• Journal of the Korean Chemical Society
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• v.54 no.1
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• pp.43-48
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• 2010

Polyamide derived from azo compound of o-amino phenol coupled with acetyl acetone, maleic anhydride acid and p-phenylene diamine were prepared. The prepared polyamide (PA) was refluxed with metal salts of transition metal ions include, $Co^{+2},\;Cr^{+2},\;Ni^{+2},\;Cu^{+2},\;Zn^{+2},\;Cd^{+2}$ and $Fe^{+3}$ in dimethyl formamide (DMF) in different molar ratios. These complexes were characterized and identified by elemental and thermal analysis, IR, 1H NMR spectra. The data showed that PA ligand coordinates with metal ions in abidentate manner through donating N=N and O-H groups. The metal ions are surrounded by coordinated water molecules and anions to establish the geometrical structure of the complexes. The thermal analysis degradation at different temperatures explained the weight loss of hydrated water and the decompositions of complexes until a constant weight loss of metal oxides is obtained.

• Journal of Energy Engineering
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• v.13 no.1
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• pp.82-91
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• 2004

In order to utilize inorganic components in coal and wastewater sludge as an environmentally stable material, slag-forming is considered as one of the suitable methods better than producing as an ash. Coal slag that was produced by gasification as well as the slag made from wastewater sludge by incineration or melting process have been analyzed with the viewpoint of recyclability. Slags produced by water quenching exhibited a cracked shape that has a size of few millimeters with sharp edges. Slags contain the unburned carbon content below 0.15％ and expose mostly amorphous structural characteristics. Analysis results in the extraction of heavy metal compounds demonstrate that both slags from coal and wastewater sludge could be utilized as a safe recycle material even with a Japanese environmental regulation that is ten times more stringent than the current Korean standard. Slags from coal and wastewater sludge show significant differences in contents of each heavy metal compound. Since the future trend of environmental regulation shifts to the control of total content for each heavy metal compound, proper mixing of slags that contain different heavy metal contents might be an option for manufacturing recycle materials.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.252-255
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• 2004

Various Semiconductor/Metal structured nanowires were synthesized from the simple thermal annealing of ball-milled compound powders and the thermal evaporation of metals. Their structural properties were investigated by Scanning Electron Microscopy(SEM) and Transmission Electron Microscopy(TEM), Energy Dispersive X-ray spectroscopy(EDX). Depending on the type of metals and the material of nanowires, uniform somiconductor/metal nanowires(GaN/Al, GaN/Ag) or isolated metal particles on semiconductor nanowires$(SnO_2/Ti,\;Si/Ti)$ were formed on the surface of nanowires.

• Bulletin of the Korean Chemical Society
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• v.31 no.12
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• pp.3549-3552
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• 2010

The complex formation between diazocalix[4]dipropyl (1) and diazocalix[4]crown-6 ether (2) with alkali, alkaline earth and transition metal ions was investigated by voltammetry. Electrochemical properties of compounds 1 and 2 and their selectivity toward metal ions were evaluated in $CH_3CN$ solution by comparison of voltammetric behaviors of two phenols in each compound. Compounds 1 and 2 showed almost same voltammetric behavior which is two irreversible oxidation peaks caused by intramolecular hydrogen bonding between two phenols in 1 and 2. While, however, upon interacting with various metal ions, 1 with two propyl ether groups showed no significant changes in voltammetry, 2 with crown ether group caused significant voltammetric changes upon the addition of $Ba^{2+}$ to 2. Their behavior is closely related to the complex formation by entrapment of metal ion into crown ether cavity, and ion-dipole interaction between metal ion and two phenolic groups in calix[4]crown-6.

• Journal of the Korean Chemical Society
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• v.33 no.1
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• pp.113-119
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• 1989

Chelating resins containing hydrazide or triethylenetetramine side chain were prepared using a commercial cation exchage resin, Diaion WK 11, and their nitrogen contents were determined by elemental analysis. The synthesized resin, and commercial chelating resins, (Diaion-CR 10 and-CR 20) were treated with various metal chelates of which metal contents were subsequently determined by chelatometry. Sectioned beads of the resin-metal chelates were also observed using electron microprobs X-ray analyzer. To examine the catalytic activity of the resin-metal chelates, they were applied to the oxidation of various hydroxy compounds and l-ascorbic acid, and found to be effective catalysts.

• Proceedings of the KWS Conference
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• 2003.11a
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• pp.240-241
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• 2003

The iron aluminides have been among the most widely studied intermetallics because of their low cost, low density, good wear resistance, ease of fabrication and resistance to oxidation and corrosion. In this study, weld overlay was performed with JIS-YGW11 and A14043 wire on the base metal.

• Macromolecular Research
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• v.15 no.3
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• pp.202-204
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• 2007

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.198-198
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• 2013

Metal-Oxide-Semiconductor (MOS)에서 사용되는 다양한 channel materials로 high electron mobility을 가지는 III-V compound semiconductor가 대두되고 있다 [1,2]. 하지만 이러한 III-V compound semiconductor는 Si에 비해 안정적인 native oxide가 부족하기 때문에 Si, Ge, Al2O3과 BeO 등과 같은 다양한 물질들의 interface passivation layers (IPLs)에 대한 연구가 많이 되고 있다. 이러한 IPLs 물질은 0.5~1.0 nm의 매우 얇은 physical thickness를 가지고 있고 또한 chemical inert하기 때문에 플라즈마 식각에 대한 연구가 되고 있지만 IPLs 식각 후 기판인 III-V compound semiconductor에 physical damage과 substrate recess를 줄이기 위해서 높은 선택비가 필요하다. 이러한 식각의 대안으로 원자층 식각이 연구되고 있으며 이러한 원자층 식각은 반응성 있는 BCl3의 adsorption과 low energy의 Ar bombardment로 desorption으로 self-limited한 one monolayer 식각을 가능하게 한다. 그러므로 본 연구에서는, III-V compound semiconductor 위에 IPLs의 adsorption과 desorption의 cyclic process를 이용한 원자층식각으로 다양한 물질인 SiO2, Al2O3 (self-limited one monolayer etch rate=about 1 ${\AA}$/cycle), BeO (self-limited one monolayer etch rate=about 0.75 ${\AA}$/cycle)를 얻었으며 그 결과 precise한 etch depth control로 minimal substrate recess 식각을 할 수 있었다.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.4
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• pp.126-133
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• 2015

To enhance the productivity and quality of the compound process of progressive dies and transfer dies, the semi-progressive method is applied in the material supply step to produce blanks, and then the transfer method is applied. Parts are transferred among processes by means of the finger and transfer bar in the transfer die, and the final seat cushion panel is produced. The main challenge in the current study is how to deform a seat cushion panel while meeting the design specifications without any defects. In order to obtain this technology, a sheet metal-forming simulation and die forming of the seat cushion panel were adopted; as a result, a compound die-forming technology for the automotive seat cushion panel, combining both semi-progressive die and transfer die for continuous production, was successfully developed.

• Journal of the Korean Society of Safety
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• v.30 no.6
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• pp.12-17
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• 2015

In this study, the collapse characteristic of CFRP/Al compound square tube was investigated experimentally. The conclusions are as follows; The impact collapse characteristic of CFRP/Al compound square tube was found to be the most superior stacking conditions $[90^{\circ}]_8$. It showed that a very stable collapse mode was crushing. In the member with $[0_2{^{\circ}}/90_2{^{\circ}}]_s$ and $[90_2{^{\circ}}/0_2{^{\circ}}]_s$, stacking conditions, $0^{\circ}$ fibers were splayed to the external by laminar bending, while the $90^{\circ}$ fibers were held between the folds of the aluminum member by laminar bending, local buckling and transverse crack. In the member with $[45_2{^{\circ}}/45_2{^{\circ}}]_s$ stacking conditions, fibers were held between the folds of the aluminum member by local buckling and transverse crack.