Bowen mechanism

Bowen J P and N L Allinger 1991. Molecular Mechanics The Art and Science of Parameterisation. I Lipkowitz K B and D B Boyd (Editors). Reviews in Computational Chemistry Volume 2. New Yorl VCH Publishers, pp. 81-97. 

J. P. Bowen, New vistas in molecular mechanics calculations, in Drug Design, Marcel Dekker, Inc., New York (1997), pp. 495-538. 

J. Phillip Bowen and Norman L. Allinger, Molecular Mechanics The Art and... 

Bowen, R.D. Derrick, P.J. The Mechanism of Ethylene Loss From the Oxonium Ion [CH3CH20=CHCH2CH3]7 J. Chem. Soc., Chem. Commun. 1990, 1539-1541. 

Figure 7.3 depicts phase stability relations in the pseudobinary system CaMgSi206-CaAl2Si208 (diopside-anorthite). The original study of Bowen (1915) described crystallization behavior identical to the previously discussed case a mechanical mixture (Di-An) in equilibrium with a completely miscible melt. A later investigation (Osborn, 1942) showed that the system is not strictly binary... 

The extension of direct photooxygenation reactions to polycyclic aromatic hydrocarbons as well as to aryl-substituted carbocyclic and heterocyclic pentadienes is due to the (exclusively preparative) work of Dufraisse and Etienne.5-20-29 Investigations on the mechanisms of these reactions were made by Bowen,2 Livingston,3 and Cherkasov and Vember.30-31... 

However, the ft values were probably incorrectly taken from Bowen s work.150 If the ft values obtained by this author are used, Pa = 0.42 and j3s = 0.057 (see Table VII), a better agreement between the calculated slope (=0.14) and the observed slope is obtained. The range of experimental error in determining the individual ft values as well as in obtaining a reliable slope from the competitive photooxygenation reaction appears to be fairly large. The difference between the calculated and the experimental slope, therefore, does not allow the abandonment of the energy-transfer mechanism. 

Figure 4.40 Illustration of diffusion mechanisms in alloys and ionic solids (a) interchange (exchange) (b) ring rotation (rare) (c) interstitial migration and (d) vacancy migration. From W. D. Kingery, H. K. Bowen, and D. R. Uhlmann, Introduction to Ceramics. Copyright 1976 by John Wiley Sons, Inc. This material is used by permission of John Wiley Sons, Inc.

Courville, S. and Crucefix, D. 2004. Existing and potential models and mechanisms for harmonisation, equivalency and mutual recognition. In Michaud, J., Wynen, E. and Bowen,... 

In presence of dissolved oxygen, photooxidation may also occur. Bowen and Williams (19) carried out some early experiments with benzene, some of its methyl derivatives, and certain other aromatic hydrocarbons in hexane solutions illuminated with light at 2537 A. They found low values for the quantum yields of fluorescence and of oxygen take-up the sum of these quantities being less than unity. At higher temperatures (>50°C.) chain propagation by a radical mechanism... 

Bowen, J., Hinchliffe, J.R., Horder, T.J., Reeve, A.M.F. (1989). The fate map of the chick forelimb-bud and its bearing on hypothesized developmental control mechanisms. Anat. Embryol. 179, 269-283. 

The uptake of barium by fish and marine organisms is also an important removal mechanism (Bowen 1966 Schroeder 1970). Barium levels in sea water range from 2 to 63 mg/L with a mean concentration of about 13 pg/L (Bowen 1979). Barium was found to bioconcentrate in marine plants by a factor of 1,000 times the level present in the water. Bioconcentration factors in marine animals, plankton, and in brown algae of 100, 120, and 260, respectively, have been reported (Bowen 1966 Schroeder 1970). 

J.M. Bowen et al., Comparison of sample preparation methods for the Fourier transform infrared analysis of an organo-clay mineral sorption mechanism. Anal. Chem. 61, 2047-2050 (1989)... 

However, since the QSSA has been used to elucidate most reaction mechanisms and to determine most rate coefficients of elementary processes, a fundamental answer to the question of the validity of the approximation seems desirable. The true mathematical significance of QSSA was elucidated for the first time by Bowen et al. [163] (see also refs. 164 and 165 for history and other references) by means of the theory of singular perturbations, but only in the case of very simple reaction mechanisms. The singular perturbation theory has been applied by Come to reaction mechanisms of any complexity with isothermal CFSTR [118] and batch or plug flow reactors [148, 149]. The main conclusions arrived at for a free radical straight chain reaction (with only quadratic terminations) carried out in an isothermal reactor can be summarized as follows. 

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