Laser-induced bubbles

These results were in contrast to the previous experiments described above, where nucleation was always observed. It is thought that as nucleation is a stochastic process, a single oscillation of a laser-induced bubble may not always lead to the nucleation. The probability of nucleation is increased by the continuously oscillating bubble produced by the standing wave system, and it is increased further by the multicavitation events produced by the ultrasonic horn. 

Ohl CD, Arora M, Dijkink R, Janve V, Lohse D (2006) Surface cleaning from laser-induced cavitation bubbles. Appl Phys Lett 89 074102 (3 pages)... 

Fig. 4. Dynamics of bubble motion. Laser-induced cavitation in silicone oil upper portion is the experimental observations at 75,000 frames/second lower curve compares the experimentally observed radius versus theory. [W. Lauterborn (47).]...

In the gas-liquid two-phase flows illuminated by a laser sheet, for example, the intensity of light reflected from the gas-liquid interface (mostly the gas bubble s surface) not only saturate the CCD camera, but also overwhelm the intensity of light from the seeded tracer particles in its vicinity. Fluorescent particles are often used to realize the laser-induced fluorescence (LIF) technique together with PIV (e.g., Broder and Sommerfeld, 2002 Fujiwara et al., 2004a, b Kitagawa et al., 2005 Liu et al., 2005 Tokuhiro et al., 1998,1999), so that both images of gas-liquid interface (e.g., bubble s geometry) and velocity distribution in the liquid phase around the gas bubbles can be obtained. Issues on PIV measurement of gas-liquid two-phase flows will be further illustrated in the latter sections. 

Recent developments include the work by the Blake group,and Zhang et The behavior of a gas-vapor bubble oscillating at low pressure (0.04-0.05 bar) in a 60-Hz acoustic field was recorded by Coleman et al (Fig. 20),i and Fig. 21 shows the behavior of a laser-induced cavity imploding next to a solid boundary.84/i09... 

Figure 21 - Cavitation of a laser-induced vapor bubble in water near an extended surface 75,000 frames sec ...

It was pointed out that measurements of laser-induced breakdown suffer from the same artifacts as DC-breakdown measurements. Impurities of low ionization energy, submicroscopic particles (dust or ice), and microscopic gas bubbles may serve as centers for the initiation of the breakdown process and mask the development of a pure avalanche breakdown (Brueck and Kildal, 1981). Subsequent investigations on the optical breakdown of liquid helium (Abrikosova and Anshukov, 1973 ... 

Laser-induced cavitation in polymeric hquids was the subject of studies. In accordance with theoretical predictions, it was found that deviation from of a spherical form in the course of bubble collapse is reduced to a great extent even in diluted solutions. 

In addition to pulse duration, laser-induced phase changes must be considered carefully in the studies and/or models of particle heating dynamics. First, the particle melting and the subsequent shape transformation may be observed at high temperatures. Second, a phase change in the surrounding medium of the particle may be observed. Either of these phase transformation will cause drastic changes in the heat transfer properties and lead to a requirement for more complicated models (i.e. a solution for the fuU set of compressible equations) to represent the effects of pressure and bubble formation around the particle. 

Biswal M, Suryawanshi A, Thakare V, Jouen S, Hannoyer B, Aravindan V, Madhavi S, Ogale S (2013) Mesoscopic magnetic iron oxide spheres for high performance Li-ion battery anode a new pulsed laser induced reactive micro-bubble synthesis process. J Mater Chem A 1 13932-13940... 

Figure 20 Time profiles of induced absorbance at 580 nm after focusing a 30-psec, 532-nm laser pulse at various fluences F onto gold clusters, 30 nm diameter. Dotted line time profile of the pulse. The fast amplitude increase, up to a maximum in less than 1 nsec for fluences >0.9 J cm , is assigned to light scattering by expanded metal clusters. The delayed increase with a maximum at 3 nsec occurs at fluences >0.18 J cm already, and is assigned to light scattering by solvent bubbles. (From Ref. 213.)...

Let us now examine the case of a nonlinear scattering process. Ispasoiu et al. deduced from considerations regarding the excited-state lifetime that the optical limiting observed using nanosecond laser pulses at X = 532 nm in their silver-dendrimer nanocomposite aqueous solution was due to absorption-induced nonlinear scattering [142]. They suggested that the scattering centres were micro-bubbles... 

Further experiments showed that the laser bubble did not always induce ice. The probability of ice nucleation in a 15 wt% sucrose solution supercooled to -4.74 1.75°C was 91.7%. The probability of nucleation was increased if the bubble became asymmetric or fragmented. 

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