• 한국연소학회:학술대회논문집
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• 2006.10a
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• pp.36-41
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• 2006

A simplified model of plastic layer and internal gas pressure In a coke oven is presented. We calculate internal gas pressure using presented model. And results are compared with calculated results using experimental data. Results show the difference of internal gas pressure by coal composition. The model is used to show that the permeability at the resolidification end of the plastic layer is a key determinant of the magnitude of the internal gas pressure.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.10
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• pp.1869-1873
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• 2010

For reliable operation of oil-filled electrical equipment, monitoring and maintenance of insulating oil is essential. Dissolved gas analysis(DGA) is widely used for monitoring faults in high voltage electrical equipment in service. Therefore, oil analysis should be monitored regularly during its service life. KEPCO has investigated thousands of dissolved gas analysis data since 1985, and conducted studies on the relationship of gas in oil analysis and internal inspection results of transformer. As the results, KEPCO revised criteria for transformer diagnosis and has applied it since 2008. Almost of 100 cases of internal inspection results since 2001 have been investigated. This paper presents the correlation of the fault-identifying gases with faults found in actual transformers and how should we approach to internal inspection of transformer by dissolved gas analysis.

• Journal of the Korean Institute of Gas
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• v.18 no.6
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• pp.40-44
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• 2014

In this study, it is analyzed that a change in the shape of small propane containers made of STS304 when increasing of internal pressure. When internal pressure of a small propane container increased, bottom of end plate is convexly changed. This test is applied to a water bath pressure test to analyze the characteristics of the container. Water bath is able to analyze relationship between internal pressure and volume. In result, shape change section is confirmed because bottom of end plate is convexly changed. In addition, this section tend to decrease internal pressure because a volume increment increase out of proportion to pressure. The results of this study are expected to contribute to improving the safety of the pressure vessel, as well as various small propane container.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.215-216
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• 2006

At maritime safety committee 78th of IMO, the Norway suggested the development of provisions for installation and operation of gas fuelled internal combustion engine with the exception of LNG carrier. At first, this document decribes gas fuelled internal combustion engine, describes IMO's tredency under FP sub-committee, DE sub-committee and BLG sub-committee's purview. Furthermore, this paper proposes actions requested the development of this provisions in Republic of Korea.

• Journal of Yeungnam Medical Science
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• v.32 no.1
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• pp.13-16
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• 2015

Portal vein gas and pneumatosis cystoides intestinalis are uncommon conditions and have been associated with poor prognosis. They are most commonly caused by necrotizing enterocolitis but may have other causes, and they can be associated with necrotizing and ischemic colitis, intra-abdominal abscess, small bowel obstruction, diverticulitis, colon cancer, and acute pancreatitis. With the more frequent use of computed tomography (CT) scans, portal vein gas and pneumatosis cystoides intestinalis have been increasingly detected in recent years. Because of its high mortality rate, necrotizing enteritis with portal vein gas and pneumatosis cystoides intestinalis may be treated with emergent exploratory laparotomy. We report a case of necrotizing enteritis with portal vein gas and pneumatosis cystoides intestinalis in a 47-year-old man treated with intensive medical management and delayed operation due to unstable condition and surgical mortality. He had good clinical results without complications after the delayed operation.

• Tuberculosis and Respiratory Diseases
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• v.38 no.1
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• pp.70-73
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• 1991

We have experienced a case of lung injury caused by accidental inhalation of ammonia gas in a 34 year-old-man. By the explosion of ammonia tank in a refrigerator boat he inhaled ammonia gas. Several minutes later, he suffered from severe dyspnea and visual loss. On arrival at emergency room, analysis of arterial blood gas revealed severe hypoxemia and his chest film showed bilateral pulmonary infiltrates. Under the impression of adult respiratory distress syndrome, mechanical ventilator was applied to the patient. After recovery from ARDS and tracheal edema, he complained of some hemoptysis and productive sputum during the admission. So we checked bronchoscopy and bronchograpy which showed tracheal bullae just above carina and tubular bronchiectatic change in the right lower lobe. We report a case of lung injuries-ARDS, tracheal bullae, and bronchiectasis-caused by inhalation of ammonia gas with the review of the relevant literatures.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.5
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• pp.82-88
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• 2001

The EGR is needed fur one of various strategies to reduce NOx emission. But to get the proper EGR rate, the intake and exhaust system become complicated. That is a reason why we consider using the internal EGR system. The internal EGR is a system which reduces NOx by controling the residual gas fraction in cylinder by changing valve timing and valve lift of intake and exhaust. In this paper, characteristics of volumetric efficiency and residual gas fraction in cylinder were investigated for various engine speeds by changing valve timing and valve lift of intake and exhaust in the 4 stroke-cycle diesel engine. Volumetric efficiency and residual gas fraction were calculated by the method of characteristics. As the results, residual gas fraction and volumetric efficiency in cylinder by variable valve timing were visualized.

• Tuberculosis and Respiratory Diseases
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• v.74 no.3
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• pp.120-123
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• 2013

Inhalation of toxic gases can lead to pneumonitis. It has been known that methane gas intoxication causes loss of consciousness or asphyxia. There is, however, a paucity of information about acute pulmonary toxicity from methane gas inhalation. A 21-year-old man was presented with respiratory distress after an accidental exposure to methane gas for one minute. He came in with a drowsy mentality and hypoxemia. Mechanical ventilation was applied immediately. The patient's symptoms and chest radiographic findings were consistent with acute pneumonitis. He recovered spontaneously and was discharged after 5 days without other specific treatment. His pulmonary function test, 4 days after methane gas exposure, revealed a restrictive ventilatory defect. In conclusion, acute pulmonary injury can occur with a restrictive ventilator defect after a short exposure to methane gas. The lung injury was spontaneously resolved without any significant sequela.

• Nuclear Engineering and Technology
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• v.23 no.4
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• pp.363-373
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• 1991

The current rod internal pressure criterion permits fuel rods to operate with internal pressures in excess of system pressure only if internal overpressure does not cause the diametral gap enlargement. In this study, the generic allowable internal gas pressure not violating this criterion is estimated as a function of rod power. The results show that the generic allowable internal gas pressure decreases linearly with the increase of rod power. Application of the generic allowable internal gas pressure for the rod internal pressure design criterion will result in the simplication of the current design procedure for checking the diametral gap enlargement caused by internal overpressure because according to the current design procedure the cladding creepout rate should be compared with the fuel swelling rate at each axial node at each time step whenever internal pressure exceeds the system pressure.

• Transactions of the Korean Society of Mechanical Engineers
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• v.3 no.4
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• pp.173-180
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• 1979

Temperature distriburion in a hollow chlinder has been analyzed mathematically. Unsteady condition considered assumed a constant heat flux input from the inside. The results are compared with experimental results of surface temperature rise of a gun barrel during continuous firing. Their agreements are acceptable. Effects of various dimensionless parameters on the surface temperature rise are discussed. For small Biot numbers, the external survface temperature approaches more rapidly to the steady temperature. Temperature difference between internal and external surfaces becomes greater for small Biot number. Steady solution assumed that the gas temperature inside the cylinder varies periodically. Relative amplitude and phase angles between the gas temperature and the internal or external surface temperature are obtained. Phase angles become smaller for large radiancy of gas temperature variation, small external Biot number, or large internal biot number. Relative amplitudes become samller as radiancy of gas temperature variation and internal Biot number become smaller. or external Biot number becomes larger. The solution obtained in this paper can be applied to gun barrels, heat pipes used in heat excangers, and reciprocation engines.