Biomedical Translational Research Drug Design and Discovery (R.C. Sobti, Naranjan S. Dhalla)

The self-diffusion coefﬁcient was found to decrease in the proximity of the

conﬁning walls of nano-channel and hence affected the ﬂuidity of the ﬂuid. Thus,

we observe that when the particle is within 10 atomic distances from the wall, the

frequency gradually increases and reaches a maximum value in a region adjacent

to the wall which indicates trapping of the particle resulting in reduced self-

diffusion coefﬁcient. This effect on the macroscopic self-diffusion coefﬁcient

gets more pronounced for the denser ﬂuid as seen in Fig. 16.11. In fact, the denser

ﬂuid contributed in the formation of an extra artiﬁcial wall which further restricts

the ﬂow of ﬂuid. This realization and analysis ﬁnd a great relevance to the study

of ﬂow of blood like ﬂuid in arteries. In general, this model could be easily

applied to any complex liquids since the structural complexity of the liquids

deﬁnes the frequencies ω and τ¹. A similar and signiﬁcant analysis has also been

carried out for blood ﬂowing in capillaries/arteries/arterioles of varying

concentrations. The analysis demonstrated that the denser the blood, the lower

the diffusion coefﬁcient near the wall, thus resulting in narrower effective width

of an artery or meta arteriole which, in turn, would further restrict the ﬂow of

blood. Thus, we observe that ﬂuid in proximity to the wall works as if it is in super

cooled state or frozen to the solid state. These ﬁndings have an important

application in biological studies. The present results imply that thicker blood

(with large cholesterol) reduces the effective width of an artery.

2. Double Conﬁnement in Rectangular Nanotube: Particle in a speciﬁc cell

experiences a compression owing to its conﬁnement and hence causes an effec-

tive decrease in its amplitude (Aggarwal et al. 2007; Devi et al. 2011) by d1 and

d2 along perpendicular y and z directions, respectively, as shown in Fig. 16.12.

Here, Fig. 16.13 represents a 3D plot of diffusion of particle. Behavior of

Fig. 16.11 Variation of ratio of D(z) to the bulk value as function of z for two different densities.

Solid line corresponds to more dense system

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K. Tankeshwar and S. Srivastava