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Dong Van VU1,Tai Van PHAM2,Ghi Nha TRAN3,Anh Phuong Thi NGUYEN4,Cong Van NGUYEN5 한국유통과학회 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.6
This study seeks to examine the relationship between business resources (through VRIN: Valuable - valuable, Rare - scarce; Inimitable - difficult to adapt, Irreplaceable - hard to replace), dynamic capability, external cooperation, and efficiency of startups operating in the seafood export sector. Research data was collected randomly and conveniently from 250 enterprises in Ba Ria-Vung Tau province, Vietnam, from October 2020 to December 2020. After excluding those ineligible, the remaining 204 enterprises meet the research conditions. With the support of SPSS-AMOS 22 dedicated software, using the 5-step Likert scale and Structural Equation Modeling (SEM), the study conducted analysis steps such as verifying convergence, discriminant value, unidirectional and scale reliability when giving the components correlated freely in the critical model by Confirmatory Factor Analysis (CFA) analysis. Results of the study have shown that the enterprise resource factor - VRIN has a positive impact on dynamic capability, and outside cooperation. However, in contrast to previous studies, we found that the relationship between enterprise resources - VRIN and performance as well as the relationship between dynamics capacity and performance is not clear. This shows that seafood exporters need to promote, exploit and effectively use this precious resource to improve business efficiency.
Determinants of Intra-Industry Trade between Vietnam and Countries in TPP
NGUYEN, Ha Minh,QUAN, Binh Quoc Minh,LE, Huong Van,TRAN, Thinh Van Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.1
Intra-industry trade (IIT) has played an important role in international trade of Vietnam as a result of rapid growth of the country. This article investigates the level of IIT between Vietnam and 11 trading partners in Trans-Pacific Partnership (TPP) over the period 2000-2014. Although there have been a large number of empirical researches contributed to the determinants of IIT, most of them only pay attention on developed countries where the trade flows are similar due to similar demand structure and production technology. Until now, there is no study on intra-industry trade between Vietnam and countries in TPP that Vietnam recently signed a trade agreement in early 2016. IIT is measured by the Grubel-Lloyd index. The index shows that the extent of intra-industry trade between Vietnam and the trading countries is not high due to the level of economic development and the market size. The determinants of IIT are examined using a panel regression model. In the empirical analysis, the results indicate that Vietnam's intra-industry trade is positively correlated with country size, while it is negatively correlated with income dissimilarity, the trade openness, and geographical distance. This study contributes to the new theoretical trade theory on the evidence of developing country's IIT.
Tran Thi Tuong Van,Nguyen Duc Linh,Nguyen Chi Hieu,Bui Tan Nghia 한국화학공학회 2024 Korean Journal of Chemical Engineering Vol.41 No.4
The plating industry is one of the causes of hexavalent chromium Cr (VI) pollution in surface water, raising problems for human health and other living things. In this study, we synthesized CoFe 2 O 4 magnetic nanoparticles and coated them with cetyltrimethylammonium bromide (CTAB), a commonly used cationic surfactant, to form CTAB/CoFe 2 O 4 magnetic nanocomposite for Cr (VI) adsorptive removal application from aqueous solution. Characteristic properties of CTAB/ CoFe 2 O 4 were examined using scanning electron spectrometry, surface area apparatus, X-ray diff ractometer, Fourier transform infrared spectrometry, zeta potential analyzer, and vibrating sample magnetometer. The CTAB/CoFe 2 O 4 had superparamagnetic properties, being easily isolated from an aqueous solution and well regenerated by an external magnet. Besides, the CTAB molecules anchored onto the Co 2 FeO 4 nanoparticle surfaces could increase the positive charge and thus facilitate the electrostatic interaction with the Cr (VI) anions. Accordingly, the CTAB/CoFe 2 O 4 reached the Cr (VI) adsorption effi ciency of 89%, two times higher than the pure CoFe 2 O 4 , at an optimal pH of 2, an adsorbent dose of 1 g/L, and an initial Cr (VI) concentration of 10 mg/L. The CTAB/CoFe 2 O 4 magnetic nanocomposite would promise a high potential for Cr (VI) treatment from plating wastewater with simple separation, good adsorption capacity, and an inexpensive, nontoxic production process.
Significant enhancement of blue emission and electrical conductivity of N-doped graphene
Van Khai, Tran,Na, Han Gil,Kwak, Dong Sub,Kwon, Yong Jung,Ham, Heon,Shim, Kwang Bo,Kim, Hyoun Woo The Royal Society of Chemistry 2012 Journal of materials chemistry Vol.22 No.34
<P>Nitrogen (N)-doped graphene with different atomic percentages (2.3–4.7 at%) of N has been synthesized by thermal annealing of reduced graphene oxide (RGO) in ammonia gas for different times. The effects of annealing time on the structure, electrical and optical properties of N-doped graphene have been systematically investigated by using various analytical techniques. XPS, FTIR, Raman, and XRD studies show that there is a gradual structural change in N-doped graphene sheets with increasing annealing time, resulting from the increase of carbon and simultaneous decrease of oxygen and N contents. High resolution N1s spectra reveal that the pyridine-N and pyrrolic-N contents decrease with increasing annealing time, whereas the amount of quaternary-N increases. Importantly, it has been found that the annealing time caused significant changes in both the electrical and the optical properties of N-doped graphene. The electrical resistance of N-doped graphene is greatly reduced compared to that of GO and RGO, and found to further decrease with increasing annealing time, possibly due to the increase of sp<SUP>2</SUP> carbon networks and decrease of oxygen content as well as defects associated with the incorporation of N. The room-temperature photoluminescence (PL) properties of graphene oxide (GO), RGO and N-doped graphene were systematically studied with regard to the annealing time. The results showed that the PL spectrum of GO exhibits a peak emission maximum at around 700 nm, while that of RGO is found to be strongly blue-shifted with two distinct emission peaks: green emission at 485–500 nm and blue emission at 420–428 nm. For N-doped graphene samples, the blue emission intensity could significantly be enhanced by controlling the annealing time, which leads to a promising blue and green light-emitting material with controllable optical properties.</P> <P>Graphic Abstract</P><P>N-doped graphene was fabricated by annealing reduced graphene oxide in ammonia, by which electrical conductivity and blue emission were drastically enhanced. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c2jm33194b'> </P>
Magnetic-Assembly Mechanism of Superparamagneto-Plasmonic Nanoparticles on a Charged Surface
Tran, Van Tan,Zhou, Hongjian,Lee, Seunghun,Hong, Seong Cheol,Kim, Jeonghyo,Jeong, Se-Young,Lee, Jaebeom American Chemical Society 2015 ACS APPLIED MATERIALS & INTERFACES Vol.7 No.16
<P>One-dimensional magnetoplasmonic nanochains (MPNCs) were self-assembled using Au-coated Fe<SUB>3</SUB>O<SUB>4</SUB> core–shell superparamagnetic nanoparticles (Fe<SUB>3</SUB>O<SUB>4</SUB>@Au NPs) by applying an external static magnetic field. The assembly mechanism of the Fe<SUB>3</SUB>O<SUB>4</SUB>@Au NPs was investigated thoroughly, revealing that substrate–particle interactions, van der Waals forces, and magnetic forces play important roles in the formation and control of the MPNCs. Magnetic force microscopy (MFM) and vibrating sample magnetometry (VSM) were used to study the magnetic properties of the MPNCs, which were compared with those of Fe<SUB>3</SUB>O<SUB>4</SUB> nanochains.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2015/aamick.2015.7.issue-16/acsami.5b00904/production/images/medium/am-2015-00904e_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am5b00904'>ACS Electronic Supporting Info</A></P>
Data-driven approach to machine condition prognosis using least square regression tree
Van Tung Tran,양보석 대한기계학회 2009 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.23 No.5
Machine fault prognosis techniques have been profoundly considered in the recent time due to their substantial profit for reducing unexpected faults or unscheduled maintenance. With those techniques, the working conditions of components, the trending of fault propagation, and the time-to-failure are precisely forecasted before they reach the failure thresholds. In this work, we propose the least square regression tree (LSRT) approach, which is an extension of the classification and regression tree (CART), in association with one-step-ahead prediction of time-series forecasting techniques to predict the future machine condition. In this technique, the number of available observations is first determined by using Cao’s method and LSRT is employed as a prediction model in the next step. The proposed approach is evaluated by real data of a low methane compressor. Furthermore, a comparative study of the predicted results obtained from CART and LSRT are carried out to prove the accuracy. The predicted results show that LSRT offers the potential for machine condition prognosis.