• Determination of caffeine in the leaves and flowers of Camellia chrysantha by high-performance liquid chromatography with dad detectionDetermination of caffeine in the leaves and flowers of Camellia chrysantha by high-performance liquid chromatography with dad detection

    Abstract. Caffeine (1,3,7-trimethylxanthine) is naturally found in the leaves, seeds or fruits of over 63 plants species worldwide. It is contained highly in coffee, tea, cacao beverage products. Caffeine showed good effects in enhancing performance and perception of exercise, reducing fatigue and drowsiness, and improving memory and learning ef...

    pdf7 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 590 | Lượt tải: 0

  • Study on the removal of ammonium in wastewater using adsorbent prepared from rice hull and magnesium chlorideStudy on the removal of ammonium in wastewater using adsorbent prepared from rice hull and magnesium chloride

    Abstract. This study aimed to evaluate the ability of magnesium chloride modified carbonized rice hull (MCRH) material for ammonium removal from synthetic and domestic wastewater. The MCRH material was prepared by using waste rice hull from a household rice-processing factory and magnesium chloride salt via a simple mixing and annealing method. ...

    pdf11 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 760 | Lượt tải: 0

  • Macro-zooplankton abundance in relation to metal accumulation and water quality in Truc Bach lakeMacro-zooplankton abundance in relation to metal accumulation and water quality in Truc Bach lake

    Abstract. Urban lake pollution is one of the serious issues due to suffering of waste discharged from householders. However, there is a gap of knowledge about the diversity of zooplankton species and how metals accumulate in zooplankton in urban ecosystems. We addressed this by determining the rule of blooming macro-zooplankton in the Truc Bach ...

    pdf8 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 522 | Lượt tải: 0

  • Removal of nickel, copper, and zinc ions from aqueous solution using coffee bean husk (CFH)Removal of nickel, copper, and zinc ions from aqueous solution using coffee bean husk (CFH)

    Abstract. Agricultural waste has received much attention for its potential of being efficient and low-cost adsorbents to remove heavy metals from water. This paper presents a batch investigation of the potential of an adsorbent produced from coffee bean husk for removing copper, nickel and zinc ions from aqueous solution. At the initial pH of 5....

    pdf7 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 579 | Lượt tải: 0

  • Removal of norfloxacin by TiO2-SBA-15 photocatalystRemoval of norfloxacin by TiO2-SBA-15 photocatalyst

    Abstract. Ordered SBA-15 mesoporous silica support was synthesized by a sol-gel method using triblock copolymer Pluronic P123 and immobilized with different amounts of photocatalyst TiO2. The synthesized composites were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and N2 adsorption-desorption isotherms. The s...

    pdf7 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 484 | Lượt tải: 0

  • PM2.5 - Bound pahs in the indoor and outdoor air of nursery schools in Ha Noi, Viet Nam and health implicationPM2.5 - Bound pahs in the indoor and outdoor air of nursery schools in Ha Noi, Viet Nam and health implication

    Abstract. Thirty two daily indoor and outdoor PM2.5 samples at sixteen nursery schools in Ha Noi were taken from March to April 2018. 15 individual PAHs were analyzed by GC/MS. Mutagenic potential (MP) and carcinogenic potential (CP) were used to evaluate carcinogenic and mutagenic risk contribution. The average PM2.5 concentrations were 38.7 μg...

    pdf9 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 487 | Lượt tải: 0

  • Đề xuất cải tiến quy trình công nghệ sản xuất phèn nhôm từ cao lanhĐề xuất cải tiến quy trình công nghệ sản xuất phèn nhôm từ cao lanh

    TÓM TẮT Nhôm sunfat được sử dụng rộng rãi trong công nghiệp xử lí nước, công nghiệp giấy và công nghiệp dệt. Có nhiều hướng để sản xuất sản phẩm này và ở Việt Nam, cao lanh là nguồn khoáng dồi dào. Do đó chúng tôi đã nghiên cứu sản xuất nó bằng phương pháp hòa tách cao lanh trong dung dịch axit sunphuric. Trên cơ sở các thông số công nghệ tối ư...

    pdf6 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 552 | Lượt tải: 0

  • Nghiên cứu hoạt tính kháng khuẩn của hoạt chất α-Mangostin tách ra từ vỏ quả măng cụt Garcinia mangostana LNghiên cứu hoạt tính kháng khuẩn của hoạt chất α-Mangostin tách ra từ vỏ quả măng cụt Garcinia mangostana L

    TÓM TẮT Trong số các hợp chất xanthone từ vỏ quả măng cụt, hợp chất α- mangostin được chứng minh là có hàm lượng cao nhất chiếm khoảng 0,02 - 0,2 %. Nhiều nghiên cứu đã chứng minh, hoạt chất α- mangostin có hoạt tính kháng khuẩn, chống viêm, chống oxy hóa và chống ung thư. Trong bài báo này, hoạt chất α- mangostin được tinh sạch từ vỏ của quả m...

    pdf8 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 663 | Lượt tải: 0

  • Production of poly(3-hydroxybutyrate) from raw cassava starch by Bacillus megaterium D8Production of poly(3-hydroxybutyrate) from raw cassava starch by Bacillus megaterium D8

    Abstract. Biosynthesis of polyhydroxyalkanoate (PHA) from raw cassava starch as the carbon source by bacteria was investigated in this study. About 300 bacterial colonies were isolated from soil samples. Among them, sixteen bacterial strains were found to produce PHA from cassava starch. Strain D8 produced the highest poly(3-hydroxybutyrate) (P...

    pdf9 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 565 | Lượt tải: 0

  • Reaction of some salicyl aldehyde derivatives with amines andphenyl acetyleneReaction of some salicyl aldehyde derivatives with amines andphenyl acetylene

    Abstract.Salicylic aldehydes, amine, and phenyl acetylene could react under the solvent-free, metal-free conditions to form propargylamines 1-4 via A3 coupling reaction. The yield of the reaction was up to 83% for 5h. In acetonitrile, the amine became a catalyst to form 6-bromo-3-(5-bromo-2-hydroxybenzyl)-2-phenyl-4Hchromen-4-one (5). Under micr...

    pdf6 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 592 | Lượt tải: 0