• Journal of Energy Engineering
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• v.12 no.3
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• pp.216-222
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• 2003

An experimental study on the characteristics of a dewatering due to vacuum evaporation in the waste lubrication oil were performed using a lab scale system. Evaporation characteristics were investigated for various performance factors. Results of evaporation characteristics as a function of vacuum pressure, oil temperature, initial water concentration, and nozzle type were obtained. Increasing the oil temperature and altering the nozzle type were found to increase the evaporation rate without increasing vacuum pressure requirement. The best performance is achieved for the nozzle which made porous material.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.6
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• pp.579-582
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• 2012

Removing residual water in a fuel cell is a critical operational process for managing its performance and controlling its lifetime. Understanding the mechanism of water transport in fuel cells is essential for the design of the water removal process. In this study, an experimental method for measuring the water evaporation rate through a gas diffusion layer, which is a porous medium, under steady-state conditions was developed. Experimental bench tests were conducted to apply the developed method. Then, the effects of various parameters of the drying gas and the gas diffusion layer were experimentally measured. The water evaporation rate increased as the humidity of the drying gas decreased and the flow rate of the drying gas increased. In addition, a thinner gas diffusion layer yielded a higher water evaporation rate.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.11
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• pp.776-780
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• 2013

TPH degrdation patterns in diesel contaminated soil was investigated with microwave radiation. When microwave radiation on the soil was applied, temperature increment of the aridic soil was quite low, but temperature in the moist soil was dramatically increased even if short period of running time. Up to 20% of the moisture content, the higher moisture content has more increment of temperature, whereas over 20% of the moisture content, temperature in the soil was rather decreased. when 100~700 W power of microwave radiation was applied into the contaminated soil, a lot of TPH removals was observed under 300 W, but negligible increment of TPH removal was detected over 300 W. 60% of TPH removal was achieved with initial 20% moisture content and microwave radiation. Additional 25% removal was accomplished when moisture content was kept constant during radiation period. It indicated that maintaining of constant moisture is an important factor for TPH removal with microwave radiation because moisture and temperature in the soil are decreased with reaction time.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.1
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• pp.51-58
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• 2020

As interest in lunar exploration increases, studies on lunar surface environment simulation including a lunar soil simulant are being conducted. One of the problems when creating a vacuum environment with lunar soil is that it takes long time to reach high vacuum due to outgas from the soil. Most of the outgas is water, and the time to reach high vacuum can be significantly reduced by a pretreatment process that removes moisture adhering to the surface of the lunar soil before putting soil into a vacuum chamber. The existing soil drying methods were examined to determine how these methods were effective to remove moisture from the lunar simulant soil. Drying experiments of lunar soil samples were carried out using a dry oven, a microwave oven, direct heating method and a vacuum oven, and the results of the drying experiment were presented. Drying soil at 110℃ using a dry oven and drying soil by a microwave oven were not enough to remove moisture, and vacuum oven drying method and direct heating drying method at more than 200℃ were effective in water removal.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1998.06a
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• pp.22-26
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• 1998

토양오염 정화방법의 하나인 토양증기추출법(soil vapor extraction, SVE)은 오염된 토양에 진공 또는 가압의 공기를 공급하여 연속적인 공기 흐름을 유도함으로써 토양의 기공에 잔류하는 유해화합물의 증발을 촉진하여 오염물질을 제거하는 공정이다. 본 연구에서는 토양증기추출법의 효율에 영향을 주는 인자들 가운데에서 토양의 수분함량과 오염물질의 종류가 오염물질의 제거효율에 미치는 영향에 대한 실험과 계산을 수행하였다. 인공토양으로 glass bead, sand, molecular sieve가 사용되었으며. 오염물질로는 톨루엔. 메틸에틸케톤, 트리클로로에틸렌이 사용되었다. 각 실험에 대하여 프로인들리히 등온식과 기공확산모델 등을 고려하여 계산을 수행한 결과, 수분이 없는 경우에는 탈착식에 의해, 수분이 있는 경우에는 interparticle에서의 확산 현상에 의해 오염물질의 제거속도가 지배됨을 알 수 있었다. 이러한 연구결과는 정화대상지역에 SVE를 이용한 적절한 정화방법을 설계하는데 기초자료로 이용할 수 있을 것이다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.25-33
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• 2018

Renewable energy has been of interests in the area of modern alternative fuels. Biogas is produced in waste landfill sites through anaerobic digestion processes, including hydrolysis, acidogenesis, organic acid fermentation (acetogenesis), and methane fermentation (methanogenesis). High contents of fine dust and moisture limited its utilization for direct combustion, town gas and vehicle fuel. Thus, this study proposed a new design for a cooling device using a centrifugal cyclone for simultaneous removal of fine dust and moisture as a pretreatment in the purification processes. A heat exchanger and an ID fan, which are installed inside and outside of the cyclone, in order to cool the humid gas below the freezing point and form a foggy mist. Such an atmosphere enhanced to capture fine dust as recirculating the cold mist flow. The water removal rate was 80.8% at a relative humidity of 95%, and the particle removal efficiency was 98.3% for $2.5{\mu}m$. Simultaneous removal efficiency was 70.8% and 99.6% for particle and moisture respectively.

• Membrane Journal
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• v.23 no.2
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• pp.119-128
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• 2013

In this research, PEI/PEBAX composite hollow fiber membrane was used for the removal of water vapor from gases. PEI (Polyetherimide) substrate membrane was spinned by dry-wet phase inversion method and coated with PEBAX (Polyether block amides) 3533 and PEBAX1657. Fabricated fibers typically had an asymmetric structure of a dense top layer supported by a sponge-like substructure through scanning electron microscopy (SEM). $H_2O/N_2$ mixture gas was used to compare the performance of separation according to temperature, pressure and water activity. The results of PEBAX3533 and PEBAX1657 composite membranes respectively showed $H_2O/N_2$ selectivity of 61.7~118.5 and 85.3~175.4 according to operating conditions. PEBAX3533 composite hollow fiber membranes module showed the water vapor removal of 90%.

• 한국문화재보존과학회:학술대회논문집
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• 2005.03a
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• pp.71-88
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• 2005

With biological organism brown pollutants layers are thickly formed on inner stone materials in Gyeongjuseokbinggo(Ice storage in Gyeongju). Some simples were taken from this layer and its chemical composition, mineral composition, salt and microstructures were analyzed. This study shows that the pollutants layer can be removed easily, because it attached softly in stone surface. But because of its serious weathering state the stone surface also can be removed during the removing process. The origins of brown layer are assumed to be the soil in the mound over the Seokbinggo and the coarse sandy soil in the entrance. For the preservation of the Seokbinggo Waterproof and replacement of the coarse sandy soil should take precedence over the remove works. Subsequently moistureproof works should be enforced.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2007.05a
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• pp.65-68
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• 2007

수분선택흡착-VOCs흡착-압축응축식 hybrid 공정에서 수분의 선택분리가 가능한 흡착제를 선정하였다. 또한 수분흡착탑에서 미리 수분을 제거하여 VOCs의 흡착효율을 높임으로써 배출환경기준을 만족시키고 수분 혼합성 VOCs와 수분 비혼합성 VOCs 회수가 가능한 공정 운영이 가능함을 알 수 있었고, 회수된 VOCs를 곧바로 생산 공정에 재투입할 수 있는 원료물질 수준으로 회수가 가능하였다.

• Journal of Korean Society of Forest Science
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• v.98 no.6
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• pp.696-702
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• 2009

Yellow poplar (Liriodendron tulipifera L.) is an insect-pollinated tree species with large, perfect flower, and its seed sets average only about 10 percent naturally. In its controlled pollination, pollination bags are usually taken to prevent unwanted pollination, but bagging is an expensive and time-consuming process. Therefore, this study was conducted to determine the need of pollination bag by estimating how much unintended pollination would occur when different cross methods were applied. Five different pollination methods were applied as follows: 1) natural open pollination (i.e. insect pollination) as a reference, 2) self-pollination; no removing reproductive organs with bagging, 3) open pollination; emasculated(removing sepal, petal and stamen) without bagging, 4) controlled pollination; emasculated with bagging and 5) controlled pollination; emasculated without bagging. Very low value of full seed rate (0.2%) was observed in method 3, it was suggested that removing stamen and petal restrict the activity of pollen vectors like bee. Difference in the full seed rate between method 4 and method 5 was not significant (27.9% versus 24.0%, respectively). Consequently, controlled pollination without bagging might be an alternative method for extensive breeding and mass production of seeds in yellow poplar.