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This paper employs the theoretical foundations for subjective well-being to examine the impacts of two underlying dimensions of subjective well-being (psychological well-being and social well-being) on pro-environmental consumption behaviors (PECBs). In this research, the moderating role of exposure to positive environmental messages on media in the relationship between subjective well-being and PECBs is also examined.

This research uses a quantitative research method with data collected from an online survey questionnaire posted in Facebook groups related to PECBs in Vietnam.

Psychological well-being and social well-being are found to be separate significant predictors of PECBs. More importantly, exposure to positive environmental messages on media was found to reinforce the impacts of psychological well-being on PECB but not moderate the relationship between social well-being and PECB.

This research offers a new insight for encouraging PECB from the perspective of subjective well-being. Different from the extant perspectives, which usually examine subjective well-being as a unidimensional antecedent of PECB, the authors highlight that subjective well-being can influence PECB in two separate dimensions. Moreover, this research extends existing literature by accentuating the role of exposure to environmental messages in the association between different types of social well-being and PECB.

This paper employed the self-determination theory (SDT) to examine the synergistic impacts of intrinsic, extrinsic and prosocial motivations in promoting sustained pro-environmental consumption behaviors (PECB). To provide evidence for the study’s theoretical framework, the authors focus on the behavior of reducing single-use plastics.

A mall-intercept survey for consumption of single-use plastic products in three big cities of Vietnam (Hanoi, Da Nang and Ho Chi Minh city) was conducted to test the theoretical framework. In total, 468 consumers completed the questionnaires. Data were analyzed with SPSS and AMOS.

Intrinsic and prosocial motivations are found to be significant predictors of sustained PECB. More importantly, beyond the direct effects of intrinsic and prosocial motivations, the authors also found positive interaction effects between intrinsic and extrinsic motivation and between intrinsic and prosocial motivation on encouraging sustained PECB.

This research offers a new insight for encouraging sustained PECB. Different from the extant perspectives which usually deal with initiating PECB, the authors emphasize sustaining the behavior. Moreover, this research examines the interaction effects between intrinsic and extrinsic motivations and between intrinsic and prosocial motivations in sustaining PECB.

Depending on an experimental approach to find optimal parameters for producing fully dense (relative density > 99%) Inconel 718 (IN718) components in the selective laser melting (SLM) process is expensive and offers no guarantee of success. Accordingly, this study aims to propose a multi-scale simulation framework to guide the choice of processing parameters in a more pragmatic manner.

In the proposed approach, a powder layer, ray tracing and heat transfer simulation models are used to calculate the melt pool dimensions and evaporation volume corresponding to a small number of laser power and scanning speed conditions within the input design space. A layer-heating model is then used to determine the inter-layer idle time required to maximize the temperature convergence rate of the solidified layer beneath the power bed. The simulation results are used to train surrogate models to construct SLM process maps for 3,600 pairs of the laser power and scanning speed within the input design space given three different values of the underlying solidified layer temperature (i.e., 353 K, 673 K and 873 K). The ideal selection of laser power and scanning speed of each process map is chosen based on four quality-related criteria listed as follows: without the appearance of key-hole melting; an evaporation volume less than the volume of the d90 powder particles; ensuring the stability of single scan tracks; and avoiding a weak contact between the melt pool and substrate. Finally, the optimal laser power and scanning speed parameters for the SLM process are determined by superimposing the optimal regions of the individual process maps.

The feasibility of the proposed approach is demonstrated by fabricating IN718 test specimens using the optimal processing conditions identified by the simulation framework. It is shown that the maximum density of the fabricated parts is 99.94%, while the average density is 99.88% and the standard deviation is less than 0.05%.

The present study proposed a multi-scale simulation model which can efficiently predict the optimal processing conditions for producing fully dense components in the SLM process. If the geometry of the three-dimensional printed part is changed or the machine and powder material is altered, users can use the proposed method for predicting the processing conditions that can produce the high-density part.

This paper aims to examine the economic efficiency of Vietnamese 172 higher education (HE) institutions within the 2012–2016 inclusive period through the Data Envelopment Analysis (DEA) approach. The authors also compare public and private, multidisciplinary and mono-disciplinary, non-autonomy and autonomy, non-international and international HE Institutions’ efficiency.

This study derived from an unique dataset from the Ministry of Education and Training (MOET) of Vietnam. The data set comprises financial and academic annual reports of higher education institutions (HEIs). The authors achieved totally 204 Vietnamese HEIs, and the sample for analysis is 172 after the elimination of missing units, accounting for 84.3% entire of Vietnamese HEIs. The authors estimate the efficiency scores relying on these selected inputs and outputs by using the DEA method.

Overall, HEIs in Vietnam decreased their operational efficiency during the 2012–2016. It also seems that public universities operate in the absence of market mechanism so that they tend to be less efficient than their counterparts in private sector. Based on our analysis, the authors observe that the HEIs including the international programmes have higher efficiency scores rather than these without international programmes.

This study contributes to the theoretical aspects as follows. First, it enriches the existent efficiency literature on HE using the DEA approach. This stands out among similar studies in Vietnam in terms of duration (from 2012–2016) and data size (172 entities). Second, the research is the first to examine HEIs in terms of disciplinary (mono or multi-disciplinary) and autonomy (autonomous and non-autonomous), internalization (international programmes). These aspects have been silent in previous studies of HEIs in Vietnam.

Shipping is a major source of air pollution, causing severe impacts on the environment and human health, greatly contributing to the creation of greenhouse gases and influencing climate change. The research was investigated to provide a better insight into the emission inventories in the Red River in Hanoi (Vietnam) that is often heavily occupied as the primary route for inner-city waterway traffic.

The total emissions of seven different pollutants (PM₁₀, PM_2.5, SO_x, CO, CO₂, NO_x and HC) were estimated using the SPD-GIZ emission calculation model.

The results show that CO₂ has the most significant contribution to the gas volume emitted: 103.21 tons/day. Remarkably, bulk carriers are the largest emission vehicle, accounting for more than 97% of total emissions, due to their superior number and large capacity.

The result to have a roadmap for making efforts to fulfil its commitment so that it could achieve its net-zero climate target by 2050 in Vietnam as committed at COP26.

In this research, the number of vehicles and types of vessels travelling on the Red River flowing within Hanoi territory and other activity data are reported. The tally data will be used to estimate emissions of seven different pollutants (PM₁₀, PM_2.5, SO_x, CO, CO₂, NO_x and HC) using a method combining both top-down and bottom-up approaches.

The authors investigate the impact of standards compliance on the participation in the global value chain and labour value-added of Vietnam’s small and medium-sized enterprises (SMEs).

The authors use a three-period panel dataset of SMEs combined with Vietnam’s Provincial Competitiveness Index. The authors also use multiple econometric models; and with each model, the authors include all independent variables that are available from the study's data and that are suggested by the literature.

The authors find that standards compliance by Vietnam’s SMEs improved their participation in the global value chain via subcontracts with FDI multinational firms. The authors also find that standards compliance improved the value-added of labour in Vietnam’s SMEs, which is robust to the choice of econometric models.

The study's results suggest that better outcomes for firms and society will be possible if standards are recognised and respected.

This paper complements scant literature on the impact of standards compliance on global value chain participation via subcontracting work and labour value-added, especially in developing countries.

In Vietnam, there is a phenomenon that domestic tourists return to some tourist destinations despite their reputation of tourists being scammed. This study aims to focusses on Vung Tau City in Vietnam as a popular seaside destination to explain this interesting phenomenon.

Thereby, 22 domestic tourists who are repeated visitors and had experienced scams directly and/or indirectly in Vung Tau were interviewed and later took part in a self-evaluation.

The data shows that unreasonable charges, switching products, false reporting and dishonest middle-persons are the major dominant scams in the city. Furthermore, all visitors could be scammed regardless of gender, educational background or age. Even though scams may occur, the city remains to be a popular getaway destination for the Southern part of Vietnam due to its irreplaceable natural resources and visit intention of domestic tourists. The local authority has tried different ways to suppress issues related to tourist scams, however, due to their sociocultural and economic conditions, scams find ways to exist. Under this circumstance, domestic tourists tend to figure out how to handle scams by themselves whilst very few of them rely on the public sector to deal with them.

Finally, some practical strategies and recommendations are given as a reference for the local authority and businesses for long-term tourist business development.

This paper, respectively, investigates the common scams against domestic tourists in Vung Tau, reasons they still return to this destination, and finally, how these visitors attempt to avoid scams.

The consumption of rice that contains high levels of inorganic arsenic may cause human health risk. This study aims to determine As species concentrations, particularly iAs, in raw rice in Ho Chi Minh (HCM) City and its health risks.

A total of 60 polished raw composite samples of rice were purchased from traditional markets and supermarkets in HCM City. All samples were analyzed by HPLC-ICPMS for As species determination.

Mean concentrations of inorganic arsenic in all samples, which were purchased from supermarket and traditional market, were 88.8 µg/kg and 80.6 µg/kg, respectively. Overall, inorganic arsenic level was 84.7 µg/kg and contributed the highest proportion of arsenic species in rice with 67.7%. The proportion profiles for arsenic species were: As (III) (60 %); dimethylarsinic acid (32.2 %); As (V) (7.7 %) and methylarsonic acid (0.1 %). Inorganic arsenic level in raw rice was below the recommendation of World Health Organization. Using the benchmark dose recommended by the Joint FAO/WHO Expert Committee on Food Additives (JECFA), all exposure doses were lower than BMDL05. However, as the doses ranged from 3.0 to 8.6 of Margin of Exposure (MOE), the health risk of iAs from rice consumption remains public health concern.

The study results report on the surveillance data of the presence of inorganic arsenic in raw rice products, which are available in the supermarkets and traditional markets, and its health risk to consumers in a metropolitan city in Vietnam.