Adhesive dentistry is the foundation on the basis of which there have been global changes in the concept of adhesion of composite materials in therapeutic dentistry, protocols for fixing ceramic restorations in orthopedic dentistry. But a number of unsolved problems remained – the adhesion of composite materials to sclerosed dentin and tooth root cement, the sensitivity of the components of the adhesive systems to the wet environment of the oral cavity and spatial stability in the presence of dentinal fluid moving centrifugally in the dentinal tubules, the lack of restoration of periodontal attachment to the defect that occurs during tooth root caries. The review analyzes the results of studies on the use of self-etching adhesive systems in the treatment of root caries. The physician's ability to choose an adhesive system in a particular clinical case demonstrates his fundamental knowledge and minimizes the percentage of errors that he can make during the treatment phase.

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Four-wire distribution electrical networks of 0.4 kV equipped with automated systems of electrical energy accounting are considered. The problem of identifying the resistances of the wires of the distribution network is solved on the basis of the effective values of voltages and currents, as well as of their phase shift angles obtained by the accounting system in the power supply node of the network and from its subscribers for the selected observation intervals. A brief analysis of the known methods and technologies used in this area of research is carried out. The importance of the formulated problem for applied problems, such as control and diagnostics of electrical energy losses, as well as the technical condition of the network, is noted. A method (algorithm) is proposed that allows determining unknown, unequal complex resistances of inter-subscriber sections of the distribution network. In these resistances, the reactive components are considered equal within the inter-subscriber section; the active components differ due to the influence of unequal flowing currents and/or weather factors. At the same time, data from two different network operating modes are required, which are selected based on the analysis of the dynamics of changes of supply currents and/or voltages by the accounting system device connected to the power supply node. Considering that the active resistances of the wires must remain unchanged, the mode that is used for calculations is the one that is before the change in power consumption in the network and the next one immediately (about 0.1 s) after it. An example of a calculation that demonstrates the reliability of the proposed equations of the method that has been developed on a simulated distribution network is given. The research results are focused on the improvement of automated accounting systems and the implementation of their new functions that elevate the reliability of distribution networks, as well as allowing for the rapid identification of non-technical losses of electrical energy.

THE PURPOSE. The process of o n-line calculation of electricity losses in three phase distribution electric networks (DEN) with a voltage of a 0,4 kV, where monitoring of electricity losses (commercial accounting) is carried out by an automated information measuring system of electrici ty monitoring and accounting (AIMS EMA) is considered. The problem of operative detecting of unauthorized power take -offs in the DEN under condition of unknown values of parameters of the network equivalent circuit, i.e. resistances of its interpersonal sections, which can change significantly over time because of external climatic factors (temperature, humidity, etc.) is being solved. METHODS. The procedure of the proposed calculation can be implemented by the available means of AIMS EMA. It is based on simultaneous measurements for the same observation interval of effective values of current and voltage, active and reactive powers at the beginning of the DEN and at each subscriber. In the course of periodic measurements of these mode parameters, the initial data used in the proposed calculation are formed. RESULTS. The analysis of the known methods of solving this problem is carried out, their disadvantages are shown and the new methodology, which is based on a preliminary operative calculation of reliable values of the resistances of interpersonal sections, provided that unauthorized power take -offs are possible in DEN is presented. While solving, the conditions of equality of resistances of the phase and neutral wires within the interpersonal section of th e DEN are used. The proposed method makes available the implementation of the operative calculation of technical losses in DEN and the identification of the commercial losses (unauthorized power take -offs) in it, as well as a detailed analysis of subscribe r data in order to detect the location (coordinate) and the amount of unaccounted electricity. CONCLUSIONS. The proposed methodology can be used in existing AIMS EMA without the introduction of additional measuring means (functions).