Catalytic activity of catalase (CAT, EC 1.11.1.6), immobilized on carbon black NORIT and soot PM-100, with respect to decomposition of dibenzoyl peroxide (BPO) in non-aqueous media (acetonitrile and tetrachloromethane), was investigated with a quantitative UV-spectrophotometrical approach. Progress of the above reaction was controlled by selected kinetic parameters: the apparent Michaelis const...

The enzymic reactions of ectothermic (cold-blooded) species differ from those of avian and mammalian species in terms of the magnitudes of the three thermodynamic activation parameters, the free energy of activation (DeltaG()), the enthalpy of activation (DeltaH()), and the entropy of activation (DeltaS()). Ectothermic enzymes are more efficient than the homologous enzymes of birds and mammals ...

the oxidation of complexes of ti(iii), (til6)3+ (l=ur, meur, dmeur, deture, n-bu-ur, and phur), by iodine as i3- in ethanol and acetonitrile solutions, appears to proceed as a second order reaction and is much faster in ethanol solution (where solvolysis occurs) than in acetonitrile. the enthalpy of activation appears to decrease as ligand's size increases which suggest that the kinetic stabili...

Transmetalation is the rate-limiting step. [R-Pd-Ar] was suggested to be the resting species from the kinetic studies. Quantitative measurement of the transmetalation of ArZnCl with [R-Pd-Ar] from a live Pd-catalysed oxidative coupling reaction was conducted and the corresponding activation enthalpy was determined as 12.3 kcal mol(-1).

Internal friction (IF) was measured in two non-stoichiometric Ni2MnGa alloys. Several IF peaks attributed to some restructuring of the martensitic lattice were observed below Ms. From the strain dependence of IF, the activation enthalpy for movement of twin boundaries between martensitic domains was estimated to be equal to 0.02–0.04 eV. 2003 Acta Materialia Inc. Published by Elsevier Ltd. All ...

We have performed a detailed study of the thermodynamics of the titration process in an isothermal titration calorimeter with full cells. We show that the relationship between the enthalpy and the heat measured is better described in terms of the equation Delta H = W(inj) + Q (where W(inj) is the work necessary to carry out the titration) than in terms of DeltaH = Q. Moreover, we show that the ...