Al-xMg-CNT 복합분말체의 용융특성에 미치는 마그네슘 첨가와 온도의 영향

임정규 ( Jung Kyu Lim ),최경환 ( Kyong Hwan Choe ),김상섭 ( Sang Sub Kim ),조규섭 ( Gue Serb Cho ) 대한금속재료학회(구 대한금속학회) 2013 대한금속·재료학회지 Vol.51 No.4

We conducted melt-down experiments on Al-xMg-carbon nanotube (CNT) complex powder compacts at 700℃ and 800℃ for carrying the CNTs into the molten Al7021 matrix alloy. The parameters in the melting experiments were the holding temperatures and the amount of Mg content. The microstructures of the melt-down compacts were observed by optical microscopy (OM) and field emission scanning electro-microscopy (FESEM). The several phases obtained from the reaction products within the Al-xMg-CNT compacts were identified by energy dispersive X-ray spectroscopy (EDXS) and X-Ray diffractometry (XRD). The complete melt-down area was increased due to a large addition of Mg in the compacts and outer areas remained as undissolved powder compacts due to the large number of oxidation products such as MgO, MgAl2O4 and Al2O3. CNTs were observed on the surface of Al powders with oxidation products at 700℃ in a melting experiment. However, at 800℃, the CNT agglomerates moved away from the center because of the poor wettability and low density of the CNTs.

Al-CNT 복합펠렛의 계면반응에 미치는 마그네슘 첨가 및 제조 조건의 영향

임정규 ( Jung Kyu Lim ),최순열 ( Soon Yool Choi ),최경환 ( Kyong Hwan Choe ),김상섭 ( Sang Sub Kim ),조규섭 ( Gue Serb Cho ) 대한금속재료학회(구 대한금속학회) 2013 대한금속·재료학회지 Vol.51 No.5

In the present study, Al-CNT pellets were investigated to understand the effect of Mg addition and manufacturing conditions on the interfacial reactions between Al and CNTs in Al-CNT pellets. The pellets were heated and held at 700 ℃ and 800 ℃ for 2 hours under nitrogen (N2) atmosphere. To confirm the reactions between Al and CNT in the pellets under different manufacturing conditions, the microstructures were observed by optical microscopy (OM) and field emission scanning electro microscopy (FESEM). And, the composition and reaction phases were analyzed by energy dispersive X-ray spectroscory (EDXS) and X-ray diffractometry (XRD). The presence of oxidation products and Mg on the surface of Al powder in the pellets appeared to prevent the formation of Al4C3. But, Al4C3 reaction products were increased due to the high temperature of 800 ℃, which produced a high amount of reduced aluminium and increased the reaction areas between Al and CNT. The Al-CNT pellets compacted under air atmosphere prohibited the reaction between Al and CNT because of the high amount of oxidation products, such as MgO and MgAl2O4.

모 일산화 연 제조 업체 근로자들의 연 폭로에 관한 연구

임상복,임정규,이성수,안규동,이병국,Lim, Sang-Bok,Lim, Jung-Kyu,Lee, Sung-Soo,Ahn, Kyu-Dong,Lee, Byung-Kook 대한예방의학회 1995 예방의학회지 Vol.28 No.4

In order to investigate the level of lead exposure of workers in litharge making industry and to evaluate how lead exposure, personal habit such as smoking and drinking affect the prevalence of lead related symptoms and other study variables, we investigate 114 workers(24 office workers and 90 lead exposed workers) in a litharge making industry. Study variables chosen were blood lead(PbB), zinc protoporphyrin in whole blood(ZPP), Hemoglobin(Hb), hematocrit (Hct), SGOT and SGPT symptom questionnaires which had 15 lead exposure related symptoms were provided to all workers and filled up by themselves and reconfirmed by physician. The results obtained were as follows; 1. The mean value of PbB, ZPP and SGOT in lead exposed group were higher than those of non-exposed group, and there were no differences of means in other study variables. 2. The smoking and drinking rate of study subjects were 65.8% and 71.0% as a whole. Smoking rates were lower in non-exposed group than exposed group, but drinking rate were not. 3. There were no differences of mean values of study variables between smoker and non-smoker in non-exposed and exposed group, but there was a difference of mean value of SGOT between drinker and lion-drinker in lead exposed group. 4. While the symptom prevalence of lead exposed group were higher in neuromuscular category than non-exposed group, those of non-exposed group were higher or same with exposed group in gastrointestinal and general symptom category. 5. The symptom prevalence of smoker were higher than non-smoker regardless of exposure. 6. The symptom prevalence of drinker were only higher in gastrointestinal symptom category than non-drinker. 7. In multiple stepwise regression analysis of lead related symptoms as dependent variable and blood lead, smoking habit, drinking habit and work duration as independent variables, drinking habit contributed to the gastrointestinal symptom category, whereas blood lead and smoking contributed to the neuromuscular symptom category. For the total symptoms work duration and smoking habit contributed significantly.

흰쥐 뇌 미토콘드리아에 의한 superoxide radical의 생성과 이 radical이 미토콘드리아 및 미토콘드리아 외 물질에 대한 독작용과 그 기전에 관한 연구

노재규(Jae-Kyu Roh),표장근(Jang-Geun Pyo),정명희(Myung-Hee Chung),임정규(Jung-Kyoo Lim),명호진(Ho-Jin Myung) 대한약리학회 1985 대한약리학잡지 Vol.21 No.1

흰쥐 뇌 미토콘드리아에 의한 O₂^-⋅ 의 생성과 이 radical의 유해작용 및 그 작용기전을 알아보기 위하여 본실험을 수행하였다. Succinate와 antimycin존재하에서 미토콘드리아는 O₂^-⋅을 생성하였으며 이는 SOD-inhibitable NBT환원으로 확인되었다. 동일 조건에서 H₂O₂는 일차생성물인 O₂^-⋅의 dismutation으로 생성됨을 알수 있었다. 상기조건에서 미토콘드리아의 막지질이 파괴되었고 반응액에 첨가된 isocitrate dehydrogenase와 적혈구에 각각 불활성화와 용혈이 초래되었다. 이같은 작용은 Fe⁺⁺이 있을때만 관찰 되었다. 그리고 독작용은 superoxide dismutase 혹은 castalase에 의해서 억제되었다. 또한 methional을 첨가하였을 때 ethylene이 생성되었으며 그 생성은 Fe⁺⁺에 의하여 현저히 증가하였다. Ethylene 생성 역시 상기 효소에 의하여 억제되었다. 따라서 미토콘드리아에서 발생된 O₂^-⋅은 거대분자 및 세포에 독성을 나타낼수 있으며 이같은 작용은 Fe⁺⁺의 촉매작용에 의한 O₂^-⋅와 H₂O₂의 상호작용으로 발생되는 OH⋅ 에 의한것으로 추측되었다. 이상의 결과는 미토콘드리아가 유독성 산소 radical을 발생하므로 조직손상을 시킬 수 있다는 가능성을 시사하는 증거라고 생각되었다. The generation of O₂^-⋅ and its toxic effects were studied with rat brain mitochondria. The production of O₂^-⋅ from mitochondria in the presence of succinate and antimycin was demonstrated by SOD-inhibitable reduction of NBT. Although succinate can support the O₂^-⋅ formation, the highest rate needs antimycin indicating that blockade of electron flow in the respiratory chain augments the univalent reduction of molecular oxygen. Under this condition, H₂O₂ was also observed to be produced. But its formation appears to be derived from the dismutation of the primary product, O₂^-⋅ since the rate of H₂O₂ production was markedly decreased by NBT and ferricytochrome c. The O₂^-⋅ and H₂O₂ produced were able to cause toxic actions to mitochondrial and extra-mitochondrial components as shown by lipid peroxidation of mitochondrial membrane, and inactivation and lysis of isocitrate dehydrogenase and erythrocytes added to the medium, respectively. In all the toxic actions observed, Fe⁺⁺ was required. It appears that in the toxic actions OH⋅ generated from the iron-catalyzed Haber-Weiss reaction acts as a mediator. This was supported by the finding that mitochondria in the presence of succinate and antimycin produced ethylene from methional, and Fe⁺⁺ added increased the ethylene production. The observed toxic actions of mitochondrial O₂^-⋅ may provide evidence supporting a potential role of mitochondria as a source of oxygen radicals to cause tissue damage.

A Study on Introduction of Licenced Title Examiner Reflecting Theory of Real Estate Title Analysis in Korea

이규열(Lee, Kyu-Yull),이동찬(Lee, Dong-Chan),이창석(Lee, Chang-Suck),임정규(Lim, Jung-Kyou) 한국부동산학회 2014 不動産學報 Vol.56 No.-

1. 내용 (1) 연구목적 본 연구는 부동산개발, 부동산중개, 부동산감정평가활동을 중심으로 살펴보고 이에 근거하여 부동산권리분석활동의 필요성을 제시하고자 한다. (2) 연구방법 한국의 대표 문헌연구를 통해 부동산권리분석업의 현황과 문제점, 권리분석사 제도의 필요성을 유추하고자 한다. (3) 연구결과 우리나라에는 부동산 권리를 조사하는 공식적이고 독립적인 업이 아직 존재하지 않는다. 자주 발생하는 부동산거래사고의 안전을 위해서 또한 부동산권을 보호하기 위한 초기 단계의 전문직이 필요하다. 2. 결과 부동산 권리분석은 부동산거래의 안전과 국민경제의 발전에 이바지하고 각종 거래사고를 미연에 방지함으로써 부동산과 인간과의 관계개선에 이바지 한다. 또한 분쟁의 소지를 감소시키고, 국민의 재산권 보호와 부동산거래질서 확립에 이바지하기 위해서는 공인된 권리분석사 제도의 수립이 절실히 요구된다.

논문 : 탄소나노튜브 표면의 무전해 니켈입자 코팅

조규섭 ( Gue Serb Cho ),임정규 ( Jung Kyu Lim ),장훈 ( Hoon Jang ),최경환 ( Kyeong Hwan Choe ) 대한금속재료학회 ( 구 대한금속학회 ) 2010 대한금속·재료학회지 Vol.48 No.5

Carbon Nanotubes (CNTs) have recently emerged as a material with outstanding properties. It has shown promising potential for applications in many engineering fields as electronic devices, thermal conductors, and light-weight composites. Researchers have investigated their use as reinforcements in themetal matrix composites of CNTs. In the present work, we decorated CNTs with Ni particles by electroless plating. The CNTs were wet-ball milled for various milling times with a nickel sulfate solution. The precipitated Ni particles were observed mainly by FESEM. In this study, the dispersion of the CNTs and Ni particles was improved with the addition of the surfactant. Also, as the CNTs were shortened and widened by an increased ball milling time, the size of the precipitated Ni particles increased. It was estimated that the CNTs were deformed and caused some defects on their surface during the ball milling process. Those defects were assumed to be heterogeneous nucleation sites for the Ni particles.

Generation of Superoxide Radical from Rat Brain Mitochondria and Mechanism of Its Toxic Action to Mitochondrial and Extra-mitochondrial Components

노재규,표장근,정명희,임정규,명호진,Roh, Jae-Kyu,Pyo, Jang-Geun,Chung, Myung-Hee,Lim, Jung-Kyoo,Myung, Ho-Jin The Korean Society of Pharmacology 1985 대한약리학잡지 Vol.21 No.1

흰쥐 뇌 미토콘드리아에 의한 $O^{-}_{2}{\cdot}$ 의 생성과 이 radical의 유해작용 및 그 작용기전을 알아보기 위하여 본실험을 수행하였다. Succinate와 antimycin존재하에서 미토콘드리아는 $O^{-}_{2}{\cdot}$을 생성하였으며 이는 SOD-inhibitable NBT환원으로 확인되었다. 동일 조건에서 $H_2O_2$는 일차생성물인 $O^{-}_{2}{\cdot}$의 dismutation으로 생성됨을 알수 있었다. 상기조건에서 미토콘드리아의 막지질이 파괴되었고 반응액에 첨가된 isocitrate dehydrogenase와 적혈구에 각각 불활성화와 용혈이 초래되었다. 이같은 작용은 $Fe^{++}$이 있을때만 관찰 되었다. 그리고 독작용은 superoxide dismutase 혹은 castalase에 의해서 억제되었다. 또한 methional을 첨가하였을 때 ethylene이 생성되었으며 그 생성은 $Fe^{++}$에 의하여 현저히 증가하였다. Ethylene 생성 역시 상기 효소에 의하여 억제되었다. 따라서 미토콘드리아에서 발생된 $O^{-}_{2}{\cdot}$은 거대분자 및 세포에 독성을 나타낼수 있으며 이같은 작용은 $Fe^{++}$의 촉매작용에 의한 $O^{-}_{2}{\cdot}$와 $H_2O_2$의 상호작용으로 발생되는 $OH{\cdot}$ 에 의한것으로 추측되었다. 이상의 결과는 미토콘드리아가 유독성 산소 radical을 발생하므로 조직손상을 시킬 수 있다는 가능성을 시사하는 증거라고 생각되었다. The generation of $O^{-}_{2}{\cdot}$ and its toxic effects were studied with rat brain mitochondria. The production of $O^{-}_{2}{\cdot}$ from mitochondria in the presence of succinate and antimycin was demonstrated by SOD-inhibitable reduction of NBT. Although succinate can support the $O^{-}_{2}{\cdot}$ formation, the highest rate needs antimycin indicating that blockade of electron flow in the respiratory chain augments the univalent reduction of molecular oxygen. Under this condition, $H_2O_2$ was also observed to be produced. But its formation appears to be derived from the dismutation of the primary product, $O^{-}_{2}{\cdot}$ since the rate of $H_2O_2$ production was markedly decreased by NBT and ferricytochrome c. The $O^{-}_{2}{\cdot}$ and $H_2O_2$ produced were able to cause toxic actions to mitochondrial and extra-mitochondrial components as shown by lipid peroxidation of mitochondrial membrane, and inactivation and lysis of isocitrate dehydrogenase and erythrocytes added to the medium, respectively. In all the toxic actions observed, $Fe^{++}$ was required. It appears that in the toxic actions $OH{\cdot}$ generated from the iron-catalyzed Haber-Weiss reaction acts as a mediator. This was supported by the finding that mitochondria in the presence of succinate and antimycin produced ethylene from methional, and $Fe^{++}$ added increased the ethylene production. The observed toxic actions of mitochondrial $O^{-}_{2}{\cdot}$ may provide evidence supporting a potential role of mitochondria as a source of oxygen radicals to cause tissue damage.

Diphenylhydantoin 및 수종(數種)의 중추신경계(中樞神經系)에 작용(作用)하는 약물(藥物)이 흰쥐 대뇌피질절편(大腦皮質切片)의 산소소비량(酸素消費量) 및 non-inulin space Na⁺, K⁺농도(濃度)에 미치는 영향(影響)

마천일(Mahr, Chun-Il),임정규(Lim, Jung-Kyu),박찬웅(Park, Chan-Woong) 대한약리학회 1969 대한약리학잡지 Vol.5 No.2

The effects of dephenylhydantoin, strychnine, coramine, d-amphetamine and chlorpromazine on Qo₂ and non-inulin space Na⁺, K⁺ concentration of rat cerebral cortical slices incubated in pH 7.4 glycylglycine glucose saline was investigated. In general, there are decreased non-inulin space Na⁺ concentration or increased non-inulin space K⁺ concentration or both when the ratio of respiration to non-inulin space is greater than control group except in case of chlorpromazine 10^-4 M. And it is suggested that the ratio of respiration to non-inulin space is responsible more closely for the non-inulin space Na, K concentration than Qo₂ expressed per tissue wet weight. Effects of diphenylhydantoin and several other agents on electrolytes and the electroshock seizure threshold are discussed.

초음파 진동에 의한 A328 알루미늄 합금 용탕의 탈가스

최경환 ( Kyeong Hwan Choe ),장훈 ( Hoon Jang ),임정규 ( Jung Kyu Lim ),김상섭 ( Sang Sub Kim ),조규섭 ( Gue Serb Cho ) 한국주조공학회 2011 한국주조공학회지 Vol.31 No.6

A328 alloy is an attractive candidate for recycle-friendly aluminum alloy in the recycling of automotive components. In this study, A328 alloy melt was degassed by ultrasonic vibration and the effect of treatment time on the density, fluidity and mechanical properties was investigated. Experimental results reveal that a constant value of density can be reached after less than 180 seconds of ultrasonic treatment time, but the density decreased when the treatment time was 300 seconds. Ti which was dissolved from the horn during ultrasonic treatment reduced the fluidity of melt. After degassing by ultrasonic vibration for 180 seconds, tensile strength increased from 201MPa to 250MPa, and elongation increased from 2.38% to 3.50%, however, further treatment deteriorated the mechanical properties.

영산강수계 소하천에서의 토지이용특성에 따른 수질변화 분석

박혜린 ( Hye Lin Park ),정재운 ( Jae Woon Jung ),송광덕 ( Kwang Duck Song ),김정규 ( Jung Kyu Kim ),김해성 ( Hae Sung Kim ),임병진 ( Byung Jin Lim ),이영재 ( Young Jae Lee ),김상돈 ( Sang Don Kim ) 한국물환경학회(구 한국수질보전학회) 2011 한국물환경학회·대한상하수도학회 공동 춘계학술발표회 Vol.2011 No.-