Sustainability assessment of coastal ecosystems: DPSIR analysis for beaches at the Northeast Coast of Vietnam

The Northeastern coastal zone of Vietnam possesses high biodiversity and rich ecosystems like coral reefs, seagrasses, beaches and mangroves. It also includes the Ha Long Bay Natural Heritage site (UNESCO 1994) and the Cat Ba Biosphere Reserve (MAB/UNESCO 2004) as well as hosts the Economic Development Triangle (Hai Phong-Ha Noi-Quang Ninh) established by the Government of Vietnam. As one of the coastal ecosystems, sandy beach ecosystems attracted more attention during recent decades because of their essential role for human welfare and in environmental protection. A few studies concentrated on sustainable management of sandy beach based on environmental and ecological protection and enhance the beach quality for recreational use. The DPSIR (Driving force Pressure State Impact Response) framework describes the logical interaction among systems and finds out the cause and consequence of social-economic development activities to the environment and resources. In this study, the DPSIR was applied on the sandy beaches in the Northeastern coast of Vietnam to reveal the main environmental problems on sandy beaches including the decline of the natural landscape around the beaches and the degradation of the environment. It also pointed out that tourism development in association with urbanization and sea reclamation is the main driving forces for environmental degradation of the sandy beaches. Therefore, local authorities of Hai Phong and Quang Ninh should take into account several main responses to policies on inter-province coordination and managerial measures with a wider scope, which integrate socio-economic and physical factors, proximity, accessibility, and neighborhood to manage healthy coastal ecosystems and sandy beaches in particular. An integrated coastal management program for the Northeastern coast of Vietnam needs to be developed and carried out to follow the laws of Vietnam as well as to meet local urgent requirements

MACRO-ZOOPLANKTON ABUNDANCE IN RELATION TO METAL ACCUMULATION AND WATER QUALITY IN TRUC BACH LAKE

Urban lake pollution is one of the serious issues due to suffering of waste discharged from householders. However, there is a gap of knowledge about the diversity of zooplankton species and how metals accumulate in zooplankton in urban ecosystems. We addressed this by determining the rule of blooming macro-zooplankton in Truc Bach lake and levels of two essential metals: copper (Cu), and zinc (Zn) and of three non-essential metals: arsenic (As), and lead (Pb) in water samples were determined. The results showed that Cladocerans and copepods are macro-zooplankton dominant species in Truc Bach Lake. Water temperature significantly affects the variety of copepod blooming. Arsenic concentration in water collected from the lake exceeded the safety level of current Vietnamese regulation. As concentration in macro-zooplankton positively correlated with metal concentrations in the water (p 0.05) while the concentration of Cu, Zn, and Pb in water has no significant correlation with the metal in zooplankton’s body. The relative abundance of adult copepods in Truc Bach lake had a negative correlation with As concentration in water (p = 0.01). The higher As concentration in water, the lower relative abundance of copepods was found in the sample

Factors Affecting Intention to Transact by Electronic Payment in Supermarkets in Hanoi (Vietnam)

The study is conducted based on 391 observational samples in Hanoi with the context that Vietnam is promoting digital transformation in all aspects of life. Research has shown that: “Performance Expectancy”, “Effort Expectancy”, “Social Influence”, “Facility Conditions” and “Security and Privacy” have a positive impact on the e-payment intention of shoppers in supermarkets in Hanoi, especially Facility Condition is the most influential factor. In addition, the result also found that the age variable also acts as a crucial driver factor in the process of forming human intentions, while the gender variable has no impact on that process. The study of factors that can affect the intention of electronic payment contributes more theoretical basis in this field, as well as provide a more realistic view of the situation of using electronic payment in Vietnam in general, creating a driving force for the promotion of the development of electronic payment regularly in terms of frequency of application and diversity of application forms. In this study, the authors, besides inheriting domestic and foreign studies on electronic payment, also develop innovative points compared to previous studies. The study uses the new approach to study electronic payment through transactions in supermarkets and assess the role of demographic variables on user intention. Keywords: electronic payment, supermarket, solutions DOI: 10.7176/EJBM/13-11-02 Publication date:June 30th 202

An efficient neural optimizer for resonant nanostructures: demonstration of highly-saturated red silicon structural color

Freeform nanostructures have the potential to support complex resonances and their interactions, which are crucial for achieving desired spectral responses. However, the design optimization of such structures is nontrivial and computationally intensive. Furthermore, the current "black box" design approaches for freeform nanostructures often neglect the underlying physics. Here, we present a hybrid data-efficient neural optimizer for resonant nanostructures by combining a reinforcement learning algorithm and Powell's local optimization technique. As a case study, we design and experimentally demonstrate silicon nanostructures with a highly-saturated red color. Specifically, we achieved CIE color coordinates of (0.677, 0.304)-close to the ideal Schrodinger's red, with polarization independence, high reflectance (>85%), and a large viewing angle (i.e., up to ~ 25deg). The remarkable performance is attributed to underlying generalized multipolar interferences within each nanostructure rather than the collective array effects. Based on that, we were able to demonstrate pixel size down to ~400 nm, corresponding to a printing resolution of 65,000 pixels per inch. Moreover, the proposed design model requires only ~300 iterations to effectively search a 13-dimensional design space - an order of magnitude more efficient than the previously reported approaches. Our work significantly extends the free-form optical design toolbox for high-performance flat-optical components and metadevices

RESEARCH ON FACTORS INFLUENCING THE INTENT TO USE NETFLIX MOVIES IN VIETNAM

Abstract The Netflix movies market is steadily growing, especially during the complex COVID-19 pandemic. Consumers, instead of opting for free movie streaming services with potential risks and copyright violations, are choosing to pay for a better experience while emphasizing responsibility for protecting copyrights and supporting authors and producers. This research aims to examine the factors influencing the intent to use Netflix movie streaming services among surveyed individuals, primarily focusing on employees aged 18 to 22 in Vietnam. Participants were surveyed through online and offline questionnaires. The author conducted logistic regression analysis, treating the use of Netflix movies as the dependent variable, with five independent variables sourced from a literature review. Through online and offline survey questionnaires and multivariate regression models, the study identified and concluded the factors influencing employees' intent to use Netflix movie streaming services in Vietnam. Data were quantitatively analyzed using IBM SPSS 20.0. The research results identified five positively influencing factors on the intent to use Netflix movie streaming services: Price perception, Risk perception, Attitude, Ethical awareness, Subjective norms. Among these factors, Price perception had the strongest influence on the intent to use Netflix movies, while the Subjective norms factor was found to be insignificant. Consequently, the article suggests managerial implications for businesses to attract customers and promote the Netflix movies market

The Impact of FDI, International Trade, and National Economy on People’s Standard of Living in ASEAN Countries

This research paper analyzes the impact of foreign direct investment (FDI), international trade, and national economy on the standard of living of people in ASEAN member countries, using data from 2012-2021. The study uses data from this period to examine the effects of these variables on the standard of living in ASEAN member countries. The results indicate that international trade and national economy have a significant influence on people's standard of living in the region. However, the effect of FDI varies depending on the level of development of the country. While FDI doesn't have much effect on developing countries, it has a negative impact on developed countries. The study also provides insights for policymakers on how to promote economic growth and improve the quality of life for people in the ASEAN. Keywords: FDI, international trade, national economy, the standard of living, ASEAN DOI: 10.7176/EJBM/15-6-10 Publication date:March 31st 2023

IDENTIFICATION AND CHARACTERIZATION OF A PURPLE NONSULFUR BACTERIUM ISOLATED FROM COASTAL AREA OF HAI PHONG FOR USING IN PRODUCTION OF UNSATURATED FATTY ACID (OMEGA 6, 7, 9)

Purple nonsulfur bacteria are a group that has so much biotechnological applications, particularly in producing of functional food rich with unsaturated fatty acids. A purple nonsulfur bacterium (named HPB.6) was chosen based on its strong growth, high lipid and synthesis of unsaturated fatty acid (omega 6,7,9). Studying on basic biological characteristics showed that the cells of HPB.6 were observed as ovoid-rod shape, none motility, Gram negative staining. The diameter of single bacterium was about 0.8-1.0 µm. The cells divide by binary fission and had bacteriochlorophyll a (Bchl a). This bacterium grew well on medium with carbon and nitrogen sources such as acetate, succinate, pyruvate, butyrate, glutamate, arginine, leucine, tyrosine, alanine, methionine, threonine, glutamine, yeast extract and NH4Cl. This selected strain grew well on medium with salt concentrations from 1.5 - 6.0% (optimum 3%), pH from 5.0 to 8.0 (optimum at pH 6.5) and could withstand Na2S at 4.0 - 5.2 mM. Based on morphological, physiological properties and 16S rRNA analysis received demonstrated that HPB.6 strain belongs to the species Rhodovulum sulfidophilum

Room-temperature strong coupling in a single photon emitter-dielectric metasurface system

Single-photon sources with high brightness and long coherence time are promising qubit candidates for quantum technology. To this end, interfacing emitters with high-finesse cavities is required, especially in the strong coupling regime, which so far has only been limited to cryogenic temperatures. Here, we experimentally demonstrate, at room temperature, strong coupling between a single photon emitter and a novel cavity based on optical bound states in the continuum. A remarkably large Rabi splitting of ~4 meV is achieved thanks to the combination of the narrow linewidth and large oscillator strength of emitters in hexagonal boron nitride and the efficient photon trapping of the cavity. Our findings unveil new opportunities to realise scalable quantum devices and explore fundamentally new regimes of strong coupling in quantum systems at room-temperature