• Restorative Dentistry and Endodontics
• /
• v.20 no.1
• /
• pp.372-383
• /
• 1995

The staining tendency of esthetic restorative material was very important factor for the people who are great concern about the esthetics. Most external stains were superficial and adjustable by routine prophylactic procedure. But some of these stains were remained under superficial stain. Some of these stains were accumulative on external tooth surface and it's removal alter the anatomic contour of restoration. The purpose of this study was to evaluate and compare the staining tendency of esthetic restorative materials to staining solution. In this study two glass-ionomer cements (Fuji II Glass-Ionomer Cement and Fuji II LC Glass-Ionomer Cement) and three composite resins (Sil$\ddot{u}$x Plus, APH and P-50) were evaluated and compared. Total 8 disc-shaped specimens of each material (17mm diameter, Imm thick) were immersed in coffee staining solution. These specimens were divided into one control and 3 experimental groups according to the immersion period as follows : Control: immersed in distilled water during each testing period Group 1 : immersed in staining solution for 6 hours Group 2 : immersed in staining solution for 24 hours Group 3 : immersed in staining solution for 72 hours Staining tendency was evaluated by total color difference(${\Delta}E^*$) of specimen before and after staining by spectorcolorimeteric readings (ColorQUEST Spectrophotometer, U.SA.). The results were as follows : 1. The total color differences of each testing materials were increased with time. 2. Among the experimental groups, the Fuji II Glass Ionomer Cement showed the highest total color difference(6.803) and the Silux Plus showed the lowest total color difference(1.637). 3. In comparison of glass ionomer cements, the total color difference of chemical cured glass ionomer cements(6.803) were higher than light cured glass ionomer cements(3.891) (P<0.01). 4. In comparison of composite resins, the P-50 showed the highest total color difference and the Silux Plus showed the lowest total color difference, but there was not significant difference among composite resins(P>0.05).

• Journal of the Korea Fashion and Costume Design Association
• /
• v.3 no.1
• /
• pp.33-46
• /
• 2001

The purpose of this study was to investigate the natural dyeability of silk on extract of Artemisia princeps, The experimental items were divided into the mordanting method. comonent of fabric, kind of mordant. The experimental study was done by laundering fastness, abrasion(dry/wet) fastness, perspiration(acid/alkali) fastness, light fastness test and color difference by C.C.M system. The summarized finding resulted from experiments and investigation are suggested as follows; First, in the C. C. M test on mordanting methods, color difference was significantly improved when mordants were treatmented. And the premordanting method showed the highest color difference, color was most yellow-greenish, Second, in the C.C.M test on component of fabrics, color difference of silk was higher than cotton. It is considered that silk has -$NH_2$ , -COOH, -OH than more than cotton. Third, in dyeing-fastness on mordants, laundering fastness showed that color-change was 2~3 grade, the contamination on attached fabric was 4~5 grade. perspiration fastness(acid/alkali) showed 4~5 grade nearly and those of acid was higher than alkali. abrasion fastness(dry/wet) was 4~5 grade and in Fe(3~4 grade) was lower than the other mordants. Forth, in color difference analysis on mordants, Fe(50.0) showed the highest and the order of color difference was alum(16.0), Cu(7.2), Sn(3.5), Al(3.1), Cr(2.3), The Hue was turned into yellow-greenish in alum mordant treatment, the luminocity of color was most dark in Fe(-48.9) and Cu(-7.2), chroma was the highest in alum (15.7) method.

• Journal of the Korea Furniture Society
• /
• v.24 no.4
• /
• pp.408-415
• /
• 2013

In order to evaluate a feasibility of industrial art use of veneer such as cylindrical laminated veneer lumber, the veneers of 4 species of Korean pine, radiata pine, yellow poplar and Japanese cypress were natural dye-colored and clear finished. Natural dyes were red color originated from sappanwood, blue color from polygonum indigo, and yellow color from Amur cork tree and gardenia. the clear coats of crack seal clear and UV protection oil were applied on the dyed veneer. The dyeing and finishing characteristics through fading test were summarized as follows; In non-dyed and non-finished Korean pine veneer, lightness was decreased and yellow and red hues increased after fading test. In natural dyed- and finished-veneer, color difference of gardenia-mixed Amur cork tree was generally highest, and that of polygonum indigo was lowest. Compared to non-treatment of veneers of Korean pine and yellow poplar, color difference decreasing effect by finishing was shown in crack seal clear and UV protection oil. In addition, UV protection oil was more favorable than crack seal clear with more decreased color difference. In result, maximum values of color difference after fading for 8 days were recorded about 16 to 20, which are remarked 'very much' of 12.1 or more when reviewing with 'National bureau of standards unit in USA'.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.15 no.1
• /
• pp.85-96
• /
• 1997

The color difference between original and printed copy is affected mainly by ink trapping and optical properties of overprinted ink layer. Since the general expression itself about ink trapping is affected also by the optical properties, the analysis of color difference using the ink trapping only cannot be certain. This study will show a new approaching method for optical analysis of spectral reflectance and the effect of printing sequence on color difference in multi-color overprints under the condition of excluding completely the ink trapping problems by means of using transparent film as a substrate.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.16 no.1
• /
• pp.13-24
• /
• 1998

The color difference caused by the overprinting sequence of ink in multicolor printing is due to both trapping and optical properties of ink layers. Hence the effect of optical properties only cannot be analyzed without removing the effect of ink trapping This study was carrier out for the purpose of analyzing optically the color difference caused by only the optical properties of ink under the various printing sequence. The present optical analysis for overprints showed a good agreement with the experimental result. It is expected that this study may contribute to decreasing the color difference between the original and the printed reproduction in multi-color printing.

• The Transactions of the Korea Information Processing Society
• /
• v.5 no.3
• /
• pp.715-719
• /
• 1998

In this paper, we propose a color enhancement system which is based on the improvement of transition time problem and specific color detection stability. The proposcd system apply the time difference correction step to corrects time difference which is taken place at the transimission process between color signal and color subcarrier signal and to reduce detection errors. And also, we proposed stability method to improve transition time problem and detection efficiency as the control of reference color. The proposed system controls specific color when the mean difference value of detected voltages greater than the value of minimum discriminate voltages of two adjacent color signals. Thus, the color enhancement system improves detection efficiency and controls specific color from the color signal without overlapping of correction range.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2010.05a
• /
• pp.77-81
• /
• 2010

This study deals with the analysis of color-difference and physical property of anti-corrosion coatings using at inside of concrete tank for drinking water. Because anti-corrosion coatings are effected by chemical attack, color and physical property are changed. So in this study when epoxy resin coatings of 3 types were received chemical attack by Cl- and NaOH, we present the co-relationship between color-difference and bond strength. For this study, we used the colorimetry, which can measure the degree of color difference on surface of materials. As the results, in case of Cl-, color change is appeared, bond strength also is decreased. From this experiment, we could know that color change due to chemical aging has the deep relationship with physical performance(bond strength) materials. further researches are needed.

• Journal of the Korea Furniture Society
• /
• v.22 no.3
• /
• pp.199-207
• /
• 2011

Examined the color of ten species of Korean broadleaf trees were experimented based on $L^*a^*b^*$ values and color difference (${\Delta}E^*ab$) between sapwood and heartwood, in order to analyze and determine the color, a critical visual and decorative factor of the broadleaf trees that can be used for making woodcraft and furniture. According to the result, the entire sapwood and heartwood, except the heartwood of Populus tomentiglandulosa, showed positive value in whiteness, redness, and yellowness and therefore contained yellow and red. None of the species showed color difference between sapwood and heartwood that was trace (0~0.5), slight (0.6~1.5), or very much; whereas Populus maximowiczii showed noticeable color difference (1.5~3.0); Salix koreensis, Betula platyphylla var japonica, Carpinus laxiflora, and Castanea crenata, appreciable and Populus tomentiglandulosa, Juglans mandshurica, Betula schmidtii, Alnus japonica, and Quercus variabilis, much. The color characteristics of heartwood and sapwood of the ten Korean broadleaf tree species studied in this research can be used as basic data for woodcraft or furniture production, especially when replacing foreign woods with Korean ones, and also contribute to convergence researches for science, engineering, and design fields.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.37 no.5 s.113
• /
• pp.8-14
• /
• 2005

The difference of whiteness, brightness and lightness was clearly explained in this paper by use of a tinting dye and a fluorescent whitening agent which are commercially widely used to make paper look whiter. Other optical properties such as tint, color shade, and color difference were also discussed. It is concluded that in comparing two tinting dyes, lightness (L*) is the most important property to be compared, while whiteness data should be used in caution in order not to surpass its significant range, and a*, b* values can also be used to find the change of color shades together with ${\Delta}E$ as color difference. In comparing two fluorescent whitening agents, whiteness or brightness values are most important to be compared, but lightness values are not suitable for this purpose; a*, b* and color difference ${\Delta}E$ can also be referred, but with less significance.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.30 no.1 s.149
• /
• pp.115-124
• /
• 2006

Natural dyes are environmentally and human compatible. But they are not various or not fast in color. The mixed dyeing have been attempted to solve these disadventages of natural dyes. The persimmon juice dyed fabrics have brown-color and good hygienic properities however low color fastness. The onion dyeing show similar brown-color and have good color fastness caused by querectin existed in onion outer skins. Mixed dyeing was carryied out on silk fabrics using persimmion juice and onion outer skin extract in this study. The mixing method were persimmon juice dyeing and then onion dyeing(P-O), onion dyeing and then persimmon juice dyeing(O-P) and dyeing in the mixture of persimmon juice and onion outer skin extract simultaneously(P+O). The mordants were none-mordent, gallic acid after-treatment and alum after-treatment. Several persimmon juice dyed fabrics were irradiated for 2 hours before onion dyeing(PU-O). The color values of dyed silk fabrics were as follows. The persimmon juice dyed silk fabric developed to yellow-red color after 2 hours of uv irradiation. Onion dyed fabrics show similar yellow-red color after dyeing without uv irradiation. The effect of alum after-treatment on color difference were highest in onion dyeing. The dyeabilities of both P-O and O-P were higher than persimmom juice dyeing and onion dyeing. The dyeabilities of P+O was lower than persimmom juice dyeing and onion dyeing. The value of color difference of alum-treated fabric was the highest. The color difference of P-O and O-P caused from 2 to 4 hours of uv-irradiation were lower than those of persimmon juice dyed fabrics. Onion skin extract could prevent the color-change of persimmon juice dyed fabrics in mixed dyeing. The color difference of PU-O was higher than the P-O.