# mathematical model

## INVESTIGATION OF THE INFLUENCE OF ELECTROMAGNETIC RADIATION ON THE INCREASEOF CHLOROPHYLL - PRODUCING MICROALGAE

It is well known that humanity has to deal with a large number of environmental problems. Every year the level of the Earth's electromagnetic field is only increasing, which is associated with human activity. Promising was the solution of the problem of carbon dioxide absorption by chlorophyll synthesizing microalgae under the influence of microwave electromagnetic radiation.

## INVESTIGATION OF THE IMPACT OF NITROGEN OXIDES ON THE CARBON DIOXIDE UPTAKE RATE BY CHLOROPHYLL-PRODUCING MICROALGAE IN THE AQUATIC HABITAT

As of today, humanity has to deal with a large number of environmental problems. Such problems include climate changes on Earth, which makes the worldwide scientific community and today’s world leaders of countries to raise the alarm. The impetus for the drawing of attention was the rapid rise in the earth temperature, threatening to raise the level of the World Ocean and cause catastrophic consequences in general.

## PROCESSES OF HEAT AND MASS TRANSFER IN GAS AND HEAT PROTECTIVE SUIT WITH ICE-WATER COLD-STORAGE ACCUMULATORS

The article dwells on the mathematical model of heat and mass transfer processes in „environment-protective clothing-human” system which takes into account simultaneous penetration of ambient heat and toxic chemicals in the multi-layer membrane of garments with air gap. On the basis of this model, the parameters of a gas and heat protective suit are reasonably defined.

## THE ROLE OF THE WAVELENGTH OF LIGHT IN THE DYNAMICS OF LIGHT IN THE DYNAMICS MICROALGAE DUE TO THE ABSORPTION OF CARBON DIOXIDE

The effect of light wave length on the rate of carbon dioxide absorption by microalgae has been studied. The mechanism of transfer of carbon dioxide from the air into the internal environment of the cells of microalgae has been described. The coefficient of microalgae growth based on the mathematical model has been determined. The analytical dependence of the mentioned coefficient on the light wave length has been obtained. The optimum length of light wave has been determined to design the flow chart for eliminating carbon dioxide from industrial gas emissions by the biological method.

## Інформаційно-розрахунковий метод для визначення теплофізичних характеристик композитних матеріалів

The work is devoted to the development of applied methodology for determination of thermophysical parameters of composite materials.

## Моделювання розпилювання колоди розвальним способом на пиломатеріали з урахуванням її реальної форми

Mathematical model of log sawing to parallel of linear regressive axis by through-andthrough method into lumber with consideration of surface shape of real logs based on results of scanning for surface shape of log cross sections was developed. The features of calculation for mathematical model of sawing pattern taking account log rotation or sawing pattern around log axis at the fixed angle under cutting (sawing) by vertical and horizontal cutting planes were validated.

## Математичне моделювання та аналіз деформаційно-релаксаційного стану в деревині у процесі сушіння

The article develops a mathematical model of non-isothermal moisture transfer and viscoelastic deformation of wood during drying, which takes into account the anisotropy and variability of heat-mechanic characteristics. By finite element method was formulated by the implementation of mathematical models for viscoelasticity with regard to the accumulation of irreversible deformation. By object-oriented analysis is designed and implemented software implementation model in the form of documented classes.

## Modelling and quality of diagnostic systems monitoring

The example of improvement of the mathematical model of monitoring of difficult objects of technique and medicine with the low level of dynamics of processes is examined. The article of researches is normative documents, which should be expediented to specify and perfect on the basis of thein formation, got as a result of analysis of results, mathematical models of monitoring of difficult objects of technique, medicine got with a help with the low level of dynamics of processes.

## Analysis of boundary conditions of efficiency for immitance measuring transducers based on operational amplifiers

Development of specialized portable measurement tools for impedance spectroscopy is quite challenging and up-to-date technical task. Portable impedance analyzers are required to satisfy certain criteria among which the most important are the following: stability of metrological characteristics of measurement channel over a wide frequency range, high dynamics, fast frequency sweep and the probe signal with appropriate step as well as high resolution of impedance/admittance measurement results. Autobalancing circuits are widely used in impedance analyzers design.