• Tunnel and Underground Space
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• v.16 no.1 s.60
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• pp.38-49
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• 2006

LNG storage in lined rock cavern demands various techniques concerned with rock mechanics, thermo-mechanics and hydrogeology in design, construction and maintenance stage. LNG pilot cavern was constructed in Daejeon in order to verify these techniques. In this paper, evaluation of drainage system and ice ring formation was studied by numerical simulation. By Modflow analysis in the viewpoint of aquifer and Seep/W analysis in the viewpoint of flow system, it was verified that the drainage system in the pilot cavern was efficiently operated. Since ice ring formation can be simulated by interactive relation between heat transfer and water flow, coupled analysis of those was performed. In this analysis, the position of ice ring was presumed and it was demonstrated that the formation is affected by velocity and direction of groundwater flow.

• Journal of Korean Academy of Nursing
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• v.40 no.5
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• pp.714-723
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• 2010

Purpose: The purpose of this study was to examine the effects of using gauze frozen with normal saline or ice on thirstrelief and oral condition of laparoscopic cholecystectomy patients. Methods: A quasi-experimental nonequivalent control group, pretest-posttest design was used. Participants (n=53) received either gauze frozen with normal saline (n=17), ice (n=18) or wet gauze (n=18) for thirst-relief. The subjective thirst level and oral condition of the participants were assessed before the intervention, 15 min after the first intervention and 15 min after the second intervention. Results: After oral care was provided twice, there were significant differences in thirst level among the groups. When oral care was provided twice, the oral condition of tongue, saliva, mucosal membrane, and gingiva was improved in patients receiving gauze frozen with normal saline or ice. Conclusion: Gauze frozen with normal saline and ice can be effective for oral care in reducing the thirst level and improving the condition of the oral cavity.

• Tunnel and Underground Space
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• v.16 no.3 s.62
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• pp.241-250
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• 2006

Ice ring formation, one of the core techniques in LNG storage in a lined rock cavern, is investigated through hydro-thermal coupled analysis. An ice ring acts as a secondary barrier in case of leakage of cryogenic liquid and as a primary barrier for groundwater intrusion into an LNG cavern. Therefore, the thickness and location of the ice ring are crucial factors for the safe operation of an LNG storage cavern, especially for maintaining the integrity of a primary barrier composed of concrete, PU foam, and steel membrane. Through numerical analyses, the position and thickness of the ice ring are estimated, and the temperature and groundwater level are compared with measured values. The temperature md groundwater level by numerical analyses show good agreement with the field measurements when temperature-dependent properties and phase change are taken into account. The schemes used in this paper can be applied for estimation of ice ring formation in designing a full-scale LNG cavern.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2005.10a
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• pp.347-359
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• 2005

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2014.06a
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• pp.8-10
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• 2014

정부의 북극항로 시험운항이 시행된 2013년 NSR횡단 선박 척수는 전년도에 비해 54%가 늘어난 71척에 이르렀으나 실제 화물수송량은 당초 예상량인 150만톤에도 못 미치는 1,355,897톤으로 전년도에 비해 7.5% 증가에 그치고 말았다. 이는 2013년 하절기 북극해의 얼음이 2012년도에 비해 훨씬 적게 녹았기 때문으로 분석되고 있다. 그러나 지구온난화로 인한 전체적인 해빙 크기의 감소추세는 큰 틀에서 벗어나지 않고 있으므로 NSR의 선점을 위해서는 화물의 경제성 평가와 더불어 고효율선의 운항에 대비할 필요가 있다.

• CELLMED
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• v.3 no.1
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• pp.5.1-5.5
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• 2013

In this pilot dual-site study with LifeWave IceWave$^{(R)}$ patches, using subjects as their own controls, data were acquired from a convenience sample of 16 males and 24 females, 50% Caucasian-Americans, 50% Hispanic-Americans, ages 20 - 85 with neuromuscular pain. The hypothesis was: the application of IceWave$^{(R)}$ patches to the skin will reduce one's perception of pain. Subjects were tested at baseline (without any patches), and then at 1 and 3 h on day 1 and at 1 h on days 2 - 5 after patch application. At every time point, the mean change, indicative of one's perception of pain, was highly significantly (p < 0.0001) reduced, with a statistical power of 100% compared to baseline. Based on these findings, the hypothesis was accepted as true.

• KSBB Journal
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• v.30 no.6
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• pp.345-349
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• 2015

Antifreeze proteins (AFP) inhibit growth and recrystallization of ice, and permit organisms to survive in cold environments. The AFP from an Antarctic bacterium, Flavobacterium frigoris PS1, FfIBP (Flavobacterium frigoris icebinding protein), was produced in E. coli using a cold shock induction system. The culture temperature was shifted from $37^{\circ}C$ to $15^{\circ}C$ and a 20 L culture scale was used. The final weights of dried cell and FfIBP were estimated to be 126 g and 8.4 g, respectively. The thermal hysteresis (TH) activity ($1.53^{\circ}C$) of the produced FfIBP was 3.6-fold higher than that of the LeIBP (Leucosporidium ice-binding protein) produced in Picha. The current study demonstrates that large-scale production of FfIBP was successful and the result could be extended to further application studies using recombinant AFPs.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2014.11a
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• pp.204-206
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• 2014

석탄 화력발전소에는 연소가스의 질소산화물(NOx) 저감을 위한 SCR(selective catalytic reduction)설비가 운전되고 있으며, SCR은 환원제인 암모니아($NH_3$)를 이용하여 연소가스 내에 질소산화물을 물과 질소로 분해하는 역할을 한다. 그러나, 연소가스 중의 일부 삼산화황($SO_3$)과 미반응 암모니아가 결합하여 황산암모늄염(Ammonium bisulfate; $NH_4HSO_4$)을 생성하며, 이는 후단 APH(air preheater)의 열소자에 점착된 후 분진들과 함께 성장하여 막힘을 야기한다. 막힘이 발생된 APH는 연소가스의 흐름을 방해하기 때문에 차압을 증가시키며, 이는 발전효율의 감소뿐만 아니라 급전정지를 초래한다. 이를 해결하기 위하여 $CO_2$ 드라이아이스 세정 방법을 적용하였으며, pilot-scale plant에서 실험을 수행하였다. 또한, 드라이아이스 공정변수인 분사압력과 분사시간을 제어하여 pilot-scale plant의 APH 열소자 표면에 생성되어있는 오염물질들의 제거효율을 관찰한 결과 95 %의 높은 제거효율을 보였다.

• Geophysics and Geophysical Exploration
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• v.8 no.1
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• pp.67-72
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• 2005

To investigate the feasibility of a new concept of storing Liquefied Natural Gas (LNG) in a lined hard rock cavern, and to develop essential technologies for constructing underground LNG storage facilities, a small pilot plant storing liquid nitrogen (LN2) has been constructed at the Korea Institute of Geoscience and Mineral Resources (KIGAM). The LN2 stored in the cavern will subject the host rock around the cavern to very low temperatures, which is expected to cause the development of an ice ring and the change of ground condition around the storage cavern. To investigate and monitor changes in ground conditions at this pilot plant site, geophysical, hydrogeological, and rock mechanical investigations were carried out. In particular, geophysical methods including borehole radar and three-dimensional (3D) resistivity surveys were used to identify and monitor the development of an ice ring, and other possible changes in ground conditions resulting from the very low temperature of LN2 in the storage tank. We acquired 3D resistivity data before and after storing the LN2, and the results were compared. From the 3D images obtained during the three phases of the resistivity monitoring survey, we delineated zones of distinct resistivity changes that are closely related to the storage of LN2. In these results, we observed a decrease in resistivity at the eastern part of the storage cavern. Comparing the hydrogeological data and Joint patterns around the storage cavern, we interpret this change in resistivity to result from changes in the groundwater flow pattern. Freezing of the host rock by the very low temperature of LN2 causes a drastic change in the hydrogeological conditions and groundwater flow patterns in this pilot plant.

• Journal of the Ergonomics Society of Korea
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• v.23 no.1
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• pp.49-63
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• 2004

In this study. differences in attention allocation patterns between expert and novIce pilots were investigated by a verbal protocol when pilots were engaged in a task during the instrument flight. Ten pilots including experts and novices were participated to conduct a pre-determined task(a fix-to-fix) on F-5E Cockpit Procedure Trainer Simulator. Experts show better performance as expected with more stable variations in speed. altitude. and attitude. In attention allocation patterns. novices allocated about 83% of attentional resources on the primary instruments (airspeed indicator. altitude indicator. and attitude) relating to the task of the basic flight while experts spent 57%. This difference in the availability of attentional resources allowed expert pilots to accomplish the task better than novices. In other words. training a pilot should consider a program for building up wider instrument scanning patterns to become an expert in a shorter time.