• The Journal of Engineering Geology
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• v.19 no.3
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• pp.389-400
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• 2009

Iron and manganese contents are usually over the limit of drinking water standard (0.3 mg/L) in unconsolidated aquifer of river bank filtration site in Nakdong river. Surge block and air surging techniques used in this study are useful tools to remove the slime within gravels and pebbles, to increase permeability of aquifer, to provide oxygen into aquifer, and to discharge iron and manganese oxides from a well. Surging activity brought about $5{\sim}8$ and $5{\sim}9$ times decreases in $Fe_{(total)}$ and $Fe^{2+}$ contents, and also 10 times decrease in $Mn^{2+}$ contents compared to non-surging condition, respectively. Additionally, iron oxide and manganese oxide increased up $1{\sim}1.2$ times after surging. This result shows that air injection into the aquifer can help iron and manganese content decreased and in-situ treatment technology needs to be introduced in river bank filtration project in South Korea.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2000.06a
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• pp.54-61
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• 2000

A method and results of classification of 4 types metallic wear debris were presented by using their color features. The color image of wear debris was used (or the initial data, and the color properties of the debris were specified by HSI color model. Particle was characterized by a set of statistical features derived from the distribution of HSI color model components. The initial feature set was optimized by a principal component analysis, and multidimensional scaling procedure was used for the definition of classification plane. It was found that five features, which include mean values of H and S, median S, skewness of distribution of S and I, allow to distinguish copper based alloys, red and dark iron oxides and steel particles. In this work, a method of probabilistic decision-making of class label assignment was proposed, which was based on the analysis of debris-coordinates distribution in the classification plane. The obtained results demonstrated a good availability for the automated wear particle analysis.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.5
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• pp.503-513
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• 2003

A single particle analytical technique, called low-Z electron probe X-ray microanalysis (low-Z EPMA) was applied to characterize atmospheric particles collected in Busan, Korea, over a daytime period in Dec. 2001. The ability to quantitatively analyze the low-Z elements, such as C, N, and 0, in microscopic volume enables the low-Z EPMA to specify the chemical composition of individual atmospheric particle. Various types of atmospheric particles such as organics, carbon-rich, aluminosilicates, silicon oxide, calcium carbonate, iron oxide, sodium chloride, sodium nitrate, ammonium sulfate, and titanium oxide were identified. In the sample collected in Busan, sodium nitrate particles produced as a result of the reaction between sea salt and nitrogen oxides in the atmosphere were most abundantly encountered both in the coarse and fine fractions. On the contrary, original sea salt particles were rarely observed. The fact that most of the carbonaceous particles were distributed in the fine fraction implies that their origin is anthropogenic.

• Journal of the Korean Ceramic Society
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• v.33 no.8
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• pp.871-876
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• 1996

It is believed that fly ash could be suitable for preparing the sialon by carbothermal reduction method because the total amount of SiO2 and Al2O3 is above 80% and the unburned residual carbon is above 5% within the fly ash. The effects of reaction temperature (1350, 1400, 145$0^{\circ}C$) reaction time (1, 5, 10 hours) and the amount of carbon additions (C/SiO2=2, 3, 4 mole) on the $\beta$-sialon synthesis were obserbed, It was conformed that $\beta$-sialon (Z=2.15~2.18) was formed as major phase under all of the synthesis conditions and small amount of Si2ON2 SiC, AlN and Si3N4 was formed depending on the synthesis conditions. FeSix intermetal-lic compound was formed above 140$0^{\circ}C$ reaction temperature due to the large amount of iron oxides within the raw fly ash.

• Transactions of the Korean hydrogen and new energy society
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• v.18 no.3
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• pp.301-308
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• 2007

Silicate mineral serpentine with magnesium and calcium was selected as a mineral carbonation mediators for carbon dioxide storage. Serpentine has various metallic elements as an oxides form of magnesium, iron, calcium, aluminium etc. Magnesium and calcium could be carbonation salt preferentially than other metal component within serpentine. Systemic thermochemical treatment for serpentine could change physicochemical properties like a surface area and pore dimensions. Due to the rapid chemical reaction rate depended on dimensional values, carbonation formation could determined by surface property change of thermochemical treated serpentine.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.193-193
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• 2010

Magnetic separation is expected to be applied for material refinement as an important supporting technology. In the superconducting magnetic separation, the cohesive force between particles is strong compared with that in the other magnetic separation. The use of high magnetic field by the superconducting magnet enhances the magnetic substance capture ability of the magnetic separation. Industrial raw materials was used for the superconducting magnetic separation. Cry-cooled, NB-Ti superconducting magnet with. 100 mm room temperature bore and 600 mm of height was used for magnetic separator.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.25 no.4 s.34
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• pp.7-16
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• 1999

Silver-containing antimicrobial inorganic pigments that have been developed so far still have problems, which result from silver's unique metallic color and discoloration. Therefore, those things are used only for make-up cosmetics or just the restricted amount is used. Although the use of white-base pigments or iron oxides has been considered to solve those problems, they virtually fail to serve as a perfect substitute. So it seems difficult to use enough quantity of those materials or to apply them to diverse kinds of products. The purpose of this study was, accordingly, to attain the complete removal of metallic color and the maintenance of color. Additionally, a rosemary extract was employed to develop a silver-containing inorganic antimicrobial pigment(Ag-AIP-R) that has an improved antimicrobial effect and anti oxidative effect.

• Journal of the Korean Society of Safety
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• v.6 no.4
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• pp.26-33
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• 1991

To remove SO$_2$ from flus gas, cupric oxide, manganese oxide and iron oxide were studied with varying loading value. The experiment was carried out in a flow reactor and the reactants were prepared by impregnation method using alumina. The reaction temperature was varied from 30$0^{\circ}C$ to 45$0^{\circ}C$. Experimental results showed that all of these metal oxides were effective on SO$_2$ removal reaction and cupric oxide was the best reactant. The sample with 10wt％ loading value was better reactant than with 20wt％ because in case of 20wt％ loading, metal dispersion on the alumina surface was not uniform. And the SO$_2$ removal efficiency was increased with the reaction temperature.

• Journal of the Korean institute of surface engineering
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• v.35 no.6
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• pp.371-376
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• 2002

Steam turbine components of power generators are subjected to severe damages from the particle erosion by iron oxides (mainly $Fe_3$$O_4$) which are formed due to the oxidation of boiler tubes, causing high costs for maintaining and repairing. One of the practical ways to minimize the particle erosion is to apply the erosion resistant boride coating on the turbine components which is composed of boride apply. But the evaluation of its performance has not been carried out. A particle erosion tester, which can offer the erosion condition of steam turbine components, was developed to evaluate the performances of the boronized Cr/Mo alloy. The result showed that the boronized Cr/Mo alloy showed superior resistance to particle erosion to the bare Cr/Mo alloy in all test conditions.

• KSTLE International Journal
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• v.1 no.1
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• pp.34-42
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• 2000

A method and results of classification of four different metallic wear debris were presented by using their color features. The color image of wear debris was used far the initial data, and the color properties of the debris were specified by HSI color model. Particles were characterized by a set of statistical features derived from the distribution of HSI color model components. The initial feature set was optimized by a principal component analysis, and multidimensional scaling procedure was used fer the definition of a classification plane. It was found that five features, which include mean values of H and S, median S, skewness of distribution of S and I, allow to distinguish copper based alloys, red and dark iron oxides and steel particles. In this work, a method of probabilistic decision-making of class label assignment was proposed, which was based on the analysis of debris-coordinates distribution in the classification plane. The obtained results demonstrated a good availability for the automated wear particle analysis.