Abstract Recently, one of the authors suggested calculating void fraction, an essential element in thermalhydraulics, working with the ‘thermodynamic’ quality instead of the usual ‘flow’ quality. However, the standard heat balance is currently stated as a function of the ‘flow’ quality. Therefore, we should search a new energy balance between the mixture enthalpy, based on ‘thermodynamic’ quali...

A study of the [C6 H6 Ir(PH3 )3 ]+ iridatropylium cation structure based on frontier orbital analysis, thermodynamic analysis, and natural bond orbital (NBO) theory is the main aim of the present research. Also, HOMO, LUMO energies, hardness, electrophilicity and chemical potential were calculated. Structural analysis indicated the optimized geometry shows a good agreement with the experimental...

The standard molar enthalpy of formation of the ionic liquid 1-butyl-1-methylpyrrolidinium dicyanamide has been determined at 298 K by means of combustion calorimetry, while the enthalpy of vaporization and the mass spectrum of the vapor (ion pairs) have been determined by temperature-programmed desorption and line of sight mass spectrometry. Ab initio calculations for 1-butyl-1-methylpyrrolidi...

Current Isothermal Titration Calorimetry (ITC) data in the literature have relatively high errors in the measured enthalpies of protein-ligand binding reactions. There is a need for universal validation standards for titration calorimeters. Several inorganic salt co-precipitation and buffer protonation reactions have been suggested as possible enthalpy standards. The performances of several com...

Additives to polymeric materials can lead to appreciable changes in the rates of relaxation and reaction in these mixtures that can profoundly alter material properties and function. We develop a general theoretical framework for quantifying changes in the "high-frequency" relaxation dynamics of mixtures based on classical transition state theory, in conjunction with mathematical statements reg...

During the past year the activities of the Chemical Thermodynamics Data Center and the JANAF Thermochemical Tables project have been combined to obtain an extensive collection of thermodynamic information for many chemical species, including the elements. Currently available are extensive bibliographic collections and data files of heat capacity, enthalpy, vapor pressure, phase transitions, etc...

The binding enthalpy of a triphenylphosphine ligand in Ru(CO)Cl(PPh(3))(3)(CHCHPh) is studied with "standard" (BP86 and B3LYP), dispersion-corrected (B3LYP-D and B97-D), and highly parametrized (M05 and M06 series) density functionals. An appropriate treatment of noncovalent interactions is mandatory because these turn out to account for a large fraction of the metal-ligand interaction energy. ...

Thermal unfolding curves have been measured for a series of short alanine-based peptides that contain repeating sequences and varying chain lengths. Standard helix-coil theory successfully fits the observed transition curves, even for these short peptides. The results provide values for sigma, the helix nucleation constant, delta H0, the enthalpy change on helix formation, and for s (0 degree C...

The heat capacity of a Ni36Nb24Zr40 glassy alloy was measured by adiabatic calorimetry from 13 to 300K. The smoothed values of molar heat capacity were calculated from the data using a least-squares method. The standard enthalpy, entropy, and Gibbs energy were calculated from the smoothed heat capacity values. Assuming Hð0Þ 1⁄4 0 and Sð0Þ 1⁄4 0 at 0K, the heat capacity, enthalpy, entropy, and G...

The chemical reactivity of fully maleylated horse heart cytochrome c with oxidants, reductants, and iron ligands was studied in the presence and absence of MgCl2. In the absence of salt, the partly unfolded protein reacts rapidly with cyanide in the ferric state (k = 235 M-1s-1); the reaction is exothermic (delta H = -9.4 kcal/mol) and entropically unfavored (delta S = -7.0 e.u.). In 0.01 M MgC...