• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.7
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• pp.1051-1057
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• 2003

This study is about controlled impurities, which make metal alloys, especially AC4CH alloy that is made by restraining 0.2％ Fe and Aluminum to make a matrix material. A metal matrix composite is produced using the squeeze casting method. The first step in the squeeze casting method is to add some organic binder including aluminum borate whisker into the matrix. After the fabrication of a metal matrix composite, each is individually appended to an inanimate binder such as SiO$_2$, Al$_2$O$_3$, and TiO$_2$. Through experiments the mechanical property changes were investigated between the metal matrix composite and AC4CH alloy. This study proves the superiority of the mechanical property of a metal matrix composites over AC4CH according to the previous tests and results that were mentioned above. One excellent property of matrix material composites is the infiltrated TiO$_2$ reinforcement. This material is a good substitute for the existing materials that are used in the development of industries today.

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.198-203
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• 2001

This study is about controlled impurities, which make metal alloys, especially AC4CH alloy that is made by restraining 0.2% Fe and Aluminum to make a matrix material. A metal matrix composite is produced using the squeeze casting method. The first step in the squeeze casting method is to add some organic binder including aluminum borate whisker into the matrix. After the fabrication of a metal matrix composite, each is individually appended to an inanimate binder such as $SiO_2,\;Al_2O_3$, and $TiO_2$. Through experiments the mechanical property changes were investigated between the metal matrix composite and AC4CH alloy. This study proves the superiority of the mechanical property of a metal matrix composites over AC4CH according to the previous tests and results that were mentioned above. One excellent property of matrix material composites is the infiltrated $TiO_2$ reinforcement. This material is a good substitute for the existing materials that are used in the development of industries today.

• Analytical Science and Technology
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• v.27 no.1
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• pp.11-21
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• 2014

An investigation of grain size, organic compounds and metal distribution in 23 sediment samples of the Geum-River basin (Korea) was conducted in two seasons of 2012 (dry season and rainy season). The samples of sediment were collected from the basin and investigated for concentrations of some metal and general indexes containing grain size. Concentrations of Pb, Zn, Cu, Cr, Ni, As, Cd, Hg, Al and Li have been determined by inductively coupled plasma spectrometer (ICP) and the sediments organic matter content was determined by the loss on ignition, and sediments were fractionated with three different nylon sieves. Correlation analysis was made for grain size, organic material and metal concentrations, and the Pearson correlation coefficients between their concentrations were determined. As a result, the higher metal concentrations were found in the period of the dry season than in another season. The metal concentrations showed high correlation with that of organic material (COD and TOC). Thereby, the high distribution of metal concentrations in sediment containing high organic compound is suggesting an interaction with organic matter.

• Journal of the East Asian Society of Dietary Life
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• v.16 no.4
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• pp.468-473
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• 2006

This study was conducted to develop pigment of flowers as a food material and the red rose(Rosa hybrida L.) was used for this study. To check the possibility of using the rose pigment as a food additive we have extracted the pigment from rose and examined all the factors (pH, temperature, free sugars, organic acids, metal ions) for stability. The results obtained are as follows: In examining the stability of the pigment, the residue of the pigment noticeably decreased with the increase of the pH and the temperature, and among free sugars (fructose, glucose, sucrose) the addition of fructose made the residue the lowest. With the addition of organic acids the samples exhibited the hyperchromic effect throughout the period of the storage. The pigment residue decreased when the amount of the metal ions increased and especially the Cu$^{2+}$ ion was most destructive.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.6
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• pp.582-586
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• 2005

We have grown GaN layers with in-situ SiN mask by metal organic chemical vapor deposition (MOCVD) and study the physical properties of the GaN layer. We have also investigate the effect of the SiN mask on its optical property. By inserting a SiN mask, (102) the full width at half maximum (FWHM) decreased from 480 arcsec to 409 arcsec and threading dislocation (TD) density decreased from $3.21\times10^9\;cm^{-2}\;to\;9.7\times10^8\;cm^{-2}$. The PL intensity of GaN with SiN mask improved 2 times to that without SiN mask. We have thus shown that the SiN mask improved significantly the physical and optical properties of the GaN layer.

• Journal of environmental and Sanitary engineering
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• v.9 no.2
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• pp.110-119
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• 1994

The objective of the this study was to evaluate the effects of heavy metals on the sewage treatment process designed to remove organic material and nutrients using Water- hyacinth ( Eichhornia crassipes ). Batch experiments were carried out using domestic sewage spiked with different level of heavy metal mixtures ( Cd, Pb and Cu ). The specific growth rates of Water- hyacinth ranged from 0.0008 to 0.0015 1/day( operated at water temperatures of 22 ∼30$\circ $c ) and increased as the concentration of heavy metals decreased. The test result showed that the permissible maximum concentrations Cd, Pb and Cu for the growth of Water- hyacinth were 0.5, 1, and 6 mg/ℓ respectively. Under these maximum permissible heavy metal loads, removal rate of organic material, nitrogen and phosphorus were 85%,75% and 75% , respectively, during 40days of the test period.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.47-47
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• 2007

Indium oxide conducting films were dep9sited on Si(100) substrates at various temperatures by liquid delivery metal organic chemical vapor deposition using Indium (III) tris (2,2,6,6-tetramethyl-3.5-heptanedionato) $(dpm)_3$ precursors. The films deposited at $200{\sim}400^{\circ}C$ were grown with a (111) preferred orientation and exhibit an increase of grain size from 21 to 33nm with increasing deposition temperature. In the range of deposition temperature, there is no metallic indium phase in deposited films.

• 한국초전도학회:학술대회논문집
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• 2009.07a
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• pp.81-81
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• 2009

• Textile Coloration and Finishing
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• v.26 no.4
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• pp.277-282
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• 2014

Two tert-butyl substituted phthalocyanines(Pcs), in metal-free and metallated forms, were synthesized and the fluorescence responses toward various nitro derivatives, including picric acid(PA), 2,4-dinitrotoluene(DNT), 1,4-dinitrobenzene(DNB), 4-nitrotoluene(NT), nitrobenzene(NB), 1,4-benzoquinone(BQ), and nitromethane(NM) were investigated. Among the various nitro derivatives, current Pc derivatives exhibited efficient and exclusive fluorescence quenching in the presence of picric acid, which was readily observed by a naked eye. Quenching efficiency was estimated by the Stern-Volmer relationship, in which quenching constant, KSV, was calculated to be in the range of $10^4M^{-1}$. It was also found out that the aggregational behaviors of these Pcs are heavily dependent on the nature of solvent systems, subsequently affecting the quenching efficiency.

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.2
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• pp.97-109
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• 2003

This study was conducted to investigate use possibility on waste water sludges of water disposal plant as raw materials of organic compost at Fertilizer Official Regulation of Fertilizer Management Law in 2002. In heavy metal contents, some water service sludges were discovered a little over than the standard levels of raw material regulated in organic compost and most of them were not reached the levels. But they were difficult for using the raw materials of organic compost owing to shortage of the organic content. It was judged that the fiber and leather sludges were much in the heavy metal contents and they couldn't use as the raw materials of organic compost. There was afraid that a little heavy metal contents of cosmetic sludge were less than the levels, but it was possible to use selectively as a raw material.