bluuebunny/crossref_metadata_2025 huggingface dataset:
The Use of Google Meet For Online Microteaching
Authors: Riyanti Dwi
Published: December 2021

The social distancing and the closure of schools during the Pandemic force both teachers and students to teach and study remotely. In order to facilitate pre-service teachers learning to teach, the instructor of the Microteaching who is also the researcher opted to use Google Meet (GM) as a teaching platform in Microteaching class. Aiming at uncovering the perspectives of pre-service teachers in using GM as an online teaching platform for teaching their peers, the current study involved the sixth semester students in Microteaching class as its research participants. The main data were obtained through open-ended questionnaire. To triangulate the data, the videos of five pre-service teachers’ teaching demonstrations and five students’ written reflections were also used as a source of data. The obtained data were analyzed thematically based on the emerging themes. In so doing, the researcher firstly read the results of the open-ended questionnaire and the students’ reflection closely and started codifying the data. The findings show that preservice teachers have positive impression toward the use of GM and consider that as useful in the pandemic time. In terms of the challenge they faced, internet connection was found to be the major obstacle in teaching peers using GM.
Farklı ISG-Risk Değerlendirme Yöntemlerinin Bir Yeraltı Maden İşletmesinde Karşılaştırmalı Uygulanması Ve Yöntem Önerisi
Authors: Akkoyun Özgür , Ekinci Ğurbet
Published: December 2021

Bu çalışmada bir yeraltı maden işletmesinde iş sağlığı güvenliği risk değerlendirme çalışması yapılmıştır. Türkiye’de en çok kullanılan risk değerlendirme yöntemlerinden olan 5x5 L matris ve Fine-Kinney yöntemleri ile çok bilinmeyen HRNS risk değerlendirme yöntemi bir yeraltı maden işletmesine uygulanarak karşılaştırılmışlardır. Buna göre 5x5 L matris yönteminin esnek olduğu, düşük seviyeli riskleri görmeye yatkın olduğu, Fine-Kinney yönteminin daha az esnek olduğu görülmüştür. Ayrıca HRNS yönteminin ise riskleri görmek konusunda daha iyi olduğu, özellikle tehlike seviyesi yüksek riskleri görme konusunda diğerlerine göre daha iyi olduğu sonuçlarına varılmış ve HRNS yöntemi önerilmiştir.
Como pulgas en el lomo de un perro salvaje
Authors: Conger John
Published: December 2021

Como pulgas en el lomo de un perro salvaje describe la historia evolutiva del cuerpo del que nos ocupamos como terapeutas somáticos. Un terapeuta competente debe hacer un historial completo de sus pacientes, y este artículo habla de una historia ignorada y arrinconada en relación con el propio cuerpo. En nuestra actividad como terapeutas de orientación corporal, el cuerpo histórico que tenemos delante, tanto como la historia psicológica, cobra con frecuencia una relevancia inesperada. Este cuerpo en el que deambulamos por el mundo no ha salido de pronto de la nada. Nuestras actitudes instintivas tienen una historia que nos da una comprensión profunda de los movimientos intencionados del cuerpo y de sus frustraciones. Si no tenemos esa información, nos falta parte del historial. Este artículo trata de algunas de las habilidades innatas que aún están en la base de nuestra experiencia de vida actual.
Sentido estadístico en la formación de las y los estudiantes del Grado de Educación Infantil. Una aproximación desde un contexto de aprendizaje STEAM
Authors: Berciano Ainhoa , Anasagasti Jon , Zamalloa Teresa
Published: December 2021

Una de las características fundamentales que determinan el nivel de sentido estadístico se manifiesta cuando el conocimiento disciplinar asociado es transferido y aplicado a contextos a priori ajenos a la matemática. La finalidad de este estudio se centra en analizar cuáles son los conocimientos estadísticos previos y los criterios de selección respecto a gráficos de las y los estudiantes del Grado de Educación Infantil y cómo varían cuando se plantea la mediación grupal en un contexto STEAM, como fase previa de una propuesta metodológica de aprendizaje basado en proyectos. Para tal fin, se ha llevado a cabo un estudio con un diseño mixto (cualitativo-cuantitativo), con un total de 25 participantes. Los resultados muestran la poca importancia que dan a la estadística en contextos STEAM, la clara confusión sobre qué son los gráficos estadísticos y la influencia relativa de la dinámica grupal en estos dos aspectos, mostrando una mejoría parcial en su sentido estadístico.
Diseño y aplicación de instrumentos de análisis y valoración de textos escolares de matemáticas

Authors: Monterrubio María Consuelo , Ortega Tomás
Published: December 2021

Se presenta el proceso que ha permitido elaborar distintos modelos de análisis y valoración de textos escolares de matemáticas y, también, ejemplos de su puesta en práctica. Se trata de facilitar al profesorado de educación secundaria la tarea de elegir un libro de texto adecuado al contexto en el que se desarrolla la práctica educativa. Los instrumentos de valoración construidos también pueden constituir herramientas importantes en la elaboración de materiales curriculares por parte del profesorado, e indicadores de calidad profesional. Design and Implementation of Instruments for Analyzing and Assessing Mathematics School Textbooks We present the process that allowed us to elaborate different analysis and evaluation models of mathematics school texts and, also, examples of their application. The aim is to facilitate to secondary education teachers the task of choosing a textbook adapted to the context in which the educational practice is developed. The constructed evaluation instruments can constitute important tools for elaborating curricular materials by teachers as well as indicators of professional quality.Handle: http://hdl.handle.net/10481/14594Nº de citas en WOS (2017): 4 (Citas de 2º orden, 0)Nº de citas en SCOPUS (2017): 1 (Citas de 2º orden, 1)
Spontaneous meta-arithmetic as the first step toward school algebra

Authors: Caspi Shai , Sfard Anna
Published: December 2021

Taking as a point of departure the vision of school algebra as a formalized meta-discourse of arithmetic, we have been following six pairs of 7th-grade students (12-13 years old) as they gradually modify their spontaneous meta-arithmetic toward the “official” algebraic form of talk. In this paper we take a look at the very beginning of this process. Preliminary analyses of data have shown, unsurprisingly, that while reflecting on arithmetic processes and relations, the uninitiated 7th graders were employing colloquial means, which could not protect them against occasional ambiguities. More unexpectedly, this spontaneous meta-arithmetic, although not supported by any previous algebraic schooling, displayed some algebra-like features, not to be normally found in everyday discourses. La meta-aritmética espontánea como el primer paso hacia el álgebra escolar Tomando como punto de partida la visión del álgebra escolar como un meta-discurso formalizado de la aritmética, hemos estado siguiendo a seis pares de estudiantes de 7º curso (12-13 años) cuando modifican gradualmente su meta-aritmética espontánea hacia la forma algebraica “oficial” de hablar. En este artículo miramos el principio de este proceso. Los análisis preliminares de los datos han mostrado, como era de esperar, que mientras reflexionaban sobre los procesos y relaciones aritméticas, los alumnos no iniciados emplearon medios coloquiales que no evitaban las ambigüedades ocasionales. Más inesperadamente, esta meta-aritmética espontánea, a pesar de no apoyarse en ninguna enseñanza algebraica previa, desplegó algunas características similares al álgebra que no se encuentran normalmente en los discursos diarios.Handle: http://hdl.handle.net/10481/18313
Extending the coordination of cognitive and social perspectives

Authors: Simon Martin A.
Published: December 2021

Cognitive analyses are typically used to study individuals, whereas social analyses are typically used to study groups. In this article, I make a distinction between what one is looking with⎯one’s theoretical lens⎯and what one is looking at⎯e.g., an individual or a group⎯. By emphasizing the former, I discuss social analyses of individuals and cognitive analyses of groups, additional analyses that can enhance mathematics education research. I give examples of each and raise questions about the appropriateness of such analyses. Extensión de la coordinación de las perspectivas cognitiva y social Los análisis cognitivos se usan típicamente para estudiar individuos mientras que los análisis sociales se usan normalmente para estudiar grupos. En este artículo, distingo entre lo que se usa para mirar ⎯el lente teórico propio⎯ y lo que se mira ⎯por ejemplo, un individuo o un grupo⎯. Enfatizando lo primero, discuto los análisis sociales de individuos y los análisis cognitivos de grupos sociales, análisis adicionales que pueden enriquecer la investigación en educación matemática. Presento ejemplos de cada uno de ellos y planteo preguntas respecto de la conveniencia de estos análisis.Handle: http://hdl.handle.net/10481/18314
Supporting students with learning disabilities to explore linear relationships using online learning objects

Authors: Beatty Ruth , Bruce Catherine D.
Published: December 2021

The study of linear relationships is foundational for mathematics teaching and learning. However, students’ abilities to connect different representations of linear relationships have proven to be challenging. In response, a computer-based instructional sequence was designed to support students’ understanding of the connections among representations. In this paper we report on the affordances of this dynamic mode of representation specifically for students with learning disabilities. We outline four results identified by teachers as they implemented the online lessons.Apoyo a estudiantes con problemas de aprendizaje para explorar relaciones lineales mediante el uso de objetos de aprendizaje en líneaEl estudio de las relaciones lineales es fundamental en la enseñanza y el aprendizaje de las matemáticas. Sin embargo, las habilidades de los estudiantes para conectar distintas representaciones de las relaciones lineales han demostrado ser un reto. Ante esto, hemos diseñado una secuencia de enseñanza basada en ordenadores para fomentar en los estudiantes la comprensión de las conexiones entre estas representaciones.Presentamos las potencialidades de este tipo de representación dinámica para estudiantes con dificultades de aprendizaje, destacando cuatro resultados identificados por maestros al implementar las lecciones en línea.Handle: http://hdl.handle.net/10481/21535
Teacher knowledge and classroom practice: Examining the connection

Authors: Gilbert Michael , Gilbert Barbara
Published: December 2021

This paper extends existing research regarding content knowledge for teaching (CKT) and the role it plays in advancing student learning. Two teachers, with high and low measured CKT respectively, are observed on the same day teaching similar content. Many studies have recently been published linking student achievement to teacher’s CKT and many US schools have begun including CKT measures in teacher hiring and retention decisions. Teaching observed for this study illustrates that content can be taught effectively by teachers across the spectrum of CKT levels, but observable and significant differences in teaching leads to important questions for in-service and pre-service teacher educators.Conocimiento del profesor y práctica en el aula: estudio de su conexiónEste artículo amplía la investigación existente sobre el conocimiento del contenido para la enseñanza (CKT) y su papel en el progreso del aprendizaje del alumno. Dos profesores, con medidas altas y bajas de CKT respectivamente, fueron observados el mismo día enseñando contenidos similares. Numerosos estudios publicados recientemente relacionan el logro de los estudiantes con el CKT del profesor y muchos colegios estadounidenses han empezado a considerar medidas de CKT en la toma de decisiones para la contratación y permanencia de profesores. La enseñanza observada en este estudio muestra que el contenido puede ser enseñado efectivamente por profesores con niveles distintos de CKT. No obstante, se observan diferencias significativas en la enseñanza que conducen a cuestiones importantes para formadores de profesores en formación y en ejercicio.Handle: http://hdl.handle.net/10481/22366
Problemas de estimación de magnitudes no alcanzables: estrategias y éxito en la resolución

Authors: Albarracín Lluís , Gorgorió Núria
Published: December 2021

Llamamos problemas de Fermi a aquellos problemas que, siendo de difícil resolución, admiten una aproximación a su solución a base de romper el problema en partes más pequeñas y resolverlas por separado. En este artículo presentamos los problemas de estimación de magnitudes no alcanzables (PEMNA) como un subconjunto de los problemas de Fermi. A partir de los datos recopilados en un estudio hecho con alumnos de 12 a 16 años, caracterizamos las distintas estrategias de resolución propuestas por estos y discutimos sobre la potencialidad de estas estrategias para resolver los problemas con éxito.Unrachable magnitude estimation problems: strategies and solving successFermi problems are problems that, being difficult to solve, can be satisfactorily solved if they are broken down into smaller pieces that are solved separately. In this article, we present inconceivable magnitude estimation problems as a subset of Fermi problems. Based on data collected from a study carried out with 12 to 16 years old students, we describe the different strategies for solving the problems that were proposed by the students, and discuss the potential of these strategies to successfully solve the problems.Handle: http://hdl.handle.net/10481/23476Nº de citas en WOS (2017): 1 (Citas de 2º orden, 0)
The width of a proof

Authors: Hanna Gila
Published: December 2021

This paper’s aim is to discuss the concept of width of a proof put forward by Timothy Gowers. It explains what this concept means and attempts to show how it relates to other concepts discussed in the existing literature on proof and proving. It also explores how the concept of width of a proof might be used productively in the mathematics curriculum and how it might fit with the various perspectives on learning to prove.La amplitud de una demostraciónEl objetivo de este artículo es discutir el concepto de amplitud de una demostración presentado por Timothy Gowers. Se explica el significado de este concepto y se trata de mostrar cómo se relaciona con otros conceptos discutidos en la literatura existente sobre prueba y demostraciones. También se explora cómo el concepto de amplitud de una demostración podría utilizarse productivamente en el currículo de matemáticas y cómo podría encajar con las diferentes perspectivas sobre el aprendizaje de la demostración.Handle: http://hdl.handle.net/10481/33233Nº de citas en SCOPUS (2017): 1 (Citas de 2º orden, 0)
Análisis de las representaciones geométricas en los libros de texto

Authors: Barrantes Manuel , López Marco , Fernández Manuel Ángel
Published: December 2021

La investigación analiza y clasifica las imágenes gráficas relacionadas con la enseñanza-aprendizaje de la geometría en libros de textos. Se estudian varios aspectos de las representaciones geométricas a lo largo de las unidades de geometría de los libros. Algunos de estos aspectos son la variedad de representaciones al introducir conceptos geométricos, los elementos de las imágenes que puedan derivar en dificultades en el proceso de enseñanza-aprendizaje de la geometría, la representación plana de figuras tridimensionales y las imágenes reales que se utilizan para aludir a elementos geométricos abstractos. Se realiza una categorización que sirve como instrumento de análisis de los textos.Analysis of geometric representations in textbooksIn this research, we analyze and classify the graphical images related to the teaching-learning of geometry appearing in textbooks. It focuses on the study of several aspects of the geometrical representations included in the Geometry units of the books. Some of the these aspects are the variety of representations used when introducing geometrical concepts, the elements of these figures which could lead to difficulties in the Geometry teaching-learning process, the plane representation of tridimensional figures and the real images that are used to refer to abstract geometrical elements. We develop a categorization that serves as an instrument of text analysis.Handle: http://hdl.handle.net/10481/34157WOS-ESCI
Generalización de patrones y formas de pensamiento algebraico temprano

Authors: Vergel Rodolfo
Published: December 2021

Este artículo aborda la emergencia de formas de pensamiento algebraico en estudiantes jóvenes y muestra evidencias sobre su evolución. En la primera parte se expone el problema, investigado a partir de la forma en que surgen y evolucionan nuevas relaciones entre el cuerpo, la percepción y el inicio del uso de símbolos a medida que los estudiantes participan en actividades sobre generalización de patrones. La segunda parte presenta algunos constructos analíticos de la teoría de la objetivación. En la tercera se expone la metodología, destacando la recolección de los datos y su análisis. En el resto del trabajo se discuten algunos resultados que alimentan reflexiones sobre el desarrollo del pensamiento algebraico.Generalization of patterns and forms of early algebraic thinkingThis paper addresses the emergence of algebraic thinking forms in young students and we show evidences of their evolution. First, we present the research problem, it is tackled from the way in which new relationships between the body, perception and initiation of use of symbols are emerged and evolved while students participate in activities about generalization of patterns. In the second part, we show some analytical constructs on the theory of objectification. In the third part, we present methodology, highlighting data collection and their analysis. Finally, we discuss some results that feed reflections on the development of algebraic thinking.Handle: http://hdl.handle.net/10481/34991WOS-ESCINº de citas en WOS (2017): 1 (Citas de 2º orden, 1)
Nomenclatural standards of apple cultivars developed at Sverdlovsk Horticultural Breeding Station. Part I
Authors: Shlyavas A. V. , Telezhinskiy D. D. , Bagmet L. V.
Published: December 2021

Researchers of the N.I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR) and Sverdlovsk Horticultural Breeding Station developed nomenclatural standards for 18 apple cultivars released at the said station: ‘Aksyona’ (WIR-53949), ‘Blagaya Vest’ (WIR-53950), ‘Danila’ (WIR-53952), ‘Isetskoye Pozdneye’ (WIR-53953), ‘Iset Belaya’ (WIR-53954), ‘Krasa Sverdlovska’ (WIR-53955), ‘Papiroyantarnoye’ (WIR-53956), ‘Pervouralskaya’ (WIR-53957), ‘Rodnikovaya’ (WIR-53958), ‘Rumyanka Sverdlovskaya’ (WIR-53959), ‘Sverdlovchanin’ (WIR-53960), ‘Serebryanoye Kopyttse’ (WIR-53961), ‘Sokovoye 3’ (WIR-53962), ‘Tavatuy’ (WIR-53963), ‘Uralets’ (WIR-53964), ‘Fakel’ (WIR-53965), ‘Fermer’ (WIR-53966), and ‘Ekrannoye’ (WIR-53967). Nomenclatural standards serve to confirm the authenticity of a cultivar and its name. They should be kept perpetually in the scientific herbarium collection. Herbarium specimens of nomenclatural standards are formatted in accordance with the recommendations of the International Code of Nomenclature for Cultivated Plants (ICNCP), registered in the VIR Herbarium Database and included in the Herbarium of Cultivated Plants of the World, Their Wild Relatives, and Weeds (WIR).
Tatyana Yakovlevna Serebryakova: a forgotten hemp expert
Authors: McPartland J. M.
Published: December 2021

Tatyana Yakovlevna Serebryakova (1893-?) conducted taxonomic research on Cannabis sativa L. for 20 years. She published important papers and a book on the subject. Next to every great man stands a great woman, and Serebryakova was Vavilov’s hemp expert. Yet her biography has never been written, and many details are lost. We have reconstructed her history based on historical archives, her publications, and her-barium specimen labels. Highlights of her scientific contributions are presented.
Source material from the VIR collection for hybrid breeding of multiple-ear maize
Authors: Boyko V. N. , Khatefov E. B.
Published: December 2021

Background. Expanding the genetic polymorphism of maize is an effective way to increase its productivity by involving multiple-ear genotypes in breeding.

Materials and methods. In 2007, 596 maize accessions from VIR were assessed at the Kuban Experiment Station of VIR. In 2020, 52 hybrids between multiple-ear and single-ear maize lines were tested in the steppe zone of Kabardino-Balkaria at the site of the OTBOR Agrifirm. Useful agronomic traits were recorded, the coefficient of prolificacy (kmc) was calculated for the source lines and their hybrid progeny from crosses with a single-ear tester, and 52 parent lines were ranked according to the type of inheritance of the prolificacy feature.

Results. Accessions that combined prolificacy with other useful agronomic traits were identified. The following accessions were selected for their plant height (score 5, 126–175 cm): k-8819, k-9054, k-15269, k-15355, k-15360, k-15331, k-15877, k-15442, k-15443, k-15445, k-8009, k-14344, k-15195, k-15226 and k-17385. Accessions that excelled in the height of the ear attachment for mechanized harvesting (score 5, 50–70 cm) were as follows: k-8819, k-15269, k-15355, k-15360, k-14394, k-14904, k-14979, k-14968, k-15292, k-15391, k-9289, k-15322, k-15439, k-15442, k-15443 and k-14344. Sources of the following traits were identified: long cob (score 9, > 20 cm): k-9054, k-4535, k-13730, k-14817 and k-14996; higher number of rows per ear (score 5–9, > 16 grain rows): k-14904, k-14979, k-14968, k-15442, k-15330, k-15322 and k-9257; and higher number of grains in a row (score 5–9, > 31 grains per row): k-14904, k-14996, k-15639, k-15353, k-15330, k-15322, k-15344, k-15281, k-15439, k-9357 and k-15237. Ranking 52 accessions according to the test cross results showed that 9 of them produced progeny of the maternal type (no more than one ear), 26 of the intermediate type (1.1–1.5 ears per plant), 11 of the paternal type (1.6–2,0 ears) and 6 of heterotic type (more than 2 ears).
Fostering the Political Participation of EU Non-national Citizens: The Case of Brussels
Authors: Russo Luana , Huddleston Thomas
Published: December 2021

Political participation is considered an essential feature of democracy. The European Union (EU) aimed to foster political participation with the introduction of European citizenship, which gives the right to vote and stand as a candidate in municipal and European Parliament elections in whichever EU country the citizen resides. However, from the few figures available, registration and turnout rates among mobile EU citizens seem very low. In this article, we investigate the effectiveness of a proactive campaign in order to promote the participation of European non-national residents in municipal elections by focusing on a specific initiative: the VoteBrussels Campaign. Focusing on Brussels, and in the general on the Belgian case, offers us the opportunity to carry out a quasi-experimental design. Our findings suggest that a mobilisation campaign has a positive regionwide effect on the participation of mobile EU citizens.
Pottery Styles in Transition in Iron Age Crete
Authors: Pappalardo Eleonora
Published: December 2021

This paper presents the preliminary results of the study carried out by the author on a precise class of materials: Protogeometric B pottery from the site of Prinias, in central Crete. The pottery comes from the excavations conducted in the necropolis of Siderospilia, used from the end of XII century BC until the VII/VI century. A large assemblage of material has been so far analyzed, mostly consisting on figured specimens. Among this, a particular class of pithoi, characterized by straight sides and mostly used as cinerary urns, stands out for its quite unique features, finding comparisons just in Knossos and in few other Cretan sites. The impressive figured repertoire adopted in decorating PGB pottery (850-800 BC) does not find comparisons in continental Greece and it seems to reflect some sort of mixed tendency between Near Eastern influences, involving Crete in Early Iron age, and Minoan background. Keywords: Prinias, Protogeometric B, Pithos, Crete, Aegean
Investigation of the influence of an additional viscoelastic support mass-inertial characteristics on the rectangular plate non-stationary deformation
Authors: Voropay Alexey , Yegorov Pavel
Published: December 2021

Modeling additional supports that affect the non-stationary deformation of lamellar structural elements is associated with a number of idealizations and assumptions. Many sources describe the deformation of supported structural elements using absolutely rigid additional supports or stiffeners. In reality, additional supports have viscoelastic properties (viscous and elastic components). When studying non-stationary vibrations, one should also take into account the mass-inertial properties of additional supports. Goal. The goal of the work is: 1) refinement of the existing mathematical model of an additional viscoelastic support by taking into account the influence of its mass-inertial characteristics; 2) study of the influence of these characteristics on the non-stationary deformation of a rectangular plate. Methodology. The non-stationary deformation of beams or plates is described by systems of partial differential equations. For these objects, good results are given by models based on the hypotheses of S.P. Timoshenko, taking into account the inertia of rotation and shear. Such systems of equations can be solved by expanding the sought functions (displacements and angles of rotation) in the corresponding series and using the direct and inverse integral Laplace transform. The determination of the unknown reaction of the additional viscoelastic support, taking into account its mass-inertial characteristics, is carried out on the basis of solving the Volterra integral equations. Results. In this work, an analytical and numerical solution in a general form is obtained, which makes it possible to determine the dependence of the change in time of reaction between the plate and the additional support for various parameters of the mechanical system. Originality. The solution to this problem is based on the further development by the authors of an approach to modeling additional supports in the form of additional unknown non-stationary loads, which are determined from the analysis of Volterra integral equations. Practical value. Examples of calculations for the considered mechanical system at three different values of mass are given. It is shown that the mass-inertial characteristics of the additional support cause a noticeable effect on the oscillatory process, and the changes concern both amplitude and phase characteristics.
Experimental determination of the critical depth of cutting of blocked soil cutting by cutters and the length of the ploughshare of chain excavators
Authors: Kravets Svyatoslav , Suponyev Vladimir , Goponov Aleksei , Ragulin Vitaliy , Shchukin Oleksandr , Dmytrenko Oleksii
Published: December 2021

The development of civil and industrial construction and the growing trend of construction of underground communications have led to an increase in the volume of work on the laying of gas and oil pipelines, water mains, sewerage systems, power cables and communication cables. Much of the excavation work in the construction of these communications is performed by trench excavators.
Measuring system for monitoring the polydimensional deformation of superstructures of bridges and over-bridges improvement of volume hydraulic drive construction and road machines using flow shareholders
Authors: Pimonov Igor
Published: December 2021

Due to its advantages, the hydraulic drive is widely used in road construction machines. Depending on its design, the share of the hydraulic drive, which is the most expensive unit of a road construction machine, accounts for thirty to eighty percent of all failures. Reliable hydraulic drive, provides, to a large extent, the reliability of the whole machine and the efficiency of the construction organization as a whole. The efficiency of the hydraulic drive of construction machines, and, as a consequence, the machines themselves, is ensured by a set of measures, among which the most important is the quality design, manufacture and operation, combined into a single structural system. Depending on the quality of cleaning of the working fluid, the service life of hydraulic machines can be increased or decreased several times. Accumulation of pollutants in the hydraulic drive, the hardness of which is significantly higher than the hardness of metals, causes rapid wear of the surfaces of hydraulic units and the service life is rapidly reduced. Cavitation in the pump is accompanied by a pulsation of fluid pressure and noise. These pulsations are due to the return flow of fluid from the discharge cavity of the pump, which is accompanied by hydraulic shocks and as a result of alternating shocks, a pressure pulsation in the discharge line of the pump. The amplitude of these pulsations can, under known conditions, reach a value that causes the destruction of the pump. The possibility of cavitation can be reduced by rational choice of modes of operation of the hydraulic system and the correct design of its units, but this phenomenon can be completely eliminated only by using auxiliary pumping pumps, as well as increasing the pressure in the suction line of the pump. On the basis of the analysis of perspective directions of improvement of the hydraulic drive of the excavator the following improved scheme of it is developed. Usually only high-flow hydraulic motors can be used in flow dividers. But in our case it is necessary that the device had, first of all, small mechanical losses and small cost, and accuracy of division of working liquid which follows on filters can be small. In the volume flow divider, hydraulic motors are used: gear, piston, vane, screw, roller. The simplest dividers of volume type are paired (connected by shafts) hydraulic motors of lamellar (vane) and roller types. Hydraulic motors in this scheme are flow measuring devices (dispensers), which supply for one revolution the volume of liquid, equal without taking into account the leaks in the hydraulic motor, its working volume. The use of a flow divider as a source of hydraulic energy makes it possible to improve the hydraulic drive by combining in a single system the purification of the working fluid and the ejector feed of the pump. The most promising, in terms of cost, are flow dividers based on vane and rotary hydraulic motors..
Methodology for calculating rope drums for stability
Authors: Fidrovska Nаtalya , Nesterenko Viktoria , Karavan Ruslan
Published: December 2021

. The problems of the stability of rope drums are quite urgent. The rope drum is in most cases a thin-walled shell, which, under the influence of external pressure from the rope, can lead to loss of stability. The stability issues of the drum shell, which is loaded with rope turns, are very important, because the safety and reliability of the rope hoist is directly related to them The studies carried out made it possible to obtain a new method for calculating the stability of cylindrical shells, which takes into account not only the length of the shell, but also the rigidity of the connection with the head. In addition, a calculation formula was obtained to determine the critical pressure of the oval shell, which gives a fairly good agreement with the experiments of American scientists. The work also considered the effect of the difference in wall thickness on the critical load of the drum. The studies carried out made it possible to conclude that the parameters of the rope drums make it possible to completely eliminate the need to install rings and stiffeners. Also as a result of research it was found that the shell of the crane drum under the influence of a radial load cannot lose stability. Studies have shown that in all cases the stability margin of the rope drum shell is greater than the strength margin. In this case, the load created by the rope wound on the drum is considered, with the ratios of the radius of the drum and the rope typical for crane construction. In addition, a coefficient was established that takes into account the elasticity of the shell-head joint. The studies carried out have shown that such initial deviations of the drum shell shape as ovality do not give a significant increase in the critical load. The results obtained are quite important, since they allow reducing the metal consumption of the rope drum shell and at the same time ensuring its reliable operation. A decrease in metal consumption is achieved by reducing the thickness of the shell and the absence of the need to install rings and stiffeners. This will lead to a decrease in metal consumption and energy consumption of the crane itself, and also simplifies the technology of manufacturing a rope drum.
Estimation of possibility of applying electric buses in Kharkiv
Authors: Zinchenko Olena , Krakhmalyov Oleksandr , Ostroverkh Oleksandr , Krasnokytsiy Volodimir , Razarenov Leonid
Published: December 2021

The chief characteristics of electric buses in terms of efficiency, environmental friendliness, and convenience for passengers are analyzed. It makes it possible to speak of advantages of electric transport compared with transportation means on traditional fuels. Considering the issue of rational application of electric buses in cities, it is possible to rely on European cities’   positive experience.  Ever more and more of developed countries all over the world use ecological transport in the urban transportation networks. On the example of the studied Polish cities, namely Katowice, a positive trend in the growth of electric buses application in the city’s transportation grid can be observed, which  enables the authors to conclude that the city of  Kharkiv alsohas a great technical potential for introducing electric buses to the city routes network.

Electric buses are already starting to appear in several cities of Ukraine in the transport network, but it is necessary to increase the percentage of ecological buses, to develop certain concepts and strategies to increase this type of transport.
Method of selecting automatic control system of a motor grader
Authors: Ilge Igor
Published: December 2021

Problem. Effective use of motor graders is impossible without the use of automatic control systems, especially in modern conditions of large volumes of road construction. However, among the large number of samples of such systems, which differ in various parameters, it is impossible to make an appropriate choice without a scientifically sound approach, taking into account the set of their characteristics. It was found that these systems are characterized by a large set of parameters, with the values of some of them unknown, and the reliability of the values of many parameters is questionable, i.e. the choice must take place in conditions of fuzzy information. The methods of choosing alternatives in conditions of uncertainty described in the literature, in particular when choosing technical systems based on Analytic Hierarchy Process and fuzzy set theory, are analyzed and the latter is taken to develop a method of choosing a motor grader ACS. The goal of the work is to increase the efficiency of motor graders in road construction due to the appropriate choice of ACS. The methodology of constructing the method is the theory of fuzzy sets. The economic, technical-operational and ergonomic groups of criteria for choosing a motor grader ACS are determined and substantiated. The construction of the method was performed to select the ACS in the 3D class. As the alternatives, the systems which are the leaders of this segment were chosen. The above criteria are a set of criteria. The solution to the problem of choice is an alternative that best meets the requirements of the whole set of criteria. The results of the work are the development of a method of fuzzy multicriterion analysis for the selection of a motor grader ACS in the class of 3D systems. Originality lies in constructing the method of choosing a motor grader ACS in conditions of fuzzy information on the basis of reasonable criteria. The practical value is the fact that the use of the developed method will allow to make a scientifically sound choice of the ACS of a motor grader taking into account the whole set of criteria.
Effects of genetic polymorphism on the development of hepatocellular carcinoma in patients with metabolic-associated fatty liver disease. Review
Authors: Antonenko A. V. , Beregova T. V.
Published: December 2021

Non‑alcoholic fatty liver disease (NAFLD) takes the first place among liver diseases in the countries with developed economies. In the year 2020, the group of experts proposed a new term, metabolic‑associated fatty liver disease, that allows to specify the diagnosis, to divide different NAFLD phenotypes and to optimize its treatment. The course of metabolic‑associated liver disease can range from mild forms (simple nonalcoholic steatosis, characterized by the accumulation of triglycerides in liver cells) up to an aggressive course with the development of cirrhosis and hepatocellular carcinoma (HCC). Aggressive course of the disease is observed in patients with type 2 diabetes mellitus, high body mass index, abdominal obesity and histologically confirmed steatohepatitis. Epidemiological and genetic studies have shown an association between the morphological stage of metabolic‑associated liver disease and hereditary factors. Progression to HCC is common in patients with severe steatohepatitis, although recent literature data showed a significant increase in the proportion of patients with F1/F2 fibrosis and НСС. This is due to the presence of metabolic syndrome and gene polymorphism. Three main genes can be singled out, the polymorphism of which is associated with the development of metabolic‑associated liver disease, insulin resistance, dyslipidemia, and fibrogenesis: PNPLA3, TM6SF2 and GCKR. Recently, an MBOAT7 gene polymorphism has been also identified, it peculiarly increases the risk of steatohepatitis development in patients who are alcohol abusers and/or have chronic viral hepatitis C. Detection of polymorphisms in these genes is useful for identifying groups at high risk for disease progression. Early diagnosis of HCC and risk stratification will allow to diagnose the disease at an early stage and optimize its treatment.
Memories from the Darkness in the Films of Pedro Costa and Affonso Uchôa
Authors: Costa Júnior Edson Pereira da
Published: December 2021

This essay analyses realist works from contemporary world cinema wherein the representation of space-time is directly affected by the color black, referring to both night and dark shadows. It investigates exactly how darkness participates in moments when the filmed subjects remember traumatic events and confront them through their courageous retellings. My hypothesis is that the color black converts the space—realistic and concerning the characters’ present time—into a place where different temporalities coexist. Through a comparative analysis of films made by the Portuguese filmmaker Pedro Costa and the Brazilian filmmaker Affonso Uchôa in the past two decades, I show how this modulation in space-time produced through color has a political meaning, since the narrated memories are related to a social experience of class and race.
The True Colors of “False” Color: Representing Data Chromatically in NASA Films
Authors: Harris C. E.
Published: December 2021

This paper investigates the multifaceted uses of color — not (only) to aesthetic ends, but as a tool for translating data into narrative — in a corpus of recent NASA films. Often called ‘false’ color or accused of manipulation, these uses of digital color stray from photorealism but nonetheless have a direct, measurable relationship with physical reality: they use data to render visible that which lies outside the spectrum of visible light. The focus of this paper is on the truth status of these digital films and on the practices used to produce them. It situates them, as a corpus, within and in response to film studies historiographies of color centered around spectacle and the dichotomy of fantasy versus reality, addressing how color can deploy the powers of the false to reveal otherwise invisible truths through art and artifice.
True Colors: Chromaticity, Realism and Technological Honesty
Authors: Philip Andrew I. Iain
Published: December 2021

I propose an application of agential realism to my practice as research, a film about my mother getting one tattoo covered with a new one, to investigate the material-discursive role played by the camera in determining meaning within the film image. I use my practice as a comparative case study, considering how a specific camera apparatus determines and negotiates standards of colour accuracy, and what it means to remove those colour values in post-production. I argue that the different colour processing of the same footage produces perceptible onto-epistemological difference, even while it remains indexically equivalent. Second, I will show exactly how this particular digital photosensitive technology meets the pro-filmic event to record colour, enacting agencies that reduce matter to fit a specifically programmed colour system, prior to any manipulation in post-production. The system itself draws the boundaries of accuracy it claims to achieve, with inevitable ethical implications.
Reproductive features of the biology of some ticks of the family Ixodidae Murray, 1877 widespread in the southeast of the North Caucasus
Authors: Atayev A. M. , Zubairova M. M. , Karsakov N. T.
Published: December 2021

The purpose of the research is study of some reproductive characteristics of the biology of ticks of the family Ixodidae which are widespread in the southeast of the North Caucasus.

Materials and methods. In 2000–2010, 9 series of experiments were carried out in the conditions of the plain belt in Dagestan. The first, second, and third series of experiments were intended to find out the duration of the tick searching for a place to fix on the animal, the duration of the skin incised and the proboscis inserted into the wound, and the engorgement duration; and the fourth series was intended to clarify the tick wintering on the animal. Such experiments were performed on two-year-old calf bulls on the Educational and Experimental Farm of the Dagestan State Agrarian University with Boophilus annulatus, Rhipicephalus bursa, Hyalomma detritum, H. scupense, and H. anatolicum in 2000. Five hungry adult female ticks were placed onto all 5 calf bulls in the middle third of the neck. We conducted experiments on searching for a place for egg-laying, egg-laying duration in the environment, number of eggs in a clutch, duration of the larva formed and the hatching rate, distance of the larvae from the hatching place, and larvae death rate in five specially equipped sites of pastures of 1 m2 . Five adult female ticks of B. annulatus, R. bursa, H. detritum, H. scupense, and H. anatolicum were placed after engorgement in each biological site.

Results and discussion. Ixodid ticks perform their natural physiological functions associated with feeding and reproduction with significant time fluctuations. The search for a place to fix on the animal took 4–8 hours; the skin incised and proboscis inserted in the wound took 2–5 hours; the engorgement took 4–6 hours; the search for an egg-laying place took 10– 22 hours; the egg-laying duration in the environment was 18–23 hours; the number of eggs in a clutch was 4–13K; the duration of the larva formed and the hatching rate was 10–15 days and 58.0–75% respectively; the distance of the larva from the hatching place was 0.5–1.5 m; death rate of the larva in captivity was 100%; and the tick wintering on the animal was near the neck, ears, in the dewlap, the flank and the udder. These features are typical for the analyzed tick species in the southeast of the North Caucasus and, probably, for other taxa of these genera.
Assessment of the therapeutic efficacy of various drugs against cryptosporidiosis in calves
Authors: Klimova E. S. , Mkrtchyan M. E. , Ivanov I. S. , Krylovay T. G.
Published: December 2021

The purpose of the research is studying the spread of cryptosporidiosis in calves and assessment of the extenseeffectiveness of antiprotozoal drugs.

Materials and methods. The spread, seasonal and age-specific trends of cryptosporidiosis was studied on 395 spontaneously infected animals of five age groups. The first group was formed of calves up to 10 days of age, the second group of calves aged from 11 days to 2 months, the third group of calves from 2 to 4 months, the fourth group of calves from 4 to 6 months of age, and the fifth group of young animals from 6 months up to 1 year. To assess the efficacy of various drugs against cryptosporidiosis in calves, 5 groups of infected animals (4 experimental and 1 control), 10 animals each, were formed according to the principle of analogous pairs. The infection rate in cattle was determined by generally accepted coprological flotation methods, as well as by native smears with further staining according to Ziehl-Nielsen. We also considered clinical signs of cryptosporidiosis (diarrhea, dehydration).

Results and discussion. We established the widespread occurrence of cryptosporidiosis in cattle on the farms of the Igrinsky, Uvinsky, Zavyalovsky Districts of the Udmurt Republic. The infection rate ranged from 20.25 to 80.0%. The largest percentage of infected calves was observed in the winter-spring period which was associated with the synchronization of the reproductive cycles of cows and a decrease in the resistance of the animal organism. Toltarox 5% and Galokur drugs in work environments showed 100% extense-effectiveness. It is not recommended to apply Amprolium 25% on these farms due to the low efficacy and the development of parasite resistance to this drug.
Complex therapy against toxascariosis of caged silver foxes
Authors: Konovalov A. P. , Tsepilova I. I. , Vasilevich F. I.
Published: December 2021

The purpose of the research is evaluating the efficacy of complex therapy using dironet, lactobifadol and keratin food supplement (DLK) against toxascariosis of the arctic fox.

Materials and methods. To determine the helminth fauna in the conditions of Vyatka Fur Breeding Farm, 61 females silver fox and 55 females voilevoy arctic fox were used as study objects. To conduct complex therapy against toxascariosis, the study object was 24 females culled from the breeding herd, spontaneously infected with toxascariosis and being clinically healthy. The morphological and biochemical blood parameters in female foxes were determined before and after dehelminthization, and control weighing of animals from experimental groups was carried out before and after the experiment.

Results and discussion. Of the studied 116 fur-bearing animals, 26 (22.4%) were infected with Toxascaris leonina. Infection rate of Toxascaris sp. in silver fox females aged 5–7 years was 42.6% when 7-9 eggs were found in one microscope field (magnification 7 × 9). Infection with Toxascaris sp. affects on the body weight of infected animals. The females silver fox from the second experimental group infected with Toxascaris sp., which were not treated, had an average live weight of 1.3 kg less (16.6%) as compared to the control. The complex therapy with the DLK treatment-and-prophylactic complex contributed to the improved metabolic processes and digestion. The applicability of the DLK treatment-and-prophylactic complex for therapy against toxascariosis was proved.