bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of saga (Abrus precatorius) seed extract as a green corrosion inhibitor in API 5l Grade B under 1m HCL solutions
Authors: Riastuti Rini , Setiawidiani Dinar , Soedarsono Johny Wahyuadi , Aribowo Sidhi , Kaban Agus Paul Setiawan 
Published: September 2022

The critical role of newly green corrosion inhibitors shows the disruption of cathodic and anodic reactions at the metals and solution interface. The object of this study is the development of Saga as a corrosion inhibitor to mitigate the effect of corrosive HCl 1M оn mild steel. The inhibitor was extracted using methanol to prepare various concentrations. Fourier transform infrared (FTIR) spectroscopy was used to determine the functional group of the inhibitor. The electrochemical impedance spectroscopy aided by the potentiodynamic polarization was utilized to evaluate the inhibitor’s effectiveness. Optical emission spectroscopy (OES) was implemented to determine the percentage of elements in mild steel. Based on the FTIR results, C=O, -OH, C=C, benzene, and C-O are accountable for the inhibitor to donate its lone pair of an electron to the 3-d orbital of iron metal. Increasing the inhibitor concentration decreases the capacitive double layer to elevate the inhibitor resistance. The higher inhibitor resistance of 29.33 Ω cm-1 increases as the concentration increases due to the depression of Cdl 420.16 µF cm2 at 10 ml inhibitor solution. Parallelly, it increases the inhibition efficiency at 65.58 %, slightly lower than the PP measurement of nearly 88 %. The higher value of adsorption/desorption constant, Kads, at 2.9 L mol-1 shows the strength of the inhibitor, which lowers the value of Gibbs free energy (ΔGads). The Saga inhibitor is considered a chemisorption inhibitor ΔGads –36.87 kJ/mol. The value demonstrates the formation of dative covalent bonding, which promotes the transferred electron from the inhibitor to the substrate. On the other hand, the Saga inhibitor abides by the Langmuir adsorption isotherm as the R2 value is 0.99.
Improving the efficiency of condensation installations of steam turbines by applying liquid-vapor ejector
Authors: Sharapov Serhii , Yevtushenko Sviatoslav , Panchenko Vitalii , Kozin Viktor , Ivchenko Oleksandr 
Published: September 2022

This paper considers the possibility of using liquid-vapor ejectors in condensing units of steam turbines. This unit is designed for pumping out a steam-air mixture from a steam turbine condenser, in which the process occurs at a pressure lower than atmospheric. In the traditional scheme, this is provided by a two-stage steam-jet ejector unit. The proposed scheme involves the use of a single-stage liquid-vapor ejector and its possible pre-vacuum mode of operation in conjunction with a liquid-ring vacuum pump. A working process of the liquid-vapor ejector does not require the supply of working steam from the outside since its generation occurs in the active nozzle of the liquid-vapor ejector. A description of the traditional scheme and the proposed options is given, which are different both in the scheme solution and in the operating parameters. The object of this study is a liquid-vapor ejector, which is used in the condensing system of a steam turbine. Thermodynamic calculation of the proposed circuit solutions was carried out. As a result, the necessary mode parameters of the schemes were determined. To assess the feasibility of using a liquid-vapor ejector in the condensation systems of steam turbines, an exergy analysis was performed. The proposed scheme makes it possible to increase efficiency by 2.3 times, and when used with a liquid-ring vacuum pump – by 2.44 times. To assess the economic efficiency of the modernization of the condensing system, thermoeconomic analysis was performed. The use of the proposed scheme makes it possible to reduce the cost of generating boiler steam and reduce the cost of the resulting product of the steam turbine unit by about 51 %. The estimated cost of a unit of the amount of boiler steam consumed per ton of product and the unit cost of steam were established.
Evaluation of creep-fatigue life and strength for AA7001-T6 under constant amplitude loading
Authors: Mahdi Huda Salih , Alalkawi Hussain J. , Mohamed Muzher T. , Faris Saad T. 
Published: September 2022

Aluminum alloys were widely used in the construction, automotive, marine, and aviation industries due to their low specific strength, ease of manufacture, and low weight. The fatigue behavior of aluminum alloys at different temperatures is investigated. Thanks to the rapid development of armament in recent years, 7XXX ultra-high strength aluminum alloys are now used more frequently because of their non-corrosive qualities and low weight. Aluminum alloy 7001-T6 behavior is examined at the Company State for Engineering, Rehabilitation, and Inspection (SIER) in Iraq, where chemical analysis of the AA7001 is supported. Most engineering components that operate at high temperatures will eventually fail from fatigue strain, creep damage is a time-dependent process that is primarily influenced by the history of stress and temperature applied to the component. When the two damaging factors combine their effects, This study used AA7001-T6 to conduct experiments on mechanical characteristics (UTS, YS, E, and ductility) and the interaction between creep and fatigue at four distinct temperatures: room temperature (25, 150, 280, and 330) °C, the UTS, YS, and E were lowered by 37.2, 37.2, and 24) %, respectively, as compared to the result at room temperature, but the ductility increased by 28.27 %. It has been noted that rising temperatures cause mechanical and fatigue characteristics to decline. Experimental S-N fatigue test findings showed a significant loss of fatigue strength, After 107cycles, the endurance fatigue limit was reduced from 208 MPa at (RT) to 184 MPa at 330 °C, an 11.5 % reduction. Overall, it can be said that AA7001-T6 demonstrates a significant drop in mechanical and fatigue properties at high temperatures
Establishing a dependence of the efficiency of low-pressure reverse osmotic membranes on the level of water mineralization
Authors: Gomelya Mykola , Vakulenko Anna , Makarenko Iryna , Shabliy Tetyana 
Published: September 2022

This paper has established the dependence of the effectiveness of the reverse-osmotic low-pressure membranes Filmtec TW30-1812-50 on the initial concentrations of sulfate and sodium chloride in the range of 20–1000 mg/dm3 at the degrees of permeate selection of 1–90 % with the use of pressure of 3.6–10.0 atm. The dynamics of increasing the content of sulfates and chlorides in concentrates with an increase in the degree of permeate selection, selectivity, productivity, and filtration coefficient of the membrane have been determined. The conditions for calculating the membrane performance depending on the working pressure for sodium sulfate and sodium chloride have been defined.
It is shown that the concentrations of sulfates and chlorides in permeates depend on their initial concentration in solutions and increase both with an increase in the initial concentration and with an increase in the degree of permeate selection. The latter factor is quite significant at the initial concentrations of chlorides and sulfates at a concentration of 1000 mg/dm3. The productivity of the membrane increases with a decrease in the salt content in water and decreases as the degree of permeate selection increases, which leads to an increase in the concentration of salts in the premembrane space.
The selectivity of the membrane increases with increasing concentration of sodium sulfate and sodium chloride solutions in solutions, despite a certain increase in salt concentrations in permeates. For solutions of Na2SO4 and NaCl (20–1000 mg/dm3) at their reverse-osmotic desalting on the membrane, the filtration coefficients have constant values. For these initial concentrations, the filtration coefficient for Na2SO4 is 3.4–3.8 dm3/(m2∙atm), and for NaCl – 2.6–3.2 dm3/(m2∙atm). The data reported here allow us to conclude about the permissible level of mineralization, at which it is advisable to use reverse-osmotic low-pressure membranes. It is shown that an increase in the concentration of salts in concentrates leads to an increase in osmotic and working pressures
Establishing the influence of the type of micro- and nanofillers on the thermophysical properties of highly heat conductive polymer composites based on polyamide 6
Authors: Fialko Nataliia , Dinzhos Roman , Sherenkovskii Julii , Meranova Nataliia , Babak Vitalii , Korzhyk Volodymyr , Lazarenko Maxim , Polozenko Nina , Parkhomenko Оlexander , Makhrovskyi Volodymyr 
Published: September 2022

The object of this study is the thermophysical properties of polymer micro- and nanocomposites, as well as the dependence of their heat conductivity with structural characteristics when using different types of fillers. A set of experimental studies of heat conductivity and specific heat capacity of polymer micro- and nanocomposite materials for polyamide 6 and carbon nanotubes, copper and aluminum as matrix and fillers was carried out. When obtaining composites, a method was used that is based on the mixing of components in the polymer melt. The content of fillers varied from 0.3 to 10 %, and the temperature of composite materials – from 305 to 500 K.
Experimental dependences of heat conductivity coefficients of the studied composites on the content of the filler were derived. It was established that according to the value of these coefficients in order of their reduction, these composite materials are ranked as follows: composites with fillers with carbon nanotubes, copper, and aluminum. It was found that only one percolation threshold is observed, when using a polyamide 6 matrix.
The regularities of changes in the specific heat capacity of the composites under consideration on their temperature when varying within the above limits of the filler content were investigated.
The analysis of the influence of the content of fillers on the degree of crystallinity of the polymer matrix of the investigated composite materials was carried out. It is shown that with an increase in the content of fillers, the degree of crystallinity decreases. The relationship between the thermally conductive properties of the composites under consideration and the specified degree of crystallinity has been established. Higher values of heat conductivity of composites correspond to lower values of the degree of crystallinity.
The reported results can be widely used in the development of highly heat conductive composites for various engineering applications.
Development of the control system for taking off the maximum power of an autonomous wind plant with a synchronous magnetoelectric generator
Authors: Ostroverkhov Mykola , Chumack Vadim , Kovalenko Mykhailo , Kovalenko Iryna 
Published: September 2022

The object of this study is electromechanical processes in an autonomous wind power plant with a magnetoelectrical generator.
Under actual conditions, the wind speed is constantly changing. The wind turbine works as efficiently as possible only at the rated value of wind speed. When the wind speed changes, the efficiency of converting mechanical wind energy into electrical energy decreases. Controlling the power of the electric generator when the wind speed changes is a relevant scientific and technical task.
A maximum power selection control system based on the parameters of an experimental sample of a synchronous magnetoelectric generator has been designed and investigated. A feature of the synthesized control system is that it was developed on the basis of the concept of inverse dynamics problems in combination with minimization of local functionals of instantaneous energy values. The control law provides weak sensitivity to parametric perturbations of the object and carries out dynamic decomposition of the interdependent nonlinear system, which predetermines its practical implementation. Transient processes of the power, voltage, and current of the stator, as well as the voltage and excitation current were established when the wind speed changes from 3 to 8 m/s, as well as when the active electrical resistance of the load changes.
The results of this study confirm the effectiveness of the maximum power take-off control system when wind speed and load change. When the wind speed changes within 3–8 m/s and the load by 50 %, the efficiency of converting mechanical wind energy into electrical energy increases by 15–40 % compared to the traditional magnetoelectric system.
The findings of the current study are recommended for practical use in autonomous power plants based on wind turbines with generators with permanent magnets.
Automating the customer verification process in a car sharing system based on machine learning methods
Authors: Amirgaliyev Beibut , Yegemberdiyeva Gulzhan , Kuchansky Alexander , Andrashko Yurii , Korol Ihor 
Published: September 2022

Convenient and accurate verification of the user of a car sharing system is one of the key components of the successful functioning of the car sharing system as a whole. The machine learning-based KYC (Know your customer) process algorithm makes it possible to improve the accuracy of customer data validation and verification. This makes it possible to eliminate possible losses and reputational losses of the company in case of unforeseen situations while using the client's car sharing services. The object of this study is to find a solution to the problem of user verification in a car sharing system based on the KYC process using deep learning methods with a combination of OCR (Optical Character Recognition) methods.
The statement of the user verification problem in the car sharing system was formalized and the key parameters for the KYC process have been determined. The algorithm of the KYC process was constructed. The algorithm includes six successive stages: separating a face in the photograph, comparing faces, checking documents and their validity period, establishing and recognizing ROI (region of interest), formulating a verification decision. To separate the face in the client's photograph and compare faces, methods based on deep learning, as well as the quick HoG method (Histogram of oriented gradients), were considered and implemented. Verification of these methods on a test dataset, which includes images of documents of two thousand clients, showed that the recognition accuracy was 91 % according to Jaccard's metric. The average time of face separation using the HoG method was 0.2 seconds and when using trained models – 3.3 seconds. Using a combination of ROI and ORC separation methods makes it possible to significantly improve the accuracy of verification. The proposed client verification algorithm is implemented as an API on an ML server and integrated into the car sharing system.
Implementation of business culture for Mexican SMEs versus globalization 4.0
Authors: Sandoval-Gomez Raul Junior , Alvarez-Cedillo Jesus Antonio , Sarabia-Alonso Maria Teresa , Alvarez-Sanchez Teodoro , Perez-Garcia Rebeca , Gonzalez-Vasquez Alexis 
Published: September 2022

Businesses carried out worldwide have been influenced by the phenomenon of Globalization 4.0. has allowed us to make various changes in all aspects and activities of the human being in different countries where an essential interdependence of markets was reflected. However, they allow reflection on all economic activities. In the particular case of small and medium-sized enterprises (SMEs), this phenomenon creates an uncertain environment and opens the opportunity to develop a competitive environment and identify challenges and opportunities. Many elements are considered incident factors caused by Globalization 4.0 that affect Mexican SMEs. This work shows what factors affect the economic aspects and how the cultural factor is significant; the challenge of teamwork, cooperation, unity, and management of existing resources is also considered. Although Mexico has an influential business culture, it is not implemented in these companies; some seem unaware of a situation limiting their participation in conducting international business and improving their global competitiveness. This article shows the results of qualitative research based on the grounded theory proposed by Glaser and Strauss in 1967; the results obtained show how it is necessary to develop cultural aspects so that SMEs can achieve development and permanence over time. Globalization 4.0 is a phenomenon that affects international companies and represents actions and strategies to have an advantage over other companies, but what happens with SMEs is different; these types of companies do not have economic resources, and globalization 4.0 becomes a disadvantage. In our study, 80 % of SMEs do not have a business culture and are not prepared for globalization 4.0, and we also found that time is wasted on bad practices in 35 % of Mexican SMEs; training was lacking in 32 % of educational cases.
Synthesis of the control system for the positioning pneumatic drive of shut-off fittings according to the criteria of technological efficiency
Authors: Kryvoplias-Volodina Liudmyla , Gavva Oleksandr , Sukhenko Vladyslav , Myronchuk Valerij , Tokarchuk Serhii , Volodin Oleksandr 
Published: September 2022

This paper reports the new design of an experimental bench to study the effectiveness of the positional drive control system of shut-off fittings. For research, the operating modes of the disk flap and ball valve, based on proportional elements with feedback (4–20 mA), were programmatically formed and described.
The mathematical model of control over shut-off devices has been analytically described on the example of a disk rotary valve with the possibility of further analysis of individual stages in accordance with the accepted assumptions. The operating control signal is justified with a serial asynchronous interface with an offset operating range of permissible values of –16.0 mA.
Separate stages in the operation of the synthesized shut-off fittings based on accepted assumptions have been described. Measurements were performed for disc damper angles of 30°, 60°, 90° by variable value of the pressure control signal (1...4 bar) with sampling of measuring indicators for the control system in real time. The results obtained experimentally confirmed the adequacy of numerical modeling regarding the study of the disk rotary inter-flange valve, as well as preliminary assumptions in the mathematical model. Data were obtained to test the efficiency of controlled shut-off fittings (V-shaped ball valve, disc rotary inter-flange valve) at a sugar factory. The average angle of rotation for a ball is 17.61 degrees; the average value of the vapor temperature after cooling is 130.91 °C (subject to a given value of 130.0 °C). The deviation of the set value is 0.7 %. The average value for the angle of rotation of the disc damper at 43.0 degrees showed the largest deviation of technological parameters of 1.45 %.
Effects of rotational speed on the natural frequency of the differential bevel gear
Authors: Hassan Ali Raad 
Published: September 2022

With the development of techniques for the use of gears and their many shapes and types, the mechanical need for them has become great, especially in the use of them in the field of cars, and the most important of these types are bevel gears, as these gears are considered essential in differential gears.
The use of differential gears in mechanics in general helps to reduce noise in the movement, but there must be vibration resulting from this movement, and accordingly, bevel gears and the effect of rotating gears on free vibration have been studied.
Variable gears were used according to a simulation program and the study of the free vibrations that occur to them. The effect of rotational speed on the natural vibration greatly affects the transmission of movement in the car and increases the fault distortions that occur in the differential gearbox.
The result shows the natural vibration reached at the speed of 5000 rpm, and the value of the vibration reached 3564.5 Hz, which is the highest value compared to the remaining speed. The distortion at a speed of 1,000 rpm. The process of rotation and natural vibration affects the deformations and stresses that get on the gears themselves. The natural vibration is greatly reduced when the number of clamping places for the differential gear is increased. Compared to the presence of two spinning tires, the vibration value reduced. At a rotating speed of 5000 rpm, it is known that increasing the rotational speed raises the value 3015.9 Hz with one tire revolution with one tire rotation, the huge strains influence the little gears in the differential gearbox. The greatest value of distortion is 0.00067 m at 5000 rpm, which is the largest value of deformation compared to the rest of the employed rotational rates with one tire revolution.
The first phase of research and manufacturing of bridge deformation monitoring equipment using position sensor: case study in Vietnam
Authors: Nguyen Viet Ha , Vu Ngoc Quang 
Published: September 2022

This paper is the first result of an experimental study of manufacturing deformation monitoring equipment using a position sensor, an efficient solution for contractors in bridge monitoring during either process of construction or operation in the context of the increasing number of large bridges. The object of the research is bridgework. And the work is aimed at achieving two tasks, which include meeting the need of the surveyors in real-time monitoring and warning during the construction process with a suitable price and reducing the reliance on manufacturers in supplying and operating monitoring systems.
The study used a KTR position sensor, a Linear Variable Differential Transformer, and an Arduino board for embedded coding. Data from the KTR sensor are acquired, processed, and controlled by a program written in Python. The results of the study are compared to the true observations from a Mitutoyo Palmer which has 0.01 mm accuracy in a laboratory.
The initial results from the laboratory show prospects for applications in reality, and accuracy is suitable for technical measurements. This is also a good choice for surveyors in acquiring continuously monitoring data at high accuracy for bridge monitoring in general and structure in particular. The study is fundamental to expanding the number of channels from 1 to 8 or 16 for monitoring a full cross-section. At the same time, cable connection mode will be developed to Wi-Fi or Bluetooth mode for online observation. The results of the study confirm the scientificity, and feasibility of the solution. This solution can be applied for either bridge monitoring or other monitoring fields and can be produced by contractors. The cost of monitoring projects will be significantly reduced and there will be no more disruption of monitoring projects after suppliers leave as a new system will be quickly added or replaced.