title: Effect of temperature on rectified diffusion during ultrasound-induced heating.
abstract: Experimental observations of delayed-onset cavitation during ultrasound insonation have been suggested as being caused by a change in the size distribution of the bubble population due to rectified diffusion. To investigate this hypothesis, a single bubble model is used here to explore the effect of heating and the subsequent elevated temperatures on the rectified diffusion process. Numerical solution of the model, which includes the temperature dependences of seven relevant physical parameters, allows quantification of the change in the pressure threshold for rectified diffusion, as well as the importance of the bulk liquid saturation concentration in determining bubble evolution. Although elevated temperatures and liquid supersaturation reduce the rectified diffusion threshold, it remains coincident with the inertial cavitation thresholds at submicron bubble sizes at all temperatures. This observation suggests that changes in the nucleation environment, rather than bubble growth due to rectified diffusion, is a more likely cause of delayed-onset cavitation events.
authors.affiliation: Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, United Kingdom.
authors.forename: Ian R
authors.initials: IR
authors.lastname: Webb
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Payne
authors.forename: Constantin-C
authors.initials: CC
authors.lastname: Coussios
mesh_terms: D003198:Computer Simulation; D004058:Diffusion; D008962:Models, Theoretical; D009038:Motion; D009716:Numerical Analysis, Computer-Assisted; D010100:Oxygen; D010316:Particle Size; D011312:Pressure; D013010:Sonication; D013500:Surface Tension; D013696:Temperature; D013997:Time Factors; D014465:Ultrasonics; D014867:Water
chemical_list: D014867:Water; D010100:Oxygen