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2. Investigation of cation self-diffusion mechanisms in UO2+-x using molecular dynamics

Author

Boyarchenkov, A. S., Potashnikov, S. I., Nekrasov, K. A., and Kupryazhkin, A. Ya.

Subjects
Condensed Matter - Materials Science, Physics - Atomic and Molecular Clusters, Physics - Chemical Physics
Abstract

This article is devoted to investigation of cation self-diffusion mechanisms, taking place in UO2, UO2+x, and UO2-x crystals simulated under periodic (PBC) and isolated (IBC) boundary conditions using the method of molecular dynamics in the approximation of rigid ions and pair interactions. It is shown that under PBC the cations diffuse via an exchange mechanism (with the formation of Frenkel defects) with activation energy of 15-22 eV, while under IBC there is competition between the exchange and vacancy (via Schottky defects) diffusion mechanisms, which give the effective activation energy of 11-13 eV near the melting temperature of the simulated UO2.00 nanocrystals. Vacancy diffusion with lower activation energy of 6-7 eV was dominant in the non-stoichiometric crystals UO2.10, UO2.15 and UO1.85. Observations showed that a cation vacancy is accompanied by different number of anion vacancies depending on the deviation from stoichiometry: no vacancies in UO2.15, single vacancy in UO2.00 and four vacancies in UO1.85. The corresponding law of mass action formulas derived within the Lidiard-Matzke model allowed explaining the obtained activation energies and predicting a change in the activation energy within the temperature range of the superionic phase transition. The diffusion of cations on the surface of nanocrystals had activation energy of 3.1-3.6 eV., Comment: 22 pages, 6 tables, 15 figures

Published
2013
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3. High-precision molecular dynamics simulation of UO2-PuO2: Anion self-diffusion in UO2

Author

Potashnikov, S. I., Boyarchenkov, A. S., Nekrasov, K. A., and Kupryazhkin, A. Ya.

Subjects
Condensed Matter - Materials Science, Physics - Chemical Physics
Abstract

Our series of articles is devoted to high-precision molecular dynamics simulation of mixed actinide-oxide (MOX) fuel in the approximation of rigid ions and pair interactions (RIPI) using high-performance graphics processors (GPU). In this article we study self-diffusion mechanisms of oxygen anions in uranium dioxide (UO2) with the ten recent and widely used sets of interatomic pair potentials (SPP) under periodic (PBC) and isolated (IBC) boundary conditions. Wide range of measured diffusion coefficients (from 10^-3 cm^2/s at melting point down to 10^-12 cm^2/s at 1400 K) made possible a direct comparison (without extrapolation) of the simulation results with the experimental data, which have been known only at low temperatures (T < 1500 K). A highly detailed (with the temperature step of 1 K) calculation of the diffusion coefficient allowed us to plot temperature dependences of the diffusion activation energy and its derivative, both of which show a wide (~1000 K) superionic transition region confirming the broad lambda-peaks of heat capacity obtained by us earlier. It is shown that regardless of SPP the anion self-diffusion in model crystals without surface or artificially embedded defects goes on via exchange mechanism, rather than interstitial or vacancy mechanisms suggested by the previous works. The activation energy of exchange diffusion turned out to coincide with the anti-Frenkel defect formation energy calculated by the lattice statics., Comment: 18 pages, 11 figures, 5 tables

Published
2012
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4. Molecular dynamics simulation of UO2 nanocrystals melting under isolated and periodic boundary conditions

Author

Boyarchenkov, A. S., Potashnikov, S. I., Nekrasov, K. A., and Kupryazhkin, A. Ya.

Subjects
Condensed Matter - Materials Science, Physics - Chemical Physics
Abstract

Melting of uranium dioxide (UO2) nanocrystals has been studied by molecular dynamics (MD) simulation. Ten recent and widely used sets of pair potentials were assessed in the rigid ion approximation. Both isolated (in vacuum) and periodic boundary conditions (PBC) were explored. Using barostat under PBC the pressure dependences of melting point were obtained. These curves intersected zero near -20 GPa, saturated near 25 GPa and increased nonlinearly in between. Using simulation of surface under isolated boundary conditions (IBC) recommended melting temperature and density jump were successfully reproduced. However, the heat of fusion is still underestimated. These melting characteristics were calculated for nanocrystals of cubic shape in the range of 768-49 152 particles (volume range of 10-1000 nm^3). The obtained reciprocal size dependences decreased nonlinearly. Linear and parabolic extrapolations to macroscopic values are considered. The parabolic one is found to be better suited for analysis of the data on temperature and heat of melting., Comment: 19 pages, 15 figures, 4 tables

Published
2011
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5. Molecular dynamics simulation of UO2 nanocrystals surface

Author

Boyarchenkov, A. S., Potashnikov, S. I., Nekrasov, K. A., and Kupryazhkin, A. Ya.

Subjects
Condensed Matter - Materials Science, Physics - Chemical Physics
Abstract

In this article we investigated surface of nanocrystals (NC) of uranium dioxide (UO2) using molecular dynamics (MD) under isolated (non-periodic) boundary conditions with the approximation of pair potentials and rigid ions. It is shown that a cubic shape of the model NCs is metastable and the stable equilibrium is reached in the process of structural relaxation to the octahedral shape over a time of 1000 ns (200 million MD steps), which increases with the size of NC. We measured the size dependences of the lattice parameter and the surface energy density for NC of cubic and octahedral shape with volume up to 1000 nm3 (50000 particles) at temperatures of 2200K and 2300K. For the surfaces {100} and {111} we obtained the energy density {\sigma}100=1.602\pm0.016 J/m^2, {\sigma}111=1.137\pm0.032 J/m^2 and surface tension constant {\gamma}111=0.875\pm0.008 J/m^2. The resulting ratio of {\sigma}100/{\sigma}111=1.408\pm0.042 within the error coincides with the experimental value of 1.42\pm0.05 measured for microscopic cavities in monocrystals of UO2., Comment: 11 pages, 8 figures, 5 tables

Published
2011
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6. High-precision molecular dynamics simulation of UO2-PuO2: superionic transition in uranium dioxide

Author

Potashnikov, S. I., Boyarchenkov, A. S., Nekrasov, K. A., and Kupryazhkin, A. Ya.

Subjects
Condensed Matter - Materials Science, Physics - Chemical Physics
Abstract

Our series of articles is devoted to high-precision molecular dynamics simulation of mixed actinide-oxide (MOX) fuel in the rigid ions approximation using high-performance graphics processors (GPU). In this article we assess the 10 most relevant interatomic sets of pair potential (SPP) by reproduction of the Bredig superionic phase transition (anion sublattice premelting) in uranium dioxide. The measurements carried out in a wide temperature range from 300K up to melting point with 1K accuracy allowed reliable detection of this phase transition with each SPP. The {\lambda}-peaks obtained are smoother and wider than it was assumed previously. In addition, for the first time a pressure dependence of the {\lambda}-peak characteristics was measured, in a range from -5 GPa to 5 GPa its amplitudes had parabolic plot and temperatures had linear (that is similar to the Clausius-Clapeyron equation for melting temperature)., Comment: 7 pages, 6 figures, 1 table

Published
2011
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7. High-precision molecular dynamics simulation of UO2-PuO2: pair potentials comparison in UO2

Author

Potashnikov, S. I., Boyarchenkov, A. S., Nekrasov, K. A., and Kupryazhkin, A. Ya.

Subjects
Condensed Matter - Materials Science, Physics - Chemical Physics
Abstract

Our series of articles is devoted to high-precision molecular dynamics simulation of mixed actinide-oxide (MOX) fuel in the approximation of rigid ions and pair interactions (RIPI) using high-performance graphics processors (GPU). In this first article 10 most recent and widely used interatomic sets of pair potentials (SPP) are assessed by reproduction of solid phase properties of uranium dioxide (UO2) - temperature dependences of the lattice constant, bulk modulus, enthalpy and heat capacity. Measurements were performed with 1K accuracy in a wide temperature range from 300K up to melting points. The best results are demonstrated by two recent SPPs MOX-07 and Yakub-09, which both had been fitted to the recommended thermal expansion in the range of temperatures 300-3100K. They reproduce the experimental data better than the widely used SPPs Basak-03 and Morelon-03 at temperatures above 2500K., Comment: 11 pages, 9 figures, 4 tables

Published
2011
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8. The structure of the logistics supply chains of the EU countries in the context of the Covid-19 pandemic.

Author

Nekrasov, K. V.

Subjects
*COVID-19 pandemic, *SUPPLY chains, *ECONOMIC stabilization, *TRANSPORTATION industry, *LOGISTICS, *COVID-19
Abstract

The article shows that the crisis phenomena taking place in the world have an impact on many socio-economic processes. The scale of these negative consequences affected not only the local markets of countries, but also made significant adjustments to the existing economic relations in supply chains and their structure on a global scale. The analysis of the current situation is based on reports and statistics from the European Union and the World Bank. An assessment of the sectors of the EU transport sector and the change in their share of participation in trade and economic relations of the EU member states during the COVID-19 pandemic was made. The main directions for overcoming the crisis were offered. [ABSTRACT FROM AUTHOR]

Published
2023
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15. A mechanism of cation diffusion in ThO2 nanocrystal bulk. A molecular dynamic simulation.

Author

Seitov, D. D., Pitskhelaury, S. S., Nekrasov, K. A., Boyarchenkov, A. S., and Kupryazhkin, A. Ya.

Subjects
DYNAMIC simulation, MOLECULAR dynamics, VACANCIES in crystals, FREE surfaces, CATIONS
Abstract

A molecular dynamics simulation of the self-diffusion of thorium cations in ThO2 nanocrystals with a free surface is conducted. It is shown that a vacancy in the bulk of a crystal initiates a complex collective movement of cations, in which the interstitial positions surrounding the vacancy are involved. The diffusion coefficients of cations in the temperature range are calculated. The effective activation energy of diffusion is ED = (7.6 ± 0.7) eV. [ABSTRACT FROM AUTHOR]

Published
2022
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16. Проблемы организации мультимодальных грузоперевозок в период пандемии

Author

Mokina, A. I., Nekrasov, K. V., Мокина, А. И., Некрасов, К. В., Mokina, A. I., Nekrasov, K. V., Мокина, А. И., and Некрасов, К. В.

Abstract

The article presents the trends in the logistics sector in 2020. A comparative analysis of the trade of the Russian Federation with foreign countries based on the results of previous years has been carried out. The concept of multimodal transportation has been investigated. The impact of the Covid-19 coronavirus infection on the work of enterprises was also considered., В статье представлены тенденции логистической сферы в 2020 году. Произведен сравнительный анализ торговли Российской Федерации с зарубежными странами по итогам прошлых лет. Исследовано понятие мультимодальных перевозок. Так же рассмотрено влияние коронавирусной инфекции Covid-19 на работу предприятий.

Published
2021

17. Влияние пандемии на структуру логистической цепи поставок и торговлю Евросоюза

Author

Allahverdiyeva, G. Z. kyzy, Nekrasov, K. V., Аллахвердиева, Г. З. кызы, Некрасов, К. В., Allahverdiyeva, G. Z. kyzy, Nekrasov, K. V., Аллахвердиева, Г. З. кызы, and Некрасов, К. В.

Abstract

This article focuses on the most relevant topics for the period 2019-2021 - the coronavirus pandemic. The pandemic in this article is the subject of influence on large areas, which are considered in the article-logistics and economics (using the example of the European Union). The importance of logistics as one of the key sectors of the world economy is determined. Attention is paid to the problems of the studied directions and the main development trends. Using available sources of information, the main indicators of industry performance are considered. Their dynamics and rates of change are determined., В данной статье уделяется внимание наиболее актуализированной тематике на период 2019-2021 годов- пандемии коронавируса. Пандемия в данной статье выступает предметом влияния на крупные направления, которые и рассматриваются в статье-логистика и экономика (на примере Европейского союза). Определяется значимость логистики как одного из ключевых секторов мировой экономики. Обращается внимание на проблематику изучаемых направлений и основные тенденции развития. Используя доступные источники информации, рассматриваются основные показатели деятельности отраслей. Определяются их динамика и темпы изменения.

Published
2021

18. Diffusion of Oxygen in Hypostoichiometric Uranium Dioxide Nanocrystals. A Molecular Dynamics Simulation

Author

Nekrasov, K. A., Galashev, A. E., Seitov, D. D., Gupta, S. K., Nekrasov, K. A., Galashev, A. E., Seitov, D. D., and Gupta, S. K.

Abstract

A molecular dynamic simulation of diffusion of intrinsic oxygen anions in the bulk of hypostoichiometric UO2-x nanocrystals with a free surface was carried out. The main diffusion mechanism turned out to be the migration of oxygen by the anionic vacancies. It is shown that in the range of values of the non-stoichiometry parameter 0.05 ≤x ≥ 0.275 the oxygen diffusion coefficient D is weakly dependent on temperature, despite the uniform distribution of the vacancies over the model crystallite. The reliable D values calculated for the temperature T = 923 K are in the range from 3∙10-9 to 7∙10-8 cm2/s, in quantitative agreement with the experimental data. The corresponding diffusion activation energy is in the range from 0.57 eV to 0.65 eV, depending on the interaction potentials used for the calculations.

Published
2021

19. Main Factors of the Spatial Development in Promoting and Hindering Agriculture Robotization in Russia

Author

Nabokov, V. I., Skvortsov, E. A., Sharapova, N. V., Ziablitckaia, N. V., Pryadilina, N. K., Nekrasov, K. V., Nabokov, V. I., Skvortsov, E. A., Sharapova, N. V., Ziablitckaia, N. V., Pryadilina, N. K., and Nekrasov, K. V.

Abstract

This research determines the significant differences in the level of robotization of agriculture in Russia. As the processes of robotization of agriculture can be associated with certain socio-economic characteristics of the spatial development of regions, this study aims to analyze the factors of the spatial development of regions that promote and hinder the robotization of agriculture. Having identified and systematized influencing factors makes it possible to reduce the impact of obstacles and intensify the influence of factors contributing to the introduction of robotics. A 2D projection of the characteristics of the expert group (the Phi contingency coefficient) and the results of the expert survey (the Pearson's correlation coefficient) was developed. The most significant factor in the spatial development of regions, which currently hinders the robotization of agriculture, is a share of profitable agricultural organizations in the region. According to the experts, the factors of the spatial development of region, hindering the robotization of agriculture are insufficient volumes of subsidies for the technical renewal of agriculture and investment risks in the region. The most significant factor in the spatial development of regions, contributing to the robotization of agriculture is the availability of a Developed network of servicing for robotics. Considering these factors will make it possible to choose the optimal measures of influence in order to intensify the activity in robotizing the production and rural areas. (C) 2021 INT TRANS J ENG MANAG SCI TECH.

Published
2021

20. IMPACT OF THE PANDEMIC ON THE STRUCTURE OF THE LOGISTIC SUPPLY CHAIN AND TRADE OF THE EUROPEAN UNION

Author

Allahverdiyeva, G. Z. kyzy and Nekrasov, K. V.

Subjects
ЛОГИСТИЧЕСКИЕ ТЕНДЕНЦИИ, ПАНДЕМИЯ, ЕВРОПЕЙСКИЙ СОЮЗ, LOGISTICS TRENDS, ECONOMY, ЭКОНОМИКА, PANDEMIC, EUROPEAN UNION
Abstract

This article focuses on the most relevant topics for the period 2019-2021 - the coronavirus pandemic. The pandemic in this article is the subject of influence on large areas, which are considered in the article-logistics and economics (using the example of the European Union). The importance of logistics as one of the key sectors of the world economy is determined. Attention is paid to the problems of the studied directions and the main development trends. Using available sources of information, the main indicators of industry performance are considered. Their dynamics and rates of change are determined. В данной статье уделяется внимание наиболее актуализированной тематике на период 2019-2021 годов- пандемии коронавируса. Пандемия в данной статье выступает предметом влияния на крупные направления, которые и рассматриваются в статье-логистика и экономика (на примере Европейского союза). Определяется значимость логистики как одного из ключевых секторов мировой экономики. Обращается внимание на проблематику изучаемых направлений и основные тенденции развития. Используя доступные источники информации, рассматриваются основные показатели деятельности отраслей. Определяются их динамика и темпы изменения.

Published
2021

25. Single-stage plasma-arc synthesis of metallo-endofullerences

Author

Gerasimov, V. I., Kalinin, G. V., Nikonov, Yu. A., Titovets, Yu. F., Kalabushkin, A. E., Alekhin, O. S., Nekrasov, K. V., Rusetskaya, S. N., Arapov, O. V., Alekseev, N. I., Kustova, E. V., Lishchuk, V. V., Pleshkov, M. A., Semenov, K. N., Keskinov, V. A., and Charykov, N. A.

Published
2007
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26. BRAF status in сito-morphological diagnosis of thyroid nodules

Author

Tarashchenko, Yu. M., Kovalenko, A. Ye., Ostafiichuk, M. V., and Nekrasov, K. A.

Subjects
хірургічне лікування, мутация BRAF V600E, щитоподібна залоза, endocrine system diseases, тонкоигольная аспирационная пункционная биопсия, papillary thyroid, surgical treatment, BRAF V600E mutation, мутація BRAF V600E, digestive system diseases, тонкоголкова аспіраційна пункційна біопсія, хирургическое лечение, карцинома, fine needle aspiration biopsy, cancer, щитовидная железа, neoplasms
Abstract

The aim of study – to determine the significance of the BRAF V600E mutation presence in the cytomorphological diagnosis of thyroid nodules.Materials and methods. The study included 65 patients requiring surgical treatment for thyroid nodular pathology. Material to determine the BRAF V600E mutation was taken by means of a fine needle aspiration biopsy before surgery. The BRAF V600E mutation was detected by real-time PCR analysis.Results. A pathomorphological study of the removed thyroid nodules showed that all 22 benign nodules were BRAF-negative. Among the 43 papillary thyroid cancer only 20 were BRAF-positive (46.5 %). BRAF mutations were found more often (P < 0.001) in patients with classical and oxyphilic cell papillary thyroid cancer (60 % and 100 %, respectively) than in patients with follicular variant of PTC (6.7 %). Locally invasive tumors were more often BRAF-negative cases (P < 0.05) than non-invasive tumors and amounted to 75.0 % and 37.5 %, respectively. But, when comparing the morphological variant and invasive properties of the tumor, it was found that all cases of the follicular variant of the PC had signs of invasion and were significantly more often observed (P < 0.01) compared with the classical and oxyphilic cell variants. The BRAF V600E mutation was observed both in tumors with metastasis to the regional lymph nodes (55.0 %) and in tumors without metastases (37.5 %), with no significant difference.Conclusions. The presence of the BRAF V600E mutation is a diagnostic marker for papillary thyroid carcinoma, and its detection confirms the presence of malignancy. BRAF positive carcinomas were in 46.5 % of cases. The combination of BRAF-negative and the cytology of groups V and VI by Bethesda may indicate about a follicular variant of PTC. An increase in the number of molecular genetic markers in the preoperative diagnosis of thyroid cancer can significantly improve the quality of diagnosis and surgical treatment., Цель работы – определение значимости наличии мутации BRAF V600E в цитоморфологической диагностике тиреоидных узлов.Материалы и методы. В исследование включены 65 пациентов, нуждающихся в хирургическом лечении по поводу узловой патологии щитовидной железы (ЩЖ). Материал для определения мутации BRAF V600E брали путем тонкоигольной пункционной аспирационной биопсии на дооперационном этапе. Мутацию BRAF V600E определяли путем проведения анализа методом ПЦР в режиме реального времени.Результаты. Окончательное морфологическое исследование удаленных узлов показало отсутствие BRAF-мутаций во всех 22 доброкачественных узлах. Среди 43 папиллярных карцином (ПК) BRAF-положительными были 20 (46,5 %).BRAF-мутации достоверно чаще (p < 0,001) обнаружены у пациентов с классическим и оксифильноклеточным вариантами папиллярной карциномы (60 % и 100 % соответственно) по сравнению с фолликулярным вариантом (6,7 %). При оценке инвазивности опухолей обнаружено, что среди локально инвазивных ПК щитовидной железы достоверно чаще преобладали BRAF-отрицательные случаи (p < 0,05) над неинвазивными ПК (75,0 % и 37,5 % соответственно). В ходе анализа инвазивности опухоли и морфологического варианта установлено, что все случаи фолликулярного варианта ПК имели признаки инвазии, их достоверно чаще отмечали (p < 0,01) по сравнению с классическим и оксифильноклеточным вариантами. Мутация BRAF V600E обнаружена и в опухолях с метастазированием в регионарные лимфатические узлы шеи (55,0 %), и в опухолях без метастазов (37,5 %), без вероятной разницы.Выводы. Наличие мутации гена BRAF V600E – диагностический маркер папиллярной карциномы щитовидной железы, и ее установление подтверждает наличие злокачественности. BRAF-положительные карциномы отмечены в 46,5 % наблюдений. Отсутствие мутации гена BRAF V600E в сочетании с цитологическим заключением V и VI групп по Bethesda может свидетельствовать о наличии фолликулярного варианта ПК. Расширение количества молекулярно-генетических маркеров в дооперационный диагностике рака щитовидной железы может значительно улучшить качество диагностики и хирургического лечения., Мета роботи – визначення значущості наявності мутації BRAF V600E в цитоморфологічній діагностиці тиреоїдних вузлів.Матеріали та методи. У дослідження залучили 65 пацієнтів, які потребували хірургічного лікування з приводу вузлової патології щитоподібної залози (ЩЗ). Матеріал для визначення мутації BRAF V600E брали шляхом тонкоголкової пункційної аспіраційної біопсії на доопераційному етапі. Мутацію BRAF V600E визначали шляхом здійснення аналізу методом ПЛР у режимі реального часу.Результати. Остаточне морфологічне дослідження видалених вузлів показало відсутність BRAF-мутацій у всіх 22 доброякісних вузлах. Серед патогістологічно підтверджених 43 папілярних карцином (ПК) BRAF-позитивними були 20 (46,5 %).Аналізуючи наявність генетичних мутацій залежно від підтипів папілярних карцином ЩЗ, виявили: BRAF-мутації достовірно частіше (p < 0,001) визначали у пацієнтів із класичним та оксифільноклітинним варіантами папілярної карциноми (60 % і 100 % відповідно) порівняно з фолікулярним варіантом папілярної карциноми ЩЗ (6,7 %). Оцінюючи інвазивність пухлин, встановили, що серед локально інвазивних ПК ЩЗ вірогідно частіше переважали BRAF-негативні випадки (p < 0,05) над неінвазивними ПК (75,0 % і 37,5 % відповідно). Під час аналізу інвазивності пухлини залежно від її морфологічного варіанта виявили, що всі випадки фолікулярного варіанта ПК мали ознаки інвазії, їх вірогідно частіше визначали (p < 0,01) порівняно з класичним та оксифільноклітинними варіантами. Мутація BRAF V600E встановлена і в пухлинах із метастазуванням у реґіонарні лімфатичні вузли шиї (55,0 %), і в пухлинах без метастазів (37,5 %) без вірогідної різниці. Висновки. Наявність мутації гена BRAF V600E – діагностичний маркер папілярної карциноми щитоподібної залози, його виявлення підтверджує наявність злоякісності. BRAF-позитивні карциноми виявили в 46,5 % спостережень. Відсутність мутації гена BRAFV600E в поєднанні з цитологічними висновками груп V і VI за Bethesda може свідчити про наявність фолікулярного варіанта ПК. Розширення кількості молекулярно-генетичних маркерів у доопераційній діагностиці раку ЩЗ може значно поліпшити якість діагностики та хірургічного лікування.

Published
2020

27. THE INTERPARTICLE POTENTIALS FOR MOLECULAR DYNAMIC SIMULATION OF THE IMPACT OF COLLISION CASCADES ON GAS BUBBLES IN PLUTONIUM DIOXIDE

Author

Seitov, D. D., Pitskhelaury, S. S., Nekrasov, K. A., Kupryazhkin, A. Ya., and Пицхелаури, С. C.

Abstract

The influence of interaction potentials choice on the molecular dynamics simulation of radiogenic gas bubble resolution under the collision cascades impact in PuO2 crystal is studied. This choice is shown to fundamentally affect the amount of energy transferred to a bubble from the fast particles. Исследование выполнено при финансовой поддержке РФФИ в рамках научного проекта № 19-32-90274.

Published
2020

28. A MOLECULAR DYNAMICS SIMULATION OF URANIUM CARBONITRIDE CRYSTALS USING A MODIFIED EMBEDDED ATOM MODEL METHOD

Author

Pitskhelaury, S. S., Seitov, D. D., Nekrasov, K. A., Gupta, S. K., and Пицхелаури, С. C.

Abstract

A molecular dynamic simulation of uranium carbonitrides is carried out. Parameters and potentials for dynamic variation of particle charges are proposed. The lattice constant, bulk modulus, heat capacity dependences on temperature and the melting points are determined in the framework of the model. Исследование выполнено при финансовой поддержке РФФИ в рамках научного про-екта №16-52-48008 ИНД_оми. С.К. Гупта также благодарит Департамент науки и технологии (Индия) и РФФИ за поддержку по гранту INT/RUS/RFBR/IDIR/P-6/2016.

Published
2020

29. HELIUM DIFFUSION ALONG A RING DISLOCATION IN URANIUM DIOXIDE. A MOLECULAR DYNAMICS SIMULATION

Author

Shekunov, G. S. and Nekrasov, K. A.

Abstract

A simulation of helium migration along a ring dislocation in uranium dioxide is done. Two sets of He interaction potentials are compared, fundamentally differing in the strength of binding of the atom to uranium ions. Helium diffusion coefficients are obtained at temperatures from 375 to 1000 K. Исследование выполнено при финансовой поддержке РФФИ в рамках научного проекта № 16-52-48008 ИНД_оми.

Published
2020

32. The density of robotization of agriculture in Russia and its regions

Author

Nabokov, V. I., Semin, A. N., Pryadilina, N. K., Skvortsov, E. A., Gusev, A. S., Nekrasov, K. V., Nabokov, V. I., Semin, A. N., Pryadilina, N. K., Skvortsov, E. A., Gusev, A. S., and Nekrasov, K. V.

Abstract

According to the Rosstat data a share of agricultural organizations which introduce technological innovations is low (2.7%). The study aims to determine the density of agricultural robotization in Russia and its regions. The density of agricultural robotization is influenced by the average annual number of employees in the industry, which was 5802 thousand people in 2013-2019 and decreased by 22% over the studied period. The data show that 435 units of robotics were introduced in agricultural organizations in the Russian Federation in 2006-2019. The vast majority of robotics used in agriculture in Russia is milking robots mainly by European manufacturers. Robotics is used in the agricultural sector in the Central (185 units), Volga (95 units), NorthWest (66 units) and Ural (68 units) federal districts. The introduction of robotics in agriculture in the Southern, Siberian and North Caucasian federal districts is practically not carried out. The highest density of agricultural robotization is observed in the Kaluga (42.67 robots per 10 thousand employees in the industry), the Ryazan (14.8), the Sverdlovsk (6.32) and the Vologda Region (6.21). The results of the study will allow development of a mechanism that promotes priority robotization of rural areas where robotization is slow or is not carried out to prevent their technological lagging behind and the further development of a stagnation processes. The scientific significance of the research results will contribute to the development of theoretical aspects of robotics application in agriculture and the spatial aspects of robotization. © 2020, World Scientific and Engineering Academy and Society. All rights reserved., The study was funded by RFBR, a project number is 20-010-00636 А «Spatial development of agricultural robotization in Russia: trends, factors, mechanisms»

Published
2020

33. Ab initio calculations of pure and Co+2-doped MgF2 crystals

Author

Usseinov, A. B., Gryaznov, D., Popov, A. I., Kotomin, E. A., Seitov, D., Abuova, F., Nekrasov, K. A., Akilbekov, A. T., Usseinov, A. B., Gryaznov, D., Popov, A. I., Kotomin, E. A., Seitov, D., Abuova, F., Nekrasov, K. A., and Akilbekov, A. T.

Abstract

Ab initio calculations of the atomic, electronic and vibrational structure of a pure and Co+2 doped MgF2 crystals were performed and discussed. We demonstrate that Co+2 (3d7) ions substituting for Mg is in the high spin state. In particular, the role of exact non-local exchange is emphasized for a proper reproduction of not only the band gap but also other MgF2 bulk properties. It allows us for reliable estimate of the dopant energy levels position in the band gap, and its comparison with the experimental data. Thus, the present ab initio calculations and experiment data demonstrate that the Co+2 ground state level lies at ≈2 eV above the valence band top. © 2020 Elsevier B.V.

Published
2020

48. Fuel loading optimization into the active zone of the BN-800 reactor for the purpose of the most balanced distribution of the energy releasing field

Author

Osanova, E. R. and Nekrasov, K. A.

Abstract

During the research, the optimization of fuel loading into the active zone of the BN-800 reactor was conducted using the simplest method by the mass of fissile material without the possibility of installing different types of fuel in one zone. The simulation was carried out in the software-hardware complex GEFEST-800.

Published
2019

49. Ab-initio calculations of CO2 adsorption on nonpolar (100) ZnO surface

Author

Usseinov, A., Akilbekov, A., Dauletbekova, A., Geniyatova, Sh., Soltanbek, N., Nekrasov, K., and Seitov, D.

Subjects
Condensed Matter::Materials Science, Physics::Chemical Physics
Abstract

In this paper, the ab-initio calculations of the CO2 molecule adsorption on the nonpolar ZnO surface were carried out in order to find the equilibrium configuration of the adsorbed molecule, as well as we studied the effect of impurity concentration and the presence of native point defects onto binding energy of molecule. Also, the potential for-mation of a new molecular complex is considered. All results were compared with known experimental data.

Published
2019

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