• Journal of Korean Society for Quality Management
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• v.45 no.4
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• pp.995-1002
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• 2017

Purpose: The purpose of this study was to evaluate the color stability of composite resins used for splinting teeth by comparing a self-cure resin cement (Superbond C&B, SB), a flowable composite resin (G-aenial Universal Flo A2, GU), and a composite resin exclusively used for splinting teeth (G-Fix, GF) before and after aging in NaOCl. Methods: Resin samples were fabricated to a size of 2 mm thickness and 8.5 mm diameter and light-cured with an LED light curing unit (G-Light, n = 12). Immediately after fabrication, CIE L*a*b* values of the resin samples were measured with a spectrophotometer (CM-5) as baseline. Then, the resin samples were immersed in 5% NaOCl at $60^{\circ}C$ and the color was measured after 23 hours every day for 4 days. Data were analyzed with one-way ANOVA followed by Duncan post hoc test (p<0.05), and color differences (${\Delta}E$) of resin samples before and after NaOCl aging were also calculated. Results: For SB, there were no changes in L* and a* values but changes were observed in b* values. For GU, there were no changes in L* and b* values but in a* values. For GF, changes were observed in L*, a*, and b* values. All resin samples showed highest ${\Delta}E$ between baseline and the 1st day of NaOCl immersion. ${\Delta}E$ of SB, GU, and GF was 4.6 - 5.8, 4.9 - 7.9, and 9.9 - 16.9, respectively. GF showed highest color change during NaOCl aging. Conclusion: The results of this color quality evaluation showed that the composite resin exclusively used for splinting teeth might be more vulnerable to color change during intraoral service.

• Journal of the Korean Wood Science and Technology
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• v.49 no.6
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• pp.566-573
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• 2021

We investigated color changes on the outer surfaces of Phyllostachys bambusoides bam-boo by heat treatment under three different temperatures (180℃, 200℃, and 220℃) for three different durations (60 min, 90 min, and 120 min). A method of predicting the bam-boo surface color change after heat treatment was developed to provide valuable information and increase the added value of domestic bamboo products. The three average color parameters L^*, a^*, and b^* decreased, and the overall color changes increased as the severity factor increased. The values of L^* × a^* × b^* were highly related to the severity factor, and the optimal duration time for the desired bamboo surface color with a certain heat-treatment temperature could be estimated.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.90.1-90.1
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• 2013

Nature utilizes various of the colorization process. Some species of birds can express their mood of tempers by changing their collagen structures on skin. For example, turkey can change their skin color by expansion of the collagen structures, which are associated with the distinct color changes. Here, we developed bioinspired virus-based colorimetric sensors which can be genetically tuned for target molecule. Using M 13 bacteriophage, we fabricated responsive self-assembled color matrices composed of quasi-ordered fiber bundle structures. These virus matrices can exhibit color change by stimuli through fiber bundle structure modulation. Upon exposure of volatile organic compounds, the resulting multi-colored matrices exhibited distinct color changes with different ratios that can be recognized by the naked eyes. Using the directed evolutionary approaches, we genetically engineered the virus matrix to incorporate binding motif for explosive detection (i.e., trinitrotoluene (TNT)). Through utilizing a common handheld device (i.e., iPhone), we could distinguish TNT molecules down to 20 ppb in a selective manner. Our novel biomimetic virus colorimetric sensor can overcome current limitation for low response selectivity.

• Proceedings of the IEEK Conference
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• 2000.11d
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• pp.143-146
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• 2000

In this paper, luminance mapping for uniform color distribution and gamut mapping for maximum chroma reproduction are proposed. In the conventional lightness mapping, the average lightness difference between the two gamut is increased and different color changes in bright and dark regions are also increased. To solve these problems, a lightness mapping is proposed that minimizes the lightness difference of the cusps at each hue angle and produces same color changes in bright and dark regions. Also, chroma mapping that utilize variable anchor point and an anchor point are proposed for maximum chroma reproduction and uniform color change. The proposed algorithm reduce a sudden color change on the gamut boundary of the printer and to maintain a uniform color change during the mapping process. Accordingly, the proposed algorithm can reproduce high quality images with low-cost color devices.

• The Korean Journal of Food And Nutrition
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• v.9 no.3
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• pp.314-318
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• 1996

The purpore of this study was to elucidate the nutritional significance of the fruit-vegetable mixed juice during storage and distribution by examining the chemical composition of the mixed Juice for storage. The fruit-vegetable mixed Juices were sueriliged at 95$^{\circ}C$ for 30, 70, 100 seconds and the results of the changes in vitamin C contents, colors, total carotenoid contents, total aerobic counts and sensory evaluation of the mixed Juice were as follows: Vitamin C contents were drastically decreased at 7 day's storage and were not significantly different between the mixed Juices at p< 0.05 level after 7 day's storage. The longer the sterilization time and storage period of the mixed Juice was the higher changes in color was. The color changes in the sterilized samples were higher in order of 100, 70 and 30 seconds. Total carotenoid contents were slightly decreased according to storage period but were not affected by sterilization time. Total aerobic counts were 1.1 $\times$ 101 cfu/ml before sterilization, but it was negative after sterilization at 95t regardless of sterilization time. Sensory qualities such as color, flavor, taste and total acceptability of the mixed juice tended to be decreased by the Increased storage period and sterilization time. Especially, the sterilized sample for 100 seconds showed lots of changes In color.

• Journal of Applied Reliability
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• v.12 no.4
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• pp.275-285
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• 2012

This paper presents a changes of luminescence property for converted white LEDs with the commercially available silicate phosphor. If silicate phosphor's quantity increase step by step. luminescence property will be changing. we analyze luminescence property for these change and carry out the high temperature aging test for 7,000 hours, the high temperature and humidity aging test for 7,000 hours for reliability. LED degradation not only results in reduced light output but also in color changes. so we monitor correlated color temperature (CCT), chromaticity coordinates(x, y) and spectrum intensity. Those results suggest that humidity factor more bad effect in color changes than temperature factor and Lighting quality is related with quantity of phosphor.

• Journal of Fashion Business
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• v.13 no.2
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• pp.136-144
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• 2009

The purpose of this study is to investigate various phenomena quantitatively occurring during the course of changing dyeing conditions of cotton and silk fibers in natural dyeing using Caesalpinia sappan. Paying attention to the fact that the color may be varied according to the extraction conditions of dyestuffs in Caesalpinia sappan dyeing, the color changes were investigated after dyeing using dyestuffs extracted at elevated temperature and dyestuffs extracted at room temperature. According to the extraction methods, the degree of color development for the category of red color and the category of yellow color has changed.

• The Research Journal of the Costume Culture
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• v.6 no.1
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• pp.58-70
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• 1998

The color difference value of fabrics dyed with browning extracts from mushroom were as follows. 1. Two hours of dyeing depending on pH at 95℃ exhibited colors of YR and Y. The color of wool and nylon was darkest brown at pH 4, but light brown or yellow as pH increased. The color of silk was darkest brown at pH 5 and pH changes resulted in the same tendency as in wool. 2. In wool the color was changed to darker brown as time prolonged, however, there was no further color change after 9hr and value and chroma of wool declined. 3. At pH 4, the increase in temperature turned colors of sil, wool and nylon into dark brown from light yellow. 4. As the result of repetitive dyeing, colors of silk, wool and nylon gradually turned into darker brown. The repetitive dyeing was more effective in dark color and high colorfastness compared to a prolonged dyeing. 5. The amount of mordant resulted in color changes between light yellow and dark brown without various color changed. 6. In color change according to methods of mordant, post-mordant with CuSO₄·5H₂O and with SnCl·2H₂O showed colors of green and light yellow, respectively.

• The Journal of Advanced Prosthodontics
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• v.11 no.1
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• pp.16-22
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• 2019

PURPOSE. The purpose of this study was to compare the translucency and color changes of ceramic laminate veneers of different composition following glazing process. MATERIALS AND METHODS. $10mm{\times}10mm$ square specimens of 0.6 mm and 1.0 mm thicknesses were fabricated with IPS e.max Press (EM) and IPS e.max ZirPress (ZP) (n=10 per group). The color coordinates (CIE $L^*$ $a^*$ $b^*$) of the specimens were recorded with a colorimeter before and after glazing. The color changes and translucency parameter (TP) were calculated. For the comparisons with the composition and thicknesses between the 'not glazed' and 'glazed' groups, statistical analyses were done through paired T-test, independent two-sample T-test, and multiple regression analysis using SPSS 18.0 (P<.05). RESULTS. The TP of 0.6 mm EM was higher than that of 0.6 mm ZP. Total color difference (${\Delta}E^*$) between bare and glazed specimens of 1.0 mm EM was greater than that of 1.0 mm ZP with statistical significance. Following glazing, specimens from all groups showed statistically significant amount of decrease in $L^*$ and $a^*$, and statistically significant increase in $b^*$. The result of multiple regression analysis of EM and ZP showed that ${\Delta}L^*$ improved ${\Delta}E^*$. CONCLUSION. Within the limitations of present study, we conclude that translucency and color of ceramic laminate veneers change significantly after glazing process, and the nature and amount of changes vary with different compositions.

• The Journal of Korean Academy of Prosthodontics
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• v.40 no.1
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• pp.79-87
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• 2002

The purpose of this study was to investigate the color stability of composite resins used widely as esthetic restorative material. Surefil(Dentsply, U.S.A.), Esthet X(Dentsply, U.S.A.), Filtek P60(3M, U.S.A.) , Filtek Z250(3M, U.S.A.), Synergy Compact(Coltene, Switzerland), and Synergy Duo(Coltene, Switzerland) were chosen for this study. Thirty six specimens($7mm{\times}2mm$) of each composite resin were fabricated and polished after polymerization. Treatment conditions designed for this study were thermocycling, methylene blue staining, and filtered coffee staining. The color changes before and after treatment were measured by colorimeter(colorimeter, Model Tc-6Fx, Tokyo Denshoku Co.) and analyzed. The followings were drawn from this study: 1. The color changes of Filtek Z250, Surefil, Filtek P60 and Esthet X after thermocycling for 3 weeks were greater than those of the others. 2. The color changes of Surefil and Esthet X after methylene blue stainig and those of Surefil, Filtek Z250 and Filtek P60 after coffee staining were great. 3. The color changes or Synergy Duo and Synergy Compact after thermocycling and coffee staining were relatively lesser than those of other composite resins.