bluuebunny/crossref_metadata_2025 huggingface dataset:
Anti-arthritic potential of ethyl acetate fraction of Pinus roxburghii Sargent stem bark in Freund's complete adjuvant induced arthritis in Wistar rats
Authors: Hajare Pratiksha , Rai Vaishali , Nipate Sonali , Balap Aishwarya , Pimple Bhushan , Chumbhale Deshraj , Gaikwad Asmita , Tare Harshal
Published: August 2023

Traditional and folk medicine regularly make use of the Pinus roxburghii Sargent (Pinaceae) plant. Unfortunately, there is a lack of data on this plant's potential anti-arthritic effects.Pinus roxburghii Sargent ethyl acetate stem bark has anti-arthritic properties in Wistar rats with arthritis produced by Freund's Complete adjuvant. As a positive control, diclofenac was administered. To define the anti-arthritic activity, the influence on pain perception parameter, haematological parameters, the effect on rheumatoid factor, CRP, and serum parameters were evaluated.In this study, the ethyl acetate fraction of Pinus roxburgii Sargent was found to significantly inhibit pain perception parameters at doses of 250 and 500 mg/kg. Serum levels of RF, NO, and CRP were significantly lower in the Pinus roxburghii Sargent group compared to the disease control group. In disease-free rats, Pinus roxburghii Sargent significantly raised RBC and lowered WBC, both of which point to a suppressive effect on inflammatory mediators. The number of inflammatory cells had decreased, as seen by histopathology. Several imaging parameters, including spur formation, joint spacing, bone erosion, etc., were significantly reduced in a radiological assessment.In this study, authors noted that Pinus roxburghii Sargent had a direct effect on slowing the progression of arthritis, reducing inflammation and synovitis, and protecting arthritic joints from cartilage and bone deterioration. Stem bark extract of Pinus roxburghii Sargent has been shown to have anti-arthritic action based on clinical, biochemical, and histological analysis. Yet more research is required to pin down the precise mechanism of action.
Application of the structural guidance model for mualaf banda aceh in strengthening education islamic values
Authors: Misbah T. Lembong , Asyura Khairun , Wirianto Dicky , Masrizal  , Rustan Edhy
Published: August 2023

This article discusses the application of the structural guidance model for Mualaf (converts to Islam) in Banda Aceh, Indonesia, and the importance of strengthening education in Islamic values. The study was conducted using a qualitative research method with an analytical knife approach based on the pattern of Da'wah Fardiyah (interpersonal Da'wah). The findings revealed that the development of Mualaf in Banda Aceh is carried out by the Government of Banda Aceh, Islamic Shari'a service, Baitul Mal, and the Ministry of Religion (externally), while the internal guidance assistance is carried out by the Formula, which has now changed its name to the association for the study of the Persatuan Mualaf Aceh Sejahtera (PMAS). This study is important for promoting education in Islamic values and providing guidance and support for Mualaf in their journey towards becoming strong Moslems.
The monitoring of bridges to alert accidents using rasberry PI
Authors: Shaikh Sajid W.
Published: August 2023

In recent years, bridge collapse tragedy becomes a serious problem in India as it leads to loss of life and property damage The bridge monitoring system is developed to monitor the bridges 24X7 by considering the elements such as overflow of water, earthquake (Haritos and Qwen 2024), scour depth, and bridge collapse. If any accident occurs on the bridge, the monitoring system closes the bridge and an alert message is sent to the user of the bridge until the problem is fixed. The system is fully automatic and implemented by using Raspberry Pi and electronic sensors.
Infections caused by Elizabethkingia meningoseptica in a tertiary care centre - A retrospective study
Authors: Mishra Swati , Dash Sumesh Kumar , Rout Bidyut Prava , Sahu Kundan Kumar , Otta Sarita
Published: August 2023

Elizabethkingia meningoseptica (EM) has emerged as important opportunistic pathogens that can cause sporadic nosocomial outbreaks as well as infections in neonates. They are known for their multidrug resistance and their unique susceptibility pattern. Present study is a retrospective single centre study where the sensitivity pattern and comorbidities associated with infection by this organism is systematically being noted. All samples received in the microbiology lab and yielding EMas identified by automated method (Vitek2, Biomerieux) from October 2020 to September 2021 were included in the study. The strains were re-identified to species level by polymerase chain reaction amplification of 16s r RNA gene.All samples where clinical significance could not be proven and repeat samples from same patient were excluded from analysis. The case sheets of the patients were collected from record section and analyzed for presence of various risk factors.In this study 57 patients were included withmean age of patients being 47.12 and most of the patients belonged to 51-60 age group (22.81%).Most common sample of isolation was blood (57.89%) followed by respiratory samples (26.32%). Majority (89.28%) of patients were in ICU and most of the infections were hospital acquired (92.9%).  Mean duration of ICU stay before isolation was 13.8±8.07. Other major associated factors were diabetes mellitus (42.86%), high dose steroid use (57.14%) and post COVID pneumonia (35.71%). The isolates were resistant to betalactams and combination agents; minocycline (98.2%) followed by cotrimoxazole (47.2%) and levofloxacin (45.6%) and ciprofloxacin (35.1%) were the most useful antibiotics.EM is an emerging nosocomial pathogen in ICU setting. Clinicians and microbiologists need to be aware of its unique sensitivity pattern. In contrast to previous studies we find a high degree of resistance to tigecycline and piperacillintazobactam. Thus in planning combination regimen this should be kept in mind.
Identification of fake currency using soft computing
Authors: Shinde Sagar , Wadhwa Lalitkumar , Bhalke D. G. , Sherje Nitin , Naik Shreenand , Kudale Rohan , Mohnani Karan
Published: August 2023

Advancements in color printing techniques have led to a surge in the creation and duplication of counterfeit currency notes, which has become prevalent in India. Although it was previously difficult to carry out this type of operation, anyone with a laser printer now has the capability to do it. This issue is considered a major problem due to the country's various problems, such as frauds, corruption and black money. It is needed to develop the system for the detection of fake currency. A system that can quickly identify counterfeit money is being developed. The proposed solution will utilize image processing to authenticate Indian currency notes. The proposed system will involve extracting different features from the notes, such as the security thread, Bleed Line, edges, shapes, textures, colors and Fluorescence. It is being developed using the software known as MATLAB. The supervised learning model of support vector machine for the extraction of the notes' features is also being used. This is utilized for analyzing the data related to classification and regression. Once the statistical features have been extracted, they were matched with the features stored in MAT file using SVM (Support Vector Machine) classifier. We have also conducted a test of other methods, such as the black box algorithm. The proposed solution is very fast and simple to implement, allowing it to identify if the notes are fake or real. The outcome of proposed system is the remarkable working of proposed system for the detection of fake currency and accuracy has been measured with the help of confusion matrix. The accuracy, precision & F- score are best by using SVM as compare to SVC (support Vector Classifier) & GBC (Genetic Bee Colony) algorithm.
Comparative Study of Hisbah Institutions and Consumer Protection Institutions In Indonesia In A Review of Islamic Business Ethics
Authors: Triwibowo Ananto , Pratomo Dimas , Sya'adi Nur , Adam Muhammad Afani
Published: August 2023

Islam does not teach people to be concerned with the world or the events of the afterlife, but both must be in harmony. Islam not only gives its followers the freedom to do business, but it also provides some basic principles for doing business: unity, balance, free will, responsibility, and truth, including virtue and honesty. The Hisba is a government-controlled religious organization that oversees the proper fulfillment of its obligations by the community when society begins to neglect its obligations, and when people become accustomed to this error, society does wrong. Its general purpose is to protect the communal environment from harm, preserve its existing destiny, and ensure the well-being of the community, both in terms of religion and daily conduct, according to divine law
Digital Islamic Business Ethics: Video Unboxing as a Khiyar mechanism in Online Buying and Selling Transactions
Authors: Harmoko Andrian , Ambarwati Diana
Published: August 2023

This article describes unboxing video content as a khiyar mechanism in online transactions. The sale and purchase transaction is declared invalid if one of the parties feels compelled and disadvantaged due to product defects. The method used in this article is a field research study with a phenomemological approach. The findings of this study are that video unboxing becomes the mechanism of choice for buyers to Khiyar or the choice to continue or cancel the transaction made. Buyers who upload unboxing videos showing product defects are given the opportunity to cancel the transaction or exchange it for a new product. This mechanism arises because sellers and buyers do not meet directly in the online transaction process. Video unboxing is done as a form of awareness and responsibility (responsibility) in muamalah as a form of ethics in business. The unboxing video will ultimately give pleasure to both the seller and the buyer as a condition for the fulfillment of blessings in the transaction
Company Zakat Distribution Model in Metro Lampung
Authors: Arifin Zainal , Purnamasari Nova
Published: August 2023

This article aims to describe the corporate zakat implementation model in Metro City, as implemented by the Grand Sekuntum Syariah Metro hotel. This research is a field research, data collection techniques using documentation and interviews. The analysis technique used is a qualitative technique. The results of this study indicate that the distribution of company zakat is carried out by taking into account two criteria, namely consumptive and productive. Consumptive zakat is given directly to mustahik without empowerment. This zakat is distributed directly to the underprivileged people who are around the hotel in the form of consumable needs, such as food, clothing, and housing needs in general. Meanwhile, for productive zakat distribution, the hotel cooperates with the Amil Zakat Institution in Metro City, the hotel gives its zakat funds to the amil zakat institution. The zakat funds are used to support productive zakat distribution programs in Metro City.
Problematics of Mudharabah Financing at PT BPRS Aman Syariah Lampung
Authors: Puspitasari Dian
Published: August 2023

This article describes how the problems faced by management in the implementation of mudharabah financing at BPRS Aman Syariah Lampung. The research method used is a qualitative research method in which the primary data is obtained from the results of interviews conducted with the leadership and stakeholders of Islamic banks. And then the data will be analyzed using content analysis. The results of this study indicate that there are several problems faced by Islamic bank management when deciding to apply mudharabah financing. Mudharabah is the only contract that uses the principle of profit sharing. However, this problem arises when the fact is that this financing is not very attractive to customers. Ideally, profit sharing is a mechanism that dominates products in Islamic banks. But in reality, the profit sharing mechanism does not show a high enough percentage, it even tends to be low. The cause is the high level of risk in mudharabah financing. From the customer side, there are customers with moral hazard, lack of transparency when providing financial reports to the bank. This results in the amount of profit sharing distributed which tends to be flat and not in accordance with the portion it should be. This happens because of the low level of honesty on the part of the customer so that it damages the mudharabah financing contract from both parties.
Коефіцієнт гідравлічного опору тертя капілярів за малих чисел Рейнольдса
Authors: Selezen Oleh , Shliakhov Mark , Orlov Roman
Published: August 2023

Heat transfer pump circuits with liquid or two-phase heat transfer fluids are widely used in thermal management systems in both space and ground applications. These systems play an important role in maintaining the optimal temperature and heat distribution in various processes and devices. Such systems use throttles to ensure efficient distribution of coolant flows through the hydraulic network. It is especially important to ensure the reliability of the system at low coolant consumption. Therefore, a rational approach is to manufacture throttles in the form of capillary segments. Capillary throttles can regulate the flow of coolant with high accuracy, which makes it possible to improve control over the thermal regime of the system. To calculate and determine the characteristics of such throttles, it is important to know the coefficient of hydraulic friction resistance λ, which is used in the Darcy formula. This coefficient depends on various factors, including the geometry of the throttle, physical properties of the heat transfer fluid, and flow conditions. Therefore, the aim of this study was to determine the value of the hydraulic friction resistance coefficient λ. In this work, experiments were performed with the shedding of copper capillaries of different internal diameters (0.8-1.2 mm) in water and isopropyl alcohol. The experiments were carried out in the laminar and transient regions, in the range of Reynolds numbers from 250 to 6050. Conclusions. In the laminar region (Re < 1185), it is recommended to use the Poiseuille formula. In the transitional and turbulent regions (1185 < Re < 6050), it is recommended to use the Blasius formula. The results of the experiments made it possible to obtain data on the value of the hydraulic friction resistance coefficient λ. These data can be used to calculate throttles in similar heat transfer systems. Moreover, the paper provides recommendations on the use of well-known formulas for calculating throttles, which allows engineers and designers to effectively implement these elements in their projects. Thus, the research conducted in this paper has important practical implications for the development and optimization of heat transfer systems in space and terrestrial applications.
Оцінка впливу канавок у дифузорі на втрати повного тиску
Authors: Yudin Illia
Published: August 2023

The subject of the study is the total pressure in the diffuser channel with passive control of the boundary layer. The object of this research is a diffuser channel with riblets. The mechanism of total pressure reduction due to the presence of longitudinal grooves on the streamlined surface is related to the strengthening of viscous forces acting in the transverse direction caused by them. These forces generate a relatively calm flow inside the riblets, which pushes out the turbulent flow, which causes surface friction, pushing it away from the surface. Thus, the process of generation and growth of elongated wall turbulent formations. In addition, in the presence of riblets, a change in the pressure field in the transverse direction is possible, as well as the creation of a quasi-two-dimensional flow in the immediate vicinity of the wall. In this work, the aim of research to investigate the influence of riblets on total pressure loss in the diffuser channel with the purpose of evaluating the influence of riblets on the change in the nature of the flow and the change in pressure, using numerical modeling. To study the nature of the flow in the diffuser channel, we resolved the following tasks: a diffuser channel was modeled with the following dimensions: length L=50 mm, hydraulic diameter at the inlet X=25 mm, hydraulic diameter at the outlet Y=40 mm, riblets diameter d=4 mm, number of riblets n =4 and n=8. The study was compared with a diffuser with the following dimensions: length L=50 mm, diameter at the inlet X=25 mm, diameter at the outlet Y=40 mm. To research the flow in the diffuser, the method of numerical experiment was chosen. An unstructured calculation grid was used in the diffuser for the research. The calculation of the turbulent gas flow was performed by numerically solving the averaged Navier-Stokes equations. During the numerical simulation of the flow, the Reynolds stress turbulent viscosity model will be used. As a result, using a diffuser with riblets increases the coefficient of hydraulic resistance compared to a smooth diffuser. The resistance reduction mechanism does not work due to the relatively short length of the diffuser and small longitudinal vortices of the riblets scale do not have time to form. There are pressure increasing instead of laminization of the flow and pressure decreasing. Scientific novelty - received new data on the effect of riblets in the diffuser channel on the total pressure loss coefficient. Practical significance - the obtained results can be used to control the boundary layer in diffuser channels (in diffuser compressor grates) to improve their characteristics.
Progress in electric propulsion numerical simulation
Authors: Ramasamy Sai Vigness , Bazyma Leonid
Published: August 2023

Electric propulsion has been developed since the early 1960s, and its use onboard satellites, orbiting platforms, and interplanetary probes have increased significantly in the 21st century. The need for a detailed understanding of the working physics and a more accurate assessment of performance to create innovative designs has stimulated the development of several numerical simulation codes. The choice of method for modelling a specific thruster should be dictated by the physical characteristics of the flow in the device, and by the level of accuracy required from the simulation. There are various conditions in different types of thrusters. This means that different methods and computer codes must be developed for each of the different thrusters. The successful development of physically accurate numerical methods for simulating gas and plasma flows in electric propulsion thrusters can significantly improve the design process of these devices. In recent years, numerical simulations have increasingly beneﬁted the basic understanding and engineering optimization of electric thrusters. This is due to several concurrent contributions: the evolution of computer hardware that has allowed the representation of multidimensional geometries and multiscale phenomena; implementation of sophisticated new algorithms and numerical diagnostic tools; and availability of new collisional and surface interaction data. There are two main directions for future work to continue to improve the numerical modelling of electric thrusters. First, the numerical methods themselves must be improved in terms of their physical accuracy and computational speed. The second main direction for improvement in the simulations involves more accurate determination of physical parameters that are required by the numerical formulations. This paper outlines efforts to develop models of various electrical propulsion concepts, from the first attempts in the early 90s to the latest sophisticated multidimensional simulations.
Тестова задача моделювання течії у ступені компресора Rotor 37
Authors: Duliepov Andrii , Hlobin Yevhenіі , Kovtun Artem , Khyzhniak Mykhailo , Balalaieva Kateryna
Published: August 2023

The subject of the study is the dependence of the degree of pressure increase on the airflow in the impeller of the axial compressor degree. The object of study is the Rotor 37 axial compressor. The purpose of this study was to select a turbulent viscosity model when conducting a test task in the Rotor 37 compressor. To achieve this goal, the following tasks were solved: to create a three-dimensional model of the object under study; develop a grid model of the object under study; to simulate the flow in a certain range of air flow; to compare the data of numerical and physical experience; evaluate the flow visualization in the Rotor 37 axial compressor stage for all studied turbulent viscosity models. When studying the flow in the stage of the axial compressor Rotor 37, the numerical experiment method was used. The flow simulation was carried out by solving the system of Navier-Stokes equations, which was closed by the turbulent viscosity model. The study used seven turbulent viscosity models: k-ε, k-ε EARSM, SST, BSL, BSL Reynolds Stress, SSG Reynolds Stress, and QI Reynolds Stress. For simulation, a computational grid was built with the adaptation of the boundary layer. This study presents the results of a flow simulation test problem in the Rotor 37 compressor. The results of the study show that all the tested turbulent viscosity models can be used to simulate the flow in an axial compressor. However, the flow calculation with the SSG Reynolds Stress turbulent viscosity model has the smallest error. An analysis of the visualization of streamlines in the interblade channel of the Rotor 37 compressor showed that in all cases, the flow pattern with all turbulent viscosity models is similar. Some differences are observed when modeling the flow with the BSL Reynolds Stress and SST turbulence models. An important factor that should also be taken into account when modeling is the calculation time. In this case, the shortest calculation time was observed for simulation with SST model. Scientific novelty and practical significance is that new data were obtained when testing the following turbulent viscosity models: k-ε, k-ε EARSM, SST, BSL, BSL Reynolds Stress, SSG Reynolds Stress, QI Reynolds Stress. The results obtained made it possible to choose a turbulent viscosity model for further research.
Використання термоакустичних технологій в суднових гібридних енергетичних установках з паливними комірками
Authors: Korobko Volodymyr , Shevtsov Anatoliy
Published: August 2023

Recently, hybrid power plants have gained significant popularity in marine energy systems. These power plants, in addition to traditional thermal engines, include electrochemical power generation systems based on fuel cells. Hybrid marine power plants represent a relatively new technical solution for the maritime fleet, driven by strict environmental emission regulations imposed by international organizations. These regulations primarily target greenhouse gas (GHG) emissions, such as carbon oxides, methane, nitrogen oxides, and other compounds. An analysis of the current state of marine energy and its development trends concludes that the problem lies in the working processes of thermal engines, which are based on fuel combustion. Achieving ecological cleanliness in maritime transport is possible by transitioning to new principles of mechanical energy production that do not rely on chemical fuel combustion. Fuel cells, which generate electricity through electrochemical processes, have the potential to solve this problem. However, the implementation of such electrochemical generators requires a systematic approach to the development of schematic solutions capable of achieving a synergistic effect. The subject of the research is the regularities and parameters of energy exchange processes in hybrid power plants. This study focuses on hybrid power plants with electrochemical generators based on proton exchange membrane fuel cells (PEM FC). The effective operation of hybrid power plants involves the utilization of waste heat from ship equipment. PEM FC is the most widely used type of fuel cell in energy and transportation sectors. The operating temperatures of PEM FCs, depending on their type, range from 60 to 80°C or 120 to 200°C, which poses a challenge for the development of efficient waste heat utilization systems. The aim of the research is to develop waste heat utilization schemes for hybrid power plants with PEM FCs using thermoacoustic heat engines. The study establishes that electrochemical generators can be integrated into the thermal system of modern power plants, and the application of thermoacoustic heat engines expands the potential of waste heat utilization systems. Low-temperature thermoacoustic engines have the capability to convert waste heat generated by PEM FC systems into mechanical work, thereby increasing the overall efficiency of hybrid power plants by 8 to 15%.
Investigation of the autorotation stability of a turbofan engine with a detached fan blade
Authors: Filipkovskij Sergey , Chigrin Valentin , Soboliev Alexandr , Vasilevskij Yevgeny , Topal Nikolay , Filipkovska Larisa
Published: August 2023

One of the requirements for the aircraft being designed is the ability to continue flying and landing if one engine fails. One of the calculated cases of engine failure is the separation of the fan blade. This phenomenon causes large vibrations in both the engine itself and the aircraft structure. A calculation model and method for studying engine oscillations with damage in the form of blade separation have been developed. Numerical studies of the oscillations of the engine suspended on a pylon were conducted. The operation of an engine with an unbalance of the fan after switching off during the transition to autorotation is considered. Numerical simulation was performed using the ANSYS Workbench package. The front supports of the rotors are ball bearings installed in the elastic elements of the "squirrel cage". Ball bearings are modeled as a rigid hinge. There are two thin-walled shells, which are intermediate power elements outside the elastic element. With an increase in the imbalance of the fan rotor, the gap in the oil damper closes, the damper housing sits on the shells, switching on their rigidity to work. Thus the support stiffness characteristic is bilinear. The stiffness coefficients of the elastic element "squirrel cage" and the shells of the front support are determined by numerical simulation. The fan rotor is modeled as a rigid body on bearings. The motor stator is modeled by a rigid body on an elastic suspension. The pylon and elements of the elastic suspension of the engine are modeled by beams of variable section, working simultaneously in tension, torsion, and bending. Numerical analysis of the transient oscillations of the D-436-148FM engine mounted on the pylon of the AN-178 aircraft was performed. The amplitude-frequency response of oscillations is obtained in the frequency range below the fan speed in the cruising mode. The stability of engine oscillations at a resonant frequency close to the autorotation frequency has been studied. The results of the numerical simulation are presented in the form of diagrams. Orbits of the centers of gravity of the fan rotor and the motor casing in the resonant mode are constructed. Poincaré mappings of oscillations of the same points of the structure are also constructed.
Результати експериментальних досліджень акустичних характеристик звукопоглинаючих конструкцій для ТРДД
Authors: Rymarenko Yevhen
Published: August 2023

The subject of the research in this article is an acoustic liner designed to reduce aircraft noise in a wide frequency range. The purpose of the study is to determine the acoustic characteristics of an acoustic liner. Tasks: development of a theoretical model of the acoustic liner in the form of tubes of different lengths, calculation of the natural frequencies of each tube of the developed liner, determination of the frequency range in which sound absorption will occur, production of a test sample, and experimental determination of the sound absorption coefficient. An experimental setup is used to determine the sound absorption coefficient of the developed liner, which determines the acoustic characteristics of the acoustic liners using the standing wave method. This study presents the results of: calculation of the natural frequencies of the proposed liner, calculation of the dependence between the amplitude transmission coefficient and the frequency of the exciting force, and measurement of the acoustic characteristics of the proposed acoustic liner. The scientific and practical novelty of the obtained results is as follows: to solve the problem of noise absorption in a wide frequency range, a theoretical model of the acoustic liner, which should consist of tubes of different lengths, was developed. Each tube has its own frequency of oscillation of the air inside the tube. As the path of sound travel inside the tube increases, the natural frequency of the tube decreases. When tubes of different lengths are placed on the test sample, it is possible to obtain an acoustic liner with a significant number of natural frequencies, that is, noise will be absorbed in a wide frequency range. According to the calculation results, the proposed acoustic liner, consisting of seven types of tubes of different lengths, has more than 20 natural frequencies in the frequency range from 500 Hz to 4500 Hz, that is, the frequency range of absorption is quite wide. In order to verify the theoretical calculations with the help of a 3D printer, experimental samples of the proposed acoustic liner, as well as a real acoustic liner used to reduce the noise of the D-18T engine, were made and their experimental studies were carried out. The research results show that the proposed acoustic liner reduces noise in a wide frequency range. In the frequency range from 1300 Hz to 3500 Hz, the sound absorption coefficient exceeds 0.4, and in the range from 1500 Hz to 2600 Hz, the sound absorption coefficient is above 0.5. In the specified frequency ranges, the proposed acoustic liner has significant advantages over the D-18T acoustic liner. By reducing the cross-section of the tubes, or increasing the number of tubes of the experimental sample, it is possible to significantly increase the frequency range of sound absorption.
Ідентифікація параметрів математичних моделей та визначення діагностичних ознак
Authors: Hung Tran Manh
Published: August 2023

In this article, the object of research is two main units of the AR20N aggregate – electrohydraulic amplifier (EHA) and power cylinder (PC). Detection of the occurrence and development of faults in them will be considered on the basis of the identification of parameters of the developed mathematical models. The main objectives of the research were to identify the parameters of mathematical models of EHA and PC using different steps of time quantization, determination of the optimal step of time quantization for numerical integration of differential equations; determination of diagnostic features that have the most probable influence on the operation of aggregate units at the occurrence of various faults. For achievement of the set objectives the following tasks were solved: mathematical models of EHA, PC, and simulation model of the aggregate research on the test bench were developed; identification of parameters of mathematical models of EHA and PC by the method of least squares (MLS) was carried out; the permissible step of time quantization was determined; upper and lower permissible limits of the identifiable parameters for a serviceable aggregate were determined; a methodology for determining the diagnostic features that are most probable to determine the emerging faults of the aggregate has been developed. Methods are used for this purpose: analytical, numerical, statistical, hydraulic systems theory, and system identification theory. The following results were obtained: differential equations describing the displacements of the distributive spool (DS) of the EHA and the output link (OL) of the PC; algorithms for identifying the parameters of mathematical models by MLS; the permissible step of time quantization was determined; and a technique for determining the diagnostic features using the Shewhart diagnostic chart for the parameters of mathematical models was developed. The scientific and practical novelty of the obtained results consists of the following: mathematical models of EHA and PC of the aggregate have been developed; simulation model of the aggregate on the test bench has been developed; simulation of various faults of the aggregate units has been carried out and identification of parameters of mathematical models of these units has been carried out; changes of estimations of parameters of mathematical models of EHA and PC depending on changes of each influencing factor have been obtained; upper and lower permissible limits of parameters and average values of these parameters have been determined; diagnostic features that are most probable to influence aggregate performance have been determined. It is shown that time quantization step D t = 0.01 (c) provides the determination of DS and OL displacements with errors of 1.914×10-6mm and 2.157×10-5 mm.
Формування математичної моделі турбовального двигуна
Authors: Yepifanov Sergiy , Bondarenko Oleksii
Published: August 2023

The subject of the study is the process of forming a mathematical model (MM) of a turboshaft gas turbine engine and a twin-engine helicopter power plant, which provides the determination of parameters of the working process in steady and transient operating modes for use in the estimation of dynamic characteristics, in the analysis and synthesis of engine and helicopter automatic control systems. The goal is to substantiate the structure and methodology of MM formation intended for use in real and accelerated time scale systems. Tasks: implementation of the previously proposed MM structure taking into account the turboshaft engine performances, development of a methodology for determining the MM coefficients based on known information about the static and dynamic properties of the engine, and formation of the MM structure of a two-engine helicopter power plant. For this, the methods of the theory of airjet engines and the theory of linear dynamic systems are used. The following results were obtained: the structure of a multimode high-speed MM of a turboshaft engine and a two-engine power plant was formed and tested. The scientific and practical novelty of the obtained results is as follows: the structure of the multimode linearized MM of the turboshaft engine is formed, which consists of static and dynamic submodels implemented in corrected parameters; the modeling technique was worked out on a simplified model, compiled considering expert information about the static and dynamic properties of the engine in the considered operation area. Formulas were obtained that relate the coefficients of the linear dynamic model to the values of the time constants of the rotors and the sensitivities obtained from the static characteristics; transient characteristics of the engine based on changes in fuel consumption and load power are determined, which correspond to physical knowledge about the engine; the modeling methodology and MM structure of a two-engine power plant were formed, which is distinguished by the combination of individual static and linear dynamic models of two engines with a single nonlinear dynamic model of the helicopter rotor; a simplified MM load necessary for testing the MM of the engine installation is proposed, which provides the calculation of the power consumed by the rotor, depending on the angular position of the blades.
Порівняльний аналіз систем програмування мікроконтролерів серії STM32 у виробах авіаційного застосування
Authors: Vialov Serhii , Dunai Andrii
Published: August 2023

The subject of the research is the software development environment for STM32 series microcontrollers, which play an important role in the electronic support of modern aviation and are an integral part of the development process of aircraft systems. Goal. The selection of the most current STM32 series microcontroller programming system for aviation products. Tasks. Overview of major popular software development environments for STM32 microcontrollers such as STM32CubeIDE, VisualGDB, IAR Embedded Workbench for ARM, Keil MDK, Arm Development Studio, and Simulink. Various aspects of programming systems are considered, including software development, feature availability, and integration with development tools and environments. Research methods. Carrying out a comparative analysis; separation of the characteristic features of the use of programming environments in avionic devices using the example of JSC "Element". In view of the use of environments in the field of avionics, special attention was paid to certification and reliability using examples of safety standards, verification, and testing tools. The results. It was found that code debugging, memory analysis, code optimization, and other basic functions are inherent to all considered development environments. Distinguishing features inherent in individual programming environments are identified, including microcontroller robot simulation, high performance and compilation speed, open source code, optimization, support from the manufacturer, and a wealth of documentation, including user manuals, code examples, support forums, training courses, webinars, and articles from development companies. Conclusions (scientific and practical novelty). The results of the analysis provide important conclusions regarding the better choice of STM32 microcontroller programming systems in aviation products. The comparisons and analyses made will help software developers choose the most suitable programming system for their specific needs. A conclusion was made about the feasibility of using development environments such as IAR Embedded Workbench for ARM and STM32CubelIDE for developing aviation software based on STM32.
Вплив температурного перепаду на ступінь підвищення тиску у вентиляторному контурі турбовентиляторної приставки ГТД
Authors: Maiboroda Roman
Published: August 2023

The subject of this study is the working process in a turbofan attachment of a gas turbine engine. The object of study is the fan part of the impeller of a turbofan attachment. The aim of this study was to evaluate the effect of temperature difference in a two-tier impeller on the degree of pressure increase in the fan part of a two-tier impeller of a turbofan attachment of a three-circuit engine. To achieve this goal, the following tasks were solved: to simulate the flow in a turbofan attachment; to calculate the dependence of the degree of pressure increase in the fan part of the impeller of the turbofan attachment on the Mach number for the operating mode at altitudes of 0 km, 9 km and 11 km; to evaluate the temperature difference in the two-tier impeller of the turbofan attachment. The study was carried out by the method of numerical experiment. Results: The dependence of the degree of pressure increase of the fan circuit of the turbofan attachment on the Mach number at the inlet is obtained, taking into account the effect of hot gases of the turbine circuit of the turbofan attachment. It is shown that the flow of hot gases affects the degree of pressure increase in the fan circuit. The presence of the turbine part of the two-tier impeller leads to a slight deterioration in the characteristics of the fan part. The degree of pressure increase is reduced by 0.2 ... 4.8 %. The greatest influence is manifested in the operating mode H = 11 km. Visualization of the flow velocity field in the fan part of the turbofan unit showed that during the operation of the turbine circuit, the nature of the leakage in the fan part changes by approximately 50% of the blade height. An increase in temperature contributes to the intensification of the energy of the boundary layer around the lower part of the blade of the fan circuit, which has a positive effect on the reduction of zero velocity zones during the flow. Scientific novelty and practical significance: new data were obtained on the effect of temperature difference in a two-tier impeller on the degree of pressure increase in the fan part of a two-tier impeller of a turbofan attachment of a three-circuit engine. The results obtained can be used to optimize the turbofan attachment of a gas turbine engine.
Дослідження впливу температури газу процесу холодного газодинамічного напилювання на адгезійну міцність нікелевмісних покриттів
Authors: Shorinov Oleksandr , Dolmatov Anatolii , Polyviany Sergii , Balushok Kostyantyn
Published: August 2023

The subject of the research is the influence of low-pressure cold spraying process parameters on the adhesive strength of the coatings. The goal is to ensure the maximum values of the adhesive strength of nickel-based coatings deposited by cold spraying by controlling the gas temperature at the nozzle inlet. The task is to investigate the effect of the temperature mode of the DYMET-405 machine on the adhesive strength of the coatings obtained from the Ni+Zn+Al2O3 powder mixture at constant other spraying parameters. Research methods. The experimental study of the adhesive strength was conducted on the tear using adhesive method in accordance with DSTU 2639-94. The metal-matrix composite powder mixture Ni+Zn+Al2O3 was used as powder material. VT3-1 titanium alloy was chosen as substrate material. Coatings were deposited using DYMET-405 low-pressure cold spraying machine. Temperature regulation at the nozzle inlet was performed by turning on the required temperature mode on the equipment control panel. Other spraying parameters remained constant during coating deposition process. The results. It was established that with an increase in the temperature of the gas in the nozzle, an increase in the adhesive strength of coatings is observed, on average from 9.5 MPa to 28.7 MPa. This can be explained by the fact that an increase in gas temperature leads to an increase in the velocity of the gas flow and, accordingly, of the powder particles in this flow. Higher particle impact velocity has a positive effect on the process of their deforming, filling of pores, densifying of coating layers, and finally increasing the adhesive and cohesive strength. The scientific novelty of the obtained results is that the dependence of the gas temperature at the nozzle inlet during low-pressure cold spraying on the adhesive strength of Ni+Zn+Al2O3 powder mixture coatings deposited on VT3-1 titanium alloy substrates was obtained. Conclusions. The practical value of the obtained results is that the obtained dependences of adhesive strength on gas temperature can be used for the development of cold spraying recommendations for the deposition of restorative coatings on parts made of titanium alloys, in particular in aircraft engines to eliminate operational defects.
Influence of carbon nanoparticle inoculation on the structure of ML5 casting magnesium alloy
Authors: Makovskyi Spartak , Balushok Kostyantyn , Obnosov Kyryl , Greshta Viktor , Shalomeyev Vadym , Tkach Daria
Published: August 2023

The object of this study is to investigate the structure of cast magnesium alloy (Mg-Al-Zn) inoculated with nano particles of different allotropic forms of carbon. The aim of this study is to improve the processability and quality of critical load bearing magnesium alloy part castings. The tasks of the study are: attainment of efficient control of the alloy structural features by introduction of incremental additions of carbon nano particles; determination of the relationship between the quantity of the added inoculating carbon agent and α - solid solution grain size; determination of the influence of allotropic forms of carbon on the morphologic characteristics of the intergranular borders and the eutectoid (a+Mg17Al12); and comparative analysis of the phase composition of the standard ML5 alloy and the experimental alloy ML5 inoculated with carbon black, nanographite, and single-wall carbon nanotubes. The phase composition was determined by X-ray diffraction analysis using copper radiation. Micro X-ray spectral analysis was performed. The following findings were obtained. Using an optical microscope α – solid solution grain size was measured in the standard and inoculated alloy. In the samples of the alloy variants inoculated with 0.1 % wt. of carbon black, nanographite, and single-wall carbon nanotubes, the grain size was reduced by appox. 50 % compared with the standard alloy. In the samples of the alloy inoculated with 0.1 % wt. of nanographite and single wall carbon nanotubes, eutectoid (a+Mg17Al12) precipitates along the grain boundaries were thinner than those in the standard alloy samples and those inoculated with carbon black. X-ray diffraction analysis revealed no new phase formation. The X-ray diffraction patterns of the alloy samples with nanographite and nanotubes display weak peaks of free carbon, which may indicate the presence of free carbon in small quantities in the structure. The scientific and practical originality of the obtained results consists of the following: a technology of inoculation with incremental additions of allotropic forms of nano carbon, namely carbon black, nanographite, and single-wall carbon nanotubes, has been tested on a standard cast magnesium alloy (Mg-Al-Zn system) in an environment similar to the industrial production of critical magnesium cast components. It has been shown that the introduction of nanocarbon in a quantity of 0.1 % wt. can have a beneficial effect on the structural characteristics of ML5 cast magnesium alloy with no change in its phase composition. Nanographite and single wall carbon nanotubes with a regular structure contribute to the formation of thinner intergranular boundaries than amorphous carbon black.
PENINGKATAN PERENCANAAN KARIER MELALUI BIMBINGAN EKSPLORASI KARIER PADA SISWA SMA
Authors: Rafa Sakina Mifta Wahyu
Published: August 2023

Penelitian ini bertujuan untuk mengetahui efektivitas peningkatan perencanaan karier melalui pemberian bimbingan karier pada siswa SMA. Penelitian ini menggunakan pendekatan eksperimen dengan jenis penelitian single case experimental design. Perbandingan dalam penelitian single case experimental design ini tidak dilakukan antara individu maupun kelompok namun dibandingan pada subjek yang sama dalam kondisi yang berbeda yaitu antara konsisi baseline dan kondisi intervensi. Teknik yang digunakan untuk mengumpulkan data yaitu dengan teknik observasi, wawancara dan tes psikologi. Subjek dalam penelitian ini adalah siswa SMA kelas XI yang mengalami kebingungan karier. Intervensi dilakukan selama 5 hari dan hasil intervensi menunjukkan adanya perubahan dari kondisi baseline ke kondisi intervensi. Pada kondisi baseline subjek belum mengenal dirinya sendiri, belum memahami jenis-jenis fakultas dan jurusan yang ada di bangku perkuliahan dan tidak dapat membuat perencanaan karier yang cocok dengan dirinya. Pada kondisi intervensi subjek dapat mengobservasi diri, mengenal dirinya sendiri dan mampu mengevaluasi diri berdasarkan potensi dan kepribadian yang dimiliki sehingga dapat membuat perencanaan karier yang cocok dengan kondisi dirinya.

Kata Kunci: Kebingungan Karier, Bimbingan karier, Eksplorasi Karier, Siswa SMA
ФІНАНСУВАННЯ ДЕФІЦИТУ ДЕРЖАВНОГО БЮДЖЕТУ: МАНЕВРЕНІСТЬ У КОНТЕКСТІ УПРАВЛІННЯ ДЕРЖАВНИМ БОРГОМ
Authors: Буряченко Андрій , Болдова Антоніна , Москаленко Наталія
Published: August 2023

У статті досліджено ключові аспекти фінансування дефіциту державного бюджету з позиції врахування перспектив розширення можливостей формування гнучкої політики управління державним боргом. Напрям дослідження визначається актуальністю для України, яка перебуває в умовах різкого зростання дефіциту бюджетних коштів та необхідності фінансування військових потреб із максимальним збереженням макроекономічної стабільності. В цьому руслі, за неможливості відмови від зовнішніх та внутрішніх запозичень, єдиним ефективних рішенням є досягнення максимально можливої маневреності політики управління державним боргом, який ілюструє різке зростання. Обґрунтовано вибір джерел фінансування дефіциту бюджету та здійснено опис факторів, що провокують його зростання. В статті представлено та проаналізовано базові показники, що відображають структуру фінансування бюджету України, в тому числі за рахунок запозичень.