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2. Problem statement for practical modeling of temperature fields of gyroscopes in space navigation systems

Author

Pankratov V M, Golikov A V, Barulina M. A., Pankratova E V, and Efremov M V

Subjects
Environmental sciences, GE1-350
Abstract

The paper describes a method of studying temperature fields in fiber-optic gyroscopes that are part of complex navigation systems, using the example fiber-optic gyroscope as part of the angular velocity measurement system BIUS-M-1, developed by “Antares” (Saratov). The work relevance is due to the fact that currently existing methods for studying external and internal thermal effects on precision devices, and the resulting three-dimensional non-stationary temperature fields may be too complicated for practical application, or require significant computation and time resource. Also, not all contemporary models take into account such parameters, as low pressure and vacuum, the importance of which for devices operating in space orbital conditions cannot be underestimated. Therefore, modeling of the thermal process in various devices should be carried out at the design stage. At the same time, such modeling should not be labor-intensive, do not require large financial investment and computing resources. In this paper, the authors formulate a research problem, develop a thermal model, and present the main relations that are the components of the mathematical model of nonstationary three-dimensional inhomogeneous temperature fields in the fiber-optic gyroscope. The resulting model can be implemented quite simply in computational algorithms and software.

Published
2020
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3. Practical modeling of non-stationary temperature fields of fiber-optic gyroscopes in space flight conditions

Author

Pankratov V M, Barulina M. A., Golikov A V, Pankratova E V, and Efremov M V

Subjects
Environmental sciences, GE1-350
Abstract

Based on the mathematical model presented in the first part of this paper, specialized software was created and computer modeling of nonstationary inhomogeneous temperature fields in a fiber-optic gyroscope was performed. The simulation aimed to analyze the temperature distribution in the gyroscope structural elements, especially in the fiber-optic coil and the electronics unit, since temperature fluctuations in them are one of the main sources of device errors. To achieve this goal, a three-dimensional unsteady field was calculated in a fiber-optic gyroscope. Based on the results of computer modeling, comparative data on the temperature distribution in the gyroscope structural elements on earth and orbital flight conditions, and the degree of influence of space and zero-gravity conditions are obtained.

Published
2020
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6. Bright-soliton frequency combs and dressed states in chi(2) microresonators

Author

Puzyrev, D. N., Pankratov, V. V., Villois, A., and Skryabin, D. V.

Subjects
Physics - Optics, Nonlinear Sciences - Pattern Formation and Solitons
Abstract

We present a theory of the frequency comb generation in the high-Q ring microresonators with quadratic nonlinearity and normal dispersion and demonstrate that the naturally large difference of the repetition rates at the fundamental and 2nd harmonic frequencies supports a family of the bright soliton frequency combs providing the parametric gain is moderated by tuning the index-matching parameter to exceed the repetition rate difference by a significant factor. This factor equals the sideband number associated with the high-order phase-matched sum-frequency process. The theoretical framework, i.e., the dressed-resonator method, to study the frequency conversion and comb generation is formulated by including the sum-frequency nonlinearity into the definition of the resonator spectrum. The Rabi splitting of the dressed frequencies leads to the four distinct parametric down-conversion conditions (signal-idler-pump photon energy conservation laws). The parametric instability tongues associated with the generation of the sparse, i.e., Turing-pattern-like, frequency combs with varying repetition rates are analysed in details. The sum-frequency matched sideband exhibits the optical Pockels nonlinearity and strongly modified dispersion, which limit the soliton bandwidth and also play a distinct role in the Turing comb generation. Our methodology and data highlight the analogy between the driven multimode resonators and the photon-atom interaction., Comment: 17 figures, and >20 pages

Published
2021
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8. Photon-photon polaritons in chi(2) microresonators

Author

Skryabin, D. V., Pankratov, V. V., Villois, A., and Puzyrev, D. N.

Subjects
Physics - Optics, Condensed Matter - Quantum Gases, Quantum Physics
Abstract

We consider a high-Q microresonator with $\chi^{(2)}$ nonlinearity under conditions when the coupling rates between the sidebands around the pump and second harmonic exceed the damping rates, implying the strong coupling regime (SC). Using the dressed-resonator approach we demonstrate that this regime leads to the dominance of the Hermitian part of the operator driving the side-band dynamics over its non-Hermitian part responsible for the parametric gain. This has allowed us to introduce and apply the cross-area concept of the polariton quasi-particles and define their effective masses in the context of $\chi^{(2)}$ ring-microresonators. We further use polaritons to predict the modified spectral response of the resonator to a weak probe field, and to reveal splitting of the bare-resonator resonances, avoided crossings, and Rabi dynamics. Polariton basis also allows deriving a discrete sequence of the parametric thresholds for the generation of sidebands of different orders., Comment: 7 pages

Published
2021
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22. International comparison CCQM-K3.2019 automotive exhaust gases

Author

Veen, Adriaan M H van der, primary, Zalewska, Ewelina T, additional, Wijk, Janneke I T van, additional, Kobayashi, Midori, additional, Akima, Dai, additional, Uehara, Shinji, additional, Fioravante, Andreia L, additional, Augusto, Cristiane R, additional, Ribeiro, Claudia C, additional, Silva, Viviane, additional, Dias, Florbela, additional, Botas, Alda, additional, Costa, Carlos, additional, Lee, Joengsoon, additional, Lee, Jinbok, additional, Lim, Jeongsik, additional, Bae, Hyun-Kil, additional, Kang, Namgoo, additional, Cecelski, Christina E, additional, Harris, Kimberly J, additional, Jr, Walter R Miller, additional, Carney, Jennifer, additional, Tshilongo, James, additional, Ntsasa, Napo G, additional, Jozela, Mudalo I, additional, Leshabane, Nompumelelo, additional, Marebane, Prelly Mohweledi, additional, Worton, David R, additional, Webber, Eric B Mussell, additional, Moreno, Sergi, additional, Brewer, Paul J, additional, Konopelko, Leonid A, additional, Kolobova, Anna V, additional, Pankratov, V V, additional, and Efremova, Olga V, additional

Published
2023
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25. Основные проблемы в применении здоровьесберегающих технологий в современной системе образования

Author

Pankratov, V. V.

Subjects
СОВРЕМЕННАЯ СИСТЕМА ОБРАЗОВАНИЯ, ЗДОРОВЬЕСБЕРЕГАЮЩИЕ ТЕХНОЛОГИИ, MODERN EDUCATION SYSTEM, HEALTH-SAVING TECHNOLOGIES
Abstract

В статье рассматриваются основные проблемы здоровьесберегающей деятельности в системе образования: низкий уровень профессиональной компетентности педагогических работников, научно-методической, материально-технической, информационной базы; неудовлетворительное использование здоровьесберегающего потенциала ряда образовательных программ; отсутствие механизма ведомственного и межведомственного сотрудничества, неразвитость нормативно-правовой базы. Ставятся неотложные задачи по решению этих проблем и определяются основные направления деятельности созданного координационного совета по вопросам здоровья обучающихся и педагогов в рамках современной системы образования. The article discusses the main problems of health-saving activities in the education system: low level of professional competence of teaching staff, scientific and methodological, material and technical, information base; unsatisfactory use of health-saving potential of a number of educational programs; lack of a mechanism of departmental and interdepartmental cooperation, underdevelopment of the regulatory framework. Urgent tasks are set to solve these problems and the main activities of the created coordinating council on the health of students and teachers within the framework of the modern education system are determined.

Published
2023

33. Toward on-line slag composition analysis:optical emissions from laboratory electric arc

Author

Pauna, H. (H.), Tuomela, A. (A.), Aula, M. (M.), Turunen, P. (P.), Pankratov, V. (V.), Huttula, M. (M.), and Fabritius, T. (T.)

Abstract

Electric arc furnaces and ladle furnaces have an important role in the future of steelmaking where CO₂ emissions have to be mitigated to an acceptable level. One way to address this goal is to optimize and improve the current practices by adjusting the chemistry and reactions with material additions or gas injections. These procedures would greatly benefit from on-line slag composition analysis. Since the electric arcs radiate throughout the melting, optical emission spectroscopy is a potential method for such analysis. In this study, optical emissions from the electric arc are measured in a laboratory environment. Dozens of atomic emission lines were correlated with Cr₂O₃, Fe₂O₃, Al₂O₃, SiO₂, MnO, MgO, CaO, CaF₂, V₂O₅, and Ni content of the slag together with correlation between CaF₂ and molecular optical emission bands of CaF. Optimal spectral resolution for industrial applications was deducted to be between 0.022 and 0.179 nm.

Published
2022

34. Filterless visible-range color sensing and wavelength-selective photodetection based on barium/nickel codoped bandgap-engineered potassium sodium niobate ferroelectric ceramics

Author

Balanov, V. A. (Vasilii A.), Temerov, F. (Filipp), Pankratov, V. (Vladimir), Cao, W. (Wei), and Bai, Y. (Yang)

Subjects
photodielectrics, KNBNNO, perovskites, photoferroelectrics, photoluminescence, photosensors
Abstract

Photosensors, photodetectors, or color sensors are key components for various optical and optoelectronic applications. Semiconductor-based photodetection has been a dominator which is excellent at measuring the photon intensity of incident light. However, the wavelength of the incident light to be measured must be known beforehand and it mostly depends on auxiliary methods to filter unknown wavelengths. Herein, an alternative but simple mechanism that is using a monolithic, bandgap-engineered photoferroelectric ceramic to blindly determine the wavelength and intensity of incident light at the same time is demonstrated. The photoferroelectric compound is Ba- and Ni-codoped (K,Na)NbO₃ exhibiting a direct bandgap of ≈2 eV and a spontaneous polarization of ≈0.25 C m⁻². The band–band charge carrier transition is confirmed by multiple characterization methods of photoluminescence, photodielectric spectroscopy, and photoconductivity. The existent optoelectrical cumulative effect enabled by the simultaneous narrow bandgap and strong ferroelectricity allows to reliably distinguish the wavelengths of 405, 552, and 660 nm as well as the power density ranging from ≈0.1 to 10 W cm⁻², with the photoresponsivity of up to 60 μA W⁻¹. Consequently, this work proposes an alternative to semiconductor-based counterparts for filterless, wavelength-selective photodetection and color sensing.

Published
2022

37. International comparison CCQM-K118 natural gas

Author

Veen, Adriaan M H van der, primary, Zalewska, Ewelina T, additional, Kipphardt, Heinrich, additional, Beelen, Roel R, additional, Tuma, Dirk, additional, Maiwald, Michael, additional, Fükő, Judit, additional, Büki, Tamás, additional, Nagyné Szilágyi, Zsófia, additional, Beránek, Jan, additional, Cieciora, Dariusz, additional, Ochman, Grzegorz, additional, Kolasiński, Piotr, additional, Garnuszek, Magdalena, additional, Lis, Anna, additional, Kang, Namgoo, additional, Bae, Hyun-Kil, additional, Moon, Dong-Min, additional, Lee, Sangil, additional, Wu, Hai, additional, Ma, Haomiao, additional, Han, Qiao, additional, Smeulders, Damian E, additional, McCallum, John B, additional, Satumba, Raymond, additional, Shimosaka, Takuya, additional, Watanabe, Takuro, additional, Matsumoto, Nobuhiro, additional, Tshilongo, James, additional, Mogale, David Mphara, additional, Jozela, Mudalo, additional, Culleton, Lucy P, additional, Morris, Abigail, additional, Shah, Nirav, additional, Murugan, Arul, additional, Brewer, Paul J, additional, Brown, Richard J C, additional, Val'ková, Miroslava, additional, Tarhan, Tanıl, additional, Engin, Erinç, additional, Konopelko, L A, additional, Kustikov, Yu A, additional, Kolobova, A V, additional, Pankratov, V V, additional, Popova, T A, additional, Meshkov, A V, additional, and Efremova, O V, additional

Published
2022
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38. International comparison CCQM-K165: dimethyl sulfide in nitrogen at 5 nmol mol-1

Author

Lee, S, primary, Kang, J H, additional, Kim, Y D, additional, Kim, D H, additional, Jung, J, additional, Ma, H, additional, Wu, H, additional, Bartlett, S, additional, Worton, D, additional, Murugan, A, additional, Brewer, P J, additional, Konopelko, L A, additional, Kolobova, A V, additional, Malginov, A V, additional, Dobryakov, Y G, additional, Pankratov, V V, additional, and Efremova, O V, additional

Published
2022
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