The Impact of Global Uncertainty Shocks on Macroeconomics: The Case of Vietnam

Ha Hong TRAN(Ha Hong TRAN ),Vinh Thi Hong NGUYEN(Vinh Thi Hong NGUYEN ),Nam Hoang TRINH(Nam Hoang TRINH ) 한국유통과학회 2022 The Journal of Asian Finance, Economics and Busine Vol.9 No.9

The global financial crisis of 2008–2009 and the COVID-19 pandemic that started in 2019 along with the slow and unstable recovery of the global economy have raised concerns about the impact of global uncertainty on the macroeconomics of the countries. The paper used the Structural Vector Autoregression (SVAR) model to examine the impact of global uncertainty shocks on Vietnam’s economy from the period 2008–2022. We found that Vietnam’s output dropped following the shock of global uncertainty, the peak was in the third month, and lasted for one year. Inflation in Vietnam had a rapid downturn in the first month, peaked in the seventh month, and took a long time to cease. When the economy experienced the shock of increased global uncertainty, Vietnam’s policy interest rate was adjusted downward. Additionally, we included a long-term interest rate to consider the overall impact of monetary policy into account. A decreasing trend was also found with this rate. The global uncertainty shock effects acted as the aggregate demand shocks, reducing output and inflation as the uncertainty increases and vice versa, thus monetary policy can be used to regulate Vietnam’s economy to deal with negative shocks without the trade-offs between output and inflation as aggregate supply shocks.

Korean Direct Investment in Vietnam An overview Analysis

Tran Chi Thien - Hoang Ha 대구대학교 경제경영연구소 2006 경제경영연구 Vol.4 No.1

Republic of Korea (RoK) and Vietnam share many complementary economic potentials. RoK has become the fourth largest foreign investor in Vietnam. This paper tries to review the basic information on the role of Korean direct investment (KDI), the KDI flow development, the KDI composition, competitiveness of Korean products, in where KDI should invest, make profits and the prospects of RoK Vietnam cooperation.

The potential efficacy of the E2-subunit vaccine to protect pigs against different genotypes of classical swine fever virus circulating in Vietnam

Ha Thi Thanh Tran,Duc Anh Truong,Viet Duc Ly,Hao Thi Vu,Tuan Van Hoang,Chinh Thi Nguyen,Nhu Thi Chu,Vinh The Nguyen,Duyen Thuy Nguyen,Kohtaroh Miyazawa,Takehiro Kokuho,Hoang Vu Dang 대한백신학회 2020 Clinical and Experimental Vaccine Research Vol.9 No.1

Purpose: To date, many kinds of classical swine fever (CSF) vaccines have been developed to protect against this disease. However, the efficacy of these vaccines to protect the pig against field CSF strains needs to be considered, based on circulating strains of classical swine fever virus (CSFV). Materials and Methods: Recombinant E2-CSFV protein produced by baculovirus/insect cell system was analyzed by western blots and immunoperoxidase monolayer assay. The effect of CSFV-E2 subunit vaccines was evaluated in experimental pigs with three genotypes of CSFV challenge. Anti-E2 specific and neutralizing antibodies in experimental pigs were analyzed by blocking enzyme-linked immunosorbent assay and neutralization peroxidize-linked assay. Results: The data showed that CSFV VN91-E2 subunit vaccine provided clinical protection in pigs against three different genotypes of CSFV without noticeable clinical signs, symptoms, and mortality. In addition, no CSFV was isolated from the spleen of the vaccinated pigs. However, the unvaccinated pigs exhibited high clinical scores and the successful virus isolation from spleen. These results showed that the E2-specific and neutralizing antibodies induced by VN91-E2 antigen appeared at day 24 after first boost and a significant increase was observed at day 28 (p<0.01). This response reached a peak at day 35 and continued until day 63 when compared to controls. Importantly, VN91-E2 induced E2-specific and neutralizing antibodies protected experimental pigs against high virulence of CSFVs circulating in Vietnam, including genotype 1.1, 2.1, and 2.2. Conclusion: These findings also suggested that CSFV VN91-E2 subunit vaccine could be a promising vaccine candidate for the control and prevention of CSFV in Vietnam.

Vietnam’s Bilateral Defense Diplomacy with Major Powers

Hoang Hai Ha 한국국방연구원 2018 The Korean Journal of Defense Analysis Vol.30 No.4

The paper explores the development of Vietnam’s bilateral defense diplomacy with world and regional powers including the United States, India, and Japan, with a particular focus on the period from 2009 to 2018. The paper nds that Vietnam’s multidirectional defense diplomacy is fundamentally shaped by its historical experience, the contemporary shift in the balance of power and the strategic challenges caused by China’s emerging power. By pursuing a multi–polar balance among major partners, Vietnam avoids being pulled into their rivalry, and keeps its non-alignment as well as strategic autonomy. The international defense cooperation has become further deepened and more substantive to satisfy Vietnam’s strategic interests including national security, territorial integrity, economic development and regime legitimacy. However, domestic and geo–strategic constraints, and asymmetrical economic interdependence with China lead this paper to suppose further challenges in the future of Vietnam’s defense diplomacy.

Unusually High‐Performing Organic Field‐Effect Transistors Based on π‐Extended Semiconducting Porphyrins

Hoang, Mai Ha,Kim, Youngmee,Kim, Minsik,Kim, Kyung Hwan,Lee, Tae Wan,Nguyen, Duc Nghia,Kim, Sung‐,Jin,Lee, Kwangyeol,Lee, Suk Joong,Choi, Dong Hoon WILEY‐VCH Verlag 2012 Advanced Materials Vol.24 No.39

<P><B>Highly conjugated porphyrin derivatives, H<SUB>2</SUB>TP and ZnTP, are synthesized.</B> J‐aggregations of the H‐aggregated dimeric porphyrin pairs are clearly observed by their single crystal structures that facilitate slip‐stacked charge transport phenomenon. In particular, their SC‐FETs show the highest field‐effect mobilities of 0.85–2.90 cm<SUP>2</SUP> V<SUP>−1</SUP>s<SUP>−1</SUP>. Furthermore, the ZnTP‐based OPT displays a dramatic photoinduced current enhancement with a high photoresponsivity of 22 000 A W<SUP>−1</SUP> under a very low light intensity (5.6 m W cm<SUP>−2</SUP>).</P>

Ampicillin adsorption onto amine-functionalized magnetic graphene oxide: synthesis, characterization and removal mechanism

Hoang Thu Ha,Tran Dinh Minh,Ha Minh Nguyet,Ajit Kumar Sharma 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.1

There are various chemical, physical and biological methods that have been applied to remove antibiotic residuals from aqueous environment. We investigated the removal of ampicillin (AMP) by a novel nanometer-size Fe3O4/graphene oxide/aminopropyltrimethoxysilane (FGOA). Based on the sol-gel method, the graphene oxide (GO) was first modified by aminopropyltrimethoxysilane (APTMS) to form GOA material containing both acidic and basic surface functional groups. The nanomagnetic iron oxide was then decorated to the GOA surface at various weight ratios by ultra-sonication in ethanol, resulting in different FGOA samples. The as-synthesized FGOA had single-layer structure and parallel array-like well-distributed Fe3O4. In laboratory-scale, the AMP treatment efficiency by FGOA with the ratio of Fe3O4 :GOA as 1 : 5 ratio reached the highest value around 94% within 100 min and only lost 1% after five regeneration cycles. The maximum adsorption capacity of FGOA was 294mg g1, significantly much higher than the previously published materials applied to AMP uptake. Interestingly, the optimum pH of FGOA ranged extensively from 4 to 9, revealing high application potential to real wastewater without any pH adjustment. The reasonable mechanism might be mainly attributed to electrostatic attraction, hydrophilic, and π-π interaction.

Uptake of arsenic and heavy metals by native plants growing near Nui Phao multi-metal mine, northern Vietnam

Ha, Nguyen Thi Hoang,Ha, Nguyen Thi,Nga, Tran Thi Huyen,Minh, Nguyen Ngoc,Anh, Bui Thi Kim,Hang, Nguyen Thi An,Duc, Nguyen Anh,Nhuan, Mai Trong,Kim, Kyoung-Woong Elsevier 2019 Applied geochemistry Vol.108 No.-

<P><B>Abstract</B></P> <P>Phytoremediation is a plant-based, environment-friendly, and cost-effective technology that can be potentially used to remediate contaminated media. This study was conducted to evaluate the phytoextraction and phytostabilization potential, two common techniques of phytoremediation, of 21 plant species growing naturally at the largest tungsten (W) mine in Vietnam—the second largest production of W in the world. The average concentrations in different soil fractions were in the following order: residue > organically complexed, Fe- and Mn oxide-bound > carbonate bound > exchangeable. The total concentrations of arsenic (As), cadmium (Cd), copper (Cu), and zinc (Zn) in the soil varied by 34–3390, 4.87–81.6, 14.3–2080, and 21.9–370 mg/kg, respectively. The concentrations of As, Cd, Cu, and Zn in the shoots ranged 0.71–2400, 0.05–5.55, 4.81–249, and 13.3–380 mg/kg-DW, respectively. The concentrations of As and Cd in all soil samples and Cu in 70% of soil samples collected around the mine fluctuated within 2–227, 3–54, and up to 21-folds higher than the maximum allowable limit for agricultural soils in Vietnam (QCVN 03-MT:2015/BTNMT). The results indicated that hyperaccumulation levels (mg/kg-DW) were obtained for only As in <I>Pityrogramma calomelanos</I> (2400) and <I>Pteris vittata</I> L. (1860). Based on the recorded hyperaccumulation levels, translocation and accumulation factors, biomass, and fast growth of these plants, <I>P. calomelanos</I> and <I>P. vittata</I> were considered to be promising native plants for the phytoextraction of As contaminated soils. <I>Bidens pilosa</I> L. also has great potential for phytostabilization of mining soils contaminated with As and heavy metals.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Soils near multi-metal (W–F–Cu–Au–Bi) mine were contaminated with As, Cd, Cu. </LI> <LI> Arsenic in shoots were in order of Fern > Monocotyledonae > Dicotyledonae. </LI> <LI> <I>Pityrogramma calomelanos</I> and <I>Pteris vittata</I> L. suggested for phytoextraction of As. </LI> <LI> <I>Bidens pilosa</I> L. suggested for the phytostabilization of mining contaminated soils. </LI> </UL> </P>

Sustainable Development of Rice Production in the Mekong Delta, Vietnam

Hoang Thi Viet Ha(황티 비엣 하) 대한지리학회 2017 대한지리학회 학술대회논문집 Vol.2017 No.6

New π-extended triphenylene-based organic semiconductors in field-effect transistors

Hoang, Mai Ha,Nguyen, Duc Nghia,Ngo, Trinh Tung,Cho, Min Ju,Lee, Suk Joong,Choi, Dong Hoon Elsevier 2015 Synthetic metals Vol.209 No.-

<P><B>Abstract</B></P> <P>We demonstrated the synthesis of two new solution-processed triphenylene-based semiconductors and characterized their physical, optical, and electrochemical properties. Both were intriguingly capable of producing smooth films and high-quality microcrystalline objects. The single-crystal-based field-effect transistors (FETs) using these semiconductors displayed a maximum carrier mobility of ∼0.03cm<SUP>2</SUP> V<SUP>−1</SUP> s<SUP>−1</SUP> and a high on/off current ratio of ∼10<SUP>3</SUP>. Notably, the mobilities of the single-crystal-based FETs were measured to be two orders of magnitude greater than those of the thin-film transistors. To our knowledge, the carrier mobility obtained in this work is the highest ever reported for single-crystal FETs made of triphenylene analogues.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Two new disk-shaped semiconducting triphenylenes were synthesized. </LI> <LI> These molecules showed relatively low bandgap energies of ∼2.5eV. </LI> <LI> Their single-crystal-based field-effect transistors displayed a maximum carrier mobility of ∼0.03cm<SUP>2</SUP> V<SUP>−1</SUP> s<SUP>−1</SUP>. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Semiconducting 2,3,6,7,10,11-Hexakis{[4-(5-dodecylthiophen-2-yl)phenyl]ethynyl}triphenylene and Its Discotic Liquid Crystalline Properties

Hoang, Mai Ha,Cho, Min Ju,Kim, Kyung Hwan,Lee, Tae Wan,Jin, Jung-Il,Choi, Dong Hoon The Chemical Society of Japan 2010 Chemistry letters Vol.39 No.4

<P>We report on the design and synthesis of a new discotic liquid crystalline (LC) semiconducting material based on a triphenylene core. The molecule is readily soluble in common organic solvents to exhibit self-organizing long fiber structures with supramolecularly ordered columnar stacks that lie parallel to the substrate. Compared to all the previously reported triphenylene derivatives, this molecule has a relatively lower band gap energy (<I>E</I><SUB>g</SUB> = 2.53 eV), which makes it suitable for electronic and optoelectronic applications.</P>