• 대한치과보철학회지
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• 제39권1호
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• pp.37-48
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• 2001

Ceromers, new indirect resin system, are now being adopted for esthetic restorations. Despite of its translucency and good color matching, color stability after long-term use was unknown till now. This in vitro study was designed to evaluate color stability of some ceromers when subjected to brushing after thermocycling. Three types of ceromers: Scupture, Targis, Artglass and a direct resin system, Z100 were prepared to disks 12 mm in diameter, 2.5 mm in thickness. All specimens were polished, and Sculpture and Targis specimens were divided two groups, respectively. Then, half of them were glazed according to manufacturer's instructions. All specimen were brushed 20,000 times after 10,000 cycle thermocycling. Color was measured with spectrophotometer after 1,000, 3,000, 10,000 times thermocycling and 20,000 time brushing, respectively. Color difference (${\Delta}E$) was calculated according to CIE LAB system. During thermocycling, Sculpture & Targis system with polished surface showed greater color change than any other groups. After brushing, color difference was reduced significantly. Mean values of ${\Delta}E$ ranged 0.98 to 2.98. All Ceromers were considered clinically acceptable after thermocycling and brushing, and color change mechanism was affected by the brands and finishing methods. It might be concluded that color change of ceromer is due to surface alteration.

• 한국세라믹학회지
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• 제48권5호
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• pp.454-457
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• 2011

We report the preparation of nanocrystalline cobalt ferrite, $CoFe_2O_4$, particles using recycled $Co_3O_4$ and their surface coating with silica using micro emulsion method. Firstly, the $Co_3O_4$ powders were separated from waste cemented carbide with acid-base chemical treatment. The cobalt ferrite nanoparticles with the size 10 nm are prepared by thermal decomposition method using recycled $Co_3O_4$. $SiO_2$ was coated onto the $CoFe_2O_4$ particles by the micro-emulsion method. The $SiO_2$-coated $CoFe_2O_4$ particles were studied their physical properties and characterized by X-ray diffraction (XRD), high resolution-transmission electron microscopy (TEM) analysis and CIE Lab value.

• 패션비즈니스
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• 제23권1호
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• pp.64-73
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• 2019

The objective of this study was to investigate dyeing characteristics of silk, cotton and rayon fabrics using dyeing solution extracted from different varieties of tea. Comparative results of CIE Lab values of 360 pieces of dyed fabrics were studied to quantify the effects of dye concentrations (100%, 150%, and 200%) and mordants (Fe, Cu, Sn, Al). In addition, the color difference values (${\Delta}E$) of the dyed and mordanted fabrics were evaluated. The results of the study were as follows: First, among all of the 360 pieces of silk, cotton and rayon fabrics, the best dyeing effects was observed on silk fabrics. Second, the dyeing effect of the eight different types of tealeaves belonging to green tea, oolong tea, black tea, and dark tea tended to enhance as the degree of fermentation increased. Third, when the fabrics were mordanted with Fe, Cu, Sn, Al mordants, various colors such as brown, brownish red, brownish yellow, gray, and reddish brown were obtained.

• 한국수산과학회지
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• 제57권1호
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• pp.88-97
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• 2024

The underwater color environment was assessed by conducting color calculations based on underwater spectral irradiance measurements at various depths. Changes in the distribution of underwater spectral irradiance values between 1 and 3 m, exhibited similar trends in areas Stn. 1, 5, and 6. Likewise, changes between 5 and 20 m displayed comparable patterns in areas Stn. 1, 2, 4, and 6. Color values for each observed area fell between 0.14 and 0.26 (x-values) and 0.2 and 0.36 (y-values), with the y-values exhibiting a variation 1-3 times greater than the x-values. Color a_* and b_* values ranged from a maximum of -17 and -6 to a minimum of -63 and -30, respectively. By classifying fishing grounds based on observed variations, Stn. 1, 9, Stn. 2, 3, Stn. 7, 8 and Stn. 4, 5, 6 were grouped independently. Particularly, Stn. 5, 6, 7, and 8 were categorized into distinct groups that could be visually differentiated, especially when considering the significant changes in color a_* as the water depth increased from 10 to 20 m. Tokyo Bay were classified into different color groups, and Wakayama Prefecture offshore was classified into the same color group as the surveyed fishing grounds.

• Restorative Dentistry and Endodontics
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• 제32권1호
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• pp.19-27
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• 2007

본 연구는 새로운 치과용 색체계 개발을 목적으로 현재 치과에서 사용되고 있는 Vita shade를 사용하는 9 제조사의 12종의 광중합형 복합레진과 1종의 치과용 도재의 색상을 diffuse/$8^{\circ}$ 수광 방식을 사용하는 분광색체계 (MiniScan XE plus, Model 4000S, Hunter Lab, USA)를 이용해 D65 표준광과 10도 관찰자 시야 하에서 CIE $L^*a^*b^*$ 값을 측정하고 색상 범위를 분석하였다. 분석한 정보를 color sorting system을 응용한 CNU Cons Dental Color Chart의 색상 표현 방식인 T###에 치과용 수복 재료들의 범위를 적용하여 다음의 결과를 얻었다. 측정된 $L^*a^*b^*$ 값의 분포를 분석해 보면 $L^*$ 값은 80.40과 52.70 사이에, $a^*$ 값은 10.60과 -3.60 사이에, 그리고 $b^*$ 값은 28.40과 2.21 사이에 분포한다. $L^*$ 값의 평균값은 67.40, 중앙값은 67.30이며, $a^*$ 값은 2.89와 2.91, $b^*$ 값은 14.30과 13.90 이다. 이러한 분석을 토대로 CNU Cons Dental Color Chart의 T###의 첫 번째 숫자에 해당하는 $L^*$ 값의 각 숫자간의 차이는 2.0으로, 그리고 2번째 숫자인 $a^*$ 값의 각 숫자간의 차이는 1, 그리고 세 번째 숫자인 $b^*$ 값의 각 숫자간의 차이는 2로 정하였다. T555에 해당하는 $L^*$ 값의 범위는 66.0이상, 68.0미만으로, $a^*$ 값의 범위는 3이상 4미만으로, $b^*$ 값의 범위는 14이상 16미만으로 결정하였다.

• 한국축산식품학회지
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• 제29권3호
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• pp.325-333
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• 2009

쇠고기의 저장 중 이취발생을 대변할 수 있는 품질인자를 탐색하고자 온도의존성의 관점에서 상호관계를 분석하였다. 특수관능기법인 R-index에 의한 이취검지시간을 탐지하였고, 이화학적, 생물학적 품질인자를 측정하였다. 먼저, 이취검지시간의 온도의존성의 관계식을 개발하여, 이에 따른 이취발생 indicator의 선발 요건을 유도하였다. 이화학적 분석은 VBN, pH, 육색, Warner-Bratzler shear force,그리고 생물학적 분석은 Pseudomonas spp., Lactic acid bacteria를 대상으로 하였다. 품질인자의 온도의존성은 Arrhenius 상수인 활성화에너지를 사용하여 분석하였다. 그 결과 VBN, pH, $a^*$값, LAB, Pseudomonas spp., WBSF, $L^*$값, $b^*$값의 순으로 이취발생과의 온도의존성이 유사하게 나타났으며, 상위권에 있는 pH와 $a^*$값에 비하여 환경적 요인에 안정한 VBN이 쇠고기 저장 중 이취발생의 최적 indicator인 것으로 탐색되었다.

• 한국분말재료학회지
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• 제16권6호
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• pp.396-402
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• 2009

Tantalum nitrides ($Ta_3N_5$) have been developed to substitute the Cd based pigments for non-toxic red pigment. Various doping elements were doped to reduce the amount of high price Tantalum element used and preserve the red color tonality. Doping elements were added in the synthesizing process of precursor of amorphous tantalum oxides and then Tantalum nitrides doped with various elements were obtained by ammonolysis process. The average particle size of final nitrides with secondary phases was larger than the nitride without the secondary phases. Also secondary phases reduced the red color tonality of final products. On the other hand, final nitrides without secondary phase had orthorhombic crystal system and presented good red color. In other words, in the case of nitrides without secondary phases, doping elements made a solid solution of tantalum nitride. In this context, doping process controlled the ionic state of nitrides and the amount of oxygen/nitrogen in final nitrides affected the color tonality.

• The Journal of Advanced Prosthodontics
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• 제12권3호
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• pp.150-156
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• 2020

PURPOSE. The aim of this study was to evaluate the effect of different surface finishing processes on the color stabilities of lithium disilicate glass-ceramics, zirconia-reinforced lithium silicate ceramics, and resin nanoceramics after artificial ageing. MATERIALS AND METHODS. 216 samples were prepared from 3 different CAD/CAM materials (LAVA Ultimate, IPS e.max CAD, VITA Suprinity) with A1 HT color at a size of 14 × 12 mm and a thickness of 0.5 ± 0.05 mm. Color measurements of the samples were performed with a spectrophotometer using color parameters and CIE Lab color system on a gray backing between baseline color and after 5000 cycles of artificial ageing in 4 stages (i.e. the first measurement before the treatment, the second measurement after polishing, the third measurement after cement application, and the fourth measurement after artificial ageing). The results were evaluated using the Variance analysis and Fisher's LSD test. RESULTS. Resin nanoceramics (LU) exhibited higher color change values than zirconia-reinforced lithium silicate (VS) and lithium disilicate (EC) ceramics after artificial ageing. Manual polishing and glazing resulted in similar color change for LU and VS (P>.05). In the EC group, glazing provided statistically different results as compared to the manual polishing and control groups (P<.05). Among the ceramic groups, color change values of the subgroup, which was treated by glazing, of the zirconia-reinforced lithium silicate (VS) and lithium disilicate (EC) samples were below the clinically acceptable level (ΔE < 3.5). CONCLUSION. The lowest color change for all stages was observed in Vita Suprinity.

• 한국분말재료학회지
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• 제23권5호
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• pp.343-347
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• 2016

Fe-based pigments have attracted much interest owing to their eco-friendliness. In particular, the color of nanosized pigments can be tuned by controlling their size and morphology. This study reports on the effect of length on the coloration of ${\beta}$-FeOOH pigments prepared using an $NH_4OH$ solution. First, rod-type ${\beta}$-FeOOH is prepared by the hydrolysis of $FeCl_3{\cdot}6H_2O$ and $NH_4OH$. When the amount of $NH_4OH$ is increased, the length of the rods decreases. Thus, the length of the nanorods can be adjusted from 10 nm to 300 nm. The color of ${\beta}$-FeOOH changes from orangered to yellow depending on the length of ${\beta}$-FeOOH. The color and phase structure of ${\beta}$-FeOOH is characterized by UV-vis spectroscopy, CIE Lab color parameter measurements, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and powder X-ray diffraction (XRD).

• Asian-Australasian Journal of Animal Sciences
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• 제18권9호
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• pp.1294-1298
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• 2005

The objective of the present study was to investigate the effects on growth performance, meat quality parameters and fatty acids of meat by restricted diet amount on finishing Berkshires. A total of 180 pigs (Berkshire, initially 52 kg BW) at 100 days of age were allotted in arrangement in a completely randomized design (10 pigs per pen), blocked arrangement of treatments with 3 replications. The variables were market ages (180, 200 and 220 days) and in which was also included sex (gilts and barrow). All the pigs were restrictively fed so that day could be marked at 103 kg. Pork quality was evaluated from 4 pigs of each treatment. Average daily gain (ADG) and average daily feed intake (ADFI) were decreased (p<0.05) with age increase. The ratio of feed to gain was increased (p<0.05) at 200 and 220 days compared to that of 180 days. Moisture and crude protein of longissimus dorsi muscle (LM) at 180 days were increased (p<0.05) compared to 200 and 220 days. Crude fat was increased (p<0.05) by age and crude ash was lower (p<0.05) at 180 days than at 220 days. Red to green meat color scale (CIE a$^{*}$) increased (p<0.05) at 200 and 220 days more than at 180 days. Regarding fatty acid composition in meat, saturated fatty acids (SFA) was increased more (p<0.05) at 220 days than at 180 and 200 days. The results indicate that even with a restricted diet of low nutrient supplement, there was an improvement in Berkshire meat quality parameters.