• 연구논문집
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• 통권31호
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• pp.149-156
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• 2001

Hydrogen damage affects carbon steel tubes in many fossil-fuel-fired boilers, often causing large tube ruptures that necessitate an immediate shutdown. Therefore, equipment handling high-temperature, high-pressure hydrogen must undergo careful periodic inspection because of its susceptibility to hydrogen attack. This paper describes the application of an ultrasonic technique for detecting the presence of hydrogen damage in utility boiler tubes. The accuracy of the technique has been shown in laboratory tests. However, it is difficult to evaluate hydrogen attack quantitatively by this technique, because ultrasonic wave is influenced by the test conditions and the material itself.

• Clinics in Shoulder and Elbow
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• 제26권3호
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• pp.222-230
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• 2023

Background: Distal biceps tendon repairs are commonly performed using open techniques. A minimally invasive distal biceps tendon repair technique using a speculum and hooded endoscope was developed to improve visualization, reduce soft-tissue dissection, and minimize complications. This paper describes the technique and reports the outcomes of 75 minimally invasive distal biceps tendon repairs. Methods: The operation reports and outcomes of 75 patients who underwent distal biceps tendon repair using this technique between 2011 and 2021 were retrospectively reviewed. Results: Median time to follow-up was 12 months (interquartile range [IQR], 6-56 months). Primary outcomes were function as measured by the Disabilities of Arm, Shoulder and Hand Score (DASH) questionnaire, and rate of complications. Median DASH score was 1.7 of 100 (IQR, 0-6.8). There were 2 of 75 (2.7%) re-ruptures of the distal tendon. There were no cases of vascular injury, proximal radius fracture, or posterior interosseous nerve, median, or ulnar nerve palsy. Conclusions: In this series, minimally invasive distal biceps repair was safe and effective with a low rate of major complications. Recovery of function, as indicated by low DASH scores, was satisfactory, and inconvenience during recovery was minimized. Level of evidence: IV.

• Journal of Chest Surgery
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• 제33권1호
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• pp.79-84
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• 2000

Background: Esophageal perforation is an extremely lethal injury that requires careful management for survival,. Material and Method: We performed a retrospective clinical revi-ew of 14 patients treated for esophageal perforation at the Department of Thoracic and Cardiovascular Surgery hanyang University Hospital between July 1986 and August 1998. Cardiovascular Surgery Hanyang University Hospital between July 1986 and August 1998. Result: The ration between male and female patients was 12:2 and their ages ranged from 9 to 68 years( average: 446 years). Iatrogenic perforations were found in 6 patients(42.9%) spontaneous perforations in 3 patients(21.4%) traumatic perforations in 2 patients(14.3%) and caustic perforations foreign body origin and esophagel cancer in 1 patient (7.1%) each. Four of the patients(28.6%) had esophageal ruptures located cancer in 1 patient (7.1%) each. Four of the patients (28.6%) had esophageal ruptures located in the cervical esophagus and 10 patients (71.4%) in the thoracic esophagus, The most frequent location was in the mid third portion of the esophagus (35.7%) there were also 2 patients(14.3%) in the upper third portion and 3 patients(21.4%) in the lower third portion. Complications encountered included mediastinitis empyema or pleural effusion mediastinal or lung abscess sepsis and aspiration pneumonia. The most frequent complication that occurred was mediastinitis in 9 cases (57%) Three patients underwent conservative treatment. Among the patients who underwent surgical treatment 5 patients underwent primary closure 6 patients underwent open drainage and 2 patients underwent reconstrumction (1 patients had an initial primary closure and 1 patient had an initial open drainage procedure). The mortality rates for those with conservative and surgical treatment were 66.7% (2cases) and 9.1% (1 cases) respec- tively. Conclusion: Perforation of the esophagus although very rare has a high mortality rate and thus aggressive operative therapy is necessary.

• Clinics in Shoulder and Elbow
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• 제12권2호
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• pp.137-141
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• 2009

목적: 회전근 개의 하나인 견갑하근 단독 손상 시 봉합나사를 이용한 파열부 봉합술에 대해 문헌 고찰과 함께 그 결과를 알아보고자 한다. 대상 및 방법: 2001년 2월부터 2007년 10월까지 본원에서 견갑하근의 단독손상에 대해 봉합나사를 이용한 관절경적 처치를 시행한 29명의 환자를 대상으로 하였다. 전례에서 다른 회전근 개의 손상이 없는 견갑하근 단독 손상이었고, 견갑하근 손상의 범위는 상부 1/3인 경우가 19예, 상부 2/3인 경우가 7예, 완전 파열인 경우가 3예 였다. 평균 추시 기간은 12.2개월 (6~26개월) 이었다. 결과의 판정은 최초 내원 시점과 최종 추시의 constant shoulder score 결과를 비교하였다. 결과: 술후 constant shoulder score 는 술 전 평균 $49.9\pm7.3$ 에서 술 후 평균 $73.8\pm3.0$으로 constant shoulder score 중 pain points 는 술 전 평균 $4.3\pm3.2$ 에서 술 후 평균 $11.2\pm3.0$으로 향상되었다. 결론: 견갑하근의 단독손상 시 봉합나사를 이용한 견갑하근 봉합술은 좋은 치료방법 중 하나로 고려할 수 있다.

• 생물환경조절학회지
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• 제4권2호
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• pp.167-174
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• 1995

This study was carried out to find a way of improving the windproof capability of greenhouse foundations. Generally, greenhouses are often collapsed due to the strong winds, because they are very light weight structures. In such a critical situations, the foundations are very often subjected to uplift and vibration at the same time. This paper describes both the wind disaster of greenhouses by the typhoon FAEY and the uplift resistance of greenhouse foundations. Followings are the results obtained from this study ; Judging from the view point of year round cultural aspects, it is recommended that some measures be taken for the preventions of greenhouse film ruptures because greenhouse structural damages are found to be directly associated with the local rupture of cover film. In the case of surveyed area, movable pipe-houses or pipe-houses of 1-2W type were found to be completely destroyed when the maximum instantaneous wind velocity was over 30m/sec or so. In the case of movable pipe-houses, the uplift resistance of greenhouse was expected to increase with the increase of pipe diameter and/or the embedment pipe length. But at present situations there is a limitation in raising the uplift resistance of movable pipe-house, because pipe diameters as well as pipe lengths customarily selected by farmers are quite a much limited.

• 대한수학교육학회지:수학교육학연구
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• 제23권2호
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• pp.237-252
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• 2013

수학교육학 내의 논의에서 Bachelard의 과학철학은 인식론적 장애 개념을 중심으로 소개되어 있다. 그의 과학철학에서 인식론적 장애는 과학의 변증법적 발달과 연결되어 있다. 과학은 기존에 명백한 것으로 인식된 것을 부정하여 얻은 개념의 재구성과 일반화를 통해서 발달한다. 이 과정에서 기존의 인식에 대한 단절이 필요하다. 인식론적 장애는 재구성이 필요한 시점에서 기존의 것과 단절하지 못하고 고수함으로써 나타나내는 발달의 지연이며, 지식의 형성 혹은 학습 과정에 내재적인 어려움이 존재한다는 것을 의미한다. 이상과 같은 Bachelard 관점을 수학교육학에서 널리 적용되고 있는, '내면화-압축화-대상화'의 단계적인 반영적 추상화 도식과 비교하고 논의하였다.

• Journal of Chest Surgery
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• 제18권2호
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• pp.265-272
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• 1985

Congenital aneurysm of sinus of Valsalva is one of the rare congenital heart disease, which is usually asymptomatic until rupture. The aneurysm usually ruptures into a cardiac chamber and produces an aorto-intracardiac fistula. Ruptured aneurysm is a grave lesion in that it causes heart failure and subsequent death. If, however, it is discovered in its early stages and operated on properly, it can be corrected with considerable success. Form January 1975 through December 1984, 18 consecutive patients with congenital aneurysm of sinus of Valsalva underwent corrective surgery using total cardiopulmonary bypass in our department of Thoracic Surgery. 1. The incidence was about 0.9% of surgical cases of congenital heart disease during that period. 2. 13 were males and 5 females, with ages ranging 12 years to 52 years. 3. Associated anomalies were VSD in 14, infundibular PS in 1, aberrant muscle band in RVOT in 1, and secondary aortic insufficiency in 9. 4. 17 were suggested to arise from right coronary sinus and 1 from noncoronary sinus; Among 17, 12 ruptured into right ventricle, and one from noncoronary sinus into right atrium. 5. Surgical correction was performed by means of direct suture closure with combined pledget or patch graft after aneurysm resection, and associated lesions were also corrected simultaneously. 6. There was only one case of operative mortality, and all the other patients were relatively uneventful in their follow-up studies.

• Journal of Chest Surgery
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• 제18권3호
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• pp.407-413
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• 1985

Ruptured aneurysms of the sinus Valsalva are relatively rare, and the incidence seems to be higher in oriental than in western countries. Five patients underwent operative treatment in Catholic Medical Center in recent 2.5 year period. Three patients were male and two patients were female, ages ranged from 20 to 54 years. Bacterial endocarditis was suspected or proved in 3 patients. In 3 patients in our series had a ruptured congenital aneurysms and in 2 patients acquired aneurysms by bacterial endocarditis. Associated cardiac lesions were common; such as aortic insufficiency in 3 patients, atrial septal defect in 2 patients, mitral stenoinsufficiency in 1 patient and tricuspid insufficiency in 1 patient. All aneurysmal ruptures of the sinus Valsalva arose from right coronary sinus and in 4 patients ruptured into right ventricle and in 1 patient into right atrium. Surgical techniques consisted of direct closure 4 in patients and closure with Dacron patch in 1 patient. And we preferred double approach, that is, through both the aorta and the involved cardiac chamber in cases in whom aortic insufficiency was present. So additional aortic valve replacement performed in 2 patients due to severe aortic insufficiency and aortic valvuloplasty performed in 1 patient. One patient who underwent direct closure of ruptured sinus Valsalva and double valve replacement died due to low cardiac output syndrome just after the operation. Operative results were relatively good in remainders.

• Smart Structures and Systems
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• 제3권2호
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• pp.133-146
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• 2007

This paper addresses a new type of broad and stage-based hybrid carbon fiber reinforced polymer (HCFRP) sensor that is suitable for the sensing of infrastructures. The HCFRP sensors, a type of composite sensor, are fabricated with three types of carbon tows of different strength and moduli. For all of the specimens, the active materials are carbon tows by virtue of their electrical conductivity and piezoresistivity. The measurement principles are based on the micro- and macro-fractures of different types of carbon tows. A series of experiments are carried out to investigate the sensing performances of the HCFRP sensors. The main variables include the stack order and volume fractions of different types of carbon tows. It is shown that the change in electrical resistance is in direct proportion to the strain/load in low strain ranges. However, the fractional change in electrical resistance (${\Delta}R/R_0$) is smaller than 2% prior to the macrofractures of carbon tows. In order to improve the resistance changes, measures are taken that can enhance the values of ${\Delta}R/R_0$ by more than 2 times during low strain ranges. In high strain ranges, the electrical resistance changes markedly with strain/load in a step-wise manner due to the gradual ruptures of different types of carbon tows at different strain amplitudes. The values of ${\Delta}R/R_0$ due to the fracture of high modulus carbon tows are larger than 36%. Thus, it is demonstrated that the HCFRP sensors have a broad and stage-based sensing capability.

• 한국식품과학회지
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• 제13권2호
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• pp.101-106
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• 1981

균류의 세포벽은 복합 다당류의 매우 견고한 막으로 되어있기 때문에 균체의 이용이나 세포막 관련성 효소연구등에 직접적으로 방해가 되어왔기 때문에 이의 제거를 위해 본 실험에서는 Trichoderma viride $TO_4$ 균주에서 얻은 섬유소 가수분해효소와 토양에서 직접 분리한 Streptomyces sp. 115-5균주에서 얻은 chitinase를 혼용하여 각종 균사체에 작용시켜 세포벽의 제거정도에 따른 원형질체 생성을 균체별로 측정하여 그 결과를 얻었다. (1) Ascomycetes 류에서는 반응 3시간후 $3{\times}10^{7}$개의 원형질체가 생성되었다. (2) Zygomycetes류에서는 반응 3시간후 $9{\times}10^7$개의 원형질체가 생성 되었다. (3) 효모류는 이 혼합효소작용에 대하여 별다른 반응을 나타내지 않았다.