Fingering pattern

An isolated atom has a characteristic set of discrete energy levels. Then if one electron is removed from an inner shell of the atom, electronic relaxation occurs due to one of the outer shell electrons filling the electron hole left in the inner shell. This leads to the emission of a characteristic X-ray. In such cases, only one spectral line, originating from the X-ray transition between an inner shell and one of the discrete outer shells, can be observed. However, when multiple ionization occurs during a single excitation process, as in the case of enei etic ion impact, a fine structure or finger pattern is necessarily observed in the spectrum. In PIXE,... 

Generally, for light ion impacts, the observed intensity distributions of satellite structures or finger patterns can be reproduced by eq. (6). Shown in Fig. 2 are examples for the impact of on K and Cr, and the impact of... 

S.T. Thoroddsen, J. Sakakibara Evolution of the fingering pattern of an impacting drop, Phys. Fluids, 10, 1359-74 (1998). 

Finite L Optical micrographs of time evolution ofdeformed circular rims with nodes. The growing nodes form a fingering pattern. Scale bar is 10pm. 

Figure 5. Typical fingering patterns for PPG as well as the 2.5 and 7.5 wt % silica suspensions dispersed in PPG at the injection pressure of 6.0 kPa from...

In a typical experiment, stable, vertical, liquid films were formed from the model PU formulation (see Section 5.3.1.1). These films were stable for two to five minutes. The series of photographs in Figure 5.3 depicts many of the physical features of these films. Thirty to sixty seconds after film formation, dark horizontal interference fringes were observed that initially appeared at the top of the film and steadily moved downward. Over time, the number of fringes decreased. Flow patterns, including eddy currents, fingering patterns and swirls, appeared at the bottom and sides of the films and rose upwards. The rate and amount of these flows decreased as the lifetime of the film increased. 

However, it should be noted that the motion of the film is also associated with a change in its height and the formation of a rim arotmd the advancing interface. This rim was shown to become unstable and to lead to the formation of a fingering pattern with a wavelength (X) which scales as X(3Ca), where h) is the film thickness and Ca = pt//y is the capillary number U being the advance velocity). It can be shown that the film is stable if the width of the layer is smaller than X. 

When the capillary spaces in a fabric are not uniform, the liquid may not spread as a continuous front but penetrate some capillaries before others and form a fingering pattern. A nonuniform wicking patterns complicates the measurement of the wetted area, even when using imaging techniques. However, the pattern itself provides useful information about the wetting characteristics of the fabric. 

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