bluuebunny/crossref_metadata_2025_split huggingface dataset:
Computational method for studying the thermal conductivity of molecular crystals in the course of condensed matter physics
Authors: Pursky O I , Dubovyk T V , Babenko V O , Gamaliy V F , Rasulov R A , Romanenko R P 
Published: March 2021

Abstract
This paper presents a computational method for studying the thermal conductivity of molecular crystals that can be used in the educational course of condensed matter physics. This method is based on the Debye model of thermal conductivity in the approximation of the corresponding relaxation times and allows studying the heat transfer processes features in simple molecular crystals at temperatures close to or above Debye temperature. The thermal conductivity is analysed in the framework of modified Debye model in which heat is transferred by low-frequency phonons and above the phonon mobility edge by “diffusive” modes migrating randomly from site to site. The mobility edge ω0
is found from the condition that the phonon mean-free path cannot become smaller than half the phonon wavelength. The contributions of phonon-phonon, one-, and two-phonon scattering to the total thermal resistance of molecular crystals are calculated under the assumption that the different scattering mechanisms contribute additively. The presented computational method will be useful in pedagogical activities for teaching students of physical faculties.
Use of augmented reality-enabled prototyping of cyber-physical systems for improving cyber-security education
Authors: Skorenkyy Yu , Kozak R , Zagorodna N , Kramar O , Baran I 
Published: March 2021

Abstract
The use of augmented reality-enabled scenarios in cybersecurity teaching is proposed in the article to respond to new requirements for the rapid adoption of new technologies and profound knowledge of cybersecurity issues by professionals. Implementation of project-type activities based on real cybersecurity issues in application fields of cyber-physical systems is suggested to improve the competence forming. A use-case of agricultural cyber-physical system of systems is discussed as a viable example of augmented reality-enabled prototyping of cybersecurity risk-aware architecture. The necessary steps are analysis of general and business-specific tasks on cybersecurity, creation of a list of competencies, formalized in educational standards and curricula, development of gaming scenarios for the formation of hard and soft skills, development of the scenario management system for AR interfaces. The system using AR tools can be easily adapted to different cybersecurity training activities. Industrial cyber-physical systems may be vulnerable due to insecure wireless connectivity, lack of encryption, inadequate access policy. The project-based learning complex is focused on the implementation of a data acquisition, storage and processing platform for new sensor networks and instruments. Representing all the diverse information on different layers will be greatly improved by use of the developed holographic projection AR tools.
The use of online coding platforms as additional distance tools in programming education
Authors: Zinovieva I S , Artemchuk V O , Iatsyshyn Anna V , Popov O O , Kovach V O , Iatsyshyn Andrii V , Romanenko Y O , Radchenko O V 
Published: March 2021

AbstractThis study analyzes various publications of scientists on the training of future IT specialists and the features of training programming using online simulators. The authors of the article made a comparative description of different online platforms for teaching programming according to certain criteria, selected interesting tasks from the online platform hackerrank.com, which have already been used to teach students. Online programming simulators have significant potential in organizing an effective distance learning system in Ukrainian universities. It is important to use online simulators in the learning process as an additional tool for the formation of professional competencies, which provides more intensive involvement of students in the process of writing code and practical (situational) application of existing knowledge. Gamification of the process of training future IT specialists helps to increase cognitive activity, and hence – the quality of the educational process and distance learning in particular. The authors recommend the use of online programming simulators as an additional tool for teaching computer science disciplines, taking into account their functionality, as well as the level of preparation of students and the expected learning outcomes.
Project-based learning in a computer modelling course
Authors: Balyk N , Grod I , Vasylenko Y , Oleksiuk V , Rogovchenko Yu 
Published: March 2021

AbstractThe paper reports authors’ experience of implementing educational projects in a computer modelling course offered to the students majoring in “Secondary Education (Computer Science)” at Ternopil Volodymyr Hnatiuk National Pedagogical University. We analyze approaches to teaching mathematical and computer modelling such as: integration of modelling tasks, naturalistic case study, using of role-playing games, possibilities of STEM-education, motivation and positive attitude to modelling training, etc. Then we illustrate the implementation of the project to study the population dynamics of the grape snail Helix pomatia. The implementation of the project splits into several stages: formulation of the problem, presentation of project tasks, brainstorming, development, testing, presentation of results. The study was conducted at Ternopil Volodymyr Hnatiuk National Pedagogical University within the Norwegian-Ukrainian Project “Development of students' mathematical competencies through Digital Mathematical Modelling” (DeDiMaMo) in partnership with the University of Agder (Norway) and Borys Grinchenko Kyiv University.
The impact of artificial intelligence on employment before and during pandemic: A comparative analysis
Authors: Abuselidze G , Mamaladze L 
Published: March 2021

Abstract
Current trends in scientific research and the development of information technologies cover more and more areas of business. In these conditions, the findings of scientific-technical revolution and the innovations most important factors for the country’s economic development and crucial to become a competitive state. The gradual establishment and the scope of use of artificial intelligence on the world innovative technology market increases daily. The purpose of this work is to investigate its impact on business based on the experience of the world and particularly, in Georgia. Accordingly, the study discusses the stages and main trends of artificial intelligence development. Depending on the scale of implementation, Georgia’s current trends in job cuts / disappearances along with automation are analysed and future prospects are assessed. The paper discusses the use and increased importance of artificial intelligence 4.0 industry in the context of pandemic restrictions in various sectors of the economy and assessed the role in the post-pandemic period. The paper uses both qualitative and quantitative research methods. Content analysis of the scientific literature, statistical indicators and practical examples of different countries and international organizations is provided. Studies of leading analytical institutions are also included to analyse the current situation and prospects for development.
Application of ICT tools in teaching American English for computer science students in the context of global challenges
Authors: Symonenko S V , Zaitseva N V , Vynogradova M S , Osadchyi V V , Sushchenko A V 
Published: March 2021

AbstractThe article deals with the urgent issue of American English learning for IT-professionals under challenging conditions of the changeable economic situation in the world. Some statistical data on global education trends and its analysis are given to confirm the topicality of the problem. State-of-the-art trends in foreign language teaching in the context of global challenges are presented. It is stated that informal education environments, distant learning platforms, virtual reality environments, artificial intelligence applications and collaboration platforms are to be mastered by Ukrainian undergraduates. Certain peculiarities of choosing and studying British and American English course by students of IT-specialities at three Ukrainian universities are given: the course choice procedure, the reasons for course preference, and the syllabus content. The best technologies, applications and tools for classroom activities and independent learning are substantiated, specific examples of their application for British and American English course learning are presented. The transferability of the skills inculcated in the course participants through implementation of the certain tools is founded.
PhD student training: principles and implementation
Authors: Panchenko L F , Korzhov H O , Kolomiiets T V , Yenin M N 
Published: March 2021

AbstractThe article deals with the problem of PhD student training. The Salzburg Principles about the improvement and quality assurance of doctoral programs at universities in every country from European University Association are analysed and materials of LERU on quality culture in Doctoral Education in Europe are used. The three focuses of the research component of doctoral program are proposed. The first focus relates to reproducible research principle. The second focus is related to the use of multivariate models of phenomena’s study and SEM methodology. The SEM methodology is mostly based on deductive logic, involves the preliminary construction of a structural model of the relationships between the variables in order to further check for consistency with the experimental data. The third focus combines qualitative and quantitative methods and the use of triangulation (data triangulation, investigation triangulation, theory triangulation etc.). The content of selected courses for doctorate students is proposed: Reproducible Research and Multivariate Methods in Scientific Research courses. The importance of courses related to the future career is demonstrated, in particular the career of academic researcher. Further development of our work is the creation of teaching and methodological support for selected course “Twitter for professional development of PhD students”.
Arrays of combined antennas excited by high-voltage bipolar pulses
Authors: Koshelev V I , Plisko V V 
Published: March 2021

Abstract
The main characteristics of the TEM antenna and the combined antenna (KA) with extended bandwidth are compared using numerical simulation. The influence of the high-voltage coaxial-strip junction on the KA characteristics is shown. The effective radiation potential is compared relative to the utmost one for high-power UWB radiation sources based on KA arrays, as well as single IRA, HIRA, TEM, and KA antennas.
Ultrawideband antenna arrays based on planar combined antennas for the frequency range of 3.1-10.6 GHz
Authors: Balzovsky E V , Buyanov Y I , Koshelev V I 
Published: March 2021

Abstract
The characteristics of ultrawideband antenna arrays, the element of which is a planar combined antenna with an operating frequency band of 3.1-10.6 GHz, are studied. The results of time-domain studies for a four-element linear array, as well as for a dual polarized module consisting of 2×2 antennas, are presented. The antenna array element is a combination of electric and magnetic radiators. The combined antenna is printed on a dielectric plate with a size of 20×30 mm.
Studying a low-temperature engine with external heat supply
Authors: Mekhtiyev A D , Yugay V V , Alkina A D , Neshina Y G , Kapanova D E 
Published: March 2021

Abstract
The article presents some results of studying the most optimal parameters of the displacer and the piston of a low-temperature engine with external heat supply to increase its efficiency when converting low-grade heat. The developed design of the engine does not have a displacer rod, which provides better sealing and reduces mechanical friction losses. Synchronization of the piston and the displacer movement is ensured by the permanent magnets interaction. The analysis of the results of computer simulation of the PV diagram with an increased diameter of the displacer in relation to the piston diameter plays a positive role in increasing the efficiency and power of the engine. Increasing the diameter of the displacer also leads to increasing the area of the PV diagram and its approach to the ideal thermal Stirling cycle. The simulation results show that increasing the diameter of the displacer above 17/1 does not lead to increasing the area of the PV diagram, and with a larger ratio, on the contrary, it reduces the parameters of the engine efficiency. Further increasing the diameter of the displacer is not advisable in terms of technical and economic ratios. The proposed engine with external heat supply is capable of converting heat from geothermal or industrial wastewater, as well as heated water using a solar collector.
Improving a device for identifying and marking parts of territory with chemical and radioactive contamination
Authors: Msallam M , Syryamkin V I 
Published: March 2021

Abstract
There is an urgent need to conduct a survey of areas exposed to chemical and radioactive contamination, assess the level of risk in these areas, and work on cleansing them of their remnants. Hence the need for advanced robots arises, where they should be capable of carrying out all hard tasks in different environments in all weather conditions and around the clock. In this article, we detail the components of an advanced device that consists of a robot capable of terrestrial-aerial movement and wirelessly connected with computerized workstations. Here we show the multiple advantages that the robot has compared to other previous models. We pay special attention to the technical vision system in the robot, and offer some proposals for the purpose of developing this system.
Development of a generalized physical and mathematical model of working substance processes in an axial turbine stage
Authors: Kalytka V A , Korovkin M V , Madi P Sh , Mekhtiyev A D , Bashirov A V , Mekhtiev R A 
Published: March 2021

Abstract
Methods of continuum mechanics and equilibrium thermodynamics are used to study a generalized physical and mathematical model of the processes of a working substance (steam, gas) moving in the flow part of an axial turbine stage in the nominal operating mode of the turbine. The mathematical description of the hydrodynamics and thermodynamics of the process is carried out for a one-dimensional model, based on the energy equation in thermomechanical form (the first law of thermodynamics in combination with the Bernoulli equation) for the gas (or steam) flow during its adiabatic (isentropic) expansion in the direction of the axis of the turbine stage. The energy equation is written taking into account both thermodynamic (due to the thermal movement of particles) and hydraulic pressure forces (due to the mechanical action of a continuous medium) of the working substance flow on the walls of the stage flow channel. Numerical calculation of flow rates and enthalpy losses on various elements of the stage (nozzle and working blades) is performed on the example of a model turbine with eight axial-type stages, under specified initial conditions of the process.
Determination of the test-samples electron density via dual energy computer tomography
Authors: Grigorieva A A , Bulavskaya A A , Miloichikova I A , Cherepennikov Yu M , Stuchebrov S G 
Published: March 2021

Abstract
In this work we determines electron density using data obtained via CT scanner with one radiation source operating in two modes: with 80 kV and 120 kV voltage. We perform tomography study of calibration phantom with predetermined electron densities. Single linear relationship between energy-subtracted Hounsfield unit and relative electron density is determined. Using determined relationship the relative electron densities of phantom calibration samples is calculated. The comparison of calculated and nominal values proves the possibility of the samples relative electron density determination using energy-subtracted Hounsfield unit with error less than 2%.
Application of a precision programmable DC power supply for spectrometer calibration
Authors: Kobelev D I , Jordan V I 
Published: March 2021

Abstract
The paper presents the circuitry solutions on the basis of which a precision programmable DC power supply was created and tested. The principle of operation of the DC power supply uses a high-precision method of controlling a pulse current stabilizer, based on the adaptation of the duty cycle of the pulse-width modulation (PWM) signal to control the inverter when the load mode changes. From the output of the inverter, the signal is converted by the rectifier into a DC signal with subsequent smoothing of the ripple and enters the load circuit. From a precision low-resistance shunt connected to the load circuit, the signal through the ADC in digital form enters the control unit (CU), implemented on the basis of FPGA, which has a embedded programme for controlling the voltage / current stabilization modes in the load circuit. In addition, the paper shows the use of a precision programmable DC power supply for solving the problem of calibrating the BTC-110S spectrometer. The block diagram of the test stand for spectrometer calibration is presented and relations for the correction of the recorded signals of the thermal radiation spectrum of the objects under study are derived.
Bladder muscle regeneration enhanced by sustainable delivery of heparin from bilayer scaffolds carrying stem cells in a rat bladder partial cystectomy model
Authors: Wang Chengyuan , Wang Hui , Guo Qianping , Ang Xiaojie , Li Bin , Han Fengxuan , Fu Yingxi , Chen Weiguo 
Published: March 2021

Abstract
In bladder tissue engineering, regeneration of muscle is of equal importance to epithelial regeneration. However, as yet there is no effective strategy for promoting bladder muscle regeneration. In this study we aim to promote bladder muscle regeneration by sustainably delivering heparin from a bilayer scaffold carrying stem cells. The bilayer scaffold [heparin–polycaprolactone (PCL)/bladder decellularized matrix (BAM) Hep-PB/PCL] comprises an electrospun layer (Hep-PB electrospun membrane) and a three-dimensional (3D) printed layer (PCL scaffold), fabricated via coaxial-electrospinning and 3D printing, respectively. Heparin was encapsulated into the core of the Hep-PB fibers with a core–shell structure to sustain its release. The morphology of the bilayer scaffold and the microstructure of the electrospun fibers were characterized. The release behavior of heparin from various electrospun membranes was evaluated. The role of Hep-PB in promoting myogenic differentiation of the adipose-derived stem cells (ADSCs) through sustainable release of heparin was also evaluated. After 7 d culture, Hep-PB/PCL scaffolds carrying ADSCs (defined as ASHP) were used for bladder reconstruction in a rat partial cystotomy model. The result shows that the PCL printed scaffold has ordered macropores (∼370 μm), unlike the compact microstructure of electrospun films. The Hep-PB membrane exhibits a sustained release behavior for heparin. This membrane also shows better growth and proliferation of ADSCs than the other membranes. The polymerase chain reaction results show that the expression of smooth muscle cell markers in ADSCs is enhanced by the Hep-PB scaffold. The results of retrograde urethrography and histological staining indicate that the bladder volume in the ASHP group recovers better, and the regenerated bladder muscle bundles are arranged in a more orderly fashion compared with the direct suture and bladder decellularized matrix groups. Therefore, findings from this study show that bladder muscle regeneration could be enhanced by bilayer scaffolds delivering heparin and carrying stem cells, which may provide a new strategy for bladder tissue engineering.
Beyond biomass to carbon fluxes: application and evaluation of a comprehensive forest carbon monitoring system
Authors: Zhou Yu , Williams Christopher A , Hasler Natalia , Gu Huan , Kennedy Robert 
Published: March 2021

Abstract
Accurate quantification of forest carbon stocks and fluxes over regions is needed to monitor forest resources as they respond to changes in climate, disturbance and management, and also to evaluate contributions of forest sector to the regional and global carbon balances. In previous work we introduced a national forest carbon monitoring system (NFCMS) that combines forest inventory data, satellite remote sensing of stand biomass and forest disturbances, and an ecosystem carbon cycle model to assess contemporary forest carbon dynamics at a 30 m resolution. In this study, we evaluate the NFCMS estimates of biomass and carbon fluxes with available data products for the Pacific Northwest (PNW) region, and then analyze the regional carbon balance over the period 1986–2010. The biomass estimates have good agreements with evaluation datasets (eMapR, NBCD2000, and Hagen2005) at regional and forest type levels, and at spatial scales of 1 km2 and larger. Regionwide, PNW forests acted as a stable net sink for atmospheric CO2 (18.5 Tg C yr–1) within forestlands. However, harvesting activities removed significant amounts of carbon, equating to over 75% of annual net carbon sink, though only 25% of this (∼3.5 Tg C yr–1) is emitted to the atmosphere within 50 years. Wildfires contributed modestly to carbon emissions in most years, however, the severe fires of 2002 and 2006 released 16.6 and 7.1 Tg C, respectively. The study demonstrates the potential of the NFCMS framework to serve as a candidate measuring, reporting and verification system, informed by field and remotely sensed inventories, and tracking the carbon balance of the forest sector across the United States.
Impact of climate change on soil nitric oxide and nitrous oxide emissions from typical land uses in Scotland
Authors: Medinets S , White S , Cowan N , Drewer J , Dick J , Jones M , Andrews C , Harvey D , Skiba U 
Published: March 2021

Abstract
Soil emissions of NO and N2O from typical land uses across Lowland and Highland Scotland were simulated under climate change conditions, during a short-term laboratory study. All locations investigated were significant sources of N2O (range: 157–277 µg N2O–N m−2 h−1) and low-to-moderate sources of NO emissions (range: 0.4–30.5 µg NO–N m−2 h−1), with a general tendency to decrease with altitude and increase with fertiliser and atmospheric N inputs. Simulated climate warming and extreme events (drought, intensive rainfall) increased soil NO pulses and N2O emissions from both natural and managed ecosystems in the following order: natural Highlands < natural Lowlands < grazed grasslands < natural moorland receiving high NH3 deposition rates. Largest NO emission rates were observed from natural moorlands exposed to high NH3 deposition rates. Although soil NO emissions were much smaller (6–660 times) than those of N2O, their impact on air quality is likely to increase as combustion sources of NO
x
are declining as a result of successful mitigation. This study provides evidence of high N emission rates from natural ecosystems and calls for urgent action to improve existing national and intergovernmental inventories for NO and N2O, which at present do not fully account for emissions from natural soils receiving no direct anthropogenic N inputs.