• Journal of the Korean Ceramic Society
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• v.52 no.6
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• pp.497-501
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• 2015

Inkjet printing is a widespread technology, offering advantages such as high-quality decoration, a continuous process, and the accurate direct reproduction of patterns or pictures. In inkjet printing technology, the dispersion stability of ceramic ink is one of the most important factors. In this study, the dispersion stability of blue $CoAl_2O_4$ ink for ceramic inkjet printing is systematically investigated. Blue $CoAl_2O_4$ pigment was synthesized by a solid-state reaction and then milled to less than 300nm in size. In order to investigate the influence of the viscosity on the dispersion stability, two types of $CoAl_2O_4$ ceramic inks (termed here Blue L and Blue H) were prepared using different volume ratios of ethylene glycol and ethanol. The Blue L and Blue H ink solutions contained cetyltrimethylammonium bromide(CTAB) as a dispersive agent. The viscosity, surface tension and jetting stability of the $CoAl_2O_4$ ceramic inks were analyzed using a rheometer, a surface tension meter and a dropwatcher. The dispersion stability of the $CoAl_2O_4$ ceramic ink was investigated by a multiple light-scattering method. Blue H, a ceramic ink with higher viscosity, showed much better dispersion stability than the Blue L ceramic ink.

• KIEAE Journal
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• v.9 no.1
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• pp.77-83
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• 2009

In this experiment, we used different addition ratio of the pigment and straw, to improve the decorative effect of the finishing touch while finding the kinds of clay colors taking on many sophisticated images, through the comparison between the various colors and textures of the surface. (1) To test the plaster material, added were the pigment of Red, Yellow, Black, and Green by the percentages of 0.5, 1, 1.5, 2, and 2.5, respectively, followed by the analysis of the color changes of the plaster material using the Photoshop (RGB). The results showed the bigger the addition ratio of the red color is, the higher the numeral values of RGB after it dried. However the brightness after drying didn't showed a big difference depending on the addition ratio. With the addition of the yellow pigment, the color difference between after and before drying was bigger in the order of Blue, Green and Red; the brightness increasingly rose while the saturation changed little. (2) When we scratched the plaster surface with U and V shape carving knives, the U knife didn't make a clean shape digging around the clay plaster material but with smooth textures, while the V knife made a clean cut, which represents its readily use in terms of the decorative function of the clay plaster. (3) In an experiment the surface texture was tested with different lengths and additions ratio of the straw, addition of 2cm straw by 1, 2, and 3% presented the most appropriate surface of the plaster.

• Korean Journal of Materials Research
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• v.23 no.4
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• pp.233-239
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• 2013

We collected Seokganju minerals (regions in Gyeryong Mountain, Sangsin-ri, Banpo-myeon, Gongju Chungcheongnam-province), which were used as natural color pigments for grayish-blue during the 15th~16th centuries of the Joseon era, and investigated their crystallographic features to develop a black pigment having a spinel structure. By a Raman analysis, the color of Seokganju under transparent glaze as a pigment for painting was black because hematite ($Fe_2O_3$) in Seokganju was converted to magnetite ($Fe_3O_4$) However, Seokganju into the transparent glaze as a pigment was brown because of hematite ($Fe_2O_3$) and small amounts of maghemite (${\gamma}-Fe_2O_3$) in Seokganju minerals. Only Seokganju mineral is used, it is not suitable for black pigment into the transparent glaze. This study tried to develop a spinel crystal black pigment stabilized by Seokganju with CoO, $Cr_2O_3$, NiO, and $MnO_2$ at $1280^{\circ}C$. A Raman spectroscopy analysis was performed to verify the presence of Mn The results showed that it existed as spinel, and two crystal phases $CoFe_2O_4$ and $MnFe_2O_4$ were mixed. $CoFe_2O_4$ spinel has a dark grayish black color and $MnFe_2O_4$ spinel has a greenish black color, and these two appeared as black. The color of a specimen calcined by adding 6 wt% of pigment mixed with 5 wt% of $MnO_2$ added to lime glaze was analyzed with a UV spectrophotometer. When applying the color pigment, it appeared black stabilized with $L^*$24.23, $a^*$ 0.12, $b^*$ -2.29 at $1260^{\circ}C$ oxidative calcination, With $1240^{\circ}C$ reduction firing, it is appeared black stabilized with low brightness of $L^*$ 23.13, $a^*$ -1.12, $b^*$ 0.54.

• 한국문화재보존과학회:학술대회논문집
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• 2002.02a
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• pp.12-20
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• 2002

The analysis of danchung pigments at the Geunjeongjeon Hall in the Gyeongbokgung Palace were carried out by EXRF and MXRD. The analytical results showed that mineral pigments were employed for the inside of the Geunjeongjeon Hall. The main ingredients of green pigments were chalcanthite and celadonite. Red pigment was cinnnabar. It was also revealed that synthetic pigments were applied for the outside of the Hall. Yellow pigment was chrome yellow. The main ingredients of red pigments were red lead and hematite. Green pigments were emeral green and chrome green. Lazurite was employed for blue pigment and titanium dioxide for white one.

• Horticultural Science & Technology
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• v.30 no.1
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• pp.6-12
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• 2012

Early growth, pigmentation, protein content, and phenylalanine ammonia-lyase (PAL) activity of red curly lettuces (Lactuca sativa L.) grown under different lighting conditions were investigated. Fluorescent lamps (control), blue, red, and blue plus red light-emitting diodes (LEDs) were used as light sources for 10 days. An equal proportion (1:1) of blue and red LEDs was used in the mixed radiation condition. Compared with the control, monochromic red or blue lighting increased fresh and dry weights of 'Ttuksum' and 'Jaju' lettuces. Anthocyanin synthesis was also significantly promoted by the mixed radiation of blue and red LEDs. The mixed radiation also increased the protein content and PAL enzyme activity of 'Ttuksum' leaves by about 200% compared to other treatments. Anthocyanin content was the highest in lettuces subjected to the mixture radiation of blue and red light treatment, while anthocyanin synthesis was inhibited by monochromic red light. The results of the present study indicate that growth and pigment synthesis in lettuces are significantly enhanced by exposure to mixed radiation from blue and red LEDs.

• Archives of Craniofacial Surgery
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• v.24 no.2
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• pp.78-82
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• 2023

Blue nevi, which are characterized by collections of pigment-producing melanocytes in the dermis, have a variety of clinicopathological characteristics. Plaque-type blue nevus (PTBN) is a variant of blue nevi. PTBN presents at birth or arises in early childhood, and it shows a combination of the features found in common blue nevus and cellular blue nevus. It is typically found on the dorsal surface of the hands and feet or on the head and neck, and it is usually benign and stable over time. However, reports have occasionally described malignant melanomas developing in or associated with a PTBN. Malignant blue nevi are most commonly found on the scalp. We report the case of an 88-year-old woman with a malignant melanoma associated with a PTBN of the cheek.

• Korean Journal of Ichthyology
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• v.17 no.4
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• pp.248-254
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• 2005

Integumentary structure of the amberjack, Seriola dumerili, was examined by light and transmission electron microscopy. Integument of the amberjack consists of epidermal and dermal layers. The epidermal thickness is about $28.32{\mu}m$. The epidermal layer could be classified into superficial, intermediate, and basal layers by morphology and position of the supporting cells. Secretory cells of the epidermal layer were classified into mucous cells and club cells in the amberjack. Mucous cells contained acidic mucous and were alcian-blue positive with AB-PAS (pH 2.5) reaction. The club cells contained well-developed rough endoplasmic reticula and large central vacuole. Also, filament-rich cells were identified in the epidermal layer. The dermal layer consists mainly of collagenous fiber, and it contains fibrocytes and pigment cells. The cytoplasm of fibrocyte had a well-developed rough endoplasmic reticulum. The pigment cells contained electron-dense melanin granules.

• Journal of the Korean Society of Safety
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• v.30 no.2
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• pp.14-20
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• 2015

The content of hazardous heavy metal of materials used in playground facility for children was investigated using X-ray fluorescence (XRF) and inductively coupled plasma (ICP) analyses, In order to examine the content of hazardous heavy metals according to the material color, four colors, i.e., green, red, yellow and blue, were categorized on the materials used. The highest lead content is observed in the yellow plastic samples. The yellow samples with relatively high lead content show that the chrome content is also high. This can explained that lead chromate, so-called chromium yellow, is normally used as a main pigment to express the yellow color. Therefore, it is concluded that hazardous heavy metal detected in the materials of playground facility for children is due to the pigments used for coloring. Based on above findings, the relationship between the color of materials used in playground facility for children and the content of hazardous heavy metal is discussed.

• Journal of the Korean Graphic Arts Communication Society
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• v.8 no.1
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• pp.53-70
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• 1990

It is well known that viologens such as 1.1 - disubstituted 4, 4` - bipyridinium salts and those used as redox indicator, herbicide and electrocheromic display device because those possess the lowest redox potential in any organic system. Viologen salts produced reversible high blue color under the influence of radical cation by photoreduction This study is related to the synthesis of viologen derivatives and the photoreduction property in water solution stats and the polar aprotic polyvinylpyrrolidone(PVP) matrix.

• The Korean Journal of Food And Nutrition
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• v.12 no.5
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• pp.508-512
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• 1999

In order to qualify and quantify carotenoid pigment of pumpukin were analyzed by HPLC column chromatography and spectrophotometry. Eightyseven percent of total carotenoids in the pumpkin was in the fiber amounting 65.33mg%. however flesh and skin contained 6.61 and 3.31mg% respectvely. A silica gel column chromatography of the carotenoids produced 2 different peaks. The components eluted in peak II showed blue color when treated with hydrochloric acid. The fact suggested it contained epoxide and the component in peak II was a monol. By the separation with HPLC. $\alpha$ and $\beta$-carotene were the major compounds in the carotenoids. In fiber the total $\beta$-carotene content was 1.6 times higher than in the flesh and skin. The fiber contained less unidentified compounds than other part which contained 27.3~32.8%.