Review on active brownian particle
Download as PPTX, PDF1 like407 views
This document provides an overview of active Brownian motion. It defines passive and active Brownian motion, with passive motion determined solely by collisions with surrounding particles and active motion also involving the uptake of energy from the surrounding medium. The motion of active Brownian particles is described by the Langevin equation. The project aims to simulate Brownian motion through random walks and study properties of active Brownian particles like bacterial motion and dynamic phase transitions using the equations of motion. Several key literature on active Brownian motion models are also reviewed from 1995 onward.
Review on active brownian particle
- 1. Review on Active Brownian particle Presented by :-GITA KRUSHNA SATAPATHY Regd. No:-160705120038 Guided by:-Dr. Subrata Sarangi School of Applied Sciences
- 2. CONTENTS INTRODUCTION ▪ BROWNIAN MOTION ▪ TYPES OF BROWNIAN MOTION AIM OF OUR PROJECT LITERATURE
- 3. Brownian motion It is the random motion of particles suspended in a fluid (a liquid or a gas) resulting from their collision with the fast-moving atoms or molecules in the gas or liquid. Sizes (radius or diameter) Brownian particle: a few microns (10−6 m) Atom: 10−10m
- 5. Passive Brownian Motion The behaviour of ordinary Brownian motion is determined by the (passive) stochastic collisions, the particles suffer from the surrounding medium, as well as due to the viscous force. There is no active transfer of energy to the particles. This type of motion is called as Passive Brownian Motion.
- 6. Contd. Brownian motion is described by Newtonian dynamics including friction and stochastic forces 𝒅𝒓 𝒅𝒕 =v ; m 𝒅𝒗 𝒅𝒕 =- ζv-∇U(r) + F(t) Where ζ = Stokes frictional co-efficient U(r) = space-dependent potential F(t)= random force exerted on the particle by the fluid The above equation can be written as This equation is also called Langevin equation 𝒅𝒓 𝒅𝒕 =v ; 𝒅𝒗 𝒅𝒕 =- 𝜻 𝒎 𝒗- 𝛻𝑈(𝑟) 𝑚 + 2𝐷ξ(t) ξ(t)= frictional co-efficient per unit volume D= self diffusion constant= 𝑲 𝑩 𝑻 ζ
- 7. Active Brownian Motion This class of models not only take into account random or stochastic collisions , the particles suffer from the surrounding medium & viscous force, but also uptake energy (negative dissipation) from the medium. This type of motion is called as Active Brownian Motion. On an average they are moving in a bulk. This type of motion is also called as self-propelled motion.
- 8. Contd. The motion of Brownian particles with general velocity and space- dependent friction in a space-dependent potential U(r) can be described again by the Langevin equation 𝒅𝒓 𝒅𝒕 =v ; 𝒅𝒗 𝒅𝒕 =F diss-∇U(r) + F(t) The new feature is the dissipative force which is now given with a position and velocity dependent coefficient F diss = − ζ(r, v)v The above equation can be written as 𝒅𝒓 𝒅𝒕 =v ; 𝒅𝒗 𝒅𝒕 = − ζ(r, v)v -∇U(r) + 2𝐷ξ(t) ξ(t)= frictional co-efficient per unit volume D= self diffusion constant= 𝑲 𝑩 𝑻 ζ
- 9. Aim of our Project Simulation Of Brownian motion through Random Walk 1D random walk
- 10. Contd. To study different properties of ABP by using equation of motion Bacterial Motion Giant Density Fluctuation Dynamic Phase transitions Ability to Power Microscopic Motors
- 11. Literature Review On 7 August 1995 T. Vicsek present a simple model and novel type dynamics & introduce in order to investigate the self-ordered motion in system of particles. On 4 DECEMBER 1995 Vicsek et al. propose a non-equilibrium continuum dynamical model for the collective motion of large groups of biological organisms in physics review letter of Toner & Tu models. On OCTOBER 1998 John Toner first present a quantitative continuum theory of ‘‘flocking’’: the collective coherent motion of large numbers of self-propelled organisms. B. Lindnera and E.M. Nicola in 2008 present the effective diffusion coefficient of ABP model.(RH & SET model ) On December 2011 R.Witti investigated arbitrary shape of Brownian dynamics of an individual active colloidal particle. On 11th feb 2012 M. Bar, W. Ebeling, B. Lindner published theoretical models of individual motility as well as collective dynamics and pattern formation of ABP.