• 한국의류학회지
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• 제35권1호
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• pp.115-124
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• 2011

This study provides an eco-friendly dyeing processing for chitosan fiber using Oenothera odorata jacquin as a dye. The effects of chemical mordants (Al, Cu, Fe) and natural mordant (Chestnut shell) on the color change for dyed chitosan fibers were measured by K/S values, L, $a^*$, $b^*$, H, V, C values, color fastness, and antimicrobial activity. The results are as follows. Dyeing conditions of Oenothera odorata jacquin on chitosan fibers were optimized to $70^{\circ}C$, 30 minutes and 200% on weight of fabric (o.w.f.). The pre-mordant concentration of aluminium (Al), copper (Cu) and iron (Fe) of chitosan fibers was optimized to 3% (o.w.f.) and 1% (o.w.f.), respectively. The post-mordant concentration of chemicals, such as Al, Cu and Fe, on chitosan was determined to 1% (o.w.f.). The hue of chitosan fibers by chemical mordants was measured to be reddish & yellow. The pre-mordant concentration of Chestnut shell of chitosan was optimized to 70% (o.w.f.). The post-mordant concentration of Chestnut shell on chitosan was determined to be 50% (o.w.f.). The hue of chitosan fibers by Chestnut shell mordant was measured to be reddish & yellow. The wet cleaning fastness of chitosan fibers was improved by a pre-mordant that used chemical mordants. In the case of the Chestnut shell mordant, the wet cleaning fastness was improved by a post-mordant. The dry cleaning fastness of chitosan fibers was excellent regardless of mordants and mordant methods. The antimicrobial activity of the chitosan fiber was shown at 99.9% and its excellent qualities remained after the dyeing and mordant processing.

• Journal of Welding and Joining
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• 제32권3호
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• pp.60-67
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• 2014

The ability of electronic packages and assemblies to resist solder joint failure is becoming a growing concern. This paper reports on a study of high speed shear energy of Sn-4.0wt%Ag-0.5wt%Cu (SAC405) solder with different electroless Ni-P thickness, with $HNO_3$ vapor's status, and with various pre-conditions. A high speed shear testing of solder joints was conducted to find a relationship between the thickness of Ni-P deposit and the brittle fracture in electroless Ni-P deposit/SAC405 solder interconnection. A focused ion beam (FIB) was used to polish the cross sections to reveal details of the microstructure of the fractured pad surface with and without $HNO_3$ vapor treatment. A scanning electron microscopy (SEM) and an energy dispersive x-ray analysis (EDS) confirmed that there were three intermetallic compound (IMC) layers at the SAC405 solder joint interface: $(Ni,Cu)_3Sn_4$ layer, $(Ni,Cu)_2SnP$ layer, and $(Ni,Sn)_3P$ layer. The high speed shear energy of SAC405 solder joint with $3{\mu}m$ Ni-P deposit was found to be lower in pre-condition level#2, compared to that of $6{\mu}m$ Ni-P deposit. Results of focused ion beam and energy dispersive x-ray analysis of the fractured pad surfaces support the suggestion that the brittle fracture of $3{\mu}m$ Ni-P deposit is the result of Ni corrosion in the pre-condition level#2 and the $HNO_3$ vapor treatment.

• Transactions on Electrical and Electronic Materials
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• 제10권3호
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• pp.71-74
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• 2009

Electroplated Cu is a cost efficient metallization method in microelectronic packaging applications. Typically in 3-D chip staking technology, utilizing through silicon via (TSV), electroplated Cu metallization is inevitable for the throughput as well as reducing the cost of ownership (COO).To achieve a comparable film quality to sputtering or CVD, a pre-cleaning process as well as plating process is crucial. In this research, atmospheric plasma is employed to reduce the usage of chemicals, such as trichloroethylene (TCE) and sodium hydroxide (NaHO), by substituting the chemical assisted organic cleaning process with plasma surface treatment for Cu electroplating. By employing atmospheric plasma treatment, marginally acceptable electroplating and cleaning results are achieved without the use of hazardous chemicals. The experimental results show that the substitution of the chemical process with plasma treatment is plausible from an environmentally friendly aspect. In addition, plasma treatment on immersion Sn/Cu was also performed to find out the solderability of plasma treated Sn/Cu for practical industrial applications.

• International Journal of Industrial Entomology and Biomaterials
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• 제13권1호
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• pp.23-30
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• 2006

BmCu/Zn SOD was isolated from early embryo of Bombyx mori using microarray analysis. The BmCu/Zn SOD gene was observed during the early embryonic stage with the strongest signal found at the unfertilizaion, fertilization and blastoderm stages. The BmCu/Zn SOD gene encodes a protein of 154 amino acids with a calculated Mr of 15 kDa. The deduced amino acid sequence of BmCu/Zn SOD indicated that the residues that form on the Cu/Zn binding site are conserved and that the sequence is a 60% identity to that of M. domestica. In a phylogenetic tree, Bm SOD was also close to Drosophila SODs rather than other insect SODs. The BmCu/Zn SOD gene exists as a single copy in the genome. Transcripts of BmCu/Zn SOD cDNA were identified by northern blot analysis. The expression of the BmCu/Zn SOD gene was observed weakly in most of larvae, pre-pupae, pupae and adult tissues. Also, the BmCu/Zn SOD gene was observed in early embryonic stage. Although the roles of SODs remains to be further elucidated, the high expression of BmCu/Zn SOD gene at before 24 h post fertilization suggests that this gene is of general importance during early embryogenesis in the Bombyx mod.

• 한국분말재료학회지
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• 제26권5호
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• pp.410-414
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• 2019

The hydrogen reduction behavior of the $CuO-SCo_3O_4$ powder mixture for the synthesis of the homogeneous Cu-15at%Co composite powder has been investigated. The composite powder is prepared by ball milling the oxide powders, followed by a hydrogen reduction process. The reduction behavior of the ball-milled powder mixture is analyzed by X-ray diffraction (XRD) and temperature-programmed reduction at different heating rates in an Ar-10%H2 atmosphere. The scanning electron microscopy and XRD results reveal that the hydrogen-reduced powder mixture is composed of fine agglomerates of nanosized Cu and Co particles. The hydrogen reduction kinetics is studied by determining the degree of peak shift as a function of the heating rate. The activation energies for the reduction of the oxide powders estimated from the slopes of the Kissinger plots are 58.1 kJ/mol and 65.8 kJ/mol, depending on the reduction reaction: CuO to Cu and $SCo_3O_4$ to Co, respectively. The measured temperature and activation energy for the reduction of $SCo_3O_4$ are explained on the basis of the effect of pre-reduced Cu particles.

• Progress in Superconductivity
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• 제11권1호
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• pp.42-46
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• 2009

With an aim of comparison, single grain Y-Ba-Cu-O (YBCO) bulk superconductors were fabricated using a liquid infiltration growth (LIG) process and a conventional melt growth (MTG) process with top seeding. The MTG process uses an $YBa_2Cu_3O_{7-x}$(Y123) powder as a precursor, while the LIG process uses $Y_2BaCuO_5(Y211)/Ba_3Cu_5O_8(Y035)$ pre-forms. The growth of a single Y123 domain on the top seed was successful in the both processes. Different feature between the two processes is the interior microstructure regarding the critical current density ($J_c$). The LIG-processed YBCO sample showed a lower porosity, more uniform distribution of Y211 particles and the enhanced Y211 refinement compared to the conventional MTG process. The $J_c$ improvement in the LIG process is attributed to the dispersion of finer Y211 particles as well as lower porosity within the Y123 superconducting matrix.

• 자원리싸이클링
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• 제2권4호
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• pp.33-41
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• 1993

본 연구에서는 전로슬래그 중에서 슬래그 부산에 의한 Cu의 회수 및 자산, 체질에 의한 Cu의 조기회수방법을 조사하였으며, 부산공정 시 부산용수로서 폐수사용의 가능성을 검사하였다. 또한 부산 등의 산별과정에 의해 얻어진 산물의 화학분석을 통하여 각 성분별 신화력을 조사하였다. 건식자산의 경우 300 Gauss에서 2시간 영각고화 슬래그에 있어서는 Cu 품위 60.7%, 회수율 39.2%의 정광을 얻고, 10시간 영각 고화 슬래그에 있어서는 Cu품위 54.0%, 회수율 17.9%의 정광을 얻었다. 습식자산의 경우 600 Gauss에서 10시간 영각 고화 슬래그의 경우 Cu품위 64.1%, 회수율 1.8%의 정광을 얻었다. 마광을 행한 영각 고화 10시간 시과에 대해, 사상산물에 대새서는 자산을 행하였고, 사하산물에 대해서는 부산을 행하였다. 이 결과 Cu품위 45.2%의 정광을 얻을 수 있었으며 이때 회수율은 93.5%를 나타냈다. 부산정광에서 Cu품위가 높을수록 As 품위는 상승하였으냐, Zn 및 Fe 품위는 감소하였으며, Pb 품위는 무관하였다. 이 결과 Cu품위 37.74%의 정광을 얻을 수 있었으며 이때 회수율은 94.79%를 나타내었다.

• 패션비즈니스
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• 제7권5호
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• pp.83-100
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• 2003

It has been known that the chitosan pre-treated fabrics can be dyed without the aid of mordanting process. It is due to the fact that chitosan treatment increases the dye uptake. However, the effect of chitosan on the dyeing mechanism has not been elucidated thus far. Following explanations have been presented regrading the action of the chitosan on the dyeing mechanisms: 1. Chitosan absorbs dyestuffs and facilitates dyeing since the chitosan itself has a good affinity toward dyestuffs. 2. Chitosan acts as a metallic mordant between the fiber molecule and dyestuff. 3. Fiber molecules and chitosan form a coordinate covalent bond. This study aims the quantitative investigation on the effect of the chitosan and the effect of sequence of the mordanting, pre-mordanting or post-mordanting, on the dyeing of the fabrics. Cotton fabrics and acylic fabrics were pre-treated with chitosan before dyeing with cochineal dyestuffs. Method 1: Fabrics were, firstly, mordanted with Al, Sn, Cu, and Fe; mordanted fabrics were, secondly, treated with chitosan; mordanted and chitosan-treated fabrics were, thirdly, dyed. Method 2: Fabrics were, firstly, treated with chitosan; chitosan-treated fabrics were, secondly, mordanted with Al, Sn, Cu, and Fe; these were dyed then. Method 2 gave distinguished specific color development with darker shade. Apart from this, chitosan-treated fabrics yielded darker shade compared to the pre-mordanted fabrics without chitosan-treatment.

• 한국염색가공학회지
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• 제18권5호
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• pp.22-29
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• 2006

The purpose of this study was to investigate the dyeability and antibacterial activity on wool fabric dyed with cochineal at variable dyeing conditions. Al, Cr, Fe, Cu and Sn were used as mordants and adsorption was compared with different mordanting methods. The optimum dyeing conditions of wool fabrics were dyeing concentration 2.0%(o.w.s), dyeing temperature $60^{\circ}C$, pH 3 and dyeing time 30 minutes. The pre-mordanting method was preferred for Al and Cr, and the post-mordanting one was preferred for Cu, Sn and Fe to achieve better dyeing. The optimum mordanting conditions of wool fabrics dyed with cochineal were mordanting concentration of 1%(o.w.s), mordanting temperature $60^{\circ}C$, and dyeing time 30 minutes. Wool fabrics dyed with cochineal showed a little antibacterial activity, but it was increased by Cu and Sn mordanting. The light fastness and perspiration fastness of wool fabric treated with cochineal were improved by mordanting.

• 한국전기전자재료학회논문지
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• 제15권3호
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• pp.275-280
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• 2002

The peculiarities of using Self-propagating High-temperature Synthesis (SHS) and solid-stave chase synthesis for production of high temperature superconductor materials were discussed. Oxide superconductors with general formula of $ReBa_2Cu_3O_{7-x}$ (Re=Y, Sm) haute been made by using barium oxide initial powder instead of traditional barium carbonate. Phenomena observed during the grinding of the reactants mixture are presented. Mechano-chemical activation - as a pre-treatment of the reactants mixture - strongly influences the kinetic parameters, the reaction mechanism, and the composition and structure of the final product.