A new type of apparatus for the production of single bubbles of adjustable size is presented. A single bubble is generated by injecting a short burst of gas into a liquid channel flow. The radius of the bubble can be varied continuously from 300 mm up to a 3 mm by adjusting the timing of a valve injecting the gas. The device works also in liquids with variable pressure and can be microcomputer ...

Due to the formation of corrosion products, natural gas liquids and gas hydrates in long distance pipelines, timely and effective pigging operations are necessary to improve the gas transmission efficiency, reduce pressure loss, as well as guarantee the safe operation of gas wells, pipelines and networks. Gas transmission efficiency is a parameter to reflect the working condition and cleanlines...

Insect tracheae form during embryonic development and initially contain liquid, which impedes transport of oxygen and carbon dioxide. Only later do tracheae fill with gas and come to support high rates of gas flux. This liquid-to-gas transition is poorly understood. Using eggs of the sphingid moth Manduca sexta, we show that longitudinal tracheae in embryos fill with gas in less than 5 s, witho...

We measure the magnetic susceptibility of a Fermi gas with tunable interactions in the low-temperature limit and compare it to quantum Monte Carlo calculations. Experiment and theory are in excellent agreement and fully compatible with the Landau theory of Fermi liquids. We show that these measurements shed new light on the nature of the excitations of the normal phase of a strongly interacting...

For the operation of high void fraction bubbly flows in bubble columns, insight in primary parameters such as bubble size, shape and velocity as well as gas volume fraction is essential. At high gas volume fractions the flow system becomes opaque, ruling out non-intrusive optical techniques. As an alternative optical fibre probes can be used, which have the advantage of low cost, simplicity of ...

The main challenge facing the oil industry is to reduce development costs while accelerating recovery with maximizing reserves. One of the key enabling technologies in this area is intelligent well completions. Intelligent well technology (IWT) is a relatively new technology that has been adopted by many operators in recent years to improve oil and gas recovery. Intelligent well completions emp...

The fundamental equations which describe the flow through gas and liquid pipelines are formally identical. However, the wide gap between the compressibility ranges of gases and liquids leads to quite different transport characteristics for both kinds of media. While for oil pipelines and pump stations specific topics like batch operation, surges, and possible slack line scenarios have to be con...