• 한국염색가공학회지
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• 제11권1호
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• pp.48-60
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• 1999

In this paper, a new regenerated celluosic fiber, "Tencel" was treated with cellulase enzyme. Also Tencel fabrics were pretreated with NaOH and dyed with various reactive dyes, and subsequently finished with DMDHEU. $\Delta{E}^*_{ab}$ value was calculated by measuring color difference before and after wet abrasion test to rubbing. The fibrillation propensity was estimated on Tencel by means of weight loss, $\Delta{E}^*_{ab}$ value, and SEM observation. Weight loss of NaOH pretreated Tencel fabric is more lower than that of original fabric. The cellulase treatment decreased tensile strength but improved wet abrasion strength, wrinkle recovery, and bending properties. Tendency of fibrillation for Tencel fabric was reduced by NaOH-pretreatment, dyeing with multifunctional reactive dyes, and afterfinishing by DMDHEU.by DMDHEU.

• 한국염색가공학회지
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• 제9권2호
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• pp.32-40
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• 1997

This study was carried out to examine the effect of paint dyeing by Gloiopeltis paste in the various painting sizes and concentrations of paste. In the tonality diagram of Lab, surface colors were changed to +a(red), +b(yellow) and -b(blue) by treating of Gloiopelis paste and L value was the tendency of increasing. The penetration decreased with increasing concentration of paste, except for 3% of red and yellow. While it was decreased steadily in the case of Nue. The best penetration of dye was at 3% of concentration of Gloiopeltis paste and it's viscosity was measured 1500cps. As concentration of paste increased, ${\Delta}E_{ab}$increased after 40 hr. irradiation and water fastness and washing fastness test in red and blue. But in the case of ${\Delta}E_{ab}$yellow decreased slightly or not changed.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2008년도 추계학술대회 초록집
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• pp.53-53
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• 2008

기존의 Al 합금 소재의 단점을 보완한 Al-Mg 합금 소재를 이용해 다이캐스팅으로 만들어진 핸드폰 케이스에 적용하고자 titanium 타겟을 사용한 반응성 스퍼터링 공정을 연구하였다. 코팅특성은 스펙트로포토 미터를 이용하여 색상분석을 하였고, 미세표면이미지는 FE-SEM을 이용하였다. DC 마그네트론 스퍼터링에 의한 착색코팅은 산소유량이 많은 경우 밝기 L*값이 더 커졌다. 색상의 편차와 재현성을 나타내주는 ${\Delta}E^*ab$ 값을 비교해보면, 모든 경우 ${\Delta}E^*ab^*$<1로 매우 우수한 색상균일성을 보여준다. FE-SEM에 의한 표면이미지는 전반적으로 산소유량이 많은 0.8SCCM에서 코팅한 경우보다 산소유량이 적은 0.375SCCM에서 코팅한 경우가 결정립계의 구별이 확실하고 결정립 모양이 선명하고 결정립크기도 증가함을 확인할 수 있다.

• 대한화학회지
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• 제24권1호
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• pp.44-52
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• 1980

동적 핵자기공명법에 대하여 toluene-$d_8$ 및 carbon tetrachloride 용매속에서의 $\alpha$-chlorobenzyl ethyl ether의 이온해리속도를 측정하였다. 먼저, 동적NMR spectra를 얻고 $J_{AB}, T_2,{\Delta}_{vAB}$ 값 등을 이용하여 computer simulation에 의한 이론spectra를 얻었는데 실측spectra와 매우 잘 일치하였으며, 이로부터 해리속도정수 k를 얻고 이 k의 Eyring plot에 의하여 기울기와 절편의 길이를 알고 이로부터 동력학적 parameter를 얻었다. 이온 해리의 난역도는 용매의 극성에 의존하였으며 활성화 enthalpy는 toluene-$d_8$ 용매중에서 4.7kcal/mole 이었고 carbon tetrachloride 용매중에서 10.7kcal/mole 이었다. 활성화 entropy는 toluene-$d_8$ 용매중에서 -35.8 e.u. 이었고 carbon tetrachloride 용매중에서 -14.4 e.u. 이었다. $S_N$ mechanism의 초기단계로 볼 수 있는 이 이온 해리는 ${\Delta}H^{neq}$ 값이 작아도 비극성 비양자성용매중에서 이온해리가 용역함을 알았으며 작은 ${\Delta}H^{neq}$에 비하여 ${\Delta}S^{neq}$는 음의 큰 값을 가졌음은 주목할 필요가 있다.

• 대한치과보철학회지
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• 제33권4호
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• pp.645-661
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• 1995

As the mechanical property of composite resin improved, composite resin has been widely used esthetic dentistry. In the field of esthetic dentistry, the color of prosthetic material is very important. The purpose of this study was to evaluate the color difference of specimens, by the types of alloys and gold electrodeposit. Experimental groups were as follows : Group Prec : Au-Pt alloy with no gold coating and no resin veneer. Group Semi : Pd-Ag alloy with no gold coating and no resin veneer. Group BAse : Ni-Cr alloy with no gold coating and no resin veneer. Group Gsem : Pd-Ag alloy with no gold coating and no resin veneer. Group Gbas : Ni-Cr alloy with no gold coating and no resin veneer. Group PreR : Resin veneer on the Pd-Ag alloy without gold coating. Group SemR : Resin veneer on the Pd-Ag alloy without gold coating. Group GbsR : Resin veneer on the Ni-Cr alloy with gold coating Group BasR : Resin veneer on the Ni-Cr alloy without gold coating. In this study, colors of metal surfaces and veneered resins were evaluated by the CIE $L^{*}a^{*}b$ system. The results obtained were as follows : 1. different alloy types and gold coating make the $L^{*}a^{*}b$ system. 2. The ${\Delta}E^*$ab value between groups semi and Base was less than 1.5 and there was no $a^*$ and $b^*$ value difference between groups Gsem and Gbas 3. The values of $L^*$ and $a^*$ ain groups GsemR and GbasR were so similar that the ${\Delta}E^*$ab value was as small as 0.58. 4. In resin specimens with gold coated semiprecious or base alloys showed yellower and redder deviation than the resin specimens with precious alloy. 5. The ${\Delta}E^*$ab values between goups PreR-GsemR and groups PreR-GbasR were as small as 2.68 and 2.22 respectively.

• Journal of the Optical Society of Korea
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• 제15권3호
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• pp.310-317
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• 2011

Perceptibility and acceptability are the most often used threshold units in the field of color science. The former refers to a just perceptible difference and the latter evokes a tolerable color difference. Such thresholds can be very significant to color quality control processes in the printing industry and should be defined in quality measure units. Optical density (OD) and color difference models are usually utilized as color quality measures and have been provided in a considerable number of commercial measuring devices such as spectrophotometers. However, their merits and traits are far less understood in the literature. The present study intends to evaluate performance of those color quality measures including the OD and widely known color difference models, e.g. ${\Delta}E{^*}_{ab}$, ${\Delta}E_{CMC(l:c)}$ and ${\Delta}E{^*}_{00}$. A set of psychophysical assessments were carried out in order to accumulate the perceptibility and acceptability thresholds data, and their central trend was compared with the color quality measure estimates.

• 헤리티지:역사와 과학
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• 제44권4호
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• pp.130-141
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• 2011

본 연구에서는 넓은 pH영역에서도 증점효과를 가지는 카보풀 수지 940, 934를 가지고 중화제(sodium meta silicate, triethylamine)별 겔을 제조하여 10% 과산화요소를 첨가하고, 이에 따른 표백효과를 알아보았다. 실험 결과 메타규산나트륨(sodium meta silicate) 1.6g을 첨가한 실험군에서 표백효과의 최적 조건인 pH 10을 충족시키고 있다. 또한 각군별 대조군 Baseline 색 변화량(${\Delta}E*ab$)과 시간별 색 변화량(${\Delta}E*ab$)을 비교해 보면 1군(카보풀 940, 메카규산나트륨, 과산화요소)은 CS-2에서 112%, CS-4는 63.3%, CS-6은 87.4%의 표백효율을 나타냈으며, 2군(카보풀 934, 메카규산나트륨, 과산화요소; CS-8, CS-10, CS-12)에서는 순서대로 77.3%, 67.3%, 109.%로 나타났다. 그리고 3군(카보풀 940, 트리에탄올아민, 과산화요소;CT-1, CT-3, CT-5)에서 36.8%, 73.2%, 74% 순으로, 4군(카보풀 934, 트리에탄올아민, 과산화요소; CT-6, CT-8, CT-10)에서는 81.7%, 95.4%, 95.7%의 표백효율을 보였다. 따라서 중화제 비율이 증가함에 따라 표백표율이 높아지는 것을 알 수 있었으며 메타규산나트륨을 중화제로 첨가한 것보다 트리에탄올을 중화제로 첨가한 것이 표백효율이 다소 높은 것을 알 수 있었다. 그러나 실험에 사용된 겔의 점도는 메타규산나트륨을 첨가한 군에서 점도가 트리에탄올아민을 첨가한 겔보다 높았다. 이는 유약이 시유된 경사진 도자기 표면에 표백겔이 흐르지 않고 부착되는 장점이 될 수 있다. 그러므로 10% 과산화요소 표백겔을 만들고자 할 때 메타규산 나트륨을 첨가하면 증점효과와 원하는 표백효과를 얻을 수 있을 것으로 판단된다.

• Bulletin of the Korean Chemical Society
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• 제25권6호
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• pp.819-822
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• 2004

Protonation constants of calix[4]-cyclen-benzo-crown-6, L in 1X$10^{-2}$ M $Bu_4NCF_3SO_3$ in 40% $CH_2Cl_2/CH_3OH$ at $25^{\circ}C$ determined by potentiometric titration are log $K_1$ = 10.91, log $K_2$ = 10.30, log $K_3$ = 6.24 and log $K_4$ = 2.55. Stability constants for the receptor L complexes with Cu(II) and Zn(II) in 1X$10^{-2}$ M $Bu_4NCF_3SO_3$ in 40% $CH_2Cl_2/CH_3OH$ at $25^{\circ}C$ were determined by UV-VIS spectrometric titration. Stability constants of the CuL and ZnL complexes as log $\beta$ are 4.37 and 3.45, respectively. Stabilization energies for protonations of receptor L, derived from ab initio Hartree-Fock method with 6-31G basis set, are ${\Delta}E_1$ = -290.1, ${\Delta}E_2$ = -205.0, ${\Delta}E_3$ = -124.9 and ${\Delta}E_4$ = -26.9 kcal/mol and complexation energy of ZnL complex is -370.3 kcal/mol.

• 구강회복응용과학지
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• 제23권2호
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• pp.157-170
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• 2007

Purpose: This investigation was designed to determine the translucency and color stability of various core ceramics for all-ceramic restoration using the CIE $L^*a^*b^*$ system. Material and Methods: IPS e.max Press ceramic(Ivoclar-Vivadent, Liechtenstein), $LAVA^{TM}$ All Ceramic(3M-Espe, Germany), Cercon Smart Ceramic(Dentsply, Germany), and Z-match Ceramic(DentAim, Korea) were used for this study. For the specimens of zirconia oxide ceramics, the as-sintered cylindrical blanks($11.0{\times}25.0mm$) were machined into the shape of a disk(0.4, 0.8, 1.5 mm in thickness, 10 mm in diameters) with a diamond grind machine. The IPS e.max Press specimens ($0.8{\times}10mm$) were fabricated using the "lost wax" technique. CIE $L^*a^*b^*$ coordinates and light transmission were recorded for each specimen with a spectrophotometer(CM-2600d, Minolta, Japan). Color differences were calculated using the equation, ${\Delta}E^*ab=[({\Delta}L^*)2+({\Delta}a^*)2+({\Delta}b^*)2]1/2$. Results: The results were obtained as follows: 1. The most translucent group was IPS e.max Press ceramic that is a glass-ceramic, and $Lava^{TM}$ and Z-match ceramic were more translucent than Cercon Smart ceramic in zirconia ceramic group. 2. In the all groups, there was no significant translucent change after 6 times heat-treatments required to make a final restoration. 3. Colored zirconia was showed more yellowish and dark than uncolored zirconia. 4. After heat-pressing, IPS e.max Press ceramic was showed high ${\Delta}E^*ab$ value(4.1 of eM1, 6.8 of eM2) that means to be more whiter than before heat-pressing. However, there was no color change after additive heat treatments for final restoration. 5. In the colored zirconia groups, there was no significant color change after some heat-treatments required to make a final restoration.

• 대한화학회지
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• 제29권4호
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• pp.356-364
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• 1985

이소부틸렌 2가 음이온 및 디리티오이소보틸렌 이성질체들에 대하여 STO-3G최적화 계산을 수행하여 이들 화학종의 기하구조, 에너지, Mulliken 점유도등을 고찰하였다. 이들 화학종의 생성과 관련되는 몇 가지 isodesmic반응의 반응에너지 및 그로부터 추정된 상대적 생성에너지로부터 Y-형 2가 음이온에 대한 "Y-방향족성"의 기여와 이들 2가 음이온 유사체를 거치는 알킬화 반응을 좌우하는 구조적 요인을 고찰하였다.