0000000000172498
AUTHOR
Ilmārs Kangro
Promocijas darbs
Elektroniskā versija nesatur pielikumus
THE MATHEMATICAL MODELING OF METALS CONTENT IN PEAT
Metals deposition in peat can aid to evaluate impact of atmospheric or wastewaters pollution and thus can be a good indicator of recent and historical changes in the pollution loading. For peat using in agriculture, industrial, heat production etc. knowledge of peat metals content is important. Experimental determination of metals in peat is very long and expensive work. Using experimental data the mathematical model for calculation of concentrations of metals in different points for different layers is developed. The values of the metals (Ca, Mg, Fe, Sr, Cu, Zn, Mn, Pb, Cr, Ni, Se, Co, Cd, V, Mo) concentrations in different layers in peat taken from Knavu peat bog from four sites are deter…
Competence as a Career Opportunity's Guarantor
<p><em>The aim of the research is to investigate the essence of the notion ”competence” and the differences in the usage of the </em><em>career's terminology in semantic, methodological and pragmatic areas in academic theories of the second part of the 20 century; to work out evaluation criteria by comparing the succession of the </em><em>notions capacity. The research is based on the Latvian and international sources of scientific literature – books, magazines, sources in digital form, and etc. A </em><em>personality was </em><em>investigated holistically </em><em>( Džarviss (Jarvis, 2010); Devis (Dove, 1976); Kross (C…
On Mathematical Modelling of Metals Distribution in Peat Layers
In this paper we consider averaging and finite difference methods for solving the 3-D boundary-value problem in multilayered domain. We consider the metals Fe and Ca concentration in the layered peat blocks. Using experimental data the mathematical model for calculation of concentration of metals in different points in peat layers is developed. A specific feature of these problems is that it is necessary to solve the 3-D boundary-value problems for elliptic type partial differential equations (PDEs) of second order with piece-wise diffusion coefficients in the layered domain. We develop here a finite-difference method for solving of a problem of one, two and three peat blocks with periodica…