• Journal of the Korean Society for Nondestructive Testing
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• v.21 no.5
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• pp.556-560
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• 2001

Remote field eddy current testing (RFECT) with through-wall transmission characteristic is being applied to pipes ranging from small tubes of heat exchanger to natural gas supply pipelines. Cast iron pipes with nominal diameter of 100mm are used primarily as the waterline pipes. The leakage of water occurs due to defects in the pipes caused by vibration of automobiles and corrosion. But, the use of direct inspection methods such as insertion of inspection equipment inside the pipelines has been limited due to its lack of economical efficiency. Economical development of inspection equipments is possible since RFECT method can be easily employed for system integration and quantitative evaluation of both inside and outside defects. In this study, the development of underground pipeline inspection system was tarried out by using RFECT method in consideration of the characteristics of waterline network. This paper specifically describes the design and production of RFECT pipeline inspection pig using centralizer mechanism, development of remote field eddy current signal acquisition and processing software, and review of RFECT system operation procedures.

• Polymer(Korea)
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• v.29 no.1
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• pp.69-73
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• 2005

To overcome the main disadvantages of non-viral gene delivery systems such as repeated administration due to the low transfection efficiency, poly(D,L-lactide-co-glycolide) was applied to encapsulate pDNA in its microsphere formulation. Free pDNA or various ratios (w/w) of chitosan/pDNA complexes was used for encapsulation, with the resulting encapsulation efficiency of 44%, 5%, and 8% for free pDNA, 0.7:1 and 1:1 ratios, respectively. Scanning electron micrographs of poly(D,L-lactic-co-glycolic acid) (PLGA) microspheres encapsulating pDNA or chitosan-condensed pDNA revealed a smooth spherical shape immediately after microsphere preparation and a collapsed porous shape in 41 days due to the degradation of PLGA. In vitro release profile showed that the 0.7:1 (w/w) ratio formulation exerted 47% release in 26 days, whereas free pDNA or 1:1 (w/w) ratio formulation did only 15% or 32%, respectively.

• 한국가스학회:학술대회논문집
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• 1997.09a
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• pp.284-291
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• 1997

배관망의 해석은 유체역학을 필요로 하며 관내의 유체의 거동과 운전 상태에 따른 유동해석을 위해 여러 식들이 사용되어왔다. 본 연구에서는 정상상태의 유량방정식을 사용해 경인지역가스 배관망에 대한 수학적 모델을 만들고 모사 및 분석을 수행하였다. 개발된 수학적 모델에서 얻어진 데이터에 통계학적인 방법을 도입해 통계학적 모델을 만듦으로써 통계학적 모델을 이용한 배관망 해석의 가능성에 대해 검토하였다.

• Journal of Chest Surgery
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• v.32 no.8
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• pp.768-771
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• 1999

A 45 year old man was admitted for further examination of an abnormal shadow of the right posterior mediastinum. The patient suffered from dysesthesia in the right thoracic wall of dermatome T7. CT scan and MRI revealed that two separate tumors had developed in the right paravertebral area linked to the vertebral canal via an intervertebral foramina. One-stage removal of the tumors were performed safely through the right posterolateral thoracotomy following the resection of the rib head and vertebral pedicle. The tumors were confirmed as histologically neurilemomas. The postoperative course was uneventful.

• Journal of Advanced Marine Engineering and Technology
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• v.18 no.1
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• pp.41-50
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• 1994

동심 이중관내에서 외관내벽의 사각돌출형 조도요소에 의한 비대칭 난류유동과 열전달 특성을, 열전달과 마찰계수에 미치는 조도의 합성효과를 조사하기 위해, 연구하였다. 이론해석에서는 수정 플란틀 혼합길이(mixing length)이론의 난류모델을 속도분포와 마찰계수를 구하는데 사용하였다. 최대 속도지점에서 안쪽과 바깥쪽의 두 속도 형상들은 힘의 평형에 의해 일치시켰다. 그리고나서, 온도분포와 열전달 계수를 계산하였다. 속도형상과 마찰계수들의 해석결과는 반경비 (${\alpha}$)= 0.13, 0.26, 0.4, 그리고 0.56 경우의 실험과 매우 잘 일치하였다. 마찰계수와 Nusselt number에 미치는 반경비, 조도비, 그리고 조도에 대한 피치비 등과 같은 여러 변수들의 효과들을 조사하였다. 본 연구는 일정 조도 요소들이 전체적 효율 측면에서 볼 때 열전달을 우리하게 향상시킨다는 것을 증명하였다.

• YAKHAK HOEJI
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• v.44 no.5
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• pp.424-431
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• 2000

A biopharmaceutics drug classification system for correlation between in vitro dissolution and in vivo bioavailability is proposed based on recognizing that drug dissolution and gastrointestinal permeability are the fundamental parameters controlling the rate and extent of drug absorption. The objective of this study was to assess whether in vitro dissolution profiles of immediate-release beta-blocker tablets can be correlated with intestinal membrane permeability and/or in vivo bioavailability In vitro dissolution of the beta-blocker tablets was examined using KP VII Apparatus II methods at various pH. Intestinal membrane permeability was determined in vitro using the diffusion chamber method. Bioavailablity parameters were cited from literatures. The dissolution profiles did not accurately represent the in vivo bioavailablity However there were good correlations between intestinal membrane permeability and log P (noctanol/buffer). The correlations obtained in this study indicated that in vitro diffusion chamber method could be used to predict intestinal absorption in vivo.

• Clinical and Experimental Pediatrics
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• v.46 no.6
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• pp.572-575
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• 2003

Purpose : This study was performed to analyze the endoscopic findings in Henoch-Schonlein purpura patients, and to compare the differences in endoscopic findings according to age and gastrointestinal symptoms. Methods : We examined children with Henoch-Schonlein purpura aged 3 to 15 years between September 1996 and October 2002. The total number studied was 65, consisting of 41 boys and 24 girls. Endoscopy was performed and the results were analysed. Results : Among 65 cases, 12 cases of duodenitis, nine cases of gastritis and duodenitis, six cases of duodenal erosion, five cases of gastritis, five cases of duodenal ulcer, two cases of gastric ulcer and one case of colonic erosion were noted. Endoscopic abnormality was found in 38 of 53 who had gastrointestinal symptoms, and in two of 12 who didn't have gastrointestinal symptoms. Conclusion : Most of the gastrointestinal symptoms in Henoch-Schonlein purpura patients were relieved without complication. But in some cases severe symptoms such as hematemesis, melena, and abdominal pain localized to epigastric area were developed when diagnosis was delayed. Prompt endoscopy will be helpful for diagnosis and therapy of Henoch-Schonlein purpura with gastrointestinal involvement.

• Journal of Yeungnam Medical Science
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• v.18 no.1
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• pp.75-84
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• 2001

Background: The accidental swallowing of foreign body is a common problem in the children. Ingested foreign bodies may be managed by endoscopy, observation, or surgery. So we analyzed the methods of removal, type, location and complications of foreign bodies. Materials and Methods: This report reviewed 37 cases of ingested foreign body in the gastrointestinal tract at the Department of Pediatrics, Yeungnam University Hospital between January 1997 and April 2001. Results: The age ranged from 8 months to 8 years. The most prevalent age group was between 1 year and 2 years of age(19%). The male to female ratio was 2.1:1 with 25 male and 12 female patients. The type of foreign bodies were coins in 20 cases(54%), nail in 4 cases(11%), key in 4 cases(11%), pin in 2 cases(5.5%), necklace in 2 cases(5.5%) and others. The locations of foreign bodies were upper esophagus in 12 cases(32.5%), lower esophagus in 4 cases(10.8%), stomach in 16 cases(43.2%), small bowel in 5 cases(13.5%). 4. Presenting symptoms were variable with asymptomatic(59.4%), vomiting(19.0%), epigastric pain(8.1%), dysphagia(5.4%) and others. The methods for removal of foreign bodies included 20 cases of endoscopic removal(54.0%). 3 cases of spontaneous removal(8.1%) and there was no surgical removal. 14 cases(37.9%) did not confirmed removal of foreign body because of no revisit of our hospital. Endoscopic finding of patients were normal(15 cases), ulceration(2 cases), erosion(1 case), inflammation(1 case), mucosal scratch(1 case). Conclusion: It appears that the endoscopic approach is the preferable method for the removal of upper gastrointestinal foreign bodies in the children.

• Journal of Digestive Cancer Research
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• v.3 no.1
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• pp.35-38
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• 2015

62-year-old patient who had past history of endoscopic submucosal dissection for early gastric cancer at September 2008, underwent endoscopic submucosal dissection of esophagus for early esophageal cancer at mid esophagus during health screening service. Because there was a high risk of lymph node metastasis at biopsy results, concurrent chemoradiotherapy was added to endoscopic submucosal dissection. There was a metachronous cancer at mid-esophagus at March 2013. He underwent endoscopic mucosal resection and photodynamic therapy. Concurrentchemoradiotherapy after endoscopic submucosal dissection is an effective treatment method.

• Journal of Chest Surgery
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• v.30 no.4
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• pp.453-456
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• 1997

Acquired tracheoesophageal fistula is a rare but serious condition which is usually a result of prolonged intubation or tracheostomy statc, and is difficult to treat. A fifty-seven year old woman who was in a state of prolonged intubation and tracheostomy following a traf%c accident, presented with recurrent aspirati n. A tracheoesophageal fistula was demonstrated ) cm above the carina by csophagogram. We confirmed a subglottic web and tracheoesophageal fistula by bronchoscopic examination. Fistulectomy was performed with collor incision and partial sternotomy. The esophagus was repaired by two-layer interrupted suture using 4-0 Vicr)1, and the trachea was repaired by single layer suture using a 4-0 PDS. The sternohyoid muscle was interposed between the trachea and the esophagus. A T-tube was inserted through the previous tracheostomy site for easy tracheal suction and maintenance of the tun:on. The T-tube was removed on the 14th postoperative day, and the patient recovered well without any complications.