Pub Date : 2023-08-02DOI: 10.15625/2525-2518/16452
Trinh Dinh Minh Viet, N. Tuan, Minh, Nguyen Thi, Phương Thảo, Phung Linh Phuong, T. Tuyen
Blast-furnace slag (BFS) is enormously generated each year and has been considered as hazardous solid waste which is posing a significant pressure on waste treatment in terms of storage and transportation. This study aims to recycle BFS as a material for ammonium adsorption from an aqueous solution. Natural-state BFS and acidic-modified by using HNO3 at various concentration of 0.5M, 1M, and 3M (A-BFS1, A-BFS2, and A-BFS3) was examined. The surface characteristics of the materials were examined by BET analysis and Scanning Electron Microscope. The adsorption of ammonium on the BFS materials was conducted in batch mode at various conditions of contact time, pH level, adsorbent dosage, and initial concentration of ammonium. The results indicated that the HNO3 modification exhibited pore creations and surface enhancement as the A-BFS3 has 25.7 times larger surface area and 10.3 times pore size improvement. The A-BFS3 showed good ammonium adsorption capacity compared to other materials, which is 1.81 mg/g at the optimum conditions of pH 6, contact time of 120 minutes, and dosage of 0.5 g in 50 mL of 20 mg/L ammonium solution. Langmuir and Freundlich adsorption isotherm models of the A-BFS3 material showed a relatively good correlation with R2 values of 0.999 and 0.9625, respectively.
{"title":"Study on recycle of granulated blast-furnace slag as an adsorbent for ammonium remediation in wastewater","authors":"Trinh Dinh Minh Viet, N. Tuan, Minh, Nguyen Thi, Phương Thảo, Phung Linh Phuong, T. Tuyen","doi":"10.15625/2525-2518/16452","DOIUrl":"https://doi.org/10.15625/2525-2518/16452","url":null,"abstract":"Blast-furnace slag (BFS) is enormously generated each year and has been considered as hazardous solid waste which is posing a significant pressure on waste treatment in terms of storage and transportation. This study aims to recycle BFS as a material for ammonium adsorption from an aqueous solution. Natural-state BFS and acidic-modified by using HNO3 at various concentration of 0.5M, 1M, and 3M (A-BFS1, A-BFS2, and A-BFS3) was examined. The surface characteristics of the materials were examined by BET analysis and Scanning Electron Microscope. The adsorption of ammonium on the BFS materials was conducted in batch mode at various conditions of contact time, pH level, adsorbent dosage, and initial concentration of ammonium. The results indicated that the HNO3 modification exhibited pore creations and surface enhancement as the A-BFS3 has 25.7 times larger surface area and 10.3 times pore size improvement. The A-BFS3 showed good ammonium adsorption capacity compared to other materials, which is 1.81 mg/g at the optimum conditions of pH 6, contact time of 120 minutes, and dosage of 0.5 g in 50 mL of 20 mg/L ammonium solution. Langmuir and Freundlich adsorption isotherm models of the A-BFS3 material showed a relatively good correlation with R2 values of 0.999 and 0.9625, respectively.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87419854","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 : 2023-08-02DOI: 10.15625/2525-2518/17303
Nguyen Thi Hai Ha, Nguyen Van Tuyen, N. Son, L. Anh, Nguyen Thi Thuy Linh, Pham Minh Quan, Le Thi Hai Yen, Nguyen Van Du
Alocasia odora is a common plant species in Viet Nam. A phytochemical investigation of the ethyl acetate extract (EtOAc) of A. odora rhizomes collected in Tuyen Quang province led to the isolation and determination of five compounds, including three alkaloids, alocasin A (1), hyrtiosin B (2), hyrtiosulawesine (3), one mono-phenol, p-hydroxycinamic acid (4), and one fatty acid, myristic acid (5). The chemical structures of those compounds were determined by 1D and 2D-NMR spectroscopic, MS data and compared with those reported in the literature. Antimicrobial activity against microorganisms was evaluated using the broth microdilution method, showing that alkaloids 1 - 3 exhibited antimicrobial activity against reference strains with MIC values ranging from 8 µg/mL to 128 µg/mL, in which compound 1 was the most active with MIC values calculated between 8 µg/mL and 32 µg/mL. Compound 4-5 did not display antimicrobial activity at the studied concentration, MIC > 128 µg/mL. This is the first time the antimicrobial effect of A. odora has been reported.
{"title":"Phytochemical investigation and antimicrobial activity from rhizomes of alocasia odora K. Koch","authors":"Nguyen Thi Hai Ha, Nguyen Van Tuyen, N. Son, L. Anh, Nguyen Thi Thuy Linh, Pham Minh Quan, Le Thi Hai Yen, Nguyen Van Du","doi":"10.15625/2525-2518/17303","DOIUrl":"https://doi.org/10.15625/2525-2518/17303","url":null,"abstract":"Alocasia odora is a common plant species in Viet Nam. A phytochemical investigation of the ethyl acetate extract (EtOAc) of A. odora rhizomes collected in Tuyen Quang province led to the isolation and determination of five compounds, including three alkaloids, alocasin A (1), hyrtiosin B (2), hyrtiosulawesine (3), one mono-phenol, p-hydroxycinamic acid (4), and one fatty acid, myristic acid (5). The chemical structures of those compounds were determined by 1D and 2D-NMR spectroscopic, MS data and compared with those reported in the literature. Antimicrobial activity against microorganisms was evaluated using the broth microdilution method, showing that alkaloids 1 - 3 exhibited antimicrobial activity against reference strains with MIC values ranging from 8 µg/mL to 128 µg/mL, in which compound 1 was the most active with MIC values calculated between 8 µg/mL and 32 µg/mL. Compound 4-5 did not display antimicrobial activity at the studied concentration, MIC > 128 µg/mL. This is the first time the antimicrobial effect of A. odora has been reported.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139352059","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 : 2023-08-01DOI: 10.15625/2525-2518/16418
N. Thanh, N. Dong, Thi Thu, Trang, N. Việt, Hoang Pham Tuan, Pham Thi Linh, Yen
In this study, a simple, selective, and accurate analysis method was developed for the simultaneous determination of anti-inflammatory drugs (paracetamol and diclofenac) existing inlet and outlet of the wastewater treatment system. This method used solid-phase extraction (SPE) and reversed-phase high-performance liquid chromatography with a photodiode array detector (HPLC-PDA). Separation was performed using an HSR C18 column (250 mm × 4.6 mm; 5 µm) with a mobile phase consisting of acetonitrile: sodium dihydrogen orthophosphate in the ratio 60:40 v/v. The flow rate was 1 ml/min, and PDA was detected at 243 nm with paracetamol and 276 nm with diclofenac. The duration of paracetamol and diclofenac was 2.39 and 4.39 min, respectively. The developed method was validated in terms of accuracy, precision, and linearity for two drugs found in the range of 0.01 - 1 µg/ml, and 0.02 - 1 µg/ml for paracetamol, and diclofenac, respectively. The limits of detection for paracetamol and diclofenac were 0.003 µg/ml and 0.006 µg/ml, respectively, whereas the limits of quantification were 0.01 µg /ml and 0.02 µg/ml, respectively. The recoveries for paracetamol and diclofenac were greater than 95 %. The described method also has been applied to determine paracetamol and diclofenac simultaneously in the wastewater of the treatment system.
{"title":"Simultaneous determination of paracetamol and diclofenac in wastewater by high-performance liquid chromatography method","authors":"N. Thanh, N. Dong, Thi Thu, Trang, N. Việt, Hoang Pham Tuan, Pham Thi Linh, Yen","doi":"10.15625/2525-2518/16418","DOIUrl":"https://doi.org/10.15625/2525-2518/16418","url":null,"abstract":"In this study, a simple, selective, and accurate analysis method was developed for the simultaneous determination of anti-inflammatory drugs (paracetamol and diclofenac) existing inlet and outlet of the wastewater treatment system. This method used solid-phase extraction (SPE) and reversed-phase high-performance liquid chromatography with a photodiode array detector (HPLC-PDA). Separation was performed using an HSR C18 column (250 mm × 4.6 mm; 5 µm) with a mobile phase consisting of acetonitrile: sodium dihydrogen orthophosphate in the ratio 60:40 v/v. The flow rate was 1 ml/min, and PDA was detected at 243 nm with paracetamol and 276 nm with diclofenac. The duration of paracetamol and diclofenac was 2.39 and 4.39 min, respectively. The developed method was validated in terms of accuracy, precision, and linearity for two drugs found in the range of 0.01 - 1 µg/ml, and 0.02 - 1 µg/ml for paracetamol, and diclofenac, respectively. The limits of detection for paracetamol and diclofenac were 0.003 µg/ml and 0.006 µg/ml, respectively, whereas the limits of quantification were 0.01 µg /ml and 0.02 µg/ml, respectively. The recoveries for paracetamol and diclofenac were greater than 95 %. The described method also has been applied to determine paracetamol and diclofenac simultaneously in the wastewater of the treatment system.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"52 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81156229","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 : 2023-08-01DOI: 10.15625/2525-2518/16686
Nguyen Thuy Chinh, Dao Phi Hung, Nguyen Xuan Thai, Nguyen Anh Hiep, T. Hoang
Water-borne acrylic resin has attracted much attention thanks to its environmetally friendly, high weather stability, good mechanical properties, high toughness. It is widely used in coatings, ships, bridges, locomotives, etc. In this work, the effect of ZrO2 nanoparticles content which were modified with (3-glycidyloxypropyl)triethoxysilane (GPTS) on the weather resistance of the acrylic emulsion coatings was tested and discussed. The change in functional groups, carbonyl index value, gloss, weight and morphology of the coatings before and after accelerated weathering test was investigated. The obtained results showed that the GPTS modified ZrO2 nanoparticle content had a significant effect on the characteristics of acrylic emulsion coatings. The 2 wt.% content of GPTS modified ZrO2 nanoparticles exhibited a highest efficiency in improvement of weather resistance of acrylic emulsion coatings. This result indicated that acrylic emulsion coating filled by the GPTS modified ZrO2 nanoparticles is potential for outdoor applications.
{"title":"Assessment of influence of silane modified zirconia nanoparticle content on weather resistance of water-borne acrylic coating","authors":"Nguyen Thuy Chinh, Dao Phi Hung, Nguyen Xuan Thai, Nguyen Anh Hiep, T. Hoang","doi":"10.15625/2525-2518/16686","DOIUrl":"https://doi.org/10.15625/2525-2518/16686","url":null,"abstract":"Water-borne acrylic resin has attracted much attention thanks to its environmetally friendly, high weather stability, good mechanical properties, high toughness. It is widely used in coatings, ships, bridges, locomotives, etc. In this work, the effect of ZrO2 nanoparticles content which were modified with (3-glycidyloxypropyl)triethoxysilane (GPTS) on the weather resistance of the acrylic emulsion coatings was tested and discussed. The change in functional groups, carbonyl index value, gloss, weight and morphology of the coatings before and after accelerated weathering test was investigated. The obtained results showed that the GPTS modified ZrO2 nanoparticle content had a significant effect on the characteristics of acrylic emulsion coatings. The 2 wt.% content of GPTS modified ZrO2 nanoparticles exhibited a highest efficiency in improvement of weather resistance of acrylic emulsion coatings. This result indicated that acrylic emulsion coating filled by the GPTS modified ZrO2 nanoparticles is potential for outdoor applications.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"80 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139352345","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 : 2023-08-01DOI: 10.15625/2525-2518/17507
Vu Thi, An Ninh
The novelty of the present work is to study the simultaneous influence of porosities and partial Pasternak foundation support on dynamics of functionally graded (FG) beams carrying a moving load. The beams are made from an open-cell steel foam with symmetric and asymmetric porosity distributions in the thickness direction. Based on a refined third-order shear deformation theory, a two-node beam element with ten degrees of freedom is derived and employed to construct the discretized equation of motion for the beams. Dynamic characteristics, including the time histories for mid-span deflection, dynamic magnification factor (DMF) and the stress distribution, are computed with the aid of the Newmark method. The numerical result reveals that the foundation supporting length has an important role on the dynamics of the beams, and the dependence of the DMF upon the porosity coefficient is governed by the foundation supporting length. It is also found that the asymmetric porosity distribution has more impact on the dynamic response of the beams than the symmetric one does, and the difference between the DMFs obtained from the two porosity distributions is more significant for the beam with a higher porosity coefficient. The effects of the porosities, the foundation support and the moving load velocity on the dynamic behavior of the beams are examined in detail and highlighted
{"title":"Dynamics of functionally graded beams carrying a moving load with influence of porosities and partial foundation support","authors":"Vu Thi, An Ninh","doi":"10.15625/2525-2518/17507","DOIUrl":"https://doi.org/10.15625/2525-2518/17507","url":null,"abstract":"The novelty of the present work is to study the simultaneous influence of porosities and partial Pasternak foundation support on dynamics of functionally graded (FG) beams carrying a moving load. The beams are made from an open-cell steel foam with symmetric and asymmetric porosity distributions in the thickness direction. Based on a refined third-order shear deformation theory, a two-node beam element with ten degrees of freedom is derived and employed to construct the discretized equation of motion for the beams. Dynamic characteristics, including the time histories for mid-span deflection, dynamic magnification factor (DMF) and the stress distribution, are computed with the aid of the Newmark method. The numerical result reveals that the foundation supporting length has an important role on the dynamics of the beams, and the dependence of the DMF upon the porosity coefficient is governed by the foundation supporting length. It is also found that the asymmetric porosity distribution has more impact on the dynamic response of the beams than the symmetric one does, and the difference between the DMFs obtained from the two porosity distributions is more significant for the beam with a higher porosity coefficient. The effects of the porosities, the foundation support and the moving load velocity on the dynamic behavior of the beams are examined in detail and highlighted","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"434 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83612649","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 : 2023-06-30DOI: 10.15625/2525-2518/18131
Nguyen Mung Xuan, Lanh Le Thanh, The Mich Nguyen
Quadrotors have gained popularity in a wide range of applications. In this paper, a new approach for solving the tracking control problem of quadrotors with full-state constraints is presented. The proposed method involves a backstepping control scheme integrated with a fast finite-time filter. First, necessary state transformations are performed to support the design of the finite-time filter and controller. Next, the controller is formulated based on the backstepping technique. All the state constraints are taken into consideration in the controller. However, it is well-known that the backstepping control design can lead to the “explosion of complexity” when calculating time derivatives of certain nonlinear functions. Therefore, the proposed filter comes to provide a solution for estimating the time derivatives with the estimation errors converging to zero in finite time. The closed-loop system's finite-time stability is rigorously proved using the Lyapunov theory, despite the state constraints. Simulation results demonstrate the feasibility and efficacy of the proposed method.
{"title":"Fast finite-time backstepping controller for a quadrotor UAV under state constraints","authors":"Nguyen Mung Xuan, Lanh Le Thanh, The Mich Nguyen","doi":"10.15625/2525-2518/18131","DOIUrl":"https://doi.org/10.15625/2525-2518/18131","url":null,"abstract":"Quadrotors have gained popularity in a wide range of applications. In this paper, a new approach for solving the tracking control problem of quadrotors with full-state constraints is presented. The proposed method involves a backstepping control scheme integrated with a fast finite-time filter. First, necessary state transformations are performed to support the design of the finite-time filter and controller. Next, the controller is formulated based on the backstepping technique. All the state constraints are taken into consideration in the controller. However, it is well-known that the backstepping control design can lead to the “explosion of complexity” when calculating time derivatives of certain nonlinear functions. Therefore, the proposed filter comes to provide a solution for estimating the time derivatives with the estimation errors converging to zero in finite time. The closed-loop system's finite-time stability is rigorously proved using the Lyapunov theory, despite the state constraints. Simulation results demonstrate the feasibility and efficacy of the proposed method.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"114 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139367521","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 : 2023-06-23DOI: 10.15625/2525-2518/17926
H. Mai, Thi Thao Ngo, Danh Thien Nguyen, V. Bui, T. D. Dao, Thi Thom Dang, V. M. Do
Microplastics (MPs) are of emerging widespread concern, but amount of research done in freshwater environments and organisms is scarce compared to that in marine environments. Thus, the MPs identification in four freshwater fish at four districts of Bac Ninh province were documented, including common carp (Cyprynus carpio), grass carp (Ctenopharyngodon idella), tilapia (Oreochromis niloticus), and red-tilapia (Oreochromis sp.). MPs were found in the gastrointestinal tracts (GIT) of 100% of examined fish. MPs abundances have significant differences between all freshwater fish collected from ponds and local markets (except for red-tilapia), while no difference by individual of each species neither in pond nor in local markets. The median sizes of microplastics ranged from 1410 µm to 2706 µm. The MPs were dominated by purple in color (in pond with average 38%; in local market with average 33%). µ-FTIR analysis showed that polymers found in fish GIT mainly were polyethylene terephthalate, polyethylene, polypropylene and nylon. These results showed that the microplastics was widely ingested by freshwater fish and help to aware people which fish are more contaminated with MPs to human consumption in Bac Ninh province.
{"title":"Preliminary assessment of microplastic pollution in commercial freshwater fish species collected from four districts in Bac Ninh province","authors":"H. Mai, Thi Thao Ngo, Danh Thien Nguyen, V. Bui, T. D. Dao, Thi Thom Dang, V. M. Do","doi":"10.15625/2525-2518/17926","DOIUrl":"https://doi.org/10.15625/2525-2518/17926","url":null,"abstract":"Microplastics (MPs) are of emerging widespread concern, but amount of research done in freshwater environments and organisms is scarce compared to that in marine environments. Thus, the MPs identification in four freshwater fish at four districts of Bac Ninh province were documented, including \u0000common carp (Cyprynus carpio), grass carp (Ctenopharyngodon idella), tilapia (Oreochromis niloticus), and red-tilapia (Oreochromis sp.). MPs were found in the gastrointestinal tracts (GIT) of 100% of examined fish. MPs abundances have significant differences between all freshwater fish collected from ponds and local markets (except for red-tilapia), while no difference by individual of each species neither in pond nor in local markets. The median sizes of microplastics ranged from 1410 µm to 2706 µm. The MPs were dominated by purple in color (in pond with average 38%; in local market with average 33%). µ-FTIR analysis showed that polymers found in fish GIT mainly were polyethylene terephthalate, polyethylene, polypropylene and nylon. These results showed that the microplastics was widely ingested by freshwater fish and help to aware people which fish are more contaminated with MPs to human consumption in Bac Ninh province.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79547079","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 : 2023-06-20DOI: 10.15625/2525-2518/17538
Ngo Tra Mai, Van Huu Tap, Nguyen Duy Hai, Phan Thi Thanh Hang, Trinh Thi Tham, Vu Duc Toan, Nguyen Thi Thuy Hang, Khuat Thi Hong, Nghiem Thi Ha Lien, Vu B. Duong, Do Quang Hoa, Nguyen Trong Nghia, Nguyen Thi Hoa, Do Thi Lan Chi, Dao Thanh Duong
In this study, 16 seasonal fly ash samples of municipal solid waste incinerator (MSWI) were collected in from waste-to energy power plant Cantho city to analysis the physical properties and heavy metals content. The results showed that the fly ash samples are very alkaline with porous and spherical shape, and the particle size of 1-100 µm. The analytical results disclosed that in these fly ash samples, the Zn, Pb, Al, Fe and Cr metals were found at high content range from 0.36-19.05 mg/kg while the toxic metals Ni and Hg are also found in fly ash, with the content from 0.141 to 0.51 mg/kg. Thus, fly ash is not hazardous waste and can be used for reuse in industries or land reclamation. The analysis results of SEM/EDX and XRF were quite similar with a difference of below 5%, indicating that both methods can be applied to research heavy metals. The findings in this study can guide the management, treatment and reuse of fly ash from MSWI incineration plants in Vietnam.
{"title":"Characteristics of fly ash from the municipal solid waste incineration plant in Can Tho","authors":"Ngo Tra Mai, Van Huu Tap, Nguyen Duy Hai, Phan Thi Thanh Hang, Trinh Thi Tham, Vu Duc Toan, Nguyen Thi Thuy Hang, Khuat Thi Hong, Nghiem Thi Ha Lien, Vu B. Duong, Do Quang Hoa, Nguyen Trong Nghia, Nguyen Thi Hoa, Do Thi Lan Chi, Dao Thanh Duong","doi":"10.15625/2525-2518/17538","DOIUrl":"https://doi.org/10.15625/2525-2518/17538","url":null,"abstract":"In this study, 16 seasonal fly ash samples of municipal solid waste incinerator (MSWI) were collected in from waste-to energy power plant Cantho city to analysis the physical properties and heavy metals content. The results showed that the fly ash samples are very alkaline with porous and spherical shape, and the particle size of 1-100 µm. The analytical results disclosed that in these fly ash samples, the Zn, Pb, Al, Fe and Cr metals were found at high content range from 0.36-19.05 mg/kg while the toxic metals Ni and Hg are also found in fly ash, with the content from 0.141 to 0.51 mg/kg. Thus, fly ash is not hazardous waste and can be used for reuse in industries or land reclamation. The analysis results of SEM/EDX and XRF were quite similar with a difference of below 5%, indicating that both methods can be applied to research heavy metals. The findings in this study can guide the management, treatment and reuse of fly ash from MSWI incineration plants in Vietnam.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90364561","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 : 2023-06-09DOI: 10.15625/2525-2518/18069
P. Khoi
Robot application in mechanical machining is growing day by day because it has many advantages over conventional machines such as high flexibility, large working space, and high repeatability. Many degrees of freedom of motion give robots the ability to perform complex technological operations, but also because of that, methods of controlling robots based on dynamic models have difficulties. Applying fuzzy logic to robot control can partially or completely exclude the calculation of the robot's dynamic model as well as overcome other uncertainties of the whole technological system. The variables and parameters of the fuzzy logic-based controller are modeled in a linguistic form, called linguistic variables, and are defined by the linguistic semantic values. Fuzzy rules are an important basis for the performance of operations defining the control quantities of the controller. Fuzzy rules are constructed by natural human inference and are based on expert intelligence. The main tasks of applying fuzzy logic control include “Fuzzification” to determine fuzzy parameters in the form of fuzzy sets of input-output data; “Fuzzy Rules and Fuzzy Inference Mechanism” to perform fuzzy operations defining control quantities, and finally “Defuzzification” to convert control quantities from linguistic values to physical values for controller operation. There have been many types of research on applying fuzzy logic to control robots in general, but the percentage of fuzzy control research work for mechanical machining robots is still limited. The article is based on published works on fuzzy control for robots in general and mechanical processing robots to analyze the applicability of fuzzy control for mechanical machining robots. The article provides detailed information on fuzzy controller design, on determining input and output variables, proportional mapping to determine the number of fuzzy sets and the corresponding type of membership function. The construction of fuzzy rule base system and fuzzy inference mechanism is presented, and finally defuzzification. Prospects for the use of methods to perfect and develop fuzzy control systems for mechanical machining robots are also presented. Collectively, the information in this document is intended to guide the implementation of fuzzy logic-based controller designs for application to machining robots, as well as to general robot control.
{"title":"APPLICATION OF FUZZY LOGIC IN THE ROBOT CONTROL FOR MECHANICAL PROCESSING","authors":"P. Khoi","doi":"10.15625/2525-2518/18069","DOIUrl":"https://doi.org/10.15625/2525-2518/18069","url":null,"abstract":"Robot application in mechanical machining is growing day by day because it has many advantages over conventional machines such as high flexibility, large working space, and high repeatability. Many degrees of freedom of motion give robots the ability to perform complex technological operations, but also because of that, methods of controlling robots based on dynamic models have difficulties. Applying fuzzy logic to robot control can partially or completely exclude the calculation of the robot's dynamic model as well as overcome other uncertainties of the whole technological system. The variables and parameters of the fuzzy logic-based controller are modeled in a linguistic form, called linguistic variables, and are defined by the linguistic semantic values. Fuzzy rules are an important basis for the performance of operations defining the control quantities of the controller. Fuzzy rules are constructed by natural human inference and are based on expert intelligence. The main tasks of applying fuzzy logic control include “Fuzzification” to determine fuzzy parameters in the form of fuzzy sets of input-output data; “Fuzzy Rules and Fuzzy Inference Mechanism” to perform fuzzy operations defining control quantities, and finally “Defuzzification” to convert control quantities from linguistic values to physical values for controller operation. There have been many types of research on applying fuzzy logic to control robots in general, but the percentage of fuzzy control research work for mechanical machining robots is still limited. \u0000The article is based on published works on fuzzy control for robots in general and mechanical processing robots to analyze the applicability of fuzzy control for mechanical machining robots. The article provides detailed information on fuzzy controller design, on determining input and output variables, proportional mapping to determine the number of fuzzy sets and the corresponding type of membership function. The construction of fuzzy rule base system and fuzzy inference mechanism is presented, and finally defuzzification. Prospects for the use of methods to perfect and develop fuzzy control systems for mechanical machining robots are also presented. Collectively, the information in this document is intended to guide the implementation of fuzzy logic-based controller designs for application to machining robots, as well as to general robot control.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87187042","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 : 2023-06-09DOI: 10.15625/2525-2518/17355
Tu Vo Thanh, Le Huu Binh, Vu Phan Dinh Nguyen
Flying ad hoc network (FANET) is becoming more popular in both military and civilian applications. The primary characteristic of the FANET is high mobility, which results in a constantly changing topology. This is a significant challenge for protocols that control data transmission from nodes to base stations. As a result, many research groups have recently been attracted to the study of data transmission control protocols in FANET, typically routing protocols. This paper presents the application of the Destination Sequenced Distance Vector (DSDV) routing protocols for FANET. We improve the DSDV routing protocol by considering signal-to-noise ratio (SNR) when discovering new routes. The simulation results show that the improved DSDV algorithm outperforms the traditional DSDV algorithm in terms of network throughput, end-to-end delay and SNR.
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