Wyniki wyszukiwania - Biblioteka Nauki

1

Mathematic's models in metabolic engineering

100%

Szewczyk K. W.

Biotechnologia

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2005

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nr 2

7-31

EN

Metabolic engineering is an integrating methodology of analysis and synthesis for improvement of flux distribution of metabolic pathways. It has two main aspects: modeling and analysis of metabolic networks to establish strategies for pathway engineering and actual molecular level engineering the pathway. Mathematical modeling is one of the key methodologies of metabolic engineering. The review presents the currently used metabolic modeling approaches. Metabolite balancing is the basis for analysis of metabolic flux and cell capability to form a targeted product. The use of isotope ? labeled substrates with nuclear magnetic resonance (NMR) and gas chromatography-mass spectrometry (GCMS) analyses of intracellular and extracellular metabolites enables determination of metabolic flux distribution. Metabolic Control Analysis (MCA) is a theoretical framework for investigation of control mechanism of metabolic network to identify key parameters influencing productivity. Kinetics models present a more detailed approach to simulate metabolic net behavior. Linear approximation of kinetic model, the so called (log)linear kinetics, is useful for modeling spatiotemporal variations of the net. The including of genetic regulation to metabolic models, the next step in the development of metabolism models, needs new methods of experimental approaches and mathematic and computational resources. Metabolic engineering is barely a decade old, but its significance is already widely recognized in the research-intensive biotechnology community and attracts great interest of industry.

2

Studies on susceptibility of selected pretreated ligninocellulosic materials on enzymic hydrolysis

100%

Pielecki J. , Targonski Z.

Biotechnologia

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2001

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nr 1

153-160

EN

Studies described in this paper were conducted in order to determine the dependence between the conditions of ligninocellulosic substrate pretreatment and its suceptibility to enzymic hydrolysis. In view of this, a semi-empirical mathematical model was used to examine the process of enzymic hydrolysis of cellulose by assuming that this reaction proceeds as a sum of two first order reactions with different rates of reactions. The application of quasi-Newtonian equations allowed for the determination of percentage fractions of easily and non-easily hydrolised cellulose in the structures of pretreated substrates.

3

Modeling the meta-dynamics of lymphocyte repertoires

100%

Mahr R.

Archivum Immunologiae et Therapiae Experimentalis

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2001

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tom 49

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nr 2

111-120

EN

The complexity of biological systems, and the explosion of the quantity of biological information which is rapidly becoming available from experimental and clinical studies, necessitate the use of theoretical tools, namely, mathematical and computational modeling. The vertebrate adaptive immune system, with its learning and memory capabilities, is a particularly rich source of modeling challenges. Most difficult within this area is the study of lymphocyte repertoires ? the generation of their diversity and the forces that shape the ever-changing dynamics of lymphocyte clones. I review several examples of problems in lymphocyte repertoire modeling, demonstrate the types of solutions employed, and highlight the contribution of these theoretical studies to immunological research.

4

THE ANALYSIS OF PERIODIC PROCESSES OF ECONOMIC GROWTH ON THE BASIS OF MODEL OF SENSITIVITY (Analiz periodychnykh protsesiv ekonomichnoho zrostannia na osnovi modeli chutlyvosti)

100%

Bilyi L. A. , Dutka H. Y.

Rehionalna ekonomika (Regional Economy)

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2009

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nr 1(51)

201-207

EN

The publication is devoted to the analysis of the Harrod-Domar nonlinear model of economic growth, based on the model of sensitivity to initial conditions. This model is based on assumptions on the nonlinearity of the production function and periodic character of the volume of consumption. Instead of the traditional solution of the Cauchy problem and the definition of economic growth as the end of the transition process it is proposed to seek T-periodic solution. Equation of the model with initial conditions at the edges of the period has the form of two-point boundary value problem. Numerical integration of differential equation in the interval of time equal to the period T and the found solution for t=T is specified by the iterative formula of Newton. The condition for determining periodic solutions is equal to zero objective function.

5

The modification of light flux leaving a wind-roughened, oil covered sea surface: example of computations for hallow seas

100%

Otremba Z. , Piskozub P. J. , Piskozub J.

Oceanological Studies

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2000

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tom 29

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nr 1

117-133

EN

This paper presents chosen results of modelling of upward light flux over a rough sea surface covered with an oil film. In upward irradiance computations (by means of Monte Carlo method), the optical parameters of two types of water were taken into consideration: water typical for bays of the Baltic Sea (Case 2 water) and ocean (Case 1) waters, both covered with an oil layer 5 mum thick (Romashkino). Coefficients of reflectance and transmission for the oil film were used for the calculations. These coefficients were obtained through the mathematical simulation of the route of light rays, both upward and downward, through the oil film. The obtained results show that oil films influence upward light fluxes over the sea surface, and that this influence depends on the depth and roughness of the sea. The analyses of oil film visibility on sea surfaces revealed also the influence of the direction of observation.

6

Landfill as bioreactor

88%

Kaczorek K. , Ledakowicz S.

Biotechnologia

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2005

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nr 2

69-87

EN

In this paper, landfill is described as bioreactor. Firstly, the bioprocesses taking part within the landfill together with their mathematical descriptions are presented. Secondly, the investigations on various landfill operational procedures are shown. The method which enables the studies on landfill behaviour is also described. Three basic concepts for a landfill design operation are explained: dry landfill, bioreactor landfill and final storage quality landfill. The advantages of landfill operating as bioreactor are stressed.

7

Matematicheskaya model' dlya opredeleniya e'kologicheskogo i e'konomicheskogo ushcherba pri tochechnom kratkovremennom vybrose zagryaznyayushchih veshchestv v atmosferu

88%

Dolgikh V. M.

Mekhanizm Rehuluvannya Economiky

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2011

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tom 2 (52)

13-22

EN

Considered a mathematical model, describing processes of the spreading the pollution in atmosphere from short-time source, processes of the damaging of objects in zone of the contamination, allowing to evaluate the damage in consequence of environmental pollutions.

8

MATHEMATICAL MODELS AS ABSTRACTIONS

75%

Zámečník L.

Organon F. medzinárodný časopis pre analytickú filozofiu

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2018

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tom 25

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nr 2

244 - 264

EN

The paper concerns a contemporary problem emerging in philosophy of science about the explanatory status of mathematical models as abstractions. The starting point lies in the analysis of Morrison’s discrimination of models as idealizations and models as abstractions. There abstraction has a special status because its non-realistic nature (e.g. an infinite number of particles, an infinite structure of fractal etc.) is the very reason for its explanatory success and usefulness. The paper presents two new examples of mathematical models as abstractions – the fractal invariant of phase space transformations in the dynamic systems theory and infinite sets in the formal grammar and automata theory. The author is convinced about the indispensability of mathematical models as abstraction, but somehow disagrees with the interpretation of its explanatory power.

9

Efektyvnist' mekhanizmiv transformatsiyisystemy orhanizatsiyno-tekhnichnoho rehulyuvannya ekonomiky: metodychnyy pidkhid do otsinky

75%

Deyatlova V. V.

Mekhanizm Rehuluvannya Economiky

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2013

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tom 1 (59)

70-77

EN

Transformation of organizational and technical regulation’s system of the national economy actualizes the issue of evaluation of input mechanisms. The following issues are proposed and justified in the article: a methodical approach to the determination of the effectiveness of mechanisms of the transformation of the organizational and technical regulation of the national economy as a socially significant innovation and investment project with the calculation of the cumulative effect of the government budget and business sectors as net present value, which is defined as an increase in gross domestic product in the current and future periods as a result of the regulatory instruments' implementation. A mathematical model for calculating the total annual economic impact of regulatory tools – technical regulations and standards – is developed. The expediency of its application for identifying activities and export commodity groups for priority development and implementation of technical regulations, that will optimize the choice of regulatory instruments, is calculated.