Study on Microstructure and Mechanical Properties of the Al–25Cr–5Si (at%) Alloy Powder Using Gas-Atomization and SPS Process

Yong‑Ho Kim,Hyo‑Sang Yoo,Jeong‑Han Lee,Ik‑Hyun Oh,Hyun‑Kuk Park,Hyeon‑Taek Son 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.7

In order to investigate the microstructure and mechanical properties on Al–25Cr–5Si (at%) alloy, a mixed powder with pureelements and an alloy powder using a gas atomization process were used. Fine and high purity Al–25Cr–5Si (at%) alloypowder was successfully prepared by gas atomization and densified using a spark plasma sintering (SPS) process. The overallpowder size distribution of the mixed Al, Cr, and Si elemental powders was in the range of 10–15 μm. The atomized Al–Cr–Sialloy powder was fine and spherical in morphology and difficult to be formed by intermetallic formation. Densification wasclearly confirmed at 1000 °C, with almost isolated pores formed, by clear removal of pores between particles, deformationof particles, an increase in the number of contacts, and a change in size between particles. As a result of XRD analysis ofthe sintered compacts, single phase was observed using the mixed powder, but the compact using gas atomization remainedthe alloy phase even at the process temperature. The Vickers hardness of the compacts by mixed powder was observed at59.70 Hv and the compact using gas atomized powders on the temperature 1000 °C of the Vickers hardness increased to702.6 Hv. The compressive yield strength of the compact with mixed powder was 195.24 MPa and the compressive strengthof the compact with gas atomized powder increased to 802.07 MPa. It is considered not to be decomposed by the AlCrSi,Al13Cr4Si4and Al8Cr5phases sintering process, resulting from the improvement of mechanical properties.

약물의 폐 전달을 위한 염화 벤제토늄 기반 리포좀의 제조 및 평가

문용현, 유소열, 안지선, 이한솔, 김혜림, 이은주, 이재영 충남대학교 약학대학 의약품개발연구소 2021 藥學論文集 Vol.36 No.-

Benzethonium chloride-containing egg phosphatidylcholine-based liposomes (BC/EPC-LIPOs) were developed for lung-targeted drug delivery. BC/EPC-LIPOs were fabricated via thin-film hydration method with various BC-to-EPC molar ratios of 1:4 (F1), 1:1 (F2), and 4:1 (F3). Cyanine5.5 (Cy5.5) was loaded as a fluorescent probe for the biodistribution study during the film-forming step. BC/EPC-LIPOs were evaluated by using dynamic light scattering analysis, where the mean diameter and zeta-potential values of F1, F2, and F3 were observed to be 69.5 ± 3.1 nm and 50.06 ± 1.00 mV, 59.0 ± 2.3 nm and 51.30 ± 2.98 mV, and 694.2 ± 243.3 nm and 55.01 ± 3.16 mV, respectively. To evaluate the lung distribution efficiency of the developed liposomes, F1 and F2, which possess suitable particle sizes for the intravenous administration, were injected into the tail vein of ICR mice. At 6 h post-injection, the lung, liver, kidney, heart, spleen, and brain were dissected, and the radiant efficiency (RE) values of the or- gans were measured using the near-infrared fluorescence imaging method. The lung RE value of F2 was 1.69-fold higher than that of F1, indicating a more efficient lung targetability of F2. This phenomenon can be attributed to the higher content of BC in F2 than F1. Considering the lung-targetability, as well as the biocompatible natures of BC and EPC, the developed BC/EPC-LIPOs can be used as an efficient lung-targeted drug delivery system.

韓·日 神話의 比較

玄容駿 제주대학 1976 논문집 Vol.8 No.1

Ⅰ Myt on the Beginning of the World 1) There appears the view which a land had teen floated in the water originally by the myth of beginning of the world of Kojiki and Nihenshoki in Japan. In Korea, such a view has been transmitted from generation to generation by the legend of Bi-yang Island, Neung-la Island, and Going-ju Mountain, etc. Such a similarity establishes the fact that both country had the sane myth of the begining of the world in ancient times. 2) By the myth of Izanaki, Izanami in Japan, they say that the fire divided the heaven and the earth, and the myth of shamanism in Korea explains that the Heaven and the earth was divided by the sun. Both myths are similar to cause of explanation for the division of the heaven and the earth. Ⅱ Myth on Living and Dying The myth visiting Hades written in Izanaki of Japan and the myth producing gods written in shamanism of Korea are similar to explanation on originality of living and dying of human being. Both myths explain that god of this world is living god, and god of the world beyond is dying god, and they say that the gods of both world had a constest of ability, as the result of it god of this world won the game, so that human being increase. Those explanations are just the same in both myths. Ⅲ Myth on Foundation of Country Myths of Foundation of both Korea and Japan are similar to explanation that the god descending on the forests of mountain established the country, that the god drifting ashore assisted to established the country. And both is also similar to explanation which the fellow who had ruled over the country handed his country over to heavenly descendant asserting his orthodoxy en foundation of the country. Considered that both country is adjoining georaphically, kept in historical contact and the cultural relation, the similarity of above all the myths not only proves its true that they are the same system but it is right in their assumption that the myth of Japan was transmitted and formed through Korea, for Korea has acted as an intermediary constantly. Such a fact gives suggestion to us that culture of the ruling class in Japan was transmitted to them by way of the Peninsula of Korea.

올레산의 비율에 따른 아데노신의 경피 투과의 영향

남현빈,정세진,구민석,오예진,김용민,이훈희,윤수정,임정균 순천향대학교 부설 산업기술연구소 2021 순천향 산업기술연구소논문집 Vol.27 No.2

In addition to the development of functional cosmetics, technology to increase percutaneous absorption rate when applied to the skin is an important task. In this experiment, oleic acid was used as a skin absorption promoter, and its effect on transdermal permeability of adenosine was studied and analyzed using a skin-like membrane. As a result of the experiment, it was investigated that the permeability coefficient and concentration of adenosine are proportional to the content of oleic acid. This indicates that a high proportion of oleic acid is effective as a skin absorption promoter.

韓國傳承童謠에 드러난 靑少年의 意識

玄容駿,金榮敦 제주대학교 1980 논문집 Vol.12 No.1

1.0. 오늘날 靑少年들의 문제는 世界性을 띠고 있다. 한국의 경우에는 특히 요마적 2,30년 사이 近代化 기간의 단축으로 말미암은 逆機能이 크고 正體危機의 심각성이 따른다. 1.1. 그 正體危機를 극복하기 위해서는 韓國靑少年文化의 定立이 시급하며, 그 한 방법으로 文化遺産의 하나인 전승동요를 이용할 수 있을 것이다. 1.2. 다만, 그 수집연구가 여태껏 본격화되지 못했으므로, 이런 계제에 한국전승등요에 드러난 靑少年의 意識分析作業을 試圖함을 그 작업의 한계를 스스로 안게 마련이다. 1.3. 韓國傳承童謠에 드러난 靑少年의 의식을 밝히는 방법은 갖가지이겠지만, 그 가운데서 題材別 分析과 그 主題에 드러난 두드러진 의식을 밝히는 데 역점을 두려 한다. 2.0. 韓國傳承童謠에 담긴 意識을 살피기 위한 한 방법으로 몇 분의 전승동요 분류안을 참고 하면서, 그 題材分析을 試圖해 볼 수 있다. 2.1. 金素雲·任東權·박두진의 分類案을 참고하면서, 필자는 한국의 전승동요를 ① 動植物謠, ② 天體·氣象謠, ③ 遊戱謠, ④ 諷笑謠, ⑤ 語戱謠, ⑥ 자장가, ⑦ 其他謠로 나누는 게 우선 무난할 듯하다는 확신이 섰다. 2.2. 動植物謠와 天體氣象謠는 다같이 자연을 노래했다는 면에서 自然謠라 볼 수 있고, 어 린이들은 이 自然謠를 즐겨 부르며 노는 사이에 道와 德과 秩序를 배운다. 2.3. 또한 諷笑謠와 語戱謠는 일종의 말놀이이므로, 넓은 뜻으로는 遊戱謠에 포괄된다. 自然謠(動植物謠 天體氣象謠) 역시 어린이들의 靜的, 動的인 한갖 놀이로 불러지므로, 傳承童謠의 主宗은 遊戱謠라 말할 수 있다 2.4. 따라서, 한국의 전승등요는 자연을 무대로 하거나, 집단적 놀이 그 자체를 위한 遊戱謠라고 말할 수 있다. 3.0. 민요처럼 두렷하지는 않지마는, 몇몇 동요집등에 수록된 동요를 살피다 보면, 동요에서도 여러 패턴의 의식을 간추려낼 수 있다. 동요에 드러난 청소년의 의식 가운데 두드러진 바는 ① 隣助協同意識, ② 同類意識, ③樂天的 生活意慾, ④ 水平的 民主意識, ⑤ 秩序意識과 더불어, ⑥ 아름다운 꿈과 ⑦ 깊은 愛情등을 내세울 수 있다. 3.1. 어린이들은 傳來的 韓國社會에서의 친족과 이웃끼리의 協扶意識을 고스란히 받아들인 채 동요로 쏟고 있다. 서로 돕고 괴로움을 서로 나누는 내용의 사설을 즐겁게 노래하며 集團的인 놀이를 되풀이하는 가운데, 사회에 적응하는 능력을 기름으로써 寬容化, 協同化의 정신을 배운다. 3.2. 전승동요에 보면, 또한 同類意識이 꽤 드러난다. 많은 노래의 내용에서도 살필 수 있거니와, 四足獸를 제재하기보다, 자그만 동물을 노래하는 경향이 많음도 또한 同類意識에 근거함인 줄 안다. 3.3. 또한 한국의 전승동요에는 樂天的 快朗性이 두드러지게 드러난다 이 樂天性은 세게 모든 어린이들의 일반적 성향이겠지마는, 한국 전승동요의 경우에는 그 快朗催에 멋이 깃들어있다. 3.4. 어린이들은 民主主義의 信奉者다. 水平的 民主意識이 짙게 깔렸는가 하면, 「類同의 引力」(the attraction of likes)에 따른 交友 또한 민주주의에 터전한 것이다. 3.5. 한국의 어린이들은 벗들과 어울리며 뛰놀면서 道德的 規準과 集團的 思考를 배우며 익히는 가운데, 生活秩序를 짙게 터득해 간다. 3.6. 전승등요 가운데는 곱고 소담스러운 꿈이 흐른다. 어린이들에게 주어지는 꿈은 관념적이요, 허황한 게 아니라, 우선은 비록 자그맣더라도 일상적, 구체적인 것이다. 3.7. 또한 전승동요에는 父母兄第 특히 母情으로부터 출발하여 벗과 이웃으로 擴散되는 따스한 愛情이 넘친다. 1.0. Today, the problems of youth are a worldwide issue. In the case of Korea, its rapid modernization during the past 20 or 30 years has had harmful side effects, resulting in crises that are typical in a modernizing society. 1.1. To overcome the such crises, Korea's youth culture must be integrated into society as soon as possible. we can utilize orally-handed-down children's songs one of our cultural inheritances, as a method to overcome these crises. 1.2. Since orally-handed-down children's songs has not yet been collected and studied on a scale, there are limits to this attempt to analyze Korean youths' attitudes in the structure of Korean oral folktales. 1.3. There are various ways to analyzing youths's attitudes in Korean orally-handed down children's songs. This essay will put emphasis on analyzing folktale materials and on disclosing youths's attitudes in the themes of these tales. 2.0. By consulting several classification schemes of Korean orally-handed-down children's songs materials can be analyzed as one method of studying the structure of attitudes in Korean orally-handed-down children's songs. 2.1. In regard to Kim So-woon' s, Im Dong-kwon's and Park Doo-jin's classification schemes, Korean orally-handed-down children's songs are divided into seven parts, including the following: 1. Songs of animal & plants, 2. songs of the celestial sphere & atmospheric phenomena, 3. songs of merrymaking, 4. songs of satire, 5, songs of language, 6, cradlesongs, 7. others. 2.2. songs of animal & plants, and of the celestial sphere & atmospheric phenomena, can be said to be "songs of nature" since the two songs celebrate nature. Children learn morality, virtue and public order in the course of enjoying themselves while singing the "songs of nature". 2.3. The songs of satire and language are "language songs" of a sort. Therefore, broadly speaking, they refer to merrymaking. Since songs of nature (songs of animal & plants, and of the celestial sphere) are dynamic and static song·s for children, the main songs of Korean orally-handed-down can be said to be songs of satire. 2.4. Therefore, most of Korean orally·-handed-down children's songs are songs of nature, or songs of merrymaking 3.0. Though orally-handed-down children's in the category of nursery rhymes are not as clear as songs, youths's attitudes in orally-handed-down children's can to divided into several patterns. The most striking patterns of youths' attitudes are here: 1. attitudes of cooperation, 2. attitudes of same sort, 3. attitudes of optimistic life, 4. attitudes of liberal democracy. 5. attitudes of public order, 6. attitudes of beautiful dreams, 7 attitudes of deep love. 3.1. Children learn and enjoy their songs while learning attitudes of cooperation front their family and from neighbors. They also learn the sprit of generosity by developing their contribution to society in the course of singing songs of joys and sorrows, and while living ill a group. 3.2. Attitudes of same sort are often presented in the orally-handed-down children's songs and in the many songs. Notably, regarding attitudes of same sort, most of the songs were not about big, four-legged animals, but about small animals. 3.3. An optimistic cheerfulness is remarkly present in Korean orally-handed-down children's songs The cheerfulness is typical of a child's inclination toward the world. In addition, Korean orally-handed-down children's songs characteristically reflects zest in addition to cheerfulness. 3.4. Children are devotees of democracy. They are attracted to equality as well as the haying attitudes of liberal democracy. 3.5. Korean children learn the conventions of social life in the course of familiarizing themselves with the moral canons and the thought manners of their peer group. 3.6. There are beautiful and attractive dreams in the orally-handed-down children's songs Children's dreams are not ideological and unreliable, but substantial and actual even when they are small in scale. 3.7. Finally, in Korean orally-handed-down children's songs, there is evidence of affection spreading to friends and neighbor from parents, affection between brothers and sisters, and especially of a mother's devotion.

건강한 한국인에서의 배변 조영술 소견

나용호,장명규,김태현,김형언,유광현,진경민 大韓消化器病學會 1995 大韓消化器病學會誌 Vol.27 No.3

백서 두개관세포에서 Ipriflavone이 골조직 개조에 미치는 영향

이용승,김영준,이기헌,황현식 대한치과교정학회 2005 대한치과교정학회지 Vol.35 No.4

본 연구는 ipriflavone (isopropoxyisoflavone)의 투여가 백서 두개관세포의 증식과 골조직 개조에 미치는 영향을 알아보고자 시도되었다. 태령 20-21일째의 백서 두개관세포를 분리 배양한 후, 10^(-9) M부터 10^(-5) M까지 농도의 ipriflavone을 투여하고 1일째와 3일째에 MTT 분석을 시행하여 흡광도를 평가한 결과, 모든 농도에서 백서 두개관세포의 증식을 보이지 않았다. 한편 골조직 개조에 미치는 영향을 알아보기 위하여 14일째에 alizarin red염색을 시행하여, 형성된 석회화 결절 면적을 측정하였을 때, 10^(-8) M, 10^(-7) M, 10^(-6) M 농도를 투여한 경우 석회화 결절 형성이 유의하게 증가하였다. 골아세포의 분화에 미치는 영향을 알아보기 위하여 ipriflavone을 투여하고 7일째와 14일째에 추출한 RNA를 역전사 중합효소 연쇄반응(RT-PCR)을 시켜 bone sialoprotein (BSP), type 1 collagen (COL I), osteocalcin (OCN) 유전자 발현을 관찰한 결과 BSP와 COL I 유전자는 배양 7일째 높은 발현을 보였고, OCN 유전자는 배양 14일째 높은 발현을 보였다. 이상의 연구결과 ipriflavone이 백서 두개관세포에서 석회화를 촉진시키고 골아세포의 분화에 관여하는 BSP, COL I 및 OCN 유전자 발현을 증가시켜 골조직의 개조를 빠르게 할 수 있음을 시사하였다. lpriflavone (isoprofoxyisoflavone), a synthetic derivative from soy isoflavone diazein, has been shown to inhibit bone resorption and perhaps stimulate bone formation. This study was performed to examine the effects of ipriflavone on the proliferation and bone remodeling in rat calvarial cells in vitro. The rat calvarial cells were isolated from fetus aged 20 to 21 days and cultured in BGJb media. The graded concentration of ipriflavone (10^(-9)-10^(-5) M) was administered into cultured cells. When the cell proliferation was estimated through the measurement of MTT assay, there was no increase in cellular proliferation of the rat calvarial cell at any ipriflavone concentration. The cellular activity was evaluated through the formation of mineralized nodules stained by alizarin red. The formation of mineralized nodules significantly increased at concentrations of 10^(-8) M, 10^(-7) M and 10^(-6) M ipriflavone. Reverse transcription-polymerase chain reaction analyses (RT-PCR) were done at 7 and 14 days after culture to detect the expression of Bone Sialoprotein (BSP), Type I collagen (COL I) and Osteocalcin (OCN). As a result, the expressions of BSP and COL I increased of the 7th day of culture and the expression of OCN increased on the 14th day of culture. These results indicate that ipriflavone facilitates the bone remodeling process by promoting rat calvarial cell differentiation and stimulating mineralization through increased expression of extracellular matrix genes, such as BSP, COL I and OCN.

기관과 외국인투자가의 투자행태

김용현 한세대학교 2001 敎授論叢 Vol.17 No.-

사탕수수에 있어서 揷植時期와 비닐멀칭이 主要形質에 미치는 影響

吳現道,金龍湖 濟州大學校 亞熱帶農業硏究所 1990 亞熱帶農業硏究 Vol.7 No.-

사탕수수의 揷植時期에 따른 비닐멀칭이 主要形質에 미치는 影響을 究明하기 위하여 1986年 3月 20日부터 11月 15日 까지 亞熱帶 農業硏究所에 POJ 2725 供試하여 3月 20日, 30日, 4月 10日, 20日, 30日에 揷植하고 폴리에칠렌 필름으로 멀칭하여 표준구와 比較 分析한 結果를 要約하면 다음과 같다. 1) 草長, 莖長은 4月 10日 揷植區에서 긴편이었고, 멀칭구는 표준구에 비해 길었다. 2) -2b;出芽日數는 揷植時期가 늦어질수록 短縮되었고 멀칭구는 표준구에 비해 18日이나 빨랐다. 3) 4月 10日 揷植區에서 收量이 가장 많은 경향이었고 멀칭효과도 현저하였다. 4) 收量은 草長, 莖長, 株當葉重과 正의 相關을 나타내어 이들 形質이 增加될수록 收量이 增加되었다. 5) 段階別 多重回歸分析方法에 의해 收量에 가장 크게 영향을 미치는 形質은 節數, 株當 葉重, 莖長 順이었다. This experiment was carried out at the Research Institute for Subtropical Agriculture, Cheju National University, Cheju, Korea to elucidate the effect of cutting time and polyethylene mulching on the growth and yield characters in sugarcane. Stems of sugarcane(Saccharum officinarum L. cv POJ 2725) were cutted at an interval of 10 days from March 20 to April 30. 1986 and grown with or without polyethylene film mulching. The results obtained are summarized as follows. Plant height and stalk height tended to greater at April 10 cutting and were significantly increased by polyethylene mulching. The earlier the cutting time, the longer days to emergence and polyethylene film mulching reduced days to emergemce by 18days compand to control. Yield was the greatest of April 10 cutting which appeared optimum cutting date and was significantly increased by polyethylene mulching. Yield was significantly and positively correlated with plant height, stalk height and fresh of leaves/plant. Yield characters which had a great influence on the yield were primarily no. of nodes, secondly fresh weight of leaves/plant and thirdly stalk height.

한국증권시장의 효율성에 대한 연구 : 필터기법을 이용

김용현,정진호 한세대학교 1999 敎授論叢 Vol.15 No.-