• Journal of Fashion Business
• /
• v.10 no.5
• /
• pp.45-57
• /
• 2006

In the previous study, african marigold petals extract was valued as an excellent natural yellow dye because of its distinguished reactivity with various mordants and color fastness. In this study, we were studied on effect of absorbed metal ion by after-treatment of mordants on the color and fastness in human hair and wool fiber dyed with african marigold petals extract because the proteinic and cellulosic fiber were very well dyed. The dyed human hair showed better dyeing ability in the color fastness than wool fiber on tests of light, wash and perspiration. The absorbed metal ion concentration of mordanted human hairs were 1 or 5 times higher than wool fibers. However, excess of absorbed metal ion haven't consistent effect on K/S and surface color. Human hairs dyed using african marigold extract and mordanted with Al, Sn, Cu and Fe were showed various reddish yellow color groups and good dyeing ability on african marigold extract.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.23 no.3
• /
• pp.237-242
• /
• 2014

Recently much research are has been done into the compositions of lead-free solders. As a result, there has been a rapid increase in the number of new compositions. In the past, the properties of these new compositions were determined and verified through drop-impact tests. However, these drop tests were expensive and it took a long time to obtain a result. The main goal of this study was to establish an analytical method capable of predicting the impact life-time of a new solder composition for board-level flip chips though the application of drop simulations using LS-DYNA. Based on the reaction load obtain with LS-DYNA, the drop-impact fracture cycles were predicted. The study was performed using a Sn-3.0Ag-0.5Cu solder (305 composition). To verify the reliability of the proposed analytical method, the results of the drop-impact tests and life-time analysis were compared, and were found to be in good agreement. Thus, the new analytical method was shown to be very useful and effective.

• Fashion & Textile Research Journal
• /
• v.20 no.2
• /
• pp.210-218
• /
• 2018

The natural dye product market is expanding due to the recent interest in environmentally friendly products. This study examines dyeing using natural Coptidis Rhizoma. Chitosan and Tannin was treated to improve dyeability of Coptidis Rhizoma after finding the proper dyeing condition. In addition, dyeing characteristics were compared according to mordant types along with the mordanting methods for dye fixing and color change. The results indicated that the optimum dyeing condition was to treat the concentration of 5% (o.w.b.) at $80^{\circ}C$ for 90 minutes. By the chitosan and tannin treatments, K/S value of cotton fabrics by 3 times and those of wool fabrics by 2 times increased and color depthing of dyed fabrics was achieved after 2 cycles repetition. To improve dyeability, iron mordanting was most effective; in addition, the K/S Value of pre-mordanting fabrics versus post-mordanting fabrics increased the most. The color of the surface was changed to reddish yellow when Sn, Cu mordanting, and to greenish blue when Fe mordanting. The lightfastness of dyeing fabric with mordanting was weak at 1-2 grades, but the washing fastness was good for 4 grades and the rubbing fastness and sweat fastness were as good as those of the 3-4 grades. As a result, this study could help improve the dyeability of expensive Coptidis Rhizoma.

• Fashion & Textile Research Journal
• /
• v.17 no.3
• /
• pp.476-485
• /
• 2015

The purpose of this research is to analyze the effects of persimmon juice and hibiscus flowers extract to perform combination dyeing of silk fabrics, with respect to color changes, fastness, and functionality. The optimal conditions as a result, were shown at 100% of dye concentration, $40^{\circ}C$ of dyeing temperature and 30 minutes of dyeing time while in terms of dye uptake depending on the kind of mordants and methods. The highest K/S value was recorded at pH 3, pre-mordants of $CuSO_4$, and $SnCl_2$, post-mordanting. After repeated dyeing and post-mordanting, various color change occurred with mordant treatments. Color fastness of dyed fabrics with hibiscus flowers extract was improve considerably by combination dyeing with persimmon juice extract. In aspects of functional properties, it showed excellent results of 99% deodorization rate, 99.9% Staphylococcus aureus rate and 99.9% Klebsiella pneumoniae.

• Journal of Welding and Joining
• /
• v.27 no.1
• /
• pp.85-89
• /
• 2009

Reflow process conditions were investigated for 0402 electric parts with Sn-3.0Ag-0.5Cu solders. Circle hole shape metal mask with 100 m thickness showed excellent printability. Self alignment abilities were 71% for 1005 chips, 52% for 0603 chips, and 3% for 0402 chips. Average joining strengos were 1990 gf for 1005 chips, 867 gf for 0603 chips, and 525 gf for 0402 chips. As mis-mounting angle increased, joining strength decreased. Considering self-alignment ability, mounting angle had to be under $5^{\circ}$ and contact area of the chips had to be over 40% for Pb-free soldering process for 0402 chips.

• Journal of Surface Science and Engineering
• /
• v.45 no.1
• /
• pp.37-42
• /
• 2012

$WS_2$ powder was added to the Cu/Sn bond metal of diamond micro-blades for machining of semi-conductor and IC chips to improve cutting efficiency. The effect of $WS_2$ additive on cutting efficiency was investigated and compared with the micro-blades with $MoS_2$ developed in previous research. Flexural strength, frictional coefficient, and wear resistance of blades decreased with $WS_2$ but wear depth increased. It was found that the blades including $WS_2$ consumed less momentary energy than the blades containing $MoS_2$ during dicing test. Micro-blades containing $WS_2$ exhibited lower flexural strength than the blades with $MoS_2$ resulting from higher amount of sintering defects relevant to the less effectiveness of $WS_2$ on fluidity. The effect of $WS_2$ and $MoS_2$ on fluidity during sintering was analyzed in terms of mismatching degree between the longitudinal direction of lubricant particles and the perpendicular direction to the compact loading. The blade with 8.1 vol.% of $WS_2$ showed the best cutting efficiency.

• Journal of the Mineralogical Society of Korea
• /
• v.24 no.3
• /
• pp.245-252
• /
• 2011

콜롬비아는 안데스 산맥의 북단에 위치하며 NS 방향의 단층대를 기준으로 지질 환경의 차이가 크다. 단층대를 기준으로 동부지역은 원생대 변성암류와 이를 피복하는 고생대 변성퇴적암류가 주로 분포하며, 서부 지역은 고생대 퇴적암류, 중생대 화성암류, 제 3 기 화산양류 및 퇴적암류가 주로 분포한다. 지화학이상대는 6개 그룹으로 분류되며, 철 (Fe), 귀금속(Au, Ag, Pt), 기초금속(Cu, Pb, Zn), 희유금속(Sn, Cr, Co, Mn, Mo, Ni, Nb, W, V, Mg, Ti, Be, REE, Ga, Zr, Hf, Se, Te, Ta, Cd, In, Li 등) 빛 핵원료자원인 U 이상대로 구성된다. 콜롬비아의 주요 부존자원은 석탄, 니켈, 금 및 에메랄드이다. 에메랄드, 석탄 및 니켈은 세계적인 매장규모와 생산량을 보인다. 콜롬비아는 탐사가 거의 수행되지 않은 지역이 전 국토의 49%에 달해 광물부존 잠재성은 현재보다 크게 높을 것으로 보인다. 따라서 최근 콜롬비아와의 광물자원 협력이 강화되고 있는 시점에서 미탐사 지역을 대상한 공동탐사를 지화학 이상대가 확인된 지역을 중심으로 수행하여 신규광체를 확보하고, 광물자원 협력을 강화함으로써 공동개발 여건을 마련할 필요가 있다고 판단된다.

• Textile Coloration and Finishing
• /
• v.26 no.3
• /
• pp.263-271
• /
• 2014

The purpose of this study is to investigate the dyeability of silk fabrics with Humulus japonicus (Hwansam) extract which is a kind of weeds that grows wild in the suburbs. In the research, the general extract method was conducted with the extract from fresh herb of root-removed Humulus japonicus while we investigated the optimal dyeing conditions and dyeability depending on the changes of the kind of mordants, methods and temperature. The functional properties such as antibacterial activities, deodorization and UV protection were also reviewed. The ideal output, as a result, was shown at 100% of dye concentration, $90^{\circ}C$ of dyeing temperature and 40 minutes of dyeing time while in terms of dye uptake depending on the kind of mordants and methods, it was found that among four mordants of $SnCl_2$, $AlK(SO_4)_2$, $CuSO_4$, and $FeSO_4$ post-mordanting with $FeSO_4$ showed the best result. Color fastness to washing, dry cleaning and rubbing was found strong at grade 4-5 and the grade to light was as good as 3 while to perspiration was good at 4-5 as well. In aspects of functional properties, it showed excellent results of 99% deodorization rate, 98% UV protection rate and 99.9% bacterial reduction against Staphylococcus aureus.

• Textile Coloration and Finishing
• /
• v.25 no.4
• /
• pp.327-336
• /
• 2013

The purpose of this study was to evaluate the color image of the natural-dyed silk fabrics. The dye was extracted from pine needle by boiling pine needle with ethanol at $78^{\circ}C$ for 3hours and distilled water at $100^{\circ}C$ for 2hours. The 100% silk fabric was dyed of extract in pH 5 at $90-100^{\circ}C$ for 1 hr. As mordants used were compounds of Al, Sn, Fe, and Cr, color image of pine-needle dyed silk fabrics was classified into 5 factors (pure, gentle, sophisticate, comfortable, pastorale) and the factor pure is most important one of those. Most cheerful image in pure factor was from the fabrics dyed with ethanol extract and then, none and Cr mordanting. Dignified image was from the fabrics dyed with ethanol extract and then, Cu or Fe mordanting. In production, products dyed with ethanol extracts was preferred to those dyed with distilled water extracts. Color image and preference of the silk fabrics dyed with pine needles extracted was affected by extraction solvents and mordants.

• Bulletin of the Korean Chemical Society
• /
• v.25 no.1
• /
• pp.79-84
• /
• 2004

The existing technological schemes for processing rhenium-containing raw materials involve the recovery of Re from solutions, which can be effectively achieved by anion exchange method. The application of anion exchange also allows to study rhenium state in aqueous solutions and to develop analytical control methods. The present work is focused on investigation of ion exchange equilibrium in the analytical system Re(VII)-HCl-$SnCl_2$-KSCN-anion exchanger by means of sorption-desorption method as well as by electron, IR- and diffuse reflection spectroscopy. It was shown that rhenium can be quantitatively recovered from this system. It is proposed to use the sorption-spectroscopic method for Re(VII) determination in aqueous solutions. The calibration curve is linear in the concentration range of 0.5-20.0 mg/L (sample volume is 25.0 mL) and the detection limit is 0.05 mg/L. The presence of Mo(VI), Cu(II), Fe(II, III), Ni(II), Zn(II) as well as $K^+,\;Na^+$ do not hinder the solid-phase determination of rhenium. Rhenium (VII) determination by diffuse reflection spectroscopy was carried out in model solutions as well as in samples of river-derived water and in solutions obtained after the dissolution of spent catalysts.