scholarly journals Effects of Diffusion Controlled Reaction on Mass Transfer from a Single Sphere

1964 ◽  
Vol 28 (6) ◽  
pp. 436-444,a1
Author(s):  
Yoshiyuki Kitaura ◽  
Hisaya Tanaka
2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
H. P. Li

Energy-efficient processing of TiB compound with nanowhiskers by micropyretic synthesis is investigated in this paper. Micropyretic synthesis not only offers shorter processing time but also excludes the requirement for high-temperature sintering and it is considered as the one of the novel energy-saving processing techniques. Experimental study and numerical simulation are both carried out to investigate the correlation of the processing parameters on the microstructures of the micropyretically synthesized products. The diffusion-controlled reaction mechanism is proposed in this study. It is noted that nanosize TiB whiskers only occurred when the combustion temperature is lower than the melting point of TiB but higher than the extinguished temperature. The results generated in the numerical calculation can be used as a helpful reference to select the proper route of processing nanosize materials. The Arrhenius-type plot of size and temperature is used to calculate the activation energy of TiB reaction. In addition to verifying the accuracy of the experimental measures, the reaction temperature for producing the micropyretically synthesized products with nanofeatures can be predicted.


2010 ◽  
Vol 114 (49) ◽  
pp. 16584-16593 ◽  
Author(s):  
Horacio Botti ◽  
Matías N. Möller ◽  
Daniel Steinmann ◽  
Thomas Nauser ◽  
Willem H. Koppenol ◽  
...  

2010 ◽  
Vol 65 (1-2) ◽  
pp. 132-140 ◽  
Author(s):  
Yevhen Yu. Kalishyn ◽  
Małgorzata Rachwalska ◽  
Peter E. Strizhak

AbstractWe have studied the stirring effect on the time-delayed bifurcations of transient oscillations in the Belousov-Zhabotinsky (BZ) oscillating chemical reaction in a closed system. Experiments show that oscillations disappear through the time-delayed Hopf bifurcations, whose parameters depend on the stirring rate. The explanation of the stirring effect is based on the theories of diffusion-controlled reactions and hydrodynamic turbulence. We show that an increase of the stirring rate leads to an increase of the rate constant for the diffusion-controlled reaction. We propose a kinetic scheme that describes the effect observed in the experiments. A good agreement between the experimental data and the simulations is obtained.


1992 ◽  
Vol 191 (1-4) ◽  
pp. 143-152 ◽  
Author(s):  
S. Havlin ◽  
M. Araujo ◽  
H. Larralde ◽  
H.E. Stanley ◽  
P. Trunfio

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