http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Van Phuoc Nhan Le,Duc Vinh Bui,Thi Hai Vinh Chu,김인태,안진희,Duy Kien Dao 국제구조공학회 2016 Structural Engineering and Mechanics, An Int'l Jou Vol.60 No.6
The connector is the most important part of a composite beam and promotes a composite action between a steel beam and concrete slab. This paper presents the experiment results for three large-scale beams with a newly puzzle shape of crestbond. The behavior of this connector in a composite beam was investigated, and the results were correlated with those obtained from push-out-test specimens. Four-pointbending load testing was carried out on steel-concrete composite beam models to consider the effects of the concrete strength, number of transverse rebars in the crestbond, and width of the concrete slab. Then, the deflection, ultimate load, and strains of the concrete, steel beam, and crestbond; the relative slip between the steel beam and the concrete slab at the end of the beams; and the failure mechanism were observed. The results showed that the general behavior of a steel-concrete composite beam using the newly puzzle shape of crestbond shear connectors was similar to that of a steel-concrete composite beam using conventional shear connectors. These newly puzzle shape of crestbond shear connectors can be used as shear connectors, and should be considered for application in composite bridges, which have a large number of steel beams.
Effect of hydrothermal time on the structure and property of graphene oxide membrane
Tran Van Khai,Pham Thuy Trang,Le Ngoc Long,Le Van Thang,Tran Duc Chau,Vuong Vinh Dat,Mai Thanh Phong 한양대학교 세라믹연구소 2021 Journal of Ceramic Processing Research Vol.22 No.4
Two dimensional graphene oxide (GO) has potential application in membrane separation owing to its unique structure andphysicochemical properties. In this study, the reduced graphene oxide (rGO) was synthesized from GO via hydrothermaltreatment at 160 oC for 1, 2, 3 and 4 h, and the rGO membranes were prepared on cellulose nitrate supporting membranesby vacuum filtration. The structural change and chemical composition of GO were investigated using X-ray diffraction (XRD),Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM),atomic force microscopy (AFM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS) andcontact angle measurements. The result shows that uniformly intact rGO membranes with good hydrophobicity could beachieved by adjusting the reduction degree of GO through changing the hydrothermal reaction time. The huge improvementof the hydrophobic property of rGO could be attributed to the removal of the most the hydrophilic oxygen-containingfunctional groups on the surface of GO. Additionally, the structure, chemical composition, and d-spacing of the GO can alsobe controlled by adjusting the reduction time. This method holds great potential because it can be prepared in large quantitiesat low cost, and suitable for applications in membrane technologies.
Alpha-Glucosidase Inhibitory Activity of Saponins Isolated from Vernonia gratiosa Hance
Cong Pham Van,Anh Hoang Le Tuan,Vinh Le Ba,Han Yoo Kyong,Trung Nguyen Quang,Minh Bui Quang,Duc Ngo Viet,Ngoc Tran Minh,Hien Nguyen Thi Thu,Manh Hoang Duc,Lien Le Thi,Lee Ki Yong 한국미생물·생명공학회 2023 Journal of microbiology and biotechnology Vol.33 No.6
Species belonging to the Vernonia (Asteraceae), the largest genus in the tribe Vernonieae (consisting of about 1,000 species), are widely used in food and medicine. These plants are rich sources of bioactive sesquiterpene lactones and steroid saponins, likely including many as yet undiscovered chemical components. A phytochemical investigation resulted in the separation of three new stigmastane-type steroidal saponins (1 – 3), designated as vernogratiosides A–C, from whole plants of V. gratiosa. Their structures were elucidated based on infrared spectroscopy (IR), one-dimensional (1D) and two-dimensional nuclear magnetic resonance (2D NMR), high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), and electronic circular dichroism analyses (ECD), as well as chemical reactivity. Molecular docking analysis of representative saponins with αglucosidase inhibitory activity was performed. Additionally, the intended substances were tested for their ability to inhibit α-glucosidase activity in a laboratory setting. The results suggested that stigmastane-type steroidal saponins from V. gratiosa are promising candidate antidiabetic agents.
Van Thanh, Nguyen,Jang, Hyun-Jae,Vinh, Le Ba,Linh, Kieu Thi Phuong,Huong, Phan Thi Thanh,Cuong, Nguyen Xuan,Nam, Nguyen Hoai,Van Minh, Chau,Kim, Young Ho,Yang, Seo Young Elsevier 2019 Bioorganic chemistry Vol.88 No.-
<P><B>Abstract</B></P> <P>In a search for anti-inflammatory activity in resources from Vietnamese mangroves, we found that a methanolic extract from the leaves of <I>Calophyllum inophyllum</I> (CIL) showed significant anti-inflammatory effects <I>in vitro</I>. Using various chromatographic techniques, we subsequently isolated 12 compounds (<B>1</B>–<B>12</B>) from a methanolic extract of CIL, including two novel compounds (<B>1</B>–<B>2</B>). The inhibitory effects of these compounds on lipopolysaccharide-induced nitric oxide (NO) production in RAW264.7 cells were also evaluated. Compound <B>1</B> significantly suppressed NO production (IC<SUB>50</SUB> = 2.44 ± 0.88 µM), the secretion of pro-inflammatory cytokines (including interleukin-1 beta and tumor necrosis factor alpha), and the expression of inducible nitric oxide synthase through downregulation of nuclear factor-kappa-B signaling cascades. These results suggest that <I>C. inophyllum</I> leaves might be a useful resource for the development of drugs for the treatment of inflammation.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Twelve compounds were isolated from Vietnamese mangrove <I>Calophyllum inophyllum</I>. </LI> <LI> Two new compounds <B>1</B> and <B>2</B> were determined by spectroscopic methods. </LI> <LI> Compound <B>1</B> showed significant anti-inflammatory activity. </LI> <LI> These results suggested that <I>C. inophyllum</I> might useful as the anti-inflammation drug. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Van Hai Pham,Thi Ngoc Lan Tran,Giang Vinh Le,Mehrnoosh Movahed,Ying Jiang,Nguyen Ha Pham,Hisashi Ogawa,Ken Takahashi 한국산업안전보건공단 산업안전보건연구원 2013 Safety and health at work Vol.4 No.2
This paper describes progress on formulating a national asbestos profile for the country of Vietnam. The Center of Asbestos Resource, Vietnam, formulated a National Profile on Asbestos-related Occupational Health, with due reference to the International Labor Organization/World Health Organization National Asbestos Profile. The Center of Asbestos Resource was established by the Vietnamese Health Environment Management Agency and the National Institute of Labor Protection, with the support of the Australian Agency for International Development, as a coordinating point for asbestos-related issues in Vietnam. Under the National Profile on Asbestos-related Occupational Health framework, the Center of Asbestos Resource succeeded in compiling relevant information for 15 of the 18 designated items outlined in the International Labor Organization/World Health Organization National Asbestos Profile, some overlaps of the information items notwithstanding. Today, Vietnam continues to import and use an average of more than 60,000 metric tons of raw asbestos per year. Information on asbestos-related diseases is limited, but the country has begun to diagnose mesothelioma cases, with the technical cooperation of Japan. As it stands, the National Profile on Asbestos-related Occupational Health needs further work and updating. However, we envisage that the National Profile on Asbestos-related Occupational Health will ultimately facilitate the smooth transition to an asbestos-free Vietnam.
Le-Phuc Nguyen,Yen Thi Hai Pham,Phuong Thuy Ngo,Tri Van Tran,Loc Vinh Tran,Nam Thi Hoai Le,Luong Huu Nguyen,Tung Thanh Dang,Duc Anh Nguyen,Marco Wenzel,David Hartmann,Karsten Gloe,Jan J. Weigand,Klaus 한국화학공학회 2018 Korean Journal of Chemical Engineering Vol.35 No.5
Acid leaching and a two-step solvent extraction procedure were developed to produce high purity mixture of La and Ce from iron-rich spent FCC catalyst discharged from Dzung Quat refinery (Vietnam). Acid leaching of the spent catalyst with 2M HNO3 and a solid-to-liquid ratio of 1/3 at 80 oC in 1 h dissolved almost 90% of La while 12% of Al and 25% of Fe were transferred to the leachate. The extraction of RE metals and main impurities such as Al and Fe by a mixture of di-2-ethylhexyl phosphoric acid (D2EHPA) and tributyl phosphate (TBP) was investigated. Experiments showed that it was necessary to remove Fe before extracting RE and the optimum extraction conditions for a high recovery of RE while 0% of Al extraction were pH1, contact time=10min, and D2EHPA/TBP volume ratio= 4 : 1. At these conditions, the extraction yields of La(III) and Ce(III) were 72% and 89%, respectively. A two-step solvent extraction was developed to achieve a high purity of RE mixture, which included (1) the removal of impurity Fe by 25% (v/v) diisooctyl phosphinic acid (DiOPA) in n-octane for 140 min, (2) the extraction of rare earths by a mixture of di-2-ethylhexyl phosphoric acid (D2EHPA) and tributyl phosphate (TBP) in n-octane for 10 min without the need for adjusting the pH of the leaching solution.
Unipolar Resistance Switching Characteristics in a Thick ZnO/Cu/ZnO Multilayer Structure
Tran Le,Hoang Cao Son Tran,Van Hieu Le,Tuan Tran,Cao Vinh Tran,Thanh Tan Vo,Mau Chien Dang,김상섭,이재찬,Bach Thang Phan 한국물리학회 2012 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.60 No.7
The resistance switching mechanism and the electrical conduction of thick Cu/ZnO/Cu/ZnO/Cu structures were investigated for various ZnO thicknesses (40, 80, 160, and 320 nm) when the thickness of the middle Cu layer was 2 nm. The ZnO films had a microstructure with columnar grains normal to the substrate. The switching voltages (VSET and VRESET) varied with the thickness of the ZnO layer. A symmetric electrode structure exhibited a unipolar resistance switching. The electrical transport of both high-resistance state (HRS) and low-resistance state (LRS) was Ohmic conduction, and the resistance switching mechanism was driven by the formation and the rupture of Cu conducting paths.
Hoang Vinh Tran,Hai Van Nguyen,Doanh Viet Vu,Thu Dieu Le,Binh Thanh Nguyen,Dang Hai Le 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.2
We report here a simple approach for synthesis of carbon coated magnetite (C@MFe2O4, M=Co, Ni, Fe) with shell@core nanostructured composites that we used as magnetic-nanosorbents for direct yellow (DYG) and moderacid red (RS) as pollutant textile dyes removal via an adsorption process. The synthesized C@MFe2O4 was characterized by TEM, SEM, EDX, XRD, FT-IR and VSM techniques. TEM results indicated that C@MFe2O4 nanocomposites have 20-30 nm of MFe2O4 nanoparticle core and 2-3 nm in thickness of the amorphous carbon shell. The synthesized C@MFe2O4 nanocomposites have the zero point charge (pHZPC) at 5.5, which suggests that DYG and RS, anionic dyes can be adsorbed onto the C@MFe2O4 nanosorbents in the acidic medium. Adsorption of DYG and RS onto magnetic nanosorbents was optimized and adsorption thermodynamic parameters were evaluated, clearly indicating that the adsorption of RS onto synthesized magnetic-nanosorbents was facile more than that DYG. The adsorption isotherm data showed that the adsorption processes of DYG and RS onto Fe3O4 or C@MFe2O4 nanosorbents are more suitable for the Langmuir model than Freundlich model. The maximum adsorption capacity (qmax) of DYG dye onto Fe3O4, C@Fe3O4 and C@CoFe2O4 adsorbents was 14.641, 36.232 and 7.85mg g1, respectively; meanwhile, these values were 41.152, 61.728 and 39.683mg g1 for RS dye. These obtained data indicate that the developed Fe3O4, C@Fe3O4 and C@CoFe2O4 nanoparticles can be used as recoverable and recyclable adsorbents for not only organic pigments adsorption but also for heavy metal ion removal or protein extraction as well.