scholarly journals Mathematical Calculations of the Mass Transport of Radionuclides in the Water Flow of the River Yenisei, in the Impact Zone of the Mining and Chemical Combine

2017 ◽  
Vol 2 (1) ◽  
Author(s):  
Bondareva Lydia ◽  
◽  
Fedorova Natalya ◽  
Rakitskii Valerii ◽  
◽  
...  
2020 ◽  
Vol 117 (6) ◽  
pp. 619
Author(s):  
Rui Xu ◽  
Haitao Ling ◽  
Haijun Wang ◽  
Lizhong Chang ◽  
Shengtao Qiu

The transient multiphase flow behavior in a single-strand tundish during ladle change was studied using physical modeling. The water and silicon oil were employed to simulate the liquid steel and slag. The effect of the turbulence inhibitor on the slag entrainment and the steel exposure during ladle change were evaluated and discussed. The effect of the slag carry-over on the water-oil-air flow was also analyzed. For the original tundish, the top oil phase in the impact zone was continuously dragged into the tundish bath and opened during ladle change, forming an emulsification phenomenon. By decreasing the liquid velocities in the upper part of the impact zone, the turbulence inhibitor decreased considerably the amount of entrained slag and the steel exposure during ladle change, thereby eliminating the emulsification phenomenon. Furthermore, the use of the TI-2 effectively lowered the effect of the slag carry-over on the steel cleanliness by controlling the movement of slag droplets. The results from industrial trials indicated that the application of the TI-2 reduced considerably the number of linear inclusions caused by ladle change in hot-rolled strip coils.


Author(s):  
V.V. Zinchenko ◽  
◽  
E.S Fedorenko ◽  
A.V Gorovtsov ◽  
T.M Minkina ◽  
...  

As a result of the model experiment, an increase in the enzymatic activity of meadow chernozem of the impact zone of Ataman Lake with the introduction of a strains mixture of metal-resistant microorganisms into the soil was established. The experiment has shown that the application of bacterial strains increases the dehydrogenase activity of contaminated soil by 51.8% compared to the variant without remediation


2019 ◽  
Vol 52 (12) ◽  
pp. 1477-1498 ◽  
Author(s):  
N. B. Khitrov ◽  
V. L. Ubugunov ◽  
V. I. Ubugunova ◽  
Yu. A. Rupyshev ◽  
T. A. Ayushina ◽  
...  
Keyword(s):  

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Matthias Galinsky ◽  
Ulf Sénéchal ◽  
Cornelia Breitkopf

The microstructure of porous materials used in heterogeneous catalysis determines the mass transport inside networks, which may vary over many length scales. The theoretical prediction of mass transport phenomena in porous materials, however, is incomplete and is still not completely understood. Therefore, experimental data for every specific porous system is needed. One possible experimental technique for characterizing the mass transport in such pore networks is pulse experiments. The general evaluation of experimental outcomes of these techniques follows the solution of Fick’s second law where an integral and effective diffusion coefficient is recognized. However, a detailed local understanding of diffusion and sorption processes remains a challenge. As there is lack of proved models covering different length scales, existing classical concepts need to be evaluated with respect to their ability to reflect local geometries on the nanometer level. In this study, DSMC (Direct Simulation Monte Carlo) models were used to investigate the impact of pore microstructures on the diffusion behaviour of gases. It can be understood as a virtual pulse experiment within a single pore or a combination of different pore geometries.


2001 ◽  
Author(s):  
Randall S. Gemmen

Abstract The effect of inverter ripple current on fuel cell stack performance and stack lifetime remains uncertain. This paper provides a first attempt to examine the impact of inverter load dynamics on the fuel cell. Since reactant utilization is known to impact the mechanical state of a fuel cell, it is suggested that the varying reactant conditions surrounding the cell govern, at least in part, the lifetime of the cells. This paper investigates these conditions through the use of a dynamic model for the bulk conditions within the stack, as well as a one-dimensional model for the detailed mass transport occurring within the electrode of a cell. These two independent modeling approaches help to verify their respective numerical procedures. In this work, the inverter load is imposed as a boundary condition to the models. Results show the transient behavior of the reactant concentrations within the stack, and of the mass diffusion within the electrode under inverter loads with frequencies between 30 Hz and 1250 Hz.


Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1129
Author(s):  
Ruidi Bai ◽  
Chang Liu ◽  
Bingyang Feng ◽  
Shanjun Liu ◽  
Faxing Zhang

Chute aerators introduce a large air discharge through air supply ducts to prevent cavitation erosion on spillways. There is not much information on the microcosmic air bubble characteristics near the chute bottom. This study was focused on examining the bottom air-water flow properties by performing a series of model tests that eliminated the upper aeration and illustrated the potential for bubble variation processes on the chute bottom. In comparison with the strong air detrainment in the impact zone, the bottom air bubble frequency decreased slightly. Observations showed that range of probability of the bubble chord length tended to decrease sharply in the impact zone and by a lesser extent in the equilibrium zone. A distinct mechanism to control the bubble size distribution, depending on bubble diameter, was proposed. For bubbles larger than about 1–2 mm, the bubble size distribution followed a—5/3 power-law scaling with diameter. Using the relationship between the local dissipation rate and bubble size, the bottom dissipation rate was found to increase along the chute bottom, and the corresponding Hinze scale showed a good agreement with the observations.


1996 ◽  
Vol 54 (1-2) ◽  
pp. 85-98 ◽  
Author(s):  
K. L. Bristow ◽  
R. Horton
Keyword(s):  

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