Article
Mechanics
Yongbo Liu, Jingnan Xing, Jiandong Pi
Summary: In recent years, the electrokinetic energy conversion in pressure-driven flow through hydrophobic nanochannels has gained much attention. However, the reported efficiencies may be overestimated due to neglecting the surface charge mobility effect. This paper develops a theoretical model for electrokinetic energy conversion in graphene nanochannels, considering the influence of surface charge mobility.
Article
Physics, Multidisciplinary
S. R. R. Reddy, H. Thameem Basha, Prakash Duraisamy
Summary: The study focuses on the energy loss in biological systems, particularly in the form of blood perfusion, and its consequences such as hypothermia and cardiovascular problems. It also examines the use of entropy generation in cancer treatment. A mathematical model is used to analyze the entropy generation of a gold-blood pseudoplastic nanofluid flow in a microchannel, considering electrokinetic force and electro-conductive heating. The results show that certain parameters, such as Hartmann number and electro-osmosis parameter, have significant effects on velocity and temperature profiles. The research sheds light on the understanding of energy loss in biological systems and has potential implications for medical treatments.
EUROPEAN PHYSICAL JOURNAL-SPECIAL TOPICS
(2022)
Article
Mathematics, Applied
Farida Aslam, Saima Noreen
Summary: An important mathematical model is created to investigate the effects of slip velocity and varied zeta potentials in an inclined asymmetric channel. The study focuses on the rheological impacts of these factors in an isotropic porous medium using the Bingham-Papanastasiou model. Analytical and numerical methods are used to evaluate the resulting non-dimensional system of equations, and the effects of various parameters on pumping, temperature, axial velocity, and trapping are studied. The results show the need for higher pressure in an inclined channel, the influence of zeta potentials and velocity slip conditions on channel flow, and the potential applications of the model in building pumping-based devices for physiological samples and fluids.
ZAMM-ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK
(2023)
Article
Chemistry, Multidisciplinary
Turash Haque Pial, Harnoor Singh Sachar, Parth Rakesh Desai, Siddhartha Das
Summary: This study uses molecular dynamics simulations to investigate the possibility of changing the direction of electroosmotic liquid flow in nanochannels by adjusting the electric field strength. The research explores the behavior of nanoconfined polyelectrolyte brushes, revealing an overscreening effect, specific ion distributions, and changes in brush height that lead to a reversal in the direction of electroosmotic transport.
Article
Mechanics
Yuki Uematsu
Summary: A general framework is constructed to calculate the nonlinear electrokinetic coefficients of strongly confined electrolytes, and analytic expressions are obtained. The study demonstrates the important role of high hydrodynamic permeability and ion-wall friction in nonlinear electrokinetics.
Article
Chemistry, Multidisciplinary
Chengfa Wang, Qi Gao, Yongxin Song
Summary: This paper investigates the electrokinetic effect at a two-liquid interface within a microchannel and explores the influence of surface zeta-potential and liquid phase height on the interface velocity. The results demonstrate that the direction and velocity of interface movement are determined by the zeta-potentials and height differences between the two liquids and the microchannel. This study has significant importance in understanding and manipulating fluid interface electrokinetic effects.
Article
Electrochemistry
Amin Alinezhad, Mahdi Khatibi, Seyed Nezameddin Ashrafizadeh
Summary: This article examines the use of nanofluidic membranes containing straight nanopores as nanotransistors, focusing on the PNP nanotransistor with its three regions representing the emitter, base, and collector. Applying voltage to the base region increases the current flowing between the emitter and collector regions. The study investigates the effect of electrolyte concentrations on the PNP nanotransistor's performance and suggests that adjusting these concentrations can enhance the device's functionality and open up new opportunities for nanoscale electronics.
ELECTROCHIMICA ACTA
(2023)
Article
Mathematics, Applied
Sameh A. Hussein, Sameh E. Ahmed, Anas A. M. Arafa
Summary: This paper presents a comprehensive study on the non-linear peristaltic transport in a vertical uniform/non-uniform channel filled with a Jeffery non-Newtonian nanofluid in the presence of oxytactic microorganisms. The effects of electrical and magnetic fields, linear radiation, and viscous dissipation on flow and heat transfer are analyzed. Numerical solutions for the governing system are introduced and the variations of parameters are discussed. The results show that maximizing the Brinkman number leads to higher features of the extra stress tensor. The velocity, microorganism density, and NP distributions are affected by me${m_e}$, while the temperature distributions are maximized as me${m_e}$ increases.
ZAMM-ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK
(2023)
Article
Thermodynamics
Shuai Yuan, Mingyong Zhou, Xijiang Liu, Bingyan Jiang
Summary: The coupling effect of pressure-driven flow (PDF) and electroosmotic flow (EOF) was studied in microfluidics. Numerical simulations were conducted to explore the interaction between these two flows under different Reynolds numbers (Re) to understand the pressure effect on mass species transport and sample separation. It was found that the pressure induced by PDF reduced separation quality and caused sample deformation. However, a novel porous polymer plug was introduced in the EOF channel to neutralize the outlet pressure and improve the separation effect.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Chemistry, Multidisciplinary
Peng Wu, Tao Sun, Xikai Jiang
Summary: This study investigates the influence of end-charged PELs and EDLs on the strength of EOF in nanochannels. The results show a non-monotonic variation of V-0 as the distance decreases, correlated with the conformation of PEs. These insights are important for designing highly efficient EKEC systems by grafting end-charged PELs onto channel surfaces.
Article
Mathematics
Jiaxuan Zheng, Beinan Jia, Yongjun Jian
Summary: The influence of steric effects on the performances of space electroosmotic thrusters (EOTs) was numerically analyzed in soft nanochannels covered with polyelectrolyte materials. The size effect of ionic species, known as steric effect, has significant impacts on electrostatic potential and electroosmotic velocity, affecting the thruster's thrust, specific impulse, total input power, efficiency, and thrust-to-power ratio. Although the thruster's thrust may increase with the steric parameter, the efficiency is only 30-70% in real situations taking ion size into consideration, with the peak values of thrust-to-power ratio diminishing.
Article
Engineering, Chemical
Jianglong Du, Haolan Tao, Jie Yang, Cheng Lian, Sen Lin, Honglai Liu
Summary: This study investigates the electrokinetic energy conversion efficiency in nanochannels through analysis and numerical calculations, finding that increasing the pore radius can improve efficiency, while surface roughness can affect fluid flow and ion transport, leading to variations in efficiency.
CHINESE JOURNAL OF CHEMICAL ENGINEERING
(2021)
Article
Chemistry, Physical
Mohammad Karimzadeh, Mahdi Khatibi, Seyed Nezameddin Ashrafizadeh, Pranab Kumar Mondal
Summary: This study investigates the effects of temperature and concentration gradients on salinity energy generation and determines the optimal conditions for maximum efficiency in funnel-shaped soft nanochannels. The results show that increasing temperature and concentration ratios significantly increase the salinity energy generation.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Mechanics
Souradeep Roychowdhury, Rajarshi Chattopadhyay, Sandip Sarkar
Summary: The thermofluidic characteristics of a combined pressure-driven and electrical field mediated flow of immiscible Newtonian and viscoelastic fluids in a microchannel were analyzed in this study. The results showed that increasing the viscoelastic parameter enhanced the velocity, flow rate, and stress of the fluid. Additionally, it was found that Joule heating and viscous dissipation altered the temperature distribution and decreased the Nusselt number.
Article
Chemistry, Physical
Amin Alinezhad, Mahdi Khatibi, Seyed Nezameddin Ashrafizadeh
Summary: This study investigated the impact of considering different properties for the soft layer and electrolyte on ion current rectification in bipolar soft nanochannels. The findings demonstrated that taking into account the differences in properties of the soft layer and electrolyte greatly improved the rectification factor.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Engineering, Chemical
Tong Liu, Moran Wang
Summary: Digital rock analysis provides a powerful tool for predicting geophysical properties and studying fluid and interfacial transport mechanisms in rocks, but there is a struggle to balance scanning resolution and sample size due to imaging technology limitations. The critical size of REV for multiphase flow in porous media is found beyond twice that for single-phase flow in this study, indicating the influence of phase interaction and wettability on relative permeability-saturation curve in multiphase flow.
TRANSPORT IN POROUS MEDIA
(2022)
Article
Mathematics, Interdisciplinary Applications
Fanli Liu, Moran Wang
Summary: This study evaluates the applicability of the macroscopic approach for the displacing process of droplets in micropores, identifying three size effects affecting the displacement results: Laplace pressure, low interfacial density, and breakdown of macroscopic description. The influence of system scale and fluid type on these size effects are further investigated, indicating that traditional macroscopic approach may be invalid even when continuum assumption still holds due to other size effects.
JOURNAL OF MULTISCALE MODELLING
(2022)
Article
Chemistry, Physical
Bin Liu, Yangyu Guo, Vladimir I. Khvesyuk, Alexander A. Barinov, Moran Wang
Summary: This theoretical investigation explores coherent-to-incoherent heat conduction in multilayer nanostructures, demonstrating that in the coherent regime, accurate predictions can be made using the elastic continuum model. The study shows that as temperature or system size increases, phonon dephasing scattering results in deviation from coherent-limit calculation, and by introducing phonon incoherence, classical minimum thermal conductivity can be reproduced, extending the pure wave model into the wave-particle crossing regime.
Article
Mechanics
Fanli Liu, Moran Wang
Summary: The preference of two-phase displacements was studied systematically through theoretical derivations and numerical simulations using a non-uniform pore doublet model. All major impact factors were taken into consideration to obtain a complete phase diagram for preferential flow. The results validate the simple treatment for dual-permeability media and extend the phase diagram's applicability to disordered permeable media in general, contributing to the understanding and manipulation of preferential flow in heterogeneous permeable media.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Energy & Fuels
Weiwei Zhu, Xupeng He, Yiteng Li, Gang Lei, Ryan Santoso, Moran Wang
Summary: This study uses a stochastic discrete fracture network method to simulate fractures in subsurface formations and conducts a sensitivity analysis. The results show that critically stressed fractures form the backbone of the stimulated reservoir volume (SRV), while partially open fractures can significantly enlarge the size of SRV. Fracture roughness is the most influential factor for the total length of critically stressed fractures, and the probability of open fractures is the most significant factor for the relative increase of SRV.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Geosciences, Multidisciplinary
Weiwei Zhu, Xupeng He, Gang Lei, Moran Wang
Summary: The systematic analysis of the complexity of fracture systems, especially in three-dimensional (3D) fracture networks, is currently insufficient. In this study, various fracture networks with different geometries were generated using a stochastic discrete fracture network method, and their complexity was quantified using fractal dimension and singularity variation in a multifractal spectrum. The influential factors of complexity, such as geometrical fracture properties and system size, were systematically investigated. The results show that different parameters have varying degrees of significance on the complexity at different stages of fracture network development.
JOURNAL OF STRUCTURAL GEOLOGY
(2022)
Article
Chemistry, Physical
Wenhai Lei, Xukang Lu, Moran Wang
Summary: Micro/nanoparticle suspensions can adjust multiphase displacement in porous media, which has wide applications in various scientific and industrial contexts. Direct observation of suspension flow dynamics and corresponding multiphase patterns is challenging due to the opaque realistic porous media. However, microfluidic experiments provide alternative methods to observe suspension influence on interface and multiphase flow behaviors at high resolutions, improving understanding and optimization of displacement mechanisms.
ADVANCES IN COLLOID AND INTERFACE SCIENCE
(2023)
Article
Thermodynamics
Van-Phung Mai, Tsung-Yu Lee, Ruey-Jen Yang
Summary: This study fabricated different types of droplet-triboelectric nanogenerators and investigated the effect of electrowetting-assisted charge injection on their performance. The results showed that composite materials doped with silk powder and polytetrafluoroethylene particles significantly increased the output current, and further performance enhancement could be achieved through appropriate design of the dielectric layer and operating conditions.
Article
Thermodynamics
Xin Ran, Yunfan Huang, Moran Wang
Summary: This paper proposes a hybrid Monte Carlo-discrete ordinates method (MC-DOM) for predicting phonon transport in mesoscopic systems with complex interfaces. The method combines the computational efficiency of DOM in the bulk region with the flexibility of MC near complex interfaces. It has been shown that the hybrid method runs faster than the pure particle method and is applicable for high-precision temperature calculation. The method enriches numerical tools for mesoscopic phonon transport simulation and contributes to the understanding and optimization of heat transport in micro/nanosystems with complex geometries.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Thermodynamics
Wuli Miao, Moran Wang
Summary: This study investigates thermal transport in metal/semiconductor multilayer films using the coupled electron and phonon Boltzmann transport equations combined with the phonon diffuse mismatch model. The importance of electron-phonon coupling transport and the critical thickness of the metal layer for considering this transport are demonstrated. The research findings provide insight into the manipulation of thermal conductivity in multilayers.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Engineering, Mechanical
Amer Alizadeh, Yunfan Huang, Fanli Liu, Hirofumi Daiguji, Moran Wang
Summary: Surface charging plays a crucial role in the stability of immiscible liquid-liquid interfaces, surfactant adsorption, drug delivery, and mineral flotation. This study presents an alternative experimental method using a streaming potential setup. A Y-Y shaped microchannel with a polymer-coated inner wall was employed to establish a flat and stable liquid-liquid interface. The method was successfully verified by investigating the charging of aqueous solution-silicon surface. The proposed method offers simplicity and flexibility for studying liquid-liquid interface charging mechanisms and inspiring quantitative macroscopic interfacial modeling.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Engineering, Chemical
Van-Phung Mai, Wei-Hao Huang, Yong-Lin Chang, Ruey-Jen Yang
Summary: This study investigates the capillary-driven energy conversion performance of a 2D composite membrane consisting of a graphene oxide (GO) matrix and natural silk fibers. The results show that the composite structure of the GO@silk membrane provides enhanced physical robustness and improved ion selectivity. The experimental results demonstrate high voltage and current outputs of 0.22 V and 12 μA, respectively, indicating the feasibility of using composite membrane structures for environmental energy conversion on a larger scale.
JOURNAL OF MEMBRANE SCIENCE
(2023)
Article
Thermodynamics
Wei-Hao Huang, Chih-Chang Chang, Ruey-Jen Yang
Summary: This study conducted numerical simulations to investigate the thermoelectric response in nanofluidic channels with slip mechanism. The results showed that temperature-dependent ion electrophoretic mobility and thermoosmosis dominate the thermoelectric performance. This study provides valuable insights for developing efficient nanofluidic-based thermoelectric generators.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Engineering, Multidisciplinary
Chun-Han Li, Zih-Jyun Lin, Chih-Chang Chang, Saman Rashidi, Wei-Mon Yan
Summary: In this study, an experimental investigation is conducted on a planar vacuum membrane dehumidifier equipped with a four-serpentine flow channel plate. The effects of different parameters on the dehumidification performance are investigated. The results show that the water collection capacity and water flux increase with increasing inlet air temperature; humidity has less effect on the pressure drop, and increasing vacuum pressure can reduce the pressure drop and total pumping power.
ALEXANDRIA ENGINEERING JOURNAL
(2023)
