bluuebunny/crossref_metadata_2025 huggingface dataset:
Az óvodáskorú gyermekek ellenálló képességének előmozdítása: egy akciókutatási program eredményei
Authors: Erdei Róbert
Published: January 2025

The negative impact of developmental risk often manifests itself as early as the formative years. Counteracting these risks and mitigating or modifying the factors that threaten optimal development seem feasible through pedagogical means. This study presents the initial results of a program whose primary goal is to support resilient functioning in preschool-aged children who exhibit at least four concurrent risk factors. Methods: The applied methods focused on assessing cognitive abilities, the frequency and severity of behavioral problems, and the perceived resilience as reported by the educators and parents. Children enrolled in the program participated in regular sessions, and the effectiveness of these interventions was evaluated through follow-up assessments at the end of the school year. Results: The findings indicated a slight but statistically significant improvement in cognitive abilities among the selected population. There was also a notable reduction in the risk of learning disabilities. Behavioral problems showed a significant decrease. According to both parents and educators, resilient functioning was significantly higher in the follow-up assessments compared to the initial evaluations. Conclusions: Overall, the program's impact can be considered positive. Although the sample size was not large and other factors beyond the sessions might have influenced the participants' outcomes, positive progress was achieved across all indicators. The program employs a complex methodological repertoire that extends beyond conventional pedagogical support services, which, based on the initial results, appears suitable for counteracting risk factors in preschool-aged children.
Óvodai intézményvezetők (igazgatók) véleménye a sajátos nevelési igényű gyermekek ellátásával és integrációjával kapcsolatban
Authors: Mező Katalin , Juhász Anna
Published: January 2025

Providing the opportunity for integrated education has become an expectation in all public education institutions today. The success of integration primarily depends on the inclusive perspective of the institutions implementing integrated education and the institutional inclusive culture developed as a result, in which institutional leaders play a significant role. This study explored the opinions of preschool directors regarding the integration of children with special educational needs. A total of 74 preschool directors from religious, local goverment, private, and other types of institutions were contacted for the study. Data analysis was conducted both descriptively and with a mathematical statistical approach. The applied mathematical statistical methods were the chi-square test and the Kruskal-Wallis test. According to our results, the type of institution has an impact on directors' views regarding the integration of children with special educational needs. Regarding integration, 75% of directors believed that the care of children with special educational needs imposes an additional burden on preschool teachers. The results also highlighted that a lack of expertise required for integration remains a problem in preschools. The majority of institutional leaders were at least moderately satisfied with the approach of the institutions' sponsors in providing material conditions to support integration, but they were less positive about the availability of personnel resources.
A szülői bevonódás és eredményesség összefüggései Magyarországon az országos kompetenciamérés adatai alapján
Authors: Bacskai Katinka , Bencze Ádám , Dorogi Alexandra , Hegedűs Gabriella , Major Enikő , Rétháti Csilla , Pusztai Gabriella
Published: January 2025

The aim of our study is to review the wide-ranging network of relationships between schools and parents based on investigations carried out along various indicators in diverse social grups. By analyzing the National Competence Measurement database, we examined parental involvement, a factor known to influence academic outcomes, particularly in the 6th and 10th grades in Hungary. Principal component analysis and crosstabulation analysis were used in order to unveil correlations between the gained results and both the students' family background and age. It was found that although the level of parental involvement decreases with the child’s age, it still has an impact on parental participation. Additionally, we have demonstrated that lower-status families have a different involvement strategy, but the level of involvement is not as high as families from higher socioeconomic backgrounds, leading to misunderstandings between families and schools
Autizmus spektrum zavarral korán diagnosztizált óvodás gyermekek mozgásfejlesztésének tapasztalatai szülői szemmel
Authors: Müller Anetta , Mező Katalin , Szilágyiné Popovics Zita , Vargáné Nagy Anikó , Laoues-Czimbalmos Nóra
Published: January 2025

The movement and the developmental of motor skills is a crucial role for every child, as motor and cognitive states and development are closely interconnected. Preschool years represent a particularly important period for motor development, as the motor skills and abilities developed during this time are decisive for the entire later life. This study addresses the characteristics of movement and the effectiveness of interventions for children with autism spectrum disorder, examined from the parents' perspective. The investigation, based on personal interviews (n=28), involved parents raising children who were diagnosed early with autism spectrum disorder. The data obtained from the interviews we were analyzed using both qualitative and quantitative methods, including frequency and content analysis, to identify recurring patterns and individual differences. Through thematic coding and categorization of responses, three main themes we were identified: 1) Characteristics of motor functions, 2) The significance of early diagnosis, 3) Development and developmental interventions.
From Boardroom to Stadium: How International Sports Organizations Recruit Talent
Authors: Fangni Li
Published: January 2025

Recruitment forms the basis of achievement for international sports organizations and both board members and athletes in the playing area. In this research, the approaches, issues and trends that influence the identification, sourcing and management of human capital in these organizations in the chasm of a competitive and fast growing environment are examined. It explores the provision of boardroom executives and actual players; emphasizes the place of technology, cultural diversity, and ethical issues in the present day recruitment. By analysing strategic, IT and SAP recruitment successes and failures the research provides understanding on sustainable talent sourcing and changes happening in the industry. The results support the need for the use of analytics, diversity, and creativity to achieve strategic human resource management in recruitment. The purpose of this research is to develop a broad understanding of the diverse nature of the recruitment challenges within sports whilst focusing on it being a strategic factor for improved operational output and organisational competitive advantage.
Valuable Lessons Learnt From a Global Tele-Rehabilitation Partnership Program During COVID-19
Authors: Coutinho Franzina , Storr Caroline , Brien Marie , Krishna Dinesh , Saxena Gauri , Ponnusamy Ramasubramanian , Navami V.
Published: January 2025

Objective:The study aimed to evaluate the experiences of stakeholders—including Canadian occupational and physical therapy students, parents of children with disabilities, Indian rehabilitation workers, and North American supervisors—participating in a novel global tele-rehabilitation program developed by Amar Seva Sangam in partnership with five Canadian universities. The program facilitates online fieldwork for Canadian students in rural Tamil Nadu, India, especially during the COVID-19 pandemic.

Methods:A mixed methods design was employed to gather comprehensive insights into stakeholder experiences. Quantitative data were collected through surveys assessing perceptions of service delivery and educational outcomes, while qualitative data were gathered through interviews and focus groups to explore the depth of participant experiences and cross-cultural interactions.

Results:The findings indicated that the majority of participants believed the tele-rehabilitation program effectively provided necessary rehabilitation services to children with disabilities, with service quality comparable to traditional on-site fieldwork. Additionally, student stakeholders reported significant capacity building through cross-cultural learning opportunities, enhancing their understanding of global rehabilitation practices.

Conclusions:The global tele-rehabilitation program not only maintained essential rehabilitation services during the COVID-19 pandemic but also fostered meaningful learning experiences for Canadian students. These insights underline the potential of tele-rehabilitation as a sustainable model for delivering rehabilitation education and services in underserved regions, promoting collaboration and understanding between diverse cultural contexts.
Empowering Academic Diversity: The Lived Experience of Faculty With Disabilities in Rehabilitation Counseling Education
Authors: Ong Lee Za , Chen Roy K. , Pawlowski-Farr Julia I. , Nguyen Erika Mai Khanh
Published: January 2025

Background:Flourishing in the highly competitive world of academia poses challenges for all faculty members, especially for those with disabilities.

Objective:The purpose of this study was to explore the experience of faculty with disabilities in rehabilitation counseling education (RCE).

Methods:The participants were five faculty members in a REC program in the United States. Each faculty member participated in a virtual 45–60-minute semistructured interview.

Findings:Using thematic analysis, four themes were obtained: (a) grit and self-efficacy, (b) social support, (c) lack of awareness, and (d) accessibility and accommodations.

Conclusions:Strategies to advance the progress and success of faculty with disabilities in REC are discussed.
Islamic Law Frameworks for Addressing Marriage Delays during Public Health Crises
Authors: Desminar Desminar , Habibulloh Habibulloh , Saputra Romi , Abrar Sulthani Dinil , Irawan Andi
Published: January 2025

This study examines the postponement of marriages at the Office of Religious Affairs (KUA) in Koto Tangah District during the COVID-19 pandemic as an effort to address health and social challenges, focusing on the perspective of Islamic law. The government's social restrictions led many couples to postpone or cancel their weddings, especially during the large-scale social restrictions period. This research aims to understand marriage postponement as a strategy to navigate pandemic challenges from an Islamic law perspective in Koto Tangah District, Padang City, and its impact on couples and society. The method used is field research with a descriptive qualitative approach. The findings show that marriage postponement was effectively carried out through schedule coordination with couples despite pressure from the brides and grooms. Health protocols were the primary reason for the delay, and KUA strictly limited the number of weddings if safety standards were not met. The postponements had significant psychological and economic effects on the couples, while society had mixed responses to the policy. KUA faced challenges in implementing marriage delays, especially regarding facilities and communication with engaged couples
Scoping the Development of Implementing an Undergraduate Operating Department Practitioners Buddy Scheme
Authors: Crisp Elizabeth , Latham Callum , Phillips Charlotte , Smith Hazel A , Olukun Olutayo Isaac , Gurney Elizabeth , Wilton Kelly , Woodrow-Hirst Ben , Jones Sarahjane
Published: January 2025

Introduction: In England, higher education institutions (HEIs) are modifying their processes to implement support strategies to decrease attrition rates. Some HEIs offer student buddy schemes to foster support networks, and knowledge exchange, build friendships, and increase confidence. Buddy schemes include peer-to-peer support coordinated by institutions, pairing experienced and non-experienced individuals aimed to provide support, advice, and training. At present, there is a lack of evidence capturing Operating Department Practitioner (ODP) students’ opinions about the implementation of a buddy scheme to improve student retention. Thus, to address this gap, a qualitative study with second year ODP students was undertaken.
Methods: Nine second year ODP students in the Midlands, England attended two focus groups. Questions relating to students’ thoughts and perceptions of barriers, and facilitators to a buddy scheme guided the discussion. All focus groups were audio-recorded and transcribed verbatim, and data were analysed using reflexive thematic analysis.
Results: All students regarded the buddy scheme to be potentially advantageous.  The reflexive thematic analysis identified three main themes: (1) the value of having a buddy in supporting wellness; (2) the sharing of students’ experiences; and (3) the structure of the buddy scheme.  
Implications For Practice: All participants agreed that a buddy scheme would greatly support fellow students both academically and professionally. ODP students see buddy schemes as critical for support and shared experience in completing their studies. Co-design is vital for developing the buddy scheme for ODP students, and further studies are needed to inform the effectiveness of evidence-based buddy schemes.
Determination of an Interval Between Certifications of the Standard Based on the Measurement Process Model in Time
Authors: Teteruk R. A. , Firsanov N. A. , Pimenova A. A. , Koksharov A. A.
Published: January 2025

Determination and assignment of reasonable intervals between certifications of standards is an important task to ensure the uniformity of measurements. The standards are intended for further transfer of the unit to standards and measuring instruments lower down the verification scheme, which means that exceeding the permissible values by metrological characteristics during operation is unacceptable, since it may lead to unreliability of the further transfer of the unit along the traceability chain. This risk can be reduced by finding the optimal interval between certifications, during which the metrological characteristics of the standard will not exceed the permissible values.

The article proposes one of the options for determining the interval between certifications based on the analysis of the measurement model of the standard and modeling the time dependence of the error limits of the estimates of input quantities, including taking into account factors that are not directly involved in the measurement process but influence this process.
Improvement of the State Primary Standard in the Field of Organic Analysis GET 208
Authors: Mikheeva A. Yu. , Lopushanskaya E. M. , Krylov A. I.
Published: January 2025

In the context of the rapid development of the Russian pharmaceutical industry, there is an urgent need to improve the State Primary Standard for the units of mass (molar) fraction and mass (molar) concentration of organic components in liquid and solid substances and materials based on liquid and gas chromatography-mass spectrometry with isotope dilution and gravimetry (GET 208).

As a result of the improvement of GET 208 carried out in 2023, a new installation based on the highperformance liquid chromatography/high-resolution mass spectrometry method was included in the standard. Thus, the functionality of the GPE was expanded in accordance with the current requirements of the domestic industry and for the purpose of Russia’s successful participation in international comparisons in the field of organic analysis now and in the medium term.

The article presents materials on the study of the capabilities of the new installation for solving various measurement problems in the field of organic analysis, describes specific analytical techniques and measurement methods, and provides experimental data and summarized results. Based on the completed studies, the metrological characteristics of GET 208 have been improved in terms of reproducing units of mass (molar) fraction of the main component in pure organic substances, mass fraction of organic components in solutions and materials.

Improvement of GET 208 made it possible to create a scientific, methodological and instrumental basis for reproducing measurement units for a wide range of organic compounds.
Improvement of the State Primary Reference Measurement Procedure for the Determination of Mass Fraction of Fat Content in Food Products and Food Raw Materials
Authors: Sergeeva A. S.
Published: January 2025

In order to ensure metrological traceability of fat mass fraction measurements, the State Primary Reference Measurement Procedure (SPRMP) for the Determination of Mass Fraction of Fat in Food Products and Food Raw Materials was developed, certified and approved in 2018. The SPRMP applies to samples of milk powder, sour cream, cottage cheese, cheese, meat and meat products, dry egg products, milk mixtures, grain porridge, grain-milk mixtures, canned baby food and establishes requirements for the procedure for measuring the mass fraction of fat using the Randall extractiongravimetric method. In the process of applying the SPRMP, the need to expand the scope of its application was identified. The purpose of the research is to improve the SPRMP of the mass fraction of fat in food products and food raw materials. An analysis of regulatory documents defining requirements for new measurement objects, measurement ranges and accuracy indicators has been completed. The measurement parameters and their permissible variation limits for new objects have been established. As a result of improvement, the scope of application of the SPRMP includes drinking milk and cream, condensed milk and cream, fish fillet, fish meat, including minced meat, bakery products, f lour confectionery, pasta, cocoa powder, chocolate, flour from cereals, nuts, nut paste, including peanut. An assessment of the accuracy indicators of the SPRMP was carried out using certified reference materials, food products and food raw materials. The developed measurement procedure made it possible to ensure a margin of accuracy of the measurement results using the SPRMP in comparison with standardized measurement procedures from 2 to 25 times, depending on the object and the measurement range. As part of the interlaboratory comparison tests, the procedure for using the SPRMP to assess the correctness of measurement results obtained using standardized measurement procedures was tested. During the COOMET pilot comparisons, as well as the analysis of foreign reference materials, the equivalence of the SPRMP to similar measurement methods of foreign countries was demonstrated. The applicability of the SPRMP for determining the certified value of the mass fraction of fat during the characterization of reference materials was demonstrated.
Dynamic Methods for Preparing Gas Mixtures
Authors: Kolobova A. V. , Malginov A. V. , Nechaev A. A. , Koshev V. A.
Published: January 2025

Metrological support of gas analytical measurements is carried out by transferring units of molar fraction and mass concentration of components from the State Primary Standard of units of molar fraction, mass fraction and mass concentration of components in gas and gas condensate environs. Reference materials (RMs) for the composition of gas mixtures in cylinders under pressure are used as transmission means, as well as gas mixture generators, the output of which is a gas mixture with known metrological characteristics. The main problem of this method is to ensure long-term stability of the mixture. The use of dynamic methods implemented in gas mixture generators, when the prepared gas mixture is used directly from the generator output, allows to significantly minimize or completely avoid this problem.

In recent years, quite a lot of gas mixture generators manufactured by domestic and foreign manufacturers have appeared on the market. Therefore, a comparative analysis of various methods of dosing the initial components implemented in gas mixture generators and used for metrological support of gas analytical measurements seems relevant.

The practical significance of the study lies in the analysis of the metrological, technical and operational characteristics of generators implementing various methods of dosing components of gas mixtures, which can be used by manufacturers of these measuring instruments to develop optimal technical solutions in the development and creation of new types of generators and dynamic installations designed to reproduce and transmit units of component content in gas environs.

The presented review may be useful for teachers and students of specialized higher education institutions to enhance their knowledge in the field of metrological support for gas analytical measurements.
On the Application of the Bayesian Approach to Estimating the Coverage Interval of a Bounded Measurand
Authors: Stepanov A. V. , Chunovkina A. G.
Published: January 2025

The problem of estimating the measurement uncertainty near the natural measurand limits is of significant interest to practicing metrologists and is far from being resolved. The article considers the Bayesian approach to constructing an asymmetric coverage interval and estimating measurement uncertainty in the case where the set of permissible values of the measured quantity is bounded. Of particular interest is the case when the measured value is located near the boundary of the set of its permissible values, since the constructed «traditional» symmetric interval corresponding to a coverage factor value of two (for a confidence level of 95 %) goes beyond the boundaries of this set and, as a consequence, do not provide the specified level of confidence probability.

When implementing the Bayesian approach, an important starting point is the choice of a priori density distribution. Four options for choosing a prior probability density are considered, including an asymmetric distribution from the family of two-sided power distributions (TSP). Recommendations are given for their selection and application depending on the proximity of the a priori estimate of the lower limit of the measured value, as well as the measured value, to the upper limit of the range of permissible values, relative to the measurement uncertainty value.

A specialized software has been developed to estimate the posterior density characteristics (expectation, mode and standard deviation) of measurand distributions and construct the shortest coverage interval, as well as to calculate the confidence level corresponding to the «traditional» coverage interval obtained using expanded uncertainty. The use of this software allows to obtain complete information about the measurement accuracy and to make an informed choice when presenting the measurement result.

The results obtained may be of interest to practicing metrologists in the development and certification of measurement techniques, processing of experimental data and presentation of measurement results when characterizing standard samples, as well as specialists involved in the application of methods of probability theory and mathematical statistics in solving practical problems.
The Influence of Learning Experience on Silence in WhatsApp-Based English Classrooms: Insights from Computer Engineering Students
Authors: Ramdhan Vickry , Erlangga Fajar
Published: January 2025

Silence in online learning, particularly in WhatsApp-based classroom, is an essential yet underexplored aspect of student engagement, especially among Computer Engineering students. While traditional theories suggest that silence fosters reflection, in practice, it often leads to discomfort or passivity, highlighting a gap between theoretical expectations and classroom realities. This study employing a quantitative ex post facto design aims to address this discrepancy by exploring how Computer Engineering students perceive silence in WhatsApp-based English classroom, focusing on the influence of age, gender, class type, and learning experience. Data were collected through two questionnaires. The first one assessed learning experiences and the second one examined silence of students in WhatsApp-based English classrooms. The data analysis included descriptive statistics and non-parametric tests (Mann-Whitney U and Kruskal-Wallis H tests) using SPSS 27.00. The findings revealed that students generally perceived silence as a natural yet sometimes uncomfortable part of learning. Age significantly influenced students’ comfort with silence, while gender and class type had minimal impact. Students with more experience in WhatsApp-based learning environment recognized reflective benefits of silence, whereas less experienced students tended to struggle with it. Despite this, both groups shared similar reasons for and discomfort with silence. The study concludes that while silence can support reflective learning, it may also cause discomfort due to students' hesitancy to interrupt discussions. To enhance engagement, the study suggests that teaching methods be adapted based on students' age and familiarity with the platform, ensuring that silence fosters meaningful learning rather than students’ passivity.
Mathematical description of the probability of capturing rod-shaped stepped blanks in hopper feeding devices with an inclined disk and tangential pockets
Authors: Pantyukhina E. V. , Borisov A. A. , Vasin S. A. , Klentak А. S.
Published: January 2025

In this work, we present a mathematical model of the capture probability of rod-shaped stepped blanks in mechanical disk hopper feeding devices with an inclined disk and tangential pockets. The model must take into account the influence of the design and kinematic parameters of the device on its performance, as well as those of the workpieces. The object of the research was a mechanical disk hopper feeding device having an inclined rotating disk and pockets tangentially located along its periphery, whose active orientation of the mentioned blanks is implemented by overturning them on special supports placed under the rotating disk. The tipping action is carried out under the action of gravity. For the construction of mathematical models, methods based on probability theory, analytical spatial geometry, theoretical mechanics, and general physical laws were used. The methodology for constructing a mathematical model of the probability of capture of rod-shaped step blanks of bodies of revolution in the studied devices with an inclined disk and tangential pockets is described. Algorithms for determining each coefficient of the developed model are presented. The developed model is a product of the probability of finding the rod blanks in a position favorable for their gripping in the direction of the tangentially located pocket, the probable absence of encumbrance during gripping of the blank due to its interlocking with other blanks, and the probable absence of encumbrance as a result of the peripheral speed of the gripping organs of the device. Thus, the developed mathematical models for calculating the capture probability of rod-shaped step blanks of rotational parts can be used at early design stages to estimate with high accuracy the actual productivity of mechanical disk hopper feeding devices with an inclined rotating disk and pockets tangentially located along their periphery.
Effect of FDM printing direction on the mechanical properties of products
Authors: Raspopina V. B. , Martynova V. V. , Stupina E. A.
Published: January 2025

The study aims to examine the effect of printing direction in the FDM-technology (Fused Deposition Modeling) on the mechanical properties of products. Laboratory tests of type B specimens were conducted in accordance with GOST 11262-2017 using a Shimadzu AGS-10kNXD tensile tester with a loading rate of 2 mm/ min. The specimens were made of ABS (acrylonitrile butadiene styrene) thermoplastic. Under otherwise equal conditions, the printing direction of the specimens was changed. As a parameter representing this factor, the study adopted the inclination angle of printing filaments in the infill of the specimen α to its longitudinal axis. The test results of FDM specimens showed that at different inclination angles α, a consistent variation in experimental data is observed. The specimen comprises two components: the first is the infill of the specimen; the second is the shell of the specimen. An analysis (based on 3D models of specimens in the slicer) of the filament path in the layers and the structure of each layer revealed that the mechanical properties of test specimens are affected by both components. In the shell of the specimen, this effect is produced by its upper and lower edges. A detailed analysis of models representing each layer of the specimens helped explain the variation in the response of specimens with different α to the action of the same tensile load in terms of the magnitude of the failure load. In particular, the features of the infill structure are such that its effect on the magnitude of failure load is limited by an increase in the angle α from 0 to 45°. A further increase in α leads to a mirror repeat pattern. In this case, the effect of the shell on the magnitude of the failure load corresponds to the range of 0°≤α≤90°. Thus, the conducted research provided insights that can help lay the theoretical groundwork for a procedure for producing FDM parts with specified mechanical properties.
Suppression efficiency of self-excited vibrations in machining evaluated by changes in their energy
Authors: Svinin V. M. , Ushakov V. A. , Savilov A. V. , Pyatykh А. S. , Irincheev A. A.
Published: January 2025

The aim was to develop an approach for evaluation and suppression of undesirable self-excited vibrations during the machining process. The suppression efficiency of self-excited vibrations was evaluated by the amount of their internal energy created by the radial cutting force. This force was assumed to be proportional to the difference in the area of the cut metal layer at the tool exit from the workpiece and penetration in each vibration. The research object was a low-rigidity shaft with a diameter of 48 mm, cantilevered with an outreach of 150 mm. Changes in the energy of self-excited vibrations were evaluated using a software package in the SciLab language. The shaft was machined with a cutting tool at a spindle speed of 208 rpm with a feed of 0.122 mm/rev and a cutting depth of 0.8 mm. The modulation frequency of the cutting speed per workpiece revolution was assumed to be 0.5. The difference in the area of the cut metal layer at the tool exit from the workpiece and penetration was calculated sequentially when varying the depth of cutting speed modulation in the range from 0 to 30% with an interval of 1%. The results obtained were used to draw a plot of changes in the relative difference of the cut layer areas (proportional to the internal energy of self-excited vibrations), similar to a cosine curve with a decreasing magnitude. An increase in the depth of cutting speed modulation was established to sharply reduce the internal energy of self-excited vibrations, periodically pulsing around zero values. The local minima of the plot corresponded to the condition of suppression of self-excited vibrations. The fourth local minimum corresponding to the depth of cutting speed modulation equal to 13.5% was selected as a parameter for practical use. At this depth, cutting speed modulation ensured a more than 10-fold decrease in the vibration range and a 12-fold decrease in the vibration amplitude, in comparison with similar parameters at the constant cutting speed. The results obtained confirm the efficiency of the proposed method for evaluating changes in the energy of self-excited vibrations during the machining process.
Multi-channel adaptive median signal filter
Authors: Akhtyrskiy K. A. , Kabirov V. A. , Semenov V. D. , Torgaeva D. S.
Published: January 2025

This study aims to develop a novel structure of an N-channel adaptive median signal filter with dynamic input exclusion. The proposed design is intended for highly reliable, fault-tolerant modular redundant power supply systems for spacecraft. To investigate the functionality of the proposed N-channel filter, we developed a simulation model for a 7-channel median signal filter using MATLAB Simulink. A model-based design approach was applied to validate the performance of the proposed element using the Altera Cyclone IV EP4CE115F29C7 field-programmable gate array (FPGA). The verification process involved the use of automatic code generation tools within MATLAB Simulink for the FPGA implementation. A novel structure of the N-channel median signal filter was proposed, featuring a dynamic exclusion of unused inputs from the median calculation. This guarantees that only valid input signals from operational modules within the power supply system be included in the median calculation. The simulation results demonstrated that, in contrast to existing counterparts, the proposed filter is capable of reliably outputting the median signal as the number of active input signals decreases from N to 1. The implementation of the filter as an intellectual property (IP) block based on the Altera Cyclone IV EP4CE115F29C7 FPGA demonstrated efficient resource utilisation, occupying 541 logic cells, while fully adhering to the specified operational logic. The proposed structure of the adaptive median signal filter can be employed in highly reliable, fault-tolerant spacecraft redundant power supply systems, maintaining functionality even in the event of multiple module failures, down to the last operational module. The developed solution meets the stringent fault-tolerance requirements of spacecraft power systems.
ginal article Application of a microprocessor-based relay protection unit for identifying internal faults of electrical equipment of electrical installations
Authors: Bannov D. M. , Polishchuk V. I.
Published: January 2025

We aim to determine the applicability of standard microprocessor units of relay protection and automatics for obtaining a digital signal of currents for their subsequent mathematical processing with the purpose of identifying internal faults of electrical equipment. Mathematical processing of experimental data (time series) based on regression analysis approximation in orthogonal basis was carried out. To that end, the weight coefficients of basis functions obtained by the least squares method were compared in terms of multidimensional space vectors, corresponding to the coordinates of this space. The investigated signal was a data set obtained by field experiments conducted with an induction motor, which assumed the possibility of creating artificial internal damage. Experimental data were obtained using two devices with different sampling rates and quantization levels. The first set of data was obtained using a 12-bit PCI board of analog-to-digital converter for installation in a National Instruments 6024E PC at a sampling rate of 10 kHz. The second set of data was obtained using a standard block of microprocessor relay protection and automation at a sampling rate of 2.4 kHz. Indicators for the presence of internal damage to the rotor circuit of an induction motor, which reduces the motor energy characteristics without affecting its operation significantly, were determined. The indicators of the damaged and undamaged state differed by a factor of five. The proposed method for selecting the diagnostic sign of internal damage of electrical equipment of electrical installations detects a 3% deviation in their parameters from the normal state, ignoring the presence of electrical/mechanical load. The diagnostic sign was established to behave similarly in the presence of internal damage, in both sets of signals under study. Thus, the possibility of obtaining a digital signal of acceptable accuracy from standard relay protection units for ensuring reliable identification of internal faults of electrical equipment of electrical installations is confirmed.
Green energy systems for powering electric vehicles considering telecommunication system with case study of Pakistan
Authors: Bilal Ali M. , Abbas Kazmi S. A.
Published: January 2025

The objective is to analyze the sustainability and efficiency of Pakistan’s telecommunication sector by developing a framework for base transceiver stations integrating renewable energy and charging stations. Various renewable energy sources such as solar, wind, biomass and hydropower were considered as the object of research. The following methodological steps were implemented in this work: site analysis; determination of optimal sizing of plants, energy storage systems and electric vehicle charging stations; cost-benefit analysis methods; greenhouse gas emissions estimation; and system design methods for integrating selected renewable energy sources and energy storage solutions, taking into account the operational requirements of the base transceiver stations. It is found that switching to hybrid renewable energy systems can significantly reduce dependence on diesel generators. It is shown that operating costs can be reduced by more than 80% compared to conventional diesel-fueled systems. Also, the introduction of hybrid renewable energy sources can lead to significant reductions in CO2 emissions. The integration of battery storage systems has been shown to improve the reliability of energy supply by ensuring uninterrupted operation during periods of high demand and blackouts. The proposed structure scheme for base transceiver stations is designed to accommodate future growth in the share of electric vehicles and technological advancements in renewable energy and electric vehicle charging. By prioritizing the integration of renewable technologies along with charging station infrastructure, telecom service providers in Pakistan can reduce their carbon footprint and operational costs. This approach not only addresses the unpredictability of the electricity grid, especially in rural areas, but also positions the telecoms sector as an active participant in global efforts to combat climate change.
Selection of generating equipment for a solar-diesel complex
Authors: Vaskov A. G.
Published: January 2025

A methodology for selecting the composition of generating equipment included in a solar-diesel complex to optimize its operating mode by minimizing the specific fuel consumption of diesel generator units is described. Software developed according to the principle of real-time integer nonlinear programming is used to calculate the minimum operating costs during the operation of the complex. Various restrictions on the operating modes of electrical equipment were taken into account. For a diesel power plant having a minimum capacity not less than 30% of the nominal capacity, the distribution of capacity between diesel generator units takes into account individual consumption characteristics. For an electrical energy storage system whose permissible change in capacity varies from 50 to 100%, the charge/discharge rate is limited to “1C”. For the solar power plant, the change in inverter efficiency was taken into account depending on its load as predicted for a 24-hour period. The research used a model to simulate full-scale equipment of a solar-diesel complex comprising two diesel generator units of 12 and 30 kW, a solar power plant simulator having a capacity of 6.6 kW, an energy storage system, and an active load simulator with a capacity of up to 50 kW. An algorithmic description of the operational principles of an automated control system for ensuring the energy efficiency of solar-diesel complexes in operation is provided. The developed SCADA system is suitable for modeling the operating modes of a solar-diesel complex under conditions close to actual. Depending on the operating conditions of the solar-diesel complex and the equipment parameters (the number of diesel generator units and their nominal capacities, the capacity and power of the electrical energy storage system, as well as the installed capacity of the grid solar power plant), operating mode modeling accuracy can be increased by as much as 30%. Thus, the obtained results of modeling the operating mode of a solar-diesel complex demonstrate the possibility of significantly refining the estimates of the operating parameters of such energy facilities by taking into account the actual energy characteristics of diesel generator units.
Numerical simulation of the melting process of a cylindrical sample with a localized heat source
Authors: Donskoy I. G.
Published: January 2025

The work set out to determine the conditions for the onset of melting and complete melting of the sample (in a stationary setting), as well as to study the dynamic modes of propagation of the melting front at different thermophysical parameters (heating and cooling intensity, change in material properties during melting, geometric characteristics of the sample). A numerical model of the heat conduction process in a heterogeneous medium is used as a research tool. For the numerical solution, non-stationary one-dimensional heat transfer equations are reduced to a differential form, taking the phase transition into account using an enthalpy scheme; in order to improve the stability of the numerical method, the melting and heat conduction processes are separated. The parameters are varied to determine the dependence of the characteristic times of the onset of melting and complete melting of the sample on the process conditions. The trajectories for reaching stationary states, whose solutions were obtained in the first part of the article, were calculated using a numerical model. The melting rate is shown to depend significantly on the ratio of the thermal diffusivity coefficients of the phases, as well as the intensity of heat supply and the thermal effect of melting. Critical values of dimensionless parameters reflecting the relative intensity of heat exchange and heat release obtained for stationary conditions are associated with the effective thermal resistances of the heat-insulating layer and heat transfer to the environment. The model can be used to calculate the dynamics of melting at low enthalpies of fusion (large values of the Stefan number), when the quasi-stationary approximation becomes inapplicable (i.e., when the characteristic time of movement of the melting front is comparable to or less than the thermal relaxation time). The calculations can be used to assess the thermomechanical stability of materials when heated by an internal local energy source (for example, Joule heat). The developed numerical model can be used to investigate melting processes under a wide range of conditions.
Ecologically sound use of sulfur-containing coal resources of the Irkutsk basin as a factor in the evolution of the regional thermal power industry
Authors: Rogov V. Yu.
Published: January 2025

The article aims to identify possible directions for developing heat technology systems in Irkutsk Oblast, taking into account the integration of resources of the Irkutsk coal basin with high sulfur content. The study applied a systems analysis of trends in the development of high-capacity coal-fired power boilers, considering the possibility of reducing harmful emissions (NOx, CO, SOx) primarily through rational design solutions and the use of coal-water slurry. It is shown that swirl processes realized in fuel combustion schemes that are applied at the TPPs of the Irkutsk power system help to improve the ecological and economic efficiency of heat technology systems, primarily by reducing the combustion temperature and increasing the residence time in the furnace. Experience is available in applying the low-temperature swirl combustion scheme at Ust-Ilimskaya TPP (boiler 6) and a circular furnace at Novo-Irkutskaya TPP (boiler No. 8). It is proposed to redesign the existing power boilers according to the scheme of low-temperature swirl combustion (i.e., the maximum temperature in the furnace is no higher than 1000–1100℃), with the subsequent use of partially demineralized and desulphurized coal-water slurry obtained at the place of extraction and transported by slurry pipeline. Fuel can be burned in a two-stage furnace: it is ignited in its lower part where the low-temperature fluidized bed of inert material is located; then, it is burned completely in the upper part of the furnace at a temperature of 1000–1200℃. Thus, in the context of the growing use of highsulfur coal, the evolution of technological systems in the thermal power industry of Irkutsk Oblast places its cleaning within the scope of activities of power companies. The main method of reducing the emissions of sulfur compounds consists in the low-temperature combustion of fuel using desulfurized coal water slurry.
An approach to estimate the equivalent parameters of a wind farm with DFIGs during wind gusts based on data-driven analysis
Authors: Chen Jianhua , Wang Liguo , Dreglea А. , Chistyakova Е. , Yu Chunlai
Published: January 2025

The purpose of the study is to develop an approach based on online measurements and the theory of Ritta–Wu characteristic sets from the field of algebraic geometry and computer algebra to solve one of the main tasks of wind energy studies such “abandon wind” caused by wind gusts. The Ritt-Wu theory is effective in studying polynomial systems and their solutions. To obtain an equivalent double-fed induction generator, the following basic steps are used: build the characteristic sets by modeling a wind farm; establish the polynomial rings based on the real-time aggregation data; derive analytical expressions of a model of an equivalent double-fed induction generator; validate of the developed approach to modeling an double-fed induction generator using mathematical modeling in the PSCAD software environment and analysis of a combination of model data and telemetry data. A general solution procedure is used, which can be applied to obtain the analytical expressions of the inductance and impedance of an equivalent wind farm. The expediency and effectiveness of the developed approach is illustrated by the example of a real wind farm with a capacity of 50 MW with 34 double-fed induction generators. The simulation results demonstrate that the obtained parameters of an equivalent double-fed induction generator can accurately follow wind speed fluctuations with a lower error. Thus, this study presents a new effective method for estimating the exact equivalent parameters of a wind farm during wind gusts. The developed method is suitable for obtaining the analytical solutions of equivalent wind farm parameters in real time. Validation of the accuracy and speed of the author’s method has been carried out. Moreover, this study can be applied to any wind farms equipped with double-fed induction generators.