• Applied Microscopy
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• 제45권3호
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• pp.177-182
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• 2015

The boiler tubes of X20CrMoV12.1 used in fossil-fired power plants were obtained and analyzed for the effect of water treatment on the steam corrosion-induced oxide scale in an effort to better understand the oxide formation mechanism, as well as pertinent method of maintenance and lifetime extension. The specimens were analyzed using various microscopy and microanalysis techniques, with focuses on the effect of water treatment on the characters of scale. X-ray diffraction analysis showed that the scales of specimens were composed of hematite ($Fe_2O_3$), magnetite ($Fe_3O_4$), and chromite ($FeCr_2O_4$). Electron backscatter diffraction analysis showed that the oxides were present in the following order on the matrix: outer $Fe_2O_3$, intermediate $Fe_3O_4$, and inner $FeCr_2O_4$. After all volatile treatment or oxygenated treatment, a dense protective $Fe_2O_3$ layer was formed on the $Fe_3O_4$ layer of the specimen, retarding further progression of corrosion.

• 한국응용과학기술학회지
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• 제38권4호
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• pp.994-1002
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• 2021

양이온성 계면활성제(DTAB, TTAB 및 CTAB)에 의한 4-할로겐화 아닐린의 가용화상수(K_s)값을 UV-Vis법으로 측정하였다. 그 결과, 모든 아닐린 유도체에서 온도의 증가에 따라 K_s은 모두 감소하였으며, 할로겐 치환기의 반지름과 계면활성제의 소수기길이를 증가할수록 K_s값은 더욱 증가하였다. 이들 가용화상수 값을 이용하여 계산한 ΔG^o와 ΔH^o값은 측정한 범위 내에서 모두 음의 값을 그리고 ΔS^o값은 모두 양의 값을 나타내었다. 모든 아닐린 유도체에서 온도를 증가함에 따라 ΔG^o값은 감소하는 경향을 보였다. 그러나 온도의 증가에 따라 ΔH^o와 ΔS^o값은 모두 증가하는 경향을 보였다. 한편 할로겐치환기의 반지름을 증가할수록 이들 열역학 함수 값들은 대체적으로 감소하는 경향을 보였다. 그러나 계면활성제의 소수기길이를 증가하였을 때 이들 열역학 함수 값은 아닐린유도체의 종류에 따라 다르지만 대체적으로 증가하는 경향을 보였다. 이런 열역학 함수 값들의 변화로부터 4-할로겐화 아닐린과 미셀과의 상호작용의 종류와 세기를 그리고 이들이 미셀 내에서 가용화되는 위치를 추정할 수 있었다.

• 화약ㆍ발파
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• 제11권4호
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• pp.4-8
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• 1993

This paper was reported on the seminar of Korean-Japanese professional engineers. The first of all, it was described the comparative rifle between Korea, Japan & USA on fatal accident on the construction works. Next, it was described that some accidents was occured in typical reason and it will help us to prevent the future accident.

• 대한소아치과학회지
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• 제31권3호
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• pp.486-494
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• 2004

본 연구는 all-in-one adhesive를 사용하여 전색하는 술식을 통상적인 탈회 술식 및 single-bottle 결합제를 이용하여 전색하는 술식과 비교하여 법랑질과 전색재 사이의 미세누출의 차이를 알아보고자 하는 것이다. 75개의 제3대구치를 5군으로 나누어 1군을 대조군으로 하여 only Etching(1군), $Adper^{TM}$ Single $Bond^{TM}$(2군), $Adper^{TM}\;Prompt^{TM}$ L-Pop(3군), Ad-bond(4군), One-up bond F(5군)로 처리한 후 전색재 도포 후 열순환을 시 행한 뒤 미세누출도를 검사하여 다음과 같은 결론을 얻었다. 1. All-in-one adhesive를 사용한 3, 4, 5군은 1군에 비해 유의성 있게 높은 평균미세누출도를 보였다(p<0.05). 2. 가장 낮은 평균미세누출도는 2군(0.14)에서 보였고 1군(1.05), 3군(1.65), 4군(2.85), 5군(3.05) 순으로 증가하였다. 3. All-in-one adhesive를 사용한 3, 4, 5군중에서 3군은 4, 5군에 비해 통계적으로 유의성 있게 낮은 평균미세누출 도를 보여주었지만(p<0.05) 1군과 2군에 비해 유의성 있게 높은 평균값을 보여주었다(p<0.05). 4. 4군과 5군 사이의 평균미세누출도는 통계적으로 유의성 있는 차이를 보이지 않았다(p>0.05). 5. 주사전자현미경관찰결과 all-in-one adhesive를 사용한 3, 4, 5군은 1, 2군에 비해 레진돌기가 짧고 불규칙하게 관찰되었다.

• Clinical and Experimental Reproductive Medicine
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• 제19권1호
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• pp.15-29
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• 1992

In the present study, it was aimed to find the role of calcium on the maturation of mouse follicular oocytes as well as for the role of calcium inhibitors, $Ni^{2+}$ and $La^{3+}$. Mouse follicular oocytes were cultivated in different media at $37^{\circ}C$, in 100% humidified $CO_2$ incubator for 3 and 17 hrs. The results were as follows; 1. There was no differences in GVBD between the control and experimental groups during the 3 hr culture. 2. Mouse oocytes were matured to higher rate in MHBS rather than HTF for 17 hr culture. 3. Maturation rate was significantly lower in $Ca^{2+}$-free and $Ca^{2+}$ 0.4 mM which were tested, compared to other calcium concentration used in the present study. 4. Calcium inhibitor, $Ni^{2+}$, it showed highest degeneration rate at all calcium concentrations and additionally in $Ni^{2+}$ $100{\mu}M$ treated group next. Maturation rate was significantly decrease as the $Ca^{2+}$ inhibitor concentration increased. 5. In all Lanthanum treated groups of calcium-free, degeneration were significantly high treated groups at 0.4 mM $Ca^{2+}$ concentrations degeneration rates of all group were significantly lower than that of the control but maturation rates were not significantly different in any group. In lanthanum $100{\mu}M$ treated group at 0.4 mM and 0.8 mM calcium concentration, its maturation rate was significantly higher than that of the control. Maturation rates of all groups of lanthanum treated at 1.71 mM calcium concentration were not significantly different among groups. 6. In the calcium treated group (0.4mM-1.7 mM), the presence of phosphate does not seem to be needed for oocyte maturation. However, the presence of phosphate at $Ca^{2+}$ 0.8 mM only seems to stimulated maturation.

• 한국식품조리과학회지
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• 제8권3호
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• pp.309-314
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• 1992

The purpose of this study was to investigate me effects of garlic or lemon juice on quality characteristics of fish muscle. The samples treated with garlic or lemon juice by me amount of 5% or 10% (w/w) of fish muscIe were stored at $4{\pm}1^{\circ}C$ and $-18{\pm}2^{\circ}C$ for 10 and 40 days, respectively. The results are summarized as follows; 1. In me taste of samples, me samples treated with 5% garlic juice showed me most favorite tendency all me storage time at $4{\pm}1^{\circ}C$ and $-18{\pm}2^{\circ}C$. 2. There were significant in fishy odor after 5 days of storage at $4{\pm}1^{\circ}C$ and 40 days of storage at $-18{\pm}2^{\circ}C$ . The fishy odor of samples treated with garlic juice were weaker man those of samples untreated or treated with lemon juice. 3. The appearance was evaluated the worst in 10% lemon juice treated sample among all me samples. 4. The hardness of the samples treated with lemon juice were lower man those of samples untreated or treated with garlic juice during all the storage time at $4{\pm}1^{\circ}C$ and $-18{\pm}2^{\circ}C$. 5. The score of overall quality was the highest in sample treated with 5% garlic juice during all the storage time at $-18{\pm}2^{\circ}C$.

• 한국임상수의학회지
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• 제17권1호
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• pp.62-69
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• 2000

The effects of vaselin, silver sulfadiazine and propolis on healing of full-thickness skin defects were evaluated in rabbits. Two wounds measuring 2{times}2cm$ were created bilaterally (4 wounds/rabbit) on the dorsolateral aspect of the trunk of 17 Ne Zealand white. Wound treatments were evenly distributed 4 sites, using a Latin square design. Treatments evaluated were: vaselin(group A), silver sulfadiazine(group B), 5% propolis (group C) and 10% propolis(group D). On days 3, 7 and 14, mean percentage of wound in group A, B, and C. On days 21 and 28, mean percentage of wound contraction in group D were significantly higher than those of groups B and C, but were not higher than that of group A. Microscopically fibersis and epithelialization were noticed on days 14 and 28 after wounding in all group. Rates of fibrosis of collagen fiber and epithelialization of groups C and D were exceeded those of groups A and B. All wounds in all group achieved 100% healing during the 28-day study period. Results indicate that use of propolis as would ointment on full-thickness skin wounds in rabbits increase rate of healing.

• 산업경영시스템학회지
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• 제2권2호
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• pp.19-32
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• 1979

The title of research is a study on the leadership in Korean management. The purpose of research is that I build up the ideal management-leadership in future which is objective and suitable studying through the existing theory at all points, and analyzing the leadership in Korean management concentrated on situational factors. Moreover it contributes to the promotion of productivity, the contents of research 1. The importance of management-leadership. 2. The development in theory concentrated on a principle of leadership. 3. The development in behavioral scientific leadership, which adopts situational approach to its methodology. 4. The study on the leadership-style and the pursuit of the ideal management-leadership in accordance with behavioral analysis. 5. The build up of leadership in Korean management. The refore I learn the following facts through the study on the leadership in modern management. 1. Leadership consists of the relations among all interdependant variables composing of system. 2. The problem of the increase in the management-leadership effectiveness. 3. The pursuit oriented ideal management-leadership. 4. The build-up of leadership in Korean management. So far 1 have studied the theory of management-leadership at all points and the leadership in Korean management concentrated on situational factors. I learn that leadership is made of the relations among these in building the future management-leadership. Therefore I try to come to the conclusion by raising the following three problems. 1. The increase in leadership effectiveness. 2. Leadership-oriented. 3. The build-up of the leadership in Korean management.

• 수산해양교육연구
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• 제23권4호
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• pp.779-785
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• 2011

In order to improve the employment rate of graduates in maritime and fisheries universities, we investigated the employment situations of the those graduates for the last 7 years. The results were as follows, The ratio of graduates in maritime and fisheries universities to total graduates of on-board departments are 69.1% and 30.9% respectively. The on-board employment rate of maritime universities and fisheries universities graduates are 63.2% and 26.7% respectively. Nearly all of the maritime universities students were employed to merchant ship and fisheries universities students were employed to merchant ship 77.2% and only 22.8% of them got a job on fisheries ship. The ratio of getting a job in maritime universities to ocean-going ship was 76.7%, that was the highest ratio and the ratio of fisheries universities got a job to ocean-going ship was 55.1%. The on-board career of maritime universities graduates was 1~5 years, which took 86.4% of all careers and that of fisheries universities was less than 1 year, which took 60.0% of all careers. We should make the various efforts to improve the employment rate of getting job to fisheries ship in the fisheries university gradustes.

• 호남수학학술지
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• 제35권4호
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• pp.765-773
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• 2013

We show that for the logistic map, almost every x is a normal number mod 2 with respect to all intervals except for $[a,b]=[\frac{1}{4},1]\;or\;[a,b]=[\frac{1}{2}-\frac{\sqrt{3}}{4},\frac{1}{2}+\frac{\sqrt{3}}{4}]$.