• Journal of Chest Surgery
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• v.44 no.6
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• pp.418-422
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• 2011

Background: It has recently become most general to use the small bore catheter to perform closed thoracostomy in treating iatrogenic pneumothorax. This study was performed for analysis of the efficacy of treatment methods by using small bore catheter such as 7 F (French) central venous catheter, 10 F trocar catheter, 12 F pigtail catheter and for analysis of the appropriateness of each procedure. Materials and Methods: From March 2007 to February 2010, Retrospective review of 105 patients with iatrogenic pneumothorax, who underwent closed thoracostomy by using small bore catheter, was performed. We analyzed the total success rate for all procedures as well as the individual success rate for each procedure, and analyzed the cause of failure, additional treatment method for failure, influential factors of treatment outcome, and complications. Results: The most common causes of iatrogenic pneumothorax were presented as percutaneous needle aspiration(PCNA) in 48 cases (45.7%), and central venous catheterization in 26 cases (24.8%). The mean interval to thoracostomy after the procedure was measured as 5.2 hours (1~34 hours). Total success rate of thoracostomy was 78.1%. The success rate was not significantly difference by tube type, with 7 F central venous catheter as 80%, 10 F trocar catheter as 81.6%, and 12 F pigtail catheter as 71%. Twenty one out of 23 patients that had failed with small bore catheter treatment added large bore conventional thoracostomy, and another 2 patients received surgery. The causes for treatment failure were presented as continuous air leakage in 12 cases (52.2%) and tube malfunction in 7 cases (30%). The causes for failure did not present significant differences by tube type. Statistically significant factors affecting treatment performance were not discovered. Conclusion: Closed thoracostomy with small bore catheter proved to be effective for iatrogenic pneumothorax. The success rate was not difference for each type. However, it is important to select the appropriate catheter by considering the patient status, pneumothorax aspect, and medical personnel in the cardiothoracic surgery department of the relevant hospital.

• Corrosion Science and Technology
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• v.12 no.5
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• pp.227-232
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• 2013

A number of components installed in the secondary system of nuclear power plants are exposed to aging mechanisms such as FAC (Flow-Accelerated Corrosion), Cavitation, Flashing, and LDIE (Liquid Droplet Impingement Erosion). Those aging mechanisms can lead to thinning of the components. In April 2013, one (1) inch small bore piping branched from the main steam line experienced leakage resulting from wall thinning in a 1,000 MWe Korean PWR nuclear power plant. During the normal operation, extracted steam from the main steam line goes to condenser through the small bore piping. The leak occurred in the downstream of an orifice. A control valve with vertical flow path was placed on in front of the orifice. This paper deals with UT (Ultrasonic Test) thickness data, SEM images, and numerical simulation results in order to analyze the extent of damage and the cause of leakage in the small bore piping. As a result, it is concluded that the main cause of the small bore pipe wall thinning is liquid droplet impingement erosion. Moreover, it is observed that the leak occurred at the reattachment point of the vortex flow in the downstream side of the orifice.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.4
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• pp.429-435
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• 2010

In approximately fifty utilities, including KHNP (Korea Hydro & Nuclear Power), CHECWORKS is used as a tool for predicting and managing the wall thinning of carbon steel piping; this wall thinning is caused by flow-accelerated corrosion (FAC). It is known that CHECWORKS is only applicable to predict the wall thinning of piping with large bores. When dealing with small-bore steel piping, FAC engineers measure the thickness of the susceptible area that is selected on the basis of the experience and judgment of the engineer. This paper proposes the application of CHECWORKS for the management of wall thinning of small-bore piping. Four small-bore pipelines of a domestic nuclear power plant were analyzed from the viewpoints of FAC and fluid dynamics by using CHECWORKS and FLUENT code. Depending on the engineer's skill, CHECWORKS can also be used for the management of wall thinning of small-bore piping.

• Journal of the Korea Concrete Institute
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• v.11 no.6
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• pp.121-128
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• 1999

The SHO PATCH System Mortar is a mortar shotcreting system which uses fairly small machine and equipment, and is applied for shotcrete tunnel linings, in particular for small bore tunnels of aqueducts by the TBM(Tunnel Boring Machine) method, and for reparing tunnels suffering from spring water and deterioration. This study shows the characteristics of the new mortar shotcreting system, the SHOT PATCh System Mortar, which exhibits excellent shotcrete performance.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10b
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• pp.871-876
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• 1998

The SHOT PATCH System Remitar is a mortar shotcreting system which used fairly small machine and equipment, and is applied for shortcrete tunnel linings, in particular for small bore tunnels of aqueducts by the TBM(Tunnel Boring Machine) method, and for repairing tunnels suffering from spring water and deterioration. This study shows the characteristics of the new mortar shotcreting system, the SHOT PATCH System Remitar, which exhibits excellent shotcrete performance.

• Journal of the Korea Institute of Military Science and Technology
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• v.9 no.3
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• pp.5-11
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• 2006

This paper is launched to get an exact bore-sighting value in the process of assembling for a dual-barrel weapon. Image processing method with a CCD(Charged Coupled Device) camera is chosen for the error reduction of bore-sighting. The results of this method by using a CCD camera and the testing target method are described in this paper. After the performance of the dual-barrel weapon and that of the fire-control system in the dual barrel weapon system is confirmed, the bore-sighting which is a part of the process in the system assembly is accomplished. In this process, the position of the barrel is identified by using the testing target method that is an existing bore-sighting method. Then, the fixing line of the fire-control system is checked by a day-optical part. The precision of the bore-sighting is required within several mils, however the manual method using the naked eyes makes it worse. Therefore, a CCD camera is installed in the eyepieces. Next, we can get an image of the sighting and the center coordinate values of the laser-pointer from each barrel by image processing method. A required bore-sighting value is calculated from the eccentricity of the center coordinate. Finally, It can be applied to adopt this result in the assembling process of the dual-barrel weapon.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.2
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• pp.143-150
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• 2007

Ring and cylinder bore wear may not be a problem in most current automotive engines. However, a small change in ring face and cylinder bore diameter can significantly affect the lubrication characteristics and ring axial motion. This in turn can cause to change inter-ring pressure, blow-by and oil consumption in an engine. Therefore, by predicting the wear of piston ring face and cylinder bore altogether, the changed ring end gap and the changed volume of gas reservoir can be calculated. Then the excessive oil consumption can be predicted. Here, the oil amount through top ring gap into combustion chamber is estimated as engine oil consumption. Furthermore, the wear theories of ring and cylinder bore are included. The changed oil consumption caused by the new end gap and the new volume of oil reservoir around second land, can be calculated at some engine running interval. Meanwhile, the wear amount and oil consumption occurred during engine durability cycle are compared with the calculated values. The wear data of rings and cylinder bore are obtained from three engines after engine durability test. The calculated wear data of each part are turn out to be around the band of averaged test values or a little below. It is shown that the important factor regarding oil consumption increasement is the wear of ring face.

• Journal of the Korean Society for Nondestructive Testing
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• v.33 no.1
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• pp.34-39
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• 2013

In the advanced research deducted infrared thermography (IRT) test using 4 inch pipe with artificial wall-thinning defect to measure on the wall-thinned nuclear pipe components. This study conducted for defect detection condition of nuclear small-bore pipe research using deducted condition in the advanced research. Defect process is processed by change for defect length, circumferential direction angle, wall-thinning depth. In the used equipment IR camera and two halogen lamps, whose full power capacitany is 1 kW, halogen lamps and Target pipe experiment performed to the distance of the changed 1 m, 1.5 m, 2 m. To analysis of the experimental results ensure for the temperature distribution data, by this data measure for defect length. artificial defect of 4 inch pipe is high reliability in the 2 m, but small-bore pipe is in the 1.5 m from the defect clearly was detected.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.14 no.1
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• pp.58-65
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• 2018

The purpose of this study is to develop a Half Nozzle Repair(HNR) process to prevent the leakage from welds on small bore piping in Reactor Coolant System. The Codes & Standards of tempered bead and design requirements of J-Groove welds are reviewed. Automatic machine GTAW welding and machining equipments are developed to perform HNR process. Single pass welding and overlay welding equipments are conducted in order to obtain the optimal temper bead welding process parameters with Alloy 52M filler wire. Coarse grain heat affected zone(CGHAZ) is formed by rapid cooling rate in heat affected zone after welding. Accordingly, a proper temper bead technique is required to reduce CGHAZ in 1-Layer of welds by 2- and 3-Layers. Mock-up tests show that the developed HNR process is possible to meet ASME Code & Standard requirements without any defect.

• Journal of Chest Surgery
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• v.53 no.2
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• pp.49-52
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• 2020

Background: Primary spontaneous pneumothorax is commonly treated with chest tube insertion, which requires hospitalization. In this study, we evaluated the efficacy, costs, and benefits of a portable small-bore chest tube (Thoracic Egg; Sumitomo Bakelite Co. Ltd., Tokyo, Japan) compared with a conventional chest tube. Methods: We retrospectively analyzed all primary spontaneous pneumothorax patients who underwent treatment at Gangnam Severance Hospital between August 2014 and May 2018. Results: A total of 279 patients were divided into 2 groups: the conventional group (n=236) and the Thoracic Egg group (n=43). Of the 236 patients in the conventional group, 100 were excluded because they underwent surgery during the study period. The efficacy and cost were compared between the 2 groups. There was no statistically significant difference between the groups regarding recurrence (conventional group, 36 patients [26.5%]; Thoracic Egg group, 15 patients [29.4%]; p=0.287). However, the Egg group had statistically significantly lower mean medical expenses than the conventional group (433,413 Korean won and 522,146 Korean won, respectively; p<0.001). Conclusion: Although portable small-bore chest tubes may not be significantly more efficacious than conventional chest tubes, their use is significantly less expensive. We believe that the Thoracic Egg catheter could be a less costly alternative to conventional chest tube insertion.