• 제목/요약/키워드: ASCT

검색결과 215건 처리시간 0.032초

Numerical Modeling of Floating Electrodes in a Plasma Processing System

  • Joo, Junghoon
    • Applied Science and Convergence Technology
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    • 제24권4호
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    • pp.102-110
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    • 2015
  • Fluid model based numerical analysis is done to simulate a plasma processing system with electrodes at floating potential. $V_f$ is a function of electron temperature, electron mass and ion mass. Commercial plasma fluid simulation softwares do not provide options for floating electrode boundary value condition. We developed a user subroutine in CFD-ACE+ and compared four different cases: grounded, dielectric, zero normal electric field and floating electric potential for a 2D-CCP (capacitively coupled plasma) with a ring electrode.

Formation of Crystalline Copper Thin Films by a Sputtering-assisted Magnetic Field System at Room Temperature

  • Kim, Hyun Sung
    • Applied Science and Convergence Technology
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    • 제27권1호
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    • pp.1-4
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    • 2018
  • A sputtering-assisted magnetic field system was successfully developed for depositing crystalline Cu thin films at room temperature. This system employs a plasma source and an ion-beam gun with two magnetic field generators, which is covered with sputtering target and the ion-beam gun, simultaneously serving as sputtering plasma and a magnetic field generator. The formation of crystalline Cu thin films at room temperature was dominated by magnetic fields, which was revealed by preliminary experiments. This system can be employed for producing crystalline metal thin films at room temperature.

Analysis of Plasma Treatment Effects on a Compliant Substrate for High Conductive, Stretchable Ag Nanowires

  • Jeong, Jonghyun;Jeong, Jaewook
    • Applied Science and Convergence Technology
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    • 제27권1호
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    • pp.5-8
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    • 2018
  • In this paper, plasma treatment effects on a ploy(dimethyl siloxane) substrate were analyzed for the applications of stretchable silver nanowire (Ag NWs) electrodes. The oxygen plasma treated sample shows the best performance compared to nitrogen treated and untreated samples. The lowest sheet resistance and reasonable stretching capability was achieved up to 20% strain condition without open circuit fail for the oxygen plasma treated sample.

A Three-Dimensional Calculation of the Reactor Impedance for Planar-Type Cylindrical Inductively Coupled Plasma Sources

  • Kwon, Deuk-Chul;Yoon, Nam-Sik
    • Applied Science and Convergence Technology
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    • 제24권6호
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    • pp.237-241
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    • 2015
  • The reactor impedance is calculated for a planar-type cylindrical inductively coupled plasma source by expanding the electromagnetic fields into their Fourier-Bessel series forms including the three-dimensional shape of the antenna. The mode excitation method is utilized to determine the electromagnetic fields based on a Poynting theorem-like relationship. From the obtained electromagnetic fields, a tractable form of the reactor impedance is obtained as a function of various plasma and geometrical parameters and applied to carry out a parametric study.

Fabrication of Gallium Phosphide Tapered Nanostructures on Selective Surfaces

  • Song, Young Min;Park, Hyun Gi
    • Applied Science and Convergence Technology
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    • 제23권5호
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    • pp.284-288
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    • 2014
  • We present tapered nanostructures fabricated on a selective area of gallium phosphide substrates for advanced optoelectronic device applications. A lithography-free fabrication process was accomplished by dry etching of metal nanoparticles. Thermal dewetting of micro-patterned metal thin films provides etch masks for tapered nanostructures. This simple process also allows the formation of plasmonic surfaces with corrugated shapes. Rigorous coupled-wave analysis calculations provide design guidelines for tapered nanostructures on gallium phosphide substrates.

Positron Annihilation Study of Vacancy Type Defects in Ti, Si, and BaSrFBr:Eu

  • Lee, Chong Yong
    • Applied Science and Convergence Technology
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    • 제25권5호
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    • pp.85-87
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    • 2016
  • Coincidence Doppler broadening and positron lifetime methods in positron annihilation spectroscopy has been used to analyze defect structures in metal, semiconductor and polycrystal, respectively. The S parameter and the lifetime (${\tau}$) value show that the defects were strongly related with vacancies. A positive relationship existed between the scanning electron microscope (SEM) images and the positron annihilation spectroscopy (PAS). According to the SEM images and PAS results, measurements of the defects with PAS indicate that it was more affected by the defect than the purity.

An Overview of Techniques in Enzyme Immobilization

  • Nguyen, Hoang Hiep;Kim, Moonil
    • Applied Science and Convergence Technology
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    • 제26권6호
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    • pp.157-163
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    • 2017
  • Immobilized enzymes have become the subject of considerable interest due to their excellent functional properties such as reusability, cost-effectiveness, and optimality during the past decades. Enzyme immobilization technology is not only used in industrial processes, but also a component technology of products for medical diagnostics, therapy, food industry, bio energy, and biomaterial detection. In this review, new methods for enzyme immobilization are introduced, and the advantages and disadvantages of a variety of techniques in enzyme immobilization will be also discussed.

Numerical Simulation: Effects of Gas Flow and Heat Transfer on Polymer Deposition in a Plasma Dry Etcher

  • Joo, Junghoon
    • Applied Science and Convergence Technology
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    • 제26권6호
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    • pp.184-188
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    • 2017
  • Polymer deposition pattern on the ceramic lid surface is analyzed by numerical modeling. Assumption was made that is affected by gas flow pattern from the horizontal and vertical nozzles, temperature profile from the finger-like branches made of graphite and electrostatic potential effect. Calculated results showed gas flow dynamics is less relevant than two others. Temperature and electrostatic effects are likely determining the polymer deposition pattern based on our numerical simulation results.

Development of a Plasma Training Lab kart: System Setup and Numerical Simulation

  • Joo, Junghoon
    • Applied Science and Convergence Technology
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    • 제26권6호
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    • pp.195-200
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    • 2017
  • A mobile lab kart for plasma training is developed with a high vacuum pumping system, vacuum gauges and a glass discharge tube powered by a high voltage transformer connected to a household 60 Hz line. A numerical model is developed by using a commercial multiphysics software package, CFD-ACE+ to analyze the experimental data. Simulations for argon and nitrogen were carried out to provide fundamental discharge characteristics. Variations of the kart configuration were demonstrated: a glass tube with three electric probes, optical emission spectrometer attachment and infra red thermal imaging system to give more detailed analysis of the discharge characteristics.

Resveratrol enhances cisplatin-induced apoptosis in human hepatoma cells via glutamine metabolism inhibition

  • Liu, Zhaoyuan;Peng, Qing;Li, Yang;Gao, Yi
    • BMB Reports
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    • 제51권9호
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    • pp.474-479
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    • 2018
  • Cisplatin is one of the most effective chemotherapeutic drugs used in the treatment of HCC, but many patients will ultimately relapse with cisplatin-resistant disease. Used in combination with cisplatin, resveratrol has synergistic effect of increasing chemosensitivity of cisplatin in various cancer cells. However, the mechanisms of resveratrol enhancing cisplatin-induced toxicity have not been well characterized. Our study showed that resveratrol enhances cisplatin toxicity in human hepatoma cells via an apoptosis-dependent mechanism. Further studies reveal that resveratrol decreases the absorption of glutamine and glutathione content by reducing the expression of glutamine transporter ASCT2. Flow cytometric analyses demonstrate that resveratrol and cisplatin combined treatment leads to a significant increase in ROS production compared to resveratrol or cisplatin treated hepatoma cells alone. Phosphorylated H2AX (${\gamma}H2AX$) foci assay demonstrate that both resveratrol and cisplatin treatment result in a significant increase of ${\gamma}H2AX$ foci in hepatoma cells, and the resveratrol and cisplatin combined treatment results in much more ${\gamma}H2AX$ foci formation than either resveratrol or cisplatin treatment alone. Furthermore, our studies show that over-expression of ASCT2 can attenuate cisplatin-induced ROS production, ${\gamma}H2AX$ foci formation and apoptosis in human hepatoma cells. Collectively, our studies suggest resveratrol may sensitize human hepatoma cells to cisplatin chemotherapy via gluta${\gamma}H2AX$mine metabolism inhibition.