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Anadara antiquata belongs to the Mollusca phylum, class Bivalvia, distributed in the coastal areas of Vietnam, with high nutritional and economic value. This study focused on the morphological characteristics and genetic diversity of A. antiquata in six regions of central Vietnam (Da Nang, Quang Nam, Phu Yen, Nha Trang, Binh Thuan and Thanh Hoa). The analysis of morphology of A. antiquata had the following results: shell width (SW: 41.45 mm), shell length (SL: 22.54 mm), right shell height (HRV: 29.27 mm), height left sheath (Coach: 28.49 mm), ligament length (LL: 25.74 mm), right trochanteric cavity depth (UHR: 7.90 mm), left trochanteric space depth (UHL: 8, 33 mm), right case symmetry (SRV: 8.58 mm) and left case symmetry (SLV: 8.41 mm). The mean shell volume (SV) and shell cavity volume (DSWT) were 4.45 ml and 11.11 ml, respectively. The average dry peel weight was 11.17 g. Genetic diversity showed that the 8 random primers used to analyze DNA polymorphisms of 41 A. antiquata had 87 amplified polymorphic DNA bands.

In this study, samples from 429 dog individuals across three main regions of Vietnam (Southern Vietnam (SVN), Central Vietnam (CVN), and Northern Vietnam (NVN)) were collected to analyze the 582 bp region mtDNA HVI, so as to study the genetic diversity and to screen the rare haplotype E in the Vietnamese village dog population. Nine new haplotypes A, two new haplotypes B, and three haplotypes C were unique to Vietnam dogs, in which the new haplotypes An3, An7, Cn1, and Cn3 concerned mutations at new polymorphism sites (15,517, 15,505, 15,479, and 15,933, respectively) which have not been previously reported. The detection of haplotypes A9 and A29, and the appearance of haplotype A200 in the two individual dogs sampled support that the Southeast Asian dog is the ancestor of today’s Australian dingo and Polynesian dog. The two rare haplotypes E (E1 and E4) were reconfirmed in Vietnamese dogs and discussed. This study also contributes to strengthening the theory of domestication of dogs to the south of the Yangtze River and the Southeast Asian origin of the dingo.

Interflow is an important water source contributing to river flow. It directly influences the near-surface water cycles for water resource management. This study focuses on assessing the interflow potential and quantifying the interflow in the downstream area along the Kaoping River in southern Taiwan. The interflow potential is first determined based on the modified index-overlay model, which employs the analytical hierarchy process (AHP) to calculate the ratings and weightings of the selected factors. The groundwater and surface water flow (GSFLOW) numerical model is then used to link the index-overlay model to quantify the interflow potential for practical applications. This study uses the Monte Carlo simulations to assess the influence of rainfall-induced variations on the interflow uncertainty in the study area. Results show that the high potential interflow zones are located in the high to middle elevation regions along the Kaoping River. Numerical simulations of the GSFLOW model show an interflow variation pattern that is similar to the interflow potential results obtained from the index-overlay model. The average interflow rates are approximately 3.5 × 104 (m3/d) in the high elevation zones and 2.0 × 104 (m3/d) near the coastal zones. The rainfall uncertainty strongly influences interflow rates in the wet seasons, especially the peaks of the storms or heavy rainfall events. Interflow rates are relatively stable in the dry seasons, indicating that interflow is a reliable water resource in the study area.

The slow positron beam system is an important device in the study of positron physics and techniques, especially in materials research. This paper presents obtained results in studying and applying a charged particles trajectory simulation program – Simion for building feasible design models for the system. The built models with different designs based on reference designs of some typical systems include a straight-shaped model, a 500 bent-shaped model and a 900 bent-shaped model. Some positron beam trajectory calculation tests have been performed for comparison between the models. From the tests, the 500 bent-shaped model has been proposed as a conceptual design for building a real slow positron beam system in the future in Vietnam.

The landforms and human activities play important roles in quantifying surface water and groundwater interactions (SGIs) for water resources management. The study uses the groundwater and surface water flow (GSFLOW) model to quantify the dynamics of SGIs in the Pingtung Plain groundwater basin (PPGB) in southern Taiwan. Specifically, the study uses a physical-based numerical model to quantify the spatial and seasonal variations of water cycles influenced by complex fluvial landform conditions and human activities. Results of the model calibrations show good agreement with the data obtained from the available groundwater monitoring network and the selected stream stations. The basin-scale water budgets show highly nonuniform precipitation in the study area, and over 80% annual precipitation is from wet seasons in the PPGB. With high permeable surficial deposits in the PPGB, the year-averaged surface runoff and infiltration are approximately 57% and 40% of the total precipitation. The fluvial landforms with the high slope in the PPGB lead to 70% of annual surface runoff that becomes the streamflow, and the interflow dominates water interactions near streambeds. Results show that the interflow rate in the wet seasons is 200% more than that in the dry seasons. The net groundwater discharge to the streams is relatively small as compared to the interflow. Only 10% of the river flow is from the net groundwater discharge. In the PPGB, The pumping-induced variations of groundwater levels are insignificant as compared with the factor of the natural landforms. Because of the relatively small area of the proposed artificial lake, the contribution of the artificial lake on the local water budgets is insignificant, indicating the low impact of the artificial recharge lake on the surface water environment.

Slow Positron Beam (PB) is an important device in the study of positron physics and techniques, especially in material research. For the purpose of conceptual designing a PB system, we have simulated a PB system with the parameters of an existing system – SPONSOR, using SIMION software. The simulation results have been compared with the SPONSOR published results. The effect of magnetic field in controlling beam trajectory has been investigated in the preaccelerated and accelerated stages. The simulation results of using steering coils to adjust the beam trajectory are also presented in this report.

The theoretical study of the positron annihilation in complex material such as zeolite is greatly significant to support and increase the accuracy analysis of the material structure from the experimental data of the positron annihilation. The mordenite zeolite is a big and complicated structure consisting of channels and cavities. The analysis of the mordenite structure is studied by the PALS so depending on the selection of the positron lifetime components of the positron annihilation spectra fitting methods. Therefore, these positron life times in on TO4, Na, Ca, K, Fe, H2O and the rings which form the channels and cavities are sophisticatedly studied by the DFT calculation using Ab-initio. The mordenite and modified mordenite zeolite structures are precisely analyzed, and the physical behaviors of the positron in these are more understood by these theoretical results.