• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.38 no.3 s.116
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• pp.23-28
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• 2006

Xylan in hemicellulose has been reported as one of the reasons of the yellowing of chemical pulp and paper. But little relevant information is available in literature. In this study, we examined into the influence that glucuronoxylan or glucomannan and metallic ion($Cu^{2+},\;Fe^{2+},\;Fe^{3+},\;Mn^{2+}$) residued in pulp get each or when mixed at yellowing. Filter paper was treated with each metallic ion, glucuronoxylan and the mixture of glucuronoxylan and metal ions, and brightness and CIE $L^*a^*b^*$ was measured after accelerated aging. As the results of measurements, the filter paper processed by 10% glucuronoxylan was dropped $2{\sim}3%$ on the brightness after accelerated aging for 24 hours. Also, the filter paper treated with glucuronoxylan and $Fe^{2+}$ was dropped 7% on the brightness.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06b
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• pp.361-364
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• 2006

Generally, aging of paper is evaluated by folding endurance and degree of yellowing. It was known as that lignin, hemicellulose and metallic ion affect yellowing of mechanical or chemical pulps. Among these elements, especially, the study of hemicellulose that affect at yellowing of pulp is insufficient. In this study, we examined into the influence that glucuronoxylan or glucomannan and metallic ion($Cu^{2+},\;Fe^{2+},\;Fe^{3+},Mn^{2+}$) residued in pulp get each or when mixed at yellowing. Filter paper was treated with each metallic ion, glucuronoxylan and the mixture of glucuronoxylan and metal ions, and brightness and CIE $L^*a^*b^*$ was measured after accelerated aging. As the results of measurements, the filter paper processed by 10% glucuronoxylan was dropped 2-3% on the brightness after accelerated aging for 24 hours. Also, the filter paper treated with glucuronoxylan and $Fe^{2+}$ was dropped 7% on the brightness.

• Journal of Dental Rehabilitation and Applied Science
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• v.31 no.1
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• pp.20-25
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• 2015

Purpose: This study was evaluated the shade of feldspathic porcelain with various concentration of silver ion. Materials and Methods: The control group was conventional feldspathic porcelain with no silver ion, the experimental groups were the feldpathic porcelain with 5%, 10%, 20%, 30% silver ion. The number of specimens on the each group was 5. Commission Internationale de I'Eclairage (CIE) $L^*a^*b^*$ parameters were recorded twice for each specimen with a spectrophotometer (Model CM-2600d, Minolta, Japan). One-way Anova was used for statistical analysis. Results: L value was similar. a value was increasing and b value was decreasing with silver ion statistically significantly. ${\Delta}E$ was increasing according to silver ion significantly. Conclusion: The shade of feldspahtic porcelain was influenced by silver ion. Ag ion under 10% concentration is acceptable clinically.

• Journal of Dental Rehabilitation and Applied Science
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• v.36 no.2
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• pp.128-137
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• 2020

Over the last 30 years, the use of chairside computer-aided design (CAD) and computer-aided manufacturing (CAM) systems has evolved and has become increasingly popular in dentistry. Although CAD/CAM restorations have been used in the anterior dentition, satisfying the esthetic requirements of clinicians and patients, where the restorations are limited to the chairside, remains a challenge. To reproduce multi-shades of CAD/CAM restorations in the clinic, a preliminary experiment to express several shades on A2 lithium disilicate (LS2) blocks using a staining kit was performed. After measurement of the CIE L^*a^*b^* value of specimens, it was compared with that of the commercial shade guide. This report presents two cases with individual customization of shade and surface characterization of the CAD/CAM restorations using predictable methods based on the preliminary experimental data. The anatomical shape of restoration was obtained from 'copy and paste technique' and 'mirror image acquisition technique'. All treatment procedures and fabrication of restorations performed in this report were executed in the clinic itself.

• Journal of the korean academy of Pediatric Dentistry
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• v.49 no.1
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• pp.1-13
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• 2022

The purpose of this study was to compare the color of maxillary primary central incisors, lateral incisors, canines with the color of various composite resins using a spectrophotometer VITA Easyshade^®V. One researcher measured the color of sound maxillary primary anterior teeth of 100 children aged 1 to 6 and specimens which were made by composite resins with a total of 10 types and 31 shades, and CIE L^*, a^*, b^* values were obtained. There was no clinically recognizable color difference between the maxillary primary central and lateral incisors. However, the maxillary primary canines showed difference in color above the clinical acceptability threshold with the primary central and lateral incisors. These findings showed no significant color differences between men and women, and no significant color changes with age. A1 shade is the most common in all maxillary primary anterior teeth. Composite resins, which are thought to be similar to the color of maxillary primary anterior teeth were selected from 9 types of maxillary primary central incisors, 6 types of primary lateral incisors, 6 types of primary canines.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.12
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• pp.1865-1873
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• 2007

An experiment was performed to evaluate the effects of dietary metabolizable energy (ME) and lysine on carcass characteristics and meat quality in Arbor Acres (AA) broilers from 1 to 56 days of age. A total of 2,970 1-d-old male broiler chicks were randomly allocated to nine dietary treatments (three ME levels in combination with three lysine levels), and dietary ME and lysine concentrations were formulated by varying corn, soybean meal, tallow, and L-lysine sulfate concentrations. Live body weight (BW), carcass weight (CW), dressing percent, breast muscle weight (BMW), yield of breast muscle, muscle color (CIE L*, a*, and b*), pH values 45 min and 24 h postmortem ($pH_{45}$, and $pH_{24}$), meat shear force value (SFV), and water loss rate (WLR) were evaluated. Results showed that live body weight and dressing percent increased (p<0.05) as dietary energy increased. Higher dietary lysine content improved breast muscle weight. Neither carcass weight nor yield of breast muscle was affected by dietary energy or lysine content. Higher ME increased the b* value (p = 0.067) and $pH_{24}$ value (p<0.05), whereas it decreased SFV (p<0.05) and WLR (p = 0.06). Only water loss rate was influenced (p<0.01) by dietary lysine, which was higher in broilers from the high lysine diet as compared to those from medium or low lysine diets. The $pH_{45}$ value and L* value of breast muscle were not affected by ME or lysine. Significant interaction of dietary ME and lysine was found on a* value of breast muscle. These results indicated that dietary ME and lysine had important effects on breast muscle growth and meat quality, however their effects were different. Different concentrations of dietary ME and lysine might be considered to improve meat quality.

• Journal of the Korean Wood Science and Technology
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• v.43 no.4
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• pp.438-445
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• 2015

Among several thermal wood modification methods German oil heating technology was applied to Korean pine specimens by heat treatment at $180^{\circ}C$ and $200^{\circ}C$. In addition the matched specimens were heat-treated by Thermowood method. The heat-treated specimens were planed and their colors were measured with a colorimeter at 1 mm and 4 mm below the surfaces. The average lightness index (L*) of Oil-180 specimens was the largest followed by Oil-200 and Tmo-200 specimens. The average redness indexes (a*) of all specimens were increased by heat treatment, while the average yellowness indexes (b*) were variable. The average color differences (${\Delta}E*$) of Oil-200 and Tmo-200 specimens were above 30.0, while that of Oil-180 specimens was only 18.4. It can be concluded that the colors of the heat-teated specimens were uniformly changed because their average color difference indexes (${\Delta}E*$) between the inner layers were below 6.0.

• 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.

• Journal of the Korean Graphic Arts Communication Society
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• v.21 no.2
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• pp.43-53
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• 2003

As information-communication network has been developed rapidly, internet users' circumstances also have been changed for the better, in result, more information can be applied than before. At this moment, there are many differences between real color and reappeared color on the CRT. When we observe a material object, our eyes perceive the multiplied form of light sources and nature spectral reflection. However, when the photographed signal is reappeared, illumination at that time of photographing and spectral reflection of a material object are converted into signal, and this converted RGB signal is observed on the CRT under another illumination. At this time, RGB signal is the reflected result of illumination at that time of photographing Therefore, this signal is influenced by the illumination at present, so it can be perceived another color. To accord the colro reflections of another color source, the study has been reported by S.C.Ahn$^{[1]}$, which study is about the color reapperarance system using neuron network. Furthermore, color reappearing method become independent of its circumstances has been reported by Y.Miyake$^{[2]}$. This method can make the same illuminations even if the observe circumstances are changed. To assume the light sources of observe circumstances, the study about color reappearing system using CCD sensor also have been studied by S.C.Ahn$^{[3]}$. In these studies, a population is fixed, first, on ab coordinates of CIE L${\ast}$a${\ast}$b${\ast}$. Then, color reappearing can be possible using every population and existing digital camera. However, the color is changed curvedly, not straightly, according to value's changes on the ab coordinates of CIE L${\ast}$a${\ast}$b. To solve these problems in this study, first of all, Labeling techniques are introduced. Next, basis color-it is based on Munsell color system-is divided into 10 color fields. And then, 4 special color- skin color, grass color, sky color, and gray-are added to the basis color. Finally, 14 color fields are fixed. After analyzing of the principle elements of new-defined-color fields' population, utility value and propriety value are going to be examined in 3-Band system from now on.

• Journal of Dental Rehabilitation and Applied Science
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• v.31 no.4
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• pp.294-300
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• 2015

Purpose: The purpose of this study was to measure the color of low viscosity bulk-fill resin with a capping layer and to compare it with the color of microhybrid composite resin. Materials and Methods: A low viscosity bulk-fill resin (SDR) and microhybrid composite resin of shade A2 (A2) or A3 (A3) were fabricated to 4 mm thickness and light cured for 20 seconds. CIE $L^*a^*b^*$ values of the resin specimens were measured with a colorimeter. Then shade A2 and A3 microhybrid composite resin was capped over low viscosity bulk-fill resins in 2 mm thickness (SA2, SA3). The resin specimens were light cured for 20 seconds and the color was measured and analyzed (n = 10). Color differences (${\Delta}E$) between SA2 and A2, SA3 and A3 were also calculated. Results: $L^*$ value was highest in SDR followed by SA2 and SA3. $L^*$ value of A2 and A3 was the lowest. $a^*$ value was lowest in SDR followed by SA2 and SA3, and A2 and A3 was the highest. $b^*$ value was lowest in SDR followed by A2 and SA2, and A3 and SA3 was the highest. ${\Delta}E$ between A2 and SA2 (${\Delta}E=3.4$), and that between A3 and SA3 (${\Delta}E=3.1$) was lower than the perceptible color difference threshold of ${\Delta}E=3.7$. Conclusion: ${\Delta}E$ between low viscosity bulk-fill resin with a capping layer and microhybrid resin was lower than the perceptible color difference threshold.