• Title/Summary/Keyword: OC-1

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Improvement of Fouling Resistance with Reverse Osmosis Membrane Using Multi-layer Silane-Epoxy Surface Modification (실란-에폭시 다층 표면개질을 통한 역삼투막의 내오염성 향상)

  • Kwon, Sei;Lee, Yong Taek
    • Membrane Journal
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    • v.25 no.4
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    • pp.332-342
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    • 2015
  • In this study, to solve the major problem of reverse osmosis (RO) membrane, surface of reverse osmosis membrane was modified by silane-epoxy multi layer. Octyltrimethoxysilane (OcTES) was polymerized to membrane surface via cross-linking by Sol-gel method. n = 8 alkylgroup of OcTES formed the branch structure by self assembly. And for improve fouling resistance of RO membrane, Ether group of ethylene glycol diglycidyl ether (EGDE) was given to improve hydrophilicity of RO membrane surface by ring-opening. To analyze structure of RO membrane surface with FE-TEM and AFM. Membrane surface of the ridge and valley structure and the bridge structure was confirmed due to the multi-layer surface modification of OcTES and EGDE. And through the increase of the roughness, the branch structure was formed well on membrane surface. Through the XPS analysis was identified chemical structure of membrane surface. And confirmed that the hydrophilic surface modification is given to the surface of the film through a Contact angle analysis. In optimization of EGDE surface modification condition, was suitable 0.5 wt% EGDE concentraion and $70^{\circ}C$ ring-opening temperature. In result of fouling resistance test and MFI is SUL-H10, $PA-OcTES_{1.0}$, $PA-OcTES_{1.0}-EGDE_{0.5}$ 68.7, 60.4, 5.4 ($10E-8hr/mL^2$), multi-layer surface modified membrane improved fouling resistance.

Electrical Characteristics of Ambipolar Thin Film Transistor Depending on Gate Insulators (게이트 절연특성에 의존하는 양방향성 박막 트랜지스터의 동작특성)

  • Oh, Teresa
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.5
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    • pp.1149-1154
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    • 2014
  • To observe the tunneling phenomenon of oxide semiconductor transistor, The Indium-gallum-zinc-oxide thin film transistors deposited on SiOC as a gate insulator was prepared. The interface characteristics between a dielectric and channel were changed in according to the properties of SiOC dielectric materials. The transfer characteristics of a drain-source current ($I_{DS}$) and gate-source voltage ($V_{GS}$) showed the ambipolar or unipolar features according to the Schottky or Ohmic contacts. The ambipolar transfer characteristics was obtained at a transistor with Schottky contact in a range of ${\pm}1V$ bias voltage. However, the unipolar transfer characteristics was shown in a transistor with Ohmic contact by the electron trapping conduction. Moreover, it was improved the on/off switching in a ambipolar transistor by the tunneling phenomenon.

Contact Angle and Electrical Properties in the Carbon Centered System (탄소를 포함한 절연박막의 접촉각 및 전기적인 특성)

  • Oh, Teresa;Kim, Jong-Wook
    • Journal of the Korean Vacuum Society
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    • v.17 no.2
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    • pp.117-121
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    • 2008
  • The SiOC film of carbon centered system was prepared using bistrimethylsilylmethane and oxygen mixed precursor by the chemical vapor deposition. The chemical properties of the SiOC film were analyzed by the I-V measurement and FTIR spectra analysis. The main bond of $950{\sim}1200cm^{-1}$ was composed of the Si-C, Si-O-C and Si-O bonds. The leakage current of the SiOC film increased with the increasing of the carbon content, and the drift of the current was in proportion to the Si-O-C bond content. The deconvoluted data of FTIR spectra could be classified the three types such as organic, hybrid and inorganic types, and the contact angle showed the difference of three types.

Correlation between Dielectric Constant and Electronic Polarization by the Reflective Index (굴절률에 의한 유전상수와 전자에 의한 분극에 대한 상관성)

  • Oh, Teresa
    • Journal of the Korean Vacuum Society
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    • v.18 no.1
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    • pp.24-29
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    • 2009
  • The SiOC film as inter layer insulator was researched the reason of the decreasing the dielectric constant by the ionic polarization and electronic polarization, respectively. The dielectric constant was measured using the conventional C-V measurement system, and the reflective index owing to the electronic polarization. Two kinds of dielectric constants were compared and then induced the origin of low-k materials. The chemical properties of the SiOC film were analyzed by the FTIR spectra, and the carbon content was obtained by the deconvoluted data of FTIR spectra. The variation of the carbon content tended to similar to the trend of reflective index, but was in inverse proportion to the dielectric constant. The effect of the electronic polarization did not affect the decreasing the dielectric constant, however the ionic polarization decreased effectively the dielectric constant of the SiOC film.

Atomic Layer Deposition and Characterization of Tantalum Oxide Films Using Ta(OC2H5)5 and $\textrm{NH}_3$ ($\textrm{Ta}(\textrm{OC}_{2}\textrm{H}_{5})_{5}$$\textrm{NH}_3$를 이용한 산화탄탈륨 막의 원자층 증착 및 특성)

  • Song, Hyeon-Jeong;Sim, Gyu-Chan;Lee, Chun-Su;Gang, Sang-Won
    • Korean Journal of Materials Research
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    • v.8 no.10
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    • pp.945-949
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    • 1998
  • Ta(OC2H5)5와 NH3를 이용하여 Cycle-CVD법으로 산화탄탈륨 막을 증착하였다. Cycle-CVD법에서는 Ta(OC2H5)5와 NH3사이에 불활성 기체를 주입한다. 하나의 cycle은 Ta(OC2H5)5주입, Ar주입, NH3 주입, Ar 주입의 네 단계로 이루어진다. Cycle-CVD법으로 산화탄탈륨 막을 증착할 때, 온도 $250-280^{\circ}C$에서 박막의 증착 기구는 원자층 증착(Atomic Layer Deposition:ALD)이었다. $265^{\circ}C$에서 Ta(OC2H5)5:Ar:NH3:Ar:NH3:Ar의 한 cycle에서 각 단계의 주입 시간을 1-60초:5초:5초:5초로 Ta(OC2H5)5 주입 시간을 변화시키면서 산화탄탈륨 막을 Cycle-CVD법으로 증착하였다. Ta(OC2H5)5주입시간이 증가하여도 cycle 당 두께가 $1.5\AA$/cycle로 일정하였다. $265^{\circ}C$에서 증착된 박막의 누설 전류는 2MV/cm에서 2x10-2A/$\textrm{cm}^2$이었고 열처리후의 산화탄탈륨 막의 누설 전류값은 $10-4A\textrm{cm}^2$ 이하고 감소하였다. 증착한 산화탄탈륨 막의 성분을 Auger 전자 분광법으로 분석하였다. 2$65^{\circ}C$에서 증착한 막의 성분은 탄탈륨 33at%, 산소 50at%, 탄소 5at%, 질소 12at% 이었으며 90$0^{\circ}C$, O2300torr에서 10분 동안 열처리한 박막은 탄탈륨 33at%, 산소 60wt%, 탄소 4at%, 질소 3at%이었다. 박막의 열처리 온도가 높을수록 불순물인 탄소와 질소의 박막 내 잔류량이 감소하였다. 열처리 후의 박막은 O/Ta 화학정량비가 증가하였으며 Ta의 4f7/5와 4f 5/2의 결합 강도가 열처리 전 박막보다 증가하였다. 열처리 후 누설 전류가 감소하는 것은 불순물 감소와 화학정량비 개선 및 Ta-O 결합 강도의증가에 의한 것으로 생각된다.

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Osteoclasts in the Inflammatory Arthritis: Implications for Pathologic Osteolysis

  • Youn-Kwan Jung;Young-Mo Kang;Seungwoo Han
    • IMMUNE NETWORK
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    • v.19 no.1
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    • pp.2.1-2.13
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    • 2019
  • The enhanced differentiation and activation of osteoclasts (OCs) in the inflammatory arthritis such as rheumatoid arthritis (RA) and gout causes not only local bone erosion, but also systemic osteoporosis, leading to functional disabilities and morbidity. The induction and amplification of NFATc1, a master regulator of OC differentiation, is mainly regulated by receptor activator of NF-κB (RANK) ligand-RANK and calcium signaling which are amplified in the inflammatory milieu, as well as by inflammatory cytokines such as TNFα, IL-1β and IL-6. Moreover, the predominance of CD4+ T cell subsets, which varies depending on the condition of inflammatory diseases, can determine the fate of OC differentiation. Anti-citrullinated peptide antibodies which are critical in the pathogenesis of RA can bind to the citrullinated vimentin on the surface of OC precursors, and in turn promote OC differentiation and function via IL-8. In addition to adaptive immunity, the activation of innate immune system including the nucleotide oligomerization domain leucine rich repeat with a pyrin domain 3 inflammasome and TLRs can regulate OC maturation. The emerging perspectives about the diverse and close interactions between the immune cells and OCs in inflammatory milieu can have a significant impact on the future direction of drug development.

Anti-oxidant Effects of the Water Extracts from the Inonotus Obliquus against Cisplatin- Induced Damage in HEI-OC1 Cells (차가버섯 물 추출물의 cisplatin에 의해 유도된 HEI-OC1세포 손상에 대한 항산화효과)

  • Youn, Myung-Ja;O, Kwang-Joong;Park, Kie-In
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.25 no.3
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    • pp.451-458
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    • 2011
  • The medicinal mushroom Inonotus obliquus is a traditional and widely used multi-functional fungus. In this study, we have investigated whether Inonotus obliquus (Chaga mushroom) extracts exerts anti-oxidant effects on cisplatin-induced cytotoxicity in auditory cell line, HEI-OC1 cells. First of all, Chaga extracts has no harmful effects on viability of HEI-OC1 cells in the dose range of $65{\sim}125{\mu}g/m{\ell}$. Moreover, it shows cyto-protective effects on the cells treated with cisplatin-induced cytotoxicity in HEI-OC1 cells and the damage of hair cells arrays of the rat primary organ of Corti explants in the presence of cisplatin. Pretreatment with Chaga extracts inhibited the cell death, reactive oxygen species generation (ROS), lipid peroxidation induced by cisplatin. These effects were associated with the induction of antioxidant enzyme by Chaga extracts. We further investigated the effects of Chaga extracts on expression of antioxidant enzymes such as Cu, Zn superoxide dismutase (SOD 1) and Mn SOD (SOD 2) by RT-PCR. In addition, Chaga extracts shows SOD activity and SOD protein expression in cisplatin treated group induced similar to control group. Taken together, these results indicate that Chaga extracts can prevent cisplatin-induced cytotoxicity by radical-scavenging activity (SOD activity) in HEI-OC1 cells. It might be an effective as antioxidant and further studies on the chemo-preventive mechanisms of Inonotus obliquus are needed.

Effects of Onchung-eum Administration along with Samhwangseze-gamibang on Treatment Atopic Dermatitis Development in NC/Nga Mice (온청음(溫淸飮)과 삼황세제가미방(三黃洗劑加味方) 병용이 NC/Nga 아토피 생쥐에 미치는 영향)

  • Hong, Chul-Hee;Seo, Eun-Sung;Weon, Young-Ho;Kim, Yeong-Geun;Hwang, Chung-Yeon
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.21 no.3
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    • pp.679-687
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    • 2007
  • The purpose of this study is to examine closely effect that Onchung-eum(OC) and Samhwangseze-gamibang(SG) used to atopic dermatitis disease patient get in atopy eruption control experimentally. Atopic dermatitis(AD) of molecular mechanism underlying it's effectiveness is unknown. We analyzed the expression the clinical severities in 13 and 16 weeks old NC/Nga mice, and the spleen weight of OC with SG treated NC/Nga mice, and mRNA expression levels of IL-4, IL-5, and CCR3 in the skin tissues of OC with SG treated NC/Nga mice, and IL-1${\beta}$, TNF-${\alpha}$, IL-6 express of gene, and Histological observation of the ear and skin tissues, and than IgE, IL-4, IL-5, IL-6, IgM, IgGl levels in the serum of OC with SG treated NC/Nga mouse group compared to the untreated control mouse group. Also, We examined cell toxicity that of OC is safety the strength of 10, 50, 100ppm and inflammatory RAW 264.7 in the serum of OC. Thus in these present study diverse immune responses in terms of chemical mediators related to AD were investigated using an atopic mouse model NC/Nga after OC along with 5G. At the result that OC along with SG treat is can effective use for the treatment of atopic dermatitis(AD).

The Characteristics of Dielectric Properties of SiOC(-H) film with the Variation of Dielectric Components on SiOC Structure

  • Chi Gyu, Choe;Heon Ju, Lee;Gwang Man, Lee
    • Proceedings of the Korean Society Of Semiconductor Equipment Technology
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    • 2003.12a
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    • pp.130-135
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    • 2003
  • Low dielectric constant SiOC(-H) films have been prepared by inductively coupled plasma chemical vapor deposition using bis-trymethylsilyl-methane (BTMSM) and $O_2$ precursors. The annealing effects on the structural and electrical properties were studied. The results indicate post-annealing could efficiently remove the hydroxyl (-OH) related groups from the as-deposited films and cause the chemical structure re-arrangement, resulting in the more nano-pores being formed in the annealed SiOC(-H) films. The dielectric constant decreased from 2.7 to 2.1, and the refractive index decreased from 1.427 to 1.32.

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Model test and numerical simulation of OC3 spar type floating offshore wind turbine

  • Ahn, Hyeon-Jeong;Shin, Hyunkyoung
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.11 no.1
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    • pp.1-10
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    • 2019
  • Nowadays, the study on Floating Offshore Wind Turbines (FOWTs) is being performed globally. Dozens of numerical simulation tools have been developed for designing FOWTs and simulating their performances in combined wave and wind environments. On the other hand, model tests are still required to verify the results obtained from numerical simulation tools. To predict seakeeping performance of the OC3-Hywind platform, a OC3 spar model moored by a 3-leg catenary spread mooring system with a delta connection was built with a 1/128 scale ratio. The model tests were carried out for various sea states, including rotating rotor effect with wind in the Ocean Engineering Wide Tank, University Of Ulsan (UOU). The model test results are compared with the numerical simulations by UOU in-house code and FAST.