• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.133-133
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• 2015

Recently, it has been shown that the ${\omega}B97X-D/aVTZ$ method is strongly recommended as the best practical density functional theory(DFT) for rigorous and extensive studies of saturated or unsaturated $C_4F_8$ species because of its high performance and reliability especially for van der Waals interactions. All the feasible isomerization and dissociation paths of $C_4F_8$ molecules were investigated at this theoretical level and rate constants of their chemical reactions were computed by using variational transition-state theory for a deep insight into $C_4F_8$ reaction mechanisms. Fates and roles of C4F8 molecules and their fragments in plasma phases could be clearly explained based on our computational results.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.30A no.1
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• pp.44-50
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• 1993

In an attempt to improve the electrical characteristics of tantalum pentoxide dielectric film, silicon substrate was reacted with a nitrogen plasma to form a silicon nitride of 50.angs. and then tantalum pentoxide thin films were formed by reactive sputtering in the same chamber. Breakdown field and leakage current density were measured to be 2.9 MV/cm and 9${\times}10^{8}\;A/cm^{2}$ respectively in these films whose thickness was about 180.angs.. With annealing at rectangular waveguides with a slant grid are investigated here. In particular, 900.deg. C in oxygen ambient for 100 minutes, breakdown field and leakage current density were improved to be 4.8 MV/cm and 1.61.6${\times}10^{8}\;A/cm^{2}$ respectively. It turned out that the electrical characteristics could also be improved by oxygen plasma post-treatment and the conduction mechanism at high electric field proved to be Schottky emission in these double-layered films.

• YAKHAK HOEJI
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• v.53 no.6
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• pp.357-367
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• 2009

A meta-analysis of 63 randomized controlled trials of Pioglitazone and Rosiglitazone in patients with type 2 diabetes was conducted. Pioglitazone significantly lowered fasting plasma glucose and triglyceride (TG) level and increased high-density lipoprotein cholesterol (HDL) level. Rosiglitazone significantly lowered hemoglobin A1C level and fasting plasma glucose, whereas it increased all kinds of lipids (HDL, LDL (low-density lipoprotein cholesterol), TG, total cholesterol). In comparison, glucose lowering effect was higher in Rosiglitazone, and Pioglitazone produced a more favorable lipid profile.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1398-1399
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• 2006

현재 상용화된 OLED 소자는 최대 단점인 수분 취약성의 원인으로 top emission과 flexible 타입으로 제조되는데 장애가 되고 있다. 따라서 top emission 방식과 flexible한 소자를 실현하기 위해 수분 및 산소 침투를 방지하기 위한 유전체 막의 실험이 진행되고 있는데, 본 실험에서는 기존의 PECVD보다 plasma의 density가 높은 HDP(High Density Plasma)-CVD를 사용해 SiOx 및 SiNx 유전체 film을 증착하였고 MOCON 테스트를 통한 수분침투 방지막으로써의 가능성을 검증하였다.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.529-530
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• 2006

This paper concerned with SPS (spark plasma sintering), hot pressing of sinter nanometer WC-Co powder and discussed the density, hardness, microstructures and grain sizes of the alloys sintered. The results showed that the two sintered techniques could produce high density alloys and play well on the grain growth, but SPS could lower the sintering temperature and shorten sintering time. Besides, the hardness of the sintered cemented alloys that was dependent on the grain size and densification could also be improved.

• Applied Science and Convergence Technology
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• v.26 no.4
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• pp.74-78
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• 2017

The discharge characteristics of the radio frequency (RF) surface dielectric barrier discharge have been simulated for the investigation of the ratio of the ion transit time to the RF period. From one-dimensional particle-in-cell (PIC) simulation for a planar dielectric barrier discharge (DBD), it was observed that the high-frequency driving voltage confines the ions in the plasma because of a shorter RF period than the ion transit time. For two-dimensional surface dielectric barrier discharges, a fluid simulation is performed to investigate the characteristics of RF discharges from 1 MHz to 40 MHz. The ratio of the peak density to the average density decreases with the increasing frequency, and the spatiotemporal discharge patterns change abruptly with the change in the ratio of ion transit time to the RF period.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.3
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• pp.133-136
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• 2004

Low-Pressure inductively coupled RF discharge sources have important industrial applications mainly because they can provide a high-density electrodeless plasma source with low ion energy and low power loss. In an inductive discharge, the RF power is coupled to the plasma by an electromagnetic interaction with the current flowing in a coil. In this paper, the experiments have been focussed on the electric characteristic and carried out using a single Langmuir probe. The internal electric characteristics of inductively coupled Ar RF discharge at 13.56(MHz) have been measured over a wide range of power at gas pressure ranging from 1∼70(mTorr).

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.8
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• pp.713-719
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• 2002

In this study, the vertically well-aligned CNTs were synthesized by DC bias-assisted inductively coupled plasma hot-filament chemical vapor deposition (ICPHFCVD) using radio-frequence plasma of high density and that CNTs were vertically grown on Ni(300 )/Cr(200 )-deposited glass substrates at 58$0^{\circ}C$. This system(ICPHFCVD) added to tungsten filament in order to get thermal decompound and DC bias in order to vertically grow to general Inductively Coupled Plasma CVD. The grown CNTs by ICPHFCVD were developed to higher graphitization and fewer field emission properties than those by general ICPCVD. In this system, DC bias was effect of vortical alignment to growing CNTs. The measured turn-on fields of field emission property by general ICPCVD and DC bias-assisted ICPHFCVD were 5 V/${\mu}{\textrm}{m}$ and 3 V/${\mu}{\textrm}{m}$, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.26-29
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• 2001

$SrBi_2Ta_2O_{9}$ thin films were etched at high-density $Cl_2/CF_4/Ar$ in inductively coupled plasma system. The etching of SBT thin films in $Cl_2/CF_4/Ar$ were chemically assisted reactive ion etching. The maximum etch rate was 1300 $\AA$/min at 900W in $Cl_2(20)/CF_4(20)/Ar(80)$. As rf power increase, radicals (F, Cl) and ion(Ar) increase. The influence of plasma induced damage during etching process was investigated in terms of the surface morphology and th phase of X-ray diffraction. The chemical residue was investigated with secondary ion mass sperometry.

• Tribology and Lubricants
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• v.11 no.5
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• pp.108-113
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• 1995

Wear and friction behavior of plasma-sprayed coatings in Mo- and Co-based alloy were studied for the application of piston-ring automobile engine. The plasma-sprayed coatings were varied with gun current density, gas flow, and distance. The surface roughness, microhardness, and wear volume were measured depending on the spray distances. The high temperature hardness value were also measured as a function of temperature. Ball-on-disc geometry configuration tribometer was utilized in air. The wear tests were performed in the temperature ranges from room temperature to 825$^{\circ}$C to investigate the tribological trend of the piston-ring materials in the lack of lubricant. The cross sections of wear track were investigated, using microscopy.