In this work, the cholesterol concentration in the supercritical (SC) CO2, under working conditions, is calculated by implementing the modified Peng Robinson equation of state (EoS) combined with the Van Der Waals mixing rules. Here, optimisations of the interaction coefficient (kij) between solvent and solute and the solute critical parameters (i.e. critical pressure and temperature) are the m...

In this report we present a general formulation to calculate the van der Waals interaction between two protein molecules in an electrolyte solution using boundary element method of solving linearized Poisson-Boltzmann equation. Our formulation is based upon an inhomogeneous dielectric model of proteins at the residue level. Our results for bovine pancreatic trypsin inhibitor at various relative...

BACKGROUND The response of molecular crystal structures to changes in externally applied conditions such as temperature and pressure are the result of a complex balance between strong intramolecular bonding, medium strength intermolecular interactions such as hydrogen bonds, and weaker intermolecular van der Waals contacts. At high pressure the additional thermodynamic requirement to fill space...

Critical to biological processes such as membrane fusion and secretion, ion-lipid interactions at the membrane-water interface still raise many unanswered questions. Using reconstituted phosphatidylcholine membranes, we confirm here that multilamellar vesicles swell in salt solutions, a direct indication that salt modifies the interactions between neighboring membranes. By varying sample histor...

Molecules held together by van der Waals forces generally posess bond strengths which are -0 1-1.0% of normal chemical bonds, i.e. 0.1-1.0 Kcal/mole (.35-350 cmi ). Such extremely weak bonds exhi~it vibrational frequencies which lie in the far-infrared, eq. 10-100 cm(1000-100 11m). In order to measure vibration-rotation spectra of van der Waals bonds, one must devise a method which possesses ve...

We show that universal properties of a many-atom quantum system exist at a much higher density, or a much shorter length scale, than those implied by traditional theories for a dilute Bose gas. In particular, a universal equation of state at length scale β6 = (mC6/h̄) (corresponding to the van der Waals interaction) is defined and investigated by combining the concept of effective potential, the...

The computer program DOT quickly finds low-energy docked structures for two proteins by performing a systematic search over six degrees of freedom. A novel feature of DOT is its energy function, which is the sum of both a Poisson-Boltzmann electrostatic energy and a van der Waals energy, each represented as a grid-based correlation function. DOT evaluates the energy of interaction for many orie...

Experimental demonstrations of one-dimensional (1D) van der Waals material tellurium (Te) have been presented by Raman spectroscopy under strain and magneto-transport. Raman spectroscopy measurements have been performed under strains along different principle axes. Pronounced strain response along the c-axis is observed due to the strong intrachain covalent bonds, while no strain response is ob...

The robotic manipulation of microscopic objects is disturbed directly by the adhesion between the endeffector and the objects. In the microscale, no reliable model of adhesion is available and currently the behaviour of the micro-objects cannot be predicted before experiments. This paper proposes a new model of adhesion based on the analytical resolution of the coupling between the mechanical d...

The application of the van der Waals equation state to asymmetric nuclear matter is considered in a critical region. corrections pressure and free energy due Fermi statistics are obtained starting from Thomas - entropy expression which ensures fulfilment Nernst theorem. derived account for effective nucleon mass neutron-proton isotopic asymmetry. parameters deduced by taking experimental value ...