Вимірювальна техніка та метрологія. – 2022. – Випуск 83, №2

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Measuring Equipment and Metrology : scientific journal. – Lviv : Lviv Politechnic Publishing House, 2022. – Volume 83, № 2. – 48 р.

Вимірювальна техніка та метрологія

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    Зміст до “Вимірювальна техніка та метрологія”
    (Видавництво Львівської політехніки, 2022-02-28)
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    Comparative analysis of technical characteristics of charging stations of electric vehicles
    (Видавництво Львівської політехніки, 2022-02-28) Velychko, Oleh; Gordiyenko, Tetyana; State Enterprise “Ukrmetrteststandard”; State University of Telecommunications
    The article analyzes and compares charging stations for electric vehicles and their components. The analysis of charging modes of electric vehicles showed that four internationally standardized modes are used, three of which use alternating current with single-phase and three-phase switching and only one – direct current. When charging on direct current, the fastest charging is provided. There are four standardized cases of connecting charging stations to electric vehicles. Three cases of cable connection can be used on alternating current, only the third case – on direct current, and the fourth case – when wirelessly charging an electric car. Analysis of the principles of use of charging stations showed that they classify portable, wall, and stationary stations. National standards introduce road signs for electric vehicles, and a European standard establishes harmonized identifiers for the power supply of electric vehicles. There are some standardized protocols for the interaction of the charging station and the control server, which are designed to optimize energy resources and energy production systems. A comparison of existing types of connectors for charging electric vehicles has shown that the standardized interface between the charging station and the electric vehicle remains one of the most acute problems. Recommendations on approaches to metrological support of charging stations are formulated. The issue of international and regional standardization of electricity meters of direct current for use in charging stations remains relevant. International standards are transformed into relevant European standards without changes. However, in some cases, it is necessary to develop a special European standard, in particular for meters of active electrical energy of the direct current.
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    Methodology for assessing the life cycle processes of scaffolds
    (Видавництво Львівської політехніки, 2022-02-28) Chernobrovchenko, Vadym; Dyadyura, Kostiantyn; Sumy State University; Odesa Polytechnik National University
    Due to the increase in diseases in the musculoskeletal system, regenerative medicine is now developing various bone substitutes. Not all scaffolds, due to their shortcomings, are applied for every application. Patients should be provided with basic product information and other warnings about health risks or measures to be taken. From the establishment of the purpose of the biomaterial to apply, several stages of the life cycle can pass. To ensure the biocompatibility of medical devices, there is a legislative framework and standards. They cover the full cycle from testing to market authorization, surveillance, and recall (ISO 15225:2010, ISO/IEC 33001:2015). We have developed the life cycle of bone substitutes and can offer an approach to evaluate operations based on the requirements of the ISO/IEC 33001:2015 series.
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    Characteristics of thermometric material Lu1-xScxNiSb
    (Видавництво Львівської політехніки, 2022-02-28) Pashkevych, Volodymyr; Krayovskyy, Volodymyr; Horpenyuk, Andriy; Romaka, Volodymyr; Stadnyk, Yuriy; Romaka, Lyubov; Horyn, Andriy; Romaka, Vitaliy; Lviv Polytechnic National University; Ivan Franko National University of Lviv; Technische Universität Dresden
    The results of modeling the properties of the semiconductor solid solution Lu1-xScxNiSb, x=0–0.10, which is a promising thermometric material for the manufacture of sensitive elements of thermocouples, are presented. Modeling of the electronic structure of Lu1-xScxNiSb was performed by the Korringa-Kohn-Rostoker (KKR) method in the approximation of coherent potential and local density and by the full-potential method of linearized plane waves (FLAPW). KKR simulations were performed using the AkaiKKR software package in the local density approximation for the exchange-correlation potential with parameterization Moruzzi, Janak, Williams. The Elk software package was used in the FLAPW calculations. To check the limits of the existence of the thermometric material Lu1-xScxNiSb by the KKR method, the change of the values of the period of the unit cell a(x) in the range x=0–0.10 was calculated. It is established that the substitution of Lu atoms in the crystallographic position 4a by Sc atoms is accompanied by a decrease in the values of the unit cell period a(x) Lu1-xScxNiSb. This behavior of a(x) Lu1-xScxNiSb is since the atomic radius Sc (rSc=0.164 nm) is smaller than that of Lu (rLu=0.173 nm). In this case, structural defects of neutral nature are generated in Lu1-xScxNiSb, because the atoms Lu (5d16s2) and Sc (3d14s2) are located in the same group of the Periodic Table of the Elements and contain the same number of d-electrons. To study the conditions for obtaining thermometric material Lu1-xScxNiSb, x=0–0.10, and to establish the energy feasibility of its formation in the form of a continuous solid solution, modeling of thermodynamic characteristics in the approximation of harmonic oscillations of atoms within the DFT density functional theory. The low values of the enthalpy of mixing ΔHmix(x) and the nature of the dependence behavior indicate the energy expediency of substitution in the crystallographic position 4a of Lu atoms for Sc atoms and the existence of a solid substitution solution for the studied samples Lu1-xScxNiSb, x=0–0.10. To understand the mechanisms of electrical conductivity of the thermometric material Lu1-xScxNiSb, x=0–0.10, various models of crystal and electronic structures of the basic semiconductor LuNiSb are considered. Assuming that the crystal structure of Lu1-xScxNiSb is ordered (crystallographic positions are occupied by atoms according to the MgAgAs structural type), the Elk software package was used to model the DOS electronic state density distribution for LuNiSb and Lu0.875Sc0.125NiSb. It is shown that in the LuNiSb compound the Fermi level lies in the middle of the band gap , and the bandwidth is =190.5 meV. DOS simulations for the ordered variant of the Lu0.875Sc0.125NiSb crystal structure show a redistribution of the density of DOS electronic states and an increase in the band gap . In this case, the Fermi level , as in the case of LuNiSb, lies in the middle of the band gap , and the generated structural defects are neutral. The DOS calculation for the disordered variant of the crystal structure of the LuNiSb compound was performed using a model that can be described by the formula Lu1+yNi1-2ySb. In this model, the Lu atoms partially move to the 4c position of the Ni atoms, and in this position, a vacancy (y) occurs simultaneously. Moreover, as many Lu atoms additionally move to the 4c position of Ni atoms, so many vacancies arise in this position. In this model of the crystal structure of the LuNiSb compound and the absence of vacancies (y=0), the calculation of the DOS electronic state density distribution indicates the presence of the band gap εg, and the Fermi level εF lies near the valence band εV. In the model of the structure of the LuNiSb compound at vacancy concentrations y=0.01, the DOS calculation also shows the presence of the band gap εg, and the Fermi level εF still lies near the valence band εV. Since Ni atoms make the greatest contribution to the formation of the conduction band εC, even at a concentration of y=0.02, the DOS calculation shows that the Fermi level εF now lies near the conduction band εC. This means that the main carriers of the electric current of the LuNiSb compound at y=0.02 are electrons, which does not correspond to the results of experimental studies. Based on the above model of the disordered crystal structure of the LuNiSb compound, the density distribution of DOS electronic states was calculated for the disordered variant of the crystal structure of the thermometric material Lu1-xScxNiSb, which is described by the formula Lu1-x+yScxNi1-2ySb. In this model of the Lu1-xScxNiSb crystal structure, the calculation of the DOS electronic state density distribution shows the presence of a band gap εg, in which small energy levels ("tail tails") are formed, which overlap with the zones of continuous energies. In this case, the Fermi level εF is localized at low energy levels, which makes it impossible to accurately determine the depth from the Fermi level εF. The proposed model is correct only for a small number of impurity Sc atoms since the partial occupation of the 4c position of Ni atoms by Lu atoms significantly deforms the structure with its subsequent decay. The results of experimental studies of the kinetic, energy, and magnetic properties of the thermometric material Lu1-xScxNiSb will show the degree of adequacy of the proposed model.
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    Electrical properties of Ti-Cu-Co-Si high-entropy alloy
    (Видавництво Львівської політехніки, 2022-02-28) Yatsyshyn, Svyatoslav; Skoropad, Pylyp; Karpinski, Mikolaj; Lviv Polytechnic National University
    To study the metrological characteristics, there were studied manufactured based on the Ti-Cu-Co-Si alloy, obtained by quenching from the melt, the sensitive element of the resistance thermotransducer. The instability of its metrological characteristics as a function of temperature up to 350 oC and operation time up to 3000 hours was investigated; it does not exceed 0.025 % under the worst operating conditions. In addition, the methodological error of measurement caused by heating of the sensitive element by the measuring current was examined. It was shown that the recorded changes in electrical resistance were outside the value of the methodological error. They may be due to the presence of nanostructured fields of mechanical stresses and the formation of nanoprecipitates as a consequence of manufacturing.
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    Impact of the interaction of moving planets on their orbits
    (Видавництво Львівської політехніки, 2022-02-28) Chaban, Vasil; Bartman, Jacek; Lviv Polytechnic National University
    The research raises the problem of determining and measuring the interaction of planets on the trajectory of their orbits around the Sun. Its solution becomes possible only based on an adequate mathematical model. For this purpose, Newton's law of universal gravitation was adapted to the case of moving masses in a wide range of velocities in flat Euclidean space and physical time. The finite speed of propagating the gravitational field is considered. Differential equations of planets’ motion are obtained. Transients in the threemass system of a star and two planets close to the Sun-Mercury-Venus system are simulated. To reveal deeply the essence of physical interaction, a hyperbolized transition process is simulated under artificially close moving masses.
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    Data cleaning method in wireless sensor-based on intelligence technology
    (Видавництво Львівської політехніки, 2022-02-28) Diachok, Roman; Klym, Halyna; Lviv Polytechnic National University
    The method of cleaning management data in wireless sensor networks based on intelligence technology has been studied. Specific forms of application of wireless sensor networks are analyzed. The characteristics of the structure of wireless sensor networks are presented and the data cleaning technology based on the clustering model is offered. An algorithm for deleting a cluster-based replication record is proposed and the accuracy of data cleaning methods is tested. The obtained results testify to the efficiency of using the studied method.
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    Титульний аркуш до “Вимірювальна техніка та метрологія”
    (Видавництво Львівської політехніки, 2022-02-28)