냉간성형용 고강도강의 미세조직과 기계적 성질에 미치는 열처리의 영향

朱起運,李昌吉,金成俊,崔日東 대한금속재료학회 2002 대한금속·재료학회지 Vol.40 No.6

The main emphasis of the present study has been placed on understanding the effects of heat-treatment (austenitizing and isothermal treatment) on the microstructures and mechanical properties of a 0.20C-0.25Si-2,0Mn high strength steel for cold forming. The steel was austenitized, and isothermally treated at bainitic region followed by air cooling. Microstructural observation, tensile tests, and Charpy impact tests were conducted. The mechanical properties and microstructures of the steel were changed by heat-treatment conditions. The size of prior austenite increased with increasing austenitizing temperature, resulting in decrease of impact toughness. Microstructure was changed from bainite + pearlite to martensite + bainite with decreasing isothermal treatment temperature, and yield or tensile strength, yield ratio, and reduction of area were increased. From the results of the present study, it is confirmed that it is possible to develop a new C-Si-Mn high strength steel for cold forming through optimization of heat treatment.

저강도 자전거에르고미터 운동프로그램이 혈장지질 농도에 미치는 영향

성봉주,남형천,김상우 한국학교체육학회 2001 한국학교 체육학회지 Vol.11 No.1

본 연구의 목적은 8주간의 저강도 자전거 에르고미터 운동프로그램이 혈중지질(TC, LDL-C, HDL-C, TG, TC/ HDL-D에 미치는 영향을 규명하는데 있다. 연구의 대상자는 서울시 K대 여자학생 중 각종 질병이 없고, 건강 상태가 양호한 16명을 무작위 표집하고, 두 집단으로 구분하였다 · 실험집단(8명), 통제집단(8명). 실험전 실험집단의 최대심박수를 측정하기 위하여 Bruce Protocol로 운동부하 검사를 실시하였다. 혈액검사는 훈련 전과 훈련 4주 후, 훈련 8주 후에 전완 정맥에서 채혈하였다. 실험집단의 운동프로그램은 (1) 운동강도와 기간은 각자의 60%HRmax인 저강도로 주 3회, (2) 운동시간은 20분부터 시작하고 2주마다 10분씩 증가, (3) 운동기간은 8주. 자료 분석은 두 집단과 처치기간에 따른 실험변인(TC, LDL-C, HDL-C, TG, C-Ratio)에 미치는 반응을 검증하기 위해 2(실험 집단, 통제 집단)×3(훈련 전, 훈련 4주 후, 훈련 8주 후) 반복적 측정의 이원 변량분석 및 두 집단간의 독립적 그룹의 T-test, 각 집단의 처치기간별 반복적 측정의 일원 변량분석을 실시하였다 유의수준은 5%로 하였다. 이러한 절차로부터 다음과 같은 결론을 얻을 수 있었다. 첫째, 두 집단간 처치기간별 TC수준의 차이는 유의하지 않았다. 또한 각 집단의 처치기간별 TC수준에서 실험집단은 유의한 감소를 보이지는 못했다. 통제집단은 유의한 차이가 나타나지 않았다. 둘째, 두 집단간 처치기간별 LDL-C수준의 차이는 유의하지 않았다. 또한 각 집단의 처치기간별 LDL-C 수준에서 실험집단은 훈련 전과 훈련 4주 후에 유의하게 감소하였다. 통제집단은 유의한 차이가 나타나지 않았다. 셋째, 두 집단간 처치기간별 HDL-C수준의 차이는 훈련 전에는 유의하지 않았으나 훈련 4주 후와 훈련 8주 후에서는 유의하게 나타났다. 또한 실험집단의 처치기간별 HDL-C수준에서 유의한 증가를 보이지는 못했다. 통제집단은 유의한 차이가 나타나지 않았다. 넷째, 두 집단간 처치기간별 TG수준의 차이는 유의하게 나타나지 않았다. 또한 실험집단의 처치기간별 TG수준에서 유의한 감소를 보이지는 못했다. 통제집단은 유의한 차이가 나타나지 않았다. 다섯째, 두 집단간 처치기간별 C-Ratio수준의 차이는 유의하지 않았다. 또한 실험집단의 처치기간별 C-Ratio수준에서 유의한 감소를 보이지는 못했다. 통제집단은 유의한 차이가 나타나지 않다. 이상과 같은 결과를 종합해보면 저강도 자전거에르고미터 운동프로그램도 일반 여자대학생들의 혈장지질농도에 긍정적인 영향을 미쳤다. 그러나 콜레스테롤 대사의 전반적 향상을 위해서는 자전거에르고미터의 운동강도를 높이거나 운동기간을 늘여야 할 것으로 사료된다. The purpose of this study is to investigate the effect of low intensity bicycle ergometer exercise program on blood lipid. The subject of this study, 16 fㄷmale university students in Seoul who are health, and have no diseases, are randomly sampled and divided into two groups : experimental group(n=8), and control group (n=8). Pre-test is done the exercise load to measure for HRmax of experimental group using Bruce protocol. I gather blood from antecubital vein of experimental group for blood test at three times, just before test, after 4 week exercise and 8 week exercise. The experimental group takes bicycle ergometer training on these conditions: (1) exercise three times in a week at low intensity of 60^ HRmax, (2) Increase time in 10 Min. at every two weeks, (3) group was trained for 8 weeks. I use statistical techniques for data analysis, 2*3 repeated measure two way ANOVA to determine the differences between tow groups and training times, independent group T-test to determine the differences between two groups, and repeated measure one way ANOVA for training time. The 5% level of significance is utilized. The following results are obtained this study; First, the TC levels of two groups are not significantly different in the training period. Although TC level of experimental goop decrease in after-exercise (4 week, 8 week) to comparison with TC level of before-exercise, it is not significant decrease. And it was no significant difference in control group. Second, the LDL-C levels of two groups are not significantly different in the training period. The LDL-C level of experimental group decreased in after-exercise (4 week, 8 week) in comparison with before-exercise. Specially it decrease significant after 4 week exercise. And it is no significant difference in control group. Third, the HDL-C levels of two groups are not signif4cantly different before exercise, but are significant different after exercise (4 week, 8 week). Although the HDL-C level of the experimental group decrease in after-exercise (4 week, 8 week), but it is not significant decrease. And it is not significant difference in control group. Fourth, the TG levels of tow groups are not significantly different during training period. Although the TG level of experimental group decrease in after-exercise(4 week, 8 week) in comparison with before-exercise, but it is not significant decrease. And it is no significant difference in control group. Fifth, the C-Ratio levels of tow groups are not significantly different during training period. Although the C-Ratio level of experimental group decrease in after-exercise(4 week, 8 week) in comparison with before- exercise, but it is not significant decrease. And it is no significant difference in control group. From the result, because the low intensity bicycle ergometer exercise program effect blood lipids of the female university students, it will contribute for improving health and the prevention adult disease. Synthesizing all the results, low intensity bicycle ergometer exercise program had a positive effect on LDL-C, HDL-C. From the results, Furthermore, In order to maximize the effect of training. it will be better to increase the period of exercise.

남성 건강검진 수진자에서 간기능 장애 및 비알코올성 지방간과 대사 증후군과의 관련성

최태성,유재영,김진석,장은철,박주언,김병익 순천향의학연구소 2006 Journal of Soonchunhyang Medical Science Vol.12 No.2

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[논문]도시하수처리장으로부터 분리한 호기성 탈질균의 특성

정용주,조순자,이상준 부산대학교 환경문제연구소 2004 環境硏究報 Vol.22 No.-

Characterization of an Aerobic Denitrifier Isolated from Municipal Sewage Treatment Plant

지류문화재의 보존처리

천주현,김성희 국립중앙박물관 2001 박물관보존과학 Vol.3 No.-

국립중앙박물관에서는 “고려·조선의 대외교류전”을 대비하여 고지도, 고서, 고문서 등의 지류문화재에 대하여 보존처리를 실시하였다. 일반적으로 지류문화재는 자연적인 노화 외에도 온·습도, 빛, 물리적 힘 등의 여러 가지 주변 환경에 민감하게 반응하게 된다. 온·습도 변화에 의한 수축과 팽창, 유물에 직접적으로 가해지는 곤충·곰팡이 등에 의한 생물학적 손상, 그리고 인위적으로 행해지는 물리적 힘에 의한 손상 등이 그 대표적인 예일 것이다. 이번에 보존처리를 실시한 유물들에서도 그러한 손상들을 쉽게 확인할 수 있었다. 따라서 고서, 고문서 등의 보존처리 과정에서 볼 수 있었던 손상상태와 그 보존처리 내용, 그리고 지류문화재의 손상방지를 위한 간단한 응급처리 내용을 소개하고자 한다. In National Museum of Korea, we recently preserved paper cultural assets, such as ancient maps, books and antique documents etc, to prepare “A Dynamic World of External Relations in Goryeo & Joseon Dynasty”. The paper cultural assets generally react sensitively to their environments; temperature, humidity, light and physical force acting. Biologic Biological damages, which are caused by microbe, contraction, swelling and damage from insects occurred. Wrinkles on relics, which are made my physical force, stains on relics which are due to moisture, weakening of adhesive strength and damages from insects were found during the recent preservation handling. Therefore we are trying to find out any damage, which could be occurred in paper cultural assets and introduce brief emergency operation to prevent the damages and develop the preservation handling.

Effect of short-term combinatorial application of flurbiprofen plaster and wrist extensor taping on pain while carrying out a badminton technique in badminton athletes with chronic wrist pain: Case study

주성범 남서울대학교 2018 남서울대학교 논문집 Vol.24 No.-

한국인 환자에서 Vancomycin의 집단약동학 (Population Pharmacokinetics)에 관한 연구

유경상,배균섭,이주연,조주연,장인진,신상구,신완균 大韓臨床藥理學會 1998 臨床藥理學會誌 Vol.6 No.2

피혁슬러지 고형화시 시멘트 혼화제의 영향

주소영,박상찬,전태성,손종렬,김태영 대한위생학회 2003 대한환경위생공학회지 Vol.18 No.4

The cement-based system among S/S(Solidification/Stabilization) is widely used to treat hazardous wastes. In this study, tannery sludge was solidified to evaluate the stabilization effects of using admixtures in the cement-based S/S. Fly ash as substitute also used to increase the strength of the S/S of hazardous waste. The compressive strength measurement and leaching experiment of chromium metal of solidified mortar were carried out to compare and evaluate the physical and chemical characteristics of solidified hazardous waste sludge. From the result of this study, there was increased of compressive strength by using AEW-3(early-hardening AE water reducing agent), and leaching concentration of chromium became low enough to satisfy the regulatory criteria. The successful solidification for the organic contaminant and heavy metal in hazardous waste should enable to treat by cement-based system using early-hardening AE water reducing admixture and fly ash as substituted cement.

뇌 심혈관계 관련질환 유소견 근로자들의 의료이용에 관한 연구

최태성,유재영,김진석,장은철,박주언,우극현 순천향의학연구소 2006 Journal of Soonchunhyang Medical Science Vol.12 No.2

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졸겔법에 의해 제조된 결정질 LiMn₂O₄의 전기화학적 반응 특성연구

朱宰伯,曺星美 弘益大學校 科學技術硏究所 2001 科學技術硏究論文集 Vol.12 No.-

Lithium secondary batteries is expected to be highlighted as the future mobile electric power source since it is more outstanding in energy density and many other properties compared with the existing secondary batteries. Among the cathode materials of lithium secondary battery, LiMn₂O₄ consists of spinel structure and shows the highest level of operative voltage. The citric acid method, one of the moisture present methods, is easy to control the composition rate and gets less amount of inflow impurities and even the grain size is adjustable in microscopic level so that possibly obtains the sample powder with large surface area and evenly distributed grains, subsequently a lot of research proceeded so far. The initial discharge capacity was 110Ah/g which is corresponding to 74.2% of the theoretical capacity of LiMn₂O₄, 148.21mAh/g. After 20 cycle, it showed 92mAh/g and after 30 cycle, it became 75mAh/g that is a large capacity fading of 31.8%.