scholarly journals Kuramoto-Like Synchronization Mediated through Faraday Surface Waves

Fluids ◽  
2020 ◽  
Vol 5 (4) ◽  
pp. 226
Author(s):  
André Nachbin
Keyword(s):  
Nonlinear Dynamics ◽  
Surface Waves ◽  
Theory Model ◽  
Kuramoto Model ◽  
General Interest ◽  
New Class ◽  
Silicon Oil ◽  
Pilot Wave ◽  
Oscillator Synchronization ◽  
Surface Wave Field

A new class of problems in free surface hydrodynamics appeared after the groundbreaking discovery by Yves Couder and Emmanuel Fort. A bouncing droplet in association with Faraday surface waves gives rise to new nonlinear dynamics, in analogy with the pilot-wave proposed by de Broglie. The droplet and the underlying vibrating bath are of silicon oil. A weakly viscous potential theory model should be used. Numerical simulations are presented with one and two bouncing droplets oscillating while confined to their cavities. These oscillators are implicitly coupled by the underlying surface wave field. In certain regimes, the oscillators can spontaneously synchronize, even when placed at a distance. Cavity parameters are varied in order to highlight the sensitive wave-mediated coupling. The present nonlinear wave-mediated oscillator synchronization is more general than that displayed by the celebrated Kuramoto model and therefore of general interest.

scholarly journals A Millennial Myosin Census

2001 ◽  
Vol 12 (4) ◽  
pp. 780-794 ◽  
Author(s):  
Jonathan S. Berg ◽  
Bradford C. Powell ◽  
Richard E. Cheney
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Phylogenetic Analysis ◽  
Molecular Basis ◽  
General Interest ◽  
Class Iii ◽  
New Class ◽  
The Past ◽  
Human Genes ◽  
Complete Set ◽  
Myosin Superfamily

The past decade has seen a remarkable explosion in our knowledge of the size and diversity of the myosin superfamily. Since these actin-based motors are candidates to provide the molecular basis for many cellular movements, it is essential that motility researchers be aware of the complete set of myosins in a given organism. The availability of cDNA and/or draft genomic sequences from humans,Drosophila melanogaster, Caenorhabditis elegans, Arabidopsis thaliana,Saccharomyces cerevisiae, Schizosaccharomyces pombe, andDictyostelium discoideum has allowed us to tentatively define and compare the sets of myosin genes in these organisms. This analysis has also led to the identification of several putative myosin genes that may be of general interest. In humans, for example, we find a total of 40 known or predicted myosin genes including two new myosins-I, three new class II (conventional) myosins, a second member of the class III/ninaC myosins, a gene similar to the class XV deafness myosin, and a novel myosin sharing at most 33% identity with other members of the superfamily. These myosins are in addition to the recently discovered class XVI myosin with N-terminal ankyrin repeats and two human genes with similarity to the class XVIII PDZ-myosin from mouse. We briefly describe these newly recognized myosins and extend our previous phylogenetic analysis of the myosin superfamily to include a comparison of the complete or nearly complete inventories of myosin genes from several experimentally important organisms.

scholarly journals The Contribution of High-Frequency Wind-Generated Surface Waves to the Stokes Drift

2020 ◽  
Vol 50 (12) ◽  
pp. 3455-3465
Author(s):  
Luc Lenain ◽  
Nick Pizzo
Keyword(s):  
Surface Waves ◽  
Wave Spectrum ◽  
Ocean Dynamics ◽  
Stokes Drift ◽  
Upper Ocean ◽  
Sea State ◽  
Instrument Measurement ◽  
Wave Models ◽  
Surface Wave Field

AbstractThe effects of nonbreaking surface waves on upper-ocean dynamics enter the wave-averaged primitive equations through the Stokes drift. Through the resulting upper-ocean dynamics, Stokes drift is a catalyst for the fluxes of heat and trace gases between the atmosphere and ocean. However, estimates of the Stokes drift rely crucially on properly resolving the wave spectrum. In this paper, using state-of-the-art spatial measurements (in situ and airborne remote sensing) from a number of different field campaigns, with environmental conditions ranging from 2 to 13 m s−1 wind speed and significant wave height of up to 4 m, we characterize the properties of the surface wave field across the equilibrium and saturation ranges and provide a simple parameterization of the transition between the two regimes that can easily be implemented in numerical wave models. We quantify the error associated with instrument measurement limitations, or incomplete numerical parameterizations, and propose forms for the continuation of these spectra to properly estimate the Stokes drift. Depending on the instrument and the sea state, predictions of surface Stokes drift may be underestimated by more than 50%.

A new triad resonance between co-propagating surface and interfacial waves

2011 ◽  
Vol 691 ◽  
pp. 267-278 ◽  
Author(s):  
Mohammad-Reza Alam
Keyword(s):  
Theoretical Analysis ◽  
Surface Waves ◽  
Wave Train ◽  
Stratified Fluid ◽  
Direct Simulation ◽  
Interfacial Wave ◽  
Higher Harmonics ◽  
New Class ◽  
Near Resonance ◽  
Littoral Zones

AbstractIn a two-layer density-stratified fluid it is known, due to Ball (J. Fluid Mech., vol. 19, 1964, p. 465), that two oppositely travelling surface waves may form a triad resonance with an interfacial wave. Ball claims ‘there are no other interactions’ between two surface waves and one interfacial wave. Contrary to this, here we present a new class of triad resonance that occurs between two co-propagating surface waves and one interfacial wave. While in Ball’s resonance the interfacial wave has a wavelength of about half of two surface waves, in the new resonance presented here the interfacial wave has a much higher wavelength compared to those of surface waves. This, together with the unidirectionality of the participant triplet, makes the realization of the new resonance more likely in real ocean scenarios. We further show, via theoretical analysis and direct simulation, that, unique to this new class of resonance, the triad inevitably undergoes a cascade of (near-) resonance interaction that spreads the energy of initial waves to a number of lower and higher harmonics. The significance of the resonance studied here is, particularly, more emphasized in the littoral zones, where the spectrum refracts toward a unidirectional wave train.

Compositional Mapping in Dynamic Atomic Force Microscopy in High-Q vs. Low-Q Environments: Effects of Cantilever Nonlinear Dynamics

2010 ◽  
Author(s):  
John Melcher ◽  
Arvind Raman
Keyword(s):  
Nonlinear Dynamics ◽  
Atomic Force Microscopy ◽  
Quality Factors ◽  
Force Microscopy ◽  
High Q ◽  
New Class ◽  
Atomic Force ◽  
Nanoscale Metrology ◽  
Q Factors ◽  
Local Stiffness

The ability to simultaneously map variations in topography and composition (local stiffness, adhesion, charge, hydrophillicity/phobicity, viscoelasticity) of samples in ambient and liquid environments has made dynamic atomic force microscopy (dAFM) a powerful tool for nanoscale metrology. In ambient and vacuum environments, quality factors (Q-factors) of the fundamental resonance are typically large, and the contrast channels in dAFM are relatively well understood. In liquid environments, however, Q-factors are typically low due to cantilever interactions with the surrounding viscous liquid, which introduces a new class of nonlinear dynamics that is accompanied by new contrast channels, such as, higher harmonic amplitudes and phases. In particular, we find that the interpretation of the traditional contrast channels is quite different in low-Q environments compared to high-Q environments. We present a theoretical investigation of the contrast channels in dAFM in the context of frequency modulation and tapping mode dAFM with an emphasis on low-Q environments.

Insights on the SASW nondestructive testing method

1993 ◽  
Vol 20 (6) ◽  
pp. 940-950 ◽  
Author(s):  
M. O. Al-Hunaidi
Keyword(s):  
Surface Wave ◽  
Nondestructive Testing ◽  
Surface Waves ◽  
Field Tests ◽  
Actual Surface ◽  
Usual Test ◽  
Underlying Causes ◽  
Nondestructive Testing Method ◽  
Surface Wave Field ◽  
Surface Wave Method

Spectral analysis of surface waves (SASW) is a nondestructive and in-situ method used for determining the thickness and elastic properties of pavement and soil sites using the dispersion characteristics of surface waves. In this paper, computer simulations of actual surface wave field tests are used to clarify errors that may arise in experimental dispersion curves of pavement sites when the usual test and data analysis procedures of the SASW method are followed. Two aspects of these procedures are considered: (i) relative phase angle unwrapping and (ii) source-to-near-receiver distance. The results of these simulations reveal that the currently used procedures may lead to erroneous results for some sites; the simulations offer valuable insights on the underlying causes. An overview of the theoretical aspects and field procedures of the surface wave method is briefly presented. Key words: surface waves, nondestructive testing, pavements, soils, elastic modulus.

Convective instability of stably stratified water in the ocean

1977 ◽  
Vol 82 (3) ◽  
pp. 561-581 ◽  
Author(s):  
S. Leibovich
Keyword(s):  
Surface Waves ◽  
Convective Instability ◽  
Normal Modes ◽  
Present Theory ◽  
Theoretical Description ◽  
Density Stratification ◽  
Unstable Region ◽  
Random Surface ◽  
Waves And Currents ◽  
Surface Wave Field

A recent theoretical description of interactions between surface waves and currents in the ocean is extended to allow density stratification. The interaction leads to a convective instability even when the density stratification is statically stable. An unspecified random surface wave field is permitted provided that it is statistically stationary.The instability can be traced to torques produced by variations of a ‘vortex force’. Non-diffusive instabilities produced by this mechanism in water of infinite depth are explored in detail for arbitrary distributions of the destabilizing force. Stability is determined by an eigenvalue problem formally identical to that determining normal modes of infinitesimal internal waves in fluid with a density profile that is not monotone and thereby has a statically unstable region. Some tentative remarks are offered about the problem when dissipation is allowed.Application of the present theory to Langmuir circulations is discussed. Also, according to the present theory, internal wave propagation should be modified by the vortex force arising from the interaction between the surface waves and the current.

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