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Hien P.X.,Dongguk University | Jeon B.-H.,Dongguk University | Tuan D.A.,Hung Yen University of Technology and Education
Journal of the Physical Society of Japan | Year: 2013

A consistent set of low-energy electron collision cross sections for the boron trifluoride (BF3) molecule has been derived from the measured electron transport coefficients for a pure BF3 molecule using an electron swarm study and a two-term approximation of the Boltzmann equation for energy. The electron transport coefficients, which were calculated using the derived set, are consistent with the experimental data over a wide range of E=N values (ratio of the electric field E to the neutral number density N). The present set of electron collision cross sections for the BF3 molecule, therefore, is the best available so far for the quantitative numerical modeling of plasma discharges for processing procedures with materials containing BF3 molecules. The electron-transport coefficients for BF3-Ar and BF3-SiH4 mixtures were also calculated and analyzed in a wide range of E=N ratios for the first time. The presence of a remarkable synergism in the Townsend first ionization coefficient has been pointed out in BF3-SiH4 mixtures. © 2013 The Physical Society of Japan.


Han N.D.,Hung Yen University of Technology and Education | Chung Y.,Korea University | Jo M.,Korea University
IEEE Network | Year: 2015

Cloud-assisted mobile ad-hoc networks are expected to be so popular in future fifth generation (5G) mobile network because the significantly faster performance of 5G communications enables clouds to provide realistic services. On the other hand, the energy consumption problem will become serious due to the highly increased cloud computing speed. Mobile communication link loss occurs when a mobile device leaves the network. Link loss can cause serious energy consumption when the lost link is directly connected to a cloud data server, which is required to do excessive searching and link routing transactions. None of the existing normal methods have solved the problem. We show how this problem can be solved using our proposed mechanism. The experimental results demonstrate that our proposed mechanism saves nine times more energy than normal methods. © 1986-2012 IEEE.


Tuan D.A.,Hung Yen University of Technology and Education
Journal of Electrical Engineering and Technology | Year: 2015

Insulating characteristics of Cl2-He mixture gases in gas discharges were analysed to evaluate ability of these gases for using in medium voltage and many industries. These are electron transport coefficients, which are the electron drift velocity, density-normalized longitudinal diffusion coefficient, and density-normalized effective ionization coefficient, in Cl2-He mixtures. A two-term approximation of the Boltzmann equation was used to calculate the electron transport coefficients for the first time over a wide range of E/N (ratio of the electric field E to the neutral number density N). The limiting field strength values of E/N, (E/N) lim, for these binary gas mixtures were also derived and compared with those of the pure SF 6 gas. © 2015 The Korean Institute of Electrical Engineers.


Tuan D.A.,Hung Yen University of Technology and Education
Journal of the Korean Physical Society | Year: 2014

In order to understand quantitatively plasma phenomena and ionized gases, accurate electron collision cross-sections and electron transport coefficients for not only pure atoms and molecules but also for the binary gas mixtures are necessary. Electron transport coefficients (electron drift velocity, density-normalized longitudinal diffusion coefficient, and density-normalized effective ionization coefficient) in mixture gases of Cl2 with Ar, Xe and O2, therefore, were calculated and analyzed by using a two-term approximation of the Boltzmann equation over a wide E/N range (ratio of the electric field E to the neutral number density N). The limiting field strength values of E/N, (E/N)lim, for these binary gas mixtures were also derived and compared with those of pure SF6 gas. These binary gas mixtures are being considered for use in many industries, depending on the mixture ratio and the particular application of the gas and the electrical equipment. © 2014 The Korean Physical Society.


Tuan D.A.,Hung Yen University of Technology and Education
Journal of Electrical Engineering and Technology | Year: 2016

The electron transport coefficients in not only pure atoms and molecules but also in the binary gas mixtures are necessary, especially on understanding quantitatively plasma phenomena and ionized gases. Electron transport coefficients (electron drift velocity, density-normalized longitudinal diffusion coefficient, and density-normalized effective ionization coefficient) in binary mixtures of TEOS gas with buffer gases such as Kr, Xe, He, and Ne gases, therefore, was analyzed and calculated by a two-term approximation of the Boltzmann equation in the E/N range (ratio of the electric field E to the neutral number density N) of 0.1 - 1000 Td (1 Td = 10-17 V.cm2). These binary gas mixtures can be considered to use as the silicon sources in many industrial applications depending on mixture ratio and particular application of gas, especially on plasma assisted thin-film deposition. © The Korean Institute of Electrical Engineers.


Tran V.-T.,Hung Yen University of Technology and Education
ARPN Journal of Engineering and Applied Sciences | Year: 2016

A helical gear is crowned in both the cross-profile and longitudinal directions called a double-crowned gear. The tooth surface of the gear can be generated by hobbing, shaving, honing processes. In this paper, the hobbing process is used for double-crowning the tooth surface of work gear with three different hobbing methods included conventional method, variable tooth thickness (VTT) method and modifying the work gear rotation angle method. A computer simulation example is implemented to compare the meshing-conditions, contact ellipses, and transmission errors under various assembly errors of the double-crowned gear pairs that are generated by the three hobbing methods. © 2006-2016 Asian Research Publishing Network (ARPN).


Tuan D.A.,Hung Yen University of Technology and Education
Journal of Electrical Engineering and Technology | Year: 2015

Insulating characteristics of Cl2-He mixture gases in gas discharges were analysed to evaluate ability of these gases for using in medium voltage and many industries. These are electron transport coefficients, which are the electron drift velocity, density-normalized longitudinal diffusion coefficient, and density-normalized effective ionization coefficient, in Cl2-He mixtures. A two-term approximation of the Boltzmann equation was used to calculate the electron transport coefficients for the first time over a wide range of E/N (ratio of the electric field E to the neutral number density N). The limiting field strength values of E/N, (E/N)lim, for these binary gas mixtures were also derived and compared with those of the pure SF6gas. © The Korean Institute of Electrical Engineers.


Tran V.-T.,Hung Yen University of Technology and Education
ARPN Journal of Engineering and Applied Sciences | Year: 2016

The variable tooth thickness (VTT) hob is usually applied for longitudinal crowning work gear surface with twist free tooth flank. It is an important cutting tool for manufacturing the high precision helical gear. However, the manufacturing process fora VTT hob has not investigated yet. Therefore, in this study, we proposed a method for generating profile of VTT hob by using form grinding wheel on CNC grinding machine. A mathematical model for the tooth profile of VTT hob is established by setting the center distance between the grinding wheel and hob as a second order function of hob's longitudinal feed movement. A numeral example is presented to illustrate and verify the merits of the proposed form grinding method. © 2006-2016 Asian Research Publishing Network (ARPN).


Tran V.-T.,Hung Yen University of Technology and Education
ARPN Journal of Engineering and Applied Sciences | Year: 2016

Most rotors of twin-screw compressors are ground by a horizontal form grinding machine. A mathematical model of the rotors generated on horizontal form grinding machine is needed to establish. Therefore, this paper constructs a coordinate system for the screw rotor form grinding and connected it to a horizontal five-axis form grinding machine to simulate lobe profile of ground male and female rotors. A numerical example is implemented to verify the correctness of the established mathematical model of the form grinding machine. The normal errors of tooth surface on the male and female rotors are negligible. © 2006-2016 Asian Research Publishing Network (ARPN).


Tuan C.V.,Hanoi University of Science and Technology | Tuan M.A.,Hanoi University of Science and Technology | Hieu N.V.,Hanoi University of Science and Technology | Trung T.,Hung Yen University of Technology and Education
Current Applied Physics | Year: 2012

In this work, we have successfully developed a facile and effective electrochemical route for directly growing polyaniline (PANI) nanowires (NWs) on platinum interdigitated microelectrode. The as-prepared NWs were characterized by field-emission scanning electron microscopy, transmission electron microscopy and Fourier-transform infrared spectroscopy. They revealed that the PANI NWs were obtained with diameters ranging from 50 to 200 nm and length up to hundreds of micro meters, depending on growth time. The as-obtained PANI NWs on the electrode exhibited a porous nature and the conducting emeraldine type structure. The gas sensing properties of PNAI NWs were explored by monitoring NH 3 in synthetic air in the concentration range of 25-500 ppm at room temperature. The results obtained demonstrated that PANI NWs have good potential as novel room temperature sensors for practical applications. © 2011 Elsevier B.V. All rights reserved.

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