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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...

9 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 652 | Lượt tải: 0

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...

6 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 694 | Lượt tải: 0

Abstract. Molecular dynamics simulations of Cu80Ni20 (Cu:Ni = 8:2) model with the size of 8788 atoms have been carried out to study the structure and mechanical behavior at high pressure of 45 GPa. The interactions between atoms of the system were calculated by the Quantum Sutton-Chen embedded-atom potentials. The crystallization has occurred d...

8 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 619 | Lượt tải: 0

Abstract. Zinc-oxide nanoparticles (ZnO-NPs) has positive effects on the growth and development of plants at appropriate concentrations. This study aimed to test the effect of ZnO nanoparticles with concentrations from 0 mg/L to 5 mg/L individually or in combination with ZnSO4 on growth and development of in vitro Dendrobium officinal at 3 stag...

6 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 665 | Lượt tải: 0

Abstract. The purpose of this paper is to consider the project scheduling problem under such limited constraint, called Multi-Skill Resource-Constrained Project Scheduling Problem or MS-RCPSP. The algorithm proposed in this paper is to find the optimal schedule, determine the start time for each task so that the execution time (also called make...

12 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 583 | Lượt tải: 0

function of center of mass velocity has been used to deduce the mass diffusion coefficient (D) of water diluted in nitrogen using the Classical Molecular Dynamics Simulations (CMDS). The calculations have been performed at room temperature (296 K) for different mixtures of H2O in N2 and for 2.107 molecules from a five-sites potential. The results s...

7 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 634 | Lượt tải: 0

Tóm tắt Tốc độ bốc bay (vận tốc lắng đọng) của các phân tử trên bề mặt đế có ảnh hưởng trực tiếp tới chất lượng của màng mỏng. Nguyên lý tạo màng mỏng là quá trình đốt nóng (gia nhiệt) cho vật liệu màng làm cho vật liệu nóng chảy rồi bay hơi và lắng đọng (hoặc không lắng đọng) trên bề mặt đế trong môi trường chân không. Sự lắng đọng hay không lắng...

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

Abstract The adsorption kinetics and equilibrium of methylene blue from aqueous solution onto activated carbon derived from coffee husk using one step ZnCl2 activation were investigated. The influence of initial methylene blue concentration and temperature were evaluated employing the batch experiment. To the experimental data, different kinetics ...

12 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 744 | Lượt tải: 0

Microsoft Teams is an integrated application of Office 365 that allows teachers to use in teaching as a learning management system. This article focuses on analyzing the features of Teams used in online teaching while proposing 4 measures to strengthen students' self-study activities through Teams application including: (1) Organize students to ...

12 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 726 | Lượt tải: 0

ABSTRACT Proposing STEM teaching Competency framework of pre-chemistry service teachers Nguyen Thi Thuy Trang1, Dang Thi Oanh2 and Pham Thi Binh2 1 Faculty of Chemistry, Hue University of Education 2Faculty of Chemistry, Hanoi National University of Education Competency framework of pre-chemistry service teachers STEM teaching was investigate...

8 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 588 | Lượt tải: 0