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Thermomechanical approach to calculating mechanical stresses in inhomogeneous fluids and its applications to ionic fluids
Journal of Statistical Mechanics: Theory and Experiment. 2024. Vol. 2024. No. 12. Article 123201.
This extended article presents a thermomechanical approach for calculating the stress tensor from the thermodynamic potential of inhomogeneous fluids and some applications to ionic fluids. The technique, based on the invariance of the fluid's thermodynamic potential with respect to spatial transformations of translation and rotation, offers an alternative to the general covariant approach developed by two of the authors. We apply this technique to both pure mean-field theories of fluids in general and a theory that includes thermal fluctuations of the order parameter, using the example of ionic fluids. Additionally, we apply the thermomechanical approach to fluid models with vector order parameters, such as liquid dielectrics. For this case, we obtain a general expression for the stress tensor. Furthermore, we discuss specific issues related to the calculation of disjoining pressure in ionic fluids confined in nanoscale slit-like pores with metal or dielectric walls, using the Coulomb gas model. To test the robustness of the proposed approach, we reproduce a number of known results from the statistical theory of inhomogeneous fluids and obtain several new ones.
German O., Illarionov A., Известия РАН. Серия математическая 2026 Т. 90 № 3 С. 3–18
Пусть симплекс с целочисленными вершинами - содержащий ровно одну целочисленную точку, отличную от своих вершин. В работе доказывается, что если точка находится во внутренности симплекса или в относительной внутренности некоторой гиперграни симплекса, то объем симплекса ограничен величиной, зависящей только от размерности, в противном случае объем симплекса может быть сколь угодно большим. Этот результат применяется для вывода асимптотической формулы для среднего числа вершин полиэдров ...
Added: June 29, 2026
Ivchenko A., Nigmatullin R. R., Dorokhin S. V., Mathematics 2026 Vol. 9 No. 4 Article 381
n this paper, we focus on the generalization of the Hurst empirical law and suggest a set of reduced parameters for quantitative description of long-time series. These series are usually considered as a specific response of a complex system (economic, geophysical, electromagnetic and other systems), where successive fixations of external factors become impossible. We consider ...
Added: June 27, 2026
Ivchenko A., Шестопёров А. И., Фомина Е. В., Microgravity Science and Technology 2025 Vol. 37 No. 19 P. 1–19
The paper is dedicated to the analysis of medico-biological data obtained during locomotor testing of astronauts. Accurate data interpretation plays a crucial role in locomotion system monitoring, prophylaxis of long-duration spaceflight negative effects and thus in the development of an autonomous medical support system for deep space expeditions. During the locomotor testing the astronaut changes ...
Added: June 26, 2026
Gadzhimirzaev S., Хельвас А. В., 2023 3rd International Conference on Innovative Research in Applied Science, Engineering and Technology (IRASET) Mohammedia, Morocco 2023 P. 1–6
The article proposes the architecture for eventdriven Emergency Operation Center with Machine Vision Component. Sources of information are analyzed and approaches to machine vision events for tactical situations detection and estimation are discussed. Messages from Machine Vision Components are converted to Common Alerting Protocol and processed by Operation Center environment for tactical situations recognition. ...
Added: June 26, 2026
Gadzhimirzaev S., Хельвас А. В., Лукьянченко П. П., Computer Research and Modeling 2023 Vol. 15 No. 1 P. 129–140
In this article we propose a new approach to the analysis of econometric industry parameters for the industry consolidation level. The research is based on the simple industry automatic control model. The state of the industry is measured by quarterly obtained econometric parameters from each industry’s company provided by the tax control regulator. An approach ...
Added: June 26, 2026
Gadzhimirzaev S., Хельвас А. В., International Frequency Sensor Association (IFSA) Publishing, 19-21 February 2025 Granada, Spain 2025 P. 172–176
The paper presents models for an innovative fully robotic warehouse for storing boxed goods. A discrete multiagent simulation of the movement of shuttles in a warehouse for a given sequence of pallet shipments has been implemented. Different strategies for placement of boxes in various areas of a warehouse are evaluated, as well as optimal routing ...
Added: June 26, 2026
Medvedev M., Journal of Chemical Theory and Computation 2026 Vol. 22 No. 9
Density functional theory (DFT) is the workhorse of modern reactions and materials modeling. While the exact functional remains unknown, many approximations to it have been constructed either by hand-crafting functional forms to satisfy exact constraints or by machine learning. In this work, we show how both of these approaches can be fused to build both ...
Added: June 26, 2026
Никонов В. Д., Никитин С. С., Патракеев М. В., Ionics 2025 Vol. 31 No. 1 P. 675–687
Modification of perovskite-type oxides is an effective way to develop functional materials with advanced properties. The effects of cerium introduction into the A sublattice of La0.5Sr0.5FeO3−δ and variation of La:Sr ratio on the defect structure and charge transfer characteristics were studied in this work. The LaxSr0.85−xCe0.15FeO3−δ oxides were found to be single-phase with cubic (x = 0.1) and orthorhombic ...
Added: June 26, 2026
Fedorov Timofey, Moscow Mathematical Journal 2026 Vol. 26 No. 1 P. 73–85
We obtain a complete list of smooth projective threefolds over C for which the dimension of the space of vanishing cycles (in H2(Y,Q) of the smooth hyperplane section Y) equals 2. We also obtain a complete list of rank 2 very ample vector bundles E on smooth projective surfaces with c2(E)=3. ...
Added: June 25, 2026
Воронеж: Издательский дом ВГУ, 2026.
В сборнике представлены материалы докладов и лекций, включенных в программу весенней математической школы. ...
Added: June 25, 2026
Petr E. Brandyshev, Yury A. Budkov, Journal of Mathematical Physics 2025 Vol. 66 No. 12 Article 123301
We present a quantum theory of Casimir forces between perfect electrical conductors, based on quantum electrodynamics and quantum statistical physics. This theory utilizes Kapusta’s finite-temperature field theory, combined with the Faddeev–Popov ghost formalism. This approach allows us to calculate Casimir forces at finite temperatures, providing both previously known and new physical insights from a unified ...
Added: December 1, 2025
Nesterova I., Kondratyuk N., Budkov Y. et al., Advances in Colloid and Interface Science 2025 Vol. 346 Article 103623
Room temperature ionic liquids show great promise as electrolytes in various technological applications, such as energy storage or electrotunable lubrication. These applications are particularly intriguing due to the specific behavior of ionic liquids in nanoconfinement. While previous research has been focused on optimizing the required characteristics through the selection of electrolyte properties, the contribution of ...
Added: September 2, 2025
Dmitry Vasilyev, Journal of Physics: Conference Series 2021 Vol. 1942 Article 012017
In this work, structural, elastic and thermal properties of the Laves phase Fe2Mo (λ-) with the C14-type structure existing in the Fe – Mo system have been investigated using the quantum mechanical calculations within the frame of the density functional theory (DFT). The equilibrium lattice parameters, atoms position coordinates and average magnetic moment of atoms ...
Added: July 26, 2025
Vasilyev Dmitry, Physica B: Condensed Matter 2021 Vol. 621 No. 15 Article 413307
In this work, a new method of searching a most energetically favorable free energy calculated along different thermal expansion paths of a compound is proposed. This makes it possible to reduce the problem to a one-dimensional case and to consider free energy as having one variable - volume. The method was applied to study the ...
Added: July 25, 2025
Victoria A. Vasileva, Daria A. Mazur, Petr E. Brandyshev et al., Journal of Chemical Physics 2025 Vol. 163 No. 3 Article 034709
This study employs modified Poisson–Boltzmann theory to systematically investigate the influence of zwitterionic osmolyte additives to an electrolyte solution on disjoining pressure and electric differential capacitance within charged, slit-like nanopores with conductive walls. We demonstrate that increasing concentrations of zwitterionic osmolytes synergistically enhance both disjoining pressure and differential capacitance, highlighting their dual role in the ...
Added: July 16, 2025
Darya L. Gurina, Kruchinin S. E., Yury A. Budkov, Electrochimica Acta 2025 Vol. 535 Article 146711
Supercapacitors are becoming increasingly important in energy storage applications due to their high power density, long cycle life, and fast charging capabilities. However, to further enhance supercapacitor performance, a deeper understanding of the electric double layer (EDL) structure at the electrode-electrolyte interface is essential. This molecular dynamics (MD) study explores the structure and electrochemical behavior ...
Added: June 16, 2025
Odintsova E., Darya L. Gurina, Kruchinin S. E. et al., Industrial & Engineering Chemistry Research 2025 Vol. 64 No. 6 P. 3531–3543
The ability to predict transport properties, such as viscosity, through molecular simulation is a valuable advantage. Obtaining reliable estimates for these properties can be more challenging compared to equilibrium properties. Our manuscript focuses on an in-depth discussion of two prominent methods for predicting transport properties: equilibrium molecular dynamics (EMD) using the Green−Kubo approach and nonequilibrium ...
Added: February 5, 2025
Darya Gurina, Budkov Y., Journal of Molecular Liquids 2025 Vol. 419 Article 126734
In this study, we used molecular dynamics simulations to investigate the effects of diluting [EMIM][NTf2] with DMSO on the behavior of the electrolyte within negatively charged slit-like micropores. Our results demonstrate clear differences in electrolyte composition between confined and bulk phase. Increasing the DMSO content leads to higher concentrations of counterions within the pores, particularly ...
Added: December 22, 2024
Yury A. Budkov, Kalikin N., Springer, 2024.
This book presents statistical physics methods based on self-consistent field theory for describing the thermodynamic properties of ion-molecular systems, including electrolyte solutions, ionic liquids, polymeric ionic liquids, and metal-organic complexes. The methods are applicable in both the bulk and at interfaces, taking into account the molecular structure of these systems. The book also provides a ...
Added: October 1, 2024
Plyashechnik A., Alexey A. Sokolik, Yurii E. Lozovik, Physical Review A: Atomic, Molecular, and Optical physics 2024 Vol. 110 No. 1 Article 013301
We consider Bose-Einstein condensation of noninteracting homogeneous three-dimensional gas in canonical ensemble when both particle number N and total momentum P of all particles are fixed. Using the saddle-point method, we derive the large-N analytical approximations for partition function, free energy, and statistical distributions of occupation numbers of different single-particle energy levels. At temperatures below ...
Added: July 22, 2024
Darya L. Gurina, Yury A. Budkov, Colloids and Surfaces A: Physicochemical and Engineering Aspects 2024 Vol. 695 Article 134209
Molecular dynamics (MD) simulations were employed to investigate the self-assembly of water reverse micelles
(RMs) with imidazolium ionic liquids (ILs) stabilized by dodecyl polyoxyethylene (3) polyoxypropylene (6) ether
(LS-36) in supercritical carbon dioxide (scCO2) at 308 K and 20 MPa. The study explored the impact of various
factors, including the IL concentration, the alkyl chain length of the ...
Added: May 20, 2024
Darya L. Gurina, Odintsova E., Yury A. Budkov, Journal of Physical Chemistry B 2024 Vol. 128 No. 9 P. 2215–2218
We present all-atom molecular simulations to investigate the behavior of 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM][BF4]) in negatively charged carbon nanopores of different widths (h = 5÷15 nm) and lengths (l = 4÷10 nm). The goal of our study was to determine how the disjoining pressure varies as a function of the pore width at different lengths and to understand ...
Added: March 4, 2024
Ilyin S., Kostyuk A., Anokhina T. et al., International Journal of Molecular Sciences 2023 Vol. 24 No. 9 Article 8057
The weak point of ionic liquids is their high viscosity, limiting the maximum polymer concentration in the forming solutions. A low-viscous co-solvent can reduce viscosity, but cellulose has none. This study demonstrates that dimethyl sulfoxide (DMSO), being non-solvent for cellulose, can act as a nominal co-solvent to improve its processing into a nanofiltration membrane by ...
Added: January 30, 2024
Petr E Brandyshev, Yury A Budkov, Journal of Statistical Mechanics: Theory and Experiment 2023 No. 12 Article 123206
In this paper, we introduce a statistical field theory that describes the macroscopic mechanical forces in inhomogeneous Coulomb fluids. Our approach employs the generalization of Noether's first theorem for the case of a fluctuating order parameter to calculate the stress tensor for Coulomb fluids. This tensor encompasses the mean-field stress tensor and fluctuation corrections derived ...
Added: December 18, 2023