Hydrogen impurity content of Ba2NaNb5O15

1969 ◽  
Vol 7 (13) ◽  
pp. 937-939 ◽  
Author(s):  
L.C. Bobb ◽  
I. Lefkowitz ◽  
L. Muldawer
2019 ◽  
Vol 525 ◽  
pp. 119669 ◽  
Author(s):  
A.P. Velmuzhov ◽  
M.V. Sukhanov ◽  
V.G. Plotnichenko ◽  
A.D. Plekhovich ◽  
V.S. Shiryaev ◽  
...  

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2064
Author(s):  
Liang Yu ◽  
Xiaoan Kang ◽  
Luona Chen ◽  
Kun Luo ◽  
Yanli Jiang ◽  
...  

The zone refining method is a physical method for effectively purifying metals. Increasing yield and reducing impurity content have always been the focus of its research. This article systematically summarizes the relevant research on the production of high-purity metals by zone refining, including mechanisms, parameter optimization, zone refining types, analysis methods, limitations, and future development directions, and it provides relevant theoretical foundations for the production of high-purity metals as well.


Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 393
Author(s):  
Zhemin Du ◽  
Congmin Liu ◽  
Junxiang Zhai ◽  
Xiuying Guo ◽  
Yalin Xiong ◽  
...  

Nowadays, we face a series of global challenges, including the growing depletion of fossil energy, environmental pollution, and global warming. The replacement of coal, petroleum, and natural gas by secondary energy resources is vital for sustainable development. Hydrogen (H2) energy is considered the ultimate energy in the 21st century because of its diverse sources, cleanliness, low carbon emission, flexibility, and high efficiency. H2 fuel cell vehicles are commonly the end-point application of H2 energy. Owing to their zero carbon emission, they are gradually replacing traditional vehicles powered by fossil fuel. As the H2 fuel cell vehicle industry rapidly develops, H2 fuel supply, especially H2 quality, attracts increasing attention. Compared with H2 for industrial use, the H2 purity requirements for fuel cells are not high. Still, the impurity content is strictly controlled since even a low amount of some impurities may irreversibly damage fuel cells’ performance and running life. This paper reviews different versions of current standards concerning H2 for fuel cell vehicles in China and abroad. Furthermore, we analyze the causes and developing trends for the changes in these standards in detail. On the other hand, according to characteristics of H2 for fuel cell vehicles, standard H2 purification technologies, such as pressure swing adsorption (PSA), membrane separation and metal hydride separation, were analyzed, and the latest research progress was reviewed.


MRS Advances ◽  
2018 ◽  
Vol 3 (54) ◽  
pp. 3227-3232
Author(s):  
Sergey M. Karabanov ◽  
Vladimir G. Litvinov ◽  
Nikolay B. Rybin ◽  
Evgeniy V. Slivkin ◽  
Vladimir V. Oreshkin ◽  
...  

ABSTRACTIn this work, we present the results of investigation of the nanoporous material – carbon fabrics, which is used as electrodes in rechargeable energy storage capacitors (ultracapacitors). The impurity composition in the fabrics, the influence of thermal annealing conditions on the impurity concentration is studied. The performed studies resulted in determination of the investigated carbon material structure, determination of impurity composition of carbon material and change of impurity content depending on thermal treatment in vacuum at different temperatures and time intervals. The optimum temperature range for the treatment of carbon fabrics in vacuum that is important for its application in energy storage devices is found.


2007 ◽  
Vol 75 (3) ◽  
pp. 374-378 ◽  
Author(s):  
Luis Villamagua ◽  
Rafael Barreto ◽  
Luis Miguel Prócel ◽  
Arvids Stashans

2018 ◽  
Vol 84 (6) ◽  
Author(s):  
L. Hesslow ◽  
O. Embréus ◽  
M. Hoppe ◽  
T. C. DuBois ◽  
G. Papp ◽  
...  

Accurate modelling of the interaction between fast electrons and partially ionized atoms is important for evaluating tokamak disruption mitigation schemes based on material injection. This requires accounting for the effect of screening of the impurity nuclei by the cloud of bound electrons. In this paper, we generalize the Fokker–Planck operator in a fully ionized plasma by accounting for the effect of screening. We detail the derivation of this generalized operator, and calculate the effective ion length scales, needed in the components of the collision operator, for a number of ion species commonly appearing in fusion experiments. We show that for high electric fields, the secondary runaway growth rate can be substantially larger than in a fully ionized plasma with the same effective charge, although the growth rate is significantly reduced at near-critical electric fields. Furthermore, by comparison with the Boltzmann collision operator, we show that the Fokker–Planck formalism is accurate even for large impurity content.


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