Most reservoir fluids contain heavy paraffinic compounds that may precipitate as a solid or solid like material called wax if the fluid is cooled down. Wax precipitation is a phenomenon of considerable importance in oil industry. An increase in aggregation results in enhanced oil viscosity. This however causes significant negative effects on production, transportation and processing of crude oi...

Assessment of chemical properties can often require a computationally costly sampling of a high-dimensional phase space in order accurately to predict ensemble-averaged values. Molecular mechanics simulations offer an efficient way to sample such ensembles, with the quality of the results depending on the ability of the force field adequately to describe the energetics of the system under the c...

Leukocytes roll along the endothelium of postcapillary venules in response to inflammatory signals. Rolling under the hydrodynamic drag forces of blood flow is mediated by the interaction between selectins and their ligands across the leukocyte and endothelial cell surfaces. Here we present force-spectroscopy experiments on single complexes of P-selectin and P-selectin glycoprotein ligand-1 by ...

There are several facets to our interest in temperature, solvent, and isotope effects on NMR chemical shifts. Excepting molecular beam studies, the application of NMR to the elucidation of molecular structure and mechanisms of molecular reactions nearly always involves observations of molecules in some environment. Before NMR can be used to obtain structural and mechanistic information unambigu...

Tetracyclines (Tcs) are an important family of antibiotics that bind to the ribosome and several proteins. To model Tc interactions with protein and RNA, we have developed a molecular mechanics force field for 12 tetracyclines, consistent with the CHARMM force field. We considered each Tc variant in its zwitterionic tautomer, with and without a bound Mg(2+). We used structures from the Cambridg...

the virial coefficients can be obtained from statistical mechanics in connection with the intermolecular potentials. the intermolecular potential of polyatomic molecules is usually assumed to consist of a spherically symmetric component plus a contribution due to asphericaity of the molecular charge distribution. in this study, the second virial coefficients have been calculated for n2, co and ...

AbstractThe research, entitled “The Effect of Using Prezi Desktop Learning Media on Students Outcomes Intermolecular Force Material”, was conducted in class X IPA MAS Ulumul Qur’an Banda Aceh City. The purpose this study to analyze the affect using learning media outcomes, describe student activities and responses applied intermolecular forces material. This used a quantitative approach with qu...