• 비파괴검사학회지
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• 제35권5호
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• pp.321-331
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• 2015

냉각 위상잠금 적외선열화상 기법을 이용하여 원전 배관 루프시스템의 가열결함 검출의 선행연구를 통하여 냉각결함 검출조건의 적용에 관한 연구를 수행하였다. 배관의 결함가공은 감육 길이, 감육 깊이를 변화시켜 결함조건을 가공하여 루프시스템을 제작하였다. 사용된 장비는 적외선열화상 카메라와 냉각장치를 사용하였으며 냉각장치와 대상 루프시스템과의 거리는 2m로 고정시켜 실험을 수행하였다. 실험 결과의 분석을 위하여 냉각온도 분포, 위상데이터를 확보하고, 이를 분석하여 결함 길이를 측정하였다. 냉각결함 검출조건은 적외선열화상 데이터보다 위상잠금 적외선열화상 데이터가 측정 결과의 신뢰도가 높았다.

• Journal of Periodontal and Implant Science
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• 제42권2호
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• pp.50-58
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• 2012

Purpose: This study evaluated histologically the tissue responses to and the effects of a customized nano-hydroxyapatite (n-HA) block bone graft on periodontal regeneration in a one-wall periodontal-defect model. Methods: A customized block bone for filling in the standardized periodontal defect was fabricated from prefabricated n-HA powders and a polymeric sponge. Bilateral $4{\times}{\times}4{\times}5$ mm (buccolingual width${\times}$mesiodistal width${\times}$depth), one-wall, critical-size intrabony periodontal defects were surgically created at the mandibular second and fourth premolars of five Beagle dogs. In each dog, one defect was filled with block-type HA and the other served as a sham-surgery control. The animals were sacrificed following an 8-week healing interval for clinical and histological evaluations. Results: Although the sites that received an n-HA block showed minimal bone formation, the n-HA block was maintained within the defect with its original hexahedral shape. In addition, only a limited inflammatory reaction was observed at sites that received an n-HA block, which might have been due to the high stability of the customized block bone. Conclusions: In the limitation of this study, customized n-HA block could provide a space for periodontal tissue engineering, with minimal inflammation.

• Journal of Microbiology
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• 제41권3호
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• pp.224-231
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• 2003

The null pigmentation mutant (npgA1) of Aspergillus nidulans was previously characterized by its production of no pigment at any stage of its life cycle, its reduction in hyphal branching, and its delay in the asexual spore development. The chemical composition of the cell wall was also altered in npgA1 mutants that became more sensitive to Novozyme 234$\^$TM/, which is possibly due to a structural defect in the cell wall. To investigate the effects of the cell wall structure on these pleiomorphic phenomena, we examined the ultrastructure of the cell wall in the npgA1 mutant (WX17). Scanning electron micrographs (SEM) showed that after being cultured for six days, the outermost layer of the conidial wall of WX17 peeled off. Although this phenotype suggested that the cell wall structure in WX17 may be modified, examination using TEM of the fine structure of cross-sectioned hyphal wall of WX17 did not show any differences from that of FGSC4. However, staining for carbohydrates of wall layers showed that the electron-translucent layer of the cell wall was missing in WX17. In addition, the outermost layer H1 of the hyphal wall was also absent in WX17. The ultrastructural observation and cytochemical analysis of cell walls suggested that the pigmentation defect in WX17 may be attributed to the lack of a layer in the cell wall.

• 에너지공학
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• 제24권4호
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• pp.55-62
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• 2015

It is expected that the size of welding defect affects the mechanical performance of welded medium density polyethylene (MDPE) pipe joints. In this study, butt fusion welded MDPE pipe joints with a single spherical or planar defect of various sizes were studied using experimental crush testing and also by finite element method. The crush test showed that the mechanical performance of crush was not affected by the size and geometry of a single welding defect when the defect size was increased to 45% of the pipe's wall thickness. The simulation results indicated that the effect of the single welding defect on the Von Mises stress distribution near the defect explained the reason of the test results.

• 한국안전학회지
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• 제30권1호
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• pp.144-149
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• 2015

This study aims to quantitatively evaluate failure pressure of wall-thinned elbow under combined load along with internal pressure, by conducting real-scale burst test and finite element analysis together. For quantitative evaluation, failure pressure data was extracted from the real-scale burst test first, and then finite element analysis was carried out to compare with the test result. For the test, the wall-thinning defect of the extrados or intrados inside the center of 90-degree elbow was considered and the loading modes to open or close the specimen maintaining a certain load or displacement were applied. Internal pressure was applied until failure occurred. As a result, when the bending load was applied under the load control condition, the intrados of the defect was more affected by failure pressure than the extrados, and the opening mode was more vulnerable to failure pressure than the closing mode. When the bending load was applied under the displacement control, it was hardly affected by failure pressure though it was slightly different from the defect position. The result of the finite element analysis showed a similar aspect with the test. Moreover, when major factors such as material properties and pipeline thickness were calibrated to accurate values, the analytical results was more similar to the test results.

• Corrosion Science and Technology
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• 제13권3호
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• pp.112-119
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• 2014

In this work, it is aimed to develop the fabrication method of axial stress corrosion cracking (SCC) defects having various sizes, on the outer diameter surface of the steam generator (SG) tubings. To control the length of the artificial SCC defect, the specific area of the SG tubing samples was exposed to an acidic solution after a sensitization heat treatment. During the exposure to an acidic solution, a direct current potential drop (DCPD) method was adopted to monitor the crack depth. The size of the SCC defect was first evaluated by an eddy current test (ECT), and then confirmed by a destructive examination. From the comparison, it was found that the actual crack length was well controlled to be similar to the length of the surface exposed to an acidic solution (5, 10, 20 or 30 mm in this work) with small standard deviation. From in-situ monitoring of the crack depth using the DCPD method, it was possible to distinguish a non-through wall crack from a through wall crack, even though the depth of the non-through wall crack was not able to be precisely controlled. The fabrication method established in this work was useful to simulate the SCC defect having similar size and ECT signals as compared to the field cracks in the SG tubings of the operating Korean PWRs.

• 대한두경부종양학회지
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• 제37권1호
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• pp.63-66
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• 2021

Supracricoid partial laryngectomy (SCPL) with cricohyoidoepiglottopexy (CHEP) or cricohyoidopexy (CHP) involves the removal of the whole thyroid cartilage, both true and false vocal cords, the ventricles, and the paraglottic spaces, sparing the cricoid cartilage, hyoid bone, and at least one functional and mobile cricoarytenoid unit. Reconstruction is performed by suturing of the cricoid cartilage up tightly to the hyoid bone, so trachea-releasing procedures are needed to prevent leakage at anastomosis site. In case of advanced tranglottic cancer invading tracheal tracheal wall, we need to perform additional circumferentrial circumferential tracheal wall resection. However, when we perform SCPL, circumferential resection of tracheal wall is limited because SCPL procedure itself needs releasing of tracheal length. We report a case of advanced transglottic cancer involving tracheal wall treated with induction chemotherapy and SCPL including tracheal wall resection with reconstruction of tracheal defect by sternocleidomastoid muscle flap covered with skin graft.

• Journal of Trauma and Injury
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• 제31권2호
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• pp.91-95
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• 2018

Managing large infected midline abdominal defects are clinically challenging and technically demanding. The alloplastic materials, regional flaps, and component separation are usually infeasible because of the size, location, depth, and state of the defects. In these cases, the free flap is the only option with a large well-vascularized tissue that is free to inset regardless of the location. Herein, we report a case of 44-year-old man with a large infected midline abdominal wall defect who was completely treated with a latissimus dorsi myocutaeous free flap followed by negative pressure wound therapy.

• Journal of Chest Surgery
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• 제26권3호
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• pp.234-235
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• 1993

We have experienced a case of congenital heart disease who developed pulmonaryaspergilloma and then had open heart surgery associated with pulmonary resection. A 53 year old female patient was admitted of fever and chill without cyanosis and hemoptysis. Chest CT showed cavitary lesion with enhanced wall in right midle lung and huge pulmonary artery. Secundum atrial septal defect was identified by echocardiography and catheterization, preoperatively. The patient was identified finally as atrial septal defect associated with pulmonary aspergilloma, in operation and pathology.

• 대한두개안면성형외과학회지
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• 제10권1호
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• pp.49-54
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• 2009

상악골 악성종양의 경우 적출 후 골편들을 이식해 상악동 전체를 재건하는 경우는 재발이 많아 잘 시행하지 않는다. 이러한 이유로 안와하연의 재건을 통해 안구 및 안면윤곽만을 재건하는데, 저자들이 시행한 혈행화된 부분 두께의 골이식(vascularized split thickeness calvarium)은 술기방법에 있어 골피판이 혈관경에서 쉽게 분리되는 성질이 있어 시행에 주의가 필요하고 혈관경을 포함한 temporalis muscle이 부피감을 주므로 미용상 불리한 점이 있는 반면에 골편의 높은 생존율이 보장된다는 장점과 공여부의 합병증이 적다는 장점을 가진다. 또한 술후 복시 현상이나 안구함몰이 관찰되지 않았다는 점이 합리적인 술기임을 지지해준다. 따라서 측두동맥 및 정맥을 혈관경으로 하는 혈행화된 두정골 부분층 이식술은 안와하벽을 재건하는데 있어 안전하게 시행가능 한 술기였음을 보고하는 바이다.