Pub Date : 2024-11-26DOI: 10.1016/j.sajce.2024.11.007
Pantita Trongjitraksa , Mohammad Yazdanpanah , Mohammad Fereidooni , Piyasan Praserthdam , Bunjerd Jongsomjit
In this study, the WO3/MCF-Si and WO3/SBA-15 catalysts were developed for the ethanol dehydration reaction under different ethanol concentrations including 99, 70, and 50 % v/v in water. It aims to evaluate the effect of water presence in the reaction medium on the catalytic performance and properties of the catalyst which can be applied to developing industrial process. Both catalysts were tested under the vapor phase ethanol dehydration at temperature of 400 °C for 10 h via time on stream. WO3/MCF-Si exhibited superior catalytic activity and greater resistance to both coke formation and water in the feedstock compared to WO3/SBA-15. It was found that variations in ethanol concentrations had negligible influence on the textural properties of the developed catalysts. Nevertheless, a discernible effect on the acidity of the catalyst was observed. Additionally, the use of lower ethanol concentrations (with higher water content) as a feed enhanced the selectivity of ethylene and inhibited the formation of Bronsted acid sites leading to a decrease of coke formation. On the contrary, it also had an adverse effect by attenuating the ethanol conversion. WO3/MCF-Si with using 70 % v/v ethanol as feed demonstrated highest steady-state activity showing the maximal yield of ethylene between 95 and 96.6 %.
{"title":"Effect of ethanol concentration on the catalytic performance of WO3/MCF-Si and WO3/SBA-15 catalysts toward ethanol dehydration to ethylene","authors":"Pantita Trongjitraksa , Mohammad Yazdanpanah , Mohammad Fereidooni , Piyasan Praserthdam , Bunjerd Jongsomjit","doi":"10.1016/j.sajce.2024.11.007","DOIUrl":"10.1016/j.sajce.2024.11.007","url":null,"abstract":"<div><div>In this study, the WO<sub>3</sub>/MCF-Si and WO<sub>3</sub>/SBA-15 catalysts were developed for the ethanol dehydration reaction under different ethanol concentrations including 99, 70, and 50 % v/v in water. It aims to evaluate the effect of water presence in the reaction medium on the catalytic performance and properties of the catalyst which can be applied to developing industrial process. Both catalysts were tested under the vapor phase ethanol dehydration at temperature of 400 <sup>°</sup>C for 10 h via time on stream. WO<sub>3</sub>/MCF-Si exhibited superior catalytic activity and greater resistance to both coke formation and water in the feedstock compared to WO<sub>3</sub>/SBA-15. It was found that variations in ethanol concentrations had negligible influence on the textural properties of the developed catalysts. Nevertheless, a discernible effect on the acidity of the catalyst was observed. Additionally, the use of lower ethanol concentrations (with higher water content) as a feed enhanced the selectivity of ethylene and inhibited the formation of Bronsted acid sites leading to a decrease of coke formation. On the contrary, it also had an adverse effect by attenuating the ethanol conversion. WO<sub>3</sub>/MCF-Si with using 70 % v/v ethanol as feed demonstrated highest steady-state activity showing the maximal yield of ethylene between 95 and 96.6 %.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"51 ","pages":"Pages 180-187"},"PeriodicalIF":0.0,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142745325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-26DOI: 10.1016/j.sajce.2024.11.009
Muthiah N. Najah , Frida A. Rahmania , Integralita Cahyanti , Maulida Hesnaty , Siti Hajar Alias , Djoko Hartanto , Wahyu Prasetyo Utomo , Retno Sari , Hadi Nur
This study investigates fabrication of transparent conductive glass using fluorine-doped tin oxide (FTO) as a more affordable alternative to indium tin oxide (ITO) in photovoltaic applications. To enhance conductivity, a ZnO layer was deposited on FTO, followed by a Cu2O layer via electrodeposition. The synthesis parameters are varied to determine their effect on the reaction and to identify the optimal conditions. The characteristic of FTO/ZnO/Cu2O studied using XRD, SEM annexed with EDX, IV testing and visible light absorption spectroscopy to disclose its optoelectronic applications. The FTO layers were produced via spray pyrolysis, with optimal deposition achieved at 400 °C and efficiency value 0.0149 %, resulting in a dense, transparent structure. Meanwhile the efficiency of samples at temperatures of 350°C, 450°C, and 500°C are 0.0032 %, 0.0042 %, and 0.0037 %. From the efficiency results, the optimal thickness of the Cu2O layer was obtained at a duration of 30 min, which was 0.0380 %, while the other durations of 1 hour, 2 h, and 3 h were 0.0149 %, 0.0076 %, and 0.0056 %. The best efficiency was obtained at an optimum pH of 10 with a value of 0.0038 %, promoting crystal growth along the (111) plane. While at pH variations of 8, 9, 11, and 12, the efficiency values were 0.0016 %, 0.0083 %, 0.0083 %, and 0.0073 %, respectively. I-V testing of FTO/ZnO:Mg/ Cu2O with varying electrodeposition voltage show that the efficiency of samples at voltage 5 V, 10 V, 15 V, 20 V, and 0.0128, 0.0093, 0.0036, 0.0053 and 0.0383 %. The optimum conditions for fabricated the samples was achieved with a 30-minute electrodeposition duration at 25 V and pH 10, as confirmed through I-V testing. The study highlights the influence of pyrolysis temperature, electrodeposition time, and pH on the optical and electrical properties of the glass, with optimized conditions yielding improved photoresponse performance.
{"title":"Parameter influences of FTO/ZnO/Cu₂O photodetectors fabricated by electrodeposition and spray pyrolysis techniques","authors":"Muthiah N. Najah , Frida A. Rahmania , Integralita Cahyanti , Maulida Hesnaty , Siti Hajar Alias , Djoko Hartanto , Wahyu Prasetyo Utomo , Retno Sari , Hadi Nur","doi":"10.1016/j.sajce.2024.11.009","DOIUrl":"10.1016/j.sajce.2024.11.009","url":null,"abstract":"<div><div>This study investigates fabrication of transparent conductive glass using fluorine-doped tin oxide (FTO) as a more affordable alternative to indium tin oxide (ITO) in photovoltaic applications. To enhance conductivity, a ZnO layer was deposited on FTO, followed by a Cu<sub>2</sub>O layer via electrodeposition. The synthesis parameters are varied to determine their effect on the reaction and to identify the optimal conditions. The characteristic of FTO/ZnO/Cu<sub>2</sub>O studied using XRD, SEM annexed with EDX, IV testing and visible light absorption spectroscopy to disclose its optoelectronic applications. The FTO layers were produced via spray pyrolysis, with optimal deposition achieved at 400 °C and efficiency value 0.0149 %, resulting in a dense, transparent structure. Meanwhile the efficiency of samples at temperatures of 350°C, 450°C, and 500°C are 0.0032 %, 0.0042 %, and 0.0037 %. From the efficiency results, the optimal thickness of the Cu<sub>2</sub>O layer was obtained at a duration of 30 min, which was 0.0380 %, while the other durations of 1 hour, 2 h, and 3 h were 0.0149 %, 0.0076 %, and 0.0056 %. The best efficiency was obtained at an optimum pH of 10 with a value of 0.0038 %, promoting crystal growth along the (111) plane. While at pH variations of 8, 9, 11, and 12, the efficiency values were 0.0016 %, 0.0083 %, 0.0083 %, and 0.0073 %, respectively. I-V testing of FTO/ZnO:Mg/ Cu<sub>2</sub>O with varying electrodeposition voltage show that the efficiency of samples at voltage 5 V, 10 V, 15 V, 20 V, and 0.0128, 0.0093, 0.0036, 0.0053 and 0.0383 %. The optimum conditions for fabricated the samples was achieved with a 30-minute electrodeposition duration at 25 V and pH 10, as confirmed through I-V testing. The study highlights the influence of pyrolysis temperature, electrodeposition time, and pH on the optical and electrical properties of the glass, with optimized conditions yielding improved photoresponse performance.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"51 ","pages":"Pages 188-201"},"PeriodicalIF":0.0,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142745327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The aim of this study was to predict ash and water contents in coal samples using machine learning regression techniques, specifically LassoCV, RidgeCV, ElasticNetCV and LassoLarsCV. The analysis focused on finding non-zero coefficients at specific wavenumbers and highlighted the influence of infrared (IR) intensity on prediction accuracy. These determined wavenumbers were correlated with experimental ash and water contents in coal samples. The study showed a strong relationship between spectral features and regression coefficients, thus enabling accurate prediction of ash and water contents. For ash content, significant spectral features were identified at around 600 cm⁻¹ and 1600 cm⁻¹, corresponding to C=C and aromatic carbon vibrations. The prediction of water content was significantly influenced by O-H vibration at around 3700 cm⁻¹. The performance of the regression models was evaluated by comparing the predicted ash and water contents with experimental data, thus ensuring a strong correlation between the predicted and experimental values. This study highlighted the effectiveness of regression analysis and machine learning models in predicting coal properties and provided valuable information for better assessment of direct coal parameters.
{"title":"Predicting ash content and water content in coal using full infrared spectra and machine learning models","authors":"Suprapto Suprapto, Antin Wahyuningtyas, Kartika Anoraga Madurani, Yatim Lailun Ni'mah","doi":"10.1016/j.sajce.2024.11.006","DOIUrl":"10.1016/j.sajce.2024.11.006","url":null,"abstract":"<div><div>The aim of this study was to predict ash and water contents in coal samples using machine learning regression techniques, specifically LassoCV, RidgeCV, ElasticNetCV and LassoLarsCV. The analysis focused on finding non-zero coefficients at specific wavenumbers and highlighted the influence of infrared (IR) intensity on prediction accuracy. These determined wavenumbers were correlated with experimental ash and water contents in coal samples. The study showed a strong relationship between spectral features and regression coefficients, thus enabling accurate prediction of ash and water contents. For ash content, significant spectral features were identified at around 600 cm⁻¹ and 1600 cm⁻¹, corresponding to C=C and aromatic carbon vibrations. The prediction of water content was significantly influenced by O-H vibration at around 3700 cm⁻¹. The performance of the regression models was evaluated by comparing the predicted ash and water contents with experimental data, thus ensuring a strong correlation between the predicted and experimental values. This study highlighted the effectiveness of regression analysis and machine learning models in predicting coal properties and provided valuable information for better assessment of direct coal parameters.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"51 ","pages":"Pages 170-179"},"PeriodicalIF":0.0,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142702717","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-18DOI: 10.1016/j.sajce.2024.11.005
Md. Mahmudur Rahman , Mohd. Maniruzzaman , Ripon Kumar Saha
As a result of the excessive dependency on synthetic polymer/plastic products, both industries and mankind have been generating a huge amount of hazardous plastic waste. That could be recognized as a breakneck tread on for total environment due to their nonbiodegradable nature. Thus, to solve this problem replacement of the hazardous synthetic fossil-based plastic with biopolymeric materials is very crucial. But, due to the deficiency of the most critical understanding, designing of the biopolymeric materials from natural resources have signified a big challenge. However, researchers are trying to develop a suitable route to solve this issue. By this study a green route of production of antibacterial films from the agro-waste biomass has been developed. Whereas the highly active chitosan were extracted from shrimp (Penaeus monodon) shells by conducting demineralization, de-proteinization, and deacetylation reaction. The chitosan-acetate films were fabricated by using the EIPS operation to enhance their overall properties. The samples were characterized by SEM, ATR-FTIR, 13C CPMAS NMR, TGA, TS, biodegradability, and antimicrobial activity exploration. The results advised that the newly fabricated biofilms are highly thermally stable, possessed several active binding sites with a uniform nonporous solid microstructure. Also exhibited a higher mechanical tensile strength (nearly 120.27 ± 0.091 N/mm2), elongation properties (around 43.98 ± 0.098 %), and a high antimicrobial activity. While the maximum zone of inhibition and MIC value were found around 45 mm and 5 µg for Staphylococcus aureus. Due to these outstanding properties, this biofilm would be beneficially used in several engineering, industrial, and bio-medical sectors for the green environmental protection.
{"title":"A green route of antibacterial films production from shrimp (Penaeus monodon) shell waste biomass derived chitosan: Physicochemical, thermomechanical, morphological and antimicrobial activity analysis","authors":"Md. Mahmudur Rahman , Mohd. Maniruzzaman , Ripon Kumar Saha","doi":"10.1016/j.sajce.2024.11.005","DOIUrl":"10.1016/j.sajce.2024.11.005","url":null,"abstract":"<div><div>As a result of the excessive dependency on synthetic polymer/plastic products, both industries and mankind have been generating a huge amount of hazardous plastic waste. That could be recognized as a breakneck tread on for total environment due to their nonbiodegradable nature. Thus, to solve this problem replacement of the hazardous synthetic fossil-based plastic with biopolymeric materials is very crucial. But, due to the deficiency of the most critical understanding, designing of the biopolymeric materials from natural resources have signified a big challenge. However, researchers are trying to develop a suitable route to solve this issue. By this study a green route of production of antibacterial films from the agro-waste biomass has been developed. Whereas the highly active chitosan were extracted from shrimp (<em>Penaeus monodon</em>) shells by conducting demineralization, de-proteinization, and deacetylation reaction. The chitosan-acetate films were fabricated by using the EIPS operation to enhance their overall properties. The samples were characterized by SEM, ATR-FTIR, <sup>13</sup>C CPMAS NMR, TGA, TS, biodegradability, and antimicrobial activity exploration. The results advised that the newly fabricated biofilms are highly thermally stable, possessed several active binding sites with a uniform nonporous solid microstructure. Also exhibited a higher mechanical tensile strength (nearly 120.27 ± 0.091 N/mm<sup>2</sup>), elongation properties (around 43.98 ± 0.098 %), and a high antimicrobial activity. While the maximum zone of inhibition and MIC value were found around 45 mm and 5 µg for <em>Staphylococcus aureus</em>. Due to these outstanding properties, this biofilm would be beneficially used in several engineering, industrial, and bio-medical sectors for the green environmental protection.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"51 ","pages":"Pages 153-169"},"PeriodicalIF":0.0,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142702716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-07DOI: 10.1016/j.sajce.2024.10.012
Kashif Ali Abro , Imran Qasim Memon , Ali Yousef , Qasem M. Al-Mdallal
The convective heat transfer is one of the most important mechanism of heat transference for controlling the chaotic characteristics in porous media. A comparative study of thermal non-equilibrium model is proposed for fractal porous under the consideration of chaotic convection. A novel chaos control is focused between fractal porous and fractional porous by means of newly proposed differential and integral techniques. The sensitivity analysis for chaos expansion and uncertainty quantification for the flow in heterogeneous media have been perceived to the problem of chaotic convection through numerical simulations. In order to approximate the propagation of chaos, two types of simulations have been carried out in terms of chaotic attractors through fractal and fractional approaches. For examining a variety of chaos under the numerical simulations in which fractal domain is varied and fractional domain is fixed, fractal domain is fixed and fractional domain is varied, and both fractal as well as fractional domain are varied. Finally, it is observed that the fractional and fractal memory effects have caused by interactions between uncertain parameters and disclosed the microstructures on the permeability of porous media.
{"title":"A comparative analysis of fractal and fractionalized thermal non-equilibrium model for chaotic convection saturated by porous medium","authors":"Kashif Ali Abro , Imran Qasim Memon , Ali Yousef , Qasem M. Al-Mdallal","doi":"10.1016/j.sajce.2024.10.012","DOIUrl":"10.1016/j.sajce.2024.10.012","url":null,"abstract":"<div><div>The convective heat transfer is one of the most important mechanism of heat transference for controlling the chaotic characteristics in porous media. A comparative study of thermal non-equilibrium model is proposed for fractal porous under the consideration of chaotic convection. A novel chaos control is focused between fractal porous and fractional porous by means of newly proposed differential and integral techniques. The sensitivity analysis for chaos expansion and uncertainty quantification for the flow in heterogeneous media have been perceived to the problem of chaotic convection through numerical simulations. In order to approximate the propagation of chaos, two types of simulations have been carried out in terms of chaotic attractors through fractal and fractional approaches. For examining a variety of chaos under the numerical simulations in which fractal domain is varied and fractional domain is fixed, fractal domain is fixed and fractional domain is varied, and both fractal as well as fractional domain are varied. Finally, it is observed that the fractional and fractal memory effects have caused by interactions between uncertain parameters and disclosed the microstructures on the permeability of porous media.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"51 ","pages":"Pages 124-135"},"PeriodicalIF":0.0,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142702712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-07DOI: 10.1016/j.sajce.2024.11.003
Antonius Herry Cahyana , Ikrimah Desta , Laely Amaliyah , Aida Nadia , Hilna Diana Sahaya , Dicky Annas , Bayu Ardiansah , Mohammad Jihad Madiabu , Inda Mapiliandari , Kang Hyun Park
This research aimed to synthesis of N-base compounds based on benzimidazole derivatives and their potential as antibacterials, antioxidants, and anticancer. The synthesis was conducted in two stages, namely the intermediate (benzimidazole derivatives) and the final product (N-mannich base), using five variations of organic acids and SiO2OAlCl2 as catalyst. The results showed that the catalyst was successfully synthesized and characterized by The Fourier transform infrared (FTIR), X-ray diffraction (XRD), and Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS). The purity of the synthesized compounds was monitored by Thin layer chromatography (TLC), melting point test, Ultraviolet-visible (UV–Vis), and Liquid chromatography-Mass spectrometry (LC-MS). The five intermediate compounds and five mannich base products yield 77 %-89 % and 65 %-85 %, respectively. The final products were applied through antibacterial testing against Staphylococcus aureus (Gram-positive bacteria) and Escherichia coli (Gram-negative bacteria) by disc diffusion. Mannich base compounds have potential antibacterial agents, but only 4A and 4E gave the best inhibition zone diameter. Meanwhile, the antioxidant testing result using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method showed the best activity in the mannich base compound 4E. The anticancer test result showed that the five mannich base compounds had potential as anticancer agents.
本研究旨在合成基于苯并咪唑衍生物的 N-基化合物，并探讨其作为抗菌剂、抗氧化剂和抗癌剂的潜力。合成过程分为两个阶段，即中间产物（苯并咪唑衍生物）和最终产物（N-曼尼希碱），使用了五种不同的有机酸和 SiO2OAlCl2 作为催化剂。结果表明，催化剂合成成功，并通过傅立叶变换红外光谱（FTIR）、X 射线衍射（XRD）和扫描电子显微镜与能量色散 X 射线光谱（SEM-EDS）进行了表征。通过薄层色谱法（TLC）、熔点测试、紫外可见光（UV-Vis）和液相色谱-质谱法（LC-MS）监测合成化合物的纯度。五种中间化合物和五种曼尼希碱产品的收率分别为 77 %-89 % 和 65 %-85%。最终产品通过盘扩散法对金黄色葡萄球菌（革兰氏阳性菌）和大肠杆菌（革兰氏阴性菌）进行了抗菌测试。曼尼希碱化合物具有潜在的抗菌作用，但只有 4A 和 4E 的抑菌区直径最大。同时，用 1,1-二苯基-2-苦基肼（DPPH）法进行的抗氧化测试结果表明，曼尼希碱化合物 4E 的活性最好。抗癌测试结果表明，这五种甘露碱化合物具有抗癌潜力。
{"title":"Synthesis of Mannich N-bases based on benzimidazole derivatives using SiO2OAlCl2 catalyst and their potential as antioxidant, antibacterial, and anticancer agents","authors":"Antonius Herry Cahyana , Ikrimah Desta , Laely Amaliyah , Aida Nadia , Hilna Diana Sahaya , Dicky Annas , Bayu Ardiansah , Mohammad Jihad Madiabu , Inda Mapiliandari , Kang Hyun Park","doi":"10.1016/j.sajce.2024.11.003","DOIUrl":"10.1016/j.sajce.2024.11.003","url":null,"abstract":"<div><div>This research aimed to synthesis of <em>N</em>-base compounds based on benzimidazole derivatives and their potential as antibacterials, antioxidants, and anticancer. The synthesis was conducted in two stages, namely the intermediate (benzimidazole derivatives) and the final product (<em>N</em>-mannich base), using five variations of organic acids and SiO<sub>2<img></sub>OAlCl<sub>2</sub> as catalyst. The results showed that the catalyst was successfully synthesized and characterized by The Fourier transform infrared (FTIR), X-ray diffraction (XRD), and Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS). The purity of the synthesized compounds was monitored by Thin layer chromatography (TLC), melting point test, Ultraviolet-visible (UV–Vis), and Liquid chromatography-Mass spectrometry (LC-MS). The five intermediate compounds and five mannich base products yield 77 %-89 % and 65 %-85 %, respectively. The final products were applied through antibacterial testing against <em>Staphylococcus aureus</em> (Gram-positive bacteria) and <em>Escherichia coli</em> (Gram-negative bacteria) by disc diffusion. Mannich base compounds have potential antibacterial agents, but only 4A and 4E gave the best inhibition zone diameter. Meanwhile, the antioxidant testing result using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method showed the best activity in the mannich base compound 4E. The anticancer test result showed that the five mannich base compounds had potential as anticancer agents.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"51 ","pages":"Pages 95-111"},"PeriodicalIF":0.0,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142657526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-07DOI: 10.1016/j.sajce.2024.10.005
Maressa O. Camilo , Romero F. Carvalho , Ariany B.S. Costa , Esly F.C. Junior , Andréa O.S. Costa , Robson C. Sousa
The application of a versatile approach for modeling and prediction the moisture content of dried peels was evaluated using both empirical and semi-empirical equations (Lewis, Page, Henderson and Pabis, Modified Page, Logarithmic, and Modified Logistic) as well as machine learning models (K-nearest neighbor | KNN, Decision Tree | DT, Artificial Neural Network | ANN and Support Vector Regression | SVR). Heuristic optimization methods, including genetic algorithms (GA) and nonlinear programming (NLP), were employed to identify the best empirical and semi-empirical models for estimating moisture content during the drying process of lemon peel layers. The parameters of the drying kinetics models were optimized using GA to achieve the best results. It was found that as the number of model parameters increases, particularly in models such as the logarithmic one, the optimization problem becomes more complex. Consequently, accurate initial guesses become increasingly important, emphasizing the need for heuristic methods like genetic algorithms. This optimization approach provided excellent performance metrics (R2 > 0.9715, SSR 〈 0.0625 and MSE < 0.0026 for endocarp and R2 〉 0.9678, SSR < 0.0755 and MSE < 0.0030 for epicarp). The models proposed in this study achieved the best results with the modified logistic equation (R2 > 0.9923, MSE 〈 0.0001 and SSR < 0.0013 for endocarp and R2 〉 0.9905, MSE < 0.0001 and SSR < 0.0013 for epicarp). In particular, the multilayer perceptron neural network of the machine learning proved to be the optimal choice as it best accounts for the complexity of the drying kinetics of lemons. This neural network model outperformed traditional empirical and semi-empirical models, demonstrating superior performance metrics (R2 > 0.9979, MSE 〈 0.0002 and SSR < 0.0012 for endocarp and R2 〉 0.9989, MSE < 0.0001 and SSR < 0.0008 for epicarp) when tested against validation data.
{"title":"Drying kinetic for moisture content prediction of peels Tahiti lemon (Citrus latifolia): Approach by machine learning and optimization - genetic algorithms and nonlinear programming","authors":"Maressa O. Camilo , Romero F. Carvalho , Ariany B.S. Costa , Esly F.C. Junior , Andréa O.S. Costa , Robson C. Sousa","doi":"10.1016/j.sajce.2024.10.005","DOIUrl":"10.1016/j.sajce.2024.10.005","url":null,"abstract":"<div><div>The application of a versatile approach for modeling and prediction the moisture content of dried peels was evaluated using both empirical and semi-empirical equations (Lewis, Page, Henderson and Pabis, Modified Page, Logarithmic, and Modified Logistic) as well as machine learning models (K-nearest neighbor | KNN, Decision Tree | DT, Artificial Neural Network | ANN and Support Vector Regression | SVR). Heuristic optimization methods, including genetic algorithms (GA) and nonlinear programming (NLP), were employed to identify the best empirical and semi-empirical models for estimating moisture content during the drying process of lemon peel layers. The parameters of the drying kinetics models were optimized using GA to achieve the best results. It was found that as the number of model parameters increases, particularly in models such as the logarithmic one, the optimization problem becomes more complex. Consequently, accurate initial guesses become increasingly important, emphasizing the need for heuristic methods like genetic algorithms. This optimization approach provided excellent performance metrics (R<sup>2</sup> > 0.9715, SSR 〈 0.0625 and MSE < 0.0026 for endocarp and R<sup>2</sup> 〉 0.9678, SSR < 0.0755 and MSE < 0.0030 for epicarp). The models proposed in this study achieved the best results with the modified logistic equation (R<sup>2</sup> > 0.9923, MSE 〈 0.0001 and SSR < 0.0013 for endocarp and R<sup>2</sup> 〉 0.9905, MSE < 0.0001 and SSR < 0.0013 for epicarp). In particular, the multilayer perceptron neural network of the machine learning proved to be the optimal choice as it best accounts for the complexity of the drying kinetics of lemons. This neural network model outperformed traditional empirical and semi-empirical models, demonstrating superior performance metrics (R<sup>2</sup> > 0.9979, MSE 〈 0.0002 and SSR < 0.0012 for endocarp and R<sup>2</sup> 〉 0.9989, MSE < 0.0001 and SSR < 0.0008 for epicarp) when tested against validation data.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"51 ","pages":"Pages 136-152"},"PeriodicalIF":0.0,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142702715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-06DOI: 10.1016/j.sajce.2024.11.001
Sayuri Naicker, Neeraj Kuarsingh, Milan Carsky, David Lokhat
Coal continues to be one of the most important primary energy sources and is a major contributor to economic growth, especially in the developing world. Coal fines are an unavoidable by-product of coal extraction. Fine coal is classified as waste when it is too difficult or uneconomical to process and thus disposed of into waste ponds. This leads to environmental liability and loss of valuable high-quality product. There have been numerous studies regarding the efficient processing of fine coal particles, to realise the full economic potential whilst reducing the product's environmental risks. Fluidization is commonly used in the processing of powders or fine particles since it enables continuous powder handling and promotes good particulate mixing. However, the fluidization of fine particles is challenging due to the propensity for channelling, clustering and elutriation. Enhanced fluidization methods have been used to overcome these problems. Several methods that have been employed include electric or magnetic fields, mechanical vibrations, centrifugal forces, introduction of foreign particles, the use of microjets and the use of acoustic sound waves. This study considered the use of in-situ ultrasound as a new alternative enhanced fluidization technique. The overall aim of this research project was to quantitatively determine the improvement in the fluidization behaviour of fine coal particles, under the influence of ultrasound. This new technique helped prevent channel formation, and bed cracking, and improvement in fluidization regimes were observed. Decreasing minimum fluidization velocities were observed for increasing ultrasonic intensities, across various bed heights. The addition of the ultrasound correction factor was able to improve the prediction capability of the model that was developed for the minimum fluidization velocity. The reduction in minimum fluidization velocity shows promise for reduced energy consumption, and increased production throughput, of the fine coal particle processing industry. Overall the novel application of ultrasound improved the quality and operability of the fluidization of fine coal particles.
{"title":"Fluidization of fine coal particles in an ultrasound enhanced gas-solid fluidized bed","authors":"Sayuri Naicker, Neeraj Kuarsingh, Milan Carsky, David Lokhat","doi":"10.1016/j.sajce.2024.11.001","DOIUrl":"10.1016/j.sajce.2024.11.001","url":null,"abstract":"<div><div>Coal continues to be one of the most important primary energy sources and is a major contributor to economic growth, especially in the developing world. Coal fines are an unavoidable by-product of coal extraction. Fine coal is classified as waste when it is too difficult or uneconomical to process and thus disposed of into waste ponds. This leads to environmental liability and loss of valuable high-quality product. There have been numerous studies regarding the efficient processing of fine coal particles, to realise the full economic potential whilst reducing the product's environmental risks. Fluidization is commonly used in the processing of powders or fine particles since it enables continuous powder handling and promotes good particulate mixing. However, the fluidization of fine particles is challenging due to the propensity for channelling, clustering and elutriation. Enhanced fluidization methods have been used to overcome these problems. Several methods that have been employed include electric or magnetic fields, mechanical vibrations, centrifugal forces, introduction of foreign particles, the use of microjets and the use of acoustic sound waves. This study considered the use of in-situ ultrasound as a new alternative enhanced fluidization technique. The overall aim of this research project was to quantitatively determine the improvement in the fluidization behaviour of fine coal particles, under the influence of ultrasound. This new technique helped prevent channel formation, and bed cracking, and improvement in fluidization regimes were observed. Decreasing minimum fluidization velocities were observed for increasing ultrasonic intensities, across various bed heights. The addition of the ultrasound correction factor was able to improve the prediction capability of the model that was developed for the minimum fluidization velocity. The reduction in minimum fluidization velocity shows promise for reduced energy consumption, and increased production throughput, of the fine coal particle processing industry. Overall the novel application of ultrasound improved the quality and operability of the fluidization of fine coal particles.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"51 ","pages":"Pages 78-85"},"PeriodicalIF":0.0,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142657523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-05DOI: 10.1016/j.sajce.2024.11.004
Yvonne Maphosa , Oladayo Adeyi , Daniel Imwansi Ikhu-Omoregbe , Victoria A. Jideani
Due to their inherent thermodynamic instability, emulsions require stabilisers to maintain their integrity and prevent destabilisation. The effect of emulsion components (Bambara groundnut starch-soluble dietary fibre nanocomposite (STASOL), orange oil and water) on the rheological and stability properties of STASOL-stabilised emulsions was optimised. A randomised d-optimal exchange mixture design was used to determine the ratio of STASOL, orange oil and water required for a stable emulsion. The stability of these emulsions was evaluated using the initial mean backscattering index (BSAVO), Turbiscan stability index (TSI) and hysteresis loop area (HLA). The BSAVO (%), TSI and HLA of the emulsions ranged from 50.73 % (14:30:56 STASOL:oil:water) to 70.47 % (20:30:50 STASOL:oil:water), 0.0005 (20:30:50 STASOL:oil:water) to 0.1000 (8:42:50 STASOL:oil:water) and 0.37 Pas-1 (10:32:58 STASOL:oil:water) to 5.69 Pas-1 (20:30:50 STASOL:oil:water), respectively. Emulsions exhibited a direct relationship between STASOL concentration and stability metrics, with the highest stability achieved at 20 % STASOL concentration, 30 % orange oil and 50 % water. An increase in STASOL concentration coupled with a decrease in oil concentration results in a stable emulsion. Numerical optimisation and experimental validation confirmed the effectiveness of the selected formulation, demonstrating STASOL's potential as a natural stabiliser in beverage emulsions and its ability to enhance stability compared to synthetic alternatives.
{"title":"Bambara groundnut starch-soluble dietary fibre nanocomposite stabilised emulsions: Optimisation of emulsion stability and studies on time-dependent rheological properties","authors":"Yvonne Maphosa , Oladayo Adeyi , Daniel Imwansi Ikhu-Omoregbe , Victoria A. Jideani","doi":"10.1016/j.sajce.2024.11.004","DOIUrl":"10.1016/j.sajce.2024.11.004","url":null,"abstract":"<div><div>Due to their inherent thermodynamic instability, emulsions require stabilisers to maintain their integrity and prevent destabilisation. The effect of emulsion components (Bambara groundnut starch-soluble dietary fibre nanocomposite (STASOL), orange oil and water) on the rheological and stability properties of STASOL-stabilised emulsions was optimised. A randomised <span>d</span>-optimal exchange mixture design was used to determine the ratio of STASOL, orange oil and water required for a stable emulsion. The stability of these emulsions was evaluated using the initial mean backscattering index (BS<sub>AVO</sub>), Turbiscan stability index (TSI) and hysteresis loop area (HLA). The BS<sub>AVO</sub> (%), TSI and HLA of the emulsions ranged from 50.73 % (14:30:56 STASOL:oil:water) to 70.47 % (20:30:50 STASOL:oil:water), 0.0005 (20:30:50 STASOL:oil:water) to 0.1000 (8:42:50 STASOL:oil:water) and 0.37 Pas<sup>-1</sup> (10:32:58 STASOL:oil:water) to 5.69 Pas<sup>-1</sup> (20:30:50 STASOL:oil:water), respectively. Emulsions exhibited a direct relationship between STASOL concentration and stability metrics, with the highest stability achieved at 20 % STASOL concentration, 30 % orange oil and 50 % water. An increase in STASOL concentration coupled with a decrease in oil concentration results in a stable emulsion. Numerical optimisation and experimental validation confirmed the effectiveness of the selected formulation, demonstrating STASOL's potential as a natural stabiliser in beverage emulsions and its ability to enhance stability compared to synthetic alternatives.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"51 ","pages":"Pages 86-94"},"PeriodicalIF":0.0,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142657524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-04DOI: 10.1016/j.sajce.2024.11.002
Pati Kemala , Rinaldi Idroes , Khairan Khairan , Muliadi Ramli , Binawati Ginting , Zuchra Helwani , Rifki Aulia , Ghazi Mauer Idroes , Muhammad Yusuf , Rustam Efendi
Green synthesis methods for producing silver nanoparticles (AgNPs) have garnered significant attention for their potential in medical applications. Despite the known potential of Lantana camara in AgNP synthesis, there is a lack of studies investigating its application when grown in extreme geothermal environments, which may influence the properties and efficacy of the synthesized nanoparticles. This research aimed to fabricate AgNPs utilizing aqueous extract from L. camara, a plant growing in an extreme geothermal manifestation area. Another aim of this study is to evaluate their antimicrobial activity. Qualitative and quantitative phytochemical analyses of the plant's leaves were also conducted. Reaction optimization was performed using response surface methodology (RSM), employing a central composite design (CCD) approach. The characterization of AgNPs involved UV–vis spectroscopy, FTIR, SEM-EDX, and PSA. The antimicrobial testing was conducted against Gram-positive bacterium (S. aureus), Gram-negative bacterium (E. coli), and the fungus (C. albicans). The phytochemicals analysis revealed that the L. camara leaf extract contains flavonoids, phenolics, saponins, tannins, and steroids, lacking alkaloids and terpenoids, with total phenolic and flavonoid contents of 11.94 mg (GAE/g) and 6.70 mg (QE/g), respectively. The AgNPs exhibited a spherical shape with a surface plasmon resonance (SPR) peak at a wavelength of 417 nm, and the smallest particle size measured was 44 nm. Based on FTIR analysis, AgNPs have functional groups such as OH, NH, CC, and CH that were identified as groups involved in the reduction of Ag+ to Ag0 during the green synthesis of AgNPs. The AgNPs demonstrated the lowest antifungal activity against C. albicans. In summary, the aqueous leaf extract of L. camara from geothermal manifestation areas can serve as a bioreductant for AgNPs, exhibiting higher antibacterial activity against Gram-positive bacteria compared to Gram-negative ones.
{"title":"Eco-friendly synthesis of silver nanoparticles: Enhancing optimization reaction, characterization, and antimicrobial properties with Lantana camara from geothermal area","authors":"Pati Kemala , Rinaldi Idroes , Khairan Khairan , Muliadi Ramli , Binawati Ginting , Zuchra Helwani , Rifki Aulia , Ghazi Mauer Idroes , Muhammad Yusuf , Rustam Efendi","doi":"10.1016/j.sajce.2024.11.002","DOIUrl":"10.1016/j.sajce.2024.11.002","url":null,"abstract":"<div><div>Green synthesis methods for producing silver nanoparticles (AgNPs) have garnered significant attention for their potential in medical applications. Despite the known potential of <em>Lantana camara</em> in AgNP synthesis, there is a lack of studies investigating its application when grown in extreme geothermal environments, which may influence the properties and efficacy of the synthesized nanoparticles. This research aimed to fabricate AgNPs utilizing aqueous extract from <em>L. camara</em>, a plant growing in an extreme geothermal manifestation area. Another aim of this study is to evaluate their antimicrobial activity. Qualitative and quantitative phytochemical analyses of the plant's leaves were also conducted. Reaction optimization was performed using response surface methodology (RSM), employing a central composite design (CCD) approach. The characterization of AgNPs involved UV–vis spectroscopy, FTIR, SEM-EDX, and PSA. The antimicrobial testing was conducted against Gram-positive bacterium (<em>S. aureus</em>), Gram-negative bacterium (<em>E. coli</em>), and the fungus (<em>C. albicans</em>). The phytochemicals analysis revealed that the <em>L. camara</em> leaf extract contains flavonoids, phenolics, saponins, tannins, and steroids, lacking alkaloids and terpenoids, with total phenolic and flavonoid contents of 11.94 mg (GAE/g) and 6.70 mg (QE/g), respectively. The AgNPs exhibited a spherical shape with a surface plasmon resonance (SPR) peak at a wavelength of 417 nm, and the smallest particle size measured was 44 nm. Based on FTIR analysis, AgNPs have functional groups such as <img>OH, <img>NH, C<img>C, and C<img>H that were identified as groups involved in the reduction of Ag<sup>+</sup> to Ag<sup>0</sup> during the green synthesis of AgNPs. The AgNPs demonstrated the lowest antifungal activity against <em>C. albicans</em>. In summary, the aqueous leaf extract of <em>L. camara</em> from geothermal manifestation areas can serve as a bioreductant for AgNPs, exhibiting higher antibacterial activity against Gram-positive bacteria compared to Gram-negative ones.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"51 ","pages":"Pages 57-67"},"PeriodicalIF":0.0,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142657521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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