0.5 gpm 미만 소량 원자로냉각재 누설 감지를 위한 베타선 측정 시스템의 N-16 교정 값 간접 산출법

김용현,이상민,김재창,정재영,양한철,김용균,조영식,권태순,박준식,김종헌 대한방사선방어학회 2022 대한방사선방어학회 학술발표회 논문요약집 Vol.2022 No.04

증분동적해석을 통한 비보강 조적벽식 건물의 내진성능 평가

권기혁,김만회,김형준 한국구조물진단유지관리공학회 2013 한국구조물진단유지관리공학회 논문집 Vol.17 No.3

비보강 조적벽체를 이용한 저층 건축물은 국내에 가장 흔히 볼 수 있는 주거형태이지만, 비보강 조적벽체는 높은 횡강성에 비하여 연성능력 부족 등의 이유로 지진으로부터 구조적 피해를 피하기 힘든 횡력저항시스템으로 알려져 있다. 하지만, 국내 비보강 조적벽체 전단강도와 전단강성에 대한 실험적 연구는 부족한 편이며, 실제 지진이 발생했을 비보강 조적벽체를 횡력저항요소로 사용하는 건축물의 내진성능에 대한 연구는 상대적으로 부족한 실정이다. 이로 인하여 국내 비보강 조적벽체의 특성을 반영하고 있다고 볼 수 없는 FEMA 356에서 제시하고 있는 비보강 조적벽체의 전단강도와 강성을 준용하여 사용하고 있다. 본 연구에서는 우선 FEMA 356에서 제시하고 비보강 조적벽체의 전단강도와 강성을 실험결과와의 차이에 대해 기술하고, 이 차이가 현황조사와 실험데이터를 바탕으로 결정한 표본 비보강 조적조 건축물의 내진성능에 미치는 영향과 경과년수에 따른 영향을 증분동적해석을 이용하여 계산된 붕괴여유비와 구조성능의 불확실성을 표현하는 베타값을 이용하여 분석하였다. 해석결과를 통하여 FEMA 356에 의한 전단강도와 강성을 사용할 경우 조적조 건축물의 붕괴여유비와 베타값을 과소평가하는 것으로 나타났다. 하지만, 두 경우 모두 국내 내진설계기준에서 제시하는 성능기준을 만족하지 않는 것으로 나타났으며, 경과연수가 클수록 이런 현상은 뚜렷해지며, 30년 이상 경과된 조적조 건축물은 2400년 재현주기의 지진에 붕괴확률이 약 90%에 도달하는 것으로 나타났다. The most common housing type in Korea is low-rise buildings with unreinforced masonry walls (UMWs) that have been known as a vulnerable seismic-force-resisting system (SFRS) due to the lack of ductility capacities compared to high lateral stiffness of an UMW. However, there are still a little experimental investigation on the shear strength and stiffness of UMWs and on the seismic performance of buildings using UMWs as a SFRS. In Korea, the shear strength and stiffness of UMWs have been evaluated with the equations suggested in FEMA 356 which can not reflect the structural and material characteristics, and workmanship of domestic UMW construction. First of all, this study demonstrates the differences in shear strength and stiffness of UMWs obtained from between FEMA 356 and test results. The influence of these differences on the seismic performance of UMW buildings is then discussed with incremental dynamic analyses results of a prototype UMW building that were selected by the site survey of more than 200 UMW buildings and existing test results of UMWs. The seismic performance assessment of the prototype UMW building are analyzed based on collapse margin ratios and beta values repesenting uncertainty of seismic capacity. Analysis results show that the seismic performance of the UMW building estimated using the equations in FEMA 356 underestimates both a collapse margin ratio and a beta value compared to that estimated by test results. Whatever the estimation is carried out two cases, the seismic performance of the prototype building does not meet the criteria prescribed in a current Korean seismic code and about 90% collapse probability presents for more than 30-year-old UMW buildings under earthquakes with 2400 return years.

포스포리파제 D 촉매반응에서 포스파티딜 전달반응 활성에 미치는 알코올의 영향

고은희,Koh, Eun-Hie 대한화학회 2010 대한화학회지 Vol.54 No.2

포스포리파제 D(PLD)는 알코올 존재 하에서 포스파티딜 전달반응이 일어나며 동시에 PLD의 전체 반응속도도 증가하는 것으로 알려져 있다. 이 포스파티딜 전달반응을 자세히 구명하기위해 본 실험에서는 양배추에서 정제한 ${\alpha}$-type PLD를 가지고 여러 종류의 알코올 존재 하에서 포스파티딜 전달반응의 반응속도를 검토하였다. 실험 결과 검토한 1차 알코올들에 의해 PLD의 포스파티딜 전달반응 속도는 기대했던 대로 크게 증가하였다. 부탄올의 경우 2차 반응속도는 $33.33{\pm}1.33M^{-1}sec^{-1}$로 얻어졌으며, 이 전달반응 속도를 물의 농도를 고려한 가수분해 속도($0.078M^{-1}sec^{-1}$)와 비교하면 무려 400배 이상의 격차를 보여주었다. 알코올의 $pK_a$과 포스파티딜 전달반응 속도와의 자유에너지 선형 관계로부터 브뢴스테드 ${\beta}_{nu}$ 값 $0.12{\pm}0.03$을 얻었다. 비교적 적은 ${\beta}_{nu}$ 값으로 미루어보아 끊어지는 포스파티딜-효소 중간체(E-P)의 전이상태는 상당히 해리된 상태일 것으로 추정된다. 이들 결과와 양배추 PLD의 활성부위의 히스티딘 잔기를 참작하여 양배추 PLD의 반응메커니즘을 제안하였다. In the presence of alcohol, phospholipase D (PLD) is known to perform transphosphatidylation activity, during which the overall reaction rate of PLD increased. To elucidate the reaction mechanism of transphosphatidylation further, we investigated rate constants of transphosphatidylation reaction of the purified ${\alpha}$-type PLD from cabbage in the presence of various alcohols. The second-oder rate constants of PLD transphosphatidylation showed a large increase with the primary alcohols examined as expected. In the case of butanol we observed the second-oder rate constant of $33.33{\pm}1.33M^{-1}sec^{-1}$. This second-order rate constant of transphosphatidylation was as 400 times greater as the second-order hydrolysis rate constant of $0.078M^{-1}sec^{-1}$ which was adjusted for the water concentration. A linear free energy relationship between the $pK_a$ of alcohol and transphosphatidylation rate gives a Br${\o}$nsted slope of ${\beta}_{nu}$ = 0.12 ${\pm}$ 0.03. This small ${\beta}_{nu}$ value implicates that the transition state of break down of phosphatidyl-enzyme intermediate (E-P) is likely dissociative. Finally, a reaction mechanism of cabbage PLD is suggested on the basis of our results presented here and the histidine residue known to be located in the active site of cabbage PLD.

자연풍의 변동 특성을 이용한 쾌적 공조시스템에 관한 연구

강기남(Kang Ki-Nam),송두삼(Song Doo-Sam),함희정(Ham Hee-Jung),서국정(Seo Kook-Jeong),윤인철(Yun In-Cheol) 한국건축친환경설비학회 2007 한국건축친환경설비학회 학술발표대회 논문집 Vol.- No.-

Recently the demand for cooling is rapidly increasing in Korea due to climate change resulting from global environmental changes and the residential culture centered on apartment houses. Furthermore, there is a concern for increasing energy consumption due to the quickly rising demands for comfortableness of air conditioning with the increasing expectations on quality of life of occupants in rooms. The existing air conditioning system can not satisfied the human thermal need as compared to the natural breeze in country side where located near mountains and river side. What is short in air conditioning? The natural wind fluctuates all the time in all directions and we can not recognize its behaviors. If the fluctuation characteristics of natural wind would be generated with existing cooling system, it could be a comfortable wind for us. In this study, the characteristics of natural wind will be analyzed through chaotic analyzing methods and will be compared to the mechanical wind. In this paper, the field measurement for natural wind which accomplished at near mountain in summer will be reported. Moreover the characteristics of mechanical wind will be analyze through laboratory experiment. If fluctuation of air flow would be generated by a chaotic theory, it could be a comfortable wind for us.

자연풍의 변동 특성을 이용한 쾌적 공조시스템에 관한 연구

강기남(Kang Ki-Nam),송두삼(Song Doo-Sam),함희정(Ham Hee-Jung) 대한건축학회 2007 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.27 No.1

Recently the demand for cooling is rapidly increasing in Korea due to climate change resulting from global environmental changes and the residential culture centered on apartment houses. Furthermore, there is a concern for increasing energy consumption due to the quickly rising demands for comfortableness of air conditioning with the increasing expectations on quality of life of occupants in rooms. The existing air conditioning system can not satisfied the human thermal need as compared to the natural breeze in country side where located near mountains and river side. What is short in air conditioning? The natural wind fluctuates all the time in all directions and we can not recognize its behaviors. If the fluctuation characteristics of natural wind would be generated with existing cooling system, it could be a comfortable wind for us. In this study, the characteristics of natural wind will be analyzed through chaotic analyzing methods and will be compared to the mechanical wind. In this paper, the field measurement for natural wind which accomplished at near mountain in summer will be reported. Moreover the characteristics of mechanical wind will be analyze through laboratory experiment. If fluctuation of air flow would be generated by a chaotic theory, it could be a comfortable wind for us.

실측을 통한 인체에 쾌적한 자연풍 특성의 검토

강기남(Kang Ki-Nam),송두삼(Song Doo-Sam),함희정(Song Doo-Sam) 대한건축학회 2008 대한건축학회논문집 Vol.24 No.6

The purpose of this study is to propose a new cooling system that can improve the problems of conventional cooling systems such as constant and monotonous air-flow, lower temperature than the ambient conditions, and energy efficiency. To improve these drawbacks, this study focuses on the dynamic characteristics of natural wind and the use of these characteristics as a control strategy of indoor cooling systems. In this paper, based on the field measurements, the characteristics of natural wind fluctuation are analyzed by the Fast Fourier Transform(FFT) analysis. The correlations between natural wind and thermal sense of the human subject can be found by using the PSD analysis, and the relationships can be modeled as a slope of the low frequencies of the natural wind spectrum, β-value. It is expected that the proper selection of β-value can simulate a comfortable wind and will improve the energy efficiency of cooling systems.