• Title/Summary/Keyword: Chromaticity analysis

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A Study on the Characteristics of Verdigris Manufactured by Acid Corrosion Method (산부식법으로 제조한 동록안료의 특성에 관한 연구)

  • Kang, Yeong Seok;Mun, Seong Woo;Lee, Sun Myung;Jeong, Hye Young
    • Journal of Conservation Science
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    • v.36 no.3
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    • pp.178-186
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    • 2020
  • Verdigris is a traditional artificial pigment reported on old research papers and according to the methods mentioned in the literature, it is manufactured by the corrosion of copper or copper alloys using vinegar and by further scraping the generated rust. Since the Three Kingdoms Period, various household products with copper alloys, such as bronze and brass, have been used, and pigment analysis of these cultural heritage items has revealed the presence of tin, zinc, lead, and copper in green pigments. Based on these data, five types of verdigris were prepared from copper and copper alloys, and analyzed. the analysis results revealed a bluish green pigmentation, and the chromaticity, particle shape, and oil absorption quantity of each verdigris differed based on the type of copper alloy used in its preparation. The main components of verdigris are Cu, Sn, Zn and Pb, and their proportions depended on the type of copper alloy used during manufacturing. However, the main constituent mineral of the pigments is the same as 'hoganite[Cu(CH3COO)2·H2O]', regardless of the copper alloy used. The result of accelerated weathering test for stability evaluation revealed that verdigris was discolored rapidly, thereby indicating that its stability was low, in particular, the pigments comprising lead presented relatively lower stability.

Restoration of Gold Gilding Using Plum Acid for Geumdong-samjonpanbul Excavated from Walji, Gyeongju (매실산을 이용한 월지 출토 금동삼존판불의 금도금법 복원)

  • Yun, Yong Hyun;Cho, Nam Chul;Yoon, Dae-Sik;Lee, Tae Sub;Bae, Chaerin
    • Journal of Conservation Science
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    • v.33 no.2
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    • pp.107-120
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    • 2017
  • This research involves a gilding experiment using plum acid that has previously been reported to restore Geumdongsamjonpanbul excavated from Wolji, Gyeongju. Chromaticity analysis revealed that the yellowness of the samples was high, and the samples treated with acid for more than 10 minutes showed high brightness. SEM studies revealed that the sample subjected to amalgam application and immediate heating was rarely gilded with gold. When the amalgam application time was longer than 36 h, the gold layer observed was uneven. Therefore, the optimum amalgam application time was 12-24 h. EDS analysis showed that mercury content was ~5 wt.% for samples with an acid treatment time of 20 min, lower than that in other samples. Gold gilding was successful for the sample with amalgam application time of 24 h and acid treatment time of 20 min. This sample showed the high-resolution XPS peak corresponding to Au and retains a little Hg compared with the other samples. In other words, experimental and analytical results using plum acid showed that gilding was successful when acid treatment time was 20 min and amalgam application time was 24 h. Based on these results, Geumdongsamjonpanbul excavated from Wolji, Gyeongju can be restored.

A Textile Analysis of Woolen Carpet Excavated from Seongjeonggak Hall, in Changdeokgung Palace (창덕궁 성정각 출토 모담(毛毯) 직물 분석)

  • Pak, Seonghee;Lee, Ryangmi;An, Boyeon;Cho, Misook
    • Journal of Conservation Science
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    • v.37 no.2
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    • pp.120-134
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    • 2021
  • A Woolen carpet from the late Joseon Dynasty was unearthed in the process of repairing Seongjeonggak in Changdeokgung. Since relics are rarer than documentary records, the woolen carpet is highly valued as a relics. It is presumed to have been woven in the late 19th or early 20th century because there is a record of repairing Seongjeonggak in 1907. In the carpet, a pattern is made by inserting colored yarn dyed yellow and red onto a reddish-purple ground weave. The selvage of the woolen carpet used cotton thread, and jute is used for the warp and weft of the ground weave. The colored patterns is made of wool in the form of loop pile. Cut piles may appear occasionally when the colored yarn changes, but are almost invisible from the surface because they are pressed tightly with a shuttered weft. Making carpets with jute and wool is thought to be influenced by the Brussels carpets of the mid-18th century. Furthermore, the woolen carpet is torn and the pattern is completely unclear; however, it is understandable that the pattern is partially repeated. Microscopic and Fourier transform-Infrared spectrometer(FT-IR) analyses were performed for the above investigation. To identify the dyes used in relics, we compared them with natural dyed fabric samples based on chromaticity measurements and Ultraviolet/Visible spectrophotometer(UV-Vis) analysis. These analyses revealed that the woolen carpet's dyed green yarn did not use indigo, and reddish-purple ground weave is estimated to have used Caesalpinia sappan.

Effect of Freeze Dried Ramie Leaf Powder on the Quality Characteristics of Pork Patties (동결건조 모시잎 분말 첨가가 돈육패티의 품질특성에 미치는 영향)

  • Ahn, Su Mi;Jang, Seri;Park, Inshik
    • The Korean Journal of Food And Nutrition
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    • v.28 no.3
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    • pp.478-485
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    • 2015
  • This study was conducted to investigate the effects of ramie leaf powder on the quality characteristics of pork patties. The moisture, crude protein, crude fat, and crude ash in freeze-dried ramie leaf powder were found to be 4.67% (w/w), 25.61% (w/w), 6.66% (w/w), and 16.88% (w/w), respectively. Pork patties were prepared by adding varying amounts of ramie leaf powders up to 1.5% (w/w) of the pork patty formulation. The moisture contents of meat patties containing ramie leaf powder were lower than that of the control patty, but there was no significant difference in pH values between the patties. With increasing amounts of ramie leaf powder, chromaticity decreased in brightness ($L^*$) and redness ($a^*$), but increased in yellowness ($b^*$) in the raw patties. In texture analysis, hardness, springiness, cohesiveness, and chewiness of the pork patties increased as more ramie leaf powder was added to the pork patties. Thiobarbituric acid reactive substances (TBARS) values increased during storage in pork patties without ramie leaf powder, but those formulated with ramie leaf powder showed lower TBARS values than those in the control groups. Sensory panels determined that pork patties containing 0.5% ramie leaf powder had higher scores for overall acceptability.

Quality Characteristics of Dasik with Added Silkworm Powder (누에 분말을 첨가한 다식의 기호도 특성)

  • Kim, Ji-Eung
    • Journal of the East Asian Society of Dietary Life
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    • v.18 no.2
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    • pp.221-225
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    • 2008
  • The objective of the study was to examine the distinct qualities of Dasik containing added silkworm powder. In order to discern the differences in characteristics among samples the silkworm powder was added as at ratios of (0%, 10%, 20%, 30% and 40%), respectively. Measurements for moisture, chromaticity and mechanical and physical properties were performed, in addition to sensory evaluations. The results were as follows. The moisture contents of the Dasik samples changed as the added silkworm powder content increased. A lower L-value resulted as the amount of silkworm powder increased (p<0.05), the a and b values also showed decreasing tendencies. In the texture analysis, hardness increased as the amount of added silkworm powder increased from 0% to 40% (p<0.05). Adhesiveness was highest in the 40% silkworm powder group, and the 30% and 20% groups had the highest springiness values respectively (p<0.05). In terms of sensory quality overall surface color, texture and taste were perceived as superior for the 30% and 20% add silkworm powder groups gumminess was lowest for the 0% group (p<0.05), and overall quality was lowest for the 40% added silkworm powder group. Consequently, there was greater preference for the samples containing less than 40% added silkworm powder, and the 30% treatment had the best overall quality.

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The Physicochemical and Quality Properties of the Bread Added with Soy Fiber Powder (콩식이섬유를 첨가한 식빵의 이화학적 및 품질 특성)

  • Lee, Myung-Ho;Byun, Jong-Beom;Kim, Sun-Kyung;Choi, Young-Sim
    • Culinary science and hospitality research
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    • v.18 no.1
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    • pp.1-14
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    • 2012
  • This study examines the physiochemical and quality properties of the bread added with soy fiber powder to promote the intake of soy fiber. For this study, the powder for making bread was mixed with soy fiber, wheat flour and SF-1450 and SF-1260 at the ratio of 0~12% each. The ratios of the edible fiber contained in the soy fiber power samples were 72.0% in the SF-1450 sample and 67.8% in the SF-1260 sample. The mixograph characteristics tended to be conspicuons in proportion to the amount of the soy fiber added at midline peak height, width at peak and, width at 8.00. The specific volume of the bread tended to decrease significantly as the amount of the soy fiber increased from 2 to 12%. In terms of crust chromaticity change, L-value increased more significantly in the samples added with 4 to 12% than the control. For a-value, SF-1450 in the samples with 6 to 12% and SF-1260 in the samples with 8 to 12% more significantly decreased than the control. For such characteristics of texture as hardness, SF-1450 in the samples with 10 to 12% and SF-1260 in the samples with 6 to 12% increased more than the control. As discussed above, the sensual characteristics of the white pan bread with soy fiber added tended to be worse as the amount of the additive increased, compared with the control samples. Summing up the results of the physico-chemical analysis and the overall acceptability, those samples with 2~4% of SF-1450 and 2% of SF-1260 were found excellent.

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Effect of Physiochemical Properties of Seokganju on Functionality and Light Fastness (석간주의 이화학적 특성이 기능성 및 내광성에 미치는 영향 연구)

  • Park, Ju Hyun;Jeong, Hye Yeong;Mun, Seong Woo;Woo, In Suk
    • Journal of Conservation Science
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    • v.33 no.6
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    • pp.485-495
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    • 2017
  • The purpose of this study is to evaluate the functionality and lightfastness of the natural pigments according to the type of Seokganju used as Dancheong. The commercially available red iron-oxide-based natural pigments that are called Seokganju and Daija manufactured by traditional methods in Korea and Japan were selected. The analysis of the constituent minerals and constituents of 8 kinds of collected Seokganju showed that most of them contained hematite. There are two types of Seokganju according to the $Fe_2O_3$ contents. The type of Seokganju can be characterized not only using the main component but also from the burn-out processing. The chromaticity results for Seokganju with a high $Fe_2O_3$ concentration indicate dark red or grayish brown, while those for Seokganju with a low $Fe_2O_3$ concentration indicate yellowish red or yellowish brown. Samples were prepared by mixing with a glue solution and functional properties were evaluated based on the opacity and spreadability. Coated samples were used in the lightfastness test. The spreadability and opacity of the pigments were measured differently depending on the main component. Most Seokganju samples a showed slight color change until $9,000kJ/m^2$ but rapid color changes were detected after $18,000kJ/m^2$. In particular, burnt Seokganju showed superior lightfastness.

Quality Characteristics and Antioxidant Activities of Yanggaeng with Aronia Juice (아로니아즙 첨가 양갱의 품질특성 및 항산화활성)

  • Hwang, Eun-Sun;Lee, Yae-Jin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.42 no.8
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    • pp.1220-1226
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    • 2013
  • The objective of this study is to investigate the quality characteristics and antioxidant activities of yanggaeng prepared with different amounts of aronia juice. Aronia juice was incorporated into yanggaeng at different levels (containing 50, 100, and 150 g of aronia juice in AJ 50, AJ 100, and AJ 150, respectively) based on the total weight of water. Total acidity and sugar contents showed a significant increase, however, pH showed a decrease with increasing levels of aronia juice. Hardness also showed an increase with increasing levels of aronia juice. Regarding texture profile analysis, hardness, springiness, and chewiness of yanggaeng were increased, however, cohesiveness was similar compared to the control and aronia juice added treatments. In chromaticity determination, L and b values showed a decrease, however, a value increased with increasing levels of aronia juice. The total polyphenols, flavonoids, and anthocyanin contents were increased proportionally with increasing levels of aronia juice. Antioxidant activity measured by DPPH and ABTS radical scavenging activities were significantly higher than those of control and increased proportionally according to the concentration of aronia juice. The sensory evaluation indicated that AJ 100 showed the best preference in color, taste, texture, flavor, and overall acceptance. These results suggest that aronia juice may be a useful ingredient in yanggaeng for improvement of quality and antioxidant potential.

Applicability as a Dancheong Pigment Raw Materials of Korean Low Grade Kaolin (국내산 저품위 고령토자원의 단청안료 원료로써의 활용 가능성)

  • Moon, Dong Hyeok;Han, Min Su;Cho, Hyen Goo;Kim, Myoung Nam;Kim, Jae Hwan
    • Journal of the Mineralogical Society of Korea
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    • v.29 no.4
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    • pp.179-190
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    • 2016
  • X-ray diffraction analysis, chromaticity measurement, execution and evaluation by Dancheong artisan, accelerated weathering test, and fire resistance test were conducted to test the applicability as a Dancheong pigment raw materials of Korean low grade kaolin in cultural properties. The ores that feldspar rich and composed of fine particles (< $38.1{\mu}m$) showing advantageous for the inherent purpose of the white pigment than that of high grade kaolin. And the test of whiteness, concealment force, outdoor exposure durability and fire resistance shows similar or better result than existing products (Hobun and Sanhwa jidang). In conclusion, it is expected that the use of fine feldspar rich white soil and low-grade kaolin can be used as a white pigment raw materials which have similar to better material properties and economic efficiency than existing products.

UV Degradation Characteristics and Applicability of Coating Agent for Conservation of FRP Artifacts (FRP 작품 보존을 위한 자외선 열화 특성 및 자외선 차단 코팅제 적용 연구)

  • Han, Ye Bin;Chung, Yong Jae
    • Journal of Conservation Science
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    • v.33 no.3
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    • pp.203-214
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    • 2017
  • This study evaluated the degradation characteristics of FRP by ultraviolet (UV) rays and applied a UV-resistant coating to prevent the degradation of the surface of these sculptures. As a result of the degradation caused by UV rays, there were slight changes in the FRP surface and contact angle. The chromaticity sharply increased in the early phase of degradation. After applying the coating to the FRP, no significant surface changes were observed. However, it had lower changes in color as compared to the uncoated specimen, so it was verified that the control of discoloration could be possible. Some changes in the gloss and contact angle were observed depending on the extent of degradation, but the UV coating agent remained relatively stable. Analysis of the infrared light spectrum showed that there were almost no chemical changes, and it could be concluded that the coating treatment prevented degradation for a certain period. This study investigated the degradation of FRP used as materials in artwork exposed to UV rays, and it was found that there was a delay in the onset of degradation in the FRP with the UV-resistant coating when compared to the uncoated FRP.