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1

Increasing the accuracy of measuring the physicochemical parameters of wastewater samples when implementing a new informative method

Sebko V. V., Zdorenko V. G., Zashchepkina N. M., Barylko S. V.

Journal of Achievements in Materials and Manufacturing Engineering

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2023

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Vol. 118, nr 1

28--41

EN

Purpose The necessity of developing new multi-parameter electromagnetic methods to obtain the information on controlled wastewater samples from fruit juice production has been proved. Based on the universal transformation functions G = f(x) and φ = f(x) obtained in the work, which relates the amplitude and phase components of the multi-parameter MFP signal with the parameters of wastewater samples, a three-parameter method for joint measurement control of the electrical conductivity χ, relative dielectric constant εr and temperature t of wastewater samples from the production of apple juice. An algorithm for joint multi-parameter measurements of the parameters χ, εr and t based on a transformer electromagnetic transducer (MFP) has been developed, the switching scheme provides for heating a wastewater sample during measurement control to simulate production conditions. Since the amplitude and phase components of the MFP multi-parameter signal depend on the temperature t, sample heating also makes it possible to create information redundancy and improve the accuracy of wastewater sample identification. The implementation of the proposed method makes it possible to indirectly determine the composition of wastewater samples, using only one transducer with known physical properties, all this leads to an increase in the accuracy of measuring the parameters of wastewater samples in comparison with reference methods and measuring instruments and ultimately allows choosing a promising method of wastewater treatment in accordance with the analysis of experimental data. The data obtained indicate the acidic composition of wastewater; therefore, it is proposed to neutralise industrial waste at the outlet of the finished product. The methodology of the above studies lies in the fact that, within the framework of a specific scientific approach, it is necessary to expand the functional and technical capabilities of the electromagnetic device by implementing a new multi-parameter electromagnetic method for joint measurements of the physicochemical parameters of wastewater samples. Design/methodology/approach The essence of the proposed three-parameter method of joint measurement control of parameters χt, εr and t is based on the analysis of the interaction of an external homogeneous magnetic field with the magnetic field of eddy currents induced in a conductive electrolytic liquid (in a wastewater sample). Based on the input of special normalised parameters, as well as the obtained universal transformation functions G = f(x) and φ = f(x), which relate the physicochemical parameters χ, εr and t of the electrolytic liquid medium (wastewater samples from apple juice production) with the amplitude and phase components of the multi-parameter signal MFP, at a constant frequency of the magnetic field f, the implementation of a three-parameter electromagnetic method of joint measurement control of the electrical conductivity χ, relative permittivity εr and temperature t have been proposed. At the same time, using the thermal MFP switching circuit, it is necessary to measure two magnetic fluxes: the reference magnetic flux F0 in the absence of a glass tube with liquid in the converter and the magnetic flux F2 (if there is a wastewater sample in the converter) and the phase angle φ between the flows F0 and F2. To this end, three wastewater parameters, χt, εr and t, are determined jointly by the same MFP in the same control zone. Implementing the proposed method makes it possible to indirectly assess the composition of wastewater, select a promising treatment method, and then take preventive measures related to environmental protection. Findings The possibility of applying the MFP operating theory to the realisation of an informative three-parameter electromagnetic method of joint measurements of specific conductivity χ, relative permittivity εr and temperature t parameters of wastewater has been studied. An algorithm for modelling the process of joint multi-parameter measurements of specific conductivity χ, relative permittivity εr and temperature t based on MFP has been developed. The basic relations describing a three-parameter method of joint measurements of specific conductivity χ, relative permittivity εr and temperature t of controlled wastewater samples are presented. The obtained numerical values of the physicochemical parameters of the wastewater sample are in good agreement with the data obtained using the controlling methods. Implementation of the proposed three-parameter method allows to increase in the accuracy of identification of wastewater samples due to the obtained multi-parameter information, as well as to determine indirectly the composition of wastewater samples, using a single transducer with certain physical properties; all this leads to increased accuracy of wastewater sample parameters in comparison with the reference methods and measuring tools, and allows to choose a rational and inexpensive treatment method. Research limitations/implications The method studied has the following limitations: the range of variation of the diameters is 20 mm to 55 mm. The lower limit is set by the frequency of the electromagnetic field, and the upper limit by the diameter of the transducer frame, 57 mm. Measurements are made in homogeneous longitudinal magnetic fields, and the length of the MFP winding must be ten times the diameter to achieve such field homogeneity. The sample length must be greater than or equal to the winding length of the transducer, i.e., lo⩾ ln. The radial misalignment of the product does not affect the measurement results, as the magnetic field of the transducer is homogeneous. The MFP frame limits product misalignment. It is found that sample misalignment in the range of ±4% to 6% has no practical effect on the measurement results of physicochemical parameters of wastewater samples. The change in temperature causes a change in the resistance r of the magnetising winding, so the windings of the converter must be thermally insulated from the environment (wrapped with mitre tape, coated with BF-19 adhesive and then this structure is baked at the temperature t = 300°C in the EKPS-500 muffle furnace). Practical implications The practical significance of the work lies in the fact that as a result of the analysis of the obtained values of the physicochemical parameters of wastewater samples, it is possible to timely prevent the reasons for the deviation of wastewater from the specified indicators of international standards governing the discharge of wastewater into the city sewerage and to take measures to prevent pollution of artificial and natural reservoirs located in the residential areas, as well as to develop effective methods of wastewater treatment of food and processing industries. The obtained relations, which describe the universal transformation functions G = f(x) and φ = f(x), algorithms for measuring and calculating operations for determining the specific electrical conductivity χ, relative permittivity εr and temperature t of wastewater samples based on MFP, make it possible to design, construct and create automated measuring installations based on intelligent devices that have a phenomenological approach to the measuring control of physical and chemical parameters of electrolytic liquid media as the basis of their operating theory. Originality/value The electromagnetic transducer (EMT) theory has been further developed with a sample of a weak electrolytic liquid with an acidic composition (a sample of wastewater from apple juice production).

2

Gas temperature meter

Zashchepkina N. M., Svyta M. P.

Journal of Achievements in Materials and Manufacturing Engineering

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2022

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Vol. 111, nr 1

33--41

EN

Purpose: of the article is to develop a digital portable gas temperature meter in the range of -50…+600°C. To measure the temperature of dusty gas flows in the air pollution sources with the least significant digit of the digital device 1°C. Design/methodology/approach: The microprocessor measuring unit, probe and software is proposed. It leads to build a high-precision temperature meter based on a thin film sensor HM220 type "pt100". Findings: The calculation of the electrical schematic diagram parameters for signal conditioning of the sensor relative to the input range of the analog-to-digital converter. The experimental measuring unit and the probe of the gas temperature meter are assembled. The principle of the gas temperature meter calibration with the help of a precision resistance box MSR-60M is considered. The experimental gas temperature meter has a total standard uncertainty determined by type B for a maximum value of the measurement range of 1.94°C. The error of the sensor "pt100" makes the largest contribution to the total standard uncertainty, so the error increases in proportion to the value of the measured temperature. Research limitations/implications: On the basis of the proposed design of gas temperature meter it is possible to construct devices with various lengths of probes. Practical implications: The proposed meter is designed for environmental laboratories that measure the velocity, flow and sampling of dust and gas emissions from sources of air pollution. Originality/value: The device design differs due to the use of thermostable wire made of constantan as extending conductors of the temperature sensor, which is included in the unbalanced Wheatstone bridge. This solution allows the use of unipolar power supply 3.3 V for both analog and digital part of the meter. Temperature meter based on a thin film resistance thermometer is characterized by relative ease of manufacture, low material consumption, cost and high reliability.

3

Four-parameter electromagnetic method for determining the parameters of brewery effluents

Sebko V. V., Pyrozhenko Ye. V., Zashchepkina N. M., Zdorenko V. G., Markina O. M.

Journal of Achievements in Materials and Manufacturing Engineering

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2022

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Vol. 113, nr 2

49--64

EN

Purpose: of the article is to study a four-parameter electromagnetic method for joint measurements of electrical resistivity k, relative permittivity εr, temperature t and density ρ of samples of acidic, alkaline and average effluents from a microbrewery based on a magnetic flux probe (MFP), which considers the influence of informative parameters of beer effluents on the components of the amplitude and phase signals of a multiparameter device. Design/methodology/approach: The implementation of the four-parameter method is carried out on the basis of the dependences G1 = f (A1) and G2 = f (A2) at two frequencies of the electromagnetic field f0 and f1 for acid, alkaline and average effluent and allows you to jointly determine the four parameters of effluent samples with the same converter in the same control area. The proposed method makes it possible to improve the accuracy of identifying effluent samples since the obtained multiparameter information makes it possible to determine the nature and properties of effluent samples using only one transducer with certain physical characteristics. The research results lead to the expansion of the technical capabilities of electromagnetic measurement methods, as well as to an increase in the metrological characteristics of electromagnetic transducers and an increase in the accuracy of measuring the parameters of effluent samples compared to reference methods and measuring instruments. Thus, the implementation of this approach contributes to the prediction and prevention of the reasons for the deviation of beer effluent samples from the specified indicators of environmental safety. Findings: The universal conversion functions MFP have been established, connecting the amplitude and phase components of the converter signals with the parameters k, εr, t and ρ of acidic, alkaline and average effluents. Based on the universal transformation functions G1 = f (A1) and G2 = f (A2), a four-parameter electromagnetic method for joint measurements of electrical resistivity k, relative permittivity εr, temperature t and density ρ of acidic, alkaline, and average effluents from breweries has been developed. When conducting research at two close frequencies of the electromagnetic field f0 = 20.3 MHz and f1 = 22 MHz, algorithms were obtained for measuring and calculating procedures for determining k, εr, t and ρ for samples of acidic, alkaline and average effluents from the brewing industry. Research limitations/implications: Research perspectives consist in the creation of automated systems for multiparameter measuring control of the physicochemical characteristics of acidic and alkaline effluent from food and processing industries based on the immersed electromagnetic transducer. Based on the data obtained using informative methods to measure the parameters of effluent samples, an integrated method for treating beer effluents of various compositions will be proposed. At the same time, the scheme of the integrated treatment method should include a filter that provides the introduction of a magnetic fluid and a separation device that allows us to remove a fraction, including pollution in itself. Practical implications: Is that the proposed four-parameter electromagnetic method makes it possible to determine to what composition the controlled samples of wastewater should be attributed (acidic or alkaline). It, in turn, makes it possible to choose a rational method for treating beer effluents and to prevent the reasons for the deviation of effluent samples from the environmental safety indicators set by the standards. Originality/value: of the article is the research related to the expansion of the functional and technical capabilities of the electromagnetic two-frequency transducer MFP through the implementation of a four-parameter electromagnetic method of joint measurements of electrical resistivity k, relative permittivity εr, temperature t and density ρ of acidic, alkaline and average effluents from breweries. The universal transformation functions G1 = f (A1) and G2 = f (A2) found in the work at two close magnetic field frequencies, f0 = 20.3 MHz and f1 = 22 MHz, make it possible to control four physicochemical parameters of acidic, alkaline and average wastewater at the same time by the same MFP. An algorithm has been developed for determining the signal components of a two-frequency thermal MFP, the ranges of which correspond to the ranges of changes in electrical resistivity k, relative permittivity εr, temperature t and density ρ of acidic, alkaline, and average brewery effluents. The basic relations that describe the two-frequency four-parameter electromagnetic method of joint measurements of the physicochemical parameters of acidic, alkaline and averaged beer effluents have been obtained.

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Contactless ultrasonic method for determining knitted fabrics tension

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

Journal of Achievements in Materials and Manufacturing Engineering

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2022

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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.

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Active system for reduction of noise parameters of car muffler with the use of pressure sensors based on silicon microcrystals

Zinko R.V., Kutrakov A.P., Shybanov S.V., Zashchepkina N.M., Markina O.M.

Archives of Materials Science and Engineering

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2021

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Vol. 109, nr 1

35--41

EN

Purpose: The article contains the results of research and development of a system for active noise damping of an automobile engine. The proposed system of active noise suppression can significantly reduce the sound pressure level in the frequency band up to 500 Hz. The robotic principle of the developed system is based on the addition of an additional buffer tank with a variable volume in the silencer system. The use of high-temperature sensors with strain gauges based on silicon microcrystals to obtain information on the parameters of sound vibrations arising during the exhaust gas outflow made it possible to create a control system for changing the volume of the buffer tank. The results of testing the proposed system of active noise suppression of an internal combustion engine are presented. Design/methodology/approach: The active noise suppression system based on the Helmholtz resonator used tools to control general noise levels, experimental tests, complex mathematical modelling of acoustic processes in Solidworks, taking into account the conditions of propagation and attenuation of sound energy by intermediate closed volumes. Findings: The use of an additional resonator chamber with variable volume in the exhaust muffler of the internal combustion engine allowed to reduce the resonant phenomena in the zone of low-frequency pulsations of exhaust gas pressure from 57 Hz to 43 Hz at frequency drift in the range of 310… 350 Hz, which significantly improved its noise characteristics. Research limitations/implications: For further research, to improve the characteristics of the active noise suppression system, it is advisable to consider the use of several in in transient modes of engine operation. Practical implications: The developed design of active noise reduction is simpler in comparison with analogs and allows reducing the noise of exhaust gases in a low-frequency range. Originality/value: To reduce the noise, a variable-volume Helmholtz resonator was used, the efficiency of which is provided by high-temperature sensors of the original design.

6

Improving the method for determining the dust penetration of textile materials for the human protective equipment manufacture

Avahumian A. A., Zashchepkina N. M.

Journal of Achievements in Materials and Manufacturing Engineering

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2020

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Vol. 102, nr 2

49--54

EN

Purpose: Improving the accuracy of determining the coefficient of dust permeability of textile materials and protective products from them. Design/methodology/approach: The problem solution of human protection from the negative effects of road dust is to improve the quality control procedures of textile materials using modern measurement methods. A methodology has been developed for investigating the dust penetration coefficient of materials based on the use of a television informationmeasuring system (TIMS). Findings: The methodology for determining the dust permeability of textile materials through the use of a television information-measuring system has been improved, by increasing the accuracy of measurement and determining the patterns of the influence of structure on the permeability of textile materials. Research limitations/implications: Improving methods of quality control of textile materials through the use of modern methods of measuring techniques is by solving an important problem of human protection from the negative effects of road dust. Known methods do not take into account the forceful effect of the airflow on the structure of the test sample, which is essential for textile materials that are easily deformed, which affects the objectivity of the results. Significant inconvenience, complexity, and duration of the test process give a large measurement error. Practical implications: The methodology for determining the dust permeability of textile materials through the use of a television information-measuring system has been improved. This system allows an increase in the accuracy of measurements by 15%, and the availability of software to increase the speed of displaying the results of investigations on the screen. Originality/value: The main disadvantages of methods and means of determining the dust permeability of textile materials - is the inability to determine the duration and dynamics of the process of dust retention. Known methods do not take into account the force of air flow on the structure of the test sample, which is significant, especially for materials that are easily deformed, which affects the objectivity of the results. Significant inconveniences, complexity and duration of the test process give a large measurement error. A scientific novelty is the development of a modern and completely new method for determining the permeability of textile materials using a television information - measuring system, by increasing the accuracy of measurement and determining the patterns of influence of the structure of textile materials on dust permeability.

7

Informative testing method of beer sewage samples for mini-breweries

Pyrozhenko Ye. V., Sebko V. V., Zdorenko V. G., Zashchepkina N. M., Markina O. M.

Archives of Materials Science and Engineering

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2020

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Vol. 106, nr 1

28--41

EN

Purpose: of the article is to investigate the theoretical rules of thermal transformer eddy current converter (TTC) during the preparation of ecological monitoring of brewery sewage samples based on the implementation of contactless two-parameter eddy current method of testing of the specific electrical conductivity λt and the temperature t of the beer sewage sample. It should be noted that this makes it possible to simultaneously prevent the causes of beer sewage samples deviation from the specified environmental safety indicators and to take adjustments. Design/methodology/approach: The theory of TTC operation concerning the electrical and temperature characteristics testing of beer sewage samples has been further developed by implement new universal transformation functions Δφt = f (Gt) and Δφ = f (xt), which relate the normalized difference components of the converter signals to physical and chemical characteristics of the sample. Due to this, it is possible to simultaneously prevent the causes of beer sewage samples deviation from the specified ecological safety indicators and to take appropriate adjustments. Findings: The method of two-parameter measuring test of the specific electrical conductivity λt and the temperature t of the beer sewage sample was developed on the basis of new universal transformation functions. Analysing the numerical data of electrical conductivity λ, TDS and pH at the initial temperature t1 = 15°C, the alkaline nature of beer sewage was determined. Research limitations/implications: The frequency range of the magnetic field f = 80-100 MHz, it is difficult to maintain in laboratory conditions, so the proposed method requires the use of modern high-frequency equipment, the radius of the probe depends on the radius of the primary converter frame. And therefore is quite a complicate to find appropriate tank. Practical implications: is to determine the nature of beer sewage based on the results of electrical and temperature parameters measurements during implementing a two-parameter eddy current method, which allows to prevent the reasons for beer sewage samples deviations from the specified environmental safety measures and to take appropriate adjustments. An important practical result is also the determination of the signal components and the normalized characteristics of the primary eddy current converter with a sample of beer sewage. They allow to calculate, design and create multi-parameter automated devices for measuring test of the physicochemical parameters of beer sewage samples. In turn, as a result of the physicochemical composition analysis of the sample, improving the accuracy of measurements of physicochemical parameters - there is an opportunity to improve and create advanced methods of wastewater purification on a weak electrolytic basis. Originality/value: The article originality is the investigation of the theoretical rules of thermal TTC by implementing a new multi-parameter eddy current method of measuring the specific electrical conductivity λt and the temperature t of the beer sewage sample based on the implementation of universal transformation functions Δφt = f (Gt) and Δφ = f (xt) that relate the converter signals to the physicochemical characteristics of the beer sewage sample, which helps to prevent the causes of the beer sewage samples deviation from the specified environmental safety indicators and take appropriate adjustments.

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Identification of the eddy current method features in the implementation of computer simulation algorithms for controlling the characteristics of the food production equipment parts

Zashchepkina N. M., Zdorenko V. G., Sebko V., Markina O. M.

Journal of Achievements in Materials and Manufacturing Engineering

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2019

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Vol. 97, nr 1

31--40

EN

Purpose: The purpose of this article is to study the theoretical provisions of the operation of a vortex device in the implementation of a non-contact method of controlling the details of brewing equipment using computer simulation algorithms. Design/methodology/approach: The theoretical positions of thermal ECT operation with a copper product are obtained, which is controlled while maintaining a constant value of the magnetic field frequency f1 = 70.0 Hz, with small values of the generalized parameter x≤1.1 and increasing the parameter x due to the increase in the frequency of thermal ECT, that is, at x≥3.5. Findings: On the basis of computer simulation algorithms the results of the joint measuring control of diameter d, electrical resistance ρ and temperature t of the sample made of copper (in the temperature range from 20-160°C) and the results of determination of thermally dependent thermal ECT signals with the sample of equipment details and the values of specific normalized values that relate the ECT signals to the physical and mechanical characteristics of the samples of the equipment being monitored. Research limitations/implications: Product diameters range is 5 mm to 50 mm. The lower boundary is limited by the frequency of the magnetic field f = 20 Hz and the upper boundary by the diameter of the frame of the thermal eddy current transformer transducer is 50 mm. Perspective positions of work require further development in the direction of extending the limits of control of geometrical parameters of the samples due to the use of automated control systems based on overhead eddy current transformer transducers. Practical implications: The practical value of the work is to increase the overall likelihood of control of the parameters of brewing equipment parts by increasing its instrumental component Di, due to the reduction of measurement errors due to instrumental techniques and on the basis of computer modelling algorithms for three-parameter control of parts of brewing equipment, electrical and temperature parameters, allows to obtain the value of the overall control probability Dz = 0.998. Originality/value: The originality of the article is the study of the theoretical provisions of the eddy current transformer transducer and the implementation of a non-contact method of controlling the details of brewing equipment using computer simulation algorithms that take into account the modes of joint three-parameter control: at high values of the generalized parameter x (with three-parameter surface control), at small values of x (while controlling the value of the average cross section geometry, electrical, temperature settings) at a fixed frequency magnetic field (get information on the diameter d, resistivity ρ and temperature t with a certain depth of penetration of the magnetic field in the sample Δ).

9

Ultrasonic method of quality control for textile materials

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

Archives of Materials Science and Engineering

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2019

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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.

10

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

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

Archives of Materials Science and Engineering

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2019

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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.

11

Thermal modification of wood by the method of thermo-mechanical dehydration with pressure drop

Zashchepkina N.M., Prokopovich O.V., Makarenko D.S.

Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology

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2019

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No. 106

128--133

EN

Thermal Modification of Wood by the Method of Thermo-Mechanical Dehydration with Pressure Drop. The results of experimental research of thermal wood processing by the method of high temperature drying with pressure drop are presented. Drying was carried out cyclically by heating the material under pressure to the temperature 100-140 oC followed by pressure drop. After that the temperature was raised up 160-210 oC and the samples were processed briefly in those conditions. This treatment is shown to be effective for largesized wood.

PL

Termiczna modyfikacja drewna metodą termo-mechanicznego suszenia z redukcją ciśnienia. Przedstawiono wyniki badań eksperymentalnych obróbki termicznej drewna metodą suszenia wysokotemperaturowego ze spadkiem ciśnienia. Suszenie prowadzono cyklicznie poprzez ogrzewanie materiału pod ciśnieniem do temperatury 100- 140 oC, a następnie redukcji ciśnienia. Kolejno temperaturę podwyższano do 160-210 oC i realizowano obróbkę termiczną. Modyfikacja tego typu okazała się szczególnie skuteczna w przypadku elementów drewnianych o dużych rozmiarach.