bluuebunny/crossref_metadata_2025 huggingface dataset:
Social and Economic Impact of Rural Out Migration on Agriculture of Roshi Rural Municipality of Kavrepalanchok
Authors: Neupane Bidhya , Poudel Amir
Published: November 2024

Rural out-migration is a major challenge being faced in Nepal, particularly in the agricultural sector. This study investigated the social and economic impacts of rural out-migration on agriculture in Roshi Rural Municipality (RM), a rural region in the Kavrepalanchok district. The study used a snowball sampling method to collect both qualitative and quantitative data from 60 households, 30 of which had no migration within the past year and 30 of which had at least one migrant. The results showed that households with no migration had higher agricultural income than households with migration. However, there was no significant difference in agricultural expenditure between the two groups. The study also found that rural out-migration had a number of social and environmental impacts. These included increased labour shortages, rising wages, increased empowerment of Tamang households, increased burden of agricultural responsibilities on left-behind family members, increased fallow land, and increased monkey attacks. To cope with these impacts, farmers have started to introduce mechanization, use herbicides, and consider cash crop farming. The findings of this study demonstrate the push factors that are causing rural out-migration in Roshi RM. The study also provides insights for policymakers, future researchers, and development practitioners.
Assessing ICT Competence among Secondary-Level Teachers in Kathmandu Valley
Authors: Simkhada Anusha , Gelal Arpan
Published: November 2024

This study investigates the state of ICT integration in Kathmandu's school education system, particularly the ICT competency of secondary-level teachers. The research employed a quantitative methodology utilizing a close-ended questionnaire with 41 teachers from four community schools. The collected data was analyzed using  t-tests and ANOVA through SPSS. Additionally, the qualitative insights from the interview complemented the research. The findings of the study reveal a moderate proficiency in ICT competency among secondary-level teachers, with the low competence observed in ICT knowledge and practice. This suggests that while teachers possess some basic ICT skills, they may not fully utilize ICT's potential in their teaching practices. Further, statistically significant relationship between age and ICT competency, with lower proficiency among older teachers, highlights a potential need for targeted training programs to address the skills gap. Regarding the qualitative aspects of ICT integration, a persistent reliance on traditional teaching methods despite the acknowledgment of ICT's potential was prevalent, particularly among the old teachers. This disconnect between awareness and implementation underscores the need for deeper pedagogical integration of ICT into the curriculum and teaching practices. Additionally, the research identifies gaps in policy and uneven training in ICT integration across schools, emphasizing the need for a more systematic and standardized approach to ICT adoption. Overall, the study provides valuable insights into the current state of ICT integration in the secondary education system in Kathmandu Valley and highlights the challenges and opportunities for enhancing ICT competency among secondary-level teachers. The findings offer practical recommendations for policymakers, school management, and individual teachers to promote effective ICT integration and elevate the quality of school education in Kathmandu
How Intense and Authentic Communication in Foreign Language Classes Has a Positive Effect on Learner Emotions
Authors: Dewaele Jean-Marc , Guedat-Bittighoffer Delphine , Botes Elouise , Dat Marie-Ange
Published: November 2024

This cross-sectional mixed methods study investigates how intense and authentic communication shapes learners’ enjoyment (FLE), anxiety (FLCA), and boredom (FLCB) in class. Participants were 181 beginning English foreign language learners aged 11 in three secondary schools in France. Statistical analyses revealed that pupils in classes with a special focus on intense and authentic communication experienced significantly more FLE and less FLCA and FLCB than their peers in standard classes. Structural equation modelling revealed that intense and authentic communication had the strongest (positive) effect on FLE, followed by negative effects on FLCB and FLCA. FLE was found to be negatively correlated with FLCA and FLCB, while FLCA and FLCB were positively correlated. An axiological analysis of the qualitative data showed that pupils in intense, authentic communication classes reported more FLE, less FLCB, and equal FLCA compared with peers in the standard teaching classes. Pedagogical implications are presented.
Understanding the Well-Being Literacy of EFL Learners: Towards a Framework of Learners’ Knowledge and Skills
Authors: Smid Dávid , Mercer Sarah , Murillo-Miranda Carlos , Baum Miri Tashma
Published: November 2024

Well-being has been recognized as a basic human right, a core determinant of success in education, and a skill that can be developed. In language education, the literature suggests that higher well-being is likely to lead to more classroom engagement and ultimately greater success for learners. For English language teachers, there is a need to understand what learners know about well-being, what kinds of support they feel they need, and how best to integrate such support into regular language teaching practice. This paper reports on a qualitative study using focus group data that set out to understand the well-being literacy of a group of 42 Austrian learners of English as a foreign language (EFL) in their final year of school. The findings reveal five categories in which learners demonstrated knowledge of well-being: conceptual understanding of well-being, factors impacting well-being, coping strategies, the role of systemic factors, and issues in the English language teaching context specifically. Based on analysis of these data, we present an initial practical framework for evaluating and guiding EFL student well-being literacy development.
How Can Drama Tasks Interact with Second Language Learners’ Willingness to Communicate? A Theoretical Perspective
Authors: Hameau Florian
Published: November 2024

If oral communication in a second language (L2) is considered a skill to be prioritized, it is also particularly anxiety-provoking for L2 learners. This is why their willingness to communicate, predicted in particular by the emotions experienced, has been the focus of recent studies to examine its evolution and factors likely to interact with it. However, little research has focused on how pedagogical tasks could support L2 learners’ willingness to communicate by creating a constructive and positive learning environment. This article focuses on drama as a pedagogical task that could potentially support L2 learners’ willingness to communicate. It thus aims to develop a theoretical framework to demonstrate how drama can help learners overcome barriers to L2 communication by interacting with situated affective factors, motivational propensities, affective and cognitive context, and social and individual context. This demonstration is particularly relevant for making more explicit the potential of experiential tasks in L2 learning to provide more positive and constructive learning experiences. We conclude this paper by emphasizing pedagogical implications to support L2 learners better and promote more research into drama.
Mnenie pervokursnikov meditsinskogo vuza o nekotorykh aspektakh uchebnogo protsessa
Authors: Sudakov Dmitrii Valerievich , Sudakov Oleg Valerievich , Gordeeva Olga Igorevna
Published: November 2024

The chapter is devoted to the study of some aspects of the educational process in a medical university, according to first-year students, which ultimately became the goal of the work. This topic is very relevant in view of the fact that, despite the fact that many authors conduct similar studies, they rarely directly affect first-year students who have just entered the university, analyzing their first impressions. This work can become a definite step in a long-term study for many years, with the study of the dynamics of the thoughts and opinions of the students included in the study. At the same time, the work is given additional relevance by the fact that the opinions of students of different forms of tuition payment were studied. Thus, 200 students of the first year of the medical faculty, divided into 2 groups of 100 people, served as the objects of the study: the 1st group included students studying in the budget and targeted form of education; the 2nd group included students studying on a commercial basis. The basis of the study was a questionnaire specially developed by the authors, containing a number of questions concerning some aspects of admission to a university and, in particular, the choice of a university, the first opinion and general impression of the educational process were studied, the main positive and negative points were analyzed. The obtained data are of interest not only for teachers of the higher medical school, but also for all those teachers who are engaged in the educational process with first-year students.
Tekhnologii sozdaniia i psikhologo-pedagogicheskogo soprovozhdeniia subektivnogo blagopoluchiia shkol'nogo soobshchestva v usloviiakh intensivnykh informatsionnykh potokov spetsial'no smodelirovannoi tsifrovoi obrazovatel'noi sredy
Authors: Khomova Natalia Aleksandrovna , Sannikova Svetlana Vladimirovna , Frolova Natalia Khaidarovna
Published: November 2024

The modern education system contributes to the creation of a special educational environment, a specially modeled place and conditions conducive to determining the optimal trajectory of personal development and maturation. Today's schools are free to choose the means and forms, directions and approaches of development, the school has become client-oriented: the school is a resource center, with its own strategy, subject-based learning from the first grade, the development and implementation of author's programs, etc. The introduction of Federal State Educational Standards of the third generation actualizes the importance of scientific rethinking of approaches to modeling the educational environment in the process of learning and socialization. The article presents the results of studying the psychological well-being of the school community. Technologies have been analyzed and developed to create a favorable psychological climate. The basic principle of these technologies is defined – the constant reflection of participants and the development of their interaction, which allows members of the educational community to realize how their actions are perceived by others and what consequences they may have. An important aspect is the construction of elements of interaction between participants in the educational process, including the use of the digital educational environment as an effective way of virtual communication. The key role in this context is played by the psychological factor and «Digital hygiene», which sets a radically new trend in safe work with information and digital assets in conditions of mega-intensive information flows.
Temperament, skorost' fiziologicheskikh protsessov i professional'noe samoopredelenie starsheklassnikov
Authors: Kogut Anna Aleksandrovna , Pilipenko Aleksandra Romanovna
Published: November 2024

This chapter examines the relationship between the predominant type of temperament of high school students and the choice of their educational profile and their professional preferences. Using the methods of E. P. Ilyin and Ya. Strelyau, the characteristics of the nervous system and the predominant type of temperament of eleventh-grade students of the Murmansk Polytechnic Lyceum of three different educational profiles are determined. The results of diagnostics and conclusions of the study are described.
Comparison of the Radiation Protection Effectiveness between Lead and Antimony-Tungsten Bed Skirt in Fluoroscopic-guided Simulated Urological Surgery
Authors: Prasanchaimontri Phornphen , Sudchai Waraporn , Sangondee Peerawan
Published: November 2024

Objective: This study aimed to develop a new shielding device, a bed skirt, and compare the radiation protection effectiveness between lead and antimony-tungsten (Sb-W) bed skirts in fluoroscopic-guided urological surgery. Material and Methods: The simulated surgery of ureteroscopy (URS) and percutaneous nephrolithotomy (PCNL), using the phantoms, was set. The lead and Sb-W skirts were mounted around the operating table. The fluoroscopy time was 120 seconds, and the experiment was repeated 10 times. The radiation dose to the body parts of the patient, surgeon, and anesthesiologist was measured with optically stimulated luminescent dosimeters and compared in the following conditions: conventional operating table, Sb-W bed skirt, and lead bed skirt.Results: By installing a bed skirt, the radiation dose was decreased, with lead being dominant in all areas. The lead bed skirt reduced the radiation dose by 20% to the patient, 66% to the surgeon, and 91% to the anesthesiologist. The absorbed radiation dose of the lead bed skirt was lower than the Sb-W bed skirt in URS settings (23.3±1.8 µGy vs 32.0±1.9 µGy, p-value<0.001) as well as PCNL settings (257.2±15.6 µGy vs 296.5±24.6 µGy, p-value<0.001). There was no statistically significant difference between the conventional operating table and the Sb-W bed skirt in both URS settings (p-value=0.066) and PCNL settings (p-value=0.153).Conclusion: The lead bed skirt significantly reduced the radiation exposure and provided superior radiation protection compared with the Sb-W bed skirt. This shielding technique is practical to minimize the harmful effects of radiation from fluoroscopy.
Tinjauan Literatur: Kinerja Turbin Screw Archimedes Pembangkit Listrik Tenaga Pikohidro (PLTPH) Pada Aliran Air Dengan Head Rendah
Authors: Atifoqkymin Bambang
Published: November 2024

Pembangkit Listrik Tenaga Pikohidro (PLTPH) dengan turbin screw archimedes menawarkan solusi potensial untuk pemanfaatan energi terbarukan pada aliran air dengan head rendah di Indonesia. Penelitian ini bertujuan mengkaji kinerja turbin screw archimedes untuk aplikasi PLTPH, dengan fokus pada karakteristik desain, integrasi sistem, dan analisis kelayakan ekonomi. Metode yang digunakan adalah studi literatur komprehensif dan analisis data sekunder untuk meninjau terkait parameter-parameter yang mempengaruhi kinerja turbin. Hasil yang didapatkan bahwa turbin screw archimedes dapat beroperasi efektif pada head 1-10 meter dengan efisiensi mencapai 70-85%. Turbin dapat bekerja dengan optimal pada desain dengan parameter jumlah 5 – 9 sudu, sudut kemiringan turbin 28o – 35o, ratio pitch to diameter 1,2 – 1,5, debit air 3,5 – 4,5 L/s, head efektif 3 – 5 meter, penambahan gearbox efisiensi naik hingga 20%, penambahan kontrol elektronik efisiensi naik hingga 2% – 3%.
Rekayasa Mesin Pembersih Sisik Ikan Untuk Meningkatkan Produktivitas Dan Kebersihan Pada Proses Pengolahan Hasil Perikanan
Authors: Khalid Anhar , Norhafani Norhafani
Published: November 2024

Salah satu pemanfaatan umum sumber daya laut oleh masyarakat adalah melalui penangkapan ikan, yang menjadi sumber mata pencaharian utama bagi nelayan dan pedagang ikan. Setelah penangkapan, ikan perlu diolah dengan membersihkan sisik dan membuangisiperutnya.Prosesinibiasanyamemakanwaktusekitar2-3menitperikan, sehinggatidakefisien dankurang optimalbagipedagangikan,terutamaketikajumlah ikan yang harus diproses cukup besar, yang dapat menyebabkan pembeli harus menunggu cukup lama. Berdasarkan latar belakang tersebut, penulis akan melakukan penelitiandenganmerekayasasebuahmesinsebagaisaranapenerapanteknologibagi masyarakat dan kontribusi terhadap pengembangan ilmu pengetahuan dan teknologi di bidang pendidikan. Penelitian ini bertujuan mengembangkan sebuah mesin yang dirancang khusus untuk membersihkan sisik ikan secara otomatis, dengan harapan dapat meningkatkan produktivitas dan kebersihan dalam proses pengolahan hasil perikanan,sertamemberikankemudahanbagiUMKMdalammengolahhasilperikanan melalui mekanisasi. Penelitian ini dilakukan dengan metode analisis, perancangan, pengembangan, implementasi, dan evaluasi pada akhir kegiatan. Alat ini mampu membantupekerjaanyangsebelumnyamembutuhkanwaktuyanglamamenjadilebih singkat, sehingga tentu saja menjadikan pekerjaan membersihkan menjadi lebih efektif, efisien dan higienis dalam proses pengelolaan hasil perikanan.
Long-term variations in the diet composition of Atlantic wolffish, Anarhichas lupus marisalbi (Zoarcoidei: Anarhichadidae), in Kandalaksha Bay, White Sea
Authors: Yershov P.N. , Khaitov V.M.
Published: November 2024

Understanding the diet variability of the White Sea wolffish, Anarhichas lupus marisalbi Barsukov, 1956, is essential for explaining its population dynamics and variations in its life cycle. This study examined the food spectrum of wolffish from the coastal waters of Chupa Inlet (Kandalaksha Bay, White Sea) and analyzed interannual and seasonal changes in the species composition of its diet. During the summer period, wolffish feeds on a variety of macrobenthic organisms in its feeding grounds, particularly molluscs, echinoderms, crustaceans, and ascidians. The diet was predominantly composed of bivalves and gastropods, with Buccinum undatum Linnaeus, 1758 and Serripes groenlandicus (Mohr, 1786) being the most important prey species. Statistical analysis of multi-year diet data from 2001 to 2023 revealed interannual variations in the frequency of occurrence of key food organisms in wolffish stomachs. The results showed that in the early 2000s, the role of epibenthic crustaceans Hyas araneus (Linnaeus, 1758) and Pagurus pubescens Krøyer, 1838 in the wolffish diet was significantly greater compared to other years of the study. The dietary importance of the bivalve S. groenlandicus increased gradually and statistically significantly during the observation period, while Buccinum undatum dominated the wolffish diet throughout the entire study period. Overall, three species (B. undatum, S. groenlandicus, and Mytilus edulis Linnaeus, 1758) accounted for a significant portion of the wolffish diet during 2001–2023. In some years, other mollusc species, as well as crustaceans and the ascidian Styela rustica Linnaeus, 1767, were also included in the group of important prey items. The feeding intensity of wolffish in Chupa Inlet showed interannual variability. Throughout the observation period, certain years were identified as having the greatest frequency of fish with empty stomachs. Female wolffish showed a seasonal pattern in the frequency of occurrence of individuals with empty stomachs: the highest occurrence of such fish was observed during the spawning period of wolffish, in late July to early August. No significant seasonal changes in the frequency of occurrence of individuals with empty stomachs were found in males.
Розвиток творчого самовираження дітей дошкільного віку засобами альтернативних прийомів малювання
Authors: Тодосієнко Наталія , Андрійців Орест
Published: November 2024

The article reveals the pedagogical potential of visual arts as a means of creative self-expression of preschool children. The directions of the formation of aesthetic culture in the education of preschoolers, which is important in the modern educational environment, are considered; «concepts of self-expression», «creative self-expression», «personal self-expression»; the connection between the desire for recognition, self-realization of the individual and self-expression. The use of non-traditional drawing methods for the development of creative abilities of preschoolers and its impact on the general development of preschool children, which is an important part of the educational process, is substantiated; the use of art, in particular fine art, plays an important role, reflects and summarizes the emotional attitude to life in a figurative and colorful form, reveals the psychological and pedagogical foundations of the formation of the aesthetic attitude of children to art during creative activity. Methodological recommendations for the organization of the process of aesthetic education and artistic space in the preschool education institution are presented; the mechanism of using the experience of artistic and creative activities of preschool children in the process of using non-traditional techniques and alternative methods of drawing is revealed. A study of the use of non-traditional drawing techniques as a means of activating the creative self-expression of older preschool children was conducted. Peculiarities of preschool children – the first stage of real personality formation, culture formation, the ability to verbalize their life experiences and express valuable attitudes towards others, as well as the development of the ability to creatively perceive the surrounding world, as well as the tendency to self-expression that manifests itself at an early age due to the desire to freedom of movement and creative efforts. The results of the positive dynamics of the use of non-traditional drawing methods for the development of creative abilities of preschoolers are considered; artistic activity aimed at forming moral and aesthetic qualities and the foundations of artistic culture in children; owning certain artistic means of expression and using them to express one's feelings, outlook and creative ideas; providing education and learning through art. The organization of creative and developmental work with children for the purpose of forming self-expression, which consists in activating participation in various types and forms of artistic and creative activities, such as musical, artistic and speech, visual, pictorial, decorative and applied, and theatrical, is highlighted.
Transvenous embolization with detachable coils for a hypoglossal canal dural arteriovenous fistula: illustrative case
Authors: Hagstrom Rory , Raz Eytan , Chung Charlotte , Save Akshay V. , Khawaja Ayaz M. , Ponchione Elizabeth , Frome Spencer , Sharashidze Vera , Baranoski Jacob , Rutledge Caleb W. , Nossek Erez , Shapiro Maksim , Nelson Peter K. , Riina Howard A.
Published: November 2024

BACKGROUND

Hypoglossal canal dural arteriovenous fistulas (HCDAVFs) are a relatively rare subtype of dural arteriovenous fistula (dAVF), representing 3%–5% of all dAVFs. The complex angio- and venous architecture predisposed to numerous anastomoses and nearby anatomical structures, including the posterior fossa sinuses and cranial nerves, can complicate both the diagnosis and treatment of these lesions.

OBSERVATIONS

The authors describe the case of HCDAVF in a 74-year-old male who presented with pulsatile tinnitus (PT) lasting 3 months and significant fatigue, headaches, and dizziness. Diagnostic cerebral angiography demonstrated a left-sided HCDAVF with bilateral supply from the ascending pharyngeal arteries and fistulous connection at the level of the left anterior condylar vein (ACV). This lesion was consistent with a Cognard and Borden type I dAVF.

LESSONS

The authors present a case in which transvenous embolization (TVE) with detachable coils via the ipsilateral internal jugular vein successfully occluded the previously visualized shunt to the left ACV and provided a clinical cure for the patient’s PT and headaches without complication. Selecting the appropriate treatment strategy for the successful treatment of HCDAVFs is predicated on a comprehensive understanding of the anatomical features of the lesion, namely arterial feeders, venous drainage pattern, and location of the fistulous connection. TVE is a safe and efficacious treatment option for HCDAVFs.

https://thejns.org/doi/10.3171/CASE24606
Administrative Law and International Law. An Attempt at Systematics
Authors: Tyrawa Dominik
Published: November 2024

ternational law. These interdependencies have their source in the constitutional systematics. Moreover, the idea of the source of law binds these two concepts. Additionally, the international law is able to inspire and generate the administrative law, whereas the administrative law can inspire and generate the international law. The considerations are based on diversified views of Polish science of international, constitutional and administrative laws, as well as on attitudes presented in worldwide studies.
CHARACTERIZATION OF GEOPOLYMER CONCRETE MADE FROM PEJATEN ROOF TILE WASTE AS PRECURSOR
Authors: Supriyadi A. Siagian, , Suradharmika I. G. A. , T. Nugroho  , Amal M. I. , Subari  , Sundari K. N. , B. Prajoko  , Kristyawan I. P. A.
Published: November 2024

This research focused on fabricating geopolymers using roof tile waste from the Pejaten area, which has high alumina (Al2O3) and silica (SiO2) content. Binder-to-aggregate ratios of 35:65, 40:60, and 45:55 were tested to examine their effects on structural and mechanical properties. The characterization revealed that the geopolymers had water absorption capacities and compressive strengths of 12.59% and 12.43 MPa, 15.36% and 10.99 MPa, and 18.43% and 6.21 MPa, respectively. Results indicated that increasing the binder ratio raises water absorption capacity but lowers compressive strength. Augite, the main mineral in ferro-sialate type geopolymer, increased from 0% in the precursor to 24% in the binder. Recycling roof tile waste is currently limited and requires optimization. XRD tests confirmed that the Pejaten roof tile waste's high alumina and silica content meets geopolymer precursor requirements. Consequently, geopolymers were made with binder-to-aggregate ratios of 35:65, 40:60, and 45:55. The tests showed that the 35:65 ratio had a water absorption rate of 12.59% and compressive strength of 12.43 MPa; the 40:60 ratio had a water absorption capacity of 15.36% and compressive strength of 10.99 MPa; and the 45:55 ratio had a water absorption capacity of 18.42% and compressive strength of 6.21 MPa. The main mineral in the geopolymer concrete specimens was augite, which grew from 0% in the precursor to 24% in the binder. The findings suggest that higher binder ratios result in higher water absorption capacities and lower compressive strengths.
INNOVATIVE CHARACTERIZATION OF CURCUMIN NANOPARTICLES AS ADVANCED PHYTOPHARMACEUTICALS
Authors: Sodik J. J. , Dinata D. I. , G. Jafar  , Fakih T. M. , Putranto M. F. , F. Syarifuddin  , S. Wijayanti
Published: November 2024

Curcumin provides numerous advantages, including its antioxidant, antibacterial, anticancer, and anti-inflammatory properties. Despite these advantages, its ability to be absorbed by the body is limited. One effective method to improve curcumin's absorption is by developing curcumin nanoparticles. These nano-sized particles have several advantages over larger particles, notably a larger surface area that enhances absorption and improves penetration into cells. The nanoparticles produced will undergo analysis to determine their formulation characteristics by using particle size analysis (PSA) instruments to evaluate parameters such as particle dimensions, polydispersity index (PDI), and zeta potential. Morphology will also be examined using Fourier Transform Infrared Spectroscopy (FTIR) and Transmission Electron Microscopy (TEM). TEM results indicate that curcumin nanoparticles are smaller than 100 nm. FTIR analysis of nano-curcumin reveals the presence of functional groups typical of curcumin (C=O and O-H).
Genetic species concept as applied to multilocus nuclear data
Authors: Lebedev V. S. , Kosushkin S. A. , Bannikova A. A.
Published: November 2024

Using the example of multiple species groups and species complexes, it is empirically shown that the resolving power of a set of 10–20 nuclear loci is insufficient for the study of their genetic differentiation. For the adequate analysis of phylogenetic relationships (including reticulation events) and assessment of divergence levels within such groups of closely related species, it is necessary to multiply the number of nuclear loci and transit to high-throughput next-generation deep sequencing. However, the question of the genomic coverage required for the purposes of such study remains open. In other words, exactly how many genes in a set are needed to measure the genetic distance resolving the relationships between branches on the phylogenetic tree reconstruction of a complex of closely related species? We chose protein-coding sequences as a standard set of markers. Distances for 160–180 genes with a combined length of 270 000–300 000 bp were used to estimate the divergence levels of closely related mammalian species. In most cases, the interspecific distances are within the 0.15–0.75% range (median of 0.33%). The range of distances between semi-species is 0.12–0.28% (median of 0.14%). Intraspecific distances are always lower than 0.11%. Rodents show higher values of interspecific distances, 0.25–2.3% (median of 0.72%); distances between half-species range from 0.1 to 0.35%. To determine the number of nuclear loci and their combined length sufficient for the calculation of a genetic distance, we use simulations based on a model that included the following parameters: the average rate of gene evolution, its dispersion, and the level of polymorphism in the modern and ancestral populations. We performed a preliminary analysis of the distribution of loci evolution rates among mammalian taxa based on the data on ~50 thousand nuclear markers. It is shown that a relative error of 10–15%, comparable to the same value for mitochondrial distances between close species based on individual genes (approximately 1000 bp in length), is achieved using approximately 100 loci of 300 bp in length. Based on these data, we propose the following working hypothesis: the threshold of interspecific/intraspecific genetic distance calculated on the basis of the exons most frequently used in mammalian molecular phylogenetics is approximately 0.15%. This hypothesis assumes a species rank for the forms in statu nascendi. It should be noted that not all “good” species have significant genetic distances, since in some cases reproductive barriers form faster than substitutions accumulate in the genome.
Influence of Raoul Husson’s neurochronaxic theory for the development of research on the physiological mechanisms of voice production in the Soviet Union (1950–1970s)
Authors: Nikol’skii A. A.
Published: November 2024

The influence of the neurochronaxic theory of phonation of the French physiologist Raoul Husson (1901–1967) on the development of research on voice formation in the Soviet Union, mainly in the 1950–1970s, is discussed. Husson contrasted the neurochronaxic theory with the traditional myoelastic theory of voice formation. The myoelastic theory considers the vocal folds as a self-oscillatory system. Vibrations are caused by the energy of the air flow. According to Husson’s concept, vibrations of the vocal cords do not depend on subglottic pressure. The frequency of vibration of the vocal cords corresponds to the frequency of impulses arriving along the recurrent nerve. To explain the high frequency of vibration of the vocal cords, Husson used Wever’s “Volley Principle”. According to this principle, the activity of each subsequent nerve fiber occurs during the refractory phase of the previous fiber. The responses of all nerve fibers are summed up into a common high-frequency oscillation. In 1950–1970s, Soviet physiologists took an active part in testing the new concept proposed by Husson. They came to the conclusion that both mechanisms, myoelastic and neurochronaxic, are involved in the functioning of the vocal apparatus. But the recurrent nerve does not directly control the vibrations of the vocal cords, but indirectly. Žhinkin called this control system the “code principle,” when a command is sent to the vocal cords to change their physical characteristics, changing the properties of the self-oscillating system.
Modeling of the modern climatic range of Cydalima perspectalis (Lepidoptera, Crambidae) in Eurasia
Authors: Popov I. O. , Popova E. N.
Published: November 2024

Modeling of the modern climatic range of a dangerous plant pest of the genus Buxus L. box tree moth Cydalima perspectalis (Walker, 1859) is carried out in order to determine possible territories of its further expansion in Eurasia. Information on the loci of actual C. perspectalis detection both in native (East and South Asia) and invasive (Europe and West Asia) parts of the range was collected from various sources (species distribution databases and publications). Six bioclimatic (three temperature and three humidity) parameters are used as distribution predictors. Original methods for determining the number of pseudo-absence points and their selective generation are developed and applied. The final classification and partitioning of the space of bioclimatic factors is carried out using gradient boosting. The modern Eurasian climatic range of the box tree moth is calculated and mapped. It is shown that the invasion has not yet reached its limits and there are a number of territories in Eurasia where climatic conditions are favorable for the emergence of C. perspectalis populations both in the native part of the range (certain southern and eastern regions of China, the DPRK, the southern foothills of the Himalayas) and in its invasive part (Northern and Eastern Europe, Caucasus, and Turkey). A comparative assessment of the importance of different climatic factors in determining the box tree moth distribution area is given. It has been found out that the sum of the driest month precipitation is of greatest importance for constructing a model of the C. perspectalis climatic range (47.6%). A significant difference in climatic conditions between the native and invasive parts of the range is revealed and assumptions about the possible causes of its occurrence are made.
Theory of thin elastic plate: history and current state of the problem
Authors: Vasil'ev V. V.
Published: November 2024

The article is an analytical review and is devoted to the theory of thin, isotropic elastic plates. There are basic relations of the theory based on the kinematic hypothesis confirming that the tangential displacements are distributed linearly along the thickness of the plate and its deflection does not depend on the normal coordinate. As a result, a system of equations of the sixth order with respect to two potential functions – the penetrating potential, which determines the plate deflection, and the boundary potential which makes it possible to set three boundary conditions on the plate edge and eliminate the known contradiction of Kirchhoff's plate theory was obtained. Problems that have no correct solution in the framework of Kirchhoff's theory – cylindrical bending of a plate with a free edge, bending of a rectangular plate with non-classical hinge fixing, torsion of a square plate by moments distributed along the contour, and bending of a plate by a rigid die – are considered. In conclusion, a brief historical review of the papers devoted to the theory of plate bending was presented.
Quaternion regular equations of the two-body problem and the problem of the motion of a satellite in the gravitational field of the earth in the Kustaanheimo-Stifel variables and modified four-dimensional variables: dynamics of relative motion
Authors: Chelnokov Yu. N.
Published: November 2024

The article develops the quaternion regularization of differential equations (DE) of the relative perturbed motion of the body under study, which we previously proposed within the framework of the perturbed spatial problem of two bodies: the equations of motion of the center of mass of this body in a coordinate system rotating in an inertial coordinate system according to an arbitrarily given law, and also develops a quaternion regularization of the motion DEs for the body under study relative to the coordinate system associated with the Earth. New quaternion DEs for the perturbed motion of an artificial Earth satellite relative to the coordinate system associated with the Earth are proposed. These equations have (in new times) the form of DE for the relative motion of a perturbed four-dimensional oscillator in the Kustaanheimo-Stiefel variables or in the modified four-dimensional variables we proposed, supplemented by DEs for the satellite’s motion energy and time. These equations for the perturbed relative motion of the satellite take into account the zonal, tesseral and sectorial harmonics of the Earth’s gravitational field. The proposed equations, in contrast to classical equations, are regular (do not contain special points such as singularity (division by zero)) for the relative motion of a satellite in the Newtonian gravitational field of the Earth. The equations are convenient for applying methods of nonlinear mechanics and high-precision numerical calculations when studying the orbital motion of a satellite relative to the Earth and predicting its motion.
Membrane piezoelectric MDS-actuator with a flat double spiral of interacting electrodes
Authors: Pan’kov A. A.
Published: November 2024

A schematic diagram and mathematical model of functioning of a new piezoelectric membrane (MDS) actuator with double spiral (DS) electrodes on the upper and/or lower surfaces of a thin piezoelectric layer with axisymmetric and periodic (with a small period) in radial coordinate mutual reversed electric polarization are presented. The polarization of the layer was realized as a result of connecting the polarizing electric voltage of the appropriate value to the outputs of the double spirals of the electrodes. The electrodes of each (upper and lower) double spiral of the MDS-actuator are made in the form of electrodeposited ribbon coatings on the surfaces of the piezoelectric layer in close proximity to each other (due to the small spiral pitch) to create high values of electric field strength along the lines of force in localized areas of the piezoelectric layer between them when an alternating or constant control electric voltage is connected to the electrodes, in particular, with positive and negative values of the electrical potentials. Importantly, the electric field force lines and, as a consequence, the polarization of the piezoelectric layer of the MDS actuator are oriented mainly along (i.e. towards or against) the radial coordinate of the membrane, in contrast to many conventional actuator schemes. The results of numerical modeling for a circular elastic membrane with piezoelectric actuators installed on its upper and lower surfaces confirmed the effectiveness of the proposed piezoelectric MDS-actuator when it functions according to the “bimorph” scheme, including the use of the proposed new structural element (section) – a piezoelectric “compression ring” MDS at various geometric and control parameters. The effect of a significant increase in the membrane deflection with installed piezoelectric MDS-actuators compared to the use of traditional homogeneous plate piezoelectric actuators of bimorph type for different conditions of the membrane fixation, in particular, stationary (rigid) fixation of its center is revealed. For a hybrid piezoelectric MDS-actuator including independent concentric round and circular (i.e. “compression ring”) sections, the non-monotonic nature and numerical analysis of the nonlinear dependence of the largest deflection at the center of a hinge-immobile membrane fixed at the edge on the ratio of the radii of its round and circular MDS sections were revealed. The cases in which the effect of the “compression ring” is manifested, i.e. when the maximum deflection of a membrane with the “compression ring” exceeds the best possible value of the deflection of this membrane without its use in the traditional “bimorph” scheme, are identified. The new piezoelectric MDS-actuator can be used in micromechanics, controlled optics, sensor technology, acoustics, in particular, in the manufacture of piezoelectric acoustic or sensor elements of membrane type, electromechanical transducers for vibration energy collection.
Calculation of the effective normal stiffness of a deformable wheel with a tilted rotation axis
Authors: Balakina E. V. , Kochetov M. S.
Published: November 2024

The research is relevant for the trajectory movement design modeling of the of vehicles on deformable support wheels. The purpose of the research: to obtain a theoretical dependence for calculating the effective normal stiffness of a deformable wheel with an inclined rotation axis. Mathematical relationships between this stiffness and the rotation axis tilt angle of the wheel are defined. It is determined that the effective normal stiffness changes by a factor of Kaz at specified tilt angle. A theoretical dependence for calculating the correction factor Kaz was obtained. The dependence is a function of the wheel design parameters and the rotation axis tilt angle. The dependence is correct at angles up to 10 degrees. At tilt angles that are permissible under the conditions of wheel wear (up to 5 degrees), the effective normal stiffness is significantly reduced, for example, for the study object, up to 25%. The validity of the theoretical dependence is confirmed by laboratory experiments on a specially designed stand for measuring the parameters of the elastic properties of the deformable wheel at different positions of its rotation axis. Based on the processing of the experimental data, the calculation error of Kaz according to the obtained theoretical dependence was determined, which does not exceed 6%.
Wear Calculation for a Shaft Lip Seal under Randomly Changing Temperature and Load
Authors: Soldatenkov I. A.
Published: November 2024

A stochastic model of the wear process of a shaft lip seal that takes into account random changes in the temperature and external load was described. The results of a numerical analysis of the process of seal wear in relation to the conditions of operation in open space at near-Earth orbital stations are presented. The importance of taking into account random changes in temperature and external load for predicting the seal durability was evaluated.
Compatibility of strains and the three-fold differentiability of the displacement field
Authors: Georgievskii D. V.
Published: November 2024

The problem of the necessary class of smoothness of solutions to quasi-static problems of deformable solid mechanics in terms of displacements was discussed. It is shown that in order for the equations of compatibility of deformations to become identities when displacements are substituted in them, the existence of some third mixed derivatives of displacements is required. A counterexample for a linearly elastic compressible isotropic elastic medium was given. In this counterexample, the displacement field, being a doubly differentiable solution to the boundary value problem for the system of Lame equations in the entire domain, is not a solution to the displacement problem at all points in this domain.
Damage indicators evolution during cyclic loading of composite plate with hole
Authors: Dzuba A. S. , Eleonsky S. I. , Zajtsev M. D. , Pisarev V. S.
Published: November 2024

Novel experimental method, which provides quantitative description of damage indicators evolution caused by fatigue loading of composite specimens with stress concentrators, was developed. Damage parameters are derived as deformation response to artificial notch inserting. This notch is extended from the edge of central through hole in plane rectangular specimen under constant external load. Current values of damage indicators are obtained at different stages of fatigue loading. These data reveal dependencies of required parameters on loading cycle number. The damage accumulation function for involved cycle range is quantitatively constructed on this base. It is found that this function is related to the first stage of the process investigated. The results obtained represent the essential link in the design of further experiments.
Influence of cyclic loading on physical and mechanical properties of thin-film membrane structures
Authors: Djuzhev N. A. , Gusev E. E. , Portnova E. O. , Novikova O. V.
Published: November 2024

The principle of modification of mechanical properties of thin-film membrane structures of arbitrary shape by non-contact method was proposed, realized and explained for the first time. The idea was tested on an aluminum thin-film membrane formed by magnetron method on a silicon substrate. The external influence was realized by means of cyclic loading in the form of discharge and supply of excess air pressure to the membrane. As a result of repeated impacts, physical properties of materials (grain size and roughness) and mechanical properties (internal mechanical stresses and critical overpressure) are changed. Changing the magnitude of residual mechanical stresses in the membrane material allows the formation of a surface with a desired curvature value. In this work, after cyclic loading with pressure equal to half of the critical pressure, the following effects were revealed: the deflection of the membrane in the absence of external influence increased by more than an order of magnitude, the structure shifted to the plastic type of deformation, the critical rupture pressure decreased by several tens of percent. Application of this methodology allows to create new materials with unique mechanical properties.
Precession motions of a gyrostat, having a fixed point, in three homogeneous force fields
Authors: Gorr G. V.
Published: November 2024

The subject of investigation is the problem on precession motions of a gyrostat with a fixed point in three homogeneous force fields. The class of precessions under consideration is characterized by the constancy of the precession angle and by the commensurability of the precession and proper rotation velocities. Equations of a gyrostat motion are reduced to a system of three second order differential equations with respect to velocities of precession and proper rotation. Integration of these equations was conducted in the case of precessionally isoconic motions (the precession velocity equals to the proper rotation velocity) and in the case of 2:1 resonance, when the precession velocity is two times more, than the proper rotation velocity. It was proved that the obtained solutions can be described by elementary functions of time.
Non-axisymmetric coupled non-stationary problem of thermoelectroelasticity for a long piezoceramic cylinder
Authors: Shlyahin D. A. , Jurin V. A.
Published: November 2024

A new closed solution to the non-axisymmetric coupled non-stationary problem of thermoelectroelasticity was constructed for a long piezoceramic cylinder for the case of satisfaction of the first and the third kind boundary conditions. Cylindrical surfaces were made as electrodes and connected to a measurement device with large input resistance. Limitation of a temperature change “load” rate made it possible to include equations of statics, electrostatics and thermal conductivity in the initial formula. The finite biorthogonal transforms are applying to explore a non-selfadjoint system of differential equations and to develop a closed solution. The obtained relations made it possible to determine the temperature and electric fields, and the stress-strain state in the piezoceramic cylinder, as well as the potential difference between cylindrical surfaces (electrodes) under non-stationary non-axisymmetric temperature impact.