OBJECTIVE Children and adults with type 1 diabetes who receive insulin pump therapy have reported hypoglycemia during air travel. We studied the effects of atmospheric pressure on insulin pump delivery. RESEARCH DESIGN AND METHODS Ten insulin pumps were connected to capillary tubes. The effects of changes in ambient pressure on insulin delivery, bubble formation, bubble size, and cartridge pl...

In order to study the effect of viscosity on bubbles in a cavitating fluid, the properties of laser-induced bubbles and the resulting luminescence pulses are examined for various glycerol-water mixtures over 1-8 bars of pressure. Bubbles are generated by a Nd:YAG laser, with the bubble radius monitored by a laser-beam photodiode system and the luminescence structure measured by fast photomultip...

Carbon dioxide flooding is considered to be one of the most effective enhanced oil recovery methods for the light oil reservoirs. Depending on the operating pressure, the process might be miscible or immiscible. Minimum miscibility pressure (MMP) is the most important parameter for assessing the applicability of any miscible gas flood for an oil reservoir. The miscibility condition is determine...

The activation of bubbles by an acoustic field has been shown to temporarily open the blood-brain barrier (BBB), but the trigger cause responsible for the physiological effects involved in the process of BBB opening remains unknown. Here, the trigger cause (i.e., physical mechanism) of the focused ultrasound-induced BBB opening with monodispersed microbubbles is identified. Sixty-seven mice wer...

This paper discusses our efforts to simulate large systems of bubbles in complex geometries, with specific application to modeling cavitation instabilities. An important unstable regime is the transition from sheet-to-cloud cavitation (SCC). Experiments performed by Callenaere et al. (2001) highlight the unsteady flow structures of SCC, which is characterized by unstable regions of vapor bubble...

Electric discharges and streamers in liquids typically proceed through vapour phase channels produced by the streamer or in gaseous bubbles. The bubbles can originate by enthalpy changes produced by the discharge or can be artificially injected into the liquid. Experiments on streamers in bubbles immersed in liquids have shown that the discharge propagates either along the surface of the bubble...

An investigation into the effects of a single sliding air bubble on heat transfer from a submerged, inclined surface has been undertaken. Existing literature has shown that both vapour and gas bubbles can increase heat transfer rates from adjacent heated surfaces. However, the mechanisms involved are complex and dynamic and in some cases poorly understood. The present study utilises high speed,...

This paper presents a CFD modelling study of the bubble driven hydrodynamics in aluminium reduction cells. A time-averaged (steady state) bubble driven flow model has been developed using a full scale air-water model of part of an aluminium reduction cell as a test-bed. Simulated results have been compared with experimental data taken under similar conditions using Particle Image Velocimetry (P...

We present a new unbiased search and analysis of all B stars in the solar neighbourhood (within a volume of 400 pc diameter) using the Arivel data base to track down the remains of the OB associations, which hosted the supernovae responsible for the Local Bubble in the interstellar gas. We find after careful dereddening and by comparison with theoretical isochrones, that besides the Upper Scorp...