• 대한기계학회:학술대회논문집
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• 대한기계학회 2005년도 창립60주년 기념 추계 학술대회
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• pp.129.2-129.2
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• 2005

• 한국임상수의학회:학술대회논문집
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• 한국임상수의학회 2006년도 춘계학술대회
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• pp.189-189
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• 2006

• Journal of Korean Neurosurgical Society
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• 제41권2호
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• pp.120-122
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• 2007

Meningiomas arise from meningothelial cells that line the arachnoid membrane. So most meningiomas are dural-based lesion. But meningiomas without dural-attachment do occur and are less common. We report our experience of intraparenchymal sylvian fissure menigioma. A 21-year-old female presented with a one-month history of headache that was associated with long-term intermittent partial seizure. CT revealed about $4.5{\times}4.3{\times}5.5cm$ sized calcified mass with enhancement in right temporal lobe. On MR imaging, the lesion was observed in the right temporal lobe that was low-signal intensity on T2WI and iso-signal intensity on T1WI with well enhancement. Operation was performed via right orbitocranial approach. The internal surface of dura was intact. Tumor was totally removed except the capsule of tumor adhered to main trunk of middle cerebral artery. The histopathology showed meningioma, psammomatous type. Intraparenchymal meningioma should be considered in the differential diagnosis of intraaxial lesions in patients of any age group.

• Journal of Chest Surgery
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• 제20권1호
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• pp.161-170
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• 1987

Fifty-nine cases of congenital chest wall defects experienced in the department of thoracic surgery of Seoul National University Hospital were analyzed and the relevant literatures were reviewed. They are 52 cases of funnel chest, 3 cases of pigeon breast, one case of superior sternal fissure, one case of costochondral incurvation, one case of Cantrell`s pentalogy, and one case of Poland`s syndrome. Funnel chest affected males more frequently than females by 44 to 8. All of the funnel deformities were corrected by Ravitch operation or its modification except one which was the first case of this series and was corrected by a sterno-turnover. Two cases required a mechanical ventilation for 3 days and 5 days respectively. Four minor complications which were two cases of skin wound infection and 2 cases of fluid accumulation were noted. Skin would infection was repaired by a secondary closure and fluid accumulation was treated by aspiration only. The result are all excellent without recurrence or reoperation. In 3 cases of pigeon breast, they were treated by subperichondrial resection of all of the involved costal cartilages and shortening their course with reefing sutures in the perichondrium with excellent result. The superior sternal fissure which was combined by a ventricular septal defect was treated by a simple wire closure with a good result. The costochondral incurvation was corrected by subperichondrial resection of deformed cartilages and a rib graft removed from the contralateral normal side. The Poland syndrome and the Cantrell`s pentalogy was already presented previously.

• 한국안광학회지
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• 제4권1호
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• pp.83-88
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• 1999

본 연구는 한국 성인 여성에 대한 외안부 형태를 조사하기 위해 시도한 것이다. 다음과 같은 결과를 얻었다. 1. 내안각간의 거리의 최적길이는 35-36mm이다. 그러나 18-19세는 20-25세에 비해서 폭의 범위가 넓다. 2. 검열의 최적길이는 30-31mm이다. 한편 우안과 좌안은 비슷한 결과를 가진다. 3. 검열의 최적 폭은 8mm이다. 그리고 우안과 좌안은 비슷한 결과를 가진다. 4. 근거리에서 대부분의 PD는 28-31mm(76.7%)이다. 그리고 우안과 좌안은 비슷한 결과를 가진다. 5. 원거리에서 대부분의 PD는 30-33(75.8%)mm이다. 그러나 18-21세는 우안이 좌안에 비해서 길다. 6. 우성안은 거의 우안이다.

• 대한기계학회논문집A
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• 제27권3호
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• pp.455-463
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• 2003

The aim of this study is to investigate the hydrogen embrittlement of Zr-2.5Nb CANDU pressure tube at room temperature. The transverse tensile and fracture toughness tests were performed at various hydrogen concentrations using transverse tensile specimens and CCT (curved compact tension) specimens. These specimens were directly machined from the pressure tube retaining original curvatures. Based on the results of these tests. the hydrogen embrittlement phenomenon was clearly observed and fracture toughness parameters of Zr-2.5Nb pressure tube materials such as, $K_{J(0.2)}$.$J_{ML}$.dJ/da, were dramatically decreased with the increasement of the hydrogen concentration. From microscopic observation by SEM and TEM, it was also revealed that various shapes dimples, fissures and quasi-cleavage were found at the hydrogen-absorbed materials with hydrides while traditional shape dimples were generally located at the as-received materials Through the comparison of the hydride and fissure lengths with the hydrogen concentration the new evaluation method of hydrogen embrittlement was suggested.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집A
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• pp.93-98
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• 2000

Unpredictable failures can occur due to the DHC (delayed hydride cracking) or the degradation of fracture toughness by hydride embrittlement in CANDU pressure tube which can result from the absorption of hydrogen or deuterium in the high temperature coolant. To investigate the hydride embrittlement of CANDU Zr-2.5Nb pressure tube, the transverse tensile test and the fracture toughness test were performed from room temperature to $300^{\circ}C$ using three different specimens which have an AR (As Received), 100, and 200 ppm hydrogen. As the amount of absorbed hydrogen was increased, the transverse yield strength and the ultimate tensile strength were also increased. In addition, as the test temperature became higher they were decreased linearly. While, at room temperature, the hydrogenbsorbed specimens represented the embrittlement which resulted in sudden decreasing of fracture toughness, the fracture characteristics became ductile such as AR specimen at high temperatures. Through the observation of fracture surface using SEM, it was found that the stress state of mixed mode could be related to the fissure which was believed to decrease the global fracture toughness.

• 대한지하수환경학회지
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• 제4권2호
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• pp.95-102
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• 1997

지금까지 균열대수층에 관한 많은 모델들이 제안되었다. 본 연구에서는 block의 상부에 일정수두 경계가 규정되어 있으며 이중공극 대수층내에서 block으로부터 균열로 향하여 흐르는 부정류의 새로운 프락탈 모델이 개발되었다. 이 모델은 양수정의 우물저장 효과와 우물손실 효과를 고려하고 있으며, 아울러 block과 균열간의 fracture skin도 고려하는 것이다. 본 모델은 fracture skin이 존재하지 않는 경우에는 Hantush(1960)의 수정식 또는 Boulton과 Streltsova(1978)의 식을 2차원의 해로서 포함하는 일반화된 모델이 된다. 0.5, 1, 1.5, 2, 2.5, 3의 유동 차원과 띠러 가지 누수계수 및 fracture skin에 대해서 그리고 양수정과 관측정에 대해서 무차원의 시간에 대한 무차원의 수위하강 표준곡선이 작성되었다.

• 자원환경지질
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• 제29권3호
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• pp.395-405
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• 1996

The Donjin deposits which is located in the Chinan Basin, are emplaced along $N10{\sim}40^{\circ}E$ trending fissure sets. So it is a sort of fissure-filling ore deposits. The results of paragenetic studies suggest two stages of hydrothermal mineralization; stage I: base-metal sulfides stage, stage II: late base-metal sulfides, electrum and silver-bearing sulfosalts stage. Au: Ag ratios of the electrums show that Ag atomic% are higher than that of Au. The temperature and salinity of the Donjin deposits estimated from fluid inclusion and sulfur isotope geothermometry are as follows; stage I: $240{\sim}315^{\circ}C$, 2.4~7.1 NaCl eq. wt.%, stage II: $190{\sim}268^{\circ}C$, 4.6~8.4 NaCl eq. wt.%. The estimated oxygen and sulfur fugacity during first stage mineralization, based on phase relation of associated minerals, range from $10^{-35}{\sim}10^{-39.7}$ atm. and$10^{-11}{\sim}10^{-13.4}$ atm., respectively. All these evidences suggest that the Dongjin deposits are polymetallic meso-epithermal ore deposits.

• Journal of Welding and Joining
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• 제9권4호
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• pp.60-68
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• 1991

The weld quality of end cap welds in Pressurized Heavy Water Reactor (PHWR) Fuel is extremely important for the fuel performance in the nuclear reactor. The quality of resistance upset welds is currently evaluated mainly by the metallographic examination although it reveals only two weld cross-sections in a circumference welds. This investigation was, firstly, carried out to determine whether the ultrasonic examination would be applied to detect weld defects in the end cap welds and, secondly, to measure the mechanical strength of upset butt welds as a function of phase shift percentage. The major results obtained in this study are as follows: 1. The weld current and amount of upset shrinkage linearly increased with increasing the phase shift percentage. 2. Above the phase shift 55%, the defects in the welds were completely eliminated with increasing the phase of sound weld was over the thickness of cladding tube. 3. The ultrasonic testing well detected such defects in the end cap welds as upset external crack, upset split, corner crack and irregular weld flash comparing with the results of metallography. 4. The micro-fissure in the corner of the end cap welds was reliably detected by ultrasonic testing. 5. The mechanical strength in the welds increased with increasing phase shift percentage but the fracture did't occur in the welds above 55%.