• Tribology and Lubricants
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• v.31 no.3
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• pp.79-85
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• 2015

RC delay is a critical issue for achieving high performance of ULSI devices. In order to minimize the RC delay time, we uses the CMP process to introduce high-conductivity Cu and low-k materials on the damascene. The low-k materials are generally soft and fragile, resulting in structure collapse during the conventional high-pressure CMP process. One troubleshooting method is electrochemical mechanical polishing (ECMP) which has the advantages of high removal rate, and low polishing pressure, resulting in a well-polished surface because of high removal rate, low polishing pressure, and well-polished surface, due to the electrochemical acceleration of the copper dissolution. This study analyzes an electrochemical state (active, passive, transpassive state) on a potentiodynamic curve using a three-electrode cell consisting of a working electrode (WE), counter electrode (CE), and reference electrode (RE) in a potentiostat to verify an electrochemical removal mechanism. This study also tries to find optimum conditions for ECMP through experimentation. Furthermore, during the low-pressure ECMP process, we investigate the effect of current density on surface roughness and removal rate through anodic oxidation, dissolution, and reaction with a chelating agent. In addition, according to the Faraday’s law, as the current density increases, the amount of oxidized and dissolved copper increases. Finally, we confirm that the surface roughness improves with polishing time, and the current decreases in this process.

• Textile Coloration and Finishing
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• v.16 no.6
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• pp.1-9
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• 2004

The dyeings of cotton and silk fabric with Laurus tree extracts were investigated. The colorant was extracted with distilled water at $100^{\circ}C$ for lh. Dyeability(K/S), color fastness and antibacterial property of cotton and silk fabric were tested under conditions of various time, temperature, concentration, repeat-number of dyeing and mordants. The characteristics of dyeings Laurus extracts were figured out by K/S and CIELab values and color-fastness test was estimated in terms of wash fastness and light fastness. The maximum wavelength of spectrum was 670nm. The K/S value of cotton and silk fabric increased with increasing dyeing time and the exhaustion was saturated in 90min. Optical dyeing temperatures of cotton and silk fabrics were $60^{\circ}C$ and $80^{\circ}C$, respectively. The mordant effect on cotton fabric was achieved using Fe mordant. On the other hand, the mordant effect on silk fabric was obtained using Fe and Cu mordants. The wash fastness of cotton fabric was higher than that of silk fabric. Antibacterial property of silk dyeing was greater than that of cotton dyeing. In addition, the excellent antibacterial effect was imparted by Fe-post mordant method.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.10
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• pp.615-619
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• 2015

In this study, in order to develop the composition ceramics with the excellent electrocaloric properties, 8/65/35 PLZT ceramics were fabricated by the conventional solid-state method with the addition of $Bi_2O_3$, CuO, $Li_2CO_3$ and the variation of sintering temperature from $930^{\circ}C$ to $990^{\circ}C$. The XRD pattern of all specimens indicated general perovskite structure and the rhombohedral phase were observed. Curie temperature ($T_c$) of all specimens was observed in the vicinity of about $190^{\circ}C$. Density, coercive field and remnant polarization of the specimen sintered at $950^{\circ}C$ was $7.55g/cm^3$, 8.895 kV/cm, $11.22{\mu}C/cm^2$, respectively. EC effect of PLZT ceramics was measured by indirect method and the temperature change ${\Delta}T$ due to the electrocaloric effect was calculated by Maxwell's relations. ${\Delta}T$ of ceramic sintered at $950^{\circ}C$ was $0.21^{\circ}C$ under application of 40 kV/cm at $190^{\circ}C$.

• Korean Journal of Food Science and Technology
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• v.36 no.2
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• pp.311-316
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• 2004

Antioxidant effects of Rosa davurica Pall extract on copper-mediated LDL oxidative modification were investigated. Oxidation products of LDL were determined based on TBA value, formation of conjugate diene, and apolipoprotein carbonyl value. As revealed through TBA values, ethyl acetate and butanol fractions of R. davurica Pall root showed strong antioxidant effect, with 85.3 and 93.2% inhibitions at $30\;{\mu}g/mL$ each, respectively. Ethyl acetate and butanol fractions at $30\;{\mu}g/mL$ inhibited LDL oxidation up to 8 hr. Conjugate diene formation by lipid oxidation with $Cu^{2+}$ addition in ethyl acetate and butanol fractions decreased 2.2-and 5.6-fold, respectively, compared to control. Carbonyl value decreased in the presence of butanol and ethyl acetate fractions. Methanol and ethyl acetate extracts of R. davurica Pall root showed higher absorbancy at 285 nm. Ethanol extract of R. davurica Pall root and stem contained 10.6 g/100 g total phenolic compounds. Results reveal phenolic compound as major biological component in R. davurica Pall extracts. Ethyl acetate and butanol fraction showed strongest antioxidant effect on LDL oxidation.

• Journal of the Microelectronics and Packaging Society
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• v.12 no.1 s.34
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• pp.35-40
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• 2005

The oxidation of pure Sn and Sn-0.7Cu, Sn-3.5Ag, Sn-lZn, and Sn-9Zn alloys at $150^{\circ}C$ was investigated. Both the chemical nature and the amount of oxides were characterized using electrochemical reduction analysis by measuring the electrolytic reduction potential and total transferred electrical charges. X-ray photoelectron spectroscopy (XPS) was also conducted to support the results of reduction analysis. The effect of Cu, Ag and Zn addition on surface oxidation of Sn alloys is reported. For Sn, Sn-0.7Cu and Sn-3.5Ag, SnO grew first and then the mixture of SnO and $SnO_2$ was found. $SnO_2$ grew predominantly for a long-time aging. For Zn containing Sn alloys, both ZnO and $SnO_2$ were formed. Zn promotes the formation of $SnO_2$. Sn oxide growth rate of Pb-free solder alloys was also discussed in terms of alloying elements.

• Nutritional Sciences
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• v.4 no.2
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• pp.79-84
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• 2001

The influence of Rhodiola extract on tissue antioxidant status, plasma lipid levels, cholesterol contents of liver and fores were investigated in rats find oxidized linoleic acid. Groups of five-week old male Sprague-Dawley rats fed ad libitum with a diet containing 20% oxidized linoleic acid with or without 300 mg/kg body weight freeze-dried Rhodiola water extract. The antioxidant effect of dietary Rhodiola extract supplementation on the peroxidation potential of rats was investigated. The microsomal thiobarbiruric acid reactive substance (TBARS) contents were changed significantly by Rhodiola extract supplementation. Hepatic Catalase activities were increased in Rhodiola supplemented rats, whereas hepatic Manganese Superoxide Dismutase (MnSOD) or Copper Zinc Superoxide Dismutase (CuZnSOD) were not elevated. In addition, plasma cholesterol lowering effect was observed along with the stimulated excretion of cholesterol through the feces were observed with Rhodiola feeding. Supplementation with Rhodiola extract did not alter high density lipoprotein (HDL) cholesterol. These results support that Rhodiola extract may be effective in protection against oxidative stress, and prevention and treatment of blood dyslipidemia. It demonstntes that Rhodiola extract has a potential to exert anti-atherogenic properties antioxidative capacities .

• Journal of the Korean institute of surface engineering
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• v.41 no.6
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• pp.335-340
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• 2008

Cutting performance and wear behavior were studied with the diamond micro-blade of Cu/Sn bond materials containing various amount of lubricant materials such as graphite and $MoS_2$. Measurement of instantaneous electric power consumption for cutting glass workpiece at the constant velocity was conducted and proposed as a method to assess cutting efficiency. The energy consumption of micro-blade for glass cutting decreased with the content of graphite and $MoS_2$ while wear amount of blade in volume increased with the amount of lubricant addition during the dicing test. It is because that hardness, flexural strength, and fracture toughness ($K_{IC}$) reduced with the amount of lubricant addition. Blades with $MoS_2$ additive showed higher mechanical properties than those with graphite additives when the same amount of the lubricant additive in wt.% was added. Due to the lower density of graphite than $MoS_2$, higher volume fraction of graphite could result in stronger effect on lowering electric power consumption by reducing the friction between blade and work piece however increasing wear rate due to the reduction in strength and fracture toughness. Adhesive wearing mode of micro blade could be remarkably improved by the addition of graphite as well as $MoS_2$.

• Fashion & Textile Research Journal
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• v.6 no.3
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• pp.384-392
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• 2004

The purpose of this study is in development of effective filter-type polymer adsorbent for removal of pollutants from wastewater by UV irradiation graft polymerization. Photografting of acrylic acid (AA) on polypropylene (PP) nonwoven fabric using benzophenone (BP) as a photosensitizer was investigated. Inhibition of homopolymerization was achieved by adding various concentrations of $FeSO_4{\cdot}7H_2O$, $CuSO_4{\cdot}5H_2O$ and Mohr's salt. As AA concentration was increased, the degree of grafting was increased as to a specific value and then decreased, and the effect of BP concentration showed the same tendency. It was also found that the degree of grafting increased with reaction time and reaction temperature. Addition of the polyfunctional monomers and $H_2SO_4$ to the grafting system accelerated the photografting. The melting temperature, molecular weight and breaking stress and breaking strain were decreased with the increase in the degree of grafting.

• Journal of Environmental Health Sciences
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• v.24 no.3
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• pp.6-10
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• 1998

This study was attempted to carry out the effects of heavy metals when sea urchins (Hemicentrotus pulcherrimus, Anthocidaris crassispina, Scahhechinus brevis) formed early embryos. Results of the experiment for the effects of heavy metals on the development of sea urchins, in most sea urchins, the ranking of heavy metals according to decreasing effects upon fertilization and development of urchin eggs was follows: Hg, Cu, Zn, CA, Ni, Cr, Pb, As,and Fe. In addition, in most heavy metals, the ranking of experimental animals according to decreasing effects upon fertilization and development of urchin eggs in the same concentration of heaw metals was follows: H. pulcherrimus, A. crassispina, and S. brevis.

• Journal of Soil and Groundwater Environment
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• v.25 no.4
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• pp.7-13
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• 2020

In this study, a stabilization method was applied to stabilize heavy metals in soils collected from a domestic contaminated area and a Canadian mine site. The stabilizing agent used in the experiment was a solidifying agent developed by KERT Co., Ltd., Korea. The agent was applied to the samples at varying weight ratios of 0, 2, 5, 7, and 10% (w/w). and the concentrations of heavy metals in the effluent were monitored at predetemined time intervals. The results indicated that the stabilization efficiency of heavy metals (Cd, Cu, Pb) increased proportionally until the agent was increased to 5%, which showed almost no leaching of heavy metals after 28 days after agent application. Therefore, addition of 5% relative to soil mass was proposed to be the optimum dose for the stabilization agent.