Thematische Bibliographien / Équations de Poisson-Nernst Planck

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Veröffentlicht am 28. September 2024

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Zeitschriftenartikel zum Thema "Équations de Poisson-Nernst Planck"

Zheng, Qiong, und Guo-Wei Wei. „Poisson–Boltzmann–Nernst–Planck model“. Journal of Chemical Physics 134, Nr. 19 (21.05.2011): 194101. http://dx.doi.org/10.1063/1.3581031.

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Xie, Yan, Jie Cheng, Benzhuo Lu und Linbo Zhang. „Parallel Adaptive Finite Element Algorithms for Solving the Coupled Electro-diffusion Equations“. Computational and Mathematical Biophysics 1 (24.04.2013): 90–108. http://dx.doi.org/10.2478/mlbmb-2013-0005.

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Abstractrithms for solving the 3D electro-diffusion equations such as the Poisson-Nernst-Planck equations and the size-modified Poisson-Nernst-Planck equations in simulations of biomolecular systems in ionic liquid. A set of transformation methods based on the generalized Slotboom variables is used to solve the coupled equations. Calculations of the diffusion-reaction rate coefficients, electrostatic potential and ion concentrations for various systems verify the method’s validity and stability. The iterations between the Poisson equation and the Nernst- Planck equations in the primitive method and in the transformation method are compared to illustrate how the new method accelerates the convergence of the solution. To speed up the convergence, we introduce the DIIS (direct inversion of the iterative subspace) method including Simple Mixing and Anderson Mixing as under-relaxation techniques, the effectiveness of which on acceleration is shown by numerical tests. It is worth noting that the primitive method fails to solve the size-modified Poisson-Nernst-Planck equations for real protein systems but the transformation method succeeds in the simulations of the ACh-AChE reaction system and the DNA fragment. To improve the accuracy of the solution, we introduce high order elements and mesh adaptation based on an a posteriori error estimator. Numerical results indicate that our mesh adaptation process leads to quasi-optimal convergence. We implement our algorithms using the parallel adaptive finite element package PHG [53] and high parallel efficiency is obtained.

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Yang, Ying, und Benzhuo Lu. „An Error Analysis for the Finite Element Approximation to the Steady-State Poisson-Nernst-Planck Equations“. Advances in Applied Mathematics and Mechanics 5, Nr. 1 (Februar 2013): 113–30. http://dx.doi.org/10.4208/aamm.11-m11184.

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AbstractPoisson-Nernst-Planck equations are a coupled system of nonlinear partial differential equations consisting of the Nernst-Planck equation and the electrostatic Poisson equation with delta distribution sources, which describe the electrodiffusion of ions in a solvated biomolecular system. In this paper, some error bounds for a piecewise finite element approximation to this problem are derived. Several numerical examples including biomolecular problems are shown to support our analysis.

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Hineman, Jay L., und Rolf J. Ryham. „Very weak solutions for Poisson–Nernst–Planck system“. Nonlinear Analysis: Theory, Methods & Applications 115 (März 2015): 12–24. http://dx.doi.org/10.1016/j.na.2014.11.018.

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Eisenberg, Bob, Tzyy-Leng Horng, Tai-Chia Lin und Chun Liu. „Steric PNP (Poisson-Nernst-Planck): Ions in Channels“. Biophysical Journal 104, Nr. 2 (Januar 2013): 509a. http://dx.doi.org/10.1016/j.bpj.2012.11.2809.

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González Granada, José Rodrigo, und Victor A. Kovtunenko. „Entropy method for generalized Poisson–Nernst–Planck equations“. Analysis and Mathematical Physics 8, Nr. 4 (November 2018): 603–19. http://dx.doi.org/10.1007/s13324-018-0257-1.

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Prohl, Andreas, und Markus Schmuck. „Convergent discretizations for the Nernst–Planck–Poisson system“. Numerische Mathematik 111, Nr. 4 (26.11.2008): 591–630. http://dx.doi.org/10.1007/s00211-008-0194-2.

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Kato, Masayuki. „Numerical analysis of the Nernst-Planck-Poisson system“. Journal of Theoretical Biology 177, Nr. 3 (Dezember 1995): 299–304. http://dx.doi.org/10.1006/jtbi.1995.0247.

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Meng, Da, Bin Zheng, Guang Lin und Maria L. Sushko. „Numerical Solution of 3D Poisson-Nernst-Planck Equations Coupled with Classical Density Functional Theory for Modeling Ion and Electron Transport in a Confined Environment“. Communications in Computational Physics 16, Nr. 5 (November 2014): 1298–322. http://dx.doi.org/10.4208/cicp.040913.120514a.

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AbstractWe have developed efficient numerical algorithms for solving 3D steady-state Poisson-Nernst-Planck (PNP) equations with excess chemical potentials described by the classical density functional theory (cDFT). The coupled PNP equations are discretized by a finite difference scheme and solved iteratively using the Gummel method with relaxation. The Nernst-Planck equations are transformed into Laplace equations through the Slotboom transformation. Then, the algebraic multigrid method is applied to efficiently solve the Poisson equation and the transformed Nernst-Planck equations. A novel strategy for calculating excess chemical potentials through fast Fourier transforms is proposed, which reduces computational complexity from O(N2) to O(NlogN), where N is the number of grid points. Integrals involving the Dirac delta function are evaluated directly by coordinate transformation, which yields more accurate results compared to applying numerical quadrature to an approximated delta function. Numerical results for ion and electron transport in solid electrolyte for lithiumion (Li-ion) batteries are shown to be in good agreement with the experimental data and the results from previous studies.

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Chaudhry, Jehanzeb Hameed, Jeffrey Comer, Aleksei Aksimentiev und Luke N. Olson. „A Stabilized Finite Element Method for Modified Poisson-Nernst-Planck Equations to Determine Ion Flow Through a Nanopore“. Communications in Computational Physics 15, Nr. 1 (Januar 2014): 93–125. http://dx.doi.org/10.4208/cicp.101112.100413a.

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AbstractThe conventional Poisson-Nernst-Planck equations do not account for the finite size of ions explicitly. This leads to solutions featuring unrealistically high ionic concentrations in the regions subject to external potentials, in particular, near highly charged surfaces. A modified form of the Poisson-Nernst-Planck equations accounts for steric effects and results in solutions with finite ion concentrations. Here, we evaluate numerical methods for solving the modified Poisson-Nernst-Planck equations by modeling electric field-driven transport of ions through a nanopore. We describe a novel, robust finite element solver that combines the applications of the Newton’s method to the nonlinear Galerkin form of the equations, augmented with stabilization terms to appropriately handle the drift-diffusion processes.To make direct comparison with particle-based simulations possible, our method is specifically designed to produce solutions under periodic boundary conditions and to conserve the number of ions in the solution domain. We test our finite element solver on a set of challenging numerical experiments that include calculations of the ion distribution in a volume confined between two charged plates, calculations of the ionic current though a nanopore subject to an external electric field, and modeling the effect of a DNA molecule on the ion concentration and nanopore current.

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Dissertationen zum Thema "Équations de Poisson-Nernst Planck"

Paragot, Paul. „Analyse numérique du système d'équations Poisson-Nernst Planck pour étudier la propagation d'un signal transitoire dans les neurones“. Electronic Thesis or Diss., Université Côte d'Azur, 2024. http://www.theses.fr/2024COAZ5020.

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Les questions neuroscientifiques concernant les dendrites incluent la compréhension de leur plasticité structurale en réponse à l'apprentissage et la manière dont elles intègrent les signaux. Les chercheurs visent à élucider ces aspects pour améliorer notre compréhension de la fonction neuronale et de ses complexités. Cette thèse vise à offrir des perspectives numériques concernant la dynamique du voltage et des ions dans les dendrites. Notre objectif est de modéliser l'excitation neuronale dans les dendrites. Nous abordons la dynamique ionique suite à l'afflux de signaux nerveux. Pour les simuler précisément, nous résolvons le système d'équations Poisson-Nernst-Planck (PNP). Le système PNP est reconnu comme le modèle standard pour caractériser le phénomène d'électrodiffusion des ions dans les électrolytes, y compris les structures dendritiques. Ce système non linéaire présente des défis en modélisation et en calcul en raison de la présence de couches limites rigides (BL). Nous proposons des schémas numériques basés sur la méthode des volumes finis Discrete Duality Finite Volumes (DDFV) pour résoudre le système PNP. Elle permet un raffinement local du maillage au niveau de la BL, en utilisant des maillages généraux. Cette approche facilite la résolution du système sur un domaine 2D représentant la géométrie des dendrites. Nous utilisons des schémas numériques préservant la positivité des concentrations ioniques. Chapitres 1 et 2 présentent le système PNP et la méthode DDFV ainsi que ses opérateurs discrets. Le chapitre 2 présente un couplage "linéaire" des équations et explore son schéma numérique associé. Ce couplage a des problèmes de convergence, où nous illustrons ses limites à travers des résultats numériques. Le chapitre 3 introduit un couplage "non linéaire", permettant une résolution numérique précise du système PNP. Les deux couplages sont effectués avec la méthode DDFV. Dans le chapitre 3, nous illustrons la convergence d'ordre 2 en espace. Nous simulons un cas test impliquant la BL. Nous appliquons le schéma DDFV à la géométrie des épines dendritiques en 2D et discutons nos simulations en les comparant avec des simulations en 1D de la littérature. Nous introduisons également deux configurations originales de dendrites, fournissant des informations sur la manière dont les épines dendritiques s'influencent mutuellement, révélant l'étendue de leur influence mutuelle. Nos simulations montrent la distance de propagation de l'influx ionique lors des connexions synaptiques. Dans le chapitre 4, nous résolvons le système PNP sur un système multi-domaines 2D composé d'une membrane, d'un milieu interne et d'un milieu externe. Cette approche permet la modélisation de la dynamique du voltage de manière plus réaliste, et aide également à vérifier la cohérence des résultats du chapitre 3. Nous utilisons le logiciel FreeFem++ pour résoudre le système PNP dans ce contexte. Nous présentons des simulations correspondant aux résultats du chapitre 3, démontrant la sommation linéaire dans une bifurcation dendritique. Nous étudions la sommation des signaux en ajoutant des entrées à la membrane d'une branche dendritique. Nous identifions un seuil d'excitabilité où la dynamique du voltage est significativement influencée par le nombre d'entrées. Nous offrons également des illustrations numériques de la BL à l'intérieur du milieu intracellulaire, observant de petites fluctuations. Ces résultats sont préliminaires, visant à fournir des informations pour comprendre la dynamique dendritique. Le chapitre 5 présente un travail collaboratif mené lors du Cemracs 2022. Nous nous concentrons sur un schéma de volumes finis composite où nous visons à dériver les équations d'Euler avec des termes sources sur des maillages non structurés
Neuroscientific questions about dendrites include understanding their structural plasticityin response to learning and how they integrate signals. Researchers aim to unravel these aspects to enhance our understanding of neural function and its complexities. This thesis aims at offering numerical insights concerning voltage and ionic dynamics in dendrites. Our primary focus is on modeling neuronal excitation, particularly in dendritic small compartments. We address ionic dynamics following the influx of nerve signals from synapses, including dendritic spines. To accurately represent their small scale, we solve the well-known Poisson-Nernst-Planck (PNP) system of equations, within this real application. The PNP system is widely recognized as the standard model for characterizing the electrodiffusion phenomenon of ions in electrolytes, including dendritic structures. This non-linear system presents challenges in both modeling and computation due to the presence of stiff boundary layers (BL). We begin by proposing numerical schemes based on the Discrete Duality Finite Volumes method (DDFV) to solve the PNP system. This method enables local mesh refinement at the BL, using general meshes. This approach facilitates solving the system on a 2D domain that represents the geometry of dendritic arborization. Additionally, we employ numerical schemes that preserve the positivity of ionic concentrations. Chapters 1 and 2 present the PNP system and the DDFV method along with its discrete operators. Chapter 2 presents a "linear" coupling of equations and investigate its associated numerical scheme. This coupling poses convergence challenges, where we demonstrate its limitations through numerical results. Chapter 3 introduces a "nonlinear" coupling, which enables accurate numerical resolution of the PNP system. Both of couplings are performed using DDFV method. However, in Chapter 3, we demonstrate the accuracy of the DDFV scheme, achieving second-order accuracy in space. Furthermore, we simulate a test case involving the BL. Finally, we apply the DDFV scheme to the geometry of dendritic spines and discuss our numerical simulations by comparing them with 1D existing simulations in the literature. Our approach considers the complexities of 2D dendritic structures. We also introduce two original configurations of dendrites, providing insights into how dendritic spines influence each other, revealing the extent of their mutual influence. Our simulations show the propagation distance of ionic influx during synaptic connections. In Chapter 4, we solve the PNP system over a 2D multi-domain consisting of a membrane, an internal and external medium. This approach allows the modeling of voltage dynamics in a more realistic way, and further helps checking consistency of the results in Chapter 3. To achieve this, we employ the FreeFem++ software to solve the PNP system within this 2D context. We present simulations that correspond to the results obtained in Chapter 3, demonstrating linear summation in a dendrite bifurcation. Furthermore, we investigate signal summation by adding inputs to the membrane of a dendritic branch. We identify an excitability threshold where the voltage dynamics are significantly influenced by the number of inputs. Finally, we also offer numerical illustrations of the BL within the intracellular medium, observing small fluctuations. These results are preliminary, aiming to provide insights into understanding dendritic dynamics. Chapter 5 presents collaborative work conducted during the Cemracs 2022. We focus on a composite finite volume scheme where we aim to derive the Euler equations with source terms on unstructured meshes

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Cartailler, Jérôme. „Asymptotic of Poisson-Nernst-Planck equations and application to the voltage distribution in cellular micro-domains“. Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066297/document.

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Dans cette thèse j’étudie l’impact de la géométrie de micro et nano-domaines biologiques sur les propriétés d'électrodiffusion, ceci à l'aide des équations aux dérivées partielles de Poisson-Nernst-Planck. Je considère des domaines non-triviaux ayant une forme cuspide ou elliptique. Mon objectif est de développer des modèles ainsi que des méthodes mathématiques afin d'étudier les caractéristiques électriques de ces nano/micro-domaines, et ainsi mieux comprendre comment les signaux électriques sont modulés à ces échelles. Dans la première partie j’étudie le voltage à l'équilibre pour un électrolyte dans un domaine borné, et ayant un fort excès de charges positives. Je montre que le premier temps de sortie dans une boule chargée dépend de la surface et non du volume. J’étudie ensuite la géométrie composées d'une boule à laquelle est attachée un domaine cuspide. Je construis ensuite une solution asymptotique pour le voltage dans les cas 2D et 3D et je montre qu’ils sont donnés au premier ordre par la même expression. Enfin, j’obtiens la même conclusion en considérant une géométrie formée d'une ellipse, dont je construis une solution asymptotique du voltage en 2D et 3D. La seconde partie porte sur la modélisation de la compartimentalisation électrique des épines dendritiques. A partir de simulations numériques, je mets en évidence le lien entre la polarisation de concentration dans l'épine et sa géométrie. Je compare ensuite mon modèle à des données de microscopie. Je développe une méthode de déconvolution pour extraire la dynamique rapide du voltage à partir des données de microscopie. Enfin j’estime la résistance du cou et montre que celle-ci ne suit pas la loi d'Ohm
In this PhD I study how electro-diffusion within biological micro and nano-domains is affected by their shapes using the Poisson-Nernst-Planck (PNP) partial differential equations. I consider non-trivial shapes such as domains with cusp and ellipses. Our goal is to develop models, as well as mathematical tools, to study the electrical properties of micro and nano-domains, to understand better how electrical neuronal signaling is regulated at those scales. In the first part I estimate the steady-state voltage inside an electrolyte confined in a bounded domain, within which we assume an excess of positive charge. I show the mean first passage time in a charged ball depends on the surface and not on the volume. I further study a geometry composed of a ball with an attached cusp-shaped domain. I construct an asymptotic solution for the voltage in 2D and 3D and I show that to leading order expressions for the voltage in 2D and 3D are identical. Finally, I obtain similar conclusion considering an elliptical-shaped domain for which I construct an asymptotic solution for the voltage in 2D and 3D. In the second part, I model the electrical compartmentalization in dendritic spines. Based on numerical simulations, I show how spines non-cylindrical geometry leads to concentration polarization effects. I then compare my model to experimental data of microscopy imaging. I develop a deconvolution method to recover the fast voltage dynamic from the data. I estimate the neck resistance, and we found that, contrary to Ohm's law, the spine neck resistance can be inversely proportional to its radius

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Abdul, Samad Feras. „Polarisation provoquée : expérimentation, modélisation et applications géophysiques“. Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066049/document.

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Les mécanismes produisant les signaux observés par la méthode de Polarisation Provoquée (PP) sur une large gamme de fréquences (entre 1 mHz et 20 kHz) ne sont pas encore complètement identifiés. Deux sujets particuliers ont été abordés dans cette thèse. L'origine du signal observé à haute fréquence (>1 kHz) a été analysé en effectuant des mesures de la résistivité complexe sur de l'eau à différentes salinités. Les résultats montrent des écarts sur la phase par rapport à la réponse attendue à haute fréquence. Ils dépendent du type d'électrode de mesures et de la conductivité du milieu. Un modèle basé sur un circuit électrique équivalent a été proposé pour modéliser ces effets. Nous avons aussi exploré le mécanisme responsable de la polarisation en présence de grains semi-conducteurs en analysant la dépendance de temps de relaxation. La réponse spectrale d'un milieu sableux saturé a été étudiée en variant la concentration et le type de l'électrolyte, la taille, le type et la quantité de grains semi-conducteurs insérés. En utilisant la méthode des éléments finis, nous avons entrepris une simulation numérique 2D basée sur la solution des équations de Poisson-Nernst-Planck dans le domaine temporel et spectral. Les résultats expérimentaux sont conformes à ceux issus de la simulation numérique et montrent une décroissance comparable du temps de relaxation avec l'augmentation de la concentration de l'électrolyte. Finalement, une campagne géophysique de terrain sur un site paléo-miniers contenant des grains semi-conducteurs complète l'approche de laboratoire. Des mesures de PP temporelles permettent de délimiter les zones de scories sur le site et d'en estimer le volume
The physical mechanisms responsible for the induced polarization response over the frequency range (from 1 mHz to 20 kHz) are not completely understood. In particular, within the framework of this thesis, two subjects have been addressed. The origin of the signal observed at high frequency (HF) (>1 kHz) was analyzed by carrying out Spectral IP measurements on tap water samples. A phase deviation from the expected response has been observed at HF. The resulted deviation in phase appears to be dependent on the measuring electrode type (potential electrodes) and conductivity of the medium. A model based on an equivalent electrical circuit and designed to represent HF response, has been proposed to correct these effects. The mechanism responsible for the polarization in a medium containing semi-conductor grains has been investigated by analyzing the dependence of the relaxation time. We carried out experimental measurements on a sand medium containing different types of semi-conductors. The spectral response was studied by varying the concentration and type of the electrolyte, the size and content of semi-conductor grains. By using the finite element method, a 2D numerical simulation based on Poisson-Nernst-Planck equations was performed in time and frequency domains. The experimental results are qualitatively in accordance with numerical simulation. It showed a comparable decrease in the relaxation time when increasing the electrolyte concentration. Finally, field measurements on a paleo-mining site containing semi-conductor grains have been acquired. Time-domain IP measurements allowed us to define the zones of slag in the site and led to estimate the slag volume

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Abdul, Samad Feras. „Polarisation provoquée : expérimentation, modélisation et applications géophysiques“. Electronic Thesis or Diss., Paris 6, 2017. http://www.theses.fr/2017PA066049.

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Lefebvre, Xavier. „Etude des modèles de transfert en nanofiltration : application du modèle hybride basé sur les équations de Nernst-Planck étendues par le développement du logiciel de simulation "nanoflux"“. Montpellier 2, 2003. http://www.theses.fr/2003MON20082.

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Moreau, Antoine. „Calcul des propriétés homogénéisées de transfert dans les matériaux poreux par des méthodes de réduction de modèle : Application aux matériaux cimentaires“. Thesis, La Rochelle, 2022. http://www.theses.fr/2022LAROS024.

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Cette thèse propose de coupler deux outils préexistant pour la modélisation mathématique en mécanique : l’homogénéisation périodique et la réduction de modèle, afin de modéliser la corrosion des structures de béton armé exposées à la pollution atmosphérique et au sel marin. Cette dégradation est en effet difficile à simuler numériquement, eu égard la forte hétérogénéité des matériaux concernés, et la variabilité de leur microstructure. L’homogénéisation périodique fournit un modèle multi-échelle permettant de s’affranchir de la première de ces deux difficultés. Néanmoins, elle repose sur l’existence d’un volume élémentaire représentatif (VER) de la microstructure du matériau poreux modélisé. Afin de prendre en compte la variabilité de cette dernière, on est amenés à résoudre en temps réduit les équations issues du modèle multi-échelle pour un grand nombre VER. Ceci motive l’utilisation de la méthode POD de réduction de modèle. Cette thèse propose de recourir à des transformations géométriques pour transporter ces équations sur la phase fluide d’un VER de référence. La méthode POD ne peut, en effet, pas être utilisée directement sur un domaine spatial variable (ici le réseau de pores du matériau). Dans un deuxième temps, on adapte ce nouvel outil à l’équation de Poisson-Boltzmann, fortement non linéaire, qui régit la diffusion ionique à l’échelle de la longueur de Debye. Enfin, on combine ces nouvelles méthodes à des techniques existant en réduction de modèle (MPS, interpolation ITSGM), pour tenir compte du couplage micro-macroscopique entre les équations issues de l’homogénéisation périodique
In this thesis, we manage to combine two existing tools in mechanics: periodic homogenization, and reduced-order modelling, to modelize corrosion of reinforced concrete structures. Indeed, chloride and carbonate diffusion take place their pores and eventually oxydate their steel skeleton. The simulation of this degradation is difficult to afford because of both the material heterogenenity, and its microstructure variability. Periodic homogenization provides a multiscale model which takes care of the first of these issues. Nevertheless, it assumes the existence of a representative elementary volume (REV) of the material at the microscopical scale. I order to afford the microstructure variability, we must solve the equations which arise from periodic homogenization in a reduced time. This motivates the use of model order reduction, and especially the POD. In this work we design geometrical transformations that transport the original homogenization equations on the fluid domain of a unique REV. Indeed, the POD method can’t be directly performed on a variable geometrical space like the material pore network. Secondly, we adapt model order reduction to the Poisson-Boltzmann equation, which is strongly nonlinear, and which rules ionic electro diffusion at the Debye length scale. Finally, we combine these new methods to other existing tools in model order reduction (ITSGM interpolatin, MPS method), in order to couple the micro- and macroscopic components of periodic homogenization

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Herda, Maxime. „Analyse asymptotique et numérique de quelques modèles pour le transport de particules chargées“. Thesis, Lyon, 2017. http://www.theses.fr/2017LYSE1165/document.

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Cette thèse est consacrée à l'étude mathématique de quelques modèles d'équations aux dérivées partielles issues de la physique des plasmas. On s'intéresse principalement à l'analyse théorique de différents régimes asymptotiques de systèmes d'équations cinétiques de type Vlasov-Poisson-Fokker-Planck. Dans un premier temps, en présence d'un champ magnétique extérieur on se concentre sur l'approximation des électrons sans masse fournissant des modèles réduits lorsque le rapport me{mi entre la masse me d'un électron et la masse mi d'un ion tend vers 0 dans les modèles. Suivant le régime considéré, on montre qu'à la limite les solutions vérifient des modèles hydrodynamiques de type convection-diffusion ou sont données par des densités de type Maxwell-Boltzmann-Gibbs, suivant l'intensité des collisions dans la mise à l'échelle. En utilisant les propriétés hypocoercives et hypoelliptiques des équations, on est capable d'obtenir des taux de convergence en fonction du rapport de masse. Dans un second temps, par des méthodes similaires, on montre la convergence exponentielle en temps long vers l'équilibre des solutions du système de Vlasov-Poisson-Fokker-Planck sans champ magnétique avec des taux explicites en les paramètres du modèles. Enfin, on conçoit un nouveau type de schéma volumes finis pour des équations de convection-diffusion non-linéaires assurant le bon comportement en temps long des solutions discrètes. Ces propriétés sont vérifiées numériquement sur plusieurs modèles dont l'équation de Fokker-Planck avec champ magnétique
This thesis is devoted to the mathematical study of some models of partial differential equations from plasma physics. We are mainly interested in the theoretical study of various asymptotic regimes of Vlasov-Poisson-Fokker-Planck systems. First, in the presence of an external magnetic field, we focus on the approximation of massless electrons providing reduced models when the ratio me{mi between the mass me of an electron and the mass mi of an ion tends to 0 in the equations. Depending on the scaling, it is shown that, at the limit, solutions satisfy hydrodynamic models of convection-diffusion type or are given by Maxwell-Boltzmann-Gibbs densities depending on the intensity of collisions. Using hypocoercive and hypoelliptic properties of the equations, we are able to obtain convergence rates as a function of the mass ratio. In a second step, by similar methods, we show exponential convergence of solutions of the Vlasov-Poisson-Fokker-Planck system without magnetic field towards the steady state, with explicit rates depending on the parameters of the model. Finally, we design a new type of finite volume scheme for a class of nonlinear convection-diffusion equations ensuring the satisfying long-time behavior of discrete solutions. These properties are verified numerically on several models including the Fokker-Planck equation with magnetic field

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Minton, Geraint Philip. „Modelling the static and dynamic behaviour of electrolytes : a modified Poisson-Nernst-Planck approach“. Thesis, University of Manchester, 2014. https://www.research.manchester.ac.uk/portal/en/theses/modelling-the-static-and-dynamic-behaviour-of-electrolytes-a-modified-poissonnernstplanck-approach(de9671fd-feb5-4870-b0a9-ad6a28ff953d).html.

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In this thesis a method is presented for the modelling the effects of the excluded volume (ion-ion) and ion excess polarisability (ion-solvent) interactions in an electrolyte at a smooth planar electrode. The impact of these interactions is studied in terms of the equilibrium state of single and mixed electrolytes, the dynamic response of single electrolytes to a time-dependent applied potential, and their effect on the reaction rate, for both steady and time-dependent applied potentials. For reacting systems, the reaction rate is modelled using a modified form of the Frumkin-Butler-Volmer equation, in which the interactions are explicitly accounted for. At equilibrium, the model offers improvement over models which only account for the excluded volume interaction, in terms of both the predicted electrolyte structure and the electrical properties of the electrode. For example accounting for the polarisability interaction is shown to limit and then reverse the growth in the differential capacitance at the point of zero charge as the bulk concentration increases, an effect is not seen when only the excluded volume interaction is accounted for. Another example is for mixed electrolytes, in which accounting for the polarisability interaction leads to better agreement with experimental data regarding the composition of the double layer. For the response of an electrolyte to a potential step, the two interactions both lead to peaks in the time taken to reach equilibrium as a function of the potential. The effect of the domain length on the equilibration time is qualitatively discussed, together with the differences between the two interaction models. The response to a time-dependent potential is analysed through simulated electrochemical impedance spectroscopy and consideration of the capacitance dispersion effect. Between this and the potential step response data it is shown that the interactions themselves have little direct effect on the dynamic processes beyond the way in which they limit the ion concentrations in the double layer and alter the differential capacitance of the system. The investigation of the effect of the ion interactions on the reaction rate shows that both terms can either increase or decrease the rate, relative to a system with no interactions, depending on the details of the reaction and the applied potential. This is linked to the changes in the electric field within the double layer, which are caused by the interactions, and how this affects the reactant flux in that region. In terms of simulated EIS, deviations are observed relative to the equivalent circuit for the system, the reasons for which are discussed.

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Lim, Jong Il. „Transient finite element analysis of electric double layer using Nernst-Planck-Poisson equations with a modified stern layer“. Texas A&M University, 2006. http://hdl.handle.net/1969.1/4703.

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Finite element analysis of electric double layer capacitors using a transient nonlinear Nernst-Planck-Poisson (NPP) model and Nernst-Planck-Poisson-modified Stern layer (NPPMS) model are presented in 1D and 2D. The NPP model provided unrealistic ion concentrations for high electrode surface potential. The NPPMS model uses a modified Stern layer to account for finite ion size, resulting in realistic ion concentrations even at high surface potential. The finite element solution algorithm uses the Newton-Raphson method to solve the nonlinear problem and the alpha family approximation for time integration to solve the NPP and NPPMS models for transient cases. Cubic Hermite elements are used for interfacing the modified Stern and diffuse layers in 1D while serendipity elements are used for the same in 2D. Effects of the surface potential and bulk molarity on the electric potential and ion concentrations are studied. The ability of the models to predict energy storage capacity is investigated and the predicted solutions from the 1D NPP and NPPMS models are compared for various cases. It is observed that NPPMS model provided realistic and correct results for low and high values of surface potential. Furthermore, the 1D NPPMS model is extended into 2D. The pore structure on the electrode surface, the electrode surface area and its geometry are important factors in determining the performance of the electric double layer capacitor. Thus 2D models containing a porous electrode are modeled and analyzed for understanding of the behavior of the electric double layer capacitor. The effect of pore radius and pore depth on the predicted electric potential, ion concentrations, surface charge density, surface energy density, and charging time are discussed using the 2D Nernst-Planck-Poissonmodified Stern layer (NPPMS) model.

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Neuen, Christian P. T. [Verfasser]. „Numerical Simulation of Ion Migration with Particle Dynamics and the Heat-Poisson-Nernst-Planck System / Christian P. T. Neuen“. Bonn : Universitäts- und Landesbibliothek Bonn, 2016. http://d-nb.info/1124540164/34.

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Buchteile zum Thema "Équations de Poisson-Nernst Planck"

Lu, Benzhuo. „Poisson-Nernst-Planck Equation“. In Encyclopedia of Applied and Computational Mathematics, 1159–62. Berlin, Heidelberg: Springer Berlin Heidelberg, 2015. http://dx.doi.org/10.1007/978-3-540-70529-1_276.

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Horgmo Jæger, Karoline, und Aslak Tveito. „The Poisson-Nernst-Planck (PNP) Model“. In Differential Equations for Studies in Computational Electrophysiology, 119–25. Cham: Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-30852-9_12.

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AbstractIn these notes, we have considered models of electrophysiology across several scales. The first was the membrane model. It assumes that the action potential is similar across the whole cell membrane, and the model represents the action potential as a function of time alone. No spatial variable is involved in the pure membrane models, so a length scale of these models does not make sense.

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Holcman, David, und Zeev Schuss. „The Poisson–Nernst–Planck Equations in a Ball“. In Applied Mathematical Sciences, 341–83. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-76895-3_10.

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Zubkova, Anna V. „The Generalized Poisson–Nernst–Planck System with Nonlinear Interface Conditions“. In Trends in Mathematics, 101–6. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-030-01153-6_18.

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Fuhrmann, Jürgen. „Activity Based Finite Volume Methods for Generalised Nernst-Planck-Poisson Systems“. In Finite Volumes for Complex Applications VII-Elliptic, Parabolic and Hyperbolic Problems, 597–605. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-05591-6_59.

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Lefraich, H. „Computational Modeling of Membrane Blockage via Precipitation: A 2D Extended Poisson-Nernst-Planck Model“. In Trends in Biomathematics: Modeling Epidemiological, Neuronal, and Social Dynamics, 375–88. Cham: Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-33050-6_21.

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Kovtunenko, Victor A., und Anna V. Zubkova. „Solvability and Lyapunov Stability of a Two-component System of Generalized Poisson–Nernst–Planck Equations“. In Recent Trends in Operator Theory and Partial Differential Equations, 173–91. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-47079-5_9.

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Fuhrmann, Jürgen, und Clemens Guhlke. „A Finite Volume Scheme for Nernst-Planck-Poisson Systems with Ion Size and Solvation Effects“. In Springer Proceedings in Mathematics & Statistics, 497–505. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-57394-6_52.

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Cancès, Clément, Maxime Herda und Annamaria Massimini. „Finite Volumes for a Generalized Poisson-Nernst-Planck System with Cross-Diffusion and Size Exclusion“. In Springer Proceedings in Mathematics & Statistics, 57–73. Cham: Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-40864-9_4.

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Fuhrmann, Jürgen, Benoît Gaudeul und Christine Keller. „Two Entropic Finite Volume Schemes for a Nernst–Planck–Poisson System with Ion Volume Constraints“. In Springer Proceedings in Mathematics & Statistics, 285–94. Cham: Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-40864-9_23.

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Konferenzberichte zum Thema "Équations de Poisson-Nernst Planck"

Shi, XiaoMin, JiaChun Le, KaiRong Qin und YuFan Zheng. „The singular perturbation analysis for one-dimensional poisson-nernst-planck equation“. In 2010 8th IEEE International Conference on Control and Automation (ICCA). IEEE, 2010. http://dx.doi.org/10.1109/icca.2010.5524264.

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Tano, M., S. Walker und A. Abou-Jaoude. „Flow-Informed Corrosion in Molten Salts Using the Poisson-Nernst-Planck Model“. In 20th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-20). Illinois: American Nuclear Society, 2023. http://dx.doi.org/10.13182/nureth20-40838.

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Mathur, Sanjay R., und Jayathi Y. Murthy. „A Multigrid Method for the Solution of Ion Transport Using the Poisson Nernst Planck Equations“. In ASME 2007 InterPACK Conference collocated with the ASME/JSME 2007 Thermal Engineering Heat Transfer Summer Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/ipack2007-33410.

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Recently there has been much interest in simulating ion transport in biological and synthetic ion channels using the Poisson-Nernst-Planck (PNP) equations. However, many published methods exhibit poor convergence rates, particularly at high driving voltages, and for long-aspect ratio channels. The paper addresses the development of a fast and efficient coupled multigrid method for the solution of the PNP equations. An unstructured cell-centered finite volume method is used to discretize the governing equations. An iterative procedure, based on a Newton-Raphson linearization accounting for the non-linear coupling between the Poisson and charge transport equations, is employed. The resulting linear system of equations is solved using an algebraic multigrid method, with coarse level systems being created by agglomerating finer-level equations based on the largest coefficients of the Poisson equation. A block Gauss-Seidel update is used as the relaxation method. The method is shown to perform well for ion transport in a synthetic channel for aspect ratios ranging from 16.67 to 1667 for a range of operating parameters.

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Furini, S., F. Zerbetto und S. Cavalcanti. „A numerical solver of 3D Poisson Nernst Planck equations for functional studies of ion channels“. In BIOMEDICINE 2005. Southampton, UK: WIT Press, 2005. http://dx.doi.org/10.2495/bio050111.

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Wang, Yiwei, Lijun Zhang und Mingji Zhang. „A special case study of boundary layer effects via Poisson-Nernst-Planck systems with permanent charges“. In 2020 International Conference on Information Technology and Nanotechnology (ITNT). IEEE, 2020. http://dx.doi.org/10.1109/itnt49337.2020.9253312.

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Aureli, Matteo, und Maurizio Porfiri. „On a Physics-Based Model for Nonlinear Sensing in Ionic Polymer Metal Composites“. In ASME 2012 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/smasis2012-7983.

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In this paper, we propose a physics-based model of ionic polymer metal composites (IPMCs) charge dynamics in response to dynamic mechanical deformation by developing a perturbation solution of a particular form of the Poisson-Nernst-Planck equations. We derive an equivalent nonlinear circuit model whose components are directly controlled by the imposed mechanical deformation. We show results for a variety of loading scenarios to gather insight on the nonlinear characteristics of IPMC electrical response and its potential application in sensors and energy harvesting devices.

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Kovtunenko, Victor A., und Anna V. Zubkova (Buchynskaja). „Homogenization of the generalized Poisson–Nernst–Planck problem in two-phase medium: The corrector due to nonlinear interface condition“. In MODERN TREATMENT OF SYMMETRIES, DIFFERENTIAL EQUATIONS AND APPLICATIONS (Symmetry 2019). AIP Publishing, 2019. http://dx.doi.org/10.1063/1.5125075.

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Tang, G. Y., C. Yang, C. J. Chai und H. Q. Gong. „Joule Heating Induced Thermal and Hydrodynamic Development in Microfluidic Electroosmotic Flow“. In ASME 2004 2nd International Conference on Microchannels and Minichannels. ASMEDC, 2004. http://dx.doi.org/10.1115/icmm2004-2442.

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Joule heating is present in electrokinetically driven flow and mass transport in microfluidic systems. Specifically, in the cases of high applied voltages and concentrated buffer solutions, the thermal management may become a problem. In this study, a mathematical model is developed to describe the Joule heating and its effects on electroosmotic flow and mass species transport in microchannels. The proposed model includes the Poisson equation, the modified Navier-Stokes equation, and the conjugate energy equation (for the liquid solution and the capillary wall). Specifically, the ionic concentration distributions are modeled using (i) the general Nernst-Planck equation, and (ii) the simple Boltzmann distribution. These governing equations are coupled through temperature-dependent phenomenological thermal-physical coefficients, and hence they are numerically solved using a finite-volume based CFD technique. A comparison has been made for the results of the ionic concentration distributions and the electroosmotic flow velocity and temperature fields obtained from the Nernst-Planck equation and the Boltzmann equation. The time and spatial developments for both the electroosmotic flow fields and the Joule heating induced temperature fields are presented. In addition, sample species concentration is obtained by numerically solving the mass transport equation, taking into account of the temperature-dependent mass diffusivity and electrophoresis mobility. The results show that the presence of the Joule heating can result in significantly different electroosomotic flow and mass species transport characteristics.

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Banerjee, A., und A. K. Nayak. „Electroosmotic Flow Separation in a Corrugated Micro-Channel: A Numerical Study“. In ASME 2018 5th Joint US-European Fluids Engineering Division Summer Meeting. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/fedsm2018-83026.

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A two dimensional numerical study is made on the electroosmotic flow separation and vortex formation in a symmetric wavy micro/nano channel filled with a Newtonian, incompressible electrolyte. Flow domain is modelled by two superimposed sinusoidal functions which is mapped into a simpler rectangular computational domain using a suitable coordinate transformation. The distributions of flow field and electric potential are obtained by solving a coupled set of nonlinear governing equations involving Poisson-Nernst-Planck equation and Navier-Stokes equation using finite volume method. Threshold value of the scaled wave amplitude for flow reversal is obtained for fixed Debye-Hückel parameter and solute strength where flow separation plays a vital role for micromixing which can be a major interest for many research problems of biological flows.

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Chein, Reiyu, und Baogan Chung. „Electrokinetic Transport in Micro-Nanofluidic Systems With Sudden-Expansion and Contraction Cross Sections“. In ASME 2009 Second International Conference on Micro/Nanoscale Heat and Mass Transfer. ASMEDC, 2009. http://dx.doi.org/10.1115/mnhmt2009-18120.

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In this study, electrokinetic transport in a micro-nanofluidic system is numerically investigated by solving the transient Poisson, Nernst-Planck, and Navier-Stokes equations simultaneously. The system considered is a nanochannel connected with two microchannels at its ends. Under various applied electric potential biases, the effect of concentration polarization on the fluid flow, induced pressure and electric current is examined. By comparing with the Donnan equilibrium condition and electroosmotic flow in microscale dimension, electric body force due to non-zero charge density is the mechanism for producing vortex flow and inducing positive pressure gradient in the anodic side of the system. The diffusive boundary layer thickness is reduced due to the stirring of the generated vortex flow and results in the over-limiting current when the applied electric potential bias is high.

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