• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2000년도 추계학술대회 논문집(Proceeding of the KOSME 2000 Autumn Annual Meeting)
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• pp.61-67
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• 2000

Many research works for improving a boundary lubrication performance have been executed by using solid lubricants, and been tried to apply an engine lubrication. However those general lubricants like MoS$_2$ or PTFE have not been applied on engines due to the extreme conditions such as very high temperature and pressure by combustion process in a cylinder. A copper nickel alloy fine particle has been introduced and studied. In this Paper the lubricant using the alloy Particles is applied on a marine diesel engine and assessed by the engine performance test The results showed the increase of cylinder pressure related strongly to the engine efficiency as well as the improving the engine lubrication performance.

• BMB Reports
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• 제28권3호
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• pp.254-260
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• 1995

Cytochrome oxidase was purified from bovine-heart mitochondria and its enzymatic properties were examined. The purified cytochrome oxidase was identified by its absorption spectrum and chromatogram through gel filtration. The specific activity, purification degree and yield of purified cytochrome oxidase were 18 nmol/mg/ml/min, 24.83 fold and 0.93%, respectively. The activity of the enzyme assayed by a ferrocytochrome $c-O_2$ system was optimized at $25^{\circ}C$ and pH 6.5. Examining the effect of nonionic detergents established that cytochrome oxidase was deactivated by Triton X-100. The oxidase was activated by Tween 80 and deactivated by Tween 20. The Michaelis constant and maximum velocity of the oxidase for ferrocytochrome c were 0.032~0.044 mM and 0.019~0.021 mM/min, respectively. After adaption to basal diet for a week, experimental diets containing 6 mg Cu/kg, or zero mg Cu/kg, or 12 mg Cu/kg were fed to a control group, a copper-free group and a copper-rich group of Sprague-Dawley rats, respectively, for 4 weeks. The specific activities assayed for the ferrocytochrome $c-O_2$ system of isolated cytochrome oxidase from the rat liver of control, copper-free, and copper-rich group were 1.00, 1.19, and 0.878 nmol/mg/ml/min, respectively. Their degrees of purification were 11.38, 10.82 and 8.78 fold, respectively. The specific activities for liver and heart mitochondrial cytochrome oxidase of copper-free/copper-rich groups assayed using the ferrocytochrome $c-O_2$ system were 81.4% and 96.4%/64.1% and 61.1%, respectively, compared with those of the control.

• Journal of Microbiology and Biotechnology
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• 제11권2호
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• pp.211-216
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• 2001

The growth of Selenastrum capricornutum in culture was investigated as a function of ionic copper concentrations to verify the toxicity and physiological variation. In a $Cu^{++}$ excess culture (E: $Cu^{++}$ of $130{\mu}g/l$), the growth rate (K)(0.32) was lower than that of the control culture (C: $Cu^{++}$ of $0.065{\mu}g/l$) (0.61) after 8 days and the exponential growth rate ($R_E$) was also found to be lower in culture E (1.1) than culture C (2.9). On the contrary, the K of S. capricornutum in trace $Cu^{++}$ culture ($T_1$ and $T_2$, 0.72) after 6 days tended to be more increased than culture C (0.68). From 8 to 14 days of culture, the amounts of chlorophyllls a and b were increased in culture C (chlorophyll a, $106->126{\mu}g/g$ dry wt; chlorophyll b, $158->208{\mu}g/g$ dry wt; chlorophyll b were decreased in culture E (chlorophyll a, $309->235{\mu}g/g$ dry wt; chlorophyll b, $405->352{\mu}g/g$ dry wt). The amounts of chlorophylls in ionic copper trace culture ($T_1$ and $T_2$) [(chl a/b) of $T_1$: $384/620\;{\mu}g/g$ dry wt; (chl a/b) of $T^2$:$320/467{\mu}g/g$ dry wt] were increased more than the culture C($260/387{\mu}g/g$ dry wt). Howeveer, when photosynthetic rates were normalized to the dry weight of algae, the control culture continued to showed higher values than the treated culture ($T_1$). An appropriate amount of ionic copper ($T_1:\;26\;{\mu}g/l$) stimulated the grwoth of S. capricornutum than the ionic copper content of $13\;{\mu}g/l$ ($T_2$), while the excess amount of ionic copper ($130\;{\mu}g/l$) resulted in the highest toxicity to the growth of S. capricornutum.

• Asian-Australasian Journal of Animal Sciences
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• 제12권4호
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• pp.579-584
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• 1999

The trace mineral status of cattle in the smallholder grazing areas of Sanyati and Chinamhora in Zimbabwe was evaluated during the rainy and dry seasons of 1994 and 1995. The evaluation was done in terms of mineral concentration in blood plasma. Plasma copper in calves, steers and cows in the dry season was; Sanyati: 0.55, 0.59, and 0.61; Chinamhora: 0.59, 0.58, and $0.60{\mu}g/ml$, respectively versus a normal of $0.65{\mu}g/ml$. In the rainy season, copper was deficient at both sites (averaging $0.56{\mu}g/ml$ and $0.59{\mu}g/ml$ at Sanyati and Chinamhora, respectively). Plasma selenium in the dry season was 0.017, 0.025, and $0.017{\mu}g/ml$ for calves, steers and cows, respectively at Sanyati versus a normal of $0.03{\mu}g/ml$ and therefore considered to be deficient. Iron, zinc and cobalt were found to be generally high and therefore unlikely to be deficient. Copper and selenium are recommended in salt licks in these environments.

• 한국환경보건학회지
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• 제29권3호
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• pp.65-71
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• 2003

The injection concentration of corrosion inhibitor increases under the pH 7, temperature of 2$0^{\circ}C$, and alkalinity of 35 mg/l (as CaCO$_3$), the corrosion rate gradually decreased. When the corrosion inhibitor of 10 mg/l is injected, the corrosion rate for carbon steel pipe, galvanized steel pipe, and copper pipe reduces for 37, 66 and 61 % respectively that it is more efficient on galvanized steel pipe and copper pipe. As a result of examination of corrosion rate at pH 6, 7, and 8 when injecting 10 mg/l of corrosion inhibitor under the conditions of 2$0^{\circ}C$ in water temperature and 35 mg/l (as CaCO$_3$) in alkalinity, the efficiency of the corrosion inhibitor increases as the pH increases. For carbon steel pipe, it does not show much a difference with the change of the pH condition, but galvanized steel pipe and copper pipe clearly show the corrosion rate depending on the change of the pH condition. The efficiency of corrosion inhibitor is low as the concentration of residual chlorine is high, but it does not show a great influence at 0.4 mg/l or less. For each pipe type, in the case of carbon steel pipe, the range of increase of corrosion speed following the residual chloride is higher than the other pipe types. In the meantime, the effect following the residual chlorine in copper pipe is low.

• Journal of Applied Biological Chemistry
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• 제61권4호
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• pp.367-370
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• 2018

Lysozyme is an antibacterial enzyme that is found in most of body fluids. Lysozyme in tears plays a primary role in protecting eye from harmful environments; if lysozyme is degraded or inhibited, eyes are likely to be more vulnerable to bacterial infection. In this study, lysozyme activity was evaluated according to varying concentrations of heavy metals, copper, zinc, cobalt and manganese and light metal, calcium that are frequently found in airborne particulate matters and was assayed using a dye-quenching lysozyme substrate, Micrococcus lysodeikticus. Less fluorescence intensity was observed with increasing amounts of copper, zinc, manganese and cobalt but not with calcium suggesting that these metals have some affinity with lysozyme and inhibit lysozyme activity. When albumin, the second most common protein in tears, was added on the reaction of lysozyme and metals, lysozyme activity was partially restored. This finding suggests that the albumin might protect damage caused by metals on lysozyme. To identify whether the decrease in enzymatic activity was related to structural changes of lysozyme, SDS-PAGE was conducted and only with copper did lysozyme show marked smearing bands on the SDS-gel, meaning that copper degraded lysozyme consistent with the sharpest activity decrease.

• 한국식품위생안전성학회지
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• 제35권2호
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• pp.177-182
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• 2020

본 연구에서는 건조 고춧가루의 가공 및 저장라인에서 구리의 이용가능성을 조사하였다. 구리와 스테인리스강 표면과의 접촉을 통한 고춧가루의 색도 변화를 평가한 결과, 55℃에서 2시간 구리 판에 처리한 시료의 명도가 다소 증가하였다. 구리와 스테인리스강 접촉에 의한 고춧가루 내 미생물 저해는 중온성의 호기성 세균보다 곰팡이 및 효모의 저해에 더 효과적이었고, 55℃에서 2시간 구리 접촉에 의해 곰팡이와 효모의 수는 0.64 log 감소하여 유의적인 효과를 나타내었다. 산화방지 활성은 구리와 스테인리스강 접촉 고춧가루의 DPPH 라디칼 소거활성은 감소한 반면 ABTS 라디칼 소거활성은 증가하였다. 본 연구는 구리 또는 구리와 스테인리스강 등의 합금을 이용하여 고춧가루를 포함한 다양한 분말 식품의 가공 및 저장 과정에 활용할 수 있는 가능성을 제시하고 있다.

• 한국기계가공학회지
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• 제12권4호
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• pp.61-68
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• 2013

As an advance study for the development of a heat sink for special purpose high power illumination, an investigation was made to find feasibility for the application of copper plated EP to a heat sink of small LED light of less than 10W installed in commercial product. In this study, the plated heat sink with EP copper was fabricated for the conventional LED light. It was used actually for finding heat radiation property and effectiveness of the heat sink accompanied with measurement of luminous intensity. The heat is radiated by transfer and dissipation only through the copper plated surface due to extremely low heat conductivity of EP in case of EP heat sink; however the total area of the plate plays the function of heat transfer as well as heat radiation in case of the aluminum heat sink. It seems that the volume difference of heat radiating material is so big that the temperature $P_1$ is 9.0~12.3% higher in 3W and 42.7~54.0% higher in case of 6W volume difference of heat radiating material is so big that the temperature $P_1$ is 9.0~12.3% higher in 3W and 42.7~54.0% higher in case of 6W even though heat transfer rate of copper is approximately 1.9 times higher than that of aluminum. It was thought that this is useful to utilize for heat sink for low power LED light with the low heating rate. Also, the illumination could be greatly influenced by the surrounding temperature of the place where it is installed. Therefore, it seems that the illumination installation environment must be taken into consideration when selecting illumination. Further study was expected on order to aims at development of an exterior surface itself made into heat radiation plate by application of this technology in future.

• 한국수산과학회지
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• 제4권2호
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• pp.61-65
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• 1971

장항만 연안에 서식하는 굴과 대천지방에 서식하는 굴의 연체부의 동함량에 관하여 1970년 10월 부터 1971년 2월까지 4개월에 걸쳐 채집 분석했다. 이 양군간에 굴 연체부의 동함량에는 현저한 유의차가 인정되였다. 장항만 연안에 서식하는 굴은 장항제연소에서 흘러나오는 폐수와 광재에서 용출하는 동에 의하여 주로 오염되었다고 볼 수 있다. 장항만 연안에 서식하는 굴은 동함량이 $434.4{\pm}141.9mg$ Cu/kg wet base였으며, 대천지방에 서식하는 비오염된 굴은 평균 $19.0{\pm}4.9mg/kg$ wet base의 수치를 나타냈다. 끝으로, 본 실험을 도와준 최병선군과 전의식군에게 사의를 표하는 바이다.

• Nuclear Engineering and Technology
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• 제45권3호
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• pp.277-294
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• 2013

In the early 1980s, attention focused on the possibility that pressurized thermal shock (PTS) events could challenge the integrity of a nuclear reactor pressure vessel (RPV) because operational experience suggested that overcooling events, while not common, did occur, and because the results of in-reactor materials surveillance programs showed that RPV steels and welds, particularly those having high copper content, experience a loss of toughness with time due to neutron irradiation embrittlement. These recognitions motivated analysis of PTS and the development of toughness limits for safe operation. It is now widely recognized that state of knowledge and data limitations from this time necessitated conservative treatment of several key parameters and models used in the probabilistic calculations that provided the technical of the PTS Rule, 10 CFR 50.61. To remove the unnecessary burden imposed by these conservatisms, and to improve the NRC's efficiency in processing exemption and license exemption requests, the NRC undertook the PTS re-evaluation project. This paper provides a synopsis of the results of that project, and the resulting Alternate PTS rule, 10 CFR 50.61a.