Plasma-chemical processing devices are widely used in practice and are an integral part in microelectronics, medicine, light industry and nanotechnology. In addition, they are used as methods for modifying the modern materials surfaces and in liquids processing. The paper considers preparation of the aromatic compound nitro derivatives under the action of capacitive high-frequency electrodeless discharge at the gas--liquid interface with the reduced pressure. During the plasma-chemical treatment of the reaction mixture containing the 1,2-dihydroacenaphthylene (acenaphthene), its complete conversion was observed, which was confirmed by detection of the acenaphthene mono- and dinitro-derivatives, as well as of the side chain oxidation products, in the reaction products. The proposed method of implementing nitration reaction of the aromatic substances, which belongs to the new instrumental methods of organic synthesis along with photochemistry and electrochemical synthesis, allows direct binding of the molecular nitrogen and oxygen into the valuable nitrogen-containing organic compounds. Study results demonstrate effective introduction of the plasma chemistry methods in chemical technology not only for the purposes of oxidative destruction of the organic substances, but also as the physicochemical tools for the fine organic synthesis allowing selective functionalization of the polynuclear aromatic compounds
{"title":"Acenaphthene Nitro Derivatives Plasma-Chemical Synthesis in the High-Frequency Currents Field at Reduced Pressure","authors":"A.A. Lubin, R.V. Yakushin, M.S. Oshchepkov, Yu.V. Ulyanova, D.O. Botev, A.V. Chistolinov, N.Ya. Podhaluzina, I.N. Solovieva, V.S. Boldyrev","doi":"10.18698/1812-3368-2023-4-123-140","DOIUrl":"https://doi.org/10.18698/1812-3368-2023-4-123-140","url":null,"abstract":"Plasma-chemical processing devices are widely used in practice and are an integral part in microelectronics, medicine, light industry and nanotechnology. In addition, they are used as methods for modifying the modern materials surfaces and in liquids processing. The paper considers preparation of the aromatic compound nitro derivatives under the action of capacitive high-frequency electrodeless discharge at the gas--liquid interface with the reduced pressure. During the plasma-chemical treatment of the reaction mixture containing the 1,2-dihydroacenaphthylene (acenaphthene), its complete conversion was observed, which was confirmed by detection of the acenaphthene mono- and dinitro-derivatives, as well as of the side chain oxidation products, in the reaction products. The proposed method of implementing nitration reaction of the aromatic substances, which belongs to the new instrumental methods of organic synthesis along with photochemistry and electrochemical synthesis, allows direct binding of the molecular nitrogen and oxygen into the valuable nitrogen-containing organic compounds. Study results demonstrate effective introduction of the plasma chemistry methods in chemical technology not only for the purposes of oxidative destruction of the organic substances, but also as the physicochemical tools for the fine organic synthesis allowing selective functionalization of the polynuclear aromatic compounds","PeriodicalId":12961,"journal":{"name":"Herald of the Bauman Moscow State Technical University. Series Natural Sciences","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134997861","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 : 2023-08-01DOI: 10.18698/1812-3368-2023-4-108-122
N.I. Yurasov
The paper considers the problem of finding energy levels in the 1D quantum well in case of its width alteration at the nonrelativistic rate. According to the reviewed literature, the exact solution is known only in the case of nonrelativistic motion of the 1D quantum well wall at the constant rate. It is shown that motion with the constant rate is physically unrealizable. Therefore, it is necessary to find at least small areas of the Schrodinger equation solution for a wider range of nonrelativistic alterations in the 1D quantum well width. Analysis results presented in the study show existence of such areas. The found areas correspond to the instantaneous stationary states satisfying the Bohr quantization condition. In this case, the Dirichlet condition is also satisfied on the moving wall. It means that in this case energy of the level with the n number also becomes a function of the k second quantum number, which takes into account dynamic alteration in the 1D quantum well width. Variants were found of the k second quantum number spectrum and of the quantum level spectrum in various cases of the wall continuous motion with zero initial speed and finite acceleration. Within the framework of the analysis used, formulas were obtained to change the difference between energies of the two arbitrary levels. An analysis was made for the boundaries of the wall speed and the 1D quantum well width in considering the nonrelativistic problem. The obtained results and their possible applications are under discussion, including analysis of the problems related to nanotechnology
{"title":"Energy Level Quantization in the 1D Quantum Well in Case of Instantaneous Stationary State with the Non-Relativistic Wall and Particle Motion","authors":"N.I. Yurasov","doi":"10.18698/1812-3368-2023-4-108-122","DOIUrl":"https://doi.org/10.18698/1812-3368-2023-4-108-122","url":null,"abstract":"The paper considers the problem of finding energy levels in the 1D quantum well in case of its width alteration at the nonrelativistic rate. According to the reviewed literature, the exact solution is known only in the case of nonrelativistic motion of the 1D quantum well wall at the constant rate. It is shown that motion with the constant rate is physically unrealizable. Therefore, it is necessary to find at least small areas of the Schrodinger equation solution for a wider range of nonrelativistic alterations in the 1D quantum well width. Analysis results presented in the study show existence of such areas. The found areas correspond to the instantaneous stationary states satisfying the Bohr quantization condition. In this case, the Dirichlet condition is also satisfied on the moving wall. It means that in this case energy of the level with the n number also becomes a function of the k second quantum number, which takes into account dynamic alteration in the 1D quantum well width. Variants were found of the k second quantum number spectrum and of the quantum level spectrum in various cases of the wall continuous motion with zero initial speed and finite acceleration. Within the framework of the analysis used, formulas were obtained to change the difference between energies of the two arbitrary levels. An analysis was made for the boundaries of the wall speed and the 1D quantum well width in considering the nonrelativistic problem. The obtained results and their possible applications are under discussion, including analysis of the problems related to nanotechnology","PeriodicalId":12961,"journal":{"name":"Herald of the Bauman Moscow State Technical University. Series Natural Sciences","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134998267","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 : 2023-08-01DOI: 10.18698/1812-3368-2023-4-18-38
A.V. Lapin, N.E. Zubov, A.V. Proletarskii
A compact analytical formula is obtained that determines the entire set of solutions of the modal control problem for a wide class of multidimensional dynamical systems with vector input, where the number of states is divisible by the number of control inputs, and the controllability index is equal to the quotient of this division. This formula generalizes to systems with the vector input the Ackermann formula applied to multidimensional systems with scalar input. The basis to obtaining the generalized Ackermann formula lies in the original concepts of the Luenberger generalized canonical form and operations of the matrices block transposition. For the most convenient calculation of controller, the original system with vector input is reduced to the generalized Luenberger canonical form using the two successive similarity transformations. A lemma is proved that demonstrates the compact analytical form of the inverse transformation matrix. Transition equivalence makes it possible to obtain a complete countably infinite parametrized set of solutions to the modal control problem under consideration. Its parametrization is provided by selecting block coefficients of the matrix polynomial, which determinant corresponds to the given scalar characteristic polynomial. In cases, where the matrix polynomial involved in parametrization is not reduced to the multipliers, the generalized Ackermann formula contains solutions to the modal control problem that could not be obtained using the existing decomposition method. Examples are presented demonstrating both suitability of the proposed formula for analytical synthesis of modal controllers by state in systems with vector input and its advantages in comparison with the decomposition method
{"title":"Generalization of Ackermann Formula for a Certain Class of Multidimensional Dynamic Systems with Vector Input","authors":"A.V. Lapin, N.E. Zubov, A.V. Proletarskii","doi":"10.18698/1812-3368-2023-4-18-38","DOIUrl":"https://doi.org/10.18698/1812-3368-2023-4-18-38","url":null,"abstract":"A compact analytical formula is obtained that determines the entire set of solutions of the modal control problem for a wide class of multidimensional dynamical systems with vector input, where the number of states is divisible by the number of control inputs, and the controllability index is equal to the quotient of this division. This formula generalizes to systems with the vector input the Ackermann formula applied to multidimensional systems with scalar input. The basis to obtaining the generalized Ackermann formula lies in the original concepts of the Luenberger generalized canonical form and operations of the matrices block transposition. For the most convenient calculation of controller, the original system with vector input is reduced to the generalized Luenberger canonical form using the two successive similarity transformations. A lemma is proved that demonstrates the compact analytical form of the inverse transformation matrix. Transition equivalence makes it possible to obtain a complete countably infinite parametrized set of solutions to the modal control problem under consideration. Its parametrization is provided by selecting block coefficients of the matrix polynomial, which determinant corresponds to the given scalar characteristic polynomial. In cases, where the matrix polynomial involved in parametrization is not reduced to the multipliers, the generalized Ackermann formula contains solutions to the modal control problem that could not be obtained using the existing decomposition method. Examples are presented demonstrating both suitability of the proposed formula for analytical synthesis of modal controllers by state in systems with vector input and its advantages in comparison with the decomposition method","PeriodicalId":12961,"journal":{"name":"Herald of the Bauman Moscow State Technical University. Series Natural Sciences","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134998269","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 : 2023-08-01DOI: 10.18698/1812-3368-2023-4-175-193
N.A. Villacres, E.T.G. Cavalheiro, A.P.G. Ferreira, T. Venancio, H.A. Alarcon, A.C. Valderrama
This work focused on the development of a new biomaterial from polysaccharides. Thus composite films of sodium alginate, κ-carrageenan, and ι-carra-geenan plasticized with glycerol and poly(ethylene glycol) 400 (PEG 400) were prepared. The surface properties of the resulting films in terms of surface morphology were investigated. The best ratio between glycerol and PEG 400 used as plasticizers to prepare sodium alginate films was determined. Opacity, water content, SEM, TGA, and FTIR studies determined the optimal ratio between glycerol and PEG 400. The addition of carrageenans in the composite films showed differences in the TGA curves and on surface of the films. The composite film was loaded with an ethanolic solution of aminoethoxyvinylglycine (AVG). The AVG loaded in the composite film exhibited improved surface area, increased percent of crystallinity, and higher percent release at a lower temperature and its release kinetics were studied
{"title":"Preparation and Сharacterization of Biocomposite Films of Sodium Alginate/Kappa-Carrageenan/Iota-Carrageenan Loaded with Aminoethoxyvinylglycine","authors":"N.A. Villacres, E.T.G. Cavalheiro, A.P.G. Ferreira, T. Venancio, H.A. Alarcon, A.C. Valderrama","doi":"10.18698/1812-3368-2023-4-175-193","DOIUrl":"https://doi.org/10.18698/1812-3368-2023-4-175-193","url":null,"abstract":"This work focused on the development of a new biomaterial from polysaccharides. Thus composite films of sodium alginate, κ-carrageenan, and ι-carra-geenan plasticized with glycerol and poly(ethylene glycol) 400 (PEG 400) were prepared. The surface properties of the resulting films in terms of surface morphology were investigated. The best ratio between glycerol and PEG 400 used as plasticizers to prepare sodium alginate films was determined. Opacity, water content, SEM, TGA, and FTIR studies determined the optimal ratio between glycerol and PEG 400. The addition of carrageenans in the composite films showed differences in the TGA curves and on surface of the films. The composite film was loaded with an ethanolic solution of aminoethoxyvinylglycine (AVG). The AVG loaded in the composite film exhibited improved surface area, increased percent of crystallinity, and higher percent release at a lower temperature and its release kinetics were studied","PeriodicalId":12961,"journal":{"name":"Herald of the Bauman Moscow State Technical University. Series Natural Sciences","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134998262","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}
Electron paramagnetic resonance (EPR) spectrometry makes it possible to study the formation of free radicals during the transfer of energy to the object. The decay kinetics of free radicals is an integral part of the study since this phenomenon directly interferes with the goals of accurate identification of the irradiation fact and dosimetry using EPR spectrometry. In this work, we have studied the time dependence of the intensity and characteristics of the EPR signal of analytical sucrose irradiated with gamma rays at doses from 0.3 to 9 kGy. It has been shown that irradiated sucrose gives a stable EPR peak after 60 days. A change in the spectral characteristics of the signal was recorded in the first 23 hours after irradiation. The signal intensity tends to increase in the first 72 hours after irradiation for a sample with an irradiation dose of 300 Gy and 48 hours for 1000 Gy. The dependence of the signal intensity on the absorbed dose is linear in the range of studied doses. The g-factor value at the intersection point of the derivative contour with the zero line is 2.013. Based on the data obtained, it can be assumed that sucrose (sugar) is one of the best candidates among solid radiation-sensitive materials for identifying the fact of irradiation using EPR spectrometry
{"title":"EPR-Study the Decay Kinetics of Free Radicals in Irradiated Sucrose","authors":"I.M. Medzhidov, I.V. Polyakova, S.A. Gorbatov, D.I. Petrukhina, V.I. Shishko, O.V. Tkhorik, V.A. Kharlamov","doi":"10.18698/1812-3368-2023-4-141-158","DOIUrl":"https://doi.org/10.18698/1812-3368-2023-4-141-158","url":null,"abstract":"Electron paramagnetic resonance (EPR) spectrometry makes it possible to study the formation of free radicals during the transfer of energy to the object. The decay kinetics of free radicals is an integral part of the study since this phenomenon directly interferes with the goals of accurate identification of the irradiation fact and dosimetry using EPR spectrometry. In this work, we have studied the time dependence of the intensity and characteristics of the EPR signal of analytical sucrose irradiated with gamma rays at doses from 0.3 to 9 kGy. It has been shown that irradiated sucrose gives a stable EPR peak after 60 days. A change in the spectral characteristics of the signal was recorded in the first 23 hours after irradiation. The signal intensity tends to increase in the first 72 hours after irradiation for a sample with an irradiation dose of 300 Gy and 48 hours for 1000 Gy. The dependence of the signal intensity on the absorbed dose is linear in the range of studied doses. The g-factor value at the intersection point of the derivative contour with the zero line is 2.013. Based on the data obtained, it can be assumed that sucrose (sugar) is one of the best candidates among solid radiation-sensitive materials for identifying the fact of irradiation using EPR spectrometry","PeriodicalId":12961,"journal":{"name":"Herald of the Bauman Moscow State Technical University. Series Natural Sciences","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134998265","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 : 2023-08-01DOI: 10.18698/1812-3368-2023-4-39-51
I.N. Aliev, Z.A. Samedova, R.E. Lyatifov
The paper considers the London equation semi-classical generalization leading to a connection between the Cooper pairs magnetic flux quantization and the electric charge discreteness. Using the Bohr --- Sommerfeld quantization rule, a derivation of the magnetic flux quantization was made on the basis of the fluxoid uniqueness. The resulting quantization was applied to the magnetic monopoles hypothesis proposed by Dirac, which remains relevant due to the asymmetry present in the modern physics in describing electrical and magnetic properties of matter. On a fairly simple model of the possible experiment, an option of registering a monopole by a jump in the magnetic induction flux and the associated alteration in the circuit current were studied. The paper analyzed the problems of the monopole different measurement units and the results similar to those obtained on the basis of the Schwinger series of works, where he proceeded from considering introduction of a hypothetical particle with the electric and magnetic charges, i.e., the dyon. Possible explanation of the Abrikosov vortex is presented, it is based on vortex representation in the form of a magnetized thin thread through the magnetic tubes, at the ends of which monopoles of different charges (dipole) are positioned. Unlike most the works devoted to this problem, calculations were performed in the SI system. The monopole quantization conditions were derived
{"title":"Semi-Classical Quantum Generalization of the London Equations and the Monopole Hypothesis","authors":"I.N. Aliev, Z.A. Samedova, R.E. Lyatifov","doi":"10.18698/1812-3368-2023-4-39-51","DOIUrl":"https://doi.org/10.18698/1812-3368-2023-4-39-51","url":null,"abstract":"The paper considers the London equation semi-classical generalization leading to a connection between the Cooper pairs magnetic flux quantization and the electric charge discreteness. Using the Bohr --- Sommerfeld quantization rule, a derivation of the magnetic flux quantization was made on the basis of the fluxoid uniqueness. The resulting quantization was applied to the magnetic monopoles hypothesis proposed by Dirac, which remains relevant due to the asymmetry present in the modern physics in describing electrical and magnetic properties of matter. On a fairly simple model of the possible experiment, an option of registering a monopole by a jump in the magnetic induction flux and the associated alteration in the circuit current were studied. The paper analyzed the problems of the monopole different measurement units and the results similar to those obtained on the basis of the Schwinger series of works, where he proceeded from considering introduction of a hypothetical particle with the electric and magnetic charges, i.e., the dyon. Possible explanation of the Abrikosov vortex is presented, it is based on vortex representation in the form of a magnetized thin thread through the magnetic tubes, at the ends of which monopoles of different charges (dipole) are positioned. Unlike most the works devoted to this problem, calculations were performed in the SI system. The monopole quantization conditions were derived","PeriodicalId":12961,"journal":{"name":"Herald of the Bauman Moscow State Technical University. Series Natural Sciences","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134996848","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}
The paper presents experimental results of studying the macrokinetic intensification and stabilization processes of methane oxidation (combustion) in the high-enthalpy oxygen-containing flow inside the constant cross section channel being finite along its length. Calculation and experimental data are presented on the methane oxidation gas-dynamic intensification and stabilization in the recirculation zone of the high-enthalpy oxygen-containing flow formed behind the wedge-shaped bluff body. Computational and experimental studies enabled to consider various configurations of the bluff bodies differing in their number and degree of the constant cross section channel obstruction. Dependence of the gas relative residence time in the recirculation zone behind the bluff bodies was determined for various configurations. Range of the initial enthalpy values of the high-enthalpy oxygen-containing flow of 350--700 kJ/kg was considered. Regularities were established for the influence of the flow obstruction degree on the physical and chemical processes completion in the channel under study. Methane oxidation intensity in the high-enthalpy oxygen-containing flow was compared with and without the gas-dynamic stabilization. The level of lower limit value of the fuel excess coefficient corresponding to the stable methane ignition and combustion was determined. The data obtained indicate intensification in the methane oxidation diffusion-kinetic regimes and make it possible to evaluate the factors that are limiting completion of the physical and chemical processes
{"title":"Gas-Dynamic Stabilization and Intensification of the Methane Oxidation Macrokinetic Processes in the High-Enthalpy Oxygen-Containing Flow","authors":"K.Yu. Arefyev, I.M. Grishin, V.S. Zakharov, A.V. Nikoporenko","doi":"10.18698/1812-3368-2023-4-52-78","DOIUrl":"https://doi.org/10.18698/1812-3368-2023-4-52-78","url":null,"abstract":"The paper presents experimental results of studying the macrokinetic intensification and stabilization processes of methane oxidation (combustion) in the high-enthalpy oxygen-containing flow inside the constant cross section channel being finite along its length. Calculation and experimental data are presented on the methane oxidation gas-dynamic intensification and stabilization in the recirculation zone of the high-enthalpy oxygen-containing flow formed behind the wedge-shaped bluff body. Computational and experimental studies enabled to consider various configurations of the bluff bodies differing in their number and degree of the constant cross section channel obstruction. Dependence of the gas relative residence time in the recirculation zone behind the bluff bodies was determined for various configurations. Range of the initial enthalpy values of the high-enthalpy oxygen-containing flow of 350--700 kJ/kg was considered. Regularities were established for the influence of the flow obstruction degree on the physical and chemical processes completion in the channel under study. Methane oxidation intensity in the high-enthalpy oxygen-containing flow was compared with and without the gas-dynamic stabilization. The level of lower limit value of the fuel excess coefficient corresponding to the stable methane ignition and combustion was determined. The data obtained indicate intensification in the methane oxidation diffusion-kinetic regimes and make it possible to evaluate the factors that are limiting completion of the physical and chemical processes","PeriodicalId":12961,"journal":{"name":"Herald of the Bauman Moscow State Technical University. Series Natural Sciences","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134997858","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}
The increasing world energy needs are not matched by the limited availability of fossil fuels thus the development of clean and sustainable fuels is the right solution. Biodiesel is one of these fuels and can be produced through transesterification reactions of vegetable oils in the presence of a catalyst. Acidic natural clay can be an option because of its large abundance, especially in the Indonesia and is heterogeneous in the solution it catalyzes. In this study, clay samples were obtained from an area in Bukittinggi City, West Sumatra Province, and then combined by wet impregnation with nickel as a catalyst in the transesterification reaction of used cooking oil to produce fatty acid methyl esters. Based on X-Ray diffraction (XRD) analysis, the presence of nickel ions does not affect the diffraction pattern of clay minerals contained in the soil consisting of kaolinite and illite. Measurements with X-Ray fluorescence (XRF) showed that the silicon-aluminum mole ratio also did not show a significant change where before mixing the value was 2.0 and after that it only decreased about 5 % to 1.9. The pore diameter of the catalyst was 3.03 nm known by Surface Area Analyzer (SAA). Several variations have been carried out to optimize the catalytic performance of the nickel supported clay and the best conditions were obtained when the catalyst concentration was 3 wt %, the methanol-oil mole ratio was 6:1, the reaction temperature was 70 °C and the reaction carried out for 3 hours. Under these conditions, the yield of methyl ester produced was 63 %
{"title":"Kaolinite and Illite Based Clay Supporting Nickel: its Synthesis, Characterization, and Catalytic Optimazion in a Lab-Scale Fatty Acid Methyl Ester Production","authors":"Febiola Fifi, None Rahmayeni, None Admi, None Syukri","doi":"10.18698/1812-3368-2023-4-159-174","DOIUrl":"https://doi.org/10.18698/1812-3368-2023-4-159-174","url":null,"abstract":"The increasing world energy needs are not matched by the limited availability of fossil fuels thus the development of clean and sustainable fuels is the right solution. Biodiesel is one of these fuels and can be produced through transesterification reactions of vegetable oils in the presence of a catalyst. Acidic natural clay can be an option because of its large abundance, especially in the Indonesia and is heterogeneous in the solution it catalyzes. In this study, clay samples were obtained from an area in Bukittinggi City, West Sumatra Province, and then combined by wet impregnation with nickel as a catalyst in the transesterification reaction of used cooking oil to produce fatty acid methyl esters. Based on X-Ray diffraction (XRD) analysis, the presence of nickel ions does not affect the diffraction pattern of clay minerals contained in the soil consisting of kaolinite and illite. Measurements with X-Ray fluorescence (XRF) showed that the silicon-aluminum mole ratio also did not show a significant change where before mixing the value was 2.0 and after that it only decreased about 5 % to 1.9. The pore diameter of the catalyst was 3.03 nm known by Surface Area Analyzer (SAA). Several variations have been carried out to optimize the catalytic performance of the nickel supported clay and the best conditions were obtained when the catalyst concentration was 3 wt %, the methanol-oil mole ratio was 6:1, the reaction temperature was 70 °C and the reaction carried out for 3 hours. Under these conditions, the yield of methyl ester produced was 63 %","PeriodicalId":12961,"journal":{"name":"Herald of the Bauman Moscow State Technical University. Series Natural Sciences","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134998070","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}
Currently, substances are being actively sought that could serve as the alternative fuel or fuel additive reducing formation and emission of the carbon nanoparticles. Here, processes of the polyaromatic hydrocarbons (precursors of the carbon condensed phase formation) and carbon black nanoparticles formation during the ethylene pyrolysis with addition of the tetrahydrofuran were studied by laser-induced fluorescence and laser extinction methods. Spectral dependences of laser-induced fluorescence of the polyaromatic hydrocarbons were obtained by laser-induced fluorescence at various temperatures and pyrolysis stages, and optical density of the reacting gas mixtures at wavelengths of 405 and 633 nm was obtained by laser extinction. Measurements were carried out on a shock tube behind the reflected shock waves in the temperature range of 1,695--2,500 K and pressure range of 2.7--4.1 atm. It is shown that during the ethylene pyrolysis with the tetrahydrofuran addition soot formation process is intensifying, and the temperature range of the carbon nanoparticles formation is expanding. Using the kinetic simulation, it was found that acceleration in the carbon nanoparticles formation was caused by formation of methyl radical and propylene in the tetrahydrofuran pyrolysis
{"title":"Investigation of the PAH and Carbon Nanoparticles Formation Processes in the Ethylene Pyrolysis with the Tetrahydrofuran Addition Behind the Shock Waves","authors":"A.V. Drakon, A.V. Eremin, M.R. Korshunova, E.Yu. Mikheyeva","doi":"10.18698/1812-3368-2023-4-79-107","DOIUrl":"https://doi.org/10.18698/1812-3368-2023-4-79-107","url":null,"abstract":"Currently, substances are being actively sought that could serve as the alternative fuel or fuel additive reducing formation and emission of the carbon nanoparticles. Here, processes of the polyaromatic hydrocarbons (precursors of the carbon condensed phase formation) and carbon black nanoparticles formation during the ethylene pyrolysis with addition of the tetrahydrofuran were studied by laser-induced fluorescence and laser extinction methods. Spectral dependences of laser-induced fluorescence of the polyaromatic hydrocarbons were obtained by laser-induced fluorescence at various temperatures and pyrolysis stages, and optical density of the reacting gas mixtures at wavelengths of 405 and 633 nm was obtained by laser extinction. Measurements were carried out on a shock tube behind the reflected shock waves in the temperature range of 1,695--2,500 K and pressure range of 2.7--4.1 atm. It is shown that during the ethylene pyrolysis with the tetrahydrofuran addition soot formation process is intensifying, and the temperature range of the carbon nanoparticles formation is expanding. Using the kinetic simulation, it was found that acceleration in the carbon nanoparticles formation was caused by formation of methyl radical and propylene in the tetrahydrofuran pyrolysis","PeriodicalId":12961,"journal":{"name":"Herald of the Bauman Moscow State Technical University. Series Natural Sciences","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134996854","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 : 2023-08-01DOI: 10.18698/1812-3368-2023-4-4-17
G.N. Kuvyrkin, A.A. Sokolov
Simulating the modern structural materials requires introduction of a model that takes into account structural features at the micro-level. The Eringen’s nonlocal elasticity theory model could be referred to such models. This model introduction was considered in comparison with the elasticity classical model. Main feature of the nonlocal model is that it takes into consideration the long-range interactions between the continuous medium particles; classical formulation is its special case. In this case, equations are having the integral differential form, which significantly complicates obtaining the analytical solutions. In this regard, the finite elements method was applied to find a solution using the isoparametric finite elements. Here, the main balance relations are satisfied, as in the classical elasticity theory model. However, the solutions obtained are differing to a larger extent from the classical solutions, since such solutions exhibit the edge effect in vicinity of the domain free boundaries. This effect, as well as preservation of the balance of forces, are demonstrated on the example of the Saint-Venant principle feasibility at stretching the rectangular plate. Solutions obtained in the nonlocal formulation have a significant decrease in the tensile stress decrease near the free boundaries and shear stresses in the cross section
{"title":"Saint-Venant Principle on Problems of Nonlocal Elasticity Theory","authors":"G.N. Kuvyrkin, A.A. Sokolov","doi":"10.18698/1812-3368-2023-4-4-17","DOIUrl":"https://doi.org/10.18698/1812-3368-2023-4-4-17","url":null,"abstract":"Simulating the modern structural materials requires introduction of a model that takes into account structural features at the micro-level. The Eringen’s nonlocal elasticity theory model could be referred to such models. This model introduction was considered in comparison with the elasticity classical model. Main feature of the nonlocal model is that it takes into consideration the long-range interactions between the continuous medium particles; classical formulation is its special case. In this case, equations are having the integral differential form, which significantly complicates obtaining the analytical solutions. In this regard, the finite elements method was applied to find a solution using the isoparametric finite elements. Here, the main balance relations are satisfied, as in the classical elasticity theory model. However, the solutions obtained are differing to a larger extent from the classical solutions, since such solutions exhibit the edge effect in vicinity of the domain free boundaries. This effect, as well as preservation of the balance of forces, are demonstrated on the example of the Saint-Venant principle feasibility at stretching the rectangular plate. Solutions obtained in the nonlocal formulation have a significant decrease in the tensile stress decrease near the free boundaries and shear stresses in the cross section","PeriodicalId":12961,"journal":{"name":"Herald of the Bauman Moscow State Technical University. Series Natural Sciences","volume":"84 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134997859","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：