• Title/Summary/Keyword: Air buffer

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Study on the Behavior of Gaseous Mercury and its Influencing Factors in Urban AMbient Air (都市大氣의 水銀動態와 影響因子에 關한 硏究)

  • 김민영;박상현;박성배
    • Journal of Korean Society for Atmospheric Environment
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    • v.5 no.1
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    • pp.11-21
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    • 1989
  • Atmospheric gaseous mercury was automatically measured by a mercury air monitor (Mercury monitor AM-1). The sample air was led to a scrubber and washed with buffer solution, and mercury was trapped with gold coated chromosorb P(AW) was successively eluted by heating the chromosorb and then detected by the cold vapor atomic absorption spectrophotometry. $SO_2, TSP, NO_x, CO, THC$. and some of meteorological factors were also measured simultaneously with mercury. A significant correlation between the concentration of mercury and those of 2,513 measurements, gaseous mercury concentration ranged from 4.73 to 112.8 $ng/m^3$ with an annual mean of 14.7$ng/m^3$ in urban area. At this place there was a clear seasonal variation with a maximuminDecember-January and aminimum in March-June. A secondary maximum existed in August to September. THe seasonal variation was found that the gaseous mercury in ambient air has a tendency to become low in spring and high in winter. Namely, the average of concentration in winter was about two times, 19.2 $ng/m^3$, higher than that in spring. In Seoul mercury levels on some months mainly Septermber-October increase with increasing relative humidity of the atmosphere. In Olympic park air levels were 8.2 (range 4.4-23.7)$ng/m^3$ with an coefficients of variation of 0.34 and in Seoul sports complex those were 7.7 (rnage 4.4-25.5) $ng/m^3$ with an coefficients of variation of 0.38 within the Seoul olympiad holding period of time. A significant diurnal mercury variation occurs both at the measuring sites and in the period of observation.

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Stability Analysis of Concrete Plugs Installed in Pilot Tunnels for the Storage of Compressed Air (압축공기 저장용 파일롯 터널에 설치된 콘크리트 플러그의 안정성 해석)

  • Lee, Youn-Kyou;Song, Won-Kyoung;Park, Chul-Whan;Choi, Byung-Hee
    • Tunnel and Underground Space
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    • v.20 no.6
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    • pp.446-454
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    • 2010
  • CAES-G/T (Compressed Air Energy Storage - Gas Turbine) power generation is a likely option for the buffer facility stabilizing the fluctuation of the renewable powers, such as wind and solar powers. Considering the geological conditions, the underground CAES facility is most probable if the CAES-G/T generation is planed in Korea. In this kind of facility, a concrete plug is installed to seal the compressed air in the container, so that the selection of the shape and dimension of concrete plug could be a critical design factor. The stability evaluation of two types of plug was carried out by investigating the distribution of the factor of safety in the plugs and the distribution of contact pressure over the contact surface. The analysis result shows that the taper-shaped plug is more structurally stable than the wedge-shaped plug for the given geological condition. Possible separation of the rock-concrete interface around the spring line of the wedge-shaped plug is anticipated, which means the possible leakage of compressed air through the side wall and also means the poor mobilization of frictional resistance on that area.

A Study on Green Space Management Planning Considering Urban Thermal Environment (도시 열환경을 고려한 녹지관리방안 수립 연구)

  • Joo, Chang-Hun;Kim, Jeong-Ho;Yoon, Yong-Han
    • Journal of Environmental Science International
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    • v.23 no.7
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    • pp.1349-1358
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    • 2014
  • This study suggests plan of green space management based on the result of research apprehending the characteristic through sorting types of city thermal environment targeting summer which thermal pollution is the most serious. Considering anthropogenic heat, development level of wind road, thermal environment, as a result of types of thermal environment process, it is appeared 36 types, and 10 types is relevant of this research subject. Type I-1, size of building is large, artificial covering area is wide, and thermal load of anthropogenic heat is high, type II-1, development condition of wind road is incomplete as IIlevel, entering cold air is difficult and thermal management and improvement is needed area. Type III-1, scale is large and it is area of origin of cold air, development level of wind road is mostly favorable, type III-2 is revealed as smaller scale than III-1, and small area of origin of cold air. Type IV, anthropogenic heat is $81{\sim}150W/m^2$, average, but development function of wind road is very favorable. Type V, large area of thermal load and the origin of cold air are distributed as similar ratio, and level of development function of wind road is revealed as II level. According to standard of type classification of thermal environment, as a result of suggesting plan of green space management and biotops area ratio, type I-1 is buffer green space and waterway creation, goal biotops area ratio 35%, type II-1 afforestation in site and goal biotops area ratio 40%, type III-1, preservation plan to display the current function continuously is requested. Type IV suggests afforestation of stream current, and type V suggests quantitative increase of green space and goal biotops area ratio 45%.

A CFD Simulation Study on the Isolation Performance of a Isolation Ward (CFD를 이용한 격리병동의 격리성능 검토)

  • Sohn, Deokyoung;Kwon, Soonjung;Choi, Yunho
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.20 no.1
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    • pp.7-14
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    • 2014
  • Purpose: In this study, we performed ventilation simulations for a standard isolation ward including three intensive care rooms, one anteroom(buffer room), and its recommended ventilation equipments. The purpose of this study is to predict outflow of pathogenic bacteria from patient breath to verify the reliability and the safety of the isolation ward. Methods: We suppose three scenarios of the movement of medical staff. The leakage of patient's breath to out of the ward is predicted in these scenarios using CFD simulations. Results: The patient's breath leakage rate to out of the ward in scenario 1 according to room air changes per hour(ACH : 6 and 12) is predicted to be 0.000057% and 0.00002%, respectively. The patient's breath leakage rate to out of the ward in scenario 2 according to room air changes(ACH : 6 and 12) is predicted to be 0.00063% and 0.00019%, respectively. The patient's breath leakage rate to out of the ward in scenario 3, which is the worst case(6 room air changes) is predicted to be 0.1%. Implications: Through the ventilation simulation like that in this study, the reliability and the safety on isolation performance of various plan of isolation ward are predicted quantitatively.

The Impact of Double-Skin Façades on Indoor Airflow in Naturally Ventilated Tall Office Buildings

  • Yohan, Kim;Mahjoub M. Elnimeiri;Raymond J. Clark
    • International Journal of High-Rise Buildings
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    • v.12 no.2
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    • pp.129-136
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    • 2023
  • Natural ventilation has proven to be an effective passive strategy in improving energy efficiency and providing healthy environments. However, such a strategy has not been commonly adopted to tall office buildings that traditionally rely on single-skin façades (SSFs), due to the high wind pressure that creates excessive air velocities and occupant discomfort at upper floors. Double-skin façades (DSFs) can provide an opportunity to facilitate natural ventilation in tall office buildings, as the fundamental components such as the additional skin and openings create a buffer to regulate the direct impact of wind pressure and the airflow around the buildings. This study investigates the impact of modified multi-story type DSFs on indoor airflow in a 60-story, 780-foot (238 m) naturally ventilated tall office building under isothermal conditions. Thus, the performance of wind effect related components was assessed based on the criteria (e.g., air velocity and airflow distribution), particularly with respect to opening size. Computational fluid dynamics (CFD) was utilized to simulate outdoor airflow around the tall office building, and indoor airflow at multiple heights in case of various DSF opening configurations. The simulation results indicate that the outer skin opening is the more influential parameter than the inner skin opening on the indoor airflow behavior. On the other hand, the variations of inner skin opening size help improve the indoor airflow with respect to the desired air velocity and airflow distribution. Despite some vortexes observed in the indoor spaces, cross ventilation can occur as positive pressure on the windward side and negative pressure on the other sides generate productive pressure differential. The results also demonstrate that DSFs with smaller openings suitably reduce not only the impact of wind pressure, but also the concentration of high air velocity near the windows on the windward side, compared to SSFs. Further insight on indoor airflow behaviors depending on DSF opening configurations leads to a better understanding of the DSF design strategies for effective natural ventilation in tall office buildings.

Effects of Various Factors on the Energy Consumption of Korean-Style Apartment Houses (한국형 아파트의 냉난방 에너지에 미치는 제 인자의 영향)

  • 유호선;현석균;홍희기
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.14 no.11
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    • pp.972-980
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    • 2002
  • This work is aimed at estimating the effects of various factors on the energy consumption of Korean-style apartment houses using TRNSYS. The factors considered here include the nominal size of floor area, type of remodeling, azimuth, sidewall insulation, and window type. Based on some assumptions, an actual apartment house is simplified into a model that is used for thermal load calculations. The simplified model is validated by showing a good agreement with the actual one in the predicted result. Remodeling balconies into unconditioned buffer spaces yields a favorable thermal performance in comparison with the original type regardless of the nominal size. Incorporating balconies into a conditioned indoor space leads to sharp increases in thermal loads, which must be avoided in view of energy conservation as well as structural problem. A quantitative assessment on the azimuthal effect indicates that the heating energy can be saved up to 16% by taking the south or southeast direction. Reduction in the heating load with enhancing the sidewall insulation is gradual, so that a cost-effectiveness analysis may be needed when amending the regulations concerned. Glazing appears to significantly affect the heat transfer through window. A typical case illustrates that the heating load is decreased about 25% by simply adopting triple glazing instead of double glazing.

Membrane Injury of Nocardia mediterranei upon Lyophilization and Viability Depending on Rehydration Methods (동결건조법에 있어 Nocardia mediterranei의 세포막 손상과 재수화 방법에 따른 생존도)

  • 이동희;이노운;최남희
    • Microbiology and Biotechnology Letters
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    • v.20 no.3
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    • pp.243-248
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    • 1992
  • In order to examine the viability depending on rehydration process and membrane injury of Nocardia mediterranei upon lyophilization, We labeled $3^H$-thymidine in deoxyribonucleic acid of N. mediterrranei to obtain information on the mechanisms of injury caused by lyophilization. Suspensions of rehydrated cells were incubated with added DNase in a buffer solution. Extracellular radioactivity levels appeared to be high in the rehydrated solutions after lyophilization than freezing-thawing. Thus, the membrane systems were injured by lyophilization, but not ovenvhelmed. These considerations were confirmed by electron microscopy. In effects of rehydration, the cell membrane was seriously damaged by strong atmospheric pressure as soon as the inner ampule was opened, but this was not the case without admitting air under vacuum. N. rnediterranei cells, with no additives, were lyophilized and reconstituted without admitting air, virtually about 84% of the cells were viable.

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A Experimental Study on the Complex Waterproofing Method of Exposure using PE Textiles of Mesh type and Highly Viscous Urethane (망사형 PE직물과 고점도 우레탄을 이용한 복층형 노출 방수공법에 관한연구)

  • Shao, Xu-Dong;Song, Je-Young;Kim, Young-Suk;Oh, Sang-Keun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2011.05a
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    • pp.127-130
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    • 2011
  • The duplex waterproofing construction method has been investigated to improve various problems (how to fix the sheet, breaking, air/water pocket, and cracks caused by different materials) of the existing rooftop exposed waterproofing construction method. By using fiber sheet, Net PE fabric, and thixotropy urethane with high viscosity, the waterproofing construction method is to glue the ground and waterproof course by circular dot. The method is also to construct the waterproof course with high hardness by using waterproof membrane coatings in upper hybrid system. By gluing the ground and the waterproof course by circular dot, the study is expected to be useful to minimize the simultaneous breaking in the waterproof course as tensile stress is buffer in case of the ground crackling. Also, since the waterproofing construction method is good at moving and emitting vapor from the ground, it is considered to be effective to minimize any damages caused by air/water pocket and get loose of the waterproof course.

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소 비장유래 Macrophage의 체외배양시 배양액 중 호르몬적 변화

  • 최선호;류일선;박성재;연성흠;이장희;우제석;백광수;손동수;박춘근
    • Proceedings of the Korean Society of Developmental Biology Conference
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    • 2003.10a
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    • pp.141-141
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    • 2003
  • 소에 있어서 수정란이식이 활성화되고, 수정란이식 기술이 첨단기술도입의 근간이 되면서, 수태율의 향상은 첨단기술의 활성화에 필수적인 요소가 되었다. 또한 수태율 향상을 위해 임신유지를 도와주는 progesterone의 정기적인 투여나 수정란이식 시기에 hCG 등을 투여하여 수태율을 향상시키고자 여러가지 방법이 시도되고 있으나, 수태율 향상에 대한 명확한 기술이 정립되지 않은 상태이다. 따라서 본 연구는 착상시 황체의 Progesterone의 분비를 촉진시키는 것으로 보고되고 있는 비장유래의 macrophage의 체외배양을 통하여 배양액 중 호르몬적 변화를 관찰하고 착상을 유도하는 기전을 밝히고자 시도하였다. 임신 및 비임신 도축암소의 비장을 채취하여 알루미늄박으로 포장하여 얼음에 채운 뒤 실험실로 운반하였고, 비장을 70% alcohol로 외부를 잘 세척한후 표피를 제거하였다. 표피를 제거한 비장조직을 가위로 잘게 세절하고 buffer A 용액으로 조직속의 세포를 분리하였다. 분리된 세포는 1,700 rpm으로 5분간 3회 세정하였으며, 세정된 세포는 유리 petri dish에 넣어 39$^{\circ}C$, 5% $CO_2$, 95% air인 배양기에서 2시간 동안 배양을 실시하였다. (중략)

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Determination of Epinephrine Using Sodium Iodate in Chemiluminescence

  • Lee, J.S.;Lim, H.B.
    • Bulletin of the Korean Chemical Society
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    • v.28 no.12
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    • pp.2315-2318
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    • 2007
  • Epinephrine was determined using a lab-made chemiluminescence (CL) system with air pump. Luminolsodium IO4? chemiluminescence system was employed to produce the luminescence of epinephrine. In the reaction, epinephrine was oxidized to produce superoxide or singlet oxygen by periodate in alkaline solution, which enhanced CL of luminol. For optimization, various buffers, such as phosphate, borate, and tris, were studied in this experiment. Compared to NaOH, the phosphate and borate buffer showed better reproducibility with similar sensitivity. Small amount of sample, 22 μL, was required for a measurement. The limit of quantification for epinephrine was obtained to be ~10?9 g/mL after optimization.