해수 환경에서의 철근과 GFRP리바의 굽힘강도 특성에 관한 연구

한길영,최명선,곽상묵 朝鮮大學校 機械技術硏究所 2003 機械技術硏究 Vol.6 No.1

Fiber reinforced plastics(FRP) attracted muGh attention as a form of concrete reinforcement in the past decade. Compared with existing construction matrials, FRP possesses many advantages such as light-weight. high-strength, corrosion resistant properties, etc. Among other fabrication process of GFRP, pultrusion is one of the promising ones for civil infrastructure application. This paper describes the need for a ductile Fiber Reinforced Plastics (FRP) reinforcement for concrete structures. To promte the degradation of the adhesive condition a t the fiber-matrix micro interface without matrix dissolution loss were carried out in salt water surrounding. The absorption properties and the bending strength were compared about GFRP rebar and steel bar. Due to the fiber permeability absorption of moisture take place through both the fiber and the matrix. The diffusivities obtained for Glass-Polyester are found to be in good agreement with those available in the existing literature.

Mercury wet deposition in rural Korea: concentrations and fluxes

Ahn, Myeong-Chan,Yi, Seung-Muk,Holsen, Thomas M.,Han, Young-Ji Royal Society of Chemistry 2011 Journal of environmental monitoring Vol.13 No.10

<P>The characteristics of Hg wet deposition were investigated in a rural area of Korea from August 2006 to July 2008. The volume weighted mean (VWM) Hg(T) concentration and cumulative Hg(T) flux were 8.8 ng L<SUP>−1</SUP> and 9.4 μg m<SUP>−2</SUP> per year, respectively. The VWM Hg(T) concentration varied seasonally, similar to the seasonal pattern in atmospheric Hg(p) concentration. The enhancement of both VWM Hg(T) and atmospheric Hg(p) concentrations in spring and winter was likely caused by the long-range transport of Hg from China. Monthly VWM Hg(T) and atmospheric Hg(p) concentrations were well correlated (<I>R</I><SUP>2</SUP> = 0.36); however, there was no correlation between VWM Hg(T) and RGM (reactive gaseous mercury) concentrations, suggesting that Hg(p) was responsible for the majority of the Hg in wet deposition at this site. The VWM Hg(T) concentration in snow was statistically higher than in rain. In addition, the atmospheric Hg(p) concentration appeared to be elevated for snow events as well. This suggests that both elevated Hg(p) concentrations and the enhanced scavenging efficiency of snow for Hg(p) were responsible for the elevated VWM Hg(T) concentrations measured during snow events.</P> <P>Graphic Abstract</P><P>Elevated Hg(p) concentrations and the enhanced scavenging efficiency of snow for Hg(p) were responsible for the elevated VWM Hg(T) concentrations during snow events. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c1em10014a'> </P>

협심증 이야기

이명묵,Lee, Myeong-Muk 한국건강관리협회 1996 건강소식 Vol.20 No.3

젖소의 파이로프라스마증(症)의 효과적인 집단검색과 치료방법에 관한 연구

이주묵,김명철,Lee, Joo-muk,Kim, Myeong-cheol 대한수의학회 1987 大韓獸醫學會誌 Vol.27 No.2

In the endemic area of bovine piroplasmosis in Chonbuk Province, total of 486 heads of Holstein cow selected from 14 farms randomly were examined the infection status of piroplasma and their blood values. The results obtained were summarized as follows: 1. The etiological agent was only Theileria sergenti and none of the Babesia sp. infection. 2. All of the 486 heads of examined cow were infected with Theileria sergenti (100%). 3. In the initial examination of 11 farms in early summer, the means of blood values were as follows; RBC:$526{\pm}84(10^4/mm^3$), Ht:$27.9{\pm}2.8%$, SP:$7.5{\pm}0.6g/dl$, WBC: $11586{\pm}354/mm^3$, and Fibrinogen: $578.5{\pm}164.1mg/dl$. 4. In the second examinations in slimmer season, the blood values of examined cows had little varieties. But in the winter season, cows housed in the barn, the blood values were greatly increased; RBC: $601{\pm}77(10^4/mm^3)$, (F-value: 37.186**), Ht: $30.5{\pm}1.3%$(F-value: 15.626**) Hb: $12.2{\pm}1.3g/dl$(F-value: 5.899**), SP: $7.4{\pm}0.6g/dl$(F-value: 5.05**). 5. To determine the piroplasma infection in the many herds of cow, the measurement of Ht, Hb, and SP values etc. were more effective and helpful to find the weak cow because the examined process are not only to be easily carry out many samples but also to be done very simple and rapidly. 6. The indications of therapeutic standard values were stablished as follows; the less than 20% in the Ht value, below the 10g/dl in the Hb value, and less than 6g/dl in SP value. When the one among the therapeutic standard values, Ht, Hb, and SP was below the therapeutic standard value, the cow was treated with nutriments. When more than two among them were below the therapeutic standard, the cow was treated with Berenil, at once. In this way, there was no one head which represented clinical signs of piroplasmosis among 486 heads of cow at 14 farms during the year of 1986. 7. In a Korean native cattle infected with Thieleria sergenti seriously, the recovery of blood values was very prolonged by the treatment of Berenil only. But by the transfusion of 300ml blood collected from normal cow, the blood values were recovered rapidly.

Cement/Slag Composite 수화반응의 물리/화학적 특성분석

박홍락(Pak, Hong Rak),고명희(Ko, Myeong-Hee),배승묵(Bae, Seung-Muk),황진하(Hwang, Jin-Ha),강준원(Kang, Jun Won) 대한토목학회 2016 대한토목학회 학술대회 Vol.2016 No.10

Application of Atomic Layer Deposition to Electrodes in Solid Oxide Fuel Cells

Eui-Hyeon Kim,Heui-Soo Hwang,Myeong-Hee Ko,Seung-Muk Bae,Jin-Ha Hwang 한국진공학회 2013 한국진공학회 학술발표회초록집 Vol.2013 No.8

4방향 탄소/탄소 복합재의 열충격 및 삭마 특성

홍명호,오인석,최돈묵,주혁종,박인서,Hong, Myeong-Ho,O, In-Seok,Choe, Don-Muk,Ju, Hyeok-Jong,Park, In-Seo 한국재료학회 1995 한국재료학회지 Vol.5 No.5

PAN계 탄소섬유와 페놀수지를 이용하여 rod를 인발성형 한 후, 다른 섬유분율을 갖는 두종류의 hexagonal type 4D 프리폼을 제작하였다. 석탄계 핏치를 가압함침 탄화공정을 통하여 함침한 후 탄화와 고온열처리를 하였다. 이와 같은 공정을 반복하여 고밀도화된 4D CRFC를 제조하였다. 열충결 시험 후 새로운 크랙이 생성되었을 뿐만 아니라 기존의 크랙이 확장되었으며 이와 같은 크랙들은 공기와의 접촉면을 제공하여 중량감소를 보였다. 공기 산화 저항성을 고온열처리 공정을 거친 것이 약 20% 우수하게 나타났다. 4D CFRC의 밀도와 섬유의 분율이 높을 수록 삭마 저항성이 커지고, 삭마량은 시간에 따라 선형적으로 증가하였으며 type II가 type I보다 삭마저항성이 우수하였다. 삭마 메카니즘을 관찰한 결과 1차적으 기질의탈리가 먼저 일어난 다음 섬유가 삭마되었다.

섬유보강 복합재의 마찰 및 마모특성

주혁종,최돈묵,오인석,홍명호,Ju, Hyeok-Jong,Choe, Don-Muk,O, In-Seok,Hong, Myeong-Ho 한국재료학회 1994 한국재료학회지 Vol.4 No.7

페놀수지 결합재에 보강섬유의 종류에 따라서 내염섬유 보강 복합재(OFRP), 탄소섬유 보강 복합재(CFRP), 유리섬유 보강 복합재(GFRP), 아라미드 섬유 보강 복합재(AFRP)를 제조하였다. 각 보강섬유의 분율을 달리함에 따라 마찰계수 및 마모율을 측정하여 각 보강섬유의 특성이 미치는 영향을 관찰하였다. 아라미드의 섬유량이 45tw%일 때 평균 마찰계수가 0.353-0.383으로 가장 높게 나타난 반면에 핏치계 탄소섬유를 45wt% 보강한 경우 0.164-0.190으로 가장 낮게 나타났다. AFRP와 CFRP의 마모율은 낮게 나타내었으며, GFRP와 OFRP는 섬유분율이 증가함에 따라 급격히 증가하는 양상을 보였다. OFRP는 마모 diagram이 불안정하였으며 CFRP와 AFRP는 대체적으로 안정한 형태를 나타내었다. GFRp는 상당히 불안정한 마모diagram을 나타낸 것으로 보아 마찰 안정성이 가장 떨어짐을 알 수 있었다. Oxidized-PAN fiber reinforced composite(OFRP), carbon fiber reinforced composite(CFRP), aramid fiber reinforced composite(AFRP), and glass fiber reinforced composite(GFRP) were fabricated with phenolic resin matrix by hot press molding. We tested the friction coefficient and wear rate varying with fiber weight fraction and observed the effect of fibers according to characteristics of individual reinforcement. When the amount of aramid fiber was 45wt%, average friction coefficient was maximum value of 0.353~0.383, where as, when the amount of pitch based carbon fiber was 45wt%, average friction coefficient was the lowest value of 0.164~0.190. The wear rate of AFRP and CFRP was low, but that of GFRP and OFRP increases drastically in the case of increasing of fiber weight fraction. Wear diagram of OFRP was unstable, but that of CFRP and AFRP was a bit stable. Through very unstable diagram of GFRP, we found that friction stability of GFRP was the lowest.

Effects of difructose dianhydride (DFA)-IV on <i>in vitro</i> fertilization in pigs

Yi, Young-Joo,Kamala-Kannan, S.,Lim, Jeong-Muk,Oh, Byung-Taek,Lee, Sang-Myeong Editorial Department of Journal of Biomedical Rese 2017 JOURNAL OF BIOMEDICAL RESEARCH -ELSEVIER- ENGLISH Vol.31 No.5

<P>Difructose dianhydride IV (DFA-IV) is produced from levan, which is a natural polysaccharide that belongs to the fructan family, through the activity of levan fructotransferase (LF) derived from microorganisms. Recently, DFA-IV has been expected to have diverse applications in the food and medical industry. Here, we examined the potential application of DFA-IV for<I>in vitro</I> fertilization (IVF) in pigs. In the assessment of acrosomal integrity during incubation, intact acrosomal or viable spermatozoa were highly sustained in 0.1% or 0.25% DFA-IV (69.8%-70.8%,<I>P</I><0.05). Reactive oxygen species (ROS) levels during sperm incubation decreased following the addition of DFA-IV, and 0.1%-0.5% DFA-IV in particular significantly decreased ROS production relative to that seen with no addition or 0.75% DFA-IV. Total fertilization (mono+ polyspermic oocyte) rate was significantly higher in the addition of 0.1% DFA-IV (94.2%) than with other concentrations (71.8%-86.7%,<I>P</I><0.05). When using reduced IVF times and lower sperm numbers, we found that addition of 0.1%–0.5% DFA-IV significantly increased the fertilization rate (<I>P</I><0.05). Fertilized oocytes treated with 0.1% DFA-IV exhibited higher embryonic development and blastocyst formation than those treated with other concentrations (<I>P</I><0.05). Consequently, the addition of DFA-IV during IVF improved fertilization and embryonic development, suggesting the possible use of novel sugars for enhancement of assisted reproductive technology (ART) in mammals. </P>

UL1699 기반 아크모의발생장치에 관한 연구

권완성(Wan-Sung Kwon),김영식(Young-Sik Kim),이영진(Young-Jin Lee),최중묵(Jung-Muk Choi),유재근(Jae-Geun Yoo),최명일(Myeong-Il Choe),최규하(Gyu-Ha Choe) 전력전자학회 2008 전력전자학술대회 논문집 Vol.- No.-

전기로 인한 화재의 주요원인 중 하나는 전기회로에서 발생되는 아크이며, 기존 사용되고 있는 보호장치인 휴즈나 배선용 차단기가 제공하는 과부하, 누전, 단락뿐만 아니라 아크현상에 대한 보호기능을 갖춘 통합 전기화재 감시 및 보호장치의 필요성과 이에 대한 효율적인 운용시스템이 요구된다. 이처럼 다양한 전기화재 사고 중에서 주요 사고 사례 중의 하나가 선로 혹은 전선의 절열 파괴로 일어나는 직렬아크, 스파크(series arc, spark) 현상(누전차단기 혹은 과전류차단기가 동작하지 않는 범위의 아크사고 모의)이다. 이러한 사고를 모의하기 위한 아크발생장치를 설계하여 UL-1699에서 규정하는 아크의 발생여부를 확인할 수 있다.