• Journal of Environmental Science International
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• v.24 no.1
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• pp.97-115
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• 2015

For the purpose of protecting the health of citizens and creating a delightful environment, the Government shall establish the environmental standards, and make such standards keep their propriety according to any changes in environmental conditions. The Special Metropolitan City, Metropolitan City or Do may, in case where deemed necessary in view of the speciality of regional environments, set forth the separate environmental standards which are more expanded and strengthened than the environmental standards by the Municipal Ordinance of the relevant City/Do. The purpose of this study was for the management of stream waters of Jeju Island and proposed the appropriate Jeju local river environmental standards. Jeju-Do and Daejeon-si applies the Local River Environmental Standards in Korea. While each nation? circumstances and environment are different, for the most part, environmental standards and purposes of use are similar to those in Korea. Proposed Jeju River Local Environment Standards followed The River Environment Standards of Nation(Korea) for Living Environment Standards. Newly Strengthened Value is Cd, Carbon tetrachloride, 1,2-dichloroethene, Tetrachloroethylene(PCE) and add Items is Fluorine, Selenium, Phenol and Toluene for Human Health Protection.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.335-338
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• 2007

Cost effectiveness is an important parameter for producing DSSCs as compared to the widely used conventional silicon based solar cells. A fluorine-doped tin oxide (FTO) substrate coated with a catalytic amount of platinum is used as counter electrode in dye-sensitized solar cell. Carbonaceous materials are quite attractive to replace platinum due to their high electronic conductivity, corrosion resistance towards $I_{2}$, good catalytic effect and low cost. In this paper, the unit DSSCs with Pt and CNT as a counter electrode were connected in series-parallel externally, then the current-voltage curves were investigated to find out the connection characteristics of the DSSC with CNT counter electrode. The connection characteristics of the DSSC with CNT counter electrode is superior to that of the DSSC with Pt counter electrode. And a parallel connection of the DSSC with CNT counter electrode has higher efficiency than a series connection of that.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.8
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• pp.697-703
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• 2017

A teflon ionization modeling has been conducted to predict the performance of a PPT(Pulsed Plasma Thruster). One dimensional unsteady circuit model and Teflon ablation model were implemented. The Saha equation was adapted to predict the ionization of Carbon and Fluorine gas. The lumped circuit model including a resistance and a inductance model of a plasma was adapted to predict the magnitude of a discharge current. Numerical simulation results had good agreements with pervious research. The degree of current change according to PPT operating voltage was examined.

• Proceedings of the KAIS Fall Conference
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• 2011.05b
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• pp.836-839
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• 2011

염료감응형 태양전지의 상대전극으로 MWCNT(multi-walled carbon nanotube)의 농도 (0.01~0.06g)를 달리하여 FTO(fluorine-doped tin oxide) glass에 분산시켜 상대전극을 만들었다. 그리고 glass/FTO/$TiO_2$/Dye(N719)/electrolyte(C6DMII,GSCN)/MWCNT/FTO/glass 구조를 가진 0.45$cm^2$급 DSSC(dye-sensitized solar cells) 소자를 만들었다. 소자의 미세구조, 분산정도, 광특성은 각각 광학현미경, SEM, source measure unit (Keithley model 2400) 장비를 이용하여 확인하였다. MWCNT 농도 증가와 FTO의 거친 표면형상에 따라 비선형적으로 MWCNT 분산면적이 증가하였고, MWCNT 농도 0.06g일 때 FTO 표면에 전체적으로 MWCNT가 완전히 분산됨을 확인하였다. 소자의 광변환 효율은 MWCNT 분산면적에 비례하는 효율을 보였고, MWCNT 분산농도인 0.06g 일 때 4.49%의 광변환 효율을 얻을 수 있었다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.6
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• pp.472-476
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• 1998

The surface reactions of silica film($SiO_2-P_2O_5-B_2O_3-GeO_2$) with fluorocarbon plasma has been studied by using angle -resolved x-ray photoelectron spectroscopy(XPS). It has been confirmed that residual carbon consists of C-C and C-CFx bonds and fluorine mainly binds silicon in the case of etched silica by using $CF_4$ gas plasma. The surface reaction of silica with various fluorocarbon gases, such as $CF_4,C_2F_6 and CHF_3$ were investigated. XPS results showed that though the etching gases were changed, the elements and binding states of the residual layers on the etched silica by using various fluorocarbon gas plasma were nearly the same . This seems to be due to the high volatility of byproducts, that is, $SiF_4 and CO_2$ etc..

• Korean Journal of Materials Research
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• v.8 no.9
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• pp.825-830
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• 1998

자화된 유도결합형 C4F8 플라즈마로 SiO2를 건식식각시 실리콘 표면에 발생하는 손상과 오염에 대하여 연구하였다. 오염의 분석을 위해서 XPS, SIMS, TEM을 사용하였으며, 손상정도를 측정하기 위해서 HRTEM과 Schottky-diode 구성을 통한 I-V특성 측정을 사용하였다. 유도 결합형 C4F8 플라스마에 0에서 18Gauss까지의 자장이 가해짐에 따라서 실리콘 표면에 생기는 잔류막의 두께가 SiO2식각속도와 선택비의 증가와 함께 증가하였으며, XPS를 통하여 그 조성이 fluorine-rich에서 carbon-rich 한 상태로 변화함을 알 수 있었다. 자장을 가하지 않는 상태에서는 표면에서 $40\AA$부근까지 고밀도의 손상층이 관찰되었으나, 자장을 가함에 따라서 노출된 손상층의 깊이는 깊어지나 그 밀도는 줄어들음을 HRTEM을 통하여 관찰 할 수 있었다. Schottky-diode를 통한 I-V특성곡선의 분석으로 자장이 증가함에 따라서 전기적인 손상이 감소함을 알 수 있었다.

• Proceedings of the KIEE Conference
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• 1999.11d
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• pp.879-881
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• 1999

Radical and ion densities in a CF4 plasma have been calculated as a function of input power density. 9as pressure and feed gas flow rate using simple 0 dimensional global model. Fluorine atom is found to be the most abundant neutral particle. Highly fragmented species such as CF and CF+ become dominant neutral and ionic radical at the high power condition. As the pressure increases. ion density increases but ionization rate decreases due to the decrease in electron temperature. The fractional dissociation of CF4 feed gas decreases with pressure after increasing at the low pressure range. Electron density and temperature are almost independent of flow rate within calculation conditions studied. The fractional dissociation of CF4 monotonically decreases with flow rate. which results in increase in CF3 and decrease in CF density. The calculation results show that the SiO2 etch selectivity improvement correlates to the increase in the relative density of fluorocarbon ion and neutral radicals which has high C/F ratio.

• Journal of the Korean Applied Science and Technology
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• v.28 no.2
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• pp.232-239
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• 2011

Fabric fibrous filter has been used in various industrial applications owing to the low cost and wide generality. However, the basic properties of fabric materials often limit the practical utilization including hot gas cleaning. This study attempts to find new coatings of porous fibrous filter media in order to overcome its insufficient thermal resistance and durability. Teflon was one of the plausible chemicals to supplement the vulnerability against frequent external thermal impacts. A foaming agent composed of Teflon and some organic additives was tentatively coated on the glass fiber mat. The present test Teflon foam coated filter was fount to be useful for hot gas cleaning, up to $250^{\circ}C$-$300^{\circ}C$. Close examination using XPS(X-ray Photoelectron Spectroscopy) and Contact angle proved the binding interactions between carbon and fluorine, which implies coating stability. The PTFE/Glass foam coated filter consisted of more than 95% (C-F)n bond, and showed super-hydrophobic with good-oleophobic characteristics. The contact angle of liquid droplets on the filter surface enabled to find the filter wet-ability against liquid water or oil.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.9
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• pp.714-719
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• 2001

SrBi$_2$Ta$_2$$O_{9}$ thn films were etched in inductively coupled Cl$_2$/CF$_4$/Ar plasma. THe maximum etch rate was 1060 $\AA$/min at a Cl$_2$/(Cl$_2$+CF$_4$+Ar)=0.2. The 20% additive Cl$_2$ into CF$_4$/Ar plasma decreased carbon and fluorine radicals, but increased Cl radicals. Sr was effectively removed by reacting with Cl radical because the boiling point of SrCl$_2$(125$0^{\circ}C$) is lower than that of SrF$_2$(246$0^{\circ}C$). The chemical reactions on the etched surface were studied with x-ray photoelectron spectroscopy and secondary ion mass spectrometry. The etching profile was evaluated by using scanning electron microscopy.y.

• Transactions on Electrical and Electronic Materials
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• v.7 no.4
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• pp.204-209
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• 2006

Photo Resist (PR) ashing process was carried out with the atmospheric pressure- dielectric barrier discharge (ADBD) using $SF_6/N_2/O_2$. Ashing rate (AR) was sensitive to the mixing ratio of the oxygen and nitrogen of the blower type of ADBD asher. The maximum AR of 5000 A/min was achieved at 2% of oxygen in the $N_2$ plasma. With increasing the oxygen concentration to more than 2% in the $N_2$ plasma, the discharge becomes weak due to the high electron affinity of oxygen, resulting in the decrease of AR. When adding 0.5% of SF6 to $O_2/N_2$ mixed plasma, the PR AR increased drastically to 9000 A/min and the ashed surface of PR was smoother compared to the processed surface without $SF_6$. Carbon Fluorinated polymer may passivate the PR surface. It was also observed that the glass surface was not damaged by the fluorine.