Accelerated and stress stability data is often used to predict shelf life of pharmaceuticals. Temperature, combined with humidity accelerates chemical decomposition and the Arrhenius equation is used to extrapolate accelerated stability results to long-term stability. Statistical estimation of the humidity-corrected Arrhenius equation is not straightforward due to its non-linearity. A two stage...

Molecular dynamics simulations have been used extensively to model the folding and unfolding of proteins. The rates of folding and unfolding should follow the Arrhenius equation over a limited range of temperatures. This study shows that molecular dynamic simulations of the unfolding of crambin between 500K and 560K do follow the Arrhenius equation. They also show that while there is a large am...

The purpose of this article is to trace the origins of the Arrhenius equation and, in the light of the extensive data on the temperature dependence of reaction rates, assembled in just over a century of experimental endeavor, to assess in what ways its status has changed over the period since it was first proposed. The systematic study of the kinetics of chemical reactions commenced ( I ) mid-w...

Conservation and cooking of foods can be used by students and instructors to demonstrate a fundamental relation of chemical kinetics, the Arrhenius equation. By plotting the logarithms of available conservation and cooking times versus the corresponding inverse temperatures, apparent activation energies for both the deterioration and the cooking of foods of various compositions can be obtained....

The widely used Arrhenius equation describes the kinetics of simple two-state reactions, with the implicit assumption of a single transition state with a well-defined activation energy barrier DeltaE, as the rate-limiting step. However, it has become increasingly clear that the saddle point of the free-energy surface in most reactions is populated by ensembles of conformations, leading to nonex...

Many articles have been published on the uncertainty analysis of high temperature gas kinetic systems that are based on detailed reaction mechanisms. In all these articles a temperature independent relative uncertainty of the rate coefficient is assumed, although the chemical kinetics databases suggest temperature dependent uncertainty factors for most of the reactions. The temperature dependen...

The velocity of growth, taken as the reciprocal of the time required to attain a given size or stage of development, obeys with some exactness the Arrhenius equation for relation to temperature. The values of micro, and the type of "breaks" found in the curves connecting velocity and temperature, are similar to those found in the case of various other vital activities. More precise data, partic...

The compressibility and heat of reaction influence on the scalar mixing in decaying isotropic turbulence and homogeneous shear flow are examined via data generated by direct numerical simulations (DNS). The reaction is modeled as one-step, exothermic, irreversible and Arrhenius type. For the shear flow simulations, the scalar dissipation rate, as well as the time scale ratio of mechanical to sc...

The respiration rate of green capsicum cv. ‘Swarna’ fruits harvested at mature green stage were determined under closed system at 10, 15 and 20 oC temperatures. A simple Michaelis-Menten kinetic model coupled with Arrhenius-type equation, which describes temperature as a function of respiration rate, was used to model the respiration rate of capsicum. The respiration rate model parameters at de...