Prolonged exposure to elevated temperatures exceeding 47°C, which can occur during root canal obturation, can cause damage of both dental and bone tissues. In order to study the temperature distribution on the surface of the tooth root a temperature measuring device with cold-junction compensation is proposed. For in vitro measurement of the temperature distribution on the surface of the tooth, 8 thermocouples placed in direct contact with the cementum of the tooth were used. In order to eliminate the cold-junction temperature variations, the temperature equilibration device and RTD were used. The suggested linear approximation for the thermocouples' conversion function provides a nonlinearity relative error of less than 0.05% for K-type thermocouples and 0.07% for J-type thermocouples over the temperature range from 20 to 60°C.

When implementing energy saving measures, the correct choice of thermal insulation materials, the main characteristic of which is the thermal conductivity coefficient, is of key importance. Missing part of the data, which
may occur during investigation of materials under natural conditions, can lead to incorrect determination of the
corresponding characteristic, which negatively affects the effectiveness of the implemented measures and energy
saving. Therefore, reconstruction of the missing data at the stage of preliminary processing of measured signals
to obtain complete and accurate data when determining the thermal conductivity of thermal insulation materials
will enable to avoid this situation. The article presents the results of regression analysis of data obtained during
express control of thermal conductivity of thermal insulation materials based on the local thermal impact method.
Regression models were built for signal reconstruction with 10%, 20% and 30% missing data, using which a relative error of determination the thermal conductivity coefficient of less than 8% was obtained. This is acceptable for
express control of thermal conductivity and indicates the correctness of data restoration in this way. In addition, an
algorithm is provided for determining signal stationarity, which enables to reasonably reduce the duration of each
material with a given level of permissible error.
Keywords: thermal conductivity determination, insulation materials, regression analysis, missing data, data processing

The study of the influence of the elemental composition of batteries on environmental parameters has been carried out. The authors propose to predict the states of ecosystem development on the basis of their studies in stationary and dynamic modes, the latter of which is based on the solution of systems of differential equations using the numerical Runge - Kutta method of the fourth order. The methodology of forecasting and modelling situations, mapping sources of risks and monitoring ecological changes allows to develop the corrective measures of ecological catastrophe prevention.

Based on the analysis of the results of the study of the multicomponent composition of waste batteries using an X-ray fluorescence analyser “EXPERT 3L” the indicators of the danger of their multicomponent composition were evaluated and corrected taking into account the proportion of each element of the studied batteries. The article describes the new approach proposed by the authors to assess the impact of multicomponent battery composition on the environment, the peculiarity of which is to determine the resilience of ecosystems on the base of mathematical modelling of the rates of the reactions of formation and removal of individual substances in the system. In particular, quantitative indicators of resilience and loss of natural ecosystems are analysed.

This work presents main approaches to developing a programmable mixed-signal front-end for sensor electronics based on signal transimpedance amplification and integration. In accordance to Internet of Things concept requirements a Programmable System on Chip PSoC 5LP is used for mixed-signal front-end implementation. In comparison to the basic transimpedance amplification and integration circuits, the output voltage of new solution is modulated over the whole voltage range of the power supply. As a result, the enhanced resolution and accuracy of further analog-to-digital conversion are obtained. Simulation and experimental results of parameters investigations have been presented.