http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Tran Minh Ngoc,Tran Minh Man,Mai Thanh Phong,Mai Thanh Phong,Nguyen Huu Hieu 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.4
Silica nanoparticles were prepared from rice husk ash (RHA-silica) by precipitation method. The characterization of RHA-silica was studied by X-ray fluorescence, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy, and Brunauer-Emmett-Teller specific surface area. Results showed that RHA-silica was successfully synthesized with a particle size of 5-15 nm and purity of 98.08%. The obtained RHA-silica was applied with different content for fabrication of tubular ceramic-supported poly(vinyl alcohol) membranes using malic acid as a cross-linking agent (RHA-silica/MA-PVA) by dip-coating and solvent evaporation methods. The tubular ceramic-supported RHA-silica/MA-PVA membranes were used for dehydration of 95 wt% ethanol solution by pervaporation (PV) technology. Results indicated membrane with 15 wt% RHA-silica (15RHA-silica/MA-PVA) was suitable for the dehydration with permeate flux of 0.0856 kg/m2·h, separation factor of 46.6, and pervaporation separation index of 3.9 kg/m2h. The tubular ceramic-supported 15RHA-silica/MA-PVA membrane was characterized using XRD, FTIR, scanning electron microscope, differential scanning calorimetry, and contact angle measurement. Results showed that this membrane was 30 m thick, mechanical stable (swelling rate, 133.9%), hydrophobic (contact angle, 81o), and thermal stable (glass transition temperature, 138.7 oC). Therefore, the tubular ceramic-supported nanocomposite membrane could be considered as a potential alternative for PV dehydration of ethanol.
Critical Factors Affecting Selection of Travel Destinations: A Case Study in Vietnam
Thanh Phong TRAN,Trong Nghia PHAN,Hoang Thinh NGUYEN 한국유통과학회 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.9
This study is conducted to fill the research gap in proposing and testing the relationship between “Attitudes about the overall image of the destination”, “Subjective norms” and “Perceived behavioral control”. Simultaneously, we examine the relationship between these variables and tourists’ “intent to choose a destination.”. While most previous studies only deal with the relationship between destination image and intended behavior of tourists, this study uses the theory of planned behavior (Ajzen, 1991) to explain the intended behavior of tourists. In addition, the Theory of Destination Image (Echtner & Ritchie, 1991) is used to explain the factor “attitudes about the overall image of the destination”, contribute to supplementing and perfecting the Theory of Planned Behavior. This study uses a Structural Equation Modeling (SEM) to analyze a sample of 993 observations, the subjects of which are international tourists to Vietnam, to test the relationship between second-order constructs. The test results show that “Subjective norms” and “Perceived behavioral control” have an impact on “Attitudes about the overall image of the destination”. Moreover, all these three factors have an impact on “Intent to choose destination”, in which the factor “Perceived behavioral control” has the greatest impact on “intention to choose destination”.
( Khac Phong Do ),( Ba Tung Nguyen ),( Xuan Thanh Nguyen ),( Quang Hung Bui ),( Nguyen Le Tran ),( Thi Nhat Thanh Nguyen ),( Van Quynh Vuong ),( Huy Lai Nguyen ),( Thanh Ha Le ) 한국정보처리학회 2015 Journal of information processing systems Vol.11 No.4
This paper presents the applications of spatial interpolation and assimilation methods for satellite and ground meteorological data, including temperature, relative humidity, and precipitation in regions of Vietnam. In this work, Universal Kriging is used for spatially interpolating ground data and its interpolated results are assimilated with corresponding satellite data to anticipate better gridded data. The input meteorological data was collected from 98 ground weather stations located all over Vietnam; whereas, the satellite data consists of the MODIS Atmospheric Profiles product (MOD07), the ASTER Global Digital Elevation Map (ASTER DEM), and the Tropical Rainfall Measuring Mission (TRMM) in six years. The outputs are gridded fields of temperature, relative humidity, and precipitation. The empirical results were evaluated by using the Root mean square error (RMSE) and the mean percent error (MPE), which illustrate that Universal Kriging interpolation obtains higher accuracy than other forms of Kriging; whereas, the assimilation for precipitation gradually reduces RMSE and significantly MPE. It also reveals that the accuracy of temperature and humidity when employing assimilation that is not significantly improved because of low MODIS retrieval due to cloud contamination.
Do, Khac Phong,Nguyen, Ba Tung,Nguyen, Xuan Thanh,Bui, Quang Hung,Tran, Nguyen Le,Nguyen, Thi Nhat Thanh,Vuong, Van Quynh,Nguyen, Huy Lai,Le, Thanh Ha Korea Information Processing Society 2015 Journal of information processing systems Vol.11 No.4
This paper presents the applications of spatial interpolation and assimilation methods for satellite and ground meteorological data, including temperature, relative humidity, and precipitation in regions of Vietnam. In this work, Universal Kriging is used for spatially interpolating ground data and its interpolated results are assimilated with corresponding satellite data to anticipate better gridded data. The input meteorological data was collected from 98 ground weather stations located all over Vietnam; whereas, the satellite data consists of the MODIS Atmospheric Profiles product (MOD07), the ASTER Global Digital Elevation Map (ASTER DEM), and the Tropical Rainfall Measuring Mission (TRMM) in six years. The outputs are gridded fields of temperature, relative humidity, and precipitation. The empirical results were evaluated by using the Root mean square error (RMSE) and the mean percent error (MPE), which illustrate that Universal Kriging interpolation obtains higher accuracy than other forms of Kriging; whereas, the assimilation for precipitation gradually reduces RMSE and significantly MPE. It also reveals that the accuracy of temperature and humidity when employing assimilation that is not significantly improved because of low MODIS retrieval due to cloud contamination.
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.
Tran Cong Phong,Vo Thanh Lam,Bui Dinh Hoi 한국물리학회 2010 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.57 No.5
General analytic expressions for the absorption coefficient (ACF) of an intense electromagnetic wave (IEW) caused by confined electrons in doped semiconductor superlattices (DSSL) are obtained by using the quantum kinetic equation (QKE) for electrons in the case of electron-optical phonon scattering. A second-order multiphoton process is included in the result. The dependence of the ACF on the amplitude E0 and the photon energy hΩof an IEW, the plasma frequency ωp and the temperature T for a specific DSSL of n-GaAs/p-GaAs is achieved by using a numerical method. The computational results show that the dependence of ACF on the photon energy can be applied to optically detect the electric subbands in a DSSL.
Effect of Non-ionic Igepal CO-520 in Sonochemical Synthesis of Monodisperse Fe₃O₄ Nanoparticles
Vo Thanh Son,Le Van Phong,Md. Nazrul Islam,Tran Quang Hung,Sarah Kim,Jun-Ho Jeong,CheolGi Kim,Jong-Ryul Jeong 한국자기학회 2010 Journal of Magnetics Vol.15 No.3
We have investigated a surfactant-assisted sonochemical approach to produce monodisperse Fe₃O₄ nanoparticles (NPs). The non-ionic surfactant Igepal CO-520 (Poly(oxyethylene)(5) nonylphenyl ether) has been used for the preparation of NPs and the effects on the NP size, size distribution, and magnetic properties have been studied. The Fe₃O₄ NPs were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and vibrating sample magnetometry (VSM). The results reveal that the NPs prepared by a Igepal CO-520-assisted sonochemical method exhibit a narrow range of size distributions and a high monodispersity compared to the NPs from the conventional sonochemical method. The analysis of NPs prepared in the presence of the surfactant suggested that it could be used not only as a protector to prevent the oxidation of Fe (Ⅱ), but also as a controller to vary the size of the NPs.
Hoan Minh Tran,Lan Ngoc Tan Phan,Thang Van Le,Thuy Thuy Truong,Tam Huu Nguyen,Khuong Tung Truong,Le-Thu T. Nguyen,Mai Thanh Phong,Ha Tran Nguyen 한국고분자학회 2019 폴리머 Vol.43 No.4
A novel organic photocatalyst, 4-(10H-phenothiazin-10-yl)-N,N-diphenylaniline (PDPA) has been successfully synthesized from triphenylamine and phenothiazine moiety via Buchwald-Hartwig C-N coupling. The chemical structure of catalyst was characterized via proton nuclear magnetic resonance (1H NMR) and the optical properties were investigated via UV-vis spectroscopy. The PDPA has been applied as an organic photocatalyst for metal free atom transfer radical polymerization (O-ATRP). The well-controlled molecular weights of polymethacrylates have been obtained with high yield of 95% and narrow polydispersity index (Đ).