Simulation of nano elastic polymer chain displacement under pressure gradient/electroosmotic flow with the target of less dispersion of transition

AbstractSince non-scattering transfer of polymer chain in nanochannel is one of the important issue in biology, in this research, the behavior study of a long polymer chain in the nanofluid in two modes of free motion and restricted motion (fixed two ends) under two different forces including constant force (pressure gradient (PG)) and variable force (electroosmotic force (EOF)) has been investigated using dissipative particle dynamics (DPD) method. Our aim is that displacement of polymer chain carries out with less dispersion. Initially, without the presence of polymer, the results have been validated in a nanochannel by analytical results for both cases (PG, EOF) with an error of less than 10%. Then, assuming 50 beads of polymer chain, the polymer chain motion in free motion and fixed two ends modes has been examined by different spring coefficients between beads and different forces including PG (0.01 DPD unite) and EOF (zeta potential = − 25 mV, electric field = 250 V/mm, kh parameter = 8). The results show that in free polymer motion-PG mode, by increasing 1.6 times of spring coefficient of the polymer, a 40% reduction in transition of polymer is achieved, which high dispersion of polymer chain is resulted for this mode. In the EOF, the spring coefficient has a slight effect on transferring of polymer and also, EOF moves the polymer chain with extremely low polymer chain scattering. Also, for fixed two ends-PG mode, a 36% reduction in displacement is achieved and in the same way, in EOF almost 39% declining in displacement is resulted by enhancing the spring coefficients. The results have developed to 25 and 100 beads which less dispersion of polymer chain transfer for free polymer chain-EOF is reported again for both circumstances and for restricted polymer chain state in two PG and EOF modes, less differences are reported for two cases. The results show that the EOF has the benefit of low dispersion for free polymer chain transfer, also, almost equal displacement for restricted polymer chain mode is observed for both cases.

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Availability of anions in the growth medium to roots of an actively growing plant.

Netherlands Journal of Agricultural Science ◽

10.18174/njas.v23i2.17192 ◽

1975 ◽

Vol 23 (2) ◽

pp. 131-138

Author(s):

H. Van Keulen ◽

N.G. Seligman ◽

J. Goudriaan

Keyword(s):

Root System ◽

Growth Medium ◽

Mass Flow ◽

Dispersion Coefficient ◽

Anion Transport ◽

Root Density ◽

High Dispersion ◽

Rooting Zone ◽

Speed Up ◽

Low Dispersion

Analysis of anion transport to the root of an actively growing plant with a normally dense root system showed that virtually the whole of the anion store in the rooting zone is available to the plant within a few days at the most. Transport by diffusion only is enough to account for most of the depletion, but mass flow will speed up the process. The effect of mass flow will be considerable in soils with a high dispersion coefficient (loess), but very small in soils with a low dispersion coefficient (clay and sand). A rule is proposed to determine whether a given root density is sufficient to supply the nitrogen and water needs of the plant by diffusion only. (Abstract retrieved from CAB Abstracts by CABI’s permission)

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Investigation of Magneto Hydro-Dynamics Effects on a Polymer Chain Transfer in Micro-Channel Using Dissipative Particle Dynamics Method

Symmetry ◽

10.3390/sym12030397 ◽

2020 ◽

Vol 12 (3) ◽

pp. 397 ◽

Cited By ~ 2

Author(s):

Ramin Zakeri ◽

Moslem Sabouri ◽

Akbar Maleki ◽

Zahra Abdelmalek

Keyword(s):

Polymer Chain ◽

Dissipative Particle Dynamics ◽

Mhd Flow ◽

Particle Dynamics ◽

Dynamics Simulation ◽

Radius Of Gyration ◽

Micro Channel ◽

Effective Parameters ◽

The Difference ◽

Bond Constant

In this paper, the effect of Magneto Hydro-Dynamics (MHD) on a polymer chain in the micro channel is studied by employing the Dissipative Particle Dynamics simulation (DPD) method. First, in a simple symmetric micro-channel, the results are evaluated and validated for different values of Hartmann (Ha) Number. The difference between the simulation and analytical solution is below 10%. Then, two types of polymer chain including short and long polymer chain are examined in the channel and the effective parameters such as Ha number, the harmony bond coefficient or spring constant (K), and the length of the polymer chain (N) are studied in the MHD flow. It is shown that by increasing harmony bond constant to 10 times with Ha = 20, the reduction of about 80% in radius of gyration squared, and half in polymer length compared to Ha = 1 would occur for both test cases. For short and long length of polymer, proper transfer of a polymer chain through MHD particles flow is observed with less perturbations (80%) and faster polymer transfer in the symmetric micro-channel.

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Quantitative Analysis of the Effect of Azo Initiators on the Structure of α-Polymer Chain Ends in Degenerative Chain-Transfer-Mediated Living Radical Polymerization Reactions

Macromolecules ◽

10.1021/ma201761q ◽

2011 ◽

Vol 44 (21) ◽

pp. 8388-8397 ◽

Cited By ~ 36

Author(s):

Yasuyuki Nakamura ◽

Yukie Kitada ◽

Yu Kobayashi ◽

Biswajit Ray ◽

Shigeru Yamago

Keyword(s):

Quantitative Analysis ◽

Radical Polymerization ◽

Polymer Chain ◽

Chain Transfer ◽

Living Radical Polymerization ◽

Azo Initiators ◽

Degenerative Chain Transfer

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Electronic spectra of polyatomic molecules II–Acrolein

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1935.0075 ◽

1935 ◽

Vol 149 (868) ◽

pp. 446-466 ◽

Cited By ~ 12

Keyword(s):

Excited States ◽

Theoretical Description ◽

High Dispersion ◽

Molecular Spectra ◽

Orbital Structure ◽

Double Bonds ◽

Important Place ◽

Conjugated Systems ◽

The Difference ◽

Low Dispersion

In the Introduction to Part I we discussed the orbital structure of the C > C and >C = O double bonds and the difference between these structures in their excited states. With so much spectroscopic evidence upon these isolated double bonds, and at least a provisional theoretical description of each of them, it seemed natural to investigate the effect of double bonds upon each other in conjugated systems such as > C = C - C = 0. These systems occupy an important place in chemical theories of valency. Another reason for investigating such molecules was that measurements under low dispersion by Luthy upon the simplest conjugated aldehyde CH 2 = CH. C = O | H showed a spectrum which gave promise of unusual features. This promise was more than borne out by observations under high dispersion, and in fact the spectrum of acrolein reveals a tine structure which so far as we know is unique in molecular spectra at present recorded.

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On the Simple Economics of Advertising, Marketing, and Product Design

The American Economic Review ◽

10.1257/aer.96.3.756 ◽

2006 ◽

Vol 96 (3) ◽

pp. 756-784 ◽

Cited By ~ 312

Author(s):

Justin P Johnson ◽

David P Myatt

Keyword(s):

Product Design ◽

Demand Curve ◽

High Dispersion ◽

Product Lines ◽

Mass Market ◽

Low Dispersion

We propose a framework for analyzing transformations of demand. Such transformations frequently stem from changes in the dispersion of consumers' valuations, which lead to rotations of the demand curve. In many settings, profits are a U-shaped function of dispersion. High dispersion is complemented by niche production, and low dispersion is complemented by mass-market supply. We investigate numerous applications, including product design; advertising, marketing and sales advice; and the construction of quality-differentiated product lines. We also suggest a new taxonomy of advertising, distinguishing between hype, which shifts demand, and real information, which rotates demand.

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