Thermodynamic analysis of thermal measurements in thermoelastic martensitic transformations

The kinetics of the γ → α phase transformation in Fe-Mn alloys with low Mn contents was studied using differential scanning calorimetry. Analysis of the measured heat capacity yielded both the austenite fractions as a function of temperature as well as the enthalpy difference between ferrite and austenite which decreases with increases in both the temperature and the Mn concentration. The transformation was modelled using an interface controlled growth model. It was assumed that the interface velocity is proportional to the chemical potential difference of the Fe lattice. The interface mobility has a simple exponential temperature dependence. Taking into account the austenite grain size distribution, the activation energy and the pre-exponential factor for the interface mobility were estimated from the heat effects at 140 kJ mol−1 and 58 mm mol J−1 S−1 respectively.

Kinetics of γ → α phase transformation in Fe-Mn alloys containing low manganese

Techniques and Theory of Titration Calorimetry.- Applications of Titration Calorimetry.- Microcalorimetry.- Differential Scanning Calorimetry.- An Oxygen Flow Calorimeter for Determining the Heating Value of Kilogram-Size Samples of Municipal Solid Waste.- Thermogenesis by Heat Conduction Calorimetry.- The Measurement of Vapour Pressure.- The Use of a Simultaneous Torsion and Mass-Loss Effusion Apparatus for Determining Vapour Pressures And Enthalpies Of Sublimation.- Vaporization Studies by Knudsen Cell-Mass Spectrometry and Thermodynamic Stability of High Temperature Gaseous Species.- Transpiration Mass Spectrometry - A New Thermochemical Tool.- Thermodynamic Activity and Vapor Pressure Models for Silicate Systems Including Coal Slags.- Metal-Ligand Heats and Related Thermodynamic Quantities by Titration Calorimetry.- Measurement of Complexing Constants and Enthalpies of Complexing by Batch Calorimetry.- Metal Ligand Bond Strengths and Bonding Theory.- Thermochemistry of ?-diketones and metal-?-diketonates. Metal-oxygen bond enthalpies.- Thermochemistry of Metal-Polyamine Complexes.- Thermochemistry of Main-Group Organometallic Compounds.- Experimental Thermochemistry of Transition-Metal Organometallic Compounds.- Thermochemistry of Molecular Transition Metal Compounds.- Measurement of Enthalpies of Solution of Electrolytes.- Hydrophobic Hydr ation of Alkylammonium Bromides in Aqueous Mixed Solvents.- Solvation Of Alcohols, Amines, Ureas and Amides in Mixed Solvents.- Microcalorimetry as an Analytical Tool In Biology.- Application of Calorimetry to the Life Science.- Superhelicity and Energetics Of Structural Transitions Of Nucleic Acids.- Calorimetric Studies in Binding Reactions In BiochemistrY.- Cellular Thermochemistry: Resting State and Stimulation.- Differential Scanning Calorimetry Applications to Protein Solutions.- Thermochemistry of molecules, molecule-ions, and free radicals. Factors influencing bond energies in these species.- Experimental Methods to Study the Thermochemistry of Gas Phase Ions and Ion-Molecule Reactions.- The Thermochemistry of Gas Phase Ion-Molecule Reactions.- The Application of Low-Temperature Calorimetry to Some Contemporary Problems In Solid State Chemistry.- Thermodynamics of Crystals - 1982.- Calorimetry of Phase, Schottky and Other Transitions.- Thermophysics of Mineral And Rock Systems.- Computerized Adiabatic Thermophysical Calorimetry.- Lectures on Thermochemistry and Kinetics.- Barriers to Internal Rotation in Inorganic Species.- Critical Evaluation of Thermodynamic Data - A Research Activity.- Thermochemistry Today and Its Role in the Immediate Future.- List of Participants.

Thermochemistry and its applications to chemical and biochemical systems : the thermochemistry of molecules, ionic species, and free radicals in relation to the understanding of chemical and biochemical systems

Isothermal titration calorimetry (ITC) has long been used for kinetic studies in chemistry, but this remained confined to enzymatic studies in the biological field. In fact, the biological community has long had the tendency of ignoring the kinetic possibilities of ITC considering it solely as a thermodynamic technique, whereas surface plasmon resonance is seen as the kinetic technique par excellence. However, the primary signal recorded by ITC is a heat power which is directly related to the kinetics of the reaction. Here, it is shown how this kinetic signal can be recovered by using kinITC, the kinetic extension of ITC. The theoretical basis of kinITC is detailed for the most common situation of a second-order reaction A+B Ω C characterized by kinetic parameters kon, koff. A simplified kinITC-ETC method based upon the determination of an "Equilibration Time Curve" (ETC) is presented. The ETC is obtained by automatic determination of the "effective end" of each injection. The method is illustrated with experimental results with a comparison to Surface Plasmon Resonance (SPR) data. kon values were obtained in a wide range, from 10(3) to 0.5×10(6) M(-1) s(-1). All procedures were implemented in the program AFFINImeter (https://www.affinimeter.com/).

Jean-Luc Macqueron

Papers

Traitement du signal en microcalorimétrie: applications en cinétique et en thermodynamique