• Journal of the Korean institute of surface engineering
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• v.35 no.4
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• pp.206-210
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• 2002

The use of Spectra fibers as fiber cloth is increasing because of their excellent impact resistance. However, a major limitation on the use of Spectra fibers is a chemical inertness. In this Study, Spectra fibers were surface-treated using Ar$^{+}$ ion beam under oxygen environment to improve the tensile property of Spectra/vinylester composites. The effect of surface treatment of Spectra fibers on the tensile property of Spectra/vinylester composites was determined from tensile tests using Spectra/vinylester composite specimens with and without a hole. It was found that the tensile stiffness and strength of surface-treated case were 22% and 17% higher than those of untreated case for specimens with no hole. The maximum load of surface-treated case was about 15% higher than that of untreated case for specimens with a hole.

• Journal of the Korean institute of surface engineering
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• v.32 no.4
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• pp.513-520
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• 1999

In this study, we investigated the effects of variously configured magnets on the characteristics of the plasmas to enhance plasma uniformity and density of an inductively coupled plasma source. As the magnets, Helmholtz type axial electromagnets and various multi-dipole magnets types around the chamber wall were used. To characterize the plasma as a function of the combination of the magnets and magnetic field strengths, ion density, electron temperature, and plasma potential were measured using an electrostatic probe along the chamber diameter for Ar plasmas. The measured maximum ion densities were $8$\times$10^{ 11}$$cm^{-3}$ with 600W inductive power and at 5mTorr of operational pressure and the uniformity of ion density was less than 5.9% at 2mTorr of operational pressure. The combination of an optimized multi-dipole magnet type and an axial electromagnet showed the lowest electron temperature (3eV) and plasma potential ($34V{p}$ )

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.328-329
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• 2005

Inorganic alignment layer (IAL) was deposited on an indium-tin-oxide (ITO) by using reactive sputtering deposition method. After deposited, IAL was irradiated by $Ar^+$ ion beam (IB) for liquid crystal (LC) alignment. IAL treated by various conditions such as IB energy, IB incident angle, and IB irradiation time had excellent alignment property and electro-optical property the same as that of PI. We investigated into the stability of ion beam treated IAL after a lapse of long time. However IAL irradiated IB did not occur degradation of electro-optical property. The results implied that IAL irradiated IB was adopted as LC alignment layer instead of rubbed polyimide.

• Journal of the Korean Ceramic Society
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• v.34 no.8
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• pp.834-842
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• 1997

Controlled Ca impurity implanted inner crack-like pore in the high purity alumina single crystal, sapphire, had been created by micro-fabrication technique, which includes ion implantation, photo-lithography, Ar ion milling, and hot press technique. The morphological change and the healing of cracklike pore in Ca doped high purity single crystal alumina, sapphire, during high temperature heat treatment in vacuum were observed using optical microscopy. The dot-like surface roughening was developed and hexagon like crystal appeared on inner surface of crack-like pore after heat treatment. Bar type crystals, probably CaO.6Al2O3, were observed on the inner surface after 1 hour heat treatment at 1, 50$0^{\circ}C$, but this bar type crystal disappeared after 1 hour heat treatment at 1, $600^{\circ}C$. This disappearance means that there should be a little increase of Ca solubility limit to alumina at this temperatures.

• Journal of the Korean institute of surface engineering
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• v.24 no.3
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• pp.137-143
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• 1991

The relation between the ion irradiation induced grain growth and the basic parameters sinvolved in ion beam mixing process was studied. TEM micrographs showed that a significant grain growth has been induced by Ar+ irradiation at room temperature. The grain size increases rapidly in low dose region, while it approaches a saturated value in high dose region, and it has close relationship with nuclear energy deposition and thermodynamic properties such as cohesive energy ( Hc) and heat of mixing ( Hm). A model for the grain growth based on the thermal spike induced atomic migration was developed and applied to interpret experimental results.

• Journal of the Korean institute of surface engineering
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• v.43 no.3
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• pp.154-158
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• 2010

Numerical analysis is done to investigate the effects of pulse bias on the plasma processing characteristics like ion doping and ion nitriding by using fluid dynamic code with a 2D axi-symmetric model. For 10 mTorr of Ar plasma, -1 kV of pulse bias was simulated. Maximum sheath thickness was around 20 mm based on the electric potential profile. The peak electron temperature was about 20 eV, but did not affect the averaged plasma characteristics of the whole chamber. Maximum ion current density incident on the substrate was 200 $A/m^2$ at the center, but was decreased down to 1/10th at radius 100 mm, giving poor radial uniformity.

• Journal of the Korean Wood Science and Technology
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• v.21 no.3
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• pp.22-29
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• 1993

나뭇잎으로부터 발생되는 저분자량 유기산을 이온크로마토그래피를 이용하여 분석하였다. 이 방법은 자연상태의 나뭇잎 (needle litter)을 유기용매의 추출 없이 그대로 이용할 수 있어서 사용하기에 편리하다. 본 논문에서는 이온 크로마토그래피의 사용방법과 침엽수잎(Pacific Silver Fir)의 부후정도에 따른 유기산의 종류와 농도의 변이를 간략하게 소개한다. 초기의 침엽수잎 여과액으로부터는 $C_2$에서 $C_4$까지의 아세트산(acetic acid), 프로피온산(propionic acid), 옥살산(oxalic acid) 그리고 포름산(formic acid) 등이 주종을 이루지만 부후정도가 커짐에 따라 방향핵을 가진 방향핵 유기산(aromatic organic acid)이 발생한다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.877-880
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• 2008

In this article, in order to fabricate polymer based electrospray device with super hydrophobic nozzle we use PTFE(polyfluorotetraethylene) plate and PMMA(polymethylmethacrylate). To obtain the super hydrophobic surface nozzle, PTFE surface is treated by argon and oxygen plasma treatment process. And evaluate the treated surface, perform measuring contact angle, SEM(Scanning Electron Microscope) and AFM(Atomic Force Microscope). We compare the performance of the super hydrophobic PTFE surface nozzle with raw PTFE and PMMA surface nozzle. For the ion beam treated PTFE nozzle, the liquid doesn't overflow and it keeps initial position and meniscus shape. From these results, we expect in cease of superhydrophobic surface nozzle jetting becomes more stable and repeatable.

• Resources Recycling
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• v.31 no.4
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• pp.26-33
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• 2022

Owing to the demand for lithium-ion batteries, the recovery of valuable metals from waste lithium-ion batteries is required in future. A pyrometallurgical treatment is appropriate for recycling a large number of waste lithium-ion batteries, but Li loss to slag and dust present a significant challenge. This research investigated carbonation roasting and water leaching behaviors in Li-ion batteries by graphite addition to recover Li from the NCM-based cathode materials of waste Li-ion batteries. When 10 wt% of graphite was added, CO and CO₂ gases were emitted with a rapid weight reduction at apporoximately 850 K, when heated in Ar and CO₂ atmosphere. After the rapid weight reduction, NCM was decomposed and reduced to metal oxides and pure metals. In the carbonation roasting of black powder (NCM+graphite), O₂ is generated via the decomposition of NCM, and an oxides, such as Li₂O and NiO were were also generated. Subsequently, Li₂O reacts with CO₂ to generate Li₂CO₃, and a part of NiO was reduced by graphite to produce metal Ni. In addition, up to 94.5 % Li₂CO₃ with ~99.95 % purity was recovered via water leaching after carbonation roasting.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.59-59
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• 1999

DLC(diamond-like carbon)필름은 다이아몬드와 유사한 강도, 낮은 마차계수, 높은 Optical band gap, NEA(negative electron affinity)등의 우수한 특성을 가지고 있어, 내마모 코팅이나 정보저장 매체의 윤활 코팅, FED(field emission display)의 전계방출소자등 다양한 분야에의 응용이 연구되고 있다. DLC 필름은 PECVD(plasma enhanced chemical vapor deposition), IBAD(ion beam assisted deposition), Laser ablation, Cathodic vacuum arc등의 process를 이용하여 증착되고 있다. 특히 이러한 필름의 물성은 입사되는 이온의 에너지에 의해 좌우되는데, Lifshitz 등의 연구에 의하여 hyperthermal species를 이용한 DLC 필름의 성장은 초기에 subsurface로의 shallow implantation이 일어난 후 높은 sp3 fraction을 갖는 필름이 연속적으로 성장한다는 subplantation model이 제시 되었다. 본 연구에서는 기판과 subplantation 영역이 이후 계속하여 증착되는 순수 DLC 필름의 특성 변호에 미치는 영향에 대하여 관심을 가지고 실험을 행하였다. 본 실험에서는 상기 제시되어 있는 방법보다도 더욱 정확하고도 독립적으로 탄소 음이온의 에너지와 flux를 조절할 수 있는 Cs+ ion beam sputtering system을 이용하여 탄소 음이온의 에너지를 40eV에서 200eV까지 변화시키며 필름을 증착하였다. Si(100) 웨이퍼를 기판으로 사용하였고 증착 압력은 5$\times$10-7torr 였으며 인위적인 기판의 가열은 하지 않았다. 또한 Ion beam deposited DLC film의 growth process를 연구하기 위하여 200eV의 탄소 음이온을 시간(증착두께)을 변수로 하여 증착하였고, 이 때에는 Kaufman type의 gas ion beam을 이용하여 500eV의 Ar+ ion으로 pre-sputering을 행하였다. 탄소 음이온의 에너지와 증착두께에 따라 증착된 film 내의 sp3/sp2 ratio 의 변화를 XPS plasmon loss 와 Raman spectra를 이용하여 분석하였다. 또한 증착두께에 따른 interlayer의 결합상태를 관찰하기 위하여 AES와 XPS 분석을 보조로 행하였다.