bluuebunny/crossref_metadata_2025 huggingface dataset:
Establishment, evaluation and application of a gas chromatography-mass spectrometry method for quantification of volatile organic compounds in ambient air using anisole as an internal standard
Authors: Sofronievska Ivona , Stefova Marina , Petreska Stanoeva Jasmina , Bogdanov Jane
Published: December 2024

Gas chromatography coupled with mass spectrometry (GC-MS) is a standard analytical method for identifying specific volatile organic compounds (VOCs) in urban air samples. Quantification ideally relies on calibration curves using standards for each compound. However, due to the variable composition of VOCs and the limited availability of all standards, this strategy is challenging and not always feasible. Quantification using an internal standard is a simple and accurate approach, as it involves the simultaneous analysis of the internal standard and analytes, eliminating the need for a calibration curve if their concentrations fall within the linear dynamic range. In this study, quantification of VOCs from different chemical classes has been evaluated using a single standard mixture and anisole as an internal standard and compared to the external calibration as standard method for quantification by GC-MS. Both methods showed comparable results, with a relative error within ±30% of the theoretical concentration. Linearity was confirmed in the range from 100 to 4000 μg/L, and the relative standard deviation (RSD) of the relative response factors (RRFs) met the acceptance criteria of ≤30% for each target VOC. Toluene, chlorobenzene, C6-C2 and C6-C3 substituted benzenes yielded similar average RRFs, ranging from 1.280 to 1.601 with an RSD of 7.83%. The methods were applied for quantification of VOCs in ambient air on real samples collected on Radiello adsorbents at one urban location. Using anisole as an internal standard proved to be a simple and reliable method for determining VOC concentrations, offering a convenient alternative to external standard calibration.
Anodic and cathodic components of currents of quasireversible electrode reactions on rotating disk electrodes under steady state conditions
Authors: Lovrić Milivoj , Mirčeski Valentin
Published: December 2024

In a rotating disk electrode setup at constant potential, the current of a simple redox reaction becomes time-independent under steady-state conditions. This steady-state current can be expressed as a sum of two components, according to Butler-Volmer kinetics. While these components cannot be measured experimentally, they can be calculated using simple formulae based on the formal potential of the electrode reaction, which can be determined from the potential of zero current on the steady-state current-potential curve. The components can then be used to measure the transfer coefficients of quasireversible electrode reactions.
Preparing the final nails to seal the coffin of genuine science
Authors: Gulaboski Rubin
Published: December 2024

Science is meant to be shared and discussed, not sold. However, over the past two decades, the phrase "publish or perish" has led significantly to the decline of genuine scientific inquiry. Today's science is often more about profit than sharing knowledge. Neuropsychologist Bernhard Sabel, using a fake-paper detector developed by him, was "stunned" to discover that after screening approximately 5000 papers, up to 34 % of neuroscience articles published in 2020 were either fabricated or plagiarized. In medicine, the rate was 25 %. Currently, more than 11,000 scientific journals operate based on a pay-to-publish open access model (excluding the so-called "predatory journals"), contributing to an industry valued at approximately $20 billion USD. Alongside the annual publication of over 7 million papers (estimated for 2023), concerns are mounting about flawed, incorrect, or fabricated data. The recent introduction of tools like ChatGPT has further elevated ethical concerns related to irregularities, errors, falsification in published papers to a new level. This work aims to highlight the major concerns regarding how the policies of many pay-to-publish journals harm the integrity of real science. The insights presented are based on the author's personal experiences and observations over 15 years as a referee for numerous journals. Meanwhile, the metric of "number of published papers per year" and "profit margins" seem to be the only "valuable" aspects of modern "science".
Reducing greenhouse gas emissions in China’s automobile manufacturing with circular economy strategies
Authors: Tong Xin , Gao Jian , Wang Tao , Shi Xiaolei
Published: December 2024

Circular economy strategies encompass a wide range of approaches and initiatives designed to foster sustainable resource utilization and minimize waste, particularly in the context of complex products such as automobiles. These strategies encompass, among others, material recycling and reuse, energy recovery, efficiency enhancements, and circular-focused product design. To evaluate the potential of different circular economy strategies to reduce greenhouse gas emissions in China’s automobile manufacturing, this research employs the input-output subsystems approach to analyze three distinct scenarios based on the interconnections between various components: the low-carbon transition of the energy structure, closed-loop material recycling, and the transition to shared mobility. The findings reveal that spillover component emissions account for over 98% of the total emissions of the automobile manufacturing sector. The circular economy model, through material recycling, can significantly cut down emissions from these spillover components, thereby aiding the automobile manufacturing industry in meeting its emission reduction targets. Notably, compared to relying solely on the low-carbon transition of the energy structure, the closed-loop material recycling scenario can reduce greenhouse gas emissions by approximately 10% through the recycling of steel and plastics alone. Moreover, the transition to shared mobility has the potential to achieve an additional 4%-18% reduction in greenhouse gas emissions by diminishing the final demand for automotive products.
The contributory factors leading to intimate partner violence against male victims in South Africa
Authors: Rakgwata Phoke Alpha , Decent Munzhelele , Mphephu Pelewe
Published: December 2024

Intimate partner violence against male victims is an understudied phenomenon that has been neglected by traditional research methods in South Africa. This study is intended to shed light on the under-researched area of intimate partner violence against male victims in South Africa. Despite the focus on female victims of violence, male victims have historically been neglected in research. This study is concerned with identifying the contributory factors that make men vulnerable to intimate partner violence in South Africa. This study employed the qualitative research approach. The study comprised of 10 male victims of intimate partner violence to assist the research to gather in-depth data about IPV. Furthermore, data was analyzed thematically, this is a qualitative research data analysis method used to identify, code, and categorize patterns and themes with the date set. Findings from this study are set to inform policymakers and service providers to develop interventions that meet the needs of male victims in South Africa, and to strengthen the evidence base for male victimhood. This study contributes to the body of knowledge on male victimhood and ultimately to the development of policy and programs that prevent violence against men and promote their safety and well-being.
Financial behavior of Generation Z in Surabaya city: Analysis of the relationship between financial literacy and lifestyle
Authors: Retna Rahadjeng Erna , Prayogi Harsono Bagas
Published: December 2024

This research aims to determine and analyze the influence of financial literacy and lifestyle on financial behavior. This type of research is explanatory research using a quantitative approach method. The sampling technique uses probability sampling with the proportionate stratified random sampling method with a sample size of 395 people. The data analysis technique used in this research is multiple linear regression analysis using SPSS tools. The results of this research show that financial literacy has a positive and significant effect on the financial behavior of generation Z. Lifestyle has a negative and significant effect on the financial behavior of generation Z. Financial literacy and lifestyle simultaneously have a positive and significant effect on the financial behavior of generation Z in Sawahan District, Surabaya City. The results of this study suggest that generation Z must have qualified financial literacy and have a healthy lifestyle in order to form good financial management so that generation Z has an awareness of the importance of doing good financial planning as early as possible to achieve financial well-being.
An evaluation of risk management practices in South African Public Institutions
Authors: Maphangwa Takalani Emphraim , Tshikhovhokhovho Tshimangadzo Caroline , Munzhelele Ntungufhadzeni Freddy
Published: December 2024

Efficient risk management within the supply chain is essential for municipal success. This study assesses the supply chain risk management procedures of the Thulamela Municipality to guarantee service delivery. The main objectives were to evaluate the municipality's risk management structure and recommend enhancements in accordance with the MFMA and King IV requirements. The study question examined the implementation of a risk management system by Thulamela to guarantee service delivery. Utilising risk management and institutional theory, the study adopted a mixed-methods approach, applying deductive thematic analysis and SPSS software to examine data regarding the municipality's risk management procedures, team expertise, and framework suitability. The findings reveal that although Thulamela possesses a supply chain risk management framework, enhancements are necessary, specifically in (i) empowering the risk management team, (ii) incorporating technology and maintaining a record of suppliers with a history of non-compliance, and (iii) augmenting staff's risk management expertise. A favourable correlation was observed among effective risk management, institutional theory, supply chain procedures, and service delivery. This report provides essential information for policymakers to improve municipal supply chain risk management. Future research may investigate the impact of technology on mitigating risks such as non-compliance, corruption, and supplier failures, and also analyse the risk management frameworks among South African municipalities.
Support initiatives by agricultural cooperatives in facilitating women's recovery from the socio-economic impacts of the Covid-19 pandemic in Kajiado county
Authors: Munene Cynthia M. , Waweru Kennedy M , Charles K Wambu
Published: December 2024

This study investigated the impact of healthcare interventions by agricultural cooperatives on women's recovery during the post-COVID-19 period in Kajiado County, Kenya. It explored how agricultural cooperatives address women's recovery in the post-COVID-19 period in Kajiado County. It examined support initiatives for women's recovery, internal healthcare mechanisms targeting women, and cooperative-led interventions in post-COVID-19 recovery. Supported by Social Capital Theory and Empowerment theory, the study focused on Kajiado County. Kajiado County was selected for its cultural diversity and economic activities. Utilizing a mixed-methods research design, the study included a sample size of 373 respondents, members of agricultural cooperatives. The qualitative phase involved interviews and focus groups, while the quantitative data was collected using structured questionnaires. This study employed a combination of stratified random sampling and purposive sampling. Findings were presented through tables, aiming to inform government regulators in policy formulation. The study concluded that women have largely positive perceptions of the healthcare interventions offered by agricultural cooperatives. The findings also suggested a strong positive correlation between women's experiences with healthcare initiatives and their recovery from the COVID-19 pandemic. The study further concluded that logistical and cultural barriers remain significant obstacles to women's access to healthcare services provided by agricultural cooperatives. Recommending that agricultural cooperatives must develop and implement robust communication strategies to bridge the gap between awareness and actual engagement in healthcare programs for women. The study encourages policymakers to work alongside cooperatives to broaden these programs, create accessible healthcare models that consider rural challenges, and overcome existing logistical and cultural obstacles. By building such collaborative frameworks, these efforts can enhance women’s resilience, support sustainable recovery, and contribute to enduring improvements in community health and economic resilience in rural areas.
When cannabis use privately finds itself in the workplace a reflection on Enever v Barloworld equipment
Authors: Tchawouo Mbiada Carlos Joel , Joubert Gideon , Ndlovu Lonia
Published: December 2024

In this case note, we disagree with the Labour Appeal Court’s decision in which it found that the dismissal of an employee for testing positive for cannabis consumed in her private home was unfair on account of discrimination. In particular, we hold the view that the finding that the employer could not prove intoxication, was misconceived. We argue that because the employee admitted to being dependent on cannabis, proof of intoxication or impairment was unwarranted. We lean on the literature which evinces that cannabis users suffer from cognitive deficits. We then argue that cognitive decline is no more than an impairment that may affect productivity.
Steps to serenity: embracing physical activity for stress relief in Vietnamese higher education
Authors: Wang Tz-Li , Huynh Vo Thuc Quyen , Ko Ling-Mei
Published: December 2024

In recent years, increased understanding has led individuals to prioritize exercise for the purposes of sustaining health, achieving weight loss, preventing various diseases, and alleviating stress. This research aims to deepen our understanding of human exercise behavior by examining the factors that influence this trend. The writers utilize the framework of "Social Learning Theory" to elucidate the correlation among influencing factors, exercise behavior, and stress relief. This study details a survey that involved 323 participants, primarily Vietnamese college students with a focus on tourism. The analysis comprised 151 males and 172 females. This research employed structural equation modeling (SEM) for data analysis. The results showed that enabling circumstances and social impact have a positive impact on stress relief, with exercise activity playing a mediating role. The model accounts for 57.3% of the variance in exercise behavior and 57.1% in stress relief. Moreover, social impact has a direct favorable impact on students' stress relief. In conclusion, both enabling factors and social impact are associated with increased exercise activity. These characteristics increase the likelihood of students participating in exercise and reducing their academic stress. The study also that the institution introduces a course that combines academics with yoga and team sports to the general education curriculum. The institution should offer on-campus fitness or partner with local gyms. Finally, joining clubs and organizations might encourage university students to exercise.
The effect of transaction exposure, firm size, and liquidity on the firm value with leverage as mediating variable
Authors: Widyantara Raden Pandu , Aisjah Siti , Djazuli Atim
Published: December 2024

This study analyses the impact of transaction exposure, firm size, and liquidity on firm value with leverage as a mediating variable in on Consumer Non-Cylicals Sector Companies Listed on the Indonesia Stock Exchange from 2018 to 2023. Using Signalling Theory and Trade-off Theory as theoretical frameworks, the research employs path analysis to evaluate the relationships between variables. The findings reveal that transaction exposure, firm size, and liquidity have a positive significant effect on firm value. Conversely, leverage shows a negative significant impact on firm value, suggesting that excessive debt increases financial risk, thereby reducing firm value. Moreover, the study indicates that leverage does not mediate the effects of transaction exposure, firm size, or liquidity on firm value. These results highlight the importance for companies to prioritize managing liquidity and capital structure effectively to optimize firm value. Excessive use of debt should be minimized to avoid diminishing profitability and reducing market value, especially for firms with high exposure to international transactions.
PENGEMBANGAN KAWASAN EKOWISATA KEBUN RAYA MANGROVE GUNUNG ANYAR DENGAN PENDEKATAN PENTAHELIX
Authors: Churin’in Rachma Arsyieta , Soedarto Teguh , Atasa Dita
Published: December 2024

Surabaya's Mangrove Botanical Garden, with an area of 25 hectares, offers views of the mangrove forest, jogging trails, a monitoring tower, boat docks and picnic areas. Despite its great tourism potential, visitor numbers are still relatively low and there are deficiencies in facilities and services. Data shows the destruction of mangrove ecosystems in Indonesia and the need for more attention to the management and promotion of this destination. Data shows that Indonesia's mangrove ecosystems, which cover 4.25 million hectares, are significantly damaged, with 48% moderately damaged and 23% severely damaged. Several Google Reviews cite deficiencies in infrastructure and management that affect visitor satisfaction. This study involved 25 respondents from pentahelix stakeholders (government, academia, business, community, media) and used qualitative descriptive analysis to identify ecotourism development patterns and strategies. This study aims to identify efforts to develop the Mangrove Botanical Garden ecotourism area through a pentahelix perspective, which involves the government, academics, business people, the community, and the media. Data analysis uses qualitative descriptive analysis. This analysis includes organising, simplifying and synthesising data to identify patterns and main themes, as well as formulating working hypotheses. Overall, the Gunung Anyar Surabaya Mangrove Botanical Garden shows positive developments in environmental conservation efforts and ecotourism development. The botanical garden manager has planned various strategic steps to improve the attractiveness and quality of services, which are expected to have a positive impact on both visitors and the surrounding environment.
KEANEKARAGAMAN VEGETASI HUTAN MANGROVE DI KECAMATAN KURAU KABUPATEN TANAH LAUT
Authors: Fithria Abdi , Syam'ani Syam'ani , Udiansyah Udiansyah , Ruslan Muhammad , Rezekiah Arfa Agustina , Pramudya Firman , Akbar Pani , Diva Achmad Arya , Fahmi Hilman , Shiba Yasinta Nur
Published: December 2024

Kurau sub-district in Tanah Laut Regency is known to have a fairly extensive mangrove forest with great potential. One of the potentials is the variety of mangrove vegetation that grows in the forest. vegetation that grows in it. Knowing the diversity of mangrove forest species in Kurau sub-district aims to provide a scientific basis for in Kurau sub-district aims to provide a scientific basis for protecting and monitoring the forest. and forest supervision. The method used in the research is the technique of collecting data with purposive sampling and then analyzing with calculation of importance value index and Shannon-Wiener diversity index. Research The research was conducted based on the level of forest density consisting of high, medium and sparse forest density. high, medium, and sparse. The results obtained there are 11 types of vegetation that grow in mangrove forests and are dominated by the type of mangrove (Rhizophora mangle) which grows from seedling to tree level. Then followed by Rambai (Sonneratia caseolaris) and Api-api (Avicennia lanata). The level of species diversity in this mangrove forest is categorized as high with an index value of 5.5. high category with an index value of 5.46 for high forest density, 4.22 for medium forest density. While for sparse forest density included in the medium diversity category with a value of 2.34.
PERBANDINGAN NILAI TAMBAH PEMELIHARAAN LEBAH MADU KELULUT (Trigona itama) DAN LEBAH MADU LOKAL (Apis cerana) DI DESA SUMBER MAKMUR KECAMATAN TAKISUNG KABUPATEN TANAH LAUT
Authors: Sulaiman Sulaiman , Basir Basir , Helmi Muhammad
Published: December 2024

Honey is one of the leading non-timber forest products (HHBK) in Tanah Laut Regency which was stipulated through the Decree of the Tanah Laut Regent Number 188.45/463-KUM/2013 dated 10 September 2013 concerning Designation as a development area for superior Non-Timber Forest Products (HHBK) in the form of honey. The economic strength resulting from the honey bee cultivation business can be reflected in the value added (value added) of its management. Product added value, output value, production productivity, and also the amount of remuneration to the owner, as well as the factors of production, can be identified by carrying out an added value analysis. The amount of added value can be a reference for whether or not there is added value from the treatment that has been given to the product. The purpose of this research is to analyze the added value of kelulut honey cultivation. Analyzing the amount of added value from local honey cultivation. Comparing the added value of cultivating kelulut honey and local honey bees (A. carena). The object of this research is farmers who cultivate kelulut honey bees and local honey bees with a system of maintenance, production and value added management. The cultivation of kelulut honey bees produces a total output of Rp. 150.000.000 per year. The total added value generated is Rp. 41.217.500, consisting of Rp. 7.540.000, the profit is Rp. 39.859.900, and depreciation of Rp. 3,707,500. Local honey bee cultivation of A. carena produces a total output of Rp. 27.000.000 per year. The total added value generated is Rp. 13.08.000, consisting of Rp. 4.500.000, the profit is Rp. 11.730.000, and depreciation of Rp. 1.220.000. The cultivation of kelulut honey bees generates an added value of Rp. 41.217.500 more than the added value of A. carena local honey bee cultivation with an added value of Rp. 13.008.000.
Radiographic findings and body mass index in elderly patients with knee osteoarthritis: A cross-sectional study
Authors: Lie Yose Steven , Kusumaningrum Sulistyani , Budiningsih Fatichati , Wijaya Bayu Basuki
Published: December 2024

Background: Osteoarthritis (OA) is a chronic condition characterized by the gradual wearing down of joint cartilage. Its prevalence is increasing due to aging populations and obesity rates. The Kellgren and Lawrence classification system is commonly used to assess OA severity based on radiologic findings.Objective: This study aims to determine the relationship between body mass index (BMI) and the radiological severity of knee OA as classified by the Kellgren and Lawrence system, in elderly patients.Methods: We conducted a cross-sectional analysis of outpatients diagnosed with knee OA at a Dr. Moewardi Regional Public Hospital from January 2020 to August 2023. Patient records and knee X-rays graded by the Kellgren and Lawrence system were reviewed. Two radiologists independently assessedthe X-rays to ensure accuracy. BMI was calculated using the formula weight (kg) divided by height (m2), with weight and height measured suing calibrated instruments. Spearman's rho bivariate correlation analysis was performed to analyze the data.Results: A total of 96 patients were analyzed, with the majority being female (62.50%) and aged 60-69 years (59.30%). The most prevalent OA severity was grade 3 (46.89%), and the most common OA location was bilateral (73.96%). There was a significant moderate correlation between Kellgren & Lawrence and BMI (p=0.000; rho=0.401).Conclusion: A moderate correlation exists between the severity of knee OA and BMI in elderly patients. Those with a higher BMI tend to present with more severe OA.
Is climate one of the most important factors for rehabilitation patients with rheumatic disease?
Authors: Nikolić Emilija , Marić Jovana
Published: December 2024

Previous research confirms the beneficial effect of a warm climate on the general psycho-physical condition of rheumatic patients. However, the evidence for using climatotherapy to improve rehabilitation care is unclear and not concluded. We examined the efficacy of a four-week rehabilitation treatment of Norwegian rheumatology patients at the Rehabilitation Center in Igalo in different seasons using mathematical approaches.
RESEARCH OF THE PROPERTIES OF A MECHANICAL ROBOT USING THE EXAMPLE OF A PHYSICAL PENDULUM
Authors: Mygushchenko Ruslan , Kropachek Olga , Balev Volodymyr , Mygushchenko Kateryna , Finohenov Oleksii
Published: December 2024

The article examines the properties of a mechanical robot and provides recommendations for changes in its design. The relevance of the use of robots in the world is beyond doubt, such robots are used in places that pose a danger to humans or are inaccessible to humans. In each case, the accuracy of positioning and the accuracy of the robot's actions directly affect the efficiency of the tasks assigned to the robot. Practicing robot movements traditionally takes place at robotics competitions, which are widely held around the world. In recent robotics competitions, one of the exercises in the competition was an exercise where the robot had to hang from a beam using its mechanical levers. The researched robot oscillates in the air while hanging on a crossbar on mechanical levers. In the studies, the task was to overcome these negative phenomena - mechanical oscillations, by studying the problem and conducting physical research. In order to conduct physical research and study the issue, a decision was made to replace the real object – the robot – with an appropriate replacement structure. For such a replacement design, a physical pendulum (classical and reversible) is adopted. In physical pendulums, the main parameter is the moment of inertia I, which is determined from the formula: , where m is the mass of the pendulum, g is the acceleration of free fall, d is the distance from the axis of the suspension to the center of mass of the pendulum, T is the oscillation period of the pendulum. The accepted hypothesis is that an increase in the moment of inertia of a real object will lead to the need to increase the force that forces this object to swing. Experimental installations were formed during laboratory research; measured variables – I, independent variables – g, T, dependent variables – m, d were analyzed; experiments were carried out to assess the impact on the moment of inertia I of the distance from the suspension axis to the center of mass of the pendulum d and the influence on the moment of inertia I of the mass of the pendulum m. The obtained results of physical research allow us to provide recommendations on changing the design of a real object - a robot. The recommendations make it possible to eliminate the negative phenomenon – rocking the robot on the crossbar, which will allow to perform the corresponding task better. These recommendations include the following: 1. Load the structure as much as possible by increasing the mass m. 2. Extend the robot levers as much as possible by increasing the distance d. 3. Lower the center of gravity of the robot as much as possible. After making constructive changes in the structure of the robot, it is planned to build its mathematical model for further research.
ANALYSING THE ENERGY SATURATION OF CYLINDRICAL GRINDING MACHINES
Authors: Mykhailo Stepanov , Maryna Ivanova , Litovchenko Petro , Ivanova Larysa , Skydan Nataliia
Published: December 2024

Constantly rising energy prices and the current challenges of securing a sustainable power supply are driving research into how to reduce the energy consumption of metalworking equipment. To efficiently manage and reduce energy consumption by grinding machines, a system of measures to minimize energy consumption for cutting, for moving elements of the technological system, and for auxiliary equipment has been proposed. The nature of the change in power consumption depending on the period of engine operation is shown on the graph. When determining the total power of the technological system of a grinding machine, it is proposed to take into account the power of electric motors for driving the rotation of the grinding wheel, workpiece, hydraulic drive pump, cooling fan, spindle bearing lubrication pump, guide lubrication pump, coolant supply pump, magnetic separator drive, coolant cleaning filter-transporter drive.
SIMULATION 2.5-D COUNTUR MILLING ON CNC-MACHINE
Authors: Petrakov Yuri , Myhovych Artur
Published: December 2024

The article discusses a new method of modeling the cutter workpiece engagement during contour 2.5-D milling in order to determine the main process parameter - the material removal rate. A data preparation algorithm and a mathematical model of the engagement of the milling cutter with the workpiece are presented, which allow determining the instantaneous volume of the removed tool material and determining the cutting force according to the mechanical model during machining. For simulation, the representation of the workpiece and the tool in the form of polygons is used, and the cutting process is implemented using the logical operations "intersection" and "difference".  This approach allows you to detect the volume of material removed by the tool during a certain simulation iteration, taking into account the geometry of its flutes, and to display the new geometric shape of the workpiece after removing material from it. Such a new form will be used to model the next step of the algorithm, which ensures the continuity of the process. The application of the developed algorithm and mathematical model allows obtaining correct data on the instantaneous volume of removed material, which is subsequently used to predict the cutting force and solve the problem of optimizing the contour 2.5D milling process.
ASSESSMENT OF THE LUBRICATING CAPACITY OF SOLID LUBRICATING MATERIALS IN DIAMOND GRINDING OF HEAVY-PROCESSED MATERIALS
Authors: Hasanov Magomedemin , Rudnev Aleksandr , Kotlyar Oleksii , Titarenko Oksana , Korchagin Ilya
Published: December 2024

The results of research on cutting forces during diamond grinding of materials used in the manufacture and repair of aircraft equipment: titanium alloy VK6 and heat-resistant dispersion-hardening high-alloy stainless steel 10Х11Н23Т3МР were analyzed. Grinding was carried out using solid lubricating materials developed by the authors. The obtained results allow us to state that solid lubricating materials are able to effectively reduce friction. Stearic acid should be considered the basis for the creation of TZM with further improvement of their composition
THEORETICAL FOUNDATIONS FOR SUBSTANTIATING OF DESIGN SOLUTIONS FOR COMBAT VEHICLE ELEMENTS BASED ON THE ANALYSIS OF PHYSICAL AND MECHANICAL PROCESSES
Authors: Vasyliev Anton , Tkachuk Mykola M. , Tkachuk Andrey , Tkachuk Mykola A. , Shut Oleksandr , Nechaiev Roman , Zinchenko Olena , Veiler Volodymyr , Loznyi Oleg
Published: December 2024

Ensuring the world-class tactical and technical characteristics of armored vehicles is an extremely important and urgent problem in the field of national security and defense. This is due to the enormous potential of Ukraine's armored vehicle industry, which has not yet been realized in the design and development of the production of these vehicles for various reasons. One of the main problems is the lack of methods and models to substantiate the parameters of these vehicles and the properties of materials for the manufacture of the main components, primarily armor hulls and transmissions, at the stage of design research. This work involves developing the theoretical foundations and conducting research to determine the response of armored vehicle components to various factors and to determine the requirements for design solutions for their components. An extremely important factor is, for example, the prevention of critical deformations that occur in armored vehicles when exposed to munitions. Existing models do not allow for an adequate assessment of the degree of protection under the influence of various factors, which leads to fundamentally incorrect design decisions. Consequently, a new, relevant, and important scientific and technical problem arises - the study of processes and states of armored vehicles in combat use to improve their tactical and technical characteristics. The theoretical foundations of such research are described in this paper. Their significance is especially growing in the current situation in the presence of hostilities that require the manufacture and supply of military equipment with high tactical and technical characteristics. In turn, achieving the world level of these characteristics is impossible without a number of studies, in particular, based on the approach described in this paper, as a matter of priority. Research on this basis is aimed at scientific substantiation of advanced technical solutions for military equipment.
COMPARATIVE ANALYSIS OF THE ADVANTAGES AND DISADVANTAGES OF THE COMBAT USE OF DIFFERENT TYPES OF MANPADE ANTI-AIRMISSILE SYSTEMS
Authors: Ivanets Mihail , Horielyshev Stanislav , Ivanets Grigoriy , Voinov Valerii , Baulin Dmitro , Nakonechnyi Oleksandr
Published: December 2024

An analysis of the nature of armed struggle in recent decades indicates a sharp increase in the influence of modern weapons and military equipment on the course of military operations. Currently, weapons and military equipment form the basis of the combat power of the armed forces of any state and are a determining factor in achieving success in a war or armed conflict. One of the characteristic features of the Russian Federation’s aggressive military actions against Ukraine is the widespread use of air forces, in particular, airplanes, helicopters, and unmanned aerial vehicles equipped with cruise missiles of various types. To strike Ukraine, the enemy uses air-, sea-, and ground-based cruise missiles, ballistic and anti-aircraft guided missiles, and attack unmanned aerial vehicles. Today, modern man-portable anti-aircraft missile systems have become one of the most effective and widespread means of combating air targets at low altitudes during combat operations (operations). The use of such complexes sharply limits the altitude range of use of all types of manned combat aircraft and has a negative impact on the accuracy of strikes against ground and surface targets. The Armed Forces of Ukraine are actively using Soviet, Polish, American, British and French man-portable anti-aircraft missile systems (provided to Ukraine by NATO and EU countries) against Russian aviation. A comparative analysis of the main characteristics, advantages and disadvantages of various types of man-portable anti-aircraft missile systems currently in service with the Ukrainian armed forces was carried out, in the interests of increasing the effectiveness of their use in different combat conditions.
APPLICATION OF PHOTOGRAMMETRY IN REVERSE ENGINEERING OF MACHINE-BUILDING FACILITIES
Authors: Ivanov Evgen
Published: December 2024

To recreate an object in the form of a virtual model based on an existing physical detail, the paper proposes to use the Autodesk ReCap Photo cloud service. Using this service, it is possible to create virtual three-dimensional models by laser scanning a real object or using a digital camera and subsequent digital reproduction of this object in digital space. However, the widespread use of laser scanners and software is very limited due to their high cost. The paper proposes a cheaper, more accessible and no less accurate method that is easy to apply in practice - the method of digital reverse engineering photogrammetry. The method is based on creating a three-dimensional model from two-dimensional photographs using the proposed software. With its help, the user uploads a set of photos to Autodesk's servers and receives a triangulated model of the object with all real dimensions and high quality textures. The data obtained was subsequently imported for further processing into another program of this family, the Autodesk Inventor package. The Autodesk Inventor package has a user-friendly interface and a large set of tools for modeling engineering products. To demonstrate the scale and level of sophistication of ReCap Photo, we demonstrate the options included in the application: first of all, the application supports almost all laser scan file formats. In addition, point clouds can be edited arbitrarily - deleted, copied, highlighted, or even added survey points. As a result, it is possible not only to create technical documentation, but also to reconstruct objects with millimeter accuracy. Visualization and design make it possible to eliminate possible errors. It has been demonstrated that such models can be used to design and obtain working documentation. Due to the identity of the spatial virtual model and the real physical object, the accuracy and quality of design is improved. Thus, it is clearly shown that the presented methodology significantly reduces labor intensity and increases efficiency.
MESHING TRANSFERS IN AUTODESK INVENTOR
Authors: Ivanov Evgen
Published: December 2024

In order to improve the execution of drawings of gear elements in the Autodesk Inventor package, an approach to the presentation of geometric information in accordance with the requirements of current standards is proposed, based on the use of developed three-dimensional models of assembly units of gear elements in parametric shells. The basis for the development of the sketch geometry of parametric shells were the basic geometric parameters of the tooth crowns of the elements, since when making drawings of gear meshing elements, the images of the tooth crowns are made in violation of the requirements of current standards. In order to simplify the construction of drawings of gear elements in the Autodesk Inventor package, an algorithm was developed to provide geometric information through the developed three-dimensional models of the parametric shells of the gear crowns of their elements. That is, the geometric information is embedded in the parametric assembly units "gearing in shells". The algorithm is based on working with the parametric shells of the elements of the constituent units, where all the necessary geometric information is represented by a function of the main geometric parameters of real gear crowns. The method of parametric shells considers the issues of touching, implementation, methods of formation of such shells with detailed coverage of their properties and geometric parameters. The rigorous mathematical theory of parametric shells, which involves the joint processing of analytical and geometric information obtained on the basis of the geometry of the gear elements as forming elements, is characterized by generalization in approach and mathematical rigor. At the same time, the presence of toothed crowns of three-dimensional models of gear elements by meshing is ignored. The algorithm for simplified creation of gearing drawings involves making cuts based on sketches, adjusting contour lines and changing the properties of areas in accordance with the requirements of current standards. The library of parametric shells and the algorithm for creating working drawings of both elements and gearing are implemented in the educational process.
STRENGTH AND STABILITY OF MOVEMENT OF ROTOR SYSTEMS OF TANK ENGINE AIR SUPERCHARGER
Authors: Tkachuk Mykola M. , Veiler Volodymyr Volodymyr , Grabovskiy Andrey , Prokopenko Mykola , Tkachuk Mykola A. , Shut Oleksandr , Lipeiko Andrii , Ovcharov Egor , Marusenko Oleksii
Published: December 2024

The work researches the processes and states that occur in the impeller of the air supercharger of tank engine. The influence of the tension in the connection of the impeller with the shaft and the yield strength of its material on the stress-strain state and critical speeds of movement is studied. For this purpose, appropriate mathematical and numerical models were built. Parametric models of the studied processes and states have also been developed. A number of varied parameters are considered. This makes it possible to study the influence of these parameters on the performance and strength of the rotor part of the air compressor. On this basis, a specialized database with research results can be built. The analysis of these results is the basis for establishing certain regularities, as well as for substantiating progressive technical solutions of the rotor parts of the air blowers of tank engines according to the criteria of strength and performance. The impeller of the air compressor of the tank engine limits its strength and durability. As determined in the course of research, a direct increase in the mechanical properties of the aluminum alloy material from which it is made is not productive. Among the significant factors, it is necessary to take into account the acting loads from centrifugal forces and tension in the coupling "shaft - impeller", and in their combination. It is also important to take into account the elastic-plastic deformation of the material of the impeller. Recommended are not separate measures and solutions regarding the rotary parts of the air compressor, but their combination for the purposeful improvement of the characteristics of strength and durability.
ANALYSIS OF THE STRESS-STRAIN STATE OF CONTACTING ELEMENTS OF HYDRAULIC TRANSMISSIONS FOR ADVANCED TANK TRANSMISSIONS UNDER VARIATION AND PERTURBATION OF THE SHAPE OF SURFACES AND PROPERTIES OF BODY MATERIALS
Authors: Tkachuk Mykola M. , Hrechka Iryna , Sierykov Volodymyr , Grabovskiy Andrey , Veiler Volodymyr , Tkachuk Mykola A. , Loznyi Oleh , Tkachuk Ganna , Zarubina Alla , Koba Andrii
Published: December 2024

The paper describes the study of the stress-strain state and of the contact interaction of hydraulic transmission elements for advanced tank transmissions. The shape of the treadmill and the ball piston of the radial hydraulic volume transmission, as well as the stiffness of the surface layers of these elements, are varied. A change in the shape and size of the contact area between the piston and the raceway of the hydrovolumetric transmission is observed. At the same time, the distribution of contact pressure, its nature, and maximum values change. It has been established that in certain design variants, the oval shape of the contact area is transformed into a rounded rectangle, a dumbbell-shaped figure, or two isolated areas. This, in turn, has a significant impact on the stress-strain state of the ball piston and stator ring of the fluidized bed transmission. By varying these parameters, the dependence of strength characteristics on them was established. Such regularities are the basis for substantiating advanced technical solutions for hydraulic volumetric gears in terms of strength, durability, and load capacity. The developed parametric model has the property of being extended to various other parameters. This makes it possible to create specialized databases. These databases concentrate information on the dependence of the strength characteristics of hydraulic-volume gears on certain parameters. Accordingly, it is possible to solve the inverse problem of substantiating rational technical solutions for hydraulic gears. The developed approach can be extended to a wide class of structural elements.
TO THE ANNIVERSARY OF VOLODYMYR MALASCHENKO
Authors: Protsenko Vladyslav Vladyslav , Tkachuk Mykola A. , Ustynenko Oleksandr
Published: December 2024

The article is dedicated to the 85th anniversary of the famous Ukrainian scientist in the field of mechanical engineering and machine dynamics, professor of the department of technical mechanics and engineering graphics of the National University "Lviv Polytechnic", doctor of technical sciences, academician of the Lifting and Transport Academy of Sciences of Ukraine, Volodymyr Oleksandrovych Malashchenko. After the restoration of Ukraine's independence, Volodymyr Oleksandrovych was one of the organizers of the process of training highly qualified specialists. Many of the candidate's and doctoral dissertations were defended under his supervision or opposition, not only in mechanical engineering but also in lifting and transport machines, agriculture, printing, oil and gas engineering. He is the author of more than 600 works, including more than ten monographs, more than 100 patents, about 30 study guides (of which six are in French), and about 20 articles in foreign publications indexed by scientometric databases. Volodymyr Oleksandrovych is also the author of a complex of study guides on machine design, which are widely used in the educational process of almost all technical universities of Ukraine. He is a member of the editorial boards of the magazines "Lifting and Transport Technology", "Bulletin of NTU "KhPI", series of Engineering and CAD", a member of the program and organizational committee of the international scientific and technical conference "Problems of Quality and Durability of Gears and Mechanical Drive".
MODELLING CHANGES IN THE PRODUCTION COMPONENT OF FLEXIBILITY OF MANUFACTURING SMALL AND MEDIUM-SIZED MACHINE-BUILDING ENTERPRISES UNDER CONDITIONS OF SHARP FLUCTUATIONS IN MARKET SUPPLY AND DEMAND
Authors: Basova Yevheniia , Dobrotvorskiy Sergey , Yakovenko Ihor
Published: December 2024

The paper proposes an enlarged model in the form of an integral functional of enterprise flexibility, which describes the stability of small and medium-sized machine-building enterprises in the conditions of stress factor - fluctuations in supply and demand. This model allows the reduction of the reaction time of enterprise management to negative external factors and to predict the need for management decisions on resource allocation and innovation to minimize the time to restore the stability of machine-building enterprise functioning in new production realities under changes in the market. Based on the analysis of the model, its decomposition has been carried out, and four main factors related directly to the production process that affect the optimization of the proposed function have been identified. Special attention was paid to the detailed analysis of each factor: productivity, product quality, efficient inventory and resource management, and a new important factor in modern conditions, such as responsibility to standards and regulatory documents. This analysis allowed us to propose mathematical models of the influence of each of the factors on the overall flexibility functionality. The proposed mathematical models were analyzed using the benefits-based planning method. This made it possible to analyze how a small and medium-sized engineering enterprise would react to a stress situation associated with changes in market demand, to optimize the overall integral function of small and medium-sized machine-building enterprises flexibility over time, and to propose variants of anti-stress solutions to offset the impact of stress factors on the sustainability of the enterprise over time.