Vietnam and the great powers

Ausgehend von der Doi moi Poltik - einer Wirtschaftsreform die 1986 begann - hatte Vietnam seine grundsätzliche außenpolitische Linie, im speziellen sein politisches Verhalten gegenüber den Großmächten, anzupassen. Diese Arbeit möchte die entscheidenden Faktoren, die zu großen Veränderungen in der vietnamesischen Außenpolitik seit 1986 führten und die strategischen Ziele die Hanoi in den Beziehungen zu den Großmächten verfolgt (USA, China, Europäische Union, Russland, Japan und Indien), analysieren. Ich behaupte, dass die vietnamesische Außenpolitik gegenüber den Großmächten seit Doi moi einer Mischung von zwei theoretischen Paradigmen zusammensetzt: Realismus und Liberalismus. Die pragmatischen Ansätze Hanois sind Mittel zum Zweck um der Modernisierung und der Industrialisierung des Landes zu dienen. Diese Fallstudie über Vietnam versucht ein Beispiel dafür zu geben wie klein und mittelgroße Staaten Südostasiens auf die heutigen Großmächte, in der Zeit seit Ende des Kalten Krieges, reagieren. Ebenso wie die bekanntesten Zugänge westlicher Theorien im Bereich der internationalen Beziehungen dazu dienen, die Außenpolitik eines südostasiatischen Landes, in diesem Fall Vietnam, zu erforschen.Deriving momentum from Doi moi-an economic reform launched since 1986, Vietnam has to adjust its general foreign policy, especially its policy behaviors toward the great powers. This thesis aims to examine determinant factors leading to significant changes of the in Vietnamese foreign policy since 1986, and strategic approaches which Hanoi has been pursuing in dealing with the present-day great powers (the United States, China, the European Union, Russia, Japan and India). I argue that Vietnamese foreign relations toward the great powers since Doi moi can be configured by a mixture of two theoretical paradigms: realism and liberalism. Hanoi’s pragmatic approaches are aims to serve for the cause of national modernization and industrialization. This case study about Vietnam attempts to give an example of understanding how small and medium sized states in South East Asia respond to the present-day great powers in the post- Cold War era. And how mainstream approaches in Western theory of international relations make sense in identifying foreign relation pattern of a South East Asia country-Vietnam

Vietnam and the ASEAN Socio-Cultural Community (ASCC): Prospects, Challenges and Opportunities

Although there is a large literature on ASEAN regionalism, comparatively little attention has been devoted to Southeast Asia’s efforts to build a shared social and cultural community. This thesis examines how the ASEAN Socio-Cultural Community (ASCC) is understood in ASEAN and explores challenges that stand in the way of the Community being realized by its 2015 deadline. The study reviews the origins and response to the ASCC at both the regional level, and at the national level through a case-study of Vietnam’s participation. It argues that although the ASCC is an important component of the ASEAN Community building process and member states have proclaimed their determination to realize the ASCC by 2015, the reality in ASEAN with its “unity in diversity” and “ASEAN Way” norms, means there are many obstacles in the way. Divergent national interests and priorities have led to different priorities in designing and implementing the ASCC Blueprint in the period 2009-2015. The thesis concludes by speculating about the likely scenario for ASCC implementation. It argues that in 2015, the most likely scenario for the ASCC is one in which a nascent ASCC will be formed but with only some of its components in place. ASEAN needs a longer journey to realize its aspiration of a shared socio-culture community

Simulation du Comportement sous Irradiation aux Ions Lourds du Nanocomposite Au-SiO2

Metal-glass nanocomposites are interesting owing to their particular optical-properties. Ion irradiation can be used as a tool to fabricate nanocomposites. The aim of this thesis was to study, from a fundamental point of view, the behavior of gold nanoparticles (NPs) embedded in an amorphous silica matrix under irradiation. My contribution consists in the interpretation, by modeling and numerical simulation, of experimental results previously obtained by researchers of the Laboratoire des Solides Irradiés. In a first type of experiments, the system was irradiated with 4 MeV gold ions while in a second type the irradiation was performed by using 74 MeV krypton ions.For the study of the first type of experiments, the simulation by kinetic Monte Carlo (KMC) on rigid lattice was chosen and developed specifically to study the behavior of NPs irradiated at different temperatures. The simulations allows us to reproduce qualitatively the experimental results at any temperature. We found that the system evolves within a direct coarsening regime at high temperature (T>900 K) whereas at low temperatures (T60 nm) by the incident ions. We imagined a scenario for the mechanism of deformation which is based on the thermal expansion of the melted NP into the track produced by the incident ion in the matrix. Its implementation using a new simulation technique helped to refine certain elements of the scenario and to improve the overall understanding of the process. The qualitative agreement between the experimental data and the results obtained by the simulation validate the proposed mechanism.Les matériaux nanocomposites de type métal-verre sont intéressants en raison de leurs propriétés optiques particulières. La technique de fabrication utilisant les faisceaux d’ions est un outil prometteur pour les nanocomposites. L’objectif de cette thèse était d’étudier d’un point de vue fondamental le comportement sous irradiation de nanoparticules (NPs) d’or enfouies dans une matrice de silice amorphe. Ma contribution réside dans l’interprétation par modélisation et simulation numérique des résultats expérimentaux obtenus auparavant par des chercheurs du Laboratoire des Solides Irradiés. Dans le premier type d’expériences, le système a été irradié par des ions d’or de 4 MeV alors que dans le second type l’irradiation est effectuée avec des ions de krypton de 74 MeV.Dans la première partie, la simulation par Monte Carlo cinétique (KMC) sur réseau rigide a été choisie et développée spécifiquement pour étudier le comportement de NPs sous irradiation à différentes températures. Les simulations ont permis de reproduire qualitativement les résultats expérimentaux à toute température. Nous avons retrouvé en particulier le mûrissement d’Ostwald qui se produit à haute température (T>900 K) et la dissolution des NPs qui se produit à basse température (T60 nm) selon l’axe de l’ion incident. Nous avons imaginé un scénario du mécanisme de la déformation qui repose sur la dilatation thermique de la NP métallique fondue dans la région de la trace de l’ion incident. Sa mise en œuvre, grâce à une nouvelle technique de simulation développée spécialement, a permis d’affiner certains éléments du scénario et d’améliorer la compréhension globale du processus. L’accord qualitatif entre les données expérimentales et les résultats obtenus par simulation valide le mécanisme proposé

Effect of deposition time on gold nanodendrite porous structure and on signals of Hg(II) in environment

The influences of deposition time (tdep) for Au nanodendrite preparation on carbon cloth electrodes on the surface structure, electrochemical behavior and voltammetric signal for Hg(II) detection have been studied. The obtained results showed that from 60 s to 300 s, the longer deposition time, the larger dendrite length as well as the more increased density of dendrite structure became. Calculated from data showed that the electroactive surface area approached to the maximum value of 3.686 cm2 with tdep = 300 s. The typical electrochemical behaviour of the prepared electrodes was mass transfer diffusion to the electrode surface and being considered as planar diffusion. Using DPASV technique, the peak height of Hg(II) could appoach to 52 µA with tdep = 60 s. Keywords. Gold nanodendrite, deposition time, surface structure, electrochemical properties, mercury

Transformation Chlorophyll a of Spirulina platensis to Chlorin e6 Derivatives and Several Applications

BACKGROUND: Spirulina platensis contains a large amount of chlorophylls, chlorophyll a, that are starting materials to synthesize functionalized chlorins. Chlorin e6 (Ce6) as well as its derivatives are second generation sensitizers using in photodynamic therapy (PDT) of various cancers. In this study, we transfer chlorophyll a of S. platensis to Ce6derivatives and determine their several applications. AIM: to evaluate the effects of Ce6 derivatives to treat cancer cells. METHODS: Ce6 trimethylester was created from methyl pheophorbide a2 in S. platensis provided by the Hidumi Company, Nghe An province, Viet Nam. Hela cells were incubated with Ce6 trimethylester and the irradiated with the diode laser dose of 1.2 J/cm2/min through the system of filters £ 650 nm. MTT assay and clonogenic assay were used to determine survival rate and cloning efficiency of cells. Antimicrobial effect of Ce6 trimethylester with halogen light were studied with Propionibacterium acnes VTCC 0218 and Staphylococcus aureus VTCC 0173. RESULTS: From dry biomass (700 g) of S. platensis, after extracting chlorophyll a and methanolysis, 4.2 g of methyl pheophorbide a was obtained. The reaction to give Ce6 trimethylester with 82% yield was performed with potassium hydroxide (KOH) in MeOH/THF/CHCl3. After irradiation with a 650 nm laser at 1.2 J, the cell viability in all samples decreased with Ce6 trimethylester treatment, the survival declining trend of Hela cells treated with Ce6 trimethylester were proportional when concentration of Ce6 trimethylester increased. The rate of colony formation was declined as the concentration of Ce6 trimethylester treated was increased. The growth of both S. aureus and P. acnes can be inactivated by Ce6 trimethylester PDT. The MIC99 value against P. acnes VTCC 0218 and S. aureus VTCC 0173 of Ce6 trimethylester with halogen light was 1.25 μg/ml. CONCLUSION: The Ce6 trimethylester from S. platensis cultivated in Viet Nam could be used as a potential photosentizer for photodynamic therapy for treatment of cancer and acne

Evaluation of Pseudomonas stutzeri AM1 and Pseudomonas oleovorans ST1.1 isolated from shrimp pond sediments as probiotics for whiteleg shrimp, Litopenaeus vannamei culture

This study aimed to isolate the probiotic potential of nitrifying bacterial strains and to evaluate their effects on water quality and growth performance of the whiteleg shrimp, Litopenaeus vannamei. Based on an initial screening of 100 isolates identified from sediment samples, 12 strains could remove nitrogen compounds and two strains (Pseudomonas stutzeri AM1 and P. oleovorans ST1.1) showed highly efficient nitrogen removal ability. Within 96 h, total ammonia nitrogen (TAN) removal efficiency in the two strains was 28.0-31.6% and 21.5-24.9%, respectively. The water addition of 103 CFUmL-1 of P. stutzeri AM1 (T1) and P. oleovorans ST1.1 (T2) effectively reduced TAN, nitrite, nitrate, and total sulfide and increased the survival rate and biomass of shrimp. However, no significant differences were found between the control (T0) and treatment groups (T1 and T2) in the final weight, weight gain and specific growth rate of shrimp. Overall, P. stutzeri AM1 (T1) and P. oleovorans ST1.1 used as water supplements improved water quality and the survival rate of whiteleg shrimp

Preschool STEM Activities and Associated Outcomes: A Scoping Review

This review highlights the need for further investigation into the benefits of STEM activities in preschool children’s learning, girls’ engagement and learning of children with disabilities in the STEM field. The review process involved accessing 19 relevant studies from Scopus, ERIC and Google Scholar databases in March 2023. Through the synthesis of information from these studies, seven STEM activities were identified as effective in enhancing preschool children’s learning: educational robots, educational games, argumentative interactions, inquiry-based learning and engineering design, drawing and telling about engineers, free play and pretend play, and group membership. Each of these activities contributes to different learning outcomes for children. Moreover, the review emphasizes the importance of role-playing activities ‘as if’ engineers and scientists, facilitated by teachers, in fostering girls’ motivation and engagement in the STEM field from an early age. Long-term scientific interventions at home have a significant positive impact on the science literacy skills of deaf children. The implications of this review are particularly relevant for early childhood educators, as it provides valuable insights into the use of STEM activities to enhance children’s learning outcomes

DEWATS dissemination in Vietnam: achievements and lessons learnt

The speedy economic development and rapid growth of population and urbanization in Vietnam have created great pressure on the environment by its manufacturing process and human activities. Thus, it is necessary to protect the environment through policies and appropriate technology for the sustainable development of the country. The DEcentralized WAstewater Treatment Solutions (DEWATS) dissemination in Vietnam is one of the measures contributing to address this issue

Robust adaptive controller for wheel mobile robot with disturbances and wheel slips

In this paper an observer based adaptive control algorithm is built for wheel mobile robot (WMR) with considering the system uncertainties, input disturbances, and wheel slips. Firstly, the model of the kinematic and dynamic loops is shown with presence of the disturbances and system uncertainties. Next, the adaptive controller for nonlinear mismatched disturbance systems based on the disturbances observer is presented in detail. The controller includes two parts, the first one is for the stability purpose and the later is for the disturbances compensation. After that this control scheme is applied for both two loops of the system. In this paper, the stability of the closed system which consists of two control loops and the convergence of the observers is mathematically analysed based on the Lyapunov theory. Moreover, the proposed model does not require the complex calculation so it is easy for the implementation. Finally, the simulation model is built for presented method and the existed one to verify the correctness and the effectiveness of the proposed scheme. The simulation results show that the introduced controller gives the good performances even that the desired trajectory is complicated and the working condition is hard