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  • 1
    Online Resource
    Online Resource
    Belarusian National Technical University ; 2016
    In:  Devices and Methods of Measurements Vol. 7, No. 3 ( 2016-01-01), p. 256-261
    In: Devices and Methods of Measurements, Belarusian National Technical University, Vol. 7, No. 3 ( 2016-01-01), p. 256-261
    Type of Medium: Online Resource
    ISSN: 2414-0473 , 2220-9506
    URL: Issue
    Language: Unknown
    Publisher: Belarusian National Technical University
    Publication Date: 2016
    detail.hit.zdb_id: 2863749-5
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  • 2
    Online Resource
    Online Resource
    Belarusian National Technical University ; 2016
    In:  Devices and Methods of Measurements Vol. 7, No. 2 ( 2016-01-01), p. 219-226
    In: Devices and Methods of Measurements, Belarusian National Technical University, Vol. 7, No. 2 ( 2016-01-01), p. 219-226
    Type of Medium: Online Resource
    ISSN: 2414-0473 , 2220-9506
    URL: Issue
    Language: Unknown
    Publisher: Belarusian National Technical University
    Publication Date: 2016
    detail.hit.zdb_id: 2863749-5
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  • 3
    Online Resource
    Online Resource
    Belarusian National Technical University ; 2018
    In:  Devices and Methods of Measurements Vol. 9, No. 1 ( 2018-03-20), p. 40-47
    In: Devices and Methods of Measurements, Belarusian National Technical University, Vol. 9, No. 1 ( 2018-03-20), p. 40-47
    Abstract: Periodic radiation monitoring of soils today is a priority task not only for Belarus, but also for Japan, suffered by Fukushima nuclear power plant accident. Use of portable and light spectrometers with ability to perform  in situ  measurements makes it possible to quickly estimate specific activity of measured radionuclides with required accuracy in particular soil site. Basic information of a gamma radiation source (radionuclides content, effective radius of measurement area and thickness of contaminated layer) can be obtained directly during measurement. The purpose of this research is to test the feasibility of using algorithms for determination of specific activity and thickness of contaminated layer under conditions of soil measurement with variable density parameters and radiocesium distribution in soil. Monte-Carlo simulating allowed to estimate the degree of deviation of the shape of simulated spectra obtained with the use of Monte-Carlo soil model with uniformly distributed radionuclide in it, and for the case when the radionuclide distribution by soil profile can be described by an exponential function. For these cases of natural distribution of radiocesium, the pulse-amplitude spectrum is formed by an effective thickness of the contaminated site, which contains more than 90 % of radionuclides. The developed Monte-Carlo model of a probe and contaminated soil site allows to estimate the effect of the variability of soil density on the total count rate of the pulse-amplitude spectrum. As a result of theoretical estimations, the relationship between the effective radius of contaminated site is determined as a function of soil density. Analysis of the influence of radial zones of the cylindrical gamma source on  in situ  gamma-spectrometer showed that the main contribution to the total count rate of the pulse-amplitude spectrum is made by the radial zone with radius of up to 40 cm from the center of the probe, regardless of the thickness of the contaminated layer in geometry «Probe is located on the soil surface». A small site facilitates the selection of measurement area of land with a sufficiently flat surface, which is desirable during surveying the territories, especially with complex terrain.
    Type of Medium: Online Resource
    ISSN: 2414-0473 , 2220-9506
    URL: Issue
    Language: Unknown
    Publisher: Belarusian National Technical University
    Publication Date: 2018
    detail.hit.zdb_id: 2863749-5
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  • 4
    Online Resource
    Online Resource
    Elsevier BV ; 2018
    In:  Applied Radiation and Isotopes Vol. 139 ( 2018-09), p. 114-120
    In: Applied Radiation and Isotopes, Elsevier BV, Vol. 139 ( 2018-09), p. 114-120
    Type of Medium: Online Resource
    ISSN: 0969-8043
    Language: English
    Publisher: Elsevier BV
    Publication Date: 2018
    detail.hit.zdb_id: 1499873-7
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  • 5
    Online Resource
    Online Resource
    Belarusian National Technical University ; 2022
    In:  Devices and Methods of Measurements Vol. 13, No. 1 ( 2022-04-04), p. 32-39
    In: Devices and Methods of Measurements, Belarusian National Technical University, Vol. 13, No. 1 ( 2022-04-04), p. 32-39
    Abstract: Radionuclide 238 U is one of the most important radioactive elements that must be controlled in nuclear power engineering, geological exploration, control of radioactive contamination of soils and raw materials used in construction. The most optimal way to control 238 U is to use the 234m Pa radionuclide, the activity of which, due to its short lifetime (≈ 1.2 min), is unambiguously related to the activity of 238 U even if the secular equilibrium is disturbed in the sample under study Рossibility of use of the 234m Pa nuclide gamma radiation to determine 238U with a scintillation detector in a medium containing natural radionuclides is investigated and demonstrated using the simplest examples. The proposed algorithm for determining of the 238 U content is based on the Monte Carlo simulation of the detector response to the radiation of the 234m Pa radionuclide at its 1001 keV energy line and subsequent processing of the experimental spectrum, including the Wiener filtering of the signal. This method makes it possible to determine the content of 238 U in a continuous homogeneous medium while presence of natural radionuclides in it. The algorithm for determining of 238 U content includes several main steps. Filtering based on the Wiener algorithm allows selecting a slowly changing part of the spectrum. Results of Monte Carlo simulations make it possible to determine the detection efficiency in a limited informative region of the spectrum, which includes, along with the 1001 keV peak from the 234m Pa nuclide, which is a decay product of the radionuclide 234 Th, and the peak of an interfering radionuclide from the decay chain of 232 Th. This part of the spectrum does not contain any other lines of gamma radiation from natural radionuclides – decay products of both thorium and uranium chains. These two peaks in the spectral region under study can be separated from each other in a medium with a typical concentration of 234 Th. Analysis of results of the activity of depleted uranium metal measuring in accordance with the proposed algorithm shows the possibility of determining of 238 U content with an uncertainty of 3–5 %.
    Type of Medium: Online Resource
    ISSN: 2414-0473 , 2220-9506
    URL: Issue
    Language: Unknown
    Publisher: Belarusian National Technical University
    Publication Date: 2022
    detail.hit.zdb_id: 2863749-5
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  • 6
    Online Resource
    Online Resource
    Belarusian National Technical University ; 2021
    In:  ENERGETIKA. Proceedings of CIS higher education institutions and power engineering associations Vol. 64, No. 3 ( 2021-06-04), p. 239-249
    In: ENERGETIKA. Proceedings of CIS higher education institutions and power engineering associations, Belarusian National Technical University, Vol. 64, No. 3 ( 2021-06-04), p. 239-249
    Abstract: The efficiency of an enterprise’s power supply system depends on the quality of electricity and the losses of the latter in electrical networks; both being largely determined by the modes of voltage control and reactive power compensation. In practice, the problems of voltage control and reactive power compensation in power supply systems of industrial enterprises, including electric networks with a voltage of up to 1 kV, as well as 6, 10 kV and higher, are often solved separately. It triggers an irrational use of existing voltage control devices, underutilization of the installed capacity of compensating devices, and affects the voltage control in the electrical networks of the power supply organization. Since voltage management and compensation modes of reactive power are inseparable, they can be correctly determined only with the use of an integrated approach based on technical and economic criteria and taking into account technical requirements and local conditions. This article analyzes the mutual influence of voltage control and reactive power compensation modes in the electrical networks of industrial enterprises from the point of view of ensuring the quality of electricity and minimizing load power losses. The method and results of calculations (on the example of a specific industrial facility) for determining voltage deviations and losses in the electrical network as well as for selecting parameters for voltage control and reactive power compensation are presented. Due to the close relationship of these modes that affect all voltage levels, the effectiveness of measures cannot be ensured without the use of multifunctional devices for controlling the equipment of transformer substations.
    Type of Medium: Online Resource
    ISSN: 2414-0341 , 1029-7448
    URL: Issue
    Language: Unknown
    Publisher: Belarusian National Technical University
    Publication Date: 2021
    detail.hit.zdb_id: 2863606-5
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  • 7
    Online Resource
    Online Resource
    Belarusian National Technical University ; 2022
    In:  ENERGETIKA. Proceedings of CIS higher education institutions and power engineering associations Vol. 65, No. 1 ( 2022-02-02), p. 37-51
    In: ENERGETIKA. Proceedings of CIS higher education institutions and power engineering associations, Belarusian National Technical University, Vol. 65, No. 1 ( 2022-02-02), p. 37-51
    Abstract: The problems of reactive power compensation and improving the quality of electrical energy in the power supply systems of industrial enterprises are inseparable. Their relevance is due to the widespread use of electric receivers that consume reactive power and distort the quality of electrical energy in the network, as well as the implementation of new technologies, systems and equipment into production that make increased demands on the quality of electrical energy consumed. An important characteristic of the quality of electrical energy rationed by GOST 32144–2013 is the non-sinusoidal voltage. The main reason for the non-sinusoidal voltage in the electrical networks of industrial enterprises is the use of electrical equipment with a nonlinear voltage characteristic, which is a source of conductive electromagnetic interference, in particular: adjustable DC and AC electric drives, uninterruptible power supplies of electric receivers, electric welding equipment, electric arc furnaces, induction heating installations, gas-discharge radiation sources. Due to the nonlinearity of the current-voltage characteristics, the above devices consume a non-sinusoidal current from the network, which causes harmonic distortion of the supply voltage, including the fundamental harmonic component and higher harmonic components that are multiples of the fundamental frequency. Non-sinusoidal voltage, in turn, causes additional losses of power and energy in the elements of the electrical network, causes overheating and accelerated aging of the insulation of electrical equipment, reducing its operational reliability and reducing service life, worsens the accuracy of electrical measurements, causes malfunctions in automation systems, telemechanics, relay protection, electronic systems and communications. Non-sinusoidal voltage significantly complicates the compensation of reactive power in the electrical network. Compensating devices are made on the basis of capacitors, whose electrical parameters (resistance, power, current) depend on both the magnitude of the supply voltage and its harmonic composition. The present article identifies problems and proposes solutions in terms of reactive power compensation and improving the quality of electrical energy in electrical networks containing thyristor voltage converters and frequency converters used in adjustable electric drive installations of industrial enterprises.  
    Type of Medium: Online Resource
    ISSN: 2414-0341 , 1029-7448
    URL: Issue
    Language: Unknown
    Publisher: Belarusian National Technical University
    Publication Date: 2022
    detail.hit.zdb_id: 2863606-5
    Location Call Number Limitation Availability
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