• Journal of Chest Surgery
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• v.32 no.2
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• pp.198-200
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• 1999

Esophageal perforation due to the air pressure generated by forcefully evaporating gas is seldomly reported. If the diagnosis is confined to the injury of the oral cavity and the pharynx, missing the injury of the esophagus, the result may be fatal. Cases like this must be managed by early diagnosis and appropriate surgical intervention. The most important thing for early diagnosis is suspicion of esophageal injury from history and physical examination. We report two cases of esophageal pneumatic perforation caused by an explosive gas from the carbonated beverage bottle.

• The KSFM Journal of Fluid Machinery
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• v.8 no.5 s.32
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• pp.22-28
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• 2005

As the water supply facilities are recently getting larger, the domestic waterworks become multi-regional water supply system. Large water supply facilities generally consist of the intake pumping station, water treatment plant and water supply/distribution facilities. Although the pumping stations and the pipeline systems are used to pump up water, it often happens pipeline damage and flooding accident by the water hammer. In this paper, the intake pumping station is guaranteed by both the computer simulation and the field test analysis. This study is contributed to the safe operation program for the pumping station in which results of the adjustment on the safety plan of the pumping station, the air valve and the valve closing time.

• 한국전산유체공학회:학술대회논문집
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• 2003.10a
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• pp.187-188
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• 2003

In order to control the transonic flow field with shock wave, a condensing flow was produced by an expansion of moist air on a circular bump model and shock waves were occurred in the supersonic parts of the fields. Furthermore, the additional passive technique of shock - boundary layer interaction using the porous wall with a cavity underneath was adopted in this flow field. The effects of these methods on the shock wave characteristics were investigated numerically. The result showed that the flow fields might be effectively controlled by the suitable combination between non-equilibrium condensation and the position of porous wall.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1823-1828
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• 2000

Power transformers, air-intakes, stacks in a combined thermal power plant are the main noise sources. Power transformer noise among them has being get a target of public complaint due to 480Hz component of its pure tone. The source is mainly magnetostrictive vibration of the transformer core. The first countermeasures was installing sound barrier on the front of transformer. However, 500Hz, center of the frequency is not reduced. This paper includes the measurements of noise level at the near resident apartment, the identification of noise transfer and the countermeasures for noise sources. Cavity resonance type of noise reduction devices was installed on enclosuring wall of transformers. As a result, the noise level from transformer is reduced about 3dB.

• Journal of Chest Surgery
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• v.36 no.1
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• pp.43-46
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• 2003

A 45-year-old man was referred with symptoms of cough and chest pain for 3 days and small amount of hemoptysis. He had no history of pulmonary tuberculosis. Chest CT showed 2 cystic lesions with air fluid level ill right lower lobe. We performed posterior basal segmentectomy and found 2 cysts with white long parasite in each cavity. We experienced a case of pulmonary sparganosis and report it with references.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.1234-1237
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• 2002

When measuring sound transmission loss (STL) in a laboratory, the specimen location in test aperture affects considerably the measuring accuracy through the influence of so-called “tunneling effect” In this paper, for a single panel and a double panel with air cavity, experimental STL evaluations on various specimen locations on test aperture were carried out to explain the phenomenon. It is shown that the difference of STL is more than 2dB especially at the low frequency region and the case of the center-located panel yielded the lower STL than that of flushing with the end of tunnel, which confirms that the tunneling effect plays an important role in STL measurement.

• Restorative Dentistry and Endodontics
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• v.2 no.1
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• pp.7-9
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• 1976

This study was performed to reveal the effect of self-curing acrylic resin to dental pulp when the resin was used directly on the freshly cut dentin. Class V cavity preparations were made on the teeth of dogs with No. 701 carbide bur at a speed of 200,000 rpm and with an air water spray. Petrolatum jelly was coated on the inner surfaces of the cavities. After that, doughs of self-curing acrylic resin were filled in these cavities and before completely set these were removed and cemented with zinc oxide and eugenol cement. The dogs were sacrified between 1 day and 3 weeks at the intervals of one week and routinely processed with hematoxylin and eosin stain for histopathologic interpretation. The results were as followings; 1. The inflammatory changes of the pulp can be seen after the use of self-curing acrylic resin on freshly cut dentin. 2. The inflammatory changes of the pulp were not completely subsided until the end of third experimental week.

• International Journal of Automotive Technology
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• v.7 no.2
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• pp.139-143
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• 2006

As an automobile tends to be high grade, the needs for more luxurious interior and comfortable HVAC system are emerged. The defrosting ability is another major factor of the performances of HVAC system. The present work is to simulate the flow and the temperature field of cabin interior during the defrost mode. The three-dimensional incompressible Navier-Stokes equations and energy equation were solved on the multi blocked grid system by the iterative time marching method and AF scheme, respectively. The present computations were validated by the comparison of the temperature field of a driven cavity and velocity field of 1/5 model scale of an automobile. Generally good agreements were obtained. By the present computation, the complicated features of flow and temperature within the automotive cabin interior could be well understood.

• Transactions of the Korean hydrogen and new energy society
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• v.13 no.3
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• pp.204-213
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• 2002

In this work, hydrogen production by a 2-step water-spritting thermochemical cycle based on metal oxides redox pairs was investigated on the bases of the thermodynamics and technical feasibility. Also, a 2nd-law analysis performed on the closed cyclic process indicates a maximum exergy conversion efficiency of 7.1% when using a solar cavity-receiver operated at 2300K and air/Fe3O4 molar ratio = 10.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.199-207
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• 2004

Water supply facilities are recently getting larger according as domestic waterworks become multi regional water supply system. Large water supply facilities generally consist of the intake pumping station, water treatment station and water supply & distribution facilities. Although pumping stations and pipeline systems are used to pump up water, it often happens pipeline damage and flooding accident by the water hammer. As a result of this study, a pumping station is guaranteed by the computer simulation and field test analysis. Therefore these are contributed safety operation in pumping station through adjustment of the pumping station safety plan, air valve and valve closing time.