We have formulated a general approach for transforming an analytical equation of state ~EOS! into the crossover form and developed a generalized cubic ~GC! EOS for pure fluids, which incorporates nonanalytic scaling laws in the critical region and in the limit r→0 is transformed into the ideal gas equation EOS. Using the GC EOS as a reference equation, we have developed a generalized version of...

For binary mixtures with fixed concentrations of the species, various relationships between the surface tensions and the concentrations are briefly reviewed.

Using molecular dynamics (MD) simulations, a new approach based on the behavior of pressurized water out of a nanopore (1.3-2.7 nm) in a flat plate is developed to calculate the relationship between the water surface curvature and the pressure difference across water surface. It is found that the water surface curvature is inversely proportional to the pressure difference across surface at nano...

background and objectives: biosurfactants are surface active agents with broad range commercial applications in various industries and have considerable advantages over their chemical counterparts. materials and methods: in this study, bacteria were isolated from contaminated and uncontaminated soil and selected during preliminary screening using hemolytic activity, oil spreading and oil collap...

[1] The transfer of volatiles from the Earth’s interior to the atmosphere occurs through degassing of magma, the dynamics of which assert a significant control on volcanic eruptions. The first and most critical step in degassing is the nucleation of gas bubbles, which requires that a sufficient number of volatile molecules cluster together to overcome the free energy associated with the formati...

The interface tension of a smectic liquid crystal with respect to a surrounding ionic surfactant solution is investigated at concentrations above and below the critical micelle concentration (cmc). A simple measurement technique has been developed recently [Phys. Chem. Chem. Phys., 2013, 15, 7204], based on the geometrical analysis of the shape of smectic bubbles in water that are deformed by t...

Pancreatic lipase requires colipase, a protein cofactor, to counteract the in vitro inhibition by bile salt. Lipase activity is inhibited by nonsteroidic detergents regardless of their charge and structure. Detergent-inhibited lipase is reactivated by colipase but in all cases activation is limited to a narrow range of detergent concentration. Complementary studies on the bile salt and detergen...

“In the thermodynamic limit the canonical and the microcanonical ensemble are equivalent in all details and generality. ” Statements like this are found in many textbooks of statistical thermodynamics. It is the purpose of this contribution to show that this is not so, and, more importantly, that the microcanonical ensemble allows for significant insight into the mechanism of first order phase-...

Equilibrium properties of dilute binary fluid mixtures are studied in two-phase states on the basis of a Helmholtz free energy including the gradient free energy. The solute partitioning between gas and liquid (Henry's law) and the surface tension change Delta gamma are discussed. A derivation of the Gibbs law Delta gamma = -T Gamma is given with Gamma being the surface adsorption. Calculated q...