• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.14 no.3
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• pp.127-133
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• 2009

In order to determine organic carbon oxidation by manganese and iron oxides, six core sediments were obtained in slope and basin sediments of Ulleung Basin in East Sea. The basin sediments show high organic carbon contents (>2%) at the water depths deeper than 2,000 m; this is rare for deep-sea sediments, except for those of the Black Sea and Chilean upwelling regions. In the Ullleung Basin, the surface sediments were extremely enriched by Manganese oxides with more than 2%. Maximum contents of Fe oxides were found at the depth of $1{\sim}4cm$ in basin sediments. However, the high level of Mn and Fe oxides was not observed in slope sediment. Surface manganese enrichments (>2%) in Ulleung Basin may be explained by two possible mechanisms: high organic carbon contents and optimum sedimentation rates and sufficient supply of dissolved Manganese from slope to the deep basin. Reduction rates of iron and manganese oxides ranged from 0.10 to $0.24\;mmol\;m^{-2}day^{-1}$ and from 0.30 to $0.57\;mmol\;m^{-2}day^{-1}$, respectively. In Ulleung Basin sediments, $13{\sim}26%$ of organic carbon oxidation may be linked to the reduction of iron and manganese oxides. Reduction rates of metal oxides were comparable to those of Chilean upwelling regions, and lower than those of Danish coastal sediments.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.29 no.6
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• pp.317-328
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• 2019

In this work, we investigated clay and raw materials from China (black clay, red clay, white clay) and Korea (Cheonan clay, Obu clay) used for the manufacture of porcelain products. According to chemical analysis results, feldspar components containing CaO, K₂O, Na₂O and quartz are found in clay materials besides primary clay such as kaollinte, for the clay materials from Korea, which is found more in clay materials from Korea than from China. For the Fe₂O₃ content, governing whiteness of porcelain products, more iron oxide (> 5 %) is found in Korean clays (Cheonan clay, obu clay, red clay) compared to those form China (black, white clay). Through X-ray diffraction analysis, kaolinite and Halloysite are found to be main phases for all the raw materials and second phases such as quartz and pyrophyllite are found. Using these clay materials, raw materials for porcelain products were produced, and the physicochemical properties were investigated for sintered samples. Absorption rate is in order of Baekja-A < Baekja-B < Yeonbuncheong < Jinbuncheong < Cheongja, and the sample, sintered at 1250℃ in reductive atmosphere, exhibits the lowest absorption rate. Comparing the color of the sintered samples, the samples sintered in oxidative atmosphere (L^* value: 86~95 %) show higher whiteness value than those sintered in reductive atmosphere (L^* value: 81~93 %). For the Cheongja and Buncheong, the samples sintered in reductive atmosphre shows higher whiteness, L^* values, and low a^*/b^* value, which is due to reduction of iron oxide (Fe₂O₃).

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.3A
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• pp.547-553
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• 2006

To know the effect of pigments on the material properties of color concrete, mortar and concrete tests were carried out by the using 5 kinds of pigment. The major component of red, yellow and black pigments was iron oxide and coloring component of blue and green pigments was copper phthalocyanine. Properties of mortar and concrete were some of difference according to adding ratio and kind of pigments. In case of using red, yellow and black pigments, setting time of concrete speeded a little and compressive strength was tendency to increase and slump or air content of concrete was same or decreased. On the other hand, in case of using green and blue pigments, compressive strength of concrete decreased largely because of the excessive air entrainment of surfactant and sump or air content of concrete increased highly. When the antifoaming agent was added to the color concrete mixed with green and blue pigments, compressive strength of concrete was improved and similar to that of concrete without pigment.

• Journal of the Korean Society of Clothing and Textiles
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• v.6 no.2
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• pp.33-40
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• 1982

The removal and redeposition of particulate soil occur simultaneously during the washing process. In order to investigate variables which affect on the redeposition of particulate soil, cotton lawn was soiled in the ion oxide black suspension using Launder-O meter. The amount of deposited soil was estimated by means of the spectrometric analysis of iron on the fabric after soiled. The results are as follows: 1. The presence of surfactants b suspension decreased the deposition of particulate soil and the most effective surfactant was soap and the descending order was NaDBS>CTAB>PONPE. 2. The influnce of temperature on soil deposition was considerable, soil deposition was gradually increased with elevating temperature in ionic surfactants solution such as NaDBS and CTAB but that was decreased above $40^{\circ}C$ in nonionic surfactant solution. 3. The tendency of soil deposition was dwindled by adding electrolytes especially in case of polyvalent anions. 4. From the results of the experiments redeposition of particulate soil was related with suspending power of surfactants and was influenced by factors varing zeta potential.

• Journal of Conservation Science
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• v.34 no.5
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• pp.421-431
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• 2018

Analyses of the three-storied stone pagoda at the Bulguksa temple in Gyeongju were carried out in order to identify the cause for material characteristics of inorganic contaminants and conservation treatment materials. Results indicated that foreign soil or weathering soil caused yellow discoloration of the pagoda, reddish-brown contaminants were formed by goethite (FeOOH), an iron oxide mineral, and black pollutants were formed by manganese (Mn) oxide, leading to discoloration of the rock. Among the restoration materials used in the past, cement mortar could cause whitening by reacting with the external environment. The results were used as basic standards to evaluate the material characteristics of the surface contaminants and identify a set of effective conservation treatments. Nevertheless, continuous monitoring is required, as there is a high possibility of regeneration of pollutants in the future because of the continuous exposure of the pagoda to the external environment.

• Conservation Science in Museum
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• v.7
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• pp.53-62
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• 2006

The wooden armor frame and various lacquerware artifacts excavated from the low swamp remains in Imdang, Gyeongsan have very weak material and lacquer coating; in case they are exposed in the air, they are likely to be shrunken and deformed immediately. The wooden armor frame has large size and it might be dissolved during freeze-drying. The lacquer coating of lacquerware blocks the penetration of chemicals and it is very likely to swell or peel off during the treatment. Therefore, to prevent the dissolution during vacuum freeze-drying, the wooden armor frame was replaced with t-butanol and impregnated in t-butanol solution with PEG#3, 350 43%, and lacquerware was impregnated in PEG#3, 350 40% solution at room temperature and freeze-dried. According to the analysis of the lacquer fragment from the lacquerware, the lid and the mounted cup was pasted with the mixture of lacquer and black pigment (soot) on the base layer after the first coating and pasted two or three times more with natural lacquer; the red lacquered wooden cup was pasted with the mixture of lacquer and black pigment on the base layer and pasted once on the middle layer. The top lacquer (red) was pasted with the mixture of iron oxide(Fe₂O₃).

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.30 no.6
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• pp.226-231
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• 2020

Polyvinyl pyrrolidone nanofibers including nickel, zinc, and iron precursors were fabricated via the electrospinning method. To convert as-spun nanofibers to Ni0.5Zn0.5Fe2O4 oxide nanof ibers which is capable of shielding an electromagnetic wave, heat treatment conditions were optimized. To obtain the heat treatment condition that can exclude amorphous carbon black and secondary crystal phase, samples were taken at each temperature while the calcination process and analyzed. According to the X-ray diffraction (XRD) analysis, the Ni0.5Zn0.5Fe2O4 crystal phase started to appear from 300℃, but it was confirmed through energy dispersive spectroscopy (EDS) analysis that heat treatment of 500℃ or more was required to remove most of the carbon black. When the calcination temperature exceeds 650℃, crystal nuclei starts to grow and the fiber surface condition becomes rough, so it was confirmed that the heat treatment conditions should be selectively determined according to the application field.

• Conservation Science in Museum
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• v.27
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• pp.67-90
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• 2022

A C-46 transport aircraft, which can be thought of as a large cultural heritage item from the modern period, was subjected to paint analysis and conservation treatment in preparation for its exhibition. The C-46 is the first aircraft ever dispatched to overseas combat zones by the Korean Air Force and carried out missions during the Vietnam War. The aircraft is mainly made of aluminum and shows signs of corrosion on its surface, including pitting and etching, as well as gray and white powdery attachments. In the analysis of the paint, diatomite(SiO₂·nH₂O) was confirmed in the red paint, titanium dioxide(TiO₂) was identified in the white paint, black iron oxide(Fe₃O₄) was detected in the black paint, and colcothar(Fe₃O₄) mixed with putty was confirmed in the blue paint. Infrared spectroscopy revealed the use of alkyd resin in the paint on the main body and nitrocellulose in the Taegeuk pattern. During the conservation treatment, mechanical cleaning, such as sanding, was conducted to remove paint and varnish from the surface. Corrosion was removed by sanding and cleaning with chemical solvents, and new paints and varnishes were applied. Through the paint analysis and conservation treatment, the aircraft was made available for exhibition in a stable condition.

• Journal of Conservation Science
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• v.25 no.3
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• pp.283-291
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• 2009

Methyl Bromide that was used as fumigation gas turned out to be the substance of destroying the ozone layer. For that reason, at the Montreal Protocol in 1987 the use of methyl bromide was forbidden starting 2005 in the advanced country. Also according to the 2007 Bali Protocolly methyl bromide is expected to be forbidden and therefore the purpose of this study is to find out the effects of substitution fumigation gas (Ethylene Oxide+HFC 134a, Methyl Iodide, Cyanogen and Argon) on the metal(silver, copper and iron), wood(oregon pine), pigment(yellow, red, blue, white and black), textile(hemp, ramie, jute, silk1 and silk2 / indigo, safflower and cork) and paper. After the fumigation test, ethylene oxide+HFC 134a did not have changes in the weight and color of the material itself before and after the experiment. On exterior alteration, color change occurred partly on paper and metal. Also, in most materials color change extent was 0.5 to 1.5 on the average and showed scanty difference. The materials after the fumigation test with methyl iodide did not show weight changes after the test. However, color changes more than 1.0 was shown in most of the materials especially in dyed textile material. In blue pigment, the discoloration on the surface could be seen by naked eyes. Fumigation test with cyanogen gas did not show weight changes and discoloration is more than 1.5 before and after the test. The weight changes of test materials with the argon gas was decreased about 3 to 6%. It can be observed that discoloration on paper was generated. Color changes can be seen on jute dyed with safflower and cork for two weeks with argon gas and the extent was 6.3 and 6.0.

• Conservation Science in Museum
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• v.23
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• pp.71-90
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• 2020

The scientific analysis of a 'F-51D Mustang Fighter'(Registered Cultural Heritage 666), one of the War Memorial of Korean collections, was carried out. The paint layer and canopy were discolored due to a constant outdoor exhibit. The results obtained through the scientific survey and analysis processes were intended to be used as basic data for the future dismantling and restoration of the fighter. The analysis results for the pigment components have confirmed red oxide of iron, Fe₂O₃ organic pigments, such as Cobalt Blue, phthalocyanine blue, etc., yellow PbCrO₄, white TiO₂, black Fe₃O₄, and gray Fe₃O₄ + TiO₂. It has been also confirmed that Alkyd resin was mainly used for painting. The fighter's canopy was Poly methyl methacrylate(PMMA), and Al was detected as the main component of the fighter body, wings, and tails.