• Nuclear Engineering and Technology
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• 제51권2호
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• pp.410-423
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• 2019

Fire suppression using a water mist nozzle directly above an n-Heptane pool in a fire compartment with a door opening was numerically investigated using the Fire Dynamics Simulator (FDS) for the purpose of application in nuclear power plants. Input parameters for the numerical simulation were determined by experimental measurements. Water mist was activated 10 s after the fire began. The sensitivity analysis was conducted for three input parameters: total number of cubic cells of 6032-2,926,400, droplets per second of 1000-500,000, and extinguishing coefficient of 0-100. In a new simple calibration method of this study, the extinguishing coefficient yielding the fire suppression time closest to that measured by experiments was found for use as the FDS simulation input value. When the water mist jet flow made contact with the developed fire, the heat release rate instantaneously increased, and then rapidly decreased. This phenomenon occurred with a displacement of the flame near the liquid fuel pool. Changing the configuration of the door opening with different aspect ratios and opening ratios had impact on the maximum value of the heat release rate due to the flame displacement.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2003년도 추계국제학술대회
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• pp.152-152
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• 2003

The majority of the SKYBIO will be used in the treatment of water in food processing plants, swimming pools and cooling towers, in the manufacture fabric softeners in Australia. Most will eventually be released into domestic sewage system as a consequence of product use. The SKYBIO is not readily biodegradable (0% over 28 days), and is expected to have a low partition coefficient and high water solubility (285 g/L), all indicating that the material would be mobile in both aquatic and terrestrial compartment. The PEC/PNEC ratio for the aquatic environment is 56. This value is significantly greater than 1, indicating an immediate concern to the aquatic compartment. However as a consequence of it's cationic character, the SKYBIO will be expected to associate to negatively charged organic matter in soil and sediment.

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 2002년도 춘계학술대회 논문집
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• pp.273-278
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• 2002

• 대한기계학회논문집B
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• 제39권6호
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• pp.513-518
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• 2015

농도차발전은 전 세계적으로 높은 잠재적 에너지량으로 인하여 최근 많은 주목을 받고 있다. 본 연구에서는 양이온과 음이온의 선택적 분리를 통하여 전기를 생성하는 역전기투석을 이용하여 다양한 농도 공급원의 조합으로부터 성능을 평가하였다. 역전기투석 장치의 분극곡선은 전류가 증가할 때 전압이 선형적으로 감소하였고, 최대출력밀도는 내부저항과 외부저항이 일치하는 부분에서 얻어졌다. 내부 유로두께가 감소하고 공급유량이 증가할 때 역전기투석 장치에서 생성되는 출력이 증가하는 것을 발견하였고, 공급유체의 펌핑에 의해 발생되는 출력 손실을 고려한 정미출력은 공급유량이 22.5mL/min 에서 최대값을 가졌다. 최종적으로 담수화 브라인, 해수, 강물, 폐수, 기수를 조합하여 역전기투석 장치의 성능을 평가하였고 정삼투 과정에서 발생하는 브라인과 강물을 이용할 때 $1.75W/m^2$ 으로 최대값을 얻었다.

• Nuclear Engineering and Technology
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• 제34권3호
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• pp.242-249
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• 2002

The relationship between the tritium release rate from the nuclear power plant and tritium concentration in the environment around the Kori site was modeled. The tritium concentration in the atmosphere was calculated by multiplying the release rates and $\chi$/Q values, and the d3V deposition rate at each sector according to the direction and the distance was obtained using a dry deposition velocity. The area around Kori site was divided into 6 zones according to the deposition rate. The six zones were divided into 14 compartments for the numerical simulation. Transfer coefficients between the compartments were derived using site characterization data. Source terms were calculated from the dry deposition rates. Tritium concentration in surface soil water and groundwater was calculated based upon a compartment model. The semi-analytical solution of the compartment model was obtained with a computer program, AMBER. The results showed that most of tritium deposited onto the land released into the atmosphere and the sea. Also, the estimated concentration in the top soil agreed well to that measured. Using the model, tritium concentration was predicted in the case that the tritium release rates were doubled.

• Journal of Pharmaceutical Investigation
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• 제35권2호
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• pp.111-116
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• 2005

The unstirred water layer (UWL), which has been known to exist in the boundary of the intestinal lumen and intestinal wall, often behaves as an absorption barrier especially for lipophilic drugs. The intestinal absorption of drugs is often characterized using Caco-2 cell monolayers grown on Transwell polycarbonate membranes. The permeability $(P_{app})$ of drugs across the cell monolayer might be influenced by the agitation of the donor compartment, since the width of UWL on the surface of the cell monolayer would be reduced by the agitation. In this study, the effect of agitation of the donor compartment with 60 rpm on the permeability was measured for 12 drugs with a wide range of lipophilicity and permeability. The $P_{app}$ of mannitol, tributylmethyl ammonium, cimetidine, ranitidine, hydrocortisone, benzylpenicillin and loxoprofen was not influenced by the agitation, while the $P_{app}$ of theophylline, propranolol, YH439, phenylpropanolamine and testosterone was increased by the agitation. There was a significant correlation between the increase of $P_{app}$ by agitation and the lipophilicity for the compounds having $P_{app}>2{\times}10^{-5}$ cm/sec. No correlation was observed for the difference in $P_{app}$ by agitation and the molecular weight, or lipophilicity of the drugs. Therefore, the agitation rate of the donor compartment in the Caco-2 cell monolayer study should be carefully controlled in order to estimate $P_{app}$ reproducibly especially for lipophilic drugs.

• Journal of Radiation Protection and Research
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• 제29권2호
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• pp.117-127
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• 2004

핵종 누출 사고시 논으로의 핵종 이동 평가를 위한 동적격실모델을 개발하였다. 개발된 모델에는 벼 재배에 필수적인 관개수를 고려하여 표면수 격실과 줄기기부흡수 개념을 도입하였고, 이식 전 쟁기질과 관개담수에 의한 토양 혼합을 고려하였으며, 벼 성장에 따른 뿌리흡수상수, 줄기기부흡수상수의 변화를 생체량의 함수로 모델링하였다. 모델의 타당성 조사를 위해 고리, 영광 및 울진 원자력 발전소 주변 지역에서 채취한 논 토양으로 벼를 재배하면서 벼 생육단계별로 수행된 $^{137}Cs$ 모의 침적 실험 해석에 모델을 적용하였다. 모델은 대체적으로 한 승수 내에서 실험 결과와 잘 일치하였다.

• Journal of Microbiology and Biotechnology
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• 제15권1호
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• pp.80-85
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• 2005

Electrochemical control of the metabolic flux of W. kimchii sk10 on glucose and pyruvate was studied. The growing cell of W. kimchii sk10 produced 87.4 mM lactate, 69.3 mM ethanol, and 4.9mM lactate from 83.1mM glucose under oxidation condition of the anode compartment, but 98.9 mM lactate, 84.3mM ethanol, and 0.2 mM acetate were produced from 90.8 mM glucose under reduction condition of the cathode compartment for 24 h, respectively. The resting cell of W. kimchii sk10 produced 15.9 mM lactate and 15.2 mM acetate from 32.1 mM pyruvate under oxidation condition of the anode compartment, and 71.3 mM lactate and 3.8 mM acetate from 79.8mM pyruvate under reduction condition of the cathode compartment. The redox balance (NADH/$NAD^+$) of metabolites electrochemically produced from pyruvate was 1.05 and 18.76 under oxidation and reduction conditions, respectively. On the basis of these results, we suggest that the neutral red (NR) immobilized in bacterial membrane can function as an electron channel for the electron transfer between electrode and cytoplasm without dissipation of membrane potential, and that the bacterial fermentation of W. kimchii sk10 can be shifted to oxidized or reduced pathways by the electrochemical oxidation or reduction, respectively.

• Nuclear Engineering and Technology
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• 제23권4호
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• pp.387-400
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• 1991

해수유동에 의한 이류와 부유물과의 상호작용에 의한 해양에서의 핵종이동을 모사하여 시간에 따른 핵종농도의 파과곡선을 구할 수 있는 해양구획모델이 개발되었다. 해양을 임의 수의 구획으로 나누어 각 구획간의 질량수지를 통해 지배 방정식을 세우고 이에 대한 해를 stiff한 문제에 유용한 수치적분방법을 이용하여 구하였다. 2차원 해수유동모델을 이용하여 해수교체시간을 계산한 후 각 구획간의 해수유동에 의한 이류수송을 나타내는 이동계수를 구하였다. 개발된 해양구획모델에 대한 계산 예로써 해저에 위치한 가상 처분장으로 부터 방출된 저준위방사성 폐기물의 주요 핵종중 Tc-99 Cs-137 및 Pu-238에 대한 파과곡선을 5개 구획에 대해 구하였다. 또한 핵종농도 파가 곡선에 대한 파라미터의 민감도 분석을 수행한 결과 구획내의 해수체적 및 해수교체시간과 같은 주요 변수들이 파과곡선에 중요한 영향을 줌을 알 수 있었다.

• 대한조선학회논문집
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• 제42권4호
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• pp.379-387
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• 2005

A ship may suffer sinkage and heel due to flood in a compartment caused by damage on a deck. The motion and waveloads of the heeled ship floating in waves have been analyzed by making use of a three dimensional potential theory taking account of the hydrodynamic pressure in the flooded compartments. The shear forces and bending moments due to radiation-diffraction waves have been calculated by the direct integration of the 3-d hydrodynamic pressure on the outer and inner hulls of floating barges. The motion responses and the relative flow rate across the mean free surface of the water in the flooded compartments are also presented.