• The KSFM Journal of Fluid Machinery
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• v.4 no.4 s.13
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• pp.16-21
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• 2001

The field tests on the waterhammer were carried out for PalDang intake pumping station of the metropolitan water supply 5th stage project. The pumping station was equipped with the pump control valve as the main surge suppression device and the surge relief valve as auxiliary. However, the pump control valve had not been early controlled in the planned closing mode, and the slamming occurred to the valve which abruptly closed during the large reverse flow. Because the pressure wave caused by the pump failure was superposed on the slam surge, the upsurge increased so extremely that the shaft of the valve was damaged. It was desirable that the surge relief valve was installed in the pumping station or near the pump exit for the delay of response. After reforming the oil dashpot of the pump control valve, the sliming disappeared and the measured pressure was in fairly good agreement with the results of simulation. In case of three pumps for ${\phi}2,600$ pipeline being simultaneously tripped, the pressure head in the pumping station increased to 95.6 m, and the upsurge caused by the emergency stop of four pumps for ${\phi}2,800$ pipeline was 89.6m. We concluded that the pumping station acquired the safety and reliability for the pressure surge.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.3
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• pp.338-345
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• 2000

A model testing has been performed to investigate the flow characteristics of a vortex chamber, which plays a role of a flow switch and passively controls the discharge flow rate. This method of passive flow control is a matter of concern in the design of advanced nuclear reactor systems as an alternative to the active flow control to provide emergency water to the reactor core in case of postulated accidents like LOCA (Loss-Of-Coolant Accident). By changing the inflow direction in the vortex chamber and varying the flow resistance inside the chamber, the vortex chamber can control passively the injection flowrate. Fundamental characteristics such as discharge flow rate and pressure drop of the vortex chamber are measured, and its parametric effects on the performance of the vortex chamber are also systematically investigated.

• Journal of Integrative Natural Science
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• v.8 no.2
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• pp.135-140
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• 2015

Climate change which occuring the recent abrupt fluctuations in meteorological and climatological elements is bound, brings about more significant impacts and changes in human life One of the most important problems due to the impacts of climate change tends to have been decreased the food production, which is expected to make crop resources more and more important. Accordingly, agricultural meteorology should also become more important. In this study, the correlation between meteorological elements and root and tuber crops (potatoes and sweet potatoes), which are emergency crops, and meteorological elements were analyzed, and the impacts of climate changes on the production of such crops were examined. This study concludes that agriculture and food resources are important, and suggests that we should prepare for changes in crops, the weaponization of food, and the lack of water resources in the future. The meteorological element and crops element correlation analysis results. Sweet potatoes, which are negatively influenced by climate change, need breeding improvement and cultivation method development, and potatoes, which are positively influenced by climate change, require preparations for climate changes that exceed the climatic limit. The variations of agricultural production contributed to changes in crop production. Therefore, the importance of agricultural meteorology and the food crop industry should be fully recognized to prepare for climate change.

• Journal of Chest Surgery
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• v.27 no.4
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• pp.331-334
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• 1994

Pneumatic rupture is a rare cause of esophageal injury, as evidenced by only 19 cases reported in the literature. We experienced one case of esophageal rupture due to bursting of a truck inner tube. The patient, who was a 45-year old male, had severe chest pain, respiratory distress, flushing in the face and neck, and subcutaneous emphysema after tire explosion. Three days after the incident, a diagnosis of rupture of the thoracic esophagus was established by esophagogram using water soluble contrast media, and then emergency operation was done. The operation involved mediastinal and thoracic drainage and resection of the esophagus combined with cervical esophagostomy and feeding gastrostomy. On the 105th day after the operation, cervical esophagogastrostomy via substernal route was performed. The patient was successfully treated with the staged operations. As in the other reported cases, the injury was located in the lower one third of the esophagus. Four main characteristics of the clinical signs of pneumatic rupture are 1] wounds or burns to the face or mouth, 2] chest pain or epigastric pain, 3] subcutaneous emphysema, and 4] respiratory distress. We emphasize that the high index of suspicion of esophageal rupture is very important in diagnosis and that diagnosis should be based on the same findings common to other forms of esophageal injury.

• The KSFM Journal of Fluid Machinery
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• v.19 no.2
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• pp.49-54
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• 2016

A conceptual study of an air-cooled heat exchanger is conducted to achieve the long-term passive cooling of an integral reactor. A newly designed air-cooled heat exchanger is introduced in the present study and preliminary thermal sizing is demonstrated. This study mainly focuses on feasibility of an innovative air-cooled heat exchanger to extend the cooling period of the passive residual heat removal system(PRHRS) only in passive manners. A vertical shell-and-tube air-cooled heat exchanger is installed at the top of the emergency cooldown tank(ECT) to collect evaporated steam into condensate, which enables water inventory of the ECT to be kept. Finally, thermal sizing of an air-cooled heat exchanger is presented. The length and the number of tubes required, and also the height of a stack are calculated to remove the designated heat duty. The present study will contribute to an enhancement of the passive safety system of an integral reactor.

• Journal of The Korean Society of Clinical Toxicology
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• v.3 no.2
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• pp.110-113
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• 2005

Glyphosate containing herbicides are an alternative to paraquat and have been widely used with increasing frequency in suicide attempts throughout Asia. It is an organophosphorus compound that is not a cholinesterase inhibitor. Daejangun powder consists of glyphosate ammonium, surfactant and another herbicide, oxyfluorfen. A 60-year-old man ingested about 300 g of Daejangun powder with 500 ml of water in a suicide attempt. He was brought to emergency room 6 hours after the ingestion and showed severe metabolic acidosis (pH 6.75), marked leukocytosis (WBC 35,800/$mm^3$), hypoglycemia (glucose 13 mg/dL) and increased liver enzymes (AST/ALT 1,683/418 IU/L). Later he developed aspiration pneumonia, acute renal failure and hyperchloremic acidosis. Upper gastrointestinal endoscopy which performed 5 days after the ingestion revealed corrosive injuries (grade 1) in both esophagus and stomach. However, intensive treatment with supportive measures improved the abnormal findings almost completely 4 weeks after the ingestion.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2005.10a
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• pp.187-190
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• 2005

The purpose of this study was to investigate using behavior and spatial composition of activity room in skilled nursing facilities for the elderly and to provide basic information about its space planning. The design guidelines for activity room were as follows. First, the plan of activity room is based on the use of once to twice per week and for 30 minutes per use, and is mainly for the human knowledge and art programs. Second, all cases of the same and different floor of the individual room could be considered as its location. Third, the area is recommended at least more than 6 square meters per person including participating elderly, staff, furniture, equipments and restroom. Fourth, the furniture of activity room include the shelves, table for at least 8 persons with enough knee space, wheel, and stack chairs. Toilets and water closet should be arranged for the emergency, and the windows to the hall and curtain door need to be avoided for soundproofs and easy accessibility of wheelchair users.

• Nuclear Engineering and Technology
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• v.28 no.3
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• pp.257-264
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• 1996

The conventional Equipment Environment Qualification (EEQ) envelope is developed based on the containment responses during the design basis events. The Safety Depressurization System (SDS) design without In-containment Refueling Water Storage Tank (IRWST) adopted in the Ulchin 3&4 challenges the conventional EEQ envelope during long term Feed and Bleed (F&B) operation due to the direct discharge of high mass and energy into the containment. Therefore, it is necessary to confirm that the containment pressure and temperature history during the long term F&B operation does not violate the conventional EEQ envelope. However, this subject has never been quantitatively assessed before. To investigate the success path of long term F&B operation this paper analyzes the thermal hydraulic response of the containment and Reactor Coolant System (RCS) until the completion of depressurization and cooldown of RCS into Shutdown Cooling System (SCS) entry condition. It is found that the SCS entry condition can be reached within 6 hours without violating the EEQ curve by proper operation of SDS valves, High Pressure Safety Injection (HPSI) pumps and active Containment Heat Removal System (CHRS). The suggested strategy not only demonstrates the feasibility of long term F&B operation but also can be utilized in the preparation of Emergency Procedure Guidelines (EPGs)

• Nuclear Engineering and Technology
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• v.30 no.2
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• pp.112-127
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• 1998

The present study is to assess the applicability of the best-estimate thermal-hydraulic codes, RELAP5/MOD3.2 and CATHARE2V1.3U, to the analysis of thermal-hydraulic behavior in PWRs during midloop operation following the loss of RHRS. The codes simulate an integral test, BETHSY 6.94, which was conducted in the large scale test facility of BETHSY in France. The test represents the accident where the loss of RHRS occurs during midloop operation with the pressurizer and upper head vents open and the sight level indicator broken. Besides, the hot legs are half filled with water and the upper parts of the primary cooling system are filled with nitrogen, with a letdown line open and only one SG available. The purposes of this study are to understand the physical phenomena associated with reflux cooling in the 5G U-tubes when noncondensable gas is present under low pressure and to assess the applicability of the codes to simulate the loss of RHRS event by comparing the predictions with the test results. The results of the study may contribute to actual applications for plant safety evaluation and description of the emergency operating procedure.

• Korean Journal of Hazardous Materials
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• v.6 no.2
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• pp.95-104
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• 2018

Gas-liquid bubble column reactors are extensively used in industrial processes. A detailed knowledge of bubble size distribution is needed for determining the mass transfer in gas-liquid film. Experimental data on bubble size distribution and liquid-side mass transfer coefficient($k_L$) were used to calculate the estimated time to saturation in bubble column reactor. Also, the gas flux was evaluated to the liquid-side mass transfer coefficient($k_L$) and solubility data for hydrogen sulfide($H_2S$) and chlorine($Cl_2$) absorption into water. Simulation results show that $H_2S$ absorption time to 50 % of saturation concentrations are 611 sec and 1,329 sec when bubble diameters are 0.5 mm and 4.5 mm, while absorbing 1 % $H_2S$ gas. In case of $Cl_2$, absorption time range 657 to 1,400 sec when bubble size range 0.5 mm to 4.5 mm, while absorbing 1 % $Cl_2$ gas. Calculated simulation results can be used in the design of emergency relief bubble reactors.