Abstract. Investigating the challenges associated with the structural and strength degradation of ceramic fuel cells, which hold significant potential for hydrogen production through electrolysis methods, is a current focus ofresearch. Understanding the degradation processes and their occurrence rate is crucial in the assessment of the efficacy of these ceramics for applications in alternative energy production, specifically in the realm of hydrogen energy. The aim of this study is to ascertain the impact of doping ceramics with aluminum nitride NiAl2O4, irradiated with protons with a dose of approximately 50 dpa, on resistance to high-temperature degradation, and associated corrosive processes of oxidation and swelling, as well as migration processes of implanted hydrogen. Three types of ceramics were selected as objects for study: NiAl2O4ceramics, NiAl2O4ceramics stabilized with 0.05 M AlN, NiAl2O4ceramics stabilized with 0.15 M AlN, that are distinguished by the formation of impurity phases in Al7O3N8, with an orthorhombic type of crystal lattice. As a result of high-temperature tests, it was observed that NiAl2O4ceramics, when stabilized, exhibit reduced susceptibility to destructive alterations in strength characteristics, primarily attributed to the deformation distortion of the crystal structure caused by its swelling. These processes are associated with an augmentation in the thermal expansion of the crystal structure, manifested in the deformation swelling of the crystal lattice volume.
{"title":"TUDY OF THE INFLUENCE OF THE ACCUMULATED DOSE OF DAMAGE IN THE NEAR-SURFACE LAYER ON RESISTANCE TO EXTERNAL INFLUENCES ASSOCIATED WITH CORROSION PROCESSES DURING HIGH-TEMPERATURE ANNEALING","authors":"A. Kozlovskiy","doi":"10.31489/2024no1/14-20","DOIUrl":"https://doi.org/10.31489/2024no1/14-20","url":null,"abstract":"Abstract. Investigating the challenges associated with the structural and strength degradation of ceramic fuel cells, which hold significant potential for hydrogen production through electrolysis methods, is a current focus ofresearch. Understanding the degradation processes and their occurrence rate is crucial in the assessment of the efficacy of these ceramics for applications in alternative energy production, specifically in the realm of hydrogen energy. The aim of this study is to ascertain the impact of doping ceramics with aluminum nitride NiAl2O4, irradiated with protons with a dose of approximately 50 dpa, on resistance to high-temperature degradation, and associated corrosive processes of oxidation and swelling, as well as migration processes of implanted hydrogen. Three types of ceramics were selected as objects for study: NiAl2O4ceramics, NiAl2O4ceramics stabilized with 0.05 M AlN, NiAl2O4ceramics stabilized with 0.15 M AlN, that are distinguished by the formation of impurity phases in Al7O3N8, with an orthorhombic type of crystal lattice. As a result of high-temperature tests, it was observed that NiAl2O4ceramics, when stabilized, exhibit reduced susceptibility to destructive alterations in strength characteristics, primarily attributed to the deformation distortion of the crystal structure caused by its swelling. These processes are associated with an augmentation in the thermal expansion of the crystal structure, manifested in the deformation swelling of the crystal lattice volume.","PeriodicalId":11789,"journal":{"name":"Eurasian Physical Technical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140366109","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 article presents the results of modeling a multipoint contact in the thermoelectric method of testing. Sources of thermoelectromotive force (thermoEMF) have shown different influences, according to their type, on the load characteristics of the equivalent source obtained by parallel connection of several thermocouples as shown in the explanatory figures. The presented model is implemented in the NI LabVIEW package, which is freely available. The model was verified on three types of thermocouples (copper-constantan, copper-nichrome, and chromel-alumel), which have been connected in parallel in different quantities. The calculated load characteristics of the equivalent sources differ from the experimental ones by no more than 6%. The results of modeling the load characteristics of the equivalent thermoEMF sources obtained by parallel connection of different quantities of two types of thermocouples are presented. It is shown that in order to obtain reliable data, it is necessary to provide an equivalent source load of at least 1 kOhm.
文章介绍了热电测试法中多点接触建模的结果。热电动势（thermoEMF）源的类型不同，对通过并联多个热电偶获得的等效源的负载特性的影响也不同，如注释图所示。所介绍的模型是在免费提供的 NI LabVIEW 软件包中实现的。该模型在三种类型的热电偶（铜-康铜、铜-铬和铬-铝）上进行了验证，这些热电偶以不同数量并联。计算得出的等效源负载特性与实验结果相差不超过 6%。本文介绍了通过并联不同数量的两种热电偶而获得的等效热电偶源的负载特性建模结果。结果表明，为了获得可靠的数据，必须提供至少 1 千欧的等效源负载。
{"title":"SIMULATION OF MULTIPOINT CONTACT UNDER THERMOELECTRIC TESTING","authors":"Soldatov A.A","doi":"10.31489/2024no1/93-103","DOIUrl":"https://doi.org/10.31489/2024no1/93-103","url":null,"abstract":"The article presents the results of modeling a multipoint contact in the thermoelectric method of testing. Sources of thermoelectromotive force (thermoEMF) have shown different influences, according to their type, on the load characteristics of the equivalent source obtained by parallel connection of several thermocouples as shown in the explanatory figures. The presented model is implemented in the NI LabVIEW package, which is freely available. The model was verified on three types of thermocouples (copper-constantan, copper-nichrome, and chromel-alumel), which have been connected in parallel in different quantities. The calculated load characteristics of the equivalent sources differ from the experimental ones by no more than 6%. The results of modeling the load characteristics of the equivalent thermoEMF sources obtained by parallel connection of different quantities of two types of thermocouples are presented. It is shown that in order to obtain reliable data, it is necessary to provide an equivalent source load of at least 1 kOhm.","PeriodicalId":11789,"journal":{"name":"Eurasian Physical Technical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140366080","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}
This study aimed to elucidate the formation mechanisms of micro-macrostructural heterogeneities in the ingot's cortical zone and their transformation into surface defects during heating, plastic deformation, and rolling processes. The methodology and results of studying the macro-and microstructural and chemical heterogeneities of ingots and finished rolled sheets are presented. A comparative method of structural-concentration analysis of metal at theend-to-end metallurgical processing stage of ingot -slab -rolled sheets was developed. The technique utilizes metallographic methods to study the structure and perform qualitative analysis of non-metallic inclusions. The research findings indicate that the quality of the rolled sheet surface is predominantly determined by the physical heterogeneity of the ingot's crust zone, while the internal defects in thin rolled sheets are largely influenced by the contamination of the metal with non-metallic inclusions. A novel mechanism is proposed for the transformation of defects in the casting cortical zone into surface and internal defects in rolled sheets. This study contributes to a deeper understanding of the formation and transformation of defects during metal processing, enabling the development of strategies for improving the quality of rolled sheets. Additionally, the study highlights the importance of controlling the physical heterogeneity of the ingot's crust zone and minimizing non-metallic inclusion contamination to achieve high-quality rolled sheets.
{"title":"MECHANISM OF FORMATION OF INTERNAL AND SURFACE DEFECTS IN CASTING AND THEIR TRANSFORMATION INTO SURFACE DEFECTS OF SHEET","authors":"I.K. I.K. Ibraev","doi":"10.31489/2024no1/28-37","DOIUrl":"https://doi.org/10.31489/2024no1/28-37","url":null,"abstract":"This study aimed to elucidate the formation mechanisms of micro-macrostructural heterogeneities in the ingot's cortical zone and their transformation into surface defects during heating, plastic deformation, and rolling processes. The methodology and results of studying the macro-and microstructural and chemical heterogeneities of ingots and finished rolled sheets are presented. A comparative method of structural-concentration analysis of metal at theend-to-end metallurgical processing stage of ingot -slab -rolled sheets was developed. The technique utilizes metallographic methods to study the structure and perform qualitative analysis of non-metallic inclusions. The research findings indicate that the quality of the rolled sheet surface is predominantly determined by the physical heterogeneity of the ingot's crust zone, while the internal defects in thin rolled sheets are largely influenced by the contamination of the metal with non-metallic inclusions. A novel mechanism is proposed for the transformation of defects in the casting cortical zone into surface and internal defects in rolled sheets. This study contributes to a deeper understanding of the formation and transformation of defects during metal processing, enabling the development of strategies for improving the quality of rolled sheets. Additionally, the study highlights the importance of controlling the physical heterogeneity of the ingot's crust zone and minimizing non-metallic inclusion contamination to achieve high-quality rolled sheets.","PeriodicalId":11789,"journal":{"name":"Eurasian Physical Technical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140367665","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 : 2024-03-29DOI: 10.31489/2024no1/114-123
R. Gadirov
This paper provides a theoretical consideration of the process of paste extrusion using a piston dispenser. The paste is considered as a highly viscous suspension of terpineol and silver particle powder. As a result of numerical modeling, the distribution of silver particles in a steady paste flow was obtained. The excess pressure in the piston depending on its speed and the effective width of the track depending on the piston speed were obtained. Modeling showed that the viscosity of the paste has the greatest influence on the extrusion process. Application of the obtained dependencies will allow you to control the paste extrusion process.
{"title":"Numerical modeling of the process of extrusion of high-viscosity pastes","authors":"R. Gadirov","doi":"10.31489/2024no1/114-123","DOIUrl":"https://doi.org/10.31489/2024no1/114-123","url":null,"abstract":"This paper provides a theoretical consideration of the process of paste extrusion using a piston dispenser. The paste is considered as a highly viscous suspension of terpineol and silver particle powder. As a result of numerical modeling, the distribution of silver particles in a steady paste flow was obtained. The excess pressure in the piston depending on its speed and the effective width of the track depending on the piston speed were obtained. Modeling showed that the viscosity of the paste has the greatest influence on the extrusion process. Application of the obtained dependencies will allow you to control the paste extrusion process.","PeriodicalId":11789,"journal":{"name":"Eurasian Physical Technical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140367793","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}
This paper discusses the possibility of improving the ekibastuz coal quality through the use of "dry enrichment" technology. The experiments and calculations carried out made it possible to determine the optimal scheme for enrichment of samples of thermal coals from the Ekibastuzsky open-pit mineof "Angrensor-Energo" LLP. Testing of technical characteristics, such as moisture content, ash content, volatile matter yield and calculation of energy characteristics of enriched samples of thermal coal was carried out in 3 stages in a coal chemistry laboratory. As a result, it was found that the energy content of the enriched fuel samples increased to 28.5% of the original. This significantly improved consumer properties by obtaining the maximum yield of high quality coal concentrate. Consequently, the developed scheme of enrichment allows to significantly reduce the consumption of electricity, reduce emissions into the atmosphere, reduce the harmful impact on the environment, and expand the markets for coal.
{"title":"IMPROVING THE QUALITY OF EKIBASTUZ COAL USING THE DRY ENRICHMENT METHOD","authors":"K. Shaimerdenova","doi":"10.31489/2024no1/67-73","DOIUrl":"https://doi.org/10.31489/2024no1/67-73","url":null,"abstract":"This paper discusses the possibility of improving the ekibastuz coal quality through the use of \"dry enrichment\" technology. The experiments and calculations carried out made it possible to determine the optimal scheme for enrichment of samples of thermal coals from the Ekibastuzsky open-pit mineof \"Angrensor-Energo\" LLP. Testing of technical characteristics, such as moisture content, ash content, volatile matter yield and calculation of energy characteristics of enriched samples of thermal coal was carried out in 3 stages in a coal chemistry laboratory. As a result, it was found that the energy content of the enriched fuel samples increased to 28.5% of the original. This significantly improved consumer properties by obtaining the maximum yield of high quality coal concentrate. Consequently, the developed scheme of enrichment allows to significantly reduce the consumption of electricity, reduce emissions into the atmosphere, reduce the harmful impact on the environment, and expand the markets for coal.","PeriodicalId":11789,"journal":{"name":"Eurasian Physical Technical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140368171","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 influence of the plasmon effect of metal nanoparticles on electron transfer from Eosin and Rhodamine B dyes to TiO2was studied. Spectral-kineticmeasurementsshowedthat, compared to SiO2, not only the intensity but also the fluorescence lifetime of both dyes decreases on the TiO2surface, which indicates the charge transfer from the dye to the semiconductor. In the presence of core@shell (Ag@TiO2) plasmon nanostructures, an intensification of the fluorescence of both dyes is observed, as well as a decrease in the duration of the dyes emission. The optimal concentration for which the maximum plasmon effect was recorded is 3 wt% of Ag@TiO2. The plasmon effect also leads to an increase in the efficiency of sensitization of the semiconductor by molecules of the dyes under study, which is expressed as an increase in the photovoltaic and charge-transport characteristics of the semiconductor films. The results obtained on theplasmoneffect on the charge transfer process in the dye/semiconductor system can be used in the development of devices for photovoltaics, photocatalytic, and optoelectronic elements.
研究了金属纳米粒子的等离子效应对曙红和罗丹明 B 染料向二氧化钛的电子转移的影响。光谱动力学测量结果表明，与二氧化硅相比，两种染料在二氧化钛表面的荧光强度和荧光寿命都有所下降，这表明电荷从染料转移到了半导体。在核@壳（Ag@TiO2）等离子体纳米结构的存在下，两种染料的荧光都会增强，同时染料发射的持续时间也会缩短。记录到最大等离子效应的最佳浓度为 3 wt% 的 Ag@TiO2。等离子效应还能提高所研究的染料分子对半导体的敏化效率，这表现为半导体薄膜的光电和电荷传输特性的提高。关于染料/半导体系统中电荷转移过程的质子效应的研究结果可用于光伏、光催化和光电元件设备的开发。
{"title":"INFLUENCE OF PLASMON EFFECT ON THE SENSITIZATION OF TITANIUM DIOXIDE BY DYE MOLECULES","authors":"Auzhanova A.A, Ibrayev N.Kh, E. Seliverstova","doi":"10.31489/2024no1/49-56","DOIUrl":"https://doi.org/10.31489/2024no1/49-56","url":null,"abstract":"The influence of the plasmon effect of metal nanoparticles on electron transfer from Eosin and Rhodamine B dyes to TiO2was studied. Spectral-kineticmeasurementsshowedthat, compared to SiO2, not only the intensity but also the fluorescence lifetime of both dyes decreases on the TiO2surface, which indicates the charge transfer from the dye to the semiconductor. In the presence of core@shell (Ag@TiO2) plasmon nanostructures, an intensification of the fluorescence of both dyes is observed, as well as a decrease in the duration of the dyes emission. The optimal concentration for which the maximum plasmon effect was recorded is 3 wt% of Ag@TiO2. The plasmon effect also leads to an increase in the efficiency of sensitization of the semiconductor by molecules of the dyes under study, which is expressed as an increase in the photovoltaic and charge-transport characteristics of the semiconductor films. The results obtained on theplasmoneffect on the charge transfer process in the dye/semiconductor system can be used in the development of devices for photovoltaics, photocatalytic, and optoelectronic elements.","PeriodicalId":11789,"journal":{"name":"Eurasian Physical Technical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140368227","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 : 2024-03-29DOI: 10.31489/2024no1/138-144
С А Азизов
В статье предложна методика измерения диэлектрических коэффициентов полярных жидкостей для исследования объектов с большими потерями. Известные резонансные методы определения диэлектрических коэффициентов являются наиболее точными при изучении диэлектриков с малыми потерями. Применение этих методов для исследования объектов с большими потерями ограничено тем, что при внесении образца добротность резонансной системы падает настолько сильно, что ее изучение и измерения существующими методами становится невозможным. В диапазоне частот от 50 КГц до 200 МГц наибольшее распространение получил метод измерения при помощи куметра. Данный прибор допускает определение значений добротности больше 50 – 30. Между тем, в области дисперсии электромагнитных волн, значения тангенса угла потерь tgδ = (ε" / ε') зачастую превышают единицу. В этом случае применение известных методов измерения диэлектрических коэффициентов для исследования объектов с большими потерями неизбежно связано со столь большой погрешностью, что получаемые результаты не могут быть использованы для количественной интерпретации. Из – за простоты и удобства измерений при помощи куметра вопрос о расширении области измерения в сторону малых и больших потерь является приемлемым для исследований полярных жидкостей.
{"title":"Методика измерения диэлектрических коэффициентов полярных жидкостей в диапазоне микроволн","authors":"С А Азизов","doi":"10.31489/2024no1/138-144","DOIUrl":"https://doi.org/10.31489/2024no1/138-144","url":null,"abstract":"В статье предложна методика измерения диэлектрических коэффициентов полярных жидкостей для исследования объектов с большими потерями. Известные резонансные методы определения диэлектрических коэффициентов являются наиболее точными при изучении диэлектриков с малыми потерями. Применение этих методов для исследования объектов с большими потерями ограничено тем, что при внесении образца добротность резонансной системы падает настолько сильно, что ее изучение и измерения существующими методами становится невозможным. В диапазоне частот от 50 КГц до 200 МГц наибольшее распространение получил метод измерения при помощи куметра. Данный прибор допускает определение значений добротности больше 50 – 30. Между тем, в области дисперсии электромагнитных волн, значения тангенса угла потерь tgδ = (ε\" / ε') зачастую превышают единицу. В этом случае применение известных методов измерения диэлектрических коэффициентов для исследования объектов с большими потерями неизбежно связано со столь большой погрешностью, что получаемые результаты не могут быть использованы для количественной интерпретации. Из – за простоты и удобства измерений при помощи куметра вопрос о расширении области измерения в сторону малых и больших потерь является приемлемым для исследований полярных жидкостей.","PeriodicalId":11789,"journal":{"name":"Eurasian Physical Technical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140366374","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}
Abstract. The assumption that corrosion of products from X17 martensitic stainless steel in seawater occurs due to incomplete oxidation of chromium atoms in cells on the surface of the products is made in the presented work. Incomplete oxidation of chromium atoms occurs in the cells of X17 steel. This is due to the fact that oxygen molecules at temperatures up to 350 °C not having enough energy for chemical interaction with trivalent chromium atoms entering the cubic body-centeredcells of martensitic stainless steel. There is a significant decrease in the corrosion rate after placing X17 stainless steel products in 5% iodine solution in ethanol after pre-treatment of the product surface with active forms of oxygen. The treatment was carried out during 12 hours with chemically active forms of oxygen (ozone and singlet oxygen) at a temperature of 350 °С. Most of the chromium atoms on the surface of X17 steel samples were completely oxidized as a result of 12 hours exposure to highly active forms of oxygen. The density of the oxide passivation layer on the surface of the products increased significantly as a result of the formation of new bonds CHROMIUM -OXYGEN -CHROMIUM. This resulted in increased corrosion resistance. The rate of interaction with an alcohol solution containing halogen ions was reduced by 71% for the samples with the oxide passivation layer compared to samples of untreated X17 steel.
{"title":"REASON OF PITTING CORROSION OF MARTENSITIC STEELIN SEA WATER","authors":"M.I. Baikenov","doi":"10.31489/2024no1/38-48","DOIUrl":"https://doi.org/10.31489/2024no1/38-48","url":null,"abstract":"Abstract. The assumption that corrosion of products from X17 martensitic stainless steel in seawater occurs due to incomplete oxidation of chromium atoms in cells on the surface of the products is made in the presented work. Incomplete oxidation of chromium atoms occurs in the cells of X17 steel. This is due to the fact that oxygen molecules at temperatures up to 350 °C not having enough energy for chemical interaction with trivalent chromium atoms entering the cubic body-centeredcells of martensitic stainless steel. There is a significant decrease in the corrosion rate after placing X17 stainless steel products in 5% iodine solution in ethanol after pre-treatment of the product surface with active forms of oxygen. The treatment was carried out during 12 hours with chemically active forms of oxygen (ozone and singlet oxygen) at a temperature of 350 °С. Most of the chromium atoms on the surface of X17 steel samples were completely oxidized as a result of 12 hours exposure to highly active forms of oxygen. The density of the oxide passivation layer on the surface of the products increased significantly as a result of the formation of new bonds CHROMIUM -OXYGEN -CHROMIUM. This resulted in increased corrosion resistance. The rate of interaction with an alcohol solution containing halogen ions was reduced by 71% for the samples with the oxide passivation layer compared to samples of untreated X17 steel.","PeriodicalId":11789,"journal":{"name":"Eurasian Physical Technical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140367231","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}
False heat targets play an important role in the safety of aircraft and helicopters. The main task is to ensure stable ignition of the fuel grain before leaving the cartridge case. In order to optimize this process, it is important to study the influence of various parameters, such as the size of the gap between the cartridge case and the cylindrical surface of fuel grain, as well as the size of the particles coming from the initiator and fuel grain. This article offers a physical and mathematical model of the ignition and departure process of the grain, and studies the influence of the specified parameters on the ignition time. The ignition times of the grain end surface for different particle sizes equals r = 1 μm and r = 25 μm have been estimated, the gap between the cartridge case and the cylindrical surface of grain ranged from 0.5 mm to 2 mm. The output velocities of the grain from the cartridge case are obtained for particles equal to 1 μm and 25 μmand different gap between the cartridge case and the cylindrical surface of fuel grain.
{"title":"EFFECT OF TWO-PHASE FLOW ON THE FUEL GRAIN IGNITION AND ITS DEPARTURE FROM THE CARTRIDGE CASE","authors":"L. L. Minkov","doi":"10.31489/2024no1/84-92","DOIUrl":"https://doi.org/10.31489/2024no1/84-92","url":null,"abstract":"False heat targets play an important role in the safety of aircraft and helicopters. The main task is to ensure stable ignition of the fuel grain before leaving the cartridge case. In order to optimize this process, it is important to study the influence of various parameters, such as the size of the gap between the cartridge case and the cylindrical surface of fuel grain, as well as the size of the particles coming from the initiator and fuel grain. This article offers a physical and mathematical model of the ignition and departure process of the grain, and studies the influence of the specified parameters on the ignition time. The ignition times of the grain end surface for different particle sizes equals r = 1 μm and r = 25 μm have been estimated, the gap between the cartridge case and the cylindrical surface of grain ranged from 0.5 mm to 2 mm. The output velocities of the grain from the cartridge case are obtained for particles equal to 1 μm and 25 μmand different gap between the cartridge case and the cylindrical surface of fuel grain.","PeriodicalId":11789,"journal":{"name":"Eurasian Physical Technical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140368553","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}
Abstract.Anew approach to the metal/superconductor-insulator transition in doped cuprates by studying the polaron formation and localization of doped charge carriers (holes) in them and the possibility of transforming a metallic or superconducting system into an insulatorwas developed. Amore suitable criterion for such a phase transition by comparing the bandwidth (or Fermi energy) of large polarons with their binding energies in the cuprateswas derived. The possibility of the metal/superconductor-insulator transition and phase separation in doped cuprates resulting in the formation of competing metallic/superconducting and insulating phases in underdoped, optimally doped and even in overdoped high-Tccuprateswas predicted. Then the possible detrimental and beneficial effects of the different disorders (e.g. polaron formation and charge-density-wave transition) and the coexisting insulating and superconducting phases on the critical temperature 𝑇𝑐of the superconducting transition of underdoped and optimally doped cuprateswas examined. The actual superconducting transition temperature 𝑇𝑐in these materials using the theory of Bose-liquid superconductivity, and not theBardeen-Cooper-Schrieffer-like theory of Fermi-liquid superconductivity, which is incapable of predicting the relevant value of 𝑇𝑐in high-𝑇𝑐cuprateswas determined. We find thatthe suppressing of the polaronic and charge-density-waveeffects in optimally doped cuprates results in the enhancement of 𝑇𝑐, while some lattice defects (e.g., anion vacancies) in the cuprates may strongly affect, on 𝑇𝑐and enhance high-𝑇𝑐superconductivity in them.
{"title":"EW METAL/SUPERCONDUCTOR-INSULATOR TRANSITIONS AND THEIR EFFECTS ON HIGH-TCSUPERCONDUCTIVITY INUNDERDOPED AND OPTIMALLY DOPED CUPRATES","authors":"U. Kurbanov","doi":"10.31489/2024no1/21-27","DOIUrl":"https://doi.org/10.31489/2024no1/21-27","url":null,"abstract":"Abstract.Anew approach to the metal/superconductor-insulator transition in doped cuprates by studying the polaron formation and localization of doped charge carriers (holes) in them and the possibility of transforming a metallic or superconducting system into an insulatorwas developed. Amore suitable criterion for such a phase transition by comparing the bandwidth (or Fermi energy) of large polarons with their binding energies in the cuprateswas derived. The possibility of the metal/superconductor-insulator transition and phase separation in doped cuprates resulting in the formation of competing metallic/superconducting and insulating phases in underdoped, optimally doped and even in overdoped high-Tccuprateswas predicted. Then the possible detrimental and beneficial effects of the different disorders (e.g. polaron formation and charge-density-wave transition) and the coexisting insulating and superconducting phases on the critical temperature 𝑇𝑐of the superconducting transition of underdoped and optimally doped cuprateswas examined. The actual superconducting transition temperature 𝑇𝑐in these materials using the theory of Bose-liquid superconductivity, and not theBardeen-Cooper-Schrieffer-like theory of Fermi-liquid superconductivity, which is incapable of predicting the relevant value of 𝑇𝑐in high-𝑇𝑐cuprateswas determined. We find thatthe suppressing of the polaronic and charge-density-waveeffects in optimally doped cuprates results in the enhancement of 𝑇𝑐, while some lattice defects (e.g., anion vacancies) in the cuprates may strongly affect, on 𝑇𝑐and enhance high-𝑇𝑐superconductivity in them.","PeriodicalId":11789,"journal":{"name":"Eurasian Physical Technical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140368919","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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