열원이 존재하는 작업장내 기류 및 온도장 예측

정유진,하현철,김태형,유근종 한국산업위생학회 2001 한국산업보건학회지 Vol.11 No.1

A CFD simulation of airflow and temperature filed in a heated room has been described in this paper. The thermal wall jet created by a radiator greatly influences the airflow pattern, temperature distribution. The area close to a heat source has a high risk of air-borne contamination and imposes a harmful effect on occupants in that area. The predicted flow field, temperature results show good agreement with the measured data. As the results were compared with experimental data. the applicability of CFD was satisfactorily verified. Also, the CFD simulation can capture the natural convective flow features. If a CFD simulation is applied ventilation design with a heat source, An effective design will be attained. Further study is required to improve the accuracy of CFD simulation.

측정시스템의 효율적 운영에 관한 실증적 연구 : 中小製造企業을 中心으로

유현종,정수일 대한설비관리학회 2002 대한설비관리학회지 Vol.7 No.4

「All things possibly could be measured.」, measurement is a essential part in all kinds of industry, especially in manufacturing. Korean Industrial Standard has been established and announced in September, 1961. Measurement has been emphasized. But until now, measurement hasn't been located to the core of manufacturing in domestic. So, this study suggests improvement guide line for the multilateral problems of measurement system based on the investigation of 146 small and medium-sized enterprises in April, 2002.

CWOS와 황토를 이용한 농축·소화슬러지의 탈수성에 관한 연구

정병길,고현웅,주윤경,정유진,이징연 동아대학교 환경문제연구소 2002 硏究報告 Vol.25 No.1

Every year, 190,000 tons of oystershell are wasted from many oyster farms. And the fact that the main components of oystershell are CaO and Al₂O₃ which are chemically similar to those of lime leaded to an assumption that oystershell can be used as raw materials for synthesizing dewatering conditioner. In this study, the Jar-Test and the Bu˝chner funnel test were proceeded for the assessment of dewaterability of a thickened sludge and digested sludge. And TTF(Time To Filter), SRF(Specific Resistence Filtration) and TS(Total Solids) were adopted as the valuation indices of sludge dewaterability. Dewatering conditioner which composed of both oystershell and loess is much dewaterable than the one composed of only oystershell. And in the course of combining of oystershell and loess, the following fact was found that the dewaterability of the combination which have the higher ratio of oystershelI than that of loess is superior. Eventually, the most suitable ratio of dewatering conditioner complex is 9 : 1 (oystershell : loess) in treating not only thickened sludge but also digested sludge. In conclusion, the conditioner synthesized from waste oystershell and loess seems to be used as a splendid alternative material for the dewatering conditioner treating the sludge of sewage.

강화방법이 중년여성의 운동지속 및 건강에 미치는 영향

류호상,현정희,변재철,김한철 한국스포츠심리학회 2002 한국스포츠심리학회지 Vol.13 No.3

최근 10여년 동안 운동과학에 대한 다량의 문헌들에도 불구하고 여성들을 대상으로 운동지속(exercise adherence)과 운동효과에 대한 연구들은 많지 않다. 이 연구의 목적은 강화방법이 여성의 운동지속과 건강에 미치는 영향을 규명하기 위한 것이었다. 생활체육으로 에어로빅댄스를 하고자 방문한 31명의 중년여성들이 자신들이 원하는 세 개의 다론 시간대의 수업에 각각 등록을 하였다. 각 교실은 체지방 측정치로 피드백을 제공받는 집단(n=10), 출석이 양호할 시 에어로빅무용복을 보상받는 집단(n=11), 그리고 통제 집단(n=10)이 되어 실험에 참가하였다. 피험자들을 같은 강사의 지도로 하루에 45분, 주 5회(월-금), 8주 동안 에어로빅댄스를 실시하였다. 일원변량분석 결과 체지방으로 피드백을 제공받으며 운동한 집단은 다른 두 집단에 비해 높은 출석률을 보였다(p<.05). 공변량분석(ANCOVA)에서는 피드백 집단이 통제 집단보다 체지방율과 POMS의 총정서장애(Total mood disturbance)에서 유의하게 낮은 수치를 보였다(p<.05). 안면피부상태에서는 집단 간에 유의한 차이를 보이지 않았지만, 집단을 합한 운동 전·후간에는 차이가 있게 나타났다(p<.05). 이 연구는 생활체육 현장에서 피드백을 제공하여 강화를 시키면 중년여성들의 운동지속(exercise adherence)을 높일 수 있고 건강 증진에도 효과적이라는 결론에 도달하였다. 그 외 연구결과를 토대로 운동지속을 높이는 관점에서 논의가 이루어지고 장래연구를 위한 방향도 제시되었다. Despite decades of physical activity research, little is known about the patterns and effects of physical activity among women. The purpose of this research was to examine whether reinforcement strategy would positively influence participation adherence and health in women. Thirty one middle-aged females participating in an aerobic dance class were randomly assigned to three different conditions; feedback (n=10), reward (n=11), or control (n=10). The provide of feedback group was weekly informed of their body fat(%), while participant reward group was announced to win an aerobic dance tights if they miss less than 5 times over an 8 week period meeting 5 times per week. One-way ANOVA showed that the feedback group was higher than the other 2 groups in the number of attendances (p<.05). ANCOVA indicated that the feedback group exhibited statistically greater improvements in the body fat (p<.05) and the total mood disturbance (p<.05) than did the control. The facial skin condition was independently associated with reinforcement. However, repeated t-test showed that the after condition was better than the before condition. It was concluded that provide of feedback is an effective mean in increasing the exercise attendance rate and the health of middle-aged females. The findings were discussed in terms of the importance of increasing exercise adherence and mental health.

부직포활성슬러지법에 의한 하수와 침출수처리에 관한 기초연구

정유진,고현웅,김경순,윤태경,성낙창 한국환경과학회 2003 한국환경과학회지 Vol.12 No.10

In this study, it was performed using submerged nonwoven bioreactor(SNBR) for removal of organic matter, nitrogen and phosphate under different aeration intervals(intermittent aeration). We applied the SNBR at the cheap nonwoven fiber module instead of the expensive membrane. The SNBR was mainly made up of an activated sludge reactor and a transverse flow nonwoven module. with an innovative configuration being in application between them. In case of sewage, the aeration conditions experimented consist of continuous aeration and 60min/60min, 120min/60min, 120min/120min of aeration/nonaeration time intervals, respectively. In case of landfill leachate, the intermittent aeration condition was 120min/120min at aeration/nonaeration. Consequently. a high COD removal rate (about 94%) was achieved in sewage and leachate. Although nutrient removal rate was relatively high without any additional chemicals.

H9c2 심근 세포주에서 외인성 nitric oxide가 허혈에 의한 세포 독성에 미치는 영향

정성구,장현용,김명천,고영관,정주호,배영미,박원서,김대중,유영민,김성수,임성빈 대한응급의학회 2001 대한응급의학회지 Vol.12 No.4

Background: Nitric oxide(NO) is known to have protective effects on an ischemic heart and to exert triggering effects on ischemic preconditioning. However, the effects of NO during the ischemic period have not been investigated. To investigate the role of exogenous nitric oxide in a model of ischemic heart cell death, we studied the effects of ischemic preconditioning and ischemia in a normal and an ischemic buffer. Methods: Rat cardiac myoblast cells(H9c2) were cultured in a normal and an ischemic buffered medium. For the ischemic culture of heart cells, the cells were cultured in a dessicator with GasPak for 5 hrs. In ischemic preconditioning, the cells were pretreated with ischemic buffer for 5 min and then perfused with normal medium for 30 min. For the measurement of the cytotoxicity, a MTT(3-4-Sdimethylthiazol-2-yl-2,5-diphenyl tetrazolium bromide) assay was performed. A DAPI(4',6-diamidino-2-phenylindole dihydrochloride) staining procedure and a flow cytometry analysis were performed to confirm apoptotic cell death by ischemia. Results: Cell viability, as determined by using a MTT assay, showed that the preconditioned group treated with NO showed more cell death than with the not-preconditioned groups in both normal and ischemic buffers. But, In normal medium and not-preconditioned groups, NO showed protective effect according to the concentrations(100,1000μM) . No treatment with NO produced the different results. In normal medium, the protective effect of ischemic preconditioning was demonstrated, but no protective effect of ischemic preconditioning could be seen in the case of the ischemic buffer. The DAPI staining and flow cytometry analysis of heart cells showed characteristic apoptotic features. Conclusion: NO added in the ischemic phase had deterious effects on heart cells. Ischemic preconditioning was more harmful than ischemia alone. The toxicity of the cells was characteristic apoptosis.

아산시 지역 주민을 대상으로 한 당뇨병의 위험인자에

김유현,김은정,김종명,이성수 순천향의학연구소 2010 Journal of Soonchunhyang Medical Science Vol.16 No.1

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권운과 대기의 복사수지: 열대해양에서의 권운의 모사 및 광학적 성질

유정문,이지현 이화여자대학교 환경문제연구소 1997 이화환경연구 Vol.1 No.-

The spectral data obtained from Infrared Interferometer Spectrometer(IRIS) have been simulated in order to examine optical features of cirrus clouds in the tropical oceans. The sensitivity experiments of upwelling intensity to several optical and meteorological factors have been done using the models of the Mie and multiple scattering. The intensity in the experiments is highly sensitive to the particle size and ice-water content (or optical depth) of clouds, while it is less sensitive to their phase and altitude. From theoretical simulation of the infrared spectra the tropical cirrus clouds generally have a two-layer vertical ()tratification in particle size, with larger particles(∼12㎛)in their bottom and smaller ones(∼6㎛) aloft. The vertical structure of these clouds differs from those of the cirrus clouds in polar regions, in that the polar cirrus clouds have an upper layer of smaller particles(≤1㎛). Among 400-1,250() infrared region, the scattering effect due to cloud particles is strong in the relatively short wavelength of 1,050-1,250() portion, while the absorption effect is predominant in the other spectral region. The forward scattering due to the cloud particles for upwelling intensity is the strongest in the large cloud particle size and optical depth. In addition, the scattering effect in the forward direction of water particles generally is a little stronger than that of ice. The cirrus clouds which have been distributed globally and extensively are very persistent and play an important role in the earth's climate by influencing the heat balance and transport in the earth-atmosphere system.

Fly Ash를 이용한 흡수제의 SO_2/NO_x 동시제거

정종현,손병현,유경선,김현규,이형근 한국화학공학회 2003 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.41 No.3

본 연구에서는 비산재를 첨가한 개량흡수제를 이용하여 황산화물과 질소산화물을 동시에 제거하기 위하여 고정층반응기 실험을 수행하였으며, 제조한 혼합흡수제는 SEM-EDX, ICP, BET, XRD 등을 이용하여 물성분석을 수행하였다. 소성한 석회석에 비산재를 혼합하여 수화시킨 'fly ash 개량흡수제'는 SO_2와 NO_x를 동시에 효율적으로 제거할 수 있었으며, 비산재를 첨가하여 제조한 개량흡수제가 첨가하지 않은 흡수제에 비하여 SO_2와 NO_x 동시제거에 더 효과적이었다. 이러한 실험결과는 석회석과 개량흡수제에 비산재의 첨가로 인하여 규산캄슘 등과 같은 수화물 생성으로 인하여 포졸란반응이 유도되어 'fly ash 개량흡수제'의 비표면적과 흡습성 등이 증가되었기 때문이다. 또한, 비산재를 SO_2 및 NO_x 동시제거용 첨가제로 활용하기 위한 비산재와 개량흡수제의 최적 첨가비율은 1:9인 것으로 나타났다. The simultaneous removal of SO_2 and NO_x by advanced absorbent from coal fly ash was examined in a packed bed reactor. Also, the physicochemical properties of prepared absorbents have been measured using ICP, BET, SEM-EDX and XRD. We have found that both SO_2 and NO_x in dimulated flue gas can be effectively removed by use of fly ash advanced absorbent which was prepared by hydration of calcined limestone with or without coal fly ash. The addition of fly ash into the absorbents can result in the highly efficient simultaneous removal of SO_2 and NO_x from simulated flue gas. This is because the addition of fly ash into limestone and advanced absorbent increases the specific surface area and hygroscopicity of fly ash advanced absorbents by pozzolanic reaction which leads to the formation of calcium silicate compounds. The test results indicated that the optimal mixing ratio of fly ash to advanced absorbent sample is about 1:9 for the effective removal of SO_x/NO_x.

3-Cyano 및 3-Carbomethoxy Chromone과 Allenylstannane과의 반응

鄭大一,宋有淨,崔舜圭,李龍均,安賢淑,윤구식 東亞大學校附設基礎科學硏究所 1998 基礎科學硏究論文集 Vol.15 No.2

t-Butyldimethylsilyl triflate 존재에서 3-Cyano 및 3-Carbomethoxy Chromone(1a,b)과 Allenylstannane(2) 과의 반응에서 Chromone의 C-2위치에 propargyl기가 도입된 유도체(3a,b)를 합성하였다. 합성한 유도체의 상대적 구조는 ¹H-NMR을 통해 분석하였으며, T.S구조의 모델을 통하여 가능한 메카니즘을 제시하였다. Reaction of 3-Cyano and 3-Carbomethoxy Chromone(1a,b) with Allenylstannane(2) in the presence of tert-butyldimethylsilyl triflate afforded the corresponding the propargylation product(3a,b) in the moderate yield. The relative stereochemistry of 3a,b are obtained on the basis of ¹H-NMR analysis. And the possible reaction mechanism are suggested by the molecular models in the transition state.