Marija Stjepanović, Katarina Matanović, Ivana Tomac, Lidija Jakobek Barron, Mirna Habuda-Stanić
The presence of pharmaceuticals in natural waters has been the subject of numerous studies in the last decade due to their potential negative effects on human health and the environment. Indeed, the intensive use of pharmaceuticals leads to their presence in municipal wastewater. Unfortunately, international and national regulations still do not require continuous monitoring of the presence of pharmaceuticals in natural waters and drinking water, so wastewater treatment plants do not focus on removing them from wastewater. Diclofenac, 2-[2-(2,6-dichloroanilino)phenyl]acetic acid (DCF), is a nonsteroidal compound used as an analgesic, anti-inflammatory, and antipyretic drug and is therefore commonly found in wastewater. Due to its properties, DCF remains biologically active in the aquatic environment and easily enters the food chain. Therefore, DCF should be removed from wastewater before it is discharged into water bodies. Adsorption is an efficient and simple method that can be used to remove DCF from water. In this study, the possibility of removing DCF by adsorption on activated carbon is investigated. Modified hazelnut shell (MHS), modified commercial activated carbon Cullar (MC) and unmodified commercial activated carbon Cullar (C) were batch tested as adsorbents. The tested adsorbents were characterised by FTIR, zeta potential and pH pzc , while the adsorbent efficiency was tested in the pH range from 2 to 10 and described by isothermal studies. Among the tested adsorbents, the maximum uptake of 48.7 mg g −1 was found when modified activated carbon Cullar was used, while both Freundlich and Langmuir isotherm models fitted well to the data. Modified activated carbon from hazelnut shells showed effective removal of DCF.
{"title":"Adsorption of Diclofenac onto Activated Carbons","authors":"Marija Stjepanović, Katarina Matanović, Ivana Tomac, Lidija Jakobek Barron, Mirna Habuda-Stanić","doi":"10.15255/kui.2022.063","DOIUrl":"https://doi.org/10.15255/kui.2022.063","url":null,"abstract":"The presence of pharmaceuticals in natural waters has been the subject of numerous studies in the last decade due to their potential negative effects on human health and the environment. Indeed, the intensive use of pharmaceuticals leads to their presence in municipal wastewater. Unfortunately, international and national regulations still do not require continuous monitoring of the presence of pharmaceuticals in natural waters and drinking water, so wastewater treatment plants do not focus on removing them from wastewater. Diclofenac, 2-[2-(2,6-dichloroanilino)phenyl]acetic acid (DCF), is a nonsteroidal compound used as an analgesic, anti-inflammatory, and antipyretic drug and is therefore commonly found in wastewater. Due to its properties, DCF remains biologically active in the aquatic environment and easily enters the food chain. Therefore, DCF should be removed from wastewater before it is discharged into water bodies. Adsorption is an efficient and simple method that can be used to remove DCF from water. In this study, the possibility of removing DCF by adsorption on activated carbon is investigated. Modified hazelnut shell (MHS), modified commercial activated carbon Cullar (MC) and unmodified commercial activated carbon Cullar (C) were batch tested as adsorbents. The tested adsorbents were characterised by FTIR, zeta potential and pH pzc , while the adsorbent efficiency was tested in the pH range from 2 to 10 and described by isothermal studies. Among the tested adsorbents, the maximum uptake of 48.7 mg g −1 was found when modified activated carbon Cullar was used, while both Freundlich and Langmuir isotherm models fitted well to the data. Modified activated carbon from hazelnut shells showed effective removal of DCF.","PeriodicalId":43849,"journal":{"name":"Kemija u Industriji-Journal of Chemists and Chemical Engineers","volume":"2012 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135258797","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 aim of this study was to investigate the photolytic and photocatalytic degradation of neonicotinoids in an aqueous solution. Acetamiprid (ACE) and thiacloprid (TIA), two widely used insecticides, were used as model components. Experiments were performed in a flat-plate photoreactor under conditions of recirculation of the reaction mix - ture over an immobilised photocatalyst layer (TiO 2 modified by urea) using two artificial lamps for simulation of solar irradiation (2.4 % UVB and 12 % UVA; 300–700 nm). The catalyst used was characterised by XRD, UV/Vis-DRS, BET, SEM/EDX, and CHNS analysis. All experiments were performed at room temperature and atmospheric pressure, at a recirculation flow rate of 200 cm 3 min −1 , and at an initial concentration of ACE and TIA of 10 mg dm −3 . For most measurements, the reaction mixture was sonicated for 15 min immediately before charging the reactor. The study focused on the influence of the pH of the initial solution on the efficiency of photocatalytic and photolytic degradation. It was found that photocatalytic deg - radation of the two model components was most effective under acidic operating conditions, i.e. , at pH 4.5, while photolysis resulted in their minimum degradation. It was also observed that pretreatment of the reaction mixture with ultrasound promoted photocatalytic degradation, while in the case of photolytic degradation, the application of ultrasound did not contribute to better degradation. Finally, photocatalytic degradation of TIA proved to be more successful than photodegradation of ACE (66.4 % vs. 25.8 %) under identical process conditions.
{"title":"Removal of Neonicotinoid Insecticides in a Flat-plate Photoreactor","authors":"Ivana Elizabeta Zelić, Vesna Tomašić, Zoran Gomzi","doi":"10.15255/kui.2022.059","DOIUrl":"https://doi.org/10.15255/kui.2022.059","url":null,"abstract":"The aim of this study was to investigate the photolytic and photocatalytic degradation of neonicotinoids in an aqueous solution. Acetamiprid (ACE) and thiacloprid (TIA), two widely used insecticides, were used as model components. Experiments were performed in a flat-plate photoreactor under conditions of recirculation of the reaction mix - ture over an immobilised photocatalyst layer (TiO 2 modified by urea) using two artificial lamps for simulation of solar irradiation (2.4 % UVB and 12 % UVA; 300–700 nm). The catalyst used was characterised by XRD, UV/Vis-DRS, BET, SEM/EDX, and CHNS analysis. All experiments were performed at room temperature and atmospheric pressure, at a recirculation flow rate of 200 cm 3 min −1 , and at an initial concentration of ACE and TIA of 10 mg dm −3 . For most measurements, the reaction mixture was sonicated for 15 min immediately before charging the reactor. The study focused on the influence of the pH of the initial solution on the efficiency of photocatalytic and photolytic degradation. It was found that photocatalytic deg - radation of the two model components was most effective under acidic operating conditions, i.e. , at pH 4.5, while photolysis resulted in their minimum degradation. It was also observed that pretreatment of the reaction mixture with ultrasound promoted photocatalytic degradation, while in the case of photolytic degradation, the application of ultrasound did not contribute to better degradation. Finally, photocatalytic degradation of TIA proved to be more successful than photodegradation of ACE (66.4 % vs. 25.8 %) under identical process conditions.","PeriodicalId":43849,"journal":{"name":"Kemija u Industriji-Journal of Chemists and Chemical Engineers","volume":"81 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135258662","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 chemical complexity of organic contaminants (drugs, agrochemicals
{"title":"Recent Achievements in Photocatalytic Degradation of Organic Water Contaminants","authors":"Amra Bratovčić","doi":"10.15255/kui.2022.058","DOIUrl":"https://doi.org/10.15255/kui.2022.058","url":null,"abstract":"The chemical complexity of organic contaminants (drugs, agrochemicals","PeriodicalId":43849,"journal":{"name":"Kemija u Industriji-Journal of Chemists and Chemical Engineers","volume":"130 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135258664","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}
Maja Ergović Ravančić, Mirna Habuda-Stanić, Svjetlana Škrabal, Helena Marčetić, Valentina Obradović
The occurrence and concentrations of fluoride in surface and groundwater depend on pH, total dissolved solids, alkalinity, hardness, and geochemical composition of aquifers. However, in many countries, elevated fluoride concentration values are the result of fluoride-contaminated wastewater discharges. Because of fluoride pollution and the health problems that it causes, the World Health Organization (WHO) has set a maximum permissible fluoride content in drinking water of 1.5 mg l −1 . There are different ways of removing elevated concentrations of fluoride from water, such as coagulation and precipitation, membrane processes, electrochemical treatments, ion-exchange and its modification, but the adsorption process is generally accepted as the cheapest and most effective method for removing fluoride from water. Organic waste is increasing every day, especially in developed countries, and is generated in both industries and households. One of the ways to reduce such waste is the production of adsorbents for water defluorination. Adsorbents, most often pre - pared as activated carbon, can be obtained from various materials such as egg shells, fruit and vegetable peel, various leaves, stems, trunk bark, grain shells, legume shells, and many others. The aim of this paper is to provide an overview of the latest research on the use of adsorbents obtained from organic waste materials in order to remove elevated concentrations of fluoride from water.
{"title":"Fluoride Adsorption from Water on Waste Materials","authors":"Maja Ergović Ravančić, Mirna Habuda-Stanić, Svjetlana Škrabal, Helena Marčetić, Valentina Obradović","doi":"10.15255/kui.2022.057","DOIUrl":"https://doi.org/10.15255/kui.2022.057","url":null,"abstract":"The occurrence and concentrations of fluoride in surface and groundwater depend on pH, total dissolved solids, alkalinity, hardness, and geochemical composition of aquifers. However, in many countries, elevated fluoride concentration values are the result of fluoride-contaminated wastewater discharges. Because of fluoride pollution and the health problems that it causes, the World Health Organization (WHO) has set a maximum permissible fluoride content in drinking water of 1.5 mg l −1 . There are different ways of removing elevated concentrations of fluoride from water, such as coagulation and precipitation, membrane processes, electrochemical treatments, ion-exchange and its modification, but the adsorption process is generally accepted as the cheapest and most effective method for removing fluoride from water. Organic waste is increasing every day, especially in developed countries, and is generated in both industries and households. One of the ways to reduce such waste is the production of adsorbents for water defluorination. Adsorbents, most often pre - pared as activated carbon, can be obtained from various materials such as egg shells, fruit and vegetable peel, various leaves, stems, trunk bark, grain shells, legume shells, and many others. The aim of this paper is to provide an overview of the latest research on the use of adsorbents obtained from organic waste materials in order to remove elevated concentrations of fluoride from water.","PeriodicalId":43849,"journal":{"name":"Kemija u Industriji-Journal of Chemists and Chemical Engineers","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135258800","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}
Compost leachate was treated with coagulation/flocculation followed by filtration in order to obtain effluent suitable for further purification by reverse osmosis process. The poly aluminium chloride coagulant and the poly acryl amide flocculant were ap - plied for coagulation/flocculation process. Filtration tests were performed to choose the proper fabric for filtration of compost leachate. There were huge differences between compost leachate samples’ properties taken at the plant; therefore, it was difficult to determine the optimum coagulant/flocculant dosage. It was found that, among the fabrics available, only one was appropriate, and was made of polypropylene. With other filter fabrics the pressure during the filtration increased above 6 bar, which means above the highest specified allowed pressure for the device used. The filtration was carried out with several differently pretreated samples of compost leachate. The turbidity was reduced by as much as 89.8 %. The particle-size distribution analyses showed that most colloids and suspended solids were removed after the treatment. The results indicate that combination of coagulation/flocculation followed by filtration is not adequate for proper treatment of compost leachate, and some other technique, such as electrocoagulation, ultrafiltration, and nanofiltration need to be investigated.
{"title":"Compost Leachate Pretreatment by Coagulation/Flocculation Followed by Filter Press","authors":"Marjana Simonič","doi":"10.15255/kui.2022.060","DOIUrl":"https://doi.org/10.15255/kui.2022.060","url":null,"abstract":"Compost leachate was treated with coagulation/flocculation followed by filtration in order to obtain effluent suitable for further purification by reverse osmosis process. The poly aluminium chloride coagulant and the poly acryl amide flocculant were ap - plied for coagulation/flocculation process. Filtration tests were performed to choose the proper fabric for filtration of compost leachate. There were huge differences between compost leachate samples’ properties taken at the plant; therefore, it was difficult to determine the optimum coagulant/flocculant dosage. It was found that, among the fabrics available, only one was appropriate, and was made of polypropylene. With other filter fabrics the pressure during the filtration increased above 6 bar, which means above the highest specified allowed pressure for the device used. The filtration was carried out with several differently pretreated samples of compost leachate. The turbidity was reduced by as much as 89.8 %. The particle-size distribution analyses showed that most colloids and suspended solids were removed after the treatment. The results indicate that combination of coagulation/flocculation followed by filtration is not adequate for proper treatment of compost leachate, and some other technique, such as electrocoagulation, ultrafiltration, and nanofiltration need to be investigated.","PeriodicalId":43849,"journal":{"name":"Kemija u Industriji-Journal of Chemists and Chemical Engineers","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135258660","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}
Dajana Gašo-Sokač, Valentina Bušić, Dora Zobundžija, Mirna Habuda-Stanić
It is an exceptional challenge to perform organic reactions in water. In the last decade, scientific research in the field of water as a green solvent has continued to grow exponentially. Apart from being cheap, water is harmless to the environment and sometimes gives completely unexpected reactivity in reactions. There is a wide range of organic reactions that can take place in water: from common oxidation-reduction reactions, reactions involving carbocations and carbocations, pericyclic reactions, transition metal reactions, and others. Organic reactions in an aqueous medi - um are used in the chemistry of carbohydrates and in the chemical modification of biomolecules. More recently, water has been used as a medium in microwave synthesis. This review gives an insight into the importance of this field, since organic reactions in water as a solvent, take place according to the principles of green chemistry.
{"title":"Organske reakcije u vodi","authors":"Dajana Gašo-Sokač, Valentina Bušić, Dora Zobundžija, Mirna Habuda-Stanić","doi":"10.15255/kui.2022.056","DOIUrl":"https://doi.org/10.15255/kui.2022.056","url":null,"abstract":"It is an exceptional challenge to perform organic reactions in water. In the last decade, scientific research in the field of water as a green solvent has continued to grow exponentially. Apart from being cheap, water is harmless to the environment and sometimes gives completely unexpected reactivity in reactions. There is a wide range of organic reactions that can take place in water: from common oxidation-reduction reactions, reactions involving carbocations and carbocations, pericyclic reactions, transition metal reactions, and others. Organic reactions in an aqueous medi - um are used in the chemistry of carbohydrates and in the chemical modification of biomolecules. More recently, water has been used as a medium in microwave synthesis. This review gives an insight into the importance of this field, since organic reactions in water as a solvent, take place according to the principles of green chemistry.","PeriodicalId":43849,"journal":{"name":"Kemija u Industriji-Journal of Chemists and Chemical Engineers","volume":"346 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135258665","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}
{"title":"Nature-based Solutions for Integrated Local Water Management","authors":"Alenka Mubi Zalaznik, Urša Brodnik, Anja Pugelj","doi":"10.15255/kui.2022.062","DOIUrl":"https://doi.org/10.15255/kui.2022.062","url":null,"abstract":",","PeriodicalId":43849,"journal":{"name":"Kemija u Industriji-Journal of Chemists and Chemical Engineers","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135258666","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}
T. Moslavac, S. Jokić, D. Šubarić, Marta Ostojčić, S. Tomas, Mario Kovač, S. Budžaki
Investigated were the influence of drying and pressing parameters of rapeseed, sunflower, and safflower seeds on oil yield, as well as antioxidant addition on the oxidative stability of cold pressed oils. The parameters of the oilseeds and cold pressed oils quality (moisture content, iodine value, saponification value, peroxide value, free fatty acids, and insoluble impurities content) were determined using standard methods. In terms of oxidative stability, rosemary, green tea, and pomegranate extracts were used as natural antioxidants, and propyl gallate was used as synthetic antioxidant. The results showed that the moisture content of the oilseeds, as well as nozzle size and electromotor frequency of the press had an effect on the yield of cold pressed oil. By reducing the nozzle size and electromotor frequency, the volume of produced cold pressed oil increased. Rosemary extract effectively increased the oxidative stability of sunflower and safflower oils, and green tea extract increased the stability of rape - seed oil. Greater stabilisation of the tested oils was achieved with the addition of 0.4 % of natural antioxidants compared to the addition of 0.2 %. The synthetic antioxidant, propyl gallate, failed to stabilise safflower oil, and unlike the natural antioxidants, it was less protective for rapeseed and sunflower oil.
{"title":"Influence of Drying, Pressing, and Antioxidants on Yield and Oxidative Stability of Cold Pressed Oils","authors":"T. Moslavac, S. Jokić, D. Šubarić, Marta Ostojčić, S. Tomas, Mario Kovač, S. Budžaki","doi":"10.15255/kui.2022.082","DOIUrl":"https://doi.org/10.15255/kui.2022.082","url":null,"abstract":"Investigated were the influence of drying and pressing parameters of rapeseed, sunflower, and safflower seeds on oil yield, as well as antioxidant addition on the oxidative stability of cold pressed oils. The parameters of the oilseeds and cold pressed oils quality (moisture content, iodine value, saponification value, peroxide value, free fatty acids, and insoluble impurities content) were determined using standard methods. In terms of oxidative stability, rosemary, green tea, and pomegranate extracts were used as natural antioxidants, and propyl gallate was used as synthetic antioxidant. The results showed that the moisture content of the oilseeds, as well as nozzle size and electromotor frequency of the press had an effect on the yield of cold pressed oil. By reducing the nozzle size and electromotor frequency, the volume of produced cold pressed oil increased. Rosemary extract effectively increased the oxidative stability of sunflower and safflower oils, and green tea extract increased the stability of rape - seed oil. Greater stabilisation of the tested oils was achieved with the addition of 0.4 % of natural antioxidants compared to the addition of 0.2 %. The synthetic antioxidant, propyl gallate, failed to stabilise safflower oil, and unlike the natural antioxidants, it was less protective for rapeseed and sunflower oil.","PeriodicalId":43849,"journal":{"name":"Kemija u Industriji-Journal of Chemists and Chemical Engineers","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47724523","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}
Josip Sacher, Marko Sejdić, Matea Gavran, N. Bolf, Željka Ujević Andrijić
The aim of this work was to create a computer program that can be used to calculate the optimal cooling temperature profile of the batch crystalliser. Potassium nitrate dissolved in water was used as a model system for process research. To create a mathematical model of the process, population balances were used, i.e. , their moment transformation. To obtain the optimal temperature profile, a discretisation of the temperature profile was performed using a global optimisation algorithm. A genetic algorithm was used for the optimisation, while a system of ordinary differential equations was solved using the Runge-Kutta 4,5 method. The objective function was to minimise the ratio between the third moment of crystals produced by secondary nucleation, and the third moment of seed crystals at the end of the process. Firstly, the influence of the stopping conditions of the genetic algorithm on the computation time and the value of the objective function was tested. After the optimal stopping condition was determined, the influence of the number of discreti- sation points of the temperature profile on the value of the objective function and the required computation time was investigated. It was found that the optimal stopping condition was when fifteen members of a generation had objective function values that did not differ by more than the tolerance. It is shown that the optimal solution was achieved by dividing the temperature profile into eight parts. To check the repeatability of the calculation for optimal conditions, the calculation was repeated nine times. The optimal temperature profile was compared to a linear cooling of the same duration to determine the benefits of optimisation. The results of the simulation experiments indicate a significant improvement in the process when using the optimal temperature profile compared to the linear profile.
{"title":"Proračun optimalnog temperaturnog profila hlađenja šaržnog kristalizatora","authors":"Josip Sacher, Marko Sejdić, Matea Gavran, N. Bolf, Željka Ujević Andrijić","doi":"10.15255/kui.2023.001","DOIUrl":"https://doi.org/10.15255/kui.2023.001","url":null,"abstract":"The aim of this work was to create a computer program that can be used to calculate the optimal cooling temperature profile of the batch crystalliser. Potassium nitrate dissolved in water was used as a model system for process research. To create a mathematical model of the process, population balances were used, i.e. , their moment transformation. To obtain the optimal temperature profile, a discretisation of the temperature profile was performed using a global optimisation algorithm. A genetic algorithm was used for the optimisation, while a system of ordinary differential equations was solved using the Runge-Kutta 4,5 method. The objective function was to minimise the ratio between the third moment of crystals produced by secondary nucleation, and the third moment of seed crystals at the end of the process. Firstly, the influence of the stopping conditions of the genetic algorithm on the computation time and the value of the objective function was tested. After the optimal stopping condition was determined, the influence of the number of discreti- sation points of the temperature profile on the value of the objective function and the required computation time was investigated. It was found that the optimal stopping condition was when fifteen members of a generation had objective function values that did not differ by more than the tolerance. It is shown that the optimal solution was achieved by dividing the temperature profile into eight parts. To check the repeatability of the calculation for optimal conditions, the calculation was repeated nine times. The optimal temperature profile was compared to a linear cooling of the same duration to determine the benefits of optimisation. The results of the simulation experiments indicate a significant improvement in the process when using the optimal temperature profile compared to the linear profile.","PeriodicalId":43849,"journal":{"name":"Kemija u Industriji-Journal of Chemists and Chemical Engineers","volume":"58 40","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41244126","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}
Compared to cobalt-chromium and stainless steel based alloys, titanium and titanium based al - loys have found wide application in biomedicine, and are used as biomedical implants due to their excellent properties, but are yet to be widely used due to the high cost of their production. Their most important properties include: excellent biocompatibility, good mechanical properties, osseointegration, and corrosion resistance. In addition to presenting some commonly used bio - medical materials, this article gives an overview of the development of titanium biomaterials and their biomedical applications. Biomaterials are widely used in biomedicine to repair, replace or regenerate body tissue. Given that an increasing number of failed implantations caused by path - ogenic bacterial infection are known, among the functions that could be added to biomaterials is antibacterial action, which is of great importance. Recently, antibacterial metal alloys have shown great potential as a new type of biomedical material .
{"title":"Biomaterijali na bazi titana","authors":"Magdalena Jajčinović, Ljerka Slokar Benić","doi":"10.15255/kui.2023.006","DOIUrl":"https://doi.org/10.15255/kui.2023.006","url":null,"abstract":"Compared to cobalt-chromium and stainless steel based alloys, titanium and titanium based al - loys have found wide application in biomedicine, and are used as biomedical implants due to their excellent properties, but are yet to be widely used due to the high cost of their production. Their most important properties include: excellent biocompatibility, good mechanical properties, osseointegration, and corrosion resistance. In addition to presenting some commonly used bio - medical materials, this article gives an overview of the development of titanium biomaterials and their biomedical applications. Biomaterials are widely used in biomedicine to repair, replace or regenerate body tissue. Given that an increasing number of failed implantations caused by path - ogenic bacterial infection are known, among the functions that could be added to biomaterials is antibacterial action, which is of great importance. Recently, antibacterial metal alloys have shown great potential as a new type of biomedical material .","PeriodicalId":43849,"journal":{"name":"Kemija u Industriji-Journal of Chemists and Chemical Engineers","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41791179","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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