• 제목/요약/키워드: venting

검색결과 135건 처리시간 0.022초

발코니 확장에 따른 수직화염 확대 위험성에 관한 실험적 연구 (An Experimental Study on the Risk of Vertical Flame for a Extended-Balcony)

  • 신이철;윤유혁;이주희;권영진
    • 한국화재소방학회:학술대회논문집
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    • 한국화재소방학회 2008년도 추계학술논문발표회 논문집
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    • pp.283-288
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    • 2008
  • Since installing a balcony can significantly reduce the spread of fire, fire spread to the upper levels was confirmed, comparing the cases with and without balcony extension. It was confirmed that the fire can spread not only to the next higher level but also to two levels higher due to the outburst of flame which reached a significant temperature in the case without balcony, while the possibility of fire spread to the upper level reduced considerably with the balcony. this study is compared and analyzed to vertical diffusion appearance of an externally venting flame. An installed balcony is also applied to fire test 6.54kW to analyze about effect of a balcony.

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디젤류가 오염된 토양에서 공기주입법으로 처리한 토양 판별 인자들의 변화

  • 김영암;노종수;이동선;이용희
    • 한국환경보건학회:학술대회논문집
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    • 한국환경보건학회 2005년도 가을학술대회
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    • pp.110-114
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    • 2005
  • 인공적으로 디젤류에 오염시킨 5kg의 토양이 충전된 두 개의 실험 column을 이용해서 외부 온도변화 효과를 최소화하기 위해서 $25^{\circ}C{\pm}2.5$로 유지시켰으며, 유량속도도 10ml/min로 일정하게 유지시켰다. 또한 수분은 활동범위 능력의 $60{\sim}80%$에서 유지시켰다. 따라서 연속식과 간헐 주입식 모드를 운전비용의 감소 및 효율의 향상 측면에서 모드의 평가를 위한 방법으로 이용기간 동안 총세균 수, 유류분해균 수의 변화, 탈수소효소 활성도의 변화 추이 분석을 하였다. 두 venting 모드별로 본 총 종속영양균 수와 유류분해균 수는 모두 대등한 성장률을 보였으며, 반응일 수에 따라 비교된 탈수소효소 활성도 반응 90일 동안 비슷한 활성을 유지 했다.

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Simplified Modeling of Deflagration in Vessels

  • Kim, Joon-Hyun;Kim, Joo-Hyun
    • Journal of Mechanical Science and Technology
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    • 제18권8호
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    • pp.1338-1348
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    • 2004
  • A simplified method that models the deflagration process occurring in closed or vented vessels is described. When combustion occurs within the spherical or cylindrical vessels, the flame moves spherically or segmentally to the vessel periphery. The volume and area of each element along the propagating flame front are calculated by using simple geometrical rules. For instabilities and turbulence resulting in enhanced burning rates, a simple analysis results in reasonable agreement with the experimental pressure transients when two burning rates (a laminar burning rate prior to the onset of instability and an enhanced burning rate) were used. Pressure reduction caused by a vent opening at predetermined pressure was modeled. Parameters examined in the modeling include ignition location, mixture concentration, vented area, and vent opening pressure. It was found that venting was effective in reducing the peak pressure experienced in vessels. The model can be expected to estimate reasonable peak pressures and flame front distances by modeling the enhanced burning rates, that is, turbulent enhancement factor.

수술실내 공기감염억제를 위한 공조용 급배기구 위치 선정에 관한 연구 (A Study on the Diffuser Location for the Reduction of Airborne Infection in Operation Room)

  • 권순정;주영철;김천숙
    • 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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    • 제8권1호
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    • pp.7-12
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    • 2002
  • The air ventilation system of operation rooms has been studied to prevent the cross infection during the operation. Operation rooms and air ventilation systems of three University hospitals were investigated. The distribution of microbe was measured by cultivating air samples in the operation room. A two-dimensional model for the cross-section of an operation room was developed for the CFD(Computational Fluid Dynamics) analysis. The characteristics of air flow in the empty operation room and in occupied operation room were calculated by using a CFD program. The current diffuser location of an old hospital did not deliver the clean air to the operation part efficiently. A new method to locate diffusers that improve air venting with little increase of the cost of equipment was suggested.

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Aeration Factor Used To Design The Container Type of Biopile Systems for Small-Scale Petroleum-Contaminated Soil Projects

  • Jung, Hyun-Gyu
    • 한국토양비료학회지
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    • 제44권2호
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    • pp.316-319
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    • 2011
  • Biopiles which offer the potential for cost-effective treatment of contaminated soils are above-ground, engineered systems that use oxygen to stimulate the growth and reproduction of aerobic bacteria for degradation of the petroleum constituents adsorbed to soil in excavated soils. This technology involves heaping contaminated soils into piles and stimulating aerobic microbial activity within the soils through the aeration and/or addition of minerals, nutrients, and moisture. Inside the biopile, microbially mediated reactions by blowing or extracting air through the pipes can enhance degradation of the organic contaminants. The influence of a aeration system on the biopile performance was investigated. Air pressure made to compare the efficiency of suction in the pipes showed that there were slightly significant difference between the two piles in the total amount of TPH biodegradation. The normalised degradation rate was, however, considerably higher in the aeration system than in the normal system without aeration, suggesting that the vertical venting method may have improved the efficiency of the biological reactions in the pile.

유방하 횡절개를 이용한 최소침습 심장수술 (Minimal Invasive cardiac Surgery ; Small Submammary Incision)

  • 정승혁;신용철;임용택;김병일;이정호
    • Journal of Chest Surgery
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    • 제33권1호
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    • pp.96-98
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    • 2000
  • A cosmetic incision for minimal invasive cardiac surgery is described. Through a small submammary skin incision combined with partial low sternotomy some kinds of cardiac operations are possible without extra-difficulty but with excellent cosmetic effect, No special instruments nor techniques are required. By this method routine cannulations for cardiopulmonary bypass as well as aortic cross clamping bicaval snaring and venting of cardiac chambers are possible, We performed 5 cases of open heart surgeries using this approach which includes two cases of atrial septal defect closure one case of ventricular septal defect closure one case of pulmonic valvotomy and one case of mitral valve replacement.

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다중 Port로 연결된 다중 격실 Vent 해석 기법 개발 (Development of a Vent Analysis Method for Multiple Compartments Connected Through Multiple Ports)

  • 옥호남;김인선
    • 유체기계공업학회:학술대회논문집
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    • 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
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    • pp.547-550
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    • 2006
  • An analysis method is developed for the prediction of venting in multiple compartments which are connected in series or parallel through multiple ports. The existing method by the authors is modified to remove the limitation in number of ports and compartments, and the more general polytropic relation or solution of the additional energy equation replaces the previous isentropic relation allowing the prediction of pressure rise in addition to pressure drop. The accuracy of the method is verified by comparison with the results by NASA Flap code for the problem of pressure drop in a payload in the Space Shuttle cargo bay. It is expected that this method will be a useful tool in prediction of the pressure variation in a payload or payload capsule without mentioning the payload fairing itself.

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아동의 정서조절능력 및 자기유능성지각과 문제행동 (Relationships Between Children's Emotional Regulation, Perceived Self-Competence and Behavior Problem)

  • 정현희;정순화
    • 대한가정학회지
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    • 제45권7호
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    • pp.93-103
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    • 2007
  • The purpose of the study was to examine the relationships between children's emotional regulation, perceived self-competence and behavior problem. The subjects were 357 elementary school students in Busan. The questionnaires on children's emotional regulation, perceived self-competence and behavior problem were used. The results were as follows: (1) According to sex, there were significant differences in children's emotional regulation scores(venting and support pursuit), and according to birth order, there were significant differences in children's perceived self-competence scores and behavior problem scores. (2) There were significant correlations between children's emotional regulation scores and behavior problem scores, and also there were significant correlations between children's perceived self-competence scores and behavior problem scores. (3) Children's perceived self-competence and emotional regulation explained children's anxiety behavior, withdrawal behavior, aggressive behavior, distracted behavior and regressive behavior.

전산유동해석을 이용한 ORIFICE 방출 계수 예측 (PREDICTION OF THE ORIFICE DISCHARGE COEFFICIENT USING COMPUTATIONAL FLUIDS DYNAMICS)

  • 옥호남;김인선
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2006년도 추계 학술대회논문집
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    • pp.147-150
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    • 2006
  • Vent ports are installed on the walls of closed compartments of a launch vehicle to control the pressure drop in the compartments. The ports can be modelled as an orifice, and the accurate prediction of the discharge coefficient of an orifice is essential for the design of vent ports. Experimental methods have been used to determine the discharge coefficients for various shapes of orifices, and extensive databases are available. Wind tunnel tests have been also done to evaluate the effect of interaction between venting outflow and freestream for limited conditions. The goal of the present research is to predict the discharge coefficient of an orifice using CFD and evaluate the accuracy of the method, especially for the orifices exposed to the external flow.

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어머니가 지각한 아동의 기질, 어머니의 정서조절 및 양육행동과 아동의 정서조절간의 관계 (Child's Sex, Temperament, Mother's Emotion Regulation and Parenting as Related to Child's Emotion Regulation)

  • 임희수;박성연
    • 아동학회지
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    • 제23권1호
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    • pp.37-54
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    • 2002
  • The purpose of study was to examine child emotion regulation as a function of child's sex, temperament, mother's emotion regulation, and mother's parenting. The subjects were 386 mothers of fifth or sixth graders in Seoul and Kyonggi province. The data were gathered through questionnaires developed for the current study. The major findings were as follows: 1) There were significant sex differences in some categories of child's emotion regulation. 2) The more active the child's temperament, the child showed more negative emotion regulation(venting, aggressive expression, avoidance). 3) Mother's negative emotion regulation was significantly related to the child's negative emotion regulation. 4) There were significant correlations between mother's parenting and child's emotion regulation. That is, mother's positive parenting was related to child's positive emotion regulation. 5) The relationship between mother's emotion regulation and child's emotion regulation was mediated by mothers' parenting.

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