Papers by Author: A. Dawid

Abstract: Excessive amounts of homocysteine in the human body have been considered recently as a factor which increases the risk of developing diseases of the cardiovascular system. The nanosystem composed of homocysteine molecules covering a single walled carbon nanotube have been studied by MD technique. The translational and rotational velocity correlation functions have been calculated for several temperatures, including the physiological temperature of 309 K. The qualitative interpretation of translational and reorientational dynamics of homocysteine molecules in this specific environment is presented.

Abstract: Molecular dynamics (MD) simulations have been made for a cluster of cholesterols localized near the transmembrane protein at the physiological temperature of 310 K. It was observed that the cholesterol molecules form a lodgment on the surface of protein. Additional studies were made of the influence of graphene sheet on several physical observables of cholesterol molecules including: the radial distribution function, the mean square displacement, diffusion coefficient and the linear and angular velocity autocorrelation functions.

Abstract: The molecular dynamics (MD) technique was used to investigate the nano droplet composed of twenty mesogene molecules 4-cyano-4-n-pentylbiphenyl (5CB). The 5CB molecules were treated as rigid bodies, the intermolecular interaction was taken to be the full site-site pairwise additive Lennard-Jones (LJ) potential plus a Coulomb interaction. The radial distribution functions in the temperature range from 150 to 400 K, were calculated as well as the linear and angular velocity autocorrelation functions. In addition the total dipole moment autocorrelation function and dielectric loss of (5CB)22 mesogene cluster were calculated and the liquid crystal ordering in the nanoscale system was studied up to its vaporization temperature.

Abstract: The nanosystem composed of only as few as seven endohedral fullerene K+@C60 molecules was simulated using the MD method. The interaction was taken to be the full site-site pairwise additive Lennard-Jones (LJ) potential, which generates both translational and anisotropic rotational motions of each endohedral fullerene. The atomically detailed MD simulations allow the dynamics of the motion of K+@C60 molecule inside the cluster to be analysed. The radial distribution function, the mean square displacement, the translational velocity correlation functions and the Lindemann index of endohedral fullerene have been calculated for several energies of the nanosystem. The solid/liquid phase transition and the existence of the liquid phase in the endohedral potassium ion fullerene cluster was found.