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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. |
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... |
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 ... |
Currently, gaming is the world's favorite form of entertainment. Various studies have shown how games impact players' perceptions and behaviors, prompting opportunities for purposes beyond entertainment. This study uses Animal Crossing: New Horizons (ACNH)—a real-time life-simulation game—as a unique case study of how video games can affect humans' environmental perceptions. A dataset of 584 observations from a survey of ACNH players and the Hamiltonian MCMC technique have enabled us to explore the relationship between in-game behaviors and perceptions. Here we show a probabilistic trend towards exploiting the in-game environment despite players' perceptions, suggesting that the simplification of commercial game design may overlook opportunities to engage and educate players in pro-... |
This work aims to develop a novel and practical equation for predicting the axial load of rectangular concrete-filled steel tubular (CFST) columns based on soft computing techniques. More precisely, a dataset containing 880 experimental tests was first collected from the available literature for the development of an artificial neural network (ANN) model. An optimization strategy was conducted to obtain a final set of ANN’s architecture as well as its weight and bias parameters. The performance of the developed ANN was then compared to current codes (AS, EN, AIJ, ACI, AISC, LRFD, and DBJ) and existing empirical equations. The accuracy of the present model was found superior to the results obtained by others when predicting the axial load of rectangular CFST columns. For practical ap... |
Parallel robots are being applied popular in industry. They usually have many closed-loop kinematic structures, therefore their movement equations have the form of redundant coordinates and are complex. In most cases, parameters of dynamic model of the parallel robots required to be known exactly for control problem using the control laws such as PD, PID, CTC. This study is going to see in which the conditions of the Rostock Delta parallel robot should be used well with the PD control law. The movement equations of Rostock Delta robot in the form of differential equation system with redundant generalized coordinates is used to establish the PD control law. The stableness of the control law is also proved. Tracking control of a specific Rostock Delta robot is then simulated to see wh... |
Urban humans and biodiversity-related concepts are interacting with each other in many negative and positive ways. The biodiversity provides a wide array of provision and cultural-ecological services to urban residents, but it is being overexploited to the point of crisis. The crisis is largely driven by the expanding illegal wildlife trade in developing countries with a high urbanization rate and biodiversity level like Vietnam. While supply-side measures are ineffective in reducing biodiversity loss, researchers have suggested demand-side measures as supplements, such as social marketing campaigns and law enforcement in urban areas. Moreover, urban residents are also potential visitors to urban public parks and national parks, which helps generate finance for biodiversity preserva... |
