• Journal of the Korean Applied Science and Technology
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• v.24 no.3
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• pp.233-237
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• 2007

This study is focused on the possibility of copper alloy metal fiber for an antimicrobial activity in the water soluble metal working fluids. Electrochemical potential of Cu/Zn ion is -268mV, and easily makes radicals with molecular oxygen. Especially, hydroperoxide radical shows strong toxicity to the strains. Plasma membrane causes conformational change when hydroperoxide radical binds to plasma membrane. Elution of copper ion from copper alloy metal fiber is detected in metal working fluid. As a result antimicrobial activity of copper alloy metal fiber in metal working fluid is superior to that of copper fiber.

• Journal of Nutrition and Health
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• v.24 no.4
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• pp.326-336
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• 1991

Present study was to investigate the effect of dietary vegetable sources such as carrot, peahull and squash on mineral balance of Na, K, Ca, Fe, Cu, Zn and Mg in mice. It would also determine if the kind, level and feeding period of vegetables can affect the mineral balance. One hundred and thirty mice weighing $29{\sim}30g$(8 weeks of age) were randomly selected. Ten mice were fed their standard diet, and the others were divided into three experimental groups that were fed standard diet supplemented with carrot, peahull and squash. Mineral intake and urinary and fecal excretion of minerals were measured to investigate the effect of the kind, level and feeding period of vegetables on absorption rate and balance of minerals. Body-weight gain was increased in high peahull diet group compared to the control. No significant difference was observed for feed efficiency ratios between different experimental groups and urine volume was increased by vegetable fed group. Na, Ca, Fe, and Cu intake were lower in high squash-diet fed soup. K intake was higher in carrot fed mice, and Zn, and Mg intake were higher in peahull fed mice. Absorption rate and balance of mineral in control group resulted in positive balance while experimental groups showed negative. The kind of vegetable, feeding level and feeding period affected the intake of Na, K, Ca, Cu and absorption rate of Cu, Zn and balance of K, Cu, Zn to negative. In spite of the higher intake of t Zn and Mg, in experimental groups the absorption rate showed negative balance.

• Journal of Korea Foundry Society
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• v.14 no.3
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• pp.274-284
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• 1994

SiC fibers were coated with Cu, Ag and Ni metallic thin films by magnetron sputtering in order to improve wetting properties between Al matrix and SiC fiber. The wetting behavior of metal coated SiC fiber by pure Al has been studied at $670^{\circ}C{\sim}900^{\circ}C$ range for $10{\sim}90min$. under vacuum atmosphere. Besides, the effect of coated film thickness on the wettability has been investigated. The wetting behavior and interfacial reaction between Al and SiC fibers were analysed with optical microscope and SEM (scanning electron microscope). The wetting behavior of the as-received SiC fiber with Al melt was not uniform, indicated by the contact angles from less than $90^{\circ} to more Al melt was appeared in the initial stage of reation. It was considered that the metallic thin film played an important role in reducing the interfacial free energy and breaking down the aluminum oxide film by eutectic reaction with Al melt. However the wettability of Ni coated SiC fiber was not improved as much as that of Cu or Ag coated SiC fiber. The improvement of wettability by coating thickness is clearly showed in $1{\mu}m$ coated SiC fiber compared with $0.25{\mu}m$ coated SiC.

• Composites Research
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• v.28 no.5
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• pp.254-259
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• 2015

Carbon fiber/aluminum (CF/Al) composites were successfully fabricated without pressure casting using wettability modification of carbon fiber. The wettability of liquid aluminum on carbon fibers was enhanced through electroless plating of copper on carbon fibers. Liquid aluminum was well infiltrated into carbon fiber bundles with Cu coating layer due to low wetting angle, and a lot of pores that existed in CF/Al composite without Cu coating on CF were greatly removed. However, a few tiny pores existed in carbon fiber bundles, which is due to not bad wettability between CF and Al but shrinkage cavity that was generated during cooling of CF/Al composite. The tiny pores could be effectively removed by a subsequent rolling.

• Korean Journal of Crystallography
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• v.12 no.4
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• pp.233-238
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• 2001

X-ray microdiffraction which uses x-ray beam focused down to a micron size from synchrotron radiation sources allow precision measurements of local orientation and strain variations in polycrystalline materials. Using x-ray microdiffraction setup at Pohang Light Source, we investigated the tex-ture of Cu interconnects with various widths on Si wafer by collecting Laue images and focused to about 2×3㎛ ² in size. Our results show that 1㎛ wide Cu interconnect had grains in rather ran- dom orientation. On the other hand the 20㎛ wide interconnects showed a 〈111〉fiber texture near the center. The grains were 2∼5㎛ long at the 1㎛ wide interconnect and 6∼8㎛ in size at the 20㎛ wide interconnect.

• Journal of Environmental Science International
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• v.16 no.10
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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.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.1
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• pp.31-37
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• 2013

To acquire enhanced adsorption capacity for especially targeted VOCs, activated carbon fiber of which surface area was $1,100m^2/g$ was selected and active metals were loaded. After screening study, Cr and Cu were selected as a base metal for improving adsorption capacity of activated carbon fiber. For acquiring better performance, metal loading, loading temperature, loading hours and kinds of loaded metals were changed as preparing variables. Properties measurement and adsorption capacity evaluation were performed. We found that the best conditions for metal loading were 5 hours loading at $100^{\circ}C$ and the adsorption capacity was enhanced almost double. Also we confirmed that more than 0.5 seconds contact time is needed for best adsorbate diffusion and adsorption over activated carbon fiber.

• Membrane Journal
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• v.20 no.2
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• pp.151-158
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• 2010

This paper presents the synthesis of ampholyte immobilized hollow-fiber membranes and adsorption characteristic of metallic ions. This is prepared by radiation induced grafting polymerization of an epoxy group containing Glycidyl methacrylate (GMA) onto an existing polyethylene porous hollow-fiber membrane. Ampholyte ion-exchanged alkalic group, $-NH_2$ (amine function) of Taurine (TAU) is reacted with glycidyl of GMA for the synthesis of stable membrane. However, Sodium sulfite (SS) membrane is also prepared by making chemical bonds with GMA of porous hollow-fiber membrane for the comparison of adsorption characteristic of metallic ions. These are called as TAU and SS membranes, respectively. It is shown that TAU membrane shows a steady flux, 0.9 m/h regardless of the density of TAU, while the flux of SS membrane decreases rapidly as the density of $SO_3H$ group increases. SS membrane showed a negligible flux. TAU membrane with the density 0.8 mmol/g shows the amount of metallic ions adsorbed in the following order, Cu > Cd > Mg > Sb > Pb. In general, TAU membrane with high density and reaction time showed the high amount of metallic ions adsorbed and flux.

• Korean Chemical Engineering Research
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• v.55 no.2
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• pp.264-269
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• 2017

To improve heating characteristics of graphite fibers, graphite fibers were copper-plated by electroless plating. The Cu-plated graphite fibers were investigated by thermos-gravimetric analysis in air to calculate quantities of copper on surface of graphite fiber according to plating time. Also, the surface temperature with applied voltage was observed by thermos-graphic camera using a strand of graphite fiber. According to the increment of plating time, the higher quantities of plated copper on graphite fiber were obtained. The electric conductivity of plated graphite fiber for 20 minutes was resulted in 1594.3 S/cm, and surface temperature of this sample showed the maximum temperature $57.2^{\circ}C$. These result could be attributed that copper having great electric conductivity are growing on graphite fiber and followed improving heating characteristics.

• Fashion & Textile Research Journal
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• v.13 no.3
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• pp.438-444
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• 2011

Bamboo leaves, as natural dye provide unartificial fresh green, are known for expert property at anti-bacterial, anti-aging, anti-oxidation, skin whitening, moisturizing, peeling of horny, deodorizing and some skin disease like as eczema and inflammation without any allergic response. Also, It is quite common to obtain bamboo leaves from our surrounding but most of them were not in use. On purpose of development the way of recycle with common material to dye, bamboo leaves were used to dye on ramie fiber which is valuable for both of apparel and industrial field and investigated their dyeing property. Using extract from bamboo leaves, dyeing property was examined with dyeability, colorimetric property, light fastness and wash fastness under different conditions by extract density, dyeing time, dyeing method and mordants. As results, dyeing was generally colored in yellowish, K/S Value was shown more higher on hemp fiber than ramie. The most optimum dyeing condition was investigated on pre-mordant treatment, dyeing temperature $60^{\circ}C$, dyeing time 30min and extract density 400%. On the treatment with mordant(Al, Fe, Cu), dyebility on both of hemp and ramie fiber were increased by mordant. Especially with Copper(Cu) as mordant, dyebility was highly increased than any other mordants and dyeings showed in deep color. Also on the fastness test which is the most important to natural dyeing, wash-fastness showed good performance with 4-5 grade but light-fastness was above 4 grade on both of hemp and ramie fiber, lower than wash-fastness overall.