Arrhenian behavior

Experimentally, the reaction is found to be third order with reaction law of d / df=kii5pS[0] [02]. From the reaction law, it seems that the reaction is an elementary reaction. However, itwas found (Bamford and Tipper, 1972, p. 169) that kii5 = T exp(-0.187 + 1000/T) for 293 reaction mechanism that involves chain reactions that can explain the apparent negative activation energy is as follows. Suppose the above reaction is accomplished by the following two elementary reactions ... 

The degree of curvature of viscosity/temperature plots can vary over a wide range due to variations in the value of Tq relative to Tg. If To is equal to zero, the viscosity/temperature curve will exhibit Arrhenian behavior over the entire viscosity region, from very fluid liquid to the transformation range, with a single value for AH. On the other hand, as To approaches Tg, the curvature will increase and the difference between AH, for the fluid melt and in the transformation region will become very large. 

Zentel et al were also first to observe another high-frequency DR process in an unoriented mesomorphic sample. It appears at frequencies above the (5-process and shows a very broad absorption curve. The temperature dependence demonstrates non-Arrhenian behavior, i.e. an increase in the activation energy with decreasing temperature. It was assigned to the micro-Brownian segmental dynamics of the backbone, i.e. the dynamic glass transition process, and termed the a-process. ... 

Thus, at a reduced temperature (To/Tm) of approximately 0.45 the viscosity of non-Arrhenian oxide liquids tend to infinity. Caillot et al. [3] have also shown that the viscosity of a variety of liquids diverge at a reduced temperature of 0.5. This behavior is predicted by both free-volume and entropy theories of glass transition [1]. 

The HDL and LDL phases are also expected to have different rheology and relaxation behavior. In particular, the high-entropy phase has a larger configurational entropy and is thus expected to be more fragile with a strongly curved log - 1/ T relation. The lower entropy liquid stabilized at low T is most likely to be the LDL phase, that more closely approximates an Arrhenian viscosity-temperature... 

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