The scattering and backscattering properties of bubble populations in the upper ocean are estimated with Mie theory and a generalized bubble size spectrum based on in situ observations. Optical properties of both clean bubbles and bubbles coated with an organic film are analyzed; the results are compared with the corresponding optical properties of micro-organisms of similar size. Given a bubbl...

In this paper, growth and collapse of a vapour bubble generated due to a local energy input inside a rigid cylinder and in the absence of buoyancy forces is investigated using Boundary Integral Equation Method and Finite Difference Method .The fluid is treated as potential flow and Boundary Integral Equation Method is used to solve Laplace’s equation for velocity potential. Different ratios of ...

Cavitation in solid-water mixtures generated by ultrasonic waves can be used to modify the topography of metallic surfaces. During ultrasonic irradiation two kinds of processes occur in the liquid: (a) material removal by bubble formation plus collapse and the resulting micro jets; (b) material removal by colliding or sliding of accelerated particles due to bubble formation plus collapse. Both ...

purpose: to investigate the results of deep lamellar keratoplasty (dlk) by big bubble method with using shifting bubble sign in patients suffering from keratoconus or corneal opacity methods: in this prospective interventional clinical trial, 20 eyes of 18 patients (10 males and 8 females) who underwent dlk by big bubble method using shifting bubble sign were investigated. mean age of cases wer...

oscillation of newly coming bubble is between -90 to 90 degrees. Under this condition, the radius of the aggregated bubbles is determined by the ultrasonic wave frequency and the relative phase. Based on the model, numerical analysis is carried out. The Bjerknes force over (x,y) plane is evaluated for two or more bubbles cases. The stability of a couple of aggregated bubbles is also discussed. ...

OBJECTIVE This study evaluated the effects of ultrasound combined with the homemade nitric oxide (NO) micro-bubble destruction on the in vitro proliferation, apoptosis, and migration of mesenchymal stem cells (MSCs). Furthermore, we studied whether or not irradiation of the NO micro-bubble combined with bone-marrow derived MSC infusion had a better effect on treating myocardial infarction. The ...

A steady fluid flow, called microstreaming, can be generated in the vicinity of a micro-bubble excited by ultrasound. In this paper, we use this phenomenon to assemble and power a microfabricated rotor at rotation speeds as high as 625 rpm. The extractible power is estimated to be of the order of a few femtowatts. A first series of experiments with uncontrolled rotor shapes is presented, demons...

We designed and built a microfluidic device for the generation of liquid jets produced by thermocavitation. A continuous wave (CW) laser was focused inside a micro-chamber filled with a light-absorbing solution to create a rapidly expanding vapor bubble. The chamber is connected to a micro-channel which focuses and ejects the liquid jet through the exit. The bubble growth and the jet velocity w...

The parallel mechanism has become an alternative solution when micro manipulators are demanded in the fields of micro manipulation and micro assembly. In this paper, a threeDegree-Of-Freedom (3-DOF) parallel micro manipulator is presented, which is directly driven by three micro gas bubbles. Since the micro gas bubbles are generated and maintained due to the surface tension between the gas and ...

The numerical simulation and experimental validations of the growth and departure of a single bubble on a horizontal heated surface during pool boiling under reduced gravity conditions have been performed here. A finite difference scheme is used to solve the equations governing mass, momentum and energy in the vapor liquid phases. The vaporliquid interface is captured by level set method, which...