The present study aimed to evaluate the potential of mesoporous silica MCM-41 and Al-MCM-41 (molar ratio Si/Al = 20) for the removal of Rhodamine 6G (Rh6G) from aqueous solution. The adsorbents were characterised by XRD, FTIR, SEM-EDX, BET, and UV-Raman. Obtained results related to XRD analysis indicated that the MCM-41 structure remained intact after the incorporation of Al species. Kinetic adsorption study showed that the higher removal (88.75 %, 26.62 mg g −1 ) of Rh6G dye was achieved by Al-MCM-41 at 60 min. FTIR analysis showed that hydrogen bonding played the dominant role in the Rh6G removal mechanism, while the pH results showed that electrostatic interaction was also a key factor. This study shows that the prepared mesoporous materials are inexpensive and efficient adsorbents for the removal of cationic dyes.
{"title":"Adsorption of Rhodamine 6G Dye onto Al-MCM-41 and MCM-41 Mesoporous Materials","authors":"Houda Douba, O. Mohammedi, B. Cheknane","doi":"10.15255/kui.2022.001","DOIUrl":"https://doi.org/10.15255/kui.2022.001","url":null,"abstract":"The present study aimed to evaluate the potential of mesoporous silica MCM-41 and Al-MCM-41 (molar ratio Si/Al = 20) for the removal of Rhodamine 6G (Rh6G) from aqueous solution. The adsorbents were characterised by XRD, FTIR, SEM-EDX, BET, and UV-Raman. Obtained results related to XRD analysis indicated that the MCM-41 structure remained intact after the incorporation of Al species. Kinetic adsorption study showed that the higher removal (88.75 %, 26.62 mg g −1 ) of Rh6G dye was achieved by Al-MCM-41 at 60 min. FTIR analysis showed that hydrogen bonding played the dominant role in the Rh6G removal mechanism, while the pH results showed that electrostatic interaction was also a key factor. This study shows that the prepared mesoporous materials are inexpensive and efficient adsorbents for the removal of cationic dyes.","PeriodicalId":43849,"journal":{"name":"Kemija u Industriji-Journal of Chemists and Chemical Engineers","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46132071","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}
Malika Khelladi, Meriem Abaidia, Senouci Boulerial, K. Bekrentchir, A. Benhamou, A. Debab
As part of a comprehensive evaluation of post-treatment techniques for the removal of chemical and microbiological pollutants from lagoon effluents, an aerated biofilter was designed. The main objective of this study was to evaluate the performance of pozzolan and Luffa cylindrica as low-cost packing materials for the advanced treatment of Stidia natural lagoon effluent. The aerated biofilter operates in down-flow with HLR s of 11.37 to 28.43 m 3 m −2 d −1 and an air/liquid flow ratio of 3 : 1. The differ ent experiments performed on the pilot showed that the percentages of sCOD removal vary with the HLR s and the wastewater concentration at the biofilter inlet. In this study, sCOD removal efficiencies above 78.9 % were achieved depending on HLR , and a maximum removal efficiency of TSS of 71.5 % was obtained for 28.43 m 3 m −2 d −1 . At low HLR (11.37 m 3 m −2 d −1 ), the treated effluent had the following average concentrations: sCOD of 29.5 mg l −1 , BOD 5 of 21.7 mg l −1 and TSS of 26.4 mg l −1 . These experimental results were used with an empirical model to determine the media constant n and treatability factor K . The faecal coliforms and Escherichia coli detected in the treated effluent were less than 10 5 CFU/100 ml, which meet the national guidelines for wastewater reuse in irrigation.
{"title":"Low-cost Packing Materials in an Aerated Biofilter for Lagoon Effluent Treatment","authors":"Malika Khelladi, Meriem Abaidia, Senouci Boulerial, K. Bekrentchir, A. Benhamou, A. Debab","doi":"10.15255/kui.2022.017","DOIUrl":"https://doi.org/10.15255/kui.2022.017","url":null,"abstract":"As part of a comprehensive evaluation of post-treatment techniques for the removal of chemical and microbiological pollutants from lagoon effluents, an aerated biofilter was designed. The main objective of this study was to evaluate the performance of pozzolan and Luffa cylindrica as low-cost packing materials for the advanced treatment of Stidia natural lagoon effluent. The aerated biofilter operates in down-flow with HLR s of 11.37 to 28.43 m 3 m −2 d −1 and an air/liquid flow ratio of 3 : 1. The differ ent experiments performed on the pilot showed that the percentages of sCOD removal vary with the HLR s and the wastewater concentration at the biofilter inlet. In this study, sCOD removal efficiencies above 78.9 % were achieved depending on HLR , and a maximum removal efficiency of TSS of 71.5 % was obtained for 28.43 m 3 m −2 d −1 . At low HLR (11.37 m 3 m −2 d −1 ), the treated effluent had the following average concentrations: sCOD of 29.5 mg l −1 , BOD 5 of 21.7 mg l −1 and TSS of 26.4 mg l −1 . These experimental results were used with an empirical model to determine the media constant n and treatability factor K . The faecal coliforms and Escherichia coli detected in the treated effluent were less than 10 5 CFU/100 ml, which meet the national guidelines for wastewater reuse in irrigation.","PeriodicalId":43849,"journal":{"name":"Kemija u Industriji-Journal of Chemists and Chemical Engineers","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46136031","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}
Toyese OYEGOKE, F. Dabai, Saidu M. Waziri, A. Uzairu, B. Y. Jibril
The impact of molybdenum (Mo) and tungsten (W) on improving the catalytic characteristics of the chromium-based cata- lyst, Cr 2 O 3 , was explored in this study. The use of semi-empirical and density functional theory computational methods was deployed to understand the impact of the substitution of the chromium (Cr) with Mo and W on the catalyst, CrXO 3 (where X = Cr, Mo, W) in the production of propylene from propane. Findings from the investigation confirmed that the surface mod - ified with Mo showed better potential for improving the catalyst selectivity, retarding propylene dehydrogenation, cracking, and coking path than W, which offered a lower selectivity. The use of Mo was found to have better facilitated the propylene production due to its lower affinity for coke and cracking promoting adsorbates accounted for its sites, including easier deso rption of propylene and higher barrier of deep dehydrogenation for preventing the production of undesired products, unlike the use of W. This study, therefore, recommends the use of Mo for the improvement of the catalyst that could result in better propylene yield, which could aid in meeting its rising market demand.
{"title":"Impact of Mo and W on CrXO3 (X = Cr, Mo, W) Catalytic Performance in a Propane Non-oxidative Dehydrogenation Process","authors":"Toyese OYEGOKE, F. Dabai, Saidu M. Waziri, A. Uzairu, B. Y. Jibril","doi":"10.15255/kui.2022.006","DOIUrl":"https://doi.org/10.15255/kui.2022.006","url":null,"abstract":"The impact of molybdenum (Mo) and tungsten (W) on improving the catalytic characteristics of the chromium-based cata- lyst, Cr 2 O 3 , was explored in this study. The use of semi-empirical and density functional theory computational methods was deployed to understand the impact of the substitution of the chromium (Cr) with Mo and W on the catalyst, CrXO 3 (where X = Cr, Mo, W) in the production of propylene from propane. Findings from the investigation confirmed that the surface mod - ified with Mo showed better potential for improving the catalyst selectivity, retarding propylene dehydrogenation, cracking, and coking path than W, which offered a lower selectivity. The use of Mo was found to have better facilitated the propylene production due to its lower affinity for coke and cracking promoting adsorbates accounted for its sites, including easier deso rption of propylene and higher barrier of deep dehydrogenation for preventing the production of undesired products, unlike the use of W. This study, therefore, recommends the use of Mo for the improvement of the catalyst that could result in better propylene yield, which could aid in meeting its rising market demand.","PeriodicalId":43849,"journal":{"name":"Kemija u Industriji-Journal of Chemists and Chemical Engineers","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47756166","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}
Knowledge of gas holdup is important for the development of the three-phase fluidized bed reactors. This work concerns the study of the effect of different operating conditions on gas retention in a turbulent bed contactor type 2 (TBC), such as superfi cial gas and liquid velocities, liquid to gas mass flows ratio ( L / G ), particle diameter and density, static bed height and free-open area of the supporting grid. The influence of the free area of the packing support grid ( φ ) on gas holdup was demonstrated and proved. The gas holdup increased to 22.92 % when φ decreased from 0.82 to 0.32. The experimental data (1746) led to the development of two correlations to predict gas holdup, one of which incorporated the ratio ( L / G ) which is an important design factor for gas-liquid contactors. The predicted results of holdup gas were in good agreement with the experimental data.
{"title":"Gas Holdup in Turbulent Bed Contactor: Experiments and Prediction Model","authors":"B. Bensebia, F. Chaouche, S. Moustefaï","doi":"10.15255/kui.2021.094","DOIUrl":"https://doi.org/10.15255/kui.2021.094","url":null,"abstract":"Knowledge of gas holdup is important for the development of the three-phase fluidized bed reactors. This work concerns the study of the effect of different operating conditions on gas retention in a turbulent bed contactor type 2 (TBC), such as superfi cial gas and liquid velocities, liquid to gas mass flows ratio ( L / G ), particle diameter and density, static bed height and free-open area of the supporting grid. The influence of the free area of the packing support grid ( φ ) on gas holdup was demonstrated and proved. The gas holdup increased to 22.92 % when φ decreased from 0.82 to 0.32. The experimental data (1746) led to the development of two correlations to predict gas holdup, one of which incorporated the ratio ( L / G ) which is an important design factor for gas-liquid contactors. The predicted results of holdup gas were in good agreement with the experimental data.","PeriodicalId":43849,"journal":{"name":"Kemija u Industriji-Journal of Chemists and Chemical Engineers","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41742470","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}
A. Dahia, Djemai Merrcoche, A. Dadda, Amina Lyria Deghal Cheridi
This study is a contribution for radiation dose calculations of a hypothetical accident of a 1 MW research reactor Triga Mark II using HotSpot code. A postulated accidental release of noble gases and halogens were considered. The total effective dose (TED) was estimated for 1 day and 50 years after release. The total damage of fuel element cladding with a maximum radioac- tivity was considered. The obtained results show minimal TED values at the beginning of the release and at a shorter distance from the source. The maximum calculation results are acceptable and below the recommended public dose limit.
本研究是对使用HotSpot代码计算1 MW研究反应堆Triga Mark II假设事故的辐射剂量的贡献。考虑了惰性气体和卤素的假定意外释放。总有效剂量（TED）估计为释放后1天和50年。考虑了具有最大放射性的燃料元件包壳的总损伤。所获得的结果显示了在释放开始时以及在离源较短的距离处的最小TED值。最大计算结果是可接受的，并且低于建议的公众剂量限值。
{"title":"Comparative Radiation Dose Study of a Hypothetical Accident in a Research Reactor","authors":"A. Dahia, Djemai Merrcoche, A. Dadda, Amina Lyria Deghal Cheridi","doi":"10.15255/kui.2021.077","DOIUrl":"https://doi.org/10.15255/kui.2021.077","url":null,"abstract":"This study is a contribution for radiation dose calculations of a hypothetical accident of a 1 MW research reactor Triga Mark II using HotSpot code. A postulated accidental release of noble gases and halogens were considered. The total effective dose (TED) was estimated for 1 day and 50 years after release. The total damage of fuel element cladding with a maximum radioac- tivity was considered. The obtained results show minimal TED values at the beginning of the release and at a shorter distance from the source. The maximum calculation results are acceptable and below the recommended public dose limit.","PeriodicalId":43849,"journal":{"name":"Kemija u Industriji-Journal of Chemists and Chemical Engineers","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47148091","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}
K. Boutemak, Ahlam Amrane, N. Taoualit, Nabila Bensacia, Meriem Arkam
The aim of this study was the extraction, characterization, and evaluation of functional properties of mucilage extracted from Punica granatum L. peels. The isolated mucilage showed good swelling properties and emulsion capacity. The aqueous dispersion of mucilage showed pseudoplastic flow behaviour. In addition, the mucilage had good flow properties, which may be suitable for direct compression formulation. Structural analysis by FTIR indicated the presence of the characteristic binding of mucilage. Isolated mucilage was found to have good properties and could be exploited in food and pharmaceutical sector.
{"title":"Functional Properties and Physicochemical Characterization of Mucilage Extracted from Punica granatum L. Peels and Their Application in Pharmaceutical Suspension Preparation","authors":"K. Boutemak, Ahlam Amrane, N. Taoualit, Nabila Bensacia, Meriem Arkam","doi":"10.15255/kui.2021.076","DOIUrl":"https://doi.org/10.15255/kui.2021.076","url":null,"abstract":"The aim of this study was the extraction, characterization, and evaluation of functional properties of mucilage extracted from Punica granatum L. peels. The isolated mucilage showed good swelling properties and emulsion capacity. The aqueous dispersion of mucilage showed pseudoplastic flow behaviour. In addition, the mucilage had good flow properties, which may be suitable for direct compression formulation. Structural analysis by FTIR indicated the presence of the characteristic binding of mucilage. Isolated mucilage was found to have good properties and could be exploited in food and pharmaceutical sector.","PeriodicalId":43849,"journal":{"name":"Kemija u Industriji-Journal of Chemists and Chemical Engineers","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43276832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper shows the trend of the world crude steel production in the first two decades of the 21 st century. From 2000 to 2020, the world steelmaking continuously increased (total production of 28.5 billion t steel), but decreased in 2008 (1,6 %) and 2009 (7,7 %) because of the global finan cial and economic crises. For more than fifty years, the primary steelmaking processes are those by means of two technologies: oxidation of pig iron (product from blast furnace) in basic oxygen converters by means of technical oxygen, and smelting of old ferrous (steel scrap) in the electro arc furnaces. For the production of quality steel, the secondary metallurgy procedures (treatment of steel in ladle) play a greater role. In 2000, global steel production was 847.2 million t (basic ox - ygen converters share was 58.2 % and the electro arc furnaces 33.8 %), while in 2020, production reached 1.8775 billion t steel, which is an increase of 2.2 times. By 2020, the production of steel by steelmaking processes was 73.2 % by basic oxygen converters, 26.3 % by electro arc furnaces, 0.3 % by Siemens-Martin furnaces, and 0.2 % by other procedures of steel production. Primacy in steelmaking is in countries and companies from Asia (73.9 % of the world’s output). The recycling degree of steel in the period from 2011 to 2019 was 34–37 %. China is the largest world steel- making country (since 1996). China had an increase in steelmaking of 8.3 times in the period from 2000 to 2020 (from 127.2 Mt up to 1.064 Gt). China produced 56.6 % of the world’s steel. From 2000 to 2020, a share of continuous casting was increased by about 10 % (from 87 to 96.6 %).
{"title":"Svjetska proizvodnja čelika u razdoblju od 2000. do 2020. godine","authors":"M. Gojić, Ivana Ivanić, Dijana Knežević","doi":"10.15255/kui.2022.009","DOIUrl":"https://doi.org/10.15255/kui.2022.009","url":null,"abstract":"This paper shows the trend of the world crude steel production in the first two decades of the 21 st century. From 2000 to 2020, the world steelmaking continuously increased (total production of 28.5 billion t steel), but decreased in 2008 (1,6 %) and 2009 (7,7 %) because of the global finan cial and economic crises. For more than fifty years, the primary steelmaking processes are those by means of two technologies: oxidation of pig iron (product from blast furnace) in basic oxygen converters by means of technical oxygen, and smelting of old ferrous (steel scrap) in the electro arc furnaces. For the production of quality steel, the secondary metallurgy procedures (treatment of steel in ladle) play a greater role. In 2000, global steel production was 847.2 million t (basic ox - ygen converters share was 58.2 % and the electro arc furnaces 33.8 %), while in 2020, production reached 1.8775 billion t steel, which is an increase of 2.2 times. By 2020, the production of steel by steelmaking processes was 73.2 % by basic oxygen converters, 26.3 % by electro arc furnaces, 0.3 % by Siemens-Martin furnaces, and 0.2 % by other procedures of steel production. Primacy in steelmaking is in countries and companies from Asia (73.9 % of the world’s output). The recycling degree of steel in the period from 2011 to 2019 was 34–37 %. China is the largest world steel- making country (since 1996). China had an increase in steelmaking of 8.3 times in the period from 2000 to 2020 (from 127.2 Mt up to 1.064 Gt). China produced 56.6 % of the world’s steel. From 2000 to 2020, a share of continuous casting was increased by about 10 % (from 87 to 96.6 %).","PeriodicalId":43849,"journal":{"name":"Kemija u Industriji-Journal of Chemists and Chemical Engineers","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42100205","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}
Y. Ermurat, M. Öztürk, Cansu Önal, Zekiye Kılıçsaymaz
Microbial bile salt hydrolases (BSHs) catalyse the hydrolysis of glycine and taurine-linked bile salts in the small intestine of humans. Achieving the effects of structural changes in BSH molecules on biocatalytic efficiency ( k cat / K m ) and activation energy ( E a ) is necessary to determine biocatalytic performances of the enzymes. Amino acids responsible for biocatalytic activity or substrate specificity in BSH molecules were modified to determine the effects of structural changes on k cat / K m values and E a values of the bioconversion reactions. Purified wild type positive control enzyme (pCON2) and mutant recombinant target enzymes (F18L and Y24L) reacted with six conjugated pure bile salt substrates at working temperature and pH conditions. The results of the hydrolysis conversion analysis conducted at various pH conditions were used to estimate k cat / K m , and the assays conducted at various temperature conditions were used to approximate E a of the biocatalytic reactions. The quantified k cat / K m value was found remarkably highest with mutant recombinant enzymes (Y24L), while the efficiency value with wild type (pCON2) was determined as lowest, indicating that the structural modifications in BSH molecules showed higher values. The alterations with the mutant-type enzymes F18L and Y24L resulted in decreasing k cat / K m and increasing E a estimations of the hydrolysis conversion reactions.
{"title":"Effects of Structural Changes in Bile Salt Hydrolase Enzyme on Biocatalytic Efficiency and Activation Energy at Working pH and Temperature Conditions","authors":"Y. Ermurat, M. Öztürk, Cansu Önal, Zekiye Kılıçsaymaz","doi":"10.15255/kui.2021.075","DOIUrl":"https://doi.org/10.15255/kui.2021.075","url":null,"abstract":"Microbial bile salt hydrolases (BSHs) catalyse the hydrolysis of glycine and taurine-linked bile salts in the small intestine of humans. Achieving the effects of structural changes in BSH molecules on biocatalytic efficiency ( k cat / K m ) and activation energy ( E a ) is necessary to determine biocatalytic performances of the enzymes. Amino acids responsible for biocatalytic activity or substrate specificity in BSH molecules were modified to determine the effects of structural changes on k cat / K m values and E a values of the bioconversion reactions. Purified wild type positive control enzyme (pCON2) and mutant recombinant target enzymes (F18L and Y24L) reacted with six conjugated pure bile salt substrates at working temperature and pH conditions. The results of the hydrolysis conversion analysis conducted at various pH conditions were used to estimate k cat / K m , and the assays conducted at various temperature conditions were used to approximate E a of the biocatalytic reactions. The quantified k cat / K m value was found remarkably highest with mutant recombinant enzymes (Y24L), while the efficiency value with wild type (pCON2) was determined as lowest, indicating that the structural modifications in BSH molecules showed higher values. The alterations with the mutant-type enzymes F18L and Y24L resulted in decreasing k cat / K m and increasing E a estimations of the hydrolysis conversion reactions.","PeriodicalId":43849,"journal":{"name":"Kemija u Industriji-Journal of Chemists and Chemical Engineers","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47750000","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}
Matea Hunić, R. Teparić, Monika Kovačević, Lidija Barišić
The emergence of COVID-19 has caused worldwide concern due to its high infectivity and mortality. Research groups around the world have prioritised drug development against COVID-19. Repurposing of already approved drugs, including the antimalarial drug chloroquine, has attracted considerable attention. The aim of this article is to (i) provide an overview of the recent chemical methods used to synthesise chloroquine and hydroxychloroquine, and (ii) provide insight into the data collected in 2020 on their efficacy against COVID-19. Unfortunately, the promising early results have not been confirmed and a clear and unambiguous conclusion on their clinical efficacy has not yet been drawn. (English) [ FROM AUTHOR] Pojava COVIDA-19 uzrokovala je globalnu zabrinutost zbog visoke zaraznosti i mortaliteta. Stoga je razvoj lijekova protiv COVIDA-19 postao prioritet istraživačkim skupinama diljem svijeta. Pri tom je posebnu pozornost privukla moguća prenamjena prethodno odobrenih lijekova, uključujući i antimalarijski lijek klorokin. Cilj ovog rada je (i) prikazati pregled recentnih kemijskih metoda primijenjenih za sintezu klorokina i hidroksiklorokina te (ii) dati uvid u podatke o njihovoj učinkovitosti protiv COVIDA-19 prikupljene tijekom 2020. Nažalost, početni obećavajući rezultati nisu potvrđeni, a jasni i nedvosmisleni zaključci o kliničkoj učinkovitosti klorokina i hidroksiklorokina još nisu postignuti. (Croatian) [ FROM AUTHOR] Copyright of Kemija u Industriji is the property of Croatian Society of Chemical Engineers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)
新冠肺炎的出现因其高传染性和高死亡率而引起了全世界的关注。世界各地的研究小组已优先考虑针对新冠肺炎的药物开发。重新利用已经批准的药物，包括抗疟药物氯喹，引起了相当大的关注。本文的目的是（i）概述用于合成氯喹和羟氯喹的最新化学方法，以及（ii）深入了解2020年收集的关于其对新冠肺炎疗效的数据。不幸的是，有希望的早期结果尚未得到证实，也尚未就其临床疗效得出明确无误的结论。（英文）[来自作者]新冠肺炎-19引起了全球对高传染率和高死亡率的关注。因此，开发针对新冠肺炎-19的药物已成为世界研究小组的优先事项。特别注意先前授权药物的可能转让，包括抗疟药物氯因子。这项工作的目的是对最近用于合成氯因子和羟基氯因子的化学方法进行综述，并（i）对2020年期间收集的它们对新冠肺炎-19的有效性数据进行分析。不幸的是，最初有希望的结果尚未得到证实，关于氯喹和羟氯喹的临床疗效也尚未得出明确和无意义的结论。（克罗地亚）[来自作者]Kemija u Industriji的版权归克罗地亚化学工程师协会所有，未经版权持有人明确书面许可，不得将其内容复制或通过电子邮件发送到多个网站或发布到listserv。但是，用户可以打印、下载或通过电子邮件发送文章供个人使用。这可能会被删节。对复印件的准确性不作任何保证。用户应参考材料的原始发布版本以获取完整信息。（版权适用于所有人。）
{"title":"The Chloroquine Story in the First Year of the COVID-19 Pandemic","authors":"Matea Hunić, R. Teparić, Monika Kovačević, Lidija Barišić","doi":"10.15255/kui.2021.072","DOIUrl":"https://doi.org/10.15255/kui.2021.072","url":null,"abstract":"The emergence of COVID-19 has caused worldwide concern due to its high infectivity and mortality. Research groups around the world have prioritised drug development against COVID-19. Repurposing of already approved drugs, including the antimalarial drug chloroquine, has attracted considerable attention. The aim of this article is to (i) provide an overview of the recent chemical methods used to synthesise chloroquine and hydroxychloroquine, and (ii) provide insight into the data collected in 2020 on their efficacy against COVID-19. Unfortunately, the promising early results have not been confirmed and a clear and unambiguous conclusion on their clinical efficacy has not yet been drawn. (English) [ FROM AUTHOR] Pojava COVIDA-19 uzrokovala je globalnu zabrinutost zbog visoke zaraznosti i mortaliteta. Stoga je razvoj lijekova protiv COVIDA-19 postao prioritet istraživačkim skupinama diljem svijeta. Pri tom je posebnu pozornost privukla moguća prenamjena prethodno odobrenih lijekova, uključujući i antimalarijski lijek klorokin. Cilj ovog rada je (i) prikazati pregled recentnih kemijskih metoda primijenjenih za sintezu klorokina i hidroksiklorokina te (ii) dati uvid u podatke o njihovoj učinkovitosti protiv COVIDA-19 prikupljene tijekom 2020. Nažalost, početni obećavajući rezultati nisu potvrđeni, a jasni i nedvosmisleni zaključci o kliničkoj učinkovitosti klorokina i hidroksiklorokina još nisu postignuti. (Croatian) [ FROM AUTHOR] Copyright of Kemija u Industriji is the property of Croatian Society of Chemical Engineers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)","PeriodicalId":43849,"journal":{"name":"Kemija u Industriji-Journal of Chemists and Chemical Engineers","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45485139","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}
Zahira Mohamed Seghir, M. Djennad, R. Schomäcker, M. R. Ghezzar
The requirement for environmentally friendly catalysts for the isomerization of alkanes has prompted research on the tung - state-zirconia (WZ) system. The present work examines the activity and selectivity of lanthanum (La) promoted tungstate-zir conia (LWZ) and niobium (Nb) promoted tungstate-zirconia (NWZ) catalysts. In this study, 1 % La promoted WZ (1 % LWZ) and 1 % Nb promoted WZ (1 % NWZ) catalysts were investigated in isomerization of n -butane in the presence of hydrogen. The studied catalysts were characterized by different methods: nitrogen physisorption, temperature programmed desorption of NH 3 , thermogravimetric analysis, and X-ray diffraction. The catalytic activity and selectivity were significantly improved by the addition of 1 % Nb. The redox process in the Nb-containing catalyst (1 % NWZ) played a central role by providing the highest acidic sites (283.53 µmol g −1 ) with appropriate activation energies for the skeletal rearrangement of the reactant ( n -butane). Furthermore, this study highlights the determining role of the transfer process of adsorbed species from ZrO 2 to W as well as to the Nb environment. The conversion of n -butane (27.34 %) and the selectivity to i -butane (92.34 %) for NWZ were signif icantly higher than WZ and LWZ catalysts. The experimental results revealed that Nb was a more effective promoter than La.
{"title":"Study of n-Butane Isomerization on Acid Catalysts Niobium and Lanthanum Promoted Tungstated Zirconia: n-Butane Isomerization Activity","authors":"Zahira Mohamed Seghir, M. Djennad, R. Schomäcker, M. R. Ghezzar","doi":"10.15255/kui.2021.078","DOIUrl":"https://doi.org/10.15255/kui.2021.078","url":null,"abstract":"The requirement for environmentally friendly catalysts for the isomerization of alkanes has prompted research on the tung - state-zirconia (WZ) system. The present work examines the activity and selectivity of lanthanum (La) promoted tungstate-zir conia (LWZ) and niobium (Nb) promoted tungstate-zirconia (NWZ) catalysts. In this study, 1 % La promoted WZ (1 % LWZ) and 1 % Nb promoted WZ (1 % NWZ) catalysts were investigated in isomerization of n -butane in the presence of hydrogen. The studied catalysts were characterized by different methods: nitrogen physisorption, temperature programmed desorption of NH 3 , thermogravimetric analysis, and X-ray diffraction. The catalytic activity and selectivity were significantly improved by the addition of 1 % Nb. The redox process in the Nb-containing catalyst (1 % NWZ) played a central role by providing the highest acidic sites (283.53 µmol g −1 ) with appropriate activation energies for the skeletal rearrangement of the reactant ( n -butane). Furthermore, this study highlights the determining role of the transfer process of adsorbed species from ZrO 2 to W as well as to the Nb environment. The conversion of n -butane (27.34 %) and the selectivity to i -butane (92.34 %) for NWZ were signif icantly higher than WZ and LWZ catalysts. The experimental results revealed that Nb was a more effective promoter than La.","PeriodicalId":43849,"journal":{"name":"Kemija u Industriji-Journal of Chemists and Chemical Engineers","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43583274","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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