• Composites Research
• /
• v.21 no.2
• /
• pp.31-35
• /
• 2008

In order to design light weight and high efficient electromagnetic wave absorbing materials, hollow magnetic particles have been introduced in this study. The electroless plating method has been utilized to coat Ni and Fe on the substrates of synthesized polystyrene particles of submicron size. Removing polystyrene particles by heat treatment resulted in hollow structures. Observation by SEM, TEM and EDS confirmed the surface morphology and coating thickness of Ni and Fe. Polymeric composites containing hollow particles were tested in order to compare the electromagnetic properties between Ni coated and Fe costed particles. The composite of 30 wt% Fe hollow particles showed the higher complex permeability than Ni hollow particles or the conventional barium ferrite particles.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.5
• /
• pp.1377-1380
• /
• 2010

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2000.04a
• /
• pp.247-248
• /
• 2000

본 연구는 대전 3, 4 공단 지역을 대상으로 발암 금속 6종(As Be, Cd, Cr, Ni, 및 Pb)을 포함한 15종의 독성 금속을 선정하여 3, 4 공단과 주변 지역내 5개 지점에서 유도결합 플라스마 분광법(ICP-MS)을 이용하여 계절별 3회씩 1년간 분석하고 이 농도 자료에 근거하여 위해도 평가를 하고자 한다 대전 3. 4공단 지역은 110여개의 생산업체가 밀집되어 있는 지역으로 대전 1, 2 공단 지역과 더불어 대전시내 대기중 독성 금속의 오염이 가장 심하리라 예상되는 지역이다.(중략)

• Bulletin of the Korean Chemical Society
• /
• v.17 no.12
• /
• pp.1109-1111
• /
• 1996

The Podand Ⅰ (Figure 1) has been studied as cation carrier in a bulk liquid membrane system. Ag+ and some other transition metal ions (M2+=Cu, Ni, Co, Zn, and Cd) have been transported using the podand as carrier in a bulk liquid membrane system. Studies on the transport of equimolar mixtures of two or three competing components have also been carried out with the same system. Ag+ exhibited a higher transport rate than the other M2+ in the competitive experiments. Ligand structure and the equilibrium constant for complex formation are important parameters in the transport of the metal ions.

• Proceedings of the Acoustical Society of Korea Conference
• /
• autumn
• /
• pp.37-40
• /
• 1999

In this paper, we presented the prosody analysis results of five selected words according to its usage in a sentence, i.e.. the part of sentence (PoS) while changing the type of sentences such as simple, conjugate, and complex sentences. The selected five Korean words were 'U-Ri-Na-Ra' 'Bul-Kuk-Sa', 'Uh-Muh-Ni', 'Han-Ra-San', and 'Cang-A-Ji'. These five words were used as a subjective, an objective, and an adverb in each simple, conjugate, and complex sentence. The pitch, energy, and duration of each word were then analyzed and used for the synthetic speech prosody Improvement. The subjective test on the prosody improvement showed that more than $50\%$ of our listeners are affirmative to the prosody Improvement of the synthetic speech.

• Journal of the Korean institute of surface engineering
• /
• v.37 no.2
• /
• pp.76-79
• /
• 2004

Nickel chloride coated protein chip plate was developed by using a spin coating method. The ability of histidine tagged protein adsorption was investigated at various solvents. The surface of plate has a large aggregated nickel complex with high density in water. However, the surface of plate has a very small size of aggregated nickel complex with low density in isopropanol. The ability of protein adsorption decreased as increasing the size of alkyl chain in various alcohol solvents. The mechanism on the ability of protein adsorption at the plate surface is discussed.

• Journal of Environmental Health Sciences
• /
• v.24 no.3
• /
• pp.1-5
• /
• 1998

A spectrophotometric method was developed for the acidic solution stripped after an extraction of 0.5 to 2.5 ppm of Lead(II) from 50 mL of $Na_2S_2O_3$ solution into chloroform as the ion-pairs formed between their thiosulfate complexes and alkylamine, Aliquat336. Pb(II) in the stripped solution forms an complex with DDTC in pH 7.3 buffer solution, and was developed in yellow by copper replacement. The ydlow-colored solution have the maximum absorbance at 435 nm in the measurement of absorbance by UV-Visible spectrophotometer. The interference ions such as Fe(III), Hg (II), Al(III), Co, Cu, Ni, Zn, Ca, Sn, have great effects on the extraction, but they were overcomed by the usage of adequate masking agents before an extraction. At last, a good result was obtained in applying this method to synthetic water.

• Bulletin of the Korean Chemical Society
• /
• v.29 no.10
• /
• pp.2029-2032
• /
• 2008

• Bulletin of the Korean Chemical Society
• /
• v.31 no.9
• /
• pp.2701-2704
• /
• 2010

This work shows that both L2 and L3 bearing two and four N-$(CH_2)_2OCH_3$ groups, respectively, can be prepared selectively by the reaction of $L^1$ with 1-bromo-2-methoxyethane. The di-N-substituted macrocycle $L^2$ readily forms its copper(II) and nickel(II) complexes. The N-$(CH_2)_2OCH_3$ groups in $[CuL^2]^{2+}$ are coordinated to the metal ion, whereas those in $[NiL^2]^{2+}$ are not involved in coordination. Interestingly, $L^3$ reacts with $Cu^{2+}$ ion to form $[Cu(HL^3)]^{3+}$, in which one tertiary amino group is not involved in coordination.

• Bulletin of the Korean Chemical Society
• /
• v.27 no.4
• /
• pp.573-576
• /
• 2006