STS316L 용접부의 피로거동 및 초음파시럼에 의한 열화특성 평가

남기우,박소순,안석환,도재윤,박인덕 한국비파괴검사학회 2003 한국비파괴검사학회지 Vol.23 No.2

STS316L은 인성, 연성, 부식저항성 등 우수한 기계적 성질 때문에 에너지환경설비 등 구조물에 널리 이용되고 있다. 그러나, 용접구조물은 가혹한 환경하에서 경년열화가 심각하다. 지금까지의 연구들은 주로 용접부의 피로균열진전거동에 관하여 수행되었고, 피로균열진전속도식의 재료상수와 비파괴적 평가의 상관성에 관한 연구는 거의 없었다. 본 연구는 STS316L 용접부의 피로균열진전 거동을 조사하고, 초음파 파라미터로 열화특성을 평가하고 시간-주파수 분석으로 해석을 하였다. 본 연구 결과는 용접구조물의 사용기간 중 피로수명 등을 예측하기 위한 기초 데이터로서 사용될 수 있다. STS316L had been used as the structural material for energy environmental facilities, because austenite stainless steels like 316L have superior mechanical properties of which toughness, ductility, corrosion resistant and etc. However, those welded structures are receiving severe damage due to increasing of the aged degradation. Most studies until now have been carried out against fatigue bahaviors of weldments, and were not well studied on nondestructive evaluation methods. In this study, the fatigue crack propagation behavior of STS316L weldment usually used for vessels of the nuclear power plant was investigated. Also, the degradation characterstics of 316L stainless steel weldments were evaluated by the ultrasonic parameter such as ultrasonic velocity, attenuation factor and time-frequency analysis. The results of this study can be used as a basic data for the prediction of the fatigue crack life of weldments structures without disjointing or stopping service of structures in service.

타이어 설계인자를 고려한 자동차의 조종 및 안정 특성에 관한 연구

윤성운,홍석주,최규남 朝鮮大學校 機械技術硏究所 2004 機械技術硏究 Vol.7 No.2

As the technique of automobile industry is being advanced, the advancement of performance for vehicle is being required. In order to achieve this purpose, the study on the handling and stability which are produced by moving vehicle is carried out actively. Ability to predict vehicle performance using computer simulation is essential to reducing the development time for tire companies as well as car makers. From the previous research. we showed that handling simulation tool developed for J-turn and lane change maneuvers on ADAMS could be used in predicting the performance difference among tires with different specifications in vehicle mild handling behaviors. Through this study, some meaningful correlations were achieved. Also barriers to direct application of the simulation technique to tire development process and several technical problems that should be resolved were iden tified. In this results, ability to predict vehicle performance using computer simulation is essential to reducing the development time for tire companies as well as car makers.

Plus(+) Point Probe를 이용한 용접부 와전류검사

윤병식,남민우,김석곤,이희종,김용식 韓國非破壞檢査學會 1999 한국비파괴검사학회지 Vol.19 No.6

발전설비를 구성하는 주요 기기중 펌프, 발브, 배관 등의 용접부에 발생할 수 있는 균열 등의 결함을 검출하기 위한 plus-point 와전류검사탐촉자를 설계하여 결함을 검출하고 그 크기를 측정할 할 수 있는 검사기법을 연구하였다. 차동형 모드로 운전되는 plus-point 와전류탐촉자는 2개의 "I"자형 코일 이 십자형태로 교차되어 있으며, 탐촉자와 시험체 표면사이의 lift-off변화에 의한 영향이 재래식 표면 탐촉자에 비해서 작게 발생하는 특징이 있다. 결함에 대한 탐촉자 반응을 평가하기 위해서 304 스텐 인레스강 용접부에 인공결함인 균열성 노치를 방전가공하여 시험편을 제작하였으며, 이를 활용하여 plus-point 와전류탐촉자의 결함 검출, 종류 판별 및 크기를 측정할 수 있는 기법을 연구하였다. A plus-point eddy current test(ECT) probe was developed to examine the defects on the welds of pumps, valves, and pipings which are the major components of the electric power plants. non-destructive evaluation(NDE) techniques for detecting and sizing the flaws were studied adapting this probe. Differential plus-point ECT probe is consists of two "I"-type coils crossed each other and has an advantage having a small influence on the sensitivity by lift-off variation to the conventional types of probe. The specimens with crack-like electro dischrge machining(EDM) notches on the weld of type 304 stainless-steel were fabricated in order to evaluate the plus-point ECT probe response to the flaws. NDE techniques to detect and size the flaws and estimate the flaw type were established with this specimens.

하악골 골절 환자에 있어 수술후 합병증으로 발생한 골수염의 치험례

윤규호,전인성,신용길,박준호,허남오,방석준 大韓顎顔面成形再建外科學會 1996 Maxillofacial Plastic Reconstructive Surgery Vol.18 No.4

The term osteomyelitis literally means inflammation of bone marrow. It is described as an inflammatory condition of bone primarily engaging the medullary Following circulatory collapse and ischemia, the involved portions of the bone become necrotic. Cellulitis and osteomyelitis are the most frequent complications of fractures of the mandible and maxilla, because there is an abscessed tooth in the line of fracture. Since most fractures are compound fractures, infection may develop because of contact with oral secretions or outside air. The treatment of chronic osteomyelitis is still under debate. Some authors rely on antibiotics alone, while others advocate combination with surgery. But when infection occurs, establish proper drainage and administer antibiotics. Author treated a case of infected mandibular fracture with mandibular osteotomy, sequestrectomy, iliac bone graft and hyperbaric oxygen therapy, who had suffered suppurative osteomyelitis and mandibular nonunion following the open reduction of the mandibular fracture.

초등학교 교육과정과 교과서에 농업·농촌의 기능 및 가치 반영 방안

서우석,강대구,정남용,김재호,이윤조 한국농업교육학회 2006 농업교육과 인적자원개발 Vol.38 No.4

이 연구는 농업ㆍ농촌의 기능과 가치를 재정립하고 이를 초등학교 교육과정 및 교과서에 반영시킬 수 있는 방안을 제시하는데 그 목적이 있었다. 이를 위하여 먼저 선행연구 고찰을 통하여 농업ㆍ농촌의 기능과 가치를 재개념화하고, 이를 토대로 내용 분석 틀을 개발하여 초등학교 교육과정 및 교과서를 분석 하고, 그 결과를 토대로 교육과정 및 교과서에 반영시키기 위한 방안을 제시하였다. 그 주요 결과는 다음과 같다. 첫째, 농업ㆍ농촌의 기능과 가치는 크게 자연환경적 기능(수자원 함양 기능, 환경정화 기능, 생태계 보전기능, 자연재해 방지 기능), 사회문화적 기능(전통문화 보전 기능, 정서의 순화 기능, 자연학습의장 제공 기능), 사회경제적 기능(농산물 공급 기능, 직업 기회 제공 기능, 국토의 균형발전 기능, 타 산업에의 기여 기능)으로 분류하였다. 둘째, 농업ㆍ농촌의 기능과 가치를 바탕으로 초등학교 교육과정 및 교과서를 분석한 결과, 전 학년에 걸쳐서 자연학습의 장 제공 기능과 전통문화 보전 기능이 높게 나타났고, 그 다음으로는 농산물 공급기능과 정서순화기능이 높게 나타났다. 반면에 수자원함양기능과 환경정화기능은 상대적으로 낮게 나타났다. 셋째, 내용분석을 토대로 교과의 성격을 고려하여 각 교과별로 농업ㆍ농촌의 기능과 가치를 반영시킬 수 있는 방안을 제시하였다. 마지막으로, 각 교과별로 농업ㆍ농촌의 기능과 가치 반영 방안을 체계적으로 이행하기 위한 행ㆍ재정적 지원 방안을 교육과정 개발 측면, 교과서 개발 측면, 교육과정 운영측면, 정책적 지원 측면으로 구분 하여 제시하였다. The purpose of the study is to suggest the strategies for incorporating the roles and values of agriculture & rural areas as a part of the national curriculum and elementary school textbooks. For this purpose, this study was conducted as follows; First, we reclassified the roles and values of agriculture & rural areas after critically reviewing literature: environmental conservation functions, socio-cultural functions and socio-economic functions. Second, based on the new classification, we develop a framework for analyzing the national curriculum and elementary school textbooks. The functions of rural areas as places for learning about nature and purifying emotion and the importance of agriculture in providing agricultural product were frequently presented but the functions of sustaining water resources and environmental purification were relatively less presented in the national curriculum and elementary school textbooks. Third, we suggested strategies for incorporating the roles and values of agriculture & rural areas in the national curriculum and elementary school textbook based on the analysis. Finally, we suggested necessary administrative and financial assistance to systematically and effectively implement the suggested strategies for developing a new curriculum and textbooks as well as implementing the curriculum.

마취흰쥐에서 天麻鉤藤飮의 心血管作用에 對한 硏究

배남규,문석재,임동윤,권오성 대한본초학회 1997 大韓本草學會誌 Vol.12 No.2

The present study was attempted to investigate the cardiovascular effects of Cheonmagudeumg-Eum (CMGDE), which is known to be one of chinese medical prescriptions used in treatment of hypertension, in the anesthetized rats and to clarify the mechanism of its pharmacological action, making use of its water extract. 1. CMGDE (5-45 ㎎/㎏), given into a femoral vein of the rat, produced a dose-dependent hypotensive and bradycardic responses while even much larger doses of it (10-90 ㎎/㎏), given into the rectum, did induced negligible hypotensive responses. 2. CMGDE-induced depressor responses were inhibited greatly by pretreatment with phentolamine (an adrenergic α-receptor antagonist), but not by pretreatment with atropine (an antimuscarinic agent) and chlorisondamine (an autonomic ganglionic blocker). 3. Pressor responses evoked by intravenous norepinephrine were attenuated significantly by pretreatment of CMGDE-infusion with a rate of 45㎎/㎏/20min. 4. In the rat aortic strips, phenylephrine (an adrenergic α1-receptor agonist) and high potassium (a membrane depolarizing agent) caused potent contractile responses, respectively. However, in the presence of CMGDE (2㎎/㎖), the contractile responses of phenylephrine (10-5M) and high potassium (5.6×10 exp (-2)M) were markedly inhibited. Taken together, these experimental results suggest strongly that Cheonmagudeung-Eum may cause the hypotensive responses in the anesthetized normotensive rat, indicating that this cardiovascular effects of CMGDE is likely due to the blockade of adrenergic α-receptors without cholinergic effects.

외측 미칩 갑상선에서 발생하여 다발성 전이로 발현된 유두상 갑상선암 1예

천남일,이창훈,홍세인,정진욱,윤인석,조동혁,강호철,정동진,정민영 대한내분비학회 2001 Endocrinology and metabolism Vol.16 No.4-5

장기입원환자 관리 방해요인

이경석,윤석만,권희,이호,김혜경,조미자,한규남,김명성 순천향의학연구소 2003 Journal of Soonchunhyang Medical Science Vol.9 No.1

Background: Recently the health insurance review agency tried to cut off the cost of unnecessary hospital stay. It is important to reduce the prolonged occupation of the hospital beds. However, there are some obstacles of the management for the prolonged bed occupation. We report our experiences and the problems of bed-control. Methods: To increase the rate of effective bed-usage, a task force was made. This team was consisted of 4 dctors, 2 nurses and 2 personnel of the administrative department. From December 20th 2001 to May 17th 2002, the task force analysed the rate, number and causes of the prolonged (more than 60 days, regardless of the disease entities) bed occupation. We announced and explained the necessity of bed-control and actively pressed to reduce the prolonged bed occupation. Results: The number of the prolonged bed occupation was 71 at the beginning of the management. It was reduced to 46 at best, then turned back to 65 at the end. It seems to be impossible to reduce the prolonged bed occupation until there are sufficient numbers of long-term care facilities. Aggressive bed control makes the sick patients to move every two or three months, it is never desirable. Conclusion: We cannot expect any Quality Improvements without improvement of the wrong system. Prior to the management for the prolonged bed occupation, it is necessary to build a sufficient number of long-term care facilities.

천연 제올라이트를 이용한 고농도의 칼슘이온 제거 : 이온교환속도 및 이온교환능 Kinetics and Isotherm

안봉규,오재일,윤석민,임남웅 대한상하수도학회 2003 상하수도학회지 Vol.17 No.1

The concentrated calcium removal from industrial wastewater by natural zeolite was examined to reduce inhibitory effects of those ions on the biological treatment in down-stream. It is well known that natural zeolite possesses good cation exchange capacity. Kinetic studies by using a batch-type methods demonstrated that the adopted particle size(1-2, 2-2.8, 2.8-4㎜) of zeolites showed similar exchange trends of calcium ions and showed relatively fast exchange reaction within 1 hour in spite of various zeolite dosages. The influence of the temperature on the ion-exchange capacity (isotherm) was examined. It was found that calcium exchange capacity(4.464㎎-Ca^2+/g-zeolite) at low temperature of 5℃ was double up to 9.225㎎-Ca^2+/g-zeolite at the range of 22-40℃. However, ion exchange efficiencies were similar at each condition of pH 6,7,8,10.

횡문근 융해증의 Tc-99m Methylene Diphosphonate 신티그라피 소견

한창진,박찬희,윤석남,배문선,김수지,신규설 아주대학교 1997 아주의학 Vol.2 No.2

Many causes of rhabdomyolysis have been reported in the literature. Technetium-99m methylene dipho-sphonate (Tc-99m MDP) bone scintigraphy is considered to be the most sensitive and effective modality in defining the extents of disease involvement and follow-up of patients with rhabdomyolysis. In this paper, we reviewed two cases of generalized rhabdomyolysis related to seizure activities and two cases of localized rhabdomyolysis related to an excessive exercise. In addition other causes of rhabdomyolysis and possible mechanisrns of Tc-99m MDP uptake are discussed briefly.