• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2186-2191
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• 2008

An experimental study was performed to investigate the effect of swirl condition and secondary air rate on the Ion voltage and CO emission characteristics. In this study, the combustion characteristics were investigated with the variation of swirler diameter, vane angle, suction air rate. The result of this study, the Ion voltage increase with increasing the diameter of the swirler. Additionally with increasing the suction air rate, the Ion voltage is the same. The CO concentration depends on suction air rate. In the other hand, it is almost unaffected by swirler's diameter. The flame length and Ion voltage decease with decreasing O2 percentage of surrounding air.

• 한국환경과학회지
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• 제32권5호
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• pp.343-353
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• 2023

A zeolite material (ZCH) was synthesized from coal fly ash in an HD thermal power plant using a fusion/hydrothermal method. ZCH with high crystallinity could be synthesized at the NaOH/CFA ratio of 0.9. Ion-exchanged ZCH adsorbents for ammonia removal were prepared by ion-exchanging various cation (Cu²⁺, Co²⁺, Fe³⁺, and Mn²⁺) on the ZCH. They were used to evaluate the ammonia adsorption breakthrough curves and adsorption capacities. The ammonia adsorption capacities of the ZCH and ion-exchanged ZCHs were high in the order of Mn-ZCH > Cu-ZCH ≅ Co-ZCH > Fe-ZCH > ZCH according to NH₃-TPD measurements. Mn-ZCH ion-exchanged with Mn has more Brønsted acid sites than other adsorbents. The ion-exchanged Cu²⁺, Co²⁺, Fe³⁺, or Mn²⁺ ions uniformly distributed on the surface or in the pores of the ZCH, and the number of acidic sites increased on the alumina sites to form the crystal structure of zeolite material. Therefore, when the ion-exchanged ZCH was used, the adsorption capacity for ammonia gas increased.

• 대한화학회지
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• 제31권6호
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• pp.534-541
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• 1987

$Hg^{2+}$이온의 존재하에서 $[CoCl(Hedta)]^-$ 착이온에 대한 에틸렌디아민(en) 치환반응기구에 대해서 uv 및 CD스펙트럼을 이용하여 조사하였다. 속도론적인 자료로부터 $Hg^{2+}$ 이온이 금속과 작용하여 첫 en이 치환될때는 회합반응 경로를 거치며 제2, 제 3의 en은 단계적으로 치환됨을 알 수 있었다. 그리고 생성된 $[Co(en)_3]^{3+}$의 광학순도로 부터 광학수율을 결정짓는 적절한 중간체를 제시하여 치환반응에 대한 새로운 반응경로를 제시하였다.

• Journal of information and communication convergence engineering
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• 제4권4호
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• pp.158-161
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• 2006

[ $Bi_2Sr_2Ca_nCu_{n+1}O_y(n{\geq}0)$ ] thin film is fabricatedvia two different processes using an ion beam sputtering method i.e. co-deposition and layer-by-layer deposition. A single phase of Bi2212 can be fabricated via the co-deposition process. While it cannot be obtained by the layer-by-layer process. Ultra-low growth rate in our ion beam sputtering system brings out the difference in Bi element adsorption between the two processes and results in only 30% adsorption against total incident Bi amount by layer-by-layer deposition, in contrast to enough Bi adsorption by co-deposition.

• 한국자기학회지
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• 제19권6호
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• pp.216-221
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• 2009

Y-type 바리움 페라이트 $Ba_2Co_2Fe_{12}O_{22}$를 고상반응법으로 제조하고 금속이온몰비($Fe^{3+}:\;Ba^{2+}:\;Co^{2+}$)와 열처리 온도가 자기적 성 질과 미세구조에 미치는 영향에 대하여 조사하였다. 상분석과 미세구조는 각각 XRD(X-ray diffractometer)와 FESEM(field effect scanning electron microscope)을 이용하여 조사하였으며 분말의 자기적 성질은 VSM(vibrating sample magnetometer)을 이용하여 조사하였다. 금속이온몰비($Fe^{3+}:\;Ba^{2+}:\;Co^{2+}$)가 6 : 1 : 1인 조성의 분말을 $1050\;{^{\circ}C}$에서 열처리하였을 때 단일 상이 합성되었으며 8 : 1 : 1인 조성의 분말을 $1200\;{^{\circ}C}$에서 열처리하였을 때 가장 높은 포화자화값(39.1 emu/g)을 나타내었다.

• 한국전기전자재료학회논문지
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• 제11권11호
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• pp.1049-1054
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• 1998

The LiCo$O_2$ powder was synthesized by a solution phase reaction. This shows a high (003) peak intensity and low (104) or (101) peak intensities in X-ray diffraction spectra. The LiCo$O_2$/Li cell shows an initial discharge capacity of 102.9mAh/g and an average discharge potential or 3.877V at a current density of 50mA/g between 3.0~4.2V. The peaks of dQ/dV plot are associated with Li ion intercalation/deintercalation reaction. To evaluate the cycleability of an actual battery system, cylindrical lithium ion cell was manufactured using graphitized MPCF anode and LiCoO$_2$ cathode. After 100th cycle, this cel maintains 80% capacity of 10th cycle value. The LiCoO$_2$/MPCF cell has a high discharge voltage of 3.6~3.7V and a good cycle life performance on cycling between 4.2~2.7V.

• 공업화학
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• 제10권3호
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• pp.445-449
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• 1999

소수성인 poly[bis(trifluoroethoxy)phosphazene]에 methoxyethylenoxy 측쇄를 치환시켜 친수성을 증가시킨 포스파젠 고분자를 합성하였으며 합성된 고분자를 다공성 polypropylene 지지체위에 dip-coating법으로 금속이온 분리막을 제조하였다. $Cr^{3+},\;Co^{2+},\;Mn^{2-}$이온 수용액에 대한 분리실험을 $25^{\circ}C$에서 $60^{\circ}C$까지 온도범위에서 행하였다. 치환된 methoxyethylenoxy기 중의 ethylenoxy의 반복단위가 증가할수록 이온의 투과특성이 증가하는 것을 알수 있었다. Trifluoroethoxy methoxyethoxyethoxyethoxy co-substituted polyphosphazene의 경우 $Cr^{3-}$ 이온이 $60^{\circ}C$에서 분리계수 4.5의 값을 갖고 $Co^{2+},\;Mn^{2+}$ 이온들로부터 분리가 됨을 알 수 있었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.232-235
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• 2002

An 150 kV gas cluster ion accelerator was fabricated and assessed. The change of surface morphology and surface roughness were examined by an atom force microscope (AFM) after irradiation of $CO_2$ gas clusters on Si (100) surfaces at the acceleration voltages of 50 kV. The density of hillocks induced by cluster ion impact was gradually increased with the dosage up to 5$\times$10$^{11}$ ions/$\textrm{cm}^2$. At the boundary of the ion dosage of 10$^{12}$ ions/$\textrm{cm}^2$, the density of the induced hillocks was decreased and RMS (root mean square) surface roughness was not deteriorated further. At the dosage of 5x10$^{13}$ ions/$\textrm{cm}^2$, the induced hillocks completely disappeared and the surface became very flat. In addition, the irradiated region was sputtered. $CO_2$ cluster ions are irradiated at the acceleration voltage of 25 kV to remove hillocks on indium tin oxide (ITO) surface and thus to attain highly smooth surfaces. $CO_2$ monomer ions are also bombarded on the ITO surface at the same acceleration voltage to compare sputtering phenomena. From the AFM results, the irradiation of monomer ions make the hillocks sharper and the surfaces rougher On the other hand, the irradiation of $CO_2$ cluster ions reduces the hight of hillocks and planarize the ITO surfaces. From the experiment of isolated cluster ion impact on the Si surfaces, the induced hillocks m high had the surfaces embossed at the lower ion dosages. The surface roughness was slightly increased with the hillock density and the ion dosage. At higher than a critical ion dosage, the induced hillocks were sputtered and the sputtered particles migrated in order to fill valleys among the hillocks. After prolonged irradiation of cluster ions, the irradiated region was very flat and etched.

• Bulletin of the Korean Chemical Society
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• 제35권10호
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• pp.3063-3070
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• 2014

In this study, poly(N-methylol methacrylamide) (NMMAAm) and poly(N-methylol methacrylamide/vinyl sulphonic acid) (NMMAAm-VSA) hydrogels were synthesized by $^{60}Co-{\gamma}$ ray irradiation at an ambient temperature. The graphs belonging to the gelation percent- percent-dose and swelling curves were drawn by using data which were obtained from water and different pH solutions. Characterization of hydrogels was performed by FTIR and DSC-TGA analysis. Heavy metal ion ($Ni^{2+}$, $Co^{2+}$) removal capacities of hydrogels were investigated in aqueous solutions, which had different concentrations (100-1500 mg/L). In metal ion removal studies, pH value of aqueous medium was kept constant at 5.0. Maximum metal ion removal values were obtained for NMMAAm-VSA (1:3 mole ratio) hydrogels. Metal ion removal capacities of NMMAAm-VSA (1:3 mole ratio) hydrogels were found as 82 mg/g and 98 mg/g for $Ni^{2+}$ and $Co^{2+}$ ions, respectively.

• 한국표면공학회지
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• 제32권3호
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• pp.389-392
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• 1999

We employed cobalt-disilicide for high-speed logic devices. We prepared stable and low resistant $CoSi_2$ through typical fabrication process including wet cleaning and rapid thermal process (RTP). We sputtered 15nm thick cobalt on the wafer and performed RTP annealing 2 times to obtain 60nm thick $CoSi_2$. We observed spherical shape voids with diameter of 40nm in the surface and inside $CoSi_2$ layers. The voids resulted in taking over abnormal junction leakage current and contact resistance values. We report that the voids in $CoSi_2$ layers are resulted from surface pits during the ion implantation previous to deposit cobalt layer. Silicide reaction rate around pits was enhanced due to Gibbs-Thompson effects and the volume expansion of the silicidation of the flat active regime trapped dimples. We confirmed that keeping the buffer oxide layer during ion implantation and annealing the silicon surface after ion implantation were required to prevent void defects in CoSi$_2$ layers.