• Title/Summary/Keyword: Pre-oxidation

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Development of Rapid Thermal Processor for Large Glass LTPS Production

  • Kim, Hyoung-June;Shin, Dong-Hoon
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.533-536
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    • 2006
  • VIATRON TECHNOLOGIES has developed Field-Enhanced Rapid Thermal Processor (FERTP) system that enables LTPS LCD and AMOLED manufacturers to produce poly-Si films at low cost, high throughput, and high yield. The FE-RTP allows the diverse process options including crystallization, thermal oxidation of gate oxides and fast pre-compactions. The process and equipment compatibility with a-Si TFT lines is able to provide a viable solution to produce poly-Si TFTs using a-Si TFT lines.

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Bone-like Apatite Formation on Ti-6Al-4V in Solution Containing Mn, Mg, and Si Ions after Plasma Electrolytic Oxidation in the SBF Solution

  • Lim, Sang-Gyu;Choe, Han Cheol
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2017.05a
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    • pp.157-157
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    • 2017
  • Titanium and its alloys that have a good biocompatibility, corrosion resistance, and mechanical properties such as hardness and wear resistance are widely used in dental and orthopedic implant applications. They can directly connect to bone. However, they do not form a chemical bond with bone tissue. Plasma electrolytic oxidation (PEO) that combines the high voltage spark and electrochemical oxidation is a novel method to form ceramic coatings on light metals such as titanium and its alloys. This is an excellent reproducibility and economical, because the size and shape control of the nano-structure is relatively easy. Silicon (Si), manganese (Mn), and magnesium (Mg) has a useful to bone. Particularly, Si has been found to be essential for normal bone, cartilage growth and development. Manganese influences regulation of bone remodeling because its low content in body is connected with the rise of the concentration of calcium, phosphates and phosphatase out of cells. Insufficience of Mn in human body is probably contributing cause of osteoporosis. Pre-studies have shown that Mg plays very important roles in essential for normal growth and metabolism of skeletal tissue in vertebrates and can be detected as minor constituents in teeth and bone. The objective of this work was to study nucleation and growth of bone-like apatite formation on Ti-6Al-4V in solution containing Mn, Mg, and Si ions after plasma electrolytic oxidation. Anodized alloys was prepared at 270V~300V voltages. And bone-like apatite formation was carried out in SBF solution for 1, 3, 5, and 7 days. The morphologies of PEO-treated Ti-6Al-4V alloy in containing Mn, Mg, and Si ions were examined by FE-SEM, EDS, and XRD.

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Research for the antiinflamation and antioxidation effect on the Lycoris squamigera Maxim (소염 및 항산화제 개발을 위한 상사화의 효능 연구)

  • Kim, Bo-Mi;Yoo, Myung-Ja;Song, Mi-Seon;Kwon, Tae-Oh;Lee, Young-Hang;Chai, Kyu-Yun
    • Herbal Formula Science
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    • v.19 no.2
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    • pp.109-118
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    • 2011
  • Objectives : The Lycoris squamigera Maxim has been used traditionally for treatment of various diseases. However, the studies on the effect of Lycoris squamigera Maxim have not been carried out. In the present study, extract of Lycoris squamigera Maxim were tested for their anti-inflammatory and anti-oxidation effect. Methods : The anti-inflammatory effect of the various solvent extract was studied in lipopolysaccharide (lps)-treated mouse macrophage cells. RAW 264.7 cells were pre-incubated with Lycoris squamigera Maxim extracts for 4h and treated with $1\;{\mu}g/m{\ell}$ lps for 18h, and then the anti-inflammatory effects of extracts were determined. The anti-oxidation effect of extracts measured by DPPH method, reductive potential test, total phenolics test. Results : Extracted root's ethyl acetate layer showed a significant decrease in nitric oxide. And that layer (root's ethyl acetate extract) was showed decrease in TNF-${\alpha}$ concentration dependently. Separated from Root's ethyl acetate extract was fraction 1 has $0.1{\sim}5\;{\mu}M$ range, fraction 2 has $0.1{\sim}10\;{\mu}M$ range did not showed cytotoxicity. Anti-oxidation result as DPPH test showed the best was root ethyl acetate extract. Redusing power was made a comparison between fractions and standard. They were showed similar value. Fraction's total phenol containing result was better then standard. Conclusions : These results suggest that these extracts can be used as anti-inflammatory, anti-axidation materials.

Application of Ozone Oxidation to Reduce the Biological Treatment Time of Petrochemical Wastewater (석유화학 폐수의 생물학적 처리시간 단축을 위한 오존 산화의 적용)

  • Hong, Eun-Sik;Kim, Hyun-Suk;Lee, Sang-Hee;Chung, Jin-Suk;Shin, Eun-Woo;Ryu, Keun-Garp;Yoo, Ik-Keun
    • Journal of Korean Society of Environmental Engineers
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    • v.28 no.5
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    • pp.573-576
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    • 2006
  • The efficacy of integrated ozone oxidation-biodegradation treatment was examined in the treatment of petrochemical wastewater with a special focus on the overall treatment time. When raw wastewater with chemical oxygen demand(COD) of 70-80 mg/L was oxidized by ozone, approximately 20% of initial COD was removed in less than 1.5 min at a dosing rate of 400 mg $O_3/L{\cdot}h $. No further decrease in COD was observed for the extended ozone treatment up to 30 min. Biological treatment alone showed a rapid reduction of COD to 40-50 mg/L, subsequently resulting in the decreased rate of COD removal. Pre-treatment by ozone before biological treatment did not significantly affect the specific rate of COD removal in a biological treatment. When ozone oxidation followed biological treatment, the extent of COD removal by ozone oxidation was greater compared to that of biologically-treated wastewater for a shorter time. Taken together, it was decided that the biological treatment time could be reduced if the treatment processes of concern will be properly arranged.

Effect of Surface Treatments of Stainless Steels on Oxidation Behavior Under Operating Condition of IT SOFC Interconnect (IT SOFC 인터커넥터 구동 조건에서의 스테인레스 소재의 산화거동에 미치는 표면전처리의 영향)

  • Moon, Min-Seok;Woo, Kee-Do;Kim, Sang-Hyuk;Yoo, Myung-Han
    • Korean Journal of Metals and Materials
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    • v.49 no.1
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    • pp.25-31
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    • 2011
  • Solid oxide fuel cells (SOFCs) have many attractive features for widespread applications in generation systems. Recently, stainless steels have attractive materials for metallic bipolar plate because metallic bipolar plates have many benefits compared to others such as graphite and composite bipolar plates. SOFC operates on high temperature of about $800{\sim}1000^{\circ}C$ than other fuel cell systems. Thus, many studies have attempted to reduced the operation temperature of SOFC to about $600{\sim}800^{\circ}C$, which is the intermediate temperature (IT) of SOFC. Low cost and high-temperature corrosion resistance are very important for the practical applications of SOFC in various industries. In this study, two specimens, 304 and 430 stainless steels with and without different pre-surface treatments on the surface were investigated. And, specimens were exposed at high temperature in the box furnace under oxidation atmosphere of $800^{\circ}C$. Oxidation behavior have been investigated with the materials exposed at different times (100 hrs and 400 hrs) by SEM, EDS and XRD. By increasing exposure time, the amount of metal oxide increased in the order like; STS304 < STS430 and As-received < As-polished < Sand-blast specimens.

Direct Bonding Characteristics of 2" 3C-SiC Wafers for Harsh Environment MEMS Applications (극한 환경 MEMS용 2" 3C-SiC기판의 직접접합 특성)

  • 정귀상
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.8
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    • pp.700-704
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    • 2003
  • This paper describes on characteristics of 2" 3C-SiC wafer bonding using PECVD (plasma enhanced chemical vapor deposition) oxide and HF (hydrofluoride acid) for SiCOI (SiC-on-Insulator) structures and MEMS (micro-electro-mechanical system) applications. In this work, insulator layers were formed on a heteroepitaxial 3C-SiC film grown on a Si (001) wafer by thermal wet oxidation and PECVD process, successively. The pre-bonding of two polished PECVD oxide layers made the surface activation in HF and bonded under applied pressure. The bonding characteristics were evaluated by the effect of HF concentration used in the surface treatment on the roughness of the oxide and pre-bonding strength. Hydrophilic character of the oxidized 3C-SiC film surface was investigated by ATR-FTIR (attenuated total reflection Fourier transformed infrared spectroscopy). The root-mean-square suface roughness of the oxidized SiC layers was measured by AFM (atomic force microscope). The strength of the bond was measured by tensile strength meter. The bonded interface was also analyzed by IR camera and SEM (scanning electron microscope), and there are no bubbles or cavities in the bonding interface. The bonding strength initially increases with increasing HF concentration and reaches the maximum value at 2.0 % and then decreases. These results indicate that the 3C-SiC wafer direct bonding technique will offers significant advantages in the harsh MEMS applications.ions.

Cu Diffusion Behavior of Ni-B Diffusion Barrier Fabricated by Electroless Deposition (무전해 도금법으로 제조된 Ni-B 확산 방지막의 Cu 확산 거동)

  • Choi, Jae-Woong;Hwang, Gil-Ho;Han, Won-Kyu;Lee, Wan-Hee;Kang, Sung-Goon
    • Korean Journal of Materials Research
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    • v.15 no.9
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    • pp.577-584
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    • 2005
  • Thin Ni-B layer, $1{\mu}m$ thick, was electrolessly deposited on Cu electrode fabricated by electro-deposition. The purpose of the layer is to encapsulate Cu electrodes for preventing Cu oxidation and to serve as a diffusion barrier. The layers were annealed at $580^{\circ}C$ with and without pre-annealing at $300^{\circ}C$ for . 30minutes. In the layer with pre-annealing, the amount of Cu diffusion was lower about 5 times than the layer without pre-annealing. The difference in Cu concentration may be attributed to $Ni_3B$ formation prior to Cu diffusion. However, the difference in Cu concentration decreased during the annealing time of 5 h due to the grain growth of Ni.

Effects of Pre-rigor Salting on the Physicochemical and Textural Properties of Ground Duck Breast Muscle

  • Lee, Sang-Hun;Choi, Ji-Hun;Choi, Yun-Sang;Kim, Hack-Youn;Kim, Hyun-Wook;Park, Jae-Hyun;Song, Dong-Heon;Kim, Yong-Jae;Kim, Cheon-Jei
    • Food Science of Animal Resources
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    • v.32 no.6
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    • pp.756-762
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    • 2012
  • The pre-rigor salting effects on physicochemical properties of ground duck breast muscle were evaluated in this study. The pre-rigor salting treatments were prepared within 30 min after slaughter, the duck breast muscles after post mortem 48 h were used to prepare the post-rigor treatments. The pre-rigor salting treatment had significantly higher pH value than post-rigor salting treatment (p<0.001), and all pre-rigor salting treatments showed a significant higher pH value. As a result, the pre-rigor salting treatment showed increased water holding capacity and decreased cooking loss compared to those in the post-rigor salting treatment. No significant differences in redness and yellowness were observed among the treatments (p>0.05). The increased solubility of salt-soluble proteins in the pre-rigor salting treatment leads to increase the hardness, gumminess, and chewiness. Also, the pre-rigor salted duck breast muscle had similar textural properties compared to those of post-rigor duck breast muscle containing sodium tri-polyphosphate (STPP). The 2-thiobarbituric acid (TBA) values of all treatments were ranged from 0.121 to 0.177 mg/kg. The lowest TBA value was observed for post-rigor duck breast muscle containing STPP, however, pre-rigor salting did not influence lipid oxidation of ground duck breast muscle. Therefore, the pre-rigor salting method, especially a single addition of sodium chloride to pre-rigor muscle, is more efficient method for improving cooking loss.

Effect of pre-treatment in 0.5 M oxalic acid containing various NH4F concentrations on PEO Film Formation of AZ91 Mg Alloy (NH4F가 첨가된 0.5 M 옥살산 전처리가 AZ91 마그네슘 합금의 PEO 피막 형성에 미치는 영향)

  • Kwon, Duyoung;Song, Pung-Keun;Moon, Sungmo
    • Journal of the Korean institute of surface engineering
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    • v.55 no.1
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    • pp.24-31
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    • 2022
  • This study investigated the effect of pre-treatment on the PEO film formation of AZ91 Mg alloy. The pre-treatment was conducted for 10 min at room temperature in 0.5 M oxalic acid (C2H2O4) solution containing various ammonium fluoride (NH4F) concentrations. The pre-treated AZ91 Mg specimens were anodized at 100 mA/cm2 of 300 Hz AC for 2 min in 0.1 M NaOH + 0.4 M Na2SiO3 solution. When AZ91 Mg alloy was pretreated in 0.5 M oxalic acid with NH4F concentration less than 0.3 M, continuous dissolution of the AZ91 Mg alloy occurred together with the formation of black smuts and arc initiation time for PEO film formation was very late. It was noticed that corrosion rate of the AZ91 Mg alloy became faster if small amount of NH4F concentration, 0.1 M, is added. The fast corrosion is attributable to fast formation of porous fluoride together with porous oxides in the reaction products. On the other hand, when AZ91 Mg alloy was pretreated in 0.5 M oxalic acid with sufficient NH4F more than 0.3 M, a thin and dense protective film was formed on the AZ91 Mg alloy surface which resulted in faster initiation of arcs and formation of PEO film.

A Study on Purification of Water Works by Multi-filter Bed Method with Aeration(Appliction of Biological Oxidation by Aerobic Microorganism) (상수 정화법에 관한 연구 (폭기식 다단여과에 의한 호기성균의 생물화학적 산화작용을 응용))

  • Chung, Yo-Han;Moon, Jae-Kyu;Jhoo, Heung-Kyu;Seo, Hwa-Jung
    • Journal of Preventive Medicine and Public Health
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    • v.5 no.1
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    • pp.43-48
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    • 1972
  • 5 bed sand filter, applying biological oxidation, was designed and studied on the treatment of water works. Never using any coagulant agent (drugs), which may cause water pollution in pre-treatment of head water, the auther attempt a high rate filtration by the microorganism (nitrofication bacteria) end plant which populate in multi layer sand beds. The result are as follows : In order to evaluate the oxygen effect on filtration, oxygen was injected in aeration tank attached to each filter tank while filtration, and $NH_3$ was tested as a representaiive ingredient. It was found out that the aeration method was more effective, with over 33% of $NH_3$ removal capacity, than the anerobic and this 5 bed filter showed double removal capacity of $NH_3$ by comparing with conventional sand bed (2 stage bed). According to the examination of two kind of head water, pre-treated with coagulant agent and activated carton, the filtration capacity was affected by the polluted condition of head water, resulting that lower value of pollution and slower velocity of filtration showed more efficiency of $NH_3$ removal. In this experiment $NH_3$ content tested in treated water had a fairly good correlation with others.

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