bluuebunny/crossref_metadata_2025 huggingface dataset:
Hubungan Motivasi Belajar dan Persepsi Siswa terhadap Gaya Mengajar Guru dengan Prestasi Belajar Matematika
Authors: Azka Raekha
Published: March 2021

Penelitian ini bertujuan untuk mengetahui seberapa besar hubungan motivasi belajar dan persepsi siswa terhadap gaya mengajar guru dengan prestasi belajar matematika siswa MA.Penelitian ini merupakan penelitian kuantitatif . Teknik pengambilan data digunakan metode tes untuk mengetahui prestasi belajar matematika siswa dan metode angket untuk mengetahui motivasi belajar dan persepsi siswa terhadap gaya mengajar guru. Analisis data menggunakan analisis regresi linear ganda.Hasil penelitian menunjukkan ada  hubungan yang positif dan signifikan antara motivasi belajar terhadap prestasi belajar matematika. Ada hubungan yang positif dan signifikan antara persepsi siswa terhadap gaya mengajar guru terhadap prestasi belajar matematika. Dan ada hubungan positif dan signifikan antara motivasi belajar dan persepsi siswa terhadapa gaya mengajar guru secara bersama-sama dengan prestasi belajar matematika siswa MA
Pembelajaran Matematika dengan Pendekatan Problem Based Learning dalam Implementasi Kurikulum 2013
Authors: Wahyuningsih Endang
Published: March 2021

Matematika merupakan ilmu universal yang mendasari perkembangan teknologi moderen dan mempunyai peran penting dalam berbagai disiplin ilmu. Setiap orang dirasa perlu untuk mempelajari dan memahami matematika. Pengetahuan matematika harus diajarkan sejak dini. Akan tetapi, sebagian besar siswa menganggap matematika merupakan pelajaran yang sulit. Kesulitan siswa dapat dilihat dari rendahnya hasil UN matematika Tahun Ajaran 2018/2019. Kenyataan tersebut berimplikasi pada kualitas pembelajaran matematika yang perlu ditingkatkan. Salah satu pendekatan pembelajaran yang dipandang efektif dalam pembelajaran matematika adalah problem based learning (PBL). Berdasarkan hasil penelitian, PBL dikatakan mampu meningkatkan siswa berpikir dan memecahkan masalah dalam kehidupan nyata yang diperlukan untuk memenuhi kebutuhan pendidikan masa kini. Saat ini, kurikulum yang sedang berlangsung di Indonesia adalah Kurikulum 2013 (K13). Karakteristik yang melekat pada K13 adalah  setiap pembelajaran menggunakan pendekatan Saintifik untuk meningkatkan kreativitas peserta didik. Pendekatan Saintifik merupakan pembelajaran yang menggunakan tahapan 5M yaitu Mengamati, Menanya, Mengumpulkan informasi (melakukan percobaan), Mengolah informasi (melakukan penalaran), dan Mengkomunikasikan hasil. Selain itu, dalam implementasi K13, guru hendaknya tidak langsung memberikan rumus-rumus yang sudah siap pakai. Tetapi, siswa sebaiknya dilibatkan dalam penemuan rumus tersebut. Salah satu usaha guru untuk memfasilitasi kegiatan tersebut adalah dengan membuat Lembar Kegiatan Siswa (LKS). Oleh karena itu, dalam pelaksanaan pembelajaran matematika dengan pendekatan PBL juga harus disesuaikan dengan tuntutan Kurikulum 2013. Dengan demikian, pembahasan pada artikel ini akan menghasilkan: (1) rancangan kegiatan pembelajaran matematika (khususnya pada sub topik keliling lingkaran) dengan pendekatan PBL yang memuat tahapan 5M sebagaimana yang diharapkan dalam implementasi K13, (2) rancangan LKS yang tidak hanya berisi latihan soal-soal, tetapi juga memuat sekumpulan kegiatan untuk memaksimalkan pemahaman siswa.
Upaya Meningkatkan Peran Aktif Siswa dalam Pembelajaran Matematika dengan Menggunakan Model Mencari Pasangan (Make A Match) Kelas XI IPS MA Salafiyah Wonoyoso Kabupaten Kebumen Tahun Ajaran 2018/2019
Authors: Wijayanti Ekaviana
Published: March 2021

Tujuan penelitian ini untuk mendeskripsikan peningkatan peran aktif siswa dengan menggunakan pembelajaran model Mencari Pasangan (Make a Match). Penelitian ini merupakan Penelitian Tindakan Kelas. Subjek penelitian ini adalah siswa kelas XI IPS 2 MA Salafiyah Wonoyoso. Hasil penelitian menunjukkan setelah 2 siklus, pembelajaran menggunakan model pembelajaran Mencari Pasangan (Make a Match) dapat meningkatkan peran aktif siswa. Pada kondisi prasiklus peranaktif siswa dalam pembelajaran sebesar 35,42% sedangkan pada siklus I meningkat menjadi 62,08%. Pada siklus ke II peran aktif siswa mencapai 77,02% dan telah menlebih dari standar keberhasilan. Pembelajaran matematika model Mencari Pasangan ( Make a Match ) dapat meningkatkan peran aktif siswa adalah dengan gambaran bahwa pada pelaksanaan pembelajaran matematika pada siklus pertama keterlaksanaanya 90%, sedangkan pada akhir siklus kedua mengalami peningkatan dengan keterlaksanaan 96,67%.
Optimalisasi Penemuan Terbimbing Guna Meningkatkan Antusiasme Belajar Matematika
Authors: Wulandari Nidya Ferry
Published: March 2021

Tujuan penelitian ini adalah untuk meningkatkan antusiasme belajar siswa kelas XI MIIA 3 SMA N 1 Seyegan dalam pembelajaran matematika melalui metode penemuan terbimbing. Penelitian ini merupakan penelitian tindakan kelas dengan model Kemmis & Mc. Taggart. Subjek penelitian ini adalah siswa kelas XI MIIA 3 SMA Negeri 1 Seyegan. Instrumen yang digunakan pada penelitian ini adalah lembar observasi, angket, dan tes tertulis. Penelitian tindakan ini mencapai kriteria yang ditetapkan pada siklus II, oleh karena itu siklus dapat dihentikan. Hasil penelitian ini adalah bahwa dengan optimalisasi penemuan terbimbing berbantuan lembar kerja siswa dapat meningkatkan antusiasme belajar matematika. Hal ini terbukti setelah dua siklus semua siswa memiliki antuasisme yang tinggi dan bahkan sangat tinggi. Sebanyak 40,6% siswa memiliki antuasiasme sangat tinggi, 59,4% siswa memiliki antusiasme tinggi, dan tidak ada siswa yang memiliki antuasiasme sedang, rendah, dan bahkan sangat rendah. Hasil penelitian ini sudah melebihi dari kriteria keberhasilan yang ditetapkan yaitu tidak ada siswa dengan antuasisme sedang, rendah dan sangat rendah serta setidaknya 60% siswa memiliki antuasisme tinggi dan 40% dengan antuasiasme sangat tinggi.Kata kunci: antusiasme belajar, matematika, penemuan terbimbing
Pengembangan Komik Matematika untuk Memfasilitasi Kemampuan Pemahaman Konsep dan Motivasi Belajar Siswa SMP
Authors: Saputra Adit , Azka Raekha
Published: March 2021

Penelitian ini merupakan penelitian pengembangan (research and development). Tujuan penelitian ini adalah untuk mengembangkan komik yang layak dan mampu memfasilitasi pemahaman konsep dan motivasi belajar siswa SMP/MTs. Pengecekan efektivitas, validitas, dan praktibilitas dilakukan pada komik untuk mengetahui kelayakan produk. Komik dinyatakan valid berdasarkan penilaian ahli yang memperoleh skor total 3,23 dari total skor 4. Komik juga dinilai efektif bersadarkan hasil post-test dan skala yang berturut turut menunjukan ketuntasan 83,87 % dan 70%. Komik dinyatakan praktis pula berdasarkan hasil analisis keterlaksanaan pembelajaran, komik mampu mencapai keterlaksanaan pembelajaran sebesar 70,24%. Oleh karena itu, komik matematika yang dihasilkan pada penelitian pengembangan ini layak digunakan untuk memfasilitasi pemahaman konsep dan motivasi belajar siswa SMP/MTs.Kata Kunci : komik, pemahaman konsep, motivasi belajar
Opportunity for all? The differential impacts of North Carolina’s revised comprehensive articulation agreement by race/ethnicity
Authors: Worsham Rachel E. , Whatley Melissa , Loss Jonathan E.
Published: March 2021

Transfer articulation agreements are employed by institutions of higher education and state legislatures alike to improve transfer efficiency between two-year and four-year institutions. These agreements often aim both to increase transfer rates and baccalaureate degree completion and to decrease time to degree. Studies exploring the efficacy of articulation agreements find that, despite being successful at decreasing the number of excess credits students earned at graduation and at increasing baccalaureate degree completion, these policies often increase time to degree. While there is considerable research on articulation agreements, few studies have examined the differential impact of these policies on students of Color who, prior literature has shown, experience barriers to realizing their baccalaureate degree aspirations. The purpose of this study was to examine whether the impact of North Carolina’s statewide articulation agreement varied by a student’s racial/ethnic identity when examining two-year post-transfer baccalaureate degree completion, time-to-degree completion, and excess credit accumulation.
Will college promise programs improve or reduce equity? Understanding the contextual conditions that influence program implementation
Authors: Perna Laura W. , Wright-Kim Jeremy , Leigh Elaine W.
Published: March 2021

Although “free tuition” programs are politically popular, some worry that these programs will exacerbate inequity. Scholars note that program outcomes depend on implementation, but few have probed the contextual conditions that contribute to differences in implementation or the consequences of implementation for equity. To address this knowledge gap, we draw on conceptual models of implementation fidelity and case studies of last-dollar, free tuition programs at four community colleges. The consequences of an implemented program for equity depend on program content and coverage and are moderated by programmatic and organizational conditions. For the studied programs, implemented content includes the financial award and non-financial academic supports. Coverage is determined by eligibility requirements. Program content and coverage are moderated by programmatic characteristics, including program goals and placement in the organizational structure, program staffing, and recruitment strategies. Organizational conditions, including sources and availability of funding, availability of synergistic programs, capacity for data collection and evaluation, and perceptions of the community college also moderate implementation. The results inform understanding of how to implement programs at community colleges that increase equity in particular contexts.
For Latinx, by Latinx: Race-conscious leadership in policy implementation
Authors: Felix Eric R.
Published: March 2021

Policy implementation research tends to document the failures of reform, describing the myriad ways implementers miss the mark in translating intent into impact; or in the words of Derrick Bell, policy scholars are left with examining the “unfilled hopes of racial reform” (2004, p. 185). In contrast, this article presents an intrinsic case study where campus leaders took a race-conscious approach to implementing a state-wide reform known as the Student Equity Policy. I constructed the TrenzaPolicy Implementation Framework to center the experience, knowledge, and assets of Latinx leaders in community college that oversee and implement policy reform. The framework highlights the raced-gendered perspectives of Latinx leaders in community college to understand their motivations to implement policy in race-conscious ways (Delgado Bernal, 2002). I conducted in-depth and sustained fieldwork to learn how implementers understood and responded to state-level reform in race-conscious ways and used the policy to target and address one of the most pressing issues in higher education, the inequitable rates of transfer for Latinx students. I share how the salience of racialized-gendered identity, cultural intuition, social context, and enacting agency allowed leaders to envision more race-conscious possibilities for policy reform and its implementation on campus.
Policy implementation as a tool for advancing equity in community college
Authors: Gonzalez Ángel de Jesus , Burgos-López Luz , Felix Eric R. , Nienhusser H. Kenny
Published: March 2021

This special issue examines the role of policy implementation in the community college context and the ways reforms are enacted to achieve or advance educational equity. In this introduction, we provide an overview of policy implementation, its current landscape within higher education, and the role it can and must serve for community colleges as a tool to advance equity efforts. The articles in this special issue provide a well-rounded overview of policy implementation efforts across various states and institutions. Authors examine promise programs, equity initiatives, articulation agreements, federally funded support programs, and race-conscious implementation. The community college context serves as a critical site of inquiry given that almost half of the undergraduate population is enrolled at a community college. Therefore, the following articles explore how to leverage policy implementation as a tool toward more equitable outcomes.
PRODUCTION AND APPLICATION OF ANGIOSTATINS FOR THE TREATMENT OF OCULAR NEOVASCULAR DISEASES
Authors:   Palladin Institute of Biochemistry of the National Academy of Sciences of Ukraine, Kyiv, BILOUS V. L.
Published: March 2021

Angiostatins comprise a group of kringle-containing proteolytically-derived fragments of plasminogen/plasmin, which act as potent inhibitory mediators of endothelial cells proliferation and migration. Angiostatins are involved in modulation of vessel growth in healthy tissues and various pathological conditions associated with aberrant neovascularization. The aim of the present paper was to summarize available information, including our own experimental data, on prospects of angiostatin application for treatment of ocular neovascular diseases (OND), focusing on retinal pathologies and corneal injury. In particular, literature data on prospective and retrospective studies, clinical trials and animal models relating to the pathophysiology, investigation and management of OND are described. Special emphasis was made on the laboratory approaches of production of different angiostatin isoforms, as well as comparison of antiangiogenic capacities of native and recombinant angiostatin polypeptides. Several studies reported that angiostatins may completely abolish pathologic angiogenesis in diabetic proliferative retinopathy without affecting normal retinal vessel development and without exhibiting adverse side effects. Angiostatins have been tested as a tool for corneal antiangiogenesis target therapy in order to manage diverse ocular surface pathological conditions induced by traumas, chemical burns, previous surgery, chronic contact lens wear, autoimmune diseases, keratitis and viral infections (herpes, COVID-19), corneal graft rejection, etc. Among all known angiostatin species, isolated K5 plasminogen fragment was shown to display the most potent inhibitory activity against proliferation of endothelial cells via triggering multiple signaling pathways, which lead to cell death and resulting angiogenesis suppression. Application of adenoviral genetic construct encoding angiostatin K5 as a promising tool for OND treatment illustrates a vivid example of upcoming revolution in local gene therapy. Further comprehensive studies are necessary to elucidate the clinical potential and optimal regimes of angiostatinbased intervention modalities for treating ocular neovascularization.
URRENT CONCEPT OF THE STRUCTURAL AND FUNCTIONAL PROPERTIES OF ALFA-FETOPROTEIN AND THE POSSIBILITIES OF ITS CLINICAL APPLICATION
Authors:   Institute for Problems of Cryobiology and Cryomedicine of the National Academy of Sciences of Ukraine, Kharkiv, Gulevskyy O. K.
Published: March 2021

This paper was aimed to review the literature data from native and foreign sources accumulated for 40-years period of research of the features of the molecular structure, functions, production and application of human alpha-fetoprotein (AFP), which is known as one of the most studied and increasingly demanded proteins. Results of fundamental studies performed with the use of modern methods, including various types of electrophoresis, chromatography, electron microscopy and immunoassay, in order to characterize the principal physicochemical capacities and localization of free and bound forms of AFP, as well as polypeptide structure, heterogeneity and topography of AFP receptors are highlighted here. The data on the mechanisms of AFP synthesis, its conformational features, binding sites and intracellular metabolism are also presented. The concepts of physiological functions and mechanisms of AFP transport in an organism are presented. Data on AFP isolation from the natural primary products and its production by means of recombinant and synthetic methods are shown. This review also summarizes information on the current possibilities of clinical application of AFP and the prospects for its usage in anticancer therapy for targeted delivery of chemotherapy drugs, with emphasis on the description of the recent progress in this field.
FECAL MICROBIOTES TRANSPLANTATION TECHNOLOGIES: MEDICAL, BIOTECHNOLOGICAL AND REGULATORY ASPECTS
Authors:   National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute”, Bakalchuk M. M.
Published: March 2021

Fecal microbiota transplantation (FMT) is a treatment method based on donor's fecal solution injection into the patient's gastrointestinal tract. FMT is effectively used in the treatment of recurrent Clostridium difficile infection. There is also growing interest in the therapeutic application of the method to treat metabolic, autoimmune and other disorders that was not previously associated with intestinal microbiota. Despite the promising results of FMT use, the organizational and legal matters and that of the safety FMT application have not yet been resolved in the European and Ukrainian medical community. The purpose of this review was to summarize information on the FMT application and the regulatory aspects of its use. The analysis of the practical instructions provisions of for FMT applying in clinical practice was carried out, and the bioethical problems associated with the FMT use were investigated.
FORMATION OF THE EUBACTERIAL COMPLEX IN THE RHYOSPHERE OF SUGAR BEET (Beta vulgaris) UNDER DIFFERENT FERTILIZATION SYSTEMS
Authors:   Taras Shevchenko National University of Kyiv, ESC ", Hudz S. O. ,   Institute of Biology and Medcine",   , Ukraine
Published: March 2021

The aim of the work was to determine the quantitative, qualitative composition and taxonomic structure of the eubacterial complex in the rhizosphere of sugar beet under different fertilizer systems. Microbiological methods were used to determine the content of microorganisms in the rhizosphere of sugar beet. Molecular methods were used to determine taxonomic structure as well as metagenome of the eubacterial complex of microorganisms. In the agrocenosis of sugar beet under different fertilizer systems the representatives of such families were prevailed as Alcaligenaceae, Pseudomonadaceae, Nitrososphaeraceae, Gaiellaceae, Micrococcaceae, Solirubrobacteraceae, Streptomycetaceae, Intrasporangiaceae, Solimonadaceae, Syntrophobacteraceae, Xanthomonadaceae, Enterobacteriaceae, Nocardioidaceae, Hyphomicrobiaceae, Comamonadaceae. It was found that under the biological system of fertilizers the species diversity of soil microbiota increased due to phyla: Alcaligenaceae, Gaiellaceae, Solirubrobacteraceae, Streptomycetaceae, Solimonadaceae, Syntrophobacteraceae, Xanthomonadaceae, Enterobacteriaceae, Nocardioidaceae, Hyphomicrobiaceae, Hyphomicrobiaceae. It was detected that the basis of the eubacterial complex of sugar beet included representatives of phyla Proteobacteria, Actinobacteria, Gemmatimonadetes, Chloroflexi, Acidobacteria, Firmicutes, Planctomycetes, Verrucomicrobia, Bacteroidetes, and the absolute dominants were Proteobacteria – 76.9%, Actinobacteria – 13,4 %.
On techniques of expert systems on the example of the Akinator program
Authors:   Taras Shevchenko National University of Kyiv, A.R. Zhangozha
Published: March 2021

On the example of the online game Akinator, the basic principles on which programs of this type are built are considered. Effective technics have been proposed by which artificial intelligence systems can build logical inferences that allow to identify an unknown subject from its description (predicate). To confirm the considered hypotheses, the terminological analysis of definition of the program "Akinator" offered by the author is carried out. Starting from the assumptions given by the author's definition, the article complements their definitions presented by other researchers and analyzes their constituent theses. Finally, some proposals are made for the next steps in improving the program. The Akinator program, at one time, became one of the most famous online games using artificial intelligence. And although this was not directly stated, it was clear to the experts in the field of artificial intelligence that the program uses the techniques of expert systems and is built on inference rules. At the moment, expert systems have lost their positions in comparison with the direction of neural networks in the field of artificial intelligence, however, in the case considered in the article, we are talking about techniques using both directions – hybrid systems. Games for filling semantics interact with the user, expanding their semantic base (knowledge base) and use certain strategies to achieve the best result. The playful form of such semantics filling programs is beneficial for researchers by involving a large number of players. The article examines the techniques used by the Akinator program, and also suggests possible modifications to it in the future. This study, first of all, focuses on how the knowledge base of the Akinator program is built, it consists of incomplete sets, which can be filled and adjusted as a result of further iterations of the program launches. It is important to note our assumption that the order of questions used by the program during the game plays a key role, because it determines its strategy. It was identified that the program is guided by the principles of nonmonotonic logic – the assumptions constructed by the program are not final and can be rejected by it during the game. The three main approaches to acquisite semantics proposed by Jakub Šimko and Mária Bieliková are considered, namely, expert work, crowdsourcing and machine learning. Paying attention to machine learning, the Akinator program using machine learning to build an effective strategy in the game presents a class of hybrid systems that combine the principles of two main areas in artificial intelligence programs – expert systems and neural networks.
Online education empowerment with artificial intelligence tools
Authors:   Institute for Information Recording of NAS of Ukraine, A.V. Boichenko , O.A. Boichenko ,   University of Education Management of the National Academy of Pedagogical Aciences of Ukraine
Published: March 2021

The experience of organizing the educational process during the quarantine caused by the COVID-19 pandemic is considered. Using of interactive technologies that allow organizing instant audio communication with a remote audience, as well as intelligent tools based on artificial intelligence that can help educational institutions to work more efficiently. Examples of sufficient use of artificial intelligence in distance learning are given. Particular attention is paid to the development of intelligent chatbots intended for use in communications with students of online courses of educational web portals. The use of technologies of ontology formation based on automatic extraction of concepts from external sources is offered, what can lead to greater acceleration of construction of the intellectual component of chatbots. Artificial intelligence tools can become an essential part of distance learning during this global COVID-19 pandemic. While educational institutions are closed to quarantine and many of them transitioned to distance learning lecturers and schoolteachers, as well as students and schoolchildren faced with the necessity to study in this new reality. The impact of these changes depends on people's ability to learn and on the role that the education system will play in meeting the demand for quality and affordable training. The experience of organizing the educational process at the University of Education Management of the National Academy of Pedagogical Sciences of Ukraine in the quarantine caused by the COVID-19 pandemic showed that higher and postgraduate institutions were mostly ready to move to distance learning. However, most distance learning systems, on whatever platform they are organized, need to be supplemented: the ability to broadcast video (at least ‒ one-way streaming), providing fast transmission of various types of information, receiving instant feedback when voting, polls and more. The structure of each section of the training course for the online learning system should fully cover the training material and meet all the objectives of the course. Appropriate language should be used, and wording, syntax, and presentation of tasks should be considered. One of the areas of application of artificial intelligence technologies in online learning is the use of chatbots which are characterrized by the following properties. It is advisable to use computer ontologies to ensure the intellectualization of chatbots. In this case, the metadata must be understandable to both humans and software and meet the requirements of modern standards in the field of information technology. The extraction of concepts from external data sources was carried out to build the ontology.
Technology for determining the speed of cars using a smartphone
Authors:   V.M.Glushkov Institute of Cybernetics of the National Academy of Sciences of Ukraine, P.Y. Sabelnikov , Y.A. Sabelnikov ,   V.M.Glushkov Institute of Cybernetics of the National Academy of Sciences of Ukraine
Published: March 2021

In the article the possibility of using a smartphone with an integrated set of necessary technical means (several video cameras, accelerometers, gyroscope, magnetometer, GPS sensor, GSM and Wi-Fi wireless communication) for implementing the technology of video recording of vehicle speed is investigated and established. The main algorithmic and software components of a smartphone are proposed, which allow to identify and to accompany a vehicle, as well as to determine its speed. Installation and initial setup of the device is simple. It is only necessary to measure and enter in the device height of its arrangement. In the article the possibility of using a smartphone with an integrated set of necessary technical means for implementing the technology of video recording of vehicle speed is investigated and established. The smartphone has a low cost and power consumption, the ability to operate in the required temperature range, as well as a set of physically built-in necessary technical means: several video cameras, accelerometers, gyroscope, magnetometer, GPS sensor, GSM and Wi-Fi wireless communication. Due to its low power consumption, it can also run on solar panels during the day when no other power source is available. The cost of a smartphone with very good characteristics does not exceed 10,000 UAH. The paper proposes the main components of the algorithmic support of the device. The use of the Lucas-Kanade method for the implementation of tracking and the calculation in the interpixel space of the coordinates of the points of the vehicle's trajectory will improve the accuracy of measurements of the traveled distance and the vehicle's speed on short sections of the trajectory. The proposed algorithm for calculating the vehicle speed requires entering only one parameter - the height of the device. Therefore, installation and initial setup of the device is simple. It is enough to measure and enter this parameter into the device. Large-scale introduction of a device for measuring vehicle speed, built on the basis of a smartphone, is possible due to relatively small investments in the development of its mechanical part, algorithmic and software.
Modulated Pseudo-hermitian dimer
Authors:   Novosibirsk State University, Suchkov S.V.
Published: March 2021

We investigate a modulated pseudo-Hermitian optical dimer. The parameter regions where the eigenmodes of the dimer retain their power are determined. It was shown that such a dimer has several exceptional points and it was found that the dimer modes can maintain their average power over the period, even if each of the segments is in the PT-broken phase. On the other hand, even if each segment is in the PT-symmetric phase, the average power of the dimer may not preserve. This feature is determined by the ratio between the length of the dimer and the beat period of the signal that occurs in individual segments of the dimer.
New collocation integrator for solving dynamic problems
Authors:   Tomsk State University (Tomsk, Russian Federation), Avdyshev V.A.
Published: March 2021

A new collocation integrator on Lobatto spacings is proposed for numerically solving mixed systems of first and second order differential equations of dynamic problems. The general theory of collocation integrators is described, from which the basic formulas of the new integrator are derived.
Determination of the gallium arsenide life time influence on the efficiency of continuous and pulse generation and detection of radiation of the terahertz frequency range
Authors:   Tomsk State University (Tomsk, Russian Federation), Kobtsev D.A. , Tyazhev A.V. ,   Tomsk State University (Tomsk, Russian Federation), Kolesnikova I.I. ,   Tomsk State University (Tomsk, Russian Federation), Redkin R.A. ,   Tomsk State University (Tomsk, Russian Federation)
Published: March 2021

A configuration and test samples of photoconductive dipole antennas based on SI-GaAs: Cr and LT-GaAs for terahertz radiation generation and detection were developed. Their operating characteristics in pulsed mode and in the mode of operation as photomixers was experimentally investigated.
Nucleation and development of plasticity in nanocrystalline BCC iron under shear loading
Authors:   Institute of Strength Physics and Materials Science of SB RAS, Zolnikov K.P. , Kryzhevich D.S. ,   Institute of Strength Physics and Materials Science of SB RAS, Korchuganov A.V. ,   Institute of Strength Physics and Materials Science of SB RAS
Published: March 2021

The features of the nucleation and development of plasticity in nanocrystalline iron with BCC lattice under shear were studied. The mechanisms of plastic deformation playing the main role in the development of structural rearrangements during loading were revealed. It was shown that the development of plasticity can be conditionally divided into several stages. The first stage of plasticity development is associated with the formation and propagation of dislocations and twins. At the second stage, intraganular slip and intergranular sliding begin to make the main contribution to plastic deformation. These processes initiate a change in the shape of the grains. At large shear, the deformation behavior of the sample is governed by the migration of the interfaces. Not only grain boundaries migrate but also twin ones do. As a result of migration processes, the grain sizes of the nanocrystalline sample are enlarged.
Two and three photonic linear circular dichroisms in semiconductors with cubic symmetry
Authors:   Fergana State University, Rasulov R.Ya. , Rasulov V. R. ,   Fergana State University, Eshboltaev I. ,   Kokand State Pedagogical Institute, Sultonov R.R. ,   Kokand State Pedagogical Institute
Published: March 2021

The linear-circular dichroism of two and three photon absorption of light in semiconductors with cubic symmetry of hole conductivity is theoretically investigated. The matrix elements of two and three-photon optical transitions occurring between the subbands of the semiconductor valence band are calculated. In this case, transitions associated with both non-simultaneous absorption of individual photons and simultaneous absorption of two photons are taken into account, and the spectral and temperature dependences of the coefficient of two and three-photon absorption of polarized light are determined.
Influence of the energy electron beam exposure regimes on the structure and mechanical properties of composite coatings
Authors:   Institute of Strength Physics and Materials Science of SB RAS, Krylova T.A. , Chumakov Y.A. ,   Institute of Strength Physics and Materials Science of SB RAS
Published: March 2021

The effect of heat treatment on the structure and properties of composite coatings based on chromium carbide with titanium carbide fabricated by non-vacuum electron beam cladding without has been studied. It was shown that tempering leads to a decrease in microhardness and wear resistance, which is associated with the decomposition of the austenitic structure with the formation of a soft ferrite-carbide structure. The post heat treatment tempering was showed to decrease of microhardness and wear resistance, which leads to the decomposition of the austenitic structure with the formation of a soft ferrite-carbide structure. The bulk quenching of coatings after tempering leads to an increase in microhardness comparable to the values of microhardness in the initial state after electron beam cladding, due to the formation of high hard martensite. The wear resistance of composite coatings after tempering is lower than after cladding due to brittle martensite, which is not able to hold solid carbide particles. The composite coatings obtained at the optimal processing conditions have a combination of improved properties and do not require additional heat treatment, resulting in structural changes, causing a decrease in mechanical properties.
Stress strain state of elastic plate with elliptical cut-out
Authors:   Institute of Strength Physics and Materials Science of SB RAS, Deryugin E.E.
Published: March 2021

The article considers a crack in the form of a narrow cut with a certain cfn at the cut out in an unbounded plate. The characteristics of the mechanical state of this system under uniaxial loading are determined: the stress concentration coefficient, the crack-driving force, and the energy of a solid with a crack. The elastic energy expenditure during crack propagation is determined. The general regularities of the mechanical state of a solid with a crack, not necessary having the form of an ellipse, are revealed. An important parameter of a crack is the curvature at the tip. It is shown that the Griffiths crack does not actually have a singularity at the tip. The stress strain state of the plate with an elliptical crack is identical to the same of the plate with a focus of homogeneous plastic deformation.
Physical principles of oblique angle deposition of calcium phosphates in RF magnetron discharge
Authors:   Institute of Strength Physics and Materials Science of SB RAS, Prosolov K.A. , Belyavskaya O.A. ,   Institute of Strength Physics and Materials Science of SB RAS, Lastovka V.V. ,   Institute of Strength Physics and Materials Science of SB RAS, Chaikina M.V. ,   Institute of Solid State Chemistry and Mechanochemistry SB RAS, Sharkeev Yu.P. ,   Institute of Strength Physics and Materials Science of SB RAS
Published: March 2021

The possibility of titanium surface functionalization by an oblique angle deposition of nanostructured bioactive calcium phosphate coatings is shown in the present work. The coatings were obtained by an RF magnetron sputtering of hydroxyapatite and antibacterial zinc-substituted hydroxyapatite-based targets. The morphology and growth features of coatings were studied in relation to the process parameters, such as the angle of substrates inclination relative to the particle flux, an RF power supplied to the target, and the distance from the target surface to the surface of the substrates. With an increase in the angle of inclination, the surface morphology of the coating’s changes significantly. It resulted inappearance of nanoscale structural elements tilted towards the source of the material flux. The arrangement of surface features is ordered in accordance with the initial surface of the substrate before sputtering. The internal structure of the coatings is represented by columnar elements inclined relative to the plane of the substrate.
Effect of deformation on the evolution of microtwinning and on curvature-torsion of the crystal lattice in polycrystalline Cu-Al alloys
Authors:   Tomsk State University of Architecture and Building, Koneva N.A. , Trishkina L.I. ,   Tomsk State University of Architecture and Building, Cherkasova T.V. ,   Tomsk State University of Architecture and Building; National Research Tomsk Polytechnic University, Solov’ev A.N. ,   Tomsk State University of Architecture and Building, Cherkasov N.V. ,   Tomsk State University of Architecture and Building
Published: March 2021

Development of misoriented dislocation substructures (DSS) appearing during large plastic deformation in polycrystalline Cu-Al alloys was studied. A qualitative analysis of defect types, which are sources of curvature-torsion (χ) of the crystal lattice, was carried out. The value of χ was measured in alloys with different grain sizes < d >. Changes in curvature-torsion of the crystal lattice in misoriented cellular-network and microtwin substructures were studied as a function of the deformation degree. The values of χ in the vicinity of microtwins and further away from themwere determined. Examples of microtwin formation with an increase of the deformation degree and grain sizes were provided.
Features of surface scale growth in the process of oxidation of V-Cr-Ta-Zr alloy in air
Authors:   Tomsk State University (Tomsk, Russian Federation), Smirnov I.V. , Grinyaev K.V. ,   Tomsk State University (Tomsk, Russian Federation), Ditenberg I.A. ,   Tomsk State University (Tomsk, Russian Federation), Tyumentsev A.N. ,   Tomsk State University (Tomsk, Russian Federation), Chernov V.M. ,   SC «A.A. Bochvar High-technology Research Institute of Inorganic Materials»
Published: March 2021

Investigation results of features of surface scale growth on samples of V-Cr-Ta-Zr vanadium alloy at a short duration of oxidation in air are presented. It is shown that at the initial stages of oxidation, regardless of the samples microstructure, the growth rate of surface scale can be an order of magnitude higher than with long-term processing. It has been established that scale is characterized by open porosity formed as a result of sticking of small plate-like V2O5 flakes together. It has been suggested that the decrease in oxidation rate is a consequence of an increase in the scale thickness, which helps to slow down the supply of oxygen to the sample surface on which the processes of nucleation and growth of scales occur, as well as diffusion saturation of the surface layer of the vanadium alloy with oxygen.
“Global” analysis of 24 ro-vibrational bands of the octad of the 76GeH4 molecule
Authors:   National Research Tomsk Polytechnic University, Raspopova N.I. , Gromova O.V. ,   National Research Tomsk Polytechnic University, Bekhtereva E.S. ,   National Research Tomsk Polytechnic University, Koshelev M.A. ,   Institute of Applied Physics RAS, Sennikov P.G. ,   Institute of Chemistry of High-Purity Substances named after G.G. Devyatykh RAS
Published: March 2021

A “global fitting” method was developed within the framework of the “SPHETOM” software implemented at the Tomsk Polytechnic University using the GeH4 molecule of T d symmetry as an example. Set of interacting states (so-called octad of interacting states) is chosen as the object of application. Band centers, rotational and resonance interaction parameters of all 24 sub-bands of the octadwere determined for the first time. Obtained information is important both for high-accurate intramolecular potential function determination of the germane molecule, andfor applications in planetary science and astrophysics.
Case of Actualizing Geometry Knowledge in Abstraction Thinking Level for Constructing a Figure
Authors: NOOR Nur , ALGHADARI Fiki
Published: March 2021

The purpose of studying geometry is for the development of student thinking, able to abstract and reason, against concepts in the object. Note on some study results that the combination of the student's conceptualization process and knowledge of geometry are a source of barriers to their learning. This study aims to investigate how students actualize their geometry knowledge for the development of thinking to the level of abstraction. Investigations on input, internal processing, and output. This study was conducted on high school students use questions regarding object and product of thought in geometry thinking at analysis and abstraction level. Based on study findings, students actualize their knowledge through figural aspects then developed into the conceptual aspect, and the two aspects are integrated with the relationship between properties. There is a mathematical connection to the integration process. However, because most students' understanding of geometry knowledge is still prototypical figural concepts, so there is an interaction issue between figural and conceptual aspects, namely the validity of relationship between properties. Therefore, students learn geometry in order to investigate the connections between objects and properties as a whole.
Ayçiçeği Sapı ile Odun karışımından üretilen Yongalevhaların Bazı Fiziksel Özelliklerinin Belirlenmesi
Authors: UĞUR Celal , BEKTAŞ İbrahim , TUTUŞ Ahmet
Published: March 2021

Bu çalışmada, laboratuvar şartlarında genel amaçlar için ayçiçeği saplarından (Helianthus annuus L.) ve odun yongalarından muhtelif oranlarda (% 100. 75. 50. 25 ve 0) üre formaldehit tutkalı kullanılarak üretilen yonga levhaların fiziksel özellikleri incelenmiştir. Levhaların üretiminde % 65’lik üre formaldehit tutkalı, sertleştirici madde olarak % 33’lük amonyum klorür kullanılmıştır. Üretilen levhalarının pres sıcaklığı 185 oC, pres süresi 7 dk. pres basıncı 4 N/mm2, levha kalınlığı 18 mm olacak şekilde tek tabakalı levhalar üretilmiştir. Üretilen levhalar ASTM-D 1037 standardına göre değerlendirilmiştir. Ayçiçeği sapı ve odun yongası karışımından üretilen test levhalarının 650 kg/m3 özgül kütlede üretilen levhalarda 2 saat suda bekletme sonucu kalınlık artışı (KA) % 20-26, su alma miktarı (SA) % 68-84, 24 saat suda bekletme sonucu kalınlık artışı % 22-32, su alma miktarı % 81-95, 96 saat suda bekletme sonucu kalınlık artışı % 29-36, su alma miktarı % 108-120, 336 saat suda bekletme sonucu kalınlık artışı % 34-41, su alma miktarı % 112-132 olarak elde edilmiştir. İstatistik analiz sonuçları, test levhalarında su alma miktarı ve kalınlık artışlarının, ayçiçeği sapı oranının artmasıyla arttığını gösterdi. Bu data ve değerlendirmelere göre, ayçiçeği saplarının genel amaçlı yonga levha üretimi için alternatif bir hammadde olabileceği söylenebilir.
FUNCTIONAL MORPHOLOGY OF BIRDS’ BLOOD LEUKOCYTES
Authors:   Department of General and Clinical Pathology, Faculty of Fundamental Medicine, Chelyabinsk State University, Chelyabinsk, Russian Federation, Kolesnik Evgeniy , Derkho Marina ,   South Ural State Agrarian University, Troitsk, Russian Federation, Strizhikov Victor ,   South Ural State Agrarian University, Troitsk, Russian Federation, Strizhikova Svetlana ,   South Ural State Agrarian University, Troitsk, Russian Federation, Sereda Tatyana ,   South Ural State Agrarian University, Troitsk, Russian Federation, Gizatullina Firdaus ,   South Ural State Agrarian University, Troitsk, Russian Federation, Rebezov Maksim ,   Ural State Agrarian University, Yekaterinburg, Russian Federation,   V.M. Gorbatov Federal Research Center for Food Systems of Russian Academy of Sciences, Moscow, Russian Federation
Published: March 2021

The present research was carried out in an attempt to identify the problems associated with the morphofunctional analysis of vertebrate animal’s leukocyte blood cells. For this blood samples of four age groups chickens (Gallus gallus L.) were collected and analysis was carried out as per the recommendations of the International Council for Standardization in Hematology for the identifying morpho-physiological characteristics of leukocytes of peripheral blood of birds. Results of the current study were based on the sample of early postnatal ontogenesis based on the analysis of high-resolution color microphotographs taken by the method of light-optical microscopy. Results of the current study revealed that the cells have the well-designed of all granular leukocytes typical "eosinophilic" nucleus with two segments. Sometimes cells contain polysegmental nuclei that are eccentrically located. Further, in contrast to heterophils, the eosinophilic nucleus has well-expressed contours, formed by irregularly shaped chromatin blocks with an optically denser structure. There are also eosinophils with stick-nuclei. The smallest blood granulocytes of the birds are basophils. Basophils differ in structure slightly basophilic color cytoplasm with intensively basophilic granules of rounded or other forms of different size. The sizes of granules in basophils are smaller than the other types of granular leukocytes. Thus, based on the analysis of qualitative color microphotographs of white blood cells of chickens of neonatal ontogenesis performed by optical microscopy, the differential morpho-physiological markers of leukocytic cells of peripheral blood of birds were marked and characterized.
EVALUATION OF ANTIOXIDANT AND ANTIMICROBIAL POTENTIAL OF Thespesia lampas ROOT EXTRACTS
Authors:   Department of Botany, Indira Gandhi National Tribal University (IGNTU), Amarkantak-484887, India, Singh Nitesh , Mansoori Aadil ,   Department of Botany, Indira Gandhi National Tribal University (IGNTU), Amarkantak-484887, India, Jiwani Gitanjali ,   ICAR-National Institute for Plant Biotechnology (NIPB), New Delhi- 110012, India., Solanke Amolkumar U. ,   ICAR-National Institute for Plant Biotechnology (NIPB), New Delhi- 110012, India., Kumar Rakesh ,   Department of Life Science, Central University of Karnataka, Kalaburagi, India, Kumar Anirudh ,   Department of Botany, Indira Gandhi National Tribal University (IGNTU), Amarkantak-484887, India
Published: March 2021

Thespesia lampas has been used as medicinal plants for centuries to treat diseases and its antimicrobial therapeutic role has been well established. However, limited information is available about its activity against phytopathogens. The current study examined the methanol and chloroform extracts of T. lampas root extracts for polyphenols (total phenol and total flavonoid) through Folin-Ciocalteu, Aluminium chloride, and Phosphomolebdenum method. The antioxidant activity such as ABTS (2,20-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid), DPPH (2,2-diphenyl-1-picrylhydrazyl radical), and FRAP (Ferric ion reducing antioxidant potential)] were performed through the free radical scavenging method (ABTS & DPPH) and reducing power evaluation method (FRAP). Results of the study suggested that Methanol extract is superior to chloroform. Phytochemical screening of crude root extract proved the occurrence of steroids, flavonoids, terpenoids, alkaloids, and saponins. FTIR analysis of crude extract was carried out and the different functional groups were detected like O-H, C-H, -C=C-, C=O, C-N, and N-H suggesting the occurrence of several metabolites in the extract. From the GC-MS study, 16 major compounds were selected for docking study, among these, Copaene and Squalene confirmed the antimicrobial nature. The antimicrobial properties of extract were also confirmed against Xanthomonas oryzae pv. oryzae (Xoo), Magnaporthe oryzae(M. oryzae) and Xanthomonas axonopodis pv. glycines (Xag). Thus, T. lampas can be used as an important ingredient in agricultural formulations against various plant diseases.