• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.1
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• pp.33-38
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• 2000

In this study, multilayer piezoelectric actuators were fabricated with 75 layers by a conventional multi-layer capacitor (MLC) techniques, using 70Ag/30Pd paste as an internal electrode which can be sintered at low temperature and have cost down effect in mass productions. The multilayer piezoelectric actua-tors had no defects such as diffusions of internal electrode to ceramic bodies and shortages of internal electrodes. The multilayer piezoelectric actuators did not show the crack in the ceramics parts and the gapping phenomena in the external eletrodes when Ag paste was used as external electrodes. The multilayer piezoelectric actuators showed a maximum displacement of 4${\mu}{\textrm}{m}$ at 100V dc voltage and kept the maximum displacement constant for 300 seconds. The multilayer piezoelectric actuators showed good matching properties between ceramic bodies and AgPd internal electrodes. We confirmed the possibility of large-scaled production of the multilayer piezoelectric actuators with superior electrical properties and cost down effect using 70Ag/30Pd paste as an internal electrodes.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.7
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• pp.139-144
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• 2008

Micro electrochemical machining was investigated to machine micro internal features. This method uses a micro disk tool electrode and can easily machine micro features inside of a micro hole, which are very difficult to make by the conventional processes. In order to limit the machining area and localize the electrochemical dissolution, ultra short pulses were used as power source and a micro disk electrode with insulating layer on its surface was used as a tool electrode. By electrochemical process, internal features, such as groove array, were fabricated on the stainless steel plate.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.428-430
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• 2008

Dye-sensitized solar cell has many internal resistant components such as Pt counter electrode, $TiO_2$/dye/electrolyte, charge diffusion, sheet resistance of TCO. Among these, the resistance about the counter electrode can be reduced by increasing the roughness factor of Pt counter electrode. This causes the increase of fill factor and improvement of efficiency. And the amount of light reflection on the counter electrode also increases as the roughness factor goes up. In our experiment, we suggest a new deposition structure of Pt thin film that is a stepped-type structure. The more step lines are in the counter electrode, the more roughness factor is. As a result, we get the improvement of fill factor and efficiency by controlling the roughness factor of counter electrode.

• Journal of the Korean Chemical Society
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• v.15 no.6
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• pp.347-352
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• 1971

The variations of the positive and negative electrode potentials, and of internal pressure were measured during the charge of the sealed type Ni-Cd cell. Both polarization characteristics of a paste type Cd-electrode as a gas diffusion electrode in 30% KOH solution and the effects of active carbon electrode as an oxygen consuming auxiliary electrode of the Ni-Cd cell on the charging characteristics of the cell were studied. Peak voltage at the end of charge of the cell is ascribed to the peak at the negative electrode potential, which is due to the concentration polarization by the lack of $Cd^{++}$ ion and oxygen concentration. And the recovery of the negative electrode potential is resulted from depolarization by the increasing diffusion limiting current density with the increasing oxygen pressure. The active carbon electrode was effective as an oxygen consuming auxiliary electrode. The internal pressure of the cell could be maintained below 200mmHg even at one hour rate charge and overcharge by the use of active carbon electrode as an auxiliary electrode.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.2
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• pp.113-119
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• 2005

A crack emanating from an internal electrode or a conducting damage path in ferroelectric ceramic actuators is analyzed. The boundary of the domain switching zone near the edge of the internal electrode in a ceramic multilayer actuator is determined based on the nonlinear electric theory. The stress intensity factor induced by a ferroelectric domain switching under small scale conditions is numerically obtained for flaws of various sizes near the electrode edge. It is found that stress intensity factor near the crack tip depends on the material property of the electrical nonlinearity.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.65 no.3
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• pp.210-215
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• 2016

The transient characteristics of the Mg/Air fuel cell were ascribed to the load current, electrolyte concentrations, air electrode area and electrode distance. It was found that transient phenomena occurred in the load current, which is due to activate of the oxidation and reduction reaction process. The transient time increase with the load current increase. The transient characteristics were investigated with regard to internal resistance. The maximum power output analysis was employed in order to explain the delayed action under various experimental conditions. The internal resistances had a significant effect on the transient characteristics. The transient curves thus obtained were in almost agreement with internal resistance characteristics.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.8
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• pp.94-101
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• 2005

The silent discharge type ozonizer with three electrodes(central electrode, internal electrode, and external electrode) and one discharge gap(discharge gap between internal electrode and external electrode) has been designed and manufactured. It is a silent discharge type ozonizer for which the AC high frequency voltages applied to the central electrode within vacuum discharge tube and the internal electrode for which the external electrode is a ground Ozone is generated by silent discharge in discharge gap. At the moment, discharge characteristics and ozone generation characteristics were investigated in accordance with vacuum of discharge tube, frequency of AC power source, discharge power of ozonizer, and quantity of supplied oxygen gas. In consequence, ozone characteristics proportional to vacuum of discharge tube and frequency of AC power source. The maximum value of ozone can be obtained 7,700[ppm], 460[mg/h] and 70[g/kwh].

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.5
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• pp.910-914
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• 2007

Recently, a study on the energy conversion efficiency and up sizing' technology of dye-sensitized solar cell (DSC) which is focused in considering a new alternative solar cell has been executed. But consideration for the cell characteristics about an internal electronic flow on a large-scaled DSC has not been carried out yet. In this study, we have chosen a solar cell width as a variable of a large-scaled DSCs and confirmed electric characteristics of an individual cell. First, Pt counter electrode surface of DSC is deposited by RF sputtering methode and the electrochemical properties of Pt electrodes was investigated by cyclic -voltammetry. With the Pt electrode, we fabricated DSC samples of different width. As a result, the higher the internal resistance of DSC becomes, the wider the width gets. Internal resistance makes it difficult to collect photoelectron generated from dye. Ultimately up sizing DSC causes the increase of internal resistance and then has a bad effect on the cell characteristics.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2003.11a
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• pp.381-385
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• 2003

In this paper, a co-axial type ozonizer varied with discharge gap was designed and manufactured for investigating $\circled1$ discharge characteristics with variation of output voltage power supply, flow rate and gap $\circled2$ ozone generation characteristics with variation of flow rate, gap and discharge power. pure oxygen was used as process gas of the co-axial type ozonizer. In this paper, a double cylindrical type superposed silent discharge type ozonizer which internal electrode can be produced a vacuum has been designed and manufactured. Discharge and ozone generation characteristics have been investigated in accordance with output voltage of power supply, flow-rate, discharge power and vacuum of internal electrode.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2004-2006
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• 1999

In this paper, double Cylindrical type ozonizer has been designed and manufactured to improve ozone yield by cooling external electrode. The ozonizer equipped with three electrodes ( central, internal and external electrodes ). Discharge and ozone characteristics are described in this paper by varying the flow rate( Q ) of oxygen supplied gas, temperature of cooling gas and supplied voltage.