Synthesis of solid acid-Base catalysts based on zn-sn and al-sn used for carbonylation of glycerol with urea into glycerol carbonate - Ba Khiem NguyenAll in all, the solid acid-base catalysts for carbonylation reaction from glycerol to glycerol carbonate was employed in this study. The structure of the products was studied using XRD, SEM. The products of glycerol conversion product was also tested by gas chromatography. As the results, the Zn-Sn catalyst for conversion, selectivity and effici...
9 trang | Chia sẻ: honghp95 | Ngày: 02/12/2020 | Lượt xem: 577 | Lượt tải: 0
Electrochemical behavior of mild steel in hcl 1m medium with the presence of rose myrtle leaves extraction -The main findings of this research were: The natural compounds in R. tomentosa (Rose myrtle) extract acts as a capable inhibitor for preventing corrosion on steel substrate in HCl 1M solution with the optimal inhibition efficiency reaches 85.6 % at 0.9 g/L from potentiodynamic polarization result. Followed the obtained results on LPR and EIS me...
8 trang | Chia sẻ: honghp95 | Ngày: 02/12/2020 | Lượt xem: 654 | Lượt tải: 0
Flavonoids from the leaves of aralia hiepiana - Nguyen Thi Dieu ThuanCompound 5 was isolated as a yellow amorphous powder. The 1H NMR spectra displayed pattern of flavone glycoside, with characteristic signals of two doublet signals in ring A at δH 6.45 (1H, d, J = 2.0 Hz, H-6) and 6.84 (1H, d, J = 2.0 Hz, H-8), signals of 1,4-disubstituted ring B of a flavonoid at δH 7.96 (2H, d, J = 8.5 Hz, H-2', H-6'), 6.96 (2...
7 trang | Chia sẻ: honghp95 | Ngày: 02/12/2020 | Lượt xem: 517 | Lượt tải: 0
Insulin-Mimetic biflavones from a vietnamese medicinal plant selaginella tamariscina - Nguyen Dinh TuanUsing combined chromatographic and spectroscopic methods, four biflavones including amentoflavone (1), robustaflavone (2), cupressuflavone (3), and 3,8′′-biapogenin (4) were isolated and structurally identified from the methanol extract of Selaginella tamariscina. All of the isolates (1‒4) were investigated for their stimulatory effects on 2-NBD...
8 trang | Chia sẻ: honghp95 | Ngày: 02/12/2020 | Lượt xem: 506 | Lượt tải: 0
Extraction of polysaccharides from lingzhi by ultrasonic-Assisted enzymatic method - Tran Quoc HoaIn this study, all the statistical indicators supported that response surface model was a successful tool to describe the ultrasonic process in extracting polysaccharides from Lingzhi. The optimal parameters of the polysaccharide extraction by ultrasonic-assisted enzymatic method were: extraction time of 144min, extraction temperature of 55 °C, ...
11 trang | Chia sẻ: honghp95 | Ngày: 02/12/2020 | Lượt xem: 526 | Lượt tải: 0
Methoxyflavones from orthosiphon stamineus and their ptp1b inhibitory activities - Hoang Duc ThuanUsing combined chromatographic and spectroscopic methods, four flavones including 5- hydroxy-3,7,3',4'-tetramethoxyflavone (1), 3,5,7,3′,4′-pentamethoxyflavone (2), 3,5,3′- trihydroxy-7,4′-dimethoxyflavone (3), and 3,3′-dihydroxy-5,7,4′-trimethoxyflavone (4) were isolated and structurally identified from the methanol extract of the aerial parts ...
7 trang | Chia sẻ: honghp95 | Ngày: 02/12/2020 | Lượt xem: 446 | Lượt tải: 0
High protection performance of coating systems based on zinc rich primer and fluoropolymer coating - Vu Ke OanhCoatings systems with primer coatings based on inorganic zinc coatings and topcoat based on fluoropolymer, high-build fluoropolymer and polyurethane were tested by exposure at Ha Noi, Ha Long and Nha Trang stations. Gloss retention and electrochemical measurement were used for evaluating the protection performance of exposed coated steel panels....
7 trang | Chia sẻ: honghp95 | Ngày: 02/12/2020 | Lượt xem: 481 | Lượt tải: 0
The role of counter anions in anticorrosive properties of silica-Polypyrrole composite - Vu Thi Hai VanThe protection performance of PVB coating containing silica/polypyrrole composites with different counter anions (dodecyl sulfate, oxalate and benzoate) was investigated by electrochemical characterizations. It was shown that the presence of counter anion significantly enhanced the effect of SiO2/PPy on protection performance of PVB coatings for...
13 trang | Chia sẻ: honghp95 | Ngày: 02/12/2020 | Lượt xem: 767 | Lượt tải: 0
Influence of graphene oxide on the corrosion inhibition effect of hydrotalcite loaded with 2-Benzothiazolythio-succinic acid - Thuy Duong NguyenHydrotalcite loaded 2-benzothiazolylthio-succinic acid and graphene oxide (HTCBSA/GO) with BSA content of 19.7 wt% was prepared. The BSA release from HTC-BSA/GO depended on chloride concentrations. After 72 h of immersion, the BSA release was 19.3 % and 61.0 % for 0.1 M and 0.5 M NaCl solutions, respectively. The presence of HTC-BSA/GO at 1 wt% ...
8 trang | Chia sẻ: honghp95 | Ngày: 02/12/2020 | Lượt xem: 679 | Lượt tải: 0
Modeling of essential oil extraction process: application for orange, pomelo, and lemongrass - Nguyen Dang Binh ThanhKinetics of theessential oil extraction from different plants (sweet orange, pomelo, and lemongrass) using steam distillation were developed on the basis of semi-theoretical models. The results showed that all models selected are in a good agreement with experimental data. Howerver, the Patriicelli model, in which both washing and desorption ste...
8 trang | Chia sẻ: honghp95 | Ngày: 02/12/2020 | Lượt xem: 621 | Lượt tải: 0
