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Abstract. To examine the occurrence and distribution of arsenic in groundwater, 137samples were collected from private wells in Southeastern Hanoi. According to the concentrations of major cations and anions, groundwater compositions vary from Ca-HCO3 to Na-HCO3 type. Groundwater has a very large range of chemical compositions and the spatial v...
8 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 477 | Lượt tải: 0
Abstract. Twelve perfluoroalkyl substances (PFASs) were investigated in fish samples collected in West Lake and Yen So Lake. Six PFASs including five perfluoroalkylcarboxylic acids (PFCAs) and only one perfluoroalkyl sulfonates acids (PFSAs) compounds were found in fish samples in both lakes. The concentration of long-chain carbon compounds suc...
8 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 621 | Lượt tải: 0
Abstract. This study focused on using a central composite design (CCD) to optimize the analytical method for simultaneous determination of choline, pantothenic acid (vitamin B5), ascorbic acid (vitamin C), and niacin (vitamin B3) by capillary zone electrophoresis (CZE). The optimization process was designed with 30 experiments, including four f...
10 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 427 | Lượt tải: 0
Abstract. The interactions of K[PtCl3(iPrEug)] (1) with either 2-aminopyridine (NH2Py) or 2-(aminomethyl)pyridine (NH2CH2Py) have been studied for the first time. The structures of obtained complexes, namely trans-[PtCl2(iPrEug)(NH2Py)] (2) and a mixture of [PtCl2(NH2CH2Py)] (3A) and trans-[PtCl2(NH2CH2Py)2] (3B), were determined by means of pl...
8 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 479 | Lượt tải: 0
Abstract. Reaction of ethyl monochloro acetate and o-aminophenol derivatives gave two new benzo[b][1,4]oxazin-3(4H)-one containing benzo[d]thiazole ring with 2 methods in high yield. Structures of two benzo[b][1,4]oxazin-3(4H)-one based derivatives were elucidated with IR, 1D NMR, 2D NMR and MS spectra.
8 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 467 | Lượt tải: 0
Abstract. Both nitration of vanillin and condensation of 5-nitrovanilllin with aniline derivatives were accelerated by using microwave oven. The nitration gave 5-nitrovanillin in 80% yield and the condensation gave twelve Schiff bases in excellent yield (80 - 97%) within short reaction time (4 - 10 min) along with other advantages like mild rea...
8 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 457 | Lượt tải: 0
Abstract. We introduce several weighted Lp(R+)-norm inequalities and integral transform related to the generalized convolution with a weight function for the Fourier cosine and Laplace transforms. Some applications of these inequalities to estimate the solutions of some partial differential equations are considered. We also obtained solutions of...
14 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 332 | Lượt tải: 0
Abstract: Increasing accumulation of CO2 in the atmosphere mainly caused by fossil fuels combustion of human activities have resulted in adverse global warming. Therefore, searching for treatment methods for effective utilization of CO2 have received a great attention worldwide. Among various methods (e.g., adsorption, absorption, storage, membr...
13 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 460 | Lượt tải: 0
Abstract: The bioaccumulation of polycyclic aromatic hydrocarbons (PAHs) in bivalves of the coastal estuary has been investigated since they are favorable seafood. In the present study, the distribution of PAHs was determined in the green mussels (Perna viridis) from Cangio area (Ho Chi Minh City). Global comparison showed a lower PAHs accumulat...
8 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 491 | Lượt tải: 0
Abstract: Amine-mesoporous silica has been considered as a promising CO2 adsorbent with high potential for the reduction of energy consumption and CO2 capture cost; however, its stability could greatly vary with synthetic method. In this study, adsorbents prepared by impregnating different amines including polyethylenimine (PEI) and 3-aminopropy...
8 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 407 | Lượt tải: 0