Pumping flow model in a microchannel with propagative rhythmic membrane contraction

Aboelkassem, Yasser

doi:10.1063/1.5092295

“…In addition, our scaling analysis is performed on the case with the fixed dimensional Debye length, which is a limitation of the hypothetical scenario. Just for the non-shear electroosmotic flow, the effects of bulk concentration on the mixing efficiency (Peng & Li 2015), flow pattern (Aboelkassem 2019;Tripathi et al 2020) and enrichment efficiency (Ouyang et al 2018) are investigated. Similarly, the concentration effect of the shear electroconvective flow may be interesting, and the experimental and theoretical studies on it deserve to be conducted in the future.…”

Section: Discussionmentioning

confidence: 99%

“…In addition, our scaling analysis is performed on the case with the fixed dimensional Debye length, which is a limitation of the hypothetical scenario. Just for the non-shear electroosmotic flow, the effects of bulk concentration on the mixing efficiency (Peng & Li 2015), flow pattern (Aboelkassem 2019; Tripathi et al. 2020) and enrichment efficiency (Ouyang et al.…”

Section: Discussionmentioning

confidence: 99%

“…To date, there are three possible explanations for the physical mechanism of ECF. One is the non-equilibrium ECF (Zaltzman & Rubinstein 2007) related to the extended space charge (ESC) layer, the other is the equilibrium ECF (Rubinstein & Zaltzman 2015;Aboelkassem 2019;Tripathi, Narla & Aboelkassem 2020;Xu et al 2020) related to the electric double layer and the last is the ECF related to charge injection (Guan, Riley & Novosselov 2020;Luo et al 2020;Su et al 2020). The non-equilibrium ECF associated with the ESC layer, which is typically triggered in electrochemical systems embedded with cation-selective membranes, is considered here, as shown in figure 1.…”

Section: Introductionmentioning

confidence: 99%

“…To date, there are three possible explanations for the physical mechanism of ECF. One is the non-equilibrium ECF (Zaltzman & Rubinstein 2007) related to the extended space charge (ESC) layer, the other is the equilibrium ECF (Rubinstein & Zaltzman 2015; Aboelkassem 2019; Tripathi, Narla & Aboelkassem 2020; Xu et al. 2020) related to the electric double layer and the last is the ECF related to charge injection (Guan, Riley & Novosselov 2020; Luo et al.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Critical selection of shear sheltering in electroconvective flow from chaotic to steady state

Liu

¹

,

Zhou

²

,

Shi

³

2022

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Ion and water are transported by electroconvection near permselective membranes, resulting in complex phenomena associated with the flow–fines interaction. Sheltering the flow chaos by the shear flow is a common strategy in plasma fluids and has recently been successfully applied to control ionic fluids. The paper herein reveals the critical selection of shear velocity regarding the fluid from a chaotic to a steady state through numerical and theoretical analyses. For the shear sheltering, the dimensionless Debye length ${\lambda _D}$ with varying channel height is introduced to achieve a comprehensive discussion of the factors and laws affecting the shear vortex state. Based on an analysis of the vortex driving mechanism, the scaling of the slip velocity ${u_s}\sim {(\lambda _D^{ - 1}\Delta {\phi ^4})^{1/3}}$ is recommended as the critical selection factor for the steady and chaotic state under a fixed shear flow velocity, which involves the dimensionless Debye length ${\lambda _D}$ and voltage difference $\Delta \phi $ . Furthermore, for ionic fluid control by shear flow, a critical shear velocity ${U_{HPC}}$ is proposed to distinguish the electroconvective flow from a chaotic state to a steady state. When the shear flow velocity ${U_{HP}} > {U_{HPC}}$ , the shear flow shelters chaos, and the scaling law is also recommended for the regulation of the critical shear flow velocity ${U_{HPC}}$ jointly by ${\lambda _D}$ and $\Delta \phi $ . The analysis is confirmed by direct numerical simulation and existing experimental data (J. Fluid Mech, vol. 813, 2017, pp. 799–823). This work provides a more comprehensive physical insight for shear sheltering and affects the design of electromembrane microfluidics.

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“…Even so, we note that there are several other ways in which the pore morphology could vary with potential impact on signal transport. For instance, it is possible that dynamic effects, such as wiggling [25] or peristaltic pumping [27], are involved in transport. Also, in large pores, it is possible that transport is enhanced by Taylor-Aris dispersion [28,29].…”

Section: Discussionmentioning

confidence: 99%

Diffusion and flow across shape-perturbed plasmodesmata nanopores in plants

Christensen

¹

,

Stone

²

,

Jensen

³

2021

Eur. Phys. J. Plus

4

0

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Plasmodesmata are slender nanochannels that link neighboring plant cells and enable the exchange of nutrients and signaling molecules. Recent experiments have demonstrated significant variability in the concentric pore shape. However, the impact of these geometric fluctuations on transport capacity is unknown. Here, we consider the effects on diffusion and advection of two ideal shape perturbations: a radial displacement of the entire central desmotubule and a harmonic variation in the cytoplasmic sleeve width along the length of the pore. We use Fick’s law and the lubrication approximation to determine the diffusive current and volumetric flow rate across the pore. Our results indicate that an off-center desmotubule always increases the pressure-driven flow rate. However, the diffusive current is only enhanced for particles comparable in size to the width of the channel. In contrast, harmonic variations in the cytoplasmic sleeve width along the length of the pore reduce both the diffusive current and the pressure-driven flow. The simple models presented here demonstrate that shape perturbations can significantly influence transport across plasmodesmata nanopores.

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