412 research outputs found
Has the U.S.-Vietnam Bilateral Trade Agreement Led to Higher FDI into Vietnam?
In December 2001, a Bilateral Trade Agreement (BTA) came into effect that normalized economic relations between the United States and Vietnam. The resulting surge in trade surpassed most expectations. The impact of the BTA on FDI, however, has been less visible, especially with regard to U.S. FDI into Vietnam. This paper uses new data that accounts for FDI by U.S. subsidiaries resident in third counties to show that U.S. firms have been much more aggressive investors in Vietnam than normally reported in typical bilateral FDI data using Balance of Payments definitions of capital flows. While the U.S. is widely reported as the 11th largest investor into Vietnam, the new data shows that U.S.-related FDI exceeded all other countries in 2004. Although a formal model is not developed, descriptive data supports strongly the conclusion that the BTA has had a major impact on FDI into Vietnam, especially with regard to FDI from U.S. multinationals.FDI; Trade Agreement
Occurrence of persistent toxic substances in soils, sediments, fishes and human breast milk in southern Vietnam
Global contamination and toxic effects of persistent toxic substances (PTSs) have been an emerging environmental issue and have received considerable attention during the past four decades. The rapid agricultural and industrial growths as well as the expansion of urban areas in Hochiminh City and Mekong River Delta, two of the most densely populated areas in the world with about 26 million peoples, result in the widespread contamination of PTSs in southern Vietnam. Due to adverse effects to human health and environment, more attention has been paid to PTSs in Vietnam since the early 1990s. However, these works mainly focused on PTSs in water, soil and sediment media. PTSs in animals, birds and human (blood, adipose tissue, breast milk, etc.) have drawn less attention due to high cost of research and the need of sophisticated analytical techniques. With the support of Swiss Agency for Development and Cooperation (SDC) project in the frame of a collaboration between Vietnam and Switzerland, we have carried out the research named "Persistent Toxic Substances in southern Vietnam; Development analytical methods, bioaccumulation and modeling". Our research has established suitable analytical methods, which is able to analyze simultaneously PCBs, PBDEs, OCls pesticides and especially, mirex and toxaphene, which are analyzed for the first time in Vietnam, in various matrices such as soil/sediment, fish and human breast milk samples by HRGC/LRMS. The sampling sites (including Hochiminh City, Dongnai â Baria Vungtau province and Mekong Delta) have been selected based on previous studies in Vietnam and collected documents from Vietnam Environment Administration and POPs Project of Vietnamese government. Twenty-one PCB congeners, twelve PBDE congeners and twenty-six organochlorine pesticides were chosen for research due to their high toxicities. Soil, sediment, fish tissue, and human breast milk were selected as the matrices to examine the PTSs residue. The obtained results showed that PTSs levels of soil and sediment samples in southern Vietnam are not so high, e.g. DDTs and PCBs levels are lower than those in previous studies in Vietnam. Endosulfans were found in almost all sites suggesting the widespread contamination due to their large usage in agriculture. Toxaphene was only found in soil close to agrichemical warehouse at high level indicating potential source of toxaphene from the pesticide stockpiles. PBDEs were detected in most of the samples but at the low levels, which shows a possibly atmospheric deposition source. Other PTSs were detected at low levels (< 5 ng/g dry wt.) or below LOD of the analytical method. PTSs concentrations in wild fish samples from Saigon and Tien Rivers are lower than those determined in previous studies in Vietnam and in the world. However, unlike DDTs, PCBs showed a slow decreasing in fish samples and this suggests a continuous contamination. Besides, due to large usage in agricultural activities, endosulfans were also found in almost all wild fish samples from Saigon and Tien River (23.9 and 8.3 ng/g lipid wt., respectively). Other PTSs were detected at low levels (< 5 ng/g dry wt.) or below LOD of the analytical method. PTSs levels in human breast milk of HCMC residents are lower than those in previous study (except PCBs and CHLs). The higher PCB residues observed in human breast milk from HCMC suggest continuously high exposure to PCBs via the food chain to human. In this study, PTSs levels in human breast milk of primiparous mother higher than those in multiparous mothers. This trend well agrees with previous study in Hanoi and HCMC. By using statistic methods for obtained results (cluster analysis and PCA), we have shown the similarity of PTSs profiles pattern between landfill soil, TN-SG River sediments and Saigon River fish samples. Logically, we might suggest that there is a transfer of PTSs compounds from landfill and TN-SG River to fish samples collected from Saigon river. Our results clearly demonstrate that municipal and industrial waste from landfill and urban activities of HCMC could be considered as PTSs pollution sources. The results of the present study have contributed to the improvement of PTSs research capability of Vietnam. This research also efficiently supports and serves the projects of monitoring, studying and evaluating impacts of PTSs on South Vietnam ecosystem during the implementation of NIP under Stockholm Convention
BLENDED LEARNING IN BADMINTON TRAINING FOR PROFESSIONALS: STUDENTSâ PERCEPTIONS AND PERFORMANCE IMPACTS
As with other subject areas, badminton instruction for practitioners is experiencing a lot of changes under the impact of technology. Recently there has been the possibility of moving badminton training classes to the online platform but there is no consensus on its efficacy. This study is conducted to study the effects of blended learning activities on the perceptions and performance of students in physical education. Forty students in physical education are selected and divided into two groups: an experimental group, and a control group. All groups in face-to-face learning sessions have the same curriculum, course-book, equipment and teaching method. The questionnaire and interview data show that students in blended class sessions had positive perceptions of learning activities. Article visualizations
Investigation of Ultrasonic Pulse Velocity Reduction in Reinforced Concrete Members Exposed to High Temperature
Nowadays, the fire resistance of reinforced concrete members is generally defined by material characteristics at elevated temperatures and temperature functions. However, the influence of steel reinforcement in concrete members exposed to high temperatures on the ultrasonic pulse velocity (UPV) measurements has still been limited. In this paper, the quality of concrete and steel reinforcement/concrete interface was assessed under high temperatures using UPV measurements. The specimens were classified into four categories: the control tested cubes without rebar; tested cubes with plain and ribbed steel rebars. Tested cubes with dimensions of 100x100x100 mm were cast and cured for 28 days at room temperature (20oC). After drying all specimens at 105oC for 48 hours, these cubes were subjected to four different temperature levels ranging from 150oC to 400oC for 4 hours before being cooled to room temperature. According to the measured values of UPV, the higher the temperature attained in specimens, the greater the following changes occurred in concrete: (i) the degradation within the concrete; (ii) the debonding of steel reinforcements in concrete
Tidal Asymmetry and Suspended-Sediment Transport in the Gironde Estuary (FRANCE)
Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv
COMPARISION OF THREE DIGESTION METHODS FOR SOIL ARSENIC DETERMINATION. APPLICATION FOR HO CHI MINH CITY SOIL ARSENIC ANALYSIS
Joint Research on Environmental Science and Technology for the Eart
A Passivity-based Control Combined with Sliding Mode Control for a DC-DC Boost Power Converter
In this paper, a passivity-based control combined with sliding mode control for a DC-DC boost power converter is proposed. Moreover, a passivity-based control for a DC-DC boost power converter is also proposed. Using a co-ordinate transformation of state variables and control input, a DC-DC boost power converter is passive. A new plant is zero-state observable and the equilibrium point at origin of this plant is asymptotically stable. Then, a passivity-based control is applied to this plant such that the capacitor voltage is equal to the desired voltage. Additionally, the sliding mode control law is chosen such that the derivative of Lyapunov function is negative semidefinite. Finally, a passivity-based control combined with sliding mode control law is applied to this plant such that the capacitor voltage is equal to the desired voltage. The simulation results of the passivity-based control, the sliding mode control and the passivity-based control combined with sliding mode control demonstrate the effectiveness and show that the capacitor voltage is kept at the desired voltage when the desired voltage, the input voltage E and the load resistor R are changed. The results show that compared with the passivity-based control, the passivity-based control combined with sliding mode control has better performance such as shorter settling time, 8.5 ms when R changes and it has smaller steady-state error, which is indicated by the value of integral absolute error (IAE), 0.0679 when the desired voltage changes. The paper has limitations such as the assumed circuit parameters
3-D numerical simulation of the tidal circulation in the Gulf of Tonkin, Vietnam
The purpose of this paper is to present 3-D numerical simulation of the tidal circulation in the Gulf of Tonkin. A sigma-coordinate system transformation is used to make possible a total fitting between the computing point-grid and the bottom topography as well as the free water surface. A turbulence-closure sub-model K-L which permits the parameterization of the turbulence mixing is also included. The studied domain, the whole Gulf of Tonkin, extends from the coastal zone of Quang-Ninh into Thua Thien Hue province and as far as Hai-Nam (China) island seawards. The model have been calibrated and verified by the observed data at six different stations for a three and seven-day periods. The results are in good agreement with the observed data. The kinetic energy distribution was considered
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