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.

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

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.

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.

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.

公園綠地의 觀光慰藥便益에 關한 考察(1)

林元炫,金龍洙 경북대학교 교육대학원 1990 논문집 Vol.22 No.-

The lake of research concerning tourism and recreation benefits of urban parks have prevented their full evaluation as environmental amenities. In this study, individual as well as social beneits of tourism and recreation activities in urban parks were examined through a questionnaire. The data for this research were collected by the interview in three parks ; Palgongsan park, Dalsung park, Bumma park. that parks draw users frome wide to narrow ranges of distances. Implications of the findings for urban parks design, and tourism and recreation policy are discussed. Travel cost method and contingent valuation method were applied essentially. That permits the estimation of relationship between distance as a total cost and visits which can be used to estimate demend functions for tourism and recreation experiences provided by a site. Applications to urban park have been gravity-type models have been used to estimate the use of the park. Finally, the tourism and recreation benefits of each parks per user·day·month·year 1988 were estimated by the total experiences of the users. It is possible to use a Travle Cost Method at city park in Korea. and a methodology to estimate tourism and recreation benefits of urban pakrk is developed combining the travel cost approach with contingent valuation approach on the urban scale. Most of the demend functions for each parks were well fitted by the variables of distance of the users for each parks were well fitted by the added cost in ㎞. and most of the demend functions were well fited when the all variables was in the form of natural logarithms. Distance has high relationship with total cost in each parks. Astimated social benefits of tourism and recreation activities in Palgongsan park was 102,248 million won. Dalsung park was 9,481 million won, and Bumman park was 1,453 million won a year 1988. But, these values should be regaded as minimum estimated. Becouse when the distance were transelated by won, time cost were excluded. This study is a small but important step in the investigation of urban park and recreation site demend and benefit. Many of the developments in contingent valuation method and travel cost modeling should now be applied at the urban scale parks and recreation site. such studies will contribute significently to the improvement of methodology for tourism and recreation benefits measuring, especially individual and social benefits for the urban parks, and provide much needed guidence for desisions concerning the allocation of scarce tourism and recreation resources.

熱帶作物의 栽培現況과 開發可能性에 관한 硏究

吳現道,金瀅玉,金龍湖 제주대학교 1984 논문집 Vol.18 No.-

世界 熱帶特用作物의 栽培現況과 開發可能性을 檢討하기 爲하여 文獻調査에 依하여 本 硏究를 遂行하였다. 1. 食糧解決을 爲하여 穀物 生産量이 1970年부터 1981年에 걸쳐 35% 增加하였다. 2. 熱帶 油脂料作物의 生産狀況을 보면 땅콩의 生産量은 亞細亞 및 아프리카 地域에서 世界 生産量의 90%를 차지 하고, 비麻子 生産은 아프리카 地域에서 70%를 차지하고 있으며 그外의 油脂作物은 東南亞細亞가 主産地를 이루고 있다. 3. 熱帶 澱粉料作物은 最近에 cassava의 生産이 두드러지게 增加하고 있으며,sago palm이 새로운 澱粉料作物로 脚光을 받고 있다. 4. 糖料作物인 sugarcane의 生産量은 1970年부터 1981年 사이에 37% 增加 하였고 앞으로 계속하여 需要가 늘어날 展望이다. 5. 嗜好作物인 coffee와 담배는 栽培面積이 10年 사이에 크게 增加하지 않았으나 單位面積當 收穫量은 顯著히 增加 하였다. 6. 熱帶纖維料作物 中에서 木花는 10年間에 栽培面積은 2% 增加에 不過하였으나 生産量은 約 30%가 增加 하였다. 7. 熱帶果實中에서 生産量이 가장 많은 것은 banana와 orange이며 이들의 年間 生産量은 各各 4,000萬ton에 이르고 있다. banana는 東南亞細亞가 主産地이며 orange는 南ㆍ北美가 主産地를 이루고 있다. 8. 嗜好料作物, 纖維料作物, 澱粉料作物, 糖料作物 및 油料作物 90 種을 木本과 草本으로 區分하여 生態를 檢討한 結果 木本性植物 47 種中 亞熱帶에 分布하는 種數는 13種에 不過하였고 草本性植物은 43 種中亞熱帶에 分布하는 種數가 33種으로 草本이 顯著히 많았다. This study required a comprehensive review of the literature referring to tropical special crops. The following information was extracted. Production of cereals increased by 35% from 1970 to 81, and this increase hepled to alleviate the world food shortage. With reference to tropical oil crops, Africa and Asia grew 90% of the total world production of groundnuts. Africa producted 70% of the world's castor bean. The chief producing area of the other oil crops was East/South Asia. In the production of tropical starch crops, cassava is increasing rapidly, sago plam is spotlighted as a new tropical starch crop. The production of sugar cane as a sugar crop increased by 37% from 1970 to 81, and the demand continues to rise, it has good future prospect s. The production of coffee and tobacco, recreation crops has not increased very much over the past 10 years. However, the yield's per area increased markedly. The acreage of cotton, a tropical fiber crop, increased by a mere 2% but yields increased by 30% over the past 10 years. The principal tropical fruits are bananas and oranges and the present production of each crop exceeds 40,000,000 tons. The main producing area for bananas is East/South Asia and for oranges is South and North America. Ecological examination of 90 species of recreation, fiber, starch, sugar and oil crops showed that only 13 species of recreation, fiber, starch, sugar and oil crops showed that only 13 species are distributed in subtropical zones out of 47 arbor crop species and 33 species are distributed in subtropical zones out of 43 species of herb crops.

운동이 지단백대사에 미치는 효과

김주현,정용진 東國專門大學 1997 金龜論叢 Vol.4 No.1

현대인의 활동량과 운동량은 급속도로 감소되고 있으며, 특히 coronary heart diease(CHD)의 위험인자의 감소를 위한 운동처방이 증가되고 있다. CHD의 예방을 위해 CHD의 위험인자중 가장 널리 인지되고 있는 lipoprotein의 수준에 미치는 운동의 효과를 조사하였다. 운동선수의 HDL-C의 수준은 일반인에 비해 유의적으로 높았으며, 운동동안 그 수준이 상승되었다. 또 평소 운동이 전혀 없던 일반인에게 낮은 강도의 유산소 운동을 실시하거나 endurance exercise를 실시한 경우에도 체내의 lipoprotein의 성분과 혈장의 지방수준이 변화하였다. 한편 여가시간의 활동정도 차에 의한 변화 역시 유의적으로 나타났다. 운동은 실시한 운동의 종류, 강도, 기간 대상자의 평소의 활동상태에 따라 lipoprotein의 변화가 상이하게 나타나는 양상을 보인다. 운동에 의한 lipoprotein의 변화는 여러 기전에 의해 일어나는 것으로 제기되고 있다. 운동량의 증가는 근육에서 소비되는 지방산의 증가를 요구하여 LPL 활성이 증가되고 증가된 LPL활성은 chylomicron과 VLDL로 부터 TG, cholesterol, phospholipid, apolipoprotein을 방출시킨다. 운동에 의해 HDL의 subfraction도 변화되는데, 증가된 LPL와 HTGL의 수준의 감소에 의해 HDL3보다 HDL2의 subfraction이 증가된다. 한편 LCAT는 증가되어 HDL3 표면의 free cholesterol, fatty acid로 부터 cholesterol ester를 형성하여 HDL molecule의 중심으로 이동하여 HDL3는 HDL2로 전환을 촉진시킨다. CETP는 운동에 의해 감소되어 HDL의 esterified cholesterol이 VLDL과 LDL로 net transfer되는 경우가 감소하게 된다. 운동이 CHD에 미치는 효과는 운동자체의 효과 뿐 아니라 대상자의 생활 환경의 여러 요인과 관련되므로 식이 조건등 여리조건을 통제시킨 연구가 계속되어야 한다고 사료된다.

小兒嘔吐의 臨床的 考察

金龍鉉,金宇煥 동의대학교 한의학연구소 1999 동의한의연구 Vol.3 No.-

Clinical studies were performed on 78 cases who had vomiting cured by oriental medicine or acupuncture from December 1998 to April 1999. The results were as follows: 1. In 78 cases of vomiting, the ratio of the male was 48.1%(38 cases) and female was 51.3%(40 cases). 2. In 78 cases of vomiting, the ratio of the under 1month was 3.9%(3 cases), under 1year was 9%(7 cases), under 3year was 62.8%(49 cases), under 6year was 24.3%(19 cases). 3. In duration of treatment, the ratio of the under 1 day was 21.8%(17 cases), under 3 day was 33.3%(26 cases), over 3 days was 44.9%(35 cases). 4. The ratio of oriental medicine and acupuncture was 67.9%(53 cases), oriental medicine was 6.5%(5 cases), acupuncture was 25.6%(20 cases) 5. The ratio of Excellent was 35.9%(28 cases), good was 44.9%(35 cases), improved was 12.8(10 cases), poor was 6.4%(5 cases).