• 한국지반공학회논문집
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• 제20권5호
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• pp.27-35
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• 2004

본 연구의 목적은 불포화토의 거동을 대변하는 흙-수분 특성곡선을 결정하는 데 있어서 액성한계상태를 이용한 비교상태접근법(reference state approach)의 적용 가능성을 확인하고 이를 바탕으로 하는 예측방법을 제안하는 데 있다. 세립잔적토를 사용하여 각기 다른 간극비로 다짐된 여러 개의 시료로부터 흙-수분 특성곡선을 구하였다. 실험결과를 바탕으로, 흙-수분 특성곡선을 예측하는 데 있어서 액성한계상태를 비교상태로 사용할 수 있음을 증명하였다. 마지막으로, Fredlund와 Xing(1994)이 제안한 흙-수분 특성곡선식을 사용하여 실험결과를 회귀분석 함으로서 액성한계를 비교상태로 하여 세립잔적토의 흙-수분 특성곡선을 예측할 수 있는 방법을 제안하였다.

• 대한가정학회지
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• 제19권1호
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• pp.39-45
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• 1981

The fishes that are mostly used in our homes such as Pacific Mackeral, hair Tail and Alaska Pollack were devided into Freezing group, Refrigerating group and Room temperature group according to storage temperature. TVB-N, TMA-N, TMA-O and pp.H. were measured in natural state, after water washing and 3% NaCl-water washing. The results are as follows: 1. Regardless of the kinds of fishes, TVB-N in room temperature showed that rottenness first appeared after 5~8 hours in raw state, 6~12 hours in water washing, and 8~12 hours in 3% NaCl-water washing. 2. Regardless of freezing and refrigeration, Pacific Mackeral became rotten after 14 days in raw state, 14~17 days in water washing and 17 days in 3% NaCl water washing. Alaska Pollack and Hair Tail showed rottenness after 8 days in raw state, 11 days in water and 3% NaCl water washing. 3. Even in hot summer days, freshness could be preserved for 10 days if fishes were freezed ($-20^{\circ}C$) or refrigerated (4~$8^{\circ}C$) after bowel excluded, washed in NaCl water and enveloped in poly-ethylene bag.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회(1)
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• pp.635-636
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• 2005

• 한국분무공학회지
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• 제11권4호
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• pp.251-265
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• 2006

To prevent the ozonosphere from being destroyed by Halon, it is an urgent task to find out Halon replacement. As one of the replacements water mist have showed broad applications by its advantages: little pollution to environment (not destroying the ozone layer or bring green house effect), extinguishing fire quickly, consuming a small quantity of water and having little damage to the protected objects. The methods of generating water mist strongly influence fire suppression effectiveness, which determine the cone angle, drop size distribution, flux uniformity, and momentum of the generating spray. The traditional water mist nozzle included pressure jet nozzles, impingement nozzles and twin-fluid nozzles. All of them have more or less disadvantages for fire suppression. Therefore, many research institutes and corporations are taking up with innovations in mist generation. This article provided some recent studies in State Key Laboratory of Fire Science (SKLFS) of University of Science and Technology of China. SKLFS have investigated new methods of generating water mist (i.e. effervescent atomization and ultrasonic atomization). and self developed a series of nozzles and developed advanced DPIVS (Digital Particle Image Velocimetry and Sizing) technique. Characteristics of water mist (the distribution of droplet sizes, flux density, spray dynamics and cone angle) produced by these nozzles were measured under different conditions (work pressure, nozzle geometry, etc.) using LDV/APV and DPTVS systems. A series of experiments were performed to study the fire suppression effectiveness in different fire scenario (different kindsof the fuel, fire size and ventilation conditions). The fire extinguishing mechanisms of water mist was also discussed.

• Computers and Concrete
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• 제15권4호
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• pp.485-501
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• 2015

Cooling by the flow of water through an embedded cooling pipe has become a common and effective artificial thermal control measure for massive concrete structures. However, an extreme thermal gradient induces significant thermal stress, resulting in thermal cracking. Using a mesoscopic finite-element (FE) mesh, three-phase composites of concrete namely aggregate, mortar matrix and interfacial transition zone (ITZ) are modeled. An equivalent probabilistic model is presented for failure study of concrete by assuming that the material properties conform to the Weibull distribution law. Meanwhile, the correlation coefficient introduced by the statistical method is incorporated into the Weibull distribution formula. Subsequently, a series of numerical analyses are used for investigating the influence of the correlation coefficient on tensile strength and the failure process of concrete based on the equivalent probabilistic model. Finally, as an engineering application, damage and failure behavior of concrete cracks induced by a water-cooling pipe are analyzed in-depth by the presented model. Results show that the random distribution of concrete mechanical parameters and the temperature gradient near water-cooling pipe have a significant influence on the pattern and failure progress of temperature-induced micro-cracking in concrete.

• Molecules and Cells
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• 제38권10호
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• pp.859-865
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• 2015

Most imprinted genes are concerned with embryonic development, especially placental development. Here, we identified a placenta-specific imprinted gene Qpct. Our results show that Qpct is widely expressed during early embryonic development and can be detected in the telecephalon, midbrain, and rhombencephalon at E9.5-E11.5. Moreover, Qpct is strikingly expressed in the brain, lung and liver in E15.5. Expression signals for Qpct achieved a peak at E15.5 during placental development and were only detected in the labyrinth layer in E15.5 placenta. ChIP assay results suggest that the modification of histone H3K4me3 can result in maternal activating of Qpct.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회(2)
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• pp.926-927
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• 2005

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회(1)
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• pp.285-286
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• 2005

• 한국물환경학회지
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• 제24권1호
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• pp.99-106
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• 2008

With globally increasing interests in climate-soil-vegetation system, a new stochastic model of soil water and plant water stress is derived for better understanding of the soil water and plant water stress dynamics and their role in water-controlled ecosystem. The steady-state assumption is used for simplifying the equations. The derived model is simple yet realistic that it can account for the essential features of the system. The model represents the general characteristics of rainfall, soil, and vegetation; i.e. the soil moisture constitutes the decrease form of the steady-state and the plant water stress becomes increasing with the steady state when the rainfall is decreased. With this model, further deep study for the effects of soil water and plant water stress on the system will be accomplished.

• Journal of Microbiology and Biotechnology
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• 제24권5호
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• pp.629-638
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• 2014

This study describes an alternative mixed culture fermentation technology to anaerobically convert lignocellulosic biomass into butyric acid, a valuable product with wide application, without supplementary cellulolytic enzymes. Rice straw was soaked in 1% NaOH solution to increase digestibility. Among the tested pretreatment conditions, soaking rice straw at $50^{\circ}C$ for 72 h removed ~66% of the lignin, but retained ~84% of the cellulose and ~71% of the hemicellulose. By using an undefined cellulose-degrading butyrate-producing microbial community as butyric acid producer in batch fermentation, about 6 g/l of butyric acid was produced from the pretreated rice straw, which accounted for ~76% of the total volatile fatty acids. In the repeated-batch operation, the butyric acid production declined batch by batch, which was most possibly caused by the shift of microbial community structure monitored by denaturing gradient gel electrophoresis. In this study, batch operation was observed to be more suitable for butyric acid production.