Many measurement schemes have been developed to study the resonant characteristics of a bubble near a surface. The desire is to be able to measure the free field characteristics of such a bubble. For experimental investigations, a trade-off must be made between the size of the apparatus and the free field measurement. Thus there is a need to study the effect of surface interference on the reson...

DESCRIPTION A preterm neonate weighing 1360 g was born at 33+2 weeks’ gestation with severe polyhydramnios. She was transferred, directly after delivery, to our neonatal intensive care unit presenting with distended upper abdomen and vomiting. A plain film of the abdomen (figure 1) was performed with the suspicion of duodenal atresia and showed a markedly distended stomach (S) and proximal duod...

This paper investigates the effect of heat transfer on the motion of a spherical bubble in the vicinity of a rigid boundary. The effects of heat transfer between the bubble and the surrounding fluid, and the resulting loss of energy from the bubble, can be incorporated into the simple spherical bubble model with the addition of a single extra ordinary differential equation. The numerical result...

Bubble point pressure is an important parameter in equilibrium calculations of reservoir fluids and having other applications in reservoir engineering. In this work, an artificial neural network (ANN) and a least square support vector machine (LS-SVM) have been used to predict the bubble point pressure of reservoir fluids. Also, the accuracy of the models have been compared to two-equation stat...

Although CO2 injection is one of the most common methods in enhanced oil recovery, it could alter fluid properties of oil and cause some problems such as asphaltene precipitation. The maximum amount of asphaltene precipitation occurs near the fluid pressure and concentration saturation. According to the description of asphaltene deposition onset, the bubble point pressure has a very special imp...

Two-phase bubble formation coupled with phase change at a submerged nozzle is studied theoretically. The whole bubble consists of a ®apor and a liquid phase. The inner ®apor phase is assumed to be surrounded by a thin condensate layer, in which the ®apor condenses partially as the two-phase bubble grows. The interface element approach is applied to describe the dynamics of bubble formation. The...

The effect of positive and negative pressure on the modes of oscillation of a multielectron bubble in liquid helium is calculated. Already at low pressures of the order of 10-100 mbar, these effects are found to significantly modify the frequencies of oscillation of the bubble. Stabilization of the bubble is shown to occur in the presence of a small negative pressure, which expands the bubble r...

In the parameter region for sonoluminescence of a single levitated bubble in a water-filled resonator it is observed that the bubble may have an enormous spatial stability leaving it "pinned" in the fluid and allowing it to emit light pulses of picosecond accuracy. We report here observations of a complex harmonic structure in the acoustic field surrounding a sonoluminescing bubble. We show tha...

The evolution of an axi-symmetric Stokes bubble is considered when the bubble volume is changed. Linear stability analysis shows that an expanding spherical bubble is stable, while a shrinking spherical bubble is unstable. Numerical calculations of the time evolution shows that for certain initial condition, such a bubble can form cusps or near cusps or undergo topological change (pinching) bef...