• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1996년도 춘계학술대회 논문집
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• pp.206-210
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• 1996

In order to investigate the electrical properties for transformer oils which contains a Pure sodium chloride, the dielectric properties is made researches. To measure the dielectric loss of specimen, a coaxial cylindrical liquid electrode is used, and its geometric capacitance is confirmed to 16[pF]. And the dielectric dissipation factor, tan$\delta$, is measured by using the Video Bridge 2150. The thermal static oven with an automatically static temperature controller is used so as to support specific temperature to the specimen. This experiments for measuring the dielectric lass is performed at 20-120[$^{\circ}C$] in the temperature range, 30∼1.5x10$\^$5/[Hz] in the frequency range and 300∼1500[mV] in the voltage range. The result of experiment for the movement of carrier and the physical constants to contribute dielectric properties of specimen with a pure sodium chloride.

• Rapid Communication in Photoscience
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• 제4권1호
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• pp.16-18
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• 2015

Luminescence properties of anthracene chromophores were investigated. Anthracene chromophores were incorporated in cyclosiloxane-based hybrid polymers through one-pot hydrosilylation reaction. Using four-armed cyclosiloxanes, divinylterminated siloxane monomers, and 9-vinylanthracenes, anthracene-labeled hybrid polymers were prepared. Free-standing hybrid polymer films were prepared successfully by doctor-blade method and thermal treatment. The polymer films exhibit strong blue fluorescence from anthracene and its fluorescence lifetime was not influenced by the temperature, indicating that the movement of anthracene chromophores was restrained in cyclosiloxane-based hybrid polymer films.

• Journal of Biosystems Engineering
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• 제28권4호
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• pp.285-294
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• 2003

This study was carried out to propose a new-concept internal combustion engine which has great potential advantages to the conventional engines. Proposed new-concept engine is a kind of rotary engine. A rotor is rotating concentrically in a cylinder which is divided into two partitioning valves, and it makes four compartments in the cylinder. The volumes of each of four compartments are changing continuously with the rotor movement and performs the functions of intake, compression. expansion and exhaust simultaneously. Expected thermal efficiency for the real cycle is 26 percent at conditions of 1,000 rpm and compression ratio of 8.0, which is 3 to 4 percent higher than that of the conventional engines such as the piston engine, gas turbine and Wankel rotary engine. A simulation procedure proved that the new concept engine is functional, and has many potential advantages compared to the existing conventional engines.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1740-1746
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• 2008

The present study performed numerical investigation to analyze the smoke behavior in the rescue station by using the commercial CFD code (FLUENT Ver 6.3). The present study adopted a 10MW ultrafast mode for simulation, and it also used the MVHS(Modify Volumetric Heat Source) model modified from the original VHS(Volumetric Heat Source) model in order to treat the product generation and the oxygen consumption under the stoichiometric state. In addition, the present simulation includes the species conservation equation for the materialization of heat source and the estimation of smoke movement. From the results, the smoke flows are moving along the ceiling because of thermal buoyancy force and as time goes, the smoke gradually moves downward at the vicinity of the entrance. Moreover, without using ventilation, it is found that the smoke flows no longer spread across the cross-passages because the pressure in the non-accident tunnel is higher than that in the accident tunnel.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2005년도 동계학술발표대회 논문집
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• pp.82-87
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• 2005

The characteristics of train-wind in the underground shopping center(UGSC) connected to subway station is investigated by field measurement for the case of train movement such as arrival and departure, etc. Also air curtain installed at the pass way between underground shopping center and subway station were considered as the parameter in order to analysis the effect on indoor air quality and thermal condition. The measurement data such as velocity, relative humidity, wind-pressure were plotted as quantity variation with time scale. The train-wind affected wind velocity, air pressure and relative humidity at the connecting area of underground shopping center and subway station, and the variation was about 4.5 m/s, 8%, 40 Pa. Also the result showed that the air curtain is not proper to reduce influence of train-wind

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.1963-1969
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• 2009

This paper introduces method to estimate pollutant negative influence to polymer type insulator according to the international standard. To accomplish this goal, effective sample collecting method was surface was collected directly with the same dimension. Distilled Through this method pollute is easily and accurately collected. The second step is pollutant analysis. Several analyze item is selected such as quantity, conductivity, contact angle, Optical Microscope(OM), IR spectrometer(FT-IR), Equivalent Salt Deposit Density(ESDD), Thermal Analyzer(TA) and ICP-AES. The third step, best represent tunnel was selected considering location, length and natural surroundings. Also to consider the difference at inside the tunnel, several bracket insulators were selected along to the location. To make the result precise, above procedure was repeated several times at the same target. Finally relation among type of train, numbers of movement, surroundings, length will be considered in combination with the pollution. With this result pollute map for KORAIL could be accomplished and inspect period will be optimized case by case.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 1998년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Spring 1998
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• pp.120-127
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• 1998

This paper deals with the dynamic responses of the multi-span continuous bridge with longitudinal shear keys. It is motivated by a need to understand the effects of longitudinal shear keys which may be used for the reduction of the longitudinal seismic force in continuous bridges. The results show that (1) The force reduction of fixed pier is proportional to the ratio of gap size and elastic maximum displacement of the bridges without shear keys ; (2) The thermal movement has little effect on the response of the continuous bridges with shear keys. Also the simplified equation is proposed to calculate the maximum response of the continuous bridges with longitudinal shear keys. The equation requires only the elastic analysis results of the bridge and the gap size between superstructure and shear keys.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.2064-2069
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• 2004

The main reason to analyze heat transfer in boiler inside through the performance test in fossil power plant is to increase plant high efficiency and energy saving movement in the government. Tins study intends to have trend and analyze the boiler heat transfer through the performance test, so it may give us the heat distribution in boiler inside in super-critical and sub-critica1 pressure type power plant

• 한국지반환경공학회 논문집
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• 제16권6호
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• pp.39-43
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• 2015

This study extends the Distributed Temperature Sensing (DTS) application to delineate the saturated zones in shallow sediment and evaluate the groundwater flow in both downward and upward directions. Dry, partially and fully saturated zones and water level in the subsurface can be recognized from this study. High resolution seepage velocity in vertical direction was estimated from the temperature data in the fully saturated zone. By a single profile, water level can be detected and seepage velocity in saturated zone can be estimated. Furthermore, thermal gradient analysis serves as a new technique to verify unsaturated and saturated zones in the subsurface. The vertical seepage velocity distribution in the recognized saturated zone is then analyzed with improvement of Bredehoeft and Papaopulos' model. This new approach provides promising potential in real-time monitoring of groundwater movement.

• Bulletin of the Korean Chemical Society
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• 제18권8호
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• pp.814-818
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• 1997

The chemical waste treatment, APEG (alkali/polyethylene glycol) process has been shown to be effective for the dechlorination of PCBs in transformer oil. Considerable amount of PCBs, however, still remains in the waste exceeding the 25-50 ppm limit set by regulatory agency. A new thermal regeneration technology has been developed in our laboratory for disposal of hazardous organic wastes. Due to the limited oxidation of carbon surface through the reverse movement of flame front to oxidant flow, this technology was termed counterflow oxidative system (COS). Specially, the oxidant flow in the COS process is a principal parameter which determines the optimum conditions regarding acceptable removal and destruction efficiency of adsorbed organic wastes at minimal carbon loss. The COS process, under optimum conditions, was found to be very effective and the removal and destruction efficiency of 99.99% or better was obtained for residual PCBs in the waste while bulk (≥90%) of carbon was recovered. Any toxic formation of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzo furans (PCDFs) were not detected in the regenerated carbon and impinger traps. The results of surface area measurement showed that the adsorptive property of regenerated carbon is mostly reclaimed during the COS process.