Article
Mathematics, Applied
Ruiqi Dong, Zhongguo Zhou, Xiangdong Chen, Huiguo Tang, Qi Zhang
Summary: In this paper, a conserved domain decomposition method for solving convection-diffusion equations with variable coefficients is analyzed. The method involves obtaining interface fluxes over subdomains using explicit and modified upwind implicit schemes, correcting interface fluxes by obtained solutions, proving mass conservatism, unconditional stability, and second-order convergence in spatial step, and extending the method to nonlinear convection-diffusion equations with error estimates. Numerical examples validate theoretical analyses and efficiencies.
MATHEMATICAL METHODS IN THE APPLIED SCIENCES
(2022)
Article
Biochemical Research Methods
Alexander T. Hwu, Masoud Madadelahi, Rie Nakajima, Ehsan Shamloo, Alexandra Perebikovsky, Horacio Kido, Aarti Jain, Algis Jasinskas, Shawna Prange, Philip Felgner, Marc Madou
Summary: This study investigated the liquid reciprocation process on a microfluidic centrifugal disc (CD), achieving continuous and bidirectional flow. The flow shear rates were determined experimentally and through simulation, and it was found that higher shear rates negatively affected fluorescence intensity. The importance of proper fluid flow considerations when integrating heterogeneous immunoassays (HI) with microfluidics was highlighted.
Article
Green & Sustainable Science & Technology
Vangelis Soultanidis, Ioannis Papaspyros, Evangelos A. Voudrias, Konstantinos N. Moutsopoulos
Summary: This study aimed to compare the leaching behavior of heavy metals from conventional and reflective cool cement blocks through leaching tests. The results showed that the leaching mechanisms were the same for all cement blocks, and the leaching process was slow, causing no difference in emissions to the underlying soil.
JOURNAL OF CLEANER PRODUCTION
(2022)
Article
Mathematics, Applied
Xuemin Tu, Jinjin Zhang
Summary: A preconditioned GMRES method is developed and analyzed for solving the linear system from advection-diffusion equations with HDG discretization. The use of BDDC as a preconditioner showed promising results, with the number of iterations being independent of subdomain quantity for large viscosity. However, convergence deteriorates with decreasing viscosity, similar to standard finite element discretizations.
COMPUTERS & MATHEMATICS WITH APPLICATIONS
(2021)
Article
Thermodynamics
Marcin Blesznowski, Monika Sikora, Jakub Kupecki, Lukasz Makowski, Wojciech Orciuch
Summary: The performance of solid oxide cells (SOCs) is influenced by factors such as lean fuel, type of fuel, velocity profile, and flow direction. These cells have multiple layers, including porous electrodes separated by a gas-tight electrolyte. Various mass transport models were investigated to understand diffusion mechanisms in porous media. Computational fluid dynamics (CFD) was used to model diffusive transport in porous electrodes, with experiments conducted to validate the results. The main goal of the study was to optimize the mass transport process through SOC's porous electrode to reduce costs and time.
Article
Computer Science, Interdisciplinary Applications
Nikolaos A. Gatsonis, Xin Tian, Michael A. Demetriou, John A. Burns
Summary: This paper develops a heterogeneous, nonoverlapping domain-decomposition, explicit, finite volume method for real-time hybrid process-state estimation of 3D unsteady, advection-diffusion concentration fields. The method can be used for stationary or moving gas sources and uses a single-point concentration measurement taken onboard a sensing aerial vehicle (SAV) to compute the concentration field in the entire domain in real-time. The method divides the computational domain into multiple subdomains and employs a Luenberger observer for the subdomain where the SAV resides and a naive estimator for the remaining subdomains.
JOURNAL OF COMPUTATIONAL PHYSICS
(2022)
Article
Mathematics, Applied
Jie Peng, Shi Shu, Junxian Wang, Liuqiang Zhong
Summary: An adaptive BDDC preconditioner is proposed for advection-diffusion problems, which extends the method to solve nonsymmetric and positive definite bilinear forms. By decomposing the original form and designing local generalized eigenvalue problems, adaptive coarse components are formed for improved performance. Published by Elsevier B.V. with all rights reserved.
APPLIED NUMERICAL MATHEMATICS
(2021)
Article
Materials Science, Multidisciplinary
M. M. Juckel, F. Grimm, S. Zischke, Y. J. Sohn, O. Guillon, N. H. Menzler
Summary: For investigating the reactivity between alternative solid oxide cell air electrode materials and forsterite (Mg2SiO4), five different phase materials were selected. The Ruddlesden-Popper phase materials, L4N3 and L3N2, showed high interest due to their stability and activity, but their polarization resistance increased when mixed with forsterite. The three titanium-based perovskite materials had high polarization resistances, making their electro-catalytic activity less significant.
JOURNAL OF MATERIALS SCIENCE
(2023)
Article
Mathematics, Applied
Vandana Sharma, Jyotshana Prajapat
Summary: Using a Lyapunov functional and duality arguments, we establish the existence of component wise non-negative global solutions in reaction diffusion systems where components diffuse inside the domain and react on the surface through mass transport type boundary conditions on an evolving domain.
DISCRETE AND CONTINUOUS DYNAMICAL SYSTEMS
(2022)
Article
Mathematics, Applied
Soura Sana, Bankim C. Mandal
Summary: This paper investigates the convergence behavior of the Dirichlet-Neumann and Neumann-Neumann waveform relaxation algorithms for time-fractional sub-diffusion and diffusion-wave equations. The paper analyzes the impact of the generalized diffusion coefficient on the convergence of the algorithms and the relationship between the convergence rate and the fractional order of the time derivative.
COMPUTERS & MATHEMATICS WITH APPLICATIONS
(2023)
Article
Mathematics, Applied
Martin J. Gander, Stephan B. Lunowa, Christian Rohde
Summary: In this paper, a non-overlapping domain decomposition algorithm of Schwarz waveform-relaxation (SWR) type is proposed for solving nonlinear advection-diffusion equations. The algorithm relies on nonlinear zeroth-order (or Robin) transmission conditions between sub-domains to ensure the continuity of the converged solution and its normal flux across the interface. Existence of unique iterative solutions and the convergence of the algorithm are proved. Numerical results confirm the theoretical findings, particularly the convergence of the algorithm.
SIAM JOURNAL ON SCIENTIFIC COMPUTING
(2023)
Article
Mechanics
Haniyeh Fattahpour, Pejman Sanaei
Summary: This article investigates the effects of several factors on tissue growth in tissue-engineering scaffolds, including nutrient flow rate, feed concentration, scaffold elasticity, and cell properties. The study develops a mathematical model and simulation to analyze the cell proliferation process and optimize the scaffold channel configuration. The results show that the rate of nutrient consumption by cells and scaffold elastic compliance impact tissue growth, and decreasing scaffold elastic compliance can enhance tissue integration and functionality through optimized channel geometry.
Article
Polymer Science
Roujin Ghaffari, Henrik Almqvist, Robin Nilsson, Gunnar Liden, Anette Larsson
Summary: This study investigated the diffusion of kraft lignin molecules through model cellulose membranes of varying pore sizes. The results showed that small pore sizes enable the diffusion of small molecules while hindering the transport of larger molecules or clusters. This study provides important insights into the mass transfer events in pulping processes.
Article
Polymer Science
Nico Marioni, Zidan Zhang, Everett S. Zofchak, Harnoor S. Sachar, Sanket Kadulkar, Benny D. Freeman, Venkat Ganesan
Summary: This study investigates the influence of ion-ion correlated motion on salt transport in ion exchange membranes using atomistic molecular dynamics simulations. The results show that ion-ion correlations have a significant impact on salt diffusivities and conductivities, which should be taken into consideration in experimental measurements of non-dilute salt solutions in polymer membranes.
Article
Engineering, Civil
S. P. Pozdniakov, V. A. Lekhov, V. A. Bakshevskaia
Summary: This study proposes a solution for long-term waste migration prediction by using an auxiliary 3D high-resolution model to estimate hydraulic heterogeneity parameters. The study finds that thickness heterogeneity of low-permeability hydrofacies has a significant impact on subsurface contaminant spreading.
JOURNAL OF HYDROLOGY
(2022)