Pub Date : 2023-09-15DOI: 10.31276/vjste.65(3).08-13
Nhu Cuong Nguyen, Bao Anh Hoang, Trung Kien Do, Thanh Tung Bui, Duc Trinh Chu, Quang Loc Do
A passive wireless sensor system integrated with capacitive fluidic flow detection is proposed and developed based on the printed circuit board (PCB) technique. The capacitive sensing structure consists of PCB-based electrodes enclosing an insulating pipe that contains the fluidic flow of interest. The conductivity of the fluidic flow and the appearance of foreign objects within the flow can be determined by analysing the resonant frequency of the detection path in the proposed system. Experimental results demonstrate that the resonant frequency increases according to the increase in electrical conductivity of the fluidic flow. In ad-dition, the sensing performance is also confirmed by the detection of sizes and electrical conductivities of NaCl droplets passing through the detection zone. Furthermore, this work indirectly verifies the effectiveness and feasibility of the integration of passive wireless sensing technique into the fluidic flow detector by using the PCB fabrication technique and demonstrates great potential for use in various applications in biomedical and chemical fields, especially in biomedical applications.
{"title":"Development of a PCB-based passive capacitive sensor for fluidic flow detection","authors":"Nhu Cuong Nguyen, Bao Anh Hoang, Trung Kien Do, Thanh Tung Bui, Duc Trinh Chu, Quang Loc Do","doi":"10.31276/vjste.65(3).08-13","DOIUrl":"https://doi.org/10.31276/vjste.65(3).08-13","url":null,"abstract":"A passive wireless sensor system integrated with capacitive fluidic flow detection is proposed and developed based on the printed circuit board (PCB) technique. The capacitive sensing structure consists of PCB-based electrodes enclosing an insulating pipe that contains the fluidic flow of interest. The conductivity of the fluidic flow and the appearance of foreign objects within the flow can be determined by analysing the resonant frequency of the detection path in the proposed system. Experimental results demonstrate that the resonant frequency increases according to the increase in electrical conductivity of the fluidic flow. In ad-dition, the sensing performance is also confirmed by the detection of sizes and electrical conductivities of NaCl droplets passing through the detection zone. Furthermore, this work indirectly verifies the effectiveness and feasibility of the integration of passive wireless sensing technique into the fluidic flow detector by using the PCB fabrication technique and demonstrates great potential for use in various applications in biomedical and chemical fields, especially in biomedical applications.","PeriodicalId":23548,"journal":{"name":"Vietnam Journal of Science, Technology and Engineering","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135395383","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 : 2023-09-15DOI: 10.31276/vjste.65(3).91-96
Thi Van Anh Mai, Kim Loan Nguyen, Dinh Trien Dang, Thi Xuan Sam Nguyen, Thanh Hang Nguyen
This study explored the growth and fermentation capabilities of four distinct yeast strains, including Saccharomyces cerevisiae var. boulardii CNCM I-745, S. cerevisiae 7012, S. cerevisiae 7028, and S. cerevisiae var. diastaticus BE-134, with the aim of identifying the most suitable strain for the production of a fermented beverage from soybean residue hydrolysate (SRH). The results were as follows: S. cerevisiae 7012 exhibited the most efficient fermentation, with residual sugar content of 2.16 g/100 ml, an ethanol concentration of 1.39% v/v, and a favourable aroma, receiving a sensory score of 4.3/5 points. Within this sensory profile, the aromatic compound 2-phenylethanol was found to be the predominant component. Additionally, S. cerevisiae var. boulardii CNCM I-745 demonstrated superior biomass production ability, achieving a cell density of 7.71 log CFU/ml after 48 hours of fermentation solution also showed the highest antioxidant activity, equivalent to 1.63 mg of ascorbic acid per 100 ml. Consequently, these two yeast strains were selected for combined use in fermentation to leverage the probiotic characteristics of S. cerevisiae var. boulardiiCNCM I-745 and the flavouring capacity of S. cerevisiae 7012 in creating fermented beverages from SRH.
本研究探讨了4株不同酵母菌的生长和发酵能力，包括酿酒酵母blardii var. CNCM I-745、酿酒酵母S. cerevisiae var. 7012、酿酒酵母S. cerevisiae var. disastaticus BE-134，目的是确定最适合用大豆渣水解物生产发酵饮料的菌株。结果表明:酿酒酵母7012发酵效率最高，残糖含量为2.16 g/100 ml，乙醇浓度为1.39% v/v，香气良好，感官评分为4.3/5分。在这个感官剖面中，芳香族化合物2-苯乙醇被发现是主要成分。此外，酿酒酵母blardii品种CNCM I-745表现出优异的生物质生产能力，发酵液在48小时后达到7.71 log CFU/ml的细胞密度，也显示出最高的抗氧化活性，相当于每100 ml产生1.63 mg抗坏血酸。选择这两种酵母菌菌株进行联合发酵，利用酿酒酵母变种boulardiiCNCM I-745的益生菌特性和酿酒酵母7012的调味能力，以SRH为原料生产发酵饮料。
{"title":"Assessment of growth and fermentation of some yeasts on soybean residue hydrolysate","authors":"Thi Van Anh Mai, Kim Loan Nguyen, Dinh Trien Dang, Thi Xuan Sam Nguyen, Thanh Hang Nguyen","doi":"10.31276/vjste.65(3).91-96","DOIUrl":"https://doi.org/10.31276/vjste.65(3).91-96","url":null,"abstract":"This study explored the growth and fermentation capabilities of four distinct yeast strains, including Saccharomyces cerevisiae var. boulardii CNCM I-745, S. cerevisiae 7012, S. cerevisiae 7028, and S. cerevisiae var. diastaticus BE-134, with the aim of identifying the most suitable strain for the production of a fermented beverage from soybean residue hydrolysate (SRH). The results were as follows: S. cerevisiae 7012 exhibited the most efficient fermentation, with residual sugar content of 2.16 g/100 ml, an ethanol concentration of 1.39% v/v, and a favourable aroma, receiving a sensory score of 4.3/5 points. Within this sensory profile, the aromatic compound 2-phenylethanol was found to be the predominant component. Additionally, S. cerevisiae var. boulardii CNCM I-745 demonstrated superior biomass production ability, achieving a cell density of 7.71 log CFU/ml after 48 hours of fermentation solution also showed the highest antioxidant activity, equivalent to 1.63 mg of ascorbic acid per 100 ml. Consequently, these two yeast strains were selected for combined use in fermentation to leverage the probiotic characteristics of S. cerevisiae var. boulardiiCNCM I-745 and the flavouring capacity of S. cerevisiae 7012 in creating fermented beverages from SRH.","PeriodicalId":23548,"journal":{"name":"Vietnam Journal of Science, Technology and Engineering","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135396063","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 : 2023-09-15DOI: 10.31276/vjste.65(3).85-90
Bui Thanh Tung, Pham Thi Kim Dung, Nguyen Nhu Son, Nguyen Bao Kim, Nguyen Hai Ha, Nguyen Thanh Tra
The epidermal growth factor receptor (EGFR) belongs to the HER/erbB receptor tyrosine kinase (RTK) family, serving as a crucial target for cancer treatment. Anti-EGFR drugs, used as a primary treatment for patients with advanced EGFR gene mutations such as T790M, C797S, and L858R, have shown greater efficacy and safety compared to standard chemotherapy. This study aimed to screen alkaloid compounds with anticancer activity, extracted from the Selleckchem database that inhibit EGFR enzyme activity. The structure of the EGFR receptor was retrieved from the Protein Data Bank, whilst compounds were gathered from the alkaloids library within the Selleckchem database, with their structures downloaded from the PubChem database. Molecular docking was performed using Autodock Vina software. Lipinski’s rule of five was employed to distinguish between compounds with drug-like and non-drug-like properties. The pharmacokinetic parameters of potential compounds were evaluated using the pkCSM tool. Our research indicates that amongst the screened alkaloids, four compounds - peiminine, sanguinarine chloride, dauricine, and irinotecan - are the most promising inhibitors of the EGFR receptor for the treatment of lung cancer. These compounds exhibit high binding affinity for the active sites of EGFR, thus inhibiting its activity. All aforementioned compounds adhere to Lipinski’s rule and possess pharmacokinetic properties (absorption, distribution, metabolism, excretion, and toxicity - ADMET) that render them suitable for development into drugs.
{"title":"In silico screening of alkaloids as potential inhibitors of epidermal growth factor receptor","authors":"Bui Thanh Tung, Pham Thi Kim Dung, Nguyen Nhu Son, Nguyen Bao Kim, Nguyen Hai Ha, Nguyen Thanh Tra","doi":"10.31276/vjste.65(3).85-90","DOIUrl":"https://doi.org/10.31276/vjste.65(3).85-90","url":null,"abstract":"The epidermal growth factor receptor (EGFR) belongs to the HER/erbB receptor tyrosine kinase (RTK) family, serving as a crucial target for cancer treatment. Anti-EGFR drugs, used as a primary treatment for patients with advanced EGFR gene mutations such as T790M, C797S, and L858R, have shown greater efficacy and safety compared to standard chemotherapy. This study aimed to screen alkaloid compounds with anticancer activity, extracted from the Selleckchem database that inhibit EGFR enzyme activity. The structure of the EGFR receptor was retrieved from the Protein Data Bank, whilst compounds were gathered from the alkaloids library within the Selleckchem database, with their structures downloaded from the PubChem database. Molecular docking was performed using Autodock Vina software. Lipinski’s rule of five was employed to distinguish between compounds with drug-like and non-drug-like properties. The pharmacokinetic parameters of potential compounds were evaluated using the pkCSM tool. Our research indicates that amongst the screened alkaloids, four compounds - peiminine, sanguinarine chloride, dauricine, and irinotecan - are the most promising inhibitors of the EGFR receptor for the treatment of lung cancer. These compounds exhibit high binding affinity for the active sites of EGFR, thus inhibiting its activity. All aforementioned compounds adhere to Lipinski’s rule and possess pharmacokinetic properties (absorption, distribution, metabolism, excretion, and toxicity - ADMET) that render them suitable for development into drugs.","PeriodicalId":23548,"journal":{"name":"Vietnam Journal of Science, Technology and Engineering","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135395896","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 : 2023-09-15DOI: 10.31276/vjste.65(3).66-74
Thi Thuy Hang Vu, Ngoc Thang Vu, Thi Tuyet Cham Le, Thi Ngoc Pham
This study determined the most appropriate and earliest soybean harvesting stage and the number of days of postharvest ripening with minimal effects on seed losses and quality when mechanical harvest and threshing were applied. Harvesting stages at four physiological maturities (60, 70, 80, and 90%) and various days of postharvest ripening treatment (1, 2, and 3 days) were applied for two soybean varieties DT12 and DT26. Harvesting at physiological maturity of 90% recorded the highest seed-shattering loss but the least seed damage (<5%) and highest seed quality, followed by a physiological maturity of 80%. There were no significant differences in seed yields between harvesting stages of 80 and 90% maturity. Harvesting soybeans at a physiological maturity of 60 and 70% resulted in no seed losses but a significant reduction in seed quality. To avoid adverse weather, an early harvest stage at a physiological maturity of 80% is suggested. Although postharvest ripening of soybeans for early harvest caused seed shattering losses (2-5%), it was necessary to ensure seed quality. These results indicate effective and practical methods for farmers at small households to use in early mechanical harvesting of soybeans.
{"title":"Soybean yield, seed quality and thresh efficiency by mechanisation at different harvesting stages and postharvest ripening","authors":"Thi Thuy Hang Vu, Ngoc Thang Vu, Thi Tuyet Cham Le, Thi Ngoc Pham","doi":"10.31276/vjste.65(3).66-74","DOIUrl":"https://doi.org/10.31276/vjste.65(3).66-74","url":null,"abstract":"This study determined the most appropriate and earliest soybean harvesting stage and the number of days of postharvest ripening with minimal effects on seed losses and quality when mechanical harvest and threshing were applied. Harvesting stages at four physiological maturities (60, 70, 80, and 90%) and various days of postharvest ripening treatment (1, 2, and 3 days) were applied for two soybean varieties DT12 and DT26. Harvesting at physiological maturity of 90% recorded the highest seed-shattering loss but the least seed damage (<5%) and highest seed quality, followed by a physiological maturity of 80%. There were no significant differences in seed yields between harvesting stages of 80 and 90% maturity. Harvesting soybeans at a physiological maturity of 60 and 70% resulted in no seed losses but a significant reduction in seed quality. To avoid adverse weather, an early harvest stage at a physiological maturity of 80% is suggested. Although postharvest ripening of soybeans for early harvest caused seed shattering losses (2-5%), it was necessary to ensure seed quality. These results indicate effective and practical methods for farmers at small households to use in early mechanical harvesting of soybeans.","PeriodicalId":23548,"journal":{"name":"Vietnam Journal of Science, Technology and Engineering","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135396066","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 : 2023-09-15DOI: 10.31276/vjste.65(3).14-20
Thi Minh Dinh, Khac Khoi Tran, Anh Trung Le, Thi Minh Nguyet Nguyen, Thi Hue Do, Ian Liau
Mentha crispa L. is one of Vietnam’s most precious folk medicines and is also a spice used in many delicious dishes in Vietnam and around the world. The use of Mentha crispa L. leaf extract as a reducing agent for Ag+ ions to synthesize silver nanoparticles is discussed in this paper. Single silver nanospheres were dispersed in biological media and their sizes were controlled in the range of 20-80 nm. Factors affecting particle size and shape such as extract concentration, AgNO3 concentration, reaction time, and temperature were investigated to determine the optimal parameters for particle synthesis. The optical properties, dispersion, crystal structure, morphology, and sizes of silver nanoparticles were investigated through UV-Vis absorption spectroscopy, dynamic light scattering (DLS) measurements, X-ray diffraction, and transmission electron microscopy (TEM). The functional groups on the L.AgNPs were determined by Fourier-transform infrared (FTIR) transmittance spectra. The synthesised silver nanoparticles were used to treat methylene blue (MB) dye, the main component of dye wastewater, based on their photocatalytic properties. The results show that in the presence of L.AgNPs, the photodegradation efficiency of NaBH4 or H2O2 reducing agents is much higher, up to 95% of illumination.
{"title":"Green synthesis of silver nanoparticles using Mentha crispa L. leaf extract for treatment of dye wastewater","authors":"Thi Minh Dinh, Khac Khoi Tran, Anh Trung Le, Thi Minh Nguyet Nguyen, Thi Hue Do, Ian Liau","doi":"10.31276/vjste.65(3).14-20","DOIUrl":"https://doi.org/10.31276/vjste.65(3).14-20","url":null,"abstract":"Mentha crispa L. is one of Vietnam’s most precious folk medicines and is also a spice used in many delicious dishes in Vietnam and around the world. The use of Mentha crispa L. leaf extract as a reducing agent for Ag+ ions to synthesize silver nanoparticles is discussed in this paper. Single silver nanospheres were dispersed in biological media and their sizes were controlled in the range of 20-80 nm. Factors affecting particle size and shape such as extract concentration, AgNO3 concentration, reaction time, and temperature were investigated to determine the optimal parameters for particle synthesis. The optical properties, dispersion, crystal structure, morphology, and sizes of silver nanoparticles were investigated through UV-Vis absorption spectroscopy, dynamic light scattering (DLS) measurements, X-ray diffraction, and transmission electron microscopy (TEM). The functional groups on the L.AgNPs were determined by Fourier-transform infrared (FTIR) transmittance spectra. The synthesised silver nanoparticles were used to treat methylene blue (MB) dye, the main component of dye wastewater, based on their photocatalytic properties. The results show that in the presence of L.AgNPs, the photodegradation efficiency of NaBH4 or H2O2 reducing agents is much higher, up to 95% of illumination.","PeriodicalId":23548,"journal":{"name":"Vietnam Journal of Science, Technology and Engineering","volume":"137 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135395738","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 : 2023-09-15DOI: 10.31276/vjste.65(3).50-58
Van Long Nguyen, Minh Thanh Le, Lan Huong Nguyen
This study successfully developed Co2SnO4@rGO nanocomposites at various composite ratios of Co2SnO4 and rGO using the sol-gel method. These nanocomposites were then used as heterogeneous catalysts to activate PMS in the heterogeneous catalytic oxidation of Co2SnO4@rGO/PMS as well as the hybrid ozonation system O3/Co2SnO4@rGO/PMS to degrade cefalexin (CFX). The physical-chemical characteristics of the fabricated catalysts were evaluated through nitrogen adsorption-deadsorption, SEM images, EDS mapping, and XRD. The catalytic activity of the nanocomposite was investigated in a degradation reaction of CFX from an aqueous solution. Besides this, CFX degradation kinetics were determined by fitting experimental data with a first-order model. The results showed that at the composite ratio of 2-Co2SnO4 and 1-rGO for CFX degradation had the highest efficiency reaching 95.07 and 99.07% for Co2SnO4@rGO/PMS and O3/Co2SnO4@rGO/PMS systems, respectively. The degradation of CFX in the O3/Co2SnO4@rGO/PMS system was higher than that of Co2SnO4@rGO/PMS. The results were due to a remarkable increase in SBET in 2-Co2SnO4@1-rGO compared to both Co2SnO4 and rGO, facilitating a catalytic reaction occurring on the catalyst’s surface. Moreover, the coupling between O3 and Co2SnO4@rGO/PMS generated a synergetic effect leading to the generation of more *SO4- and *OH radicals, which enhanced the CFX degradation rate in the hybrid ozonation system. These primary findings illustrated that the nanocomposite catalyst 2-Co2SnO4@1-rGO was feasible for the activation of PMS in hybrid ozonation to effectively degrade antibiotic residues from wastewater.
{"title":"Synthesising nanocomposite Co2SnO4@rGO for peroximonosulphate activation in a hybrid ozonation system to effectively degrade cefalexin from wastewater","authors":"Van Long Nguyen, Minh Thanh Le, Lan Huong Nguyen","doi":"10.31276/vjste.65(3).50-58","DOIUrl":"https://doi.org/10.31276/vjste.65(3).50-58","url":null,"abstract":"This study successfully developed Co2SnO4@rGO nanocomposites at various composite ratios of Co2SnO4 and rGO using the sol-gel method. These nanocomposites were then used as heterogeneous catalysts to activate PMS in the heterogeneous catalytic oxidation of Co2SnO4@rGO/PMS as well as the hybrid ozonation system O3/Co2SnO4@rGO/PMS to degrade cefalexin (CFX). The physical-chemical characteristics of the fabricated catalysts were evaluated through nitrogen adsorption-deadsorption, SEM images, EDS mapping, and XRD. The catalytic activity of the nanocomposite was investigated in a degradation reaction of CFX from an aqueous solution. Besides this, CFX degradation kinetics were determined by fitting experimental data with a first-order model. The results showed that at the composite ratio of 2-Co2SnO4 and 1-rGO for CFX degradation had the highest efficiency reaching 95.07 and 99.07% for Co2SnO4@rGO/PMS and O3/Co2SnO4@rGO/PMS systems, respectively. The degradation of CFX in the O3/Co2SnO4@rGO/PMS system was higher than that of Co2SnO4@rGO/PMS. The results were due to a remarkable increase in SBET in 2-Co2SnO4@1-rGO compared to both Co2SnO4 and rGO, facilitating a catalytic reaction occurring on the catalyst’s surface. Moreover, the coupling between O3 and Co2SnO4@rGO/PMS generated a synergetic effect leading to the generation of more *SO4- and *OH radicals, which enhanced the CFX degradation rate in the hybrid ozonation system. These primary findings illustrated that the nanocomposite catalyst 2-Co2SnO4@1-rGO was feasible for the activation of PMS in hybrid ozonation to effectively degrade antibiotic residues from wastewater.","PeriodicalId":23548,"journal":{"name":"Vietnam Journal of Science, Technology and Engineering","volume":"241 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135395890","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 : 2021-03-31DOI: 10.31276/VJSTE.63(1).21-29
Hoang-Quan Dinh, Thanh B Nguyen
: Geopolymers are a class of new binder manufactured by activating aluminosilicate source materials in a highly alkaline medium. This binder is considered “environmentally friendly” due to the recycling of industrial waste sources such as fly ash and blast furnace slag. However, in order to be widely used, this binder has to ensure both quality and economic efficiency. This paper focuses on the optimization of the composition of ground granulated blast-furnace slag and fly ash-based geopolymers activated by sodium silicate and sodium hydroxide solutions. Statistical models are developed to predict the compressive strength and cost of 1 ton of binder using Response Surface Methodology (RSM). In this regard, the effects of three principal variables (%Na 2 O, M s and %GGBS) were investigated in which: %Na 2 O - mass ratio of Na 2 O in the alkali-activated solution and total solids; M s mass ratio of SiO 2 and Na 2 O in the activated solution; %GGBS - mass ratio of ground granulated blast-furnace slag (GGBS), and total binder. Quadratic models were proposed to correlate the independent variables for the 28-d compressive strength and cost of 1 ton of binder by using the Central Composite Design (CCD) method. The study reveals that M s has a minor effect on the strength of mortar in comparison with %Na 2 O and %GGBS. The optimized mixture proportions were assessed using the multi-objective optimization technique. The optimal values found were %Na 2 O=5.18%, M s =1.16, and %GGBS=50%, with the goals of maximum compressive strength, the largest amount of fly ash, and reasonable cost for one ton of binder. The experimental results show that the compressive strength of the samples ranged between 62.95-63.54 MPa and were consistent with the optimized results (the variation between the predicted and the experimental results was obtained less than 5%).
地聚合物是一类通过在高碱性介质中活化铝硅酸盐源材料而制成的新型粘合剂。这种粘合剂被认为是“环保的”，因为它可以回收粉煤灰和高炉炉渣等工业废料。然而，为了得到广泛的应用，这种粘合剂必须保证质量和经济效益。本文主要研究了以水玻璃和氢氧化钠溶液为活化剂的磨粒高炉矿渣和粉煤灰基地聚合物的组成优化。利用响应面法(RSM)建立了预测1吨粘结剂抗压强度和成本的统计模型。在这方面，研究了三个主要变量(%Na 2o, M s和%GGBS)的影响，其中:%Na 2o -碱活化溶液中Na 2o与总固体的质量比;活化溶液中sio2与na2o的质量比;%GGBS -粉状高炉矿渣(GGBS)与总粘结剂的质量比。采用中心复合设计(CCD)方法，建立了1吨粘结剂28 d抗压强度与成本自变量的二次模型。研究表明，与% na2o和%GGBS相比，ms对砂浆强度的影响较小。采用多目标优化技术对优化后的混合比例进行了评价。以最大抗压强度、最大粉煤灰掺量和合理的吨粘结剂成本为目标，优选出最佳掺量为% na2o =5.18%， M s =1.16， %GGBS=50%。试验结果表明，试样的抗压强度范围在62.95 ~ 63.54 MPa之间，与优化结果基本一致(预测结果与试验结果相差小于5%)。
{"title":"Composition of ground granulated blast-furnace slag and fly ash-based geopolymer activated by sodium silicate and sodium hydroxide solution: multi-response optimization using Response Surface Methodology","authors":"Hoang-Quan Dinh, Thanh B Nguyen","doi":"10.31276/VJSTE.63(1).21-29","DOIUrl":"https://doi.org/10.31276/VJSTE.63(1).21-29","url":null,"abstract":": Geopolymers are a class of new binder manufactured by activating aluminosilicate source materials in a highly alkaline medium. This binder is considered “environmentally friendly” due to the recycling of industrial waste sources such as fly ash and blast furnace slag. However, in order to be widely used, this binder has to ensure both quality and economic efficiency. This paper focuses on the optimization of the composition of ground granulated blast-furnace slag and fly ash-based geopolymers activated by sodium silicate and sodium hydroxide solutions. Statistical models are developed to predict the compressive strength and cost of 1 ton of binder using Response Surface Methodology (RSM). In this regard, the effects of three principal variables (%Na 2 O, M s and %GGBS) were investigated in which: %Na 2 O - mass ratio of Na 2 O in the alkali-activated solution and total solids; M s mass ratio of SiO 2 and Na 2 O in the activated solution; %GGBS - mass ratio of ground granulated blast-furnace slag (GGBS), and total binder. Quadratic models were proposed to correlate the independent variables for the 28-d compressive strength and cost of 1 ton of binder by using the Central Composite Design (CCD) method. The study reveals that M s has a minor effect on the strength of mortar in comparison with %Na 2 O and %GGBS. The optimized mixture proportions were assessed using the multi-objective optimization technique. The optimal values found were %Na 2 O=5.18%, M s =1.16, and %GGBS=50%, with the goals of maximum compressive strength, the largest amount of fly ash, and reasonable cost for one ton of binder. The experimental results show that the compressive strength of the samples ranged between 62.95-63.54 MPa and were consistent with the optimized results (the variation between the predicted and the experimental results was obtained less than 5%).","PeriodicalId":23548,"journal":{"name":"Vietnam Journal of Science, Technology and Engineering","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74587097","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 : 2021-03-31DOI: 10.31276/VJSTE.63(1).07-14
Q. M. Do, Ngoc Tri Huynh Nguyen, Thi Hong Ngu Huynh, H. L. Pham, T. T. Ho, Do Trung Kien Kieu, N. Huynh
: Glass ionomer cement (GIC) is a particular type of cement used in dentistry. One of the most critical properties of GIC is the ability to release fluoride, which can prevent recurrent tooth decay. This study simultaneously investigated the release of fluoride, the compressive strength, and the apparent density of three GICs in deionized water (DW) and artificial saliva (AS) environments. GICs with 3 different types of glass powders were used to study. Powder B (the original) was the glass powder based on the SiO 2 -Al 2 O 3 CaF 2 -AlPO 4 -Na 3 AlF 6 system, powder HA5 was powder B supplemented with 5 wt. % hydroxyapatite powder (HA), and powder Si 2 was powder B surface-treated with 2 wt. % silane JH-S69. The results of this study showed the amount of fluoride ion (F - ) released during 28 days in AS was lower in comparison to the DW environment, and the rate slowed down significantly after 1 d. The F - release rate at 1-d age tended to be high as the compression strength was low. In AS, the powder supplemented with 5 wt.% HA improved the compressive strength and the cumulative amount of F - released by the GIC. After 28 d, the F - release of the GIC materials were able to be recharged in a NaF solution with 1,018 ppm F - concentration for 3 min and further fluoride ions were released in both the DW and AS environments.
{"title":"Study on the fluoride-releasing ability of dental GICmaterials in deionized water and artificial saliva environments","authors":"Q. M. Do, Ngoc Tri Huynh Nguyen, Thi Hong Ngu Huynh, H. L. Pham, T. T. Ho, Do Trung Kien Kieu, N. Huynh","doi":"10.31276/VJSTE.63(1).07-14","DOIUrl":"https://doi.org/10.31276/VJSTE.63(1).07-14","url":null,"abstract":": Glass ionomer cement (GIC) is a particular type of cement used in dentistry. One of the most critical properties of GIC is the ability to release fluoride, which can prevent recurrent tooth decay. This study simultaneously investigated the release of fluoride, the compressive strength, and the apparent density of three GICs in deionized water (DW) and artificial saliva (AS) environments. GICs with 3 different types of glass powders were used to study. Powder B (the original) was the glass powder based on the SiO 2 -Al 2 O 3 CaF 2 -AlPO 4 -Na 3 AlF 6 system, powder HA5 was powder B supplemented with 5 wt. % hydroxyapatite powder (HA), and powder Si 2 was powder B surface-treated with 2 wt. % silane JH-S69. The results of this study showed the amount of fluoride ion (F - ) released during 28 days in AS was lower in comparison to the DW environment, and the rate slowed down significantly after 1 d. The F - release rate at 1-d age tended to be high as the compression strength was low. In AS, the powder supplemented with 5 wt.% HA improved the compressive strength and the cumulative amount of F - released by the GIC. After 28 d, the F - release of the GIC materials were able to be recharged in a NaF solution with 1,018 ppm F - concentration for 3 min and further fluoride ions were released in both the DW and AS environments.","PeriodicalId":23548,"journal":{"name":"Vietnam Journal of Science, Technology and Engineering","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81920020","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 : 2021-03-31DOI: 10.31276/VJSTE.63(1).47-53
Le Nhat Minh, Vo Trong Nhan, Thi Thao Do, T. Huong, Lee Vien, Phung Thi Kim Hue
Despite abundant ongoing research efforts, cancer remains one of the most challenging diseases to treat globally. Due to the heterogeneous nature of cancer, one of the major clinical challenges is the ability of cancer to develop resistance in therapeutic development. It has been hypothesized that cancer stem cells (CSCs) are the cause of this resistance and targeting their treatment will lead to tumour regression [1]. CSCs accounts for a small percentage of tumours and can regenerate into various tumorous cell types causing the growth and expansion of malignancy. CSCs present drug-resistant abilities and overcome radiotherapy. Then, the survival of cancer stem cells after treatment allows the tumour to recur and spread throughout the body. Therefore, CSCs are considered a promising target for research and discovery of more effective anticancer drugs or therapies. CSCs are characterized by several specific surface markers. A pentaspan transmembrane glycoprotein, CD133, has been suggested to mark cancer stem cells in various tumour types. However, the accuracy of CD133 as a cancer stem cell biomarker has been highly controversial [1]. CD133 is known as prominin-1, a transmembrane glycoprotein, and is a common surface marker for CSCs, which are inside of various cancer tumours. This transmembrane CD133 glycoprotein includes an extracellular N-terminus and an intracellular C-terminus, which have been used as an efficacious typical surface antigen to detect and to isolate CSCs [2]. As recognized, traditionally nanotechnological biomedicine heighten pharmaceutical properties and reduce the systemic toxicity of chemotherapy through selectively targeting and effectively transferring anticancer drugs to tumours. Nanoparticles usually improve the therapeutic index of the chemotherapeutic drugs that are enveloped inside or combined with the nanoparticle surfaces. For Study on cancer stem cell labeling and inhibition efficiency of LV3 nanocomplex in vitro
{"title":"Study on cancer stem cell labeling and inhibition efficiency of LV3 nanocomplex in vitro","authors":"Le Nhat Minh, Vo Trong Nhan, Thi Thao Do, T. Huong, Lee Vien, Phung Thi Kim Hue","doi":"10.31276/VJSTE.63(1).47-53","DOIUrl":"https://doi.org/10.31276/VJSTE.63(1).47-53","url":null,"abstract":"Despite abundant ongoing research efforts, cancer remains one of the most challenging diseases to treat globally. Due to the heterogeneous nature of cancer, one of the major clinical challenges is the ability of cancer to develop resistance in therapeutic development. It has been hypothesized that cancer stem cells (CSCs) are the cause of this resistance and targeting their treatment will lead to tumour regression [1]. CSCs accounts for a small percentage of tumours and can regenerate into various tumorous cell types causing the growth and expansion of malignancy. CSCs present drug-resistant abilities and overcome radiotherapy. Then, the survival of cancer stem cells after treatment allows the tumour to recur and spread throughout the body. Therefore, CSCs are considered a promising target for research and discovery of more effective anticancer drugs or therapies. CSCs are characterized by several specific surface markers. A pentaspan transmembrane glycoprotein, CD133, has been suggested to mark cancer stem cells in various tumour types. However, the accuracy of CD133 as a cancer stem cell biomarker has been highly controversial [1]. CD133 is known as prominin-1, a transmembrane glycoprotein, and is a common surface marker for CSCs, which are inside of various cancer tumours. This transmembrane CD133 glycoprotein includes an extracellular N-terminus and an intracellular C-terminus, which have been used as an efficacious typical surface antigen to detect and to isolate CSCs [2]. As recognized, traditionally nanotechnological biomedicine heighten pharmaceutical properties and reduce the systemic toxicity of chemotherapy through selectively targeting and effectively transferring anticancer drugs to tumours. Nanoparticles usually improve the therapeutic index of the chemotherapeutic drugs that are enveloped inside or combined with the nanoparticle surfaces. For Study on cancer stem cell labeling and inhibition efficiency of LV3 nanocomplex in vitro","PeriodicalId":23548,"journal":{"name":"Vietnam Journal of Science, Technology and Engineering","volume":"54 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75896138","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 : 2021-03-31DOI: 10.31276/VJSTE.63(1).03-06
D. Thien, Nguyễn Thị Bích Thuyền, T. Quyen, N. Chiếm, V. Thuy, P. Viet
a microwave-assisted technique can be used as a green energy and to save time for synthesis of HA. Microwave irradiation is a simple method for the synthesis of HA due to its high reaction rate, time savings, rapid heating, and green energy 15]. In this process, the size and shape of HA molecules can be controlled by the synthesis parameters 15]. The purpose of this work is to prepare nanorod HA by microwave-assisted synthesis with the use of phosphoric acid, with eggshells serving as the calcium source. Furthermore, HA is a potential material for metal ion adsorption. Abstract: Nanorod hydroxyapatite (HA) was synthesised from eggshells by using a microwave-assisted technique. With eggshells and phosphoric acid as precursors, the reaction was carried out in a microwave with an irradiation power of 800 W for 45 minutes. The effects of Ca/P molar ratios and the power of microwaves were investigated. The obtained hydroxyapatite was characterised by X-ray diffraction (XRD), scanning electron microscope (SEM), and infrared spectroscopy (IR). The nanorod-like HA samples were 20-40 nm in diameter and 130-180 nm in length.
{"title":"Microwave-assisted synthesis of nanorod hydroxyapatite from eggshells","authors":"D. Thien, Nguyễn Thị Bích Thuyền, T. Quyen, N. Chiếm, V. Thuy, P. Viet","doi":"10.31276/VJSTE.63(1).03-06","DOIUrl":"https://doi.org/10.31276/VJSTE.63(1).03-06","url":null,"abstract":"a microwave-assisted technique can be used as a green energy and to save time for synthesis of HA. Microwave irradiation is a simple method for the synthesis of HA due to its high reaction rate, time savings, rapid heating, and green energy 15]. In this process, the size and shape of HA molecules can be controlled by the synthesis parameters 15]. The purpose of this work is to prepare nanorod HA by microwave-assisted synthesis with the use of phosphoric acid, with eggshells serving as the calcium source. Furthermore, HA is a potential material for metal ion adsorption. Abstract: Nanorod hydroxyapatite (HA) was synthesised from eggshells by using a microwave-assisted technique. With eggshells and phosphoric acid as precursors, the reaction was carried out in a microwave with an irradiation power of 800 W for 45 minutes. The effects of Ca/P molar ratios and the power of microwaves were investigated. The obtained hydroxyapatite was characterised by X-ray diffraction (XRD), scanning electron microscope (SEM), and infrared spectroscopy (IR). The nanorod-like HA samples were 20-40 nm in diameter and 130-180 nm in length.","PeriodicalId":23548,"journal":{"name":"Vietnam Journal of Science, Technology and Engineering","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90532482","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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