Applicability of Quasi Steady State Solutions for the Kinetics of Diffusion Controlled Solid State Reactions

1994 ◽  
pp. 47-58
Author(s):  
J.R. Frade
Keyword(s):  
Steady State ◽  
Solid State ◽  
Solid State Reactions ◽  
Quasi Steady State ◽  
Diffusion Controlled ◽  
Kinetics Of ◽  
Steady State Solutions

Dielectric spectroscopy on the kinetics of solid state reactions

1985 ◽  
Vol 17 (3) ◽  
pp. 231-240 ◽  
Author(s):  
G SCHON ◽  
R SCHMIDT
Keyword(s):  
Solid State ◽  
Dielectric Spectroscopy ◽  
Solid State Reactions ◽  
Kinetics Of

Kinetics of NO2 air space absorption in isolated rat lungs

1992 ◽  
Vol 73 (5) ◽  
pp. 1939-1945 ◽  
Author(s):  
E. M. Postlethwait ◽  
S. D. Langford ◽  
A. Bidani
Keyword(s):  
Steady State ◽  
Tidal Volume ◽  
Gas Phase ◽  
Initial Rate ◽  
Quasi Steady State ◽  
Closed Chamber ◽  
First Order ◽  
First Order Kinetics ◽  
Rat Lungs ◽  
Kinetics Of

We previously showed, during quasi-steady-state exposures, that the rate of inhaled NO2 uptake displays reaction-mediated characteristics (J. Appl. Physiol. 68: 594–603, 1990). In vitro kinetic studies of pulmonary epithelial lining fluid (ELF) demonstrated that NO2 interfacial transfer into ELF exhibits first-order kinetics with respect to NO2, attains [NO2]-dependent rate saturation, and is aqueous substrate dependent (J. Appl. Physiol. 71: 1502–1510, 1991). We have extended these observations by evaluating the kinetics of NO2 gas phase disappearance in isolated ventilating rat lungs. Transient exposures (2–3/lung at 25 degrees C) employed rebreathing (NO2-air) from a non-compliant continuously stirred closed chamber. We observed that 1) NO2 uptake rate is independent of exposure period, 2) NO2 gas phase disappearance exhibited first-order kinetics [initial rate (r*) saturation occurred when [NO2] > 11 ppm], 3) the mean effective rate constant (k*) for NO2 gas phase disappearance ([NO2] < or = 11 ppm, tidal volume = 2.3 ml, functional residual capacity = 4 ml, ventilation frequency = 50/min) was 83 +/- 5 ml/min, 4) with [NO2] < or = 11 ppm, k* and r* were proportional to tidal volume, and 5) NO2 fractional uptakes were constant across [NO2] (< or = 11 ppm) and tidal volumes but exceeded quasi-steady-state observations. Preliminary data indicate that this divergence may be related to the inspired PCO2. These results suggest that NO2 reactive uptake within rebreathing isolated lungs follows first-order kinetics and displays initial rate saturation, similar to isolated ELF.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Kinetics of Solid State Reactions in 2FeO–SiO2 and 2NiO–SiO2 Systems

1985 ◽  
Vol 26 (8) ◽  
pp. 542-548
Author(s):  
Masayasu Kawahara ◽  
Toshiharu Mitsuo ◽  
Yoshinori Shirane
Keyword(s):  
Solid State ◽  
Solid State Reactions ◽  
Kinetics Of

Theory of nucleation in solid state reactions

1968 ◽  
Vol 46 (2) ◽  
pp. 111-116 ◽  
Author(s):  
A. R. Allnatt ◽  
P. W. M. Jacobs
Keyword(s):  
Solid State ◽  
Approximate Model ◽  
Single Step ◽  
Solid State Reactions ◽  
Avrami Equation ◽  
Nucleation Process ◽  
Special Cases ◽  
New Equation ◽  
Kinetics Of ◽  
Short Times

The theory of nucleation in solid state reactions is formulated in a general way and a solution to the problem of multi-step nucleation obtained. Two special cases of the general formulation are considered: the second of these corresponds to Bagdassarian's approximate model and some corrections to his treatment are pointed out. A new equation describing the kinetics of a solid state reaction, which involves multi-step nucleation followed by a constant and isotropic rate of growth, is derived. This equation is termed the generalized Avrami equation since it removes the restriction, in Avrami's treatment, of a single-step nucleation process. Erofeev's analysis of the problem is shown to be valid only in the limit of short times: the generalized Avrami equation reduces to Erofeev's equation in this limit.

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