bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of the economical dimension of sustainable development of the ukraine’s regions based on the brightness of night lights
Authors: Zgurovsky Michael , Yefremov Kostiantyn , Gapon Sergii , Pyshnograiev Ivan
Published: August 2023

When assessing the level of development of territories, the problem of finding objective qualitative data that will characterize it arises. One of the possible sources of such data is the remote sensing of the Earth (RSE). The article is devoted to the analysis of the possibility of using the product of RSE – the map of night lights, for modeling the economical dimension of the sustainable development of the regions of Ukraine. Using the regression and correlation analysis and neural networks, appropriate models for assessing the level of economic development of the Kherson region, Donetsk region, and the AR of Crimea were obtained. The study was carried out by the team of the World Data Center for Geoinformatics and Sustainable Development of the Igor Sikorsky Kyiv Polytechnic Institute. It was part of research on the analysis of the behavior of complex socio-economic systems and processes of sustainable development in the context of the quality and safety of people’s lives.
Interval type-2 generalizing fuzzy model for monitoring the states of complex systems using expert knowledge
Authors: Kondratenko Nataliia , Snihur Olga , Kondratenko Roman
Published: August 2023

A type-2 interval generalizing fuzzy model is proposed for monitoring complex systems’ states. A set-theoretic approach is proposed to generalize the results of type-2 fuzzy models with interval membership functions. The study of the correspondence of expert assessments to the output value of the generalizing fuzzy model over the observation interval is presented. Examples of the use of generalizing fuzzy model type-2 in the task of monitoring the conditions of an artesian well are given. It is shown that in order to improve the quality of decisions made, the expert needs to pay attention to the value of the interval output of the generalizing type-2 fuzzy model. Recommendations are presented to experts to improve decision-making regarding the estimation of the output interval of the generalizing model.
Guaranteed root-mean-square estimates of the forecast of matrix observations under conditions of statistical uncertainty
Authors: Nakonechnyi Oleksandr , Kudin Grygoriy , Zinko Petro , Zinko Taras
Published: August 2023

We investigate the problem of linear estimation of unknown mathematical expectations based on observations of realizations of random matrix sequences. Constructive mathematical methods have been developed for finding linear guaranteed RMS estimates of unknown non-stationary parameters of average values based on observations of realizations of random matrix sequences. It is shown that such guaranteed estimates are obtained either as solutions to boundary value problems for systems of linear differential equations or as solutions to the corresponding Cauchy problems. We establish the form and look for errors for the guaranteed RMS quasi-minimax estimates of the special forecast vector and parameters of unknown average values. In the presence of small perturbations of known matrices in the model of matrix observations, quasi-minimax RMS estimates are found, and their guaranteed RMS errors are obtained in the first approximation of the small parameter method. Two test examples for calculating the guaranteed root mean square estimates and their errors are given.
A genetic algorithm improvement by tour constraint violation penalty discount for maritime cargo delivery
Authors: Romanuke Vadim , Romanov Andriy , Malaksiano Mykola
Published: August 2023

The problem of minimizing the cost of maritime cargo delivery is considered. The cost is equivalent to the sum of the tour lengths of feeders used for the delivery. The problem is formulated as a multiple traveling salesman problem. In order to find its solution as the shortest route of the tours of feeders, a genetic algorithm is used where we present two inequalities constraining the tour length of every feeder to lie between the shortest and longest lengths. Apart from the constant tour constraint violation penalty in the genetic algorithm, we suggest a changeable penalty as an exponential function of the algorithm iteration, where we maintain the possibility of the penalty rate to be either increasing or decreasing, whose steepness is controlled by a positive parameter. Our tests show that the changeable penalty algorithm may return shorter routes, although the constant penalty algorithms cannot be neglected. As the longest possible tour of the feeder is shortened, the changeable penalty becomes more useful owing to a penalty discount required either at the beginning or at the end of the algorithm run to improve the selectivity of the best feeder tours. In optimizing maritime cargo delivery, we propose to run the genetic algorithm by the low and constant penalties along with the increasing and decreasing penalties. The solution is the minimal value of the four route lengths. In addition, we recommend that four algorithm versions be initialized by four different pseudorandom number generator states. The expected gain is a few percent, by which the route length is shortened, but it substantially reduces expenses for maritime cargo delivery.
Villages of Heterosexual Desires: Practices, Discourses, and Customer Demographics at Filipina Hostess Pubs in Postcolonial Singapore
Authors: James Kieran Edmond , Khrisnamurti Khrisnamurti , Walsh Rex John
Published: August 2023

This article explores the author’s observations, over the 2010-2019 period, at a sample of eight (8) Singapore hostess bars/pubs. The research method is participant-observation of practices, discourses, pricing models and customer demographics, backed up by knowledge gained from conversations with hostesses, bar managers, customers and musicians. It explains how surplus-value is extracted in the production process via the high prices of ladies’ drinks, the hard work required because of the quota system (in relation to ladies’ drinks), the high prices of customers’ drinks (to a lesser extent) and long working hours. The article explains how alienation is involved in delivering heavily racialized and gendered services in an atmosphere where commissions and quotas on ladies’ drinks put pressures and constraints on hostess’s behaviour. Unruly and disrespectful customer conduct is another source of alienation, guilt and sadness for hostesses who are under pressure to act and talk in a (hetero)sexualized way.
Designing Microfluidic PCR Chip Device Using CFD Software for the Detection of Malaria
Authors: Austria Meynard R. , Garcia Jon Patrick T. , Tayo Lemmuel L. , Caparanga Alvin R. , Doma Bonifacio Jr T.
Published: August 2023

Polymerase chain reaction (PCR) technique is one of the molecular methods in amplifying DNA for the detection of malaria. However, the limitations of PCR especially when used for routine clinical practice can hamper its sensitivity and specificity. With that, this study focuses on designing a microfluidic device that will mimic the function of a conventional genus-specific PCR based on 18S rRNA gene to detect malaria parasites (Plasmodium falciparum) at low grade parasitemia. The design was drawn and simulated using ANSYS 14.5 Computational Fluid Dynamics (CFD). The simulation shows that adding loops to the design increases its relative deviation but to a minimal extent as compared to having only a straight path design, which indicates that looping is acceptable in designing a microfluidic device to minimize chip length. Also, increasing the cross-sectional area of the fluid path decreases the efficiency of the design, thus, the design with a relatively smaller cross-sectional area is favored. And lastly, among the three materials utilized, the chip made of polypropylene is the most efficient with a relative deviation of 0.94 as compared to polycarbonate and polydimethylsiloxane which have relative deviations of 2.78 and 1.92, respectively.
Ceramic Grinding Kinetics of Fine Magnetite Ores in the Batch Ball Mill
Authors: Yuan Chengfang , Wu Caibin , Ling Li , Yao Xin , Li Zheyang , Xie Feng , Tian Jingkun
Published: August 2023

Aiming to reveal the kinetic characteristics of ceramic ball grinding of fine magnetite comprehensively, two types of ceramic balls ground with the same filling rate and total weight as steel balls were researched. The results show that the breakage rate of ceramic ball grinding is only half of that of steel ball grinding with the same media filling rate. With the same total media weight and the feed size less than 0.212 mm, the breakage rate of the ceramic ball grinding approaches the steel ball grinding and is 21.43% higher than that of the steel ball grinding. The main crushing form of magnetite changed from impact to abrasion in ceramic ball grinding compared with steel ball grinding, which significantly affected the value of the zero-order output constant a. Consequently, there is a noticeable difference in the variation of the parameter β related to the fines generation rate of the ceramic ball grinding compared with the steel ball grinding.
Shoulder and neck pain in swimmers: front crawl stroke analysis, correlation with the symptomatology in 61 masters athletes and short literature review.
Authors: Rinonapoli Giuseppe , Ceccarini Paolo , Manfreda Francesco , Talesa Giuseppe Rocco , Simonetti Simonetta , Caraffa Auro
Published: August 2023

Background: Swimming and, specifically, front crawl, can be included among the "overhead" sports. Overhead sports are a risk factor for some problems of the musculoskeletal system, especially the shoulder. The aim of the study was assessing the incidence of shoulder and neck pain in a Masters Swimming Team and its correlation with the crawl stroke.

Methods: It is an observational study through video-analysis of the stroke and a questionnaire. The participants are 61 athletes of a Master team, whose prevailing training stroke was the front crawl were selected for the present study. Their stroke was analyzed during training by a go-pro camera mounted on a sliding trolley on a track, evaluating with their trainer their technical defects. A questionnaire about frequency of shoulder and neck pain during the last five years was administered to all the participants at the study.

Results: From the questionnaire, 45 and 55 out of 61 athletes had suffered from shoulder pain and cervical pain, respectively. Both types of pain were correlated with the weekly swimming volume. The swimmers with hyperflexion of the wrist and prolonged internal rotation in the pulling phase had shoulder problems. Those who suffered from current shoulder pain reduced the underwater time. The four swimmers with an excessive body roll during breathing and those who kept their heads extended, reported cervical pain.

Conclusions: Shoulder and neck pain could be prevented with the correction of specific technical errors in crawl stroke.
Characteristics of Acoustic Emission due to Gas Leak in Circular Cylinder: Theoretical and Experimental Investigation
Authors: Kim Kwang Bok , Kim Jun-Hee , Jin Je-Eon , Kim Hae-Jin , Kim Chang-Il , Kim Bong Ki , Kang Jun-Gill
Published: August 2023

Acoustic emission (AE) is caused by the sudden release of energy by a material as a result of material degradation related to deformation, crack, or fault within a solid. The same situation also occurs in leaks caused by turbulence in the fluid around the leak. In this study, analytical modeling for AE due to leakage through a circular pinhole in a gas storage cylinder was performed. The displacement fields responsible for AE, excited by the concentrated force (CF) associated with the turbulent flow though the pinhole, were derived by solving the Navier-Lamé equation. The CF as an excitation source was formulated in terms of a fluctuating Reynolds stress (FRS) and spatial Green’s function. In particular, a series of experiments were conducted under different operating conditions to explore the characteristics of the AE signals due to leak in a gas cylinder. Finally, the simulation and experimental results were compared to verify the accuracy of the simulation results.
Efficient Two-Stage Max-Pooling Engines for an FPGA-based Convolutional Neural Network
Authors: Hong Eonpyo , Choi Kang-A , Joo And Jhihoon
Published: August 2023

This paper proposes two max-pooling engines, named the RTB-MAXP engine and the CMB-MAXP engine, with a scalable window size parameter for FPGA-based convolutional neural network (CNN) implementation. The max-pooling operation for the CNN can be decomposed into two stages, i.e., a horizontal axis max-pooling operation and a vertical axis max-pooling operation. These two one-dimensional max-pooling operations are performed by tracking the rank of the values within the window in the RTB-MAXP engine and cascading the maximum operations of the values in CMB-MAXP engine. Both the RBM-MAXP engine and the CMB-MAXP engine were implemented using VHSIC Hardware Description Language (VHDL) and verified by simulations. They have been employed for and tested in our CNN accelerator targeting at the CNN model YOLOv4-CSP-S-Leaky for object detection.
Pengaruh Pemberian Gel Ekstrak Kopi Robusta (Coffea canephora) Terhadap Gambaran Makroskopis dan Mikroskopis Luka Bakar Derajat IIB Pada Tikus Long Evans
Authors: Elfiah Ulfa , Rosanti Maidy Frista , Fatimatuzzahra Fatimatuzzahra , Hidayat Mochammad Amrun
Published: August 2023

Perawatan luka bakar memerlukan penanganan khusus. Penggunaan sediaan obat topikal seperti silver sulfadiazine serta hydrocolloids yang berfungsi sebagai absorptive dressings merupakan salah satu prosedur terapi yang digunakan untuk mempercepat penyembuhan luka. Perawatan kasus luka bakar di Indonesia masih kurang optimal karena adanya pembatasan biaya perawatan oleh sistem jaminan kesehatan Indonesia, oleh karena itu, perlu adanya alternatif perawatan luka bakar dengan mengembangkan bahan-bahan herbal sebagai dressing topikal seperti ekstrak dari kopi. Tujuan dari penelitian ini ialah untuk membuktikan pengaruh pemberian gel ekstrak kopi robusta (Coffea canephora) terhadap gambaran makroskopis dan mikroskopis luka bakar derajat IIB pada tikus long evans. Metode penelitian yang digunakan adalah true experimental laboratories dengan rancangan post-test only control group design. Tikus sebanyak 24 ekor terbagi menjadi 3 kelompok perlakuan. Kelompok kontrol negatif yaitu diberi basis gel, kelompok positif diberi silver sulfadiazine, dan kelompok perlakuan diberi gel ekstrak kopi robusta 2,5%. Data luas luka bakar, perubahan intensitas warna, dan ketebalan epitel luka bakar yang telah diperoleh selanjutnya diuji secara statistik menggunakan One Way ANOVA maupun Kruskal-Wallis dan dilanjutkan dengan uji Post-Hoc. Hasil penelitian menunjukkan pada kelompok perlakuan terjadi penurunan luas makroskopis (p < 0,05), perbaikan intensitas warna (p < 0,05), dan peningkatan ketebalan epitel (p < 0,05) antara gel ekstrak kopi robusta dibandingkan dengan kelompok kelompok negatif. Kesimpulan penelitian ini adalah bahwa gel ekstrak kopi robusta (Coffea canephora) terbukti memberikan pengaruh terhadap penyembuhan luka baik secara makroskopis maupun mikroskopis sehingga gel ekstrak kopi dapat terus dikembangkan menjadi salah satu alternatif dressing dalam perawatan luka bakar.
Moringa oleifera L. Sebagai Suplemen Untuk Anemia Defisiensi Besi: Systematic Review
Authors: Kandinata Yudi , Jayani Nikmatul Ikhrom Eka , Budipramana Krisyanti , Herawati Fauna
Published: August 2023

Daun dari tanaman Moringa oleifera L. (kelor) memiliki efektivitas yang baik terhadap peningkatan kadar hemoglobin yang berkaitan dengan anemia defisiensi besi (kadar serum Fe yang rendah, peningkatan Total Iron-Binding Capacity (TIBC) dan feritin yang rendah). Penelitian ini merupakan systematic review yang bertujuan untuk menganalisis secara sistematis terkait penggunaan daun kelor untuk anemia defisiensi besi. Pencarian artikel yang digunakan untuk menyusun kajian menggunakan database Pubmed, Science Direct, dan Google Scholar, artikel yang digunakan dengan beberapa desain studi diantaranya Quasi Experimental dan Randomized Controlled Trial (RCT). Kualitas artikel dinilai dengan Joanna Briggs Institute (JBI) checklist. Hasil penelitian menunjukkan bahwa terdapat 3 artikel Quasi Experimental dan 4 artikel RCT yang memenuhi kriteria inklusi. Pemberian daun kelor dalam bentuk serbuk atau ekstrak daun pada subjek anak berusia di bawah 2 tahun (332 subjek), wanita usia produktif (129 subjek), dan wanita hamil/ menyusui (70 subjek) menunjukkan peningkatan kadar hemoglobin dengan rentang 0,3-2,6 g/dl selama pemberian 2 minggu-6 bulan. Kesimpulan dari systematic review menunjukkan bahwa daun kelor dapat meningkatkan kadar Hb pasien anemia pada subjek bayi < 2 tahun, remaja wanita/ wanita usia produktif dan pada wanita hamil/ wanita yang sedang menyusui. Daun kelor berpotensi besar untuk dikembangkan sebagai suplemen pada anemia defisiensi besi.
Analisis Tingkat Pengetahuan, Sikap dan Perilaku Apoteker Terkait Penggunaan Telefarmasi: Studi Cross-Sectional
Authors: Ilma Dewi Latifatul , Mustikaningtias Ika , Salsabila Irhamna Yulia Nikma , Sholihat Nia Kurnia , Parmasari Damairia Hayu
Published: August 2023

Telefarmasi mulai mengalami peningkatan sejak pandemi coronavirus disease-19 (COVID-19). Apoteker menggunakan telefarmasi sebagai telekomunikasi dalam berbagai aspek pelayanan kefarmasian. Penggunaan telefarmasi oleh apoteker masih sangat terbatas, sehingga penelitian ini bertujuan untuk menganalisis pengetahuan, sikap, dan perilaku apoteker terkait penggunaan telefarmasi. Penelitian dilakukan menggunakan metode cross sectional dengan menyebarkan kuesioner kepada apoteker yang bekerja di Apotek wilayah Kabupaten Banyumas. Data dianalisis secara deskriptif untuk karakteristik responden, tingkat pengetahuan, sikap, dan perilaku terkait penggunaan telefarmasi. Analisis korelasi Spearman’s rank digunakan untuk melihat hubungan antara tingkat pengetahuan dengan sikap dan perilaku, serta sikap dengan perilaku. Apoteker yang menjadi responden pada penelitian ini sejumlah 78 apoteker. Hasil penelitian ini yaitu mayoritas apoteker yang berpraktik di apotek memiliki tingkat pengetahuan dan sikap yang baik (89,74%; 66,67%), serta perilaku yang cukup (46,15%) terkait penggunaan telefarmasi, sehingga terdapat hubungan yang signifikan antara pengetahuan dengan sikap terkait penggunaan telefarmasi (p=0,006) serta sikap dengan perilaku terkait penggunaan telefarmasi (p=0,002), tetapi tidak terdapat hubungan yang signifikan terkait pengetahuan dengan perilaku penggunaan telefarmasi (p=0,573). Hal ini menunjukkan bahwa pengetahuan apoteker yang baik, belum menjamin bahwa apoteker memiliki perilaku yang baik terkait penggunaan telefarmasi.
Mathematical Modeling of the Correction of the Shape of the Rotor of the Hydraulic Unit in a Three-Dimensional Setting
Authors: Makarov Pavlo
Published: August 2023

The presented work is devoted to the wedging of the rotor rim of the hydraulic unit to restore its geometry. To assess the technical condition of the rotor, measurements of its shape are performed beforehand. The shape of the rotor is decomposed into a Fourier series, and the location of its geometric axis and ellipticity are determined. Based on this, a decision is made about the need for work on the centering of the hydraulic unit. Then, the vibrations of the critical components of the hydraulic unit are measured at idle without excitation and with excitation, under load in generator and pump modes to assess the possibility of its further operation. At this stage, the reasons for the unsatisfactory vibration condition of the hydraulic unit are determined. At the last stage, the boundary conditions are determined and the problem statement is performed for performing a mechanical calculation in a three-dimensional setting to take into account expansions that compensate for mechanical deformations. The calculation itself is carried out and a decision is made to wedge the rotor rim of the hydraulic unit.
Peculiarities of the Calculations of the Gas Turbine Cooling Systems
Authors: Tarasov Alexsandr , Lytvynenko Oksana , Myhaylova Irina , Ismailov Vladyslav , Naumenko Svetlana
Published: August 2023

Gas turbine cooling systems have the branched networks of various channels whose hydraulic and heat exchange capabilities define the air flow required for the cooling of turbine parts and, thus, directly influence the efficiency of gas turbines. Cooling system elements are, in particular, the throttles, diaphragms, seals, openings that act as regulating parts or elements to maintain pressure in the system. As a rule, the channels of this type have a significant pressure drop, and therefore during the calculations it is necessary to very carefully consider a change in air density along the channel. Therefore, we present in this paper the method developed by the authors for determining the hydraulic resistance in the openings, and the data obtained by it perfectly agree with the experimental data. It is shown how to take into account the effect of the air compressibility on the coefficient of hydraulic resistance in the cooling channels that allows for the use of the numerous experimental dependencies for the coefficients of hydraulic resistance of incompressible liquids. A method of calculating hydraulic resistances of the openings by defragmenting their total hydraulic resistance into separate components has been proposed. A generalized dependence was established for the hydraulic resistance of the discharge openings in the discs and in the mounting gaps between the shanks of the blades and the discs, taking into account the transverse air flows.
Methodology for Determining the Tension of Banding Rings of Medium-Power Turbogenerators
Authors: Tretiak Oleksii , Kravchenko Stanislav , Bogozhavets Oleg , Nazarenko Viacheslav , Zhukov Anton
Published: August 2023

The presented work is devoted to the methodology of determining the tension of the banding rings by the method of calculating the stresses in the details of the banding assembly of the rotor. Taking into account the load from the action of centrifugal forces on the part of the copper coils, thermal loads and landing of the banding ring, the data for the calculation were determined. After that, the static calculation of the centering ring at rest, the static calculation of the centering ring at the nominal rotation frequency and the static calculation of the centering ring at the stolen rotation frequency were carried out. These calculations were performed for the first time in a three-dimensional setting using the method of mathematical modeling. The maximum stresses arising in the centering ring at rest and having a local character were determined. It was also determined that for all modes the stress did not exceed the permissible value.
Construction Materials of Active Zones of New Generation Nuclear Reactors
Authors: Yefimov Olexander , Pylypenko Mykola , Tiutiunyk Larysa , Harkusha Tetyana , Yesipenko Tetyana , Motovilnik Anastasiia
Published: August 2023

The materials of the article consider the analysis of construction materials of active zones of new generation nuclear reactors. The analysis reflects general ideas about the development of reactor technologies: in the 1950s and 1960s, the first generation of reactors was created; in the early 1970s, the operation of industrial reactors began - reactors of the second generation: pressurized water reactors (WWER, PWR), boiling water reactors (RBMK, BWR), heavy water reactors (CANDU), as well as gas-cooled reactors (AGR). Further development of some types of reactors made it possible to create reactors of the third generation in the 1980s. Priority when choosing directions of development in the category of revolutionary projects should have proposals capable of bringing a new quality to solving the problems of the nuclear energy industry of the future. Promising reactors have advantages in economy, safety, reliability and non-proliferation of nuclear materials. The effectiveness and reliability of structural materials are determined by the totality of changes in the characteristics of the materials as a result of the entire complex of phenomena occurring in them in the field of irradiation, in connection with the changing parameters and operating conditions. The use of high-purity metals as initial components of new structural materials and the development or optimization of their smelting technologies should ensure the required level of characteristics and properties of products made from them. The implementation of these concepts should be ensured by the development of new structural materials: ferritic-martensitic and austenitic steels, nickel and other new alloys.
Reducing the Harmful Impact of Boiler Plants on the Environment
Authors: Voinov Oleksandr , Elkin Yurii
Published: August 2023

World production makes an ever-increasing harmful impact on the natural environment. As a matter of fact, mankind is facing the problem of saving the natural environment. As for the production branches the energy industry has the strongest harmful effect, and as for the production facilities the boiler plants that emit heat and harmful substances into the environment are the most environmentally aggressive. The global fleet of boiler plants is huge and complicated. As the boiler plant wears out, the levels of its environmental, economic and general technical efficiency are increasingly decreased, and the intensity of the harmful impact on the environment is increased worsening progressively its condition. The self-healing process of the natural environment lags behind the process of harmful effects on it. As a matter of fact, the problem of reducing the harmful effects of boiler plants on the environment has arisen. The purpose of this study was to analyze the phenomenon of interaction between the energy sector, primarily boiler plants and the natural environment and search for the ways to resolve the existing contradictions of this interaction. The task of improving the environmental friendliness of worn-out power equipment and, above all, boiler plants is an urgent issue. The purpose of this research paper was to analyze the possibilities of solving the problem of ecological interaction of boiler plants with the natural environment through their partial, full or redundant renovations. This research is relevant, because the boiler plants of the domestic fleet are extremely worn out. Full or redundant renovation is highly resource intensive and appropriate resources are currently unavailable. A realistic way to solve the problem of reducing the harmful effects of boiler plants on the environment is to increase the environmental friendliness of worn-out boiler equipment by partially upgrading it using relatively simple and affordable methods, such as normalizing the boiler air mode, reducing heat losses with exhaust gases, rationalizing and implementing daily and weekly schedules of the boiler operation in order to extend the full load carrying mode. Successful implementation of the forthcoming program of partial renovation of worn-out boiler plants will ensure a significant reduction of their harmful impact on the environment.
A SYSTEMATIC LITERATURE REVIEW ON METODE ROLE PLAY DALAM MENINGKATKAN KETERAMPILAN BERBICARA ANAK SEKOLAH DASAR
Authors: Auliyati Yetty , Mardiani Chairina Putri , Wahyudiana Endang
Published: August 2023

Speaking skills in elementary school students must be mastered by students for the continuity of communication and social life of students. this study aims to: 1) identify the influence of elementary school students' speaking skills, 2) identify the effectiveness of the role playing method to improve elementary school students' speaking skills the effectiveness of the role playing method to improve elementary school students' speaking skills, 3) analyze publication trends (objectives, methods, and research results) in scientific journals in 2010 - 2022 related to improving speaking skills using the role playing method publication trends (objectives, methods, and research results) in scientific journals in 2010 - 2022 related to improving speaking skills using the role playing method. This journal uses a systematic literature review method with all articles that have been found and processed based on the criteria of inclusion, exclusion, quality assessment then found 11 articles that have been analyzed in accordance with the research questions that have been set. The results of the research are the effectiveness of using the role playing method in improving the speaking skills of elementary school students which has been widely discussed by previous studies including the influence from within students and the influence from outside students, the techniques used in the research in the period 2010 - 2022.

Abstrak

Keterampilan berbicara pada siswa sekolah dasar harus dikuasai oleh siswa untuk keberlangsungan komunikasi dan kehidupan sosial siswa. penelitian ini bertujuan untuk : 1) mengidentifikasi pengaruh kemampuan berbicara siswa sekolah dasar, 2) mengidentifikasi efektifitas metode role playing untuk meningkatkan keterampilan berbicara siswa sekolah dasar efektifitas metode role playing untuk meningkatkan keterampilan berbicara siswa sekolah dasar, 3) menganalisis kecenderungan publikasi (tujuan, metode, dan hasil penelitian) dalam  jurnal ilmiah tahun 2010 – 2022 berkaitan dengan meningkatkan kemampuan berbicara menggunakan metode role playing kecenderungan publikasi (tujuan, metode, dan hasil penelitian) dalam  jurnal ilmiah tahun 2010 – 2022 berkaitan dengan meningkatkan kemampuan berbicara menggunakan metode role playing. Jurnal ini menggunakan metode systematic literature review dengan seluruh artikel yang telah ditemukan dan diolah berdasarkan kriteria inklusi,eksklusi,quality assessment kemudian ditemukan 11 artikel yang telah dianalisis sesuai dengan pertanyaan penelitian yang telah ditetapkan. Hasil peneliian berupa efektifitas penggunaan metode role playing dalam meningkatkan keterampilan berbicara siswa sekolah dasar yang sudah banyak dibahas oleh penelitian terdahulu termasuk pengaruh dari dalam diri siswa maupun pengaruh dari luar diri siswa, teknik yang digunakan dalam penelitian dalam kurun tahun 2010 – 2022.
Анализ динамики эпидемического процесса COVID-19 в мире за неделю с 05.08.2023 г. по 11.08.2023 г.
Authors: Зимирова Анастасия , Поспелов Михаил , Иванова Александра , Дмитриева Людмила , Чумачкова Елена , Карнаухов Игорь , Щербакова Светлана , Кутырев Владимир
Published: August 2023

В обзоре представлен анализ эпидемиологической ситуации в странах мира по COVID-19 за неделю с 05.08.2023 г. по 11.08.2023 г.
Reduction of the Electrical Resistance of Grounding Devices by the Use of a Soil Replacement Mixture Based on Graphite and Hydrogel to Stabilize the Electrophysical Parameters of the Soil
Authors: Pavlovich I. A. , Baraishuk S. M.
Published: August 2023

This article discusses the factors that affect the electrical resistance of the current spreading of the grounding device. The issue of the electrophysical parameters of the soil that affect its resistivity and the consideration of such parameters in the design of grounding devices is considered. It is shown that keeping moisture in the near-electrode space of the grounding electrode, as well as maintaining it at a certain level, facilitates improving the quality and reliability of the grounding. A relationship has been established between the ability to retain moisture and the magnitude of seasonal fluctuations in the electrical resistance of the soixl, and also the season factor, which takes into account changes under different climatic environmental conditions. The issues of application of various methods of reducing the resistivity of the soil during mounting of grounding devices are considered. One of the main ways to reduce ground resistance is the use of solutions of various mineral salts. This method is not optimal, as it accelerates the corrosion processes in the materials of the ground electrodes. Therefore, the paper also considers other ways to reduce the resistance of the ground loop; in particular, the authors propose a method for reducing the resistance of a grounding device based on the method of partial replacing the soil in the near-electrode region with a mixture with a lower resistivity capable of collecting moisture based on graphite and hydrogel. This type of mixture is environmentally friendly when used, as well as it is non-aggressive to the material of the ground loop. The principle of operation of this mixture is based on the fact that the hydrogel makes it possible to stabilize the moisture at the site of laying the circuit, while graphite increases the overall conductivity of the mixture. The paper presents the results of laboratory studies, which have been carried out in accordance with GOST 9.602–2016. For this purpose, control samples were placed in containers made of a non-conductive material (plexiglas) and dependence of resistivity on moisture, temperature, specific content of graphite and hydrogel was measured. The article presents graphs of the dependences of the mixture specific resistance on moisture, temperature, and the quantitative content of the hydrogel. From the results obtained, it can be concluded that the mixture in can be used in the energy sector to improve the reliability of electrical installations and ensure electrical safety.
Introduction of an Auxiliary Breaker into the Generator-Transformer Block for Energy Saving in Open Switchgear Circuits of Power Plants
Authors: Barukin A. S. , Kletsel M. Ya. , Dinmukhanbetova A. Zh. , Amirbek D. A.
Published: August 2023

A need in finding of new ways of energy saving at open switchgears of power plants is substantiated. In order to increase energy saving efficiency, an auxiliary breaker is suggested to be inserted between a transformer of a block and its two high-voltage circuit breakers. The reasonability of such an insertion is proved on the basis of comparing of calculations resultsof under-discharge of electricity (UE) by the tabular-logical method (Yu. B. Guk) of the obtained schemes and of the traditional ones. For the calculations, the conditions that arose due to the change in the main circuit of a power plant are studied. Also, equations are given for calculation of a decrease in UE, damage due to it during reconstruction, and costs for the construction of a power plant (the costs are assumed to be the same in all options). Russian statistical data and the predicted failure rate λEV of a 750 kV SF6 circuit breaker are used. An option of the introduction of an SF6 circuit breaker with and without replacement of other circuit breakers with SF6 circuit breakers is considered. The results of calculations of UE, damage, and costs for the introduction suggested are tabulated, where changes in them due to the introduction of the circuit breaker are estimated for 18 ring circuits and 17 “3/2” and “4/3” circuits of 330–750 kV switchgears at condensation, nuclear, and hydroelectric power plants. It is demonstrated that the presence of a generator breaker in the blocks makes it possible to reduce these energy-saving efficiency indicators several times. A technique for determining the failure rate of a hypothetical circuit breaker, which, in the case of traditional replacement, is capable of producing the same effect as an SF6 circuit breaker inserted is proposed. An example of determining this frequency is given. Results of the calculated reduction of UE, damage and costs for the case of an air circuit breaker having been substituted to an SF6 circuit breaker are presented.
Application of the Surveillance Device in the Control System for an Electromechanical System with Distributed Parameters in its Mechanical Part
Authors: Korneev A. P. , Lenevsky G. S. , Niu Yitong
Published: August 2023

A system with distributed parameters in its mechanical part is considered. Examples of such a system are given. The reason for taking into account the distribution of parameters in such systems is indicated. Existing methods of research and calculation of control systems are considered. The boundary value problem for a system with distributed parameters is presented. The use of a surveillance device as one of the ways to implement a control system for a system with distributed parameters is proposed. The necessity of using a closed control system and the complexity of its implementation are demonstrated. A block diagram of the control method being developed is presented. Also, transfer functions describing a system with distributed parameters are given; the mathematical calculation of the surveillance device is given as well. A method for implementing a closed control system along an intermediate coordinate for an electromechanical system with distributed parameters in the mechanical part using a surveillance device has been obtained. The surveillance device is in feedback and restores the output speed without measuring it directly. A general view of the transfer function is determined for the surveillance device. The advantages and disadvantages of the transfer function of the surveillance device and a graphical view of a simple implementation of the surveillance device with a dedicated auxiliary device in feedback are presented. An approximation that is used for systems with distributed parameters is described. Approximation conclusions are obtained. According to the parameters of the experimental installation, approximated transfer functions of the mechanical part of the system with distributed parameters without a surveillance device and with a surveillance device are obtained. The LACH of the mechanical part of the system with distributed parameters with a surveillance device and without a surveillance device for an experimental installation for the simplest case is presented, as well as a method for implementing a closed control system along an intermediate coordinate for an electromechanical system with distributed parameters in the mechanical part using a surveillance device.
Analysis of the Efficiency of Hydrogen Production Technology at Mini-CHP Plants Using Local Fuelsby Thermochemical Method
Authors: Sednin V. A. , Ignatovich R. S.
Published: August 2023

Within the framework of the policy of “decarbonization” of the economy, a technology for hydrogen producing from local fuels (LF) and combustible waste of human activity is proposed as a part of the development of the functionality of heating cycles of energy production. The aim of the present study is to evaluate the energy efficiency of a steam-powered mini-CHP plant operating on local fuels with a thermochemical hydrogen production module. A brief literature review of thermochemical cycles of hydrogen production is presented, and it is shown that hybrid copper-chlorine Cu–Cl cycles are recognized as the most promising. In the Aspen Hysys software environment, a mathematical model of a mini-CHP plant with a five-stage hydrogen production cycle was synthesized, which can later be used as a component in the digital twin. According to the results of the analysis of the mathematical model, it was determined that the specific consumption of electric energy per 1 kg of hydrogen for such a scheme will be 9.11 (kW×h)/kg, which is on average more than five times less than in the production of hydrogen by electrolysis, the rest of the required energy is replaced by thermal one, while the maximum fuel utilization factor of mini-CHP with a hydrogen production module using wood waste as fuel amounted to 83.1 %, including a thermal efficiency of 51.5 %, the efficiency of hydrogen production at the lowest calorific value is 31 %, the electrical efficiency for the supply of electricity to the grid is 0.6 %. For comparison, the maximum fuel utilization of a steam-powered mini-CHP of the same electrical capacity reaches 90.9 %. The expansion of mini-CHP options operating on local fuels by introducing a hydrogen production unit by hybrid thermochemical method into its scheme makes it possible to increase the maneuverability of the station, which implies the possibility of organizing the operation of mini-CHP in accordance with the requirements of thermal consumers and electrical graph-reducing the loads of the power system during the hours of maxima and minima of its consumption by changing the electrical power supply to the network or increasing the power consumption of electricity from the external network to the power required for hydrogen production. In conclusion, the possibility of developing the studied scheme of a mini-CHP operating on local fuels towards further utilization of combustion products in order to generate artificial natural gas, which in this case can be called “green”, is indicated.
Feasibility Study of Polygeneration Turbine Plants Based on Carbon Dioxide
Authors: Ovsyannik A. V. , Kliuchinski V. P.
Published: August 2023

Schemes of polygeneration plants based on carbon dioxide are presented, in which the energy source are secondary energy resources and a gas turbine plant. These polygeneration schemes make it possible to simultaneously produce electricity, heat, cold, carbon dioxide in liquid and gaseous aggregate state, as well as to dispose of part of the carbon dioxide emitted into the atmosphere, due to its absorption from combustion products and use for commercial and technological purposes. The structure of the mathematical model of the program that has been developed for the exergetic analysis of polygeneration schemes is presented. With the help of the program, an exergetic analysis of polygeneration schemes was performed, in which polygeneration turbine units with different parameters of carbon dioxide in front of the turbine, as well as single and double overheating of carbon dioxide were compared. The exergetic electrical efficiency of polygeneration plants as a whole and its individual elements were taken as the criteria to be compared. Polygeneration plants with double overheating and supercritical parameters of carbon dioxide in front of the turbine have the greatest efficiency. A method for calculating of the economic indicators of polygeneration schemes is presented, which makes it possible to take into account the influence of double overheating and carbon dioxide parameters in the cost of a polygeneration plant. The economic efficiency indicators of various versions of polygeneration schemes, such as the internal rate of return, net discounted income, static and dynamic payback periods are obtained. It has been established that all variants of polygeneration schemes have acceptable indicators of economic efficiency, the static payback period of the proposed polygeneration schemes does not exceed 5 years, while the internal rate of return does not decrease by less than 22,8%.
Evaluation of mechanical properties of glued elements for model kits
Authors: Kalinichenko M. L. , Nemenenok B. M. , Grigorchik A. N.
Published: August 2023

The work is devoted to assessing the quality of fastening the abrasive component to the metal base by gluing on the example of a clutch disc. An assessment of the operability of the patented technique for testing for conditional shear of glued joints is given. The paper proposes a method of using foamed materials to create one‑time or single model kits for the production of missing parts for mechanical engineering.
Study of the influence of the composition of saturating mixtures with standard zinc powder and zinc dust on changes in the sizes and mass of steel specimens during their thermal diffusion zinc coating
Authors: Urbanovich N. I. , Baranovsky K. E. , Bendik T. I. , Ashuyko V. A. , Matys V. G.
Published: August 2023

The influence of the composition of saturating mixtures with standard zinc powder and zinc dust on the change in the size and weight of the samples was studied under laboratory conditions. It is shown that with an increase in the amount of the zinc component in the composition of the saturating mixture in the form of zinc powder (Znst) or hot‑dip galvanizing waste‑zinc dust (Znotx), the thickness of the galvanized product also increases. The obtained graphic dependences of the growth of the thickness of the samples on the amount of zinc components have the same pattern of change. It is also shown that with an increase in the zinc component in the composition of the saturating mixture in the form of zinc powder (Znst) or hot‑dip galvanizing waste – zinc dust (Znotx), the mass of the galvanized product also increases. The graphic dependences of the growth of their mass on the amount of different zinc components also have the same character of change.

It has been established that the most intensive character of the growth in the values of the size and mass of the product is observed when the content of the zinc‑containing component in the mixture is more than 60 % for both saturating media, whether in the Znst‑Al2O3 or Znout‑Al2O3 medium. At the same time, products galvanized in a saturating Znst‑Al2O3 medium have large dimensions and masses.
Study of changes in the structure of zirconium alloy E125 after deformation by radial shear rolling
Authors: Magzhanov M. K. , Naizabekov A. B. , Kavalek A. A. , Panin E. A. , Arbuz A. S.
Published: August 2023

The rheological properties of the alloy E125 (Zr‑2.5 %Nb) were studied in the range of deformation rates 0.5–15 s‑1 and the temperature range 20–770 °C. A database for computer FEM modeling was created in the specified temperature and speed ranges. In the DEFORM‑3D software package, numerical simulation of a complex radial shear rolling process was carried out using the obtained database. The conditions conducive to the grinding of the alloy structure into an ultrafine‑grained state were determined. Based on the simulation results, a full‑scale experiment of rolling a bar made of alloy E125 on a radial shear rolling mill RSP‑14/40 in 7 passes from a diameter of 37 mm to 20 mm with a total compression in diameter of ε = 85 % was carried out. At the same time, according to the modeling, the total accumulated deformation in the most developed peripheral zone was 27,5 mm/mm. Due to the complex vortex flow of the metal, the distribution of accumulated deformation over the cross section was uneven with a gradient to the axial zone. This should also affect the change in the structure. The changes and the gradient of the structure were studied by the method of EBSD mapping of the sample section with a resolution of 2 mm. The microhardness gradient of the cross section was also investigated by the HV method. The axial and central zones of the sample were studied on the. The structure has a pronounced gradient from the formed equiaxed ultrafine‑grained (UMZ) structure on several outer millimeters of the peripheral section to an elongated rolling texture in the center of the rod. The work shows the possibility of processing with the formation of a gradient structure with enhanced properties for the E125 alloy, and also presents a database for FEM calculations.
The impact of factors of the production environment on workers in the foundry
Authors: Lazarenkov A. M. , Ivanov I. A. , Sadokha M. A.
Published: August 2023

The production factors of working conditions at the workplaces of foundry workers are considered, the actual values of the parameters under consideration and their impact on the body of workers are given. The most common among foundry workers are diseases from exposure to dust (silicosis and dust bronchitis), vibration (vibration disease), and noise (sensor neural hearing loss). When assessing the working conditions of workers in foundries, it is necessary to take into account the impact of a complex of factors of the production environment, the technological processes and equipment used, the duration of stay working in the zone of factors.