AKt;TRACT From their isothermal experiments, Murray and White drew the conclusion that the dehydration reaOions of clays are first-order with a rate factor of Arrhenius form. The object of this paper is to discuss whether differential thermal analysis can be used to confirm or refute this hypothesis. The problem, previously considered by Murray and White, of a sample heated at a constant rate t...

High-level ab initio molecular orbital theory calculations have been used to calculate the rate coefficients and Arrhenius parameters for dimer models of the propagation steps for the free-radical homopolymerization of methyl acrylate and vinyl acetate at 298.15 K. Gas-phase Arrhenius parameters, as calculated under the hindered rotormodel, showed large deviations from the corresponding solutio...

The dielectric spectra of most simple liquids are characterized by two relaxation processes: (i) the alpha-process, an intense, broad non-Debye relaxation with a non-Arrhenius temperature dependence and (ii) a beta process, evident mainly below the glass transition and having nearly Arrhenius temperature behavior. However, the dielectric spectra of monoalcohols show three processes: two that re...

Rate coefficients are reported for the gas-phase reaction of the hydroxyl radical (OH) with C2HCl3 (k(1)) and C2Cl4 (k2) over an extended temperature range at 740+/-10 Torr in a He bath gas. These absolute rate measurements were accomplished using a laser photolysis/laser-induced fluorescence (LP/LIF) technique under slow flow conditions. The simple Arrhenius equation adequately describes the l...

This study has modeled the rheological behavior of thermosonic extracted pink-fleshed guava, pink-fleshed pomelo, and soursop juice concentrates at different concentrations and temperatures. The effects of concentration on consistency coefficient (K) and flow behavior index (n) of the fruit juice concentrates was modeled using a master curve which utilized the concentration-temperature shifting...

Recombinant thermostable direct hemolysin from Grimontia hollisae (Gh-rTDH) exhibits paradoxical Arrhenius effect, where the hemolytic activity is inactivated by heating at 60 °C but is reactivated by additional heating above 80 °C. This study investigated individual or collective mutational effect of Tyr53, Thr59, and Ser63 positions of Gh-rTDH on hemolytic activity, Arrhenius effect, and biop...

The stress-strain data of 20MnNiMo alloy were collected from a series of hot compressions on Gleeble-1500 thermal-mechanical simulator in the temperature range of 1173 ∼ 1473 K and strain rate range of 0.01 ∼ 10 s(-1). Based on the experimental data, the improved Arrhenius-type constitutive model and the artificial neural network (ANN) model were established to predict the high temperature flow...

On decreasing the temperature T , supercooled water and other tetrahedral network-forming liquids, such as BeF2 or SiO2, appear to display a dynamic crossover from non-Arrhenius dynamics (with T -dependent activation energy) to Arrhenius dynamics (with constant activation energy). Simulations for water models show that this crossover occurs on crossing the Widom line TW (P ), the locus of maxim...

Mycoplasmas exhibit a novel, substrate-dependent gliding motility that is driven by approximately 400 "leg" proteins. The legs interact with the substrate and transmit the forces generated by an assembly of ATPase motors. The velocity of the cell increases linearly by nearly 10-fold over a narrow temperature range of 10-40 degrees C. This corresponds to an Arrhenius factor that decreases from a...

The nature of the CH 2 Cl 2 neutral/acidic hydrolysis reaction from ambient to supercritical conditions (25 to 600°C at 246 bar) is explored. Of primary interest is the effect of the changing dielectric behavior of the water solvent over this temperature range on this reaction. Experiments reveal that significant CH 2 Cl 2 hydrolysis occurs under subcritical temperatures, while relatively littl...