Pub Date : 2024-07-05DOI: 10.59957/jctm.v59.i4.2024.22
Asma Yamin, W. Rehman, Amin Ur Rahman, Ibrar Ahmed, Muhammad Siddique Afridi
Calcium Magnesium Acetate (CMA) has recently gained much popularity due to its emerging applications in road deicing, and as an industrial adsorbent for removal of Hydrogen Sulfide (H2S) gas and other odorous acid gases from gaseous streams. CMA is a multi-purpose, low-corrosion and concrete-safe alternative to the conventionally used sodium chloride (NaCl) deicers. CMA prevents snow and ice from bonding to either surfaces or itself. In the present study, CMA was prepared from dolomitic limestone of Abbottabad region, Pakistan. The prepared samples were characterized through various instrumental techniques like Scanning Electron Microscopy combined with Energy Dispersive X-Ray (SEM-EDX), X-Ray Diffraction (XRD), and Fourier Transform Infra-Red Spectroscopy (FT-IR).The performance of CMA was compared with NaCl. It was found that after 24 hours, 15 %, of ice melted, when no deicing agent was used. Likewise, 49.4 %, and 66.4 % of ice melted, when CMA and NaCl were used as deicing agents, respectively. Thus, the rate of ice melting increased by 70 % and 77.4 %, with CMA and NaCl respectively. The analysis showed that CMA could successfully be produced from dolomitic limestone of Abbottabad, and the same may be applied for deicing applications.
{"title":"SYNTHESIS AND DEICING PERFORMANCE OF CALCIUM MAGNESIUM ACETATE FROM DOLOMITIC LIMESTONE OF ABBOTABAD REGION, PAKISTAN","authors":"Asma Yamin, W. Rehman, Amin Ur Rahman, Ibrar Ahmed, Muhammad Siddique Afridi","doi":"10.59957/jctm.v59.i4.2024.22","DOIUrl":"https://doi.org/10.59957/jctm.v59.i4.2024.22","url":null,"abstract":"Calcium Magnesium Acetate (CMA) has recently gained much popularity due to its emerging applications in road deicing, and as an industrial adsorbent for removal of Hydrogen Sulfide (H2S) gas and other odorous acid gases from gaseous streams. CMA is a multi-purpose, low-corrosion and concrete-safe alternative to the conventionally used sodium chloride (NaCl) deicers. CMA prevents snow and ice from bonding to either surfaces or itself. In the present study, CMA was prepared from dolomitic limestone of Abbottabad region, Pakistan. The prepared samples were characterized through various instrumental techniques like Scanning Electron Microscopy combined with Energy Dispersive X-Ray (SEM-EDX), X-Ray Diffraction (XRD), and Fourier Transform Infra-Red Spectroscopy (FT-IR).The performance of CMA was compared with NaCl. It was found that after 24 hours, 15 %, of ice melted, when no deicing agent was used. Likewise, 49.4 %, and 66.4 % of ice melted, when CMA and NaCl were used as deicing agents, respectively. Thus, the rate of ice melting increased by 70 % and 77.4 %, with CMA and NaCl respectively. The analysis showed that CMA could successfully be produced from dolomitic limestone of Abbottabad, and the same may be applied for deicing applications.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":" 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141674358","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 : 2024-07-05DOI: 10.59957/jctm.v59.i4.2024.29
T. Koutzarova, S. Kolev, K. Krezhov, B. Georgieva, C. Ghelev, Todor Cholakov, L. Tran, M. Babij
Multiferroic materials are an exceptional class of magnetic materials where long-range magnetic and ferroelectric orders coexist, thus provoking the researchers’ interest from both basic and practical points of view. The magneto-electric multiferroics are materials that combine coupled electric and magnetic dipoles. Recently, research has focused on the occurrence of the magnetoelectric effect in some hexagonal ferrite types and the possibility of their use as single-phase multiferroic and magnetoelectric materials. For many years, various hexaferrites have been intensively studied as materials for permanent magnets, high-density recording media, microwave devices, biomedical applications, etc. The magnetic structure and especially the specific magnetic spin arrangement under certain conditions proved to be key factors for the realization of magneto-electric phases in hexaferrites. Here some recent advances in our studies of the magnetic phase transitions in the Y-type hexaferrites are overviewed. In particular, the influence of the replacement of non-magnetic Me2+ cations with magnetic cations and of magnetic Fe3+ cations with non-magnetic ones on the magnetic properties and occurring magnetic phase transitions in Y-type hexaferrites are exemplified with Ba0.5Sr1.5Zn2Fe12O22.
多铁氧体材料是一类特殊的磁性材料，其中长程磁序和铁电序共存，因此从基础和实用角度都引起了研究人员的兴趣。磁电多铁氧体是结合了耦合电偶极子和磁偶极子的材料。最近，研究的重点是一些六方铁氧体中磁电效应的发生，以及将其用作单相多铁氧体和磁电材料的可能性。多年来，人们对各种六方铁氧体作为永磁体、高密度记录介质、微波器件、生物医学应用等材料进行了深入研究。事实证明，磁性结构，特别是特定条件下的磁自旋排列，是实现六元晶磁电相的关键因素。在此，我们将概述最近在研究 Y 型六铁氧体磁性相变方面取得的一些进展。特别是以 Ba0.5Sr1.5Zn2Fe12O22 为例，说明了用磁性阳离子取代非磁性 Me2+ 阳离子和用非磁性阳离子取代磁性 Fe3+ 阳离子对 Y 型六价铁磁体的磁性能和磁相变的影响。
{"title":"HEXAFERRITES - SINGLE PHASE MAGNETO-ELECTRIC MULTIFERROICS","authors":"T. Koutzarova, S. Kolev, K. Krezhov, B. Georgieva, C. Ghelev, Todor Cholakov, L. Tran, M. Babij","doi":"10.59957/jctm.v59.i4.2024.29","DOIUrl":"https://doi.org/10.59957/jctm.v59.i4.2024.29","url":null,"abstract":"Multiferroic materials are an exceptional class of magnetic materials where long-range magnetic and ferroelectric orders coexist, thus provoking the researchers’ interest from both basic and practical points of view. The magneto-electric multiferroics are materials that combine coupled electric and magnetic dipoles. Recently, research has focused on the occurrence of the magnetoelectric effect in some hexagonal ferrite types and the possibility of their use as single-phase multiferroic and magnetoelectric materials. For many years, various hexaferrites have been intensively studied as materials for permanent magnets, high-density recording media, microwave devices, biomedical applications, etc. The magnetic structure and especially the specific magnetic spin arrangement under certain conditions proved to be key factors for the realization of magneto-electric phases in hexaferrites. Here some recent advances in our studies of the magnetic phase transitions in the Y-type hexaferrites are overviewed. In particular, the influence of the replacement of non-magnetic Me2+ cations with magnetic cations and of magnetic Fe3+ cations with non-magnetic ones on the magnetic properties and occurring magnetic phase transitions in Y-type hexaferrites are exemplified with Ba0.5Sr1.5Zn2Fe12O22.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":" 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141674832","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 : 2024-07-05DOI: 10.59957/jctm.v59.i4.2024.26
Ashraf Ali Basheer, Naveen Ganta
Through oxidation (H2) and reduction (O2 ) reactions, the chemical energy of the fuel is converted by proton exchange membrane fuel cell (PEMFC) into electricity and is therefore considered an energy converter. In this work, performance of a PEMFC is numerically investigated using computational fluid dynamics (CFD). To characterize the non-isothermal behavior of PEMFC, 3D transient CFD simulations are performed. The distribution of H2 and O2 mass fractions, temperature, and current density profiles are analyzed for various operational conditions. The optimum condition (voltage = 0.1 V; thickness of gas diffusion layer (GDL) = 0.0127mm; thickness of catalyst layer (CL) = 0.014mm) for an operation of PEMFC is identified Trapezoidal and rectangular baffles are proposed into the flow channels to enhance the performance of PEMFC. The rectangular baffle configuration supports maximum conversion of reactant gases (H2 = 24.16 %, O2 = 41.72 %) in comparison with the trapezoidal baffle. A significant increase in conversion is reported when the number of baffles in the gas flow channel is increases. Thus, PEMFC performance is enhanced with baffle configuration.
{"title":"CFD MODELLING OF NON-ISOTHERMAL PROTON EXCHANGE MEMBRANE FUEL CELL (PEMFC): ROLE OF BAFFLES","authors":"Ashraf Ali Basheer, Naveen Ganta","doi":"10.59957/jctm.v59.i4.2024.26","DOIUrl":"https://doi.org/10.59957/jctm.v59.i4.2024.26","url":null,"abstract":"Through oxidation (H2) and reduction (O2 ) reactions, the chemical energy of the fuel is converted by proton exchange membrane fuel cell (PEMFC) into electricity and is therefore considered an energy converter. In this work, performance of a PEMFC is numerically investigated using computational fluid dynamics (CFD). To characterize the non-isothermal behavior of PEMFC, 3D transient CFD simulations are performed. The distribution of H2 and O2 mass fractions, temperature, and current density profiles are analyzed for various operational conditions. The optimum condition (voltage = 0.1 V; thickness of gas diffusion layer (GDL) = 0.0127mm; thickness of catalyst layer (CL) = 0.014mm) for an operation of PEMFC is identified Trapezoidal and rectangular baffles are proposed into the flow channels to enhance the performance of PEMFC. The rectangular baffle configuration supports maximum conversion of reactant gases (H2 = 24.16 %, O2 = 41.72 %) in comparison with the trapezoidal baffle. A significant increase in conversion is reported when the number of baffles in the gas flow channel is increases. Thus, PEMFC performance is enhanced with baffle configuration. ","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":" 40","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141676917","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 : 2024-07-05DOI: 10.59957/jctm.v59.i4.2024.18
T. Dzimbova, Fatima Sapundzhi, P. Milanov
Endogenous opioids produce the same effects as the chemicals known as classic alkaloid opiates, which includemorphine and heroin. Endogenous opioid peptides function both as hormones and as neuromodulators. The aim ofthe present study was to analyze the results of docking of ligands with MOR to identify the key elements requiredfor selectivity. Many of the ligands have been synthesized and biologically tested by our colleagues. The other partis compounds known in the literature. The analysis of the obtained ligand-receptor complexes makes it possible todetermine the key structural elements associated with the manifestation of specificity with respect to the receptor.These results will assist in the design of new compounds with potential MOR agonistic or antagonistic effects. In order to be active and effective, a ligand must have certain properties. First, it must be stable in a biological environment so that it can reach the place where it will manifest its action. Second, be of a suitable structure to allow it to reach and interact with the receptor’s binding site. Third, upon binding, the resulting ligand-receptor complex should be stable, i.e. its energy to be small. Fourth, the ligand induces the appropriate conformations in the receptor molecule upon interaction, i.e. to bind to precisely defined amino acid residues. Therefore, the present study aims to analyze the docking results of dalargine derivatives with MOR and determine the necessary conditions for the manifestation of the biological effect.
内源性类阿片产生的效果与被称为典型生物碱类阿片剂的化学物质（包括吗啡和海洛因）相同。内源性阿片肽具有激素和神经调节剂的双重功能。本研究旨在分析配体与 MOR 的对接结果，以确定选择性所需的关键要素。许多配体已由我们的同事合成并进行了生物测试。另一部分是文献中已知的化合物。这些结果将有助于设计具有潜在 MOR 激动或拮抗作用的新化合物。配体必须具备某些特性才能发挥活性和功效。首先，配体必须在生物环境中保持稳定，这样才能到达发挥其作用的地方。其次，配体必须具有合适的结构，使其能够到达受体的结合部位并与之相互作用。第三，配体与受体结合后，所产生的配体-受体复合物应是稳定的，即其能量要小。第四，配体在与受体分子相互作用时诱导受体分子产生适当的构象，即与精确定义的氨基酸残基结合。因此，本研究旨在分析达拉京衍生物与 MOR 的对接结果，并确定生物效应显现的必要条件。
{"title":"ANALYSIS OF THE DOCKING RESULTS OF SOME SELECTIVE MOR LIGANDS","authors":"T. Dzimbova, Fatima Sapundzhi, P. Milanov","doi":"10.59957/jctm.v59.i4.2024.18","DOIUrl":"https://doi.org/10.59957/jctm.v59.i4.2024.18","url":null,"abstract":"Endogenous opioids produce the same effects as the chemicals known as classic alkaloid opiates, which includemorphine and heroin. Endogenous opioid peptides function both as hormones and as neuromodulators. The aim ofthe present study was to analyze the results of docking of ligands with MOR to identify the key elements requiredfor selectivity. Many of the ligands have been synthesized and biologically tested by our colleagues. The other partis compounds known in the literature. The analysis of the obtained ligand-receptor complexes makes it possible todetermine the key structural elements associated with the manifestation of specificity with respect to the receptor.These results will assist in the design of new compounds with potential MOR agonistic or antagonistic effects. In order to be active and effective, a ligand must have certain properties. First, it must be stable in a biological environment so that it can reach the place where it will manifest its action. Second, be of a suitable structure to allow it to reach and interact with the receptor’s binding site. Third, upon binding, the resulting ligand-receptor complex should be stable, i.e. its energy to be small. Fourth, the ligand induces the appropriate conformations in the receptor molecule upon interaction, i.e. to bind to precisely defined amino acid residues. Therefore, the present study aims to analyze the docking results of dalargine derivatives with MOR and determine the necessary conditions for the manifestation of the biological effect.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":" 21","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141673705","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 : 2024-07-05DOI: 10.59957/jctm.v59.i4.2024.25
Rozalya Alhunity, Emad El Qada, Salah H. Aljbour
The aim of this study is to conduct sustainability metrics for asphalt mix partially replaced by Jordanian Oil Shale Ash (OSA). Rapid Impact Assessment Matrix (RIAM) tool was applied to assess the environmental impact in an attempt to figure out the negative effects of using OSA in asphalt mix and to find the appropriate remediation action of these effects.Analysis of RIAM’s results indicated that using Jordanian OSA in asphalt mix will cause major positive impact resulting from Economical/Operational (EO) changes. The majority of the impacts are of class N. No negative impact on human health is expected. The Sociological/Cultural (SC) components such as the population growth and the aesthetic characteristics of the area are positively affected by the utilization of OSA-based asphalt mix. Only one negative impact is found for the Biological/Ecological (BE) category, which needs imperative attention in term of mitigation.
本研究旨在对部分使用约旦油页岩灰（OSA）替代的沥青混合料进行可持续性度量。快速影响评估矩阵（RIAM）工具被用于评估环境影响，试图找出在沥青混合料中使用油页岩灰的负面影响，并为这些影响找到适当的补救措施。RIAM的分析结果表明，在沥青混合料中使用约旦油页岩灰将在经济/运营（EO）方面产生重大积极影响。大多数影响属于 N 级，预计不会对人类健康产生负面影响。使用以 OSA 为基础的沥青混合料将对该地区的人口增长和美学特征等社会/文化（SC）方面产生积极影响。在生物/生态（BE）类别中，只发现了一个负面影响，需要引起高度重视，采取缓解措施。
{"title":"UTILIZATION OF JORDANIAN OIL SHALE ASH IN ASPHALT MIX: ENVIRONMENTAL IMPACT ASSESSMENT","authors":"Rozalya Alhunity, Emad El Qada, Salah H. Aljbour","doi":"10.59957/jctm.v59.i4.2024.25","DOIUrl":"https://doi.org/10.59957/jctm.v59.i4.2024.25","url":null,"abstract":"The aim of this study is to conduct sustainability metrics for asphalt mix partially replaced by Jordanian Oil Shale Ash (OSA). Rapid Impact Assessment Matrix (RIAM) tool was applied to assess the environmental impact in an attempt to figure out the negative effects of using OSA in asphalt mix and to find the appropriate remediation action of these effects.Analysis of RIAM’s results indicated that using Jordanian OSA in asphalt mix will cause major positive impact resulting from Economical/Operational (EO) changes. The majority of the impacts are of class N. No negative impact on human health is expected. The Sociological/Cultural (SC) components such as the population growth and the aesthetic characteristics of the area are positively affected by the utilization of OSA-based asphalt mix. Only one negative impact is found for the Biological/Ecological (BE) category, which needs imperative attention in term of mitigation.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":" 42","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141673468","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 : 2024-07-05DOI: 10.59957/jctm.v59.i4.2024.21
I. Trus, Yana Kryzhanovska, M. Gomelya
The processes of determining the efficiency of Dawex Marathon WBA anionites in removing phosphates from water and creating waste-free processes for their regeneration were studied. In the course of an experimental study of sorption, model solutions of polluted water containing phosphates in a concentration of 40-100 mg dm-3 were passed through the low-based Dawex Marathon WBA anionite in chloride form. The dependence of TDEC on pH and temperature was established when filtering through low-base anionite DOWEX MARATHON WBA in chloride form. An important aspect of the research was the determination of the principles of extracting phosphates in the form of mineral fertilizer during repeated use of regeneration solutions. The processes of anionite regeneration have been studied. Regeneration of anionite was carried out with two solutions, in parallel, namely - 10 % solutions ofsodium chloride, 10 % solution of ammonium chloride. It should be noted that the degree of regeneration is 97 - 98 %.
{"title":"REMOVAL OF PHOSPHATES ON LOW BASIC ANIONITE DOWEX MARATHON WBA","authors":"I. Trus, Yana Kryzhanovska, M. Gomelya","doi":"10.59957/jctm.v59.i4.2024.21","DOIUrl":"https://doi.org/10.59957/jctm.v59.i4.2024.21","url":null,"abstract":"The processes of determining the efficiency of Dawex Marathon WBA anionites in removing phosphates from water and creating waste-free processes for their regeneration were studied. In the course of an experimental study of sorption, model solutions of polluted water containing phosphates in a concentration of 40-100 mg dm-3 were passed through the low-based Dawex Marathon WBA anionite in chloride form. The dependence of TDEC on pH and temperature was established when filtering through low-base anionite DOWEX MARATHON WBA in chloride form. An important aspect of the research was the determination of the principles of extracting phosphates in the form of mineral fertilizer during repeated use of regeneration solutions. The processes of anionite regeneration have been studied. Regeneration of anionite was carried out with two solutions, in parallel, namely - 10 % solutions ofsodium chloride, 10 % solution of ammonium chloride. It should be noted that the degree of regeneration is 97 - 98 %. ","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":" 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141674816","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 : 2024-07-05DOI: 10.59957/jctm.v59.i4.2024.27
Ava Amideina, Petranka Petrova, Mitja Kolar, Jernej Imperl, Petko Mandjukov
The measurement uncertainty (MU) in environmental analyses is usually considered as a combination of the additive contributions from sampling, sample preparation and analytical measurement (usually instrumental). The target MU for such studies is usually relatively high due to the natural sample heterogeneity and/or the complicated pretreatment procedure required. In the analytical practice, the contribution of the sample preparation to MU is rarely evaluated. Thus, it remains a hidden part of the one related to the analysis. However, the knowledge for the contribution of sample preparation might provide important information and further possibility for optimization of the entire analytical procedure and reduction of the expanded MU of the analytical result. From statistical point of view, the separation of uncertainty contributions from the different steps is, generally, not a trivial task. Selection of the proper statistical approach depends on the data structure and quality, variables distribution, etc. In the present study, three different statistical methods for evaluation of the uncertainty contribution of the sample preparation were applied, compared, and discussed. The considered approaches are based on, both, classical and robust analysis of variances (ANOVA) applied to data from instrumental analysis of marine algae and bee honey samples, undergoing microwave digestion. Some general recommendations on the statistical approach selection are revealed based on real experimental data set.
环境分析中的测量不确定性（MU）通常被认为是取样、样品制备和分析测量（通常是仪器测量）的叠加影响的综合结果。由于样品的天然异质性和/或所需的复杂预处理程序，此类研究的目标 MU 通常相对较高。在分析实践中，很少评估样品制备对 MU 的贡献。因此，它仍然是与分析相关的一个隐藏部分。然而，了解样品制备的贡献可能会为优化整个分析程序和减少分析结果的扩大 MU 提供重要的信息和进一步的可能性。从统计学的角度来看，分离来自不同步骤的不确定性贡献通常不是一件小事。选择合适的统计方法取决于数据结构和质量、变量分布等。本研究采用了三种不同的统计方法来评估样品制备的不确定性贡献，并对其进行了比较和讨论。所考虑的方法基于经典和稳健的方差分析（ANOVA），应用于对海洋藻类和蜜蜂蜂蜜样品进行微波消解的仪器分析数据。在实际实验数据集的基础上，提出了一些关于统计方法选择的一般性建议。
{"title":"EVALUATION OF MEASUREMENT UNCERTAINTY ASSOCIATED WITH THE SAMPLE PREPARATION PROCEDURE","authors":"Ava Amideina, Petranka Petrova, Mitja Kolar, Jernej Imperl, Petko Mandjukov","doi":"10.59957/jctm.v59.i4.2024.27","DOIUrl":"https://doi.org/10.59957/jctm.v59.i4.2024.27","url":null,"abstract":"The measurement uncertainty (MU) in environmental analyses is usually considered as a combination of the additive contributions from sampling, sample preparation and analytical measurement (usually instrumental). The target MU for such studies is usually relatively high due to the natural sample heterogeneity and/or the complicated pretreatment procedure required. In the analytical practice, the contribution of the sample preparation to MU is rarely evaluated. Thus, it remains a hidden part of the one related to the analysis. However, the knowledge for the contribution of sample preparation might provide important information and further possibility for optimization of the entire analytical procedure and reduction of the expanded MU of the analytical result. From statistical point of view, the separation of uncertainty contributions from the different steps is, generally, not a trivial task. Selection of the proper statistical approach depends on the data structure and quality, variables distribution, etc. In the present study, three different statistical methods for evaluation of the uncertainty contribution of the sample preparation were applied, compared, and discussed. The considered approaches are based on, both, classical and robust analysis of variances (ANOVA) applied to data from instrumental analysis of marine algae and bee honey samples, undergoing microwave digestion. Some general recommendations on the statistical approach selection are revealed based on real experimental data set.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":" 41","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141675975","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 : 2024-07-05DOI: 10.59957/jctm.v59.i4.2024.5
B. Yakimova, Ralitza Alexova, Lili Dobreva, Yuliana Rainova, Stefan Dobrev, Svetla Danova, Silvia Angelova, I. Stoineva
Inhibition of Angiotensin-converting enzyme I (ACE I) is a modern therapeutic approach to treatment of hypertension. In recent years, research into natural ACE peptide inhibitors without side effects has become important.The aim of this study is to isolate and characterize novel bioactive peptides from skim and/or whole cow’s milk fermented with selected lactobacillus strains. Several homo/heterofermentative strains of the Lactobacillus species of dairy origin have been pre-selected and different milk fermented samples have been studied. A protocol for analyses was designed and the milk proteins were separated by centrifugation at 4°C at 10000 × g, with molecular mass cut off (MWCO) membranes of 3 and 10 kDa. The samples with molecular mass below 3 kDa were further separated by ultrafiltration by dialysis cell (cut off membrane 1 kDa) by continuous stirring at room temperature. The milk fractions under 1 kDa molecular mass were characterized by UPLC-MS. The ACE-inhibitory activity was determined using the FAPGG (N-[3-(2-Furyl) acryloyl]-L-phenylalanyl-glycyl-glycine) degradation method. All tested samples (1 kDa) exhibit ACE I inhibitory activity with IC50 in a range of 6 - 37 mg mL-1. In silico logP prediction of selected peptides was used to assess whether lipophilicity of the compounds falls within the so-called “therapeutically relevant pharmacokinetic space”.
{"title":"ISOLATION AND CHARACTERIZATION OF PEPTIDES FROM MILK AS NATURAL INHIBITORS OF ACE I AND FOOD ADDITIVES","authors":"B. Yakimova, Ralitza Alexova, Lili Dobreva, Yuliana Rainova, Stefan Dobrev, Svetla Danova, Silvia Angelova, I. Stoineva","doi":"10.59957/jctm.v59.i4.2024.5","DOIUrl":"https://doi.org/10.59957/jctm.v59.i4.2024.5","url":null,"abstract":"Inhibition of Angiotensin-converting enzyme I (ACE I) is a modern therapeutic approach to treatment of hypertension. In recent years, research into natural ACE peptide inhibitors without side effects has become important.The aim of this study is to isolate and characterize novel bioactive peptides from skim and/or whole cow’s milk fermented with selected lactobacillus strains. Several homo/heterofermentative strains of the Lactobacillus species of dairy origin have been pre-selected and different milk fermented samples have been studied. A protocol for analyses was designed and the milk proteins were separated by centrifugation at 4°C at 10000 × g, with molecular mass cut off (MWCO) membranes of 3 and 10 kDa. The samples with molecular mass below 3 kDa were further separated by ultrafiltration by dialysis cell (cut off membrane 1 kDa) by continuous stirring at room temperature. The milk fractions under 1 kDa molecular mass were characterized by UPLC-MS. The ACE-inhibitory activity was determined using the FAPGG (N-[3-(2-Furyl) acryloyl]-L-phenylalanyl-glycyl-glycine) degradation method. All tested samples (1 kDa) exhibit ACE I inhibitory activity with IC50 in a range of 6 - 37 mg mL-1. In silico logP prediction of selected peptides was used to assess whether lipophilicity of the compounds falls within the so-called “therapeutically relevant pharmacokinetic space”.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":" 45","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141673736","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 : 2024-07-05DOI: 10.59957/jctm.v59.i4.2024.19
S. Milenkova, Svetoslav Tashkov, N. Zahariev, B. Pilicheva, M. Marudova
5-Fluorouracil (5-FU) is a chemotherapeutic agent used in therapies for both systematically and topical treatment of different types of cancers. Depending on the period of application, its administration may lead to different side effects such as nausea, headache, pain or even photosensitivity. To avoid them, the drug may be encapsulated into polymeric particles. In the present study, bio polymeric spheres based on chitosan, a linear polysaccharide, are presented. The spheres are formulated by an emulsion technique with solvent evaporation. Three types of particles are synthesized: without crosslinker, with sodium tripolyphosphate and glutaraldehyde crosslinker. The resultant structures are evaluated regarding their size, morphology, and encapsulation efficiency. The crosslinking process and the drug presence in the particles is confirmed by FT-IR. A drug release study is conducted to examine the releasekinetics and understand the release behaviour depending on the presence and the type of the crosslinker.
{"title":"5-FLUOROURACIL ENCAPSULATED CHITOSAN MICROSPHERES","authors":"S. Milenkova, Svetoslav Tashkov, N. Zahariev, B. Pilicheva, M. Marudova","doi":"10.59957/jctm.v59.i4.2024.19","DOIUrl":"https://doi.org/10.59957/jctm.v59.i4.2024.19","url":null,"abstract":"5-Fluorouracil (5-FU) is a chemotherapeutic agent used in therapies for both systematically and topical treatment of different types of cancers. Depending on the period of application, its administration may lead to different side effects such as nausea, headache, pain or even photosensitivity. To avoid them, the drug may be encapsulated into polymeric particles. In the present study, bio polymeric spheres based on chitosan, a linear polysaccharide, are presented. The spheres are formulated by an emulsion technique with solvent evaporation. Three types of particles are synthesized: without crosslinker, with sodium tripolyphosphate and glutaraldehyde crosslinker. The resultant structures are evaluated regarding their size, morphology, and encapsulation efficiency. The crosslinking process and the drug presence in the particles is confirmed by FT-IR. A drug release study is conducted to examine the releasekinetics and understand the release behaviour depending on the presence and the type of the crosslinker. ","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":" 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141674670","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 : 2024-07-05DOI: 10.59957/jctm.v59.i4.2024.6
Yavor Ivanov, T. Godjevargova
The aim of this study was to determine and compare the antilipid potential of seed (GSE) and skin extracts (SE) of Pinot Noir red grape. The preparation of extracts and the evaluation of their color were performed. The antilipid potential of GSE and SE was investigated in the minced pork meat samples. Four experimental samples were prepared: with grape seed and skin extracts, with synthetic antioxidant and without additives. The samples were stored at 4oC for 10 days. During this period product color and formed thiobarbituric acid-reactive substances were determined. It was found that the GSE at concentration 1000 μg g-1 limited the oxidative processes more effectively (55.32 %) than the SE (34.04 %) with the same concentration. These results were correlated very well with the TPC and the phenolic composition of the two extracts. The obtained results with GSE (500 and 1000 μg g-1) were like those obtained with the synthetic antioxidant (200 μg g-1). The effect of added GSE and SE onto the minced meat color change during its storage was determined. The results are optimistic because they indicate that grape seed extract can be used as a natural antioxidant in the meat products.
{"title":"ТHE EFFECT OF GRAPE SEED AND SKIN EXTRACTS ON OXIDATIVE AND COLOR STABILITY OF MINCED PORK MEAT","authors":"Yavor Ivanov, T. Godjevargova","doi":"10.59957/jctm.v59.i4.2024.6","DOIUrl":"https://doi.org/10.59957/jctm.v59.i4.2024.6","url":null,"abstract":"The aim of this study was to determine and compare the antilipid potential of seed (GSE) and skin extracts (SE) of Pinot Noir red grape. The preparation of extracts and the evaluation of their color were performed. The antilipid potential of GSE and SE was investigated in the minced pork meat samples. Four experimental samples were prepared: with grape seed and skin extracts, with synthetic antioxidant and without additives. The samples were stored at 4oC for 10 days. During this period product color and formed thiobarbituric acid-reactive substances were determined. It was found that the GSE at concentration 1000 μg g-1 limited the oxidative processes more effectively (55.32 %) than the SE (34.04 %) with the same concentration. These results were correlated very well with the TPC and the phenolic composition of the two extracts. The obtained results with GSE (500 and 1000 μg g-1) were like those obtained with the synthetic antioxidant (200 μg g-1). The effect of added GSE and SE onto the minced meat color change during its storage was determined. The results are optimistic because they indicate that grape seed extract can be used as a natural antioxidant in the meat products.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":" 15","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141674859","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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