We consider the stability of periodic gravity free-surface water waves traveling downstream at a constant speed over a shear flow of finite depth. In case the free surface is flat, a sharp criterion of linear instability is established for a general class of shear flows with inflection points and the maximal unstable wave number is found. Comparison to the rigid-wall setting testifies that free...

optical interferometry is being used as an efficient tool to analyse smooth surfaces for more than a century. although, due to introduction of novel computer assisted analyzing techniques and array detectors, like ccd, the speed and the precision of processing have been increased tremendously, but the main equation involved is not changed. the main equation is the intensity distribution in the ...

in this research, we investigated the glottal wave of persian vowels, using electroglottography. in the first level, the properties of vowels glottal wave were analyzed. in the second level, the glottal wave between male and female speakers were  compared. contact quotient is the glottal wave parameter which was analyzed. data included six persian vowels and the glottal wave recorded using elec...

An overview is presented of recent progress on the relation between the pressure at the bottom of the flat water bed and the elevation of the free water boundary within the context of the onedimensional, irrotational water wave problem. We present five different approaches to this problem. All are compared to (1) numerical data for Stokes waves, one-dimensional traveling wave solutions of the f...

Ship maneuvering performance is typically predicted in calm water conditions. This provides very valuable information at the initial ship design stage. However, since the ship always sails in waves, the maneuvering performance of the ship in seaway may be significantly different from calm water condition. Therefore, if the effect of waves and the corresponding motion responses can be included i...

The periwinkle Littorina saxatilis has repeatedly evolved both a small, fragile and globose "wave ecotype" confined to wave-swept shores and a large, robust and elongated "crab ecotype" found in nearby crab-rich but less-exposed shores. This phenotypic divergence is assumed to reflect, in some part, local adaptation to wave exposure, but this hypothesis has received incomplete experimental test...

From research on stratospheric dynamics there has emerged what might prove to be some useful fresh ideas about the problem of water-wave generation by wind. As pointed out in an earlier contribution (1993), water waves can be systematically amplified by two irreversible, ratchet-like mechanisms that depend on spatio-temporal inhomogeneities, such as wind gustiness and wave groupiness. Neither m...

A mathematical model was used to study the effect of glacially induced fluctuations in sea level on the formation of wave-cut terraces on tectonically mobile rock coasts. Two deep water wave sets were used to calculate breaker height and depth, which, along with surf zone width, bottom roughness, and the gradient of the submarine slope, dictated the force exerted at the shoreline. An erosional ...

Satellite measurements and numerical forecast model reanalysis data are used to compute an updated estimate of the cloud radiative effect on the global multi-annual mean radiative energy budget of the atmosphere and surface. The cloud radiative cooling effect through reflection of short wave radiation dominates over the long wave heating effect, resulting in a net cooling of the climate system ...