• Title/Summary/Keyword: electrode length

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IBS electrode structure for enhanced performance in ac PDP

  • Yang, Seung-Hee;Moon, Jae-Seung;Kim, Kwang-Nyun;Moon, Cheol-Hee
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.589-592
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    • 2007
  • In this paper, we propose IBS(ITO-BUS Separated) electrode structure. BUS electrode lines are placed apart from the ITO electrode lines, and they are electrically connected with vertical auxiliary electrodes. We varied the lengths of the vertical electrodes as 70, 120, 320um. The highest luminous efficiency and the largest IR emission peak were obtained for 70um length.

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Characteristics of Luminance and Efficiency for External Electrode Fluorescent Lamps Driven by Square Pulses (구형파로 구동되는 외관전극 형광램프의 휘도 및 효율 특성)

  • 조태승;김영미;권남옥;김성중;강준길;최은하;조광섭
    • Journal of the Korean Vacuum Society
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    • v.11 no.1
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    • pp.76-80
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    • 2002
  • Characteristic properties of fluorescent lamps operated by capacitively-coupled external electrodes have been investigated. External electrode fluorescent lamps(EEFLs) are typically operated at low currents less than 10 mA, and high voltages of about 1.5 kV. Luminance of up to 20,000 cd/$\textrm m^2$ with efficiency of above 40 lm/W is achieved in EEFLs driven by square pulses of the frequency lower than 100 kHz. It is also found that the brightness and efficiency of external electrode fluorescent lamps depend on the electrode length whose optimum length is about 3 cm.

A study on visualization about the flow mode of ER fluid using the DME (다전극을 이용한 ER유체 유동모드 가시화에 관한 연구)

  • Lee, Yuk-Hyung
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.9 no.1
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    • pp.1-7
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    • 2010
  • A new flow mode of ER fluid available for controlling the damping force by using DME(Discrete Multi-Electrode) is presented in this study. Various characteristics about the flow of ER fluid through the experiment of ER cluster behavior visualization can be assumed. The pressure in electrode length and voltage division mode is measured. An actuator with a damping effect through DME ER damper will be developed. This damper controls the damping force by using the displacement and velocity of the plant which consists of the various electrode length and voltage modes without a controller in the real system.

Computation of Critical Length for Linear Grounding Electrodes (직선형 접지전극의 임계길이의 산정)

  • Kim, Ki-Bok;Lee, Bok-Hee;Joe, Jeong-Hyeon
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.23 no.9
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    • pp.67-74
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    • 2009
  • For the surge currents like lightning currents containing high frequency components and the abnormal currents having high frequencies which cause the EMI(Electromagnetic interference) problems for the electronic devices and communication instruments, the linear grounding electrodes have the significantly composite impedance characteristics which are dependent on the frequency of the applied current. The impedance of a grounding electrode is not lowered by expanding the dimension of the grounding electrode, and the length of grounding electrode having the minimum value of the grounding impedance for each condition of frequency and soil characteristics is existent, and it is defined as Critical length. In this paper, the critical lengths for the vertically and horizontally-buried grounding electrodes are calculated by using the distributed parameter circuit model. The propriety of the simulations has been confirmed by comparing the simulated results with the measured results.

Effect of Cross-bar Length on Luminous Efficacy in AC-PDP with Fence Electrode Stricture

  • Nam, Hyung-Woo;Choi, Yong-Suk;Bae, Hyo-Won;Kim, Yun-Gi;Ok, Jung-Woo;Kim, Dong-Hyun;Lee, Ho-Jun;Lee, Hae-June;Park, Chung-Hoo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.721-724
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    • 2009
  • In this paper, we proposed fence electrode structures. The experimental structures change cross-bar length as 145, 105, 65 and $30{\mu}m$ to improve the electro-optical characteristics. The proposed structures improve the addressing time and luminous efficacy compared with the T145 structure which has the cross-bar length of $145{\mu}m$ as the reference. Especially, in the case of the T30 structure with cross-bar length of $30{\mu}m$, it gains lower power consumption by 34%, and higher luminous efficacy by 20% than those of the reference structure.

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The Influence of Gap Length and Tip Radius on Breakdown of Electrical Insulating Oil (전기절연유의 절연파괴에 미치는 전극간격 및 곡률반경의 영향)

  • Kang, Seong-Hwa;Chae, Hong-In;Lee, Jong-Pil;Lim, Kee-Joe
    • Journal of the Korean Society of Safety
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    • v.19 no.1
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    • pp.56-59
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    • 2004
  • In this paper, we investigated the influence of gap length and tip radius on breakdown of mineral based insulation oil. Applied voltages were DC and AC voltage. Electrode system was needle-plane structure. The tip radius of needle electrode was 5, 10, 20 and 25${\mu}m$, respectively. We measured breakdown voltage for each of tip radius with increasing electrode gap, 2mm to 12mm. Electric breakdown strength at tip was calculated using Mason's equation contained geometric figure. As gap length increased, breakdown strength increased linearly. But, as tip radius of needle increased, breakdown strength decreased exponentially. It can be explained by the phenomenon that electron is easily injected, as tip radius increases, and effective work function decreases. When appling DC voltage, breakdown strength was higher when polarity of needle was negative than positive. It is because of the space charge effect in accordance with the influence of liquid motion.

Development of an Urea Sensor using Electric Conductivity Method (전기전도도법을 이용한 우레아 농도 센서 개발)

  • Choi, B.C.;Kim, K.Y.;Yang, J.Y.;Kim, H.N.
    • Journal of Power System Engineering
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    • v.15 no.2
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    • pp.55-60
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    • 2011
  • The popularity of diesel engines is derived primarily from their higher thermal efficiency resulting from higher compression ratio. NOx removal from the diesel emissions is very important to meet stringent emission regulations. NOx emission from diesel engines is removed by an urea-SCR or an LNT system. The urea-SCR system needs the urea-solution supply system with concentration and level sensor. This study was carried out to develop a sensor for the measurement of urea-solution concentration by an electric conductivity method. Considering experimental parameters were the material of electrode, two kinds of electric power(AC or DC), the distance between two electrodes, and the length of electrode. It was found that the AC electric power was more useful to measure the urea-solution concentration compared to DC, because it prevented an ionization of the urea-solution. The silver rod coated with Pt is the most useful electrode, tendency of which is similar to Pt rod, and the cost is more economic. We could also find out the optimum distance between two electrodes and the length of electrode was 10mm and 3mm, respectively.

A Study on the Measurement of Break-up Length for the Diesel Sprays (디젤분무의 분열길이 측정에 관한 연구)

  • Jang, S.H.;Ra, J.H.
    • Journal of Power System Engineering
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    • v.3 no.3
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    • pp.22-28
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    • 1999
  • The injected liquid does not break-up instantly after injection for diesel engine. There is some unbroken portion, which is the liquid core(The length of liquid core is called the break-up length) in the spray. If the liquid core is longer than the depth of the bowl in the small DI diesel engine, the liquid core impinges on the surface of the piston. Once the liquid core impinges on the surface, it cannot ignite or burn rapidly and thus prolongs burning time with a degradation in thermal efficiency. The break-up length of a diesel spray in a compressure vessel was measured by an electric resistance method, A voltage was applied between the nozzle and screen, bar, needle electrode inserted at various axial and radial positions into atomizing sprays. As a result, a current flows not only in the region of liquid core but also through the droplets of the spray. It is found that the break-up length measured with screen electrode is overestimated. The break-up length of the spray is found to be proportional to the square root of the density ratio of fuel and surrounding gas. The break-up length of the spray decreases as the injection pressure and the back pressure increase.

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Dependence of Flat Fluorescent Lamp (FFL) Efficiency on Channel Number and Channel Length (채널 개수 및 길이에 따른 면광원 램프의 효율 비교에 관한 연구)

  • Hur, Jeong-Wook
    • Journal of the Semiconductor & Display Technology
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    • v.8 no.2
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    • pp.43-47
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    • 2009
  • Glass forming technology is used to form channels of external electrode flat fluorescent lamps (FFL). The efficiency of FFL depends on the number and the length of the channels. Five FFLs with same size ($300\;mm{\times}80\;mm$), different channel number, and different channel length were fabricated. The electrical and optical characteristics of 5 FFLs were evaluated. It was found that the FFL with one channel with its channel length of 1,110 mm and channel width of 7 mm corner width was shown to have the highest efficiency at room temperature operation.

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Effects of Operating Parameters on Tetrafluoromethane Destruction by a Waterjet Gliding Arc Plasma (워터젯 글라이딩 아크 플라즈마에 의한 사불화탄소 제거에 미치는 운전변수의 영향)

  • Lee, Chae Hong;Chun, Young Nam
    • Applied Chemistry for Engineering
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    • v.22 no.1
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    • pp.31-36
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    • 2011
  • Tetrafluoromethane ($CF_4$) has been used as the plasma etching and chemical vapor deposition (CVD) gas for semiconductor manufacturing processes. However, the gas need to be removed efficiently because of their strong absorption of infrared radiation and the long atmospheric lifetime which cause global warming effects. A waterjet gliding arc plasma system in which plasma is combined with the waterjet was developed to effectively produce OH radicals, resulting in efficient destruction of $CF_4$ gas. Design factors such as electrode shape, electrode angle, gas nozzle diameter, electrode gap, and electrode length were investigated. The highest $CF_4$ destruction of 93.4% was achieved at Arc 1 electrode shape, $20^{\circ}$ electrode angle, 3 mm gas nozzle diameter, 3 mm electrode gap and 120 mm electrode length.