Bubble growth from clustered hydrogen and helium atoms in tungsten under a fusion environment

2016 ◽  
Vol 57 (1) ◽  
pp. 016006 ◽  
Author(s):  
Yu-Wei You ◽  
Xiang-Shan Kong ◽  
Xuebang Wu ◽  
C.S. Liu ◽  
J.L. Chen ◽  
...  
Keyword(s):  
Bubble Growth ◽  
Helium Atoms

Understanding gas bubble trauma in an era of hydropower expansion: how do fish compensate at depth?

2020 ◽  
Vol 77 (3) ◽  
pp. 556-563 ◽  
Author(s):  
Naomi K. Pleizier ◽  
Charlotte Nelson ◽  
Steven J. Cooke ◽  
Colin J. Brauner
Keyword(s):  
Bubble Growth ◽  
Gas Bubble ◽  
Hydroelectric Dams ◽  
Dissolved Gas ◽  
Empirical Relationships ◽  
Lethal Effects ◽  
Exposed Fish ◽  
Total Dissolved Gas ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
The Relationship

Hydrostatic pressure is known to protect fish from damage by total dissolved gas (TDG) supersaturation, but empirical relationships are lacking. In this study we demonstrate the relationship between depth, TDG, and gas bubble trauma (GBT). Hydroelectric dams generate TDG supersaturation that causes bubble growth in the tissues of aquatic animals, resulting in sublethal and lethal effects. We exposed fish to 100%, 115%, 120%, and 130% TDG at 16 and 63 cm of depth and recorded time to 50% loss of equilibrium and sublethal symptoms. Our linear model of the log-transformed time to 50% LOE (R2 = 0.94) was improved by including depth. Based on our model, a depth of 47 cm compensated for the effects of 4.1% (±1.3% SE) TDG supersaturation. Our experiment reveals that once the surface threshold for GBT from TDG supersaturation is known, depth protects rainbow trout (Oncorhynchus mykiss) from GBT by 9.7% TDG supersaturation per metre depth. Our results can be used to estimate the impacts of TDG on fish downstream of dams and to develop improved guidelines for TDG.

scholarly journals Helium Isotopes Quantum Sieving through Graphtriyne Membranes

Nanomaterials ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 73
Author(s):  
Marta I. Hernández ◽  
Massimiliano Bartolomei ◽  
José Campos-Martínez
Keyword(s):  
Low Temperatures ◽  
Quantum Tunneling ◽  
Transition State Theory ◽  
Selective Adsorption ◽  
State Theory ◽  
Helium Isotopes ◽  
Quantum Calculations ◽  
Approximate Methods ◽  
Helium Atoms ◽  
Quantum Behavior

We report accurate quantum calculations of the sieving of Helium atoms by two-dimensional (2D) graphtriyne layers with a new interaction potential. Thermal rate constants and permeances in an ample temperature range are computed and compared for both Helium isotopes. With a pore larger than graphdiyne, the most common member of the γ-graphyne family, it could be expected that the appearance of quantum effects were more limited. We find, however, a strong quantum behavior that can be attributed to the presence of selective adsorption resonances, with a pronounced effect in the low temperature regime. This effect leads to the appearance of some selectivity at very low temperatures and the possibility for the heavier isotope to cross the membrane more efficiently than the lighter, contrarily to what happened with graphdiyne membranes, where the sieving at low energy is predominantly ruled by quantum tunneling. The use of more approximate methods could be not advisable in these situations and prototypical transition state theory treatments might lead to large errors.

Monitoring damage of self-assembled monolayers using metastable excited helium atoms

2021 ◽  
Vol 154 (3) ◽  
pp. 034704
Author(s):  
Georgios Stratis ◽  
Jordan D. Zesch ◽  
Henry S. Pan ◽  
Lauren J. Webb ◽  
Mark G. Raizen
Keyword(s):  
Self Assembled Monolayers ◽  
Helium Atoms ◽  
Assembled Monolayers ◽  
Self Assembled ◽  
Excited Helium
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