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...

Wepresent a revised formof the energy balance for the coupled thermodynamics of liquid water flowing in porousmedia and give examples of situations where a commonly used formulation based on transport of enthalpy leads to erroneous results. Assuming negligible contribution from kinetic energy as well as sources and sinks such as energy from radioactive decay, total energy conservation is reduce...

Solutes added to solutions often dramatically impact molecular processes ranging from the suspension or precipitation of colloids to biomolecular associations and protein folding. Here we revisit the origins of the effective attractive interactions that emerge between and within macromolecules immersed in solutions containing cosolutes that are preferentially excluded from the macromolecular in...

The heat of vaporization of a pure substance at its normal boiling temperature is a very important property in many chemical processes. In this work, a new empirical method was developed to predict vaporization enthalpy of pure substances. This equation is a function of normal boiling temperature, critical temperature, and critical pressure. The presented model is simple to use and provides an ...

An enthalpy-balance fuel-grain regression model is presented. The regression model, based on the longitudinally averaged fuel recession rates, is shown to accurately predict the chamber pressure, thrust and specific impulse performance of small and medium scale hybrid rocket motors. The key to the model predictions is the longitudinal enthalpy balance between the fuel grain heat of ablation and...

There are several examples of heuristic rules first proposed from empirical observation, which eventually earned physicochemical validity after the fundamental derivation of a posteriori. This may be the case of Sherwood’s plot – for which a sound rationalization from first principles, entailing enthalpy and mass balances, is provided here; it applies to (fine) chemicals undergoing concentr...

Modern instrumentation for calorimetry permits direct determination of enthalpy values for binding reactions and conformational transitions in biomolecules. Complete thermodynamic profiles consisting of free energy, enthalpy, and entropy may be obtained for reactions of interest in a relatively straightforward manner. Such profiles are of enormous value in drug design because they provide infor...