A TWO-BODY POTENTIAL ENERGY FUNCTION FOR MERCURY IS DETERMINED BY MATCHING THE RADIAL DISTRIBUTION FUNCTION, OBTAINED FROM SIMULATION, WITH THAT OF EXPERIMENT. THE PAIR POTENTIAL IS USED TO SIMULATE LIQUID AND VAPOR MERCURY OVER A WIDE RANGE OF TEMPERATURES AND PRESSURES. THE AGREEMENT OF CALCULATED PROPERTIES WITH EXPERIMENT IS GOOD.

INTRODUCTION: IN ATOMISTIC SIMULATIONS THE TIME SCALES AND THE LENGTH SCALES ARE LIMITED TO NANOSECONDS AND NANOMETERS, RESPECTIVELY. THEREFORE, ONE HAS TO PAY A HUGE COMPUTATIONAL COST IN THE CASE OF LARGE SYSTEMS; FOR EXAMPLE, IN THE CASE OF SIMULATION OF BIOLOGICAL SYSTEMS, IN WHICH THE WATER MOLECULES PLAY A CENTRAL ROLE BUT THE BEHAVIOR OF WATER ITSELF IS NOT OF PRIMARY INTEREST. A POSSIBLE SOLUTION TO THIS PROBLEM IS THE DEVELOPMENT OF A FASTER METHOD, IN WHICH THE NUMBER OF DEGREES OF FREEDOM IS REDUCED TO SPEED UP THE COMPUTATIONS. COARSE GRAINING IS A METHOD, DESIGNED TO REDUCE THE COMPUTATIONAL COST AT THE EXPENSE OF LOSING THE INFORMATION HIDDEN IN THE FASTER DEGREES OF FREEDOM, WHICH ARE COARSENED. IN THIS METHOD, A GROUP OF ATOMS FORM A SUPER-ATOM (BEAD), AND THUS DECREASE THE COMPUTATIONAL COST.

MOLECULAR DYNAMICS SIMULATIONS ARE PERFORMED ON POLYAMIDE-6, 6+CARBON NANOTUBE COMPOSITES. TO EXAMINE THE EFFECT OF SURFACE CURVATURE ON THE NANOCOMPOSITE PROPERTIES, POLYMER-NANOTUBES SYSTEMS, CONTAINING NANOTUBES OF DIFFERENT DIAMETERS (CURVATURES) ARE SIMULATED. A SNAPSHOT OF THE SIMULATION BOX IS SHOWN IN FIGURE 1.THE SIMULATION RESULTS ARE ANALYZED TO DETERMINE ALTERNATION IN THE STRUCTURAL AND DYNAMICAL PROPERTIES OF POLYMER AT THE INTERFACE. THE RESULTS OF OUR SIMULATIONS ARE INDICATIVE OF FORMATION OF LAYERED POLYMER STRUCTURES BESIDE THE NANOTUBE SURFACE.POLYMER CHAINS BESIDE THE SURFACE ARE SHOWN TO ADOPT FLAT CONFORMATIONS. THE HYDROGEN BONDING IN POLYMER IS STUDIED IN DETAIL AND IT IS SHOWN THAT THE CHAINS BESIDE THE SURFACE ARE NOT CAPABLE OF HYDROGEN BOND FORMATION, BECAUSE OF THE GEOMETRICAL RESTRICTIONS. IN ALL CASES AN INTERPHASE THICKNESS AROUND 2.0 NM IS OBSERVED.AN EXAMINATION OF THE POLYMER DYNAMICS AT THE INTERFACE INDICATES THAT DYNAMIC DECELERATION DEPEND ON THE PARTICULAR DYNAMICAL QUANTITY OF INTEREST. FOR EXAMPLE, IN THE CASE OF A SHORT-TIME DYNAMICAL QUANTITY, LIKE HYDROGEN BOND FORMATION/RUPTURE, THE RELAXATION TIME IN CLOSE VICINITY OF THE SURFACE, VARIES A FEW PER CENT (COMPARED TO THE BULK SAMPLE). ON THE OTHER HAND, A SHORT-TIME DYNAMICAL PROPERTY, LIKE THE AUTOCORRELATION OF CHAIN END-TO-END VECTOR, RELAXES SEVERAL ORDERS OF MAGNITUDE SLOWER THAN THE CORRESPONDING BULK QUANTITY.

IN THIS WORK, THE EFFECT OF THE ATTRACTIVE PART OF THE POTENTIAL BETWEEN FLUID AND WALL ON THE PROPERTIES OF WATER CONFINED BETWEEN GRAPHITE SHEETS WAS STUDIED, WE PERFORM MOLECULAR DYNAMICS (MD) SIMULATIONS OF WATER WITH DIFFERENT FORMS OF POTENTIAL BETWEEN FLUID-WALL, WE STUDY THE 12-6 LJ POTENTIAL AND THE 4E (S/R)12 REPULSIVE PART OF THE LJ POTENTIAL WITH DIFFERENT VALUES OF E FOR INTERACTION BETWEEN OXYGEN AND CARBON...

ONE OF THE MOST IMPORTANT TYPES OF ANTIOXIDANTS ARE FLAVONOIDS WHICH CONTAIN FLAVONOLS, FLAVONONES, ISOFLAVONES, ETC. BECAUSE OF THE IMPORTANCE OF QUERCETIN AS AN ANTIOXIDANT, THE PRESENT STUDY PAYS SPECIAL ATTENTION TO THIS COMPOUND OF FLAVONOLS. THE MAIN FOCUS OF THIS INVESTIGATION IS TO EXPLORE STRUCTURAL PROPERTIES OF QUERCETIN BY MOLECULAR DYNAMICS SIMULATION. THE RESULTS SHOW THAT INTERMOLECULAR HYDROGEN BONDS BETWEEN QUERCETIN AND WATER ARE STRONGER THAN WATER-WATER INTERACTIONS. IN ADDITION, INTRAMOLECULAR HYDROGEN BOND IN QUERCETIN IS OBSERVED. ...