Photographic study of the shock-induced dispersion of microscopic gas bubbles

1996 ◽  
Vol 22 ◽  
pp. 141
Author(s):  
A Szumowski
Keyword(s):  
Author(s):  
O. M. Katz

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.


2011 ◽  
Author(s):  
D. V. Holliday ◽  
C. F. Greenlaw ◽  
David Thistle ◽  
Jan E. Rines

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Veton Haziri ◽  
Tu Pham Tran Nha ◽  
Avni Berisha ◽  
Jean-François Boily

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.


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

Materials ◽  
2018 ◽  
Vol 11 (6) ◽  
pp. 891 ◽  
Author(s):  
Hyun-Jin Kim ◽  
Jun-Goo Shin ◽  
Choon-Sang Park ◽  
Dae Kum ◽  
Bhum Shin ◽  
...  

2021 ◽  
pp. 105501
Author(s):  
W.H. Wu ◽  
D.G. Eskin ◽  
A. Priyadarshi ◽  
T. Subroto ◽  
I. Tzanakis ◽  
...  

2020 ◽  
pp. 116583
Author(s):  
Paul Hans Kamm ◽  
Tillmann Robert Neu ◽  
Francisco García-Moreno ◽  
John Banhart

2021 ◽  
Vol 79 ◽  
pp. 101892
Author(s):  
Hao Zhu ◽  
Alfred Rieder ◽  
Wolfgang Drahm ◽  
Yaoying Lin ◽  
Andreas Guettler ◽  
...  

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