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Miroshnikova, Elena
##### Publikationer (7 of 7) Visa alla publikationer
Antonini, G., De Lauretis, M., Ekman, J. & Miroshnikova, E. (2019). On the passivity of the Delay-Rational Green’s-function-based model for Transmission Lines. In: Karl‐Olof Lindahl,Torsten Lindström, Luigi G. Rodino, Joachim Toft, Patrik Wahlberg (Ed.), Analysis, Probability, Applications, and Computation: Proceedings of the 11th ISAAC Congress. Paper presented at ISAAC 2017 Växjö, Sweden (pp. 71-81).
Öppna denna publikation i ny flik eller fönster >>On the passivity of the Delay-Rational Green’s-function-based model for Transmission Lines
2019 (Engelska)Ingår i: Analysis, Probability, Applications, and Computation: Proceedings of the 11th ISAAC Congress / [ed] Karl‐Olof Lindahl,Torsten Lindström, Luigi G. Rodino, Joachim Toft, Patrik Wahlberg, 2019, s. 71-81Konferensbidrag, Publicerat paper (Refereegranskat)
##### Abstract [en]

In this paper, we study the delay-rational Green’s-function-based (DeRaG) model for transmission lines. This model is described in terms of impedance representation and it contains a rational and a hyperbolic part. The crucial property of transmission lines models is to be passive. The passivity of the rational part has been studied by the authors in a previous work. Here, we extend the results to the rational part of the DeRaG model. Moreover, we prove the passivity of the hyperbolic part.

##### Nationell ämneskategori
Teknik och teknologier Annan elektroteknik och elektronik Matematisk analys
##### Forskningsämne
Industriell elektronik; Matematik
##### Identifikatorer
urn:nbn:se:ltu:diva-68946 (URN)10.1007/978-3-030-04459-6_7 (DOI)2-s2.0-85065430825 (Scopus ID)978-3-030-04458-9 (ISBN)
##### Konferens
ISAAC 2017 Växjö, Sweden
##### Anmärkning

Ingår i bokserien Trends in Mathematics

Fabricius, J., Miroshnikova, E., Tsandzana, A. & Wall, P. (2019). Pressure-driven flow in thin domains. Asymptotic Analysis
Öppna denna publikation i ny flik eller fönster >>Pressure-driven flow in thin domains
2019 (Engelska)Ingår i: Asymptotic Analysis, ISSN 0921-7134, E-ISSN 1875-8576Artikel i tidskrift (Refereegranskat) Epub ahead of print
##### Abstract [en]

We study the asymptotic behavior of pressure-driven Stokes flow in a thin domain. By letting the thickness of the domain tend to zero we derive a generalized form of the classical Reynolds–Poiseuille law, i.e. the limit velocity field is a linear function of the pressure gradient. By prescribing the external pressure as a normal stress condition, we recover a Dirichlet condition for the limit pressure. In contrast, a Dirichlet condition for the velocity yields a Neumann condition for the limit pressure.

IOS Press, 2019
##### Nyckelord
Stokes equation, pressure boundary condition, two-scale convergence, thin domain, Bogovskii operator, Korn inequality
##### Nationell ämneskategori
Matematisk analys
Matematik
##### Identifikatorer
urn:nbn:se:ltu:diva-75853 (URN)10.3233/ASY-191535 (DOI)
Lishchuk, V., Lund, C., Lamberg, P. & Miroshnikova, E. (2018). Simulation of a Mining Value Chain with a Synthetic Ore Body Model: Iron Ore Example. Minerals, 8(11), Article ID 536.
Öppna denna publikation i ny flik eller fönster >>Simulation of a Mining Value Chain with a Synthetic Ore Body Model: Iron Ore Example
2018 (Engelska)Ingår i: Minerals, ISSN 2075-163X, E-ISSN 2075-163X, Vol. 8, nr 11, artikel-id 536Artikel i tidskrift (Refereegranskat) Published
##### Abstract [en]

Reconciliation of geological, mining and mineral processing information is a costly and time demanding procedure with high uncertainty due to incomplete information, especially during the early stages of a project, i.e., pre-feasibility, feasibility studies. Lack of information at those project stages can be overcome by applying synthetic data for investigating different scenarios. Generation of the synthetic data requires some minimum sparse knowledge already available from other parts of the mining value chain, i.e., geology, mining, mineral processing. This paper describes how to establish and construct a synthetic testing environment, or “synthetic ore body model” by integrating a synthetic deposit, mine production, constrained by a mine plan, and a simulated beneficiation process. The approach uses quantitative mineralogical data and liberation information for process simulation. The results of geological and process data integration are compared with the real case data of an apatite iron ore. The discussed approach allows for studying the implications in downstream processes caused by changes in upstream parts of the mining value chain. It also opens the possibility of optimising sampling campaigns by investigating different synthetic drilling scenarios including changes to the spacing between synthetic drill holes, composite length, drill hole orientation and assayed parameters.

MDPI, 2018
##### Nyckelord
synthetic ore body, simulation, iron ore, prediction
##### Nationell ämneskategori
Mineral- och gruvteknik Metallurgi och metalliska material Matematisk analys
##### Forskningsämne
Mineralteknik; Matematik
##### Identifikatorer
urn:nbn:se:ltu:diva-71577 (URN)10.3390/min8110536 (DOI)000451530500063 ()2-s2.0-85057331919 (Scopus ID)
##### Anmärkning

Fabricius, J., Miroshnikova, E. & Wall, P. (2017). Homogenization of the Stokes equation with mixed boundary condition in a porous medium. Cogent Mathamatics, 4(1), Article ID 1327502.
Öppna denna publikation i ny flik eller fönster >>Homogenization of the Stokes equation with mixed boundary condition in a porous medium
2017 (Engelska)Ingår i: Cogent Mathamatics, E-ISSN 2331-1835, Vol. 4, nr 1, artikel-id 1327502Artikel i tidskrift (Refereegranskat) Published
##### Abstract [en]

We homogenize stationary incompressible Stokes flow in a periodic porous medium. The fluid is assumed to satisfy a no-slip condition on the boundary of solid inclusions and a normal stress (traction) condition on the global boundary. Under these assumptions, the homogenized equation becomes the classical Darcy law with a Dirichlet condition for the pressure.

##### Ort, förlag, år, upplaga, sidor
Taylor & Francis, 2017
##### Nationell ämneskategori
Matematisk analys
Matematik
##### Identifikatorer
urn:nbn:se:ltu:diva-64001 (URN)10.1080/23311835.2017.1327502 (DOI)000403291100001 ()
##### Anmärkning

Fabricius, J., Hellström, G., Lundström, S., Miroshnikova, E. & Wall, P. (2016). Darcy's law for flow in a periodic thin porous medium confined between two parallel plates (ed.). Paper presented at InterPore Industry Workshop on Thin Porous Mediat as part of the 5th International Conference of the Interpore-Society, Prague, May 13 2014.. Transport in Porous Media, 115(3), 473-493
Öppna denna publikation i ny flik eller fönster >>Darcy's law for flow in a periodic thin porous medium confined between two parallel plates
2016 (Engelska)Ingår i: Transport in Porous Media, ISSN 0169-3913, E-ISSN 1573-1634, Vol. 115, nr 3, s. 473-493Artikel i tidskrift (Refereegranskat) Published
##### Abstract [en]

We study stationary incompressible fluid flow in a thin periodic porous medium. The medium under consideration is a bounded perforated 3D-domain confined between two parallel plates. The distance between the plates is $$\delta$$, and the perforation consists of $$\varepsilon$$-periodically distributed solid cylinders which connect the plates in perpendicular direction. Both parameters $$\varepsilon$$, $$\delta$$ are assumed to be small in comparison with the planar dimensions of the plates. By constructing asymptotic expansions, three cases are analysed: (1) $$\varepsilon \ll \delta$$, (2) $$\delta /\varepsilon \sim \text {constant}$$ and (3) $$\varepsilon \gg \delta$$. For each case, a permeability tensor is obtained by solving local problems. In the intermediate case, the cell problems are 3D, whereas they are 2D in the other cases, which is a considerable simplification. The dimensional reduction can be used for a wide range of $$\varepsilon$$ and $$\delta$$ with maintained accuracy. This is illustrated by some numerical examples.

##### Nyckelord
Thin porous media, Asymptotic analysis, Homogenization, Darcy’s law, Mixed boundary condition, Stress boundary condition, Permeability
##### Nationell ämneskategori
Strömningsmekanik och akustik Matematisk analys
##### Forskningsämne
Strömningslära; Matematik
##### Identifikatorer
urn:nbn:se:ltu:diva-8685 (URN)10.1007/s11242-016-0702-2 (DOI)000388983600005 ()2-s2.0-84966705369 (Scopus ID)7396f0ae-22ce-48c1-b5d8-eaeed32c8ba5 (Lokalt ID)7396f0ae-22ce-48c1-b5d8-eaeed32c8ba5 (Arkivnummer)7396f0ae-22ce-48c1-b5d8-eaeed32c8ba5 (OAI)
##### Konferens
InterPore Industry Workshop on Thin Porous Mediat as part of the 5th International Conference of the Interpore-Society, Prague, May 13 2014.
Vetenskapsrådet
##### Anmärkning

Validerad; 2016; Nivå 1; 2016-11-25 (andbra); Konferensartikel i tidskrift

Miroshnikova, E. (2016). Some new results in homogenization of flow in porous media with mixed boundary condition (ed.). (Licentiate dissertation). Paper presented at . : Luleå tekniska universitet
Öppna denna publikation i ny flik eller fönster >>Some new results in homogenization of flow in porous media with mixed boundary condition
2016 (Engelska)Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
##### Abstract [en]

The present thesis is devoted to derivation of Darcy’s Law for incompressible Newtonian fluid in perforated domains by means of homogenization techniques.The problem of describing flow in porous media occurs in the study of various physical phenomena such as filtration in sandy soils, blood circulation in capillaries etc. In all such cases physical quantities (e.g. velocity, pressure) are dependent of the characteristic size ε 1 of the microstructure of the fluid domain. However in most practical applications the significant role is played by averaged characteristics, such as permeability, average velocity etc., which do not depend on the microstructure of the domain. In order to obtain such quantities there exist several mathematical techniques collectively referred to as homogenization theory.This thesis consists of two papers (A and B) and complementary appendices. We assume that the flow is governed by the Stokes equation and that global normal stress boundary condition and local no-slip boundary condition are satisfied. Such mixed boundary condition is natural for many applications and here we develop the rigorous mathematical theory connected to it. The assumption of mixed boundary condition affects on corresponding forms of Darcy’s law in both papers and raises some essential difficulties in analysis in Paper A.In both papers the perforated domain is supposed to have periodical structure and the fluid to be incompressible and Newtonian. In Paper A the situation described above is considered in a framework of rigorous functional analysis, more precisely the theorem concerning the existence and uniqueness of weak solutions for the Stokes equation is proved and Darcy’s law is obtained by using two-scale convergence procedure. As it was mentioned, vast part of this paper is devoted to adaptation of classical results of functional analysis to the case of mixed boundary condition.In Paper B the Navier–Stokes system with mixed boundary condition is studied in thin perforated domain. In such cases it is natural to introduce another small parameter δ which corresponds to the thickness of the domain (in addition to the perforation parameter ε). For the case of thin porous medium the asymptotic behavior as both the film thickness δ and the perforation period ε tend to zero at different rates is investigated. The results are obtained by using the formal method of asymptotic expansions. Depending on how fast the two small parameters δ and ε go to zero relative to each other, different forms of Darcy’s law are obtained in all three limit cases — very thin porous medium (δ ε), proportionallythin porous medium (δ ∼ λε, λ ∈ (0,∞)) and homogeneously thin porous medium (δ ε).

##### Ort, förlag, år, upplaga, sidor
Luleå tekniska universitet, 2016
##### Serie
Licentiate thesis / Luleå University of Technology, ISSN 1402-1757
##### Nationell ämneskategori
Matematisk analys
Matematik
##### Identifikatorer
urn:nbn:se:ltu:diva-26737 (URN)fd94dfd1-f25a-4137-98dc-c65ec70122a5 (Lokalt ID)978-91-7583-611-9 (ISBN)978-91-7583-612-6 (ISBN)fd94dfd1-f25a-4137-98dc-c65ec70122a5 (Arkivnummer)fd94dfd1-f25a-4137-98dc-c65ec70122a5 (OAI)
##### Anmärkning
Godkänd; 2016; 20160420 (elemir); Nedanstående person kommer att hålla licentiatseminarium för avläggande av teknologie licentiatexamen. Namn: Elena Miroshnikova Ämne: Matematik/Mathematics Uppsats: Some New Results in Homogenization of Flow in Porous Media with Mixed Boundary Condition Examinator: Professor Peter Wall, Institutionen teknikvetenskap och matematik, Avdelning: Matematiska vetenskaper, Luleå tekniska universitet. Diskutant: Professor Andrey Piatnitski, Institutt for datateknologi og beregningsorienterte ingeniörfag, UiT Norges Arktiske Universitet, Narvik, Norge. Tid: Onsdag 8 juni, 2016 kl 10.00 Plats: E246, Luleå tekniska universitetTillgänglig från: 2016-09-30 Skapad: 2016-09-30 Senast uppdaterad: 2017-11-24Bibliografiskt granskad
Miroshnikova, E. (2014). Boundedness and invertibility of multidimensional integral operators with anisotropically homogeneous kernels in weighted L p -spaces (ed.). In: (Ed.), Seenith Sivasundaram (Ed.), 10th International conference on mathematical problems in engineering, aerosace and sciences: ICNPAA 2014 : Narvik, Norway, 15–18 July 2014. Paper presented at International conference on mathematical problems in engineering, aerosace and sciences : 15/07/2014 - 18/07/2014 (pp. 663-672). Melville, NY: American Institute of Physics (AIP)
Öppna denna publikation i ny flik eller fönster >>Boundedness and invertibility of multidimensional integral operators with anisotropically homogeneous kernels in weighted L p -spaces
2014 (Engelska)Ingår i: 10th International conference on mathematical problems in engineering, aerosace and sciences: ICNPAA 2014 : Narvik, Norway, 15–18 July 2014 / [ed] Seenith Sivasundaram, Melville, NY: American Institute of Physics (AIP), 2014, s. 663-672Konferensbidrag, Publicerat paper (Refereegranskat)
##### Abstract [en]

In weighted space L p ( R n ,ρ), 1 < p < ∞, a new broad class of integral operators with anisotropically homogeneous kernels is investigated. For such operators boundedness theorem is proved. Also the Banach algebra generated by operators with anisotropically homogeneous kernels of compact type is considered. For elements of the algebra symbolic calculation is constructed, the invertibility criterion is obtained in terms of operator symbol

##### Ort, förlag, år, upplaga, sidor
Melville, NY: American Institute of Physics (AIP), 2014
##### Serie
A I P Conference Proceedings Series, ISSN 0094-243X ; 1637
##### Nationell ämneskategori
Matematisk analys
Matematik
##### Identifikatorer
urn:nbn:se:ltu:diva-31456 (URN)10.1063/1.4904637 (DOI)000347812200080 ()5a230170-f690-4778-a677-d233205bc910 (Lokalt ID)978-0-7354-1276-7 (ISBN)5a230170-f690-4778-a677-d233205bc910 (Arkivnummer)5a230170-f690-4778-a677-d233205bc910 (OAI)
##### Konferens
International conference on mathematical problems in engineering, aerosace and sciences : 15/07/2014 - 18/07/2014