The solidification behavior of droplets as well as spray-deposit of Al-4.5 wt% Cu alloy is simulated by modeling based on heat flow analysis. The model incorporates droplet dynamics and their thermal states during atomization process. The resultant spray enthalpy is used to analyze heat flow during solidification of the spray deposit. The effect of process variables like atomization pressure, m...

The bond dissociation energy (enthalpy) is also referred to as bond disruption energy, bond energy, bond strength, or binding energy (abbreviation: BDE, BE, or D) . It is defined as the standard enthalpy change of the following fission: R−X → R + X . The BDE, denoted by Do(R−X), is usually derived by the thermochemical equation, Do(R−X) = ∆fH o(R) + ∆fH o(X) – ∆fH o(RX) . The enthalpy of format...

There is overwhelming and incontrovertible petrological and geophysical evidence for the significant role played by mantle-derived mafic magma in the generation and growth of continental crust. Likewise, intrusion of mafic magmas beneath or into continental crust is very likely the major source of enthalpy that drives intracrustal differentiation. A simple dynamical model has been constructed t...

The storage of gases in porous adsorbents, such as activated carbon and carbon nanotubes, is examined here thermodynamically from a systems viewpoint, considering the entire adsorption-desorption cycle. The results provide concrete objective criteria to guide the search for the "Holy Grail" adsorbent, for which the adsorptive delivery is maximized. It is shown that, for ambient temperature stor...

Given the three-dimensional structure of a protein, its thermodynamic properties are calculated using a recently introduced distance constraint model (DCM) within a mean-field treatment. The DCM is constructed from a free energy decomposition that partitions microscopic interactions into a variety of constraint types, i.e., covalent bonds, salt-bridges, hydrogen-bonds, and torsional-forces, eac...

The allosteric coupling free energy between ligands fructose-6-phosphate (Fru-6-P) and phospho(enol)pyruvate (PEP) for phosphofructokinase-1 (PFK) from the moderate thermophile, Bacillus stearothermophilus (BsPFK), results from compensating enthalpy and entropy components. In BsPFK the positive coupling free energy that defines inhibition is opposite in sign from the negative enthalpy term and ...

The excess enthalpy and shear strain behavior of the β-Sn (101) grain boundary containing various amounts of Ag and Cu solute atoms was investigated using molecular simulation. An increase in either type of solute at the interface lowers the excess enthalpy of the grain boundary. The enthalpies of segregation for both solute types are computed as the slope of excess enthalpy of the grain bounda...

Analysis of the experimental binding thermodynamics for approximately 100 protein-ligand complexes provides important insights into the factors governing ligand affinity and efficiency. The commonly accepted correlation between enthalpy and -TΔS is clearly observed for this relatively diverse data set. It is also clear that affinity (i.e., ΔG) is not generally correlated to either enthalpy or -...

Porous materials adsorb H2 through physisorption, a process which typically has a rather low enthalpy of adsorption (e.g. ca. 4 to 7 kJ mol(-1) for MOFs), thus requiring cryogenic temperatures for hydrogen storage. In this paper, we consider some of the issues associated with the accurate characterisation of the hydrogen adsorption properties of microporous materials. We present comparative gra...

Quantifying air–sea exchanges of enthalpy and momentum is important for understanding and skillfully predicting tropical cyclone intensity, but the magnitude of the corresponding wind speed–dependent bulk exchange coefficients is largely unknown at major hurricane wind speeds greater than 50 m s. Since direct turbulent flux measurements in these conditions are extremely difficult, the momentum ...