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A new particle size effect
Author(s) -
Kral Hans
Publication year - 1989
Publication title -
chemical engineering and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.403
H-Index - 81
eISSN - 1521-4125
pISSN - 0930-7516
DOI - 10.1002/ceat.270120120
Subject(s) - particle size , particle size distribution , kinetics , isothermal process , separable space , particle (ecology) , thermodynamics , materials science , statistical physics , chemical physics , chemistry , mathematics , physics , classical mechanics , mathematical analysis , geology , oceanography
The sintering effect of highly dispersed metals is the reason for the following phenomena: thermal deactivation, particle size effect, separable or non‐separable kinetics and the isokinetic relationship ( = compensation effect). A comparison of these phenomena reveals a contradiction which can be reconciled by a new particle size effect. This effect is characterized in the following way: The dependence of specific activity on particle size is always connected with a variation of the activation energy, caused by the particle size distribution. Therefore, this effect is referred to as the partical size and distribution effect, P.S.D.E. This new concept describes all the observed phenomena of the conventional partical size effect. Moreover, it is consistent with similar effects such as non‐separable kinetics and the isokinetic relationship. In consequence, the method of isothermal measurement of specific activity is inadequate.