wherein the second electrode is positioned at the proximal end of the capillary bore; and (d) a source of electric potential that is connected across the first and second electrodes, wherein radiation generated within the capillary bore is emitted through the at least one radiation exit and wherein the first electrode and second electrode are shielded from the emitted radiation.
Capillary saturation and desaturation.
Hilfer, R; Armstrong, R T; Berg, S; Georgiadis, A; Ott, H
2015-12-01
Capillary desaturation experiments produce disconnected (trapped) ganglia of mesoscopic sizes intermediate between pore size and system size. Experimental evidence for interactions between these mesoscale clusters during desaturation is analyzed and discussed within the established microscopic and macroscopic laws of Newton, Young-Laplace, and Darcy. A theoretical expression for capillary number correlations is introduced that seems to have remained unnoticed. It expresses capillary desaturation curves in terms of stationary capillary pressures and relative permeabilities. The theoretical expression shows that the plateau saturation in capillary desaturation curves may in general differ from the residual nonwetting saturation defined through the saturation limit of the main hysteresis loop. Hysteresis effects as well as the difference between wetting and nonwetting fluids are introduced into the analysis of capillary desaturation experiments. The article examines experiments with different desaturation protocols and discusses the existence of a mesoscopic length scale intermediate between pore scale and sample scale. The theoretical expression is derived entirely within the existing traditional theory of two-phase flow in porous media and compared to a recent experiment.
Capillary saturation and desaturation
NASA Astrophysics Data System (ADS)
Hilfer, R.; Armstrong, R. T.; Berg, S.; Georgiadis, A.; Ott, H.
2015-12-01
Capillary desaturation experiments produce disconnected (trapped) ganglia of mesoscopic sizes intermediate between pore size and system size. Experimental evidence for interactions between these mesoscale clusters during desaturation is analyzed and discussed within the established microscopic and macroscopic laws of Newton, Young-Laplace, and Darcy. A theoretical expression for capillary number correlations is introduced that seems to have remained unnoticed. It expresses capillary desaturation curves in terms of stationary capillary pressures and relative permeabilities. The theoretical expression shows that the plateau saturation in capillary desaturation curves may in general differ from the residual nonwetting saturation defined through the saturation limit of the main hysteresis loop. Hysteresis effects as well as the difference between wetting and nonwetting fluids are introduced into the analysis of capillary desaturation experiments. The article examines experiments with different desaturation protocols and discusses the existence of a mesoscopic length scale intermediate between pore scale and sample scale. The theoretical expression is derived entirely within the existing traditional theory of two-phase flow in porous media and compared to a recent experiment.
Solitons collision and freak waves in a plasma with Cairns-Tsallis particle distributions
NASA Astrophysics Data System (ADS)
El-Tantawy, S. A.; Wazwaz, A. M.; Schlickeiser, R.
2015-12-01
The solitons collision (head-on collision) and rogue waves in an unmagnetized plasma comprising nonthermal-nonextensive distributed (Cairns-Tsallis) electrons and cold ions are investigated. For solitons collision, the extended Poincaré-Lighthill-Kuo (PLK) method is employed to derive the coupled Korteweg-de Vries (KdV) equations and their corresponding phase shifts. It is found that solitons having two polarities can propagate in the present model. The coefficients of the nonlinear terms of the coupled KdV equations vanish at a critical value of nonthermality. Therefore, another set of coupled modified KdV (mKdV) equations with cubic nonlinearity is derived and the corresponding phase shifts are calculated. It is found analytically and numerically that the solutions of the coupled KdV equations allow solitons collision only when the solitons have the same polarity, whereas the coupled mKdV equations allow the collisions between the two solitons of the same and opposite polarities. The influence of the nonthermal-nonextensive parameters on the phase shifts of the solitons collision is examined. Furthermore, the rogue waves are studied in the framework of the mKdV equation. The behavior of the rogue waves is analyzed using the nonlinear Schrödinger equation (NLSE), derived from the mKdV equation. It is found that the rogue wave amplitude shrinks with the increase of the nonextensive parameter. The NLSE derived from the KdV equation cannot support the presence of rogue waves.
Effect of rogue particles on the sub-surface damage of fused silica during grinding/polishing
Suratwala, T I; Steele, R; Feit, M D; Wong, L; Miller, P E; Menapace, J A; Davis, P J
2007-05-02
The distribution and characteristics of surface cracks (i.e., sub-surface damage or scratching) on fused silica formed during grinding/polishing resulting from the addition of rogue particles in the base slurry has been investigated. Fused silica samples (10 cm diameter x 1 cm thick) were: (1) ground by loose abrasive grinding (alumina particles 9-30 {micro}m) on a glass lap with the addition of larger alumina particles at various concentrations with mean sizes ranging from 15-30 {micro}m, or (2) polished (using 0.5 {micro}m cerium oxide slurry) on various laps (polyurethanes pads or pitch) with the addition of larger rogue particles (diamond (4-45 {micro}m), pitch, dust, or dried Ceria slurry agglomerates) at various concentrations. For the resulting ground samples, the crack distributions of the as-prepared surfaces were determined using a polished taper technique. The crack depth was observed to: (1) increase at small concentrations (>10{sup -4} fraction) of rogue particles; and (2) increase with rogue particle concentration to crack depths consistent with that observed when grinding with particles the size of the rogue particles alone. For the polished samples, which were subsequently etched in HF:NH{sub 4}F to expose the surface damage, the resulting scratch properties (type, number density, width, and length) were characterized. The number density of scratches increased exponentially with the size of the rogue diamond at a fixed rogue diamond concentration suggesting that larger particles are more likely to lead to scratching. The length of the scratch was found to increase with rogue particle size, increase with lap viscosity, and decrease with applied load. At high diamond concentrations, the type of scratch transitioned from brittle to ductile and the length of the scratches dramatically increased and extended to the edge of the optic. The observed trends can explained semi-quantitatively in terms of the time needed for a rogue particle to penetrate into a
NASA Astrophysics Data System (ADS)
Steinhauer, L. C.; Kimura, W. D.
2006-11-01
We have developed a 1-D, quasi-steady-state numerical model for a gas-filled capillary discharge that is designed to aid in selecting the optimum capillary radius in order to guide a laser beam with the required intensity through the capillary. The model also includes the option for an external solenoid B-field around the capillary, which increases the depth of the parabolic density channel in the capillary, thereby allowing for propagation of smaller laser beam waists. The model has been used to select the parameters for gas-filled capillaries to be utilized during the Staged Electron Laser Acceleration — Laser Wakefield (STELLA-LW) experiment.
Wave propagation in strongly dispersive superthermal dusty plasma
NASA Astrophysics Data System (ADS)
El-Labany, S. K.; El-Shewy, E. K.; Abd El-Razek, H. N.; El-Rahman, A. A.
2017-04-01
The attributes of acoustic envelope waves in a collisionless dust ion unmagnetized plasmas model composed of cold ions, superthermal electrons and positive-negative dust grains have been studied. Using the derivative expansion technique in a strong dispersive medium, the system model is reduced to a nonlinearly form of Schrodinger equation (NLSE). Rational solution of NLSE in unstable region is responsible for the creation of large shape waves; namely rogue waves. The subjection of instability regions upon electron superthermality (via κ), carrier wave number and dusty grains charge is discussed.
Numerical simulation of unidirectional irregular nonlinear waves in the basin of intermediate depth
NASA Astrophysics Data System (ADS)
Slunyaev, Alexey; Sergeeva, Anna; Didenkulova, Ira
2016-04-01
In this paper we extend our study of intense irregular waves over infinitively deep water [1] to the situation of intermediate depth (in particular, conditions kph ≈ 2 and kph ≈ 1 are discussed, where kp is the peak wavenumber, and h is the water depth). We use a transition stage, when the nonlinearity is slowly enforcing during a few tens of wave periods, with the purpose to prepare 'natural' realizations of nonlinear waves in a quasi-stationary state. Then, the unidirectional waves are simulated by means of the High Order Spectral Method, what gives the complete data of wave evolution, and also the statistical data. Up to 100 realizations of wave trains were simulated for 20 minutes of physical time; each of the realization was about 10 km long and was characterized by the given JONSWAP spectrum. Small-scale artificial damping was introduced to eliminate the wave breaking effect. The simulation output data was collected providing sufficient resolution of the surface wave fields in time and space. The rogue wave events were identified on the basis of the wave data, and analyzed. One of the observations made in the case of infinitively deep water [1] was remarkably long lifetimes of the rogue events. This outcome was related to the formation of long-living wave groups due to two effects: absence of the transverse dimension (purely collinear waves), and nonlinear wave self-modulation. In the present study in one of the cases (i.e., kph ≈ 1 < 1.36) waves do not suffer from the Benjamin - Feir instability. Rather surprisingly, the lifetimes of the rogue waves do not show a clear dependence on the water depth. They seem to be somewhat shorter for the shallower water, but the difference is not definite. In general, the lifetime of rogue events may be up to 30-60 wave periods. The typical shape of the rogue waves was considered. Besides the crest-trough vertical asymmetry, which is natural for deep-water Stokes waves and becomes even more pronounced for intense
Derivatization in Capillary Electrophoresis.
Marina, M Luisa; Castro-Puyana, María
2016-01-01
Capillary electrophoresis is a well-established separation technique in analytical research laboratories worldwide. Its interesting advantages make CE an efficient and potent alternative to other chromatographic techniques. However, it is also recognized that its main drawback is the relatively poor sensitivity when using optical detection. One way to overcome this limitation is to perform a derivatization reaction which is intended to provide the analyte more suitable analytical characteristics enabling a high sensitive detection. Based on the analytical step where the CE derivatization takes place, it can be classified as precapillary (before separation), in-capillary (during separation), or postcapillary (after separation). This chapter describes the application of four different derivatization protocols (in-capillary and precapillary modes) to carry out the achiral and chiral analysis of different compounds in food and biological samples with three different detection modes (UV, LIF, and MS).
Capillary condenser/evaporator
NASA Technical Reports Server (NTRS)
Valenzuela, Javier A. (Inventor)
2010-01-01
A heat transfer device is disclosed for transferring heat to or from a fluid that is undergoing a phase change. The heat transfer device includes a liquid-vapor manifold in fluid communication with a capillary structure thermally connected to a heat transfer interface, all of which are disposed in a housing to contain the vapor. The liquid-vapor manifold transports liquid in a first direction and conducts vapor in a second, opposite direction. The manifold provides a distributed supply of fluid (vapor or liquid) over the surface of the capillary structure. In one embodiment, the manifold has a fractal structure including one or more layers, each layer having one or more conduits for transporting liquid and one or more openings for conducting vapor. Adjacent layers have an increasing number of openings with decreasing area, and an increasing number of conduits with decreasing cross-sectional area, moving in a direction toward the capillary structure.
Wave turbulence in a two-layer fluid: Coupling between free surface and interface waves
NASA Astrophysics Data System (ADS)
Issenmann, Bruno; Laroche, Claude; Falcon, Eric
2016-12-01
We experimentally study gravity-capillary wave turbulence on the interface between two immiscible fluids of close density with free upper surface. We locally measure the wave height at the interface between both fluids by means of a highly sensitive laser Doppler vibrometer. We show that the inertial range of the capillary wave turbulence regime is significantly extended when the upper fluid depth is increased: The crossover frequency between the gravity and capillary wave turbulence regimes is found to decrease whereas the dissipative cut-off frequency of the spectrum is found to increase. We explain these observations by the progressive decoupling between waves propagating at the interface and the ones at the free surface, using the full dispersion relation of gravity-capillary waves in a two-layer fluid of finite depths. The cut-off evolution is due to the disappearance of parasitic capillaries responsible for the main wave dissipation for a single fluid.
Regularity of rotational travelling water waves.
Escher, Joachim
2012-04-13
Several recent results on the regularity of streamlines beneath a rotational travelling wave, along with the wave profile itself, will be discussed. The survey includes the classical water wave problem in both finite and infinite depth, capillary waves and solitary waves as well. A common assumption in all models to be discussed is the absence of stagnation points.
Capillary action liquid chromatography.
Zhang, Bo; Bergström, Edmund T; Goodall, David M; Myers, Peter
2009-06-01
Capillary action LC (caLC) is introduced as a technique using capillary action as the driving force to perform LC in capillary columns packed with HPLC type microparticulate materials. A dry packing method with centrifugal force was developed to prepare capillary columns in parallel (10 columns per 3 min) to support their disposable use in caLC. Using a digital microscope for real-time imaging and recording separations of components in a dye mixture, caLC was found to have flow characteristics similar to TLC. Based on the investigation of microparticulate HPLC silica gels of different size (1.5-10 microm) and a typical TLC grade irregular medium, Merck 60G silica, the van Deemter curves suggested molecular diffusion as the major contribution to band broadening in caLC. With Waters Xbridge 2.6 microm silica, plate heights down to 8.8 microm were obtained, comparable to those achievable in HPLC. Assisted by an image-processing method, the visual caLC separation was converted to a classical chromatogram for further data analysis and such a facility confirmed the observation of highly efficient bands.
Will Russian Scientists Go Rogue? A Survey on the Threat and the Impact of Western Assistance
Ball, D Y; Gerber, T P
2004-12-27
The collapse of the Soviet Union sparked fears throughout the world that rogue nations and terrorist organizations would gain access to weapons of mass destruction (WMD). One specific concern has been 'WMD brain drain.' Russians with knowledge about nuclear, chemical, and biological weapons could now depart to any country of their choice, including rogue nations seeking to produce WMD. Meanwhile, Russian science fell into a protracted crisis, with plummeting salaries, little funding for research, and few new recruits to science. These developments increased both the incentives and the opportunities for scientists to sell their knowledge to governments and terrorist organizations with hostile intentions toward the United States. Recognizing the threat of WMD brain drain from Russia, the United States, and other governments implemented a host of programs designed to reduce the risk. Despite, or perhaps partly because of, massive assistance from the West to prevent scientists with WMD knowledge from emigrating, the threat of Russian WMD brain drain has recently faded from view. Yet we have seen no evidence that these programs are effective and little systematic assessment of the current threat of WMD migration. Our data from an unprecedented survey of 602 Russian physicists, biologists, and chemists suggest that the threat of WMD brain drain from Russia should still be at the forefront of our attention. Roughly 20 percent of Russian physicists, biologists, and chemists say they would consider working in rogue nations such as North Korea, Iran, Syria, or Iraq (still considered a rogue state at the time of the survey). At the same time, the data reveal that U.S. and Western nonproliferation assistance programs work. They significantly reduce the likelihood that Russian scientists would consider working in these countries. Moreover, Russian grants do not reduce scientists' propensity to 'go rogue'. These survey findings have clear policy implications: the U.S. and its
Noise suppressing capillary separation system
Yeung, Edward S.; Xue, Yongjun
1996-07-30
A noise-suppressing capillary separation system for detecting the real-time presence or concentration of an analyte in a sample is provided. The system contains a capillary separation means through which the analyte is moved, a coherent light source that generates a beam which is split into a reference beam and a sample beam that irradiate the capillary, and a detector for detecting the reference beam and the sample beam light that transmits through the capillary. The laser beam is of a wavelength effective to be absorbed by a chromophore in the capillary. The system includes a noise suppressing system to improve performance and accuracy without signal averaging or multiple scans.
Odake, T; Kitamori, T; Sawada, T
1997-07-01
A stationary wave of the capillary vibration effect was successfully induced by a series of short laser pulses. This wave could be applied to highly sensitive detection of capillary electrophoresis as well as the already reported capillary vibration induced by an intensity-modulated CW laser (CVL effect). Generally, pulses with much shorter width than the period of the natural frequency of the vibrating system cannot induce a standing vibration. However, utilizing the time constant of CVL determined by heat dissipation time, we found conditions which could induce a stable stationary wave of the capillary by a series of nanosecond light pulses. We used the KrF excimer laser operated at 248 nm with a pulse width of 60 ns and output of ∼10 μJ/pulse as the CVL excitation source and applied it to highly sensitive detection of nonderivatized amino acids at the femtomole level. The sensitivity was at least 2 orders of magnitude superior to that of a commercially available UV absorbance detector. This technique extends the CVL's spectral regions. For example, in the UV region, where many biological materials have significant absorption bands, this technique will extend analytical applications in capillary electrophoresis by eliminating the need for a derivatization process.
Capillary Isoelectric Focusing
NASA Astrophysics Data System (ADS)
Markuszewski, Michał J.; Bujak, Renata; Daghir, Emilia
Capillary isoelectric focusing (CIEF) is a widespread technique for the analysis of peptides and proteins in biological samples. CIEF is used to separate mixtures of compounds on the basis of differences in their isoelectric point. Aspects of sample preparation, capillary selection, zone mobilization procedures as well as various detection modes used have been described and discussed. Moreover CIEF, coupled to various types of detection techniques (MALDI or LIF), has increasingly been applied to the analysis of variety different high-molecular compounds. CIEF is considered as a highly specific analytical method which may be routinely used in the separation of rare hemoglobin variants. In addition, the application of CIEF in proteomic field have been discussed on the examples of analyses of glycoproteins and immunoglobins due to the meaning in clinical diagnostic.
Enantioseparations by capillary electrochromatography.
Fanali, S; Catarcini, P; Blaschke, G; Chankvetadze, B
2001-09-01
The review summarizes recent developments in enantioseparations by capillary electrochromatography (CEC). Selected fundamental aspects of CEC are discussed in order to stress those features which may allow the success of this technique in the competitive field of enantioseparations. In addition, the comparative characteristics of the different modes of chiral CEC and the stationary phases are presented. The effects of the characteristics of the stationary and liquid phases and operational conditions on the separation results are discussed. Finally, some future trends are briefly addressed.
Automated Parallel Capillary Electrophoretic System
Li, Qingbo; Kane, Thomas E.; Liu, Changsheng; Sonnenschein, Bernard; Sharer, Michael V.; Kernan, John R.
2000-02-22
An automated electrophoretic system is disclosed. The system employs a capillary cartridge having a plurality of capillary tubes. The cartridge has a first array of capillary ends projecting from one side of a plate. The first array of capillary ends are spaced apart in substantially the same manner as the wells of a microtitre tray of standard size. This allows one to simultaneously perform capillary electrophoresis on samples present in each of the wells of the tray. The system includes a stacked, dual carousel arrangement to eliminate cross-contamination resulting from reuse of the same buffer tray on consecutive executions from electrophoresis. The system also has a gel delivery module containing a gel syringe/a stepper motor or a high pressure chamber with a pump to quickly and uniformly deliver gel through the capillary tubes. The system further includes a multi-wavelength beam generator to generate a laser beam which produces a beam with a wide range of wavelengths. An off-line capillary reconditioner thoroughly cleans a capillary cartridge to enable simultaneous execution of electrophoresis with another capillary cartridge. The streamlined nature of the off-line capillary reconditioner offers the advantage of increased system throughput with a minimal increase in system cost.
Do the freak waves exist in soliton gas?
NASA Astrophysics Data System (ADS)
Shurgalina, Ekaterina; Pelinovsky, Efim
2016-04-01
The possibility of short-lived anomalous large waves (rogue waves) in soliton gas in the frameworks of integrable models like the Korteweg - de Vries - type equations is studied. It is shown that the dynamics of heteropolar soliton gas differs sufficiently from the dynamics of unipolar soliton fields. In particular, in the wave fields consisting of solitons with different polarities the freak wave appearance is possible. It is shown numerically in [Shurgalina and Pelinovsky, 2015]. Freak waves in the framework of the modified Korteweg-de Vries equation have been studied previously in the case of narrowband initial conditions [Grimshaw et al, 2005, 2010; Talipova, 2011]. In this case, the mechanism of freak wave generation was modulation instability of modulated quasi-sinusoidal wave packets. At the same time the modulation instability of modulated cnoidal waves was studied in the mathematical work [Driscoll & O'Neil, 1976]. Since a sequence of solitary waves can be a special case of cnoidal wave, the modulation instability can be a possible mechanism of freak wave appearance in a soliton gas. Thus, we expect that rogue wave phenomenon in soliton gas appears in nonlinear integrable models admitting an existence of modulation instability of periodic waves (like cnoidal waves). References: 1. Shurgalina E.G., Pelinovsky E.N. Dynamics of irregular wave ensembles in the coastal zone, Nizhny Novgorod State Technical University n.a. R.E. Alekseev. - Nizhny Novgorod, 2015, 179 pp. 2. Grimshaw R., Pelinovsky E., Talipova T., Sergeeva A. Rogue internal waves in the ocean: long wave model. European Physical Journal Special Topics, 2010, 185, 195 - 208. 3. Grimshaw R., Pelinovsky E., Talipova T., Ruderman M. Erdelyi R. Short-lived large-amplitude pulses in the nonlinear long-wave model described by the modified Korteweg-de Vries equation. Studied Applied Mathematics, 2005, 114 (2), 189. 4. Talipova T.G. Mechanisms of internal freak waves, Fundamental and Applied Hydrophysics
Fredholm and Wronskian representations of solutions to the KPI equation and multi-rogue waves
NASA Astrophysics Data System (ADS)
Gaillard, Pierre
2016-06-01
We construct solutions to the Kadomtsev-Petviashvili equation (KPI) in terms of Fredholm determinants. We deduce solutions written as a quotient of Wronskians of order 2N. These solutions, called solutions of order N, depend on 2N - 1 parameters. When one of these parameters tends to zero, we obtain N order rational solutions expressed as a quotient of two polynomials of degree 2N(N + 1) in x, y, and t depending on 2N - 2 parameters. So we get with this method an infinite hierarchy of solutions to the KPI equation.
Rogue Waves, Remakes, and Resurrections: Allegorical Displacement and Screen Memory in "Poseidon"
ERIC Educational Resources Information Center
King, Claire Sisco
2008-01-01
"Poseidon," the 2006 remake of the Vietnam-era disaster film "The Poseidon Adventure," functions rhetorically as a symptomatic response to the historical trauma(s) of 9/11, revising the narrative of its cinematic predecessor and producing a screen memory that marks the changed cultural and historical context that demanded its repetition in the…
NLS breathers, rogue waves, and solutions of the Lyapunov equation for Jordan blocks
NASA Astrophysics Data System (ADS)
Chvartatskyi, Oleksandr; Müller-Hoissen, Folkert
2017-04-01
The infinite families of Peregrine, Akhmediev and Kuznetsov–Ma breather solutions of the focusing nonlinear Schrödinger (NLS) equation are obtained via a matrix version of the Darboux transformation, with a spectral matrix of the form of a Jordan block. The structure of these solutions is essentially determined by the corresponding solution of the Lyapunov equation. In particular, regularity follows from properties of the Lyapunov equation.
Hall, Stephen H.
1996-01-01
The present invention is a reference half-cell electrode wherein intermingling of test fluid with reference fluid does not affect the performance of the reference half-cell over a long time. This intermingling reference half-cell may be used as a single or double junction submersible or surface reference electrode. The intermingling reference half-cell relies on a capillary tube having a first end open to reference fluid and a second end open to test fluid wherein the small diameter of the capillary tube limits free motion of fluid within the capillary to diffusion. The electrode is placed near the first end of the capillary in contact with the reference fluid. The method of operation of the present invention begins with filling the capillary tube with a reference solution. After closing the first end of the capillary, the capillary tube may be fully submerged or partially submerged with the second open end inserted into test fluid. Since the electrode is placed near the first end of the capillary, and since the test fluid may intermingle with the reference fluid through the second open end only by diffusion, this intermingling capillary reference half-cell provides a stable voltage potential for long time periods.
Hall, S.H.
1996-02-13
The present invention is a reference half-cell electrode wherein intermingling of test fluid with reference fluid does not affect the performance of the reference half-cell over a long time. This intermingling reference half-cell may be used as a single or double junction submersible or surface reference electrode. The intermingling reference half-cell relies on a capillary tube having a first end open to reference fluid and a second end open to test fluid wherein the small diameter of the capillary tube limits free motion of fluid within the capillary to diffusion. The electrode is placed near the first end of the capillary in contact with the reference fluid. The method of operation of the present invention begins with filling the capillary tube with a reference solution. After closing the first end of the capillary, the capillary tube may be fully submerged or partially submerged with the second open end inserted into test fluid. Since the electrode is placed near the first end of the capillary, and since the test fluid may intermingle with the reference fluid through the second open end only by diffusion, this intermingling capillary reference half-cell provides a stable voltage potential for long time periods. 11 figs.
Book review: Extreme ocean waves
Geist, Eric L.
2017-01-01
“Extreme Ocean Waves”, edited by E. Pelinovsky and C. Kharif, second edition, Springer International Publishing, 2016; ISBN: 978-3-319-21574-7, ISBN (eBook): 978-3-319-21575-4The second edition of “Extreme Ocean Waves” published by Springer is an update of a collection of 12 papers edited by Efim Pelinovsky and Christian Kharif following the April 2007 meeting of the General Assembly of the European Geosciences Union. In this edition, three new papers have been added and three more have been substantially revised. Color figures are now included, which greatly aids in reading several of the papers, and is especially helpful in visualizing graphs as in the paper on symbolic computation of nonlinear wave resonance (Tobisch et al.). A note on terminology: extreme waves in this volume broadly encompass different types of waves, including deep-water and shallow-water rogue waves (which are alternatively termed freak waves), and internal waves. One new paper on tsunamis (Viroulet et al.) is now included in the second edition of this volume. Throughout the book, the reader will find a combination of laboratory, theoretical, and statistical/empirical treatment necessary for the complete examination of this subject. In the Introduction, the editors underscore the importance of studying extreme waves, documenting a dramatic instance of damaging extreme waves that recently occurred in 2014.
Computationally Efficient Numerical Model for the Evolution of Directional Ocean Surface Waves
NASA Astrophysics Data System (ADS)
Malej, M.; Choi, W.; Goullet, A.
2011-12-01
The main focus of this work has been the asymptotic and numerical modeling of weakly nonlinear ocean surface wave fields. In particular, a development of an efficient numerical model for the evolution of nonlinear ocean waves, including extreme waves known as Rogue/Freak waves, is of direct interest. Due to their elusive and destructive nature, the media often portrays Rogue waves as unimaginatively huge and unpredictable monsters of the sea. To address some of these concerns, derivations of reduced phase-resolving numerical models, based on the small wave steepness assumption, are presented and their corresponding numerical simulations via Fourier pseudo-spectral methods are discussed. The simulations are initialized with a well-known JONSWAP wave spectrum and different angular distributions are employed. Both deterministic and Monte-Carlo ensemble average simulations were carried out. Furthermore, this work concerns the development of a new computationally efficient numerical model for the short term prediction of evolving weakly nonlinear ocean surface waves. The derivations are originally based on the work of West et al. (1987) and since the waves in the ocean tend to travel primarily in one direction, the aforementioned new numerical model is derived with an additional assumption of a weak transverse dependence. In turn, comparisons of the ensemble averaged randomly initialized spectra, as well as deterministic surface-to-surface correlations are presented. The new model is shown to behave well in various directional wave fields and can potentially be a candidate for computationally efficient prediction and propagation of extreme ocean surface waves - Rogue/Freak waves.
For patients with difficult-to-treat cancers, doctors increasingly rely on genomic testing of tumors to identify errors in the DNA that indicate a tumor can be targeted by existing therapies. But this approach overlooks rogue proteins that may be driving cancer cells and also could be targeted with existing treatments, according to research.
Capillary suspensions: Particle networks formed through the capillary force
Koos, Erin
2014-01-01
The addition of small amounts of a secondary fluid to a suspension can, through the attractive capillary force, lead to particle bridging and network formation. The capillary bridging phenomenon can be used to stabilize particle suspensions and precisely tune their rheological properties. This effect can even occur when the secondary fluid wets the particles less well than the bulk fluid. These materials, so-called capillary suspensions, have been the subject of recent research studying the mechanism for network formation, the properties of these suspensions, and how the material properties can be modified. Recent work in colloidal clusters is summarized and the relationship to capillary suspensions is discussed. Capillary suspensions can also be used as a pathway for new material design and some of these applications are highlighted. Results obtained to date are summarized and central questions that remain to be answered are proposed in this review. PMID:25729316
Movement and habitat use of green sturgeon Acipenser medirostris in the Rogue River, Oregon, USA
Erickson, D.L.; North, J.A.; Hightower, J.E.; Weber, J.; Lauck, L.
2002-01-01
Green sturgeon (Acipenser medirostris) movement patterns and habitat use within the Rogue River, Oregon were evaluated using radio telemetry. Nineteen specimens ranging from 154 to 225 cm total length were caught by gill netting and tagged with radio transmitters during May-July 2000. One tagged green sturgeon was verified as a female near spawning condition. Individual green sturgeons spent more than 6 months in fresh water and traveled as far as river kilometer (rkm) 39.5. Green sturgeon preferred specific holding sites within the Rogue River during summer and autumn months. These sites were typically deep (> 5 m) low-gradient reaches or off-channel coves. Home ranges within holding sites were restricted. All tagged individuals emigrated from the system to the sea during the autumn and winter, when water temperatures dropped below 10??C and flows increased. This species is extremely vulnerable to habitat alterations and overfishing because it spawns in only a few North American rivers and individuals reside within extremely small areas for extended periods of time.
Hirsch, Gregory
1998-01-01
A metal or glass wire is etched with great precision into a very narrowly tapering cone which has the shape of the desired final capillary-optics bore. By controlling the rate of removal of the wire from an etchant bath, a carefully controlled taper is produced. A sensor measures the diameter of the wire as it leaves the surface of the etchant. This signal is used for feedback control of the withdrawal speed. The etched wire undergoes a treatment to produce an extremely low surface-roughness. The etched and smoothed wire is coated with the material of choice for optimizing the reflectivity of the radiation being focused. This could be a vacuum evaporation, sputtering, CVD or aqueous chemical process. The coated wire is either electroplated, built up with electroless plating, or encapsulated in a polymer cylinder such as epoxy to increase the diameter of the wire for easier handling and greater robustness. During this process, the wire is vertically oriented and tensioned to assure that the wire is absolutely straight. The coated and electroformed wire is bonded to a flat, rigid substrate and is then periodically segmented by cutting or etching a series of narrow slits or grooves into the wire. The wire is vertically oriented and tensioned during the bonding process to assure that it is straight. The original wire material is then chemically etched away through the slits or otherwise withdrawn to leave the hollow internal bore of the final tapered-capillary optical element.
NASA Astrophysics Data System (ADS)
Pelinovsky, Efim; Chaikovskaia, Natalya; Rodin, Artem
2015-04-01
The paper presents the analysis of the formation and evolution of shock wave in shallow water with no restrictions on its amplitude in the framework of the nonlinear shallow water equations. It is shown that in the case of large-amplitude waves appears a new nonlinear effect of reflection from the shock front of incident wave. These results are important for the assessment of coastal flooding by tsunami waves and storm surges. Very often the largest number of victims was observed on the coastline where the wave moved breaking. Many people, instead of running away, were just looking at the movement of the "raging wall" and lost time. This fact highlights the importance of researching the problem of security and optimal behavior of people in situations with increased risk. Usually there is uncertainty about the exact time, when rogue waves will impact. This fact limits the ability of people to adjust their behavior psychologically to the stressful situations. It concerns specialists, who are busy both in the field of flying activity and marine service as well as adults, young people and children, who live on the coastal zone. The rogue wave research is very important and it demands cooperation of different scientists - mathematicians and physicists, as well as sociologists and psychologists, because the final goal of efforts of all scientists is minimization of the harm, brought by rogue waves to humanity.
Onorato, M; Osborne, A R; Serio, M
2006-01-13
Here we consider a simple weakly nonlinear model that describes the interaction of two-wave systems in deep water with two different directions of propagation. Under the hypothesis that both sea systems are narrow banded, we derive from the Zakharov equation two coupled nonlinear Schrödinger equations. Given a single unstable plane wave, here we show that the introduction of a second plane wave, propagating in a different direction, can result in an increase of the instability growth rates and enlargement of the instability region. We discuss these results in the context of the formation of rogue waves.
On Capillary Rise and Nucleation
ERIC Educational Resources Information Center
Prasad, R.
2008-01-01
A comparison of capillary rise and nucleation is presented. It is shown that both phenomena result from a balance between two competing energy factors: a volume energy and a surface energy. Such a comparison may help to introduce nucleation with a topic familiar to the students, capillary rise. (Contains 1 table and 3 figures.)
Capillary optics for radiation focusing
Peurrung, A.J.; Reeder, P.L.; Bliss, M.; Craig, R.A.; Lepel, E.A.; Stromswold, D.C.; Stoffels, J.; Sunberg, D.S.; Tenny, H.
1996-11-01
Capillary lens technology may ultimately bring benefits to neutron and x-ray-based science like conventional lenses with visible light. Although the technology is not yet 10 years old, these lenses have already had a significant impact in engineering, science, and medicine. Capillary lenses are advantageous when it is desirable to increase the radiation flux at a location without regard to its angular divergence. PNNL has worked to improve the technology in several ways. A single, optimally tapered capillary was manufactured, which allows intensity gains of a factor of 270 for an initially parallel, incident x-ray beam. Feasibility of constructing neutron lenses using {sup 58}Ni (particularly effective at reflecting neutrons) has been explored. Three applications for capillary optics have been identified and studied: neutron telescope, Gandolphi x-ray diffractometry, and neutron radiotherapy. A brief guide is given for determining which potential applications are likely to be helped by capillary optics.
Noise suppressing capillary separation system
Yeung, E.S.; Xue, Y.
1996-07-30
A noise-suppressing capillary separation system for detecting the real-time presence or concentration of an analyte in a sample is provided. The system contains a capillary separation means through which the analyte is moved, a coherent light source that generates a beam which is split into a reference beam and a sample beam that irradiate the capillary, and a detector for detecting the reference beam and the sample beam light that transmits through the capillary. The laser beam is of a wavelength effective to be absorbed by a chromophore in the capillary. The system includes a noise suppressing system to improve performance and accuracy without signal averaging or multiple scans. 13 figs.
Geometry-induced capillary emptying.
Rascón, Carlos; Parry, Andrew O; Aarts, Dirk G A L
2016-10-24
When a capillary is half-filled with liquid and turned to the horizontal, the liquid may flow out of the capillary or remain in it. For lack of a better criterion, the standard assumption is that the liquid will remain in a capillary of narrow cross-section, and will flow out otherwise. Here, we present a precise mathematical criterion that determines which of the two outcomes occurs for capillaries of arbitrary cross-sectional shape, and show that the standard assumption fails for certain simple geometries, leading to very rich and counterintuitive behavior. This opens the possibility of creating very sensitive microfluidic devices that respond readily to small physical changes, for instance, by triggering the sudden displacement of fluid along a capillary without the need of any external pumping.
Biomedical applications of capillary electrophoresis
NASA Astrophysics Data System (ADS)
Kartsova, L. A.; Bessonova, E. A.
2015-08-01
The review deals with modern analytical approaches used in capillary electrophoresis for solving medical and biological problems: search for biomarkers of various diseases and rapid diagnosis based on characteristic profiles of biologically active compounds by capillary electrophoresis with mass spectrometric detection; monitoring of the residual drugs in biological fluids for evaluating the efficiency of drug therapy; testing of the enantiomeric purity of pharmaceutical products; the use of novel materials as components of stationary and pseudo-stationary phases in capillary electrophoresis and capillary electrochromatography to increase the selectivity of separation of components of complex matrices; and identification of various on-line preconcentration techniques to reduce the detection limits of biologically active analytes. A topical trend in capillary electrophoresis required in clinical practice, viz., the design of microfluidic systems, is discussed. The bibliography includes 173 references.
Fluorescence and optical-resolution photoacoustic imaging through capillary waveguides
NASA Astrophysics Data System (ADS)
Stasio, Nicolino; Shibukawa, Atsushi; Papadopoulos, Ioannis N.; Farahi, Salma; Simandoux, Olivier; Huignard, Jean-Pierre; Bossy, Emmanuel; Moser, Christophe; Psaltis, Demetri
2016-03-01
Endoscopy can be used to obtain high-resolution images at large depths in biological tissues. Usually endoscopic devices have a diameter ranging from 1 to few millimeters. Using digital phase conjugation, it is possible to adapt ultrathin multimode fibers to endoscopic purposes. Recently, we demonstrated that a 330 μm diameter, water-filled silica capillary waveguide can guide high frequency ultrasound waves through a 3 cm thick fat layer, allowing optical resolution photoacoustic imaging. Here we demonstrate that using digital phase conjugation, the same water-filled capillary waveguide (3 cm long) can be used as an endoscopic probe to obtain both fluorescence and optical resolution photoacoustic imaging, with no optical or acoustic elements at the tip of the waveguide. We study the consequences of using digital phase conjugation combined with a capillary waveguide and we conclude with possible future improvements of our endoscopic approach.
Wind effects on the modulational instability of surface gravity waves
NASA Astrophysics Data System (ADS)
Brunetti, Maura; Kasparian, Jérôme
2015-04-01
The modulational instability is a fundamental mechanism for nonlinear exchanges of energy between carrier and sideband waves. It is one of the processes at the origin of rogue-wave formation in deep-water. Since the wind is the energy source in surface wave propagation, accurate modelling of the wind is critical for understanding rogue-wave phenomenon. We describe how different forcing terms, due to different modelling of the wind action, affect the band of positive gain of the modulational instability. In particular, we consider the wind-forced nonlinear Schrödinger equation obtained in the potential flow framework when the Miles growth rate is of the order of the wave steepness [1]. In this case, the form of the wind-forcing terms gives rise to the enhancement of the modulational instability and to a band of positive gain with infinite width [2]. This regime is characterised by the fact that the ratio between wave momentum and norm is not a constant of motion [2], in contrast to what happens in the standard case where the Miles growth rate is of the order of the steepness squared. References [1] M. Brunetti, N. Marchiando, N. Berti, J. Kasparian, 2014, Phys. Lett. A, 378, 1025-1030 [2] M. Brunetti, J. Kasparian, 2014, Phys. Lett. A, 378, 3626-3630
Capillary ratchet: Hydrodynamics of capillary feeding in shorebirds
NASA Astrophysics Data System (ADS)
Prakash, Manu; Quere, David; Bush, John
2008-03-01
Bill morphologies are highly specialized to particular foraging strategies in birds, as is apparent from the large diversity of beak shapes observed in nature. Here we present an experimental and analytical study of capillary feeding in shorebirds. We highlight the critical role of contact angle hysteresis in capillary feeding. Our study provides a simple physical rationalization for the observation of multiple mandibular spreading cycles in feeding, necessary to overcome contact line resistance. We also find a unique geometrical optima in beak opening and closing angles for the most efficient drop transport. This capillary ratchet mechanism may also find applications in micro scale fluid transport, such as valveless pumping of fluid drops.
Capillaries for use in a multiplexed capillary electrophoresis system
Yeung, E.S.; Chang, H.T.; Fung, E.N.
1997-12-09
The invention provides a side-entry optical excitation geometry for use in a multiplexed capillary electrophoresis system. A charge-injection device is optically coupled to capillaries in the array such that the interior of a capillary is imaged onto only one pixel. In Sanger-type 4-label DNA sequencing reactions, nucleotide identification (``base calling``) is improved by using two long-pass filters to split fluorescence emission into two emission channels. A binary poly(ethyleneoxide) matrix is used in the electrophoretic separations. 19 figs.
Capillaries for use in a multiplexed capillary electrophoresis system
Yeung, Edward S.; Chang, Huan-Tsang; Fung, Eliza N.
1997-12-09
The invention provides a side-entry optical excitation geometry for use in a multiplexed capillary electrophoresis system. A charge-injection device is optically coupled to capillaries in the array such that the interior of a capillary is imaged onto only one pixel. In Sanger-type 4-label DNA sequencing reactions, nucleotide identification ("base calling") is improved by using two long-pass filters to split fluorescence emission into two emission channels. A binary poly(ethyleneoxide) matrix is used in the electrophoretic separations.
NASA Technical Reports Server (NTRS)
Weislogel, Mark M.
1996-01-01
A steady capillary driven flow is developed for a liquid index in a circular tube which is partially coated with a surface modifier to produce a discontinuous wetting condition from one side of the tube to the other. The bulk flow is novel in that it is truly steady, and controlled solely by the physics associated with dynamic wetting. The influence of gravity on the flow is minimized through the use of small diameter tubes approximately O(1 mm) tested horizontally in a laboratory and larger tubes approximately O(10 mm) tested in the low gravity environment of a drop tower. Average steady velocities are predicted and compared against a large experimental data set which includes the effects of tube dimensions and fluid properties. The sensitivity of the velocity to surface cleanliness is dramatic and the advantages of experimentation in a microgravity environment are discussed.
NASA Astrophysics Data System (ADS)
Darbois Texier, Baptiste; Dorbolo, Stephane
2014-11-01
As used by Egyptians for irrigation and reported by Archimedes, a screw turning inside a hollow pipe can pull out a fluid againt gravity. At a centimetric scale, an analagous system can be found with a drop pending on a rotating spiral which is tilted toward the horizontal. The ascent of the drop to the top of the spiral is considered and a theoretical model based on geometrical considerations is proposed. The climb of the drop is limited by the fluid deposition on the screw at high capillary number and by a centrifugation phenomenon. We find out the range of fluid proprities and spiral characteristics for which an ascending motion of the drop is possible. Finally we discuss the efficiency of such system to extract a fluid from a bath at a centrimetric scale.
Multidimensional capillary electrophoresis.
Grochocki, Wojciech; Markuszewski, Michał J; Quirino, Joselito P
2015-01-01
Multidimensional separation where two or more orthogonal displacement mechanisms are combined is a promising approach to increase peak capacity in CE. The combinations allow dramatic improvement of analytical performance since the total peak capacity is given by a product of the peak capacities of all methods. The initial reports were concentrated on the construction of effective connections between capillaries for 2D analysis. Today, 2D and 3D CE systems are now able to separate real complex biological or environmental mixtures with good repeatability, improved resolution with minimal loss of sample. This review will present the developments in the field of multidimensional CE during the last 15 years. The endeavors in this specific field were on the development of interfaces, interface-free techniques including integrated separations, microdevices, and on-line sample concentration techniques to improve detection sensitivity.
Wang, Lei; Zhang, Jian-Hui; Wang, Zi-Qi; Liu, Chong; Li, Min; Qi, Feng-Hua; Guo, Rui
2016-01-01
We study the nonlinear waves on constant backgrounds of the higher-order generalized nonlinear Schrödinger (HGNLS) equation describing the propagation of ultrashort optical pulse in optical fibers. We derive the breather, rogue wave, and semirational solutions of the HGNLS equation. Our results show that these three types of solutions can be converted into the nonpulsating soliton solutions. In particular, we present the explicit conditions for the transitions between breathers and solitons with different structures. Further, we investigate the characteristics of the collisions between the soliton and breathers. Especially, based on the semirational solutions of the HGNLS equation, we display the novel interactions between the rogue waves and other nonlinear waves. In addition, we reveal the explicit relation between the transition and the distribution characteristics of the modulation instability growth rate.
Instability of the capillary bridge
NASA Astrophysics Data System (ADS)
Pare, Gounseti; Hoepffner, Jerome
2014-11-01
Capillary adhesion is a physical mechanism that maintains two bodies in contact by capillarity through a liquid ligament. The capillary bridge is an idealization of this capillary adhesion. In this study we first focus on the classical case of the stability of the capillary bridge. Secondly we study a slightly more complex configuration, imagining a flow in the capillary bridge as in the case of the dynamics of the neck of a liquid ligament, in its withdrawal under the effect of capillarity. Inspired by the experiments on soap films of Plateau, the configuration analyzed consists of an initially axisymmetric, mass of fluid held by surface tension forces between two parallel, coaxial, solid pipes of the same diameter. The results presented are obtained by numerical simulations using the free software, Gerris Flow Solver. We first focus on the capillary Venturi. In the static configuration the stability diagram of the capillary bridge obtained is in perfect agreement with the results of Lev A. Slobozhanin. In the dynamic case we develop a matlab code based on the one dimensional equations of Eggers and Dupont. The comparison of the bifurcation diagram obtained and the numerical simulations shows a good agreement.
Inertial Rise in Short Capillaries
NASA Astrophysics Data System (ADS)
Shardt, Orest; Waghmare, Prashant; Mitra, Sushanta; Derksen, Jos
2013-11-01
We investigate the primarily inertial rise of liquid in vertical glass capillaries that are shorter than the equilibrium rise height (Jurin height). We focus on the behavior of the liquid upon reaching the top of the capillary and use high-speed imaging to observe the motion of the liquid-air interface with high spatial and temporal resolution. We examine the dependence of the interface behavior on the meniscus speed and capillary height and describe a new phenomenon. Upon reaching the upper edge of a sufficiently short capillary, the meniscus inverts, rises upward, and bulges out radially. The bulging liquid then wets the external surface of the capillary and slides down. The meniscus inside the capillary retracts, falling below the upper edge, and then oscillates vertically with decaying amplitude, inverting several times before reaching a steady shape. A theoretical analysis is used to interpret the conditions required for this phenomenon to occur. A key assumption in the analysis is that the transient flow is inertial and therefore the capillary driving force is balanced by the weight and inertia of the rising liquid column while viscous forces are comparatively small. The analysis points to the possibility of obtaining previously-unseen behavior under reduced gravity.
Experimental study of spatiotemporally localized surface gravity water waves.
Chabchoub, A; Akhmediev, N; Hoffmann, N P
2012-07-01
We present experimental results on the study of spatiotemporally localized surface wave events on deep water that can be modeled using the Peregrine breather solution of the nonlinear Schrödinger equation. These are often considered as prototypes of oceanic rogue waves that can focus wave energy into a single wave packet. For small steepness values of the carrier gravity waves the Peregrine breathers are relatively wide, thus providing an excellent agreement between the theory and experimental results. For larger steepnesses the focusing leads to temporally and spatially shorter events. Nevertheless, agreement between measurements and the Peregrine breather theory remains reasonably good, with discrepancies of modulation gradients and spatiotemporal symmetries being tolerable. Lifetimes and travel distances of the spatiotemporally localized wave events determined from the experiment are in good agreement with the theory.
Electrospraying from nanofluidic capillary slot
NASA Astrophysics Data System (ADS)
Arscott, Steve; Troadec, David
2005-09-01
We present here an original electrospray emitter tip based on a nanofluidic capillary slot. The nanofabrication involves focused ion beam etching to form the slot which has a cross-section of 50×300nm and a length of 4μm. The liquid is deformed into the nanofluidic capillary slot by capillary action; the electrospray is produced by the application of a low voltage. Using a water-methanol-formic acid solution, we have observed an electrospray onset voltage of 125V. At a measured electrospray current of 1nA, the unforced flow-rate is estimated to be 110pLmin-1.
Integrated multiplexed capillary electrophoresis system
Yeung, Edward S.; Tan, Hongdong
2002-05-14
The present invention provides an integrated multiplexed capillary electrophoresis system for the analysis of sample analytes. The system integrates and automates multiple components, such as chromatographic columns and separation capillaries, and further provides a detector for the detection of analytes eluting from the separation capillaries. The system employs multiplexed freeze/thaw valves to manage fluid flow and sample movement. The system is computer controlled and is capable of processing samples through reaction, purification, denaturation, pre-concentration, injection, separation and detection in parallel fashion. Methods employing the system of the invention are also provided.
Computer modeling of capillary flow with superimposed pulsations
NASA Astrophysics Data System (ADS)
Yaganova, A. E.; Marfin, E. A.
2016-11-01
Increasing efficiency of methods of oil production can be achieved by the influence of elastic vibrations. It is a well-known fact that shift viscosity of oil changes under the effect of elastic vibrations. This change depends on properties of the oil and exposure mode. Existing approaches to the research of the way wave exposure impacts on viscosity are based on measuring it after the processing. This article concerns development of methods to measure viscosity of liquid right during its exposure to elastic vibrations. The suggested approach is based on combining numerical and natural experiments. We investigated the pulsating flow of viscid liquid in a capillary numerically in this article. We received allocations of fields of average velocity and pressure in a capillary. It is demonstrated that imposed pulsations in a capillary do not impact on hydrodynamics of the flow. We offered the scheme of an experimental installation for a research of the impact that wave exposure has on the viscosity of liquids. The installation is based on a capillary viscometer.
Capillary effect in salt-cemented media of particle sizes
NASA Astrophysics Data System (ADS)
Yoon, Hyung-Koo; Hung Truong, Q.; Byun, Yong-Hoon; Lee, Jong-Sub
2015-01-01
Natural cementation such as salt cementation may significantly affect the geotechnical properties of soils at low confining pressures. Capillary force plays a key role in the distribution patterns of salt cementation resulting from dehydration. The aim of this study is to investigate the effect of capillary force on salt cementation through cone penetration testing, electrical conductivity measurements, photographic imaging technique, and nondestructive elastic wave scanning. Granular media is modeled using glass beads which are saturated in salt water and cemented by oven drying. The cone tip resistance profiles, electrical conductivity profiles, and amplitudes of the scanned elastic waves are high at the top of the specimen with small-sized particles, in the middle of the specimen in medium-sized particles, and at the bottom of the specimen in the large-sized particles. Differences in the distribution of salt in the cemented specimens are confirmed from photographic images. The calculated capillary heights are associated with the areas of high salt concentration in the cemented specimens. The four investigation methods used in this study show that the behavior of salt-cemented granular media depends on capillary force in a shallow depth.
ERIC Educational Resources Information Center
Tucker, Vance A.
1971-01-01
Capillary and gravity water waves are related to the position, wavelength, and velocity of an object in flowing water. Water patterns are presented for ships and the whirling beetle with an explanation of how the design affects the objects velocity and the observed water wavelengths. (DS)
Analysis of Capillary Rise in Asymmetric Branch-Like Capillary
NASA Astrophysics Data System (ADS)
Li, Caoxiong; Shen, Yinghao; Ge, Hongkui; Yang, Zhihui; Su, Shuai; Ren, Kai; Huang, Heyu
2016-05-01
Transport in porous media is common in nature, attracting many attentions for a long time. Tree-like network model is often used as a simplification for porous space, expressing the complexity of pore spaces instead of capillary bundle. To investigate spontaneous imbibition characteristics in this network, a dynamic asymmetric branch-like capillary model is used to represent basic network structure, using fractal method to represent tortuosity. This work investigates the influence of parameters on imbibition process in the branch-like capillary model. An analytical equation for the imbibition mass versus time is derived. Parameters from capillary structures to liquid properties are taken into account and analyzed based on the numerical solution of the equation. It is found that the imbibition process in asymmetric branch-like capillary model can be recognized by four sections and brunching tubes are positive for imbibition process. Concomitantly, meniscus arrest event is simulated and discussed. Moreover, the influence of parameters on imbibition process is discussed. These parameters can be classified as static and dynamic. Static parameters mainly change the capillary force, which are related to the ultimate imbibition mass or imbibition ability, while dynamic parameters mainly have influence on resistance of flowing fluid, which are related to the imbibition speed in the imbibition process.
NASA Astrophysics Data System (ADS)
Bensel, Holly; Arianna Ashby, Colin Cai, Thomas Cox, Genna Dorrell, Gabe FitzPatrick, Meaghan FitzPatrick, Jason Mars Liu, Mitchell Moczygemba, Kieran Rooney, Emry Timmons,; Ray You, students, (St. Mary's. School)
2015-01-01
Rural areas in Oregon, including the Rogue Valley, are renowned for beautiful dark skies. Electric light came to Medford, Oregon, the largest town in the Rogue Valley, in 1894. During the past 100 years the Rogue Valley grew from 2,500 individuals in 1895 to a population of 76,462 and a metropolitan area population of 208,545, in 2012. The increased population density resulted in increased light pollution. A light pollution chart using DMSP, Defense Meteorological Satellite Program, data was published in 2006, but did not show the spatial variation in detail. In the spring of 2014, the 9th grade physics students, astronomy students, and members of the Astronomy Club from St. Mary's School conducted the first detailed night sky survey. The purpose of the survey is to create a baseline of the variations in light pollution in the Rogue Valley.The project started with a talk by Steve Bosbach, former Texas IDA coordinator, on the topic of light pollution and how it affects our lives and the environment. Groups of students were given the tasks of measuring the night sky brightness in the Rogue Valley, doing a light audit in an area of their choice, and researching what light pollution is and its effects on the environment. From this they created a presentation for a final physics grade. The basis for this project, along with procedures can be found on the Globe at Night (www.globeatnight.org) website. The light audit and research portion were developed from the Dark Sky Rangers section (www.globeatnight.org/dsr/) of the website. In the fall of 2014, astronomy students and club members extended this study to the town of Ashland and the Sothern Oregon University campus, areas of the valley not surveyed in the Spring.This survey will increase awareness of light pollution in the Rogue Valley, as well as educate developers and city planners on the impact that light pollution has on the environment in Southern Oregon. It will help determine areas of concern and areas of dark
Sound Waves Levitate Substrates
NASA Technical Reports Server (NTRS)
Lee, M. C.; Wang, T. G.
1982-01-01
System recently tested uses acoustic waves to levitate liquid drops, millimeter-sized glass microballoons, and other objects for coating by vapor deposition or capillary attraction. Cylindrical contactless coating/handling facility employs a cylindrical acoustic focusing radiator and a tapered reflector to generate a specially-shaped standing wave pattern. Article to be processed is captured by the acoustic force field under the reflector and moves as reflector is moved to different work stations.
NASA Astrophysics Data System (ADS)
Yang, Hua; Chen, Nengsong; Wang, Boyan; Tang, Pinghua; Zeng, Qilin
2016-08-01
We present an approach that enables active control of supercontinuum (SC) and rogue soliton (RS) generation through the modulation of a 500 fs input pulse by numerical simulations. The induced modulational instability contributes to the initial comb-like SC generation, which is fundamentally different from SC initiated by high-order soliton fission. The output spectrum shows great dependence on modulation frequencies and depths. It is interesting that we can manipulate the RS generation by adjusting the modulation parameters. And we also demonstrate the conditions which can be beneficial to RS generation: (i) very weak or large values of modulation depth; (ii) seeding in the vicinity of the peak of the modulational instability gain spectrum. Although RS degrades the smoothness of the SC, it is of great significance in the generation of tailored SC.
Capillary electrophoresis electrospray ionization mass spectrometry interface
Smith, Richard D.; Severs, Joanne C.
1999-01-01
The present invention is an interface between a capillary electrophoresis separation capillary end and an electrospray ionization mass spectrometry emitter capillary end, for transporting an anolyte sample from a capillary electrophoresis separation capillary to a electrospray ionization mass spectrometry emitter capillary. The interface of the present invention has: (a) a charge transfer fitting enclosing both of the capillary electrophoresis capillary end and the electrospray ionization mass spectrometry emitter capillary end; (b) a reservoir containing an electrolyte surrounding the charge transfer fitting; and (c) an electrode immersed into the electrolyte, the electrode closing a capillary electrophoresis circuit and providing charge transfer across the charge transfer fitting while avoiding substantial bulk fluid transfer across the charge transfer fitting. Advantages of the present invention have been demonstrated as effective in providing high sensitivity and efficient analyses.
Capillary fracturing in granular media.
Holtzman, Ran; Szulczewski, Michael L; Juanes, Ruben
2012-06-29
We study the displacement of immiscible fluids in deformable, noncohesive granular media. Experimentally, we inject air into a thin bed of water-saturated glass beads and observe the invasion morphology. The control parameters are the injection rate, the bead size, and the confining stress. We identify three invasion regimes: capillary fingering, viscous fingering, and "capillary fracturing," where capillary forces overcome frictional resistance and induce the opening of conduits. We derive two dimensionless numbers that govern the transition among the different regimes: a modified capillary number and a fracturing number. The experiments and analysis predict the emergence of fracturing in fine-grained media under low confining stress, a phenomenon that likely plays a fundamental role in many natural processes such as primary oil migration, methane venting from lake sediments, and the formation of desiccation cracks.
Capillary Fracturing in Granular Media
NASA Astrophysics Data System (ADS)
Holtzman, Ran; Szulczewski, Michael L.; Juanes, Ruben
2012-06-01
We study the displacement of immiscible fluids in deformable, noncohesive granular media. Experimentally, we inject air into a thin bed of water-saturated glass beads and observe the invasion morphology. The control parameters are the injection rate, the bead size, and the confining stress. We identify three invasion regimes: capillary fingering, viscous fingering, and “capillary fracturing,” where capillary forces overcome frictional resistance and induce the opening of conduits. We derive two dimensionless numbers that govern the transition among the different regimes: a modified capillary number and a fracturing number. The experiments and analysis predict the emergence of fracturing in fine-grained media under low confining stress, a phenomenon that likely plays a fundamental role in many natural processes such as primary oil migration, methane venting from lake sediments, and the formation of desiccation cracks.
DNA typing by capillary electrophoresis
Zhang, N.
1997-10-08
Capillary electrophoresis is becoming more and more important in nucleic acid analysis including DNA sequencing, typing and disease gene measurements. This work summarized the background of DNA typing. The recent development of capillary electrophoresis was also discussed. The second part of the thesis showed the principle of DNA typing based on using the allelic ladder as the absolute standard ladder in capillary electrophoresis system. Future work will be focused on demonstrating DNA typing on multiplex loci and examples of disease diagnosis in the on-line format of PCR-CE. Also capillary array electrophoresis system should allow high throughput, fast speed DNA typing. Only the introduction and conclusions for this report are available here. A reprint was removed for separate processing.
Nonlinear Coherent Structures of Alfvén Wave in a Collisional Plasma
NASA Astrophysics Data System (ADS)
Jana, Sayanee; Ghosh, Samiran; Chakrabarti, Nikhil
2016-10-01
The Alfvén wave dynamics is investigated in the framework of Lagrangian two-fluid model in a cold magnetized collisional plasma in presence of finite electron inertia. In the quasi-linear limit, the dynamics of the nonlinear Alfvén wave is shown to be governed by a modified Korteweg-de Vries Burgers (mKdVB) equation. In this mKdVB equation, the electron inertia is found to act as a source of dispersion and the electro-ion collision serves as a dissipation. In the long wavelength limit, we have also investigated wave modulation characteristics of the nonlinear Alfvén wave. The dynamics of this modulated wave is shown to be governed by a damped nonlinear Schrödinger equation (NLSE). These nonlinear equations are analysed by means of analytical and numerical simulation to elucidate the various aspects of the phase-space dynamics of the nonlinear wave. Results reveal that nonlinear Alfvén wave exhibits shock, envelope and breather like structures. Numerical simulations also predict the formation of Alfvénic rogue waves, rogue wave holes and giant breathers. These results could be useful for understanding the salient features of the Alfvénic magnetic field structures from observational data in very low- βmagnetized collisional plasmas in space and laboratory.
NASA Astrophysics Data System (ADS)
El-Labany, S. K.; El-Taibany, W. F.; Zedan, N. A.
2015-07-01
Cylindrical and spherical amplitude modulations of dust acoustic (DA) solitary wave envelopes in a strongly coupled dusty plasma containing nonthermal distributed ions are studied. Employing a reductive perturbation technique, a modified nonlinear Schrödinger equation including the geometrical effect is derived. The influences of nonthermal ions, polarization force, and the geometries on the modulational instability conditions are analyzed and the possible rogue wave structures are discussed in detail. It is found that the spherical DA waves are more structurally stable to perturbations than the cylindrical ones. Possible applications of these theoretical findings are briefly discussed.
El-Labany, S. K. Zedan, N. A.; El-Taibany, W. F. E-mail: eltaibany@du.edu.eg
2015-07-15
Cylindrical and spherical amplitude modulations of dust acoustic (DA) solitary wave envelopes in a strongly coupled dusty plasma containing nonthermal distributed ions are studied. Employing a reductive perturbation technique, a modified nonlinear Schrödinger equation including the geometrical effect is derived. The influences of nonthermal ions, polarization force, and the geometries on the modulational instability conditions are analyzed and the possible rogue wave structures are discussed in detail. It is found that the spherical DA waves are more structurally stable to perturbations than the cylindrical ones. Possible applications of these theoretical findings are briefly discussed.
Jones, Krista L.; O'Connor, Jim E.; Keith, Mackenzie K.; Mangano, Joseph F.; Wallick, J. Rose
2012-01-01
This report summarizes a preliminary assessment of bed-material transport, vertical and lateral channel changes, and existing datasets for the Rogue River basin, which encompasses 13,390 square kilometers (km2) along the southwestern Oregon coast. This study, conducted to inform permitting decisions regarding instream gravel mining, revealed that: * The Rogue River in its lowermost 178.5 kilometers (km) alternates between confined and unconfined segments, and is predominately alluvial along its lowermost 44 km. The study area on the mainstem Rogue River can be divided into five reaches based on topography, hydrology, and tidal influence. The largely confined, active channel flows over bedrock and coarse bed material composed chiefly of boulders and cobbles in the Grants Pass (river kilometers [RKM] 178.5-152.8), Merlin (RKM 152.8-132.7), and Galice Reaches (RKM 132.7-43.9). Within these confined reaches, the channel contains few bars and has stable planforms except for locally wider segments such as the Brushy Chutes area in the Merlin Reach. Conversely, the active channel flows over predominately alluvial material and contains nearly continuous gravel bars in the Lobster Creek Reach (RKM 43.9-6.7). The channel in the Tidal Reach (RKM 6.7-0) is also alluvial, but tidally affected and unconfined until RKM 2. The Lobster Creek and Tidal Reaches contain some of the most extensive bar deposits within the Rogue River study area. * For the 56.6-km-long segment of the Applegate River included in this study, the river was divided into two reaches based on topography. In the Upper Applegate River Reach (RKM 56.6-41.6), the confined, active channel flows over alluvium and bedrock and has few bars. In the Lower Applegate River Reach (RKM 41.6-0), the active channel alternates between confined and unconfined segments, flows predominantly over alluvium, shifts laterally in unconfined sections, and contains more numerous and larger bars. * The 6.5-km segment of the lower
AKNS eigenvalue spectrum for densely spaced envelope solitary waves
NASA Astrophysics Data System (ADS)
Slunyaev, Alexey; Starobor, Alexey
2010-05-01
The problem of the influence of one envelope soliton to the discrete eigenvalues of the associated scattering problem for the other envelope soliton, which is situated close to the first one, is discussed. Envelope solitons are exact solutions of the integrable nonlinear Schrödinger equation (NLS). Their generalizations (taking into account the background nonlinear waves [1-4] or strongly nonlinear effects [5, 6]) are possible candidates to rogue waves in the ocean. The envelope solitary waves could be in principle detected in the stochastic wave field by approaches based on the Inverse Scattering Technique in terms of ‘unstable modes' (see [1-3]), or envelope solitons [7-8]. However, densely spaced intense groups influence the spectrum of the associated scattering problem, so that the solitary trains cannot be considered alone. Here we solve the initial-value problem exactly for some simplified configurations of the wave field, representing two closely placed intense wave groups, within the frameworks of the NLS equation by virtue of the solution of the AKNS system [9]. We show that the analogues of the level splitting and the tunneling effects, known in quantum physics, exist in the context of the NLS equation, and thus may be observed in application to sea waves [10]. These effects make the detecting of single solitary wave groups surrounded by other nonlinear wave groups difficult. [1]. A.L. Islas, C.M. Schober (2005) Predicting rogue waves in random oceanic sea states. Phys. Fluids 17, 031701-1-4. [2]. A.R. Osborne, M. Onorato, M. Serio (2005) Nonlinear Fourier analysis of deep-water random surface waves: Theoretical formulation and and experimental observations of rogue waves. 14th Aha Huliko's Winter Workshop, Honolulu, Hawaii. [3]. C.M. Schober, A. Calini (2008) Rogue waves in higher order nonlinear Schrödinger models. In: Extreme Waves (Eds.: E. Pelinovsky & C. Kharif), Springer. [4]. N. Akhmediev, A. Ankiewicz, M. Taki (2009) Waves that appear from
Threshold capillary pressure in capillaries with curved sides
NASA Astrophysics Data System (ADS)
Lago, Marcelo; Araujo, Mariela
2003-03-01
Modeling of fluid flow through permeable media is of great importance in assessing the performance of both hydrocarbon reservoirs and aquifers. In this process, network models based on cylindrical capillaries with circular cross sections are frequently used. This type of capillaries are not able to reproduce interesting physical phenomena observed in the experiments, for example, situations where there is flow by films with the wetting fluid occupying the crevices and wedges of the structure. We present an analysis of the behavior of the capillary pressure of a droplet of non-wetting fluid with an infinite length, inside objects of cylindrical symmetry with curved sides. The calculation is based on a method proposed by Mayer and Stowe and Princen (MS-P). Different capillary geometries are considered, and the behavior of the capillary pressure and transversal fluid saturation as a function of the shape factor is studied. The results found either analytically or numerically, allow to understand the relation between geometry and flow properties, and helps in the building of more realistic pore network models for flow studies at the pore scale.
Two-dimensional capillary electrophoresis using tangentially connected capillaries.
Sahlin, Eskil
2007-06-22
A novel type of fused silica capillary system is described where channels with circular cross-sections are tangentially in contact with each other and connected through a small opening at the contact area. Since the channels are not crossing each other in the same plane, the capillaries can easily be filled with different solutions, i.e. different solutions will be in contact with each other at the contact point. The system has been used to perform different types of two-dimensional separations and the complete system is fully automated where a high voltage switch is used to control the location of the high voltage in the system. Using two model compounds it is demonstrated that a type of two-dimensional separation can be performed using capillary zone electrophoresis at two different pH values. It is also shown that a compound with acid/base properties can be concentrated using a dynamic pH junction mechanism when transferred from the first separation to the second separation. In addition, the system has been used to perform a comprehensive two-dimensional capillary electrophoresis separation of tryptic digest of bovine serum albumin using capillary zone electrophoresis followed by micellar electrokinetic chromatography.
NASA Astrophysics Data System (ADS)
Bensel, Holly; Dorrell, Genna; Feng, James; Hicks, Sean; Mars Liu, Jason; Liu, Steven; Moczygemba, Mitchell; Sheng, Jason; Sternenburg, Leah; Than, Emi; Timmons, Emry; Wen, Jerry; Yaeger, Bella; You, Ruiyang
2016-01-01
The Rogue Valley in Southwest Oregon was known for its beautiful dark skies, but due to population growth the dark skies are vanishing. A light pollution chart using Defense Meteorological Satellite Program (DMSP) data was published in 2006, but did not show the spatial variation in detail. In the spring of 2014, the 9th grade physics students, astronomy students, and members of the Astronomy Club from St. Mary's School conducted the first detailed night sky survey. The purpose of the survey is to create a baseline of the variations in light pollution in the Rogue Valley.The project continued into 2015, incorporating suggestions made at the 2014 AAS Conference to improve the study by including more light meter data and community outreach. Students used light meters, Loss of the Night app, and the Dark Sky meter app. Students researched light pollution and its effects on the environment, measured night sky brightness in the Rogue Valley, and completed a light audit in an area of their choice. They created a presentation for a final physics grade. The basis for this project, along with procedures can be found on the GaN, Globe at Night, (www.globeatnight.org) website. The light audit and research portion were developed from the Dark Sky Rangers section of the website (www.globeatnight.org/dsr/).The 2014 survey and public outreach increased awareness of light pollution in the Rogue Valley and around the state of Oregon. Examples include a local senior project to change lighting at a baseball stadium and a 4-H club in Northeast Oregon starting a GaN survey in their area. GaN shows growth in the amount of data collected in Oregon from 8 data points in 2006 to 193 in 2014. The Rogue Valley magnitude data from the spring of 2015 indicates a drop from an average magnitude of 4 to an average magnitude of 2. This is due to hazy skies from smoke drifting into the valley from a Siberian wildfire. Data collection during the summer and fall was hampered due to smoke from local
Transition, coexistence, and interaction of vector localized waves arising from higher-order effects
Liu, Chong; Yang, Zhan-Ying; Zhao, Li-Chen; Yang, Wen-Li
2015-11-15
We study vector localized waves on continuous wave background with higher-order effects in a two-mode optical fiber. The striking properties of transition, coexistence, and interaction of these localized waves arising from higher-order effects are revealed in combination with corresponding modulation instability (MI) characteristics. It shows that these vector localized wave properties have no analogues in the case without higher-order effects. Specifically, compared to the scalar case, an intriguing transition between bright–dark rogue waves and w-shaped–anti-w-shaped solitons, which occurs as a result of the attenuation of MI growth rate to vanishing in the zero-frequency perturbation region, is exhibited with the relative background frequency. In particular, our results show that the w-shaped–anti-w-shaped solitons can coexist with breathers, coinciding with the MI analysis where the coexistence condition is a mixture of a modulation stability and MI region. It is interesting that their interaction is inelastic and describes a fusion process. In addition, we demonstrate an annihilation phenomenon for the interaction of two w-shaped solitons which is identified essentially as an inelastic collision in this system. -- Highlights: •Vector rogue wave properties induced by higher-order effects are studied. •A transition between vector rogue waves and solitons is obtained. •The link between the transition and modulation instability (MI) is demonstrated. •The coexistence of vector solitons and breathers coincides with the MI features. •An annihilation phenomenon for the vector two w-shaped solitons is presented.
Capillary imbibition in parallel tubes
NASA Astrophysics Data System (ADS)
McRae, Oliver; Ramakrishnan, T. S.; Bird, James
2016-11-01
In modeling porous media two distinct approaches can be employed; the sample can be examined holistically, using global variables such as porosity, or it can be treated as a network of capillaries connected in series to various intermediate reservoirs. In forced imbibition this series-based description is sufficient to characterize the flow, due to the presence of an externally maintained pressure difference. However, in spontaneous imbibition, flow is driven by an internal capillary pressure, making it unclear whether a series-based model is appropriate. In this talk, we show using numerical simulations the dynamics of spontaneous imbibition in concentrically arranged capillary tubes. This geometry allows both tubes access to a semi-infinite reservoir but with inlets in close enough proximity to allow for interference. We compare and contrast the results of our simulations with theory and previous experiments. Schlumberger-Doll Research.
Non-Aqueous Capillary Electrophoresis
NASA Astrophysics Data System (ADS)
Szumski, Michał; Buszewski, Bogusław
Non-aqueous capillary electrophoresis and capillary electrochromatography are special variants of these techniques. Here, organic solvents or their mixtures with or without dissolved electrolytes are used as separation buffer or mobile phase, respectively. The most important features of non-aqueous systems are: better solubility of more hydrophobic ionic substances (many natural products) than in water, much less current and Joule heating allows for using highly concentrated buffers and/or larger capillary internal diameters, polar interactions are enhanced in organic solvents which is often highly advantageous in chiral separation systems. This chapter presents most frequently used solvents, their properties, as well as shows pH* scale which is often used in non-aqueous systems.
Capillary interactions in Pickering emulsions
NASA Astrophysics Data System (ADS)
Guzowski, J.; Tasinkevych, M.; Dietrich, S.
2011-09-01
The effective capillary interaction potentials for small colloidal particles trapped at the surface of liquid droplets are calculated analytically. Pair potentials between capillary monopoles and dipoles, corresponding to particles floating on a droplet with a fixed center of mass and subjected to external forces and torques, respectively, exhibit a repulsion at large angular separations and an attraction at smaller separations, with the latter resembling the typical behavior for flat interfaces. This change of character is not observed for quadrupoles, corresponding to free particles on a mechanically isolated droplet. The analytical results are compared with the numerical minimization of the surface free energy of the droplet in the presence of spherical or ellipsoidal particles.
Capillary haemangioma of the testis
Mazal, P; Kratzik, C; Kain, R; Susani, M
2000-01-01
A case of testicular capillary haemangioma is reported and the importance of intraoperative examination of this very rare lesion emphasised. Capillary haemangioma of the testis can be similar to malignant testicular tumours on clinical presentation, as well as on ultrasonography and magnetic resonance imaging, and therefore should be included in the intraoperative differential diagnosis. Because of the benign nature of this lesion, conservative surgical treatment by means of tumour enucleation with preservation of the testis is possible, if intraoperative examination of frozen sections of representative tissue can be performed. Key Words: testis • haemangioma PMID:11002773
Nonsteady Flow in Capillary Tubes
NASA Astrophysics Data System (ADS)
Hara, Ayako
2000-03-01
Surface phenomena in the field of electron devices and the problem of how long. It takes plants to absorb water during their growth in hydroponic cultivation is attraching the attention of riseachers. However, the related study of non-steady flow in capillary tubes has a number of issues that require investigation. In response to this situation, we made attempted to assess nonsteady fiow in capillary tubes, the liquid rise time and other issues, using a motion equation that takes factors including the friction force of the tube and the surface tension into consideration.
Revised Capillary Breakup Rheometer Method
NASA Astrophysics Data System (ADS)
Lu, Louise; Schultz, William; Solomon, Michael
2014-11-01
Rather than integrate the one-dimensional equation of motion for a capillary breakup rheometer, we take the axial derivative of that equation. This avoids the determination of the axial force with all of its complications and correction factors. The resulting evolutionary equation that involves either two or four derivatives of the capillary radius as a function of the axial coordinate determines the ratio of elongational viscosity to surface tension coefficient. We examine several silicone and olive oils to show the accuracy of the method for Newtonian fluids. We will discuss our surface tension measurement techniques and briefly describe measurements of viscoelastic materials, including saliva.
Nonlinear coherent structures of Alfvén wave in a collisional plasma
NASA Astrophysics Data System (ADS)
Jana, Sayanee; Ghosh, Samiran; Chakrabarti, Nikhil
2016-07-01
The Alfvén wave dynamics is investigated in the framework of two-fluid approach in a compressible collisional magnetized plasma. In the finite amplitude limit, the dynamics of the nonlinear Alfvén wave is found to be governed by a modified Korteweg-de Vries Burgers equation (mKdVB). In this mKdVB equation, the electron inertia is found to act as a source of dispersion, and the electron-ion collision serves as a dissipation. The collisional dissipation is eventually responsible for the Burgers term in mKdVB equation. In the long wavelength limit, this weakly nonlinear Alfvén wave is shown to be governed by a damped nonlinear Schrödinger equation. Furthermore, these nonlinear equations are analyzed by means of analytical calculation and numerical simulation to elucidate the various aspects of the phase-space dynamics of the nonlinear wave. Results reveal that nonlinear Alfvén wave exhibits the dissipation mediated shock, envelope, and breather like structures. Numerical simulations also predict the formation of dissipative Alfvénic rogue wave, giant breathers, and rogue wave holes. These results are discussed in the context of the space plasma.
A model and numerical method for compressible flows with capillary effects
NASA Astrophysics Data System (ADS)
Schmidmayer, Kevin; Petitpas, Fabien; Daniel, Eric; Favrie, Nicolas; Gavrilyuk, Sergey
2017-04-01
A new model for interface problems with capillary effects in compressible fluids is presented together with a specific numerical method to treat capillary flows and pressure waves propagation. This new multiphase model is in agreement with physical principles of conservation and respects the second law of thermodynamics. A new numerical method is also proposed where the global system of equations is split into several submodels. Each submodel is hyperbolic or weakly hyperbolic and can be solved with an adequate numerical method. This method is tested and validated thanks to comparisons with analytical solutions (Laplace law) and with experimental results on droplet breakup induced by a shock wave.
Experimental long term evolution of breathers in water waves
NASA Astrophysics Data System (ADS)
Chabchoub, Amin
2014-05-01
Oceanic rogue waves may occur, due to the modulation instability, also referred to as the Benjamin-Feir instability. This instability can be also discussed within the framework of the nonlinear Schrödinger equation (NLS), which describes the dynamics of unstable packets in deep-water. In particular, through exact breather solutions of the NLS. Breathers are currently under intensive study, since their recent experimental observation in optics, water waves and in plasma proved the validity of the NLS to describe strong localizations in nonlinear dispersive media. We present evolution characteristics of breather, propagating over a long propagation distance in deep-water. In addition, we present several analytical and promising techniques, based on the theory of nonlinear wave theory, how an early stage of breather dynamics may be detected, before the occurrence of strong wave focusing.
Multiplexed fluorescence detector system for capillary electrophoresis
Yeung, Edward S.; Taylor, John A.
1996-03-12
A fluorescence detection system for capillary electrophoresis is provided wherein the detection system can simultaneously excite fluorescence and substantially simultaneously monitor separations in multiple capillaries. This multiplexing approach involves laser irradiation of a sample in a plurality of capillaries through optical fibers that are coupled individually with the capillaries. The array is imaged orthogonally through a microscope onto a charge-coupled device camera for signal analysis.
Multiplexed fluorescence detector system for capillary electrophoresis
Yeung, Edward S.; Taylor, John A.
1994-06-28
A fluorescence detection system for capillary electrophoresis is provided wherein the detection system can simultaneously excite fluorescence and substantially simultaneously monitor separations in multiple capillaries. This multiplexing approach involves laser irradiation of a sample in a plurality of capillaries through optical fibers that are coupled individually with the capillaries. The array is imaged orthogonally through a microscope onto a charge-coupled device camera for signal analysis.