INTRODUCTION It has been suggested that repeated compression-decompression cycles reduce diver susceptibility to decompression sickness (DCS). This study examined whether intensive scuba dive training would reduce bubble formation and modulate endothelial function as shown by skin circulation. METHODS There were 22 military divers who were studied before and after a 90-d program of physical t...

Pool boiling heat transfer measurements using heaters of varying aspect ratio were obtained in low-g (0.01 g ± 0.025 g) aboard the KC-135 aircraft. The heater aspect ratio was varied by selectively powering 2 · 2, 2 · 4, 2 · 6, 2 · 8, and 2 · 10 arrays of heaters in a 10 · 10 heater array containing individual heaters 0.7 · 0.7 mm in size. Electronic control circuitry was used to maintain an is...

Previous studies have documented that decompression led to endothelial dysfunction with controversial results. This study aimed to clarify the relationship between endothelial dysfunction, bubble formation and decompression rate. Rats were subjected to simulated air dives with one of four decompression rates: one slow and three rapid. Bubble formation was detected ultrasonically following decom...

The common phenomenon of buoyancy-induced vapor bubble lift-off from a heated surface is of importance to many areas of science and technology. In the absence of buoyancy in zero gravity of space, non-departing bubbles coalesce to form a big dry patch on the heated surface and heat transfer deteriorates despite the high latent heat of vaporization of water. The situation is worse on an inverted...

We present experimental results on the Stokes experiment performed in a 3D dry liquid foam. The system is used as a rheometric tool: from the force exerted on a 1 cm glass bead, plunged at controlled velocity in the foam in a quasi-static regime, local foam properties are probed around the sphere. With this original and simple technique, we show the possibility of measuring the foam shear modul...

Digital Image Analysis (DIA) has been employed to characterize the time evolution of a bubble injected from a single orifice into a pseudo 2-dimansional gas-solid fluidized bed. The injected bubble diameter increased with the square root of time before detachment. During bubble free flight in the bed, its diameter remains approximately constant. The center of mass of the bubble increases with t...

Flood waves resulting from dam breaks and flash floods have been responsible for numerous losses. In the present study, sudden flood releases were investigated down a large stepped waterway initially dry. A new experimental technique was developed to obtain instantaneous void fractions, bubble count rates and velocities. Unsteady air-water flow properties were recorded with arrays of conductivi...

The breakdown voltage of mineral insulation oil was systematically investigated under the influences of moisture, acidity, pressure and particles. The standards IEC156/95 (VDE0370/Part5/96 and ASTM D1816) specified the test conditions. Moisture provides charge carriers, therefore a moisture saturation of 0 to 20 % decreases the breakdown voltage from 72 down to 61 kV. Acids as aging products de...

We review current theory, simulation and experiment for the growth of 3D bubbles in ideal dry froth. Theories assume either that the growth rate depends on bubble radius or topology. Radius based laws violate the Young-Laplace law. Topological theories can be either linear or non-linear in the number of faces (f). The growth law can hold either exactly for each bubble (as in 2D) or apply only t...