Dependence of Particle Current and Diffusion on the System Parameters in a Model Under-damped Inhomogeneous Periodic Potential System

2021 ◽  
pp. 73-83
Author(s):  
Francis Iawphniaw ◽  
Samrat Dey ◽  
Shantu Saikia
Keyword(s):  
Periodic Potential ◽  
System Parameters ◽  
Potential System ◽  
And Diffusion ◽  
Particle Current

Ratchet Effect and Particle Diffusion in an Underdamped Inhomogeneous Periodic Potential System

2020 ◽  
Vol 7 (1) ◽  
pp. 01-11
Author(s):  
Shantu Saikia ◽  
◽  
Francis Iawphniaw
Keyword(s):  
Periodic Potential ◽  
Thermal Fluctuations ◽  
Particle Dynamics ◽  
Particle Diffusion ◽  
Biological Processes ◽  
Ratchet Effect ◽  
External Bias ◽  
Potential System ◽  
Constructive Work ◽  
Random Fluctuations

Thermal fluctuations or noise assisted particle dynamics in a driven underdamped inhomogeneous periodic potential system is studied. This forms an archetypal model to study different Physical and Biological processes in the microscopic domain. The particles are shown to exhibit directed transport aided by these fluctuations without the application of any external bias. This phenomenon, also known as ratchet effect, is a counterintuitive phenomenon in which systems in the microscopic domain harnesses the energy of the random fluctuations to do constructive work. Also in the presence of random thermal fluctuations or noise, the particles undergo diffusion, the amount of which can be controlled by controlling the different parameters of the system. This can have important technological applications.

scholarly journals EFFICIENCY AND CURRENT REVERSALS IN SPATIALLY INHOMOGENEOUS RATCHETS

2000 ◽  
Vol 14 (15) ◽  
pp. 1585-1591 ◽  
Author(s):  
DEBASIS DAN ◽  
A. M. JAYANNAVAR ◽  
MANGAL C. MAHATO
Keyword(s):  
Friction Coefficient ◽  
Periodic Potential ◽  
Inhomogeneous System ◽  
Noise Strength ◽  
Spatially Inhomogeneous ◽  
Potential System ◽  
Maximum Current ◽  
Spatially Varying

Efficiency of generation of net unidirectional current in an adiabatically driven symmetric periodic potential system is studied. The efficiency shows a maximum, in the case of an inhomogeneous system with spatially varying periodic friction coefficient, as a function of temperature. The ratchet is not most efficient when it gives maximum current. The direction of current may also be reversed as a function of noise strength when, instead, an asymmetric periodic potential is considered.

scholarly journals Modeling of Drug Delivery by A Pump Driven Micro-Needle Array System

2016 ◽  
Vol 10 (1) ◽  
pp. 19-33 ◽  
Author(s):  
Kai Chen ◽  
Min Pan ◽  
Zhi-Gang Feng
Keyword(s):  
Mathematical Model ◽  
Material Properties ◽  
Time Varying ◽  
Diffusion Boundary ◽  
System Parameters ◽  
Micro Pump ◽  
Calculation Results ◽  
Spherical Expansion ◽  
Short Time ◽  
And Diffusion

Background: Micro-needles were proposed as one of the alternatives to deliver drugs painlessly passing through stratum corneum in recent years. In this work, a mathematical model is presented to characterize the in fusion flow of a hollow micro-needle array driven by a micro-pump. Methods: By assuming the injection of each micro-needle undergoes a spherical expansion and diffusion, the model is able to calculate the time-varying expansion radius, and the diffusion boundary, provided that the material properties and the micro-needle system parameters are known. Results and Conclusion: The calculation results show that the expansion caused by the infusion of micro-needles stops and the flow rate drops to zero in a short time. However, the diffusion boundary is much bigger than the expansion and the infusion continues if the surrounding material is absorptive. The experimental results of jet infusion through a single needle in silicon rubber and polyacrylamide gel agree with the calculation results qualitatively.

Current transport for a spatially periodic potential system with color noises

2018 ◽  
Vol 32 (31) ◽  
pp. 1850352
Author(s):  
Lijuan Ning ◽  
Jie Wang
Keyword(s):  
Mathematical Model ◽  
External Force ◽  
Periodic Potential ◽  
Current Transport ◽  
Absolute Value ◽  
Steady Current ◽  
Large Current ◽  
Potential System ◽  
Spatially Periodic ◽  
Current Value

The transport of an underdamped particle driven by an external force in a periodic asymmetric potential with color noises is investigated. The corresponding mathematical model is established. By the method of the numerical simulation, we present the movement of the steady current of underdamped particles. Different parameters have different influences on current transport, such as increasing or decreasing. It is shown that the cooperations among the external force and the noises parameter lead to the phenomena: when the external force is not zero, the large external force may cause the large current value or the absolute value of the current. The current value is due to the effect of the cooperations of external force and noise parameter.

scholarly journals ENSLAVING RANDOM FLUCTUATIONS IN NONEQUILIBRIUM SYSTEMS

1996 ◽  
Vol 10 (28) ◽  
pp. 3857-3873 ◽  
Author(s):  
MANGAL C. MAHATO ◽  
T.P. PAREEK ◽  
A.M. JAYANNAVAR
Keyword(s):  
Periodic Potential ◽  
Brownian Particle ◽  
Physical Models ◽  
Temperature Inhomogeneity ◽  
Stable States ◽  
Inhomogeneous Systems ◽  
Potential System ◽  
Macroscopic Motion ◽  
Random Fluctuations ◽  
Unidirectional Motion

Several physical models have recently been proposed to obtain unidirectional motion of an overdamped Brownian particle in a periodic system. The asymmetric ratchetlike form of the periodic potential and the presence of correlated nonequilibrium fluctuating forces are considered essential to obtain such a macroscopic motion in homogeneous systems. In the present work, instead, inhomogeneous systems are considered, wherein the friction coefficient and/or temperature could vary in space. We show that unidirectional motion can be obtained even in a symmetric nonratchetlike periodic potential system in the presence of white noise fluctuations. We consider four different cases of system inhomogeneity. We argue that all these different models work under the same basic principle of alteration of relative stability of otherwise locally stable states in the presence of temperature inhomogeneity.

WEAK DISORDER IN PERIODIC POTENTIALS: ANOMALOUS TRANSPORT AND DIFFUSION

2012 ◽  
Vol 11 (01) ◽  
pp. 1240004 ◽  
Author(s):  
KATJA LINDENBERG ◽  
J. M. SANCHO ◽  
M. KHOURY ◽  
A. M. LACASTA
Keyword(s):  
Periodic Potential ◽  
Model Parameters ◽  
Weak Disorder ◽  
Periodic Potentials ◽  
Normal Diffusion ◽  
Random Components ◽  
Transport And Diffusion ◽  
And Diffusion ◽  
Deterministic Force ◽  
Pronounced Peak

Particles driven through a periodic potential by an external constant force are known to exhibit a pronounced peak of the diffusion around the critical deterministic force that defines the transition between locked and running states. It has recently been shown both experimentally and numerically that this peak is greatly enhanced if some amount of spatial disorder is superimposed on the periodic potential. Here, we show that this enhancement is a fingerprint of a broad phenomenology that goes well beyond a simple augmentation. For some values of the model parameters, including the characteristic distances associated with the periodic and random components of the potential, the magnitude of the external force, and the temperature, the system can exhibit a rich variety of regimes from normal diffusion to superdiffusion, subdiffusion and even subtransport.

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