곰솔(Pinus thunbergii )에서 소나무재선충병 예방을 위한 나무주사용 약제선발

이상명(Sang Myeong Lee),김동수(Dong Soo Kim),이상길(Sang Gil Lee1),박남창(Nam Chang Park),이동운(Dong Woon Lee) 한국농약과학회 2009 농약과학회지 Vol.13 No.4

템퍼링된 2상 조직강의 준정적 및 동적 변형거동 연구

이한상,황병철,이성학,이창길,김성준 대한금속재료학회 2004 대한금속·재료학회지 Vol.42 No.2

Effects of martensite morphology and tempering on quasi-static and dynamic deformation behavior of dual phase steels were investigated in this study. Dynamic torsional tests were conducted on six steel specimens, which had different martensite morphology and tempering effect, using a torsional Kolsky bar, and then the test data were compared via microstructures, tensile properties, and fracture mode. In the intermediate annealed (IA) specimens, small martensites were well distributed in the ferrite matrix, but bulky martensites were mixed with ferrites in the step quenched (SQ) specimens. Under a dynamic loading condition, the fracture mode of SQ-specimens was changed from cleavage to ductile fracture as the tempering temperature increased, whereas IA-specimens had a ductile fracture mode, irrespective of tempering. These phenomena were analyzed using a rule of mixtures, phase continuity, and interfacial strength between martensite and ferrite.

고질소 오스테나이트계 스테인리스강에서 Cr₂N 석출상의 결정학적 특성(Ⅱ) : Ⅱ. TEM을 이용한 Cr₂N 결정구조 분석 Ⅱ. TEM Study on the Crystal Structure of Cr₂N

이태호,오창석,이창길,김성준,高木節雄 대한금속재료학회 2004 대한금속·재료학회지 Vol.42 No.11

In the second part of this study, the crystal structure of Cr₂N precipitates was investigated utilizing transmission electron microscopy (TEM). Based on the analyses of SAD patterns with various zone axes, the crystal structure of Cr₂N was confirmed to be trigonal belonging to the space group P31m, and could be explained in terms of E-type occupational-ordering model. Three sets of superlattice reflections (001), (⅓⅓0) and (⅓⅓1) distinguishing trigonal from hcp were identified in Cr₂N superstructure, and the important characteristics of these reflections were discussed in comparison with the previous studies. (Received August 23, 2004)

미소원공결함을 갖는 차량 밸브용강재의 피로크랙진전거동에 관한 연구

이동길,이상열,정재강 朝鮮大學校 機械技術硏究所 2001 機械技術硏究 Vol.4 No.1

본 연구에서는 자동차 밸브에 사용되고 있는 내열강 STR3과 STR35를 마찰용접한 후 모재, 열영향부 및 접합선(bond line)에 미소 인공결함을 가공하여 피로크랙 발생 및 전파 거동, 피로수명 및 기계적성질의 상관관계를 조사하는 연구를 수행하였다. 평활재의 피로한도시험 결과 STR3의 피로한도는 429.0MPa이며, STR35는 409.4MPa로서 항복강도가 높은 STR3의 피로한도가 약 20MPa이 높게 나타났다. 미소원공결함이 접합선으로부터 1.0mm떨어진 곳에 가공된 시험편의 피로수명은 모재보다 STR3은 약99%, STR35는 약 25%씩 증가한 반면 접합선에 미소원공결함이 가공된 시험편은 모재보다 STR3은 약 20%, STR35는 약 72% 감소하였으며 파괴전 관찰된 최종크랙길이도 크게 감소하였다. 또한 피로크랙길이와 파단수명비의 관계식에 본 시험재료를 적용한 결과 마찰용접 및 미소원공결함의 위치에 관계없이 비례관계가 있음을 알 수 있었다. The fatigue crack propagation characteristics were investigated for two kind of heat-resisting steel, STR3 and STR35, commonly using in valve material of vehicles, in order to evaluate the fatigue crack propagation behavior and fatigue life of dissimilar friction welding zone. The fatigue limits of the as-received specimens, STR3 and STR35, were 429MPa and 409.4MPa respectably. The fatigue life of the specimen showed about 99.1% for STR3, about 25.2% for STR35 higher than that of the base metal specimen. But the fatigue life of bond line notched specimen was shown about 20% for STR3 and about 72% for STR35 shorter than that of the base metal specimen.

고령자를 위한 주거시설 치수 표준화과정에 관한 연구

이특구,권순정,오은진,김상길,김석준,김노석 한국의료복지시설학회 2006 의료·복지 건축 Vol.12 No.2

The purpose of this Guideline is to provide basic standardization basis for planning and designing of the dwellings so that elderly may live, either with their family or independently, an independently comfortable life style. Dwelling facility is defined as a physical area where important activities of daily life are conducted by a person/people and is also the focal place of a family. Therefore, the Guideline classifies the areas where daily activities are conducted by type of such activities and provides standards to countermeasure for natural physical disabilities of the elders.

大田大學 캠퍼스 마스타플랜

李吉永,李達勳,金尙謙,孫世郁 大田大學校 1987 論文集 Vol.6 No.2

A2024와 SM45C 마찰용접의 열전달 해석

이상윤,고준빈,명태식,김기길,강형모 大田産業大學校 2001 한밭대학교 논문집 Vol.18 No.-

The heat transfer mechanism initiating the friction welding is examined and a transient three dimensional heat conduction model for the welding of two dissimilar cylindrical metal bars is investigated. The cylindrical metal bars are made of materials made of A2024 and SM45C. Numerical simulations of heat flow are performed using the finite volume method. Respectively, Commercial FLUENT code is used in the heat flow simulation and maximum temperature and distribution of temperature are calculated. Temperature of friction welded joining face is compared with the temperature distribution measured by experiment and numerical simulation. The maximum temperature of friction welded joining face is lower than melting point of A2024-T6 aluminum alloy using insert metal. The temperature distribution of friction welded joining face with insert metal is more uniform than that of without insert metal

미군정기 초등교육의 변화

이길상 한국교육사학회 2003 한국교육사학 Vol.25 No.2

This article examines the main changes in elementary education in Korea from 1945 to 1948, so called, the American Military Government period. At first the real situation and urgent problems to be solved in the field of elementary education at the moment of liberation is examined. Cleaning of colonial legacy in educational system, building and remodeling of school buildings, establishing new teacher training programs, supplying more textbooks were some of the problems at stake. The most prominent changes in educational system were the abolition of discriminative system and the adoption of democratic system, introduction of compulsory education, and reform of curricular system. In this article these three aspects are explained with pertinent documents and educational statistics. Expansion of educational opportunity is also one of the most outstanding changes occurred at that time. Elementary school entrance rate increased from 54% in 1945 to 73% in 1948 approximately. Explosive increase in school students caused many educational and social problems. Serious shortage of teachers demanded some temporary teacher training programs, and it caused the decrease of teachers' level of professional expertise. Textbook shortage was also a serious problem caused by the increase in student numbers which could not solved in a short time. Beyond these a lot of different problems emerged. A great amount of educational finance was required to meet these educational needs. Because of limits in legal sources, however, unlawful educational funds such as parents' donation was flourished and made a negative influence on Korean education. The historical meaning of three years, from 1945 to 1948, in the field of elementary education in Korea is that elementary education reached to a level of universal education, and some experiments to democratize educational practices were made without many successes. Transition from Japanese imperial education to American democratic education was only a superficial phenomenon.

선천성 고혈압 쥐에서 Irbesartan과 Lisinopril의 병용 투여에 의한 혈압하강 상승효과

이상길,명창선 충남대학교 약학대학 의약품개발연구소 2013 藥學論文集 Vol.28 No.-

Both irbesartan, one of the angiotensin II receptor blocker (ARB), and lisinopril, a angiotensin-converting enzyme inhibitor (ACEI), are using for the treatment of hypertension. The aim of this study was to examine the drug synergism of combined treatment of irbesartan with lisinopril in blood pressure (BP)-lowering effect. Each telemetered-spontaneous hypertensive rat (SHR) was orally received all seven treatments once with an interval of several days between each injection for washing-out and return to high BP levels and BP was monitored control (vehicle-treated), irbesartan (7.18 mg/kg/day as low-dose; 28.74 mg/kg/day as high-dose), lisinopril (0.48 mg/kg/day as low-dose; 1.92 mg/kg/day as high-dose), and low-dose or high-dose combination of irbesartan with lisinopril. The results showed that only high-dose combination of irbesartan and lisinopril exerts significant additive BP-lowering effect as compared with high-dose monotheraphy of each drug. The present study implies that drug combination of irbesartan with lisinopril can offer a clinically effective tool for treating hypertension.

초음파 및 Phased Array를 이용한 터빈 블레이드 루트부 건전성 평가에 관한 연구

길두송,박상기,조용상,이상국,허광범 한국비파괴검사학회 2003 학술대회 논문집 Vol.- No.1

Power plant is consisted of many component parts for the generation of the electricity, and occasionally, turbine equipment may be caused in break-down because of the damage of the blade root. Phased array ultrasonic testing system has become available for practical application in complicated geometry such as turbine blade root, tenon, disc in power industry, This research describes the characteristics of phased array ultrasonic testing signal for various type of blade roots in thermal Power Plant turbines. This application of Phased array ultrasonic testing system has been promoted mainly to save inspection time and labor cost of turbine inspection. The characteristic of phased array ultrasonic testing signal for power plant component in very simple to understand but to difficult for perform the inspection. This paper is focused on the safety of the turbine equipment by the ultrasonic measurement and phased array analysis. As a result of the test through ultrasonic and phased array method, we have concluded that the main damage in these turbine blade root parts could be generated by the concentrated stress and centrifugal force.