• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1583-1585
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• 1994

In this paper, we investigated the relationship between the needle electrode current and the needle electrode potential, The needle electrode potentials have influence on the needle electrode currents absolutely. So, to increase the needle electrode currents there is necessary to keep a high electric field if the charge reducer. for this, high insulation materials must be selected, and charge density of insulating oil must be high. In this experiment, the more a charge density of insulating oil increases, the more a needle electrode potential increases. So we could know what increasement of needle electrode potential increases a needle electrode current.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.10a
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• pp.201-204
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• 2008

The use of the pulsed electro acoustic (PEA) method allowed us to perform the direct observations of spatio-temporal charge distributions in Electric double layer capacitors (EDLCs) based on polarizable nanoporous carbonaceous electrode. The negative charge density became the maximum, about 205 C/$m^3$ at the region where was near to collector layer in EDLCs for case $V_{DC}$ = 2.5 V, while the positively charged density became the maximum, about 61.1 C/$m^3$ at the region where it was located around the cathode layer. The PEA measurement used here is a very useful method to quantitively investigates the spatio-temporal charge distribution in EDLCs.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.45 no.3
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• pp.386-392
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• 1996

Zinc-Borosilicate is used as a side insulator wall to make high breakdown voltage with one Field Limiting Ring in a power p-n junction device in simulation. It is known that surface charge density can be yield at the interface of Zinc-Borosilicate glass / silicon system. When the glass is used as a side insulator wall, surface charge varied potential distribution and breakdown voltage is improved 1090 V under the same structure.The breakdown voltage under varying the surface charge density has a limit value. When the epitaxial thickness is varied, the position of FLR doesn't influence to the breakdown characteristic not only under non punch-through structure but also under punch-through structure. (author). 7 refs., 12 figs., 2 tabs.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.508-509
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• 2005

In case of ITO/MEH-PPV/Al structure, the quantity of charge carriers flowing through the organic material was few and the density of them is fixed. The electric field inside of the device almost didn't change with the position. On the other hands, in case of Au/MEH-PPV/Au structure, the hole density increased rapidly nearby the anode but decreased nearby the cathode. The space charge phenomenon followed sufficient hole injection resulted in the change of the electric field with the position inside of the device. We verified that the result of the current-voltage simulation corresponded with experimental result.

• Nuclear Engineering and Technology
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• v.11 no.4
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• pp.295-301
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• 1979

For thermal-neutron-induced fission of $U^{235}$, nuclear charge distribution in the light part of the primary products has been calculated by using several postulates of charge distribution in the fission fragments. By comparing these values with the experimental results, it is revealed that those models are not appropriate for predicting the nuclear charge distribution in the fission fragments. The variation in the most probable charge, $Z_{P}$, of the isobaric distribution for the fission fragments and the charge for a mass given by unchanged charge density, $Z_{UCD}$, is turned out to be small as a function of mass. The parameter, $Z_{P}$ $-Z_{UCD}$, varies from 0.45 to 0.5 in charge units. The nuclear charge dispersion, $\sigma$, shows about 0.5 charge units for the fission fragments. Neutron odd-even effect in fission products could not be revealed clearly without considering the odd-even effect of prompt neutron emission.

• Journal of Electrical Engineering and Technology
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• v.10 no.2
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• pp.647-652
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• 2015

A fully coupled finite element analysis (FEA) technique was developed for analyzing the discharge phenomena and dielectric liquid flow while considering surface charge density effects in dielectric flow guidance. In addition, the simulated speed of surface charge propagation was compared and verified with the experimental results shown in the literature. Recently, electrohydrodynamics (EHD) techniques have been widely applied to enhance the cooling performance of electromagnetic systems by utilizing gaseous or liquid media. The main advantage of EHD techniques is the non-contact and low-noise nature of smart control using an electric field. In some cases, flow can be achieved using only a main electric field source. The driving sources in EHD flow are ionization in the breakdown region and ionic dissociation in the sub-breakdown region. Dielectric guidance can be used to enhance the speed of discharge propagation and fluidic flow along the direction of the electric field. To analyze this EHD phenomenon, in this study, the fully coupled FEA was composed of Poisson's equation for an electric field, charge continuity equations in the form of the Nernst-Planck equation for ions, and the Navier-Stokes equation for an incompressible fluidic flow. To develop a generalized numerical technique for various EHD phenomena that considers fluidic flow effects including dielectric flow guidance, we examined the surface charge accumulation on a dielectric surface and ionization, dissociation, and recombination effects.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.53 no.8
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• pp.461-465
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• 2004

This paper analysed the induced current density by electric field of human body under the 765 kV transmission line considering permittivity and conductivity. As permittivity of human body is very high as $10^6$ at 60 Hz, special numerical computation technique in Surface Charge Method(SCM) for composite media with extremely different properties is applied to reduce calculation error of induced current density and electric field inside the human body. Calculation results show that the average of the induced current density inside human body is about 3mA/$m^2$, which is less than ICNIRP criterion (10mA/$m^2$).

• Journal of Electrochemical Science and Technology
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• v.8 no.3
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• pp.197-205
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• 2017

Lead dioxide thin films were electrodeposited on nickel substrate from acidic lead nitrate solution. Current efficiency and thickness measurements, cyclic voltammetry, AFM, SEM, and X-ray diffraction experiments were conducted on $PbO_2$ surface to elucidate the effect of lead nitrate concentration, current density, temperature on the morphology, chemical behavior, and crystal structure. Experimental results showed that deposition efficiency was affected by the current density and solution concentration. The film thickness was independent of current density when deposition from high $Pb(NO_3)_2$ concentration, while it decreased for low concentration and high current density deposition. On the other hand, deposition temperature had negative effect on current efficiency more for lower current density deposition. Cyclic voltammetric study revealed that comparatively more ${\beta}-PbO_2$ produced compact deposits when deposition was carried out from high $Pb(NO_3)_2$ concentration. Such compact films gave lower charge discharge current density during cycling. SEM and AFM studies showed that deposition of regular-size sharp-edge grains occurred for all deposition conditions. The grain size for high temperature and low concentration $Pb(NO_3)_2$ deposition was bigger than from low temperature and high concentration deposition conditions. While cycling converted all grains into loosely adhered flappy deposit with numerous pores. X-ray diffraction measurement indicates that high concentration, high temperature, and high current density favored ${\beta}-PbO_2$ deposition while ${\alpha}-PbO_2$ converted to ${\beta}-PbO_2$ together with some unconverted $PbSO_4$ during cycling in $H_2SO_4$.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.15 no.4
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• pp.31-36
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• 2001

This paper investigates characteristics of spiral charge for 3 dimensional charge simulation method to calculate electric fields of special conductor bundles with spiral rods in 765kV transmission line. We finds the simulating spiral charge as constant charge density give less potential calculation error than sinusoidal charge falsity. When a spiral rod is simulated as spiral charge, we also knows two spiral charge can simulate spiral rod best.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.8
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• pp.1187-1196
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• 1989

In this paper, a method for computing the capacitance parameter for a multi-interconnection line in a multilayered dielectric region is presented. The number of interconnection lines and the number of dielectric layers are arbitrary, and the interconnection lines are finite cross section or infinite cross section. The surface of lines and dielectric interface are divided into subsection. The surface charge density of each subsection is a constant step-pulse function for each subsection. After the solution of surface charge density is effected by the method of moments, capacitance parameter is calculated.