Diffusive behaviour of PLL–PEG coated colloids on λ-DNA brushes – tuning hydrophobicity

Soft Matter ◽  
2012 ◽  
Vol 8 (25) ◽  
pp. 6792 ◽  
Author(s):  
Taiki Yanagishima ◽  
Lorenzo Di Michele ◽  
Jurij Kotar ◽  
Erika Eiser
Keyword(s):  
Diffusive Behaviour

Computational Analysis of Displacement of Particles with Given Size on the Nonstationary Bulging Membrane as a Theoretical Model of Membrane Fouling

2013 ◽  
Vol 34 (1) ◽  
pp. 109-119 ◽  
Author(s):  
Jakub M. Gac ◽  
Leon Gradoń
Keyword(s):  
Particle Size ◽  
Theoretical Model ◽  
Membrane Fouling ◽  
Computational Analysis ◽  
New Production ◽  
Mean Velocity ◽  
Production Methods ◽  
The Mean ◽  
Particle Behaviour ◽  
Diffusive Behaviour

Abstract A simple model of behaviour of a single particle on the bulging membrane was presented. As a result of numerical solution of a motion equation the influence of the amplitude and frequency of bulging as well as the particle size on particle behaviour, especially its downstream velocity was investigated. It was found that the bulging of a membrane may increase the mean velocity of a particle or reinforce its diffusive behaviour, dependeing on the permeation velocity. The obtained results may help to design new production methods of highly fouling-resistant membranes.

Diffusive behaviour of self-attractive walks

1996 ◽  
Vol 29 (12) ◽  
pp. 3037-3040 ◽  
Author(s):  
M A Prasad ◽  
D P Bhatia ◽  
D Arora
Keyword(s):  
Diffusive Behaviour

The puzzle of liquid water diffusive behaviour: recent IQENS results

2002 ◽  
Vol 304 (1-2) ◽  
pp. 59-64 ◽  
Author(s):  
V. Crupi ◽  
D. Majolino ◽  
P. Migliardo ◽  
V. Venuti
Keyword(s):  
Liquid Water ◽  
Diffusive Behaviour

A Dual-Scale Numerical Model for the Diffusive Behaviour Prediction of Biocomposites Based on Randomly Oriented Fibres

2022 ◽  
Author(s):  
Mustapha Nouri ◽  
Mahfoud Tahlaiti
Keyword(s):  
Finite Element ◽  
Numerical Model ◽  
Element Model ◽  
Numerical Approach ◽  
Optical Microscope ◽  
Diffusion Problem ◽  
Finite Element Calculation ◽  
Element Calculation ◽  
Calculation Software ◽  
Diffusive Behaviour

This work aims to present a multi-scale numerical approach based on a 2D finite element model to simulate the diffusive behaviour of biocomposites based on randomly dispersed Diss fibres during ageing in water. So, first of all, the diffusive behaviour of each phase (fibres/matrix) as well as of the biocomposite was determined experimentally. Secondly, the microstructure of the biocomposite was observed by optical microscope and scanning electron microscope (SEM), and then regenerated in a Digimat finite element calculation software thanks to its own fibre generator: "Random fibre placement". Finally, the diffusion problem based on Fick's law was solved on the Abaqus finite element calculation software. The results showed an excellent agreement between the experiment and the numerical model. The numerical model has enabled a better understanding of the diffusive behaviour of water within the biocomposite, in particular the effect of the fibre/matrix interface. In terms of durability, the layered structure of this biocomposite has proven to be effective in protecting the plant fibres from hydrothermal transfer, which preserves the durability of the material.

Diffusion of swimming model micro-organisms in a semi-dilute suspension

2007 ◽  
Vol 588 ◽  
pp. 437-462 ◽  
Author(s):  
TAKUJI ISHIKAWA ◽  
T. J. PEDLEY
Keyword(s):  
Volume Fraction ◽  
Three Dimensional ◽  
Vertical Direction ◽  
Reynolds Numbers ◽  
Surface Velocity ◽  
Biased Random Walk ◽  
Long Time ◽  
Upward Velocity ◽  
Micro Organisms ◽  
Diffusive Behaviour

The diffusive behaviour of swimming micro-organisms should be clarified in order to obtain a better continuum model for cell suspensions. In this paper, a swimming micro-organism is modelled as a squirming sphere with prescribed tangential surface velocity, in which the centre of mass of the sphere may be displaced from the geometric centre (bottom-heaviness). Effects of inertia and Brownian motion are neglected, because real micro-organisms swim at very low Reynolds numbers but are too large for Brownian effects to be important. The three-dimensional movement of 64 or 27 identical squirmers in a fluid otherwise at rest, contained in a cube with periodic boundary conditions, is dynamically computed, for random initial positions and orientations. The computation utilizes a database of pairwise interactions that has been constructed by the boundary element method. In the case of (non-bottom-heavy) squirmers, both the translational and the orientational spreading of squirmers is correctly described as a diffusive process over a sufficiently long time scale, even though all the movements of the squirmers were deterministically calculated. Scaling of the results on the assumption that the squirmer trajectories are unbiased random walks is shown to capture some but not all of the main features of the results. In the case of (bottom-heavy) squirmers, the diffusive behaviour in squirmers' orientations can be described by a biased random walk model, but only when the effect of hydrodynamic interaction dominates that of the bottom-heaviness. The spreading of bottom-heavy squirmers in the horizontal directions show diffusive behaviour, and that in the vertical direction also does when the average upward velocity is subtracted. The rotational diffusivity in this case, at a volume fractionc=0.1, is shown to be at least as large as that previously measured in very dilute populations of swimming algal cells (Chlamydomonas nivalis).

scholarly journals Efficient lattice Boltzmann algorithm for Brownian suspensions

2011 ◽  
Vol 369 (1944) ◽  
pp. 2237-2245 ◽  
Author(s):  
Mahesh Mynam ◽  
P. Sunthar ◽  
Santosh Ansumali
Keyword(s):  
Lattice Boltzmann ◽  
Thermal Noise ◽  
Hybrid Methods ◽  
Brownian Particle ◽  
Thermal Fluctuations ◽  
Fluid Level ◽  
Brownian Particles ◽  
Long Time ◽  
Short Time ◽  
Diffusive Behaviour

A lattice Boltzmann (LB)-based hybrid method is developed to simulate suspensions of Brownian particles. The method uses conventional LB discretization (without fluid- level fluctuations) for suspending fluid, and treats Brownian particles as point masses with a stochastic thermal noise. LB equations are used to compute the velocity perturbations induced by the particle motion. It is shown that this method correctly reproduces the short-time and long-time diffusive behaviour of a Brownian particle. Unlike the earlier hybrid methods that use thermal fluctuations in the fluid, this method correctly reproduces the temperature of the particle and does not require an empirical rescaling of the bare friction coefficient to obtain the correct diffusive behaviour. It is observed that the present method is at least twice as fast as the earlier method. This method is best suited for flows of polymers and Brownian suspensions in microfluidic devices.

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