• Textile Coloration and Finishing
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• v.27 no.4
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• pp.245-260
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• 2015

The effect of salt milling process on the crystal size, morphology, and color characteristics of C.I. Pigment Red 57:1 was studied. The primitive morphology and color properties of the pigment after synthesis were studied in the former series work. The size and morphology of primary particles and the second aggregation features should be considered because they are very important to determine pigment quality. We compared the primary morphology of pigment particles before drying with the secondary aggregated morphology of pigment particles after drying and salt milling process. Morphological properties were investigated by particle size analysis, X-ray diffraction, and scanning electron microscopy and color measurement was carried out. Significant reduction in particle size as well as enhanced crystallite size after salt milling process was observed. This result might give a difference in color of the pigment, turning into brighter and more blue-toned red color. It was revealed that synthesis condition affect the morphology and color of the pigment even after milling. Increase in HCl concentration in the synthesis process enhanced crystal size and quality forming bluer-red pigments but an increase in $CaCl_2$ concentration resulted in more amorphous crystals forming darker-red pigments after salt milling.

• Journal of the Optical Society of Korea
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• v.18 no.2
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• pp.184-187
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• 2014

This study examined the effects of particle size on the light scattering of a nano-sized color filter pigment used to obtain a range of colors in liquid crystal displays. The contrast ratio is one of the most important characteristics of liquid crystal displays. When a color filter is located between two crossed polarizers, the size of the pigment can give rise to a decrease in the contrast ratio due to Rayleigh scattering by the nanoparticles in the filter. The size effect of the color filter pigment on the contrast ratio was investigated in terms of the depolarization parameter. As an experimental result, the depolarization parameter increased with decreasing pigment size. Therefore, a smaller pigment size can reduce light leakage caused by light scattering in the color filter between two crossed polarizers. The depolarization function was also proposed as a useful function for predicting the decrease in the contrast ratio of the color filter.

• Journal of the Korean Applied Science and Technology
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• v.27 no.4
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• pp.515-521
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• 2010

In this research, we were prepared the glazed ceramic samples by the change of the pigment content and investigated to reveal the standardized color. The chemical composition of the pigment was analyzed using a ICP-OES. XRF mapping and UV-Vis spectroscopy were used to evaluate the color property and surface homogeneity. The color development was observed as a result of analyzing the pigment content and change of the color. The pigment content and the spectral reflection showed the relation of the inverse proportion and the standardized color which could be revealed through analysis data.

• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.71-71
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• 2003

This study was conducted to investigate effects of dietary pigment sources on shell color of juvenile abalone, Haliotis discus hannai. Three replicate groups of the abalone, average weight 173 mg, were fed the diets containing various pigment sources such as Porphyra powder, Spirulina, yeast astaxanthin and paprika extract for 16 weeks. Survival and weight gain were not affected by dietary pigment sources (P>0.05). Shell color of abalone fed diets containing Porphyra powder and Spirulina was approached to yellow-red and orange which are similar to shell color of wild abalone. However, shell color of abalone fed the diets containing yeast astaxanthin and paprika extract were similar to that of control diet showing bright green. Porphyra powder and Spirulina contain not only fat-soluble pigment such as chlorophyll and carotenoids but also water-soluble pigment such as phycoerythrin and phycocyanin. These results would be useful information to change shell color of abalone in aquaculture.

• Microbiology and Biotechnology Letters
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• v.23 no.4
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• pp.472-478
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• 1995

Mycelial growth, color difference and productivity of red pigment of beni-koji by Monascus anka KCCM 11832 were examined with respect to it's pigment in submerged culture with various medium and culture conditions. Shaking incubation was more promoted mycelial growth and the production of pigments than that for non-shaking incubation, and red color became ten times deeper. The production of red pigment was the highest when incubated at 25$\circ$C for 7 days in pH 6.0, but mycelial growth was showed the highest at 32.5$\circ$C. The levels of carbon and nitrogen source for maximum red pigment production were 2% rice powder and 0.05% peptone, respectively and the level of peptone for maximum pigment production was lower than that for maximum mycelial growth. Among pigmentation promoting agents tested, MgSO$_{4}$, was found to be suitable for the production of red pigment, and the optimum level was 0.1%.

• The Journal of Advanced Prosthodontics
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• v.5 no.2
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• pp.75-83
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• 2013

PURPOSE. Maxillofacial silicone elastomer is usually colored intrinsically with color pigments to match skin colors. The purpose of this study was to investigate the color stability of a maxillofacial silicone elastomer, colored with a thermochromic, color changing pigment. MATERIALS AND METHODS. Disc-shaped maxillofacial silicone specimens were prepared and divided into 3 groups: a conventionally colored control group, one group additionally colored with 0.2 wt% thermochromic pigment, and one group with 0.6 wt% thermochromic pigment. Half of the surface of each specimen was covered with an aluminium foil. All of the specimens were exposed to UV radiation in 6 hour cycles over 46 days. In between the UV exposures, half of the specimens were stored in darkness, at room temperature, and the other half was stored in an incubator, at a humidity of 97% and a temperature of $+37^{\circ}C$. Color measurements were made with a spectrophotometer and registered according to the CIELAB $L^*a^*b^*$ color model system. The changes in $L^*$, $a^*$ and $b^*$ values during artificial aging were statistically analyzed by using paired samples t-test and repeated measures ANOVA. P-values <.05 were considered as statistically significant. RESULTS. The UV exposure resulted in visually noticeable and statistically significant color changes in the $L^*$, $a^*$ and $b^*$ values in both of the test groups containing thermochromic pigment. Storage in the incubator lead to statistically significant color changes in the $a^*$ and $b^*$ values of the specimens containing thermochromic pigment, compared to those stored at room temperature. CONCLUSION. The specimens containing thermochromic pigment were very sensitive to UV radiation, and the thermochromic pigment is not suitable, as such, to be used in maxillofacial prostheses.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.2
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• pp.254-259
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• 2009

An experiment was conducted to evaluate the effect of different levels of extracted pigment from Dietzia natronolimnaea biomass as a source of canthaxanthin in comparison with synthetic canthaxanthin on egg yolk pigmentation. The experiment used a completely randomized design (CRD). A total of 63 laying hens, 68 weeks old, were used and the birds were allotted to 7 dietary treatments with each treatment replicated three times with three hens per replicate. Treatments consisted of 3 levels of synthetic canthaxanthin (4, 8 and 16 ppm), 3 levels of extracted pigment from D. natronolimnaea biomass (4, 8 and 16 ppm) and control. Changes in yolk color were determined in 2 eggs taken at random, during the four week experimental period from each replicate. Supplementation of extracted pigment from D. natronolimnaea biomass had a significant effect on the color of egg yolks (p<0.05). Yolk color score of the control group was 6.83 in BASF color fan and the yolk color score of different extracted pigment levels was 11.00, 12.50 and 14.50, respectively. The yolk colors of different levels of synthetic canthaxanthin were 12.00, 14.00 and 15.00, respectively. The effect of pigment supplementation on egg yolk color was better explained by polynomial response curves. The $R_{2}$ indicated that for 3 supplementation levels of each pigment studied, over 90% of the color variation could be explained by the pigment concentration. The egg yolk color after 15 and 30 days of storage was not significantly different, but boiling reduced egg yolk color significantly (p<0.05).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.6
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• pp.601-605
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• 2003

This study investigated the effect of dietary pigment sources on growth and shell color of juvenile abalone(Haliotis discus hannai). Three replicate groups of the abalone (average weight 173 mg) were fed diets containing various pigment sources such as Porphyra powder, Spirulina, yeast astaxanthin, and paprika extract for 16 weeks. Survival and weight gain were not affected by dietary pigment sources (P>0.05). Shell color of abalone fed diets containing Porphyra powder and Spirulina approached the yellow-red and orange, colors similar to wild abalone. However, shell color of abalone fed the diets containing yeast astaxanthin and paprika extract were similar to the bright green control group. These results should be useful for changing the shell color of abalone in aquaculture.

• Journal of the Korean Applied Science and Technology
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• v.30 no.2
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• pp.233-243
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• 2013

The inorganic pearlescent pigment have high physical and chemical stability, thus it is used in a variety field, which has better light stability, solvent resistance and thermostability. In this paper, we were synthesized the pearlescent pigment for cosmetics which was coated cobalt chloride for base of blue color metal oxide on mica titania substrate using hydrothermal synthesis method. To complement the color of the pigment by cobalt, pearl pigment were coated by different metal salt and cobalt ratio, to implement a variety of color value, depending on the kind of metal salts were synthesized. Synthesized pearlescent pigments appear various color as kind of added metal salt precursor and molar ration of cobalt and other metals. We controlled coating and color by composition of metal salt and type of metal salts, and that confirm the pigment characteristics of color changes through the analysis of color difference meter. Synthesized pigment was characterized by SPM, SEM, XRD, and EDS.

• Textile Coloration and Finishing
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• v.27 no.4
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• pp.229-244
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• 2015

The effects of synthesis conditions on characteristics of the calcium-azo complex pigment, C.I. Pigment Red 57:1, were studied. It was mainly considered that the industrially required synthesis conditions for lowering electrical conductivity of the pigment solution keeping pigment quality such as particle size and color characteristics. Three parameters were chosen as control factors during the synthesis. The first was the amount of hydrochloric acid added to transform sodium nitrite into nitrous acid. The second was the amount of calcium chloride added to insolubilize the synthesized azo dye. The final factor was pH control during the coupling reaction. The electrical conductivity and pigment aggregate particle size were dependent on the amount of hydrochloric acid and calcium chloride. Higher HCl concentration gave brighter yellowish-red color because of smaller particle aggregate size and narrower size distribution. Amount of charged ions in the synthesis process might affect the "lake" formation resulting different particle aggregate size and color shade.