스테인레스 강(304) 표면에 형성된 부동상태 피막의 조성

안윤선,이경철,지홍근 성균관대학교 기초과학연구소 1989 論文集 Vol.40 No.2

스테인레스 강(304) 표면의 부동상태 성질을 규명하기 위해서 "as received" 상태 표면과 CrO_3/H_2SO_4 용액으로 활성화시킨 표면을 Ar이온으로 깍아 내려가면서 ESCA로 표면원소들의 조성 및 산화상태를 측정하였다. 지금까지의 많은 보고와는 달리 "as received" 상태에서는 O₂분자가 표면층에 깊숙히 침투되어 있음을 발견하였다. 이것은 부동상태 산화피막의 형성과정이 크롬과 철의 상대적 확산 속도차에 의해서도 다르지만, bulk 속으로 산소가 확산되어 들어가는 정도에도 의존함을 나타내는 것이다. In order to study the passive state of stainless steel(304, austenite), the depth profile of surface composition as well as its oxidation state has been investigated by means of X-ray photoelectron spectroscopy. The study has been carried both on a "as received" state surface and surface activated in CrO_3/H_2SO_4 solution. Its has been found contrary to the previous works that a considerable molecular oxygen are penetrated deep into the oxide layer. This is an indication that the passive state oxide- film formation depends not only on the relative diffusion rates of chromium and iron, but also on the diffusion rate of oxygen into the hulk.

남강댐 상류유역의 유출량과 오염부하량의 관계

김옥선,김홍철,김종오 경상대학교 환경보전연구소 2000 環境保全硏究所報 Vol.8 No.-

The purpose of this study was to analysis the pollutant loading to Chinyang Reservoir according to the variation of outflow. Regression equation of the pollutant loading and outflow was represented as L=a Qb. L: pollutant loading(㎏/day), a.b: regression coefficient. Q: outflow(㎡/day). R2 of Sanchung. Shinan and Changchon site was 0.8376∼0.9818. Therefore the pollutant loading was correlated with outflow. Changchon site had minimum b value because outflow of pollutant was little compared with rainfall. The pollutant loading of SS was much affected by outflow because SS was the highest b value 1.621∼1.7834 among water quality parameters. Also. the pollutant loading and the pollutant loading unit per area were calculated in case of a dry season. an abundant season and a flood season. The pollutant loading in an abundant and a flood season except a dry season was ranked Sanchung. Shinan and Changchon site in order.

中學校 科學科의 實驗實習敎材의 開發硏究Ⅱ

朴泳喆,韓麟傳,李春雨,權寧駿,朴弘緖 공주대학교 사범대학 과학교육연구소 1982 과학교육연구 Vol.14 No.1

In this study a few laboratory teaching materials have been developed to be available for the effective performance of experiments and practices- a heart of inquiry learning-as a continuance of 'A study on the Development of Laboratory Teaching Materials for Middle School Science Course I' The present condition of science education has been investigated by means of questionaires, interviews and literature, the results of the present condition and problems in junior high schools are as follows: 1. The hours for science classes are considerably little for the teaching contents of science textbooks. 2. The level of teaching is beyond the student's capability in terms of their experience and intellectual development. 3. Science teachers are overburdened with much tasks, and laboratories and laboratory facilities are too insufficient and furthermore teaching is mainly conducted on the lecture method as a preperation for various entrance exams. 4. Teachers' eagerness and desirable attitude for teaching are required. In this study, materials for every branch of science have been developed to be available for the effective performance of experiments and practices through inquiries. The materials developed in this study are as follows: 1. In physics, measure apparatus of extremely small masses, length, and very little time intervals are developed. 2. In chemistry, new methods for gas generating apparatus and materials. are developed. 3. In biology, the size of quadrate and the method to decide the time in facilitating for the purpose of survey of botany community are introduced. The results of the investigation of natural enemy on Hyphantria cunea, and the study on collecting, breeding of Planaria are also shown. 4. In earth science, the laboratory teaching materials are developed for observing continuous spectrum and line spectrum. Putting the above results of study together, the suggestions are made to the effect as follows: 1. The quantity of learning should be reduced and the levels lowered in the new textbooks. 2. The development and distribution of various teaching materials(film, T,P., cassettes film, supplementary, textbook, program teaching material, individual learning material) is required. 3. The experimental instruments should be timely manufactured and distributed on the basis of effective administrative support to ensure their solidity and accuracy. 4. The concrete design to eliminate the teacher's burden should be contrived and the system for senion teachers in charge of science teaching in secondary schools, should be improved. 5. Teacher's research activities should be encouraged through various research institutes(Institute of science education , graduate school of education and the other research institutes.) 6. The disposition of laboratory assistant should be considered. 7. More positive supports from other societies relevant with education are much expected to be made.

지방공업화 추진과 영동지역 특성산업

박철환,김명호,김선홍 강릉대학교 영동산업문제연구소 1990 産經論叢 Vol.12 No.-

텐돈의 긴장력 손실에 따른 프리스트레스 콘크리트 격납건물의 거동해석

진재철,전영선,이홍표 충남대학교 산업기술연구소 2000 산업기술연구논문집 Vol.15 No.1

The prestressing force of tendon can be decreased by creep of concrete, shrinkage of concrete and relaxation of steel. In this paper, we describe some primary causes of time-dependent losses of prestressing tendon force. New stress reduction model is proposed to predicit time-dependent losses of prestressing tendon force in accurate way. It should be noted that the proposed model is based on the data, which are accumulated from the in-service inspection of posttensioned cotainment building system. Using the new stress reduction model, we carry out finite element analysis to investigate how the losses of prestressing force effect to the structural behaviour of containment building. From FE analysis with new stress reduction model, concrete creep appears as the primary factor which can influence the reduction of prestressing tendon force. It also appears that the relaxation of steel as the secondary influencing factor and shrinkage of concrete as the tertiary factor.

붕소확산에 의한 산화적층결함의 후면게터링

朴善宇,洪淳寬,金鐵柱 서울市立大學校 1991 論文集 Vol.25 No.-

The backside gettering phenomena of OSFs which are generated at the Si-SiO₂interface during the oxidation is observed. After the backside boron diffusion at 1200℃ for 120min, the OSFs' density on the Si(100) front surface is reduced from 10?cm-²to about 20cm-²or below. In addition to, the rate of decrease of the OSFs' density is deduced experimentally as a function of the boron diffusion time and temperature.

안정처리 되지 않은 지반 상에 건설되는 농로의 안정성 평가

문홍득,박순철 진주산업대학교 산업과학기술연구소 2007 산업과학기술연구소보 Vol.- No.14

Recently, many road construction is being performed in country side to wide the existing small agricultural road. In this case, the road is designed without the exact site investigation because of financial reason of regional government. So in some case, the road is designed on soft soils and has many problems in the process of construction. Especially agricultural road which needs to wide the existing small road overlying on the untreated soft soil is planned without the site investigation. In this case, the enlarged road will have the problems such as excess settlement or shear failure of road. In the process of designing and constructing structures on soft soils, we need to consider whether the soil properties can be economically improved. In this study, a case study was performed for the stability analysis of agricultural road overlying on the untreated soft soil. Soil tests were performed to investigate soft soil properties and plate bearing test was performed to find the bearing capacity of subbase and subgrade. Numerical analysis was also performed to evaluate the stability of new planning road overlying on the untreated soft soil using commercial soft ware which is used to analyze the consolidation settlement. We found that the new planning road overlying on the untreated soft soil has consolidation settlement in excess of the allowable settlement criteria. After evaluating the several methods available for the improvement of the engineering properties of soft clays of this site, the replacement method as safe and economical method was selected and analysed. We conclude that in case of designing new road to wide the existing small agricultural road, site investigation should be necessary and then road have to be designed rationally in according to the site soil conditions.

호흡기감염증에 대한 Cefuroxime Axetil(Zinnat�)의 임상효과

김주옥,홍석철,김남재,서지원,김선영,노흥규 中央醫學社 1991 中央醫學 Vol.56 No.2

To evaluate the efficacy and safety of Zinnat in patients with respiratory tract infections, 20 patients were treated with Zinnat (250 mg b.i.d). Among 20 cases, 5 cases had pneumonia, 5 cases exacerbation of chronic bronchitis, 4 cases acute bronchitis, 3 cases bronchiectasis with infection, and acute tonsilitis, bronchial asthma with infection and emphysema with infection 1 case, respectively. The response was cure in 12 cases, partial response in 6 cases and no response in 2 cases. There were no significant clinical and laboratory side effects except dyspepsia and nausea (1 case) and diarrhea (1 case). Zinnat was considered to be useful agent against bacterial respiratory tract infections.

고온 리튬용융염계에서 오스테나이트 스테인레스강의 부식거동

조수행,홍순석,오승철,박성원 한국공업화학회 2003 응용화학 Vol.7 No.2

In the development of the advanced spent fuel management process based on the molten salt technology, it is essential to choose the optimum material for the process equipment handling molten salt. As a part of assessment and application of the structural material for the molten salt handling system, corrosion behavior of 304, 304L and 316LN in the molten salts was investigated. Corrosion proceeded via three steps; the formation step on corrosion product in which rapid corrosion takes place until stable corrosion product is formed after the beginning of corrosion, the protection step against corrosion until breakaway occurs after the formation step of stable corrosion product and the advancing step of corrosion after the breakaway. In a molten salt of LiCl-8%Li₂O, the final oxide scales of Li₂Ni_(8)O_(10) were formed, and also Li₂Ni_(8)O_(10) in the molten salt of LiCl-8%Li₂O-1%Li_3N.

한국의 C형간염바이러스 RNA 양성인 간질환자 및 건강 공혈자에서의 C형간염바이러스 유전자형의 분포양상

이진경,홍석일,황유성,이선호,민원기,성영철,이동순 대한임상병리학회 1996 대한임상병리학회지 Vol.16 No.4