Vietnam Journal of Science, Technology and Engineering最新文献

{"title":"Phenolic compounds from Usnea baileyi (Stirt.) Zahlbr growing in Lam Dong province","authors":"Van-Kieu Nguyen, T. Duong","doi":"10.31276/vjste.61(3).12-15","DOIUrl":"https://doi.org/10.31276/vjste.61(3).12-15","url":null,"abstract":"This study entails a continuation of the phytochemical study regarding the lichen Usnea baileyi collected in Lam Dong province. Eight compounds, 8'-O-methylprotocetraric acid (1), protocetraric acid (2), virensic acid (3), subvirensic acid (4), barbatic acid (5), diffractaic acid (6), 4-O-demethylbabartic acid (7), and atranorin (8), were isolated using various chromatographic methods. Their chemical structures were elucidated through spectroscopic analysis as well as through a comparison of their data with that in the literature.","PeriodicalId":23548,"journal":{"name":"Vietnam Journal of Science, Technology and Engineering","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79005848","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}

{"title":"Application of biological methods in the treatment of gaseous ammonia","authors":"Phạm Thanh Hiền Lâm, Ngoc T. Bui, T. T. Nguyen, Thi Be Lien Nguyen, T. Vo, N. Nguyen","doi":"10.31276/vjste.61(3).71-76","DOIUrl":"https://doi.org/10.31276/vjste.61(3).71-76","url":null,"abstract":"In Vietnam, practical applications of biological methods in air pollution control are highly limited. This study evaluated and compared the ammonia removal performance in air of a cow-manure biofilter, commercial compost biofilter, and biotrickling filter with K3 biomedium cultured with attached microorganisms from activated sludge. The results indicated that with an inlet NH3 concentration of 65-80 mg/m3 (95-117 ppm), the treatment efficiency was highly promising with an output concentration in the range of 2-5 mg/m3 (3.0-7.5 ppm) and elimination capacity of 3-9 gNH3/m3.h. With an inlet concentration below 200 mg/m3, all three experimental models could remove ammonia to meet the emission standard (QCVN 19:2009/BTNMT) of 50 mg/m3. The study results indicated that the investigated biological technologies have potential for use in removing ammonia and other odorous gases in polluted air. This study investigated the removal of gaseous ammonia using cow manure, compost, and K3 material as biomedium in biofilters and biotrickling filters.","PeriodicalId":23548,"journal":{"name":"Vietnam Journal of Science, Technology and Engineering","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77025119","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}

{"title":"Quantification of greenhouse gas emissions from different municipal solid waste treatment methods - case study in Ha Noi, Vietnam","authors":"T. T. T. Pham","doi":"10.31276/vjste.61(3).81-89","DOIUrl":"https://doi.org/10.31276/vjste.61(3).81-89","url":null,"abstract":"This study focuses on defining the greenhouse gas (GHG) emissions from treatment of municipal solid waste (MSW) in Ha Noi city. Firstly, the MSW samplings at Nam Son and Xuan Son landfills were collected to identify the components. Based on the statistical data on the amount and ratio of MSW collected, the volume of MSW treated by different technologies was estimated. Then, the GHG emissions were quantified by applying the Intergovernmental Panel on Climate Change (IPCC) 2006 model. The annual GHG released from MSW in Ha Noi in 2017 was 1.1 million tons of CO2e from landfilling, 16.3 thousand tons of CO2e from incineration, and 76,100 tons of CO2e from composting. The GHG emission level from landfills is the highest (327 kg of CO2e per ton of treated waste), followed by composting (189 kg of CO2e per ton), and incineration (115 kg of CO2e per ton). The GHG emissions from landfills comprised nearly 90% of GHG emissions from MSW disposal in Ha Noi. The results also revealed that if there are no measures to recover landfill gas for energy generation, the GHG generated from MSW treatment facilities will also contribute significantly to the greenhouse effect and climate change impact. These research results also supply the basis information for decision-makers to select the appropriate MSW treatment technologies for Ha Noi in the context of increasing population pressure and environmental pollution.","PeriodicalId":23548,"journal":{"name":"Vietnam Journal of Science, Technology and Engineering","volume":"47 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74137839","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}

{"title":"The efficacy of micronano particles across NPK doses and densities on maize growth and yield in Vietnam","authors":"L. Q. Kha, N. Q. Vinh, N. Chau, Pham Vu Bao","doi":"10.31276/vjste.61(3).33-39","DOIUrl":"https://doi.org/10.31276/vjste.61(3).33-39","url":null,"abstract":"Increasing the efficiency of maize production in Vietnam is a prerequisite for increasing the quantity of maize for animal feed. With a view to reducing nitrogen-phosphorus-potassium (NPK) doses for maize production, a two-factor experiment using complex micronano particles across three NPK fertiliser doses and three densities on maize hybrid PAC999 was conducted following a randomized complete block design with plot size of 21.84 m2, in Binh Dinh province of Vietnam from May to September 2017. Three NPK fertiliser doses (kg/ha) constitute the first factor, as P1: 156 N - 86 P2O5 - 84 K2O (100% normal dose); P2: 140 N - 77 P2O5 - 76 K2O (90%); and P3: 125 N - 69 P2O5 - 67 K2O (80%). Three densities constitute the second factor, as M1: 71,429 plants/ha (100% normal density); M2: 64,935 plants/ha (90%), and M3: 57,143 plants/ha (80%). Nine combinations of M and Pwere developed into nine treatments; the control involved spraying with water rather than nano foliar fertiliser. Nano particles were applied as a foliar fertiliser solution at 20 days after sowing with 300 litres/ha, 30 days after sowing with 500 litres/ha, and 40 days after sowing with 700 litres/ha. The results show that 80% and 90% of normal NPK doses combined with 90% and 80% normal density produced a grain yield of 6.52 and 6.63 tons per ha, respectively, which is 14-16% higher than that of the control (5.71 tons/ha). The results of the experiment were demonstrated on large plots of 500 m2 each insummer/autumn 2018 in Binh Dinh and Hau Giang provinces, spring/summer 2018 in Long An, and winter/spring 2017-2018 in Dong Nai province. Over an area of 500 m2, 75% of farmers’ NPK doses and the micronano solution were applied; the control involved applying 100% NPK doses. The results of the demonstration showed that the grain yield of maize (tons/ha) with the nano fertiliser solution (9.44 in Binh Dinh, 9.2 in Dong Nai, 9.52 in Long An, and 8.7 in Hau Giang) was 0.95, 0.28, 0.68, and 0.3 tons higher than that of the control (8.49, 8.92, 8.84, and 8.4 tons/ha, respectively).","PeriodicalId":23548,"journal":{"name":"Vietnam Journal of Science, Technology and Engineering","volume":"80 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90539031","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}

{"title":"Melanosis and quality changes of Pacific white shrimps(Litopenaeus vannamei) treated with Houttuynia cordataextract during cold storage","authors":"D. Phan, N. Vo, H. M. Tran, Phan Thi Cam Bui","doi":"10.31276/vjste.61(3).40-44","DOIUrl":"https://doi.org/10.31276/vjste.61(3).40-44","url":null,"abstract":"Changes in melanosis, microbiology, and fat oxidation in Pacific white shrimps (Litopenaeus vannamei) when treated with Houttuynia cordata extract (designated E-DC) were monitored during cold storage for seven days at 20C. Whole shrimps treated with E-DC solution (0.025%, w/v) revealed slow growth of total aerobic microorganisms, Enterobacteriaceae and Pseudomonas aeruginosa, throughout cold storage in comparison to the control sample treated by water (p<0.05). The changes in pH, grey value, and TBARS value (thiobarbituric acid reactive substances) of shrimp samples treated with 0.025% E-DC solution were lower than those of control samples (p<0.05) and not different significantly in comparison to the 1.25% (w/v) sodium metabisulfite (SMS) samples (p>0.05). These results suggested the potential of using natural compounds from vegetable extraction as a safe and effective alternative for commercial chemical-derived preservatives in shrimp storage.","PeriodicalId":23548,"journal":{"name":"Vietnam Journal of Science, Technology and Engineering","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74409807","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}

{"title":"Two newly recorded species of Urticaceae among the flora of Vietnam used as green foods for H'Mong beef cattle","authors":"H. D. Nguyen, L. Fu, Yigang Wei, T. Do","doi":"10.31276/vjste.61(3).57-60","DOIUrl":"https://doi.org/10.31276/vjste.61(3).57-60","url":null,"abstract":"Oreocnide kwangsiensis Hand.-Mazz. and Boehmeria japonica (L. f.) Miq. (Urticaceae) are newly reported among the flora of Vietnam that are used as green foods for beef cattle by local H’Mong people in northern Vietnam in the winter-spring season. The authors provide descriptions, illustrations, notes on utilisation, and a diagnostic comparison of these species with ones that are morphologically similar.","PeriodicalId":23548,"journal":{"name":"Vietnam Journal of Science, Technology and Engineering","volume":"30 6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82873630","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}

{"title":"Chemical constituents from methanolic extract of Solanum procumbens Lour (Solanaceae)","authors":"Thi Thanh Thuy Tran, H. P. Dang, T. Nguyen","doi":"10.31276/vjste.61(3).09-11","DOIUrl":"https://doi.org/10.31276/vjste.61(3).09-11","url":null,"abstract":"Solanum procumbens L. (Solanaceae) were extracted respectively with n-hexane, ethyl acetate, and methanol to obtain the corresponding extracts. The methanol-soluble extract was acidified by adding HCl 0.5M; this was followed by liquid-liquid partition with CHCl3 to afford CHCl3-soluble fraction. From this fraction, four compounds were isolated and identified as ergosterol peroxide (1), 9,11-dehydroergosterol peroxide (2), N-(N-benzoyl-L-phenylalanyl)-L-phenylalanol (3), and moupinamide (4). Their structures were elucidated based on the NMR spectroscopic analysis and comparison with the literature. All isolated compounds were first reported from S. procumbens.","PeriodicalId":23548,"journal":{"name":"Vietnam Journal of Science, Technology and Engineering","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86341512","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}

{"title":"Multiplex polymerase chain reaction (M-PCR)for bacterial vaginosis detection","authors":"Tien Sang Trieu, V. K. Tran, Hannah M. Nguyen, Thi Thu Ha Nguyen, Quang Le, M. Phung, Minh Quang Diep, H. Vu, Quangninh Obstetric","doi":"10.31276/vjste.61(3).52-56","DOIUrl":"https://doi.org/10.31276/vjste.61(3).52-56","url":null,"abstract":"","PeriodicalId":23548,"journal":{"name":"Vietnam Journal of Science, Technology and Engineering","volume":"124 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88041890","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}

{"title":"Assessment and prioritisation of low-carbon technology for the waste sector in Vietnam","authors":"N. Thang, Le Ngoc Cau, Makoto Kato, S. Sugimoto","doi":"10.31276/vjste.61(3).77-80","DOIUrl":"https://doi.org/10.31276/vjste.61(3).77-80","url":null,"abstract":"This paper presents a multi-criteria assessment approach for the prioritisation of low-carbon technologies for the waste sector in order to enable the implementation of Vietnam’s nationally determined contributions (NDCs) in terms of the Paris Agreement. A four-step approach is developed for assessing and prioritising low-carbon technologies for the waste sector using this approach. A set of five criteria and indicators are defined for multi-criteria assessment. Based on mitigation options defined in the NDCs, a shortlist of 26 technological options are defined. The multi-criteria assessment and prioritisation is conducted based on the shortlist. The assessment results in eight prioritised low-carbon technologies. Of the eight technologies prioritised, semi-aerobic landfill, which is a low cost and relatively simpler technology than the other technologies evaluated and can contribute to greenhouse gas emission reduction, is given the highest priority. The technical, financial, and social and environmental feasibility of each of the technologies evaluated is presented.","PeriodicalId":23548,"journal":{"name":"Vietnam Journal of Science, Technology and Engineering","volume":"58 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82668499","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}

{"title":"Cultivation of Haematococcus pluvialis for astaxanthin production on angled bench-scale and large-scale biofilm-based photobioreactors","authors":"H. Tran, Thanh-Tri Do, Tuan-Loc Le, Minh Nguyen, C. Pham, M. Melkonian","doi":"10.31276/vjste.61(3).61-70","DOIUrl":"https://doi.org/10.31276/vjste.61(3).61-70","url":null,"abstract":"The green microalga, Haematococcus pluvialis, is currently cultivated for natural astaxanthin in suspended systems. Immobilised cultivation in a twin-layer (TL) porous substrate bioreactor is a potential revolution in microalgal biotechnology worldwide. For the first time in Vietnam, small-scale (0.05 m2) and large-scale (2 m2) biofilm-based photobioreactor systems arranged at an angle of 150 were successfully designed, assembled, and operated; the temperature, humidity, air, and light conditions for H. pluvialiscultivation were successfully controlled. Studies were conducted of both systems to determine theoptimal storage time of algae after harvest from suspension before inoculation into the TL system, carbon dioxide supply method, light intensity, and initial cell density. In the 0.05 m2 and 2 m2 systems, dry biomass productivity reached 12 g m-2 d-1 (3% astaxanthin content in the dry biomass) and 11.25 g m-2 d-1 (2.8% astaxanthin) after 10 days of cultivation. The 2 m2biofilm-based photobioreactor system provides many advantages in scaling up astaxanthin production from H. pluvialis.","PeriodicalId":23548,"journal":{"name":"Vietnam Journal of Science, Technology and Engineering","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73501458","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}