• Journal of Hydrogen and New Energy
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• v.17 no.4
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• pp.425-433
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• 2006

Sepiolite was selected as a mineral carbonation candidate ore for carbon dioxide sequestration. Carbonation salt formation from alkaline earth metal ingredient needs to dehydroxylation of sepiolite at high temperature. An evident dehydroxylation was observed over $800^{\circ}C$ and the variations of sepiolite characteristics after high temperature treatment was synthetically evaluated. Remarkable weight loss were measured after high temperature thermochemical reaction then crystallographic and spectroscopic changes were analyzed. The resulted alkaline earth metal oxides could explained by dehydroxylation based on thermochemical reaction.

• Journal of Hydrogen and New Energy
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• v.17 no.1
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• pp.109-116
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• 2006

The heat treatment characteristics of natural talc sample was investigated in diverse analytical view point. The mass decrease comes to heat treatment was resulted by the continuous and the discontinuous process and the obtained result show very similar two step profiles with 8.9 % mass decrease. The dehydroxylation of -OH groups contained talc crystal was analyzed by spectroscopic method and the crystallographic variations was also observed after heat treatment. According to XPS result, the magnesium hydroxide($Mg(OH)_2$) of untreated talc powder changed to magnesium oxides(MgO) after heat treatment.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.513-516
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• 2006

The feasibility study for tidal power plant (TPP) has been carried out for the Siwha area inside the Kyunggi bay of the Kyunggi Bay of the Yellow and East china Seas, by KORDI (Korea Ocean Research and Development Institute) and continuing research works for tidal energy development are under progress in the several sites inside the Kyunggi Bay. In this paper we describes some results of the modeling efforts in relation the tidal regime change by Siwha TPP operation, as well as other coastal oceanographic research works involved in TPP development in the coastal region.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.4
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• pp.283-296
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• 2014

The distribution of heavy metals in the stormwater runoffs from industrial sites around Shihwa Lake that implements the total pollutant load management system (TPLMS) was studied to characterize the temporal changes of metal concentrations and to assess the ecological risk in dissolved and particulate phases of the selected metals. The dissolved Co and Ni concentration demonstrated first flush and tended to decrease with increasing of the duration of rainfall. The intensity of precipitation was found to be the main controlling factor of particulate metals in the stromwater runoffs. The particulate concentration of Pb accounted for 97.2% so the particulate phase was its main form. Other metals followed the sequence: Pb>Cu>Cd>Co>Zn>Ni. The particulate-dissolved partitioning coefficient ($K_d$) indicated that the $K_d$ of Pb were bigger than that of other metals because the metal Pb in the stormwater runoffs is quickly removed into the particulate phase. In a single day rainfall event, total runoff fluxes for total metals as the sum of dissolved and particulate forms through only two sewer outlets were 2.21 kg for Co, 30.5 kg for Ni, 278.3 kg for Cu, 398.3 kg for Zn, 0.39 kg for Cd and 40.0 kg for Pb, respectively. Given the annual rainfall, the number of rain days and the basin area for total pollutant load management system (TPLMS) of Shihwa area, enormous amount of non-point metal pollutants were entered into Lake with any treatment. The dissolved metals (e.g., Ni, Cu and Zn) in the stormwater runoffs exceeded the acute water quality criteria. Additionally, all metals were significantly enriched in the particulate phase and exceeded the PEL criteria of sediment quality guidelines (SQGs). These results indicated that the heavy metals in the stormwater runoffs may pose a very high ecological risk to the coastal environments and ecosystem.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.04a
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• pp.225-228
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• 2007

The objective of this study is to characterize design parameters of rocket igniters for composite, double base and nitramine propellant. Arc image furnace and fiber optics surface reflectometer were used to measure ignition delay time and reflected optical energy of several compositions of composite, double base and nitramine base rocket propellant at different pressure levels each other. The order of ignitability was double base > composite > Nitramine propellants at initial pressure of over 75 psia. The highest ignition energy was needed to ignite nitramine propellant, however, as the pressure increased up to the range of $75{\sim}400$ psia as the ignition delay time decreased abruptly. The absorbtion of radiation energy could be increased by the addition of small amount of opacifiers as carbon black, ZrC, WC and burning catalyst.

• Journal of Korea Water Resources Association
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• v.33 no.2
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• pp.237-245
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• 2000

Sihwa seadike is originally designed to control the water level In lake Sihwa. However the sluice gate is being operated everyday to preserve the water quality of lake. Due to the frequent operation of gates the bottom of drainage canal which is composed of weathered rock and soft rock is being scoured. Recently the bottom in the front area of apron was protected by putting underwater concrete. This study is carried out to understand the hydraulic situation for protection, and to estimate the trend of scouring by comparing between energy dissipation and registance of bottom rock. Annandale(1995) introduced the erodibility index theory, and suggested a criteria to judge the erodibility of rock through the relation between the erodibility index and energy dissipation. Determenation of erodibility index of rock is based on the results of sample core analysis, and the energy dissipation of flow is calculated from the estimation of total head on the scale model. These two values are plotted on the criteria, and the erodibility of rock is determined.

• Korean Journal of Ecology and Environment
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• v.39 no.1 s.115
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• pp.93-99
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• 2006

Primary productivity was determined by using $^{13}C$ tracer according to different cell size of phytoplank-ton through in situ incubation experiments in upper stream of the Lake Shihwa. The average concentration of chlorophyll a was 14 ${\mu}g\;L^{-1}$ demonstrating an eutrophic water. The ratio of POC/Chl-a was lower than 30, reflecting that the origin of organic matter might be mainly phytoplankton. The primary productivity was 93.9 mgC m^{-2}\;d^{-1}$ at St. 1, which was about 40-fold lower than the average value of the lake (3,972 mgC m^{-2}\;d^{-1}$) determined by Choi et al. (1997) before opening of gate but it was higher than the average primary productivity (3.98 mgC m^{-2}\;d^{-1}$) reported by KOWACO in 1993 before constructing dam. The fractionated size (20 ${\sim}$ 53 ${\mu}m$) of phytoplankton community account for 51% of total primary productivity, indicating the highest assimilation rate. This study suggest that $^{13}C$ tracer methodology should be applied as a useful approach for the water ecological research in the future.

• Journal of the Korean Solar Energy Society
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• v.31 no.5
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• pp.47-59
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• 2011

The purpose of this paper is to simulate the high ozone concentration in Shiwha Banwol indusrial complex. High pollution episodes (ozone alert) of this area are the results of geographical location and its air pollutants emission. This research has used meteorological model (RAMS) and photochemical air pollution Model (CIT model). As first step of the evaluate of this combined model system simulations are done in terms of meteorological characteristics like wind fields, PBL-height, etc.. Numerical simulations are carried out with real meteorological synoptic data on June. 24-25, 2010. In comparison with real measurement and another research the model reflects well local meteorological phenomena and shows the possibility to be utilized to analyse the pollutant dispersion over irregular terrain region. The high ozone concentration is deeply correlated to the ambient air temperature, wind speed and solar radiation. Local meteorological phenomena like sea-land breeze impact on horizontal dispersion of ozone. This analysis of meteorological characteristics can, in turn, help to predict their influences on air quality and to manage the high ozone episodes.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2001.11a
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• pp.115-122
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• 2001

본 개발대상 장치인 풍력을 통한 하강류 형성장치는 심층에 산소를 공급하여 패류가 증식하게 하므로 정화를 할 수 있도록 하는 장치이다. 본 연구의 결과, 풍력 저수지 수질개선장치를 통해 모든 호소의 수질등급을 상향시킬 수 있을 것이다. 특히, 새만금, 시화호 등 문제 있는 호소까지 인간에 유익한 수질로 개선 함으로써 국가적인 이익은 물론 전세계의 수원을 정화하여 인류의 수자원 문제를 해결할 수가 있을 것이다. 동력에 의한 방법은 언제든지 적용할 수 있지만, 풍력에 의한 장치로 에너지 비용과 설치비용을 절감하는 것이 본 개발대상 장치를 통해 얻을 수 있는 효과이다. 현재 국내의 저수지는 약 12,000개소에 달한다 이 저수지들에 오염도에 따라 5대～200대 정도를 설치할 경우(소양이나 새만금 등), 장치의 대당 가격이 1,000 만원～1,500 만원이므로 국내 수요로 약 2조 4천억원의 내수시장이 형성될 수 있을 것이다.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.04a
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• pp.307-308
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• 2000

최근 들어 우리의 활동영역이 실외에서 실내로 점차 이동됨에 따라 실내공간의 공기 오염은 중요한 관심사가 되고 있다 실내공기오염은 주로 학교, 사무실, 공공건물, 지하공간 등에서 발생하는 것으로 조사되고 있으며, 그 위해성이 심각한 정도는 아니지만 하루 24시간 중 80% 이상을 실내에서 생활하는 사람들의 건강에 해를 미치는 것은 분명한 것으로 인식되고 있다(NRC, 1981； 김윤신, 1995). 이러한 실내공기 오염현상은 전세계적으로 빌딩 등이 밀집되어 있는 대도시에서 자주 보고되고 있으며, 국내의 경우도 1970년대 이후 대도시화와 에너지 소비가 급증함에 따라 실내공기 오염의 우려가 높아지고 있으나, 실외 대기오염에 비해 다소 소홀히 인식되고 있다. (중략)