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JOURNALS // Vestnik Yuzhno-Ural'skogo Universiteta. Seriya Matematicheskoe Modelirovanie i Programmirovanie // Archive

Vestnik YuUrGU. Ser. Mat. Model. Progr., 2015 Volume 8, Issue 2, Pages 55–68 (Mi vyuru263)

This article is cited in 1 paper

Mathematical Modelling

Existence of lower and upper solutions in reverse order with respect to a variable in a model of acidogenesis to anaerobic digestion

M. M. Higueraab, A. V. Sinitsync

a Faculty of Natural Sciences and Mathematics, Research Group Naturatu, University of Ibague, Ibague-Tolima, Colombia
b Faculty of Mathematics, University of Veracruz, Mexico
c Department of Mathematics, National University of Colombia, Bogota, Colombia

Abstract: We prove existence of upper and lower solutions in reverse order with respect a part of the variables in a system of nonlinear ordinary differential equations modelling acidogenesis in anaerobic digestion. The corresponding existence theorems are established. The upper and lower solutions are constructed analytically, by defining semi-trivial solutions for each of the variables in the model. We introduce the concept of indicator semi-trivial solutions. Finally, we numerically solve the system supported by the Matlab software and matching the graphs of the numerical solutions with analytical solutions is found.

Keywords: upper-lower solutions; inverse order; system of nonlinear differential equations; anaerobic digestion.

UDC: 620.95+517.927

MSC: 34A40

Received: 11.03.2015

Language: English

DOI: 10.14529/mmp150205



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