Article
Mechanics
M. Nakad, T. Witelski, J. C. Domec, S. Sevanto, G. Katul
Summary: Sucrose, a main product of photosynthesis necessary for plant growth, is transported through phloem in a process described by the Munch pressure and mass flow model. This study revisits osmotically driven flows by considering the effects of Taylor dispersion on mass transport, which has been overlooked in phloem flow studies. It is shown that Taylor dispersion can enhance sucrose transport by increasing the apparent diffusion coefficient.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Computer Science, Interdisciplinary Applications
D. Dupuy, N. Odier, C. Lapeyre
Summary: This paper examines a data-driven approach for modeling the wall shear stress in large-eddy simulation of high Reynolds number wall-bounded turbulent flows. The model is a multilayer perceptron based on flow information near the wall, and it is able to extrapolate to unseen flow conditions. The model is verified using filtered numerical data and implemented in wall-modeled large-eddy simulations, showing its ability to discriminate developed wall turbulence and separated regions.
JOURNAL OF COMPUTATIONAL PHYSICS
(2023)
Article
Biotechnology & Applied Microbiology
Zhen-Shen Liew, Yeek-Chia Ho, Woei Jye Lau, Wirote Youravong, Tippawan Sirinupong, Yong Yeow Liang
Summary: This study evaluated the potential of using polymeric membranes to concentrate coconut water at room temperature via either a pressure-driven or osmotically driven process. The results showed that the membrane tested under reverse osmosis (RO) mode could significantly concentrate coconut water by reducing its volume by up to half, with negligible loss of ions/minerals. Compared to this, the membrane tested under pressure-retarded osmosis (PRO) mode could only reduce the volume of coconut water by about 12%.
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
(2023)
Article
Computer Science, Interdisciplinary Applications
Marin Lauber, Gabriel D. Weymouth, Georges Limbert
Summary: Immersed boundary methods are widely used for simulating interactions between dynamic solid objects and fluids due to their computational efficiency and modeling flexibility. However, thin geometries often violate the boundary conditions in existing immersed boundary projection algorithms. This study proposes a minimal thickness modification for the Boundary Data Immersion Method (BDIM-sigma) to address this issue and improve the accuracy of high-speed immersed surface simulations.
JOURNAL OF COMPUTATIONAL PHYSICS
(2022)
Article
Thermodynamics
Chongyang Yan, Haoran Li, Yufei Zhang, Haixin Chen
Summary: This paper implements a data-driven Reynolds-averaged turbulence modeling approach using field inversion and machine learning to modify the Spalart-Allmaras model. The results show that the augmented model can reproduce the quantity of interest with relatively high accuracy and has a certain extent of generalization ability in similar flow conditions.
INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW
(2022)
Article
Physics, Applied
G. Sanchez, F. Mendez
Summary: This paper proposes a theoretical study on power generation through streaming potential and osmotic gradients. The system consists of an osmotic membrane with different saline concentrations on each side and a microchannel with parallel plates made of modified hydrophobic fumed silica. The equations are written in dimensionless variables and solved using integrodifferential methods, allowing for semi-analytical solutions for velocity, pressure fields, and electric potential. The study demonstrates that hydrophobic surfaces enhance induced streaming potential, but a saturation phenomenon occurs for high potentials.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Engineering, Chemical
Christian D. Peters, Daniel Yee Fan Ng, Nicholas P. Hankins, Qianhong She
Summary: Membrane deformation in pressurized membrane processes can affect membrane transport and structural characteristics, leading to lower process performance. Accurate characterization of the membrane is essential for optimizing design and operation. A novel membrane characterization method, the integrated two-stage ABS method, provides more accurate predictions of membrane properties compared to the widely used RO-FO method.
JOURNAL OF MEMBRANE SCIENCE
(2021)
Article
Engineering, Chemical
Ralph Rolly Gonzales, Keizo Nakagawa, Susumu Hasegawa, Atsushi Matsuoka, Kazuo Kumagai, Tomohisa Yoshioka, Hideto Matsuyama
Summary: Ammoniacal nitrogen is a common nitrogenous pollutant in wastewater from industrial processes. This study demonstrated the osmotically assisted reverse osmosis (OARO) process using a multi-stage hollow fiber membrane module setup, with model wastewater containing ammoniacal nitrogen as the feed solution. The OARO process aimed to concentrate and recover the ammoniacal nitrogen from the wastewater. The concentration efficiency of OARO was influenced by operational parameters such as applied pressure, feed flow rate, and reflux ratio, as well as the properties of the feed solution.
JOURNAL OF MEMBRANE SCIENCE
(2023)
Article
Engineering, Electrical & Electronic
Yong Yu, Ji-Cheng Li, Hai Lin, Kai Li, Fu-ting Yi
Summary: The performance of alternating current electroosmosis (ACEO) in ethanol solutions containing different electrolytes was investigated using asymmetric microelectrode arrays and traveling-wave microelectrode arrays in microchannels. The results showed that stable and intense ACEO flow was observed only in ethanol solutions containing KOH and CH3COONH4, with optimal flow rates achieved at specific solution conductivities and AC frequencies. Furthermore, no damage was observed on the microelectrodes after the experiments.
SENSORS AND ACTUATORS A-PHYSICAL
(2023)
Article
Biochemistry & Molecular Biology
Peng Xie, Tzahi Y. Cath, David A. Ladner
Summary: The combination of computational fluid dynamics modeling with solute transport evaluation is a reliable tool to predict water flux and study hydrodynamics and concentration polarization in osmotically driven membrane processes. Feed spacers have been found to impact the velocity and concentration distribution inside flow channels, potentially enhancing or reducing water flux depending on the specific conditions.
Article
Engineering, Multidisciplinary
Zeeshan Asghar, Muhammad Waqas, Muhammad Asif Gondal, Waqar Azeem Khan
Summary: Theoretical analysis of electro-osmosis peristaltic flow of generalized Newtonian fluid bounded in a complex wavy divergent channel is performed, considering the Ellis fluid model. The flow equations are modelled using balances of mass and momentum and the body force term is introduced using the Poisson equation. Analytical and numerical solutions are presented, analyzing the influence of diverse rheological and electrical parameters on flow characteristics via plots.
ALEXANDRIA ENGINEERING JOURNAL
(2022)
Article
Biochemistry & Molecular Biology
Endre Nagy, Imre Hegedus, Danyal Rehman, Quantum J. Wei, Yvana D. Ahdab, John H. Lienhard
Summary: This study compared the use of van 't Hoff linear relation and OLI Stream Analyzer in predicting osmotic pressure of NaCl solutions, revealing significant discrepancies in predicted values. Experimental results for membranes and theoretical equations were developed, showing the importance of considering external mass transfer coefficients in evaluating structural parameters to avoid overestimation. The deviation between the linear approach and real values increases with higher NaCl concentrations, indicating potential errors in van 't Hoff predictions.
Article
Physics, Multidisciplinary
Saraswat Bhattacharyya, Julia M. Yeomans
Summary: We present an extension of continuum theories of active nematohydrodynamics to investigate the behavior of a two-fluid mixture with separate velocity fields for each component. The interaction between active anchoring and active flows driven by concentration gradients leads to microphase separation in an active nematic fluid mixed with an isotropic fluid. These findings have potential implications for understanding cell sorting processes and the formation of lipid rafts in cell membranes.
PHYSICAL REVIEW LETTERS
(2023)
Article
Thermodynamics
Farhad A. Amiri, Junfeng Zhang
Summary: The paper introduces an immersed membrane method for simulating mass transfer across flexible semipermeable membranes, effectively addressing technical challenges. By replacing the sharp membrane interface with an immersed membrane layer, the mass transfer process can be solved using a uniform numerical scheme. Validation and demonstration simulations show that the method accurately represents the membrane effect on mass transfer.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2021)
Article
Mechanics
Yifei Guan, Tianhang Yang, Jian Wu
Summary: The study investigates electrokinetic flow in a microchannel driven by charged surface heterogeneity in the presence of an external electric field through three-dimensional simulations. It is found that the magnitude of the external electric field affects the mixing and transport enhancement of passive scalars by induced electrokinetic vortices.
Article
Plant Sciences
Grayson P. Ostermeyer, Kaare H. Jensen, Aslak R. Franzen, Winfried S. Peters, Michael Knoblauch
Summary: Conical, funnel-shaped cell wall pores have been found in plant tissues, enabling symplasmic transport. These pores decrease both diffusive and hydraulic resistance compared with cylindrical channels, and are present in specific cell-cell interfaces in plant roots.
Article
Physics, Fluids & Plasmas
Jolet de Ruiter, Emil Visby Ostergaard, Sean Marker, Kaare H. Jensen
Summary: This paper investigates the opening and closing process of telescoping boxes, and finds that the process is mainly controlled by the shape of the gap between the base and the lid. An optimal design for rapidly closing boxes is also identified.
PHYSICAL REVIEW FLUIDS
(2022)
Article
Physics, Fluids & Plasmas
Sooyoung Chang, Kaare H. Jensen, Wonjung Kim
Summary: This study presents experimental and theoretical investigations on the water flow through capillaries coated with a hydrogel layer. The results provide insights into how the absorption and swelling of hydrogel regulate capillary flow, which is significant for engineering applications of hydrogel materials.
PHYSICAL REVIEW FLUIDS
(2022)
Article
Chemistry, Multidisciplinary
Nikolaj K. Mandsberg, Anna Shneidman, Kaare H. Jensen, Rafael Taboryski, Line H. Nielsen, Joanna Aizenberg, Anja Boisen
Summary: A method of producing droplet arrays with gradients in droplet height by dip-coating uniformly patterned biphilic substrates in acceleration-mode has been developed, allowing for the adjustment of droplet characteristics and demonstrating promising applications in experiments.
ADVANCED MATERIALS INTERFACES
(2022)
Article
Biology
M. Rode, A. Bioue, F. Miano, H. Bruus, T. Kiorboe, A. Andersen
Summary: This study demonstrates the construction and application of an acoustic tethering setup for behavioral observations of individual microorganisms using simple laboratory equipment and a standard light microscope. The setup allows tethering of cells in focus in the mid-plane of the sample chamber, enabling high magnification observations without affecting flagellar beat frequencies. The method has the potential to explore appendage motion and swimming kinematics of various flagellates and ciliates.
JOURNAL OF EXPERIMENTAL BIOLOGY
(2022)
Article
Chemistry, Analytical
Fabian Lickert, Henrik Bruus, Massimiliano Rossi
Summary: This study examines the effects of supplying a piezoelectric transducer with constant voltage or constant power during a frequency sweep on acoustofluidic resonance frequencies. It is shown that providing constant average power dissipation in the transducer is the most reliable approach for characterizing the intrinsic properties of acoustofluidic devices.
Article
Chemistry, Multidisciplinary
Ritesh Prakash, Jinseok Lee, Youngkwang Moon, Diva Pradhan, Seung-Hyun Kim, Ho-Yong Lee, Jinkee Lee
Summary: This study investigates the effects of different surfactants and pH mediums on the formation, diameter, concentration, size distribution, zeta-potential, and stability of nanobubbles (NBs). The results show that the diameter, concentration, size distribution, and stability of NBs are strongly influenced by the zeta-potential rather than the solution medium. NBs have a longer lifespan in pure water, surfactant, and pH mediums, but a shorter lifespan in environments with a pH <= 3.
Article
Physics, Multidisciplinary
Jonas Helboe Joergensen, Wei Qiu, Henrik Bruus
Summary: This study investigates acoustic streaming at high acoustic energy densities in a microfluidic channel. The results obtained from theoretical, numerical, and experimental methods demonstrate that frictional heating can significantly alter the streaming pattern at energy densities above 400 J/m3. The study shows that with increasing energy density at a fixed frequency, the traditional boundary-driven four streaming rolls transition into two larger streaming rolls.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Applied
Matthew D. Biviano, Magnus Paludan, Anneline H. Christensen, Emil Ostergaard, Kaare H. Jensen
Summary: Pulsating flows are common in various systems, but are often undesired. This study explores the use of a plant-inspired nonlinear resistor to smooth the output of a peristaltic pump, significantly reducing oscillation amplitudes. The observed flow kinetics align well with a predictive model, enabling the development of optimized fluid-handling systems driven by pulsatile flow.
PHYSICAL REVIEW APPLIED
(2022)
Article
Instruments & Instrumentation
Seongsu Cho, Jihyeong Lee, Sun Cheol Park, Hoon Suk Park, Dae Hee Lee, Jinkee Lee
Summary: A pulsatile flow generator was developed to mimic blood flow, providing cost effectiveness and user convenience. The device achieved blood flow in the superior and inferior vena cava with a 3.3% error using iterative learning control. The study also measured the recirculation ratios based on different insertion directions and external pipe materials to assess the catheter's performance under different conditions.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
Article
Plant Sciences
Chen Gao, Sean J. Marker, Carsten Gundlach, Henning F. Poulsen, Tomas Bohr, Alexander Schulz
Summary: This study investigates the transportation pathway of photoassimilates and nutrients in conifer needles and reveals the functional 3D structure of the transfusion tissue in the bundle sheath. The results highlight the crucial role of the bundle sheath in nutrient and assimilate exchange.
JOURNAL OF EXPERIMENTAL BOTANY
(2023)
Article
Plant Sciences
Alexander H. Howell, Carsten Voelkner, Patrick McGreevy, Kaare H. Jensen, Rainer Waadt, Simon Gilroy, Hans-Henning Kunz, Winfried S. Peters, Michael Knoblauch
Summary: The micro-cantilever technique applied to individual leaf epidermis cells of Arabidopsis thaliana and Nicotiana tabacum revealed that compressive forces induced local calcium peaks followed by slowly moving calcium waves. Releasing the force triggered significantly faster calcium waves. Different wave characteristics suggest distinct mechanisms and the ability of plants to distinguish touch signals from release signals.
Article
Physics, Fluids & Plasmas
Bjorn G. Winckelmann, Henrik Bruus
Summary: General analytical expressions for the time-averaged acoustic radiation force on a small spherical particle suspended in a fluid and located in an axisymmetric incident acoustic wave are derived in this study. The cases of elastic solid and fluid particles are considered, and the effects of particle vibrations, acoustic scattering, acoustic microstreaming, heat conduction, and temperature-dependent fluid viscosity are all taken into account. Acoustic streaming inside the particle is also considered for the case of a fluid particle. No restrictions are placed on the widths of the viscous and thermal boundary layers relative to the particle radius. The resulting acoustic radiation force is compared with previous theories in the literature, and limits of agreement as well as deviations in specific cases of particle and fluid materials are identified.
Article
Physics, Fluids & Plasmas
Jonas Helboe Joergensen, Henrik Bruus
Summary: A theoretical and numerical model is proposed in this study to investigate the thermal boundary layers and acoustic heating in microscale acoustofluidic devices. The model allows for simulation of nonlinear thermoviscous effects and three-dimensional flow using effective boundary conditions. The results demonstrate the local heating caused by friction in the boundary layers and the dominant thermoacoustic bulk streaming at high acoustic energy densities. This model is valuable for the design and fabrication of high-throughput acoustofluidic devices.
Article
Engineering, Chemical
Saebom Lee, Jihyeong Lee, Minki Lee, Hyejeong Kim, Gyoujin Cho, Jinkee Lee
Summary: This study numerically investigated the mixing performance of a rotating channel based on the Coriolis force with herringbone grooves. Mixing was maximized when the Coriolis force was appropriately balanced with the centrifugal force. The addition of herringbone grooves improved mixing, achieving up to >90% for the shortest channel length.
CHEMICAL ENGINEERING SCIENCE
(2024)