• International Journal of Ocean System Engineering
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• 제2권4호
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• pp.209-213
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• 2012

Recently, the fuel using in the diesel engines of marine ships has been changed to a low quality of heavy oil because of the steady increase in the price of oil. Therefore, the wear and corrosion in all parts of the engine such as the cylinder liner, piston crown, and spindle and seat ring of exhaust valves has correspondingly increased. The repair welding of a piston crown is a unique method for prolonging its lifetime from an economic point of view. In this case, filler metals with a high corrosion and wear resistance are mainly being used for repair welding. However, often at a job site on a ship, a piston crown is actually welded with mild filler metals. Therefore, in this study, mild filler metals such as CSF350H, E8000B2, and 435 were welded to SS401 steel as the base metal, and the corrosion properties of the weld metals with and without post weld heat treatment were investigated using some electrochemical methods in a 0.1% $H_2SO_4$ solution. The weld metal welded with CSF350H filler metal exhibited the best corrosion resistance among these filler metals, irrespective of the heat treatment. However, the weld metal zones of the E8000B2 and 435 filler metals exhibited better and worse corrosion resistance with the heat treatment, respectively. As a result, it is suggested that in the case of repair welding with CSF350H and 435 filler metals, no heat treatment is advisable, while heat treatment is desirable if E8000B2filler metal is used with repair welding.

• Journal of Chest Surgery
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• 제31권1호
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• pp.46-51
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• 1998

식도 천공후 수술시까지 24시간이상이 경과된 환자의 치료법은 아직도 논란이 많다. 1990년이후 연세 대학교 흉부외과학 교실에서는 식도 천공후 24시간이상 경과된 환자 10예중 전예를 일차 봉합술로 치료 하였다. 그중 4명은 인위적인 천공 이었고, 3명은 자연성 천공, 2명은 이물의 연하, 나머지 한명은 외상이 원인 이었다. 식도 천공후 수술시까지 소요된 시간은 평균 116시간 이었고 중앙값은 48시간 이었다. 봉합방법은 천공된 점막부위의 위 아래로 정상 점막이 나올때까지 식도근 절개술을 시행한 후 염증이 있는 점막부위를 변연 절제한다. 식도의 원위부 폐쇄가 있을 경우 수술대에서 식도 확장술을 시행하고 점막과 근육층을 단층 혹은 층층 봉합한다. 봉합부위 위에 늑막이나 심낭 지방을 이용하여 봉합을 강화하였다. 수술 사망은 1예에서 수술후 33일째 발생 하였는데 사망원인은 위괘양의 합병증으로 위출혈이었다. 술후 5명의 환자에서 봉합부위의 유출이 있었지만 사망한 1예를 제외하고 모두 고식적 치료로 완치할 수 있었다. 식도 천공 환자에서 치료법은 여러 가지 방법이 있겠으나 비록 수술시까지 시간이 많이 지났다하더라도 천공의 원인이 양성이고 원위부 폐쇄가 교정될 수 있다면 일차 봉합과 적절한 배농이 우선 되어야 할 것이다.

• 한국결정학회:학술대회논문집
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• 한국결정학회 2003년도 춘계학술연구발표회
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• pp.16-16
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• 2003

Mismatches in a DNA duplex are mainly due to DNA duplication errors that are generated by improper function of DNA polymerase. MutS, MutL and MutH are crucial proteins for the initiation of the methyl-directed mismatch repairing in bacteria. MutS has an ATPase activity md recognize the mismatched or unpaired bases on DNA. After binding to a mismatch, MutS recruits MutL to mediate the activation of MutH an endonuclease, which cleaves the 5' site of d(GATC) on the un-methylated strand. Both MutL and MutS also have essential roles in the subsequent removal and re-synthesis of the daughter strand. We have determined the crystal structures of either intact or active fragments of each of these proteins, both alone and complexed with ligands (DNA, ADP and ATP). The biochemical and mutagenesis studies based on the detailed 3-D structures led to new insights into the role of the ATPase activity of MutS in the mismatch recognition and directions for future investigation of mismatch repair.

• Journal of Chest Surgery
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• 제53권6호
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• pp.411-413
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• 2020

A 34-year-old man who had undergone aortic valve replacement 8 years ago underwent an additional Bentall operation due to mechanical valve dehiscence 2 years later. Subsequently, he was diagnosed with Behçet disease and Batter syndrome. A week after being hospitalized again due to chest pain and dyspnea, a large pseudo-aneurysm was detected on computed tomography. Because of the excessively large size of the pseudo-aneurysm, surgical treatment seemed very risky. Therefore, we planned to perform thoracic endovascular aortic repair (TEVAR) and treated him successfully. However, the patient experienced recurrence of the same symptoms 4 months later, and was found to have type IV endoleak. He received a TEVAR procedure again, and it was successful.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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• pp.785-792
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• 2000

Repair and retrofit system of concrete structures has been developed from conventional reinforced concrete overlaying, steel plate bonding and recently to fiber composite systems. Research and study on carbon, aramid, and glass fiber composite system has been actively carried out from all over the world Glass fiber composite is proved to be competitive technically and enconomically, among fiber composite system. CAF system is a system developed locally using all domestic materal, glass fabric and epoxy, and improved in shear bonding property by utilizing silica fume mixed with epoxy. All the tests on material properties, structural behavior, constructiveness at site and quality control procedure proved to be most appropriate system so far developed. Futher research work is and will be under progress for utilization of this system which will be applied to more adverse situation.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2016년도 춘계 학술논문 발표대회
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• pp.199-200
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• 2016

Accurate fire diagnoses are needed to properly repair and strengthen buildings affected by fire. The current diagnosis method of fire takes time and is ineffective. In previous research, Melting point temperature of each sequence to grasp easily the temperature of the concrete up to 200 ~ 600 ℃ was to estimate the temperature by utilizing a different sequence representing material.But In the form of conventional hydrothermal temperature prediction simple measuring device, it is difficult in the future buried in application to the construction site, there is a problem of damage when concrete pouring, and only the extension of life measured by the zinc has a problem does not distinguish between 400 ℃ and 500 ℃. Therefore this study is conducted by utilizing a titanium metal changes the color depending on the temperature to check for the applicability of the simple apparatus for measuring the temperature prediction sequence.

• 대한관절경학회지
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• 제11권2호
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• pp.117-121
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• 2007

목적: 후방 십자 인대의 골편을 포함하지 않은 대퇴 부착 부 견열 손상에 대한 관절경적 일차 봉합술의 추시 결과를 보고한다. 대상 및 방법: 1993년 1월부터 2002년 12월까지 본원에서 관절경적 후방 십자 인대 봉합술을 시행한 13례 중 2년 이상 추시가 가능했던 10례를 대상으로 하였으며 평균 추시 기간은 $38.7{\pm}11$개월이었다. 평균 나이는 $28.2{\pm}6$세로 남자 8례, 여자 2례였다. 모든 예에서 최종 추시 시 Lysholm and Gillquist 점수 및 International Knee Documentation Committee(IKDC) criteria를 이용하여 평가 하였으며, 후방 전위 검사로 후방 불안정성을 평가하였으며, 후방 부하 측면 방사선 사진으로 경골의 후방 전위를 측정하였다. 결과: Lysholm and Gillquist 점수는 평균 $94.5{\pm}2.6$, International Knee Documentation Committee criteria에 따른 결과는 4례에서 A(normal), 6례에서 B(nearly normal)이었다. 후방 전위 검사 상 5례에서 grade I의 후방 불안정성을 보였으며, 5례에서 grade II의 후방 불안정성을 보였다. 후방 부하 측면 방사선 사진에서 경골의 후방 전위는 평균 $3{\pm}2.3mm$ 이었다. 결론: 후방 십자 인대의 골편을 포함하지 않은 대퇴 부착 부 견열 손상에 대한 관절경적 일차 봉합술은 후방 불안정성을 줄이고 기능적 회복을 향상시키기 위해 유용한 방법으로 사료된다.

• 한국문화재보존과학회:학술대회논문집
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• 한국문화재보존과학회 2002년도 제15회 발표논문집
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• pp.21-31
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• 2002

고건축물에서 구조재, 결합재, 방수재, 마감재 등의 용도로 매우 중요하게 사용된 강회다짐 재료에 관한 사용기록을 정리하고 문화재 보수 및 복원시 현장에서 느끼는 강회다짐재의 사용상 문제점을 검토하여 다음과 같은 개선방안을 제언한다. 1) 생석회를 현장에서 피우는 과정에서 발생하는 품질의 균일성에 관한 문제점을 보완하기 위해서는 강회다짐용 재료로 순도 높은 소석회를 사용하는 것이 바람직하다. 2) 강회시공시 발생하는 품질의 불균일성을 고려하여 균일한 혼합을 위한 믹서, 계량시의 오차를 줄이기 위한 Premix형태의 강회다짐재 및 다짐작업의 균일성을 확보하기 위한 다짐기계의 사용을 적극적으로 검토하여야 한다. 3) 지붕 강회다짐충의 해체 및 시공시 추가적인 구조물의 손상을 방지하기 위해서 적절한 가설구조물의 사용을 의무화 하여야 한다. 4) 문화재 수리 표준 품셈과 문화재 수리 표준 시방서에 규정된 재료 및 시공절차에 관한 내용을 구체적이고 명확히 규정할 필요성이 있다.

• Advances in Computational Design
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• 제4권4호
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• pp.343-365
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• 2019

Among the themes related to earthquake countermeasures at construction sites, those for tower cranes are particularly important. An accident involving the collapse of a crane during the construction of a skyscraper has serious consequences, such as human injury or death, enormous repair costs, and significant delays in construction. One of the causes of deadly tower crane collapses is the destruction of the site joints of the tower crane mast. This paper proposes a new design method by static elastoplastic finite element analysis using a supercomputer for the design of the end plate-type tensile bolted joints, which are generally applied to the site joints of a tower crane mast. This new design method not only enables highly accurate and reliable joint design but also allows for a design that considers construction conditions, such as the introduction of a pre-tension axial force on the bolts. By applying this new design method, the earthquake resistance of tower cranes will undoubtedly be improved.

• Genomics & Informatics
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• 제12권3호
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• pp.80-86
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• 2014

Foldback intercoil (FBI) DNA is formed by the folding back at one point of a non-helical parallel track of double-stranded DNA at as sharp as $180^{\circ}$ and the intertwining of two double helixes within each other's major groove to form an intercoil with a diameter of 2.2 nm. FBI DNA has been suggested to mediate intra-molecular homologous recombination of a deletion and inversion. Inter-molecular homologous recombination, known as site-specific insertion, on the other hand, is mediated by the direct perpendicular approach of the FBI DNA tip, as the attP site, onto the target DNA, as the attB site. Transposition of DNA transposons involves the pairing of terminal inverted repeats and 5-7-bp tandem target duplication. FBI DNA configuration effectively explains simple as well as replicative transposition, along with the involvement of an enhancer element. The majority of diverse retrotransposable elements that employ a target site duplication mechanism is also suggested to follow the FBI DNA-mediated perpendicular insertion of the paired intercoil ends by non-homologous end-joining, together with gap filling. A genome-wide perspective of transposable elements in light of FBI DNA is discussed.