• Journal of the Korean Society of Clothing and Textiles
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• v.43 no.5
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• pp.753-767
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• 2019

Dyeing behavior of indigo leaf powder was examined in regards to the effect of the amount of pigments on color and dye adsorption for silk dyed by reduction and nonreduction dyeing. The amount of indigotin and indirubin pigments adsorbed in dyed silk was examined by HPLC-DAD analysis. The color of dyed silk showed 7.7BG - 2.7B hue when silk was dyed at $50^{\circ}C$, and 3.5G - 4.9BG when dyed at $70^{\circ}C$. Blue ($b^*$) and green ($a^*$) color decreased as the pH of dyebath increased. When silk was dyed using nonreduction, R (red) and RP (red purple) hue and R hue was more apparent in samples dyed at $90^{\circ}C$. In reduction dyeing, amount of indigotin detected from silk exceeded the amount that was initially contained in the input dye. The amount of indirubin was lower than indirubin that was initially in the powder. In nonreduction dyeing, silk showed a higher amount of indirubin adsorption compared to silk dyed by reduction. The amount of indigotin adsorbed in silk was lower than the amount initially contained in the input dye. The amount of indigotin and indirubin adsorption was primarily dependent upon the dyeing method-reduction or nonreduction along with dyeing temperature and the pH of dyebath.

• Journal of Conservation Science
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• v.29 no.4
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• pp.445-450
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• 2013

This study investigated the properties of the painting materials used in the temple wall paintings of the $18^{th}$ to $19^{th}$ centuries by synthetically comparing the component analysis data on the pigments used in the temple wall paintings. The study subjects analyzed from ED-XRF are the data on the 61 temple wall paintings distributed nationwide. The colors of the wall painting coloring layers are classified into seven categories: white, incanadine, yellow, red, green, blue and black color. No big geographical and temporal differences in the type of the pigments were found in the temple paintings of the late Joseon Dynasty distributed in Gyeongsangdo and Jeollado. On the other hand, there were differences in the use of a color when mixing it with other colors depending on the painted parts.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.23 no.5
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• pp.255-264
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• 2013

Cobalt aluminate ($CoAl_2O_4$) is a highly stable pigment with excellent resistance to light, weather, etc., which has resulted in widespread use as a ceramic pigment. Due to the unique optical characteristics, $CoAl_2O_4$ is generally used as a coloring agent to decorate porcelain products, glass, paints and plastics. Here, $CoAl_2O_4$ pigments were synthesized by polymerized complex method and solid state reaction. Then $CoAl_2O_4$ pigment were grinded using the attrition milling with 1 mm size zirconia ball for 3 hours. The attrition milling process was performed at the constant speed of 800 rpm and ball to powder weight ratio (BPR) was 100 : 1. The characteristics of synthesized pigment were analyzed by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), particle size analyser (PSA) and CIE $L^*a^*b^*$. The XRD patterns of $CoAl_2O_4$ show single phase spinel structure. The particle size of $CoAl_2O_4$ measured by FE-SEM, TEM and PSA analysis was in the range of 100~200 nm. The blue color of obtained $CoAl_2O_4$ pigments could be confirmed through CIE $L^*a^*b^*$ measurement.

• ALGAE
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• v.38 no.2
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• pp.141-150
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• 2023

Light quality is a common environmental factor which influences the metabolism of biochemical substances in algae and leads to the response of algal growth and development. Pyropia yezoensis is a kind of economic macroalgae that naturally grows in the intertidal zone where the light environment changes dramatically. In the present study, P. yezoensis thalli were treated under white light (control) and monochromatic lights with primary colors (blue, green, and red) for 14 days to explore their physiological response to light quality. During the first 3 days of treatment, P. yezoensis grew faster under blue light than other light qualities. In the next 11 days, it showed better adaptation to green light, with higher growth rate and photosynthetic capacity (reflected by a higher rETR_max = 61.58 and E_k = 237.78). A higher non-photochemical quenching was observed in the treatment of red light than others for 14 days. Furthermore, the response of P. yezoensis to light quality also results in the difference of photosynthetic pigment contents. The monochromatic light could reduce the synthesis of all pigments, but the reduction degree was different, which may relate to the spectral absorption characteristics of pigments. It was speculated that P. yezoensis adapted to a specific or changing light environments by regulating the synthesis of pigments to achieve the best use of light energy in photosynthesis and premium growth and metabolism.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.8 no.2
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• pp.196-208
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• 1998

To improve the quality of environmental measurements and evaluation of the workplace air in the pigment manufacturing industries, we analyzed metal(chromium, cadmium, lead, iron, cobalt, manganese, antimony, titanium, arsenic, and selenium) concentrations by ICP-AES in sixty seven samples of inorganic bulk pigments which are produced and/or used in Korea. We also collected MSDS which has to be supplied by manufacturer and/or supplier and posted in the workplace according to the Hazard Communication Standards, and compared the number of metals listed in each MSDS with the number of metals determined by ICP-AES. Results were as followed; 1. Among seventeen yellowish-colored samples, chromium(2~19%) and lead(0.1~61%) were the two major metals. In thirteen reddish-colored samples, iron was the major component with 37~81%. Cobalt and manganese were detected in blue-colored samples with less than 1%, while antimony and titanium were the major two metals in white-colored pigments with 178~300 ppm and with 36~65%, respectively. 2. In area samples collected in workplace air(one pigments producing factory and five retailer stores), iron and manganese were detected but the concentrations not exceeded the TLVs(1 and $5mg/m^3$, respectively). In three of fifteen samples, the concentrations of lead exceeded the TLV ($0.05mg/m^3$). 3. Two out of seven companies provided MSDS, and the average provision rate was 22.4%. And the coincidence rate of the number of metals referenced in MSDS and determined by ICP-AES mostly accorded, but in one sample, different metal was detected from MSDS. In summary, metals have to be concerned in evaluation of the workplace air dealing with compounds of inorganic pigments dust are cobalt, chromium, iron, manganese, lead and antimony, and these are simultaneously determined by ICP-AES. Taking this opportunity, it is needed to reinforce that the personnel is to be concerned about prevention of workers' ill health regarding to provision of MSDS.

• Journal of Conservation Science
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• v.33 no.2
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• pp.85-95
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• 2017

Oil paints are mixtures of pigments, drying oils and additives. In the past, oil paints were mainly composed of inorganic pigments. However, recently color matching techniques vary depending on manufacturers due to the development of various kinds of synthetic pigments. Despite this, most studies of oil paints in South Korea are about durability tests, and there is no comparative study on the characteristics of commercial oil paint components. This study aims to compare the properties of four different kinds of oil paints from four manufacturers, which are the most popularity used. Extender pigments in oil paint from C brand differed from that of other manufacturers and various kinds of coloring pigments were differently used depending on the oil paints and the manufacturers. The mixing ratios and the pigment types differed even for oil paints having the same product name. It is assumed that these differences could affect the colors. The result of this study is expected to contribute to the analysis of artworks through the accumulation of scientific data of oil paints. In addition, it can be utilized as a scientific basis for art history studies, including the characteristics of artists or production year.

• Korean Journal of Environmental Biology
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• v.17 no.1
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• pp.1-9
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• 1999

Numerous observations revealed strong evidence of increased middle ultraviolet radiation or UV-B (280 ~ 320 nm) at the earth's surface resulting from stratospheric ozone depletion. UV is the waveband of electromagnetic radiation which is strongly absorbed by nucleic acids and proteins, thus causing damage to living systems. It has been recorded in the East Sea, Korea that solar UV-B impinging on the ocean surface penetrates seawater to significant depths. Recent researches showed that exposure to UV-B for as short as 2h at the ambient level (2.0 Wm$^{-2}$) decreased macroalgal growth and photosynthesis and destroyed photosynthetic pigments. These may suggest that UV-B could be an important environmental factor to determine algal survival and distribution. Some adaptive mechanisms to protect macroalgae from UV-damage have been found, which include photoreactivation and formation of UV-absorbing pigments. Post-illumination of visible light mitigated UV-induced damage in laminarian young sporophytes with blue the most effective waveband. The existence of UV-B absorbing pigments has been recognized in the green alga, Ulva pertusa and the red alga, Pachymeniopsis sp., which is likely to exert protective function for photosynthetic pigments inside the thalli from UV-damage. Further studies are however needed to confirm that these mechanisms are of general occurrence in seaweeds. Macroalgae together with phytoplankton are the primary producers to incorporate about 100 Gt of carbons per year, and provide half of the total biomass on the earth. UV-driven reduction in macroalgal biomass, if any, would therefore cause deleterious effects on marine ecosystem. The ultimate impacts of increasing UV-B flux due to ozone destruction are still unknown, but the impression from UV studies made so far seems to highlight the importance of setting up long-term monitoring system for us to be able to predict and detect the onset of large -scale deterioration in aquatic ecosystem.

• Journal of Conservation Science
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• v.32 no.1
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• pp.89-100
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• 2016

We estimated pigments and painting techniques with nondestructive analysis for Yu Eonho's portrait made in the eighteenth century, then compared with 11 portraits and painting characteristics at that time. The pigments used to Yu Eon-ho's portrait include lead white, yellow dye, cinnabar, minium, and pink dye, malachite, azurite, iron oxide red and brown dye, blue and pink dye for purple. In the result compared with painted pigments of 11 portraits, iron oxide red without cinnabar was used on the face part and organic green dye only was used instead of inorganic pigments on the other side of clothing after Yu Eonho's portraits portrait. This study is show the painting techniques on the portraits in the late $18^{th}$ century. We expect to use as useful referencing data for the study on the coloring technique of a portrait in the late Joseon Dynasty.

• Conservation Science in Museum
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• v.24
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• pp.81-98
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• 2020

This paper presents the results of a comprehensive nondestructive analysis of Portrait of Master Gowun at Wunamyeongdang Shrine (Hereafter, Portrait of Choe Chiwon), Tangible Cultural Heritage No. 187 of Gyeongsangnam-do, including the underlying images drawn at the time of its production and the pigments present. The analysis revealed that the portrait was produced in 1793 at Ssanggyesa Temple in Hadong, Gyeongsangnam-do, which makes it the earliest known example among the extant portraits of Choe Chiwon. X-ray examination found images of a half-length boy monk and a full-length boy monk on either side of the portrait, which had been painted over and became invisible to the naked eye. XRF analysis of the pigments indicated that white lead was used for white, cinnabar and red lead for red, malachite for green, azurite for blue, and gold for gold. It was revealed that the overpainted boy monks were colored using the same pigments as those applied in the portrait of the main figure. It is hoped that the analysis of the pigments used for the boy monks can provide basic materials for research on the production of copied portraits and local Buddhist paintings. Also, additional research drawing upon other fields of study is required to examine the details of the inscription of the portrait.

• Korean Journal of Environmental Agriculture
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• v.11 no.3
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• pp.261-268
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• 1992

The membranes of mitochondria and chloroplasts contain a number of pigments that can act as endogenous sensitizers to produce activated oxygen species, most efficiently in blue light, which, in turn, attack functional targets in membranes. Therefore, intense blue light from the sun can exert various adverse effects on the functional and structural integrity of the membranes: one of the biochemical events of these negative effects could be the oxidative degradation of the unsaturated fatty acid constituents of membrane polar lipid. It may be assumed that as a strategy to avoid the light induced fatty acid degradation in membranes plant cells, responding to high intensity blue light, change the fatty acid compositions of membrane lipid in such that more-unsaturated fatty acid constituents are replaced by lessunsaturated fatty acid constituents. The results obtained in the present study, most importantly the measurements of double bond index of membrane polar lipid in concert with other measurements such as light quaility-dependent membrane peroxidation and the activities of membrane-bound proteins, seem to support this assumption.