• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 C
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• pp.1589-1592
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• 1994

We developed the ion plating system, consisted of the Facing Target Magnetron Sputtering System and the r.f, electrode of the coil type, which was available to control the reactive and the adhesion between thin film and substrate, and studied about the discharge characteristics and the optimum condition in order to form the high quality thin film. The characteristics of discharge and plasma was measured as Double Probe and Electrostatic Retarding Grid Analyzer. The incident ion energy on the substrate was increased as the increasing r.f power, bias voltage. By the r.f electrode, the ionization rate of the sputtered particles was about 75%, and the mean incident ion energy depend on the value which was difference between the plasma potential and biased substrate potential.

• 자원리싸이클링
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• 제12권2호
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• pp.45-53
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• 2003

2001년 국내에서는 총 491만톤의 석탄회가 발생되어, 이중 약 63.3%가 재활용되고 있으나 이들의 대부분은 콘크리트 혼합물과 시멘트 산업에 사용되고 있다. 그러므로 본 연구에서는 석탄회의 활용도를 높이기 위한 새로운 용도개발을 위한 목적으로 마찰대전법 대신 정전유도법을 사용하였다. 정전유도법을 적용하여 석탄회로부터 1%LOI 이하의 고순도 석탄회와 70%LOI 이상의 고탄소질 석탄회를 얻을 수 있음을 확인하였으며, 본 실험에서 두 전극간의 전위차는 8～16kV 범위로 적용하였다.

• 전자공학회논문지A
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• 제30A권3호
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• pp.76-87
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• 1993

We present a self-consistent, 2-dimensional solution of the Poisson and Sch rodinger equation based on the finite difference method with a nonuniform mesh size for a AlGaAs/GaInAs/GaAs HEMT devide. During the interative self-consistent calculation, however, we calculate Schrodinger equation only a some region of device, not a fully region in order to save the moemory and the speed-up of computation, and then use the approximated data for the other region using by a interpolation method with a given values. Also we adopt the proper matrix transformation method that allows preservation of the symmetric, form of the discretized Schrodinger equation, even with the use of a nonumiform mesh size, therefor, can reduce the computation time. We calculate the wavefunction, eigenstates and the electron concentration uat channel layer nder the thermal equilibrium and the biased conditions, respectively. Also,these parameters are used to solve 2-dimensional tdistribution of potential in he entire region of device. It is proved that the method is very efficient in finding eigenstages extending over relatively large spatial area without loss of accuracy. So, it can be used rather easily in any sarbitrary modulation doped utucture.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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• pp.235-238
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• 2004

본 연구는 반도체소자 제조공정에 적용되는 CMP공정 중 LPP(Landing Plug Poly) Contact간의 소자 분리를 위해 진행되는 LPP CMP의 후 세정 과정에서 유발되는 방사형 Defect 제거에 관한 내용이다. 방사형 Defect은 LPP CMP 후에 노출되는 BPSG, Poly, Nitride Film과 연마재로 사용되는SiO2 입자, 후 세정과정에서 적용되는 SC-1, DHF, $NH_4OH$ Chemical과 Brush와의 상호작용에 의해 발생되며, Cleaning시의 산성 분위기 하에서 각 물질간의 pH와 Zeta Potential의 차이에서 기인한다. 이 Defect을 제거하기 위해 LPP CMP후에 Film 표면에 노출되는 각 물질의 표면 특성과 CMP 후 오염입자의 흡착과 재 흡착에 영향을 미치는 Electrostatic force와 Van der Waals force, PVA Brush에 의한 Mechanical force의 상호작용을 고려하여 최적 후 세정 조건을 제시 하였다.

• Bulletin of the Korean Chemical Society
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• 제13권3호
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• pp.317-324
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• 1992

Structure and dynamics of $Na^+$ ions are investigated by molecular dynamics simulations of rigid dehydrated zeolite-A at several temperatures using a simple Lennard-Jones potential plus Coulomb potential. A best-fitted set of electrostatic charges is chosen from the results of simulation at 298.15 K and Ewald summation technique is used for the long-ranged character of Coulomb interaction. The calculated x, y, and z coordinates of $Na^+$ ions are in good agreement with the positions determined by X-ray crystallography within statistical errors, their random movings in different types of closed cages are well described by time-correlation functions, and $Na_Ⅰ$ type ions are found to be less diffusive than $Na_Ⅱ$ and $Na_{III}$. At 600.0 K, the unstable $Na_{III}$ type ion pushes down one of nearest $Na_{I}$ ions into the $\beta-cage$ and sits on the stable site Ⅰ, and the captured ion in the $\beta-cage$ wanders over and attacks one of 8 $Na_{I}$ type ions.

• The Korean Journal of Physiology and Pharmacology
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• 제24권1호
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• pp.101-110
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• 2020

Transient receptor potential canonical 4 (TRPC4) channel is a nonselective calcium-permeable cation channels. In intestinal smooth muscle cells, TRPC4 currents contribute more than 80% to muscarinic cationic current (mIcat). With its inward-rectifying current-voltage relationship and high calcium permeability, TRPC4 channels permit calcium influx once the channel is opened by muscarinic receptor stimulation. Polyamines are known to inhibit nonselective cation channels that mediate the generation of mIcat. Moreover, it is reported that TRPC4 channels are blocked by the intracellular spermine through electrostatic interaction with glutamate residues (E728, E729). Here, we investigated the correlation between the magnitude of channel inactivation by spermine and the magnitude of channel conductance. We also found additional spermine binding sites in TRPC4. We evaluated channel activity with electrophysiological recordings and revalidated structural significance based on Cryo-EM structure, which was resolved recently. We found that there is no correlation between magnitude of inhibitory action of spermine and magnitude of maximum current of the channel. In intracellular region, TRPC4 attracts spermine at channel periphery by reducing access resistance, and acidic residues contribute to blocking action of intracellular spermine; channel periphery, E649; cytosolic space, D629, D649, and E687.

• 자원리싸이클링
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• 제14권6호
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• pp.60-63
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• 2005

수중에 존재하는 입자의 표면에 대한 특정 이온의 흡착특성을 흡착에 따른 입자의 PZC 와 IEP 의 변화에 근거하여 해석 가능한 것으로 검토되었다. $Cu^{2+}$와 같이 Chalcopyrite 입자표면에 Specific Adsorption을 형성하는 이온이 수중에 존재하는 경우 입자의 PZC는 낮아지는 것으로 관찰되었으며 이는 양이온의 흡착이 OH-이온의 흡착을 초래하여 새로운 PZC를 형성하기 위해 수중 H+농도의 상승이 요구됨으로 인한 결과로 파악되었다. 그러나, 이와는 반대로 IEP는 높아지는 현상이 나타난 바, 이는 양이온의 흡착으로 인해 입자의 Surface Potential 이 양의 방향으로 상승하여 이를 상쇄하기 위한 pH의 증가가 원인인 것으로 고찰되었다. Non-specific Adsorption 의 경우 입자표면의 Surface Potential 의 변화가 초래되지 않음으로 인해 입자의 PZC 및 IEP 는 변화하지 않는 것으로 파악되었다.

• 멤브레인
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• 제12권4호
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• pp.207-215
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• 2002

한정된 미세공간에서의 제한확산(hindered diffusion)은 멤브레인 기공(pore)에서 입자들의 운동에 의해 결정되는 여과 메카니즘을 매우 미세한 수준에서 이해하는데 중요한 현상이다. 구형(spherical) 콜로이드 입자에 비해 보다 복잡한 형태(conformation)인 고분자사슬 구조를 갖는 다가전해질(polyelectrolyte)의 제한확산 거동에는 다양한 인자들이 관련되어 있기 때문에, 이론 접근은 물론 실험적 접근도 한층 어려운 것이 사실이다. 본 연구에서는, 슬릿형 미세기공에 한정되어 있는 단일한 다가전해질(single polyelectrolyte)에 coarse-grained bead spring model과 먼거리(long-range) 정전상호작용(electrostatic interaction)인 Debye-Huckel potential을 적용하여 분자시뮬레이션 기법인 브라운 동력학 모사를 수행하였다. 기공과 다가전해질 사슬(Polyelectrolyte chain)의 주어진 크기에서, 용액의 전해질 이온농도가 감소함에 따른 사슬의 신장(extension)효과는 제한확산계수를 감소시켰고, 기공 벽면의 하전성은 제한확산계수를 더욱 감소시켰다. 이는, 다가전해질 사슬(polyelectrolyte chain)의 입체적 장애(steric hindrance)와 함께 정전반발력이 미세기공에서의 확산이동을 억제함을 의미한다.

• 한국전기전자재료학회논문지
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• 제23권9호
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• pp.724-729
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• 2010

We have proposed a new configuration on the cathode structure to improve a neutron yield without the application of external ion sources in an inertial electrostatic confinement (IEC) device. A neutron yield in the IEC device is closely related to the potential well structure generated inside the cathode and is proportional to the ion current. Therefore, the application of a double grid cathode structure to the IEC device is expected to produce a higher ion current and neutron yield than at a single grid cathode due to a high electric field strength generated around the cathode. These possibilities were verified as compared with the ion current calculated from both shape of the single and double grid cathode. Additionally from the results of ion's lives and trajectories examined at various outer cathode voltages and grid cathode configurations by using particle simulations, the validity of the double grid cathode was confirmed.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.113.1-113.1
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• 2011

PEMS (printed electro-mechanical system) is fabricated by means of various printing technologies. Passive and active compo-nents in 2D or 3D such as conducting lines, resistors, capacitors, inductors and TFT(Thin Film Transistor), which are printed withfunctional materials, can be classified in this category. And the issue of PEMS is applied to a R2R process in the manu-facturing process. In many electro-devices, the vacuum process is used as the manufacturing process. However, the vacuum process has a problem, it is difficult to apply to a continuous process such as a R2R(roll to roll) printing process. In this paper, we propose an ESD (electro static deposition) printing process has been used to apply an organic solar cell of thin film forming. ESD is a method of liquid atomization by electrical forces, an electrostatic atomizer sprays micro-drops from the solution injected into the capillary with electrostatic force generated by electric potential of about several tens kV. ESD method is usable in the thin film coating process of organic materials and continuous process as a R2R manufacturing process. Therefore, we experiment the thin films forming of PEDOT:PSS layer and active layer which consist of the P3HT:PCBM. The organic solar cell based on a P3HT/PCBM active layer and a PEDOT:PSS electron blocking layer prepared from ESD method shows solar-to-electrical conversion efficiency of 1.42% at AM 1.5G 1sun light illumination, while 1.86% efficiency is observed when the ESD deposition of P3HT/PCBM is performed on a spin-coated PEDOT:PSS layer.