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КОЛЛЕКЦИЯ НАХОДИТСЯ В СТАДИИ РАЗРАБОТКИ

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27-day variation of galactic cosmic ray intensity by PAMELA experiment. Relationship with heliospheric parameters
(2019) Munini, R.; Modzelewska, R.; Mayorov, A.; Майоров, Андрей Георгиевич
© Published under licence by IOP Publishing Ltd. We analyzed the dynamics of the 27-day variation of galactic cosmic rays (GCR) using PAMELA data in the solar cycle 24 covering the period of 2006-2015. We studied the time line of the proton and helium spectra for different rigidities measured by PAMELA and compared with neutron monitor (NM) observations. We studied the relationship between the 27-day variations of GCR and heliospheric parameters: solar wind velocity and heliospheric magnetic field (HMF). We found that the 27-day variation observed by PAMELA was changing over the solar cycle 24. Near the solar minimum in the 2007-2008 it was observed the stationary 27-day variation with stable amplitude and time of maximum for almost ∼8 solar rotations. Solar wind velocity and Bx component of the HMF also showed the same clear 27-day periodicity. The recurrent changes of solar wind velocity were in strong antiphase with changes of GCR. In contrary in the rising phase of the solar cycle 24 the period of quasi-recurrent GCR variations was much more variable in time and in duration, in average 27-days, but also with the strong contamination of the higher harmonics. The antiphase relation between GCR and solar wind is not so clearly pronounced. Moreover, in the rising phase of the solar cycle 24 we established in all analyzed parameters some wave packages, periodically enhanced, taking place averagely each 1.5-2 years, suggesting the occurrence of the quasi biannual oscillations (QBOs).
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A comparative study of the growth dynamics and tribological properties of nanocrystalline diamond films deposited on the (110) single crystal diamond and Si(100) substrates
(2019) Podgursky, V.; Bogatov, A.; Yashin, M.; Viljus, M.; Bolshakov, A. P.; Sedov, V.; Ralchenko, V.
© 2019 Elsevier B.V. Nanocrystalline diamond (NCD) films were grown on the High Pressure High Temperature (HPHT) (110) single crystal (SC) diamond substrates by Microwave Plasma Enhanced Chemical Vapor Deposition (MPCVD) in methane/hydrogen/nitrogen plasma. The thickness of the films was varied between 2.2 and 22.5 μm. The cauliflower-like surface morphology was observed by means of Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM). The scaling behavior of NCD films growth was investigated. The relatively high value of the roughness exponent αs = 1.5–1.6 was found indicating anomalous scaling. Therefore, shadowing and diffusional instabilities can affect the film growth. The tribological properties of the NCD films deposited on the SC(110) diamond were compared with the NCD films prepared on the Si(100) substrates. Both types of specimens were tested under similar Hertzian contact pressure. The lower wear volume losses were observed on the NCD/SC(110) specimens. Therefore, the influence of substrate and substrate/film interface properties on the tribological behavior of the NCD films grown on Si(100) can be expected to cause NCD films deflection.
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A Computational Model for Supporting Access Policies to Semantic Web
(2019) Kosikov, S. V.; Ismailova, L. Y.; Wolfengagen, V. E.; Исмаилова, Лариса Юсифовна; Вольфенгаген, Вячеслав Эрнстович
© 2019, Springer Nature Switzerland AG. The paper discusses a solution to the problem of data storage in a Web environment and providing access to the data based on their semantics. The problem involves restricting access to data in accordance with the description of the access rights for different classes of users. The information is interpreted in different ways according to the semantics assigned to users. Access policies are proposed as the main technical tool for describing access rights. The provided information is consistent with the semantic description of the user accessing the information. The semantic matching of descriptions of users and the data representation combines formal and informal moments and in general is of a cognitive character. The proposed solution is based on the use of data representation in the form of semantic networks. The solution has computational nature and involves calculating the value of the structures of a specialized control semantic network describing access policies. The solution is presented in the form of a computational model, which is based on the intensional logic. The constructions of the model include both a logical means of general type and specialized structures for control the degree of intensionality. The model provides calculation of construction values depending on the parameter - assignment point. The proposed method of parameter assigning provides the possibility of taking into account the semantic characteristics of users of different classes, as well as a number of other factors essential to support the semantic network (including the presence of different versions). The article offers the architecture of the instrumental complex to support access policies that support the developed computational model, and describes its main components. The components were tested in solving practical problems in the field of jurisprudence to ensure the manipulation and visualization of concepts.
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A DUAL HEAVY ION BEAM PROBE DIAGNOSTIC ON THE TJ-II STELLARATOR
(2019) Chmyga, O. O.; Ascasibar, E.; Barcala, J.; Drabinskiy, M. A.; Melnikov, A. V.; Мельников, Александр Владимирович
The aim of the report is to show the development of HIBP diagnostics on the TJ-II stellarator and, as a result, the expansion of the range of plasma parameters measurements. The first Heavy Ion Beam Probe (HIBP-1) diagnostic is being used on TJ-II stellarator since 2000. It has been shown significant progress in the measurements of plasma profiles and oscillations. The second HIBP-2 system was installed on TJ-II in 2012. Dual HIBP system, consisting of two identical HIBP-1 and HIBP-2 located 1/4 torus apart, provides the measurement of the long-range correlations of plasma parameters in the full plasma column. Low noise high gain (10(7) V/A) preamplifiers with 1 MHz bandwidth sampling is used. They allow to study broadband turbulence and quasi-coherent modes like geodesic acoustic modes, Alfven eigenmodes, suprathermal electron induced modes, etc. New capabilities of the dual HIBP diagnostic in plasma potential and density investigations were demonstrated on TJ-II stellarator in the measurements of the correlation between fluctuations in different poloidal and toroidal locations: on the same field line, on the same magnetic surface or on different magnetic surfaces at different points, separated toroidally and/or poloidally. PACS: 52.70.Nc
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A family of fuzzy multi-criteria sorting models FTOPSIS-Sort: Features, case study analysis, and the statistics of distinctions
(2024) Yatsalo, B.; Radaev, R.; Haktanir, E.; Skulimowski, A.; Kahraman, C.
A family of fuzzy multi-criteria sorting models, FTOPSIS-Sort, as a fuzzy extension of Multi-Criteria Decision Analysis (MCDA) ordinary method TOPSIS, is introduced and analyzed. Models from this family differ by approaches to determining functions of fuzzy numbers (approximate computations, standard fuzzy arithmetic, and transformation method) and by methods for ranking of fuzzy numbers (two defuzzification based ranking methods are considered). The features of developing and adjusting Fuzzy TOPSIS (FTOPSIS) models to sorting problematic are presented. The developed models are implemented in the case study on a healthcare supply chain alternative selection problem. For exploring distinctions in sorting alternatives by FTOPSIS-Sort models, the special algorithms have been developed along with their integrating with Monte Carlo simulation of a large number of input scenarios, each of which is a separate (and independent of the others) multicriteria problem on sorting alternatives. The results of such an analysis demonstrate a significant distinction in sorting alternatives by different FTOPSIS-Sort models. The latter has theoretical, methodological, and applied significance within the use of Fuzzy TOPSIS (Fuzzy MCDA) sorting models.
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A linear "extrinsic" compact model for short-channel MOSFET drain current asymptotic dependence on drain bias in saturation regime
(2019) Turin, V.; Shkarlat, R.; Poyarkov, V.; Kshensky, O.; Zebrev, G.; Зебрев, Геннадий Иванович
© 2019 SPIE. We derived the equation for the drain current of a short-channel MOSFET with nonzero differential conductance in saturation regime describing its nonlinear dependence on "extrinsic" drain bias and accounting for the parasitic and contact series resistances. This implicit equation could be numerically solved in the entire range of the drain biases. We have also derived the equation for the differential conductance of the "extrinsic" MOSFET in the saturation regime. Finally, we have proposed a linear approximation for asymptotic dependence of the "extrinsic" MOSFET drain current on "extrinsic" drain bias in saturation regime.
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A method for obtaining a type of scientific result from the text of an article abstract to improve the quality of recommender systems
(2019) Kuznetsov, I. A.; Guseva, A. I.; Кузнецов, Игорь Александрович; Гусева, Анна Ивановна; Факультет бизнес-информатики и управления комплексными системами
© 2019 IEEE In this paper, the authors present a method to deriving type of scientific results from the texts of scientific articles and implementing these results into recommender systems to enhance their output. Type of scientific results and text data are divided into corresponding classes, which are based on hypothetical user needs. The classes indicate the type of a scientific result in article. The proposed approach involves the determination of meaningful collocations for scientific article. Topic modeling is applied to the received collocation sets from the text of an article abstract. The topics (classes) obtained show the relationship between a scientific article and the type of scientific result.
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A method to enrich reprocessed uranium with various initial contents of even-numbered isotopes
(2019) Nevinitsa, V.; Smirnov, A.; Gusev, V.; Sulaberidze, G.; Смирнов, Андрей Юрьевич; Гусев, Владислав Евгеньевич; Сулаберидзе, Георгий Анатольевич
© 2019 Author(s). Nuclear industry needs effective recovering of fissile material from used nuclear fuel, as uranium accounting more than 90% of the spent nuclear fuel (SNF) volume. Use of reprocessed uranium (RepU) is associated with the difficulties due to the presence of 232,234,236 U isotopes in its composition. The content of these isotopes in fresh fuel is limited in accordance with specifications for low-enriched uranium (LEU). In this regard, in order to make a product of the required quality, it is necessary to modify the regular cascade scheme for enriching natural uranium and/or partially dilute the RepU with raw materials not containing 232,234,236 U (for example, natural uranium or depleted uranium). To solve such problems, a number of cascade schemes have been proposed for the last decades. However, there is still no answer what kind of scheme is preferable. In addition, most of them are unsuitable for full reuse of uranium extracted from spent fuel. Within the framework of the present paper, a double cascade scheme is proposed that allows a full use of reprocessed uranium (of any composition, including "dirty" one) in fuel production in compliance with restrictions on even-numbered isotopes. The "quasi-ideal" cascade, widely used in modeling separation processes in cascades for the separation of multicomponent mixtures, was chosen as the object of this theoretical study. The physical regularities of mass transfer in the proposed cascade scheme are analyzed. The interdependencies of cascade parameters are studied. It is shown that this scheme can be effectively employed to enrich the RepU of "dirty" composition, which are typical for SNF after several irradiation cycles.
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A methodology for evaluating the transmutation efficiency of long-lived minor actinides
(2021) Ashraf, O. ; Тихомиров, Георгий Валентинович; Tikhomirov, G. V.
© 2021 Elsevier B.V.Up to now no definite internationally recognized quantitative criterion of minor actinides (MAs) transmutation efficiency was worked out, although this would be highly desirable. The absolute and relative total mass reduction of MAs are completely inadequate because they ignore the accumulation of higher radiotoxic long-lived MAs from the transmuted nuclide. In the current work, we introduce a new criterion for transmutation efficiency of MAs in nuclear reactors and demonstrate its efficiency by comparing two molten salt reactors; the Single-fluid Double-zone Thorium-based Molten Salt Reactor (SD-TMSR) and the Small Molten Salt Fast Reactor (SMSFR). Our proposed criterion takes into account the mass of all useful actinides, short-lived MAs, and short-lived fission products (FPs). In contrast, the mass parameters calculate the reduction in the MAs mass regardless of the produced nuclides. We introduce a new approach to load MAs into both reactors. The proposed approach merges the advantages of both homogeneous and heterogeneous approaches. The overall change in the actinides and FPs mass during the irradiation has been calculated using direct SERPENT-2 calculations. The results show that the transmutation efficiency of 241Am (the prime isotope for the transmutation) in the SD-TMSR is much higher than in the SMSFR. After 1500 days of radiation, the transmutation efficiency reaches 82.6% for SD-TMSR, however, for SMSFR it reaches 52.5%.
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A Noninvasive Muonography-Based Method for Exploration of Cultural Heritage Objects
(2022) Alexandrov, A. B.; Vasina, S. G.; Galkin, V. I.; Gippius, A. A.; Grachev, V. M.; Kalinina, V. G.; Konovalov, A. S.; Konovalova, N. S.; Korolev, P. S.; Larionov, A. A.; Managadze, A. K.; Melnichenko, I. A.; Okateva, N. M.; Polukhina, N. G.; Roganova, T. M.; Sadykov, Zh. T.; Starkov, N. I.; Starkova, E. N.; Tyukov, V. E.; Chernyavsky, M. M.; Shevchenko, V. I.; Shchedrina, T. V.; Шевченко, Владимир Игоревич; Ларионов, Алексей Александрович; Полухина, Наталья Геннадьевна
An innovative noninvasive method of muonography based on emulsion detectors has been developed. The new method enables detection of changes in the fluxes of atmospheric muons passing through the object under study and determination of the specific features of its internal structure. Owing to the use of the state-of-the-art automated scanning facilities, large-scale studies of natural and industrial objects can be carried out that require processing of large quantity of photoemulsion. A major muonography experiment, in which the internal structure of buildings and the territory of the Svyato-Troitsky Danilov Monastery had been examined, is described in detail.
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A novel methodology for simulation of eeg traveling waves on the folding surface of the human cerebral cortex
(2019) Verkhlyutov, V. M.; Balaev, V. V.; Velichkovsky, B. M.; Ushakov, V. L.; Ушаков, Вадим Леонидович
© Springer Nature Switzerland AG 2019. There is an ample evidence on the existence of traveling waves in the cortex of subhuman animals such as rats, ferrets, monkey, and even birds. These waves have been registered invasively by electrical and optical imaging techniques. Such methodology is not possible in healthy humans. Non-invasive EEG recordings show scalp waves propagation at rates two orders greater than the data obtained invasively in animal experiments. At the same time, it has recently been argued that the traveling waves of both local and global nature do exist in the human cortex. In this article, we report a novel methodology for simulation of EEG spatial dynamics as produced by depolarization waves with parameters taken from animal models. Our simulation of radially propagating waves takes into account the geometry of the surface of the gyri and sulci in the areas of the visual, motor, somatosensory and auditory cortex. The dynamics of the electrical field distribution on the scalp in our simulations is fully consistent with the experimental EEG data recorded in humans.
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A simple model of ac hopping surface conductivity in ionic liquids
(2019) Raicopol, M.; Dascalu, C.; Devan, C.; Alexe-Ionescu, A. L.; Barbero, G.
© 2019 The boundary conditions proposed to discuss the charge exchange taking place in an ionic liquid in contact with non-blocking electrodes are reconsidered in a dynamic situation. Assuming that the variation of the bulk ionic current density depends linearly on the surface value of the ionic current density, the frequency dependence of the phenomenological parameter is determined. The analysis has been performed in the framework where the relaxation times are smaller than a maximum relaxation time τM, and that the response function is independent on the value of the relaxation time. Using simple physical considerations, an expression for the surface conductivity describing the ionic charge exchange at the electrode is obtained. According to our calculations, its frequency dependence is similar to that predicted for the electric conductivity in disordered materials when the mechanism is of the hopping type. From measurements of impedance spectroscopy, by the best fit of the experimental data, the temperature dependence of the hopping time, of the dc surface conductivity, and of the diffusion coefficient are derived. They are in good agreement with the theoretical predictions obtained with the random distribution of surface energy barrier.
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A strategy for a general search for new phenomena using data-derived signal regions and its application within the ATLAS experiment
(2019) Aaboud, M.; Aad, G.; Abbott, B.; Abdinov, O.; Belotskiy, K.; Belyaev, N. L.; Bulekov, O.; Kantserov, V. A.; Krasnopevtsev, D.; Ponomarenko, D.; Proklova, N.; Romaniouk, A.; Shulga, E.; Smirnov, N.; Smirnov, S. Yu.; Smirnov, Y.; Soldatov, E. Yu.; Tikhomirov, V. O.; Timoshenko, S.; Vorobev, K.; Белоцкий, Константин Михайлович; Булеков, Олег Владимирович; Романюк, Анатолий Самсонович; Смирнов, Сергей Юрьевич; Смирнов, Юрий Сергеевич; Солдатов, Евгений Юрьевич; Тихомиров, Владимир Олегович; Тимошенко, Сергей Леонидович; Воробьёв, Константин Александрович
This paper describes a strategy for a general search used by the ATLAS Collaboration to find potential indications of new physics. Events are classified according to their final state into many event classes. For each event class an automated search algorithm tests whether the data are compatible with the Monte Carlo simulated expectation in several distributions sensitive to the effects of new physics. The significance of a deviation is quantified using pseudo-experiments. A data selection with a significant deviation defines a signal region for a dedicated follow-up analysis with an improved background expectation. The analysis of the data-derived signal regions on a new dataset allows a statistical interpretation without the large look-elsewhere effect. The sensitivity of the approach is discussed using Standard Model processes and benchmark signals of new physics. As an example, results are shown for 3.2fb-1 of proton-proton collision data at a centre-of-mass energy of 13TeV collected with the ATLAS detector at the LHC in 2015, in which more than 700 event classes and more than 105 regions have been analysed. No significant deviations are found and consequently no data-derived signal regions for a follow-up analysis have been defined.
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A study into the dependence of the cladding-fuel pellet gap conductance on burn-up and the effects on the reactor core neutronic performance
(2019) Vygovskiy, S. B.; Gruzdov, F. V.; Malkawi, R. T. A.; Груздов, Фёдор Владимирович
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A study into the modes of the VVER-1000 RCP starting in an earlier inoperative loop
(2019) Bragin, I. Ye.; Belozerov, V. I.
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A study on charged compact stars
(2019) Maurya, S. K.; Ray, S.; Aziz, A.; Chardonnet, P.; Khlopov, M.; Хлопов, Максим Юрьевич
© 2019 World Scientific Publishing Company. In this paper, the Einstein-Maxwell spacetime is considered for compact stellar system. To find out solutions of the field equations, we adopt a finite and positive well-behaved metric potential. Under this particular choice, we therefore develop the expressions of the physical features, such as mass, charge, density and pressure, for stellar system in embedding class 1 spacetime. It is observed that all these features are physically viable. In the model, some known compact stars, viz. 4U1820-30, 4U1608-52 and EXO1745-248(I)&(II) are studied successfully through physical analysis. It is also interesting to note that the obtained set of regular solutions to the Einstein-Maxwell equations represents an electromagnetic mass model for isotropic fluid without invoking any negative pressure.
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A wear model for subrough surface contacts of martensitic steels
(2019) Shalygin, M. G.; Suslov, A. G.
© IMechE 2019. This article includes an analysis of techniques for determining wear of contact areas to show two lines of wear research – due to deformations and adhesion forces. It has been established that surface subroughness is not presently taken into account in calculations of wear despite the fact that this surface property is of increasing research interest. The paper aims to develop a mathematical model of wear for subrough surface contacts in the context of deformation and theories of adhesion. Mathematical wear modelling for subrough surfaces is based on studies on causes of their formation due to phase and structural heterogeneity of the material. The article considers contact interaction at the level of surface subroughness; physics of interaction of contact areas at the level of surface subroughness; a mathematical model of deformation and adhesive wear for subrough surface contacts of martensitic steels; some analytical dependences of the theoretical model for a body-centred tetragonal lattice. Analysis of the theoretical concepts shows that wear of subrough surface contacts depends largely on the deformation component, while the adhesive component is significant only during the ‘bedding-in’ period for a friction couple. The materials of the article can be used to calculate the wear for contact areas at the level of surface subroughness.
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Ab initio study of hydrocarbon prismanes and their substituted derivatives
(2019) Salem, M. A.
© 2018 Density functional calculations of hydrocarbon prismanes C2nH2n (where n = 3–10) and their substituted derivatives are carried out to analyze their structures, binding energies and electronic properties. Five substituting radicals (F, Cl, CH3, OH, NO2) are considered. The results indicate the different behavior of the prismanes by substitutions of hydrogen atoms with different radicals. Effective repulsion of substituting radicals on the pentaprismane cage is detected. The dependences of binding energies on number of substituted radicals demonstrate increasing or decreasing trends for different radicals. HOMO-LUMO gaps are slightly changed by substituting doping. All substituting reactions are found to be endothermal. Fluorination is more energetically feasible than other considered reactions.
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Abnormal operation detection in heat power plant using ensemble of binary classifiers
(2019) Korshikova, A. A.; Trofimov, A. G.; Kuznetsova, K. E.; Трофимов, Александр Геннадьевич
© Springer Nature Switzerland AG 2019. The problem of abnormal operation detection is considered for prediction of malfunctions appearance and their progress in the equipment of power plant. Abnormal operation detection method based on multivariate state estimation technique (MSET) along with machine learning algorithms is proposed. The ensemble of linear regression models is used for feature construction. The ensembles of binary classifiers (logistic regressions) together with the multilayer neural network are used for the abnormal operation index calculation based on the constructed features. The method was applied to abnormal operation detection in turbo feed pump (TFP 1100-350-17-4) at Kashirskaya heat power plant (Moscow region, Kashira). It is shown that the abnormal operation index of the pump starts to increase a few days before accidents appear and stays close to zero during the normal operation periods. The obtained results demonstrate that the developed model can be used to detect and predict operation anomalies in the power plant equipment.
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About a New Model of Engineering Training
(2019) Sysoev, A. A.; Aleksandrov, Y. I.; Весна, Елена Борисовна
The aim of the article is to present a model of training engineers based on new approaches to engineering education, taking into account the modern achievements of psychology. The authors believe that the main reason for the insufficient level of engineering training is the discrepancy between the essence of the knowledge transferred to students (both form and content) to the specifics of engineering activity. Therefore, the most important task is to eliminate this contradiction. The basis of the proposed model of engineering training is the design of the educational process in the logic of engineering process in the development of innovative technology. This learning technology called “Simulation-Activity Technology of Engineering Training” (SATET) has been developed and tested at the National Research Nuclear University MEPhI in training engineersdevelopers of innovative technology. The foundations laid in the proposed technology of engineering training, and the mechanisms for its implementation can be considered as a start for the development of a new paradigm of training engineers.