Using extensive molecular dynamics simulations, we have investigated the extensivity of the internal energy and entropy as well as the intensivity of temperature and pressure in small thermodynamic systems. Atomic systems consisting of n3 n = 2 3 10 argon-like particles interacting through the Lennard-Jones potential energy function have been studied. It is found that in small systems, contrary...

For the Sturm-Liouville operator L =L,: .VP+ -p” +pv one seeks to reconstruct the coefficient p from knowledge of the sequence of eigen-frequencies (Aj with LJ? =Ajn for some y j # 0). An implementable scheme is: for some N determine pnr so (approximately) pN has minimum norm with eigen-frequencies { A , . . . . .IN/ as given. This is the method ot’ ’generalised interpolation‘ and is shown to g...

This work represents an extended computational study of the Fermi-Pasta-Ulam experiment for the dynamical nature of energy transfer among normal modes. A 2D lattice system with 40 particles is placed on a torus, where each particle is allowed to interact with its six nearest neighbors under the Lennard-Jones potential force law. Trajectories of the particles are analyzed through a Fourier trans...

In Chapter 5 we demonstrated that in the case of the Lennard-Jones fluid, the viscosity, pressure and energy exponents are not fixed values. They depend on state point, namely, the temperature and density. We gave the results of simulations for the exponents varying with temperature and density, and we also found that the relationship can be expressed easily by a linear function of both tempera...

The accurate knowledge of transport properties of pure and mixture fluids is essential for the design of various chemical and mechanical systems that include fluxes of mass, momentum, and energy. In this study we determine the mutual diffusion coefficients of mixtures composed of heptane isomers and nitrogen using molecular dynamics (MD) simulations with fully atomistic intermolecular potential...

We consider the low-density equation of state of a fluid along its critical isotherm. An asymptotically consistent approximant is formed having the correct leading-order scaling behavior near the vapor-liquid critical point, while retaining correct low-density behavior as expressed by the virial equation of state. The formulation is demonstrated for the Lennard-Jones fluid, and models for heliu...

Main problem for Mycobacterium tuberculosis growth is time. This study evaluates the performance of Bact/Alert 3D system for isolates and identification of mycobacteria. 100 clinical specimens from the chest and tuberculosis department were included. All were positive by Lowenstein Jensen (LJ) media in different time. All samples were also tested by Bact/ALERT 3D system for time management stud...

Presented is an improved model for the prediction of phase equilibria and cage occupancy of CH4 and CO2 hydrate in aqueous systems. Different from most hydrate models that employ Kihara potential or Lennard-Jones potential with parameters derived from experimental phase equilibrium data of hydrates, we use atomic site-site potentials to account for the angle-dependent molecular interactions wit...

Using the inherent structure formalism originally proposed by Stillinger and Weber @Phys. Rev. A 25, 978 ~1982!#, we generalize the thermodynamics of an energy landscape that has an ideal glass transition and derive the consequences for its equation of state. In doing so, we identify a separation of configurational and vibrational contributions to the pressure that corresponds with simulation s...