Correlations for Interaction Layer Growth in U-Mo/Al Dispersion Fuels

2017 ◽  
Vol 375 ◽  
pp. 29-39
Author(s):  
Boris A. Tarasov ◽  
Stepan N. Nikitin ◽  
Dmitry P. Shornikov ◽  
Maria S. Tarasova ◽  
Igor I. Konovalov
Keyword(s):  
Growth Rate ◽  
Growth Process ◽  
Aluminum Matrix ◽  
Layer Growth ◽  
Radiation Diffusion ◽  
Fission Rate ◽  
Interaction Layer ◽  
The Matrix ◽  
Mechanism And Kinetics ◽  
Kinetics Of

Paper presents the results of the growth rate of the interaction layer of uranium-molybdenum dispersed fuel in aluminum matrix and influence of silicon alloying on it. The growth process of amorphous interaction layer depends on the radiation diffusion which is proportional to the fission rate in the power of 1⁄4. The alloying of the matrix by silicon does not lead to a change in the mechanism and kinetics of the interaction layer growth, but only slows it down.

The kinetics of growth control in a colonial hydroid

1981 ◽  
Vol 61 (1) ◽  
pp. 35-63 ◽  
Author(s):  
A. R. D. Stebbing
Keyword(s):  
Growth Rate ◽  
Growth Process ◽  
Control Mechanism ◽  
Specific Growth ◽  
Growth Control ◽  
Temporal Variations ◽  
Controlled Experiments ◽  
Rates Of Growth ◽  
Kinetics Of ◽  
Colonial Hydroid

It is suggested that the cumulative view of growth in which some index of biomass is plotted against time tends to obscure temporal variations in the growth process that might provide evidence of how it is controlled. Experiments with the colonial hydroid Campanularia flexuosa show that the action of a growth control mechanism can be demonstrated by considering changes in specific rates of growth determined at frequent intervals in time. However, it is also necessary to disturb the growth process slightly in order to initiate the action of the control mechanism, and having done so, to isolate the effect of the disturbance on growth and thus the action of the control mechanism. This is done by expressing the specific growth rate of organisms whose growth is disturbed as a percentage of that of control organisms of the same age.

Experimental Measurements of Nucleation Frequency and Crystal Growth Rate in Pd-Cu-Ni-P Metallic Glass

1998 ◽  
Vol 554 ◽  
Author(s):  
Nobuyuki Nishiyama ◽  
Akihisa Inoue
Keyword(s):  
Growth Rate ◽  
Crystal Growth ◽  
Annealing Temperature ◽  
Annealing Treatment ◽  
Nucleation And Growth ◽  
Crystal Growth Rate ◽  
Equilibrium Melting Temperature ◽  
Glass Forming ◽  
Mechanism And Kinetics ◽  
Kinetics Of

AbstractCrystallization mechanism and kinetics of a Pd40Cu30Ni10P20 glass was investigated in a wide temperature range from 603 (near the glass transition temperature) to 764 K (near the equilibrium melting temperature) by using an isothermal annealing treatment for nucleation and growth. The nucleus density (nv) is about 5 × 1013 nuclei/m3 and is independent of annealing temperature. Therefore, it is assumed that the crystallization of the alloy was dominated by heterogeneous nucleation due to “quenched-in nuclei”. On the other hand, the crystal growth rate (Uc) increases from 1.07 × 10− to 5.68 × 10−5 m/s with rising annealing temperature from 603 to 764 K. These values of Uc are 2–3 orders of magnitude larger than the calculated Uc on the basis of Classical Nucleation and Growth Theory (CNT). Furthermore, the glass-forming ability of the alloy will be discussed in the framework of the present results.

High-resolution observations of metastable γ’ precipitation in Al-15at.%Ag

1996 ◽  
Vol 54 ◽  
pp. 1004-1005
Author(s):  
N. V. Larcher ◽  
I. G. Solorzano
Keyword(s):  
Discontinuous Precipitation ◽  
Equilibrium Phase ◽  
Quantitative Description ◽  
Present Contribution ◽  
Α Phase ◽  
The Matrix ◽  
Aging Sequence ◽  
Matrix Precipitation ◽  
Considerable Detail ◽  
Kinetics Of

It is currently well established that, for an Al-Ag alloy quenched from the α phase and aged within the metastable solvus, the aging sequence is: supersaturated α → GP zones → γ’ → γ (Ag2Al). While GP zones and plate-shaped γ’ are metastable phases, continuously distributed in the matrix, formation of the equilibrium phase γ takes place at grain boundaries by discontinuous precipitation (DP). The crystal structure of both γ’ and γ is hep with the following orientation relationship with respect to the fee α matrix: {0001}γ′,γ // {111}α, <1120>γ′,γ, // <110>α.The mechanisms and kinetics of continuous matrix precipitation (CMP) in dilute Al-Ag alloys have been studied in considerable detail. The quantitative description of DP kinetics, however, has received less attention. The present contribution reports the microstructural evolution resulting from aging an Al-Ag alloy with Ag content higher than those previously reported in the literature, focusing the observations of γ' plate-shaped metastable precipitates.

Oil extraction from the sunflower seeds, mechanism and kinetics of the process

2020 ◽  
Vol 3 (1) ◽  
pp. 155-160
Author(s):  
Ye. M. Semenyshyn ◽  
◽  
V. M. Atamanyuk ◽  
O. Ya. Dobrovetska ◽  
T. I. Rymar ◽  
...  
Keyword(s):  
Oil Extraction ◽  
Sunflower Seeds ◽  
Mechanism And Kinetics ◽  
Kinetics Of

Studies on the Behavior Some Paints in Electro-insulating Fluid Based on Vegetable Esters

2018 ◽  
Vol 69 (5) ◽  
pp. 1139-1144
Author(s):  
Iosif Lingvay ◽  
Adriana Mariana Bors ◽  
Livia Carmen Ungureanu ◽  
Valerica Stanoi ◽  
Traian Rus
Keyword(s):  
Structural Changes ◽  
Oxidation Processes ◽  
High Oleic ◽  
Painting Materials ◽  
Insulating Paper ◽  
Different Types ◽  
Mechanism And Kinetics ◽  
Kinetics Of ◽  
Natural Ester

For the purpose of using three different types of painting materials for the inner protection of the transformer vats, their behavior was studied under actual conditions of operation in the transformer (thermal stress in electro-insulating fluid based on the natural ester in contact with copper for electro-technical use and electro-insulating paper). By comparing determination of the content in furans products (HPLC technique) and gases formed (by gas-chromatography) in the electro-insulating fluid (natural ester with high oleic content) thermally aged at 130 �C to 1000 hours in closed glass vessels, it have been found that the presence the investigated painting materials lead to a change in the mechanism and kinetics of the thermo-oxidation processes. These changes are supported by oxygen dissolved in oil, what leads to decrease both to gases formation CO2, CO, H2, CH4, C2H4 and C2H6) and furans products (5-HMF, 2-FOL, 2 -FAL and 2-ACF). The painting materials investigated during the heat treatment applied did not suffer any remarkable structural changes affecting their functionality in the electro-insulating fluid based on vegetable esters.

Mechanism and Kinetics of the Hydrogen Failure of Thermoelectric Materials during Water Electrolysis

2020 ◽  
Vol 2020 (10) ◽  
pp. 1102-1115
Author(s):  
M. A. Korzhuev ◽  
I. V. Katin ◽  
M. A. Kretova ◽  
E. S. Avilov
Keyword(s):  
Thermoelectric Materials ◽  
Water Electrolysis ◽  
Mechanism And Kinetics ◽  
Kinetics Of

Spectrocoulometry – a new spectro-electrochemical technique

1987 ◽  
Vol 52 (6) ◽  
pp. 1386-1396 ◽  
Author(s):  
Ján Mocák ◽  
Michal Németh ◽  
Mieczyslaw Lapkowski ◽  
Jerzy W. Strojek
Keyword(s):  
Optical Probe ◽  
Optical Signal ◽  
Open Circuit ◽  
Electrochemical Technique ◽  
Kinetics Of Oxidation ◽  
Hydrolytic Reaction ◽  
Experimental Errors ◽  
Mechanism And Kinetics ◽  
Kinetics Of

A spectrocoulometric macrocell with a direct-view optical probe was designed and constructed, where the optical signal is transferred by light-conducting glass or quartz fibres permitting to work at wavelengths above 410 or 300 nm. The method of measurement on the proposed equipment is described; it was tested in the study of the mechanism and kinetics of oxidation of Fe(bipy)32+ ions (bipy = 2,2'-bipyridyl) with the use of potentiostatic coulometric electrolysis with open-circuit relaxation at a suitable time. The primary product of electrolysis, Fe(bipy)33+, undergoes a follow-up hydrolytic reaction with the formation of a binuclear complex. The rate constant of the reaction of the first order involves the contributions, kBi, from all bases present in solution; the corresponding values for H2O, OH-, bipy, and CH3COO- ions at a ionic strength 0·5 mol dm-3 and 25 °C were determined as kOH = (5·0 ± 0·6) . 105 mol-1 dm3 s-1, kbipy = (1·3 ± 0·2) . 10-1 mol-1 dm3 s-1, kAc = (5·8 ± 1·0) . 10-2 mol-1 dm3 s-1, and kH2O is not significant with respect to experimental errors.

New highly efficient coulometric cell with homogenous potential distribution on the working electrode

1986 ◽  
Vol 51 (3) ◽  
pp. 636-642
Author(s):  
Michal Németh ◽  
Ján Mocák
Keyword(s):  
Chemical Reactions ◽  
Potential Distribution ◽  
Anaerobic Conditions ◽  
Highly Efficient ◽  
Working Electrode ◽  
Constant Potential ◽  
Quantitative Analyses ◽  
Mechanism And Kinetics ◽  
Kinetics Of

A highly efficient coulometric cell was designed and constructed, ensuring a constant potential over the whole surface of the working electrode and suitable for very rapid electrolysis. It consists of concentric cylindrical Teflon parts; also the working and auxiliary electrodes are cylindrical and concentric. Electrolysis can be carried out under anaerobic conditions. Functioning of the cell was tested on the oxidation of hexacyanoferrate(II) and chlorpromazine and reduction of hexacyanoferrate(III). The new cell is suitable for routine quantitative analyses and in studying the mechanism and kinetics of moderately rapid chemical reactions.

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