• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.112-112
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• 2010

The purpose of development is to localize a connector for connection of cable and GIS for underground transmission system. The cable connector for GIS provides electrical insulation of GIS housing part and makes connection of ultra high voltage electrical apparatus and power cable by controlling electrical stress between electrodes of power cable termination. Generally Korean switchgear makers are using a connector for GIS made by foreign companies. We manufactured sample by best structure design of great capacity conductor connecting part and then modified the design by analysis of shape and section. We completed the suitable sample for current cycling test condition of conductor connecting part sample and ensured surge characteristics of line by short-time current test.

• 상하수도학회지
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• 제8권3호
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• pp.19-25
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• 1994

In this research, characteristics of nitrification and denitrification using the microorganism attached on sponge and plates were examined. The denitrification and nitrification performance were investigated under the anaerobic and aerobic condition for about 2 months. Because the basins of denitrification and nitrification were connected in series, wastewater was flowed from denitrification basin to nitrification one. The 90% of influent flowrate was returned from nitrification basin to denitrification one. Most of organic material was removed in nitrification basin, wherease the only exact amount of organics required in denitrification process was removed in denitrification one. This experiment resulted in that heterotrophic bacteria existing in aerobic basin governed the removal efficiency of organic compounds. In case the influent BOD concentration into nitrification basin was 80mg/l, it did not affect to accumulation of nitrifying bacteria, the balance of heterotrophic bacteria was proved to be an important factor in nitrification/denitrification method such as anaerobic and aerobic cycling type.

• 한국응용과학기술학회지
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• 제28권3호
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• pp.329-334
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• 2011

The electrochemical performances of an asymmetric hybrid capacitor were investigated using $LiFePO_4$ as the positive electrode and active carbon fibers(ACF) as the negative electrode. The electrochemical behaviors of a nonaqueous hybrid capacitor were characterized by constant current charge/discharge test. The specific capacitance using $LiFePO_4$/ACF electrode turned out to be $0.87F/cm^2$ and the unit cell showed excellent cycling performance. This hybrid capacitor was able to deliver a specific energy as high as 178 Wh/kg at a specific power of 1,068 W/kg.

• Journal of Electrochemical Science and Technology
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• 제6권2호
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• pp.35-49
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• 2015

Advanced polymeric binders with unique functions such as improvements in the electronic conduction network, mechanical adhesion, and mechanical durability during cycling have recently gained an increasing amount of attention as a promising means of creating high-performance silicon (Si) anodes in lithium-ion batteries with high energy density levels. In this review, we describe the key challenges of Si anodes, particularly highlighting the recent progress in the area of polymeric binders for Si anodes in cells.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 춘계학술대회 논문집
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• pp.5-9
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• 2005

$LiFePO_4$ is a potential candidate for the cathode material of the lithium polymer batteries. $LiFePO_4$ cathode active materials were synthesized by coating on the $LiFePO_4$ was tried using $TiO_2$ and corbon in oreder to increase cyclic performance and electronic conductivity. Highly dispersed on the particles enhances the electronic conductivity and increases the capacity. For lithium polymer battery applications, $LiFePO_4$/SPE/Li and $LiFePO_4$-$TiO_2$/SPE/Li 'cells were characterized electrochemically by cyclic volatammetry and charge/discharge cycling. The $LiFePO_4$-carbon-$TiO_2$ cathode in PVDF-PC-EC-$LiCIO_4$ electrolyte showed high capacity at high current density.

• Journal of Electrochemical Science and Technology
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• 제7권4호
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• pp.263-268
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• 2016

This study describes the effect of coating the $Li[Ni_{0.8}Co_{0.15}Al_{0.05}]O_2$ cathode surface with a homogeneous carbon layer produced by carbonization of polyvinylidene fluoride (PVDF) as a novel organic source. The phase integrity of the above cathode was not affected by the carbon coating, whereas its rate capability and cycling performance were enhanced. Similarly, the cathode thermal stability was also improved after coating, which additionally protected the cathode surface against the reactive electrolyte containing hydrofluoric acid (HF). The results show that coating the $Li[Ni_{0.8}Co_{0.15}Al_{0.05}]O_2$ cathode with carbon using the PVDF precursor is an effective approach to enhance its electrochemical properties.

• 한국환경보건학회지
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• 제30권2호
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• pp.84-91
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• 2004

Biological nutrient removal(BNR) from wastewater was performed by adopting various process configurations. The simultaneous biological organics, phosphorus and nitrogen removal of synthetic wastewater was investigated in a sequencing batch biofilm reactor (SBBR). The other reactor was operating as a reference, without biofilm being added. The cycling time in SBR and SBBR was adjusted at 12 hours and then certainly included anaerobic and aerobic conditions. Both systems has been operated with a stable total organic carbon(TOC), nitrogen and phosphorus removal performance for over 90 days. Average removal efficiencies of TOC and total nitrogen were 83% and 95%, respectively. The nitrification rate in SBR was higher than that in SBBR. On the contrary, the denitrification rate in SBBR was higher than that in SBR. The phosphorus release was occurred in SBBR, however, not in SBR because of the inhibition effect of NO$_3$$^{[-10]}$ .

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.1088-1091
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• 2009

A boost converter with charge-recycling technique fabricated by $0.25{\mu}m$ CMOS BCD process can provide different supply voltages to drive series RGB LEDs in sequence for reducing the power consumption on the constant current generator. The proposed technique stores and restores extra energy to improve the efficiency, as well as enhances the reference tracking response. Experimental results show that the period of reference-tracking response can be improved. When the load current is 100mA, the periods of reference down-tracking and uptracking are smaller than $10{\mu}s$ and $20{\mu}s$, respectively. Experimental results demonstrate fast and efficient reference tracking performance is achieved.

• Transactions on Electrical and Electronic Materials
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• 제8권4호
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• pp.157-160
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• 2007

Lithium-sulphur batteries were fabricated in a dry room, and their electrochemical properties were analyzed by scanning electron microscopy (SEM), cyclic voltammetry (CV), and charge-discharge tests. SEM results showed that sulphur and nanocarbon powders were mixed homogeneously, and sulphur powders were enwrapped by a large amount of carbon powders. The charge-discharge test results demonstrated that the lithium-sulphur battery displayed excellent reversibility and cycling performance, which supplied a discharge capacity of $788.1mAh\;g^{-1}$ at the first cycle and $796.4mAh\;g^{-1}$ after 71 cycles at room temperature, respectively.

• Structural Engineering and Mechanics
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• 제4권6호
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• pp.679-702
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• 1996

The finite element method is employed in conjunction with micromechanical modelling in order to assess the performance of ceramic thermal barrier coatings applied to structural components. The study comprises the conditions of the deposition of the coating by plasma spraying as well as the thermal cycling of the coated component, and it addresses particularly turbine blades. They are exposed to high temperature changes strongly influencing the behaviour of the core material and inducing damage in the ceramic material by intense straining. A concept of failure analysis is discussed starting from distributed microcracking in the ceramic material, progressing to the formation of macroscopic crack patterns and examining their potential for propagation across the coating. The theory is in good agreement with experimental observations, and may therefore be utilized in proposing improvements for a delayed initiation of failure, thus increasing the lifetime of components with ceramic thermal barrier coatings.