(Видавництво Львівської політехніки, 2021-02-23) Kostiukov, Ivan; National Technical University “Kharkiv Polytechnic Institute”
This article is devoted to the analysis of components of variance of the results of measurements of dielectric
dissipation factor of insulation layers between the conductive elements of the construction of three core power cables with paper
impregnated insulation in a common sheath. The analysis of components of variance was carried out by applying presented
relations for the direct calculation of the dielectric dissipation factor. The accuracy of presented relations for the calculation of
variance components was verified. The results of carried out analysis have shown that the variance of the dielectric dissipation
factor measurements is mostly determined by the variances of multiplication of measurements of aggregate values of dielectric
dissipation factor and coefficients depending on the partial capacitances of tested three core cable.
(Видавництво Львівської політехніки, 2021-02-23) Mykyichuk, Mykola; Rudyk, Yuriy; Lviv Polytechnic National University; Lviv State University of Life Safety
In the article, both the test method features and the test results of research of thermal behavior of steel fragment
were analyzed. Two types of test conditions for steel construction material were considered. The definition and main features of
measurement techniques were presented. Fire retardant material test results for steel plates with hydrogen combustion shown the
limit of fire resistance of the tested samples is more than 30 min. The main advantages and disadvantages of the test were
determined. The positive and negative aspects of this approach were analyzed. These techniques' effective thermal condition is in
an environment of uncertainty and has no limited resources was established. Concepts and principles for establishing validity, and
frameworks and methods for validating test methods and their results are important elements of safety systems. The article
considers the safety of the technical component of a complex organizational and technical system with the study of the functional
relationship between the safety elements parameters: temperature, time, fire retardant – by hydrogen participation.
(Видавництво Львівської політехніки, 2021-02-23) Tchaban, Vasil; Lviv Polytechnic National University
Based on Newton's adapted law of universal gravitation in the case of moving masses, taking into account the
finite velocity of gravity, differential equations of motion of celestial bodies are obtained. The transient process of the precession
of the planet's perihelion was simulated for the first time. A new physical interpretation of the celestial phenomenon due to the
discovered new component of force in addition to the Newtonian and Lorentz (gravitomagnetic) is given. The problem of
measuring a new force has been formed. The results of computer simulation of the precessing perihelion of the planet considering
a new force component are discussed.
(Видавництво Львівської політехніки, 2021-02-23) Mašková, Kamila; Petrovska, Iryna; Ryshkovskyy, Oleksander; Yatsyshyn, Svyatoslav; Lviv Polytechnic National University
Automated systems that are part of cyber-physical systems provide distribution of goods or prefabricated
components, as well as their documenting and automatic tracking in real-time. Workpieces are marked with RFID transponders.
RFID antennas allow contactless reading and/or recording of information, RFID electronics process and transmit it to the
programmable logic controller via PROFIBUS DP, PROFINET, Ethernet IP, Ethernet TCP/IP, or EtherCAT interface. The
peculiarities of the universal interface for the needs of cyber-physical systems equipped with RFID means and the main
metrological characteristics of the latter are studied in the work.
(Видавництво Львівської політехніки, 2021-02-23) Kuzmenko, Iuriy; Samoilenko, Olexandr; Tsiporenko, Serhiy; State Enterprise “Ukrmetrteststandard”
The development of multipurpose measurement models is the precondition for software development for
simultaneous adjustment of the large scope and complicated combinations of the measurement results by the least-squares method.
Multipurpose measurement models for software can be a helpful tool for processing the final measurement results provided by
different measurement methods applying the mentioned software; processing the measurement results of measurement standards
comparisons, interlaboratory comparison, and calibration procedures; estimating the additive and multiplicative systematic
components of measurement errors and their uncertainty; processing complicated combinations by binding or linking up of the
interlaboratory comparison and calibration results in the time; simultaneous processing of the measurement results obtained by
various methods e.g. by the method of direct measurements and comparisons; fast-changing the multipurpose measurement models
from linear to non-linear type. Processing of the results by software based on the multipurpose measurement model algorithm can
help to established a comprehensive measurement traceability network by pooling the single traceability chains.
(Видавництво Львівської політехніки, 2021-02-23) Krayovskyy, Volodymyr; Pashkevych, Volodymyr; Horpenuk, Andriy; Romaka, Volodymyr; Stadnyk, Yuriy; Romaka, Lyubov; Horyn, Andriy; Romaka, Vitaliy; Lviv Polytechnic National University; Ivan Franko National University of Lviv; Leibniz Institute for Solid State Research
Automated The results of modeling performances of the semiconductor solid solution Er1–xScxNiSb are
presented, which can be a promising thermometric material for the manufacture of sensitive elements of thermoelectric and
electroresistive thermocouples. Fullprof Suite software was used to model the crystallographic characteristics of the Er1-xScxNiSb
thermometric material. Modeling of the electronic structure of Er1–xScxNiSb was performed by Coring-Kon-Rostocker methods in
the approximation of coherent potential and local density using the exchange-correlation potential Moruzzi-Janak-Williams and
Linear Muffin-Tin Orbital in the framework of DFT density functional theory. The Brillouin zone was divided into 1000 k-points,
which were used to model energetic performances by calculating DOS. The width of the energy window was 22 eV and was
chosen to capture all semi-core states of p-elements. Full potential (FP) was used in the representation of the linear MT orbital in
the representation of plane waves. The accuracy of calculating the position of the Fermi level was εF ± 6 meV.
To verify the existence of a continuous solid solution, Er1–xScxNiSb substitution, the change in the values of the period of
the unit cell a (x) was calculated within the framework of the DFT density functional theory in the range x = 0–1.0. It is presented
that the calculated and experimentally obtained dependences of the period of the unit cell a(x) Er1–xScxNiSb are almost parallel,
which confirms the correctness of the used tools and the obtained modeling results.
To research the possibility of obtaining thermometric material Er1–xScxNiSb in the form of a continuous solid solution was
performed modeling of thermodynamic calculations in the approximation of harmonic oscillations of atoms in the theory of DFT
density functional for a hypothetical solid solution Er1–xScxNiSb, x = 0–1.0. It is shown that the change in the values of free energy
ΔG(x) (Helmholtz potential) passes through the minimum at the concentration x≈0.1 for all temperatures of possible homogenizing
annealing of the samples, indicating the solubility limit of Sc atoms in the structure of the ErNiSb compound. The presence of this
minimum indicates that the substitution of Er atoms for Sc atoms in the ErNiSb compound is energetically advantageous only up
to the concentration of impurity atoms Sc, x ≈ 0.1. At higher concentrations of Sc atoms, x > 0.10, stratification occurs (spinoidal
phase decay). It is shown that modeling of the mixing entropy behavior S even at a hypothetical temperature T = 4000 K shows the
absence of complete solubility of Sc atoms in Er1–xScxNiSb.
To model the energetic and kinetic performances of the semiconductor thermometric material Er1–xScxNiSb, particularly the
behavior of the Fermi level e F , bandgap width e g the distribution of the density of electronic states (DOS) and the behavior of
its electrical resistance ρ(x, T) is calculated for an ordered variant of the structure in which the Er atoms in position 4a are replaced
by Sc atoms. It is shown that the ErNiSb compound is a semiconductor of the electronic conductivity type, in which the Fermi
level is located near the level of the conduction band e C . The modeling showed that at higher concentrations of Sc atoms, the
number of generated acceptors exceeds the concentration of uncontrolled donors, and the concentration of free holes exceeds the
concentration of electrons. Under these conditions, the Fermi level e F approaches, and then the level of the valence band
Er1–xScxNiSb crosses: the dielectric-metal conductivity transition occurs. The experiment should change the sign of the thermo-
EMF coefficient α(x, T) Er1–xScxNiSb from negative to positive, and the intersection of the Fermi level e F and the valence band
changes the conductivity from activating to metallic: on the dependences ln(ρ(1/T)) the activation sites disappear, and the
values of resistivity ρ increase with temperature.
(Видавництво Львівської політехніки, 2021-02-23) Mykyichuk, Mykola; Hut, Taras; Lazarenko, Nadia; Lviv Polytechnic National University
The article analyzes and proposes solutions for metrological support of weight information systems of road
vehicles in motion, including the method of classification of WIM systems by purpose and accuracy classes, metrological
requirements for them and control methods for testing and verification, as well as the main metrological risks for Weigh-in-motion
systems for road vehicles and requirements for determining and calculating reliability.
(Видавництво Львівської політехніки, 2021-02-23) Mochurad, Lesia; Kryvenchuk, Yuriy; Yatsyshyn, Svyatoslav; Lviv Polytechnic National University
The paper examines the efficiency of the application of CUDA technologies for the parallelization of the
cryptographic algorithm with the public key. The speed of execution of several implementations of the algorithm is compared:
sequential implementation on the CPU and two parallel implementations – on the CPU and GPU. A description of the public key
algorithm is presented, as well as properties that allow it to be parallelized. The advantages and disadvantages of parallel
implementations are analyzed. It is shown that each of them can be suitable for different scenarios. The software was developed
and several numerical experiments were performed. The reliability of the obtained results of encryption and decryption is
confirmed. To eliminate the influence of external factors at the time of execution the algorithm was tested ten times in a row and
the average value was calculated. Acceleration coefficients for message encryption and decryption algorithms were estimated
based on OpenMP and CUDA technology. The proposed approach focuses on the possibility of further optimization through the
prospects of developing a multi-core architecture of computer systems and graphic processors.