scholarly journals Fundamental Studies of Tritium Diffusivity in Irradiated Defective Lithium Aluminate Pellets

2020 ◽  
Author(s):  
Hari Paudel ◽  
Yuhua Duan
Keyword(s):  
2020 ◽  
Vol 86 (1) ◽  
pp. 32-37
Author(s):  
Valeria A. Brodskaya ◽  
Oksana A. Molkova ◽  
Kira B. Zhogova ◽  
Inga V. Astakhova

Powder materials are widely used in the manufacture of electrochemical elements of thermal chemical sources of current. Electrochemical behavior of the powders depends on the shape and size of their particles. The results of the study of the microstructure and particles of the powders of vanadium (III), (V) oxides and lithium aluminate obtained by transmission electron and atomic force microscopy, X-ray diffraction and gas adsorption analyses are presented. It is found that the sizes of vanadium (III) and vanadium (V) oxide particles range within 70 – 600 and 40 – 350 nm, respectively. The size of the coherent-scattering regions of the vanadium oxide particles lies in the lower range limit which can be attributed to small size of the structural elements (crystallites). An average volumetric-surface diameter calculated on the basis of the surface specific area is close to the upper range limit which can be explained by the partial agglomeration of the powder particles. Unlike the vanadium oxide particles, the range of the particle size distribution of the lithium aluminate powder is narrower — 50 – 110 nm. The values of crystallite sizes are close to the maximum of the particle size distribution. Microstructural analysis showed that the particles in the samples of vanadium oxides have a rounded (V2O3) or elongated (V2O5) shape; whereas the particles of lithium aluminate powder exhibit lamellar structure. At the same time, for different batches of the same material, the particle size distribution is similar, which indicates the reproducibility of the technologies for their manufacture. The data obtained can be used to control the constancy of the particle size distribution of powder materials.


2017 ◽  
Vol 106 ◽  
pp. 107-112 ◽  
Author(s):  
A. Kilian ◽  
P. Bilski ◽  
W. Gieszczyk

1997 ◽  
Vol 75 (4) ◽  
pp. 465-468
Author(s):  
B.K. Miremadi ◽  
K. Colbow ◽  
S. Roy Morrison

A lithium aluminate – MgO catalyst has been found to convert methane to ethylene with a high selectivity. The rate of conversion increased when a MoO3 co-catalyst was used to remove the poisoning products. It is shown that for optimum conversion and selectivity to ethylene, the oxygen pressure should be at an intermediate value, high enough to provide active sites but low enough to avoid ethylene oxidation. Thus the oxygen should be "bled-in" along the catalyst bed. In demonstration of these concepts we have shown a 28.6% CH4 conversion with 63.2% ethylene selectivity and 9.8% ethane, producing a C2 yield of about 21.4%. Keywords: methane oxidation, methane conversion, ethylene production, oxidation catalyst, aluminate catalyst.


1992 ◽  
Vol 191-194 ◽  
pp. 268-271 ◽  
Author(s):  
Yoshiyuki Asaoka ◽  
Hirotake Moriyama ◽  
Kimihiko Iwasaki ◽  
Kimikazu Moritani ◽  
Yasuhiko Ito

1991 ◽  
pp. 929-933
Author(s):  
B. RASNEUR ◽  
M. BONCOEUR ◽  
A.M. LEJUS ◽  
R. COLLONGUES

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