Biomedical subjects

R Mankin

Publications and source records attributed to R Mankin.

4 recordsLinked to original sources

PubMed2001

Correlation ratchets: four current reversals and disjunct "windows".

Multinoise correlation ratchets with a simple sawtooth potential are considered. It is proved that in the case of symmetric nonequilibrium three-level Markovian noise the direction and value of the induced current can be controlled by thermal noise. Moreover, it is established that four current reversals (CRs) occur and that for the CRs there exist characteristic disjunct "windows" in temperature and switching rate as control parameters. The necessary and sufficient conditions for the existence of the above effects are given and can be used in particle separation techniques.

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PubMed2001

Constructive role of temperature in ratchets driven by trichotomous noise.

The dynamics of an overdamped Brownian particle in a piecewise linear spatially periodic potential subjected to both thermal and colored symmetric three-level Markovian (trichotomous) noises is investigated. In the case of large flatness, the exact formula for the stationary current is presented. The dependence of the current on the system parameters is analyzed and the conditions for the occurrence of current reversals are found. It is shown that the direction and value of the current can be controlled by a thermal noise. Asymptotic formulas for the current for various limits of the noise parameters are calculated and compared with the results of other authors. For small noise amplitudes, it is demonstrated that the temperature at which the current is maximized is proportional to the height of the potential barrier, being a slowly varying function of the other system parameters.

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PubMed2000

Current reversals in ratchets driven by trichotomous noise

The colored three-level Markovian noise-driven nonequilibrium dynamics of overdamped Brownian particles in a spatially periodic asymmetric potential (ratchet) is investigated. An explicit second-order linear ordinary differential equation for the stationary probability density distribution is obtained for the process. In the case of a piecewise linear potential with an additive three-level (trichotomous) noise the exact formula for the stationary current is presented. The dependence of the current reversals on the noise parameters is investigated in detail and illustrated by a phase diagram. Asymptotic formulas for the current for various limits of the noise parameters are found and compared with the results of other authors. Applications to the fluctuation-induced separation of particles are also discussed.

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PubMed1999

Trichotomous noise-induced transitions.

A nonlinear one-dimensional process driven by a multiplicative exponentially correlated three-level Markovian noise (trichotomous noise) is considered. An explicit second-order linear ordinary differential equation for the stationary probability density distribution is obtained for the process. In the case of a linear process with an additive trichotomous noise the exact formula for the steady-state distribution is obtained. The well-known dichotomous noise can be regarded as a special case of the trichotomous noise. As a rule, the system variable has three specific values where the probability density distribution can be singular. For the case of the Hongler model the dependence of the behavior of the stationary probability density on the noise parameters is investigated in detail and illustrated by a phase diagram. Applications to the Gompertz and Verhulst models are also discussed.

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