Cusps formation

Fig. 8a d. Theoretical cusp profiles with period 1 in a gel with finite thickness 0l8. The curves in each figure represent the initial heights x = 0.8,0.796,0.7,0.6,0.5,0.4 and 0.3 before cusp formation and d is the depth of the folded part... 

Jemvall J, Kettunen P, Karavanova I, Martin LB, Thesleff I (1994) Evidence for the role of the enamel knot as a control center in mammalian tooth cusp formation non-dividing cells express growth stimulating Fgf-4 gene. Int J Dev Biol 38 463 69. 

As a consequence of this, then, another way of graphically determining absolute instability is to generate plots from the dispersion relation of constant k and variable kf, compute curves in the s plane and look for a cusp formation. At the cusp we have = 0... 

The asymptotic slice model (110) is found to pinch, i.e. S Oj after a finite time. Starting from symmetric initial conditions for S and odd ones for W, it is found that pinching occurs simultaneously at two points symmetrically placed about the center (periodic boundary conditions are used) thus giving rise to a satellite drop. This behavior is fairly for the models an was also observed by Lee in his original study. On resolution of the structures near pinching, it is found that touchdown is accompanied by a cusp formation with Sz blowing up as 5 0 at the pinch points. In fact, analysis and numerics indicate the following... 

MV/cm, cusp formation and ion emission will occur in less than 3 ns... 

JernvaUJ etaL 1994.Evidencefortheroleoftheenamelknotasacontrolcenterin mammalian tooth cusp formation Non-dividing cells express growth stimulating Fgf-4 gene. Intnl J Dev Biol 38(3) 463—469. 

Cusping occurs in the horizontal plane, that is the stabilised OWC does not lie directly beneath the producing well. The unwanted fluid, in this case water, is pulled towards the producing well along the dip of the formation. 

Campeanu et al. (1987) also discussed the behaviour of the ionization cross sections for positrons and electrons near to the ionization threshold, but our treatment of this topic is deferred until subsection 5.4.5. Furthermore, in subtracting positronium formation threshold and the first excitation threshold of the helium atom. Their derived cross section appeared to contain a cusp or threshold anomaly around EPs, but more recent experimentation and theoretical analysis has cast some doubt on the existence of a feature of this size in helium. Further discussion of these interesting phenomena is given in Chapters 3 and 4. 

Hultman, L., Wallenberg, L.R., Shinn, M. and Barnett, S.A. (1992), Formation of polyhedral voids at surface cusps during growth of epitaxial TiN/NbN superlattice and alloy films , Journal of Vacuum Science and Technology A, 10, 1618-1624. 

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