The biocidal activity of Cu(II) is greatly enhanced by the addition of H2O2 or hydroxylamine (HA), which accelerates the production of cytotoxic Cu(I) and generates a reactive oxidant (cupryl ion, Cu(III)) capable of exerting oxidative cell damages. The bimetallic Fe-Cu nanoparticles also exhibit excellent biocidal activity in the similar biocidal mechanism. These copper-based hybrid disinfection systems were assessed for their potential to inactivate surrogate bacteria and viruses. In addition, combinations of Cu(II) with HA and H2O2 (i.e., Cu(II)/HA, Cu(II)/H2O2, and Cu(II)/HA/H2O2 systems) were tested for the control of bacterial biofilms on reverse osmosis (RO) membranes. The detailed mechanisms for the cell inactivation by different copper-based disinfection systems were discussed.

Copper (Cu) is a necessary microelement for plants. However, high concentrations of Cu are toxic to plants that change the regulation of several stress-induced proteins. In this study, an annealing control primer (ACP) based approach was used to identify differentially expressed Cu-induced genes in alfalfa leaves. Two-week-old alfalfa plants (Medicago sativa L.) were exposed to Cu for 6 h. Total RNAs were isolated from treated and control leaves followed by ACP-based PCR technique. Using GeneFishing ACPs, we obtained several genes those expression levels were induced by Cu. Finally, we identified several genes including UDP-glucuronic acid decarboxylase, transmembrane protein, small heat shock protein, C-type cytochrome biogenesis protein, mitochondrial 2-oxoglutarate, and trans-2,3-enoyl-CoA reductase in alfalfa leaves. These identified genes have putative functions in cellular processes such as cell wall structural rearrangements, transduction, stress tolerance, heme transport, carbon and nitrogen assimilation, and lipid biosynthesis. Response of Cu-induced genes and their identification in alfalfa would be useful for molecular breeding to improve alfalfa with tolerance to heavy metals.

Copper nanoparticles attract much attention as substitutes of noble metals such as silver and can help reduce the manufacturing cost of electronic products due to their lower cost and good conductivity. In the present work, the chemical reduction is examined to optimize the synthesis of nano-sized copper particles from copper sulfate. Sodium borohydride and ascorbic acid are used as reducing and antioxidant agents, respectively. Polyethylene glycol (PEG) is used as a size-control and capping agent. An appropriate dose of PEG inhibits the abnormal growth of copper nanoparticles, maintaining chemical stability. The addition of ascorbic acid prevents the oxidation of nanoparticles during synthesis and storage. Transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR) are used to investigate the size of the synthesized nanoparticles and the coordination between copper nanoparticles and PEG. For chemical reduction, copper nanoparticles less than 100 nm in size without oxidized layers are successfully obtained by the present method.

탄소전극과 이온교환막을 결합한 축전식 탈염(CDI)을 이용하여 셀 구조와 셀 전위에 따른 구리 이온의 제거 특성을 연구하였다. 탄소전극과 이온교환막의 결 합 방식에 따라 4종류의 셀에 대해 실험한 결과 양이온, 음이온교환막을 결합한 셀(MCDI)에서 구리 이온의 제거율과 전하효율이 가장 높은 것으로 나타났다. 셀 전위에 따른 영향을 분석한 결과 0.6 V 이하에서는 전기이중층에 의한 전기 흡착(electrosoprtion)에 의해, 그리고 0.6 V 이상에서는 구리 이온의 전착 (electrodepostion)반응에 의해 구리 이온이 제거됨을 확인하였다. 또한 1.2 V 이상에서는 물이 전기분해되어 전하효율이 감소하였다. MCDI 셀의 운전결과 전하효율은 80% 정도로 구리 이온을 포함한 중금속 이온을 제거하는데 효과적인 것으로 판단되었다.

탄소전극과 이온교환막을 결합한 막결합 축전식 탈염(MCDI) 셀을 이용하여 환원전위가 다른 Na+과 Cu2+ 이온 혼합용액에서 Cu2+ 이온의 제거 특성을 연구 하였다. MCDI 셀에 일정한 전류밀도(1.5 mA/cm2)를 공급하면서 탈염을 실시한 결과 Cu2+ 이온은 일정한 제거속도를 유지하였지만 Na+ 이온의 제거량은 시간에 따라 감소하였다. 이는 Cu2+ 이온은 전착반응에 의해, Na+ 이온은 전기흡착 반응에 의해 제거되기 때문인 것으로 판단된다. Cu2+ 이온의 당량비가 0.14, 0.38, 0.50인 혼합용액을 탈염한 결과 제거된 이온 중 Cu2+ 이온의 당량비는 각 각 0.27, 0.60, 0.79로 나타났다. 이를 통해 Cu2+ 이온의 전착반응에 의해 혼합용 액에서 Cu2+ 이온의 제거율을 증가시킬 수 있음을 알 수 있었다.

A sintering process for copper based films using a rapid thermal process with infrared lamps is proposed to improve the electrical properties. Compared with films produced by conventional thermal sintering, the microstructure of the copper based films contained fewer internal and interfacial pores and larger grains after the rapid thermal process. This high-density microstructure is due to the high heating rate, which causes the abrupt decomposition of the organic shell at higher temperatures than is the case for the low heating rate; the high heating rate also induces densification of the copper based films. In order to confirm the effect of the rapid thermal process on copper nanoink, copper based films were prepared under varying of conditions such as the sintering temperature, time, and heating rate. As a result, the resistivity of the copper based films showed no significant changes at high temperature (300 oC) according to the sintering conditions. On the other hand, at low temperatures, the resistivity of the copper based films depended on the heating rate of the rapid thermal process.

To alloy high melting point elements such as boron, ruthenium, and iridium with copper, heat treatment was performed using metal oxides of B2O3, RuO2, and IrO2 at the temperature of 1200 oC in vacuum for 30 minutes. The microstructure analysis of the alloyed sample was confirmed using an optical microscope and FE-SEM. Hardness and trace element analyses were performed using Vickers hardness and WD-XRF, respectively. Diffusion profile analysis was performed using D-SIMS. From the microstructure analysis results, crystal grains were found to have formed with sizes of 2.97 mm. For the copper alloys formed using metal oxides of B2O3, RuO2, and IrO2 the sizes of the crystal grains were 1.24, 1.77, and 2.23 mm, respectively, while these sizes were smaller than pure copper. From the Vickers hardness results, the hardness of the Ir-copper alloy was found to have increased by a maximum of 2.2 times compared to pure copper. From the trace element analysis, the copper alloy was fabricated with the expected composition. From the diffusion profile analysis results, it can be seen that 0.059 wt%, 0.030 wt%, and 0.114 wt% of B, Ru, and Ir, respectively, were alloyed in the copper, and it led to change the hardness. Therefore, we verified that alloying of high melting point elements is possible at the low temperature of 1200 oC.

Cu-Mn과 Cu-Zn 촉매를 침전제로 다르게 하거나, 금속의 몰비율, 소성온도를 다르게 하여 공침법으로 제조하였고 CO산화반응을 수행하여 혼합산화물 촉매에서 Cu, Mn과 Zn의 영향 및 소성온 도가 미치는 영향을 조사하였다. 촉매의 물리·화학적 특성을 알아보기 위하여 XRD, N2 흡착 및 SEM 의 분석을 수행하였다. Na2CO3로 침전시켜 270℃로 소성하여 제조한 2Cu-1Mn 산화물 촉매가 저온에 서 CO 산화반응 활성이 가장 좋았으며 2Cu-1Mn 산화물 촉매는 43 m2/g으로 가장 높은 비표면적과 촉매 활성을 나타내었다. XRD로 촉매의 결정구조를 분석하였을 때 Cu0.5Mn2.5O4의 결정구조를 갖는 촉 매는 낮은 활성을 보였다. 270℃에서 소성한 촉매가 좋은 활성을 나타냈으며 Pt 촉매와 비교하여도 저 온에서 CO산화반응이 더욱 우수함을 알 수 있었다.

The food components of red sea bream(Pagrus major) cultured in copper alloy(brass) net(BN) and nylon net(NN) cages for nine months were investigated. The body weight was 234.9g at the beginning of the culture(the young fish), and then 692.1g(BN group) and 549.3g(NN group) at the fish cultured for nine months(the nine-month culture fish). The moisture content of the edible portion of the fish was higher in the young fish than in the nine-month culture fish. On the contrary, the lipid content was higher in the latter (9.1-10.6%) than in the former (7.6%).　 The lipid content in the nine-month culture fish was slightly higher in the BN group compared to the NN group. There was little difference in protein content between the young fish and the nine-month culture fish, or between the BN and NN groups. There was a slightly higher level of copper content in the liver (5ppm in the young fish and 5-6ppm in the nine-month culture fish) compared to the edible portions (1ppm in the young fish and 3-4ppm in the nine-month culture fish), but no difference was evident between the BN and NN groups. The prominent fatty acids were 16:0, 18:1n-9, 22:6n-3, 16:1n-7, 18:2n-6, 20:5n-3, and 18:0 in the edible portions of the young and cultured fish. The n-3 fatty acid content was slightly richer in the BN group.

본 연구에서는 파이로프로세싱에서 발생하는 배기체 내 요오드 포집을 위한 매질로서 고가의 은 기반 흡착제를 대체하기 위 한 상용 구리메쉬의 가능성에 대해 연구하였다. 열역학적 계산을 통해 구리 금속과 요오드 기체의 반응은 100 ~ 500℃ 온도 범위에서 자발적으로 일어나며 요오드화구리(CuI)를 형성할 것으로 예상되었다. 실험을 통해 반응 온도에 따른 요오드 포 집 효율의 영향을 분석한 결과, 1개의 구리메쉬(질량 0.26 g)를 이용하여 반응 온도를 300, 400℃로 변화하였을 때 각각 5 및 6 wt%의 요오드(초기질량 2.0 g)가 포집됨을 확인하였다. 또한, 반복 실험 결과를 토대로 구리메쉬 표면에 형성된 반응 생성 물(CuI)의 자발적인 탈리 현상으로 구리의 활용률이 증가할 수 있음을 확인하였다. 반응 생성물의 CuI 상 형성은 X-선 회절 실험을 통해 확인하였으며, 표면 분석은 주사전자현미경을 이용하여 수행하여 그 결과를 보고하였다.

The present research investigated copper and cadmium stress-induced differentially expressed genes (DEGs) using annealing control primers (ACP) with the differential display reverse transcription polymerase chain reaction technique in alfalfa (Medicago sativa L. cv. Vernal) leaves. Alfalfa leaves were subjected to 250 μM of copper and cadmium treatment for a period of 6 h. A total of 120 ACPs was used. During copper and cadmium treatment, 6 DEGs were found to be up or down regulated. During copper stress treatment, 1 DEG was up-regulated, and 3 novel genes were discovered. Similarly, during cadmium stress treatment, 1 DEG was up-regulated and 5 novel genes were identified. Among all 6 DEGs, DEG-4 was identified as the gene for trans-2,3-enoyl-CoA reductase, DEG-5 was identified as the gene for senescence-associated protein DIN1 and DEG-6 was identified for caffeic acid O-methyltransferase. All the up-regulated genes may play a role in copper and cadmium stress tolerance in alfalfa.

PCB 제조에서 photoresist와 Copper Clad Laminate(CCL)의 구리표면과의 부착력을 항상시 키기 위하여 사용되는 soft etching제를 제조하기 위하여 과산화수소 사용을 배제하고, 유기산과 유기과 산화물을 이용하여 산의 종류, 농도, 에칭시간 등에 따른 구리표면의 에칭속도, 표면 조도, 및 오염도 등 을 조사하였다. 또한 에칭 후의 표면의 얼룩을 제거하기 위한 안정제의 최적 배합 및 농도도 확립하였 다. 본 연구 결과 유기산의 종류 중에서는 아세트산이 초기 구리 에칭속도가 가장 빨랐으며, 농도가 0.04 M이었을 때 0.4 μm/min이였다. 유기과산화물인 APS의 농도는 높을수록 에칭속도가 가장 빨랐으나, 표면 오염이 심각하였다. 안정제 용액의 조성도 표면 오염도에 큰 영향을 주었다. 결과적 0.04 M 아세 트산, 0.1M APS에 4 g/L의 안정제(ST-1)를 첨가한 에칭액의 경우 0.37 μm/min의 에칭속도와 표면 오염이 전혀 없으며, 표면 조도도 가장 우수하였다. 즉, CCL과 photoresist와 접착력을 향상시킬 수 있 을 것으로 판단된다.

The sintering mechanisms of nanoscale copper powders have been investigated. A molecular dynamics (MD) simulation with the embedded-atom method (EAM) was employed for these simulations. The dimensional changes for initial-stage sintering such as characteristic lengths, neck growth, and neck angle were calculated to understand the densification behavior of copper nano-powders. Factors affecting sintering such as the temperature, powder size, and crystalline misalignment between adjacent powders have also been studied. These results could provide information of setting the processing cycles and material designs applicable to nano-powders. In addition, it is expected that MD simulation will be a foundation for the multi-scale modeling in sintering process.

Alumina dispersion strengthening copper(ADSC) alloy has great potential for use in many industrial applications such as contact supports, frictional break parts, electrode materials for lead wires, and spot welding with relatively high strength and good conductivity. In this study, we investigated the oxidation behavior of ADSC alloys. These alloys were fabricated in forms of plate and round type samples by surface oxidation reaction using Cu-0.8Al, Cu-0.4Al-0.4Ti, and Cu-0.6Al-0.4Ti(wt%) alloys. The alloys were oxidized at 980 oC for 1 h, 2 h, and 4 h in ambient atmosphere. The microstructure was observed with an optical microscope(OM) and a scanning electron microscope(SEM) equipped with energy-dispersive X-ray spectroscopy(EDS). Characterization of alumina was carried out using a 200 kV field-emission transmission electron microscope(TEM). As a result, various oxides including Ti were formed in the oxidation layer, in addition to γ-alumina. The thickness of the oxidation layer increased with Ti addition to the Cu-Al alloy and with the oxidation time. The corrected diffusion equation for the plate and round type samples showed different oxidation layer thickness under the same conditions. Diffusion length of the round type specimen had a value higher than that of its plate counterpart because the oxygen concentration per unit area of the round type specimen was higher than that of the plate type specimen at the same diffusiondepth.