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Author
- Quan-Hoang Vuong (27)
- Anh-Tuan Le (17)
- Vuong QH (12)
- Anh D. Phan (11)
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- Electrospinning (8)
- Nanoparticles (6)
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- 2020 - 2022 (482)
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Zinc Ferrite (ZnFe2O4, ZFO) nanoparticles (NPs) as a multi-sensing material are successfully synthesised via a hydrothermal method and a following annealing treatment. The as-prepared ZFO-NPs were applied in electrochemical and mass-type sensors by depositing NPs directly on the screen-printed electrode (SPE) and the active electrode of a quartz crystal microbalance (QCM), respectively. The obtained results show the ZFO-NPs possessed excellent detection performance to sulphur dioxide (SO2) in the range of 2.5–20 ppm at room temperature. QCM sensor coated with ZFO-NPs showed a high response, good repeatability, as well as short-response time. Moreover, the modified-SPE with ZFO-NPs sensitively responded to chloramphenicol (CAP) of concentration range from 5 to 50 μM in phosphate buff... |
This work presents a gas-phase approach for the synthesis of Cu2O/TiO2 powder-based photocatalysts using atomic layer deposition (ALD). The process is carried out in a fluidized bed reactor working at atmospheric pressure using (trimethylvinylsilyl)-hexafluoroacetulacetonate copper(I) as the Cu-precursor and H2O vapor as the oxidizer. The saturating regime of the chemical reactions and the linear growth of ALD are achieved. In combination with the unsaturated regime, the ALD approach enables the deposition of ultrasmall Cu2O clusters with average diameters in the range of 1.3–2.0 nm, narrow particle size distributions and tunable Cu2O loadings on P25 TiO2 nanoparticles. The photocatalytic performance of Cu2O/TiO2 photocatalysts is investigated by the degradation of organic dyes, inc... |
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... |
A large number of piezoelectric polymers have been studied and applied widely recently and become an attractive topic in both material science and applied engineering fields. Piezoelectric polymers such as Poly(vinyl fluoride) and Poly(γ-benzyl, L-glutamate) fabricated in nanofibers have shown impressive properties in the aspect of low weight, high flexibility and high piezoelectricity. One of the major parameters influencing to the piezoelectricity of electrospun fibers is the orientation. This paper reviews the contribution of fiber orientation to the piezoelectricity properties and the technique to manipulate the orientation. The research group introduces for the first time a fully integrated and compact electrospinning system which is low cost and suitable for both lab-scale and... |
Turbine blades have a very special structure. Previously, their manufacture was mainly done by casting in metal molds. This paper presents the results of research on the effects of technological parameters on the accuracy and surface roughness of turbine blades when machining on the 5-axis CNC milling machines. In the study, reverse engineering method was used to create the file designed according to the template, and the machining programming was done on Mastercam software, using the Postprocessor to output the machining code suitable for machining on the CNC milling machines. Taguchi method is applied in experiments, analyzing the influence of turbine blade machining technology parameters. Research results show that the feed rate plays the most important role to minimize the surfa... |
In this work, we are interested in studying the parallel drone scheduling traveling salesman problem (PDSTSP), where deliveries are split between a truck and a fleet of drones. The truck performs a common delivery tour, while the drones are forced to perform back and forth trips between customers and a depot. The objective is to minimize the completion time coming back to the depot of all the vehicles. We present a hybrid ant colony optimization (HACO) metaheuristic to solve the problem. Our algorithm is based on an idea from the literature that represents a PDSTSP solution as a permutation of all customers. And then a dynamic programming is used to decompose the customer sequence into a tour for the truck and trips for the drones. We propose a new dynamic programming combined with ... |
An electrochemical approach has been used for green synthesis of gold and silver nanoparticles (e-AuNPs and e-AgNPs) with high levels of purity and scalability. The electrochemically synthesized noble-metal nanoparticles were characterized by ultraviolet–visible (UV–Vis) spectroscopy and scanning electron microscopy (SEM), confirming the formation of spherical e-AuNPs and e-AgNPs with average size of 19 nm and 24 nm, respectively. These green nanoparticles were deposited on aluminum substrates using the drop-drying method for surface-enhanced Raman scattering (SERS)-based detection of Methylene Blue (MB) within the ranges from 10−5 M to 10−8 M and 10−7 M to 10−10 M, respectively. The SERS sensors also exhibited outstanding sensing performance for MB detection with limits of detectio... |
High performance encapsulation of transparent conductive polymers by spatial atomic layer deposition Poly(3,4-ethylenedioxythiophene) (PEDOT) is a transparent conductive polymer widely used in flexible photonic and optoelectronic devices because of its excellent electrical and optical properties. However, its current range of applications is limited by its poor stability under high humidity and solar radiations. Encapsulation is an attractive solution to this problem and the development of a low-temperature and scalable deposition method is highly desirable. In this study, we report the use of spatial atomic layer deposition (SALD) to deposit ultrathin layers of ZnO, TiO2, and Al2O3. These nanolayers maintain the electrical performance of the conductive polymer and its high optical transmittance. The use of SALD ensures low-cost and flexible processing with pinhole-free high-qualit... |
The field of Submodular Maximization subject to a Knapsack constraint has recently expanded to a variety of application domains, which is facing some challenges such as data explosions or additional conditions. There exist plenty of objective functions that cannot be evaluated exactly in many real cases unless they are estimated with errors. It leads to solving the problem under noise models. Somewhat surprisingly, Submodular Maximization subject to a Knapsack constraint under Noise models (SMKN) has never been discussed a lot before. Hence, in this paper, we consider the problem with two kinds of noise models which are addition and multiplication. Inspired by the traditional Greedy algorithm, we first propose a Greedy algorithm under Noises with provable theoretical bounds. In orde... |
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 |
