Pub Date : 2024-01-03DOI: 10.59957/jctm.v59.i1.2024.14
Ashraf Ali Basheer, Singh Sunil Kumar
In this work, hydrodynamics and drying characteristics of spray dryer is numerically investigated using computational fluid dynamics (CFD) using Euler-Lagrangian (EL) approach. The gas phase is modelled as the continuous phase and solid particle as the dispersed phase. The turbulence in the gas phase is predicted using RNG version of k-ε model. As air flow pattern influences the time spent by particle in drying chamber, the spatial variation of air velocity and its circulation rate is quantified. Accordingly, optimum conditions for drying the feed slurry are determined. Further, five different outlet pipe locations are chosen and the optimum location is identified which supports the highest evaporation rate. To improve the product quality, conventional nozzle is modified and particle impact positions are analyzed. The particles impact positions on the dryer’s surface are found to be minimum for the proposed nozzle configuration and it improves the final product quality.
{"title":"EFFECT OF NOZZLE CONFIGURATION ON PERFORMANCE OF A SPRAY DRYER","authors":"Ashraf Ali Basheer, Singh Sunil Kumar","doi":"10.59957/jctm.v59.i1.2024.14","DOIUrl":"https://doi.org/10.59957/jctm.v59.i1.2024.14","url":null,"abstract":"In this work, hydrodynamics and drying characteristics of spray dryer is numerically investigated using computational fluid dynamics (CFD) using Euler-Lagrangian (EL) approach. The gas phase is modelled as the continuous phase and solid particle as the dispersed phase. The turbulence in the gas phase is predicted using RNG version of k-ε model. As air flow pattern influences the time spent by particle in drying chamber, the spatial variation of air velocity and its circulation rate is quantified. Accordingly, optimum conditions for drying the feed slurry are determined. Further, five different outlet pipe locations are chosen and the optimum location is identified which supports the highest evaporation rate. To improve the product quality, conventional nozzle is modified and particle impact positions are analyzed. The particles impact positions on the dryer’s surface are found to be minimum for the proposed nozzle configuration and it improves the final product quality.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"39 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139451150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-03DOI: 10.59957/jctm.v59.i1.2024.23
F.E. Popov, N. Lutchenko, Alexandr Panichkin, S. Lezhnev, E. Panin, Leonid Vinogradov, A. Arbuz
This paper studies the behavior of a transverse through defect in an ingot during complex vortex flow of metal deformed by the radial shift rolling (RSR) method. The aim of the work was to investigate the applicability of the RSR method for the deformation treatment of oxide-dispersed strengthened steel (ODS-steel) ingots into a final semi-finished product. Vortex flow of metal promotes dispersion of alloying solid oxides and refinement of steel structure. However, the question of development or closure of possible casting defects of ODS-steel ingot remains open. For this purpose, an ODS-steel ingot with a through-hole modelling the defect was rolled according to the assumed process scheme. Also, to visualize the evolution of the defect in more detail during the rolling process, a simulation of thesame defect development in an aluminum bar has been performed in 2 mm steps. The results of both rolls showed good correlation. Based on many cross-sections of the experimental bars, detailed 3D models of the defect evolution were built. An average reduction of 50 % in defect volume was found. Welding of the outer areas occurs immediately, but the central areas remain unclosed, stretching proportionally with the drawing of the rod during rolling. For this reason, RSR cannot be used with large cavity defects in the axial zone, but this method is guaranteed to weld surface defects even at low reductions.
{"title":"MODELLING THE EVOLUTION OF CASTING DEFECT CLOSURE BY RADIAL SHEAR ROLLING","authors":"F.E. Popov, N. Lutchenko, Alexandr Panichkin, S. Lezhnev, E. Panin, Leonid Vinogradov, A. Arbuz","doi":"10.59957/jctm.v59.i1.2024.23","DOIUrl":"https://doi.org/10.59957/jctm.v59.i1.2024.23","url":null,"abstract":"This paper studies the behavior of a transverse through defect in an ingot during complex vortex flow of metal deformed by the radial shift rolling (RSR) method. The aim of the work was to investigate the applicability of the RSR method for the deformation treatment of oxide-dispersed strengthened steel (ODS-steel) ingots into a final semi-finished product. Vortex flow of metal promotes dispersion of alloying solid oxides and refinement of steel structure. However, the question of development or closure of possible casting defects of ODS-steel ingot remains open. For this purpose, an ODS-steel ingot with a through-hole modelling the defect was rolled according to the assumed process scheme. Also, to visualize the evolution of the defect in more detail during the rolling process, a simulation of thesame defect development in an aluminum bar has been performed in 2 mm steps. The results of both rolls showed good correlation. Based on many cross-sections of the experimental bars, detailed 3D models of the defect evolution were built. An average reduction of 50 % in defect volume was found. Welding of the outer areas occurs immediately, but the central areas remain unclosed, stretching proportionally with the drawing of the rod during rolling. For this reason, RSR cannot be used with large cavity defects in the axial zone, but this method is guaranteed to weld surface defects even at low reductions.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"47 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139451833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-03DOI: 10.59957/jctm.v59.i1.2024.20
Alexandr Panichkin, F.E. Popov, N. Lutchenko, Askhat Beldeubayev, Ivan Samokhvalov, Alexandr Arbuz
Investigation of the possibility of obtaining an oxide-dispersed strengthening steel alloy based on 5 different ways of fine-dispersed strengthening particles Y2O3 injection into the liquid phase of steel Fe-13Cr (wt. %) in a vacuum. For this purpose, were conducted 5 series of experiments with different conditions and regimes. 2 series of 5 melts were carried out to evaluate the possibility of mechanical injection of yttrium oxide in the melt with different entry conditions. 3 series of 5 melts were conducted to evaluate the possibility of oxidation of metallic yttrium in the melt with the formation of yttrium oxide particles. Either melt residence or residual pressure in the furnace chamber was varied in different series. The results of ingot analysis on XRF, ICP-AES, and EDS showed that significant amounts of yttrium oxide were not injected. The method with oxidation of metallic yttrium in the melt from the reduction ofspecially added iron oxide with a concentration of 0.0552 ppm showed the best result.
{"title":"RESEARCH OF INJECTION METHODS FOR Y2O3 NANOPARTICLES INTO NICKEL- FREE STAINLESS STEEL DURING INDUCTION VACUUM REMELTING","authors":"Alexandr Panichkin, F.E. Popov, N. Lutchenko, Askhat Beldeubayev, Ivan Samokhvalov, Alexandr Arbuz","doi":"10.59957/jctm.v59.i1.2024.20","DOIUrl":"https://doi.org/10.59957/jctm.v59.i1.2024.20","url":null,"abstract":"Investigation of the possibility of obtaining an oxide-dispersed strengthening steel alloy based on 5 different ways of fine-dispersed strengthening particles Y2O3 injection into the liquid phase of steel Fe-13Cr (wt. %) in a vacuum. For this purpose, were conducted 5 series of experiments with different conditions and regimes. 2 series of 5 melts were carried out to evaluate the possibility of mechanical injection of yttrium oxide in the melt with different entry conditions. 3 series of 5 melts were conducted to evaluate the possibility of oxidation of metallic yttrium in the melt with the formation of yttrium oxide particles. Either melt residence or residual pressure in the furnace chamber was varied in different series. The results of ingot analysis on XRF, ICP-AES, and EDS showed that significant amounts of yttrium oxide were not injected. The method with oxidation of metallic yttrium in the melt from the reduction ofspecially added iron oxide with a concentration of 0.0552 ppm showed the best result.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"82 17","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139388092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-03DOI: 10.59957/jctm.v59.i1.2024.3
Ivo Ganchev
The goal of this work was to investigate the effect of fermentation pH and time on the acid tolerance, glycolytic activity, and survival during freeze drying of L. delbrueckii subsp. bulgaricus WDCM 00102 strains during cultivation in the medium, based on pretreated biomass of Spirulina platensis. During the study, when the fermentation process is carried out at a constant pH, a higher value of glycolytic activity is established in the cells of the probiotic culture, which decreases when the pH is lowered. The survival rate of cells of L. delbrueckii subsp. bulgaricus WDCM 00102 after lyophilization shows similar values after cultivation for 25 and 37 h (p < 0.05), while the opposite dependence is established in experiments related to changes in the pH of the cultivation medium. pH and fermentation time significantly influence the glycolytic activity of L. delbrueckii subsp. bulgaricus WDCM 00102 and on the resistance of its cells to acid stress and lyophilization conditions.
{"title":"ТOLERANCE TO FREEZE-DRYING CONDITIONS OF Lactobacillus delbrueckii subsp. bulgaricus STRAINS AFTER ACIDIC EXPOSE","authors":"Ivo Ganchev","doi":"10.59957/jctm.v59.i1.2024.3","DOIUrl":"https://doi.org/10.59957/jctm.v59.i1.2024.3","url":null,"abstract":"The goal of this work was to investigate the effect of fermentation pH and time on the acid tolerance, glycolytic activity, and survival during freeze drying of L. delbrueckii subsp. bulgaricus WDCM 00102 strains during cultivation in the medium, based on pretreated biomass of Spirulina platensis. During the study, when the fermentation process is carried out at a constant pH, a higher value of glycolytic activity is established in the cells of the probiotic culture, which decreases when the pH is lowered. The survival rate of cells of L. delbrueckii subsp. bulgaricus WDCM 00102 after lyophilization shows similar values after cultivation for 25 and 37 h (p < 0.05), while the opposite dependence is established in experiments related to changes in the pH of the cultivation medium. pH and fermentation time significantly influence the glycolytic activity of L. delbrueckii subsp. bulgaricus WDCM 00102 and on the resistance of its cells to acid stress and lyophilization conditions.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"16 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139389357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-03DOI: 10.59957/jctm.v59.i2.2024.15
Abhinav Deep Pakki, R. K. Sharma, Neda Neykova, Petko Mandjukov, Jakub Holovský
Numerous parameters are regulated in the wet chemical oxidation process for TOPCon/POLO solar cell technology to improve silicon oxide passivation (SiO2). Understanding the electronic properties, particularly the lifetime of the carriers and their thickness, requires knowledge of the properties of the surface of crystalline silicon (c-Si), which is subjected to native oxide etching, followed by wet chemical oxidation, such as nitric acid or hot water oxidation and various hydrogenation methods. The results of these processes are tracked with lifetime measurement equipment, and spectral ellipsometry is used to measure the thickness of the oxide layer by using the single-sided polished wafers with surface orientation (1 1 1). In addition to the actual values, their time stability is also tracked.Before the hydrogenation step was introduced, the wafers’ lifetime was approximately 0.001 ms, which is less than the bulk lifetime; with the hydrogenation, the lifetime increased by more than an order of magnitude for a relatively long time with no difference between (1 1 1) and (1 0 0) wafers indicating that hydrogenation of the Si/SiO2 interface is performed.
{"title":"OPTIMIZING STABILITY OF WET CHEMISTRY OXIDE PASSIVATION OF Si (111) AND Si (100)","authors":"Abhinav Deep Pakki, R. K. Sharma, Neda Neykova, Petko Mandjukov, Jakub Holovský","doi":"10.59957/jctm.v59.i2.2024.15","DOIUrl":"https://doi.org/10.59957/jctm.v59.i2.2024.15","url":null,"abstract":"Numerous parameters are regulated in the wet chemical oxidation process for TOPCon/POLO solar cell technology to improve silicon oxide passivation (SiO2). Understanding the electronic properties, particularly the lifetime of the carriers and their thickness, requires knowledge of the properties of the surface of crystalline silicon (c-Si), which is subjected to native oxide etching, followed by wet chemical oxidation, such as nitric acid or hot water oxidation and various hydrogenation methods. The results of these processes are tracked with lifetime measurement equipment, and spectral ellipsometry is used to measure the thickness of the oxide layer by using the single-sided polished wafers with surface orientation (1 1 1). In addition to the actual values, their time stability is also tracked.Before the hydrogenation step was introduced, the wafers’ lifetime was approximately 0.001 ms, which is less than the bulk lifetime; with the hydrogenation, the lifetime increased by more than an order of magnitude for a relatively long time with no difference between (1 1 1) and (1 0 0) wafers indicating that hydrogenation of the Si/SiO2 interface is performed.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"138 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140514307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-03DOI: 10.59957/jctm.v59.i2.2024.12
A. Bachvarova-Nedelcheva, R. Iordanova, Nelly Georgieva, Veronica Nemska, Tsvetelina Foteva, A. Stoyanova
TiO2 based powders containing B2O3 and Nb2O5 were obtained through an aqueous sol-gel method. The as prepared gels were step wisely heated in the temperature range 200°C - 500°C and subsequently characterized by XRD, IR and UV-Vis analysis. The TiO2 (anatase) is the single crystalline phase which has been detected up to 500°C. Photocatalytic tests showed that the investigated samples possess photocatalytic activity toward Malachite green organic dye and TiO2/Nb2O5 exhibited higher photocatalytic activity than TiO2/B2O3 sample. The compositions exhibited good antimicrobial activity against E. coli NBIMCC K12 407 and Bacillus subtilis NBIMCC 3562.
{"title":"INFLUENCE OF Nb2O5 AND B2O3 ON THE PHOTOCATALYTIC AND ANTIBACTERIAL ACTIVITY OF SOL-GEL DERIVED TiO2 NANOPОWDERS","authors":"A. Bachvarova-Nedelcheva, R. Iordanova, Nelly Georgieva, Veronica Nemska, Tsvetelina Foteva, A. Stoyanova","doi":"10.59957/jctm.v59.i2.2024.12","DOIUrl":"https://doi.org/10.59957/jctm.v59.i2.2024.12","url":null,"abstract":"TiO2 based powders containing B2O3 and Nb2O5 were obtained through an aqueous sol-gel method. The as prepared gels were step wisely heated in the temperature range 200°C - 500°C and subsequently characterized by XRD, IR and UV-Vis analysis. The TiO2 (anatase) is the single crystalline phase which has been detected up to 500°C. Photocatalytic tests showed that the investigated samples possess photocatalytic activity toward Malachite green organic dye and TiO2/Nb2O5 exhibited higher photocatalytic activity than TiO2/B2O3 sample. The compositions exhibited good antimicrobial activity against E. coli NBIMCC K12 407 and Bacillus subtilis NBIMCC 3562.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"287 1-4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140514788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-03DOI: 10.59957/jctm.v59.i1.2024.26
Eva Mitkova, Irina Stambolova, Daniela Stoyanova, V. Toteva, Ognian Dimitrov
This article investigates the effect of the time of aging of ZrO2 powders, obtained from zirconium butoxide sols, stabilized using complexating agents on the volume phase fractions tetragonal phase (T) and baddeleyite crystalographic phase (B), pore size distribution and pore volume. It was proved that the aging time period influences ratio between these two polymorphs of zirconia. The sample Zr3d possesses the largest content of baddeleyite phase having the greatest crystallites in comparison to another two powders. The increasing of aging period leads to a gradual increase in (101) peak intensity of T phase, while all the samples are microporous regardless of the aging time. The longest time aged sample possesses higher pore volume and higher average pore diameter than the other two powders. The physico-chemical features of the prepared ZrO2 nanosized powders could be beneficial as catalysts/photocatalysts in different catalytic reactions, corrosion inhibition particles, etc.
{"title":"CORRELATION BETWEEN AGING TIME PERIOD OF METAL PRECURSOR SOL – PHASE COMPOSITION AND TEXTURAL PROPERTIES OF ZIRCONIA NANOPOWDERS","authors":"Eva Mitkova, Irina Stambolova, Daniela Stoyanova, V. Toteva, Ognian Dimitrov","doi":"10.59957/jctm.v59.i1.2024.26","DOIUrl":"https://doi.org/10.59957/jctm.v59.i1.2024.26","url":null,"abstract":"This article investigates the effect of the time of aging of ZrO2 powders, obtained from zirconium butoxide sols, stabilized using complexating agents on the volume phase fractions tetragonal phase (T) and baddeleyite crystalographic phase (B), pore size distribution and pore volume. It was proved that the aging time period influences ratio between these two polymorphs of zirconia. The sample Zr3d possesses the largest content of baddeleyite phase having the greatest crystallites in comparison to another two powders. The increasing of aging period leads to a gradual increase in (101) peak intensity of T phase, while all the samples are microporous regardless of the aging time. The longest time aged sample possesses higher pore volume and higher average pore diameter than the other two powders. The physico-chemical features of the prepared ZrO2 nanosized powders could be beneficial as catalysts/photocatalysts in different catalytic reactions, corrosion inhibition particles, etc.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"51 9","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139450953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-03DOI: 10.59957/jctm.v59.i1.2024.11
Ghusoon Shabaa, R. Zabibah
The presence of dyes in drainage water is one of the important problems that many seek to solve. This study included the preparation of the adsorbent surface using the oyster shells as a basis for the preparation of chitosan, which is a series of carbohydrates and saccharides, by treating them with some simple chemical reactions that grab the acetyl group (de-acetylation), which is a part of the structure of chitin. Then the basic formula of Chitosan is ready to carry positive charges, which act as magnet to attract molecules of any substance beside it. A series of assays were undertaken to assess the efficiency of the adsorption process, such as the weight of oyster shells, equilibrium time, effect of pH, initial concentration of toluidine blue dye, and particle size of the adsorbent. These experiments have shown that the equilibrium time was 120 min, the optimum weight of oyster shells was 0.1 g in 100 mL of dye solution, and the particle size was 150 μm. They also showed there is an effect of the pH on the adsorption of the dye. The adsorption isotherm was well fitted to both the Freundlich and Langmuir models.
{"title":"TREATMENT OF OYSTER SHELLS AND PREPARING THEM AS AN ADSORBENT SURFACE TO TOLUIDINE BLUE DYE","authors":"Ghusoon Shabaa, R. Zabibah","doi":"10.59957/jctm.v59.i1.2024.11","DOIUrl":"https://doi.org/10.59957/jctm.v59.i1.2024.11","url":null,"abstract":"The presence of dyes in drainage water is one of the important problems that many seek to solve. This study included the preparation of the adsorbent surface using the oyster shells as a basis for the preparation of chitosan, which is a series of carbohydrates and saccharides, by treating them with some simple chemical reactions that grab the acetyl group (de-acetylation), which is a part of the structure of chitin. Then the basic formula of Chitosan is ready to carry positive charges, which act as magnet to attract molecules of any substance beside it. A series of assays were undertaken to assess the efficiency of the adsorption process, such as the weight of oyster shells, equilibrium time, effect of pH, initial concentration of toluidine blue dye, and particle size of the adsorbent. These experiments have shown that the equilibrium time was 120 min, the optimum weight of oyster shells was 0.1 g in 100 mL of dye solution, and the particle size was 150 μm. They also showed there is an effect of the pH on the adsorption of the dye. The adsorption isotherm was well fitted to both the Freundlich and Langmuir models.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"58 13","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139451487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-03DOI: 10.59957/jctm.v59.i2.2024.27
Ivaylo Atanasov, D. Pilev
The digital age has brought tremendous opportunities for innovation and efficiency. However, it has also exposed businesses, governments, and individuals to a range of cyber threats, such as data breaches, network attacks, ransomware, malicious insiders, and identity theft. This requires the implementation of robust cybersecurity measures to safeguard sensitive information and ensure the uninterrupted operation of all critical IT systems. This paper aims to provide a facial recognition security system for cyber-physical security that incorporates a neural network and intelligent algorithms to assess the severity level of security breaches. The system also includes alarms with severity levels ranging from 1 (low severity) to 4 (critical), based on facial recognition and data from carbon dioxide and temperature sensors. In the event of a security breach, an incident response plan is presented. The proposed system is applicable to offices, workspaces, server rooms, data centers and other areas where information is stored, to enhance physical security and protect against cybersecurity threats.
数字时代为创新和效率带来了巨大的机遇。然而，它也使企业、政府和个人面临一系列网络威胁，如数据泄露、网络攻击、勒索软件、恶意内鬼和身份盗用。这就需要实施强有力的网络安全措施来保护敏感信息，并确保所有关键 IT 系统的不间断运行。本文旨在提供一种用于网络物理安全的面部识别安全系统，该系统结合了神经网络和智能算法来评估安全漏洞的严重程度。该系统还包括根据面部识别以及二氧化碳和温度传感器的数据发出的严重程度从 1（低严重性）到 4（严重性）不等的警报。一旦发生安全漏洞，系统将提出事故响应计划。拟议的系统适用于办公室、工作区、服务器机房、数据中心和其他存储信息的区域，以加强实体安全和防范网络安全威胁。
{"title":"CYBER-PHYSICAL SECURITY THROUGH FACIAL RECOGNITION AND SENSOR DATA ANALYSIS","authors":"Ivaylo Atanasov, D. Pilev","doi":"10.59957/jctm.v59.i2.2024.27","DOIUrl":"https://doi.org/10.59957/jctm.v59.i2.2024.27","url":null,"abstract":"The digital age has brought tremendous opportunities for innovation and efficiency. However, it has also exposed businesses, governments, and individuals to a range of cyber threats, such as data breaches, network attacks, ransomware, malicious insiders, and identity theft. This requires the implementation of robust cybersecurity measures to safeguard sensitive information and ensure the uninterrupted operation of all critical IT systems. This paper aims to provide a facial recognition security system for cyber-physical security that incorporates a neural network and intelligent algorithms to assess the severity level of security breaches. The system also includes alarms with severity levels ranging from 1 (low severity) to 4 (critical), based on facial recognition and data from carbon dioxide and temperature sensors. In the event of a security breach, an incident response plan is presented. The proposed system is applicable to offices, workspaces, server rooms, data centers and other areas where information is stored, to enhance physical security and protect against cybersecurity threats.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"194 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140514525","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}
Corrosion of mild steel in sodium sulfate solutions (1000 mg SO42- L-1) in the presence of various phosphateinhibitors was studied gravimetrically. Studies were performed under static conditions at room temperature. The known sodium polyphosphate inhibitor has been found to have low efficacy under these conditions. The inhibitor efficiency of its does not exceed 30.5 % at a concentration of 100 mg P2O5 L-1. It has been shown that a more effective inhibitor is calcium-manganese polyphosphate (Са, Mn)(PO3)2 obtained on the basis of manganese ore enrichment wastes of the Zhayrem deposit. The inhibitor efficiency of its already at a concentration of 20 mgP2O5 L-1 is 47.3 %. At a concentration of 100 mgP2O5 L-1, the inhibitor efficiency (Са, Mn)(PO3)2 is 96.2 %. Electrochemical tests confirmed the results of the gravimetric study. Infrared spectroscopic analysis showed that phosphate protective coatings were formed on the steel surface in solutions of sodium sulfate with additives of calcium-manganese polyphosphate.
{"title":"CORROSION BEHAVIOR OF MILD STEEL IN SODIUM SULFATE SOLUTION IN PRESENCE OF PHOSPHATES OF DIFFERENT COMPOSITION","authors":"A. Raimbekova, Viktoriya Kapralova, Angelina Popova, Sholpan Kubekova, Amantai Dalbanbay, Aizhan Kalenova, Bekezhan Mustahimov, Sharipa Yermekbayeva, Sharbanu Myrzabekova","doi":"10.59957/jctm.v59.i2.2024.16","DOIUrl":"https://doi.org/10.59957/jctm.v59.i2.2024.16","url":null,"abstract":"Corrosion of mild steel in sodium sulfate solutions (1000 mg SO42- L-1) in the presence of various phosphateinhibitors was studied gravimetrically. Studies were performed under static conditions at room temperature. The known sodium polyphosphate inhibitor has been found to have low efficacy under these conditions. The inhibitor efficiency of its does not exceed 30.5 % at a concentration of 100 mg P2O5 L-1. It has been shown that a more effective inhibitor is calcium-manganese polyphosphate (Са, Mn)(PO3)2 obtained on the basis of manganese ore enrichment wastes of the Zhayrem deposit. The inhibitor efficiency of its already at a concentration of 20 mgP2O5 L-1 is 47.3 %. At a concentration of 100 mgP2O5 L-1, the inhibitor efficiency (Са, Mn)(PO3)2 is 96.2 %. Electrochemical tests confirmed the results of the gravimetric study. Infrared spectroscopic analysis showed that phosphate protective coatings were formed on the steel surface in solutions of sodium sulfate with additives of calcium-manganese polyphosphate.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"207 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140514626","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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