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Remarks on the model of quasi-homogeneous binary mixtures with the NASG equations of state
Applied Mathematics Letters. 2023. Vol. 146. Article 108801.
We deal with the so-called four-equation model for dynamics of the heterogeneous binary mixtures of the Noble-Abel stiffened-gases (NASGes). In relation to the quasi-homogeneous form of the model, we suggest a new insight on a quadratic equation for the pressure, give a simple formula for the squared speed of sound and present a new proof for a formula connecting it to the Wood speed of sound. A short derivation of the balance equation for the pressure is included as well.
Aleksei Samarin, Nazarenko A., Nazarenko D. et al., Machine Learning and Knowledge Extraction 2026 Vol. 8 No. 10 Article 330
Automated microscopic image analysis is essential for quantitative microbiology, yet manual acquisition and generic recognition models struggle with morphological variability and scene artifacts. We address both ends of this pipeline. First, we present a low-cost, open-source acquisition system, based on an Arduino UNO R3 microcontroller and NEMA 17 stepper motors, that automates focusing, magnification, and ...
Added: October 14, 2026
Parkhomenko V., Kulikova S., Buzmakov A. V., Lobachevskii Journal of Mathematics 2026 Vol. 47 No. 6 P. 2979–2992
The stability of formal concepts and its generalization as robustness are considered in the paper. We use an approximation of stability in the form of Δ-measure for fast calculations. A computationally efficient method for calculating robustness based on subcontexts is presented. We also present a new method to analytically evaluate the number of preimages for ...
Added: October 14, 2026
Kuznetsov A. P., Sedova Y. V., Sataev I. R. et al., Mathematics and Computers in Simulation 2027 Vol. 2 P. 574–592
Universal bifurcation structures on the parameter plane of nonlinear systems, known as shrimps, are discussed. An overview of numerous examples from various fields of science is given. Shrimps are typical for both maps of different dimensions and flows. The varieties of shrimp are discussed and relevant examples are given. The similarity property on the parameter ...
Added: October 14, 2026
Dmitriev A., Kornilov V., Batienkov R., Lecture Notes in Civil Engineering 2026 Vol. 886 P. 249–255
Numerous studies have provided compelling evidence that the probability distribution of avalanche sizes follows a power law, and that 1/f noise is present in the stochastic dynamics of landslides. We present a theoretical explanation of these phenomena within the framework of self-organized criticality theory, proposing a discrete-time model in the form of a sandpile cellular ...
Added: October 13, 2026
Dmitriev A., Shulman I., Lebedev A., Studies in Computational Intelligence 2026 Vol. 1265 P. 266–273
A discrete-time model is presented for the self-organization of the X/Twitter social network to the edge of a phase transition, characterized by avalanche-like propagation of information in the network. The model is based on the analogy between the critical dynamics of the X social network and sandpile cellular automata with Manna rule on the Chung-Lu ...
Added: October 13, 2026
Arutyunov K., Kharitonov I. A., Petrosyants K. O., JETP Letters 2026 Vol. 124 No. 6 P. 1–16
Superconducting properties of metallic micro- and nanowires can be entirely different from those of bulk superconductors. Of particular interest is the nonequilibrium current-induced state of a quasi-one-dimensional superconducting channel. The most interesting phenomenon here is the stepped I–V characteristic, explained by a process known as phase slip center activation. If the origin of such step-like ...
Added: October 13, 2026
Makarov D. M., Kalikin N., Fashchevsky K. A. et al., Electrochimica Acta 2026 Vol. 579 Article 150159
Machine learning (ML) has become a powerful tool for accelerating the development of carbon-based supercapacitors;
however, most published models assume that a single predictive framework can describe both conventional
porous carbons and hybrid carbon electrodes. Here, we test this assumption using a comprehensive
benchmark dataset and an extended literature-curated dataset enriched with synthesis- and electrolyte-related
descriptors. Three ML algorithms ...
Added: October 13, 2026
Gusein-Zade S., Campillo A., Delgado F., Mathematische Zeitschrift 2026 Vol. 314 No. 1 P. 1–22
For a subfield $\K$ of the field $\C$ of complex numbers, we consider curve and divisorial valuations on the algebra $\K[[x,y]]$ of formal power series in two variables with the coefficients in $\K$. We compute the semigroup Poincar\'e series and the classical Poincar\'e series of a (discrete, rank one) valuation on it. ...
Added: October 13, 2026
Махлуф М., Ozhegov R., Elezov M. et al., Фотоника 2026 Vol. 20 No. 6 P. 414–423
This paper compares the ranging precision of direct time-of-flight (dToF) and non-line-of-sight (NLOS) LiDAR architectures, both using a superconducting nanowire single-photon detector (SNSPD). Both systems operate at 1550 nm with a 50 ps pulsed laser and time-correlated single-photon counting (TCSPC). The dToF configuration achieved approximately 100 µm precision at 10 m, while the NLOS configuration achieved 500 µm precision for ...
Added: October 12, 2026
Zlotnik A., Lomonosov T., Математическое моделирование 2025 Т. 37 № 1 С. 151–170
A system of four balance differential equations is used to describe dynamics of heterogeneous compressible binary mixtures with stiffened gas equations of state for mixture components, including gas and liquid ones. The main points are its quasi-homogeneous form that arises as a result of eliminating volume fractions of components from the collection of sought functions ...
Added: October 6, 2024
Zlotnik A., Lomonosov T., Doklady Mathematics 2023 Vol. 108 No. 3 P. 443–449
We consider the so-called four-equation model for dynamics of the heterogeneous compressible binary mixtures with the Noble-Abel stiffened-gas equations of state. We exploit its quasi-homogeneous form that arises after excluding the volume concentrations from the sought functions and is based on a quadratic equation for the common pressure of the components. We present new properties ...
Added: March 1, 2024
А. А. Злотник, Т. А. Ломоносов, Доклады Российской академии наук. Математика, информатика, процессы управления (ранее - Доклады Академии Наук. Математика) 2023 Т. 514 № 1 С. 26–33
Рассматривается так называемая модель из четырех уравнений динамики гетерогенных сжимаемых бинарных смесей при уравнениях состояния “сжатого” газа Ноубла-Абеля. Используется ее квазигомогенная форма, возникающая после исключения объемных концентраций из искомых функций и основанная на квадратном уравнении для общего давления компонент. Приводятся новые свойства этого уравнения и простая формула для квадрата скорости звука, предлагается альтернативный вывод формулы, ...
Added: December 23, 2023
Zlotnik A., Lomonosov T., / Series arXiv "math". 2023. No. 2305.10522.
We deal with the reduced four-equation model for dynamics of the heterogeneous compressible binary mixtures with the stiffened gas equations of state. We study its further reduced form, with the excluded volume concentrations and a quadratic equation for the common pressure of the components, that can be called a quasi-homogeneous form. We prove new properties of ...
Added: May 28, 2023
I. A. Kondratyev, S. G. Moiseenko, Lobachevskii Journal of Mathematics 2023 Vol. 44 No. 1 P. 44–56
In astrophysical fluid dynamics, some types of flows, like e.g., magnetorotational super- nova explosions, deal with a highly variable Mach number (from M ≪ 1 in the protoneutron star region to M ≫ 1 near the shock wave expelling from the stellar envelope) in presence of a strong differential rotation. The Courant–Friedrichs–Lewy (CFL) stability condition ...
Added: May 22, 2023
Fedchenko A., Journal of Mathematical Sciences 2023 Vol. 270 No. 6 P. 815–826
We consider regularizations of systems of equations for a multicomponent gas mixture dynamics in the barotropic multi-velocity and one-velocity cases. Energy balance equations are derived for them.
For the system of equations in the one-velocity case, the system linearized on a constant solution is studied, and, for the weak solutions to the initial-boundary value problem with ...
Added: May 11, 2023
Lomonosov T., В кн.: Межвузовская научно-техническая конференция студентов, аспирантов и молодых специалистов им. Е.В. Арменского.: М.: МИЭМ НИУ ВШЭ, 2019.
В работе приводятся критерии (необходимые и достаточные условия) $L^2$-устойчивости для линеаризованных на постоянном решении разностных схем, основанных на некоторой регуляризации 1D баротропных и полных уравнений газовой динамики. Техника вывода основана на спектральном подходе. ...
Added: December 11, 2019
Акимов В. С., Силаев Д. П., Симонов А. С. et al., Вычислительные методы и программирование: новые вычислительные технологии 2017 Т. 18 С. 406–415
The scalability of computations in FlowVision CFD software on the Angara-C1 cluster equipped with Angara interconnect is studied. Several test problems with 260 thousand, 5.5 million and 26.8 million computational cells are considered. Computations in FlowVision are performed using a new solver of linear systems based on the algebraic multigrid (AMG) method. It is shown ...
Added: October 30, 2019
Krasnobaev K. V., Fedchenko A., Journal of Physics: Conference Series 2018 No. 1129 P. 012012
The properties of interstellar gas produce significant effect on dynamic phenomena which occur at large heliocentric distances. HII region is a vivid example of the objects with extremely high radiation, where atoms of hydrogen are heated and ionized by ultraviolet radiation. This article deals with the HII region expansion. To study this process researches need ...
Added: October 13, 2019
Omelchenko A., Усков В. Н., Кожемякин А. О., СПб.: Издательство БГТУ, 2005.
Added: September 19, 2018
Omelchenko A., Письма в Журнал технической физики 2001 Т. 27 № 21 С. 6–12
The problem of interaction of strong and weak discontinuities is solved in the general case for a system of quasilinear hyperbolic equations with two independent variables. It is proved that the product of the left eigenvector of the system by a derivative of the vector function in a strong discontinuity direction remains constant during the ...
Added: September 11, 2018
Lomonosov T., В кн.: Межвузовская научно-техническая конференция студентов, аспирантов и молодых специалистов им. Е.В. Арменского.: МИЭМ НИУ ВШЭ, 2018.
Апробируется новая явная двухслойная по времени и симметричная трехточечная по пространству разностная схема для системы уравнений одномерной газовой дина- мики. Схема основана на специальной квазигазодинамиче- ской регуляризации этой системы и является энтропийно консервативной. Проводится численное моделирование известных в литературе вариантов задачи Римана о распа- де разрыва. ...
Added: August 27, 2018
Zlotnik A., Lomonosov T., / Series math "arxiv.org". 2018.
We consider explicit two-level three-point in space finite-difference schemes for solving 1D barotropic gas dynamics equations. The schemes are based on special quasi-gasdynamic and quasi-hydrodynamic regularizations of the system. We linearize the schemes on a constant solution and derive the von Neumann type necessary condition and a CFL type criterion (necessary and sufficient condition) for weak conservativeness in L2 for ...
Added: March 28, 2018
Злотник А.А., Ломоносов Т.А., В кн.: Межвузовская научно-техническая конференция студентов, аспирантов и молодых специалистов им. Е.В. Арменского.: М.: МИЭМ НИУ ВШЭ, 2017. С. 37–38.
Рассматриваются явные двухслойные по времени и симметричные трехточечные по пространству разностные схемы для системы уравнений одномерной баротропной газовой динамики. Схемы основаны на специальных квазигазо/гидродинамических регуляризациях этой системы. Для линеаризованных на постоянном решении схем выводятся необходимое условие типа фон Неймана и критерий слабой консервативности задачи Коши по начальным данным в пространстве суммируемых с квадратом функций. Выполнено ...
Added: December 16, 2017
Zlotnik A., Lomonosov T., , in: Differential and Difference Equations with ApplicationsVol. 230.: Springer, 2018. P. 635–647.
We consider explicit two-level three-point in space finite-difference schemes for solving 1D barotropic gas dynamics equations. The schemes are based on special quasi-gasdynamic and quasi-hydrodynamic regularizations of the system. We linearize the schemes on a constant solution and derive the von Neumann type necessary condition and a CFL type criterion (necessary and sufficient condition) for ...
Added: December 16, 2017