176 research outputs found

    DIURNAL CHANGE OF PAHS AND NITRO-PAHS IN THE ATMOSPHERIC PARTICULATE MATTER AT THE ROADSIDE IN HO CHI MINH CITY, VIETNAM

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    Joint Research on Environmental Science and Technology for the Eart

    PREMILINARY RESEARCH ON ARSENIC POLLUTION OF SURFACE AND GROUND WATER IN TRA NANG GOLD EXPLOITATION REGION-LAM DONG PROVINCE AND CAO LANH TOWN-DONG THAP PROVINCE

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    Joint Research on Environmental Science and Technology for the Eart

    The Distribution of Microplastics in Beach Sand in Tien Giang Province and Vung Tau City, Vietnam

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    Microplastics threaten the ecosystem because of undesirable properties such as non-biodegradability, easy-to-absorb persistant organic compounds, etc. They are found worldwide in marine, fresh water and beach sand environments. In this study, microplastics in beach sand samples from two sites in Tien Giang province and two sites in Vung Tau city were investigated. The results showed that the microplastics amount was 0 to 295 pieces/kg dry sand and they mainly distributed near estuarine areas. Microplastics were more prevalent at bathing sites than non-bathing sites. In Tien Giang fragments were the most dominant among the three types of shapes (fragments, fibers, granules) at 60.2%. In Vung Tau granules were most prevalent at 71.7%. The composition of the plastics was confirmed by Fourier-transform infrared spectroscopy. It was revealed that PE, PP and PS were the main types of plastics found in the sampling sites.

    Polycyclic aromatic hydrocarbons and nitro-polycyclic aromatic hydrocarbons in urban air particulate matter in Ho Chi Minh City, Viet Nam

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    Joint Research on Environmental Science and Technology for the Eart

    Distribution and Characteristics of Microplastics in Nhue - Day River Basin, Vietnam

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    The prevalence of microplastics (MPs) in the environment has had a significant impact on ecosystems and posed a major threat to human health. This study investigated the distribution and characteristics of MPs in the Nhue - Day River basin in Vietnam, which is a critical source of biodiversity and used to support the economic growth of about 12 million people. The effect of seasonal variation and anthropogenic activities on the MP abundance was assessed. The findings revealed that the MPs abundance was significant in this study area. The average abundance of MPs in the dry season (754 items/m3) was insignificantly higher than that in the rainy season (706 items/m3) with n=9. The range in the abundance of MPs in the dry and rainy seasons was 49-2,827 and 400-1,133 items/m3, respectively. Microplastics in fiber forms were dominant in both seasons. The majority of the collected MPs were in the 0.5-2.0 mm size range, varying from 71% to 100% of the total MPs depend on sampling point. The total percentage of MPs size 0.3-0.5 mm in the dry season was 56.97% compared to 119.85% in the rainy season, indicating that the MPs were broken into smaller pieces due to UV exposure and weather conditions. Colored items occupied the majority of the MPs. This study can be used to gain a better knowledge of MP pollution in Vietnam’s river water

    On the Effectiveness of Adversarial Samples against Ensemble Learning-based Windows PE Malware Detectors

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    Recently, there has been a growing focus and interest in applying machine learning (ML) to the field of cybersecurity, particularly in malware detection and prevention. Several research works on malware analysis have been proposed, offering promising results for both academic and practical applications. In these works, the use of Generative Adversarial Networks (GANs) or Reinforcement Learning (RL) can aid malware creators in crafting metamorphic malware that evades antivirus software. In this study, we propose a mutation system to counteract ensemble learning-based detectors by combining GANs and an RL model, overcoming the limitations of the MalGAN model. Our proposed FeaGAN model is built based on MalGAN by incorporating an RL model called the Deep Q-network anti-malware Engines Attacking Framework (DQEAF). The RL model addresses three key challenges in performing adversarial attacks on Windows Portable Executable malware, including format preservation, executability preservation, and maliciousness preservation. In the FeaGAN model, ensemble learning is utilized to enhance the malware detector's evasion ability, with the generated adversarial patterns. The experimental results demonstrate that 100\% of the selected mutant samples preserve the format of executable files, while certain successes in both executability preservation and maliciousness preservation are achieved, reaching a stable success rate

    Environmental Occurrence of Polycyclic Aromatic Hydrocarbons and Nitro-Polycyclic Aromatic Hydrocarbons in Particulate Matters in Ho Chi Minh City, Viet Nam and Osaka, Japan

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    大阪府立大学Viet Nam National UniversityPromoting Environmental Pesearch in Pan-Japan Sea Area : Young Researchers\u27 Network, Schedule: March 8-10,2006,Kanazawa Excel Hotel Tokyu, Japan, Organized by: Kanazawa University 21st-Century COE Program, Environmental Monitoring and Prediction of Long- & Short- Term Dynamics of Pan-Japan Sea Area ; IICRC(Ishikawa International Cooperation Research Centre), Sponsors : Japan Sea Research ; UNU-IAS(United Nations University Institute of Advanced Studies)+Ishikawa Prefecture Government ; City of Kanazaw

    CORROSION PROTECTION OF CARBON STEEL USING ZIRCONIUM OXIDE/SILANE PRETREATMENT AND POWDER COATING

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    Surface pretreatment plays important role in improvement of corrosion resistance and adhesion of organic coatings. A new generation of metal pretreatments based on nanosize zirconium oxide or ogranosilane film has been investigated recently as an alternative method to phosphatation. In this paper, ZrO2/silane composite film on carbon steel was prepared and characterised by field emission scanning electron microscopy, energy dispersive X-ray spectrum and electrochemical measurements. The effect of ZrO2/silane surface treatment on the protection properties of powder coating was studied by salt spray test and adhesion measurement. The results obtained showed that ZrO2 was rapidly precipitated on the steel surface after first 1 minute immersion and ZrO2/silane film formed after 4 minutes immersion give best protective properties. Powder coating on carbon steel with ZrO2/silane pretreatement has equivalent protection performance like powder coating with  phosphate pretreatment

    Research Priorities of Applying Low-Cost PM2.5 Sensors in Southeast Asian Countries

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    The low-cost and easy-to-use nature of rapidly developed PM2.5 sensors provide an opportunity to bring breakthroughs in PM2.5 research to resource-limited countries in Southeast Asia (SEA). This review provides an evaluation of the currently available literature and identifies research priorities in applying low-cost sensors (LCS) in PM2.5 environmental and health research in SEA. The research priority is an outcome of a series of participatory workshops under the umbrella of the International Global Atmospheric Chemistry Project–Monsoon Asia and Oceania Networking Group (IGAC–MANGO). A literature review and research prioritization are conducted with a transdisciplinary perspective of providing useful scientific evidence in assisting authorities in formulating targeted strategies to reduce severe PM2.5 pollution and health risks in this region. The PM2.5 research gaps that could be filled by LCS application are identified in five categories: source evaluation, especially for the distinctive sources in the SEA countries; hot spot investigation; peak exposure assessment; exposure–health evaluation on acute health impacts; and short-term standards. The affordability of LCS, methodology transferability, international collaboration, and stakeholder engagement are keys to success in such transdisciplinary PM2.5 research. Unique contributions to the international science community and challenges with LCS application in PM2.5 research in SEA are also discussed

    Differential Cytotoxicity of Curcumin-Loaded Micelles on Human Tumor and Stromal Cells

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    peer reviewedAlthough curcumin in the form of nanoparticles has been demonstrated as a potential anti-tumor compound, the impact of curcumin and nanocurcumin in vitro on normal cells and in vivo in animal models is largely unknown. This study evaluated the toxicity of curcumin-loaded micelles in vitro and in vivo on several tumor cell lines, primary stromal cells, and zebrafish embryos. Breast tumor cell line (MCF7) and stromal cells (human umbilical cord vein endothelial cells, human fibroblasts, and human umbilical cord-derived mesenchymal stem cells) were used in this study. A zebrafish embryotoxicity (FET) assay was conducted following the Organisation for Economic Co-operation and Development (OECD) Test 236. Compared to free curcumin, curcumin PM showed higher cytotoxicity to MCF7 cells in both monolayer culture and multicellular tumor spheroids. The curcumin-loaded micelles efficiently penetrated the MCF7 spheroids and induced apoptosis. The nanocurcumin reduced the viability and disturbed the function of stromal cells by suppressing cell migration and tube formation. The micelles demonstrated toxicity to the development of zebrafish embryos. Curcumin-loaded micelles demonstrated toxicity to both tumor and normal primary stromal cells and zebrafish embryos, indicating that the use of nanocurcumin in cancer treatment should be carefully investigated and controlled.3. Good health and well-bein
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