• Title/Summary/Keyword: Flow defect

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Clinical Studies on Congenital Atrial Septal Defects in Koreans (심방중격결손증에 대한 임상적 고찰)

  • 이두연
    • Journal of Chest Surgery
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    • v.10 no.2
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    • pp.230-240
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    • 1977
  • Atrial septal defect is one of the most frequently encountered congenital heart disease. Up to December 31, 1976, 1682 cardiac patients received cardiac catheterization in the cardiac department of Yonsei university medical college. Out of the 1682 cardiac patients 723 cases had congenital heart disease and only 116 cases had congetial atrial septal defect. This amounted to 16.04% of all those with congenital heart disease. 58 cases of congenital atrial septal defect operated in the chest surgery department were presented. Of these 58 cases of atrial septal defect, 27 cases were male and 31 cases were female. Their ages ranged from 5 years to 54 years. The systolic pressure of the main pulmonary artery of 40 out of the 58 cases of atrial septal defect was below 40% of that of the systemic blood pressure: in 6 cases, the range of the systolic pressure of the main pulmonary artery was 50-90mmHg; in 12 cases, the range of the systolic pressure of the main pulmonary artery was 40-50mmHg. Average age of these was 30. 1 years. This study tends to show that Korean patients with atrial septal defect even though younger have a slight higher systolic pressure of the main pulmonary artery than Western patients have. The pulmonary blood is 1.5-2.5 times of systemic blood flow in 52 cases out of 58 cases of atrial septal defect.In only one of the 58 cases of atrial septal defect, the Rp was found to be as high as 45% of Rs. All other cases were below this level.51 cases had ostium secundum defect, 4 out of these cases had ostium secundum defect combined with mitral incompetence and 6 out of them had double ostium secundum defect. The remaining 7 cases had ostium primum defect. Their atrial defects were repaired under direct vision utilizing extracorporeal circulation, by hemodilution technic combined with moderate hypothermia. 44 cases [2nd atrial septal defect] were repaired by direct sutures while 14 cases, including the 7 cases ostium primum defects needed patches [1 pericardium and 13 teflon patch]. In 4 cases there were single defects while showed two defects. However the associated septal defect was so small that it could be closed by direct sutures. The size of the defect ranged between 6.0cm2and 10.0cm2 in 19 cases[33.7%]: the smallest being 0. 5cm2 and the largest 24cm2. The surgical mortality was 2 cases [3.4%]. These one case with ostium primum defect, could not be resuscitated on operation table. The cause of death in this case was myocardial failure and MI. The other, a case of ostium primum defect had a second operation on the first operative day due to massive bleeding from LV vent-line insertion site.The patient died on 26th post-operative day due to sepsis.

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The Improvement of Weldline and Flow mark Defection by using Injection Molding Analysis (사출성형 해석을 통한 Weldline 및 Flow mark 개선사례)

  • Lee, Yeong Chang
    • Journal of the Korean Society for Precision Engineering
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    • v.30 no.12
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    • pp.1295-1301
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    • 2013
  • The cause of flow mark defect is known as non-uniform temperature of mold surface when the flow front meets the cold cavity. The exact definition and classification of Flow mark is not clear because the mechanism of flow mark is not figured out till now. Any injection molding analysis software can not predict the flow mark phenomena. To solve weldline and flow mark defects, the gate thickness is reduced to increase the melt front velocity and the melt front velocity of the flow mark area is increased from 82.3mm/s to 104.7mm/s. In addition, the bulk temperature of the flow mark area is increased from $178.3^{\circ}C$to $215.2^{\circ}C$ by adding a cold slug well. The flow mark phenomena can be greatly reduced by increasing the flow front velocity and elevating the bulk temperature.

Partial Anomalous Pulmonary Venous Return - Report of 1 case - (부분 폐정맥환류이상 1례 보고)

  • 조대윤
    • Journal of Chest Surgery
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    • v.21 no.1
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    • pp.148-151
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    • 1988
  • We experienced 2 years and 5 months old male patient with partial anomalous pulmonary venous return of the left lung into the coronary sinus without atrial septal defect. After incising the atrial septum and the wall between the left atrium and the coronary sinus, we made the roof of the coronary sinus and closed the artificial atrial septal defect, with using patch, then we could change the direction of the blood flow from the coronary sinus into the left atrium. The patient was discharged on the 13th postoperative day after uneventful postoperative course.

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A Sobel Operator Combined with Patch Statistics Algorithm for Fabric Defect Detection

  • Jiang, Jiein;Jin, Zilong;Wang, Boheng;Ma, Li;Cui, Yan
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.2
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    • pp.687-701
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    • 2020
  • In the production of industrial fabric, it needs automatic real-time system to detect defects on the fabric for assuring the defect-free products flow to the market. At present, many visual-based methods are designed for detecting the fabric defects, but they usually lead to high false alarm. Base on this reason, we propose a Sobel operator combined with patch statistics (SOPS) algorithm for defects detection. First, we describe the defect detection model. mean filter is applied to preprocess the acquired image. Then, Sobel operator (SO) is applied to deal with the defect image, and we can get a coarse binary image. Finally, the binary image can be divided into many patches. For a given patch, a threshold is used to decide whether the patch is defect-free or not. Finally, a new image will be reconstructed, and we did a loop for the reconstructed image to suppress defects noise. Experiments show that the proposed SOPS algorithm is effective.

Effects of Forming Depth on the Deformation Behavior of Cup-like Tubes in Tube Spinning Process (튜브 스피닝 공정에서 성형깊이가 컵형 튜브의 변형거동에 미치는 영향)

  • Shin, Y.C.;Yoon, D.J.;Lim, S.J.;Choi, H.J.
    • Transactions of Materials Processing
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    • v.21 no.6
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    • pp.360-365
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    • 2012
  • The aim of this study was to investigate the effects of forming depth on the deformation behavior of cup-like tubes made of AISI1020 steel in tube spinning process. Spinning process was performed on cup-like tubes, which had an inner diameter of 34mm and thicknesses of 7, 8.5 or 11.5mm. The forming depths achieved were 3, 4, and 5.5mm. The complex deformation behaviors occurring during the tube spinning process was explained using the experimental results. Also analyzed were the causes of the material buildup and the bulge defect of inner surface, observed on cross section of tubes. The relationship between tube spinning conditions and the height of bulge defect was examined. The results indicate that bulge defect is increased with a decrease of the forming depth. Moreover, a critical forming depth exists for preventing the generation of the bulge defect in the tube spinning process. The present results will be useful for future decisions of forming depths for successful tube spinning of cup-like tubes.

Aorticopulmonary Window: one case report (대동맥중격결손증[수술치험 1예])

  • 최영호
    • Journal of Chest Surgery
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    • v.14 no.3
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    • pp.302-306
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    • 1981
  • Aorticopulmonary window is a rare anomaly among congenital heart disease. Various terms have been suggested including A-P window, A-P fenestration, fistula, aorticseptal defect etc. The defect lies usually between the left side of the ascending aorta and right wall of the pulmonary artery just anterior to the origin of the right main pulmonary artery. We have experienced one case of aorticopulmonary septal defect which was diagnosed as V5D with pulmonary hypertension in 1 4/12 year old, 7.2 Kg, male patient. Operation was done under the hypothermic cardiopulmonary bypass using 5t. Thomas cardioplegic solution. Vertical right ventriculotomy over the anterior wall of RVOT revealed no defect in the ventricular septum, and incision was extended up to the main pulmonary artery to find the source of massive regurgitation of blood through MPA. Finger tip compression of the aorticopulmanary window was replaced with Foley bag catheter balloon, and the $7{\times}10$ mm aorticoseptal defect located 15mm above the pulmonic valve was sutured continuously wih 3-0 nylon suture during azygos flow of cardiopulmonary cannula which was located distal to the window resulted massive air pumping systemically, and temporary reversal of pumping was tried to minimize cerebral air embolism. Remained procedure was done as usual, and pump off was smooth and uneventful. Postoperatively, patient was attacked frequent opistotonic seizure with no recovery sign mentally and p.hysically. Vital signs were gradually worsen with peripheral cyanosis and oliguria, and cardiac activity was arrested 1485 minutes after operation. Autopsy was performed to find the sutured window and massive edema of the brain.

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Surgical treatment of restrictive venticular septal defect in pediatric patients (소아에서의 제한적 심실중격결손의 외과적 치료)

  • Seo, Gang-Seok;Kim, Gyu-Tae
    • Journal of Chest Surgery
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    • v.28 no.1
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    • pp.18-22
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    • 1995
  • From January 1989 to December 1993, cardiac catheterization and open heart surgery for ventricular septal defect closure were performed in 115 pediatric patients who were selected as meeting the criteria for elective closure of restrictive ventricular septal defect. These criteria included age greater than 1 year and less than 15 years, no evidence of congestive heart failure, Qp/Qs 2.0, pulmonary artery systolic pressure 35mmHg, and no associated cardiac anomalies. Mean age of patients was 5.25$\pm$ 3.53, and 72 patients were male, 43 patients were female[male:female=1.9:1 . Mean systolic pulmonary artery pressure was 19.66$\pm$4.79mmHg, and mean pulmonary to systemic flow ratio was 1.27$\pm$ 0.28. Aortic cusp prolapse was present in 30 patients [26% , aortic insufficiency was present in 1 paient, and 1 patient had prior bacterial endocarditis. There were no instances of complete atrioventricular dissociation, reoperations for bleeding, or reoperations for recurrent ventricular septal defect, but wound infection was present in 1 patient, and there were 7 patients who had the hemodynamically insignificant remnant shunt. There were no early or late deaths or major morbidity.

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Numerical Analysis of Effects of Velocity Inlet and Residual Layer Thickness of Resist on Bubble Defect Formation (레지스트 잔류층 두께와 몰드 유입속도가 기포결함에 미치는 영향에 대한 수치해석)

  • Lee, Woo Young;Kim, Nam Woong;Kim, Dong Hyun;Kim, Kug Weon
    • Journal of the Semiconductor & Display Technology
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    • v.14 no.3
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    • pp.61-66
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    • 2015
  • Recently, the major trends of NIL are high throughput and large area patterning. For UV NIL, if it can be proceeded in the non-vacuum environment, which greatly simplifies tool construction and greatly shorten process times. However, one key issue in non-vacuum environment is air bubble formation problem. In this paper, numerical analysis of bubble defect of UV NIL is performed. Fluent, flow analysis focused program was utilized and VOF (Volume of Fluid) skill was applied. For various resist-substrate and resist-mold angles, effects of velocity inlet and residual layer thickness of resist on bubble defect formation were investigated. The numerical analyses show that the increases of velocity inlet and residual layer thickness can cause the bubble defect formation, however the decreases of velocity inlet and residual layer thickness take no difference in the bubble defect formation.

Vibration Characteristics of Steam Generator U-tubes with Defect (결함을 가진 증기발생기 U-튜브의 진동특성)

  • 조종철;정명조;김웅식;김효정;김태형
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.13 no.5
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    • pp.400-408
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    • 2003
  • This paper investigates the vibration characteristics of steam generator (SG) U-tubes with defect. The operating SG shell-side flow field conditions for determining the fluidelastic instability parameters such as added mass are obtained from three-dimensional SG flow calculation. Modal analyses are performed for the U-tubes either with axial or circumferential flaw with different sizes. Special emphases are on the effects of flaw orientation and size on the modal and instability characteristics of tubes, which are expressed in terms of the natural frequency, corresponding mode shape and stability ratio. Also, addressed is the effect of the internal pressure on the vibration characteristics of the tube.

The effect of hydrogen flow rate on defects and thickness uniformity in graphene (수소량에 따른 그라핀의 두께와 결함 변화)

  • An, Hyo-Sub;Kim, Eun-Ho;Jang, Hyun-Chul;Cho, Won-Ju;Lee, Wan-Kyu;Jung, Jong-Wan
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.262-262
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    • 2010
  • To investigate the effect of the amount of hydrogen on CVD grown-graphene, the flow rate of hydrogen was changed, while other process parameters were kept constant during CVD synthesis. Substrate which consists of 300nm-nickel/$SiO_2$/Si substrate, and methane gas mixed with hydrogen and argon were used for CVD growth. Graphene was synthesized at $950^{\circ}C$. The thickness and the defect of graphene were analyzed using raman spectroscopy. The synthesized graphene shows non-uniform and more defective below a certain amount of hydrogen.

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