All articles. Vestnik MGTU

Entropy Production in Irreversible Process within the Locally Non-Equilibrium Medium

Sun, 31 May 2026 00:00:00 +0400

Abstract

The article describes Brownian motion and transfer processes in a locally non-equilibrium medium using the theory of non-Markovian physical processes. The application of this theory allowed us to derive relationships linking thermodynamic forces and thermodynamic flows for the general case of transfer processes of different physical nature, and also to obtain a formula for calculating entropy production. Besides, correlation functions were found describing the equilibrium and non-equilibrium fluctuations of the thermodynamic flows. The resulting relationships were introduced to describe the entropy production for Brownian motion, diffusion, momentum transport and thermal conductivity. Entropy production was calculated for a general case of the highly non-equilibrium transport processes with the long-term memory. It is shown that with the thermodynamic force harmonic alteration, a regime is being realized at certain time moments, where the entropy production takes the negative value. This means that at these time moments with the appearing irreversible thermodynamic process, no increase, but a decrease in the entropy, is observed. Such an effect should be registered not only with the thermodynamic force harmonic alteration, but also with its other time dependencies. The proposed method for describing transport processes in a locally nonequilibrium environment is applicable to solving a wide range of problems in physical kinetics

Please cite this article in English as:

Morozov A.N. Entropy production in irreversible process within the locally non-equilibrium medium. Herald of the Bauman Moscow State Technical University, Series Natural Sciences, 2026, no. 2 (125), pp. 62--73 (in Russ.). EDN: TPGEHI

Synthesis of Phosphazene-Containing Benzoxazine Monomers Based on Bisphenol A and Aniline with Adjustable Functionality

Sun, 31 May 2026 00:00:00 +0400

Abstract

The article describes the synthesis of phosphazene-containing benzoxazine monomers with one to three phosphazene components in a mixture with a benzoxazine monomer based on bisphenol A and aniline. The three-stage synthesis consisted of obtaining phenoxychlorocyclotriphosphazenes with different target substitution degrees (tri, tetra, penta) in the first stage, then adding bisphenol A to the resulting mixture of phenoxychlorocyclotriphosphazenes (obtaining a mixture of hydroxyaryloxyphenoxyphosphazenes) and performing Mannich condensation in the final stage of the synthesis by adding aniline and paraformaldehyde to the resulting hydroxyaryloxyphenoxyphosphazenes. Using ³¹P NMR spectroscopy, the substitution reaction time was determined in the synthesis of model systems of phenoxychlorophosphazenes: for triphenoxytrichlorocyclotriphosphazene (triPhChPh), the reaction time was 12 h, for tetraphenoxydich-lorocyclotriphosphazene (tetraPhChPh) was 12 h, for pentaphenoxymonochlorocyclotriphosphazene (pentaPhChPh) was 18 h. The experimental degrees of substitution were compared with the theoretical ones. The composition and chemical structure of the products were confirmed using ¹H, ¹³C, ³¹P NMR spectroscopy, MALDI-TOF mass spectrometry and X-ray fluorescence spectrometry (elemental analysis for P and Cl)

The work was supported by the Russian Science Foundation (grant no. 22-73-10242)

Please cite this article in English as:

Kirianova I.D., Tarasov I.V., Sokolskaya I.B., et al. Synthesis of phosphazene-containing benzoxazine monomers based on bisphenol A and aniline with adjustable functionality. Herald of the Bauman Moscow State Technical University, Series Natural Sciences, 2026, no. 2 (125), pp. 74--93 (in Russ.). EDN: VUBPHY

Study of the Efficiency of Toluene and Benzene Vapor Adsorption by Activated Carbons

Sun, 31 May 2026 00:00:00 +0400

Abstract

The article compares the efficiency of toluene and benzene vapor adsorption using activated carbons such as KAU, BAU-A, AG-3 (Russian Federation), and EcoSorb (Germany). The adsorption capacity of these sorbents is determined, and the kinetics of vapor adsorption of these solvents is studied at a temperature of 25 ± 1 °C and atmospheric pressure. The highest adsorption capacity for toluene and benzene was shown by EcoSorb activated carbon, followed by AG-3 and BAU-A activated carbons, and the lowest adsorption capacity was shown by KAU activated carbon. For benzene vapors, a faster adsorption rate was observed, which was determined by the smaller size of the molecules compared to toluene and the higher diffusion capacity. However, toluene demonstrated a slightly higher specific adsorption capacity than benzene. It is shown that the kinetics of vapor absorption of both solvents is best described by a pseudo-second-order equation for all the studied adsorbents, which indicates the limiting nature of chemisorption in the overall scheme of the process under consideration. The less pronounced correlation of the experimental data with the Morris --- Weber equation indicates a minor influence of diffusion factors on the overall adsorption rate. The obtained results allow us to draw conclusions about the commonality of the mechanism of adsorption of benzene and toluene vapors by the adsorbents used in the study, and also emphasize the importance of the influence of the physical and chemical properties of the adsorbates and adsorbents on the technical characteristics of adsorption

The work was supported by the Priority 2030 Strategic Academic Leadership Program

Please cite this article in English as:

Tewelde T.S., Markova E.B., Boldyrev V.S., et al. Study of the efficiency of toluene and benzene vapor adsorption by activated carbons. Herald of the Bauman Moscow State Technical University, Series Natural Sciences, 2026, no. 2 (125), pp. 94--110 (in Russ.). EDN: VUUZNE

Promising Luminescent Sensors Based on New Maleimide Derivatives of 1,8-Naphthalimide for the Selective Detection of Biogenic Thiols

Mon, 01 Jun 2026 00:00:00 +0400

Abstract

Cysteine, homocysteine, and glutathione are biogenic thiols. They perform important functions in the human body: they maintain the redox homeostasis of cells, regulate many signaling processes, etc. Changes in the concentration of these substances in the blood cause serious disturbances in the functioning of important body systems and can thus lead to the development of serious diseases. In this regard, the development of new sensor substances that are sensitive to these changes is an important task for modern bio-medical research. The article synthesizes two types of new 1,8-naphthalimide derivatives (fluorophores 8, 9, and 14, 17) that can be used for the detection of biogenic thiols. The first type contains a maleimide functional group in the 4th position of the aromatic ring, and the second has it at the imide nitrogen atom. For the target compounds, the effect of changing the concentration of cysteine on the spectral lumines-cence properties in a phosphate buffer solution was studied. Due to the presence of photoinduced electron transfer (PET), the initial fluorophores 8, 9, 14, and 17 have low brightness and fluorescence quantum yields. The addition of biogenic thiol to them leads to a significant increase in the fluorescence intensity of the dyes. The latter is due to the Michael reaction, accompanied by the formation of adducts with significantly more pronounced luminescent properties. For the lead compounds (fluorophores 8, and 17) detection concentration limits were calculated, which amounted to 5 and 13 nM. Their low values, combined with unique optical properties, allow the new maleimide derivatives of 1,8-naphthalimide to be considered as promising luminescent sensors for biogenic thiols

The work was carried out with support from the Ministry of Science and Higher Education of the Russian Federation as part of a State Assignment (FSSM-2025-0002)

Please cite this article in English as:

Yuriev D.Yu., Tkachenko S.V., Oshchepkov M.S., et al. Promising luminescent sensors based on new maleimide derivatives of 1,8-naphthalimide for the selective detection of biogenic thiols. Herald of the Bauman Moscow State Technical University, Series Natural Sciences, 2026, no. 2 (125), pp. 111--131 (in Russ.). EDN: VVHNQZ