Kinetics of Cathodic Processes of Deposition of Nickel–Molybdenum Alloys from an Ammonia–Citrate Electrolyte

2003 ◽  
Vol 39 (12) ◽  
pp. 1338-1341 ◽  
Author(s):  
V. V. Kuznetsov ◽  
M. R. Pavlov ◽  
K. V. Kuznetsov ◽  
V. N. Kudryavtsev
Keyword(s):  
Molybdenum Alloys ◽  
Citrate Electrolyte ◽  
Cathodic Processes ◽  
Kinetics Of

scholarly journals The oxidation kinetics of depleted uranium and its low-alloy molybdenum alloys in moist air

2019 ◽  
Vol 63 (3) ◽  
pp. 100-104
Author(s):  
T. Chmela ◽  
P. Krupička
Keyword(s):  
Relative Humidity ◽  
Reaction Kinetics ◽  
Oxidation Kinetics ◽  
Reaction Rate ◽  
Depleted Uranium ◽  
Rate Equations ◽  
Moist Air ◽  
Molybdenum Alloys ◽  
Exponential Behaviour ◽  
Kinetics Of

Abstract The oxidation kinetics of depleted uranium and its low-alloy molybdenum alloys (U-2wt.%Mo, U-5wt.%Mo) were measured in a moist air (75% relative humidity) at 60 and 75 ° C. Coefficients of reaction rate equations were determined for linear oxidation kinetics. In the oxidation of depleted uranium at 75 ° C, a change in reaction kinetics from linear to exponential behaviour was observed after about 2500 hours.

Cathodic processes of neodymium(iii) in LiF–NdF3–Nd2O3 melts

2016 ◽  
Vol 190 ◽  
pp. 339-349 ◽  
Author(s):  
Chao Huang ◽  
Xiaolong Liu ◽  
Yuan Gao ◽  
Shizhe Liu ◽  
Bing Li
Keyword(s):  
Mass Transfer ◽  
Cyclic Voltammetry ◽  
Electrochemical Reduction ◽  
Square Wave Voltammetry ◽  
Square Wave ◽  
Potentiostatic Electrolysis ◽  
Reduction Potentials ◽  
Wave Voltammetry ◽  
Cathodic Processes ◽  
Kinetics Of

In this paper, cyclic voltammetry and square wave voltammetry are applied to characterize the cathode processes of neodymium ions on a W electrode in LiF–NdF3 melts with or without the metal Nd. The results indicate that neodymium ions in the LiF–NdF3 (2 wt%) melt are reduced in two steps, i.e. Nd3+ → Nd2+ and Nd2+ → Nd0, corresponding to starting reduction potentials of 0.35 V vs. Li+/Li and 0.1 V vs. Li+/Li, respectively. The Nd3+ → Nd2+ process is controlled by mass transfer and the Nd2+ → Nd0 process is controlled by both an interfacial step and mass transfer. But in the LiF–NdF3 melt with excess metal Nd equilibrium, the kinetics of the above two processes are controlled by mass transfer. After potentiostatic electrolysis at 0.35 V in the LiF–NdF3–Nd2O3 melt NdF2 is formed on the Mo cathode, and metallic Nd is obtained by potentiostatic electrolysis at 0.1 V in the LiF–NdF3–Nd2O3–Nd melt, which validates the above electrochemical reduction results.

Direct observations of radiation-enhanced transformations in glass

1983 ◽  
Vol 41 ◽  
pp. 354-355
Author(s):  
J. F. DeNatale ◽  
D. G. Howitt
Keyword(s):  
Glass Matrix ◽  
Diffusion Mechanism ◽  
Bubble Formation ◽  
Silicate Glasses ◽  
Phase Decomposition ◽  
Direct Observations ◽  
Thin Foils ◽  
Oxygen Bubble ◽  
Electron Energy Loss ◽  
Kinetics Of

The electron irradiation of silicate glasses containing metal cations produces various types of phase separation and decomposition which includes oxygen bubble formation at intermediate temperatures figure I. The kinetics of bubble formation are too rapid to be accounted for by oxygen diffusion but the behavior is consistent with a cation diffusion mechanism if the amount of oxygen in the bubble is not significantly different from that in the same volume of silicate glass. The formation of oxygen bubbles is often accompanied by precipitation of crystalline phases and/or amorphous phase decomposition in the regions between the bubbles and the detection of differences in oxygen concentration between the bubble and matrix by electron energy loss spectroscopy cannot be discerned (figure 2) even when the bubble occupies the majority of the foil depth.The oxygen bubbles are stable, even in the thin foils, months after irradiation and if van der Waals behavior of the interior gas is assumed an oxygen pressure of about 4000 atmospheres must be sustained for a 100 bubble if the surface tension with the glass matrix is to balance against it at intermediate temperatures.

Irradiation behavior of pyrolytic silicon carbide

1983 ◽  
Vol 41 ◽  
pp. 72-73
Author(s):  
R. J. Lauf
Keyword(s):  
Silicon Carbide ◽  
Fission Products ◽  
Thermodynamics And Kinetics ◽  
Neutron Fluences ◽  
Fuel Particles ◽  
Sic Coatings ◽  
Irradiation Behavior ◽  
Kinetics Of ◽  
Htgr Fuel

Fuel particles for the High-Temperature Gas-Cooled Reactor (HTGR) contain a layer of pyrolytic silicon carbide to act as a miniature pressure vessel and primary fission product barrier. Optimization of the SiC with respect to fuel performance involves four areas of study: (a) characterization of as-deposited SiC coatings; (b) thermodynamics and kinetics of chemical reactions between SiC and fission products; (c) irradiation behavior of SiC in the absence of fission products; and (d) combined effects of irradiation and fission products. This paper reports the behavior of SiC deposited on inert microspheres and irradiated to fast neutron fluences typical of HTGR fuel at end-of-life.

The Ordered Phase Formation in Ti-Al-Ga Alloys

1970 ◽  
Vol 28 ◽  
pp. 440-441
Author(s):  
Shiro Fujishiro ◽  
Harold L. Gegel
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Titanium Alloys ◽  
Growth Kinetics ◽  
Stoichiometric Composition ◽  
Good Potential ◽  
Alpha Titanium ◽  
Cold Rolled ◽  
Kinetics Of ◽  
Thermal Stability Of

Ordered-alpha titanium alloys having a DO19 type structure have good potential for high temperature (600°C) applications, due to the thermal stability of the ordered phase and the inherent resistance to recrystallization of these alloys. Five different Ti-Al-Ga alloys consisting of equal atomic percents of aluminum and gallium solute additions up to the stoichiometric composition, Ti3(Al, Ga), were used to study the growth kinetics of the ordered phase and the nature of its interface.The alloys were homogenized in the beta region in a vacuum of about 5×10-7 torr, furnace cooled; reheated in air to 50°C below the alpha transus for hot working. The alloys were subsequently acid cleaned, annealed in vacuo, and cold rolled to about. 050 inch prior to additional homogenization

Sign in / Sign up

Export Citation Format

Share Document