• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제5권2호
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• pp.206-211
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• 2002

윌슨병의 치료제로 구리 흡착제인 D-penicillamine이 주로 사용되고 있으나, 심각한 부작용이 발생할 경우 투약을 중단하고 trientine 등을 대체약으로 사용할 수 있다. 저자들은 윌슨병으로 D-penicillamine 사용 도중 6개월만에 미세변화형 신증후군이 발생한 후 trientine으로 치료약을 대체 후 관해가 유도된 1례를 경험하였기에 보고하는 바이다.

• 한국주조공학회지
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• 제20권1호
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• pp.3-12
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• 2000

The lead content of drinking water has been restricted to less than 15 ppb by Environmental Protection Agency (EPA) in USA. This has led to extensive research and development work at the Materials Technology Laboratory (MTL) of CANMET, a Canadian Government research laboratory, on the development of low-lead and lead-free copper alloys for plumbing applications. Attentionhas also been focused on the environmentally friendly and energy efficient permanent mold casting process to minimize the disposal of foundry sand contaminated by lead due to the use of leaded alloys in the non-ferrous foundries. A new series of alloys called SeBiLOY contaning Bi and Se been introduced to replace lead in the leaded alloys. This paper addresses some important casting characteristics such as fluidity, hot tear resistance, mechanical properties and microstructure of lead-free alloys such as SeBiLOY III and low-lead alloys such as silicon brass, silicon bronze and yellow brass in gravity permanent mold casting.

• 한국레이저가공학회지
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• 제16권2호
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• pp.1-6
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• 2013

Picosecond lasers are a very effective tool for micromachining metals, especially when high accuracy, high surface roughness and no heat affected zone are required. However, low productivity has been a limit to broadening the spectrum of their industrial applications. Recently it was reported that in the micromachining of copper with a 1064nm picosecond laser, there exist the optimal pulse energy and repetition rate to achieve the maximum volume ablation rate. In this paper, we used a 515nm picosecond laser, which is more efficient for micromachining copper in terms of laser energy absorption, to obtain its optimal pulse energy and repetition rate. Theoretical analysis based on the experimental data on copper ablation showed that using a 515nm picosecond laser instead of a 1064nm picosecond laser is more favorable in that the calculated threshold fluence is 75% lower and optical penetration depth is 50% deeper.

• 보존과학연구
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• 통권31호
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• pp.131-140
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• 2010

This study shows the comparison of chemical compositions of main component with other bronze bells after the research on the component analysis by non-destructive XRF analysis. There are shrinkage cavities caused by the shrinkage defect and pores with pollutants on Bronze Bell of Heungguksa Temple with gamma radiation images and 77.3% of copper, 8.4% of tin and 10.9% of lead were determined as the main components of it with XRF analysis The tin content of Brozen Bell of Heungguksa Temple is less than those (11~18%) of other bronze bells but the lead content of that is higher. The lead content of it shows 10.91% which is quite high while generally the lead contents of other bells were controlled lower than 2.1%. Buddhist bells have the different lead content according to the period. The lead content was low until Silla Dynasty and Unified Silla period but it has been getting higher since some point of Koryo Dynasty. It is assumed that expensive copper and tin were replaced with lead.

• 대한수의학회지
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• 제25권2호
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• pp.145-148
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• 1985

Nickel toxicity and interactions of nickel with zinc, copper, and lead were studied in glowing chicks fed supplemented diet. Feed intake and growth rate of the chick were reduced by 250mg nickel as a sulfate salt per kg of feed. The toxicity of nickel was decreased by zinc or copper supplementation, but not lead. High nickel feed increased nickel level in kidney and decreased zinc levels in tibia and plasma. However, low zinc levels in tibia and in plasma were reversed by zinc supplementation. Hemoglobin, packed cell volume, and aortic elastin content were increased in chicks fed nickel. These results suggest that nickel toxicity is induced by interference with zinc metabolism.

• 청정기술
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• 제8권3호
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• pp.111-117
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• 2002

동을 담지한 모더나이트를 이용하여 고정층 연속흐름 반응기에서 NO 분해와 CO에 의한 NO 환원을 실시하였다. NO 분해에서는 많은 동함량에서 $Cu^{\circ}/HM$이 CuO/HM보다 높은 분해 활성을 나타내었다. 이것은 $Cu^{\circ}/HM$과 CuO/HM에 존재하는 $Cu^{2+}$이온의 양과 CuO의 환원성 등의 차이에 관련된다고 보인다. NO 환원에서는 적은 동함량에서 Cuo/HM이 CuO/HM보다 높은 환원 활성을 나타내었다. 이것은 $Cu^{\circ}/HM$과 CuO/HM에 존재하는 CuO의 환원성과 입자 크기 등의 차이에 관련된다고 보인다.

• 한국환경과학회지
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• 제16권10호
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• pp.1111-1118
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• 2007

A bismuth-coated carbon fiber microelectrode was prepared using cyclic voltammetry (CV). An analytical application was performed for the copper analysis with Square Wave Stripping Voltammetry (SWSV). Gallic acid n-propyl ester (PG) was used for the complex formation with a copper ion, and electrochemical measurements were performed with a pre-amplifier of a low-current module for nano am per detection. The effects of various parameters on the response were optimized. Analytical working ranges of $0.03-25.9\;{\mu}gl^{-1}$ and $0-25\'mgl^{-1}$ Cu(II) were obtained. The relative standard deviation at $13\;mgl^{-1}$ Cu was 0.9% (n = 12) in optimum conditions. The detection limit was found to have been $0.019\;{\mu}gl^{-1}$, with a 30-sec accumulation time. The developed methods were applied to a copper assay in water samples.

• 열처리공학회지
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• 제10권1호
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• pp.20-29
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• 1997

Pure copper is widely used for base material for electrical and electronic parts because of its good electrical conductivity. However, it has such a low strength that various alloying elements are added to copper to increase its strength. Nevertheless, alloying elements which exist as solid solution elements in copper matrix severely reduce the electrical conductivity. The reduction of electrical conductivity can be minimized and the strengthening can be maximized by TMT(Thermo-Mechanical Treatment) in copper alloys. In this research, the effects of TMT on mechanical and electrical properties of Cu-Ni-Al-Si-P, Cu-Ni-Al-Si-P-Zr and Cu-Ni-Si-P-Ti alloys aged at various temperatures were investigated. The Cu alloy with Ti showed the hardness of Hv 225, electrical conductivity of 59.8%IACS, tensile strength of 572MPa and elongation of 6.4%.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.800-807
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• 2001

This study was designed to investigate the antioxidative activity of a substance isolated from. The antioxidative activity of procyanidine was higher than that of dl-tocopherol and BHA on low-density lipoprotein (LDL) oxidation by thiobarbituric acid reactive substance (TBARS). Procyanidine inhibited the copper-mediated oxidation of human LDL in a dose dependent manner with almost complete inhibition at $60{\mu}g/mL$. Procyanidine at a concentration of $80{\mu}g/mL$ in hibited oxidation of LDL induced by J774. LDL oxidized by copper-mediated or cell-induced oxidation was degraded at a much greater rate than native LDL. These results suggested the importance of further research to procyanidine in the investigation of atherosclerosis and free radical-induced injury.

• Korean Chemical Engineering Research
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• 제45권6호
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• pp.560-565
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• 2007

화학환원법을 이용하여 폐동분 수용액에 환원제인 hydrazine을 첨가하여 $0.11{\sim}0.64{\mu}m$ 크기의 Cu 미립자를 제조하였으며, 이 과정 중 hydrazine의 첨가량이 얻어진 분말의 물성에 미치는 영향을 살펴보았다. 또한 분말합성 과정 중 분산제인 polyvinyl alcohol(PVA) 또는 polyvinyl pyrrolidone(PVP) 첨가가 분말의 물성에 미치는 영향도 조사하였다. 1 M 농도의 폐동분 수용액에 hydrazine이 0.8 mol, 1.0 mol 첨가된 경우에는 Cu와 $Cu_2O$의 혼합물을 나타내어 순수한 Cu 분말을 생성하지 못했다. 반면 적당량의 hydrazine(1.2 mol)이 첨가된 경우에는 순수한 Cu 분말이 생성되었다. 또한 얻어진 Cu 분말의 평균크기는 hydrazine과 분산제의 첨가량이 증가함에 따라 감소하였다. 한편 분말의 응집을 억제하는 분산제로서 PVA의 사용이 PVP 보다 더욱 효과적이었다.