• Title, Summary, Keyword: induced current

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Characterization of ion current induced by inhibitory and excitatory herbs in rat periaqueductal gray neuron (흰쥐 신경세포에서 억제성 및 흥분성 한약재가 유발한 이온전류의 특성)

  • Lee, Choong-Yeol;Cho, Sun-Hye;Seo, Jong-Eun;Han, Seung-Ho;Cho, Young-Wuk;Min, Byung-Il;Kim, Chang-Ju
    • The Journal of Korean Medicine
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    • v.19 no.2
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    • pp.450-467
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    • 1998
  • To research the characteristics of ion currents induced by inhibitory and excitatory herbs of oriental medicine, we used nystatin-perforated patch clamp technique under voltage clamp condition in periaqueductal gray neuron dissociated from Sprauge-Dawley rat, 10-15 days old. The results are as follows. 1. Ion current induced by $10mg/m{\ell}$ of Bupleuri Radix was inhibited $59.50{\pm}4.29%$ by $10^{-4}M$ bicuculline(p>0.01) but inhibition of $10.75{\pm}4.77%$ by $10^{-4}M$ tubocurarine and $4.75{\pm}4.23%$ by $10^{-4}M$ verapamil had no statistical significance(p>0.05). So ion current induced by Bupleuri Radix revealed only GABA induced $Cl^-$ current, not acetylcholine and $Ca^{2+}$ current. 2. Ion current induced by $20mg/m{\ell}$ of Coptidis Rhizoma was inhibited $47.20{\pm}7.88%$ by $10^{-4}M$ bicuculline(p<0.01) but $3.20{\pm}2.33%$ inhibition by $10^{-4}M$ tubocurarine and $1.00{\pm}1.00%$ inhibition by $10^{-4}M$ verapamil had no significance(p>0.05). So ion current induced by Coptidis Rhizoma revealed only GABA induced $Cl^-$ current, not acetylcholine and $Ca^{2+}$ current. 3. Ion current induced by $20mg/m{\ell}$ of Ecliptae Herba was inhibited $55.00{\pm}4.92%$ by $10^{-4}M$ bicuculline (p<0.01), and also inhibited $15.00{\pm}4.26%$ by $10^{-4}M$ tubocurarine(p<0.05), but inhibition of $6.00{\pm}3.03%$ by $10^{-4}M$ verapamil had no significance(p>0.05). So ion current induced by Ecliptae Herba showed GABA activated $Cl^-$ current and acetylcholine activated cation current, not $Ca^{2+}$ current 4. Ion current induced by $5mg/m{\ell}$ of Liriopis Tuber was inhibited $15.20{\pm}4.57%$ by $10^{-4}M$ bicuculline<0.05) and also inhibited $14.00{\pm}3.00%$ by $10^{-4}M$ tubocurarine(p<0.05), but inhibition of $5.20{\pm}4.80%$ by $10^{-4}M$ verapamil had no significance(p>0.05). So ion current induced by Liriopis Tuber showed GABA. activated $Cl^-$ current and acetylcholine activated cation current, not $Ca^{2+}$ current. 5. Ion current induced by $5mg/m{\ell}$ of Aconiti Tuber was inhibited $97.00{\pm}1.34%$ by $10^{-4}M$ bicuculline(p<0.01), $80.00{\pm}9.83%$ by $10^{-4}M$ tubocurarine(p<0.01), and $24.00{\pm}6.18%$ by $10^{-4}M$ verapamil(p<0.05). So ion current induced by Aconiti Tuber revealed GABA activated $Cl^-$ current and acetylcholine activated cation current and $Ca^{2+}$ current. 6. Ion current induced by $10mg/m{\ell}$ of Zingiberis Rhizoma was inhibited $33.00{\pm}7.43%$ by $10^{-4}$ bicuculline(p<0.05), $10.20{\pm}1.83%$ by $10-^{-4}M$ tubocurarine(p<0.01), and $14.00{\pm}2.16%$ by $10^{-4}M$ verapamil(p<0.01) So ion current induced by Zingiberis Rhizoma revealed GABA activated $Cl^-$ current and acetylcholine activated cation outtent and $Ca^{2+}$ current. 7. Ion current induced by $10mg/m{\ell}$ of Boshniakiae Herba was inhibited $65.00{\pm}13.75%$ by $10^{-4}M$ bicuculline(p<0.05), $38.00{\pm}9.24%$ by $10^{-4}M$ tubocurarine(p<0.05), and $33.25{\pm}7.42%$ by $10^{-4}M$ verapamiHp<0.05). So ion current induced by Bpshniakiae Herba revealed GABA activated $Cl^-$ current and acetylcholine activated cation current and $Ca^{2+}$ current. These results suggest that a point of difference between inhibitory and excitatory herbs is existence of$Ca^{2+}$ current.

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Current Characteristics in the Silicon Oxides (실리콘 산화막의 전류 특성)

  • Kang, C.S.;Lee, Jae Hak
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.29 no.10
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    • pp.595-600
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    • 2016
  • In this paper, the oxide currents of thin silicon oxides is investigated. The oxide currents associated with the on time of applied voltage were used to measure the distribution of voltage stress induced traps in thin silicon oxide films. The stress induced leakage currents were due to the charging and discharging of traps generated by stress voltage in the silicon oxides. The stress induced leakage current will affect data retention in memory devices. The oxide current for the thickness dependence of stress current and stress induced leakage currents has been measured in oxides with thicknesses between $109{\AA}$, $190{\AA}$, $387{\AA}$, and $818{\AA}$ which have the gate area $10^{-3}cm^2$. The oxide currents will affect data retention and the stress current, stress induced leakage current is used to estimate to fundamental limitations on oxide thicknesses.

SILC of Silicon Oxides

  • Kang, C.S.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.428-431
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    • 2003
  • In this paper, the stress induced leakage currents of thin silicon oxides is investigated in the ULSI implementation with nano structure transistors. The stress and transient currents associated with the on and off time of applied voltage were used to measure the distribution of high voltage stress induced traps in thin silicon oxide films. The stress and transient currents were due to the charging and discharging of traps generated by high stress voltage in the silicon oxides. The transient current was caused by the tunnel charging and discharging of the stress generated traps nearby two interfaces. The stress induced leakage current will affect data retention in electrically erasable programmable read only memories. The oxide current for the thickness dependence of stress current, transient current, and stress induced leakage currents has been measured in oxides with thicknesses between $113.4{\AA}$ and $814{\AA}$, which have the gate area 10-3cm2. The stress induced leakage currents will affect data retention and the stress current, transient current is used to estimate to fundamental limitations on oxide thicknesses.

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A Study on the Numerical Models of Wave induced Currents (파랑에 의한 연안류의 수치모델에 관한 연구)

  • Lee, Jung-Maan;Kim, Jae-Joong;Park, Jung-Chul
    • Journal of Ocean Engineering and Technology
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    • v.12 no.3
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    • pp.75-85
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    • 1998
  • A finite difference model for predicting time-dependent, wave-induced nearshore current is studied. The model includes wave refraction, wave-current interaction, bottom friction and wind effect. This model iteratively solved the linear the linear set of conservation of both mass and momentum, which were time averaged (over one wave period) and depth integrated, for mean velocities and free surface displacement. Numerical simulations of nearshore current under oblique wave attack, and for wave and wind induced current on a longshore periodic beach are carried out. Longshore velocities tend to zero in some distances outside the breaker line. And the peak velocity is shifted shoreward at the breaker line. The results represent the general characteristics of the nearshore current induced by wave.

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Measurement of Magnetic Flux and Induced Current in Magnetic Stimulation for Urinary Incontinence Treatment (요실금 치료용 자기 자극기의 자속밀도 및 유도전류 측정)

  • Han, Byung-Hee;Choi, Kyung-Moo;Cho, Min-Hyoung;Lee, Soo-Yeol
    • Journal of Biomedical Engineering Research
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    • v.30 no.4
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    • pp.318-326
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    • 2009
  • A simple method for measuring magnetic flux and induced current in magnetic nerve stimulation for urinary incontinence treatment is proposed. Unlike electric nerve stimulation, direct measurement of the induced current in magnetic nerve stimulation is impossible. Since induced currents stimulate nerves or muscles in magnetic nerve stimulation, measuring induced current is very important in validating stimulation efficacy and securing safety. The magnetic flux measuring system is composed of 6 layers with pick-up coils of 7 by 7 in each layer, and the induced current measuring system is composed of 6 layers with 7 concentric circular coils in each layer. The proposed method can be used in the design or performance test of a magnetic nerve stimulator for many clinical applications such as urinary incontinence treatment, activation of peripheral nerves, and transcranial magnetic stimulation.

Installation of Induced Current Measurement Systems in Substations and Analysis of GIC Data during Geomagnetic Storms

  • Choi, Kyu-Cheol;Park, Mi-Young;Ryu, Youngsoo;Hong, Youngsu;Yi, Jong-Hyuk;Park, Sung-Won;Kim, Jae-Hun
    • Journal of Astronomy and Space Sciences
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    • v.32 no.4
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    • pp.427-434
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    • 2015
  • Coronal Mass Ejections (CME), which originate from active regions of the Sun's surface, e.g., sunspots, result in geomagnetic storms on Earth. The variation of the Earth's geomagnetic field during such storms induces surface currents that could cause breakdowns in electricity power grids. Hence, it is essential to both monitor Geomagnetically Induced Currents (GICs) in real time and analyze previous GIC data. In 2012, in order to monitor the variation of GICs, the Korean Space Weather Center (KSWC) installed an induced current measurement system at SINGAPYEONG Substation, which is equipped with 765 kV extra-high-voltage transformers. Furthermore, in 2014, two induced current measurement systems were installed on the 345 kV high-voltage transformers at the MIGEUM and SINPOCHEON substations. This paper reports the installation process of the induced current measurement systems at these three substations. Furthermore, it presents the results of both an analysis performed using GIC data measured at the SINGAPYEONG Substation during periods of geomagnetic storms from July 2013 through April 2015 and the comparison between the obtained GIC data and magnetic field variation (dH/dt) data measured at the Icheon geomagnetic observatory.

Analysis on Induced Lightning of a 22.9kV-Y Distribution Line Using a Reduced Model (축소모델을 이용한 22.9kV-Y 배전선로의 유도뢰 분석)

  • Kim, Jeom-Sik;Kim, Do-Young;Park, Yong-Beom;Kwon, Sin-Won;Gil, Kyung-Suk
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.59 no.4
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    • pp.434-439
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    • 2010
  • This study fabricated a simulation facility which reduced the structure of a current distribution line to 50:1 in order to analyze the induced lightning shielding effect of a 22.9kV-Y distribution line according to ground resistance capacity, grounding locations, etc. When installing an overhead ground wire, the standard for grounding a distribution line with a current of 22.9kV-Y requires that ground resistance in common use with the neutral line be maintained less than $50\Omega$every 200m span. The reduced line for simulation had 7 electric poles and induced lightning was applied to the ground plane 2m apart from the line in a direction perpendicular to it using an impulse generator. If induced voltage occurred in the line and induced current flowed through the line due to the applied current, the induced voltage and current of the 'A' phase were measured respectively using an oscilloscope. When all 7 electric poles were grounded with a ground resistance of less than $50\Omega$ respectively, the combined resistance of the line was $7.4\Omega$. When an average current of 230A was applied, the average induced voltage and current measured were 1,052V and 13.8A, respectively. Under the same conditions, when the number of grounding locations was reduced, the combined resistance as well as induced voltage and current showed a tendency to increase. When all 7 electric poles were grounded with a ground resistance of less than $100\Omega$, the combined resistance of the line was $14.9\Omega$. When an average current of 236A was applied, the average induced voltage and current of the 'A' phase calculated were 1,068V and 15.6A, respectively. That is, in this case, only the combined resistance was greater than when all 7 electrical poles were grounded, and the induced voltage and current were reduced. Therefore, it is thought that even though ground resistance is slightly higher under a construction environment with the same conditions, it is advantageous to ground all electric poles to ensure system safety.

Characteristics of Trap in the Thin Silicon Oxides with Nano Structure

  • Kang, C.S.
    • Transactions on Electrical and Electronic Materials
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    • v.4 no.6
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    • pp.32-37
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    • 2003
  • In this paper, the trap characteristics of thin silicon oxides is investigated in the ULSI implementation with nano structure transistors. The stress and transient currents associated with the on and off time of applied voltage were used to measure the distribution of high voltage stress induced traps in thin silicon oxide films. The stress and transient currents were due to the charging and discharging of traps generated by high stress voltage in the silicon oxides. The transient current was caused by the tunnel charging and discharging of the stress generated traps nearby two interfaces. The stress induced leakage current will affect data retention in electrically erasable programmable read only memories. The oxide current for the thickness dependence of stress current, transient current, and stress induced leakage currents has been measured in oxides with thicknesses between 113.4nm and 814nm, which have the gate area 10$\^$-3/ $\textrm{cm}^2$. The stress induced leakage currents will affect data retention, and the stress current and transient current is used to estimate to fundamental limitations on oxide thicknesses.

The Calculation of Induced Current at the Human Body due to Magnetic Field around Power System Equipment (송변전 설비주변에서의 자기장에 의한 인체에의 유도 전류 계산)

  • Han, In-Su;Park, Jong-Keun;Myung, Sung-Ho;Lee, Byeong-Yoon;Kim, Eung-Sik;Min, Suk-Won
    • Proceedings of the KIEE Conference
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    • pp.1755-1757
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    • 1997
  • In this paper, a current calculation method based on Kirchhof's Current Law(KCL) and Kirchhof's Voltage Law(KVL) which is necessary to calculate magnetic fields and induced current around the human body is proposed in this paper. Using this method, we can solve the current values of the finite lines comprising the power system equipment. In the assumption that the current values induced in the human body are same, we calculate the induced current values.

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A Preliminary Research on Optical In-Situ Monitoring of RF Plasma Induced Ion Current Using Optical Plasma Monitoring System (OPMS)

  • Kim, Hye-Jeong;Lee, Jun-Yong;Chun, Sang-Hyun;Hong, Sang-Jeen
    • Proceedings of the Korean Vacuum Society Conference
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    • pp.523-523
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    • 2012
  • As the wafer geometric requirements continuously complicated and minutes in tens of nanometers, the expectation of real-time add-on sensors for in-situ plasma process monitoring is rapidly increasing. Various industry applications, utilizing plasma impedance monitor (PIM) and optical emission spectroscopy (OES), on etch end point detection, etch chemistry investigation, health monitoring, fault detection and classification, and advanced process control are good examples. However, process monitoring in semiconductor manufacturing industry requires non-invasiveness. The hypothesis behind the optical monitoring of plasma induced ion current is for the monitoring of plasma induced charging damage in non-invasive optical way. In plasma dielectric via etching, the bombardment of reactive ions on exposed conductor patterns may induce electrical current. Induced electrical charge can further flow down to device level, and accumulated charges in the consecutive plasma processes during back-end metallization can create plasma induced charging damage to shift the threshold voltage of device. As a preliminary research for the hypothesis, we performed two phases experiment to measure the plasma induced current in etch environmental condition. We fabricated electrical test circuits to convert induced current to flickering frequency of LED output, and the flickering frequency was measured by high speed optical plasma monitoring system (OPMS) in 10 kHz. Current-frequency calibration was done in offline by applying stepwise current increase while LED flickering was measured. Once the performance of the test circuits was evaluated, a metal pad for collecting ion bombardment during plasma etch condition was placed inside etch chamber, and the LED output frequency was measured in real-time. It was successful to acquire high speed optical emission data acquisition in 10 kHz. Offline measurement with the test circuitry was satisfactory, and we are continuously investigating the potential of real-time in-situ plasma induce current measurement via OPMS.

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