Pub Date : 2024-09-11DOI: 10.1134/s1990793124700428
K. Ya. Troshin, N. M. Rubtsov, V. I. Chernysh, G. I. Tsvetkov, I. O. Shamshin, Yu. A. Izmaylova, A. P. Kalinin, A. A. Leont’ev, A. I. Rodionov
Abstract
The patterns of catalytic ignition of deuterium–air mixtures above the surface of metallic rhodium at pressures of 1–2 atm and temperatures of 20–250°C using hyperspectrometers in the range of 400–1650 nm and high-speed filming have been established. It is established that the catalytic ignition of deuterium–air mixtures in the studied temperature range is observed at a deuterium content of more than 12%; and at a deuterium content of less than 12%, only intense heating of the catalytic wire is observed. It is shown that the initial ignition source occurs on the surface of the reactor. In subsequent experiments, under the same conditions, the location of the original center changes. It has been found that the upper limit of the catalytic ignition above the D2–air mixture is noticeably lower than the lower ignition limit of the H2–air mixture. Thus, D2 is more combustible than H2 over the surface of Rh at a pressure above 1 atm. The limits of catalytic ignition are even lower than 20°C, although the flame velocity in hydrogen–air mixtures and the flame temperature in these mixtures of the same composition are much higher than those of deuterium–air mixtures. The nature of the detected kinetic inverse isotope effect is probably determined by the high level of activity of rhodium deuteride in relation to the deuterium oxidation reaction.
{"title":"Catalytic Ignition of Deuterium–Air Mixtures Over a Metallic Rhodium Surface at Pressures of 1–2 ATM","authors":"K. Ya. Troshin, N. M. Rubtsov, V. I. Chernysh, G. I. Tsvetkov, I. O. Shamshin, Yu. A. Izmaylova, A. P. Kalinin, A. A. Leont’ev, A. I. Rodionov","doi":"10.1134/s1990793124700428","DOIUrl":"https://doi.org/10.1134/s1990793124700428","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The patterns of catalytic ignition of deuterium–air mixtures above the surface of metallic rhodium at pressures of 1–2 atm and temperatures of 20–250°C using hyperspectrometers in the range of 400–1650 nm and high-speed filming have been established. It is established that the catalytic ignition of deuterium–air mixtures in the studied temperature range is observed at a deuterium content of more than 12%; and at a deuterium content of less than 12%, only intense heating of the catalytic wire is observed. It is shown that the initial ignition source occurs on the surface of the reactor. In subsequent experiments, under the same conditions, the location of the original center changes. It has been found that the upper limit of the catalytic ignition above the D<sub>2</sub>–air mixture is noticeably lower than the lower ignition limit of the H<sub>2</sub>–air mixture. Thus, D<sub>2</sub> is more combustible than H<sub>2</sub> over the surface of Rh at a pressure above 1 atm. The limits of catalytic ignition are even lower than 20°C, although the flame velocity in hydrogen–air mixtures and the flame temperature in these mixtures of the same composition are much higher than those of deuterium–air mixtures. The nature of the detected kinetic inverse isotope effect is probably determined by the high level of activity of rhodium deuteride in relation to the deuterium oxidation reaction.</p>","PeriodicalId":768,"journal":{"name":"Russian Journal of Physical Chemistry B","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-11DOI: 10.1134/s1990793124700623
I. S. Yakovenko, A. D. Kiverin
Abstract
This paper studies the numerical analysis of the gaseous combustion process in a channel with a hydrogen-air mixture with the inflow of a fresh mixture seeded with microdroplets of water. The dynamics of microdroplets are described in the Lagrangian approximation, which makes it possible to identify the role of the local interaction between the droplets and the flame front. It is shown that the impact of droplets on the front can provoke the generation of disturbances of the flame front and intensify the development of the front’s instability, thereby causing an integral increase in the combustion rate. Using the spectral analysis of the structure of the front in the presence of microdroplets, the dynamics of the development of individual harmonics of the front’s disturbances is analyzed and the mechanisms of the evolution of the flame front under the influence of microdroplets of water are identified.
{"title":"Influence of Water Microdroplets on the Development of Hydrogen-Air Flame Instability in a Channel","authors":"I. S. Yakovenko, A. D. Kiverin","doi":"10.1134/s1990793124700623","DOIUrl":"https://doi.org/10.1134/s1990793124700623","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>This paper studies the numerical analysis of the gaseous combustion process in a channel with a hydrogen-air mixture with the inflow of a fresh mixture seeded with microdroplets of water. The dynamics of microdroplets are described in the Lagrangian approximation, which makes it possible to identify the role of the local interaction between the droplets and the flame front. It is shown that the impact of droplets on the front can provoke the generation of disturbances of the flame front and intensify the development of the front’s instability, thereby causing an integral increase in the combustion rate. Using the spectral analysis of the structure of the front in the presence of microdroplets, the dynamics of the development of individual harmonics of the front’s disturbances is analyzed and the mechanisms of the evolution of the flame front under the influence of microdroplets of water are identified.</p>","PeriodicalId":768,"journal":{"name":"Russian Journal of Physical Chemistry B","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-11DOI: 10.1134/s1990793124700325
M. N. E. Boumezrag, K. Almi, S. Lakel, H. Touhami
Abstract
The lack of successful p-type semiconductor oxides delays the future implementation of metal oxide semiconductor photovoltaic and thermoelectric devices. In the group semiconducting compounds, copper oxides present promising electrical, optical and manufacturing features that establish this family of materials suitable for p-type semiconductor applications. In this work, we focused on the growth of alkali doped CuO thin films, aiming for enhancements of their structural, optical, electrical and thermoelectric response. During this study, we highlight the effect of copper oxide doped with alkali ions (Li+, Na+, K+) prepared by the sol-gel technique and deposited on glass substrates. The effective substitution of the alkali elements into CuO lattice is analyzed by physical characterization i.e. X-ray diffraction, the spectra matched well with the monoclinic phase. Ultraviolet-visible spectroscopy showed that the band gap energy tends to increase with alkali doping and achieves a maximal value with (Li+) doping. Among the alkali ions (Li+) was the most effective to enhance electrical conductivity. Conductivity type showed by thermoelectric/hot prop confirmed the P-type conductivity. The maximum power factor PF was (9.776 × 10–10 W m–1 K–2) for Li doped CuO. The present work is worth significant for thermoelectric devices.
摘要 由于缺乏成功的 p 型半导体氧化物，金属氧化物半导体光电和热电设备的未来实施受到了延误。在半导体化合物组中，铜氧化物具有良好的电气、光学和制造特性，使该系列材料适合于 p 型半导体应用。在这项工作中，我们重点研究了碱掺杂氧化铜薄膜的生长，旨在增强其结构、光学、电学和热电响应。在这项研究中，我们强调了通过溶胶-凝胶技术制备并沉积在玻璃基底上的掺杂碱离子（Li+、Na+、K+）的氧化铜的效果。通过 X 射线衍射等物理表征分析了碱元素在氧化铜晶格中的有效取代，其光谱与单斜相非常吻合。紫外-可见光谱显示，带隙能随着碱掺杂的增加而增加，并在（Li+）掺杂时达到最大值。在各种碱离子中，（Li+）对增强导电性最有效。热电/热道具显示的导电类型证实了 P 型导电。掺杂 Li 的 CuO 的最大功率因数 PF 为（9.776 × 10-10 W m-1 K-2）。本研究对热电设备具有重要意义。
{"title":"Alkali Metals Doped Cu0.94A0.06O (A = Li, Na and K) Thin Films: Facile Synthesis, Structural, Optical and Thermoelectric Properties","authors":"M. N. E. Boumezrag, K. Almi, S. Lakel, H. Touhami","doi":"10.1134/s1990793124700325","DOIUrl":"https://doi.org/10.1134/s1990793124700325","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The lack of successful <i>p</i>-type semiconductor oxides delays the future implementation of metal oxide semiconductor photovoltaic and thermoelectric devices. In the group semiconducting compounds, copper oxides present promising electrical, optical and manufacturing features that establish this family of materials suitable for p-type semiconductor applications. In this work, we focused on the growth of alkali doped CuO thin films, aiming for enhancements of their structural, optical, electrical and thermoelectric response. During this study, we highlight the effect of copper oxide doped with alkali ions (Li<sup>+</sup>, Na<sup>+</sup>, K<sup>+</sup>) prepared by the sol-gel technique and deposited on glass substrates. The effective substitution of the alkali elements into CuO lattice is analyzed by physical characterization i.e. X-ray diffraction, the spectra matched well with the monoclinic phase. Ultraviolet-visible spectroscopy showed that the band gap energy tends to increase with alkali doping and achieves a maximal value with (Li<sup>+</sup>) doping. Among the alkali ions (Li<sup>+</sup>) was the most effective to enhance electrical conductivity. Conductivity type showed by thermoelectric/hot prop confirmed the P-type conductivity. The maximum power factor PF was (9.776 × 10<sup>–10</sup> W m<sup>–1</sup> K<sup>–2</sup>) for Li doped CuO. The present work is worth significant for thermoelectric devices.</p>","PeriodicalId":768,"journal":{"name":"Russian Journal of Physical Chemistry B","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-11DOI: 10.1134/s1990793124700386
G. Ya. Gerasimov, V. Yu. Levashov, P. V. Kozlov, N. G. Bykova, I. E. Zabelinsky
Abstract
The current state of research on measuring the electron concentration in low-temperature plasma in the vicinity of a strong shock wave, which simulates the conditions of the descend spacecraft entry into the Earth’s atmosphere, is considered. Various physicochemical processes leading to the formation of low-temperature plasma both ahead of the shock wave front and in the shock-heated gas are analyzed. A critical review of various plasma diagnostic methods is made, and their advantages and disadvantages are noted. Numerous experimental data on measuring the electron concentration in various shock-heated gases in various conditions are analyzed.
{"title":"Methods for Measuring the Electron Concentration in Shock Waves","authors":"G. Ya. Gerasimov, V. Yu. Levashov, P. V. Kozlov, N. G. Bykova, I. E. Zabelinsky","doi":"10.1134/s1990793124700386","DOIUrl":"https://doi.org/10.1134/s1990793124700386","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The current state of research on measuring the electron concentration in low-temperature plasma in the vicinity of a strong shock wave, which simulates the conditions of the descend spacecraft entry into the Earth’s atmosphere, is considered. Various physicochemical processes leading to the formation of low-temperature plasma both ahead of the shock wave front and in the shock-heated gas are analyzed. A critical review of various plasma diagnostic methods is made, and their advantages and disadvantages are noted. Numerous experimental data on measuring the electron concentration in various shock-heated gases in various conditions are analyzed.</p>","PeriodicalId":768,"journal":{"name":"Russian Journal of Physical Chemistry B","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-11DOI: 10.1134/s1990793124700313
M. N. El. Boumezrag, K. Almi, S. Lakel, H. Touhami
Abstract
This review focuses on the synthesis and Characterization of p-type metal-oxide (p-type CuO) semiconductor thin films, used for chemical-sensing applications. p-Type CuO thin film exhibit several advantages over n-type metal-oxide, including a higher catalytic effect, low humidity dependence, and improved recovery speed. However, the sensing performance of CuO thin film is strongly related to the intrinsic physicochemical properties of the material and their thickness. The latter is heavily dependent on synthesis techniques. Many techniques used for growing p-type CuO thin film are reviewed herein. Copper oxide is called a multifunctional material by dint of possessing a broad range of chemical and physical properties that are often highly sensitive to changes in processing parameters, although, extensive research and development, the optimization of the processing parameters are still in full development until today. Where, the overall research revealed that the different properties of copper oxide based on the experimental conditions. In this extensive review, we focus more on discussing the effect of major synthesis processing parameters such as precursor solution, annealing temperature, and thickness of the nanomaterial, which various researchers have obtained. These factors are critical overviewed, evaluated, and compared.
摘要 本综述侧重于用于化学传感应用的 p 型金属氧化物（p-type CuO）半导体薄膜的合成和表征。与 n 型金属氧化物相比，p-type CuO 薄膜具有多种优势，包括更高的催化效应、低湿度依赖性和更高的恢复速度。然而，氧化铜薄膜的传感性能与材料的内在物理化学特性及其厚度密切相关。后者在很大程度上取决于合成技术。本文综述了用于生长 p 型氧化铜薄膜的多种技术。氧化铜被称为多功能材料，因为它具有广泛的化学和物理特性，而这些特性往往对加工参数的变化非常敏感。总体研究表明，氧化铜的不同特性取决于实验条件。在这篇广泛的综述中，我们将重点讨论主要合成加工参数的影响，如前驱体溶液、退火温度和纳米材料的厚度，这些都是不同研究人员已经获得的结果。我们对这些因素进行了重要的概述、评估和比较。
{"title":"A Mini Review on Synthesis and Characterization of Copper Oxide Some Properties and Potential Applications","authors":"M. N. El. Boumezrag, K. Almi, S. Lakel, H. Touhami","doi":"10.1134/s1990793124700313","DOIUrl":"https://doi.org/10.1134/s1990793124700313","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>This review focuses on the synthesis and Characterization of <i>p</i>-type metal-oxide (<i>p</i>-type CuO) semiconductor thin films, used for chemical-sensing applications. <i>p</i>-Type CuO thin film exhibit several advantages over <i>n</i>-type metal-oxide, including a higher catalytic effect, low humidity dependence, and improved recovery speed. However, the sensing performance of CuO thin film is strongly related to the intrinsic physicochemical properties of the material and their thickness. The latter is heavily dependent on synthesis techniques. Many techniques used for growing <i>p</i>-type CuO thin film are reviewed herein. Copper oxide is called a multifunctional material by dint of possessing a broad range of chemical and physical properties that are often highly sensitive to changes in processing parameters, although, extensive research and development, the optimization of the processing parameters are still in full development until today. Where, the overall research revealed that the different properties of copper oxide based on the experimental conditions. In this extensive review, we focus more on discussing the effect of major synthesis processing parameters such as precursor solution, annealing temperature, and thickness of the nanomaterial, which various researchers have obtained. These factors are critical overviewed, evaluated, and compared.</p>","PeriodicalId":768,"journal":{"name":"Russian Journal of Physical Chemistry B","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-11DOI: 10.1134/s1990793124700477
H. K. Ismail, R. A. Omer, Y. H. Azeez, K. A. Omar, H. F. Alesary
Abstract
In this work, poly(p-aminophenol), a conductive polymer, was synthesized via chemical polymerization from the monomer of p-aminophenol in a basic aqueous medium using ammonium persulfate as the initiator. The polymer’s properties were assessed using ultraviolet-visible spectroscopy, fourier transform infrared, thermogravimetric analysis, scanning electron microscope, and X-ray diffraction methods. The fourier transform infrared results show a peak such as the robust signal at 3126 cm–1, corresponding to O–H vibrations associated with phenoxide ion existence in the polymer. The presence of N–H stretching vibration of an aromatic amine was affirmed by the peak at 2989 cm–1. The presence of a strong, broad peak at 2θ of 17.52° indicated amorphous behavior in poly(p-aminophenol). The weight loss was shown at 87, 276 and 517°C due to moisture removal, anion removal, and the degradation of polymer. Scanning electron microscopy showed sphere-like particles in poly(p-aminophenol) surface morphology. The electronic properties of poly(p-aminophenol) were investigated using quantum chemical calculations at the density functional theory level of theory. Density functional theory calculations were performed using two functionals, namely B3LYP and wB97XD, in combination with the 6-311+G(2d, p) basis set. These calculations aimed to determine various quantum chemical parameters, conduct natural bond orbital analysis, assess topological parameters, investigate nonlinear optical properties, and evaluate thermal properties. This approach balanced computational efficiency and accuracy to investigate reactivity, stability, charge transfer, optical properties, and thermal behavior. The calculations revealed significant changes in the reactivity and stability of the studied compound as it transitioned from the non-protonated to the protonated state, analyzed in both the gas phase and various aqueous environments. Furthermore, the presence of strong hydrogen bonds and limited nonlinear optical potential suggest the material may be suitable for applications beyond nonlinear optics. Additionally, the calculations explored static thermodynamic properties, including heat capacity, entropy, and enthalpy, highlighting their temperature-dependent behaviors. Poly(p-aminophenol) has excellent thermal stability and robust hydrogen bonding. However, its low nonlinear optical potential indicates its usefulness for uses other than nonlinear optics.
{"title":"Synthesis, Characterization, and Computational Insights Into the Conductive Poly(p-aminophenol)","authors":"H. K. Ismail, R. A. Omer, Y. H. Azeez, K. A. Omar, H. F. Alesary","doi":"10.1134/s1990793124700477","DOIUrl":"https://doi.org/10.1134/s1990793124700477","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>In this work, poly(<i>p</i>-aminophenol), a conductive polymer, was synthesized via chemical polymerization from the monomer of <i>p</i>-aminophenol in a basic aqueous medium using ammonium persulfate as the initiator. The polymer’s properties were assessed using ultraviolet-visible spectroscopy, fourier transform infrared, thermogravimetric analysis, scanning electron microscope, and X-ray diffraction methods. The fourier transform infrared results show a peak such as the robust signal at 3126 cm<sup>–1</sup>, corresponding to O–H vibrations associated with phenoxide ion existence in the polymer. The presence of N–H stretching vibration of an aromatic amine was affirmed by the peak at 2989 cm<sup>–1</sup>. The presence of a strong, broad peak at 2θ of 17.52° indicated amorphous behavior in poly(<i>p</i>-aminophenol). The weight loss was shown at 87, 276 and 517°C due to moisture removal, anion removal, and the degradation of polymer. Scanning electron microscopy showed sphere-like particles in poly(<i>p</i>-aminophenol) surface morphology. The electronic properties of poly(<i>p</i>-aminophenol) were investigated using quantum chemical calculations at the density functional theory level of theory. Density functional theory calculations were performed using two functionals, namely B3LYP and wB97XD, in combination with the 6-311+G(2<i>d</i>, <i>p</i>) basis set. These calculations aimed to determine various quantum chemical parameters, conduct natural bond orbital analysis, assess topological parameters, investigate nonlinear optical properties, and evaluate thermal properties. This approach balanced computational efficiency and accuracy to investigate reactivity, stability, charge transfer, optical properties, and thermal behavior. The calculations revealed significant changes in the reactivity and stability of the studied compound as it transitioned from the non-protonated to the protonated state, analyzed in both the gas phase and various aqueous environments. Furthermore, the presence of strong hydrogen bonds and limited nonlinear optical potential suggest the material may be suitable for applications beyond nonlinear optics. Additionally, the calculations explored static thermodynamic properties, including heat capacity, entropy, and enthalpy, highlighting their temperature-dependent behaviors. Poly(<i>p</i>-aminophenol) has excellent thermal stability and robust hydrogen bonding. However, its low nonlinear optical potential indicates its usefulness for uses other than nonlinear optics.</p>","PeriodicalId":768,"journal":{"name":"Russian Journal of Physical Chemistry B","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-11DOI: 10.1134/s1990793124700337
Z. Han, C. Wu, J. Wang, B. Wang, M. Wang
Abstract
To study the slow cook-off response characteristics of the charges with HMX-based pressed thermobaric explosives influenced by charge air gap, experiments considering different clearance ratio were carried out. The corresponding thermal reaction process was simulated by a commercial software Fluent developed by America ANSYS Inc. The results indicated that the clearance ratio had a significant influence on the response violence of the charge. The response violence was burn or combustion while charge side clearance was less than 12.11%, but the response state turned out to be deflagration or explosion when the charge side clearance became larger. With a fixed charge condition, the critical charge side clearance ratio was approximately between 12.11 and 17.35%. The numerical simulation results indicated that the initial high temperature zone was located in the edges of the explosive columns in contact with the shell, which could shift toward to the center of the charge according to the increase of the clearance ratio. The shift process strongly depended on the contact conditions. The safety of pressed charge can be optimized by eliminating charge clearance.
{"title":"Study on the Influence of Air Gap on the Thermal Response Violence of Pressed Polymer Bonded Explosive Charge in Slow Cook-Off Experiment","authors":"Z. Han, C. Wu, J. Wang, B. Wang, M. Wang","doi":"10.1134/s1990793124700337","DOIUrl":"https://doi.org/10.1134/s1990793124700337","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>To study the slow cook-off response characteristics of the charges with HMX-based pressed thermobaric explosives influenced by charge air gap, experiments considering different clearance ratio were carried out. The corresponding thermal reaction process was simulated by a commercial software Fluent developed by America ANSYS Inc. The results indicated that the clearance ratio had a significant influence on the response violence of the charge. The response violence was burn or combustion while charge side clearance was less than 12.11%, but the response state turned out to be deflagration or explosion when the charge side clearance became larger. With a fixed charge condition, the critical charge side clearance ratio was approximately between 12.11 and 17.35%. The numerical simulation results indicated that the initial high temperature zone was located in the edges of the explosive columns in contact with the shell, which could shift toward to the center of the charge according to the increase of the clearance ratio. The shift process strongly depended on the contact conditions. The safety of pressed charge can be optimized by eliminating charge clearance.</p>","PeriodicalId":768,"journal":{"name":"Russian Journal of Physical Chemistry B","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-11DOI: 10.1134/s199079312470060x
A. E. Smygalina, A. D. Kiverin
Abstract
This paper analyzes processes in the combustion chamber of spark ignition engine under direct jet injection of hydrogen during the compression stroke. Numerical modeling is used to study the features of mixing hydrogen with air and its combustion after ignition from a spark at the instant when the piston reaches the top dead center (TDC). The combustion regimes that develop when the injection pressure is varied from 20 to 140 atm, and the start of injection, from 180° to 45° of the crank angle (CA) before the TDC, are considered. In all cases the mass of hydrogen necessary for the formation of a stoichiometric mixture with air during injection into the combustion chamber is supplied. It is found that the most uniform mixture at the time of ignition is formed with advanced injection (180°–135° of the CA before the TDC) at a relatively low pressure (20–60 atm). The ignition of a uniform mixture in the conditions considered leads to detonation regime of combustion. A lower degree of uniformity of the mixture corresponds to a slow, deflagration combustion regime. It is important to note that nonuniformity of the mixture determines the ambiguity of the formation of a certain combustion regime, depending on the local mixture composition in the vicinity of a spark. At the same time, the slowest combustion regime provides the maximum hydrogen combustion incompleteness, up to 8.2%. Generally, the considered ranges of injection pressure and start of injection lead to satisfactory levels of incompleteness of hydrogen combustion of less than 4%.
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Pub Date : 2024-09-11DOI: 10.1134/s1990793124700441
Yu. F. Krupyanskii, V. V. Kovalenko, N. G. Loiko, E. V. Tereshkin, K. B. Tereshkina, A. N. Popov
Abstract
The structural organization of DNA in stressed (with increased stress resistance), anabiotic, and mummified cells obtained by introducing 4-hexylresorcinol in different concentrations at different stages of cell culture growth is studied using the synchrotron radiation diffraction technique. The experimental studies allow us to conclude that 4-hexylresorcinol is the initiator of the transition of cells into an anabiotic and mummified state in the stationary stage of growth. In the prestationary stage, in the studied concentration range, 4-hexylresorcinol initiates the transition of cells into a mummified state but not into an anabiotic state, which indicates that DNA is unprepared for the crystallization process in these bacteria. The structure of DNA inside a cell in an anabiotic dormant state (the almost complete absence of metabolism) and dormant state (starvation stress) coincide (form nanocrystalline structures). The data indicate the universality of DNA condensation or the universality of DNA protection by the Dps protein in the dormant state, regardless of the type of stress. The mummified state (the complete absence of metabolism, irreversible to life) is very different in structure (has no order within the cell).
摘要 利用同步辐射衍射技术研究了在细胞培养生长的不同阶段引入不同浓度的 4-己基间苯二酚所获得的受激细胞（抗应激能力增强）、厌氧细胞和木乃伊化细胞中 DNA 的结构组织。通过实验研究，我们得出结论：在细胞生长的静止阶段，4-己基间苯二酚是使细胞过渡到厌氧状态和木乃伊化状态的启动因子。在所研究的浓度范围内，4-己基间苯二酚能使细胞进入木乃伊化状态，但不能使细胞进入无代谢状态。处于无代谢休眠状态（几乎完全没有新陈代谢）和休眠状态（饥饿应激）的细胞内的 DNA 结构是一致的（形成纳米结晶结构）。这些数据表明，在休眠状态下，无论应激类型如何，DNA 的凝结或 DNA 受 Dps 蛋白保护具有普遍性。木乃伊状态（完全没有新陈代谢，对生命不可逆）的结构则截然不同（细胞内没有秩序）。
{"title":"The Structure of DNA in Anabiotic and Mummified Escherichia coli Cells","authors":"Yu. F. Krupyanskii, V. V. Kovalenko, N. G. Loiko, E. V. Tereshkin, K. B. Tereshkina, A. N. Popov","doi":"10.1134/s1990793124700441","DOIUrl":"https://doi.org/10.1134/s1990793124700441","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The structural organization of DNA in stressed (with increased stress resistance), anabiotic, and mummified cells obtained by introducing 4-hexylresorcinol in different concentrations at different stages of cell culture growth is studied using the synchrotron radiation diffraction technique. The experimental studies allow us to conclude that 4-hexylresorcinol is the initiator of the transition of cells into an anabiotic and mummified state in the stationary stage of growth. In the prestationary stage, in the studied concentration range, 4-hexylresorcinol initiates the transition of cells into a mummified state but not into an anabiotic state, which indicates that DNA is unprepared for the crystallization process in these bacteria. The structure of DNA inside a cell in an anabiotic dormant state (the almost complete absence of metabolism) and dormant state (starvation stress) coincide (form nanocrystalline structures). The data indicate the universality of DNA condensation or the universality of DNA protection by the Dps protein in the dormant state, regardless of the type of stress. The mummified state (the complete absence of metabolism, irreversible to life) is very different in structure (has no order within the cell).</p>","PeriodicalId":768,"journal":{"name":"Russian Journal of Physical Chemistry B","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-11DOI: 10.1134/s1990793124700453
V. N. Gorshenev, I. A. Maklakova, M. A. Yakovleva
Abstract
A new method for mixing solutions and suspensions containing thermodynamically immiscible dispersion media based on the use of ultrasonic dispersion and thermally stimulated microwave heating has been proposed. The results of a study of a number of functional composites obtained by mixing solutions of biodegradable polymers in chloroform with aqueous suspensions of natural polymers are presented. The possibility of obtaining polymer composites doped with magnetic nanoparticles and drugs by this method is considered. It has been established that the proposed method of mixing makes it possible to combine suspensions of polymers of different kinds in the composition of composites suitable for creating porous, hygroscopic, and magnetically controlled materials for biomedical and environmental applications.
{"title":"Porous Polymer Compositions Based on Mixed Colloidal Suspensions Under Ultrasonic Dispersion and Microwave Heating","authors":"V. N. Gorshenev, I. A. Maklakova, M. A. Yakovleva","doi":"10.1134/s1990793124700453","DOIUrl":"https://doi.org/10.1134/s1990793124700453","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>A new method for mixing solutions and suspensions containing thermodynamically immiscible dispersion media based on the use of ultrasonic dispersion and thermally stimulated microwave heating has been proposed. The results of a study of a number of functional composites obtained by mixing solutions of biodegradable polymers in chloroform with aqueous suspensions of natural polymers are presented. The possibility of obtaining polymer composites doped with magnetic nanoparticles and drugs by this method is considered. It has been established that the proposed method of mixing makes it possible to combine suspensions of polymers of different kinds in the composition of composites suitable for creating porous, hygroscopic, and magnetically controlled materials for biomedical and environmental applications.</p>","PeriodicalId":768,"journal":{"name":"Russian Journal of Physical Chemistry B","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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