• 한국압력기기공학회 논문집
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• 제11권1호
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• pp.20-24
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• 2015

Steam generator(S/G) tubes in pressurized water reactor (PWR's) are subject to several types of degradation. This degradation includes denting, pitting, intergranular attack(IGA), intergranular stress corrosion cracking(IGSCC), fatigue, fretting and wear. Degradation can be derived from either the primary side(inside) or the secondary side(outside) of the tube. Recent issue for tube degradation in domestic steam generator is the tube end cracking on seal weld region. The seal weld region at the tube end and tube itself is regarded as a pressure boundary between the primary side and the secondary side. One of the Westinghouse Model-F S/G has experienced tube end cracking and its number of plugging approximately becomes to the operating limit up to 5% due to tube end cracking which was reported as SAI/MAI(single/multiple axial indication) or SCI/MCI(Single/multiple circumferential indication) from the results of eddy current testing. Eddy current mock-up test was carried out to determine the origin of cracking whether it is from weld zone area or parent tube. This result was helpful to analyze crack location on ECT data. Correct action on this problem was the installation of tube-end sleeve. Last year, after removing 340 installed plugs from tubes, selected 269 tubes took tube-end sleeve installation. Tube-end sleeve brought pressure boundary from parent tube to installed sleeve tube. Tube-end sleeve has the benefit of reducing outage period and increasing more revenue than replacing S/G. This paper is provided to assist interest parties in effectively understanding this issue.

• 대한기관식도과학회지
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• 제3권1호
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• pp.61-69
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• 1997

A total of 55 patients underwent surgical managements for postintubation tracheal stenosis from July 1975 through March 1997. All but 8 had received ventilatory assistance. The patients had S cuff lesions, 17 stoma lesions, 7 at both levels, 5 at subglottic lesions. Thirty two patients underwent the sleeve tracheal resection and end-to-end anastomosis. Five patients performed a wedge resection and end-to-end anastomosis. Twenty two patients received the Montgomery T-tube for relief of airway obstruction. Simple excision of granulation tissue was done in 7 patients. Rethi procedures(anterior division of cricoid cartilage, partial wedge resection of lower thyroid cartilage and T-tube molding) were performed in 2 subglottic stenosis patients. And the other subglottic patient was received permanent tracheal fenestration at 1975. The tracheoesophageal fistula patient was done sleeve tracheal resection and end-to-end anastomosis with interrupted double layer closure of esophageal fistula site. Cervical approach was used in 49 cases, cervicomediastinal in 13 cases and median stemotomy In 6 cases. Techniques for obtaining tension-free anastomosis included a cervical neck flexion(15-30$^{\circ}$) in all sleeve resection patients and laryngeal release in one. The length of resection was 1.5 to 5.0 on A total of 41 patients(74.5%) had good(24 patients) or satisfactory(17 patients) results. But in ten cases, the restenosis of anastomosis site which is the most common complication was developed Two of them underwent a second reconstruction and 8 patients required T-tube insertion for airway maintenance. Three patients(5.4%) died. The causes of death were tracheo-innominate artery fistula(2) and sudden obstruction of airway(1).

• 한국기계가공학회지
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• 제14권1호
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• pp.29-35
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• 2015

In this study, a FEM analysis is undertaken of a rubber sleeve which is mounted onto a spreading mandrel so as to avoid marking the first wrappings of coils (known as the 'end-mark'), as occasionally occurs when a concentrated load is placed on the edge of a steel sheet, significantly reducing its quality. A commercial numerical package, ANSYS, was utilized to analyze the structural behavior of the rubber sleeve. In general, the strain of the sleeve increases as the thickness of the rubber layer (H) covering the tubes increases, thus also increasing the surface of the sleeve for a constant boundary condition, and decreasing the pitch (P) between each tube, resulting in an increase in the strain on the surface of the sleeve for all rubber thickness conditions tested here. In a comparison of two different materials, rubber and urethane, when H=3 mm and P=1.1D, the maximum total deformations in these cases are 0.12669 mm and 0.086623 mm, respectively.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 춘계학술대회 논문집
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• pp.435-439
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• 2002

In the pneumatic system, pneumatic cylinder is wildly used to factory automation. In general, Pneumatic cylinder problems are occured with colliding to stroke end part at which piston collide to end-cap, head cap and tube when piston is loading. This appearances have a short life of cylinder and is due to system destruction. This study examines the dynamic characteristics of pneumatic cushioning cylinder and cushion sleeve design. At head part cushion chamber for the vertical experimental, The decisions of cushioning effect and the results of the experimental research are obtained to the followings: i) The cushioning effects could acqure to the reserch, if the compressible energy is more than kinetic ones. ii) The collision of piston and head cover could acqure to the research, if the kinetic energy is more than compressible iii) If the load increase to the rolling car, the cushion region pressures would increase and the dynamic force.

• Journal of Chest Surgery
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• 제25권12호
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• pp.1508-1515
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• 1992

Between 1975 and 1992, forty five patients with trachea stenosis received tracheoplasty for relief of obstruction. The causes of airway problem are brain contusion[19 cases, 40%], cerebrovascular disease[3 cases, 7%], drug intoxication[8 cases, 18%], psychotic problem[2 cases, 4%], trachea tumor[3 cases, 7%], adult respiratory distress syndrome[9 cases, 20%] and direct trauma[1 case, 2%]. Direct causes of trachea stenosis were complications of tracheostomy[36 cases, 80%], complications of nasotracheal intubation[5 cases, 11%], tumor[3 cases, 6%] and trauma[1 case, 2%]. Thirty one patients underwent the sleeve resection and end-to-end anastomosis. Five patients performed a wedge resection and end-to-end anastomosis. Forteen patients received the Montgomery T-tube for relief of airway obstruction. Four patients have done simple excision of granulation tissue. Two, subglottic stenosis patients were received Rethi procedure[anterior division of cricoid cartilage, wedge partial resection of lower thyroid cartilage and Montgomery T-tube molding] and the other subglottic stenosis patient underwent permanent trachea fenestration. Including cervical flexion in all patients postoperatively, additional surgical techniques for obtain tension-free anastomosis were hyoid bone release technique in two cases, and hilar mobilization, division of inferior pulmonary ligament and mobilization of pulmonary vessel at the pericardium were performed in one case. Cervical approach was used in 39 cases, cervicomediastinal in 12 cases and transthoracic in one case. Complications of tracheoplasty were formation of granulation tissue at the anastomosis site[3 cases], restenosis[9 cases], trachea-innominate artery fistula[2 cases], wound infection[2 cases], separation of anastomosis[2 cases], air leakage[3 cases], injury to a recurrent laryngeal nerve[temporary 8 cases, permanent 2 cases] and hypoxemia[1 case]. Surgical mortality for resection with primary reconstruction was 6.7%, with one death due to postoperative respiratory failure and two deaths due to tracheo-innominate artery fistula.

• Journal of Chest Surgery
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• 제42권1호
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• pp.63-71
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• 2009

배경: 기관 협착의 치료방법은 비교적 덜 침습적인 기관지내시경을 이용한 시술 또는 침습적인 방법인 구역절제술과 문합의 방법이 있으나 가끔은 환자의 임상적 특징에 따라 이 모든 방법이 불가능할 때도 있다. 최근 실리콘 T-튜브 스텐트가 안전한 치료 대안이 되고 있다. 우리는 다양한 기저질환을 가진 기관 협착 환자에서 T-튜브의 중단기 결과를 조사하였다. 대상 및 방법: 1997년 1월부터 2007년 4월까지 10년 동안 T-튜브로 기관협착을 치료받은 환자 57명을 후향적으로 검토하였다. 환자의 의무기록과 영상검사를 기초로 하여, 임상적인 결과와 T-튜브 제거유무를 조사하였다. 결과: T-튜브와 연관된 합병증과 사망은 없었다. 경과 관찰 기간 동안 1명의 환자는 협착부위 절제와 재건술을 받았다. 13명의 환자들(13/57, 22.8%)은 성공적으로 T-튜브를 제거하여 더 이상 다른 처치는 필요하지 않았다. 또 다른 4명의 환자는 기관연화와 기관협착의 재발로 T-튜브 제거 후 다시 삽입하였다. 4명의 환자들은 기저질환과 암으로 사망하였다. 성별과 T-튜브 삽입 전 기관절개술 유무는 T-튜브 제거에 상당한 영향을 미치나 다변량 분석에서는 성별만이 T-튜브 제거 성공의 표지자로 밝혀졌다. 성별 (p=0.033)과 이전의 기관절개술(p=0.036)은 T-튜브 제거 성공군과 실패군 간의 2가지 다른 요소였다. 결론: T-튜브는 여러 원인에 의해 유발된 기관 협착에서도 믿을 만한 기도유지를 제공하였다. T-튜브는 중단기 동안 기관협착의 치료에 안전하고 효과적인 방법이라고 생각된다.

• 대한두경부종양학회지
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• 제14권2호
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• pp.236-243
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• 1998

1991년부터 1997년월까지 7년간 한림대학교 이비인후과학교실에서 국소침범한 갑상선암으로 치료를 받은 10명의 환자들을 후향적으로 검토하여 다음과 같은 결과를 얻었다. 1) 성별 분포는 남녀비는 1:2.3이었으며 연령별 분포는 60대 이상이 7명으로 노인에 호발함을 알 수 있었다. 2) 임상승상은 애성이 5례(50%)로 가장 많았으며 무증상이면서 경부종괴로 온 경우가 3례 그외에 연하곤란, 호흡곤란 객혈 등이었다. 3) 침범된 구조는 기관 7례, 반회후두신경과 종격동임파절이 각각 5례, 경부식도 3례, 경동맥 3례, 기관주위임파절 3례, 하인두 1례, 미주신경 1례 순이었다. 4) 침범된 구조물들에 대한 수술로는 기관 수상절제술 및 단단문합술이 1례. 기관 수상절제와 윤상기관성형술 1례, 기관 창절제술 및 일차봉합술 1례. 기관 창절제술 및 흉쇄유돌근-근막피판재건술 1례, 기관 면도식절제술 1례, 식도 부분절제술 2례, 식도 면도식절제술 1례, 편측 윤상후두절제술 1례, 윤상연골 부분절제술 및 흉쇄유돌근-근골막피판재건술 1례, 갑상연골 면도식절제술 1례, 반회후두신경절제술이 2례, 미주신경절제술 1례, 경동맥절제술 및 $Gortex^{\circledR}$를 이용한 재건술 2례, 경동맥 면도식절제술 1례 등이었다. 이상에서 국소침범한 갑상선암은 대부분의 경우 가능한 완전절제를 시도하였으나 광범위 절제 후 재건술의 어려움이 있었으며 또한 대부분이 노인 환자로서 전신상태에 따른 예후가 불량한 경우가 있었다. 따라서 각 환자의 나이와 침범 정도에 따른 개별적인 술식으로 치료방법을 선택하는 것이 중요할 것으로 사료된다.하다고 생각된다. 6) 횡문근육종과 골육종의 경우 3례중 2례에서 광범위한 수술적 제거후 방사선치료를 병행하였으며, 현재 무병생존 중이고, 1례는 화학요법과 방사선치료의 병합요법을 시행하였으나 실패하였다. 육종의 경우 광범위한 수술적 절제가 가장 좋은 치료로 사료되며, 미세잔존암이 남아있는 경우는 방사선 치료의 병합이 필요하리라 생각된다.\beta$4-tyrosine phosphorylation site (Clone M)을 얻었다. 암 세포의 부착 및 침투 능력의 기능적 연구로 모노 클로날 항체와 fibronectin, laminin, Matrigel을 단백질 기질로 사용하였으며 결과 비교를 위하여 pRc/CMV 벡터만 주입시켰던 클로운과 방광암 세포주를 $\beta$4 integrin 음성 대조군으로 또한 이 Integrin의 높은 발현을 보이는 두경부 편평상피암 세포주를 양성 대조군으로 이용하였다. 결과 : 세포부착능력에 있어서 온전한 $\beta$4 cytoplasmic domain이 존재하는 클로운이 laminin에 강한 부착능력을 보였으나 fibronectin의 부착정도는 $\beta$4 integrin의 표현정도와 관계없이 모든 클로운에서 비슷하였다. Matrigel을 투과하는 암세포 침윤 능력에서는 $\beta$4 integrin의 표현이 존재하는 클로운들이 투과 능력이 높았으나 세포외 리간드가 없는 control membrane을 사용하였을 때와 비교하여 투과능력의 차이를 보이지 않았다. 결론 : 유전자 주입(transfection) 방법으로