• 한국환경과학회지
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• 제4권2호
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• pp.121-139
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• 1995

Based on the Results of Marine Meteorological and Oceanographical Observations (1966 -1987), the phenomenon of chimney is found as a candidate for the formation of the Japan Sea Proper Water (JSPW). The chimney phenomenon occurs twelve times Inuring 1966∼ 1987. The water types in the chimney denoting the deep convection are similar to those of the JSPW 0∼ 1℃ in potential temperature, 34.0∼34.1 ‰ in salinity and 68∼80 cl/t in potential thermosteric anomaly from the sea surface to the deep layer. The static stabilities in the chimney stations are unstable or neutral. This indicates that the winter time convection occurs. The JSPW sunken from the surface layer of chimney in winter spreads out under the Tsushima Warm Current area, following the isosteric surface of about 76 cl/t in Potential thermosteric anomaly. The formation of the deep water of the JSPW is mainly affected by the cooling of the sea surface than the evaporation of winds because the temperature and the salinity on the isoteric surface of about 76 cl/t in potential thermosteric anomaly ate cold and low The phenomenon of chimney occurred in here and there of the area in the north of 40" 30'N, west of 138" E. This suggests that the deep water of the JSPW is formed not in a limited area but probably in the overall region of the northern open ocean.

• 한국태양에너지학회 논문집
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• 제22권3호
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• pp.39-46
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• 2002

The results of experiment on the performance of natural ventilation by insulation thickness and height system of solar chimney are described. The 3-inside wall was made of concrete and 1-wall was made of glass. The two kinds of model experiment were performed. One was the varition of the 60cm, 90cm and 120cm of solar chimney, the other was the variation of the insulation thickness 10mm and 50mm and without insulation of outside wall of solar cimney. As the temperature difference between bottom and top expressed $1.7\sim2.9^{\circ}C$, air velocity measured $0.5\sim0.8m/s$ and ventilation rate was $194.4m^3/h$ in the case of the 120cm height of solar chimney, the respect of natural ventilation performance was superior to others cases in the first model experiment. Though the case of 120cm height of solar chimney was attached 50mm insulation the ventilation rate was not so much as the case of solar chimney was attached 10mm insulation. the temperature difference between bottom and top was the largest in the other cases. From this research, the natural ventilation performance of solar chimney was affected by not only height and insulation thickness of solar chimney but also wind velocity and directon.

• 자원환경지질
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• 제35권1호
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• pp.1-12
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• 2002

남서태평양 Manus Basin은 인도-호주판과 태평양판이 충돌하여 형성된 배호분지로 열수분출작용이 활발하며, 석영 안산암 및 현무암질 안산암 계열의 산성 화산암류를 기반암으로 발달한 열 수분출구 등 열수광체가 산재되어 있다. 열수분출구는 주로 황철석, 황동석, 백철석, 섬아연석, 방연석 등의 광석광불과 이에 수반되는 경석고, 중정석, 비정질 규소 등으로 구성되어 있으며, 황동석이 괴상으로 다량 산출되는 Cu-rich chimney와 섬아연석이 괴상으로 다량 산출되는 Zn-rich chimney로 대분된다. 열수분출구글 구성하는 금속원소들의 전체적인 상관관계에Ai Zn은 Sb, Cd, Ag, 등과 그리고 Cu는 Mo, Mn, Co 등과 좋은 정의 상관관계가 인지된다. 또한, 열수분출구에 따라 Zn-rich chimney에서는 Au가 Zn과 대단히 높은 정의 상관관계를 보여주며 Cd, Mn, Sb 등이 부화되어 있는 반면에, Cu-rich chimney에서는 Au가 Zn 및 Pb와 좋은 정의 상관관계를 보여주며 Mo, Co 등이 부화되어 있는 특성을 보여준다. 연구지역 Cu-rich chimney 및 Zn-rich chimney의 Au 평균품위는 각각 15.9 ppm 및 29.0 ppm이며, Ag, Cu, Zn 등 유용금속도 상당량 부화되어 있어 경제성이 높은 것으로 평가된다. Zn-rich chimney에 산출하는 경석고 및 비정질규소의 유체포유물 균일화 온도 및 염농도는 174~22$0^{\circ}C$ 및 2.7~3.6 equiv, wt.% NaCl로. 섬아연석 등 광석광물의 주 광화 작용이 약 20$0^{\circ}C$를 전후한 범위에서 진행되었으며, 이때 산소분압은 $10^{40.8}$bar이하에서 $10^{39.5}$이상으로 황분압은 $10^{14.7}$bar이하에서 $10^{13.4}$이상으로 각각 증가 전이되는 것으로 추론된다. 한편, Cu-rich chimney는 Zn-rich chimney의 주 광화온도조건보다 높은 온도에서 광화작용이 진행되었을 것으로 판단된다.

• Earthquakes and Structures
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• 제16권3호
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• pp.321-327
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• 2019

This study investigated the possibility of using the recorded micro tremor data on ground level as ambient vibration input excitation data for investigation and application Operational Modal Analysis (OMA) on the bench-scale earthquake simulator (The Quanser Shake Table) for model chimney. As known OMA methods (such as EFDD, SSI and so on) are supposed to deal with the ambient responses. For this purpose, analytical and experimental modal analysis of a model chimney for dynamic characteristics was performed. 3D Finite element model of the chimney was evaluated based on the design drawing. Ambient excitation was provided by shake table from the recorded micro tremor ambient vibration data on ground level. Enhanced Frequency Domain Decomposition is used for the output only modal identification. From this study, best correlation is found between mode shapes. Natural frequencies and analytical frequencies in average (only) 1.996% are different.

• 헤리티지:역사와 과학
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• 제35권
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• pp.58-81
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• 2002

This article exemines YEON-GA(煙家), a kind of chimney head cover, made and used during the Baekjae Period. YEON-GA was recently excavated in Buyo and Iksan, and it generally accepted as a kind of pottery stand. However, this paper will argue that it functioned as a chimney head cover during the Baekjae Period. The design of YEON-GA is the lotus flower bud which were popular during the Sabi-Baekjae Period.It seems highly likely that it functioned to ornament a chimney head and to send up smoke smoothly. It was also found that, beside a chimnery head cover, a chimney body was made and used. It is very difficult to trace the origin of YEON-GA but it seems that it had been used until the Chosun Dynasty, based on the historical documents.

• Wind and Structures
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• 제31권1호
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• pp.59-73
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• 2020

Wind fragility analysis (WFA) of concrete chimney is often executed disregarding temperature effects. But combined wind and temperature effect is the most critical limit state to define the safety of a chimney. Hence, in this study, WFA of a 70 m tall RC chimney for combined wind and temperature effects is explored. The wind force time-history is generated by spectral representation method. The safety of chimney is assessed considering limit states of stress failure in concrete and steel. A moving-least-squares method based dual response surface method (DRSM) procedure is proposed in WFA to alleviate huge computational time requirement by the conventional direct Monte Carlo simulation (MCS) approach. The DRSM captures the record-to-record variation of wind force time-histories and uncertainty in system parameters. The proposed DRSM approach yields fragility curves which are in close conformity with the most accurate direct MCS approach within substantially less computational time. In this regard, the error by the single-level RSM and least-squares method based DRSM can be easily noted. The WFA results indicate that over temperature difference of 150℃, the temperature stress is so pronounced that the probability of failure is very high even at 30 m/s wind speed. However, below 100℃, wind governs the design.

• 한국입자에어로졸학회지
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• 제13권4호
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• pp.173-182
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• 2017

An Eulerian-Lagrangin approach is used to compute particle dispersion from a power plant chimney. For air flow, three-dimensional incompressible filtered Navier-Stokes equations are solved with a subgrid-scale model by integrating the Newton's equation, while the dispersed phase is solved in a Lagrangian framework. The velocity ratios between crossflow and a jet of 0.455 and 0.727 are considered. Flow fields and particle distribution of both cases are evaluated and compared. When the velocity ratio is 0.455, it demonstrates a Kelvin-Helmholtz vortex structure above the chimney caused by the interaction between crossflow and a jet, whereas the other case shows flow structures at the top of the chimney collapsed by fast crossflow. Also, complex wake structures cause different particle distributions behind the chimney. The case with the velocity ratio of 0.727 demonstrates strong particle concentration at the vortical region, whereas the case with the velocity ratio of 0.455 shows more dispersive particle distribution. The simulation result shows similar tendency to the experimental result.

• 기술사
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• 제17권4호
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• pp.62-68
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• 1984

• 기술사
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• 제18권1호
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• pp.26-32
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• 1985

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1835-1840
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• 2004

The HANARO, a multi-purpose research reactor of 30 MWth, open-tank-in-pool type, has been under normal operation since its initial criticality in February, 1995. The HANARO is composed of inlet plenum, grid plate, core channel with flow tubes and chimney. The reactor core channel is located at about twelve meters (12 m) depth of the reactor pool and cooled by the upward flow that the coolant enters the lower inlet of the plenum,. rises up through the grid plate and the core channel and comes out from the outlet of chimney. A guide tube is extended from the reactor core to the top of the reactor chimney for easily un/loading a target under the reactor normal operation. But active coolant through the core can be quickly raised up to the top of the chimney through the guide tube by a jet flow. This paper describes an analytical analysis that is the study of the flow behavior through the guide tube under reactor normal operation and unloading the target. As results, it was conformed through the analysis results that the guide jet is suppressed under the top of the chimney after modifying the orifice diameter of 37.5 mm to 31 mm.