Pub Date : 2024-05-07DOI: 10.59957/jctm.v59.i3.2024.6
Khoiriah Khoiriah, Reza Audina Putri, Ratnawati Ratnawati, Mega Puspita Sari
The role of hydrogen peroxide on paracetamol degradation was investigated. Photocatalysis system contains UV radiation and commercial titania (TiO2 ) as catalyst. The parameters studied for optimal photocatalysis conditions were catalyst dose (0.05 - 0.2 g), initial concentration of paracetamol (5 - 20 mg L-1), and irradiation times (0 - 210 min). Optimal condition obtained by determining the changes of paracetamol concentration converted to be degradation percentage. The influence of hydrogen peroxide concentrations (1 % - 7 %) on photocatalysis TiO2 system was studied. The highest paracetamol degradation was obtained at addition of 3 %. It gives positive effect on degradation process. Thus, hybrid process (UV / TiO2 / H2O2 ) is more effective in comparison to the process UV/ TiO2 and UV/H2O2. Paracetamol (5 mg L-1) was degraded about 90.80 % using 0.1 g TiO2 , 3 % H2O2 addition for 180 min. According to the GC-MS analysis results, paracetamol degradation forms new less toxic by-products. The hybrid process is an alternative technique for degradation of wastewater containing paracetamol.
{"title":"INVESTIGATING THE EFFECT OF HYDROGEN PEROXIDE ON PHOTOCATALYTIC DEGRADATION OF COMMERCIAL PARACETAMOL USING TiO2","authors":"Khoiriah Khoiriah, Reza Audina Putri, Ratnawati Ratnawati, Mega Puspita Sari","doi":"10.59957/jctm.v59.i3.2024.6","DOIUrl":"https://doi.org/10.59957/jctm.v59.i3.2024.6","url":null,"abstract":"The role of hydrogen peroxide on paracetamol degradation was investigated. Photocatalysis system contains UV radiation and commercial titania (TiO2 ) as catalyst. The parameters studied for optimal photocatalysis conditions were catalyst dose (0.05 - 0.2 g), initial concentration of paracetamol (5 - 20 mg L-1), and irradiation times (0 - 210 min). Optimal condition obtained by determining the changes of paracetamol concentration converted to be degradation percentage. The influence of hydrogen peroxide concentrations (1 % - 7 %) on photocatalysis TiO2 system was studied. The highest paracetamol degradation was obtained at addition of 3 %. It gives positive effect on degradation process. Thus, hybrid process (UV / TiO2 / H2O2 ) is more effective in comparison to the process UV/ TiO2 and UV/H2O2. Paracetamol (5 mg L-1) was degraded about 90.80 % using 0.1 g TiO2 , 3 % H2O2 addition for 180 min. According to the GC-MS analysis results, paracetamol degradation forms new less toxic by-products. The hybrid process is an alternative technique for degradation of wastewater containing paracetamol.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"44 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141004265","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 : 2024-05-07DOI: 10.59957/jctm.v59.i3.2024.26
Valentin Slavov, Verjinia Aleksandrova
This paper presents the results of mechano-mathematical modeling of free undamped spatial vibrations of a robot for process automation in metallurgy.A dynamic model of the robot is made. It is studied as a mechanical system with twelve degrees of freedom, contained by seven rigid bodies.Kinetic and potential energy are derived symbolically by using the kinematics study results. The matrices characterizing the mass-inertial and elastic properties of the mechanical system are obtained. The differential equations that describe the free undamped vibrations are derived. They take into account the geometrical, mass, inertial and elastic characteristics of the mechanical system.A compiled calculation algorithm is entered into a standard mathematical software product. Results are obtained in symbolic and graphical form. The natural frequencies and natural mode of a robot with concrete parameters are determined.Results of the study of free undamped vibrations represent a basis for studying of the free damped and forced vibrations of a robot for process automation in metallurgy.
{"title":"FREE UNDAMPED SPATIAL VIBRATIONS OF A ROBOT FOR PROCESS AUTOMATION IN METALLURGY","authors":"Valentin Slavov, Verjinia Aleksandrova","doi":"10.59957/jctm.v59.i3.2024.26","DOIUrl":"https://doi.org/10.59957/jctm.v59.i3.2024.26","url":null,"abstract":"This paper presents the results of mechano-mathematical modeling of free undamped spatial vibrations of a robot for process automation in metallurgy.A dynamic model of the robot is made. It is studied as a mechanical system with twelve degrees of freedom, contained by seven rigid bodies.Kinetic and potential energy are derived symbolically by using the kinematics study results. The matrices characterizing the mass-inertial and elastic properties of the mechanical system are obtained. The differential equations that describe the free undamped vibrations are derived. They take into account the geometrical, mass, inertial and elastic characteristics of the mechanical system.A compiled calculation algorithm is entered into a standard mathematical software product. Results are obtained in symbolic and graphical form. The natural frequencies and natural mode of a robot with concrete parameters are determined.Results of the study of free undamped vibrations represent a basis for studying of the free damped and forced vibrations of a robot for process automation in metallurgy.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"119 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141002167","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 : 2024-05-07DOI: 10.59957/jctm.v59.i3.2024.16
S. Sendilvelan, Kannayiram Gomathi, Larissa Sassykova, Muthuswamy Prabhahar
The internal combustion engine is critical to modern society’s development. Spark ignition engine (SI) and compression ignition engine (CI) now use gasoline and diesel as their primary fuels. As a result of burning these fuels, significant amounts of pollutants are released into the atmosphere, resulting in environmental issues. Internal combustion (IC) engines are widely acknowledged as a significant source of environmental air pollution. The engine’s fuel oxidation process not only produces useful power, but also produces significant amounts of pollutant emissions such as carbon monoxide (CO), unburned hydrocarbons (HC), nitrogen oxide (NOx ), and particulate matter (PM). When developing a new combustion process, consideration must be given to: lean homogeneous air-fuel mixture, increased compression ratio, and total and instantaneous combustion, all of which result in Port Injection Compression Ignition (PICI), that is a highly efficient and clean method of combustion. The goal of this research is to conduct an experimental investigation of PICI process of compression in a Premixed Charge Compression Ignition (PCCI) mode with Pilot Injection (PI) as the combustion activator. It was found that when compared to the conventional mode, the PICI mode produces cooler exhaust gas temperatures. Temperatures were lower in the PICI mode with biodiesel and petrol as secondary and primary fuels than in the PICI mode with other fuel combinations. In the PICI mode, the HC emission decreases at higher load with all fuels. In the biodiesel conventional mode, HC emission is minimum than in other modes. For all modes of operation, the specific fuel consumption has reduced with load. Diesel and gasoline have the lowest specific fuel consumption as primary and secondary fuels, respectively. Fuel usage in the PICI mode is lower than in the normal mode.
{"title":"PORT INJECTION OF DIESEL, BIODIESEL, AND PETROL IN A COMPRESSION IGNITION DIRECT INJECTION DIESEL ENGINE TO MITIGATE NITROGEN OXIDES AND SOOT EMISSIONS","authors":"S. Sendilvelan, Kannayiram Gomathi, Larissa Sassykova, Muthuswamy Prabhahar","doi":"10.59957/jctm.v59.i3.2024.16","DOIUrl":"https://doi.org/10.59957/jctm.v59.i3.2024.16","url":null,"abstract":"The internal combustion engine is critical to modern society’s development. Spark ignition engine (SI) and compression ignition engine (CI) now use gasoline and diesel as their primary fuels. As a result of burning these fuels, significant amounts of pollutants are released into the atmosphere, resulting in environmental issues. Internal combustion (IC) engines are widely acknowledged as a significant source of environmental air pollution. The engine’s fuel oxidation process not only produces useful power, but also produces significant amounts of pollutant emissions such as carbon monoxide (CO), unburned hydrocarbons (HC), nitrogen oxide (NOx ), and particulate matter (PM). When developing a new combustion process, consideration must be given to: lean homogeneous air-fuel mixture, increased compression ratio, and total and instantaneous combustion, all of which result in Port Injection Compression Ignition (PICI), that is a highly efficient and clean method of combustion. The goal of this research is to conduct an experimental investigation of PICI process of compression in a Premixed Charge Compression Ignition (PCCI) mode with Pilot Injection (PI) as the combustion activator. It was found that when compared to the conventional mode, the PICI mode produces cooler exhaust gas temperatures. Temperatures were lower in the PICI mode with biodiesel and petrol as secondary and primary fuels than in the PICI mode with other fuel combinations. In the PICI mode, the HC emission decreases at higher load with all fuels. In the biodiesel conventional mode, HC emission is minimum than in other modes. For all modes of operation, the specific fuel consumption has reduced with load. Diesel and gasoline have the lowest specific fuel consumption as primary and secondary fuels, respectively. Fuel usage in the PICI mode is lower than in the normal mode.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"52 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141002793","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 : 2024-05-07DOI: 10.59957/jctm.v59.i3.2024.1
Eldor Khusanov, Zhamshid Shukhurov
In this work, in order to synthesize new physiologically active substances, the solubility properties of the components in the acetate urea triethanolamine water ternary system were studied by observational polythermal method at a wide range of concentration and a temperature range from -43°C to 18°C. The solubility diagram of the studied system was constructed and the crystallization areas of all substances acetateurea, triethanolamine, ice and the new compound С3Н8O3N2∙N(C2H4OH)3 acetate ureatriethanolammonium were separated. The composition of the new substance С3Н8O3N2∙N(C2H4OH)3 was determined using the chemical analysis method. In order to determine optimal conditions for the synthesis of С3Н8O3N2∙N(C2H4OH)3 acetate ureatriethanolammonium, which has a new physiologically active property, the rheological properties of the solution were studied by adding triethanolamine to 60, 70 and 80 % acetateurea. A “composition-property” diagram was constructed based on the rheological properties of the studied system, the рH indicator, the density and viscosity of the solution, and the refractive index. The optimal conditions for the synthesis of the new substance С3Н8O3N2∙N(C2H4OH)3 acetate ureatriethanolammonium, obtained by the ratio of components, were determined by adding triethanolamine to a 60 % acetate urea solution.
{"title":"STUDY OF SOLUBILITY PROPERTIES OF COMPONENTS IN ACETATE UREA - TRIETHANOLAMINE - WATER SYSTEM","authors":"Eldor Khusanov, Zhamshid Shukhurov","doi":"10.59957/jctm.v59.i3.2024.1","DOIUrl":"https://doi.org/10.59957/jctm.v59.i3.2024.1","url":null,"abstract":"In this work, in order to synthesize new physiologically active substances, the solubility properties of the components in the acetate urea triethanolamine water ternary system were studied by observational polythermal method at a wide range of concentration and a temperature range from -43°C to 18°C. The solubility diagram of the studied system was constructed and the crystallization areas of all substances acetateurea, triethanolamine, ice and the new compound С3Н8O3N2∙N(C2H4OH)3 acetate ureatriethanolammonium were separated. The composition of the new substance С3Н8O3N2∙N(C2H4OH)3 was determined using the chemical analysis method. In order to determine optimal conditions for the synthesis of С3Н8O3N2∙N(C2H4OH)3 acetate ureatriethanolammonium, which has a new physiologically active property, the rheological properties of the solution were studied by adding triethanolamine to 60, 70 and 80 % acetateurea. A “composition-property” diagram was constructed based on the rheological properties of the studied system, the рH indicator, the density and viscosity of the solution, and the refractive index. The optimal conditions for the synthesis of the new substance С3Н8O3N2∙N(C2H4OH)3 acetate ureatriethanolammonium, obtained by the ratio of components, were determined by adding triethanolamine to a 60 % acetate urea solution.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"27 24","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141005482","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 : 2024-05-07DOI: 10.59957/jctm.v59.i3.2024.13
Khidir A. Adinaev, Zulayha Kadyrova
The composition and structure of Sherobod quartz sand and man-made waste were fully investigated using chemical, scanning electron microscope, X-ray, infrared spectroscopic and differential thermal analysis methods. It was found that the content of lead and manganese oxides in Handiza lead concentrate and manganese waste is 25 - 26 %, respectively, and silicon oxide in Sherabad quartz sand is more than 80 %. According to the results of chemical and physico-chemical analyzes of Sherabad quartz sand and man-made waste, it was found that they can be added as glass components by cleaning them from various additives.
{"title":"PHYSICO-CHEMICAL ANALYSIS OF QUARTZ SAND AND TECHNOLOGICAL WASTE USED AS A MAIN RAW MATERIAL FOR GLASS PRODUCTION","authors":"Khidir A. Adinaev, Zulayha Kadyrova","doi":"10.59957/jctm.v59.i3.2024.13","DOIUrl":"https://doi.org/10.59957/jctm.v59.i3.2024.13","url":null,"abstract":"The composition and structure of Sherobod quartz sand and man-made waste were fully investigated using chemical, scanning electron microscope, X-ray, infrared spectroscopic and differential thermal analysis methods. It was found that the content of lead and manganese oxides in Handiza lead concentrate and manganese waste is 25 - 26 %, respectively, and silicon oxide in Sherabad quartz sand is more than 80 %. According to the results of chemical and physico-chemical analyzes of Sherabad quartz sand and man-made waste, it was found that they can be added as glass components by cleaning them from various additives.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"129 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141002948","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 : 2024-05-07DOI: 10.59957/jctm.v59.i3.2024.21
A. Naizabekov, S. Lezhnev, E. Panin, A. Arbuz, A. Tolkushkin, Pavel Tsyba, Vasily Rubanik, Yury Tsarenko
This paper presents the results of computer modeling of preliminary heat treatment and radial-shear rolling of L63 brass in the Deform program by cellular automata method. Quenching and annealing were simulated as pre-heat treatment modes. Radial-shear rolling consisted of three passes with a compression of 3 mm per pass. The variable parameters were the roll rotation speed (40 rpm, 70 rpm and 100 rpm) and the workpiece heating temperature before rolling (500°C and 700°C). It was found that the most effective mode of preliminary heat treatment of L63 brass is annealing at a temperature of 500°C. The most rational value of the heating temperature of the workpiece before rolling is 500°C, since in this case, at all selected speeds the recrystallization process does not start, which contributes to intensive grain grinding. An increase of roll rotation speed causes additional deformation heating, which contributes to recrystallization and a decrease of grain grinding intensity.
{"title":"COMPUTER SIMULATION OF PRELIMINARY HEAT TREATMENT AND RADIAL-SHEAR ROLLING OF BRASS","authors":"A. Naizabekov, S. Lezhnev, E. Panin, A. Arbuz, A. Tolkushkin, Pavel Tsyba, Vasily Rubanik, Yury Tsarenko","doi":"10.59957/jctm.v59.i3.2024.21","DOIUrl":"https://doi.org/10.59957/jctm.v59.i3.2024.21","url":null,"abstract":"This paper presents the results of computer modeling of preliminary heat treatment and radial-shear rolling of L63 brass in the Deform program by cellular automata method. Quenching and annealing were simulated as pre-heat treatment modes. Radial-shear rolling consisted of three passes with a compression of 3 mm per pass. The variable parameters were the roll rotation speed (40 rpm, 70 rpm and 100 rpm) and the workpiece heating temperature before rolling (500°C and 700°C). It was found that the most effective mode of preliminary heat treatment of L63 brass is annealing at a temperature of 500°C. The most rational value of the heating temperature of the workpiece before rolling is 500°C, since in this case, at all selected speeds the recrystallization process does not start, which contributes to intensive grain grinding. An increase of roll rotation speed causes additional deformation heating, which contributes to recrystallization and a decrease of grain grinding intensity.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"83 s363","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141003077","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 : 2024-05-07DOI: 10.59957/jctm.v59.i3.2024.10
Nadezhda Dimitrova Nankova, E. Pisareva, V. Petrova, A. Tomova
Phytases, which perform the stepwise hydrolysis of phytic acid to myo-inositol and inorganic phosphate, are used worldwide to reduce phosphorus pollution and improve nutrition in monogastric animals and humans. Yeasts isolated from their natural environments represent rich and still underexplored sources of industrially valuable enzymes, including phytases; therefore, they are widely studied for the production of these enzymes. In this regard, thirteen yeast pure cultures were isolated from the microbial consortium of four types of sourdough obtained during the natural fermentation of different grain-based flours. Ten of the newly isolated yeast strains were selected as potential phytase producers based on their growth in liquid culture media with sodium phytate as the sole source of phosphorus. Using 18S rDNA and D1/D2 26S rDNA analyses, the species affiliation of the selected isolates was established. They referred to seven yeast species from 3 families, with the most significant representation of the family Saccharomycetaceae.Intracellular phytate-degrading activity was found in 8 isolates, the highest being in Nakaseomyces glabratus strain 7-4. The highest level of extracellular phytase was measured in Pichia membranifaciens strain 5-2. Both isolates showed significant antioxidant capacity higher than those of ascorbic acid.
{"title":"DIVERSITY AND PHYTATE-DEGRADING POTENTIAL OF YEAST MICROORGANISMS ISOLATED FROM SOURDOUGH","authors":"Nadezhda Dimitrova Nankova, E. Pisareva, V. Petrova, A. Tomova","doi":"10.59957/jctm.v59.i3.2024.10","DOIUrl":"https://doi.org/10.59957/jctm.v59.i3.2024.10","url":null,"abstract":"Phytases, which perform the stepwise hydrolysis of phytic acid to myo-inositol and inorganic phosphate, are used worldwide to reduce phosphorus pollution and improve nutrition in monogastric animals and humans. Yeasts isolated from their natural environments represent rich and still underexplored sources of industrially valuable enzymes, including phytases; therefore, they are widely studied for the production of these enzymes. In this regard, thirteen yeast pure cultures were isolated from the microbial consortium of four types of sourdough obtained during the natural fermentation of different grain-based flours. Ten of the newly isolated yeast strains were selected as potential phytase producers based on their growth in liquid culture media with sodium phytate as the sole source of phosphorus. Using 18S rDNA and D1/D2 26S rDNA analyses, the species affiliation of the selected isolates was established. They referred to seven yeast species from 3 families, with the most significant representation of the family Saccharomycetaceae.Intracellular phytate-degrading activity was found in 8 isolates, the highest being in Nakaseomyces glabratus strain 7-4. The highest level of extracellular phytase was measured in Pichia membranifaciens strain 5-2. Both isolates showed significant antioxidant capacity higher than those of ascorbic acid.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"5 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141004033","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 : 2024-05-07DOI: 10.59957/jctm.v59.i3.2024.20
Majid Naseri, A. Moghaddam, S. Lezhnev, Nataliya A. Shaburova, Anatoliy Pellenen, Evgenii Bodrov, E. Panin, Marina Samodurova, E. Trofimov
This study describes the strengthening mechanisms of an ultrafine-grained (UFG) Fe35Mn27Ni28Co5Cr5 high-entropy alloy (HEA) processed by severe cold rolling (SCR) process at room temperature. Microstructural evaluations were performed by field emission scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The findings demonstrated that the development of deformation microstructures consisted of a single face-centered cubic (FCC) phase with stretched grains along the rolling direction and lamellar deformation bands after a 90 % reduction in thickness. Using the Nix-Gao model, the dislocation density was determined by measuring the microhardness indentation size effect. The results indicated that an increase in rolling deformation leads to an increase in dislocation density. The dislocation density increased from 2.28 ×109 cm-2 for as-homogenized specimen to 8.65 ×109 cm-2 after 90 % reduction in thickness. The yield strength of the UFG Fe35Mn27Ni28Co5Cr5 HEA was 5.2 times (1155 MPa) higher than that of the as-homogenized state (225 MPa). Finally, an assessment was conducted on the relative contributions of individual mechanisms, such as dislocation and grain refinement, to the strengthening of the Fe35Mn27Ni28Co5Cr5 HEA.
{"title":"EXPLORING STRENGTHENING MECHANISMS OF ULTRAFINE-GRAINED Fe35Mn27Ni28Co5Cr5 HIGH-ENTROPY ALLOY PROCESSED BY SEVERE COLD ROLLING PROCESS","authors":"Majid Naseri, A. Moghaddam, S. Lezhnev, Nataliya A. Shaburova, Anatoliy Pellenen, Evgenii Bodrov, E. Panin, Marina Samodurova, E. Trofimov","doi":"10.59957/jctm.v59.i3.2024.20","DOIUrl":"https://doi.org/10.59957/jctm.v59.i3.2024.20","url":null,"abstract":"This study describes the strengthening mechanisms of an ultrafine-grained (UFG) Fe35Mn27Ni28Co5Cr5 high-entropy alloy (HEA) processed by severe cold rolling (SCR) process at room temperature. Microstructural evaluations were performed by field emission scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The findings demonstrated that the development of deformation microstructures consisted of a single face-centered cubic (FCC) phase with stretched grains along the rolling direction and lamellar deformation bands after a 90 % reduction in thickness. Using the Nix-Gao model, the dislocation density was determined by measuring the microhardness indentation size effect. The results indicated that an increase in rolling deformation leads to an increase in dislocation density. The dislocation density increased from 2.28 ×109 cm-2 for as-homogenized specimen to 8.65 ×109 cm-2 after 90 % reduction in thickness. The yield strength of the UFG Fe35Mn27Ni28Co5Cr5 HEA was 5.2 times (1155 MPa) higher than that of the as-homogenized state (225 MPa). Finally, an assessment was conducted on the relative contributions of individual mechanisms, such as dislocation and grain refinement, to the strengthening of the Fe35Mn27Ni28Co5Cr5 HEA.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"70 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141002287","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 : 2024-05-07DOI: 10.59957/jctm.v59.i3.2024.8
Hristian Staykov, R. Kalfin, L. Tancheva
LA or (±)-α-Lipoic acid (6,8-thioctic acid, 5-(1,2-dithiolan-3-yl)pentanoic acid) (LA) is a heterocyclic thia fattyacid consisting of pentanoic acid and a 1,2-dithiolan-3-yl group at the 5-position. LA is an amphiphilic pharmacophorewith excellent antioxidant, anti-inflammatory and neuroprotective effects attested by numerous studies for its potentialutility in both the treatment and diverse forms of prophylaxis of neurodegenerative disorders, especially Alzheimer’sdisease. This article aims to assess the differences in neuroprotective effect after short-term (11 days) and longterm(51 days) LA administration in an experimental rat model of scopolamine-induced dementia by correlatingbiochemical data on acetylcholinesterase activity with behavioural data. Behaviourally appraised changes in learningand memory appear to correlate with biochemical changes in AChE activity. The neuroprotective effect of LA, asascertained by its beneficial effects on learning and memory in a scopolamine animal model, appears to be associatedwith cholinergic mechanisms (a decrease in AChE activity), and to be larger after short-term administration ratherthan long-term administration. These results further underscore the candidacy of LA as a viable drug candidatesuitable for continued investigation and derivate synthesis endeavours.
{"title":"REVIEW ON THE SYNTHESIS OF ALPHA-LIPOIC ACID AND ITS THERAPEUTIC POTENTIAL IN EXPERIMENTAL MODEL OF DEMENTIA","authors":"Hristian Staykov, R. Kalfin, L. Tancheva","doi":"10.59957/jctm.v59.i3.2024.8","DOIUrl":"https://doi.org/10.59957/jctm.v59.i3.2024.8","url":null,"abstract":"LA or (±)-α-Lipoic acid (6,8-thioctic acid, 5-(1,2-dithiolan-3-yl)pentanoic acid) (LA) is a heterocyclic thia fattyacid consisting of pentanoic acid and a 1,2-dithiolan-3-yl group at the 5-position. LA is an amphiphilic pharmacophorewith excellent antioxidant, anti-inflammatory and neuroprotective effects attested by numerous studies for its potentialutility in both the treatment and diverse forms of prophylaxis of neurodegenerative disorders, especially Alzheimer’sdisease. This article aims to assess the differences in neuroprotective effect after short-term (11 days) and longterm(51 days) LA administration in an experimental rat model of scopolamine-induced dementia by correlatingbiochemical data on acetylcholinesterase activity with behavioural data. Behaviourally appraised changes in learningand memory appear to correlate with biochemical changes in AChE activity. The neuroprotective effect of LA, asascertained by its beneficial effects on learning and memory in a scopolamine animal model, appears to be associatedwith cholinergic mechanisms (a decrease in AChE activity), and to be larger after short-term administration ratherthan long-term administration. These results further underscore the candidacy of LA as a viable drug candidatesuitable for continued investigation and derivate synthesis endeavours.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"148 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141001967","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 : 2024-05-07DOI: 10.59957/jctm.v59.i3.2024.4
Azam A. Rasulov, S. Namazov, A. Seytnazarov, U. Alimov, B. Sultonov
The process of obtaining ammophosphate by means of phosphoric acid decomposition of washed dried concentrate (WDC) with 26 % Р2О5 and 10 % СО) - raw material for the production of thermally fired concentrate, has been studied. The extraction phosphoric acid contains (mass. %): 16.46 P2O5, 0.06 CaO, 1.11 MgO, 0.27 Fe2O3, 0.41 Al2O3, 2.98 SO3 and 0.99 F. The mass ratio of WPPA: WDC ranged from 100: 10 to 100: 30. Then acidic phosphate pulps (at 65°C) after 45 minutes were ammoniated to pH = 3.8, granulated and dried at 85 - 90°C. It has been shown that the nitrogen content in the finished product ranges from 4.92 - 7.11 %, total phosphorus (P2O 5t.) 41.48 - 46.44 %, phosphorus assimilated by plants (P2O5acceptable) 34.79 - 45.11 %, water-soluble phosphorus (P2O 5w.s.) 23.49 - 37.73 %. The addition of 5 - 7.5 % H2SO4 or HNO3 in the form of a monohydrate makes it possible to intensify the process of phosphoric acid decomposition of phosphate raw materials and to obtain sulfo- and nitroammophosphate with significantly highcontents of P2O5 acceptable and P2O5 w.s.. So, with a weight fraction of WDC equals to 30 and weight fractions of H2SO4 - 5 and 7.5, there have been 37.6 and 34.47 % P2O5 total in sulfoammophosphate; 24.11 and 22.06 % CaO t. , 88.75 and 96.4 % P2O5 acceptable: P2O5t., 77.39 and 79.54 % P2O5 w.s. : P2O5t., 6.03 and 7.08 % nitrogen, respectively. In the case of using HNO3, nitroammophosphate contains the largest amount of nitrogen due to additionally introduced nitric acid, but the phosphate raw material has a relatively low decomposition coefficient. The strength of granules of all brands of fertilizers averages 3.50 MPa and are quite suitable for bulk storage and transportation. Material balances for the production of ammophosphate, sulfoammophosphate and nitroammophosphate have been calculated.
{"title":"PROCESSING OF A WASHED DRY CONCENTRATE CONTAINING 26% P2O5 INTO AMMOPHOSPHATE, SULPHO- AND NITROAMMOPHOSPHATE FERTILIZERS","authors":"Azam A. Rasulov, S. Namazov, A. Seytnazarov, U. Alimov, B. Sultonov","doi":"10.59957/jctm.v59.i3.2024.4","DOIUrl":"https://doi.org/10.59957/jctm.v59.i3.2024.4","url":null,"abstract":"The process of obtaining ammophosphate by means of phosphoric acid decomposition of washed dried concentrate (WDC) with 26 % Р2О5 and 10 % СО) - raw material for the production of thermally fired concentrate, has been studied. The extraction phosphoric acid contains (mass. %): 16.46 P2O5, 0.06 CaO, 1.11 MgO, 0.27 Fe2O3, 0.41 Al2O3, 2.98 SO3 and 0.99 F. The mass ratio of WPPA: WDC ranged from 100: 10 to 100: 30. Then acidic phosphate pulps (at 65°C) after 45 minutes were ammoniated to pH = 3.8, granulated and dried at 85 - 90°C. It has been shown that the nitrogen content in the finished product ranges from 4.92 - 7.11 %, total phosphorus (P2O 5t.) 41.48 - 46.44 %, phosphorus assimilated by plants (P2O5acceptable) 34.79 - 45.11 %, water-soluble phosphorus (P2O 5w.s.) 23.49 - 37.73 %. The addition of 5 - 7.5 % H2SO4 or HNO3 in the form of a monohydrate makes it possible to intensify the process of phosphoric acid decomposition of phosphate raw materials and to obtain sulfo- and nitroammophosphate with significantly highcontents of P2O5 acceptable and P2O5 w.s.. So, with a weight fraction of WDC equals to 30 and weight fractions of H2SO4 - 5 and 7.5, there have been 37.6 and 34.47 % P2O5 total in sulfoammophosphate; 24.11 and 22.06 % CaO t. , 88.75 and 96.4 % P2O5 acceptable: P2O5t., 77.39 and 79.54 % P2O5 w.s. : P2O5t., 6.03 and 7.08 % nitrogen, respectively. In the case of using HNO3, nitroammophosphate contains the largest amount of nitrogen due to additionally introduced nitric acid, but the phosphate raw material has a relatively low decomposition coefficient. The strength of granules of all brands of fertilizers averages 3.50 MPa and are quite suitable for bulk storage and transportation. Material balances for the production of ammophosphate, sulfoammophosphate and nitroammophosphate have been calculated.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"24 42","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141005761","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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