• 대한소아치과학회지
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• 제29권3호
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• pp.455-462
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• 2002

최근 치과에 내원하는 환아의 연령이 어려지고, 장애아 및 행동조절이 어려운 환아의 치료에 관심이 높아지고 있어 이를 위한 한가지 방법으로 진정치료가 고려되고 있으며 그 중 chloral hydrate/hydroxyzine을 사용한 진정치료가 널리 오랫동안 사용되어 왔다. 이 연구에서는 강릉대학교 치과병원 소아치과에 내원하여 국소마취 하 수복치료가 필요하고, 통상의 행동조절에 반응하지 않거나 너무 어려 행동조절이 불가능한 아동을 대상으로 chloral hydrate/hydroxyzine을 사용 진정치료를 시행하고 생징후를 측정하였다. 이상의 결과 생징후는 chloral hydrate/hydroxyzine을 사용한 진정치료시 일시적 자극을 제외하고는 큰 변화를 보이지 않으며, 환아의 수면에 따른 호흡과 심박수의 감소가 관찰되었다. 따라서, 이러한 진정치료는 행동조절이 불가능하거나 아주 어린 아동에서 생징후에 영향을 적게 주면서 적절한 진정을 유도할 수 있는 방법이라 여겨진다.

• 한국전산유체공학회지
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• 제13권4호
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• pp.50-57
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• 2008

The prediction of hydrate pellet decomposition characteristics is required to design the regasification process of GTS (gas to solid) technology, which is considered as an economic alternative for LNG technology to transport natural gas produced from small and stranded gas wells. Mathematical model based on the conservation principles, the phase equilibrium relation, equation of gas state and phase change kinetics was set up and numerical solution procedure employing volume averaged fixed grid formulation and extended enthalpy method are implemented. Initially, porous methane hydrate pellet is at uniform temperature and pressure within hydrate stable region. The pressure starts to decrease with a fixed rate down to the final pressure and is kept constant afterwards while the bounding surface of pellet is heated by convection. The predicted convective heat and mass transfer accompanied by the decomposed gas flow through hydrate/ice solid matrix is reported focused on the comparison of spherical and cylindrical pellets having the same effective radius.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.107-110
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• 2008

The price of natural gas import continues to rise, as well as its domestic consumption rate. This research examined the economic feasibility of domestically developing and producing gas hydrate to substitute imported natural gas. Today, the technology to commercially produce gas hydrate is still lacking; however, if the gas hydrate is able to be commercially produced domestically and replace imported natural gas, the annual economic benefit for the Republic of Korea would be 211 - 833 USD/ton. From the industry's point of view, gas hydrate is a high value investment since one can expect an annual profit of over 150USD/ton. The commercial value of gas hydrate development will increase as long as the natural gas market continues to expand and as the increase of natural gas consumption remains steady. With further development of technology, one can anticipate an even higher expected return on the investment.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.703-704
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• 2009

Natural gas Hydrate is an ice-like crystal containing natural gas it. Natural gas hydrate is studied as a new energy resource and a factor for seafloor slope stability and global warming. The unique pressure and temperature stability conditions of natural gas hydrate have challenged the research efforts. In this study, a new tool to study hydrate-bearing sediments and the preliminary results are introduced. The device can sustain 20MPa of the fluid pressure and apply 5MPa of the vertical effective stress under the temperature control. Cell can be scanned by X-ray CT scanner and also has the capability of multi-sensor data acquisition. Preliminary results suggests various application of the cell to hydrate-bearing research.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.531-533
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• 2007

We report and discuss molecular and isotopic properties of hydrate-bound gases from 55 samples and void gases from 494 samples collected during Ocean Drilling Program (ODP) Leg 204 at Hydrate Ridge offshore Oregon. Gas hydrates appear to crystallize in sediments from two end-member gas sources (deep allochthonous and in situ) as mixtures of different proportions. In an area of high gas flux at the Southern Summit of the ridge (Sites 1248-1250), shallow (0-40 meters below the seafloor (mbsf)) gas hydrates are composed of mainly allochthonous mixed microbial and thermogenic methane and a small portion of thermogenic C2+ gases, which migrated vertically and laterally from as deep as 2-2.5 km depths. In contrast, deep (50-105 mbsf) gas hydrates at the Southern Summit (Sites 1248 and 1250) and on the flanks of the ridge (Sites 1244-1247) crystallize mainly from microbial methane and ethane generated dominantly in situ. A small contribution of allochthonous gas may also be present at sites where geologic and tectonic settings favor vertical gas migration from greater depth (e.g., Site 1244).

• 약학회지
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• 제22권1호
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• pp.8-14
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• 1978

The method that changes sodium cloxacillin from amorphous form to hydrate form was investigated. Using organic solvents of which dielectric constants are greater than 9, the amorphous sodium cloxacillin could be changed to hydrate form. The difference of water content of sodium cloxacillin hydrate caused the differences of ir spectrum at $3,350~3,360cm_{-1}$, and owing to the decrease of water content, hydrate form was changed to the morphous form, which could be identified by x-ray diffraction pattern. Regarding the stability of sodium cloxacillin in activity, the hydrate form was stable but the amorphous form was very unstable. Moreover, the stable hydrate form was scarcely hygroscopic, while the other form was hygroscopic, becoming a fused state ar $50^{\circ}$. and R.H. 50%.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 학술대회
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• pp.268-275
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• 2008

The prediction of hydrate pellet decomposition characteristics is required to design the regasification process of GTS (gas to solid) technology, which is considered as an economic alternative for LNG technology to transport natural gas produced from small and stranded gas wells. Mathematical model based on the conservation principles, the phase equilibrium relation, equation of gas state and phase change kinetics was set up and numerical solution procedure employing volume averaged fixed grid formulation and extended enthalpy method are implemented. Initially, porous methane hydrate pellet is at uniform temperature and pressure within hydrate stable region. The pressure starts to decrease with a fixed rate down to the final pressure and is kept constant afterwards while the bounding surface of pellet is heated by convection. The predicted convective heat and mass transfer accompanied by the decomposed gas flow through hydrate/ice solid matrix is reported focused on the comparison of spherical and cylindrical pellets having the same effective radius.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년 추계학술대회논문집
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• pp.268-275
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• 2008

The prediction of hydrate pellet decomposition characteristics is required to design the regasification process of GTS (gas to solid) technology, which is considered as an economic alternative for LNG technology to transport natural gas produced from small and stranded gas wells. Mathematical model based on the conservation principles, the phase equilibrium relation, equation of gas state and phase change kinetics was set up and numerical solution procedure employing volume averaged fixed grid formulation and extended enthalpy method are implemented. Initially, porous methane hydrate pellet is at uniform temperature and pressure within hydrate stable region. The pressure starts to decrease with a fixed rate down to the final pressure and is kept constant afterwards while the bounding surface of pellet is heated by convection. The predicted convective heat and mass transfer accompanied by the decomposed gas flow through hydrate/ice solid matrix is reported focused on the comparison of spherical and cylindrical pellets having the same effective radius.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.676-679
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• 2009

The bottom-simulating reflector (BSR) is the most commonly observed seismic indicator of gas hydrate in the Ulleung Basin, East Sea. We processed ten representative seismic reflection profiles, selected from a large data set, for amplitude variation with offset (AVO) analysis of the BSR to estimate gas-hydrate concentrations. First, BSRs were divided into five groups based on their seismic amplitudes and associated sediment types: (1) very high-amplitude BSRs in turbidite/hemipelagic sediments, (2) high-amplitude BSRs in debris-flow deposits, (3) moderate-amplitude BSRs in turbidite/hemipelagic sediments, (4) very low-amplitude BSRs in debris-flow deposits, and (5) very low-amplitude BSRs in seismic chimneys. The AVO responses of the group 1 and 3 BSRs are characterized by a rapid decrease and a relatively slow decrease in magnitude with offset, respectively. The AVO response of the group 2 BSR is characterized by a relatively slow increase in magnitude with offset. The AVO responses of the groups 4 and 5 BSRs are characterized by a flat AVO with very small zero-offset amplitude. Theoretical AVO curves, based on the three-phase Biot theory, suggest that the group 1 and 3 BSRs may be related to high (> 40%) concentrations of gas hydrate whereas the group 2 BSRs may indicate low (< 20%) concentrations of gas hydrate. The AVO responses of the group 4 and 5 BSRs cannot be compared with the theoretical models because of their very small zero-offset amplitudes. The comparison of the AVO response of the BSR at the UBGH-04 well with theoretical models suggests about 10% gas-hydrate concentration above the gas-hydrate stability zone.

• Korean Chemical Engineering Research
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• 제58권4호
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• pp.635-641
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• 2020

이 연구에서는 에틸렌글리콜과 염이 포함된 메탄 하이드레이트의 상평형과 형성 거동을 측정하였다. 염의 종류로는 염화나트륨(NaCl), 브롬화나트륨(NaBr), 아이오딘화나트륨(NaI)을 이용하였으며, 272~283 K의 온도 범위와 3.5~11 MPa의 압력범위에서 상평형 조건을 확인하였다. 5 wt% NaCl + 10 wt% MEG, 5 wt% NaBr + 10 wt% MEG, 5 wt% NaI + 10 wt% MEG의 순서로 메탄 하이드레이트의 억제 효과가 나타났음을 확인하였다. 에틸렌글리콜과 염이 포함된 메탄 하이드레이트의 형성 거동은 생성유도시간, 가스소모량과 성장 속도를 분석하여 확인하였다. 에틸렌글리콜과 염이 포함된 메탄 하이드레이트의 생성유도시간은 실험 조건에서 큰 차이를 보이지 않았지만, 에틸렌글리콜과 염의 첨가는 가스소모량과 성장 속도에 영향을 주었음을 확인할 수 있었다.