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- Quan-Hoang Vuong (27)
- Anh-Tuan Le (17)
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- Electrospinning (8)
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The first Sustainable Development Goals (SDGs) of The United Nations aims to “end poverty in all its forms everywhere”. Its seven associated targets aim, among others, to eradicate extreme poverty for all people everywhere. In Vietnam, poverty eradication in ethnic minorities and mountainous areas are among the top priorities. This study aims to learn about farmers’ livelihoods associated with perceived difficulties in Chau Thai Commune, Nghe An Province, a rural mountainous area in Vietnam. A random sampling technique and a face-to-face interview method were employed to conduct a field survey in the region in 2018. The dataset collected from 215 households shows that Chau Thai Commune's livelihood largely depends on agriculture and forestry. Plantation forest and livestock are majo... |
We study a solution approach for a staffing problem in multi-skill call centers. The objective is to find a minimal-cost staffing solution while meeting a target level for the quality of service to customers. We consider a common situation in which the arrival rates are unobserved random variables for which preliminary forecasts are available in a first stage when making the initial staffing decision. In a second stage, more accurate forecasts are obtained and the staffing may have to be modified at a cost, to meet the constraints. This leads to a challenging two-stage stochastic optimization problem in which the quantities involved in the (nonlinear) constraints can only be estimated via simulation, so several independent simulations are required for each first-level scenario. We p... |
Quorum sensing is a well-known term for describing bacterial cell–cell communication. Bacteria use quorum sensing pathways to respond to external factors such as nutrient availability, defense mechanisms, and coordinate host toxic behaviors such as biofilm formation, virulence production, and other pathogenesis. Discovery of novel compounds which inhibit quorum sensing without being antibiotic are currently emerging fields. Herein, the library of fifteen benzo[d]thiazole/quinoline-2-thiol bearing 2-oxo-2-substituted-phenylethan-1-yl compounds was designed, synthesized and evaluated to find novel quorum sensing inhibitors. Firstly, compounds were evaluated for their growth inhibitory activities at high concentrations up to 1000 μg mL−1 toward Pseudomonas aeruginosa. Under our conditi... |
MgO is an abundant mineral in the rocky mantle of terrestrial planets, but its melting behaviors remain enigmatic. Here we introduce a simple theoretical model to investigate the B1-liquid transition of MgO up to 370 GPa. Vibrational free energies of B1-MgO are fully computed by the moment recurrence technique in quantum statistical physics. On that basis, we associate the melting temperature with the isothermal bulk modulus via the work-heat equivalence principle. This strategy allows us to quantitatively explain recent experimental data. Our numerical analyses would yield insights into planetary dynamics and evolution. |
Freshwater shortage and the growing demand for electricity are the most common issues on the path toward achieving global sustainability. Therefore, finding creative solutions involving the use of renewable energy sources presents the main challenge. Herein, we developed a cost-effective and highly efficient 2-in-1 integrated conical device consisting of multi-walled carbon nanotubes deposited filter paper, and iron wire, capable of simultaneously generating not only freshwater but also electricity from seawater. |
We execute the quantum eraser, the Elitzur–Vaidman bomb, and the Hardy’s paradox experiment using high-level programming language on a generic, gate-based superconducting quantum processor made publicly available by IBM. The quantum circuits for these experiments use a mixture of one-qubit and multi-qubit gates and require high entanglement gate accuracy. The results aligned with theoretical predictions of quantum mechanics to high confidence on circuits using up to 3 qubits. The power of quantum computers and high-level language as a platform for experimenting and studying quantum phenomena is henceforth demonstrated. |
As hydrogen gas increasingly becomes critical as a carbon-free energy carrier, the demand for robust hydrogen sensors for leak detection and concentration monitor will continue to rise. However, to date, there are no lightweight sensors capable of meeting the required performance metrics for the safe handling of hydrogen. Here, we report an electrical hydrogen gas sensor platform based on a resistance nanonetwork derived from Pd-Co composite hole arrays (CHAs) on a glass substrate, which meets or exceeds these metrics. In optimal nanofabrication conditions, a single poly(methyl methacrylate)(PMMA)-coated CHA nanosensor exhibits a response time (t80) of 1.0 s at the lower flammability limit of H2 (40 mbar), incredible sensor accuracy (<1% across 5 decades of H2 pressure), and an extr... |
Magnoliae Flos is a traditional herbal medicine used to treat nasal congestion associated with headache, empyema, and allergic rhinitis. In our preliminary screening of crude drugs used in Japanese Kampo formulas for melanin synthesis, the methanol extract of Magnoliae Flos was found to exhibit strong melanin synthesis activity. However, there have been no studies evaluating the effects of Magnoliae Flos or its constituents on melanogenesis. The present study aimed to isolate the active compounds from Magnoliae Flos that activate melanin synthesis in melanoma cells and three-dimensional human skin equivalent, and to investigate the molecular mechanism underlying melanin induction. The methanol extract of Magnoliae Flos induced an increase of melanin content in both B16-F1 and HMV-II... |
This work presents the controlled synthesis of TiO2/graphene photocatalysts by hydrothermal method using TiCl4 as the precursor. The influence of the precursor concentration and the reaction time on the growth of TiO2 nanoparticles on graphene is studied and results in the ability to achieve the catalysts with desired TiO2 loadings and dispersion. By means of XPS, Raman, and UV-VIS diffuse reflectance spectroscopies, the chemical composition, the interaction between TiO2 and graphene, and the optical properties of the photocatalysts are investigated. The results reveal that the coupling with graphene considerably narrows the bandgap of TiO2, which stimulates the photocatalytic activity of TiO2/graphene under visible light irradiation. The photocatalytic performance of TiO2/graphene ... |
This work deals with nickel electronucleation and growth processes onto a glassy carbon electrode from NiCl2·6H2O dissolved in ethylene glycol (EG) solutions with and without 250 mM NaCl as a supporting electrolyte. The physicochemical properties of EG solutions, namely, viscosity and conductivity, were determined for different Ni(II) concentrations. From cyclic voltammetry, it was found that in the absence of the supporting electrolyte, the cathodic efficiency of Ni electrodeposition is about 88%; however, in the presence of the supporting electrolyte, the cathodic efficiency was reduced to 26% due to water (added along the supporting electrolyte) reduction on the growing surfaces of Ni nuclei |
