Biomedical subjects

Tamás Kristóf

Publications and source records attributed to Tamás Kristóf.

5 recordsLinked to original sources

PubMed2005

Magnetic properties in monolayers of a model polydisperse ferrofluid.

The influence of polydispersity on the equilibrium properties of monolayers of three-dimensional dipolar spheres with short-range repulsive interactions is studied by means of Monte Carlo simulations and a high field approximation perturbation theory. The particle distribution in the simulations is realized in the semigrand ensemble by tuning appropriately the underlying particle distribution density. The magnetization curves are calculated as functions of density and temperature, and the obtained results are compared with the data determined in a monodisperse equivalent of the system. In-plane and out-of-plane initial magnetic susceptibilities are determined using external fields applied parallel or normal to the monolayer plane. Susceptibility data for the true two- and three-dimensional counterparts of the system are also calculated for comparison. Our findings for the magnetic properties can partly be explained by the structural characteristics obtained from the simulations.

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PubMed2005

Heat capacity in a model polydisperse ferrofluid with narrow particle size distribution.

The influence of polydispersity on the phase equilibrium properties and the heat capacity of a dipolar system with additional short-range (repulsive + attractive) interactions (modeled by a shifted Lennard-Jones pair potential) is studied by means of a Monte Carlo scheme. The particle distribution of the investigated system is realized in the semigrand ensemble by tuning appropriately the underlying particle distribution density. The phase coexistence and heat capacity data are calculated with and without an applied magnetic field, and the obtained results are compared with the data determined in a monodisperse equivalent of the system.

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PubMed2004

Phase separation in model polydisperse ferrofluids.

The influence of polydispersity on the phase equilibrium properties of a dipolar system with additional short-range (repulsive+attractive) interactions (modeled by a shifted Lennard-Jones pair potential) is studied by means of Gibbs ensemble Monte Carlo simulations. The critical temperature and density as well as the magnetization at the critical point are calculated as a function of the applied magnetic field, and the obtained results are compared with the data determined in a monodisperse equivalent of the system.

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PubMed2004

Phase separation in mixtures of Yukawa and charged Yukawa particles from Gibbs ensemble Monte Carlo simulations and the mean spherical approximation.

The phase equilibrium of mixtures of Yukawa and charged Yukawa particles is studied by means of Gibbs ensemble Monte Carlo (GEMC) simulation method and the mean spherical approximation (MSA). The strength of the Coulomb energy compared to that of the Yukawa attraction is characterized by a coupling constant. For low coupling constants a classical vapor--liquid phase separation appears with a good agreement between GEMC and the MSA. For high coupling constant, a phase separation between a salt poor and a salt rich phase occurs that resembles the phase equilibrium behavior of the solvent primitive model.

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PubMed2003

Magnetic properties and structure of polydisperse ferrofluid models.

The influence of polydispersity on the equilibrium properties of dipolar systems with short range repulsive interactions (modeled by a shifted and truncated Lennard-Jones pair potential) is studied by means of canonical Monte Carlo simulation and a high field approximation perturbation theory. The particle concentrations and the average magnetic moments of the investigated systems are typical of real ferrofluids. The magnetization curves are calculated and the microstructures are analyzed as a function of density, and the obtained results are compared with the data determined in the monodisperse equivalents of the systems. At weak and moderate magnetic fields the magnetization is found to be generally higher in the polydisperse system than in the corresponding monodisperse one. Our findings for the magnetic properties can partly be explained by the structural characteristics obtained from the simulations.

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