Simulation time-pulsing mixing

Another paper describes the stretching and folding of material lines yielded by simulation and experimental imaging, induced by time-pulsing mixing via unsteady cross-flow injection in a steady-flow main channel [48],... 

From these rate equations, a number of experimental observables can be simulated. Figure 6 shows the time-dependent upconversion decay curves calculated for a set of hypothetical three-level systems involving (a, b) pure ESA, (c, d) pure ETU, and (e, f) mixed ESA ETU (40 60) rates under steady-state conditions, calculated to simulate the two experimental observables of decay following short pulses (a, c, e), as described above, and decay following long square-wave pulses during which the system has reached steady state (b, d, f). 

The results (28) of simulations of an algal bloom in a marine environment such as the coastal ocean are presented in Figure 10. The vertical flux of particulate nitrogen leaving the mixed surface layer by sedimentation is plotted as a function of time after a pulse input of nitrate from the bottom waters stimulates algal growth in surface waters. 

Fig. 16 Mixing by pressure field disturbance (a) Mean fluid velocity along the channel as function of time for in-line inlet and perpendicular inlet. The fluids are pulsed with a simulated 180° phase difference. Contour levels of mass fraction of the fluids in the Y-Z plane are shown, (b) Contour levels In the Y-X plane as a function of time as expressed in the graph in (a). Alternate puffs of fluids are created as result of the pulsation introduced within the fluid stream (Reproduced from [43] by permission of The Royal Society of Chemistry)...

Fig. 12. The magnetization-exchange experiment.(a) magnetization-exchange pulse sequence (b) = 3 C magnetization-exchange spectra of doubly C-labelled zinc acetate at different mixing times Tm (c) simulated (solid lines) and experimental ( ) magnetization-exchange curves on (top) and off (bottom) the R condition. (Parts (b) and (c) reproduced from ref. 75, 1988, with permission from Elsevier Science.)...

The narrowing of correlation trace in the four-wave mixing for a chirped pluse has been pointed out, and used to investigate the coherence property of light pulses.We have examined the possibility of high time-resolution measurement of phase relaxation time T2 with a chirped coherent pulse in the same configuration as described in Sec. 2 by means of computer simulation, which will be summarized below. Recently, a similar attempt has also been reported by other workers. 

The presence of additional bound states not included in the simplified theory does not destroy the effectiveness of the detection scheme. Such robustness was quite unexpected in the KRb simulations because the central wavelength of one of the pump pulses is just 1.2 nm away from an exact resonance with an undesired transition between the states 1) and 3) (see Figure 8.1c). We attribute the high robusmess of the scheme to the counterintuitive structure of the pulse sequence by the time the pump pulse couples the states 3> and 1), state 1) is already mixed with the target state 0) in such a way that the population of 11> remains negligible at all times. 

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