Oscillating bubble

Balasubrahmanyam A, Pandit AB (2009) Oscillating bubble concentration and its size distribution using acoustic emission spectra. Ultrason Sonochem 16 105-115... 

Abstract Sonoluminescence from alkali-metal salt solutions reveals excited state alkali - metal atom emission which exhibits asymmetrically-broadened lines. The location of the emission site is of interest as well as how nonvolatile ions are reduced and electronically excited. This chapter reviews sonoluminescence studies on alkali-metal atom emission in various environments. We focus on the emission mechanism does the emission occur in the gas phase within bubbles or in heated fluid at the bubble/liquid interface Many studies support the gas phase origin. The transfer of nonvolatile ions into bubbles is suggested to occur by means of liquid droplets, which are injected into bubbles during nonspherical bubble oscillation, bubble coalescence and/or bubble fragmentation. The line width of the alkali-metal atom emission may provide the relative density of gas at bubble collapse under the assumption of the gas phase origin. 

A plot of every fourth data point and the lines given by Eqs. (7-5) and (7-6) appears in Fig. 7.6. The gradient discontinuity corresponds approximately to the transition between nonoscillating and oscillating bubbles and drops. In the above correlation, the terminal velocity appears only in the dimensionless group J, and may be expressed explicitly as ... 

The growth and collapse of cavitation bubbles is commonly described by considering irrotational expansion of a spherical cavity in an incompressible liquid of infinite extent, subject to the unsteady form of Bernoulli s equation (B3, P5). Effects of compressibility and bubble migration must also be considered for oscillating bubbles produced by underwater explosions (B3, C5). 

Pannell, R. and Milstein, C. (1992) An oscillating bubble chamber for laboratory scale production of monoclonal antibodies as an alternative to ascitic tumors J Immunol Methods 146,43—48... 

An ultrasonicator generates sound waves above 16 kHz, which causes pressure fluctuations to form oscillating bubbles that implode violently generating shock waves. Cell disruption by an ultrasonicator is effective with most cell suspensions and is widely used in the laboratory. However, it is impractical to be used on a large scale due to its high operating cost. 

The oscillating bubble method proves to be very convenient and precise for the evaluation of the non-equilibrium elasticity of surfaces in a wide range of frequencies of external disturbances and surface coverage (adsorption of surfactant) [103-105]. It is based on registration of the sinusoidal variation of bubble volume. The bubble is situated in a capillary containing surfactant solution in which oscillations of different frequencies and amplitudes are created. The treatment of the U = f(ft)) curves (where U is the tension needed to initiate oscillations of constant amplitude) allows the determination of Marangoni elasticities [105]. 

D. O. Johnson, and K. J. Stebe, Oscillating bubble tensiometry A method for precisely measuring the kinetics of surfactant adsorptive-desorptive exchange. J. Colloid Int. Sci. 168 526-538 ( 994). 

Figure 4.27. Absolute value of the surface dilational modulus obtained by the wave technique (closed symbols) and from oscillating bubbles (open symbols). Surfactant, tridecyldimethyl phosphine oxide A, A c = 2 xlQ-S M O. c = 5 x lO M. Drawn curves fit to [4.5.431. Temperature 22°C. (Redrawn from Wantke et al. (loc. cit.).)...

Bubble/droplet diameter dp > 2.5 mm oscillating bubble surfaces ... 

Observed radius time curve for a single oscillating bubble in pure water using the single bubble levitation system at 26.73 kHz (temperatures between —0.5 and 1.1°C). 

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. 

A detailed study of the nucleation of ice by power ultrasoimd has been performed using a variety of high-speed photography systems with a particular focus on the influence of cavitation. The nucleation of ice has been shown to occur predominantly within the bubble cloud produced by a commercial ultrasonic horn. An investigation of a single oscillating bubble has confirmed that ice crystals are nucleated in the immediate vicinity of the bubble. 

It is widely thought that the high pressure emitted from a "transient" cavitation bubble is responsible for the nucleation process (Hickling, 1994) however, experiments utilizing a single oscillating bubble have shown that ice can be initiated by a "stable" cavitation bubble. The mechanism of nucleation may be related to the asymmetric bubble shape, the flow field associated with the cavitation bubble, or the production of microbubbles. 

Various experimental methods for dynamic surface tension measurements are available. Their operational timescales cover different time intervals. - Methods with a shorter characteristic operational time are the oscillating jet method, the oscillating bubble method, the fast-formed drop technique,the surface wave techniques, and the maximum bubble pressure method. Methods of longer characteristic operational time are the inclined plate method, the drop-weight/volume techniques, the funnel and overflowing cylinder methods, and the axisym-metric drop shape analysis (ADSA) " see References 54, 55, and 85 for a more detailed review. 

Static and dynamic surface tension of marine water onshore or platform-based measurements by the oscillating bubble tensiometer... 

Herein, our concern is to assess the suitability of the oscillating bubble tensiometer for marine purposes. Essentially, we conducted the present investigation with the aim of estimating the sensitivity of the measurement method, with respect to oceanographic studies and monitoring. In this paper we illustrate preliminary experimental results, obtained with a typical apparatus, working in an onshore laboratory. 

The measuring system is the oscillating bubble tensiometer, described in detail elsewhere (Loglio et al. 1996, 1998b, 2001, Kovalchuk et al. 2001, Miller et al. 2000). Figure 1 shows a schematic drawing of the measurement assembly, which is composed of three parts 1) the sample (20 mm x 20 mm x 40 mm) pyrex vessel, 2) the capillary (2.00 mm internal diameter stainless-steel tube with flat tip ), 3) an air chamber with deformable walls (made with piezoelectric discs). Possible fluidodynamic instability of the bubble has been taken into account in the design of the bubble pneumatic circuit. 

The oscillating bubble tensiometer, devised for marine studies, shows a particular feature, consisting of a couple of inlet and outlet tubes (Figure 1). Such conduit allows sea water to be fed either from the sampling bottle or directly from a continuously-flowing pumping system, submersed in the sea. Then, the tensiometer vessel can be initially flushed with sea water for... 

Kovalchuk VI, Kragel J, Aksenenko EV, Loglio G and Liggieri L (2001) "Oscillating bubble and drop techniques", in Novel Methods to Study Interfacial Layers, Studies in Interface Science, D. Mobius and R. Miller (Eds.), Vol. 11, Elsevier, Amsterdam, pp. 485-517... 

Kovalchuk VI, Kragel J, Makievski AV, Ravera F, Liggieri L, Loglio G, Fainerman VB and Miller R (2004). Rheological surface properties of C12DMPO solution as obtained from amplitude- and phase-frequency characteristics of oscillating bubble system. J Colloid Interface Sci 280 498-505... 

Kovalchuk VI, Miller R, Fainerman VB and Logho G (2005). Oscillating bubble pressure experiments for dilational rheology studies. Adv Colloid Interface Sci 114-115 303-313... 

Rusanov AI and Prokhorov VA (1996) Interfacial Tensiometry, D. Moebius and Miller R eds, Studies in Interface Science Series, Vol. 3, Elsevier, Amsterdam Zholkovskij EK, Kovalchuk VI, Fainerman VB, Loglio G, Kragel J, Miller R, Zholob SA and Dukhin SS (2000) Resonance Behavior of Oscillating Bubbles. J Colloid Interface Sci 224 47-55... 

To analyze this problem, we need to go back to a statement of the problem in general fluid dynamical terms. Thus we begin by restating the governing equations and boundary conditions for an oscillating bubble in a quiescent, incompressible fluid. These are the Navier-Stokes and continuity equations the three boundary conditions... 

Another recently developed method for determining surface rheological properties is the damping of a radial oscillating bubble, firstly described by Lunkenheimer Kretzschmar (1975) and established theoretically by Wantke et al. (1980). This technique is described in more detail in Chapter 6. It is based on damping effects and yields dilational rheological... 

One of the more recently developed methods to investigate the surface relaxation of soluble adsorption layers due to harmonic disturbances is the oscillating bubble method. The technique... 

Beside the capillary wave techniques, the oscillating bubble method belongs to the first experiments for measuring the surface dilational elasticity (Lunkenheimer Kretzschmar 1975, Wantke et al. 1980, 1993). For soluble adsorption layers it allows of the exchange of matter at a harmonically deformed bubble surface to be determined. 

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