• Journal of the Korean Society for Nondestructive Testing
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• v.33 no.6
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• pp.519-523
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• 2013

A steam generator (SG) tube is an important component of a nuclear power plant (NPP). It works as a pressure boundary between the primary and secondary systems. The integrity of a SG tube can be assessed by an eddy current test every outage. The eddy current technique(adopting a bobbin probe) is currently the main technique used to assess the integrity of the tubing of a steam generator. An eddy current signal analyst for steam generator tubes continuously analyzes data over a given period of time. However, there are possibilities that the analyst conducting the test may get tired and cause mistakes, such as: missing indications or not being able to separate a true defect signal from one that is more complicated. This error could lead to confusion and an improper interpretation of the signal analysis. In order to avoid these possibilities, many countries of opted for automated analyses. Axial ODSCC (outside diameter stress corrosion cracking) defects on the tubes of OPR1000 steam generators have been found on the tube that are in contract with tube support plates. In this study, automated analysis software called CDS (computer data screening) made by Zetec was used. This paper will discuss the results of introducing an automated analysis system for an axial ODSCC on the tubes of an OPR1000 steam generator.

• Journal of Korea Foundry Society
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• v.37 no.6
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• pp.199-206
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• 2017

In this study, the variations of microstructures and tensile properties of Ti-(44-54)at.%Al binary alloys were investigated. The heat-treated microstructure depended greatly on their solidification structure and annealing temperature. We measured the variations of volume fractions of primary and secondary lamellar structure as a function of the heat treatment temperature in a Ti-47at.%Al alloy. The variation of ductility as a function of Al content was in good agreement with the change of fracture mode in the tensile fracture surface. It can be inferred that the variations of yield stress and hardness of ${\gamma}$ phase in a single ${\gamma}$-phase field region are enhanced by anti-site defects created by deviations from the stoichiometric composition. In a Ti-47at.%Al alloy within the (${\alpha}_2+{\gamma}$) two-phase field, the yield stress tended to be the maximum at a near equal volume fraction of lamellar and ${\gamma}$ grains. The ductility depended sensitively on the overall grain size and Al content. The calculation of fracture strain using Chan's model indicated that the change of ductility as a function of annealing temperature was primarily determined by the variations in the overall grain size and lamellar volume fraction.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.7 no.2
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• pp.14-20
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• 2011

The end of design lifetime for Wolsong unit 1 will be reached on 20th November in 2012. So the license renewal documents for the continuous operation of Wolsong unit 1 is under reviewing now. Major components of primary system such as pressure tubes, feeder pipes including delayed neutron monitoring system tubing are being replaced and many components of secondary system are also being repaired. In this paper, the assessment on the wear degradation of delayed neutron monitoring system tubing(on the other hand, DN tube was called) was performed for the ageing management of the same component. The wear defects of this component was one of causes that resulted in heavy water leakage accidents. Therefore design specifications of Wolsong uint 1 and heavy water leakage accidents of pressurized heavy water reactors were reviewed and causes of wear defect for DN tubes were analyzed. Wear propagation equations based on the heavy water leakage history were made and the proper repairing time was possible to be expected if the continued operation was considered. Finally design change items of DN tubes that were conducted for the long term operation of Wolsong unit 1 are introduced.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.11 no.1
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• pp.255-260
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• 1989

Unfavorable healing of maxillary fractures may impose functional and esthetic burdens upon the trauma victim. Malunited maxillary fractures are generally a result of treatment delay, incomplete or inaccurate immobilization of the fracture fragments, or infection. Dysfunctions of mastication, distortions in speech, gross defects in facial contour, and related psychic changes are problems which may require secondary correction. When it is necessary to delay definitive treatment or when inadequate maxillary fracture reduction is recognized within the first week following injury, the maxilla can be mobilized by heavy handed dental manipulation under anesthesia or by elastic traction to an external fixation appliance attached to the maxilla by arch bars or an acrylic splint. But malunited maxillary fracture that have progressed to bony malunion require osteotomy procedure in order to establish normal anatomic relationships. This report parents two cases of malunited unilateral maxillary fracture surgically corrected by unilateral Le Fort I osteotomy.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.1
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• pp.110-115
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• 2016

The need for high-strength galvanized steel has recently increased because of the increased number of car consumers who want improved efficiency and exterior quality. High-strength galvanized steel with high corrosion resistance improves the durability of products and exterior quality. Furthermore, the gilt of zinc does not come off during machining because of the fine adhesive property of zinc. When these are welded, zinc has a lower melting temperature than iron, so zinc is more quickly vaporized than iron. Vaporized zinc can stick to electrodes, which increases spatter in welding transportation. Created spatter can enter the molten pool and develop into inner defects or blowholes and pits. Scattered spatter sticks to the product, which leads to the secondary cost of spatter removal. Therefore, in this study, comparisons of amounts of spatter generated are conducted according to the composition of shielding gas in the MIG and CMT processes to find optimal welding parameters.

• Journal of Trauma and Injury
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• v.33 no.1
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• pp.48-52
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• 2020

Composite skull defects in patients with severe head injuries are very challenging to manage. The dilemma when deciding whether to perform a definitive reconstruction is how long to wait for physiological recovery before an intervention complicates the situation. The inability of such patients to tolerate prolonged anesthetic exposure is a driving factor for performing the minimal intervention necessary to facilitate recovery. Herein, we present a case involving the successful immediate reconstructive treatment of a severely head-injured adolescent with a composite scalp defect secondary to trauma. A 14-year-old boy sustained a severe head injury from a motor vehicle accident with a composite scalp defect in the right fronto-parietal region. The frontal lobe was exposed, and the right eye was crushed and devitalized. The patient was deeply unconscious for 3 days, without any significant improvements before reconstructive surgery was proposed due to fear of possible meningitis resulting from the exposure of brain structures. We successfully managed the patient with a fronto-parieto-occipital flap, after which the patient promptly recovered consciousness.

• Archives of Plastic Surgery
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• v.47 no.5
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• pp.435-443
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• 2020

Background The innervated radial artery superficial palmar branch (iRASP) flap was designed to provide consistent innervation by the palmar cutaneous branch of the median nerve (PCMN) to a glabrous skin flap. The iRASP flap is used to achieve coverage of diverse volar defects of digits. However, unexpected anatomical variations can affect flap survival and outcomes. Methods Cases in which patients received iRASP flaps since April 1, 2014 were retrospectively investigated by reviewing the operation notes and intraoperative photographs. The injury type, flap dimensions, arterial and neural anatomy, secondary procedures, and complications were evaluated. Results Twenty-eight cases were reviewed, and no flap failures were observed. The observed anatomical variations were the absence of a direct skin perforator, large-diameter radial artery superficial palmar branch (RASP), and the PCMN not being a single branch. Debulking procedures were performed in 16 cases (57.1%) due to flap bulkiness. Conclusions In some cases, an excessively large RASP artery was observed, even when there was no direct skin perforator from the RASP or variation in the PCMN. These findings should facilitate application of the iRASP flap, as well as any surgical procedures that involve potential damage to the PCMN in the inter-thenar crease region. Additional clinical cases will provide further clarification regarding potential anatomical variations.

• Clinical and Experimental Pediatrics
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• v.45 no.4
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• pp.535-539
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• 2002

Incontinentia pigmenti is a rare neurocutaneous syndrome characterized by vesiculobullous skin disease in neonates and infants, a noninfectious disease that should be distinguished from infectious diseases with the neonatal seizure or encephalopathy. This disease is X-linked dominant with Xq28 region abnormalities and often associated with developmental defects of the ocular, skeletal, dental, and central nervous system. Central nervous system involvement in the neonatal period, or complicated by encephalopathy, may cause severe neurologic impairment, retardation or even death. We experienced a case of incontinentia pigmenti in a three-day-old female patient who had characteristic papulovesicular skin lesions and partial seizures with secondary generalization. Histopathological examination favored the diagnosis of incontinentia pigmenti and a brain MRI showed undifferentiated white matters with periventricular nodular lesions.

• Journal of Korea Foundry Society
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• v.13 no.3
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• pp.248-258
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• 1993

A semi-solid alloy in which solid and liquid phase are co-existing is obtained by stirring of A17075 molten metal. A semi-solid alloy is dependent on the corresponding temperature within the solid-liquid range, and the process parameters should be controlled accurately to obtain the homogeneous semisolid alloy. The fabrication possibility of fiber-reinforced aluminum alloy containing $Al_2O_3$ short fibers with vigorous agitation of short fibers were obtained by control of stirring time, solid fraction and impeller speed in extrusion billet fabrication processes. The microstructure to extrusion billet fabricated by low pressure casting was investigated for fiber dispersion state. The relationship between the extrustion force and velocity at hot extrustion, the flow strain and extrusion ratio were theoretically described. The surface defects with lubricants and without lubricant after hot extrusion were investigated. The composites materials after hot extrusion were measured by vickers hardness with extrusion ratio. It has become clear that the secondary working such as hot extrusion was very useful to obtained improved the mechanical properties of metal matrix composites.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.20 no.3
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• pp.147-160
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• 2007

Background and Objective : The facial nerve grading system proposed by House and Brackmann is most widely accepted for the clinical assessment of facial nerve injury. Because of the limitations and subjectivity of the House-Brackmann scale, several new scales of varying degrees of objectivity and ease of use have been introduced. To assess methods of evaluating the function of the facial nerve that have been introduced over the past 20 years, We compared with the House-Brackmann scale. Method : We referred to the information through Entrez Pubmed and Korean studies information(KSI) from 1985 to 2006 about methods of evaluating facial nerve function. We choose 7 scales that focused on objective and easy of use. Result and conclusion : Sunnybrook scale is a weighted, subjective scale with incorporation of secondary defects into a single composite score. Sunnybrook scale can be recommended over House-Brackmann scale.