A differential-scanning-calorimetric study of the thermal denaturation of a sea-anemone (Radianthus macrodactylus) 8 kDa cytolytic toxin was carried out. The calorimetric traces were found to be irreversible and scan-rate-dependent under the experimental conditions employed. Scan-rate-dependent thermograms were explained in terms of a two-state kinetic model N k -->D, where k is a first-order k...

The processes of defect formation and annealing in fullerene C 60 at T = (4000-6000) K are studied by the molecular dynamics technique with a tight-binding potential. The cluster lifetime until fragmentation due to the loss of a C 2 dimer has been calculated as a function of temperature. The activation energy and the frequency factor in the Arrhenius equation for the fragmentation rate have bee...

In spite of obvious possible sources of disturbance, the "velocity of killing" of organisms at supranormal temperatures, properly determined, tends to adhere to the Arrhenius equation for relation to temperature. Over certain ranges of temperature the relationship between log velocity of killing and 1/T degrees abs. is linear. Interpreted as due to the thermal denaturing of protein, it is possi...

The temperature characteristics (micro) for two activities (heart beat and respiratory movements) studied simultaneously in the same individual organism (Daphnia magna) were always found to differ in magnitude. The type of graph obtained when the frequency of these movements was plotted according to the Arrhenius equation was also distinctly different for each activity. The organism therefore d...

Enzyme hydrolysis kinetic model of inulin by inulinase from Kluyveromyces lactis was established. The corresponding Michaelis-Menten equation model constants were found to be related to temperature through the Arrhenius model. The kinetic model was validated by experimental data and also be utilized to predict the hydrolysis reaction rates of the inulin for substrate concentrations ranging betw...

A thermophilic bacillus with minimal, optimal, and maximal growth temperatures of 40, 64.5, and 72 C, respectively, was isolated from soil. Biochemical and morphological studies place the isolate in group 1 of the classification of Walker and Wolf. After adaption to nitrate broth, the temperature coefficient for growth was found to be 20,400 cal/mol. When the temperature coefficient for growth ...

Low-temperature oxidation of aqueous magnetite nanoparticles to maghemite has been monitored via the loss of near-IR optical absorbance. The kinetics closely follows the diffusion in a sphere model as suggested by previous literature reports. The temperature dependence of the diffusion constant is described by an Arrhenius equation with an activation energy of 21.0 kcal/mol. No intermediate opt...

Thermogravimetric studies of chitin and chitosan in air atmosphere were carried out at six rates of linear increase of the temperature. The kinetics and mechanism of the thermal decomposition reaction were evaluated from the TG data using recommended from ICTAC kinetics committee isoconversional calculation procedure of Kissinger-Akahira-Sunose, as well as 27 mechanism functions. The values of ...