Microstructure and High Temperature Mechanical Property of Fe–Cr–B Based Metal/Ceramic Composite Manufactured by Metal Injection Molding Process

Kee‑Ahn Lee,Jin‑Han Gwon,윤태식 대한금속·재료학회 2018 METALS AND MATERIALS International Vol.24 No.2

This study investigated the microstructure and the room and high temperature mechanical properties of Fe–Cr–B alloy manufacturedby metal injection molding. In addition, hot isostatic pressing was performed to increase the density of the material,and a comparison of properties was made. Microstructural observation confirmed a bi-continuous structure composedof a three-dimensional network of α-Fe phase and (Cr,Fe)2B phase. The HIPed specimen featured a well-formed adhesionbetween the α-Fe phase and boride, and the number of fine pores was significantly reduced. The tensile results confirmed thatthe HIPed specimen (RT to 900 °C) had higher strengths compared to the as-sintered specimen, and the change of elongationstarting from 700 °C was significantly greater in the HIPed specimen. Fractography suggested that cracks propagatedmostly along the interface between the α-Fe matrix and boride in the as-sintered specimen, while direct fracture of boridewas observed in addition to interface separation in the HIPed specimen.

Han’guk-kwa kŭ iut naradŭl

Han Kee-hyung(서평자) The Academy of Korean Studies 1995 Korea Journal Vol.35 No.3

당원, 삼투압 및 무기염 농도가 Panax ginseng 모상근의 생장과 Ginsenosides 생산성에 미치는 영향

한영현,임종훈,백기엽,유기원 충북대학교 한국과학재단 지정 첨단원예기술개발 연구센터 1998 연구보고서 Vol.3 No.-

인삼 형질전환체는 호르몬이 포함되지 않은 3/4SH 배지에 공구유출식 콘형 생물반응기를 이용하여 배양하였다. 초기 접종 량은 30g/3L로 하였으며 4-5일 간격으로 배양액 내의 당원, 전기 전도도와 pH의 변화를 측정하였다. 처음 pH는 5.8이었으나 배양8일 후 4.95까지 떨어졌으나, 이후 5.63까지 증가하였다. 전기전도도와 탄소원으로 제공된 sucrose는 일정하게 감소되었고, 특히 배양 미삼의 탄소원으로 제공된 sucrose는 배양 20일 후에 완전히 소모되었다. 분해산물인 glucose와 frutose는 20일 까지 점진적으로 증가되었고 이후 급격히 감소되었다. 400ml 플라스크 안에 100ml의 배지량을 첨가하고 3g의 배양 미삼을 접종하여 배양하였을 때 배양 미삼의 생장률은 탄소원의 농도에 따라 증가되었다. 이는 배양 미삼의 환원당, 전당, 그리고 전분의 저장함량이 증가되었다. 그러나 ginsenosides의 함량은 반 비례관계로 감소되었다. 배양 주간별 ginsenosides의 함량변화는 배양초기인 1,2 주에는 급격히 감소되었으며 3주에는 약간 증가하고 4,5주 사이에 급격히 증가되었다. 삼투조절제로 사용한 0.1, 0.2, 0.3M의 mannitol과 sobitol은 생장 면에서 0.1M의 실험구가 좋았으나 ginsenosides의 함량은 삼투압농도와 반비례 관계로 급격히 감소되었다. Panax ginseng roots transformed by Agrobacterium rhizogenes were cultured in the air-lifted cone type bubble bioreactor that contained a hormone-free SH medium with 3% sucrose. The inoculating vol. was 30g/3L. The pH, EC, glucose, fructose and sucrose were investigated every 4 or 5 days. The pH was 5.8 initially and become 4.95 after 8 days and then increased after to 5.63. EC and sucrose contents decreased with culture days and then especially sucrose, which is carbon source for bio-ginseng rots, were depleted after 20 days. Fructose and glucose content increased gradually till 20 days with regular intervals, and then decreased quickly. While the roots were culture in 400ml flask, the higher sucrose consents, the higher growth rate. The growth rate and starch, reducing and total sugar contents were increased with the increase of sucrose concenturations but the contents of ginsenoside decrease. Variations of ginsenosides each weeks decreased first 1 or 2 weeks, increase a little after 3 weeks and largely between 4 and 5 weeks of flask culture. The osmotic regulation regents on growth were treated the 0.1, 0.3, 0.5M sobitol and mannitol. Amount of the growth were all increased on 0.1M but largely decreased the ginsenoside.

쌀, 조, 수수 및 콩의 食餌가 흰쥐의 成長 및 血液性狀에 미치는 影響

한백수,주현규,사동민,박병순,박기웅 선문대학교 첨단과학기술연구소 1996 첨단과학기술연구소 논문집 Vol.1 No.1

쌀, 조 수수, 및 콩의 식이가 흰쥐의 성장 및 혈액 성상에 미치는 영향을 조사하기 위하여, 평균체중 180g의 Sprague-Dawley계 rat(♂) 각 5마리씩을 대조군(T_(0)), 쌀(T_(1)), 조(T_(2)), 수수(T_(3)), 콩(T_(4))급이군등 5개군으로 나누어 실온에서 6주간 사육하면서 사료섭취량, 급수량, 증체량과 6주후의 혈액상의 변화틀 조사하였다. 사료 섭취량은 대조군이 각 처리 실험군보다 높았으며 물의 급수량도 동일한 결과이었으며 그 순위는 쌀, 조, 콩, 수수 순으로 감소하였으며, 각 처리군의 증체량은 대조군 보다 낮았으며, 특히 수수는 초기보다 감소하였고, 각 처리군의 사료효율은 대조군보다 낮았으며 특히 수수처리군이 타 처리군보다 낮았다. 연액성상의 변희는 대조군에서는 큰 변화가 없으나 수수군에서 BUN, HOT지 다른군보다 높았으며 쌀의 처리군은 creatinine치가 높았고 조에서는 혈당치가 낮았으며, 콩에서는 LDH는 높았고, HGB, HCT, PI.T, RBC가 낮았고, 특히 콩 수수에서는 혈액상의 변화가 가장 컸으며 다른 실험군과 비교하였을 때 통계적인 유의성이 인정되었다. This study was conducted to investigate the effects of rice, millet, sorghum and soybean diet on the growth rate, daily intake feed ratio and change in hematology of male rats. The experimental male rats of 180g average weight were fed on control (T_(0)), rice (T_(1)), millet (T_(2)), sorghum (T_(3)) and soybean diet (T_(4)) for 6 weeks. The amount of daily feed and water intake supply in each diet group is higher than that of control group to as shown in the following order: rice, millet, soybean, sorghum. The growth ratio of each diet group is lower than that of control group. Especially, sorghum made each diet group reduce the weight even more than the initial weight. Control group is lower than each diet group in regard to the effective ratio of feed. Especially, the sorghum group is lower than other groups. Control group remained same in the change of hematology, however, sorghum group is higher than other groups for BUN, HCT. Rice group is higher in creatinine and millet group is lower in glucose content of serum than any other groups. Soybean group is higher in LDH but lower in HGB, HCT, PLT, RBC than control group. Especially, the soybean and sorghum groups showed a big change in hematology and had the statistic significance in comparison to other groups.

독일노동 운동의 黎明

韓基榮 제주대학교 1985 논문집 Vol.22 No.2

1848년 이전 독일의 가장 뚜렷한 사회주의자로 여겨지는 Whilhelm Weitling도 초기에는 Lamennais처럼,종교적인 믿음으로 충만되어 있었음이 분명하다. Weitling 의 저술에는 또한 Saint Simon,Fourier,Cabet. Owen의 영향도 엿볼 수 있다. 방랑하는 재단사였던 Weitling 은 Marx,Engels 이전에 Paris에 <의인동맹>(후에는 공산주의자 동맹)을 조직하여 정치적인 성격을 나타냈다.

初期社會主義의 硏究史的 考察

한기영 제주대학교 1993 논문집 Vol.37 No.1

인공치아우식의 재광화에 미치는 불소의 영향

한원섭,금기섭,이찬영 大韓齒科保存學會 1996 Restorative Dentistry & Endodontics Vol.21 No.1

사립체 DNA 뉴클레오타이드 3243 A→G 돌연변이 [MTTL1^*MELAS3243G]에 의한 MELAS 증후군

박기형,김승현,이영주,김희태,김주한,김명호,박성섭 대한신경과학회 1998 대한신경과학회지 Vol.16 No.4

古代 奴隸制의 硏究史的 考察

한기영 제주대학교 1987 논문집 Vol.24 No.1

J.Vogt glaubte, daβ die antike Sklaverei in den demokratischen Landern Europas und Amerikas immer noch nicht die gebuhrende Aufmerksamkeit gefunden hade, wahrend sie in der kommunistischen Welt einer feststehenden Thorie eingfugt worden sei. Mein Aufsatz ist Einfuhrung in Europas Forschungsgeschichtlicher Uberblick von antike Sklaverei. Die Meinungen von Marx und Engels duften demnach nicht als absolut gultig empfunden werden, sondern nuBten Ansatzpunkte fur weituhrende Fragestellungen und neue Forschungen sein.

운동기술의 학습에서 인지적 선행 훈련의 역할

한지영,김기웅 이화여자대학교 동작과학연구소 2004 이화체육논집 Vol.7 No.-

The study is intended to examine the influence of perceptual pretraining - one form of available pre-practice information - on teaming straight stroke techniques in golf putting and to examine what influence differing frequencies of task information have on the acquisition of golf putting techniques. The study is based on the findings of previous studies that pre-practice information exerts a significant influence on motor leaning. For this study, 24 right-handed female university students, with an average age of 23, were randomly and equally allocated to three different experimental groups. One group was given 100% pre-practice information, the second group 50%, and the third was given 0%. The experiments was designed into the following regiment: Acquisition trial blocks were performed for 8 blocks, with each block consisting of 5 trials (i. e. a total of 40 trials). Accordingly, the experiments were conducted with a 3 (groups) x 8 (blocks) factorial design with repeated-measures on block Twenty four hours after the completion of the acquisition trial block, a retention test was conducted for 2 blocks (a total of 10 trials). The score points calculated from the experiments were converted into absolute error(AE) and variable error (VE) values for accuracy and consistency The results revealed a significant statistical difference a part of AE and VE values. In terms of descriptive statistical data, the group given 100% of pre-practice information posted the best results, compared to the two other test groups, with 50% group performing better than the 0%, group. The finding of this study demonstrated that perceptual pretraining is not affected by guidance hypothesis, and therefore, providing pre-practice information with more frequency contributes to the process of acquiring motor skills.