• 대한화학회지
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• 제29권4호
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• pp.341-347
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• 1985

금속이온이 생체내에서 생체성분과 금속착물을 형성하는 것이 여러가지 생물학적 작용의 첫단계로 인정되고 있다. 본 연구에서 금속이온의 착물형성에 중요한 인자로서 과잉편극세기가 순수한 친자성 척도가 됨을 알았으며, 또한 과잉편극세기가 금속착물의 생성상수와 관련된 Irving-Williams계열을 설명할 수 있었다. 실험적으로 발암성이 밝혀진 금속이온의 과잉편극세기의 값이 0.22이상이었으며 나아가서 과잉편극세기의 값이 0.22이상인 금속이온은 발암성을 가질 수 있을 것으로 예측된다. 따라서 이 양을 금속이온의 화학발암성의 척도로 채택할 것을 제안한다.

• 대한한의학원전학회지
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• 제22권4호
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• pp.189-198
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• 2009

Considering the opinions of annotators, the remedy about excess of east and deficiency of west from "the seventy-fifth question" can be arranged as follows. "The seventy-fifth question", with "the sixty-ninth question", explains excess and deficiency of mother and son. Abatement of fire and invigoration of water[瀉火補水] in the excess of wood and deficiency of metal[木實金虛] presents a remedy, which has been applied in herbs and medicine application henceforth. "The seventy-fifth question" is a unique theory from " Nan-gyeong(難經)", and does not continue the theory of "Hwangjenaegyeong(黃帝內經)". "The seventy-fifth question" mentions the relationship of excess and deficiency of the five elements and five viscera, but does not mention excess and deficiency of invigoration and abatement of the meridian. Remedy from abatement of fire and invigoration of water[瀉火補水] in the excess of wood and deficiency of metal[木實金虛] is an abnormal, temporary and extraordinary method. This remedy is applied in Saam acupuncture[舍巖鍼] as A-variation form. The process where Son allows excess of mother[子能令母實] and mother allows deficiency of son[母能令子虛] in the abatement of fire and invigoration of water[瀉火補水] is a mechanism, not a remedy. Generation after generation, medical practitioners can be classified into those that claimed abatement of fire and invigoration of water[瀉火補水] because of the relation with excess of liver and deficiency of lung[肝實肺虛], abatement of heart(瀉心) due to the excess of liver(肝實), or invigoration of Eum and abatement of Yang[補陰瀉陽].

• 방사성폐기물학회지
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• 제18권4호
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• pp.481-496
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• 2020

After nuclear power plants are permanently shut down and decommissioned, the remaining irradiated metal components such as stainless steel, carbon steel, and Inconel can be used as neutron absorber. This study investigates the possibility of reusing these metal components as neutron absorber materials, that is burnable poison. The absorption cross section of the irradiated metals did not lose their chemical properties and performance even if they were irradiated over 40-50 years in the NPPs. To examine the absorption capability of the waste metals, the lattice calculations of WH 17×17 fuel assembly were analyzed. From the results, Inconel-718 significantly hold-down fuel assembly excess reactivity compared to stainless steel 304 and carbon steel because Inconel-718 contains a small amount of boron nuclide. From the results, a 20wt% impurity of boron in irradiated Inconel-718 enhances the excess reactivity suppression. The application of irradiated Inconel-718 as a burnable absorber for SMR core was investigated. The irradiated Inconel-718 impurity with 20wt% of boron content can maintain and suppress the whole core reactivity. We emphasize that the irradiated metal components can be used as burnable absorber materials to control the reactivity of commercial reactor power and small modular reactors.

• 한국자동차공학회논문집
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• 제10권1호
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• pp.32-44
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• 2002

Selective catalytic reduction of nitric oxide by methane in the presence of excess oxygen was investigated over copper and cobalt ion-exchanged ZSM-5 zeolites. Copper ion-exchanged ZSM-5(Cu-ZSM-5) has the limitations for commercial applications to lean-bum gasoline and diesel engines due to low thermal stability and resistance to water vapor and sulfur dioxide. But cobalt ion-exchanged ESM-5(Co-ZSM-5) is more active at high temperatures and also stable to water vapor and sulfur dioxide for catalytic reduction of nitric oxide by methane. The catalytic activity of Cu-ZSM-5 for NO reduction increases with increasing temperatures, reaches the maximum conversion of 23.0% at 350\"C. and then decreases with higher temperatures. In the meantime catalytic activities of Co-ZSM-5 show the maximum conversion of 25.8% at $500^{\circ}C$ Therefore Co-ZSM-5 catalysts have higher thermal stability at high temperatures. Catalytic activities of both zeolites were remarkably enhanced with the existence of oxygen in the exhaust. It is noted that the catalytic activity of Cu-ZSM-5 decreases with the increasing concentration of methane while the catalytic activity of Co-ZSM-5 decreases with increasing contents of methane in the exhaust. This may imply the existence of different paths of NO reduction by methane in the presence of excess oxygen fur Cu-ZSM-5 and Co-ZSM-5 catalysts. For binary metal ionexchanged ZSM-5, the primary ion-exchanged metal may be masked by secondary ion-exchanged component, which plays the important role for catalytic activities of binary metal ion-exchanged ZSM-5, Therefore CuCo-ZSM-5 catalysts show the similar volcano-shaped curves to Cu-ZSM-5 catalysts between the activity and temperature. It Is interesting that the activities of CoCu-ZSM-5 catalysts indicate almost no dependence on the concentration of methane in the exhaust.aust.

• 한국추진공학회지
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• 제23권2호
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• pp.118-125
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• 2019

산화제 과잉 예연소기는 고온/고압/산화제 과잉의 환경이며, 이러한 환경에 금속은 급격한 산화가 발생할 수 있다. 본 연구에서는 고온/고압/산화제 과잉의 환경을 모사할 수 있는 설비를 구축하고 여러 금속 재질에 대해 내산화성 평가를 진행하였다. 그 결과, 온도가 높고 압력이 높은 조건에서 금속재질의 변색, 표면 거칠기에 변화와 금속 표면의 박리 현상이 관찰되었고 무게 변화도 확인하였다. 모든 실험 결과를 종합하였을 때 산화제 과잉 예연소기는 금속 재질에 대한 내산화 코팅이 필수적으로 요구되며, 사용 금속으로는 Cr과 Ni의 함유량이 가장 높은 XM-19를 활용하는 것이 좀 더 구조적 안정성을 확보할 수 있을 것으로 판단한다.

• 한국항행학회논문지
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• 제17권6호
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• pp.700-704
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• 2013

양자 셀룰라 오토마타(QCA)는 CMOS의 기술을 상속받을 차세대 나노 전자 소자 중 하나이다. QCA는 원자규모 및 초저전력화로 이목이 집중되고 있으며 다양한 QCA 회로들이 제안되었다. 십진 출력을 요하는 전자회로와 마이크로프로세서에서 주로 사용되는 이진화 십진법(BCD)은 연산을 위한 변환은 편하지만 데이터 낭비가 심하다. 본 논문에서는 QCA 회로에서 감산 및 반올림에 효과적으로 이용될 수 있는 BCD-3초과 코드를 제안한다. 제안된 구조는 잡음을 최소화하고 공간 및 시간 복잡도를 고려하여 효율적으로 설계되었으며 시뮬레이션을 통해 검증하였다.

• 대한기계학회논문집
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• 제19권12호
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• pp.3372-3381
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• 1995

An equilibrium analysis was carried out to determine principal species of heavy metals in waste incineration and their behaviors with variation of temperature, chlorine concentration, excess air ratio, and C/H ratio. The waste was assumed as a compound of hydrocarbon fuel, chlorine, and metals. Calculated results showed that the most important parameter to determine the principal species was temperature. Chlorine concentration also affected on mole fractions of the principal species. Generally principal species at high temperature were chlorides while there were some metals of which principal species were oxides. At low temperature mole fractions of the principal species increased, but at high temperature mole fractions of some metal species decreased. C/H ratio of the hydrocarbon fuel and excess air ratio had little effect on mole fractions of the metal species, compared to the temperature and chlorine concentration.

• 소성∙가공
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• 제14권2호
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• pp.153-159
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• 2005

Design modification of the stamping die for the upper member of a front end module carrier is carried out in order to improve the surface quality of the final product. The small inferiority induced by wrinkling near the wall of the upper member has been inspected after the draw-forming process. The finite element analysis is pursued with the whole geometry in order to consider the complicated shape. The simulation shows that the excess metal is developed by the irregular contact of the blank the tool and it remains after the final stroke. This paper proposes two guidelines for the modification. One is to add the draw-bead near the critical region in order to increase the draw-in force. The other is to modify the tool shape such as the forming shape at the wall in order to absorb the excess metal before the final stroke. Simulation results show that the proposed guidelines both guarantee the improved surface quality.

• Journal of Welding and Joining
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• 제14권6호
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• pp.58-67
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• 1996

The horizontal filet welding is prevalently used in heavy and ship building industries to join the parts. The phenomena occurring in the horizonal fillet welding process are very complex and highly non-linear, so that its analysis is relatively difficult. Furthermore, various kinds of weld defect such as undercut, overlap, porosity. excess weld metal and incomplete penetration can be induced due to improper welding conditions. Among these defects, undercut, overlap and excess weld metal appear frequently in horizontal filet welding. To achieve a satisfactory weld bead geometry without weld defects, it is necessary to study the effect of welding conditions in the weld bead geometry. For analyzing the weld bead geometry with and without weld defects in horizontal fillet welding, a mathematical model was proposed in conjunction with a two-dimensional heat flow analysis adopted for computing the melting tone in . base metal. The reliability of the proposed model was evaluated through experiments. which showed that the proposed model was very effective for predicting the weld bead shape with or without weld defects in horizontal fillet welding.

• 한국결정성장학회지
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• 제12권1호
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• pp.1-6
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• 2002

본 연구에서는 금속 알콕시드를 이용하여 0.9PMN-0.1PT 소결체를 제조하는데 있어 과량으로 첨가되는 $Mg(OC_2H5)_2$, Pb$(CH_3COO)_2{\cdot}3H_2O$ 등이 페로브스카이트 상의 생성량과 소결 밀도, 유전 상수 등에 미치는 영향을 검토하였다. 졸-겔법으로 0.9PMN-0.1PT 세라믹을 제조함에 있어 $Mg(OC_2H5)_2$를 과량 첨가하는 경우 페로브스카이트 상의 생성율을 증가시키는 효과가 나타났다. 0.9PMN-0.1PT 조성에 $Mg(OC_2H5)_2$를 5wt% 과잉 텀가한 시편을 $1,150^{\circ}C$에서 1시간 소결한 경우 페로브 스카이트 단일상을 얻었으며 이 때의 밀도는 이론 밀도의 98%인 것으로 확인되었다. $1.150^{\circ}C$에서 1시간 유지하여 소결한 시편의 유전 상수는 $Mg(OC_2H5)_2$를 5wt% 과잉 첨가한 경우 증가하였으며, 주파수 1 kHz에서 최대 유전 상수는 15,000의 값을 가졌다.