Perceived Risk of Sharing Other People’s Information on Facebook: The Perspective of Young People in Ho Chi Minh City, Vietnam

Dinh Tien Minh,Tran Ngoc Thuy,Ngo Nguyen Gia Nghi,Nguyen Yen Vy,Nguyen Thi Thanh Lam,Pham Cong Minh KINFORMS 2021 Management Review Vol.16 No.2

In Vietnam, young people are gradually becoming the most accessible objects to social networks. With the development of technology, they usually use online social networks (ONS) as a tool to update information through multimedia content, which may contain other people s information. In different cases, other people s information will be shared and received for different purposes. Therefore, the risk is inevitable and may affect the privacy of individuals whose information is shared, causing turbulence in the community. This study aims to measure impact and find out the factors that influence the willingness of others to share information on social networks in Ho Chi Minh City by examining young people s perceptions that their activities on Facebook may be risky for other people s information. Besides that, the study proposes solutions to avoid possible risks when sharing information with others.

Preparation, characterization and evaluation of catalytic activity of titania modified with silver and bentonite

Dinh Bang Nguyen,Thanh Phuong Dao,Hung Thuan Tran,Van Noi Nguyen,안대희,Thi Dieu Cam Nguyen 한국공업화학회 2012 Journal of Industrial and Engineering Chemistry Vol.18 No.5

The aim of this study is to evaluate phenol degradation capability of silver modified titanium dioxide nanomaterial on bentonite support (Ag-TiO2/Bent). The material was synthesized as photocatalyst by adding Ag-TiO2 sol into bentonite suspension. The experimental results revealed that photooxidation activity of Ag-TiO2/Bent was greatly higher than that of Ag-TiO2 and TiO2/Bent. The phenol removal efficiency was 23.25%, 35.41% and 98.94% for Ag-TiO2, TiO2/Bent and Ag-TiO2/Bent, respectively. The dispersion of silver modified TiO2 on bentonite support significantly enhances photocatalytic activity under solar radiation due to surface plasmon resonance formation and prevention of anatase-to-rutile phase transformation.

Efficient Forest Fire Detection using Rule-Based Multi-color Space and Correlation Coefficient for Application in Unmanned Aerial Vehicles

Nguyen Duc Anh,Pham Van Thanh,Doan Tu Lap,Nguyen Tuan Khai,Tran Van An,Tran Duc Tan,Nguyen Huu An,Dang Nhu Dinh 한국인터넷정보학회 2022 KSII Transactions on Internet and Information Syst Vol.16 No.2

Forest fires inflict great losses of human lives and serious damages to ecological systems. Hence, numerous fire detection methods have been proposed, one of which is fire detection based on sensors. However, these methods reveal several limitations when applied in large spaces like forests such as high cost, high level of false alarm, limited battery capacity, and other problems. In this research, we propose a novel forest fire detection method based on image processing and correlation coefficient. Firstly, two fire detection conditions are applied in RGB color space to distinguish between fire pixels and the background. Secondly, the image is converted from RGB to YCbCr color space with two fire detection conditions being applied in this color space. Finally, the correlation coefficient is used to distinguish between fires and objects with fire-like colors. Our proposed algorithm is tested and evaluated on eleven fire and non-fire videos collected from the internet and achieves up to 95.87% and 97.89% of F-score and accuracy respectively in performance evaluation.

STABLE MINIMAL HYPERSURFACES WITH WEIGHTED POINCARÉ INEQUALITY IN A RIEMANNIAN MANIFOLD

Nguyen, Dinh Sang,Nguyen, Thi Thanh Korean Mathematical Society 2014 대한수학회논문집 Vol.29 No.1

In this note, we investigate stable minimal hypersurfaces with weighted Poincar$\acute{e}$ inequality. We show that we still get the vanishing property without assuming that the hypersurfaces is non-totally geodesic. This generalizes a result in [2].

Combining internal and external curing to improve quality of self-compacting concrete with consideration of climate effects

Nguyen, Hung Dinh,Mai, Luu,Nguyen, Hung Thanh Techno-Press 2021 Advances in concrete construction Vol.12 No.2

Self-compacting concrete used in reinforced concrete structures with high reinforcement ratios such as ports, tall buildings and bridges can bring benefits to the structures. However, the quality of self-compacting concrete is affected by climate conditions and curing methods. Climate conditions are dry and rainy seasons. Curing methods include external and internal curing. External curing by covering the surface of specimens with nylon sheet for zero hour, 4h, 6h and 24h was investigated in this study. Different amounts of lightweight sand to be able to hold water for internal curing were also examined. Results showed that with the combination of internal curing by using 20% lightweight sand to replace traditional sand and external curing by covering with nylon sheet for 24 hours, the compressive strength of self-compacting concrete in the dry season condition is higher than that of self-compacting concrete without lightweight sand ideally cured by soaking under water at laboratory condition.

A Study on the Poverty of Mountain People Depending on Forests

NGUYEN, Phuong Thi Minh,NGUYEN, Song Van,DO, Duc Tai,NGUYEN, Quynh Thi Thuy,DINH, Thanh Trung,NGUYEN, Hang Phan Thu Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.7

Livelihood capitals have a clear influence on livelihood development. As for the livelihood results, it has been pointed out in the analysis of the poor households that the ability of people to escape poverty depends especially on the access to livelihood capitals. This study aims to analyze the impacts of livelihood capital on poverty among mountain people who depend on forests through human capital, social capital, natural capital, physical capital and financial capital. This research employs the model of binary regression function. Independent variables x1, x2, …, xn are targets of livelihood strategy, vulnerability context, and livelihood capitals. These variables were selected to be included in the original model with dependent variable Y as poor and non-poor households. This study surveys households living in upland areas, near forests, and households of ethnic minorities. The results show that,out of the poor household rate, nearly 4% are newly-poor households or those falling back into poverty. Therefore, the government needs to pay more attention to this disadvantaged group and implements policies such as education and training policies, credit support policies, policies to support forest development, and payment for forest environmental services in the context of emerging countries like Vietnam.

Highly effective adsorption of organic dyes from aqueous solutions on longan seed-derived activated carbon

Nguyen Van Hung,Bui Thi Minh Nguyet,Nguyen Huu Nghi,Nguyen Mau Thanh,Nguyen Duc Vu Quyen,Vo Thang Nguyen,Dao Ngoc Nhiem,Dinh Quang Khieu 대한환경공학회 2023 Environmental Engineering Research Vol.28 No.3

In this study, longan seeds - an agricultural by-product was used to fabricate activated carbon (LSAC) through two-step pyrolysis with pre-carbonization at low temperature in the first step and then activation by H3PO4. LSAC with large surface area and porous structure exhibits an excellent capacity of absorption towards both cationic dyes (methylene blue (MB), rhodamine-B (RhB)) and anionic dyes (methyl orange (MO), congo red (CR)). Experimental data can be described well by the pseudo-second kinetic model. The maximum adsorption capacity based on Langmuir isotherm model was found as 502.84; 397.77; 464.66 and 350.64 mg.g−1 for MB, RhB, MO and CR, respectively. The adsorption of MB, RhB and CR on LSAC is spontaneous and endothermic, while that for MO is spontaneous but exothermic. Furthermore, the adsorption mechanism of dyes on LSAC was also studied showing that it can occur by electrostatic interaction, hydrogen bonding, the filling of pores involving the interaction between dye ions with specific functional groups such as –OH, –COOH, –NH2 and –PO43− on the LSAC surface. These results suggest that LSAC material may be envisaged as a promising adsorbent for treatment of wastewater in textile industries.

A regional approach for health risk assessment of toxicants in plastic food containers

Nguyen Lan Binh Thi,Thanh Truc Nguyen Thi,Nguyen Ngoc Tran Thi,Vu Dinh Khang,Lee Byeong-Kyu 한국독성학회 2023 Toxicological Research Vol.39 No.4

Plastic food containers are being used popularly, generating a waste of about 115 million tons in Vietnam. Such waste is causing environmental and health issues. This study conducted a field survey with 250 local people and selected 59 samples out of 135 plastic food containers collected in Go Vap district, Vietnam. Collected plastic samples identified compositions were PET 13.6%, PP 28.8%, PS 16.9%, and 40.7% undefined plastics. Collected plastic samples were classified based on the plastic type using recycling code and quantitatively analyzed with X-ray fluorescence spectroscopy method to assess concentrations of Cd, Sb, Pb, Hg, Sn, Cr, Br, Cl, and S. Most of these collected plastic samples (91.5%) were found to contain 8/9 hazardous substances and most elements contained in these plastics were below their standard thresholds. These elements in plastic samples could be divided as the result into three hazard groups: (1) high hazard group (Sb, Cl, and S); (2) medium hazard group (Cr, Br and Hg); and (3) low hazard groups (Cd, Pb and Sn). Among substances in the high hazard group, element Sb was assessed for its migration because only Sb is regulated in Vietnam in QCVN 12-1: 2011/BYT. Substances of Cl, S, Cr, Br, and Hg (group 1, 2) do not have regulations related to the method of decontamination. Thus, additional health risks need to be assessed using the USEtox model. Finally, this study proposed a screening process to assess the risk of toxicity of elements contained in plastic food containers through ISO 31000:2018.

Raman spectroscopy and quantum-mechanical analysis of tautomeric forms in cytosine and 5-methylcytosine on gold surfaces

Nguyen, Dinh Bao,Nguyen, Thanh Danh,Kim, Sangsoo,Joo, Sang-Woo Elsevier 2017 Spectrochimica acta. Part A, Molecular and biomole Vol.174 No.-

<P><B>Abstract</B></P> <P>Spectral differences between cytosine (Cyt) and 5-methylcytosine (5MC) were investigated by means of Raman spectroscopy with a combination of density functional theory (DFT) calculations. Surface-enhanced Raman scattering (SERS) revealed discriminating peaks of 5MC from those of Cyt upon adsorption on gold nanoparticles (AuNPs). Among the notable features, the multiple bands between 850 and 700cm<SUP>−1</SUP> for the ring-breathing modes of 5MC and Cyt could be correlated well with the simulated spectra based on the DFT calculations of the adsorbates on the gold cluster atoms. The relative energetic stabilities of the enol/keto and the amino/imino tautomeric forms of Cyt and 5MC have been estimated using DFT calculations, before and after binding six atom gold clusters. Among the six tautomeric forms, the 7H keto amino and the 4H imino trans forms are expected to be predominant in binding gold atoms, whereas the enol trans/cis conformers would coexist in the free gas phase. Our approach may provide useful theoretical guidelines for identifying 5MC from Cyt by analyzing Raman spectra on gold surfaces on the basis of quantum-mechanical calculations.</P> <P><B>Highlight</B></P> <P> <UL> <LI> Spectral differences between Cyt and 5MC were investigated by Raman spectroscopy. </LI> <LI> 7H keto amino and 4H imino trans tautomers were predicted to be most stable on gold atoms. </LI> <LI> Ring-breathing region modes revealed dissimilarities between Cyt and 5MC on Au. </LI> <LI> Simulated spectrum using the thermodynamic weights could be correlated with Raman data. </LI> <LI> Surface-enhanced Raman scattering provided a useful tool to discern 5MC from Cyt. </LI> </UL> </P> <P><B>Graphical Abstract</B></P> <P>[DISPLAY OMISSION]</P>

Visible light-driven photocatalytic degradation of doxycycline using ZnO/g-C₃N₄/biochar composite in aqueous solution

Nguyen Van Hung,Bui Thi Minh Nguyet,Nguyen Huu Nghi,Nguyen Minh Luon,Nguyen Ngoc Bich,Le Van Thanh Son,Nguyen Trung Kien,Dao Ngoc Nhiem,Nguyen Thanh Tuoi,Dinh Quang Khieu 대한환경공학회 2024 Environmental Engineering Research Vol.29 No.4

In the present work, ZnO/g-C₃N₄/biochar was prepared, and it was used for visible-light driven photocatalytic degradation of some colorants (methylene blue, rhodamine B, methyl orange) and some antibiotics (doxycycline, ciprofloxacin, amoxicilline). Biochar was prepared by pyrolysing Phragmites australis biomass. The ZnO/g-C₃N₄/biochar composite was synthesized with the alkaline hydrolysis method. The obtained materials were characterized by X-ray diffraction, scanning electron microscopy, transition electron microscopy, energy dispersive X-ray/elemental mapping, ultraviolet-visible-diffuse reflectance spectroscopy, photoluminescence spectroscopy, nitrogen adsorption/desorption isotherms and X-ray photoelectron spectroscopy. The results show that ZnO nanoparticles with a large surface area are highly dispersed on the g-C₃N₄ particle surface and biochar. The composite exhibits superior photocatalytic degradation ability toward doxycycline, a broad-spectrum antibiotic of the tetracycline compared with individual components (ZnO or g-C₃N₄) and satisfies stability after six treatment cycles. The kinetics and degradation mechanisms of doxycyline were also addressed. In addition, the present catalyst also exhibits the photocatalytic degradation of methylene blue, rhodamine B, methyl orange, ciprofloxacin and amoxicillin in visible-light regions.