Quantitative analysis of the synergistic effect of Au nanoparticles on SnO2–rGO nanocomposites for room temperature hydrogen sensing

The accelerating effect of gold additives on hydrogen sensing was quantitatively studied through Arrhenius analysis.

The role of mid-gap states in all-inorganic CsPbBr3 nanoparticle one photon up-conversion

CsPbBr3 nanoparticles that have been treated with NH4SCN to produce essentially trap-free surfaces show an increase of one photon up-conversion quantum yield with little change to the up-conversion energy of activation, as estimated using an Arrhenius analysis.

Sequential allosteric mechanism of ATP hydrolysis by the CCT/TRiC chaperone is revealed through Arrhenius analysis

Knowing the mechanism of allosteric switching is important for understanding how molecular machines work. The CCT/TRiC chaperonin nanomachine undergoes ATP-driven conformational changes that are crucial for its folding function. Here, we demonstrate that insight into its allosteric mechanism of ATP hydrolysis can be achieved by Arrhenius analysis. Our results show that ATP hydrolysis triggers sequential ‟conformational waves.” They also suggest that these waves start from subunits CCT6 and CCT8 (or CCT3 and CCT6) and proceed clockwise and counterclockwise, respectively.

THERMOGRAVIMETRIC ANALYSIS OF THE KINETICS OF THE REACTION OF ALKOXYSILANE WITH SILICA

ABSTRACT The surface functionalization of silica by alkoxysilane can improve its dispersion into polymers by beneficially modifying interparticle and particle–polymer interactions. Thermogravimetric analysis (TGA) has been used to study the kinetics of binding a bifunctional alkoxysilane onto silica over the temperature range of 50 to 110 °C. Derivative TGA curves of the reacted silica show distinct peaks, which correspond to the alkoxysilane bound to one or two surface silanol sites. Binding at two silanol sites is postulated to occur in a two-step series reaction model. An Arrhenius analysis for the alkoxysilane binding reactions shows that the activation energies of the two reaction steps are similar, which is expected because the alkoxysilane contains two identical binding groups. This work demonstrates the suitability of the TGA technique to investigate the reaction kinetics for modifying the surface of silica.

Effects of pH on the activity and structure of choline oxidase from Alcaligenes species.

A reversible effect of pH on the ionization of amino-acid residues at the active center of choline oxidase was observed near the optimum pH (8). Inactivation of choline oxidase took place in the pH ranges 3-6 and 9-11, in which irreversible changes in the structure occur leading to the enzyme inactivation. The first order rate constants of the enzyme's inactivation at various pH values were estimated for the irreversible changes. The Arrhenius analysis revealed no significant changes in the activation enthalpy, while an increase in the activation entropy reflected an increase in the conformational freedom.