scholarly journals Determination of the viscosity of molten salts by a capillary method. The system cadmium chloride-cadmium bromide

1948 ◽  
Vol 194 (1037) ◽  
pp. 237-244 ◽  
Keyword(s):  
Activation Energy ◽  
High Temperature ◽  
Molten Salts ◽  
Cadmium Chloride ◽  
Molar Fraction ◽  
Recording Device ◽  
Capillary Method ◽  
Cadmium Bromide ◽  
Salt Mixtures

The knowledge of the viscosity of molten salts and their mixtures is important (1) for testing recent theories by Eyring and by Frenkel, and (2) for confirming or modifying conclusions regarding the constitution of certain molten salt mixtures which were investigated by Bloom & Heymann. A capillary method based on the Ubbelohde-Bingham principle has been adapted to the conditions at high temperature. The main feature of the method is an automatic electric recording device, involving a balanced Wheatstone net with amplifier and an electric clock. The isotherms of viscosity plotted against molar fraction in the system CdCl 3 -CdBr 2 are linear. The activation energy of viscosity is 1.6 to 1.8 times as great as the activation energy of ionic migration.

The role of correlations in the determination of the transport properties of LaCl3 in high temperature molten eutectic LiCl–KCl

2017 ◽  
Vol 105 (8) ◽  
Author(s):  
Adib Samin ◽  
Evan Wu ◽  
Jinsuo Zhang
Keyword(s):  
Cyclic Voltammetry ◽  
High Temperature ◽  
Transport Properties ◽  
Molten Salts ◽  
Careful Consideration ◽  
Accurate Assessment

AbstractIt is important to develop an accurate assessment of fundamental data of lanthanides in high temperature molten salts to enable an efficient application of pyroprocessing. This requires a careful consideration of uncertainties in the reported results. In this study, cyclic voltammetry (CV) tests of LaCl

Use of two-color array pyrometry for characterization of combustion synthesis waves

2000 ◽  
Vol 15 (2) ◽  
pp. 572-580 ◽  
Author(s):  
U. Anselmi-Tamburini ◽  
F. Maglia ◽  
G. Spinolo ◽  
Z. A. Munir
Keyword(s):  
Activation Energy ◽  
Wave Propagation ◽  
High Temperature ◽  
Combustion Synthesis ◽  
Morphological Changes ◽  
Formation Of Cracks ◽  
High Temperature Reactions ◽  
Time Sequences

A two-color array pyrometer was used to investigate morphological developments on the surface of materials undergoing self-propagating high-temperature reactions. Time sequences of temperature spatial profiles during wave propagation were found to be complex in their nature and dynamics. They contain features that are interpreted in terms of morphological changes during the process. These features include formation of cracks or voids, expansion of the sample, and formation of droplets of metals on the surface. The use of the array pyrometer for determination of the activation energy of the combustion reaction between Zr and NiO is reported.

scholarly journals Determination of activation energy of sintering of ThO2-U3O8 pellets using the master sintering curve approach

2003 ◽  
Vol 35 (3) ◽  
pp. 125-132 ◽  
Author(s):  
T.R.G. Kutty ◽  
K.B. Khan ◽  
P.V. Hegde ◽  
A.K. Sengupta ◽  
S. Majumdar ◽  
...  
Keyword(s):  
Activation Energy ◽  
Solid Solution ◽  
High Temperature ◽  
Constant Heating Rate ◽  
Heavy Water Reactor ◽  
Activation Energy Of Sintering ◽  
Constant Heating ◽  
Kinetics Of ◽  
Powder Metallurgy Route

ThO2 containing around 2 to 3 % U233O2 is considered as fuel for the forthcoming Indian Advanced Heavy Water Reactor (AHWR). High-density ThO2-UO2 pellets have been fabricated by powder metallurgy route using ThO2 and U3O8 powders as the starting materials. U3O8 decomposes to UO2 during high temperature sintering and forms a solid solution with ThO2. The densification behaviour and sintering kinetics of the above were evaluated using a high temperature dilatometer using constant heating rate experiments. To evaluate the activation energy of sintering, a master sintering curve approach has been used. The activation energy for sintering for the above composition in air was found to be 500 kJ/mol.

High Temperature n- and p-type Doped Microcrystalline Silicon Layers Grown by VHF PECVD Layer-by-Layer Deposition

2003 ◽  
Vol 762 ◽  
Author(s):  
A. Gordijn ◽  
J.K. Rath ◽  
R.E.I. Schropp
Keyword(s):  
Activation Energy ◽  
High Temperature ◽  
High Temperatures ◽  
Continuous Wave ◽  
Hydrogen Plasma ◽  
Silicon Layer ◽  
Dark Conductivity ◽  
High Deposition Rate ◽  
Layer By Layer ◽  
Microcrystalline Silicon

AbstractDue to the high temperatures used for high deposition rate microcrystalline (μc-Si:H) and polycrystalline silicon, there is a need for compact and temperature-stable doped layers. In this study we report on films grown by the layer-by-layer method (LbL) using VHF PECVD. Growth of an amorphous silicon layer is alternated by a hydrogen plasma treatment. In LbL, the surface reactions are separated time-wise from the nucleation in the bulk. We observed that it is possible to incorporate dopant atoms in the layer, without disturbing the nucleation. Even at high substrate temperatures (up to 400°C) doped layers can be made microcrystalline. At these temperatures, in the continuous wave case, crystallinity is hindered, which is generally attributed to the out-diffusion of hydrogen from the surface and the presence of impurities (dopants).We observe that the parameter window for the treatment time for p-layers is smaller compared to n-layers. Moreover we observe that for high temperatures, the nucleation of p-layers is more adversely affected than for n-layers. Thin, doped layers have been structurally, optically and electrically characterized. The best n-layer made at 400°C, with a thickness of only 31 nm, had an activation energy of 0.056 eV and a dark conductivity of 2.7 S/cm, while the best p-layer made at 350°C, with a thickness of 29 nm, had an activation energy of 0.11 V and a dark conductivity of 0.1 S/cm. The suitability of these high temperature n-layers has been demonstrated in an n-i-p microcrystalline silicon solar cell with an unoptimized μc-Si:H i-layer deposited at 250°C and without buffer. The Voc of the cell is 0.48 V and the fill factor is 70 %.

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