• 한국안전학회지
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• 제27권5호
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• pp.229-234
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• 2012

Operator's action time is evaluated from MAAP4 analysis used in conventional probabilistic safety assessment(PSA) of a nuclear power plant. MAAP4 code which was developed for severe accident analysis is too conservative to perform a realistic PSA. A best-estimate code such as RELAP5/MOD3, MARS has been used to reduce the conservatism of thermal hydraulic analysis. In this study, operator's action time of core cooling recovery operation is evaluated by using the MARS code, which its Fussell-Vessely(F-V) value was evaluated as highly important in a small break loss of coolant(SBLOCA) event and loss of component cooling water(LOCCW) event in previous PSA. The main conclusions were elicited : (1) MARS analysis provides larger time window for operator's action time than MAAP4 analysis and gives the more realistic time window in PSA (2) Sufficient operator's action time can reduce human error probability and core damage frequency in PSA.

• 대한한방내과학회지
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• 제11권2호
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• pp.112-119
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• 1990

To evaluate effects of Sam so on Pye Tang(SSOPT) Water Extract plasma cortisol concentration and plasma $CO_2$ in the Rabbit. The results obtained were as follows. 1. Intravenous administration of SSOPT water extract at the dose of 0.5ml/kg remarkably increased plasma cortisol concentration on 1 hour. 2. Intravenous adminitration of SSOPT Water extract at the does of 1.0ml/kg significantly decreased plasma $CO_2$ on 1 hour. 3. Intravenous adminitration of SSOPT Water extract at the does of 0.5ml/kg remarkable decreased plasma $Na^+$ from 1 to 4 hour and 1.0ml/kg significantly decreased plasma $Na^+$ on 1 hour. 4. Intravenous administration of SSOPT Water extract at the does of 1.0ml/kg remarkably increased plasma $k^+$ from 1 to 3 hour. 5. Intravenous administration of SSOPT water extract at the does of 0.5ml/kg significantly decreased plasma $CI^-$ on 3, 4 hours. and 1.0ml/kg remarkably increased plasma $CI^-$ on 4 hour. These results suggest that therapeutic action of SSOPT water extract for athma may be reated with the increment of plasma cortisol concentration and the decrease plsma $CO_2.$.

• 한국레이저가공학회지
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• 제4권2호
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• pp.13-19
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• 2001

When a high-power laser beam is irradiated on the surface of material, it is well known that a cavity, called a keyhole induced by the pressure action of the vapor plume, is generated in the molten material. This paper describes the interaction between a pulsed CO$_2$ laser beam and water. The laser-beam is used to generate and maintain a conical depression in the water surface similar to the keyhole created during laser penetration welding. Experimental results show that the depth of laser-beam penetration is limited by hydrodynamic instability. The instability of the surface cavity can be understood by the capillary instability of a hollow jet. Theoretical computation of the steady keyhole shape has been performed. modifying the model suggested by Andrews et al. (1976). The model predicts the qualitative behavior of the keyhole but significantly underestimates the average diameter.

• Geomechanics and Engineering
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• 제39권4호
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• pp.357-368
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• 2024

The pressurized water conditions of goafs weaken the support of remaining coal and rocks, which causes instability, failure, and sudden ground collapse. The impact of pressure-bearing water and CO₂ on the tensile properties of residual coal pillars was explored in old goafs. Coal was analyzed using a pressure-water soaking device, electronic scanning microscope, and 3D full-field strain measurement system. Besides, Brazilian splitting tests were performed. The failure characteristics and energy evolution law of the macro-microscopic structure of coal specimens were analyzed under different soaking conditions-desiccation (DC), CO₂ soaking (CS), water-CO₂ soaking (WCS), and water soaking (WS). The peak stress of coal specimens and time to reach the peak decreased with varying soaking environments. Stress concentration initially occurred at the water end under the WCS condition, indicating that coal specimens deteriorated more under the pressure-bearing WCS condition compared with the CS condition. Fractures of coal specimens exhibited the highest development under the WS condition. Besides, dissolution was observed at the fractures of coal specimens, with severe failure to their internal microstructures. In conclusion, the instability failure of residual coal pillars is significant in studying the old goafs.

• Nuclear Engineering and Technology
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• 제30권5호
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• pp.403-415
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• 1998

The CANDU 6 reactor assembly consists of an array of 380 pressure tubes, which are installed horizontally in a large cylindrical vessel, the Calandria, containing the low pressure heavy water moderator. The pressure tube is located inside the calandria tube and the annulus between these tubes, which forms a closed loop with $CO_2$ gas recirculating, is called the Annulus Gas System(AGS). It is designed to give an alarm to the operator even for a small pressure tube leak by a very sensitive dew point meter so that he can take a preventive action for the pressure tube rupture incident. To judge whether the operator action time is enough or not in the design of Wolsong 2,3 & 4, the Leak Before Break(LBB) assessment is required for the analysis of the pressure tube failure accident. In order to provide the required data for the LBB assessment of Wolsong Units 2, 3, 4, a series of leak detection capability tests was performed by injecting controlled rates of heavy water vapour. The data of increased dew point and rates of rise were measured to determine the alarm set point for the dew point rate of rise of Wolsong Unit 2. It was found that the response of the dew point depends on the moisture injection rate, $CO_2$ gas flow rate and the leak location. The test showed that CANDU 6 AGS can detect the very small leaks less than few g/hr and dew point rate of rise alarm can be the most reliable alarm signal to warn the operator. Considering the present results, the first response time of dew point to the AGS $CO_2$ flow rate is approximated.

• International journal of advanced smart convergence
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• 제9권3호
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• pp.1-8
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• 2020

Water consumption has grown at more than 2.5 times, comparing the past century. About 2.8 billion people live in river basins with some form of water deficit, because more than 75 % of the river flows are withdrawn for agriculture and other needs. Challenges faced by more and more countries in their struggle for economic and social development are increasingly related to water. This paper proposes a test of an effective local river field environment management solution. And describing a part of a pilot project for the ministry of water resources of Uzbekistan. Current work focused on direct action items of the existing project and describe an IoT routing based solution for local river field environment management solutions. Suggested technological decisions provided by needs and on-site testing results. The paper describes the backbone of IoT routing based river water resources management system.

• Journal of Pharmaceutical Investigation
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• 제2권1호
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• pp.58-62
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• 1972

The stabillities of taurine, niacinamide, and pyridoxine hydrochloride under exposure to ultra violet radiation in liquid preparations were studied. And sterilization effects for E. coli in both water and liquid preparations were also comparatively evaluated. The above mentioned organic compounds were stable under this experimental conditions and viable count of E. coli reveals that organic compounds dissolved in solution display protective action for microorganisms under UV-irradiation.

• Journal of Applied Biological Chemistry
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• 제48권2호
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• pp.89-92
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• 2005

The germination of Lactuca sativa seeds was significantly inhibited by the water extract of the fresh leaves of Pulsatilla koreana N. including abundant ranunculin. Germination inhibitory activity increased in a dose-dependantly. Protoanemonin, produced from ranunculin by enzymatic action during maceration process of leaves, was proved to be the active principle with inhibitory activity was above 90% at concentration of 1 mg/ml.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.52-54
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• 2007

Laser wave length can have evaporation effect by absorption because outer skin or tissue of focus is consisted of water almost though absorption of water occurs more than 90% almost in formation thickness of very thin floor. Can operate outer skin, steam by floor and correct incision of formation is available. Suture surgical operation is available to vein or lymph system and surgical operation region can dry and see as eye and radish bleeding surgical operation is available. Specially, stability of tube both end output about pulse by weight very, this research can cause various curative effect because can reduce bulk and control easily current wave style of medical laser using electric power conversion device of high frequency way. If introduce ZVS (Zero Voltage Switching) or ZVZCS (Zero Voltage and Zero Current Switching), is more profitable because can reduce switching damage. Because electric power department of proposed medical laser can do stable soft-switching in wide subordinate extent introducing ZVZCS technique by the first help and control department composes microcontroller, output current waveform user have free form make. Result that experiment because design and manufacture, brought result that improve of 20% than existing equipment, and will be bought to get into superior result if supplement as systematic late.

• 지질공학
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• 제28권2호
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• pp.259-266
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• 2018

백두산 분화시 북풍 또는 북동풍이 발달하게 되면 국내에 화산재가 확산될 가능성이 있으며, 화산재에 의해 민감한 영향을 받는 상수도 시설의 관리기준이 필요하다. 본 연구에서는 국내 상수도 시설의 관리기준 수립을 위해 국외의 다양한 화산에 대해 분야별 피해사례를 조사하였으며, 이를 바탕으로 상수도 시설의 피해 요인을 퇴적, 흡착/침착, 마모로 나누어 예상되는 피해 정도를 유형화하였다. 또한 위험평가 결과를 바탕으로 화산재 퇴적 두께에 따라 상수도 시설의 관리 단계를 4단계로 도출하였으며, 0~1 mm은 VAD(Volcanic Ash Degree) I, 1~3 mm는 VAD II, 3~5 mm는 VAD III, 5 mm 이상은 VAD IV로 제시하였다. 최종적으로 도출된 관리 단계별 경보 기준, 화산재 영향, 피해 대응 절차 및 방안 등으로 구성된 상수도 시설 관리 기준(안)을 제시하였다.