Article
Mathematics, Applied
Orestes Tumbarell Aranda, Andre L. A. Penna, Fernando A. Oliveira
Summary: The study explored the self-organization evolution of a population using generalized reaction-diffusion equations, proposing a model based on non-local operators. By determining the conditions for spatial patterns and characteristics of the analyzed population, and simulating bacterial populations under non-homogeneous lighting conditions, the model was shown to reproduce experimental results not obtained by previous approaches.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2021)
Article
Chemistry, Physical
Junjie Chen, Jie Li, Xing Liu, Zhenglin He, Guosheng Shi
Summary: Selective transport of anions across graphene oxide membranes was found to deviate from the conventional order due to unexpectedly strong anion-pi interactions. The abnormal movement of fluoride anions in the membrane resulted in an anomalous transfer order. This study provides experimental evidence and improves our understanding of anion-pi interactions in the selective transport of anions across two-dimensional membranes.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Astronomy & Astrophysics
A. Varghese, R. P. Ratnasingam, R. Vanon, P. V. F. Edelmann, T. M. Rogers
Summary: Internal gravity waves have a significant impact on the mixing within the radiative interiors of stars. By studying the diffusion profiles of different mass and age models, we find that the mixing profile changes dramatically across age, with younger stars showing an increase in diffusion coefficient towards the surface and older stars experiencing a decreasing trend. Additionally, mixing is stronger in more massive stars. We propose a prescription to include this mixing in 1D stellar evolution models by identifying the dominant waves contributing to the mixing profiles.
ASTROPHYSICAL JOURNAL
(2023)
Article
Materials Science, Multidisciplinary
Gertjan Lippertz, Andrea Bliesener, Anjana Uday, Lino M. C. Pereira, A. A. Taskin, Yoichi Ando
Summary: Research has shown that the dissipationless state of QAHE can abruptly break down when the device dimensions are reduced or the current density is increased, with the electric field between opposing chiral edge states playing a key role, leading to electric-field-driven percolation of charge puddles as the most likely cause of the breakdown.
Article
Chemistry, Physical
Xiaorong Zhao, Yuying Liu, Dongdong Lin, Weiduo Zhu, Nan Ma, Wen Wu Xu, Wenhui Zhao, Yunxiang Sun, Xiao Cheng Zeng
Summary: This study uses molecular dynamics simulations to investigate the thermodynamic behavior of monolayer salt solution in subnanofluidic devices. The simulations demonstrate that the effective Coulombic interactions among Na+/Cl- ions have a strong impact on the behavior of the monolayer ionic aqueous solution. The findings reveal that the effective charges of the ions determine whether they dissolve in the monolayer water, assemble into nanocrystals, or exhibit gas-like behavior in the form of nanobubbles.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Multidisciplinary Sciences
Fabian R. Geisenhof, Felix Winterer, Anna M. Seiler, Jakob Lenz, Tianyi Xu, Fan Zhang, R. Thomas Weitz
Summary: In this study, a state with a conductance of 2e(2)h(-1) in bilayer graphene was discovered, exhibiting magnetic hysteresis and QAH behavior driven by orbital magnetism that can be tuned via electric and magnetic fields. The observed octet of QAH phases in bilayer graphene displays peculiar ferrimagnetic and ferrielectric order characterized by quantized anomalous charge, spin, valley and spin-valley Hall behavior.
Article
Chemistry, Multidisciplinary
Fengju Yao, Shunji Xia, Haoxiang Wei, Jiongzhi Zheng, Ziyuan Yuan, Yusheng Wang, Baoling Huang, Deyu Li, Hong Lu, Dongyan Xu
Summary: This study provides direct experimental evidence that superdiffusive thermal transport exists in SiGe alloys, as the thermal conductivity follows a power law relationship with film thickness. This research is significant for understanding the unique phenomenon of heat conduction.
Article
Materials Science, Multidisciplinary
Egor Kiselev
Summary: By using a hydrodynamic approach, it was shown that charge diffusion in two-dimensional Coulomb interacting liquids with broken momentum conservation is intrinsically anomalous. The charge relaxation is governed by an overdamped, superdiffusive plasmon mode, with diffusing particles following Levy flight trajectories. The study also explored the influence of magnetic fields on hydrodynamic collective modes, showing that they slow down the superdiffusive process.
Article
Multidisciplinary Sciences
Ankur Deep Bordoloi, David Scheidweiler, Marco Dentz, Mohammed Bouabdellaoui, Marco Abbarchi, Pietro de Anna
Summary: This study investigates the influence of dead-end pore structure on particle transport and dispersion using a microfluidic model system. The authors observe a tailing phenomenon in the arrival time distribution and explain it as a result of hopping and rolling of particles within dead-end pores. The results demonstrate the impact of microscopic flow structures on macroscopic particle transport.
NATURE COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
D. Y. Yan, M. Yang, P. B. Song, Y. T. Song, C. X. Wang, C. J. Yi, Y. G. Shi
Summary: In this study, single crystals of MnSb2Te4 were synthesized and its unique structural and magnetic properties were investigated, indicating its potential as a magnetic topological material. Below the Curie temperature, negative longitudinal magnetoresistance and anomalous Hall effect were observed, suggesting a significant connection between magnetism and transport carriers.
Article
Physics, Fluids & Plasmas
J. Cleland, M. A. K. Williams
Summary: This article explores the mathematical description of anomalous diffusion driven by internal stresses instead of thermal fluctuations. It outlines a continuous time random walk framework to describe the waiting times between displacements, and identifies the associated generalized diffusion equation. The probability density function and second moment display different characteristics at different timescales, transitioning between subdiffusive and diffusive behavior.
Article
Chemistry, Analytical
Chenliang Xie, Yanan Liu, Hao Luo, Guangyin Jing
Summary: Superdiffusion processes enhance the transport of passive particles in biological fluids. This study investigates how the activity of bacteria can improve the diffusivity of moving particles. The results show that higher activity levels significantly enhance the superdiffusion process of passive tracers. Furthermore, the number density of swimming bacteria and the surface properties of the microfluidic channel also affect the superdiffusion.
Article
Mathematics, Applied
Leszek Gasinski, Nikolaos S. Papageorgiou
Summary: This article investigates double phase problems with unbalanced and balanced growth and logistic reaction of the superdiffusive type. Existence and multiplicity results are proved, and the differences between the two cases are discussed.
NONLINEAR ANALYSIS-REAL WORLD APPLICATIONS
(2023)
Article
Engineering, Environmental
Yaqiang Wei, Xiaoyun Xu, Ling Zhao, Xiang Chen, Hao Qiu, Bin Gao, Xinde Cao
Summary: The fluctuation of groundwater table plays a significant role in the reduction of Cr(VI) in the lower soil layer, and the rise in water level leads to an increase in Cr(III) concentration. The hydrodynamic conditions impact the redox environment of soil, affecting the transformation and transport of Cr.
JOURNAL OF HAZARDOUS MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Jiaji Zhao, Bingyan Jiang, Jinying Yang, Lujunyu Wang, Hengjie Shi, Guang Tian, Zhilin Li, Enke Liu, Xiaosong Wu
Summary: In a magnetic metal, the sum of the ordinary Hall resistance and the anomalous Hall resistance is generally considered as the Hall resistance. However, this empirical relation is no longer valid when either the ordinary Hall angle or the anomalous Hall angle is not small. By using the proper conductivity relation, a B-linear magnetoresistance induced by the anomalous Hall effect (AHE) is revealed, which gives rise to a characteristic bowtie shape depending on the sign of the anomalous Hall angle. The nonlinearity of the Hall resistance in a single-band system and the appearance of a B-symmetric component in the Hall reflect the fundamental difference between the ordinary Hall effect and the AHE. Furthermore, the proposed mechanism can well explain the unusual magnetoresistance and Hall effect observed in Co3Sn2S2.
Article
Engineering, Chemical
Philippe Gouze, Alexandre Puyguiraud, Delphine Roubinet, Marco Dentz
Summary: This study investigates the pore-scale transport of a passive solute in three types of reservoir rocks with different heterogeneity characteristics. Two numerical modeling methods are used to compare the impact of pore-scale flow velocity distribution on large-scale transport behavior. Results show that the presence of numerical dispersion does not significantly affect the simulated large-scale transport compared to the impact of velocity fluctuations.
TRANSPORT IN POROUS MEDIA
(2023)
Article
Engineering, Chemical
Michael J. Schmidt, Nicholas B. Engdahl, David A. Benson, Diogo Bolster
Summary: This research provides formal criteria for choosing the optimal time step length in Lagrangian mass-transfer-based interacting particle methods and validates it through numerical experiments.
TRANSPORT IN POROUS MEDIA
(2023)
Article
Engineering, Chemical
Lazaro J. Perez, Alexandre Puyguiraud, Juan J. Hidalgo, Joaquin Jimenez-Martinez, Rishi Parashar, Marco Dentz
Summary: We study mixing-controlled chemical reactions in unsaturated porous media from a pore-scale perspective. The results show that there is a significant increase in reactive mixing for decreasing saturation, which is caused by the stronger heterogeneity of the water phase and flow field.
TRANSPORT IN POROUS MEDIA
(2023)
Article
Biochemistry & Molecular Biology
Pedro F. P. Brandao-Dias, Daniel M. C. Hallack, Elise D. D. Snyder, Jennifer L. L. Tank, Diogo Bolster, Sabrina Volponi, Arial J. J. Shogren, Gary A. A. Lamberti, Kyle Bibby, Scott P. P. Egan
Summary: Environmental DNA (eDNA) analysis is a powerful tool for detecting target organisms remotely. This study explores the possibility of obtaining longitudinal dynamics information on targets by separating different size components of eDNA within a sample. The results show that medium-sized particles decay more slowly and increase in proportion over time. Different sizes of eDNA particles do not decay independently, but a parsimonious mathematical model best explains the data. A framework for discerning target distance and abundance with eDNA data is proposed.
MOLECULAR ECOLOGY RESOURCES
(2023)
Editorial Material
Engineering, Chemical
Marco Dentz, Daniel R. Lester, Michel F. M. Speetjens
TRANSPORT IN POROUS MEDIA
(2023)
Article
Environmental Sciences
Ilan Ben-Noah, J. J. Hidalgo, Joaquin Jimenez-Martinez, Marco Dentz
Summary: In this study, the upscaling of pore-scale solute transport in partially saturated porous media at different saturation degrees was investigated. It was found that the interaction between structural heterogeneity, phases distribution, and small-scale flow dynamics leads to complex flow patterns and broad probability distributions of flow. A continuous-time random walk (CTRW) framework was used to upscale and evaluate the transport of diluted solutes, and the results were compared to direct numerical simulations. The analysis showed that the fluid phase saturation, as well as the Peclet number, influenced the advective tortuosity, characteristic length, fraction of immobile region, mean trapping time, trapping length, and trapping frequency.
WATER RESOURCES RESEARCH
(2023)
Article
Environmental Sciences
Marie-Madeleine Stettler, Marco Dentz, Olaf A. A. Cirpka
Summary: Macrodispersion in heterogeneous formations is caused by spatial variability of the velocity field. Differential advection interacts with diffusion to determine effective dispersion, while pure advection is reversible and diffusion is irreversible. We found that the reversibility of macrodispersion is bigger for ensemble dispersion than for effective dispersion, challenging the use of the latter as a metric of mixing.
WATER RESOURCES RESEARCH
(2023)
Article
Geosciences, Multidisciplinary
Oshri Borgman, Regis Turuban, Baudouin Geraud, Tanguy Le Borgne, Yves Meheust
Summary: In subsurface environments, incomplete mixing at the pore scale limits reaction rates, making it difficult to predict them using Darcy-scale models. Pore-scale concentration gradients are enhanced by the deformation of solute fronts and decay under molecular diffusion and solute filament merging. However, the dependence of concentration gradient dynamics on flow rates is still unclear. This study experimentally measures pore-scale concentrations in solute fronts and reveals that pore-scale shear flow increases concentration gradients up to a predicted time, but the flow rate-dependency of the mean concentration gradient is weaker than expected due to lamellae aggregation.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Environmental Sciences
Daniel R. Lester, Marco Dentz, Prajwal Singh, Aditya Bandopadhyay
Summary: This study compares the transverse macrodispersion in porous media with different conductivity structures under purely advective transport. It is found that porous media with smooth, locally isotropic hydraulic conductivity exhibit zero transverse macrodispersion, while non-smooth or locally anisotropic conductivity fields can generate transverse macrodispersion. These findings provide insights into the mechanisms that govern transverse macrodispersion in groundwater flow.
WATER RESOURCES RESEARCH
(2023)
Article
Physics, Fluids & Plasmas
A. Ganesh, C. Douarche, M. Dentz, H. Auradou
Summary: This paper presents a numerical study on the dispersion of bacteria in a plane Poiseuille flow, modeling the bacteria as active Brownian ellipsoids. The longitudinal and transverse macroscopic dispersion coefficients are determined and their scaling with the Peclet number is studied. Three different regimes are observed: a Taylor dispersion regime at low shear rate, an intermediate active regime with increased longitudinal dispersion and decreased transverse dispersion, and a new Taylor regime with diffusivity determined by molecular diffusion coefficient. The active regime is shown to originate from the increased time taken by particles to diffuse across the channel gap, and the transition to the active regime is delayed by decreasing the channel height.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Geosciences, Multidisciplinary
Marco Dentz, James W. Kirchner, Erwin Zehe, Brian Berkowitz
Summary: In this study, we investigate anomalous transport in a hydrological catchment system over a 36-year period at kilometer scales. Using spectral analysis, we examine the fluctuation scaling of long-term time series measurements of chloride, a natural passive tracer, for rainfall and runoff. The findings suggest that the scaling behavior can be described by a continuous time random walk (CTRW) based on a power-law distribution of transition times, indicating the presence of two distinct power-law regimes in the overall travel time distribution in the catchment. The CTRW framework provides a means to assess anomalous transport in catchments and its implications for water quality fluctuations.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geosciences, Multidisciplinary
Ran Holtzman, Marco Dentz, Ramon Planet, Jordi Ortin
Summary: We develop a thermodynamic framework for quasistatic dissipative systems with multiple metastable states by utilizing the return-point memory of cyclic macroscopic trajectories. Using this framework, we analyze and quantify the energy dissipation during quasistatic fluid-fluid displacements in disordered media. Numerical computations reveal that energy dissipation in quasistatic displacements is primarily caused by abrupt changes in the fluid-fluid configuration between consecutive metastable states (Haines jumps), which depend on microstructure and gravity. Comparison with quasistatic experiments helps determine the relative importance of viscous dissipation.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Environmental Sciences
Satoshi Izumoto, Joris Heyman, Johan Alexander Huisman, Kevin De Vriendt, Cyprien Soulaine, Francesco Gomez, Herve Tabuteau, Yves Meheust, Tanguy Le Borgne
Summary: Mixing fronts at the interface of opposing flows are compressed at a constant rate, leading to enhanced chemical gradients and biogeochemical processes. This study investigates how fluid compression controls the amplitude of mixing and reaction rates in porous media. The experimental and numerical results provide new insights into the dynamics of mixing-induced reactions in porous media.
WATER RESOURCES RESEARCH
(2023)
Article
Environmental Sciences
Aronne Dell'Oca, Marco Dentz
Summary: In this study, we focus on the upscaling and prediction of ensemble dispersion in two-dimensional heterogeneous porous media, specifically transverse dispersion. We investigate the stochastic dynamics of advective particles in the heterogeneous flow field and find that transverse dispersion exhibits ultraslow diffusion due to the solenoidal character of the flow field. By analyzing particle velocities and orientations through equidistant sampling along particle trajectories obtained from direct numerical simulations, we derive a stochastic model that combines correlated Gaussian noise for transverse motion and a spatial Markov model for particle speeds. We compare the model results with detailed numerical simulations in different heterogeneous porous media.
WATER RESOURCES RESEARCH
(2023)
Article
Geosciences, Multidisciplinary
Lucas Schauer, Michael J. Schmidt, Nicholas B. Engdahl, Stephen D. Pankavich, David A. Benson, Diogo Bolster
Summary: This article presents a parallelized domain decomposition strategy for mass-transfer particle tracking methods. Different tiling techniques for two and three dimensions are investigated and an optimal tiling is determined based on problem parameters and the number of CPU cores. The efficiency of the parallelized algorithms is demonstrated with simulations of a pure diffusion problem.
GEOSCIENTIFIC MODEL DEVELOPMENT
(2023)