scholarly journals An Experimental and Numerical Study of Polyelectrolyte Hydrogel Ionic Diodes: Towards Electrical Detection of Charged Biomolecules

Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8279
Author(s):  
Chenwei Xiong ◽  
Boyin Zhang ◽  
Rong Zhang ◽  
Yifan Liu
Keyword(s):  
Numerical Simulation ◽  
Numerical Study ◽  
Ionic Current ◽  
Ionic Currents ◽  
Microfluidic Chips ◽  
Electrical Detection ◽  
Heterogeneous Distribution ◽  
Transport Of Ions ◽  
Current Rectification ◽  
Polyelectrolyte Hydrogel

Polyelectrolyte hydrogel ionic diodes (PHIDs) have recently emerged as a unique set of iontronic devices. Such diodes are built on microfluidic chips that feature polyelectrolyte hydrogel junctions and rectify ionic currents owing to the heterogeneous distribution and transport of ions across the junctions. In this paper, we provide the first account of a study on the ion transport behavior of PHIDs through an experimental investigation and numerical simulation. The effects of bulk ionic strength and hydrogel pore confinement are experimentally investigated. The ionic current rectification (ICR) exhibits saturation in a micromolar regime and responds to hydrogel pore size, which is subsequently verified in a simulation. Furthermore, we experimentally show that the rectification is sensitive to the dose of immobilized DNA with an exhibited sensitivity of 1 ng/μL. We anticipate our findings would be beneficial to the design of PHID-based biosensors for electrical detection of charged biomolecules.

scholarly journals Modeling the Device Behavior of Biological and Synthetic Nanopores with Reduced Models

Entropy ◽  
2020 ◽  
Vol 22 (11) ◽  
pp. 1259
Author(s):  
Dezső Boda ◽  
Mónika Valiskó ◽  
Dirk Gillespie
Keyword(s):  
Ion Channels ◽  
Degrees Of Freedom ◽  
Ionic Currents ◽  
Response Functions ◽  
Reduced Models ◽  
Rules Of Thumb ◽  
Transport Of Ions ◽  
Current Rectification ◽  
The Right ◽  
Axial Concentration

Biological ion channels and synthetic nanopores are responsible for passive transport of ions through a membrane between two compartments. Modeling these ionic currents is especially amenable to reduced models because the device functions of these pores, the relation of input parameters (e.g., applied voltage, bath concentrations) and output parameters (e.g., current, rectification, selectivity), are well defined. Reduced models focus on the physics that produces the device functions (i.e., the physics of how inputs become outputs) rather than the atomic/molecular-scale physics inside the pore. Here, we propose four rules of thumb for constructing good reduced models of ion channels and nanopores. They are about (1) the importance of the axial concentration profiles, (2) the importance of the pore charges, (3) choosing the right explicit degrees of freedom, and (4) creating the proper response functions. We provide examples for how each rule of thumb helps in creating a reduced model of device behavior.

scholarly journals Development of Depth-Limited Wave Boundary Layers over a Smooth Bottom

2020 ◽  
Vol 9 (1) ◽  
pp. 27
Author(s):  
Hitoshi Tanaka ◽  
Nguyen Xuan Tinh ◽  
Xiping Yu ◽  
Guangwei Liu
Keyword(s):  
Numerical Simulation ◽  
Boundary Layer ◽  
Boundary Layers ◽  
Wave Motion ◽  
Numerical Study ◽  
Experiment Data ◽  
Tidal Motion ◽  
Long Period ◽  
Simulation Results ◽  
Wave Boundary

A theoretical and numerical study is carried out to investigate the transformation of the wave boundary layer from non-depth-limited (wave-like boundary layer) to depth-limited one (current-like boundary layer) over a smooth bottom. A long period of wave motion is not sufficient to induce depth-limited properties, although it has simply been assumed in various situations under long waves, such as tsunami and tidal currents. Four criteria are obtained theoretically for recognizing the inception of the depth-limited condition under waves. To validate the theoretical criteria, numerical simulation results using a turbulence model as well as laboratory experiment data are employed. In addition, typical field situations induced by tidal motion and tsunami are discussed to show the usefulness of the proposed criteria.

Numerical Simulation of Premixed Propane/Air Flame Propagation Using a Dynamically Thickened Flame Approach

2013 ◽  
Vol 444-445 ◽  
pp. 1574-1578 ◽  
Author(s):  
Hua Hua Xiao ◽  
Zhan Li Mao ◽  
Wei Guang An ◽  
Qing Song Wang ◽  
Jin Hua Sun
Keyword(s):  
Numerical Simulation ◽  
Flame Propagation ◽  
Numerical Study ◽  
Vortex Motion ◽  
Combustion Process ◽  
Single Step ◽  
Premixed Combustion ◽  
Premixed Flame ◽  
Flame Surface ◽  
Arrhenius Kinetics

A numerical study of premixed propane/air flame propagation in a closed duct is presented. A dynamically thickened flame (TF) method is applied to model the premixed combustion. The reaction of propane in air is taken into account using a single-step global Arrhenius kinetics. It is shown that the premixed flame undergoes four stages of dynamics in the propagation. The formation of tulip flame phenomenon is observed. The pressure during the combustion process grows exponentially at the finger-shape flame stage and then slows down until the formation of tulip shape. After tulip formation the pressure increases quickly again with the increase of the flame surface area. The vortex motion behind the flame front advects the flame into tulip shape. The study indicates that the TF model is quite reliable for the investigation of premixed propane/air flame propagation.

Numerical Simulation of Gas Flow and Heat Transfer in Cross-Wavy Primary Surface Channel for Microtubine Recuperators

2005 ◽  
Author(s):  
H. X. Liang ◽  
Q. W. Wang ◽  
L. Q. Luo ◽  
Z. P. Feng
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Gas Turbine ◽  
Numerical Study ◽  
High Reliability ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Flow And Heat Transfer ◽  
High Heat Transfer ◽  
The Cross

Three-dimensional numerical simulation was conducted to investigate the flow field and heat transfer performance of the Cross-Wavy Primary Surface (CWPS) recuperators for microturbines. Using high-effective compact recuperators to achieve high thermal efficiency is one of the key techniques in the development of microturbine in recent years. Recuperators need to have minimum volume and weight, high reliability and durability. Most important of all, they need to have high thermal-effectiveness and low pressure-losses so that the gas turbine system can achieve high thermal performances. These requirements have attracted some research efforts in designing and implementing low-cost and compact recuperators for gas turbine engines recently. One of the promising techniques to achieve this goal is the so-called primary surface channels with small hydraulic dimensions. In this paper, we conducted a three-dimensional numerical study of flow and heat transfer for the Cross-Wavy Primary Surface (CWPS) channels with two different geometries. In the CWPS configurations the secondary flow is created by means of curved and interrupted surfaces, which may disturb the thermal boundary layers and thus improve the thermal performances of the channels. To facilitate comparison, we chose the identical hydraulic diameters for the above four CWPS channels. Since our experiments on real recuperators showed that the Reynolds number ranges from 150 to 500 under the operating conditions, we implemented all the simulations under laminar flow situations. By analyzing the correlations of Nusselt numbers and friction factors vs. Reynolds numbers of the four CWPS channels, we found that the CWPS channels have superior and comprehensive thermal performance with high compactness, i.e., high heat transfer area to volume ratio, indicating excellent commercialized application in the compact recuperators.

scholarly journals Breccia interlayer effects on steam-assisted gravity drainage performance: experimental and numerical study

2021 ◽  
Author(s):  
Qichen Zhang ◽  
Xiaodong Kang ◽  
Huiqing Liu ◽  
Xiaohu Dong ◽  
Jian Wang
Keyword(s):  
Numerical Simulation ◽  
Oil Recovery ◽  
Oil Sands ◽  
Numerical Study ◽  
Middle Part ◽  
Experimental Results ◽  
Production Performance ◽  
Peak Oil ◽  
Steam Chamber ◽  
The Impact

AbstractCurrently, the reservoir heterogeneity is a serious challenge for developing oil sands with SAGD method. Nexen’s Long Lake SAGD project reported that breccia interlayer was widely distributed in lower and middle part of reservoir, impeding the steam chamber expansion and heated oil drainage. In this paper, two physical experiments were conducted to study the impact of breccia interlayer on development of steam chamber and production performance. Then, a laboratory scale numerical simulation model was established and a history match was conducted based on the 3D experimental results. Finally, the sensitivity analysis of thickness and permeability of breccia layer was performed. The influence mechanism of breccia layer on SAGD performance was analyzed by comparing the temperature profile of steam chamber and production dynamics. The experimental results indicate that the existence of breccia interlayer causes a thinner steam chamber profile and longer time to reach the peak oil rate. And, the ultimate oil recovery reduced 15.8% due to much oil stuck in breccia interlayer areas. The numerical simulation results show that a lower permeability in breccia layer area has a serious adverse impact on oil recovery if the thickness of breccia layer is larger, whereas the effect of permeability on SAGD performance is limited when the breccia layer is thinner. Besides, a thicker breccia layer can increase the time required to reach the peak oil rate, but has a little impact on the ultimate oil recovery.

scholarly journals Numerical study of gas dynamics and heat transfer in matrix channels at various rib angles

2021 ◽  
Vol 2057 (1) ◽  
pp. 012026
Author(s):  
A V Barsukov ◽  
V V Terekhov ◽  
V I Terekhov
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Reynolds Number ◽  
Gas Dynamics ◽  
Average Velocity ◽  
Numerical Study ◽  
Reynolds Numbers ◽  
Separation Flow ◽  
Maximum Heat ◽  
Maximum Heat Transfer

Abstract The results of numerical simulation of the separation flow in matrix channels by the RANS method are presented. The simulation is performed at the Reynolds number Re = 12600, determined by the mass-average velocity and the height of the channel. The distribution of the local Nusselt number is obtained for various Reynolds numbers in the range of 5÷15⋅103 and several rib angles. It is shown that the temperature distribution on the surface is highly nonuniform; in particular, the maximum heat transfer value is observed near the upper edge facets, in the vicinity of which the greatest velocity gradient is observed.

Effect of linear surface-charge non-uniformities on the electrokinetic ionic-current rectification in conical nanopores

2009 ◽  
Vol 329 (2) ◽  
pp. 376-383 ◽  
Author(s):  
Shizhi Qian ◽  
Sang W. Joo ◽  
Ye Ai ◽  
Marcos A. Cheney ◽  
Wensheng Hou
Keyword(s):  
Surface Charge ◽  
Ionic Current ◽  
Conical Nanopores ◽  
Current Rectification

scholarly journals Anoctamin 5/TMEM16E facilitates muscle precursor cell fusion

2018 ◽  
Vol 150 (11) ◽  
pp. 1498-1509 ◽  
Author(s):  
Jarred M. Whitlock ◽  
Kuai Yu ◽  
Yuan Yuan Cui ◽  
H. Criss Hartzell
Keyword(s):  
Cell Fusion ◽  
Ionic Current ◽  
Ionic Currents ◽  
Muscle Physiology ◽  
Muscle Repair ◽  
Hek 293 ◽  
293 Cells ◽  
Phospholipid Scrambling ◽  
Muscle Precursor Cell

Limb-girdle muscular dystrophy type 2L (LGMD2L) is a myopathy arising from mutations in ANO5; however, information about the contribution of ANO5 to muscle physiology is lacking. To explain the role of ANO5 in LGMD2L, we previously hypothesized that ANO5-mediated phospholipid scrambling facilitates cell–cell fusion of mononucleated muscle progenitor cells (MPCs), which is required for muscle repair. Here, we show that heterologous overexpression of ANO5 confers Ca2+-dependent phospholipid scrambling to HEK-293 cells and that scrambling is associated with the simultaneous development of a nonselective ionic current. MPCs isolated from adult Ano5−/− mice exhibit defective cell fusion in culture and produce muscle fibers with significantly fewer nuclei compared with controls. This defective fusion is associated with a decrease of Ca2+-dependent phosphatidylserine exposure on the surface of Ano5−/− MPCs and a decrease in the amplitude of Ca2+-dependent outwardly rectifying ionic currents. Viral introduction of ANO5 in Ano5−/− MPCs restores MPC fusion competence, ANO5-dependent phospholipid scrambling, and Ca2+-dependent outwardly rectifying ionic currents. ANO5-rescued MPCs produce myotubes having numbers of nuclei similar to wild-type controls. These data suggest that ANO5-mediated phospholipid scrambling or ionic currents play an important role in muscle repair.

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