Contamination of Selected Persistent Organic Pollutants (POPs) in Sediment of Some Areas in Vietnam

This chapter evaluates the contamination of selected persistent organic pollutants (S-POPs) in the sediment of some typical areas in Vietnam. S-POPs are composed of dichlorodiphenyltrichloroethanes (DDTs), hexachlorocyclohexanes (HCHs), polychlorinated biphenyl (PCBs), and polybrominated diphenyl ethers (PBDEs). The collected data and analyzed results indicated the wide occurrence of significant S-POPs residues in studied areas. The main sources of S-POPs are discussed by using composition analyses and diagnostic ratios of S-POPs indicator. Ecotoxicological risk of S-POPs is assessed. The obtained results have contributed to the assessment of S-POPs fate in the environmental sediment in Vietnam

Residue and Ecological Risk Assessment of Polybrominated Diphenyl Ethers (PBDEs) in Sediment from CauBay River, Vietnam

This research presents the first comprehensive survey of congener profiles (7 indicator congeners) of polybrominated diphenyl ethers (PBDEs) in sediment samples covering ten sites in CauBay River, Vietnam. Chemical analyses were carried out in gas chromatography–mass spectrometry (GC–MS) for tri- to hepta- brominated congeners. Results pointed out a non-homogenous contamination of the sediment with ∑7 PBDE values ranging from 8.93 to 25.64ng g−1, reflecting moderate to low contamination closely in conformity to other Asian aquatic environments. The general order of decreasing congener contribution to the total load was: BDE 47 > 99 > 100 > 154, similar to the distribution pattern worldwide. PBDEs had rare risks in the sediment of studied area. However, due to the propensity of PBDEs to accumulate in various compartments of wildlife and human food webs, evaluation of biological tissues should be undertaken as a high priority

Residue of Selected Persistent Organic Pollutants (POPs) in Soil of Some Areas in Vietnam

This chapter evaluates the contamination of selected persistent organic pollutants (S-POPs) in soil of some typical areas in Vietnam (mangrove forest, industrial, and urban areas in northern part). S-POPs are composed of polychlorinated biphenyls (PCBs) and polyaromatic hydrocarbons (PAHs). The collected data and analyzed results indicated the wide occurrence of significant S-POPs residues in study areas. The main sources of S-POPs are discussed by using composition analyses and diagnostic ratios of S-POPs indicator. Risk assessment of S-POPs in soil is assessed by using the guidance of the US Environmental Protection Agency. The obtained results have contributed to assess the S-POPs fate in the soil environment in Vietnam

Composition of animal manure and co-products

224pThis study was conducted to determine the real outflow of liquid effluents to be considered in balance calculations at the farm and regional levels in Vietnamese conditions. The variability of the chemical composition of a local dataset was analysed considering the highly heterogeneous wastes and byproducts used on crops. Near infrared spectroscopy (NIRS) was introduced to evaluate the feasibility of a rapid technique applied to animal wastes. Characterization of effluent outflows and water use and composition variation of solid co-products (compost and fish food) was carried out. Quantity of animal solid waste per pig head in the cold seasons was higher than in the hot season. Data collected from ten farms in Thai Binh (Vietnam), showed that the content of the main constituents in the fresh weight (FW) in the warm season was 17.3% OM total. Nitrogen, P2O5 and K2O totals were 160, 3.51 and 0.59%, respectively. Raising pigs in the cold season discharged 0.352kg N, 0.229 kg P2O5 and 0.148 kg K2O per metric ton live weight and he liquid part contributed 5.5, 2.1 and 12.8%, respectively. A total of 66 samples of compost and animal waste as fish feed were taken during summer, of which 46 were ready-to-spread compost, 20 others were animal excreta as fish feed. These results confirmed the fact that it is possible to use the animal waste source coming from the pig farms of Thai Binh province as a main nutrient for crops, especially for rice. After preliminary calibrations using NIRS spectrometry with local pig waste and co-products, perspectives are promising in terms of research and local development. A description of the design of the Chinese digester, more commonly called biogas digester and of the NIRS technique is provided

Deep Neural Network-Based Detector for Single-Carrier Index Modulation NOMA

In this paper, a deep neural network (DNN)-based detector for an uplink single-carrier index modulation nonorthogonal multiple access (SC-IM-NOMA) system is proposed, where SC-IM-NOMA allows users to use the same set of subcarriers for transmitting their data modulated by the sub-carrier index modulation technique. More particularly, users of SC-IMNOMA simultaneously transmit their SC-IM data at different power levels which are then exploited by their receivers to perform successive interference cancellation (SIC) multi-user detection. The existing detectors designed for SC-IM-NOMA, such as the joint maximum-likelihood (JML) detector and the maximum likelihood SIC-based (ML-SIC) detector, suffer from high computational complexity. To address this issue, we propose a DNN-based detector whose structure relies on the model-based SIC for jointly detecting both M-ary symbols and index bits of all users after trained with sufficient simulated data. The simulation results demonstrate that the proposed DNN-based detector attains near-optimal error performance and significantly reduced runtime complexity in comparison with the existing hand-crafted detectors

ANTECEDENTS OF TOURISTS’ LOYALTY: THE ROLE AND INFLUENCE OF TOURISM PRODUCTS, DESTINATION IMAGE IN HOIAN WORLD CULTURAL HERITAGE SITE

The study’s aim is to examine the antecedents of destination loyalty, and considers the role and influence of tourism products and destination image to international tourisms’ loyalty in case of HoiAn World Cultural Heritage Site. The study suggested an integrated approach to understand tourists’ loyalty model and investigate the empirical evidence about the relationship among tourism products, destination image, risk perception, tourist experience, destination satisfaction and tourists’ loyalty. This study also mentions important questions concerning how tourism products, destination image, tourist experience, risk perception, and tourists’ satisfaction affect tourists’ loyalty. Smart PLS3 is used to estimate and test the relationships in the research model. Mediation analysis and importance performance matrix analysis are also used to consider clearly the relationship between the constructs of research model. The study’s results indicate that tourism products, destination image, tourism experience, risk perception, and satisfaction are antecedents of international tourists’ loyalty in Hoi An World Cultural Heritage Site. And in them, tourism products affect significantly positively to destination imagine and satisfaction, beside destination image and satisfaction hold the role of mediator in this relationship. Implementing IPMA to identify the predecessors that have relatively high importance for loyalty but also a relatively low performance. The results pointed out that the constructs as satisfaction, tourism product, risk perception and image have a high importance for the tourist loyalty. The study added the antecedent of tourism products and risk perception to the model and could enrich the literature, pointing to be possibility of a destination loyalty model that can be applied to various contexts, especially after COVID- 19 pandemic. The study also discussed theoretical and managerial implications for marketing tourism

PSSA- INTERNATIONAL SOLUTION TO PROTECT THE BIODIVERSITY IN HA LONG BAY - CAT BA MARINE AREA

A Particularly Sensitive Sea Area (PSSA) is an important management tool for biodiversity protection of a marine area. At the time of designation of a Particularly Sensitive Sea Area, an associated protective measure, which meets the requirements of the appropriate legal instrument establishing such measure, must have been approved or adopted by IMO to prevent, reduce, or eliminate the threat or identified vulnerability. Information on each of the Particularly Sensitive Sea Areas (PSSAs) that has been designated by IMO is available on the nautical chart. The Vietnam’s coastal zones and islands are the isolated oceanic habitat of extremely rich marine life in very good condition which is important to the maintenance and dispersal of the marine life of the western tropical Pacific. Vietnam coastal areas are very high risk areas affected by maritime activities, particularly international shipping, therefore in the future identification of some Particularly Sensitive Sea Areas (PSSAs) is necessary. The first Particularly Sensitive Sea Area for Vietnam in Ha Long - Cat Ba was initially proposed in this paper