scholarly journals VOF simulation of marangoni flow of gas bubbles in 2D-axisymmetric column

2010 ◽  
Vol 1 (1) ◽  
pp. 673-680 ◽  
Author(s):  
Y. Alhendal ◽  
A. Turan ◽  
Wael I.A. Aly
Keyword(s):  
Gas Bubbles ◽  
Marangoni Flow

Fission Gas Bubbles in Fractured UO2

1968 ◽  
Vol 26 ◽  
pp. 286-287
Author(s):  
O. M. Katz
Keyword(s):  
Electron Microscopy ◽  
Thermal Gradient ◽  
Gas Bubbles ◽  
Inert Gas ◽  
Thermal Gradients ◽  
Fission Gas ◽  
Beam Heating ◽  
Limited Application ◽  
Bubble Characteristics ◽  
Electron Beam Heating

The swelling of irradiated UO2 has been attributed to the migration and agglomeration of fission gas bubbles in a thermal gradient. High temperatures and thermal gradients obtained by electron beam heating simulate reactor behavior and lead to the postulation of swelling mechanisms. Although electron microscopy studies have been reported on UO2, two experimental procedures have limited application of the results: irradiation was achieved either with a stream of inert gas ions without fission or at depletions less than 2 x 1020 fissions/cm3 (∼3/4 at % burnup). This study was not limited either of these conditions and reports on the bubble characteristics observed by transmission and fractographic electron microscopy in high density (96% theoretical) UO2 irradiated between 3.5 and 31.3 x 1020 fissions/cm3 at temperatures below l600°F. Preliminary results from replicas of the as-polished and etched surfaces of these samples were published.

Photosynthesis as a Possible Source of Gas Bubbles in Shallow Sandy Coastal Sediments

2011 ◽  
Author(s):  
D. V. Holliday ◽  
C. F. Greenlaw ◽  
David Thistle ◽  
Jan E. Rines
Keyword(s):  
Gas Bubbles ◽  
Coastal Sediments

scholarly journals Solutocapillary Marangoni flow induced in a waterbody by a solute source

2021 ◽  
Vol 922 ◽  
Author(s):  
Islam Benouaguef ◽  
Naga Musunuri ◽  
Edison C. Amah ◽  
Denis Blackmore ◽  
Ian S. Fischer ◽  
...  
Keyword(s):  
Marangoni Flow ◽  
Solute Source

Abstract

scholarly journals A gateway for ion transport on gas bubbles pinned onto solids

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Veton Haziri ◽  
Tu Pham Tran Nha ◽  
Avni Berisha ◽  
Jean-François Boily
Keyword(s):  
Ion Transport ◽  
Metal Ion ◽  
Electrochemical Impedance ◽  
Gas Bubbles ◽  
Open Circuit ◽  
Double Layers ◽  
Water Geochemistry ◽  
Chemical Potentials ◽  
Pore Water Geochemistry ◽  
Electric Potentials

AbstractGas bubbles grown on solids are more than simple vehicles for gas transport. They are charged particles with surfaces populated with exchangeable ions. We here unveil a gateway for alkali metal ion transport between oxygen bubbles and semi-conducting (iron oxide) and conducting (gold) surfaces. This gateway was identified by electrochemical impedance spectroscopy using an ultramicroelectrode in direct contact with bubbles pinned onto these solid surfaces. We show that this gateway is naturally present at open circuit potentials, and that negative electric potentials applied through the solid enhance ion transport. In contrast, positive potentials or contact with an insulator (polytetrafluoroethylene) attenuates transport. We propose that this gateway is generated by overlapping electric double layers of bubbles and surfaces of contrasting (electro)chemical potentials. Knowledge of this ion transfer phenomenon is essential for understanding electric shielding and reaction overpotential caused by bubbles on catalysts. This has especially important ramifications for predicting processes including mineral flotation, microfluidics, pore water geochemistry, and fuel cell technology.

scholarly journals Particle Accumulation Structures in a 5 cSt Silicone Oil Liquid Bridge: New Data for the Preparation of the JEREMI Experiment

2021 ◽  
Vol 33 (2) ◽  
Author(s):  
Paolo Capobianchi ◽  
Marcello Lappa
Keyword(s):  
Liquid Bridge ◽  
Silicone Oil ◽  
Fluid Dynamic ◽  
Solid Particles ◽  
Critical Threshold ◽  
Marangoni Flow ◽  
Disk Radius ◽  
Carrier Fluid ◽  
Aspect Ratios ◽  
Time Periodic

AbstractSystems of solid particles in suspension driven by a time-periodic flow tend to create structures in the carrier fluid that are reminiscent of highly regular geometrical items. Within such a line of inquiry, the present study provides numerical results in support of the space experiments JEREMI (Japanese and European Research Experiment on Marangoni flow Instabilities) planned for execution onboard the International Space Station. The problem is tackled by solving the unsteady non-linear governing equations for the same conditions that will be established in space (microgravity, 5 cSt silicone oil and different aspect ratios of the liquid bridge). The results reveal that for a fixed supporting disk radius, the dynamics are deeply influenced by the height of the liquid column. In addition to its expected link with the critical threshold for the onset of instability (which makes Marangoni flow time-periodic), this geometrical parameter can have a significant impact on the emerging waveform and therefore the topology of particle structures. While for shallow liquid bridges, pulsating flows are the preferred mode of convection, for tall floating columns the dominant outcome is represented by rotating fluid-dynamic disturbance. In the former situation, particles self-organize in circular sectors bounded internally by regions of particle depletion, whereas in the latter case, particles are forced to accumulate in a spiral-like structure. The properties of some of these particle attractors have rarely been observed in earlier studies concerned with fluids characterized by smaller values of the Prandtl number.

scholarly journals Computational study of the collapse of a cloud with 12500 gas bubbles in a liquid

2019 ◽  
Vol 4 (6) ◽  
Author(s):  
U. Rasthofer ◽  
F. Wermelinger ◽  
P. Karnakov ◽  
J. Šukys ◽  
P. Koumoutsakos
Keyword(s):  
Computational Study ◽  
Gas Bubbles

scholarly journals In-Liquid Plasma Process for Size- and Shape-Controlled Synthesis of Silver Nanoparticles by Controlling Gas Bubbles in Water

Materials ◽  
2018 ◽  
Vol 11 (6) ◽  
pp. 891 ◽  
Author(s):  
Hyun-Jin Kim ◽  
Jun-Goo Shin ◽  
Choon-Sang Park ◽  
Dae Kum ◽  
Bhum Shin ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Gas Bubbles ◽  
Controlled Synthesis ◽  
Plasma Process ◽  
Size And Shape ◽  
Shape Controlled
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