Wyniki wyszukiwania - Biblioteka Nauki

1

Single-pulse method for measuring the current-voltage characteristics of solar panels

100%

Bozhko K. M. , Zashchepkina N. M. , Markin M. O. , Markina O. M.

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2019

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tom Vol. 99, nr 1/2

24--29

EN

Purpose: The purpose of the paper is to substantiate the new method of measuring the voltage-current characteristics of solar batteries based on the use of a digital oscilloscope and a special linear sweep device. Design/methodology/approach: To solve this problem, a test bench was developed on the basis of a solar radiation simulator. Findings: Practically it is proved that within the duration of a single pulse of 40 μs, it is possible to measure the voltage-current characteristics of an SB with a short-circuit current of up to 5.8 A. Research limitations/implications: The method is relevant for all types of solar batteries, but the measurements were carried out on serial samples of mono and polycrystalline silicon with a nominal output power of 30 to 140 W and a voltage of 12 V. Practical implications: The method can find its practical application in the development of an intelligent solar module. The technology of the intelligent module is based on the periodic removal of information on the operational parameters of the solar battery based on the measured voltage-current characteristic. Originality/value: Experimental confirmation of the effectiveness of the single-pulse measurement method of the voltage-current characteristic of a solar battery based on a linear current sweep.

2

Contactless ultrasonic method for determining knitted fabrics tension

88%

Zashchepkina N. M. , Zdorenko V. G. , Markin M. O. , Barilko S. V. , Shipko D. O.

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tom Vol. 112, nr 1

13--24

EN

Purpose: of this paper is to provide operational tension control of fabric on knitting equipment using ultrasonic contactless transducers to improve the quality characteristics of the finished product. Design/methodology/approach: It has been established that the amplitude of ultrasonic waves passing through different zones of the textile material can be used to determine the tension of the knitted fabric over the entire width of its fabric. Findings: The possibility and expediency of determining the fabric tension on knitting equipment by using the ultrasonic contactless method has been shown. The tension of the knitted fabric in its manufacture is the main technological parameter, the value of which determines the physical, mechanical and consumer properties of the finished fabric, especially basis weight. The use of operational technological control of the tension of knitted fabrics directly during their production will improve the quality of finished products, and, accordingly, the reliability of use in personal protective equipment, in particular in body armour. It has been proposed to determine the tension of knitted fabrics in their production on knitting equipment by changing the amplitude of ultrasonic waves passing through the material under the action of tension, which also changes during the movement of the process equipment. The proposed contactless method is quite promising, since it has a number of significant advantages over the existing contact methods. In the course of the research, experimental measurements of the amplitude of ultrasonic waves have been carried out. These waves passed through samples of fabric of various materials while stretching. The samples of knitted fabrics were irradiated with an ultrasonic pulse signal with a wave frequency of 40 kHz. The samples of knitted fabrics from 58x2 Tex Kevlar threads and high molecular weight 44x3 Tex polyethylene yarns with double weave 1x1 elastic have been taken as a basis for the research. Research limitations/implications: For textile fabrics, the structure of which does not allow stretching through pores under the action of tension, it is necessary to additionally adjust the contactless sensors in frequency and capacity depending on the corresponding sample. Practical implications: The values of the measured amplitudes of ultrasonic vibrations that have passed the controlled material have been obtained. These values were compared with the amplitude of the waves passing through the fabric sample when the initial tension was applied to it. After that, the total current value of the tension of each sample of the knitted fabric in its three zones was determined. The distribution of the total tension in different zones of the sample material was also determined. Originality/value: The dependences of the amplitude of ultrasonic waves, transmitted through the textile material in its different zones, on the value of the total tension, and on the value of the distribution of the tension of the fabric over its entire width were obtained. The deviations δu of the tension display between the determination of this parameter by the standard and ultrasonic methods are shown. The deviations δU between the amplitudes of waves passing through different zones of the controlled fabric are also determined.

3

Ultrasonic method of quality control for textile materials

75%

Zashchepkina N. M. , Zdorenko V. G. , Tierentyeva N. R. , Markina O. M. , Markin M. O. , Bozhko K. M.

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tom Vol. 97, nr 1/2

39--49

EN

Purpose: The ultrasonic amplitude method for controlling the surface texture density of textile materials was first studied and used. Design/methodology/approach: For the first time, the surface texture density has been determined. The research was conducted using the ultrasonic method, rather than by mathematical calculations, which made it possible to invent a new approach to contactless quality control of textile materials. In order to identify the functionality of bicomponent textile material, formed from raw materials with opposite hygroscopic properties, two-layer knitted fabrics were chosen to protect the human respiratory organs. As a hydrophilic type of raw material used yarn with composition is as follows – cotton 34%, flax 33%, viscose 33%, and in the function of a hydrophobic raw material, polypropylene multifilament yarn. Using the ultrasonic method, studies of a new type of knitwear were carried out, the values of the surface density of the material were obtained. Products from this composition provide respiratory protection from dust and comfortable work in the area of road repairs up to 8 hours. Findings: The combination of natural and synthetic materials for individual masks allowed them to be used under different operating conditions. The problem of structure and design of materials was resolved through the use of computer technology and computer-aided design of textiles, and the possibility of applying the ultrasonic amplitude method to control the surface density of textile materials was substantiated. During the analysis of the results of experimental studies, it was found necessary to ensure the uniformity of the physical and mechanical properties of textile materials in the production process. Using the ultrasonic method, the thickness gauge was used to determine the surface density of various materials for the manufacture of personal protective equipment for road maintenance workers. Research limitations/implications: The method of measurement has been tested and has no limitations. However, the study was conducted on samples of textile materials that were manufactured in Ukraine and according to patents of authors. Practical implications: Individual masks for the protection of human respiratory organs are recommended for use by road workers and cyclists. Originality/value: The originality of the results of the article is the experimental data of studies on the content of textile materials and the accuracy of measuring their surface density by an ultrasonic contactless device.

4

Experimental studies of the thermal regime of the premise while using heating ceramic panels

75%

Basok B. I. , Nedbailo O. M. , Bozhko K. M. , Bozhko I. K. , Markin M. O. , Markina O. M. , Marteniuk V. O.

Archives of Materials Science and Engineering

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2023

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tom Vol. 124, nr 2

56--61

EN

Purpose: The purpose of this paper is to analyse the obtained experimental data, which is advisable to use to verify the thermophysical model of the thermal regime of a separate premise while using ceramic electric heating panels for heating purposes. Design/methodology/approach: The experimental studies were carried out at the scientific thermophysics laboratory with the help of up-to-date equipment (including the design for these studies). After gathering experimental data, it was analysed, and with its help, a CFD model of the thermal regime of the laboratory premise would be verified. Findings: The conducted experimental studies showed that in the artificially created quasi- stationary thermal regime of the laboratory premise, the air temperature varied with height in a small interval. This makes it possible to state that when using ceramic electric heaters as heating devices, the air temperature is relatively evenly distributed over the height of the premise. Research limitations/implications: The research provides original experimental data and findings for further CFD modelling of the thermal regime of the premise while using heating ceramic panels. Practical implications: The mentioned in the paper research methods as well as obtained experimental data, could be used in further studies of modern heating systems. Another use of the results – during the validation of CFD models. Originality/value: The paper includes the design and methodology of creating the original experimental stand for research of the different heating systems types.