Slip Effects on Ionic Current of Viscoelectric Electroviscous Flows through Different Length Nanofluidic Channels

Abstract

Bu çalışma, bulanık mantık algoritması oluşturularak, örnek seçilen devlet hastanelerinin hasta bakım ve tedavi alanlarının tasarım verimliliklerine göre sınıflandırılması için yürütülmüştür. Hasta bakım ve tedavi ünitelerinin kat planlarından hasta kullanım alanları ve dolaşım alanları elde edilerek bulanık mantık modeli alt kümeleri için üyelik fonksiyonları oluşturulmuştur. Girdi değişkenleri olarak hasta kullanım alanları ve dolaşım alanları modellenmiştir. Girdi değişkenleri ile çıktı değişkeni olan tasarım verimliliği arasındaki ilişkiler bulanık mantık kuralları ile ortaya çıkarılmıştır. Mevcut olan hasta bakım ünitelerini incelemek için, verimlilik çıktı değerleri modelden elde edilmiştir. Genel tasarım normları, tasarım kriterleri ve önceki çalışmalar ışığında ve de bu model aracılığıyla verimlilik sınıfları oluşturulmuştur. Verimlilik sınıflandırılması hastanelerin karşılaştırılarak incelenmesiyle sonuçlanmıştır.

Real-time tracking of ionic nano-domains under shear flow

“…Part of the problem comes from the difficulty in obtaining suitable measurements able to inform theoretical developments [26][27][28][29] . Tracking the organisation and dynamics of individual ions at interfaces is highly challenging 7,17,[30][31][32][33][34] , especially when out of equilibrium or during electro-kinetic phenomena [35][36][37] . Computer simulations can capture ions' femto-to nanosecond dynamics 38,39 , but with current capabilities, most investigations are limited both in number of atoms and in their full duration, rarely going beyond hundreds of nanoseconds 38,40 .…”

Direct measurement of the viscoelectric effect in water

“…The viscoelectric effect concerns the change in the viscosity of polar liquids in the presence of an electric field ( 1 – 3 ). It arises from the interaction of the field with the dipolar molecules, and while its molecular origins are still not well understood ( 4 – 6 ), it has considerable relevance in areas ranging from surface potential measurements ( 7 – 9 ) and boundary lubrication ( 10 ) to nanofluidics and its applications ( 11 – 13 ). Knowing the magnitude of the viscoelectric effect is thus of clear importance.…”

“…For the case of water, however, the most ubiquitous and important polar liquid, measurement of its viscosity in the presence of a strong, uniform field presents a strong challenge (as discussed later in this section), and to our knowledge no such direct measurements have been reported. Over the past six decades, therefore, the magnitude of the viscoelectric effect in water has been only indirectly estimated by extrapolation from its values for organic liquids ( 8 ), from estimates of its effect on electrokinetic phenomena ( 11 , 14 – 19 ), or by other approaches ( 7 , 12 , 20 , 21 ). These estimated values, as expressed in the viscoelectric coefficient f , vary over more than three orders of magnitude, ranging from f ∼10 −17 –2.5 × 10 −14 (V/m) 2 ( SI Appendix , Section 7 ).…”

“…For completeness, we note that results contradictory to the viscoelectric model have also been reported ( 22 ) (i.e., suggesting a decreased water viscosity in an electric field). The reasons for the large span of these estimated f values were attributed to various factors such as solid/liquid coupling, varying ionic sizes, and varying water permittivity ( 12 , 19 ); however, while these factors may play some role, there is no evidence that they could lead to such large discrepancies.…”

“…In all cases, viscosity changes were assumed to occur only in the nonuniform, rapidly decaying electrostatic potential near charged surfaces immersed in water. Changes in electrophoretic mobility, electro-osmosis, or hydrodynamic dissipation or water mobility between similarly charged solid surfaces were then attributed to some mean viscosity increase in these thin surface-adjacent layers ( 7 , 11 , 12 , 14 – 21 ). In practice, however, the effect on these electrokinetic phenomena of viscosity or water mobility changes in the thin layers where such nonuniform, rapidly decaying fields are present is not easy to quantify reliably, especially in the presence of salt ions ( 12 ).…”