Pub Date : 2024-04-10DOI: 10.21869/2223-1528-2024-14-1-30-45
D. V. Kolmykov, Yu. S. Vorobyev, V. I. Kolmykov, E. V. Trusova
The purpose of the work is to establish the regularities of the formation of the structure and phase composition of surface (modified) layers on 20X13 chromium stainless steel under intense saturation with carbon and nitrogen and, on this basis, to substantiate the possibility of surface hardening of parts made of high-chromium steels by nitrocementation.Methods. The studies were carried out on samples made of high–chromium steel 20X13, which were subjected to high-temperature nitrocementation in a paste-like medium including fine soot, sodium carbonate and potassium ferruginous oxide (paste-forming agent is an aqueous solution of carbomethylcellulose). The microstructure was studied using an optical metallographic microscope OLIMPUS OX 51 and a scanning electron microscope Qanta FEG-650 with an X-ray microanalysis system EDAX. The microhardness was determined on the Duramit-5 microhardometer, the phase composition on the XRD-7000S X-ray diffractometer.Results. Nitrocementation of high chromium steel 20X13 in the temperature range of 820–950°C provides the formation of diffusion layers on the surface, the structure of which is represented by three zones: a crust of solid carbonitrides on the surface, an eutectoid zone with a solid matrix and inclusions of carbonitrides under the crust and a transition zone including a solid solution enriched in carbon and nitrogen with grains of the base metal. The microhardness of the nitrocemented layers on 20X13 steel after quenching from 1050°C in oil and tempering at 600°C reaches Nm 750–800 on the surface and decreases smoothly enough in depth of the nitrocemented layer. The depth of nitrocemented layers with increased microhardness (more than 400 Nm), depending on the duration of treatment, can reach ~ 0.5 (860°C, 6 hours).Conclusion. Nitrocementation of high-chromium steel 20X13 at 820–880°C in an active carbon black paste with the addition of potassium ferrocarbon leads to an increase in the hardness of the surface layers by about 4 times the hardness of the base, which, combined with the high mechanical properties of the base, will significantly increase the service life of parts made of high-chromium stainless steels of type X13 operating under high contact conditions loads.
{"title":"Investigation of the Features of the Formation of Diffusion Layers During Nitrocementation of High-Chromium Steels in a Carbon Black Medium","authors":"D. V. Kolmykov, Yu. S. Vorobyev, V. I. Kolmykov, E. V. Trusova","doi":"10.21869/2223-1528-2024-14-1-30-45","DOIUrl":"https://doi.org/10.21869/2223-1528-2024-14-1-30-45","url":null,"abstract":"The purpose of the work is to establish the regularities of the formation of the structure and phase composition of surface (modified) layers on 20X13 chromium stainless steel under intense saturation with carbon and nitrogen and, on this basis, to substantiate the possibility of surface hardening of parts made of high-chromium steels by nitrocementation.Methods. The studies were carried out on samples made of high–chromium steel 20X13, which were subjected to high-temperature nitrocementation in a paste-like medium including fine soot, sodium carbonate and potassium ferruginous oxide (paste-forming agent is an aqueous solution of carbomethylcellulose). The microstructure was studied using an optical metallographic microscope OLIMPUS OX 51 and a scanning electron microscope Qanta FEG-650 with an X-ray microanalysis system EDAX. The microhardness was determined on the Duramit-5 microhardometer, the phase composition on the XRD-7000S X-ray diffractometer.Results. Nitrocementation of high chromium steel 20X13 in the temperature range of 820–950°C provides the formation of diffusion layers on the surface, the structure of which is represented by three zones: a crust of solid carbonitrides on the surface, an eutectoid zone with a solid matrix and inclusions of carbonitrides under the crust and a transition zone including a solid solution enriched in carbon and nitrogen with grains of the base metal. The microhardness of the nitrocemented layers on 20X13 steel after quenching from 1050°C in oil and tempering at 600°C reaches Nm 750–800 on the surface and decreases smoothly enough in depth of the nitrocemented layer. The depth of nitrocemented layers with increased microhardness (more than 400 Nm), depending on the duration of treatment, can reach ~ 0.5 (860°C, 6 hours).Conclusion. Nitrocementation of high-chromium steel 20X13 at 820–880°C in an active carbon black paste with the addition of potassium ferrocarbon leads to an increase in the hardness of the surface layers by about 4 times the hardness of the base, which, combined with the high mechanical properties of the base, will significantly increase the service life of parts made of high-chromium stainless steels of type X13 operating under high contact conditions loads.","PeriodicalId":117184,"journal":{"name":"Proceedings of the Southwest State University. Series: Engineering and Technology","volume":"125 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140719978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-10DOI: 10.21869/2223-1528-2024-14-1-104-114
L. V. Elnikova, V. V. Belyaev
The purpose research of the work is to illustrate the role of point surface topological defects in nematics in phase transitions using the example of inorganic sols of vanadium pentoxide in water V2O5/H2O.Methods. Basing on the measurements on polarization light microscopy and theoretically, in frames of the Landau-de Gennes model and the Kibble-Zurek model for defects, the influence of point topological defects at the surface of nematic colloid of lyotropic liquid crystals, in particular, in inorganic sols of the V2O5/H2O system, on their critical thermodynamic, electric, optical, elastic and mechanical properties is estimated. For the system V2O5/H2O, we study the developed models of nematic colloid phases with non-trivial topology composed of spindle-shaped particles, in which their topological defects are classified; geometrical parameters of nematic particles in dynamics and evolution depending on physicochemical conditions, phase stability criteria, conditions for coalescence of particles, including, under external magnetic field, and also, experimental observations confirmed the proposed theories and models, are considered.Results. With a glance of coalescence regime, the critical size of a colloid particle of the system V2O5/H2O, ~ 10 nm in the long axis direction, in which the value of magnetic energy equals to the sum of elastic and surface energy of acolloid particle, is estimated.Conclusion. We confirmed, that the prerequisite of sol particle coalescence in the system V2O5/H2O in the magnetic field is annihilation of the point topological defects at their poles, the geometrical criterion of tactoid coalescence in magnetic field is established basing on the different theories of their surface defects.
{"title":"Topological Defects in Tactoid Nematic Phase","authors":"L. V. Elnikova, V. V. Belyaev","doi":"10.21869/2223-1528-2024-14-1-104-114","DOIUrl":"https://doi.org/10.21869/2223-1528-2024-14-1-104-114","url":null,"abstract":"The purpose research of the work is to illustrate the role of point surface topological defects in nematics in phase transitions using the example of inorganic sols of vanadium pentoxide in water V2O5/H2O.Methods. Basing on the measurements on polarization light microscopy and theoretically, in frames of the Landau-de Gennes model and the Kibble-Zurek model for defects, the influence of point topological defects at the surface of nematic colloid of lyotropic liquid crystals, in particular, in inorganic sols of the V2O5/H2O system, on their critical thermodynamic, electric, optical, elastic and mechanical properties is estimated. For the system V2O5/H2O, we study the developed models of nematic colloid phases with non-trivial topology composed of spindle-shaped particles, in which their topological defects are classified; geometrical parameters of nematic particles in dynamics and evolution depending on physicochemical conditions, phase stability criteria, conditions for coalescence of particles, including, under external magnetic field, and also, experimental observations confirmed the proposed theories and models, are considered.Results. With a glance of coalescence regime, the critical size of a colloid particle of the system V2O5/H2O, ~ 10 nm in the long axis direction, in which the value of magnetic energy equals to the sum of elastic and surface energy of acolloid particle, is estimated.Conclusion. We confirmed, that the prerequisite of sol particle coalescence in the system V2O5/H2O in the magnetic field is annihilation of the point topological defects at their poles, the geometrical criterion of tactoid coalescence in magnetic field is established basing on the different theories of their surface defects.","PeriodicalId":117184,"journal":{"name":"Proceedings of the Southwest State University. Series: Engineering and Technology","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140717198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-10DOI: 10.21869/2223-1528-2024-14-1-76-87
M. Erina, M. I. Deryabin
Purpose. Establish the nature and reasons for the dependence of the change in the radiative rate constant of deactivation of triplet excitations of a number of molecules, caused by the effect of an external heavy atom, on their ionization potential from the ground state and the energy of the first excited singlet state.Methods. Kinetic methods were used to determine the rate constant for the deactivation of triplet excitations of organic molecules in solid solutions at 77 K. The solvents were n-heptane (neutral), carbon tetrachloride and benzene bromide (containing heavy chlorine and bromine atoms). The molecules studied were coronene, triphenylene, phenanthrene, naphthalene and biphenyl.Results. A linear relationship has been established between an increase in the ionization potential, the energy value of the first excited singlet state, and an increase in the change in the rate of radiative deactivation of triplet excitations of the studied molecules in carbon tetrachloride. It is shown that the increase in the change in the radiative deactivation rate of these molecules with an increase in their ionization potential is due to a decrease in the difference between the ionization energies and the first excited singlet state.Conclusion. The results of the study showed that there is a linear relationship between the increase in the radiative deactivation rate of triplet excitations of the studied molecules and their ionization potential. A linear relationship is also observed between the increase in the rate of radiative deactivation of triplet excitations of these molecules and the first excited singlet state. As the ionization potentials of the molecules under study increase, the difference between the ionization energy and the energy of the first excited singlet state decreases. This is the reason for the increase in the rate of deactivation of triplet excitations of molecules with an increase in their ionization potential.
目的确定外部重原子效应引起的一些分子三重态激发失活的辐射速率常数的变化与它们从基态电离电势和第一个激发的单重态能量的关系的性质和原因。采用动力学方法测定了有机分子在 77 K 固溶体中三重激发失活的速率常数。溶剂为正庚烷（中性）、四氯化碳和溴化苯（含有重氯和重溴原子）。研究的分子包括冠烯、三苯乙烯、菲、萘和联苯。所研究分子在四氯化碳中的电离势、第一激发单重态能值的增加与三重态激发的辐射失活速率的增加之间建立了线性关系。研究表明，这些分子的辐射去活化率的变化随着其电离势的增加而增加，这是由于电离能与第一激发单态之间的差值减小所致。研究结果表明，所研究分子的三重激发辐射失活率的增加与其电离势之间存在线性关系。这些分子的三重激发辐射失活率的增加与第一激发单重态之间也呈线性关系。随着所研究分子电离电位的增加，电离能与第一激发单线态能量之间的差值也随之减小。这就是随着分子电离势的增加，分子三重激发的失活速率增加的原因。
{"title":"On the Dependence of the Rate of Deactivation of Triplet Excitations of a Number of Molecules on Their Ionization Potential and the Charge of the Nucleus of Heavy Atoms of the Solvent","authors":"M. Erina, M. I. Deryabin","doi":"10.21869/2223-1528-2024-14-1-76-87","DOIUrl":"https://doi.org/10.21869/2223-1528-2024-14-1-76-87","url":null,"abstract":"Purpose. Establish the nature and reasons for the dependence of the change in the radiative rate constant of deactivation of triplet excitations of a number of molecules, caused by the effect of an external heavy atom, on their ionization potential from the ground state and the energy of the first excited singlet state.Methods. Kinetic methods were used to determine the rate constant for the deactivation of triplet excitations of organic molecules in solid solutions at 77 K. The solvents were n-heptane (neutral), carbon tetrachloride and benzene bromide (containing heavy chlorine and bromine atoms). The molecules studied were coronene, triphenylene, phenanthrene, naphthalene and biphenyl.Results. A linear relationship has been established between an increase in the ionization potential, the energy value of the first excited singlet state, and an increase in the change in the rate of radiative deactivation of triplet excitations of the studied molecules in carbon tetrachloride. It is shown that the increase in the change in the radiative deactivation rate of these molecules with an increase in their ionization potential is due to a decrease in the difference between the ionization energies and the first excited singlet state.Conclusion. The results of the study showed that there is a linear relationship between the increase in the radiative deactivation rate of triplet excitations of the studied molecules and their ionization potential. A linear relationship is also observed between the increase in the rate of radiative deactivation of triplet excitations of these molecules and the first excited singlet state. As the ionization potentials of the molecules under study increase, the difference between the ionization energy and the energy of the first excited singlet state decreases. This is the reason for the increase in the rate of deactivation of triplet excitations of molecules with an increase in their ionization potential.","PeriodicalId":117184,"journal":{"name":"Proceedings of the Southwest State University. Series: Engineering and Technology","volume":"143 1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140717091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-18DOI: 10.21869/2223-1528-2023-13-4-109-122
D. S. Rasseko, M. A. Pugachevskii, A. I. Zhakin
Purpose. To study the process of photodegradation of methylene blue under the influence of laser radiation with a wavelength of 660 nm, used for photodynamic therapy installations, for the formation of reactive oxygen species, in particular short-lived hydroxyl radicals, using electron paramagnetic resonance (EPR) spectroscopy.Methods. The residual concentration of methylene blue during photodegradation was determined using an HR2000 spectrometer. The formation of hydroxyl groups was detected using an EPR spectrometer SPINSCAN X.Results. Analysis of data on the photodegradation of methylene blue shows that under the influence of laser radiation with a wavelength of 660 nm, the structure of methylene blue is destroyed, manifested in the gradual discoloration of the dye solution. When trypaflavin is added to the solution, the rate of photodegradation of methylene blue slows down significantly. Analysis of ESR spectroscopy data shows that when methylene blue is exposed to a red laser, (OH’) radicals begin to intensively form in the solution. Their content increases significantly with increasing irradiation power.Conclusion. Irradiation of an aqueous solution of the thiazion dye methylene blue by a laser source with a power of 0.3÷1 W and a wavelength of 660 nm leads to its active photodegradation. The addition of trypaflavin leads to a slowdown in the process of photodegradation of methylene blue when irradiated with red light due to the consumption of part of the generated oxygen-containing radicals for the degradation of trypaflavin. According to EPR spectroscopy data using DMPO spin traps, it has been proven that when methylene blue is irradiated with a red laser, active formation of hydroxyl OH' radicals occurs. It was found that with increasing laser radiation intensity, the amount of generated hydroxyl radicals (OH') increases significantly. The presented results may contribute to the development of effective photosensitizers for photodynamic therapy of tumor tumors.
{"title":"Study of Photodegradation of Thiazion Dye Methylene Blue under Exposure to a Laser for Photodynamic Therapy","authors":"D. S. Rasseko, M. A. Pugachevskii, A. I. Zhakin","doi":"10.21869/2223-1528-2023-13-4-109-122","DOIUrl":"https://doi.org/10.21869/2223-1528-2023-13-4-109-122","url":null,"abstract":"Purpose. To study the process of photodegradation of methylene blue under the influence of laser radiation with a wavelength of 660 nm, used for photodynamic therapy installations, for the formation of reactive oxygen species, in particular short-lived hydroxyl radicals, using electron paramagnetic resonance (EPR) spectroscopy.Methods. The residual concentration of methylene blue during photodegradation was determined using an HR2000 spectrometer. The formation of hydroxyl groups was detected using an EPR spectrometer SPINSCAN X.Results. Analysis of data on the photodegradation of methylene blue shows that under the influence of laser radiation with a wavelength of 660 nm, the structure of methylene blue is destroyed, manifested in the gradual discoloration of the dye solution. When trypaflavin is added to the solution, the rate of photodegradation of methylene blue slows down significantly. Analysis of ESR spectroscopy data shows that when methylene blue is exposed to a red laser, (OH’) radicals begin to intensively form in the solution. Their content increases significantly with increasing irradiation power.Conclusion. Irradiation of an aqueous solution of the thiazion dye methylene blue by a laser source with a power of 0.3÷1 W and a wavelength of 660 nm leads to its active photodegradation. The addition of trypaflavin leads to a slowdown in the process of photodegradation of methylene blue when irradiated with red light due to the consumption of part of the generated oxygen-containing radicals for the degradation of trypaflavin. According to EPR spectroscopy data using DMPO spin traps, it has been proven that when methylene blue is irradiated with a red laser, active formation of hydroxyl OH' radicals occurs. It was found that with increasing laser radiation intensity, the amount of generated hydroxyl radicals (OH') increases significantly. The presented results may contribute to the development of effective photosensitizers for photodynamic therapy of tumor tumors. ","PeriodicalId":117184,"journal":{"name":"Proceedings of the Southwest State University. Series: Engineering and Technology","volume":"121 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139615085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-18DOI: 10.21869/2223-1528-2023-13-4-152-162
R. Lavrov, N. V. Kuvardin, S. Narmatov
The purpose of this work was to continue research on the activation of quartz raw materials using alkali metal hydroxides. This paper presents a theoretical justification and practical confirmation of the physical and chemical activation of quartz raw materials by sodium hydroxide, taking into account the eutectic ratios in the Na2O–SiO2 system.Methods. Quartz glass sand VS-030-B was chosen as a source of quartz raw materials; as a sodium-containing raw material flake sodium hydroxide brand TR. For the scientific basis, the phase diagram of Na2O-SiO2 of Berezhny was used. To study the phase composition of activated quartz sand, X-ray phase analysis was used; to study a particle of the activation product of quartz sand and sodium hydroxide, scanning electron microscopy was used. To confirm the effectiveness of the developed method, comparative pulping of sodium vitreous silicate was carried out according to the proposed method and previously known ones.Results. A method has been developed for activating quartz raw materials with sodium hydroxide to obtain vitreous sodium silicates using a mixture of two activation products, to obtain one of which parts of quartz raw materials and sodium hydroxide are taken in an eutectic ratio, and to obtain another activation product, the remainder of quartz raw materials and the calculated minimum the amount of sodium hydroxide required to obtain a shell on a quartz grain.Conclusion. Based on the results of comparative experimental cooking of tableted mixtures for silicate lumps using the developed method for activating quartz raw materials and using a mixture of quartz sand and sodium carbonate, the efficiency of the developed method, expressed in reducing the cooking temperature, is experimentally affected. The results of the study were issued in the form of a patent of the Russian Federation No. 2714415 "Method of preparing a charge for alkaline silicate glass".
{"title":"Physical and Chemical Activation of Quartz Raw Materials with Sodium Hydroxide in the Ratio of the Eutectic Composition in the Na2O – SiO2 System","authors":"R. Lavrov, N. V. Kuvardin, S. Narmatov","doi":"10.21869/2223-1528-2023-13-4-152-162","DOIUrl":"https://doi.org/10.21869/2223-1528-2023-13-4-152-162","url":null,"abstract":"The purpose of this work was to continue research on the activation of quartz raw materials using alkali metal hydroxides. This paper presents a theoretical justification and practical confirmation of the physical and chemical activation of quartz raw materials by sodium hydroxide, taking into account the eutectic ratios in the Na2O–SiO2 system.Methods. Quartz glass sand VS-030-B was chosen as a source of quartz raw materials; as a sodium-containing raw material flake sodium hydroxide brand TR. For the scientific basis, the phase diagram of Na2O-SiO2 of Berezhny was used. To study the phase composition of activated quartz sand, X-ray phase analysis was used; to study a particle of the activation product of quartz sand and sodium hydroxide, scanning electron microscopy was used. To confirm the effectiveness of the developed method, comparative pulping of sodium vitreous silicate was carried out according to the proposed method and previously known ones.Results. A method has been developed for activating quartz raw materials with sodium hydroxide to obtain vitreous sodium silicates using a mixture of two activation products, to obtain one of which parts of quartz raw materials and sodium hydroxide are taken in an eutectic ratio, and to obtain another activation product, the remainder of quartz raw materials and the calculated minimum the amount of sodium hydroxide required to obtain a shell on a quartz grain.Conclusion. Based on the results of comparative experimental cooking of tableted mixtures for silicate lumps using the developed method for activating quartz raw materials and using a mixture of quartz sand and sodium carbonate, the efficiency of the developed method, expressed in reducing the cooking temperature, is experimentally affected. The results of the study were issued in the form of a patent of the Russian Federation No. 2714415 \"Method of preparing a charge for alkaline silicate glass\".","PeriodicalId":117184,"journal":{"name":"Proceedings of the Southwest State University. Series: Engineering and Technology","volume":"110 35","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139615385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-18DOI: 10.21869/2223-1528-2023-13-4-98-108
G. A. Khokhryakova
The purpose of this work is to experimentally study the process of decomposition of a horizontal layer of a magnetic fluid lying on a liquid non-wettable substrate into an ordered system of drops under the influence of a vertical magnetic field.Methods. In the experiment, the studied liquids in the form of a two-layer system filling a cylindrical glass cuvette were placed on a horizontal platform in the center of the Helmholtz coils connected to a direct current source. The development of magnetic fluid layer free surface instability was monitored using a high-speed digital video camera installed at the top of the coil system.Results. The dependence of the critical strength of the magnetic field on the thickness of the torn layer and the magnetic susceptibility of the magnetic fluid is determined. The obtained experimental data are compared with the results of existing theoretical studies of the instability of the magnetic fluid layer. Compared to the case of a solid substrate, the rupture of the magnetic fluid layer on a liquid substrate occurred at lower values of the critical field strength. In this case, the development of instability of the free surface magnetic fluid layer on a solid substrate occurs at field strengths twice as high as the instability strength of the interface of the layer on a liquid substrate.Conclusion. The use of a liquid substrate makes it possible to break such layers of the magnetic fluid, the deformation of which on a solid substrate is limited only by a periodic perturbation of the surface. The magnitude of the critical strength leading to the disintegration of a continuous magnetic fluid layer on a liquid substrate increases with increasing thickness of this layer. An increase in the magnetic susceptibility of the magnetic fluid leads to a decrease in the critical field strength.
{"title":"The Disintegration of Magnetic Fluid Layer on Liquid and Solid Substrates in Vertical Magnetic Field","authors":"G. A. Khokhryakova","doi":"10.21869/2223-1528-2023-13-4-98-108","DOIUrl":"https://doi.org/10.21869/2223-1528-2023-13-4-98-108","url":null,"abstract":"The purpose of this work is to experimentally study the process of decomposition of a horizontal layer of a magnetic fluid lying on a liquid non-wettable substrate into an ordered system of drops under the influence of a vertical magnetic field.Methods. In the experiment, the studied liquids in the form of a two-layer system filling a cylindrical glass cuvette were placed on a horizontal platform in the center of the Helmholtz coils connected to a direct current source. The development of magnetic fluid layer free surface instability was monitored using a high-speed digital video camera installed at the top of the coil system.Results. The dependence of the critical strength of the magnetic field on the thickness of the torn layer and the magnetic susceptibility of the magnetic fluid is determined. The obtained experimental data are compared with the results of existing theoretical studies of the instability of the magnetic fluid layer. Compared to the case of a solid substrate, the rupture of the magnetic fluid layer on a liquid substrate occurred at lower values of the critical field strength. In this case, the development of instability of the free surface magnetic fluid layer on a solid substrate occurs at field strengths twice as high as the instability strength of the interface of the layer on a liquid substrate.Conclusion. The use of a liquid substrate makes it possible to break such layers of the magnetic fluid, the deformation of which on a solid substrate is limited only by a periodic perturbation of the surface. The magnitude of the critical strength leading to the disintegration of a continuous magnetic fluid layer on a liquid substrate increases with increasing thickness of this layer. An increase in the magnetic susceptibility of the magnetic fluid leads to a decrease in the critical field strength.","PeriodicalId":117184,"journal":{"name":"Proceedings of the Southwest State University. Series: Engineering and Technology","volume":"101 41","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139614809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-18DOI: 10.21869/2223-1528-2023-13-4-123-138
Y. A. Neruchev, A. I. Zhakin, A. K. Radchenko, V. A. Shkurina
Purpose. Performing measurements of sound velocity and density in the liquid phase of hexane isomers on the saturation line in a wide range of state parameters, including the critical region.Methods. Using a precision pulse-phase method for measuring the speed of sound in the liquid phase of hexane isomers and their density with a pycnometer at atmospheric pressure. The paper discusses the results of precision measurements of sound velocity and density in five hexane isomers. The speed of sound was measured on the equilibrium curve in the liquid phase of isomers by the pulse-phase method in the range from -30 to their critical point. The measurement error of the speed of sound did not exceed 1 m/s. Density measurements were performed using a pycnometer at atmospheric pressure in the range from -30 to their normal boiling point with an error not exceeding 0.05%. The results of sound velocity and density measurements were used to study the character of intermolecular forces. The necessity of taking into account the non-covalent chemical interaction of molecules of the studied substances is shown.Results. Sound velocity measurements were performed on the saturation line in the liquid phase of all five hexane isomers in the temperature range from -30 C to the critical temperature of all 5 isomers. The obtained results are used to study the features of the dependence of the energy of intermolecular forces on the parameters of the state in the field of research.Conclusion. It is shown that the energy of intermolecular forces in marginal hydrocarbons and other simple substances is the sum of 3 terms representing: 1) the energy of the dispersive attractive forces proportional to the square of the density; 2) the energy of the repulsive forces proportional to the biquadrate of the density and 3) the energy of weak chemical non-covalent binding forces proportional to the cubic root of the density of matter.
{"title":"On the Natyre of the Influence of the Architecture of Molecules on the Thermophisical Properties of Alkane Isomers","authors":"Y. A. Neruchev, A. I. Zhakin, A. K. Radchenko, V. A. Shkurina","doi":"10.21869/2223-1528-2023-13-4-123-138","DOIUrl":"https://doi.org/10.21869/2223-1528-2023-13-4-123-138","url":null,"abstract":"Purpose. Performing measurements of sound velocity and density in the liquid phase of hexane isomers on the saturation line in a wide range of state parameters, including the critical region.Methods. Using a precision pulse-phase method for measuring the speed of sound in the liquid phase of hexane isomers and their density with a pycnometer at atmospheric pressure. The paper discusses the results of precision measurements of sound velocity and density in five hexane isomers. The speed of sound was measured on the equilibrium curve in the liquid phase of isomers by the pulse-phase method in the range from -30 to their critical point. The measurement error of the speed of sound did not exceed 1 m/s. Density measurements were performed using a pycnometer at atmospheric pressure in the range from -30 to their normal boiling point with an error not exceeding 0.05%. The results of sound velocity and density measurements were used to study the character of intermolecular forces. The necessity of taking into account the non-covalent chemical interaction of molecules of the studied substances is shown.Results. Sound velocity measurements were performed on the saturation line in the liquid phase of all five hexane isomers in the temperature range from -30 C to the critical temperature of all 5 isomers. The obtained results are used to study the features of the dependence of the energy of intermolecular forces on the parameters of the state in the field of research.Conclusion. It is shown that the energy of intermolecular forces in marginal hydrocarbons and other simple substances is the sum of 3 terms representing: 1) the energy of the dispersive attractive forces proportional to the square of the density; 2) the energy of the repulsive forces proportional to the biquadrate of the density and 3) the energy of weak chemical non-covalent binding forces proportional to the cubic root of the density of matter.","PeriodicalId":117184,"journal":{"name":"Proceedings of the Southwest State University. Series: Engineering and Technology","volume":"110 43","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139615313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-18DOI: 10.21869/2223-1528-2023-13-4-139-151
M. A. Pugachevskii, V. A. Mamontov, A. A. Kryukov, S. A. Dodonova, E. Artyushkova, V. A. Pikkiev
Purpose. Study of the protective properties of ablated cerium oxide nanoparticles for cell cultures in an oxidative reaction under ultraviolet and ionizing irradiation.Methods. Cerium dioxide nanoparticles with high antioxidant activity were obtained using laser ablation. Atomic force microscopy was used to characterize ablated cerium dioxide nanoparticles and cells incubated with cerium dioxide nanoparticles. The protective properties of cerium dioxide nanoparticles were studied after 0 (without incubation), 6and 24-hour incubation using the colorimetric MTT test method.Results. Using laser ablation, cerium oxide nanoparticles with a maximum size of up to 50 nm were obtained. The resulting nanoparticles were incubated with BJ TERT cell lines for 6 and 24 hours. The samples were subjected to ultraviolet (UV) and ionizing irradiation in order to reveal the protective properties of CeO2 nanoparticles. Based on the results of the MTT test, it was found that incubation with cerium dioxide nanoparticles has a pronounced protective effect on the BJ TERT cell line. After UV irradiation, 6-hour and 24-hour incubation of cerium oxide nanoparticles with cell culture provides 15±5% and 20±5% more cell survival, respectively, than without particles. After ionizing radiation, the percentage of survival of cells incubated for 24 hours with cerium nanoparticles also increases by 20±5%.Conclusion. This work shows that ablated cerium dioxide nanoparticles have a protective effect on healthy BJ TERT cells. The work shows that cerium oxide nanoparticles are promising antioxidants that can provide a protective effect for cell cultures from ultraviolet and ionizing radiation.
{"title":"Protective Properties of Ablated Cerium Oxide Nanoparticles for Cell Cultures under Conditions of Oxidative Stress under Ultraviolet and Ionizing Irradiation","authors":"M. A. Pugachevskii, V. A. Mamontov, A. A. Kryukov, S. A. Dodonova, E. Artyushkova, V. A. Pikkiev","doi":"10.21869/2223-1528-2023-13-4-139-151","DOIUrl":"https://doi.org/10.21869/2223-1528-2023-13-4-139-151","url":null,"abstract":"Purpose. Study of the protective properties of ablated cerium oxide nanoparticles for cell cultures in an oxidative reaction under ultraviolet and ionizing irradiation.Methods. Cerium dioxide nanoparticles with high antioxidant activity were obtained using laser ablation. Atomic force microscopy was used to characterize ablated cerium dioxide nanoparticles and cells incubated with cerium dioxide nanoparticles. The protective properties of cerium dioxide nanoparticles were studied after 0 (without incubation), 6and 24-hour incubation using the colorimetric MTT test method.Results. Using laser ablation, cerium oxide nanoparticles with a maximum size of up to 50 nm were obtained. The resulting nanoparticles were incubated with BJ TERT cell lines for 6 and 24 hours. The samples were subjected to ultraviolet (UV) and ionizing irradiation in order to reveal the protective properties of CeO2 nanoparticles. Based on the results of the MTT test, it was found that incubation with cerium dioxide nanoparticles has a pronounced protective effect on the BJ TERT cell line. After UV irradiation, 6-hour and 24-hour incubation of cerium oxide nanoparticles with cell culture provides 15±5% and 20±5% more cell survival, respectively, than without particles. After ionizing radiation, the percentage of survival of cells incubated for 24 hours with cerium nanoparticles also increases by 20±5%.Conclusion. This work shows that ablated cerium dioxide nanoparticles have a protective effect on healthy BJ TERT cells. The work shows that cerium oxide nanoparticles are promising antioxidants that can provide a protective effect for cell cultures from ultraviolet and ionizing radiation.","PeriodicalId":117184,"journal":{"name":"Proceedings of the Southwest State University. Series: Engineering and Technology","volume":"101 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139614679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-18DOI: 10.21869/2223-1528-2023-13-4-163-173
E. V. Melikhova, V. Y. Solovyova
Purpose of research. The aim of the work is to optimize the conditions for gas chromatographic determination of a mixture of eight organochlorine pesticides: aldrin, hexachlorobenzene, heptachlor, α-hexachlorocyclohexane, γ-hexachlorocyclohexane, dichlorodiphenyltrichloromethylmethane, dichlorodiphenyldichloroethane and dichlorodiphenyldichloroethylene.Methods. For chromatographic studies of organochlorine pesticides we used a Shimadzu GC-2010Plus gas chromatograph (Shimadzu, Japan) equipped with an automatic equilibrium vapor sample dispenser NT200N, electron-capture detector based on 63Ni and quartz capillary nonpolar column "Chromatek" SPB-5 (30 m, 0.32 mm, film thickness on the basis of phenyl(5%) and dimethyl(95%) polysiloxanes 0.5 μm) with an operating temperature range of 60°C 320/340°C. The chromatograms were processed in the application LabSolutions GPC.Results. On the basis of experimentally obtained data the optimal conditions for gas chromatographic determination and separation of eight-component mixture of organochlorine pesticides were selected, namely: the value of mobile phase flow division 1:10, carrier gas flow rate – 1.0 ml/min, two-stage temperature programmable column mode from 160 to 240°C with the rate of increase of 5°C/min. The metrological characteristics of the analysis and validation of the results of the proposed technique with the method of high-performance liquid chromatography were evaluated. Good reproducibility of chromatography results with the possibility of detection of organochlorine pesticides at the level of 10-6 – 10-5 μg/cm3 was proved. Application of Fisher's test has shown absence of significant differences in reproducibility of sampled populations the investigated methods of chromatographic analysis of COPCs are equally accurate. Extraction sample preparation of samples of real objects was proposed, the calculated extraction degrees >84% allow to recommend the technique for quantitative determination of analytes.Conclusion. The method of gas chromatographic analysis was tested for determination of organochlorine pesticides in samples of drinking water and baby puree (Russia) by additive method. Exceeding the norms of residual contents of organochlorine pesticides in the samples of the food products under study was not detected.
{"title":"Gas Chromatographic Determination of Residual Concentrations of a Mixture of Organochlorine Pesticides in Food Products","authors":"E. V. Melikhova, V. Y. Solovyova","doi":"10.21869/2223-1528-2023-13-4-163-173","DOIUrl":"https://doi.org/10.21869/2223-1528-2023-13-4-163-173","url":null,"abstract":"Purpose of research. The aim of the work is to optimize the conditions for gas chromatographic determination of a mixture of eight organochlorine pesticides: aldrin, hexachlorobenzene, heptachlor, α-hexachlorocyclohexane, γ-hexachlorocyclohexane, dichlorodiphenyltrichloromethylmethane, dichlorodiphenyldichloroethane and dichlorodiphenyldichloroethylene.Methods. For chromatographic studies of organochlorine pesticides we used a Shimadzu GC-2010Plus gas chromatograph (Shimadzu, Japan) equipped with an automatic equilibrium vapor sample dispenser NT200N, electron-capture detector based on 63Ni and quartz capillary nonpolar column \"Chromatek\" SPB-5 (30 m, 0.32 mm, film thickness on the basis of phenyl(5%) and dimethyl(95%) polysiloxanes 0.5 μm) with an operating temperature range of 60°C 320/340°C. The chromatograms were processed in the application LabSolutions GPC.Results. On the basis of experimentally obtained data the optimal conditions for gas chromatographic determination and separation of eight-component mixture of organochlorine pesticides were selected, namely: the value of mobile phase flow division 1:10, carrier gas flow rate – 1.0 ml/min, two-stage temperature programmable column mode from 160 to 240°C with the rate of increase of 5°C/min. The metrological characteristics of the analysis and validation of the results of the proposed technique with the method of high-performance liquid chromatography were evaluated. Good reproducibility of chromatography results with the possibility of detection of organochlorine pesticides at the level of 10-6 – 10-5 μg/cm3 was proved. Application of Fisher's test has shown absence of significant differences in reproducibility of sampled populations the investigated methods of chromatographic analysis of COPCs are equally accurate. Extraction sample preparation of samples of real objects was proposed, the calculated extraction degrees >84% allow to recommend the technique for quantitative determination of analytes.Conclusion. The method of gas chromatographic analysis was tested for determination of organochlorine pesticides in samples of drinking water and baby puree (Russia) by additive method. Exceeding the norms of residual contents of organochlorine pesticides in the samples of the food products under study was not detected.","PeriodicalId":117184,"journal":{"name":"Proceedings of the Southwest State University. Series: Engineering and Technology","volume":"102 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139614798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-18DOI: 10.21869/2223-1528-2023-13-4-88-97
A. V. Lebedev
Purpose to study the temperature dependence of the viscosity of a water-based magnetic fluid.Method. Consists of measuring the dynamic viscosity of a magnetic fluid based on cobalt ferrite particles stabilized in water by a double layer of surfactant. Lauric acid (first layer) and a mixture of lauric acid and sodium dodecyl sulfate (second layer) were used as a stabilizer. Measurements were performed using a Brookfield DV-II+Pro rotational viscometer equipped with a coaxial cylinder system. The measuring system of the viscometer was thermostated using a KRIO-VT-12-1 thermostat.Results. The temperature dependences of dynamic viscosity were measured for three samples of magnetic fluid based on cobalt ferrite particles of various concentrations in the temperature range 0–90C°. The obtained temperature dependences of viscosity are radically different from the temperature dependences both predicted by known theories and experimentally observed for kerosene-based magnetic fluids. According to well-known theoretical models, the ratio of the viscosity of the magnetic fluid to the viscosity of the base medium is a certain universal function of particle concentration. Different models offer different types of this feature. But it clearly follows from them that the viscosity ratio should not depend on temperature. For magnetic fluids based on kerosene, it has been experimentally established that its relative viscosity decreases with increasing temperature. However, according to the results obtained, the relative viscosity of a water-based magnetic fluid does not decrease with increasing temperature, but increases significantly. That is, the viscosity of a water-based magnetic fluid decreases more slowly with increasing temperature than the viscosity of water.Conclusion. The observed dependencies completely contradict the known patterns, both theoretical and experimentally established for kerosene-based magnetic fluids. The results obtained may be useful for the further development of the theory of aqueous colloidal solutions with particle stabilization by a double layer of surfactants.
{"title":"Viscosity Anomalies of Magnetic Fluid Stabilized by a Double Layer of Surfactant in Water","authors":"A. V. Lebedev","doi":"10.21869/2223-1528-2023-13-4-88-97","DOIUrl":"https://doi.org/10.21869/2223-1528-2023-13-4-88-97","url":null,"abstract":"Purpose to study the temperature dependence of the viscosity of a water-based magnetic fluid.Method. Consists of measuring the dynamic viscosity of a magnetic fluid based on cobalt ferrite particles stabilized in water by a double layer of surfactant. Lauric acid (first layer) and a mixture of lauric acid and sodium dodecyl sulfate (second layer) were used as a stabilizer. Measurements were performed using a Brookfield DV-II+Pro rotational viscometer equipped with a coaxial cylinder system. The measuring system of the viscometer was thermostated using a KRIO-VT-12-1 thermostat.Results. The temperature dependences of dynamic viscosity were measured for three samples of magnetic fluid based on cobalt ferrite particles of various concentrations in the temperature range 0–90C°. The obtained temperature dependences of viscosity are radically different from the temperature dependences both predicted by known theories and experimentally observed for kerosene-based magnetic fluids. According to well-known theoretical models, the ratio of the viscosity of the magnetic fluid to the viscosity of the base medium is a certain universal function of particle concentration. Different models offer different types of this feature. But it clearly follows from them that the viscosity ratio should not depend on temperature. For magnetic fluids based on kerosene, it has been experimentally established that its relative viscosity decreases with increasing temperature. However, according to the results obtained, the relative viscosity of a water-based magnetic fluid does not decrease with increasing temperature, but increases significantly. That is, the viscosity of a water-based magnetic fluid decreases more slowly with increasing temperature than the viscosity of water.Conclusion. The observed dependencies completely contradict the known patterns, both theoretical and experimentally established for kerosene-based magnetic fluids. The results obtained may be useful for the further development of the theory of aqueous colloidal solutions with particle stabilization by a double layer of surfactants.","PeriodicalId":117184,"journal":{"name":"Proceedings of the Southwest State University. Series: Engineering and Technology","volume":"114 41","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139615640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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