• The Korean Journal of Pesticide Science
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• v.15 no.3
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• pp.298-302
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• 2011

Bacterial wilt, caused by Ralstonia, solanacearum, is a very destructive disease to tomato plants (Solanum lycopersicum) in Korea. This study was undertaken to find out the growth inhibitory effect bactericides on bacterial wilt pathogen of streptomycin, oxytetracyclin streptomycin sulfate WP and significantly suppressed the growth of bacterial wilt pathogen. Copper hydroxide WP showed control value of 62.5%. Therefore, it is concluded that the bactericide used in this study showed strong inhibitory effect to tomato bacterial wilt and they can be recommend to control the disease. And also, Copper hydroxide WP may be effective for control of bacterial wilt of tomato in conventional culture, farming without agricultural and organic farming.

• Korean Chemical Engineering Research
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• v.45 no.6
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• pp.560-565
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• 2007

Copper fine particles, ranging from $0.11{\mu}m$ to $0.64{\mu}m$ in average size, were prepared by a chemical reduction method using hydrazine ($N_2H_4$) as a reduction agent in waste copper solutions. The effect of the amount of hydrazine addition was investigated on the properties of the obtained powders. Also, the effect of the addition of dispersing agents [Polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP)] during particle synthesis was studied. The powders, obtained from 1 M waste copper solutions, showed the mixtures of Cu and $Cu_2O$ crystals at low hydrazine addition amounts of 0.8 mol and 1.0 mol, while those exhibited pure Cu crystals at adequate hydrazine addition amount of 0.12 mol. The average size of the Cu powders decreased with increasing the concentrations of hydrazine and dispersing agents. The addition of PVA to the solutions as a dispersing agent was more effective than that of PVP in preventing the aggregation of particles.

• Korean Journal of Metals and Materials
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• v.48 no.10
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• pp.951-956
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• 2010

This study examined the effect of copper and sulfuric acid concentrations on the surface morphology and physical properties of copper plated on a polyimide (PI) film. Electrochemical experiments with SEM and a four-point probe were performed to characterize the morphology and mechanical characteristics of copper electrodeposited in the composition of an electrolyte. The resistivity and peel strength were controlled using a range of electrolyte compositions. A lower resistivity and high flexibility were obtained when an electrolyte with 20 g/l of copper was used. However, a uniform surface was obtained when a high current density that exceeded $20mA/cm^2$ was applied, which was maintained at copper concentrations exceeding 40 g/l. Increasing sulfuric acid to >150 g/l decreased the peel strength and flexibility. The lowest resistivity and fine adhesion were detected at a $Cu^{2+}:H_2SO_4$ ratio of 50:100 g/l.

• Tribology and Lubricants
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• v.39 no.6
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• pp.256-261
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• 2023

This study is conducted to evaluate the durability of superhydrophobic surfaces, with a focus on two aspects: contact angle measurement and self-cleaning-performance analysis. Superhydrophobic copper and aluminum surfaces are fabricated using the immersion method and subjected to a rolling wear test, in which a 2 kg weight is placed on a rolling tester, under loaded conditions. To evaluate their durability, the contact angles of the specimens are measured for each cycle. In addition, the surface deformation of the specimens before and after the test is analyzed through SEM imaging and EDS mapping. The degradation of the self-cleaning performance is evaluated before and after the wear test. The results show that superhydrophobic aluminum is approximately 4.5 times more durable than superhydrophobic copper; the copper and aluminum specimens could endure 21,000 and 4,300 cycles of wear, respectively. The results of the self-cleaning test demonstrate that superhydrophobic aluminum is superior to superhydrophobic copper. After the wear test, the self-cleaning rates of the copper and aluminum specimens decrease to 72.7% and 83.4%, respectively. The relatively minor decrease in the self-cleaning rate of the aluminum specimen, despite the large number of wear cycles, confirms that the superhydrophobic aluminum specimen is more durable than its copper counterpart. This study is expected to aid in evaluating the durability of superhydrophobic surfaces in the future owing to the advantage of performing wear tests on superhydrophobic surfaces without damaging the surface coating.

• Steel and Composite Structures
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• v.15 no.2
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• pp.151-162
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• 2013

In this study, an electrolyzing device for the production of metal powders was designed and fabricated. The production of copper powders was performed using a variety of current densities, anode-cathode distances and power removal times. The effect of these parameters on powder particle size and shape was determined. Particle size was measured using a laser diffraction unit while the powder shape was determined by SEM. Experimental results show that an increase in current density leads to a decrease in powder particle size. In addition particle shape changed from globular dendritic to acicular dendritic with increasing the current density. Distance between the cathode and anode also showed a similar influence on powder particle size and shape. An increase in time of powder removal led to an increase in powder particle size, as the shape changed from acicular dendritic to globular dendritic.

• Journal of Nutrition and Health
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• v.26 no.2
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• pp.189-195
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• 1993

This study conducted to investigate the effect of school lunch prgram on the blood composition of 50 children at the age 11 to 12 years old. Concentration of serum total protein, albumin, zinc and copper were measured at the begining of school lunch program(pre-feeding group) and at the one year later taken school lunch program(post-feeding group). Serum total protein and albumin concentrations in post-feeding group were higher than those in pre-feeding group, but showed no significant difference between groups. While serum zinc and copper concentrations in post-feeding group were significantly lower than those in pre-feeding group. Results indicated that school lunch program effective for improvement of potein nutrition in school children and it is nessessary futher investigation to disease the concentrations of serum zinc and copper in this age.

• Journal of Korea Foundry Society
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• v.1 no.3
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• pp.2-13
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• 1981

It was one of the most important studies in materials to obtain high strength in cant iron. Therefore, malleable cast iron and spheroidal graphite cast iron were developed. However, due to the large demand of gray cast iron, a study on the development for high strength in is very important. The author published a paper on the study on the effect of Al addition. In this study, the effect of Cu addition will be assessed on strength improvement in cast iron. Copper is known as the element of graphitization and pearlitization, so it is expected to obtain valuable results. The results obtained from this study are as follows ; 1. When copper was added to cast iron, tensile strength increased by 30%, and hardness increased by 13%. 2. The tensile strength showed a maximum when copper was added 1.0%.

• Journal of Surface Science and Engineering
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• v.47 no.4
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• pp.162-167
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• 2014

The primary purpose of this research is to investigate how much the complexing agent in electroless Cu electrolytes will affect adhesion strength between copper film and Ta diffusion barrier for Cu interconnect of semiconductor. The adhesion strength using rochelle's salt as complexing agent was higher than the case of using EDTA-4Na. Effect of complexing agent on adhesion strength and electrical resistivity was studied in crystal structural point of view.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.667-668
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• 2006

Usually nanosecond pulsing laser ablation of metal is under thermal effect. Many studies of the theoretical analysis and modeling to predict a result of laser ablation of metal are suggested on the basis of the photothermal mechanism. In this paper, we investigate the etching depth and laser fluence of laser ablation of copper films. We proposed the simplified SSB Model(Srinivasan-Smrtic-Babudp model) to study the photothermal effect of nanosecond pulsing laser ablation of copper thin metal. The experimental results were obtained by using the 355nm DPSS $Nd:YVO_4$ laser.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.10
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• pp.1-8
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• 2003

Copper thin films were deposited on a Cu/Ta/Si substrate using the electroplating technique. Deposition rate was about 200 nm/min in proportion to current density and in inverse proportion to flow rate. Resistivity of copper thin film was approximately 2.1 ${\mu}$Ωcm and Int$\sub$(111)//Int$\sub$(200)/ ratio of copper film was 5.4 and no significant impurities were detected. After the deposition, electroplating copper films were annealed at various temperatures in a background pressure of 10$\^$-3/ torr. The resistivity of copper thin films were improved by ∼17 % and texture was improved by ∼40 % after annealing at 170$^{\circ}C$. The stress in films was not reduced much after annealing below 170$^{\circ}C$.