• Title/Summary/Keyword: Electrostatic capacity

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A unified analysis method for capacitance and inductance of power transmission lines (송전선의 정전용량과 인덕턴스의 통일적 해석법)

  • 황석영
    • 전기의세계
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    • v.29 no.3
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    • pp.185-192
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    • 1980
  • It is revealed that duality and similarity between both capacitance and inductance systems coexist, and also that the former is more efficient than the latter in application viewpoints in time-invariant linear cases as far as both systems are concerned. This paper, using the similarity relation, proposes a new magnetics capacity concept similar to electrostatic capacity so that inductance systems may be interpreted as the corresponding capacitance systems. The new concept makes it convenient to analyze the both systems by unified approach. Finally an example demonstrates the applicability and convenience of the proposed method, through the analysis of capacitances and inductances on the transposed transmission line.

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Study on Frequency Characteristics of Rectangle Spiral Planar Inductor (사각 나선형 평면 인덕터의 주파수 특성에 관한 연구)

  • Kim, Jae-Wook
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.4
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    • pp.2330-2334
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    • 2014
  • In this study, we confirmed the frequency characteristics of planar spiral inductor based on non-contact method AC coupling for wireless signal transmission. The dielectric constant variation of the substrate does not directly effect the inductance of device but effect the electrostatic capacity of device. Therefore, its change self-resonance frequency. The thickness increment of the substrate increase inductance but decrease self-resonance frequency. Because, the thickness decrement of the substrate make the inside electrostatic capacity increment.

Synthesis of Li2PtO3 Thin Film Electrode by an Electrostatic Spray Deposition Technique

  • Oh, Heung-Min;Kim, Ji-Young;Lee, Kyung-Keun;Chung, Kyung-Yoon;Kim, Kwang-Bum
    • Journal of Electrochemical Science and Technology
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    • v.1 no.1
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    • pp.45-49
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    • 2010
  • $Li_2PtO_3$ thin film electrodes, which might be possible candidate for the cathode materials for implantable batteries, were synthesized using an electrostatic spray deposition (ESD) technique onto a platinum foil substrate. Single phase $Li_2PtO_3$with a structure similar to layered $LiCoO_2$ structure were synthesized by spraying a precursor solution of $CH_3CO_2Li2H_2O$ in ethanol onto a Pt substrate at temperatures ranging from 200 to $400^{\circ}C$ followed by annealing at above $600^{\circ}C$. Lithium carbonate was the only major phase at temperatures up to $500^{\circ}C$. The X-ray diffraction (XRD) peaks of the Pt foil substrate and lithium carbonate disappeared at temperatures >$600^{\circ}C$. The volumetric capacity of the $Li_2PtO_3$ thin film synthesized using the ESD technique was approximately 817 mAh/$cm^3$, which exceeded that of $LiCoO_2$ (711 mAh/$cm^3$).

Study on the Causes of Malfunctions of PCBs Applied to the Power Saving Mode of Electrical Systems and its Solution (전기시스템의 절전모드에 적용되는 PCB의 오작동 원인 개선에 관한 연구)

  • Park, Hyung-Ki;Choi, Chung-Seog
    • Journal of the Korean Society of Safety
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    • v.28 no.3
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    • pp.51-55
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    • 2013
  • The purpose of this study is to find the causes of malfunctions and defective operation of printed circuit boards(PCBs) built into home refrigerators to perform power saving functions. This study performed an electrostatic test of a PCB built-in using an Auto Triggering system; lightning and impulse tests using an LSS-15AX; and an impulse test using an INS-400AX. From the analysis of a secondarily developed product, it was found that electrostatic discharge(ESD) caused more malfunctions and defective operations than electric overstress(EOS) due to overvoltage. As a result of increasing the condenser capacity of the PCB circuit, withstanding voltage was increased to 7.4 kV. In addition, this study changed the power saving mode and connected a varistor to the #2 pin of an IC chip. As a result, the system consisting of all specimens of a finally developed product was operated stably with an applied voltage of less than 10 kV. This study found it necessary to perform quality control at the manufacturing stage in order to reduce the occurrence of electrostatic accidents to IC chips built into a PCB.

Adsorption Characteristics of BTEX on Dust Collecting Electrode Coated with Activated Carbon (활성탄으로 코팅된 집진전극의 BTEX 흡착특성)

  • Nam, Sangchul;Kim, Hyun Jung;Kim, Kwang Soo
    • Journal of Korean Society for Atmospheric Environment
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    • v.29 no.6
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    • pp.773-779
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    • 2013
  • This study was performed to provide the basic data for the function of BTEX removal for compact electrostatic precipitator which are applicable to indoor environment (or closed spaces). For this purpose, the adsorption equilibrium test was conducted for BTEX of activated carbon sheet (ACS) and activated carbon (AC), and the adsorption characteristics of AC and ACS were evaluated using the Langmuir constant which was obtained from the adsorption characteristics, adsorption capacity and regression calculation. The surface area and adsorption pore volume of ACS reduced by 70% and 86%, respectively, as compared to those of AC, and the adsorption capacities of BTEX also showed a similar level. Thus, it is considered that ACS applied electrostatic precipitator is able to remove dust and BTEX simultaneously.

Phenomenon of Power Interference and Screening Factor (전력유도 현상과 차폐계수)

  • Hwang, Jong-Sun;Kim, Yeong-Min;Lee, Kyoung-Wook;Kim, Jae-Joon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11b
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    • pp.621-624
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    • 2001
  • A metal sheath provides a cable with electrostatic screening and a degree of magnetic screening. The presence of a screen on a cable also reduces the induction arising from the high-frequency components of transients caused by power-line switching and also induced transients from lightning strokes; such transient induced voltages are of increasing importance with the increasing use of miniaturized telecommunication equipment with very small thermal capacity. This paper describes electrostatic induction and electromagnetic induction caused by power interference. Also screening factors are proposed.

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Thermodynamic Elucidation of Binding Isotherms for Hemoglobin & Globin of Human and Bovine upon Interaction with Dodecyl Trimethyl Ammonium Bromide

  • Bordbar, A.K.;Nasehzadeh, A.;Ajloo, D.;Omidiyan, K.;Naghibi, H.;Mehrabi, M.;Khajehpour, H.;Rezaei-Tavirani, M.;Moosavi-Movahedi, A.A.
    • Bulletin of the Korean Chemical Society
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    • v.23 no.8
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    • pp.1073-1077
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    • 2002
  • Binding of dodecyl trimethylammonium bromide (DTAB) to human and bovine hemoglobin and globin samples has been investigated in 50 mM glycine buffer pH = 10, I = 0.0318 and 300 K by equilibrium dialysis and temperature scanning spectrophotometry techniques and method for calculation of average hydrophobicity. The binding data has been analyzed, in terms of binding capacity concept $({\theta})$, Hill coefficient (nH) and intrinsic Gibbs free energy of binding $({\Delta}Gbv).$ The results of binding data, melting point (Tm) and average hydrophobicity show that human hemoglobin has more structural stability than bovine hemoglobin sample. Moreover the results of binding data analysis represent the systems with two and one sets of binding sites for hemoglobin and globin, respectively. It seems that the destabilization of hemoglobin structure due to removal of heme group, is responsible of such behavior. The results indicating the removal of heme group from hemoglobin caused the depletion of first binding set as an electrostatic site upon interaction with DTAB and exposing the hydrophobic patches for protein.

Molecular Modeling Studies on the Functionalized MOF-5 (MOF-5 계열 화합물의 수소 흡착 용량 예측에 관한 분자모델링 연구)

  • Kim Dae Jin;Lee Tae Beom;Choi Seung Hun;Lee Eun Seong;Oh Yu Jin;Yun Ji Hye;Kim Ja Heon
    • 한국전기화학회:학술대회논문집
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    • 2004.06a
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    • pp.287-292
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    • 2004
  • In order to understand the relationship between molecular structure of Metal-Organic Framework(MOF) and capacity of hydrogen absorption, quantum mechanical calculations and grand canonical Monte Carlo simulations have been carried out on a series of MOF-5 having various organic linkers. The calculation results about specific surface area and electron density for various frameworks indicated that the capacity of the hydrogen storage is largely dependent on effective surface area rather than the free volume. Based on the iso-electrostatic potential surface from density functional calculation and the amount of adsorbed hydrogens from grand canonical Monte Carlo calculation, it was also found that the electron localization ground organic linker plays an important role in hydrogen capacity of MOFs.

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Electrochemical Characteristics of 2-Dimensional Titanium Carbide(MXene)/Silicon Anode Composite Prepared by Electrostatic Self-assembly (정전기적 자가결합법으로 제조된 2차원 티타늄 카바이드(MXene)/실리콘 음극 복합소재의 전기화학적 특성)

  • Dong Min Kim;Jong Dae Lee
    • Korean Chemical Engineering Research
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    • v.62 no.3
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    • pp.262-268
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    • 2024
  • In this study, the MXene/Si composite was prepared by electrostacic assembly with 2-dimensional structured titanium carbide (MXene) and nano silicon for anode material of high-performance lithium-ion battery. Ti3C2Tx MXene was synthesized by etching the Ti3AlC2 MAX with LiF/HCl, and the surface of nano silicon was charged to positively using CTAB (Cetyltrimethylammonium bromide). The MXene/Si anode composite was successfully manufactured by simple mixing process of synthesized MXene and charged silicon. The physical and electrochemical properties of prepared composite were investigated with MXene-silicon composition ratio, and the surface of electrode after cycles was analyzed to evaluate stability of the electrode. The MXene/Si composites demonstrated high initial discharge capacities of 1962.9, 2395.2 and 2504.3 mAh/g as the silicon composition ratio increased to 2, 3 and 4 compared to MXene, respectively. MXene/Si-4, which is MXene and silicon ratio with 1 : 4, exhibited 1387.5 mAh/g of reversible capacity, 74.5% of capacity retention at 100 cycles and high capacity of 700.5 mAh/g at high rate of 4.0 C. As the results, the MXene/Si composite prepared by electrostatic-assenbly could be applied to anode materials for high-performance LIBs.

Power Cable Insulation Diagnosis Using Low Frequency Power (저주파수 전원을 이용한 전력케이블 절연평가에 관한 연구)

  • Kim, Sung-Min;Lee, Sang-Hun;Jang, Jae-Yel
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.1603-1603
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    • 2011
  • As time goes by these cables make a insulation problems, and ask for a preventive diagnosis method. Cable has very high electrostatic capacity and insulation defects mainly caused by water-tree(WT). Dissipation factor test is very useful for detecting WT but it needs huge power supply. In this paper we presented a cable insulation diagnosis by dissipation factor using low frequency power supply.

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