We report the first experimental realization of a three-dimensional thermal cloak shielding an air bubble in a bulk metal without disturbing the external conductive thermal flux. The cloak is made of a thin layer of homogeneous and isotropic material with specially designed three-dimensional manufacturing. The cloak's thickness is 100  μm while the cloaked air bubble has a diameter of 1 cm, ach...

To investigate factors influencing nucleation of air clathrate hydrates in polar ice sheets, we have performed high-resolution mapping of the distributions of soluble impurities, air bubbles and airhydrate crystals versus depth in the Dome Fuji Antarctic ice. Significant correlation observed between the concentrations of air inclusions and impurities in ice along with frequent occurrence of imp...

We propose and demonstrate a pressure sensor based on a micro air bubble at the end facet of a single mode fiber fusion spliced with a silica tube. When immersed into the liquid such as water, the air bubble essentially acts as a Fabry-Pérot interferometer cavity. Such a cavity can be compressed by the environmental pressure and the sensitivity obtained is >1000 nm/kPa, at least one order of ma...

We present an experimental characterization of the effects of turbulence and breaking gravity waves on air-water gas exchange in standing waves. We identify two regimes that govern aeration rates: turbulent transport when no wave breaking occurs and bubble dominated transport when wave breaking occurs. In both regimes, we correlate the qualitative changes in the aeration rate with corresponding...

An ultrasonic Doppler was used to monitor embolic activity in the arterial line of an extracorporeal circuit. No differences in embolic activity were observed when either 100% N2 or 95% Oz-5% C02 gases were swept through a bubble oxygenator. Information is presented suggesting that nitrogen or air micro emboli are more deleterious than oxygen or carbogen microemboli. Consequently, this article ...

An air bubble driven by ultrasound can become shape-unstable through a parametric instability. We report time-resolved optical observations of shape oscillations (mode n=2 to 6) of micron-sized single air bubbles. The observed mode number n was found to be linearly related to the ambient radius of the bubble. Above the critical driving pressure threshold for shape oscillations, which is minimal...

The study of clustering processes is fundamentally significant in hydraulic engineering to comprehend the interactions between turbulence and particles. Previous studies on bubble clustering were carried out in plunging jets, hydraulic jumps and dropshafts. The present paper focuses on the bubble clustering process in a large-size dropshaft, and three criteria for cluster identification were ap...

Several studies report that dolphins, either captive or wild, can expel air from their blowhole to form ring bubbles. By means of an experimental setup consisting of an orifice coupled to a computer-controlled solenoid valve to simulate the dolphin’s blowhole and a vessel as the lungs, we examined the formation mechanism of a ring bubble under varying experimental conditions. With a better reco...

The motion of elongated (Taylor) bubbles in air±water vertical ̄ow is studied by processing consecutive series of digitized video images. The shape of the elongated bubbles, as well as the velocities of the liquid±gas interfaces, are measured for various ̄ow conditions. The bubble velocity variation caused by air expansion under the in ̄uence of hydrostatic pressure gradient is measured and comp...