• Journal of Conservation Science
• /
• v.33 no.3
• /
• pp.203-214
• /
• 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.

• Journal of Conservation Science
• /
• v.34 no.5
• /
• pp.345-358
• /
• 2018

The purpose of this study is to analyze the characteristics of low-grade 12th-century celadons, which were excavated from a kiln site in Noksan-dong, Busan. The physical and chemical properties of the body and the glaze are evaluated through scientific analyses. All the selected celadon shards have a similar body color, regardless of the kiln from which they originated. The celadon shards from 2 3 kilns are brighter than those from 4 5 kilns, and there are two saturations, namely gray and brown. The brightness of the glaze shows a high contribution of red and yellow. The porosity of the selected shards is 8.8% in the gray saturation and 16.1% in the brown saturation. The major chemical compositions of the body and glaze are in the typical chemical composition of the celadon, but the $TiO_2$ flux contents are different. The visible characteristic difference between the 2 3 kilns and the 4 5 kilns can be attributed to the mixing and the firing process rather than the raw materials used. The difference in the $Fe_2O_3$ and $K_2O$ flux between the 2 3 and 4 5 kilns can be attributed to changes in the ingredient combination during the process. In conclusion, Noksan-dong celadon could not be easier vitrification due to the manufacturing process that primary burning process, It is highly likely that there were process differences in kilns to produce high quality celadon.

• Korean Journal of Food Science and Technology
• /
• v.47 no.4
• /
• pp.452-459
• /
• 2015

The effects of aronia powder on the rheological and sensory characteristics of Sulgidduk were investigated. The moisture content of Sulgidduk ranged from 40.86 to 44.40%; however, addition of aronia powder to Sulgidduk tended to decrease its moisture content. With regard to the rheological properties, the addition of aronia powder decreased the hardness, springiness, adhesiveness, cohesiveness, chewiness, gumminess, and brittleness of Sulgidduk. Chromaticity determination revealed a decrease in L and b values, while the a value increased with the increasing amounts of aronia powder. Total polyphenol, total flavonoid and total anthocyanin contents increased with the increasing amounts of aronia powder. Antioxidant activity, measured by DPPH and ABTS radical scavenging activities, was significantly higher than that of the control, and increased proportionally with the amount of aronia powder. During 4 day storage, the growth of total aerobic colony and coliform content significantly decreased with increasing levels of aronia powder in Sulgidduk. Sensory evaluation demonstrated the best score in color, taste and overall acceptance when aronia powder was added at 5% of rice powder. These results suggest that 5% aronia powder can be added for the preparation of Sulgidduk.

• Conservation Science in Museum
• /
• v.6
• /
• pp.55-66
• /
• 2005

Three types of epoxy resins (Epo-Tek 301, Araldite 103, and Araldite 106) and three types of pigments (bunche, pastel, and conté), which are materials for porcelain restoration, were selected as examination materials. The tone change, porosity, and sedimental resulting from the mixtures of varying ratios of these three materials were observed. Samples were also made from the mixture of Epo-teck 301, four kinds of white pigments, and six types of fillers and subjected to ultraviolet ray penetration for 200 hours to observe the oxidation of the epoxy resins. The result showed that the chemical composition of pastel drastically changed when mixed with Epo-tek 301. Although bunche and conté displayed clear colors, those of conté were less clear when it was mixed with other substances. Adding a small amount of Epo-tek 301 tended to be driven into the corner, whereas mixing a large amount caused saturation and boiling. On the other hand, AW 106 did not display clear colors owing to its high viscosity; when mixed in large amounts, however, the clarity of colors improved. For AY 103, a similar standard of color clarity was maintained regardless of the mixture ratio. The following was ranked according to the level of porosity: [Pastel>bunche≒conté]. In terms of sedimentary, however, [bunche>conté>Pastel], [Epo-tek 301> AY 103> AW 106]. The result of measuring the degree of yellowing revealed that titanium, pastel, silicon dioxide, and kaolin tended to turn yellow, whereas bunche, conté, diatomaceous earth, and calcium hydroxide tended to resist yellowing.

• Journal of Conservation Science
• /
• v.27 no.1
• /
• pp.31-40
• /
• 2011

Copper-red (Dongwha, Jinsa) is Korean traditional inorganic pigment used for red-coloring on the porcelain surface during Goryeo and Joseon Periods. Trace amounts of copper-red porcelains are handed down because of the technical difficulty of making and coloring of the pigment. It is known that copper ore sources were extensively distributed in Korea according to old literatures and some of them are still producing copper ore at this present. Main types of copper-bearing mineral in Korea are chalcopyrite ($CuFeS_2$) and malachite ($Cu_2CO_3(OH)_2$), and they are easily collected from the ground surface. This means Korea had geographical and economic geological advantages for supplying raw material of the pigment. These two minerals showed good red-coloring in color test for porcelain pigment. As a coloring element, copper showed micro size less than $5{\mu}m$ in diameter in glaze matrix. The dispersion of copper particle is the most decisive factor for red chromaticity of copper-red porcelain, as well as copper content of the pigment.

• Journal of the East Asian Society of Dietary Life
• /
• v.27 no.1
• /
• pp.50-60
• /
• 2017

This study evaluated the quality characteristics and antioxidant activities of Spergularia marina L. Griseb powder from halophyte plants added to noodles at ratios of 0%, 0.5%, 1.0%, 1.5%, and 2.0% in order to examine its applicability as a substitute for salt. For quality characteristics of noodles with Spergularia marina L. Griseb powder, pH increased (p<0.05) and salinity decreased (p<0.01) with higher added Spergularia marina L. Griseb powder content. Water absorption ratio decreased (p<0.01) while turbidity decreased (p<0.001) with greater addition of Spergularia marina L. Griseb powder. However, volume expansion ratio increased with greater addition of Spergularia marina L. Griseb powder, but there was no significant difference. For chromaticity, L value and a value decreased (p<0.001) while b value increased (p<0.001) with greater addition of Spergularia marina L. Griseb powder. For texture, hardness (p<0.001), gumminess (p<0.001), and cohesiveness (p<0.01) increased with greater amount of added Spergularia marina L. Griseb powder; however, there were no significant differences in adhesiveness, springiness, and chewiness according to the amount of added Spergularia marina L. Griseb powder. In the sensory evaluation, for color, the score was 5.55 points when 1.5% Spergularia marina L. Griseb powder was added, which was the best preference (p<0.001); for flavor, preference was best (5.64 points) when 2.0% Spergularia marina L. Griseb powder was added; for taste, preference was best (5.36 points) (p<0.001) when 2.0% Spergularia marina L. Griseb powder was added; for overall preference (overall quality) the score was 5.55 points when 1.0% Spergularia marina L. Griseb powder was added, which was the best preference (p<0.001). For antioxidant activities, antioxidant activities including total phenol content, total flavonoid content, and DPPH free radical scavenging activity increased (p<0.001) with the amount of added Spergularia marina L. Griseb powder. As a result of the above research, preference was the highest and quality was excellent overall when 1.0% Spergularia marina L. Griseb powder was added. Thus, addition of 1.0% Spergularia marina L. Griseb instead of salt would be desirable.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.20 no.1
• /
• pp.43-52
• /
• 2010

Glass was fabricated by using refused coal ore obtained from Dogye coal mine in Samchuk. We additionally used soda ash and calcium carbonate as raw materials to make a glass with the chemical composition of soda-lime glass. And the properties of glass were measured when limestone was used as natural raw materials instead of calcium carbonate as chemical raw materials. Transparent glass was fabricated by melting raw materials at $1550^{\circ}C$ for 1 hr in an electrical furnace. The various kinds of glass samples were fabricated according to the kinds of refused coal ore and glass cullet. The optical properties of transmittance and color chromaticity were measured by UV/VIS/NIR spectrometer and the thermal properties of thermal expansion coefficient and softening point were measured. Transparent glass with the transmittance of over 70% in visible range was fabricated by using normal refused coal ore and black colored glass with the transmittance of 0~35% was fabricated by using shel1 type refused coal ore. Therefore, it is concluded that refused coal ore can be used for raw materials to manufacture secondary glass products such as a glass tile and foamed glass panel for construction material.

• Culinary science and hospitality research
• /
• v.19 no.3
• /
• pp.46-56
• /
• 2013

This study investigates the quality characteristics of Sikhye, a Korean traditional drink, made with different amounts of Monascus anka rice, or red yeast rice, and the results are as follows. During the saccharification process of red yeast rice, there was not significant change in pH, and its sugar content increased. It revealed that the optimal hours of saccharification for making Sikhye were four or five hours, which showed the highest in $^{\circ}Brix$. PH decreased significantly with increasing amounts of red yeast rice, and there was no change in sugar content and reducing sugar. Chromaticity L values decreased with increasing amounts of red yeast rice, and a value, b value and the turbidity increased. DPPH free radical scavenging activity of the samples showed significant differences in the samples with high scores as the amounts of red yeast rice increased. As a result of measuring the total microorganism number of the sample stored at $4^{\circ}C$, storability was improved with increasing amounts of red yeast rice. Preference was high in the order of 40%, 50%, 30%, 20%, 0%, and 10%, and the optimal amount of red yeast rice was less than 40-50%. Adding red yeast rice showed high scores in the sensory test, showing red color in Sikhye. In addition, its antioxidative activity effect and microbial growth inhibitory activity were considered to improve storability and preference.

• Korean Chemical Engineering Research
• /
• v.50 no.3
• /
• pp.567-573
• /
• 2012

Compared with the natural marble, the artificial marble has the advantages of excellent appearance, high degree of finish, even color, fine pressure and wear resistance, bear erosion and weathering, etc. It can be widely used in kitchen countertops, bath vanity tops, table tops, furniture, reception desks, etc. However, large amounts of artificial marble waste such as scraps or dust have been generated from sawing and polishing processes in artificial marble industry. Waste from artificial marble industry is increasing according to demand magnification of luxurious interior material. Artificial marble wastes can be recycled as aluminum oxide used as raw materials in electronic materials, ceramics production, etc., and methyl methacrylate(MMA) which become a raw material of artificial marble by pulverization, pyrolysis and distillation processes. The characteristics of artificial marble wastes was analyzed by using TGA/DSC and element analysis. Crude aluminum oxide was obtained from artificial marble waste by pulverization and thermal decomposition under nitrogen atmosphere. In this work, Box-Behnken design was used to optimize the pyrolysis process. The characteristics of crude aluminum oxide was evaluated by chromaticity analysis, element analysis, and surface area.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.45 no.11
• /
• pp.1630-1637
• /
• 2016

The object of this study was to evaluate the quality characteristics and antioxidant activities of Sikhe added with 25%, 50%, and 100% Artemisia capillaris extract instead of water. The control group showed higher sweetness and lower pH than the other groups. Longer storage time was associated with increased turbidity. In the chromaticity determination, $L^*$ value decreased while $a^*$ and $b^*$ values increased as A. capillaris extracts increased. In terms of free sugars, sucrose and maltose were detected. Maltose was generated through glycosylated action with amylase. The total polyphenol and flavonoid contents and antioxidant activities proportionally increased with levels of A. capillaris extract. In the sensory evaluation, Sikhe made with 50% A. capillaris extract showed the highest preferences for color, taste, plumpness of rice granules, and overall acceptance. These results suggest that A. capillaris maybe a useful ingredient in Sikhe to improve quality and sensory properties.