http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Mn-Ni계 산화물 박막의 특성에 대한 기판과 열처리 온도의 영향
김철수,최성호,이용성,조병렬,김병수,Kim, Cheol-Su,Cho, Seong-Ho,Lee, Yong-Seong,Cho, Byeong-Ryeol,Kim, Byeong-Su 한국재료학회 1998 한국재료학회지 Vol.8 No.5
RF magnetron sputter로 알루미나 기판 위에 증착한 NTC 써미스터용 Mn-Ni계 산화물 박막의 기판온도 변화와 열처리에 따른 미세구조, 결정상, 비저항, B정수 변화에 관하여 연구하였다. 미세구조는 $178^{\circ}C$이하에서 증착한 막의 경우 fibrous microcrystalline이었고, $320^{\circ}C$와 $400^{\circ}C$에서는 columnar grain 구조로 바뀌었다. 또한, 90$0^{\circ}C$에서 열처리한 박막의 경우 equiaxed grain 형태의 미세구조를 나타내었다. 박막의 결정상은 대부분 입방 스피넬(cubic spinel)상과 $Mn_{2}$$O_{3}$ 상이 공존하였고, $400^{\circ}C$에서 증착한 경우 $700^{\circ}C$이상에서 열처리하면 입방 스피넬의 단상으로 바뀌었다. 기판온도가 증가함에 따라 비저항과 B정수도 급격하게 감소하였으며, $600^{\circ}C$~$700^{\circ}C$로 열처리할 경우 이 값들이 대체로 낮고 안정된 특성을 보였다. 본 연구의 박막 시편들은 모두 NTC 써미스터의 특성을 나타내었다. Mn-Ni oxide thin films for NTC thermistor application were deposited on alumina substrates by using rf magnetron sputter. Effects of various substrate temperatures and annealing temperatures on the microstructure. crystal phase, resistivity and B constant were investigated. Microstructure of the films deposited below 178$^{\circ}C$ was fibrous microcrystalline and at 32$0^{\circ}C$and 40$0^{\circ}C$their microstructure was changed to columnar grain structure. After annealing at 90$0^{\circ}C$, the microstructure was transformed to equiaxed grain structure. Most of the phases were mixture of cubic spinel and $Mn_2O_2$ The crystal phase of the film deposited at 40$0^{\circ}C$ was changed to cubic spinel after annealing above 700"c. As the substrate temperature increased, the resistivity and B constant were greatly decreased, and these values become low and stable after annealing between $600^{\circ}C$and $700^{\circ}C$, All thin films deposited in the present study showed NTC thermistor characteristicsstics.
수술 후 부갑상선기능저하증 환자에서 발생한 우유-알칼리 증후군
김철수,김부경,최영식,박요한,권수경,Cheol Su Kim,Bukyung Kim,Young Sik Choi,Yo-Han Park,Su Kyoung Kwon 대한갑상선-내분비외과학회 2014 The Koreran journal of Endocrine Surgery Vol.14 No.2
Calcium plays a critical role in neuromuscular excitement and other cellular functions. Therefore, extracellular calcium concentration is maintained within a very narrow range through interaction of calcium regulating hormones such as parathyroid hormone, cal-citonin, and vitamin D. Thus, symptomatic severe hypercalcemia has rarely occurred in a clinical situation, particularly in patients with hypoparathyroidism. In general, a large amount of calcium and vitamin D should be supplied in order to avoid hypocalcemia in hypoparathyroid patients. A 63-year old female patient was admitted suffering from nausea, vomiting, and weakness for two weeks. She had a history of total thyroidectomy and subsequent permanent hypoparathyroidism and long-term calcium and vitamin D supplementation. For over 10 years she had not changed her daily amount of calcium and vitamin D intake. Her initial serum calcium was 17.5 mg/dL, creatinine was 2.57 mg/dL, and total CO2 was 33.1 meq/L. After thorough examination, we concluded that milk-alkali syndrome was the cause of severe hypercalcemia. Therefore, special pay attention should be paid to aged patients on calcium supplementation in situations of increased risk of dehydration and renal insufficiency, even though the usual amount of calcium intake was unchanged for several years.
김철수,김정규,Kim, Cheol-Su,Kim, Jeong-Gyu 대한기계학회 2001 大韓機械學會論文集A Vol.25 No.4
In this study, fatigue growth behavior of the transverse crack, which was the most dangerous damage among the various types of rail defects, was investigated using the notched keyhole specimen under constant amplitude loadings. Fatigue limit of smooth specimen in rail steel at R=0 was 110MPa, and the fatigue crack initiation life in the region of the low stress amplitude (ie. long life) occupied the major portion of the total fatigue life. The fatigue strength under variable amplitude loading was converted to the equivalent fatigue strength based upon. Miners rule, which was estimated approximately 9% lower than that under constant amplitude loading. Also, in the low ΔK(sub)rms region ($\leq$21MPa√m), fatigue crack growth rate (da/dN) under constant amplitude loading was higher than that under variable amplitude loading, whereas the tendency was reversed in the high ΔK(sub)rms region. It is believed that this behavior is due to the transition of fracture appearance.
김철수,정병두,강승규,Kim, Cheol-Su,Jung, Byung-Doo,Kang, Seung-Kyu 한국주거학회 2012 한국주거학회 논문집 Vol.23 No.5
The primary purposes of this study are to suggest a medium-sized regeneration project which includes the excluded small sites near existing regeneration site, to identify urban improvement type which fits local conditions, and to suggest proper regeneration strategies for the improvement type. Main findings of this study are follows. First, the size of the living environment improvement project in urban area should be larger than 3ha and government's incentives are required for parcel merges to make the medium-size project site. Second, independent type of urban regeneration project should consider local characteristics while center-spread type of urban regeneration project should build a center by providing neighborhood facilities and proper housings. Third, urban regeneration project should be able to utilize local assets, such as cultural heritages, natural landscapes, transportation facilities. Fourth, standards for public support should be prepared to improve local competitiveness. Last, further studies are required for urban regeneration system improvement.
김철수,김효준,Kim, Cheol-Su,Kim, Hyo-Jun 한국주거학회 2011 한국주거학회 논문집 Vol.22 No.2
This research analyzes the residents' satisfaction for the pedestrian space of multi-family housing based on quality index. For this purpose, nine apartment complexes which were built after 2000, are selected and examined by user characteristics of composition factors of pedestrian space. This research also compares residents' satisfaction by evaluation factors of walking environment. The resident survey reveals that the composit type of apartment gives the highest satisfaction to residents followed by a courtyard type, and a straight type the last. In particular, residents show high satisfaction to pedestrian-only space in the case of the composit type of apartment building. The most important factor of walking environment on residential satisfaction is the separation of car and pedestrian path of main entrance. Above all, suitability of construction laws and regulations should be reviewed for safer and more amenable walking environment.
김철수,이준형,김정규,Kim, Cheol-Su,Lee, Jun-Hyeong,Kim, Jeong-Gyu 대한기계학회 2001 大韓機械學會論文集A Vol.25 No.10
It is necessary to evaluate fatigue strength and reliability of the connecting rod which is core part in automotive engine to assure the high level of durability of automobile. For this purpose, the loading conditions in automotive engine is obtained by the dynamic analysis. Based on these results, the critical section was identified by the finite element analysis. The fatigue strength under constant amplitude was evaluated and the mean of the fatigue limit at R = -2.27 derived from the staircase method was 311.2MPa. And the failure probability( F$\sub$p/ ) derived from the strength-stress interference model is 0.0003% at the 99.99% confidence level and the mean factor of safety was 4.2.