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Cirillo, E. N. .., Colangeli, M., Moons, E., Muntean, A., Muntean, S. A. & van Stam, J. (2019). A lattice model approach to the morphology formation from ternary mixtures during the evaporation of one component. The European Physical Journal Special Topics, 228(1), 55-68
Open this publication in new window or tab >>A lattice model approach to the morphology formation from ternary mixtures during the evaporation of one component
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2019 (English)In: The European Physical Journal Special Topics, ISSN 1951-6355, E-ISSN 1951-6401, Vol. 228, no 1, p. 55-68Article in journal (Refereed) Published
Abstract [en]

Stimulated by experimental evidence in the field of solution-born thin films, we study the morphology formation in a three state lattice system subjected to the evaporation of one component. The practical problem that we address is the understanding of the parameters that govern morphology formation from a ternary mixture upon evaporation, as is the case in the fabrication of thin films from solution for organic photovoltaics. We use, as a tool, a generalized version of the Potts and Blume-Capel models in 2D, with the Monte Carlo Kawasaki-Metropolis algorithm, to simulate the phase behaviour of a ternary mixture upon evaporation of one of its components. The components with spin 1, −1 and 0 in the Blume-Capel dynamics correspond to the electron-acceptor, electron-donor and solvent molecules, respectively, in a ternary mixture used in the preparation of the active layer films in an organic solar cell. Furthermore, we introduce parameters that account for the relative composition of the mixture, temperature, and interaction between the species in the system. We identify the parameter regions that are prone to facilitate the phase separation. Furthermore, we study qualitatively the types of formed configurations. We show that even a relatively simple model, as the present one, can generate key morphological features, similar to those observed in experiments, which proves the method valuable for the study of complex systems.

Place, publisher, year, edition, pages
Springer, 2019
National Category
Physical Sciences
Research subject
Physics
Identifiers
urn:nbn:se:kau:diva-72448 (URN)10.1140/epjst/e2019-800140-1 (DOI)000469252900005 ()2-s2.0-85066267269 (Scopus ID)
Available from: 2019-06-12 Created: 2019-06-12 Last updated: 2019-07-02Bibliographically approved
Endo Kokubun, M. A., Muntean, A., Radu, F. A., Kumar, K., Pop, I. S., Keilegavlen, E. & Spildo, K. (2019). A pore-scale study of transport of inertial particles by water in porous media. Chemical Engineering Science, 207, 397-409
Open this publication in new window or tab >>A pore-scale study of transport of inertial particles by water in porous media
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2019 (English)In: Chemical Engineering Science, ISSN 0009-2509, E-ISSN 1873-4405, Vol. 207, p. 397-409Article in journal (Refereed) Published
Abstract [en]

We study the transport of inertial particles in water flow in porous media. Our interest lies in understanding the accumulation of particles including the possibility of clogging. We propose that accumulation can be a result of hydrodynamic effects: the tortuous paths of the porous medium generate regions of dominating strain, which favour the accumulation of particles. Numerical simulations show that essentially two accumulation regimes are identified: for low and for high flow velocities. When particles accumulate at the entrance of a pore throat (high-velocity region), a clog is formed. This significantly modifies the flow, as the partial blockage of the pore causes a local redistribution of pressure, which diverts the upstream water flow into neighbouring pores. Moreover, we show that accumulation in high velocity regions occurs in heterogeneous media, but not in homogeneous media, where we refer to homogeneity with respect to the distribution of the pore throat diameters.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Porous medium, particles transport, clogging, flow diversion, inertial particles
National Category
Mathematics
Research subject
Mathematics
Identifiers
urn:nbn:se:kau:diva-72906 (URN)10.1016/j.ces.2019.06.036 (DOI)000481644300031 ()
Available from: 2019-06-24 Created: 2019-06-24 Last updated: 2019-09-16Bibliographically approved
Kimura, M., Matsui, K., Muntean, A. & Notsu, H. (2019). Analysis of a projection method for the Stokes problem using an ε-Stokes approach. Japan journal of industrial and applied mathematics, 1-27
Open this publication in new window or tab >>Analysis of a projection method for the Stokes problem using an ε-Stokes approach
2019 (English)In: Japan journal of industrial and applied mathematics, ISSN 0916-7005, E-ISSN 1868-937X, p. 1-27Article in journal (Refereed) Epub ahead of print
Abstract [en]

We generalize pressure boundary conditions of an ε-Stokes problem. Our ε-Stokes problem connects the classical Stokes problem and the corresponding pressure-Poisson equation using one parameter ε>0. For the Dirichlet boundary condition, it is proven in Matsui and Muntean (Adv Math Sci Appl, 27:181–191,2018) that the solution for the ε-Stokes problem converges to the one for the Stokes problem as ε tends to 0, and to the one for the pressure-Poisson problem as εtends to ∞. Here, we extend these results to the Neumann and mixed boundary conditions. We also establis herror estimates in suitable norms between the solutions to the ε-Stokes problem, the pressure-Poisson problem and the Stokes problem, respectively. Several numerical examples are provided to show that several such error estimates are optimal in ε. Our error estimates are improved if one uses the Neumann boundary conditions. In addition, we show that the solution to the ε-Stokes problem has a nice asymptotic structure.

Place, publisher, year, edition, pages
Springer, 2019
Keywords
Stokes problem, Pressure-Poisson equation, Asymptotic analysis, Finite element method
National Category
Mathematics
Research subject
Mathematics
Identifiers
urn:nbn:se:kau:diva-73443 (URN)10.1007/s13160-019-00373-3 (DOI)
Funder
The Swedish Foundation for International Cooperation in Research and Higher Education (STINT)
Available from: 2019-07-05 Created: 2019-07-05 Last updated: 2019-08-30Bibliographically approved
Vo Anh, K. & Muntean, A. (2019). Corrector homogenization estimates for a non-stationary Stokes-Nernst-Planck-Poisson system in perforated domains. Communications in Mathematical Sciences
Open this publication in new window or tab >>Corrector homogenization estimates for a non-stationary Stokes-Nernst-Planck-Poisson system in perforated domains
2019 (English)In: Communications in Mathematical Sciences, ISSN 1539-6746, E-ISSN 1945-0796Article in journal (Refereed) Accepted
National Category
Mathematics
Research subject
Mathematics
Identifiers
urn:nbn:se:kau:diva-70797 (URN)
Available from: 2019-01-24 Created: 2019-01-24 Last updated: 2019-08-15
Ijioma, E. R. & Muntean, A. (2019). Fast Drift Effects In The Averaging Of A Filtration Combustion System: A Periodic Homogenization Approach. Quarterly of Applied Mathematics, 77(1), 71-104
Open this publication in new window or tab >>Fast Drift Effects In The Averaging Of A Filtration Combustion System: A Periodic Homogenization Approach
2019 (English)In: Quarterly of Applied Mathematics, ISSN 0033-569X, E-ISSN 1552-4485, Vol. 77, no 1, p. 71-104Article in journal (Refereed) Published
Abstract [en]

We target the periodic homogenization of a semi-linear reaction-diffusion-convection system describing filtration combustion, where fast drifts are triggered by the competition between heat and mass transfer processes in an asymptotic regime of dominant convection. In addition, we consider the interplay between surface nonlinear chemical reactions and transport processes. To handle the oscillations occurring due to the heterogeneity of the medium, we rely on the concept of two-scale convergence with drift to obtain, for suitably scaled model parameters, the upscaled system of equations together with effective transport parameters. The main difficulty is to treat the case of a coupled multi-physics problem. We proceed by extending the results reported by G. Allaire et al. and other related papers in this context to the case of a coupled system of evolution equations pertinent to filtration combustion.

Place, publisher, year, edition, pages
Brown University Boston, 2019
National Category
Mathematics
Research subject
Mathematics
Identifiers
urn:nbn:se:kau:diva-70322 (URN)10.1090/qam/1509 (DOI)000449518100003 ()
Available from: 2018-11-29 Created: 2018-11-29 Last updated: 2019-03-14Bibliographically approved
Vromans, A. J., van de Ven, F. & Muntean, A. (2019). Homogenization of a pseudo-parabolic system via a spatial-temporal decoupling: Upscaling and corrector estimates for perforated domains. Mathematics in Engineering, 1(3), 548-582
Open this publication in new window or tab >>Homogenization of a pseudo-parabolic system via a spatial-temporal decoupling: Upscaling and corrector estimates for perforated domains
2019 (English)In: Mathematics in Engineering, ISSN 2640-3501, Vol. 1, no 3, p. 548-582Article in journal (Refereed) Published
Abstract [en]

We determine corrector estimates quantifying the convergence speed of the upscaling of a pseudo-parabolic system containing drift terms incorporating the separation of length scales with relative size 1. To achieve this goal, we exploit a natural spatial-temporal decomposition, which splits the pseudo-parabolic system into an elliptic partial differential equation and an ordinary differential equation coupled together. We obtain upscaled model equations, explicit formulas for effective transport coefficients, as well as corrector estimates delimitating the quality of the upscaling. Finally, for special cases we show convergence speeds for global times, i.e., t ∈ R+, by using time intervals expanding to the whole R+ simultaneously with passing to the homogenization limit ↓ 0.

Place, publisher, year, edition, pages
AIMS Press, 2019
Keywords
periodic homogenization, pseudo-parabolic system, mixture theory, upscaled system, corrector estimates, perforated domains
National Category
Mathematics
Research subject
Mathematics; Mathematics
Identifiers
urn:nbn:se:kau:diva-72258 (URN)10.3934/mine.2019.3.548 (DOI)
Available from: 2019-06-03 Created: 2019-06-03 Last updated: 2019-08-28Bibliographically approved
Ackleh, A. S., Colombo, R. M., Goatin, P., Hille, S. & Muntean, A. (2019). Mathematical modeling with measures. Nieuw Archief voor Wiskunde, 20(September), 218-220
Open this publication in new window or tab >>Mathematical modeling with measures
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2019 (English)In: Nieuw Archief voor Wiskunde, ISSN 0028-9825, Vol. 20, no September, p. 218-220Article in journal (Refereed) Published
Place, publisher, year, edition, pages
Leiden: Koninklijk Wiskundig Genootschap, 2019
National Category
Mathematics
Research subject
Mathematics
Identifiers
urn:nbn:se:kau:diva-73532 (URN)
Available from: 2019-07-08 Created: 2019-07-08 Last updated: 2019-09-10Bibliographically approved
Colangeli, M., Muntean, A., Richardson, O. & Thieu, T. (2019). Modelling interactions between active and passive agents moving through heterogeneous environments. In: G. Libelli, N. Bellomo (Ed.), Crowd Dynamics: Vol. 1: Theory, Models and Safety Problems (pp. 211-254). Birkhäuser Verlag
Open this publication in new window or tab >>Modelling interactions between active and passive agents moving through heterogeneous environments
2019 (English)In: Crowd Dynamics: Vol. 1: Theory, Models and Safety Problems / [ed] G. Libelli, N. Bellomo, Birkhäuser Verlag, 2019, p. 211-254Chapter in book (Refereed)
Place, publisher, year, edition, pages
Birkhäuser Verlag, 2019
Series
Modeling and Simulation in Science, Engineering and Technology, ISSN 2164-3679
National Category
Mathematics
Research subject
Mathematics
Identifiers
urn:nbn:se:kau:diva-71439 (URN)10.1007/978-3-030-05129-7_8 (DOI)978-3-030-05129-7 (ISBN)
Available from: 2019-03-06 Created: 2019-03-06 Last updated: 2019-06-28Bibliographically approved
Kruschwitz, J., Lind, M., Muntean, A., Richardson, O. & Wondmagegne, Y. (2019). Modelling, simulation and parameter identification of active pollution reduction with photocatalytic asphalt. Acta Polytechnica, 59(1), 51-58
Open this publication in new window or tab >>Modelling, simulation and parameter identification of active pollution reduction with photocatalytic asphalt
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2019 (English)In: Acta Polytechnica, ISSN 1210-2709, E-ISSN 1805-2363, Vol. 59, no 1, p. 51-58Article in journal (Refereed) Published
Abstract [en]

We develop and implement a numerical model to simulate the effect of photocatalytic asphalt on reducing the concentration of nitrogen monoxide (NO) due to the presence of heavy traffic in an urban environment. The contributions in this paper are threefold: we model and simulate the spread and breakdown of pollution in an urban environment, we provide a parameter estimation process that can be used to find missing parameters, and finally, we train and compare this simulation with different data sets. We analyse the results and provide an outlook on further research.

Place, publisher, year, edition, pages
Prague: Czech Technical University in Prague, 2019
Keywords
Pollution, environmental modelling, parameter identification, finite element simulation
National Category
Mathematics
Research subject
Mathematics
Identifiers
urn:nbn:se:kau:diva-70796 (URN)10.14311/AP.2019.59.0051 (DOI)000462321600006 ()
Available from: 2019-01-24 Created: 2019-01-24 Last updated: 2019-04-11Bibliographically approved
Vromans, A., Van de Ven, F. & Muntean, A. (2019). Parameter delimitation of the weak solvability for a pseudo-parabolic system coupling chemical reactions,  diffusion and momentum equations. Advances in Mathematical Sciences and Applications, 28(1), 273-311
Open this publication in new window or tab >>Parameter delimitation of the weak solvability for a pseudo-parabolic system coupling chemical reactions,  diffusion and momentum equations
2019 (English)In: Advances in Mathematical Sciences and Applications, ISSN 1343-4373, Vol. 28, no 1, p. 273-311Article in journal (Refereed) Published
Abstract [en]

The weak solvability of a nonlinearly coupled system of parabolic and pseudo-parabolic equations describing the interplay between mechanics, chemical reac- tions, diffusion and flow modelled within a mixture theory framework is studied via energy- like estimates and Gronwall inequalities. In analytically derived parameter regimes, these estimates ensure the convergence of discretized-in-time partial differential equa- tions. These regimes are tested and extended numerically. Especially, the dependence of the temporal existence domain of physical behaviour on selected parameters is shown.

Place, publisher, year, edition, pages
Tokyo: GAKKO TOSHO CO, 2019
Keywords
System of nonlinear parabolic and pseudo-parabolic equations, reaction-diffusion, weak solu- tions, existence, Rothe method, parameter delimitation
National Category
Natural Sciences
Research subject
Mathematics
Identifiers
urn:nbn:se:kau:diva-72198 (URN)
Available from: 2019-05-29 Created: 2019-05-29 Last updated: 2019-06-24Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-1160-0007

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